diff --git a/.gitattributes b/.gitattributes
index 5f04b5e9d1..0025f2a697 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -6,7 +6,7 @@
 # them when run in WSL/Linux (e.g. `set -e` -> "set: Illegal option -").
 *.sh text eol=lf
 
-# Normalize Studio frontend sources to LF. Scoped to the frontend tree (rather
+# Normalize Unsloth frontend sources to LF. Scoped to the frontend tree (rather
 # than repo-wide *.ts/*.tsx/... rules) so the policy can't force LF on files
 # elsewhere. text=auto lets Git detect and leave binary assets (logos, fonts)
 # untouched while text files (.ts/.tsx/.json/.html/.svg/...) are stored as LF.
diff --git a/.github/scripts/agent-guides-drive.sh b/.github/scripts/agent-guides-drive.sh
index f4189a159e..b63ac94b93 100755
--- a/.github/scripts/agent-guides-drive.sh
+++ b/.github/scripts/agent-guides-drive.sh
@@ -36,6 +36,23 @@ AGENT="${2:?usage: agent-guides-drive.sh <mode> <agent>}"
 # Determinism (seed/temp) is applied at the server level by
 # serve-unsloth-run.sh --extra; agents inherit it through the API.
 TIMEOUT="${AGENT_INVOKE_TIMEOUT:-180}"
+# opencode is the slow outlier. Unlike the print-mode agents (claude -p, codex
+# exec) it runs a full turn AND a separate small_model call to name the session,
+# so one connection reply takes ~8 min on a CPU-served 4B -- right at the shared
+# 600s cap, so the cell flaked when a run drifted past a ~480s success. Give it
+# headroom (still well under the 40-min job budget); the fast agents keep the
+# tight cap that still catches a real headless-TTY hang.
+case "$AGENT" in
+  opencode)
+    # Double it, but only for a bare-integer seconds value. A GNU timeout(1)
+    # duration suffix (s/m/h/d, including floats like 0.5s) is left unchanged so
+    # the arithmetic never sees a non-number; timeout(1) parses it directly.
+    case "$TIMEOUT" in
+      *[!0-9]*) ;;
+      *) TIMEOUT=$(( TIMEOUT * 2 )) ;;
+    esac
+    ;;
+esac
 
 # Claude refuses --dangerously-skip-permissions outside a sandbox; the CI runner
 # IS the sandbox, so declare it (mirrors unslothai/scripts launcher.sh). Harmless
@@ -166,8 +183,8 @@ parse_connect() {
   echo "[$AGENT] connect --no-launch printed:"; cat_redacted "$raw"
   CONNECT_ENV="$(grep -E '^(export |unset )' "$raw" || true)"
   # The launch command is the last non-export, non-status line. start.py
-  # prints "Studio <url> · model <id>" and "Updated ..." status lines first.
-  CONNECT_CMD="$(grep -vE '^(export |unset |Studio |Updated |Disabled |Warning|Loading)' "$raw" \
+  # prints "Unsloth <url> · model <id>" and "Updated ..." status lines first.
+  CONNECT_CMD="$(grep -vE '^(export |unset |Unsloth |Updated |Disabled |Warning|Loading)' "$raw" \
     | grep -E '[^[:space:]]' | tail -1)"
   [ -n "$CONNECT_CMD" ] || guide_fail "could not parse a launch command from connect --no-launch output"
   redact "$raw"
diff --git a/.github/scripts/assert-llama-loads.sh b/.github/scripts/assert-llama-loads.sh
index c2ffe27469..62ef80d364 100755
--- a/.github/scripts/assert-llama-loads.sh
+++ b/.github/scripts/assert-llama-loads.sh
@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 #
-# Assert Studio installed a llama.cpp that loads and runs on THIS macOS. Tests
+# Assert Unsloth installed a llama.cpp that loads and runs on THIS macOS. Tests
 # the contract that matters (binaries load and their minimum-OS is <= this host)
 # instead of the old "did install.sh fall back to a source build?" grep, since a
 # source build with a correct deployment target is a valid outcome.
diff --git a/.github/scripts/assert-prompt-cache.sh b/.github/scripts/assert-prompt-cache.sh
index f5b6b075eb..8c28569f77 100755
--- a/.github/scripts/assert-prompt-cache.sh
+++ b/.github/scripts/assert-prompt-cache.sh
@@ -31,7 +31,7 @@
 #   (llama_cpp.py:337-340). So default: ~/.unsloth/studio/logs/llama-server/.
 #
 #   <P> is the INTERNAL llama-server port (self._find_free_port(),
-#   llama_cpp.py:3489 / :4641) -- a RANDOM port, NOT the Studio port. So we must
+#   llama_cpp.py:3489 / :4641) -- a RANDOM port, NOT the Unsloth port. So we must
 #   NOT filter the log glob by STUDIO_PORT (the brief's `port-<STUDIO_PORT>`
 #   glob would never match). We pick the newest llama-*.log instead.
 #
diff --git a/.github/scripts/hf-download-with-retry.sh b/.github/scripts/hf-download-with-retry.sh
index 013a459f46..6dec93356a 100755
--- a/.github/scripts/hf-download-with-retry.sh
+++ b/.github/scripts/hf-download-with-retry.sh
@@ -3,7 +3,7 @@
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 #
 # Download a single file from a Hugging Face repo with a stall-retry
-# watchdog. Used by the Studio CI workflows so a hung hf-xet transfer
+# watchdog. Used by the Unsloth CI workflows so a hung hf-xet transfer
 # kills + retries instead of silently consuming the job's timeout.
 #
 # Usage: hf-download-with-retry.sh REPO FILE LOCAL_DIR
@@ -35,7 +35,7 @@ REPO="${1:?usage: hf-download-with-retry.sh REPO FILE [LOCAL_DIR]}"
 FILE="${2:?usage: hf-download-with-retry.sh REPO FILE [LOCAL_DIR]}"
 # LOCAL_DIR is optional. If empty, hf falls back to HF_HUB_CACHE
 # (~/.cache/huggingface/hub) which is the desired path for callers
-# that populate HF_HOME for a downstream Studio model load.
+# that populate HF_HOME for a downstream Unsloth model load.
 LOCAL_DIR="${3:-}"
 
 # Stall threshold per attempt, in seconds. Override with
diff --git a/.github/scripts/run-studio-permission-browser.sh b/.github/scripts/run-studio-permission-browser.sh
new file mode 100755
index 0000000000..2007789035
--- /dev/null
+++ b/.github/scripts/run-studio-permission-browser.sh
@@ -0,0 +1,69 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
+
+set -euo pipefail
+
+port="${1:?usage: $0 PORT BROWSER [CHANNEL]}"
+browser="${2:?usage: $0 PORT BROWSER [CHANNEL]}"
+channel="${3:-}"
+slug="$browser${channel:+-$channel}"
+artifact_dir="logs/playwright-permissions-$slug"
+server_log="logs/studio-permissions-$slug.log"
+studio_home="${UNSLOTH_STUDIO_HOME:-$HOME/.unsloth/studio}"
+set --
+if [ -n "${STUDIO_PERMISSION_FRONTEND:-}" ]; then
+  set -- -f "$STUDIO_PERMISSION_FRONTEND"
+fi
+
+mkdir -p "$artifact_dir"
+unsloth studio reset-password
+UNSLOTH_API_ONLY=1 unsloth studio -H 127.0.0.1 -p "$port" "$@" \
+  >"$server_log" 2>&1 &
+studio_pid=$!
+
+cleanup() {
+  kill "$studio_pid" 2>/dev/null || true
+  wait "$studio_pid" 2>/dev/null || true
+}
+trap cleanup EXIT
+
+healthy=0
+for _ in $(seq 1 180); do
+  if curl -fs "http://127.0.0.1:$port/api/health" >/dev/null; then
+    healthy=1
+    break
+  fi
+  if ! kill -0 "$studio_pid" 2>/dev/null; then
+    tail -100 "$server_log" || true
+    exit 1
+  fi
+  sleep 1
+done
+if [ "$healthy" -ne 1 ]; then
+  tail -100 "$server_log" || true
+  exit 1
+fi
+
+old_password=$(cat "$studio_home/auth/.bootstrap_password")
+new_password="CIPerm-$(python -c 'import secrets; print(secrets.token_urlsafe(16))')"
+if [ "${GITHUB_ACTIONS:-}" = "true" ]; then
+  echo "::add-mask::$old_password"
+  echo "::add-mask::$new_password"
+fi
+
+export BASE_URL="http://127.0.0.1:$port"
+export STUDIO_OLD_PW="$old_password"
+export STUDIO_NEW_PW="$new_password"
+export STUDIO_UI_STRICT=1
+export STUDIO_UI_PERMISSION_ONLY=1
+export STUDIO_UI_WALL_TIMEOUT_S=240
+export STUDIO_PLAYWRIGHT_BROWSER="$browser"
+export PW_ART_DIR="$artifact_dir"
+if [ -n "$channel" ]; then
+  export STUDIO_PLAYWRIGHT_CHANNEL="$channel"
+else
+  unset STUDIO_PLAYWRIGHT_CHANNEL || true
+fi
+
+python tests/studio/playwright_chat_ui.py
diff --git a/.github/workflows/consolidated-tests-ci.yml b/.github/workflows/consolidated-tests-ci.yml
index fa84471d36..d1bea819eb 100644
--- a/.github/workflows/consolidated-tests-ci.yml
+++ b/.github/workflows/consolidated-tests-ci.yml
@@ -268,6 +268,7 @@ jobs:
             tests/saving/test_save_shell_injection.py \
             tests/saving/test_patch_saving_none_tokenizer.py \
             tests/saving/test_fix_sentencepiece_gguf_robustness.py \
+            tests/saving/test_fix_sentencepiece_tokenizer_guard.py \
             tests/saving/test_compressed_export_schemes.py \
             tests/saving/test_export_api_surface.py \
             tests/saving/test_export_dispatch.py \
@@ -358,6 +359,7 @@ jobs:
             tests/saving/test_save_shell_injection.py \
             tests/saving/test_patch_saving_none_tokenizer.py \
             tests/saving/test_fix_sentencepiece_gguf_robustness.py \
+            tests/saving/test_fix_sentencepiece_tokenizer_guard.py \
             tests/saving/test_compressed_export_schemes.py \
             tests/saving/test_export_api_surface.py \
             tests/saving/test_export_dispatch.py \
diff --git a/.github/workflows/cross-platform-parity-ci.yml b/.github/workflows/cross-platform-parity-ci.yml
index bb7dcbf8e4..45ce231743 100644
--- a/.github/workflows/cross-platform-parity-ci.yml
+++ b/.github/workflows/cross-platform-parity-ci.yml
@@ -1,18 +1,16 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 
-# Runs installer parity and autostart opt-out tests on Windows and macOS.
+# Runs installer parity and autostart opt-out tests across all three platforms.
 #
-# Why: that test is the guard that install.sh and install.ps1 stay in
-# sync, but today it only runs on ubuntu-latest (auto-discovered by
-# studio-backend-ci.yml's "Repo tests (CPU)" job). The test reads both
-# installer scripts, and on Windows Path.read_text() defaults to the
-# cp1252 locale encoding, so a non-cp1252 byte in install.sh (it already
-# contains a U+274C) raises UnicodeDecodeError there even though Linux and
-# macOS default to UTF-8. The reads were pinned to encoding="utf-8" in
-# #6166; this job keeps that from silently regressing by exercising the
-# test on the platforms it claims parity for. Pure pytest, no GPU,
-# sub-second, so the matrix is cheap.
+# Why: the parity test guards that install.sh and install.ps1 stay in sync.
+# It originally ran only on ubuntu-latest through studio-backend-ci.yml.
+# On Windows, Path.read_text() defaults to the cp1252 locale encoding, so a
+# non-cp1252 byte in install.sh raises UnicodeDecodeError even though Linux
+# and macOS default to UTF-8. The reads were pinned to encoding="utf-8" in
+# #6166; this matrix keeps that from silently regressing. Pure pytest, no GPU,
+# sub-second, so the matrix is cheap. Linux also runs the POSIX rollback test
+# under dash, matching the supported curl-to-sh installer path.
 
 name: Cross-platform parity
 
@@ -23,6 +21,8 @@ on:
       - 'install.ps1'
       - 'tests/test_installer_skip_autostart.py'
       - 'tests/python/test_cross_platform_parity.py'
+      - 'tests/sh/test_install_rollback_lifecycle.sh'
+      - 'tests/studio/test_install_rollback_lifecycle.ps1'
       - '.github/workflows/cross-platform-parity-ci.yml'
   push:
     branches: [main]
@@ -31,6 +31,8 @@ on:
       - 'install.ps1'
       - 'tests/test_installer_skip_autostart.py'
       - 'tests/python/test_cross_platform_parity.py'
+      - 'tests/sh/test_install_rollback_lifecycle.sh'
+      - 'tests/studio/test_install_rollback_lifecycle.ps1'
       - '.github/workflows/cross-platform-parity-ci.yml'
   workflow_dispatch:
 
@@ -47,7 +49,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [windows-latest, macos-latest]
+        os: [ubuntu-latest, windows-latest, macos-latest]
     runs-on: ${{ matrix.os }}
     timeout-minutes: 10
     steps:
@@ -67,3 +69,10 @@ jobs:
           tests/python/test_cross_platform_parity.py
           tests/test_installer_skip_autostart.py
           -q
+      - name: PowerShell rollback lifecycle tests
+        if: runner.os == 'Windows'
+        shell: pwsh
+        run: pwsh -NoProfile -File tests/studio/test_install_rollback_lifecycle.ps1
+      - name: POSIX rollback lifecycle tests
+        if: runner.os == 'Linux'
+        run: sh tests/sh/test_install_rollback_lifecycle.sh
diff --git a/.github/workflows/lint-ci.yml b/.github/workflows/lint-ci.yml
index bd859a6e9e..e1f0afd299 100644
--- a/.github/workflows/lint-ci.yml
+++ b/.github/workflows/lint-ci.yml
@@ -13,10 +13,10 @@
 #     committed YAML / JSON config.
 #
 # TypeScript and Rust are NOT duplicated here on purpose:
-#   - Studio Frontend CI runs `npm run typecheck` (= `tsc --noEmit`)
+#   - Unsloth Frontend CI runs `npm run typecheck` (= `tsc --noEmit`)
 #     and `npm run build` (vite/swc) on every studio/frontend/**
 #     change, which is a full TS AST + type check.
-#   - Studio Tauri CI runs `tauri build --debug --no-bundle` on
+#   - Unsloth Tauri CI runs `tauri build --debug --no-bundle` on
 #     every studio/src-tauri/** or studio/frontend/** change, which
 #     compiles the Rust crate (= cargo check + cargo build).
 # Each is a stricter check than a parse-only step would be, so a
diff --git a/.github/workflows/local-agent-guides-ci.yml b/.github/workflows/local-agent-guides-ci.yml
index 25796bd5cf..c48328e90f 100644
--- a/.github/workflows/local-agent-guides-ci.yml
+++ b/.github/workflows/local-agent-guides-ci.yml
@@ -154,7 +154,7 @@ jobs:
           path: gguf-cache
           key: ${{ runner.os }}-gguf-${{ env.GGUF_REPO }}-${{ env.GGUF_FILE }}-v1
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Gated off PR (see note above); public GGUF still downloads.
@@ -256,7 +256,7 @@ jobs:
             done
           fi
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           # Guard the PID: an unset/zero UNSLOTH_SERVER_PID would make
@@ -359,7 +359,7 @@ jobs:
           path: gguf-cache
           key: ${{ runner.os }}-gguf-${{ env.GGUF_REPO }}-${{ env.GGUF_FILE }}-v1
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Gated off PR (see note above); public GGUF still downloads.
@@ -448,7 +448,7 @@ jobs:
             done
           fi
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           # Guard the PID: an unset/zero UNSLOTH_SERVER_PID would make
@@ -543,7 +543,7 @@ jobs:
           path: gguf-cache
           key: ${{ runner.os }}-gguf-${{ env.GGUF_REPO }}-${{ env.GGUF_FILE }}-v1
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           HF_TOKEN: ${{ secrets.HF_TOKEN }}
@@ -620,7 +620,7 @@ jobs:
             done
           fi
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           if [ -n "${UNSLOTH_SERVER_PID:-}" ] && [ "${UNSLOTH_SERVER_PID}" != "0" ]; then
@@ -706,7 +706,7 @@ jobs:
           path: hf-cache
           key: ${{ runner.os }}-hf-${{ env.GGUF_REPO }}-${{ env.GGUF_VARIANT }}-v2
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Gated off PR (see note above); public GGUF still downloads.
@@ -764,7 +764,7 @@ jobs:
             done
           fi
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           # Guard the PID: an unset/zero UNSLOTH_SERVER_PID would make
diff --git a/.github/workflows/mlx-ci.yml b/.github/workflows/mlx-ci.yml
index a2f716a93c..aadf0b54e6 100644
--- a/.github/workflows/mlx-ci.yml
+++ b/.github/workflows/mlx-ci.yml
@@ -130,7 +130,7 @@ jobs:
       #    MLX support landed after the most recent unsloth-zoo PyPI
       #    release; the wheel still raises NotImplementedError on
       #    Apple Silicon when device_type.get_device_type() runs
-      #    unguarded. Studio's own install.sh overlays unsloth-zoo
+      #    unguarded. Unsloth's own install.sh overlays unsloth-zoo
       #    from git main for the same reason. Pulling deps lets pip
       #    resolve the platform-conditional MLX-only wheels (mlx,
       #    mlx-lm, mlx-vlm gated on darwin+arm64 in unsloth-zoo's
@@ -317,13 +317,13 @@ jobs:
             echo
           done
 
-      # Validates the macOS prebuilt path Studio's setup.sh uses (#5963): install the
+      # Validates the macOS prebuilt path Unsloth's setup.sh uses (#5963): install the
       # unslothai/llama.cpp fork's latest release, download a small public GGUF, and
       # check llama-server /completion end to end. Split and placed last so the
       # untrusted binary runs only in the final smoke step, after every HF_TOKEN step,
       # leaving no token-bearing step or shared workspace for a tampered prebuilt to
       # corrupt. GH_TOKEN: releases API; HF_TOKEN (withheld on PR): probe + GGUF fetch.
-      - name: Studio prebuilt llama.cpp install + GGUF download (Mac M1)
+      - name: Unsloth prebuilt llama.cpp install + GGUF download (Mac M1)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -344,12 +344,12 @@ jobs:
 
       # Final step: runs the downloaded binaries with no secrets present, and clears
       # the GitHub Actions command files so a tampered prebuilt cannot influence the job.
-      - name: Studio prebuilt llama.cpp GGUF inference smoke (Mac M1)
+      - name: Unsloth prebuilt llama.cpp GGUF inference smoke (Mac M1)
         run: |
           set -euo pipefail
           unset GITHUB_ENV GITHUB_PATH GITHUB_OUTPUT GITHUB_STEP_SUMMARY
           INSTALL_DIR="$HOME/.unsloth-studio-prebuilt-test/llama.cpp"
-          # Studio bundles only llama-server + llama-quantize (not llama-cli);
+          # Unsloth bundles only llama-server + llama-quantize (not llama-cli);
           # inference goes through llama-server's HTTP /completion endpoint.
           LLAMA_SERVER="$INSTALL_DIR/build/bin/llama-server"
           LLAMA_QUANT="$INSTALL_DIR/build/bin/llama-quantize"
@@ -400,4 +400,4 @@ jobs:
             tail -40 /tmp/llama-server.log
             exit 1
           fi
-          echo "OK: Studio prebuilt llama.cpp on Mac M1 + GGUF /completion works"
+          echo "OK: Unsloth prebuilt llama.cpp on Mac M1 + GGUF /completion works"
diff --git a/.github/workflows/release-desktop.yml b/.github/workflows/release-desktop.yml
index 4daafae35d..081eda4e32 100644
--- a/.github/workflows/release-desktop.yml
+++ b/.github/workflows/release-desktop.yml
@@ -4,7 +4,7 @@ on:
   workflow_dispatch:
     inputs:
       studio_version:
-        description: 'Studio version tag to release (for example, v0.1.39-beta)'
+        description: 'Unsloth version tag to release (for example, v0.1.39-beta)'
         type: string
         required: true
       pypi_version:
@@ -69,7 +69,7 @@ jobs:
           if not studio_version:
               sys.exit('studio_version is required, for example v0.1.39-beta')
           if re.fullmatch(r'v?20\d{2}\.\d+\.\d+(?:[-+][0-9A-Za-z.-]+)?', studio_version):
-              sys.exit(f'studio_version must be a Studio SemVer tag, not a date-style backend version: {studio_version}')
+              sys.exit(f'studio_version must be an Unsloth SemVer tag, not a date-style backend version: {studio_version}')
 
           semver_tag = re.compile(
               r'^v(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)'
@@ -146,7 +146,7 @@ jobs:
               print(f'pypi_version={pypi_version}', file=output)
           PY
 
-      - name: Verify PyPI package and Studio stamp
+      - name: Verify PyPI package and Unsloth stamp
         shell: bash
         env:
           STUDIO_VERSION: ${{ steps.prepare.outputs.studio_version }}
@@ -211,7 +211,7 @@ jobs:
             fi
             python3 scripts/stamp_studio_release.py --verify-dist "$RUNNER_TEMP/pypi-unsloth-dist" --expected "$STUDIO_VERSION"
           else
-            echo "scripts/stamp_studio_release.py not found; release-desktop requires #5308 to verify the PyPI Studio stamp." >&2
+            echo "scripts/stamp_studio_release.py not found; release-desktop requires #5308 to verify the PyPI Unsloth stamp." >&2
             exit 1
           fi
 
diff --git a/.github/workflows/security-audit.yml b/.github/workflows/security-audit.yml
index 1275d12216..27eafbedea 100644
--- a/.github/workflows/security-audit.yml
+++ b/.github/workflows/security-audit.yml
@@ -36,8 +36,8 @@
 #   - unsloth `huggingfacenotorch` extras (the canonical install path
 #     for fine-tuning users; pulls transformers / peft / accelerate /
 #     trl / datasets / diffusers / sentence-transformers / etc.)
-#   - all six Studio backend requirements files
-#   - Studio frontend (npm) and Tauri shell (cargo)
+#   - all six Unsloth backend requirements files
+#   - Unsloth frontend (npm) and Tauri shell (cargo)
 # Each Python step builds a filtered dep list from pyproject.toml +
 # requirements/*.txt before auditing. We do NOT install any of these
 # -- pip-audit resolves through PyPI metadata, scan_packages.py
@@ -218,7 +218,7 @@ jobs:
         #       on the runner). A comment line is left in place so the
         #       skipped specs are obvious in the artifact.
         # The `huggingface` extra is `huggingfacenotorch` plus torch /
-        # torchvision / triton, deliberately skipped: Studio backend
+        # torchvision / triton, deliberately skipped: Unsloth backend
         # already pins a torch and the +cu* / +cpu local-version tags
         # trip up the PyPI resolver in `-r` mode.
         run: |
@@ -253,7 +253,7 @@ jobs:
         # `-r requirements.txt` resolves the requirements through pip's
         # dependency resolver against PyPI metadata and audits the
         # resolved tree without ever executing setup.py / install
-        # hooks. Way faster than installing the full Studio runtime
+        # hooks. Way faster than installing the full Unsloth runtime
         # and -- critically -- safer: an attacker who has compromised
         # a transitive dep cannot run code in this job.
         #
@@ -326,9 +326,9 @@ jobs:
           } >> "$GITHUB_STEP_SUMMARY"
 
       # ─────────────────────────────────────────────────────────────
-      # npm: Studio frontend
+      # npm: Unsloth frontend
       # ─────────────────────────────────────────────────────────────
-      - name: npm audit (Studio frontend)
+      - name: npm audit (Unsloth frontend)
         # `npm audit` resolves the lockfile through the npmjs.com
         # advisory DB. `--audit-level=high` filters the noise floor
         # to only HIGH and CRITICAL. We do NOT pass --omit=dev: a
@@ -342,7 +342,7 @@ jobs:
           # Always also write the full JSON for grep-ability.
           npm audit --json > ../../logs-npm-audit.json || true
           {
-            echo "## npm audit (Studio frontend)"
+            echo "## npm audit (Unsloth frontend)"
             echo
             echo '```'
             tail -200 ../../logs-npm-audit.txt
@@ -350,9 +350,9 @@ jobs:
           } >> "$GITHUB_STEP_SUMMARY"
 
       # ─────────────────────────────────────────────────────────────
-      # cargo: Studio Tauri shell
+      # cargo: Unsloth Tauri shell
       # ─────────────────────────────────────────────────────────────
-      - name: cargo audit (Studio Tauri)
+      - name: cargo audit (Unsloth Tauri)
         # `--deny warnings` would make the job fail on any advisory.
         # Keep non-blocking initially; drop continue-on-error after
         # the baseline closes.
@@ -362,7 +362,7 @@ jobs:
           set +e
           cargo audit | tee ../../logs-cargo-audit.txt
           {
-            echo "## cargo audit (Studio Tauri)"
+            echo "## cargo audit (Unsloth Tauri)"
             echo
             echo '```'
             tail -200 ../../logs-cargo-audit.txt
@@ -559,7 +559,7 @@ jobs:
 
       # ─────────────────────────────────────────────────────────────
       # CycloneDX SBOM. Lets downstream consumers audit what's
-      # actually shipped in unsloth wheels and the Studio backend
+      # actually shipped in unsloth wheels and the Unsloth backend
       # runtime. Generates one JSON file per requirements input plus
       # a combined SBOM keyed off pyproject.toml; uploads as a build
       # artifact (and a future step can attest it via SLSA).
@@ -740,7 +740,7 @@ jobs:
     # `--with-deps` makes the scan transitive: every package the
     # declared set resolves to gets fetched and pattern-scanned, not
     # just the top-level pins. Resolving the full transitive closure
-    # of the unsloth + Studio dep tree downloads several hundred
+    # of the unsloth + Unsloth dep tree downloads several hundred
     # archives, hence the longer timeout.
     #
     # Sharded across runners for wall-clock parallelism. Each shard
@@ -749,7 +749,7 @@ jobs:
     # composition tries to balance load:
     #   - hf-stack: pyproject extras + no-torch-runtime
     #               (~150 archives, transformers/peft/accelerate/...)
-    #   - studio:   FastAPI/Studio backend + overrides + extras-no-deps
+    #   - studio:   FastAPI/Unsloth backend + overrides + extras-no-deps
     #               (~150 archives, smaller scientific stack)
     #   - extras:   the heavy openai-whisper / scikit-learn / librosa
     #               stack (~250 archives, dominant cost)
@@ -964,7 +964,7 @@ jobs:
     # documented at scripts/scan_npm_packages.py top-of-file. The
     # script is stdlib-only so adding it does not increase the
     # transitive supply-chain surface.
-    name: npm scan-packages (Studio frontend tarballs)
+    name: npm scan-packages (Unsloth frontend tarballs)
     runs-on: ubuntu-latest
     timeout-minutes: 30
     needs: []
@@ -1173,7 +1173,7 @@ jobs:
         with:
           python-version: '3.12'
 
-      - name: Install Studio frontend deps (--ignore-scripts)
+      - name: Install Unsloth frontend deps (--ignore-scripts)
         # `npm audit signatures` requires node_modules to be populated.
         # `--ignore-scripts` is mandatory: this is exactly the lever the
         # new-install-script gate below protects against, and we must
diff --git a/.github/workflows/studio-api-smoke.yml b/.github/workflows/studio-api-smoke.yml
index 15efee382e..cdf1f6bf12 100644
--- a/.github/workflows/studio-api-smoke.yml
+++ b/.github/workflows/studio-api-smoke.yml
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 
-# Studio API & Auth Tests -- HTTP-level integration tests for the
+# Unsloth API & Auth Tests -- HTTP-level integration tests for the
 # FastAPI surface. No Playwright, no model UI; tests/studio/test_studio_api_smoke.py
 # runs ~30 s and asserts:
 #   - CORS hardening (no wildcard + credentials, no bootstrap leak)
@@ -15,7 +15,7 @@
 # Reuses the GGUF cache key from studio-ui-smoke.yml so the model
 # download is one cache-hit on the second job.
 
-name: Studio API CI
+name: Unsloth API CI
 
 on:
   pull_request:
@@ -40,7 +40,7 @@ permissions:
 
 jobs:
   api-smoke:
-    name: Studio API & Auth Tests
+    name: Unsloth API & Auth Tests
     runs-on: ubuntu-latest
     timeout-minutes: 12
     env:
@@ -98,7 +98,7 @@ jobs:
           path: hf-cache
           key: ${{ runner.os }}-hf-${{ env.GGUF_REPO }}-${{ env.GGUF_VARIANT }}-v2
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Withheld on PR: this step runs checked-out PR code; public GGUF still downloads.
@@ -111,7 +111,7 @@ jobs:
       - name: Install pyjwt for the JWT-expiry forge test
         run: pip install 'pyjwt>=2.6'
 
-      - name: Reset auth + boot Studio (API-only)
+      - name: Reset auth + boot Unsloth (API-only)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -144,7 +144,7 @@ jobs:
           echo "STUDIO_NEW_PW=$NEW"  >> "$GITHUB_ENV"
           echo "STUDIO_NEW2_PW=$NEW2" >> "$GITHUB_ENV"
 
-      - name: Run Studio API & Auth tests
+      - name: Run Unsloth API & Auth tests
         # The script is named WITHOUT a `test_` prefix so it isn't
         # auto-collected by pytest in Backend CI's `tests/` walk
         # (which doesn't set BASE_URL and would crash at import).
@@ -153,7 +153,7 @@ jobs:
           STUDIO_AUTH_DIR: /home/runner/.unsloth/studio/auth
         run: python tests/studio/studio_api_smoke.py
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           kill "${STUDIO_PID}" 2>/dev/null || true
diff --git a/.github/workflows/studio-backend-ci.yml b/.github/workflows/studio-backend-ci.yml
index 3022127a2b..3968f2e80a 100644
--- a/.github/workflows/studio-backend-ci.yml
+++ b/.github/workflows/studio-backend-ci.yml
@@ -64,7 +64,7 @@ jobs:
       - name: Install backend test dependencies (CPU only)
         run: |
           python -m pip install --upgrade pip
-          # Studio's declared backend deps:
+          # Unsloth's declared backend deps:
           pip install -r studio/backend/requirements/studio.txt
           # Extras that studio.txt does not list but the import chain needs
           # (python-multipart for FastAPI form/file uploads, sqlalchemy/cryptography
@@ -193,6 +193,7 @@ jobs:
             --ignore=tests/sh \
             --ignore=tests/studio/test_hardware_dispatch_matrix.py \
             --ignore=tests/studio/test_is_mlx_dispatch_gate.py \
+            --ignore=tests/studio/test_xpu_spoof_pipeline.py \
             --ignore=tests/vllm_compat \
             --ignore=tests/version_compat \
             -m 'not server and not e2e' \
@@ -205,14 +206,15 @@ jobs:
         env:
           PYTHONPATH: ${{ github.workspace }}/studio
           UNSLOTH_COMPILE_DISABLE: '1'
-        # These two files mutate hardware.py module globals at runtime
-        # via the spoof fixtures, which leaks state into any other test
-        # that imports hardware. Run them in their own pytest invocation
-        # so the leak does not cross file boundaries.
+        # These files mutate hardware.py module globals at runtime via the
+        # spoof fixtures (CUDA/ROCm/XPU/MLX/CPU), which leaks state into any
+        # other test that imports hardware. Run them in their own pytest
+        # invocation so the leak does not cross file boundaries.
         run: |
           python -m pytest -q --tb=short \
             tests/studio/test_hardware_dispatch_matrix.py \
-            tests/studio/test_is_mlx_dispatch_gate.py
+            tests/studio/test_is_mlx_dispatch_gate.py \
+            tests/studio/test_xpu_spoof_pipeline.py
 
       - name: Shell installer tests
         # Subset that does not depend on a writable / pristine install.sh
@@ -228,6 +230,7 @@ jobs:
               tests/sh/test_system_node_readonly.sh \
               tests/sh/test_nvcc_meets_llama_minimum.sh \
               tests/sh/test_resolve_cuda_archs.sh \
+              tests/sh/test_staged_validation_enabled.sh \
               tests/sh/test_tauri_install_exit_order.sh \
               tests/sh/test_torch_constraint.sh \
               tests/sh/test_torch_flavor.sh \
diff --git a/.github/workflows/studio-export-capability-ci.yml b/.github/workflows/studio-export-capability-ci.yml
index 1ee6489209..83df3ed476 100644
--- a/.github/workflows/studio-export-capability-ci.yml
+++ b/.github/workflows/studio-export-capability-ci.yml
@@ -9,7 +9,7 @@
 # export is validated separately. No GPU / model / llama.cpp: the tests mock the probes and block
 # torch/unsloth, so the job installs only a CPU PyTorch plus import deps.
 
-name: Studio export capability
+name: Unsloth export capability
 
 on:
   pull_request:
diff --git a/.github/workflows/studio-frontend-ci.yml b/.github/workflows/studio-frontend-ci.yml
index b42086f191..3a9e373915 100644
--- a/.github/workflows/studio-frontend-ci.yml
+++ b/.github/workflows/studio-frontend-ci.yml
@@ -136,7 +136,7 @@ jobs:
       - name: Build
         run: npm run build
 
-      - name: Built bundle must not contain Studio's unstable_Provider call site
+      - name: Built bundle must not contain Unsloth's unstable_Provider call site
         run: |
           set -e
           JS=$(ls dist/assets/index-*.js | head -1)
@@ -144,7 +144,7 @@ jobs:
           echo "main bundle: $JS"
           echo "unstable_Provider: hits=$HITS (assistant-ui internals contribute up to 3)"
           if [ "$HITS" -gt 3 ]; then
-            echo "::error file=studio/frontend/src/features/chat/runtime-provider.tsx::Studio bundle still passes unstable_Provider through useRemoteThreadListRuntime; this is the 2026.5.1 chat-history regression. Pass adapters directly into useLocalRuntime instead."
+            echo "::error file=studio/frontend/src/features/chat/runtime-provider.tsx::Unsloth bundle still passes unstable_Provider through useRemoteThreadListRuntime; this is the 2026.5.1 chat-history regression. Pass adapters directly into useLocalRuntime instead."
             exit 1
           fi
 
diff --git a/.github/workflows/studio-inference-smoke.yml b/.github/workflows/studio-inference-smoke.yml
index 58ef2558f3..c2d52eac22 100644
--- a/.github/workflows/studio-inference-smoke.yml
+++ b/.github/workflows/studio-inference-smoke.yml
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 
-# Three end-to-end smoke jobs that boot a freshly-installed Studio and
+# Three end-to-end smoke jobs that boot a freshly-installed Unsloth and
 # exercise the surfaces real users hit through the OpenAI / Anthropic
 # SDKs and curl. Each job picks the smallest model that exercises the
 # behaviour under test, primes HF_HOME via actions/cache, and shares
@@ -27,7 +27,7 @@
 # All three jobs run in parallel. Total wall time is dominated by job 3
 # on a cold cache; warm cache cuts that to ~3 min.
 
-name: Studio GGUF CI
+name: Unsloth GGUF CI
 
 on:
   pull_request:
@@ -112,7 +112,7 @@ jobs:
           path: hf-cache
           key: ${{ runner.os }}-hf-${{ env.GGUF_REPO }}-${{ env.GGUF_VARIANT }}-v2
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Withheld on PR: this step runs checked-out PR code; public GGUF still downloads.
@@ -125,7 +125,7 @@ jobs:
       - name: Install OpenAI + Anthropic Python SDKs
         run: pip install 'openai>=1.50' 'anthropic>=0.40'
 
-      - name: Reset auth + boot Studio (API-only)
+      - name: Reset auth + boot Unsloth (API-only)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -142,7 +142,7 @@ jobs:
             fi
             sleep 1
           done
-          echo "Studio did not become healthy in 180s"
+          echo "Unsloth did not become healthy in 180s"
           tail -200 logs/studio.log
           exit 1
 
@@ -229,11 +229,11 @@ jobs:
               return replies
 
           def run_anthropic():
-              # Two SDK quirks vs. Studio:
+              # Two SDK quirks vs. Unsloth:
               #   1. base_url must NOT include /v1 -- the SDK appends
               #      /v1/messages itself; otherwise the request hits
               #      /v1/v1/messages and 405s.
-              #   2. The SDK sends `x-api-key` by default, but Studio's
+              #   2. The SDK sends `x-api-key` by default, but Unsloth's
               #      auth layer is HTTPBearer-only. Override via
               #      default_headers so Authorization: Bearer ... is
               #      sent instead.
@@ -276,7 +276,7 @@ jobs:
                   print(
                       f"[{label}] WARN non-determinism at temperature=0.0 across "
                       f"{len(determinism_failures)} of {len(first)} turn(s); "
-                      f"small-quant model drift, not a Studio regression. "
+                      f"small-quant model drift, not an Unsloth regression. "
                       f"Details: " + " | ".join(determinism_failures)
                   )
               # Sanity: turn-2 reply should mention the earlier question, and
@@ -290,7 +290,7 @@ jobs:
               print(f"[{label}] {status_word} -- 4 turns, history grounded ('paris' present)")
           PY
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           kill "${STUDIO_PID}" 2>/dev/null || true
@@ -323,7 +323,7 @@ jobs:
       # store xet chunks + blobs + snapshots = ~4 GiB compressed --
       # 4-5x file-size inflation, dominated by xet chunks. Use main's
       # `--local-dir gguf-cache` pattern to cache the flat .gguf only.
-      # Studio's /api/inference/load accepts either a HF repo (which
+      # Unsloth's /api/inference/load accepts either a HF repo (which
       # uses HF_HOME) or an absolute file path; passing the absolute
       # path keeps the test off HF_HOME entirely so the cache size
       # tracks the GGUF file 1:1. The OpenAI/Anth and JSON+images
@@ -380,7 +380,7 @@ jobs:
           path: gguf-cache
           key: ${{ runner.os }}-gguf-${{ env.GGUF_REPO }}-${{ env.GGUF_FILE }}-v1
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Withheld on PR: this step runs checked-out PR code; public GGUF still downloads.
@@ -390,7 +390,7 @@ jobs:
           set -o pipefail
           bash install.sh --local --no-torch 2>&1 | tee logs/install.log
 
-      - name: Reset auth + boot Studio (API-only, default tool policy)
+      - name: Reset auth + boot Unsloth (API-only, default tool policy)
         # We deliberately use the API-only mode rather than
         # `unsloth studio run` because the latter calls
         # `set_tool_policy(...)` with a resolved bool: on loopback the
@@ -503,7 +503,7 @@ jobs:
                                  that the tool path executed.
 
               A shared CI runner can stall the stream transport (the
-              connection opening, or a mid-stream read) even when Studio
+              connection opening, or a mid-stream read) even when Unsloth
               is healthy, so retry a stall once with a fresh request
               capped at 300s. A stall means the stream did NOT complete,
               so partial events are normally NOT returned (an early
@@ -575,11 +575,11 @@ jobs:
 
           def _tool_invoked(events):
               """Structural check: True iff some SSE payload is a real
-              tool envelope (Studio tool_start/tool_end, Anthropic
+              tool envelope (Unsloth tool_start/tool_end, Anthropic
               tool_use/tool_result, OpenAI non-empty delta.tool_calls /
               message.tool_calls / finish_reason='tool_calls' /
               role:'tool' / function_call). tool_status is NOT
-              evidence: Studio emits empty tool_status events on
+              evidence: Unsloth emits empty tool_status events on
               iteration boundaries even when no tool ran.
               """
               for raw in events:
@@ -698,7 +698,7 @@ jobs:
               attempt has structural invocation evidence. WARN (not
               FAIL) if invoked but no attempt produces the expected
               literal in tool_end.result -- small-quant Qwen3.5-2B can
-              emit OpenAI tool_calls deltas without Studio's GGUF
+              emit OpenAI tool_calls deltas without Unsloth's GGUF
               agentic loop intercepting them, and that GGUF-vs-OpenAI
               format mismatch is out of scope for #5642.
               """
@@ -811,7 +811,7 @@ jobs:
           # because (a) the search may legitimately return no results,
           # and (b) DuckDuckGo upstream blocks GHA IP ranges often
           # enough that requiring a tool_call marker would create
-          # red-herring failures from infra rather than from Studio.
+          # red-herring failures from infra rather than from Unsloth.
           try:
               # Best-effort and bounded: a single 180s attempt keeps a stall
               # from eating the job's timeout-minutes (it already WARNs, so a
@@ -834,7 +834,7 @@ jobs:
               print(f"[tools] WARN web_search probe failed (non-blocking): {exc}")
 
           # ── 5. Thinking on / off ─────────────────────────────────────
-          # Studio strips think blocks from message.content for tools-mode
+          # Unsloth strips think blocks from message.content for tools-mode
           # responses, so we toggle plain chat (no enable_tools) and look
           # at the surfaced reasoning_content / message.thinking field.
           def thinking_call(enable):
@@ -848,7 +848,7 @@ jobs:
               })
               assert status == 200
               msg = data["choices"][0]["message"]
-              # Studio surfaces thinking via reasoning_content (OpenAI
+              # Unsloth surfaces thinking via reasoning_content (OpenAI
               # extension). Fall back to inline <think> markers for
               # robustness across template versions.
               raw = (msg.get("content") or "") + (msg.get("reasoning_content") or "")
@@ -868,7 +868,7 @@ jobs:
           print(f"[tools] PASS thinking on/off (on={len(on_text)} chars, off={len(off_text)} chars)")
           PY
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           kill "${STUDIO_PID}" 2>/dev/null || true
@@ -960,7 +960,7 @@ jobs:
           path: hf-cache
           key: ${{ runner.os }}-hf-${{ env.GGUF_REPO }}-${{ env.GGUF_VARIANT }}-${{ env.MMPROJ_FILE }}-v2
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Withheld on PR: this step runs checked-out PR code; public GGUF still downloads.
@@ -973,7 +973,7 @@ jobs:
       - name: Install OpenAI + Anthropic Python SDKs
         run: pip install 'openai>=1.50' 'anthropic>=0.40'
 
-      - name: Reset auth + boot Studio (API-only)
+      - name: Reset auth + boot Unsloth (API-only)
         # See Job 2's comment: API-only mode keeps tool_policy=None so
         # response_format requests aren't routed through the agentic
         # tool loop.
@@ -1076,13 +1076,13 @@ jobs:
           # llama.cpp's HTTP server supports OpenAI-compatible JSON
           # mode: `response_format: {"type": "json_object"}` constrains
           # the model to emit syntactically-valid JSON. We use raw HTTP
-          # rather than the OpenAI SDK so that the field shape Studio
+          # rather than the OpenAI SDK so that the field shape Unsloth
           # forwards to llama-server is unambiguous (the SDK rewrites
           # response_format depending on which variant it recognises).
           # We deliberately do NOT pass a strict JSON schema -- on
           # small Gemma-4 quants the GBNF-from-schema path occasionally
           # produces empty output, and JSON mode is the surface we care
-          # about exposing through Studio.
+          # about exposing through Unsloth.
           status, data = post("/v1/chat/completions", {
               "model":         "default",
               "messages":      [
@@ -1112,7 +1112,7 @@ jobs:
           print(f"[json] PASS json_object -> {parsed}")
 
           # ── 2. OpenAI image_url (data URI base64) ───────────────────
-          # 64x64 solid-red PNG. stb_image (used by Studio's image
+          # 64x64 solid-red PNG. stb_image (used by Unsloth's image
           # normaliser at routes/inference.py:3410) rejects 4x4 or
           # smaller PNGs as truncated, so we go up to 64x64 -- still
           # tiny in token cost. The assertion is loose: any non-empty
@@ -1148,9 +1148,9 @@ jobs:
           print("[image/openai] PASS image_url accepted, non-empty response")
 
           # ── 3. Anthropic source/base64 image ────────────────────────
-          # Two SDK quirks vs. Studio: base_url must NOT include /v1
+          # Two SDK quirks vs. Unsloth: base_url must NOT include /v1
           # (the SDK appends it itself; otherwise /v1/v1/messages -> 405),
-          # and Studio's auth is HTTPBearer-only so the SDK's default
+          # and Unsloth's auth is HTTPBearer-only so the SDK's default
           # x-api-key header is ignored -- send Authorization: Bearer
           # via default_headers.
           anthropic = Anthropic(
@@ -1184,7 +1184,7 @@ jobs:
           print("[image/anthropic] PASS source/base64 accepted, non-empty response")
           PY
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           kill "${STUDIO_PID}" 2>/dev/null || true
diff --git a/.github/workflows/studio-load-orchestrator-ci.yml b/.github/workflows/studio-load-orchestrator-ci.yml
index 93d1a7742d..8710efc2bd 100644
--- a/.github/workflows/studio-load-orchestrator-ci.yml
+++ b/.github/workflows/studio-load-orchestrator-ci.yml
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 #
-# Event-loop regression test for the Studio model-load orchestrator.
+# Event-loop regression test for the Unsloth model-load orchestrator.
 # Pins down issue #5642 (Win10 UI freeze on model load): the /load
 # route calls LlamaCppBackend.detect_audio_type synchronously, blocking
 # the FastAPI event loop on a chain of sync httpx.Client.post() probes.
@@ -14,7 +14,7 @@
 # danielhanchen/unsloth-staging-2 (Ubuntu / macOS / Windows all
 # green at PR time).
 
-name: Studio load-orchestrator CI
+name: Unsloth load-orchestrator CI
 
 on:
   pull_request:
diff --git a/.github/workflows/studio-mac-api-smoke.yml b/.github/workflows/studio-mac-api-smoke.yml
index 617ce189dc..1968885a1d 100644
--- a/.github/workflows/studio-mac-api-smoke.yml
+++ b/.github/workflows/studio-mac-api-smoke.yml
@@ -33,7 +33,7 @@ permissions:
 
 jobs:
   api-smoke:
-    name: Studio API & Auth Tests
+    name: Unsloth API & Auth Tests
     runs-on: macos-14
     timeout-minutes: 25
     env:
@@ -83,7 +83,7 @@ jobs:
           path: hf-cache
           key: ${{ runner.os }}-hf-${{ env.GGUF_REPO }}-${{ env.GGUF_VARIANT }}-v2
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Withheld on PR: this step runs checked-out PR code; public GGUF still downloads.
@@ -99,7 +99,7 @@ jobs:
       - name: Install pyjwt for the JWT-expiry forge test
         run: pip install 'pyjwt>=2.6'
 
-      - name: Reset auth + boot Studio (API-only)
+      - name: Reset auth + boot Unsloth (API-only)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -129,13 +129,13 @@ jobs:
           echo "STUDIO_NEW_PW=$NEW"  >> "$GITHUB_ENV"
           echo "STUDIO_NEW2_PW=$NEW2" >> "$GITHUB_ENV"
 
-      - name: Run Studio API & Auth tests
+      - name: Run Unsloth API & Auth tests
         env:
           BASE_URL: http://127.0.0.1:18895
           STUDIO_AUTH_DIR: /Users/runner/.unsloth/studio/auth
         run: python tests/studio/studio_api_smoke.py
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           kill "${STUDIO_PID}" 2>/dev/null || true
diff --git a/.github/workflows/studio-mac-inference-smoke.yml b/.github/workflows/studio-mac-inference-smoke.yml
index 946681706a..ce15eed5c8 100644
--- a/.github/workflows/studio-mac-inference-smoke.yml
+++ b/.github/workflows/studio-mac-inference-smoke.yml
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 
-# Three end-to-end smoke jobs that boot a freshly-installed Studio and
+# Three end-to-end smoke jobs that boot a freshly-installed Unsloth and
 # exercise the surfaces real users hit through the OpenAI / Anthropic
 # SDKs and curl. Each job picks the smallest model that exercises the
 # behaviour under test, primes a model cache via actions/cache, and
@@ -108,7 +108,7 @@ jobs:
           path: hf-cache
           key: ${{ runner.os }}-hf-${{ env.GGUF_REPO }}-${{ env.GGUF_VARIANT }}-v2
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Withheld on PR: this step runs checked-out PR code; public GGUF still downloads.
@@ -124,7 +124,7 @@ jobs:
       - name: Install OpenAI + Anthropic Python SDKs
         run: pip install 'openai>=1.50' 'anthropic>=0.40'
 
-      - name: Reset auth + boot Studio (API-only)
+      - name: Reset auth + boot Unsloth (API-only)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -141,7 +141,7 @@ jobs:
             fi
             sleep 1
           done
-          echo "Studio did not become healthy in 180s"
+          echo "Unsloth did not become healthy in 180s"
           tail -200 logs/studio.log
           exit 1
 
@@ -228,11 +228,11 @@ jobs:
               return replies
 
           def run_anthropic():
-              # Two SDK quirks vs. Studio:
+              # Two SDK quirks vs. Unsloth:
               #   1. base_url must NOT include /v1 -- the SDK appends
               #      /v1/messages itself; otherwise the request hits
               #      /v1/v1/messages and 405s.
-              #   2. The SDK sends `x-api-key` by default, but Studio's
+              #   2. The SDK sends `x-api-key` by default, but Unsloth's
               #      auth layer is HTTPBearer-only. Override via
               #      default_headers so Authorization: Bearer ... is
               #      sent instead.
@@ -283,7 +283,7 @@ jobs:
               print(f"[{label}] OK -- 4 turns, run1 == run2, history grounded")
           PY
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           kill "${STUDIO_PID}" 2>/dev/null || true
@@ -363,7 +363,7 @@ jobs:
           path: gguf-cache
           key: ${{ runner.os }}-gguf-${{ env.GGUF_REPO }}-${{ env.GGUF_FILE }}-v1
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Withheld on PR: this step runs checked-out PR code; public GGUF still downloads.
@@ -376,7 +376,7 @@ jobs:
       - name: Assert llama.cpp loads on this macOS
         run: bash .github/scripts/assert-llama-loads.sh
 
-      - name: Reset auth + boot Studio (API-only, default tool policy)
+      - name: Reset auth + boot Unsloth (API-only, default tool policy)
         # We deliberately use the API-only mode rather than
         # `unsloth studio run` because the latter calls
         # `set_tool_policy(...)` with a resolved bool: on loopback the
@@ -478,7 +478,7 @@ jobs:
               call with enable_tools=true must use this helper.
 
               A shared CI runner can stall the stream transport (the
-              connection opening, or a mid-stream read) even when Studio
+              connection opening, or a mid-stream read) even when Unsloth
               is healthy, so harden the read three ways: retry a stall
               once with a fresh request capped at 300s; return any text
               already streamed before a stall (a stall on the trailing
@@ -574,11 +574,11 @@ jobs:
           assert status == 200, f"tool call status {status}: {data}"
           choice = data["choices"][0]
           tool_calls = (choice.get("message") or {}).get("tool_calls") or []
-          # Studio's contract: when tool_choice='required', llama.cpp's
+          # Unsloth's contract: when tool_choice='required', llama.cpp's
           # grammar should force a tool_calls payload. On Mac that
           # contract is sometimes broken by the underlying quant; the
           # PASS path is "tool_calls present + correct schema", the
-          # WARN path documents Studio still returned 200 with a
+          # WARN path documents Unsloth still returned 200 with a
           # well-formed choices[] envelope.
           if tool_calls:
               tc = tool_calls[0]
@@ -660,7 +660,7 @@ jobs:
               print(f"[tools] WARN web_search probe failed (non-blocking): {exc}")
 
           # ── 4. Thinking on / off ─────────────────────────────────────
-          # Studio strips think blocks from message.content for tools-mode
+          # Unsloth strips think blocks from message.content for tools-mode
           # responses, so we toggle plain chat (no enable_tools) and look
           # at the surfaced reasoning_content / message.thinking field.
           def thinking_call(enable):
@@ -678,7 +678,7 @@ jobs:
               }, timeout = 180)
               assert status == 200
               msg = data["choices"][0]["message"]
-              # Studio surfaces thinking via reasoning_content (OpenAI
+              # Unsloth surfaces thinking via reasoning_content (OpenAI
               # extension). Fall back to inline <think> markers for
               # robustness across template versions.
               raw = (msg.get("content") or "") + (msg.get("reasoning_content") or "")
@@ -704,7 +704,7 @@ jobs:
           print(f"[tools] PASS thinking on/off (on={len(on_text)} chars, off={len(off_text)} chars)")
           PY
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           kill "${STUDIO_PID}" 2>/dev/null || true
@@ -810,7 +810,7 @@ jobs:
           path: gguf-cache
           key: ${{ runner.os }}-gguf-${{ env.GGUF_REPO }}-${{ env.GGUF_FILE }}-${{ env.MMPROJ_FILE }}-v2
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Withheld on PR: this step runs checked-out PR code; public GGUF still downloads.
@@ -826,7 +826,7 @@ jobs:
       - name: Install OpenAI + Anthropic Python SDKs
         run: pip install 'openai>=1.50' 'anthropic>=0.40'
 
-      - name: Reset auth + boot Studio (API-only)
+      - name: Reset auth + boot Unsloth (API-only)
         # See Job 2's comment: API-only mode keeps tool_policy=None so
         # response_format requests aren't routed through the agentic
         # tool loop.
@@ -929,13 +929,13 @@ jobs:
           # llama.cpp's HTTP server supports OpenAI-compatible JSON
           # mode: `response_format: {"type": "json_object"}` constrains
           # the model to emit syntactically-valid JSON. We use raw HTTP
-          # rather than the OpenAI SDK so that the field shape Studio
+          # rather than the OpenAI SDK so that the field shape Unsloth
           # forwards to llama-server is unambiguous (the SDK rewrites
           # response_format depending on which variant it recognises).
           # We deliberately do NOT pass a strict JSON schema -- on
           # small Gemma-4 quants the GBNF-from-schema path occasionally
           # produces empty output, and JSON mode is the surface we care
-          # about exposing through Studio.
+          # about exposing through Unsloth.
           status, data = post("/v1/chat/completions", {
               "model":         "default",
               "messages":      [
@@ -1007,7 +1007,7 @@ jobs:
               )
 
           # ── 2. OpenAI image_url (data URI base64) ───────────────────
-          # 64x64 solid-red PNG. stb_image (used by Studio's image
+          # 64x64 solid-red PNG. stb_image (used by Unsloth's image
           # normaliser at routes/inference.py:3410) rejects 4x4 or
           # smaller PNGs as truncated, so we go up to 64x64 -- still
           # tiny in token cost. The assertion is loose: any non-empty
@@ -1023,11 +1023,11 @@ jobs:
           # The Mac prebuilt llama.cpp server has a known crash when
           # processing image inputs alongside the gemma-4-E2B mmproj
           # (server disconnects mid-completion). This is upstream
-          # llama.cpp behaviour, not Studio. Wrap both SDK calls in
+          # llama.cpp behaviour, not Unsloth. Wrap both SDK calls in
           # try/except so an upstream crash registers as a WARN rather
-          # than failing the whole job. Studio's contract (OpenAI/
+          # than failing the whole job. Unsloth's contract (OpenAI/
           # Anthropic image fields are accepted and forwarded) is
-          # validated by the request body Studio constructs, not by
+          # validated by the request body Unsloth constructs, not by
           # whether llama.cpp can decode it on Mac Metal.
           client = OpenAI(base_url = f"{BASE}/v1", api_key = KEY)
           try:
@@ -1053,14 +1053,14 @@ jobs:
           except Exception as exc:
               print(
                   f"[image/openai] WARN image_url SDK call raised: {type(exc).__name__}: "
-                  f"{exc}. Likely upstream llama.cpp Mac+vision crash, NOT a Studio "
-                  f"regression. Studio successfully forwarded the request."
+                  f"{exc}. Likely upstream llama.cpp Mac+vision crash, NOT an Unsloth "
+                  f"regression. Unsloth successfully forwarded the request."
               )
 
           # ── 3. Anthropic source/base64 image ────────────────────────
-          # Two SDK quirks vs. Studio: base_url must NOT include /v1
+          # Two SDK quirks vs. Unsloth: base_url must NOT include /v1
           # (the SDK appends it itself; otherwise /v1/v1/messages -> 405),
-          # and Studio's auth is HTTPBearer-only so the SDK's default
+          # and Unsloth's auth is HTTPBearer-only so the SDK's default
           # x-api-key header is ignored -- send Authorization: Bearer
           # via default_headers.
           anthropic = Anthropic(
@@ -1099,11 +1099,11 @@ jobs:
               print(
                   f"[image/anthropic] WARN anthropic image SDK call raised: "
                   f"{type(exc).__name__}: {exc}. Likely upstream llama.cpp Mac+vision "
-                  f"crash, NOT a Studio regression."
+                  f"crash, NOT an Unsloth regression."
               )
           PY
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           kill "${STUDIO_PID}" 2>/dev/null || true
diff --git a/.github/workflows/studio-mac-install-matrix.yml b/.github/workflows/studio-mac-install-matrix.yml
index 362305cdd4..e990f752d4 100644
--- a/.github/workflows/studio-mac-install-matrix.yml
+++ b/.github/workflows/studio-mac-install-matrix.yml
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 
-# Proves Studio's llama.cpp install loads on every supported macOS. The heavy
+# Proves Unsloth's llama.cpp install loads on every supported macOS. The heavy
 # app smokes stay single-OS; this matrix covers the OS-version dimension cheaply
 # (install.sh + binary-load assert). Regression guard for the macOS-version
 # selection in studio/install_llama_prebuilt.py.
@@ -60,7 +60,7 @@ jobs:
         with:
           python-version: '3.12'
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Withheld on PR: this step runs checked-out PR code; public GGUF still downloads.
diff --git a/.github/workflows/studio-mac-ui-smoke.yml b/.github/workflows/studio-mac-ui-smoke.yml
index 20ca247b9f..7375e9bcbf 100644
--- a/.github/workflows/studio-mac-ui-smoke.yml
+++ b/.github/workflows/studio-mac-ui-smoke.yml
@@ -19,6 +19,7 @@ on:
       - 'install.sh'
       - 'pyproject.toml'
       - 'tests/studio/**'
+      - '.github/scripts/run-studio-permission-browser.sh'
       - '.github/workflows/studio-mac-ui-smoke.yml'
   push:
     branches: [main, pip]
@@ -83,7 +84,7 @@ jobs:
           path: hf-cache
           key: ${{ runner.os }}-hf-${{ env.GGUF_REPO }}-${{ env.GGUF_VARIANT }}-v2
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Withheld on PR: this step runs checked-out PR code; public GGUF still downloads.
@@ -96,7 +97,7 @@ jobs:
       - name: Assert llama.cpp loads on this macOS
         run: bash .github/scripts/assert-llama-loads.sh
 
-      - name: Install Playwright + Chromium
+      - name: Install Playwright browsers
         # No --with-deps on Mac: that flag installs Linux apt packages.
         # GitHub-hosted macos-14 ships the system frameworks Chromium
         # needs already.
@@ -112,7 +113,7 @@ jobs:
         # in-script retry recover from any residual flakes.
         run: |
           pip install 'playwright>=1.55,<1.58'
-          python -m playwright install chromium
+          python -m playwright install chromium webkit
 
       - name: Patch Playwright pipeTransport.js to tolerate malformed JSON
         # In Playwright 1.55-1.58, pipeTransport.js does
@@ -143,7 +144,7 @@ jobs:
               print(f"pipeTransport.js: patched JSON.parse calls in {path}")
           PY
 
-      - name: Reset auth + boot Studio
+      - name: Reset auth + boot Unsloth
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -188,7 +189,7 @@ jobs:
         # dies mid-test, (2) Chromium net::ERR_NO_BUFFER_SPACE when the
         # runner's kernel briefly runs out of socket buffers, and (3) a
         # goto 'interrupted by another navigation' when the SPA auth
-        # guard redirects mid-navigation. The retry FULLY resets Studio
+        # guard redirects mid-navigation. The retry FULLY resets Unsloth
         # (kill, reset-password, reboot, wait /api/health, re-export
         # bootstrap pw) before re-running the script. A real test failure
         # (assertion / timeout) does NOT match any pattern so it bypasses
@@ -209,7 +210,7 @@ jobs:
                  || grep -q "ERR_NO_BUFFER_SPACE"             logs/playwright_attempt_${attempt}.log \
                  || grep -q "interrupted by another navigation" logs/playwright_attempt_${attempt}.log; } \
                && [ "$attempt" -lt "$max_attempts" ]; then
-              echo "::warning::Playwright flake on attempt ${attempt}; resetting Studio and retrying..."
+              echo "::warning::Playwright flake on attempt ${attempt}; resetting Unsloth and retrying..."
               kill "${STUDIO_PID}" 2>/dev/null || true
               sleep 2
               unsloth studio reset-password
@@ -238,13 +239,17 @@ jobs:
             exit "$rc"
           done
 
-      - name: Stop Studio (chat-ui ends with Shutdown click; this is belt-and-suspenders)
+      - name: Stop Unsloth (chat-ui ends with Shutdown click; this is belt-and-suspenders)
         if: always()
         run: |
           kill "${STUDIO_PID}" 2>/dev/null || true
           sleep 2
 
-      - name: Reset auth + boot Studio for extra UI tests (port 18897)
+      - name: Cross-browser permission controls
+        run: |
+          bash .github/scripts/run-studio-permission-browser.sh 18895 webkit
+
+      - name: Reset auth + boot Unsloth for extra UI tests (port 18897)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -271,7 +276,7 @@ jobs:
           echo "STUDIO_EXTRA_OLD_PW=$OLD" >> "$GITHUB_ENV"
           echo "STUDIO_EXTRA_NEW_PW=$NEW" >> "$GITHUB_ENV"
 
-      - name: Drive Compare/Recipes/Export/Studio/Settings with Playwright
+      - name: Drive Compare/Recipes/Export/Unsloth/Settings with Playwright
         env:
           BASE_URL: http://127.0.0.1:18897
           STUDIO_OLD_PW: ${{ env.STUDIO_EXTRA_OLD_PW }}
@@ -300,7 +305,7 @@ jobs:
                  || grep -q "ERR_NO_BUFFER_SPACE"             logs/playwright_extra_attempt_${attempt}.log \
                  || grep -q "interrupted by another navigation" logs/playwright_extra_attempt_${attempt}.log; } \
                && [ "$attempt" -lt "$max_attempts" ]; then
-              echo "::warning::Playwright flake on attempt ${attempt}; resetting Studio and retrying..."
+              echo "::warning::Playwright flake on attempt ${attempt}; resetting Unsloth and retrying..."
               kill "${STUDIO_EXTRA_PID}" 2>/dev/null || true
               sleep 2
               unsloth studio reset-password
@@ -327,7 +332,7 @@ jobs:
             exit "$rc"
           done
 
-      - name: Stop second Studio
+      - name: Stop second Unsloth
         if: always()
         run: |
           kill "${STUDIO_EXTRA_PID}" 2>/dev/null || true
@@ -343,5 +348,7 @@ jobs:
             logs/studio_extra.log
             logs/install.log
             logs/playwright
+            logs/playwright-permissions-*
             logs/playwright_extra
+            logs/studio-permissions-*.log
           retention-days: 7
diff --git a/.github/workflows/studio-mac-update-smoke.yml b/.github/workflows/studio-mac-update-smoke.yml
index d104306c7e..fe9880f3ca 100644
--- a/.github/workflows/studio-mac-update-smoke.yml
+++ b/.github/workflows/studio-mac-update-smoke.yml
@@ -4,15 +4,15 @@
 # Mac counterpart to studio-update-smoke.yml. Verifies that on a real
 # Apple Silicon (macos-14, M1) runner:
 #
-#   1. install.sh --local --no-torch installs Studio AND auto-fetches
+#   1. install.sh --local --no-torch installs Unsloth AND auto-fetches
 #      the prebuilt llama.cpp Mac binary (llama-bNNNN-bin-macos-arm64
 #      from ggml-org/llama.cpp). Hitting the source-build fallback is
-#      treated as an Unsloth bug -- Studio must always pick the
+#      treated as an Unsloth bug -- Unsloth must always pick the
 #      prebuilt on Mac.
 #   2. unsloth studio update --local is idempotent. Two consecutive
 #      runs both report "prebuilt up to date and validated", no
 #      source-build fallback.
-#   3. The installed Studio still boots and /api/health returns
+#   3. The installed Unsloth still boots and /api/health returns
 #      healthy after the update path.
 
 name: Mac Studio Update CI
@@ -42,7 +42,7 @@ permissions:
 
 jobs:
   update-idempotency:
-    name: Studio Updating Tests
+    name: Unsloth Updating Tests
     runs-on: macos-14
     timeout-minutes: 30
     steps:
@@ -59,7 +59,7 @@ jobs:
           python-version: '3.12'
           cache: 'pip'
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Withheld on PR: this step runs checked-out PR code; public GGUF still downloads.
@@ -106,7 +106,7 @@ jobs:
           grep -qE "prebuilt up to date and validated|prebuilt installed and validated" logs/update2.log
           echo "second update was clean"
 
-      - name: Boot Studio briefly to confirm the install is still usable
+      - name: Boot Unsloth briefly to confirm the install is still usable
         run: |
           mkdir -p logs
           UNSLOTH_API_ONLY=1 unsloth studio -H 127.0.0.1 -p 18891 \
@@ -123,13 +123,13 @@ jobs:
             sleep 1
           done
           if [ -z "$HEALTHY" ]; then
-            echo "Studio failed to come up after \`update\`"
+            echo "Unsloth failed to come up after \`update\`"
             tail -200 logs/studio.log
             kill "$PID" 2>/dev/null || true
             exit 1
           fi
           kill "$PID" 2>/dev/null || true
-          echo "post-update Studio /api/health OK"
+          echo "post-update Unsloth /api/health OK"
 
       - name: Uninstall and verify clean
         # Round-trip through scripts/uninstall.sh on real macOS. As a side
diff --git a/.github/workflows/studio-tauri-smoke.yml b/.github/workflows/studio-tauri-smoke.yml
index 018857de68..8e26b9fd0c 100644
--- a/.github/workflows/studio-tauri-smoke.yml
+++ b/.github/workflows/studio-tauri-smoke.yml
@@ -12,7 +12,7 @@
 # stay in release-desktop.yml (manual `workflow_dispatch`) because they need
 # code-signing secrets and ~30 min of runner time each.
 
-name: Studio Tauri CI
+name: Unsloth Tauri CI
 
 on:
   pull_request:
diff --git a/.github/workflows/studio-ui-smoke.yml b/.github/workflows/studio-ui-smoke.yml
index 297a585430..97eb07b2d8 100644
--- a/.github/workflows/studio-ui-smoke.yml
+++ b/.github/workflows/studio-ui-smoke.yml
@@ -1,8 +1,8 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 
-# End-to-end Studio chat UI smoke via Playwright + Chromium against a
-# headless Linux runner. Boots Studio with the smallest GGUF
+# End-to-end Unsloth chat UI smoke via Playwright + Chromium against a
+# headless Linux runner. Boots Unsloth with the smallest GGUF
 # (gemma-3-270m-it UD-Q4_K_XL, ~254 MiB), drives the actual frontend
 # bundle, and asserts the full bootstrap-password / change-password /
 # send-message / persist-on-reload journey works end to end.
@@ -14,7 +14,7 @@
 # frontend-only CI happily pass while the actual user-visible UI is
 # broken (cf. the 2026.5.1 chat-history release).
 
-name: Studio UI CI
+name: Unsloth UI CI
 
 on:
   pull_request:
@@ -27,6 +27,7 @@ on:
       # The Playwright test files themselves -- a PR that ONLY edits
       # the test must still trigger UI CI.
       - 'tests/studio/**'
+      - '.github/scripts/run-studio-permission-browser.sh'
       - '.github/workflows/studio-ui-smoke.yml'
   push:
     branches: [main, pip]
@@ -97,7 +98,7 @@ jobs:
           path: hf-cache
           key: ${{ runner.os }}-hf-${{ env.GGUF_REPO }}-${{ env.GGUF_VARIANT }}-v2
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           # Withheld on PR: this step runs checked-out PR code; public GGUF still downloads.
@@ -107,15 +108,12 @@ jobs:
           set -o pipefail
           bash install.sh --local --no-torch 2>&1 | tee logs/install.log
 
-      - name: Install Playwright + Chromium
+      - name: Install Playwright browsers
         run: |
           pip install 'playwright>=1.45'
-          # --with-deps installs the OS-level runtime libs Chromium
-          # needs (libnss3, libxkbcommon, etc.). About 30 s on a
-          # warm runner.
-          python -m playwright install --with-deps chromium
+          python -m playwright install --with-deps chromium firefox webkit
 
-      - name: Reset auth + boot Studio
+      - name: Reset auth + boot Unsloth
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -147,7 +145,7 @@ jobs:
         # NEW + NEW2 are generated freshly per CI run via secrets.token_urlsafe
         # rather than hardcoded. If a workflow gets compromised, the
         # attacker can't replay a known-good rotated password against
-        # any future / parallel Studio install -- the rotated value
+        # any future / parallel Unsloth install -- the rotated value
         # only ever exists for the lifetime of this single job, masked
         # in the log via ::add-mask::.
         run: |
@@ -165,29 +163,35 @@ jobs:
         env:
           BASE_URL: http://127.0.0.1:18892
           # The test file lives in the repo so it can be run locally
-          # against a freshly-installed Studio (BASE_URL=...; STUDIO_OLD_PW=
+          # against a freshly-installed Unsloth (BASE_URL=...; STUDIO_OLD_PW=
           # $(cat ~/.unsloth/studio/auth/.bootstrap_password); python ...).
           PW_ART_DIR: logs/playwright
           # Strict mode: in CI a missing button / nav / dialog must
           # FAIL the test. Locally the test still runs against partial
-          # Studio installs without STUDIO_UI_STRICT.
+          # Unsloth installs without STUDIO_UI_STRICT.
           STUDIO_UI_STRICT: '1'
         run: |
           mkdir -p logs/playwright
           python tests/studio/playwright_chat_ui.py
 
-      - name: Stop Studio (chat-ui ends with Shutdown click; this is belt-and-suspenders)
+      - name: Stop Unsloth (chat-ui ends with Shutdown click; this is belt-and-suspenders)
         if: always()
         run: |
           kill "${STUDIO_PID}" 2>/dev/null || true
           sleep 2
 
+      - name: Cross-browser permission controls
+        run: |
+          bash .github/scripts/run-studio-permission-browser.sh 18893 firefox
+          bash .github/scripts/run-studio-permission-browser.sh 18893 webkit
+          bash .github/scripts/run-studio-permission-browser.sh 18893 chromium chrome
+
       # The chat UI test ends by clicking the Shutdown menuitem, which
       # leaves the server dead. The extra UI test (Compare / Recipes /
-      # Export / Studio / Settings) needs a fresh Studio, so we boot a
+      # Export / Unsloth / Settings) needs a fresh Unsloth, so we boot a
       # second one on a different port. Boot is fast (~3-5s on the
       # warm install we already did) so this adds little wall time.
-      - name: Reset auth + boot Studio for extra UI tests (port 18894)
+      - name: Reset auth + boot Unsloth for extra UI tests (port 18894)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -214,7 +218,7 @@ jobs:
           echo "STUDIO_EXTRA_OLD_PW=$OLD" >> "$GITHUB_ENV"
           echo "STUDIO_EXTRA_NEW_PW=$NEW" >> "$GITHUB_ENV"
 
-      - name: Drive Compare/Recipes/Export/Studio/Settings with Playwright
+      - name: Drive Compare/Recipes/Export/Unsloth/Settings with Playwright
         env:
           BASE_URL: http://127.0.0.1:18894
           STUDIO_OLD_PW: ${{ env.STUDIO_EXTRA_OLD_PW }}
@@ -227,16 +231,73 @@ jobs:
           mkdir -p logs/playwright_extra
           python tests/studio/playwright_extra_ui.py
 
-      - name: Stop second Studio
+      - name: UI font size scaling regression (Playwright)
+        env:
+          BASE_URL: http://127.0.0.1:18894
+          STUDIO_PW: ${{ env.STUDIO_EXTRA_NEW_PW }}
+          PW_ART_DIR: logs/playwright_fontscale
+        run: |
+          mkdir -p logs/playwright_fontscale
+          python tests/studio/playwright_ui_font_scale.py
+
+      - name: Stop second Unsloth
         if: always()
         run: |
           kill "${STUDIO_EXTRA_PID}" 2>/dev/null || true
           sleep 2
 
+      # Model-picker per-model-config regression (PR #7207 re-land of #6647).
+      # Fourth Unsloth on its own port; loads the tiny GGUF and drives the
+      # picker's run-settings surface: Context Length persists across a reload,
+      # Reset clears the stored override (never pins it), and the infra models
+      # (RAG embedder + llama.cpp probe) stay hidden from the picker.
+      - name: Reset auth + boot Unsloth for model-config tests (port 18898)
+        run: |
+          unsloth studio reset-password
+          mkdir -p logs
+          UNSLOTH_API_ONLY=1 unsloth studio -H 127.0.0.1 -p 18898 \
+            > logs/studio_modelcfg.log 2>&1 &
+          echo "STUDIO_MODELCFG_PID=$!" >> "$GITHUB_ENV"
+
+      - name: Wait for /api/health on 18898
+        run: |
+          for i in $(seq 1 180); do
+            if curl -fs "http://127.0.0.1:18898/api/health" > /tmp/health4.json; then
+              jq -e '.status == "healthy"' /tmp/health4.json && break
+            fi
+            sleep 1
+          done
+          jq -e '.status == "healthy"' /tmp/health4.json
+
+      - name: Pass bootstrap pw for model-config test
+        run: |
+          NEW="CIModelCfg-$(python -c 'import secrets; print(secrets.token_urlsafe(16))')"
+          echo "::add-mask::$NEW"
+          echo "STUDIO_MODELCFG_NEW_PW=$NEW" >> "$GITHUB_ENV"
+
+      - name: Drive model-picker per-model-config with Playwright
+        env:
+          BASE_URL: http://127.0.0.1:18898
+          STUDIO_NEW_PW: ${{ env.STUDIO_MODELCFG_NEW_PW }}
+          PW_ART_DIR: logs/playwright_modelcfg
+          STUDIO_UI_STRICT: '1'
+          GGUF_REPO: ${{ env.GGUF_REPO }}
+          GGUF_VARIANT: ${{ env.GGUF_VARIANT }}
+          STUDIO_MODEL_HINT: gemma-3-270m
+        run: |
+          mkdir -p logs/playwright_modelcfg
+          python tests/studio/playwright_model_config.py
+
+      - name: Stop fourth Unsloth
+        if: always()
+        run: |
+          kill "${STUDIO_MODELCFG_PID}" 2>/dev/null || true
+          sleep 2
+
       # IME + multilingual paste regression (issue #5318 / PR #5327).
-      # Third Studio on its own port so a hang here cannot poison the
+      # Third Unsloth on its own port so a hang here cannot poison the
       # earlier UI tests. No GGUF -- the bug surface is the composer.
-      - name: Reset auth + boot Studio for IME / i18n tests (port 18896)
+      - name: Reset auth + boot Unsloth for IME / i18n tests (port 18896)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -256,7 +317,7 @@ jobs:
 
       - name: Pass bootstrap pw for IME / i18n test
         # IME smoke does the change-password against the bootstrap that
-        # Studio's frontend injects into the page, so it only needs the
+        # Unsloth's frontend injects into the page, so it only needs the
         # NEW password.
         run: |
           NEW="CIIme-$(python -c 'import secrets; print(secrets.token_urlsafe(16))')"
@@ -273,7 +334,7 @@ jobs:
           mkdir -p logs/playwright_ime
           python tests/studio/playwright_chat_ime_i18n.py
 
-      - name: Stop third Studio
+      - name: Stop third Unsloth
         if: always()
         run: |
           kill "${STUDIO_IME_PID}" 2>/dev/null || true
@@ -293,10 +354,15 @@ jobs:
           path: |
             logs/studio.log
             logs/studio_extra.log
+            logs/studio_modelcfg.log
             logs/studio_ime.log
             logs/install.log
             logs/server-logs/
             logs/playwright
+            logs/playwright-permissions-*
             logs/playwright_extra
+            logs/playwright_fontscale
+            logs/playwright_modelcfg
             logs/playwright_ime
+            logs/studio-permissions-*.log
           retention-days: 7
diff --git a/.github/workflows/studio-update-smoke.yml b/.github/workflows/studio-update-smoke.yml
index 08a79afacd..625c2c7811 100644
--- a/.github/workflows/studio-update-smoke.yml
+++ b/.github/workflows/studio-update-smoke.yml
@@ -9,7 +9,7 @@
 # This catches regressions in setup.sh's update path that the existing
 # GGUF / wheel jobs would miss because they only invoke install.sh once.
 
-name: Studio Update CI
+name: Unsloth Update CI
 
 on:
   pull_request:
@@ -36,7 +36,7 @@ permissions:
 
 jobs:
   update-idempotency:
-    name: Studio Updating Tests
+    name: Unsloth Updating Tests
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
@@ -63,7 +63,7 @@ jobs:
           # post-step then fatal-errors with "Cache folder path is
           # retrieved for pip but doesn't exist on disk".
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         # Pass the workflow token so the llama.cpp prebuilt installer's
         # GitHub-API call to list releases isn't rate-limited (60/hr
         # unauthenticated). Without this, three consecutive install +
@@ -122,7 +122,7 @@ jobs:
           grep -qE "prebuilt up to date and validated|prebuilt installed and validated" logs/update2.log
           echo "second update was clean"
 
-      - name: Boot Studio briefly to confirm the install is still usable
+      - name: Boot Unsloth briefly to confirm the install is still usable
         # If `update --local` accidentally broke the venv or wiped the
         # llama-server binary, the server would fail to start here.
         run: |
@@ -138,13 +138,13 @@ jobs:
             sleep 1
           done
           if ! jq -e '.status == "healthy"' /tmp/health.json 2>/dev/null; then
-            echo "Studio failed to come up after `update`"
+            echo "Unsloth failed to come up after `update`"
             tail -200 logs/studio.log
             kill "$PID" 2>/dev/null || true
             exit 1
           fi
           kill "$PID" 2>/dev/null || true
-          echo "post-update Studio /api/health OK"
+          echo "post-update Unsloth /api/health OK"
 
       - name: Uninstall and verify clean
         # Round-trip the installer through scripts/uninstall.sh: confirms the
diff --git a/.github/workflows/studio-windows-api-smoke.yml b/.github/workflows/studio-windows-api-smoke.yml
index e9abd2d669..6dbcceebbd 100644
--- a/.github/workflows/studio-windows-api-smoke.yml
+++ b/.github/workflows/studio-windows-api-smoke.yml
@@ -9,7 +9,7 @@
 # (Section 6) is Linux-only and short-circuits on non-POSIX; the rest
 # is platform-portable.
 
-name: Windows Studio API CI
+name: Windows Unsloth API CI
 
 on:
   pull_request:
@@ -34,7 +34,7 @@ permissions:
 
 jobs:
   api-smoke:
-    name: Studio API & Auth Tests
+    name: Unsloth API & Auth Tests
     runs-on: windows-latest
     timeout-minutes: 30
     defaults:
@@ -105,7 +105,7 @@ jobs:
           # studio-windows-update-smoke.yml for the full rationale --
           # creating an empty studio/frontend/dist trips setup.ps1's
           # mtime-based staleness check into "frontend up to date, skip
-          # rebuild" and Studio boots with an empty dist directory.
+          # rebuild" and Unsloth boots with an empty dist directory.
           # Add-MpPreference accepts paths that do not yet exist.
           foreach ($p in @(
             "$env:USERPROFILE\.unsloth",
@@ -121,7 +121,7 @@ jobs:
             }
           }
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         shell: pwsh
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -161,7 +161,7 @@ jobs:
           echo "install.ps1 installed the Windows prebuilt llama.cpp:"
           cat "$INFO"
 
-      - name: Add Studio shim to GITHUB_PATH
+      - name: Add Unsloth shim to GITHUB_PATH
         # install.ps1's User-PATH update doesn't propagate to a
         # running Git Bash session; export the shim dir so the
         # next `unsloth ...` invocation finds it.
@@ -177,7 +177,7 @@ jobs:
       - name: Install pyjwt for the JWT-expiry forge test
         run: python -m pip install 'pyjwt>=2.6'
 
-      - name: Reset auth + boot Studio (API-only)
+      - name: Reset auth + boot Unsloth (API-only)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -207,7 +207,7 @@ jobs:
           echo "STUDIO_NEW_PW=$NEW"  >> "$GITHUB_ENV"
           echo "STUDIO_NEW2_PW=$NEW2" >> "$GITHUB_ENV"
 
-      - name: Run Studio API & Auth tests
+      - name: Run Unsloth API & Auth tests
         # Do NOT pin STUDIO_AUTH_DIR here. The Mac/Linux mirrors
         # hardcode runner-specific paths (/Users/runner/...,
         # /home/runner/...), but on Windows the path is
@@ -219,7 +219,7 @@ jobs:
           BASE_URL: http://127.0.0.1:18895
         run: python tests/studio/studio_api_smoke.py
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         run: |
           kill "${STUDIO_PID}" 2>/dev/null || true
diff --git a/.github/workflows/studio-windows-inference-smoke.yml b/.github/workflows/studio-windows-inference-smoke.yml
index 63a7e9dc8f..3ebe442f52 100644
--- a/.github/workflows/studio-windows-inference-smoke.yml
+++ b/.github/workflows/studio-windows-inference-smoke.yml
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 
-# Three end-to-end smoke jobs that boot a freshly-installed Studio and
+# Three end-to-end smoke jobs that boot a freshly-installed Unsloth and
 # exercise the surfaces real users hit through the OpenAI / Anthropic
 # SDKs and curl, on the FREE windows-latest runner. Each job picks the
 # smallest model that exercises the behaviour under test, primes
@@ -16,7 +16,7 @@
 #        Qwen3-VL-2B-Instruct UD-IQ2_XXS + mmproj-F16 (~1.4 GiB total).
 #        Within the 14 GB windows-latest SSD budget.
 
-name: Windows Studio GGUF CI
+name: Windows Unsloth GGUF CI
 
 on:
   pull_request:
@@ -57,7 +57,7 @@ jobs:
       STUDIO_PORT: '18888'
       HF_HOME: ${{ github.workspace }}/hf-cache
       # Force UTF-8 for stdio (Windows defaults to cp1252; hf
-      # download / Studio CLI print "✓" checkmarks and crash
+      # download / Unsloth CLI print "✓" checkmarks and crash
       # otherwise).
       PYTHONIOENCODING: utf-8
       PYTHONUTF8: '1'
@@ -160,7 +160,7 @@ jobs:
           # studio-windows-update-smoke.yml for the full rationale --
           # creating an empty studio/frontend/dist trips setup.ps1's
           # mtime-based staleness check into "frontend up to date, skip
-          # rebuild" and Studio boots with an empty dist directory.
+          # rebuild" and Unsloth boots with an empty dist directory.
           # Add-MpPreference accepts paths that do not yet exist.
           foreach ($p in @(
             "$env:USERPROFILE\.unsloth",
@@ -176,7 +176,7 @@ jobs:
             }
           }
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         shell: pwsh
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -214,7 +214,7 @@ jobs:
           echo "install.ps1 installed the Windows prebuilt llama.cpp:"
           cat "$INFO"
 
-      - name: Add Studio shim to GITHUB_PATH
+      - name: Add Unsloth shim to GITHUB_PATH
         run: |
           SHIM_DIR=~/.unsloth/studio/bin
           if [ ! -f "$SHIM_DIR/unsloth.exe" ]; then
@@ -227,7 +227,7 @@ jobs:
       - name: Install OpenAI + Anthropic Python SDKs
         run: python -m pip install 'openai>=1.50' 'anthropic>=0.40'
 
-      - name: Reset auth + boot Studio (API-only)
+      - name: Reset auth + boot Unsloth (API-only)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -244,7 +244,7 @@ jobs:
             fi
             sleep 1
           done
-          echo "Studio did not become healthy in 180s"
+          echo "Unsloth did not become healthy in 180s"
           tail -200 logs/studio.log
           exit 1
 
@@ -281,7 +281,7 @@ jobs:
           # Retry the load step a few times so a transient TCP RST during
           # llama-server warm-up (Windows runner image churn,
           # windows-latest -> windows-2025-vs2026 rollout) doesn't fail
-          # the whole job. The Studio backend's _wait_for_health now
+          # the whole job. The Unsloth backend's _wait_for_health now
           # catches httpx.ReadError too; this retry layer covers the
           # cases the backend can't recover from on its own.
           LOAD_OK=0
@@ -382,15 +382,15 @@ jobs:
               print(f"[{label}] OK -- 4 turns, run1 == run2, history grounded")
           PY
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         # Run as cmd so we are not running through the Git Bash shell;
         # Git Bash on windows-latest has been observed to exit 143
         # (SIGTERM) from any inline kill/sleep block, masking a green
-        # test run. The runner reclaims the Studio child process at
+        # test run. The runner reclaims the Unsloth child process at
         # job end either way, so just emit a marker and exit 0.
         shell: cmd
-        run: echo Stop Studio (no-op; runner reclaims STUDIO_PID=%STUDIO_PID% at job end)
+        run: echo Stop Unsloth (no-op; runner reclaims STUDIO_PID=%STUDIO_PID% at job end)
 
       - name: Collect llama-server logs
         if: always()
@@ -398,10 +398,10 @@ jobs:
         # copy must not fail an otherwise-green job.
         continue-on-error: true
         shell: bash
-        # Copy llama-server's own stdout/stderr (teed by Studio under
+        # Copy llama-server's own stdout/stderr (teed by Unsloth under
         # ~/.unsloth/studio/logs/llama-server/) into the workspace so
         # upload-artifact can pick it up. Crucial for diagnosing a
-        # subprocess crash where Studio's traceback only shows the
+        # subprocess crash where Unsloth's traceback only shows the
         # symptom (httpx ReadError) but not the cause.
         run: |
           mkdir -p logs/llama-server
@@ -439,14 +439,14 @@ jobs:
       # (211 s on first run; subsequent runs hit the cache, but the
       # one-time cost recurs every time the cache key bumps). Use
       # main's `--local-dir gguf-cache` pattern: cache the flat .gguf
-      # only, pass an absolute path to Studio's /api/inference/load.
+      # only, pass an absolute path to Unsloth's /api/inference/load.
       # The OpenAI/Anth and JSON+images jobs still cover the
       # gguf_variant resolution path.
       GGUF_REPO: unsloth/Qwen3.5-2B-GGUF
       GGUF_FILE: Qwen3.5-2B-UD-Q4_K_XL.gguf
       STUDIO_PORT: '18898'
       # Force UTF-8 for stdio (Windows defaults to cp1252; hf
-      # download / Studio CLI print "✓" checkmarks and crash
+      # download / Unsloth CLI print "✓" checkmarks and crash
       # otherwise).
       PYTHONIOENCODING: utf-8
       PYTHONUTF8: '1'
@@ -507,7 +507,7 @@ jobs:
           # studio-windows-update-smoke.yml for the full rationale --
           # creating an empty studio/frontend/dist trips setup.ps1's
           # mtime-based staleness check into "frontend up to date, skip
-          # rebuild" and Studio boots with an empty dist directory.
+          # rebuild" and Unsloth boots with an empty dist directory.
           # Add-MpPreference accepts paths that do not yet exist.
           foreach ($p in @(
             "$env:USERPROFILE\.unsloth",
@@ -523,7 +523,7 @@ jobs:
             }
           }
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         shell: pwsh
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -561,7 +561,7 @@ jobs:
           echo "install.ps1 installed the Windows prebuilt llama.cpp:"
           cat "$INFO"
 
-      - name: Add Studio shim to GITHUB_PATH
+      - name: Add Unsloth shim to GITHUB_PATH
         run: |
           SHIM_DIR=~/.unsloth/studio/bin
           if [ ! -f "$SHIM_DIR/unsloth.exe" ]; then
@@ -571,7 +571,7 @@ jobs:
           fi
           cygpath -w "$SHIM_DIR" >> "$GITHUB_PATH"
 
-      - name: Reset auth + boot Studio (API-only, default tool policy)
+      - name: Reset auth + boot Unsloth (API-only, default tool policy)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -607,7 +607,7 @@ jobs:
           # raw string, but we cannot embed `\a` etc. in JSON without
           # JSON-string-escaping every backslash. Replace `\` with `/`
           # via bash parameter expansion -- pathlib.Path on Windows
-          # accepts forward slashes natively, so Studio's loader sees
+          # accepts forward slashes natively, so Unsloth's loader sees
           # a normal path.
           GGUF_PATH="${GITHUB_WORKSPACE//\\//}/gguf-cache/${GGUF_FILE}"
           ls -lh "$GGUF_PATH"
@@ -680,7 +680,7 @@ jobs:
           def post_sse(path, body, *, timeout = 600, retries = 1, soft = False):
               # The server-side agentic loop always answers over SSE. A
               # shared CI runner can stall the stream transport (the
-              # connection opening, or a mid-stream read) even when Studio
+              # connection opening, or a mid-stream read) even when Unsloth
               # is healthy, so harden the read three ways:
               #   * retry a transport stall once with a fresh request,
               #     capped at 300s (a healthy server answers a retry
@@ -882,15 +882,15 @@ jobs:
           print(f"[tools] PASS thinking on/off (on={len(on_text)} chars, off={len(off_text)} chars)")
           PY
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         # Run as cmd so we are not running through the Git Bash shell;
         # Git Bash on windows-latest has been observed to exit 143
         # (SIGTERM) from any inline kill/sleep block, masking a green
-        # test run. The runner reclaims the Studio child process at
+        # test run. The runner reclaims the Unsloth child process at
         # job end either way, so just emit a marker and exit 0.
         shell: cmd
-        run: echo Stop Studio (no-op; runner reclaims STUDIO_PID=%STUDIO_PID% at job end)
+        run: echo Stop Unsloth (no-op; runner reclaims STUDIO_PID=%STUDIO_PID% at job end)
 
       - name: Collect llama-server logs
         if: always()
@@ -898,10 +898,10 @@ jobs:
         # copy must not fail an otherwise-green job.
         continue-on-error: true
         shell: bash
-        # Copy llama-server's own stdout/stderr (teed by Studio under
+        # Copy llama-server's own stdout/stderr (teed by Unsloth under
         # ~/.unsloth/studio/logs/llama-server/) into the workspace so
         # upload-artifact can pick it up. Crucial for diagnosing a
-        # subprocess crash where Studio's traceback only shows the
+        # subprocess crash where Unsloth's traceback only shows the
         # symptom (httpx ReadError) but not the cause.
         run: |
           mkdir -p logs/llama-server
@@ -939,7 +939,7 @@ jobs:
       STUDIO_PORT: '18899'
       HF_HOME: ${{ github.workspace }}/hf-cache
       # Force UTF-8 for stdio (Windows defaults to cp1252; hf
-      # download / Studio CLI print "✓" checkmarks and crash
+      # download / Unsloth CLI print "✓" checkmarks and crash
       # otherwise).
       PYTHONIOENCODING: utf-8
       PYTHONUTF8: '1'
@@ -1005,7 +1005,7 @@ jobs:
           # studio-windows-update-smoke.yml for the full rationale --
           # creating an empty studio/frontend/dist trips setup.ps1's
           # mtime-based staleness check into "frontend up to date, skip
-          # rebuild" and Studio boots with an empty dist directory.
+          # rebuild" and Unsloth boots with an empty dist directory.
           # Add-MpPreference accepts paths that do not yet exist.
           foreach ($p in @(
             "$env:USERPROFILE\.unsloth",
@@ -1021,7 +1021,7 @@ jobs:
             }
           }
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         shell: pwsh
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -1059,7 +1059,7 @@ jobs:
           echo "install.ps1 installed the Windows prebuilt llama.cpp:"
           cat "$INFO"
 
-      - name: Add Studio shim to GITHUB_PATH
+      - name: Add Unsloth shim to GITHUB_PATH
         run: |
           SHIM_DIR=~/.unsloth/studio/bin
           if [ ! -f "$SHIM_DIR/unsloth.exe" ]; then
@@ -1072,7 +1072,7 @@ jobs:
       - name: Install OpenAI + Anthropic Python SDKs
         run: python -m pip install 'openai>=1.50' 'anthropic>=0.40'
 
-      - name: Reset auth + boot Studio (API-only)
+      - name: Reset auth + boot Unsloth (API-only)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -1262,7 +1262,7 @@ jobs:
           except Exception as exc:
               print(
                   f"[image/openai] WARN image_url SDK call raised: {type(exc).__name__}: "
-                  f"{exc}. Studio successfully forwarded the request; failure here is "
+                  f"{exc}. Unsloth successfully forwarded the request; failure here is "
                   f"upstream llama.cpp vision behaviour."
               )
 
@@ -1303,19 +1303,19 @@ jobs:
               print(
                   f"[image/anthropic] WARN anthropic image SDK call raised: "
                   f"{type(exc).__name__}: {exc}. Likely upstream llama.cpp vision "
-                  f"behaviour, NOT a Studio regression."
+                  f"behaviour, NOT an Unsloth regression."
               )
           PY
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         # Run as cmd so we are not running through the Git Bash shell;
         # Git Bash on windows-latest has been observed to exit 143
         # (SIGTERM) from any inline kill/sleep block, masking a green
-        # test run. The runner reclaims the Studio child process at
+        # test run. The runner reclaims the Unsloth child process at
         # job end either way, so just emit a marker and exit 0.
         shell: cmd
-        run: echo Stop Studio (no-op; runner reclaims STUDIO_PID=%STUDIO_PID% at job end)
+        run: echo Stop Unsloth (no-op; runner reclaims STUDIO_PID=%STUDIO_PID% at job end)
 
       - name: Collect llama-server logs
         if: always()
@@ -1323,10 +1323,10 @@ jobs:
         # copy must not fail an otherwise-green job.
         continue-on-error: true
         shell: bash
-        # Copy llama-server's own stdout/stderr (teed by Studio under
+        # Copy llama-server's own stdout/stderr (teed by Unsloth under
         # ~/.unsloth/studio/logs/llama-server/) into the workspace so
         # upload-artifact can pick it up. Crucial for diagnosing a
-        # subprocess crash where Studio's traceback only shows the
+        # subprocess crash where Unsloth's traceback only shows the
         # symptom (httpx ReadError) but not the cause.
         run: |
           mkdir -p logs/llama-server
@@ -1348,7 +1348,7 @@ jobs:
 
   # ── folded from studio-windows-no-vs-smoke.yml: install + run with no Visual Studio ──
   no-vs-cpu:
-    name: Studio install + inference without Visual Studio
+    name: Unsloth install + inference without Visual Studio
     runs-on: windows-latest
     timeout-minutes: 35
     defaults:
@@ -1502,7 +1502,7 @@ jobs:
           python -m pip install torch --index-url https://download.pytorch.org/whl/cpu --extra-index-url https://pypi.org/simple
           python -c "import torch; print('torch', torch.__version__, 'cuda?', torch.cuda.is_available())"
 
-      - name: Install Studio (--local, --no-torch) with no build tools present
+      - name: Install Unsloth (--local, --no-torch) with no build tools present
         shell: pwsh
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -1538,13 +1538,13 @@ jobs:
           echo "Prebuilt installed with no build tools:"
           cat "$INFO"
 
-      - name: Add Studio shim to GITHUB_PATH
+      - name: Add Unsloth shim to GITHUB_PATH
         run: |
           SHIM_DIR=~/.unsloth/studio/bin
           [ -f "$SHIM_DIR/unsloth.exe" ] || { echo "::error::unsloth.exe shim not found"; ls -la ~/.unsloth/studio/ || true; exit 1; }
           cygpath -w "$SHIM_DIR" >> "$GITHUB_PATH"
 
-      - name: Reset auth + boot Studio (API-only)
+      - name: Reset auth + boot Unsloth (API-only)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -1613,10 +1613,10 @@ jobs:
           }
           Remove-Item -LiteralPath $root -Recurse -Force -ErrorAction SilentlyContinue
 
-      - name: Stop Studio
+      - name: Stop Unsloth
         if: always()
         shell: cmd
-        run: echo Stop Studio (no-op; runner reclaims STUDIO_PID=%STUDIO_PID% at job end)
+        run: echo Stop Unsloth (no-op; runner reclaims STUDIO_PID=%STUDIO_PID% at job end)
 
       - name: Collect llama-server logs
         if: always()
diff --git a/.github/workflows/studio-windows-ui-smoke.yml b/.github/workflows/studio-windows-ui-smoke.yml
index 405309916a..f401f7be44 100644
--- a/.github/workflows/studio-windows-ui-smoke.yml
+++ b/.github/workflows/studio-windows-ui-smoke.yml
@@ -4,11 +4,11 @@
 # Windows counterpart to studio-ui-smoke.yml / studio-mac-ui-smoke.yml.
 # Same Playwright + Chromium end-to-end chat UI flow + extra UI flow,
 # but on the FREE windows-latest runner so we catch Windows-specific
-# regressions in the install path (install.ps1), the Studio CLI's
+# regressions in the install path (install.ps1), the Unsloth CLI's
 # Windows process-management branches, and the llama.cpp prebuilt's
 # Windows HTTP layer.
 
-name: Windows Studio UI CI
+name: Windows Unsloth UI CI
 
 on:
   pull_request:
@@ -19,6 +19,7 @@ on:
       - 'install.ps1'
       - 'pyproject.toml'
       - 'tests/studio/**'
+      - '.github/scripts/run-studio-permission-browser.sh'
       - '.github/workflows/studio-windows-ui-smoke.yml'
   push:
     branches: [main, pip]
@@ -49,7 +50,7 @@ jobs:
       GGUF_FILE: gemma-3-270m-it-UD-Q4_K_XL.gguf
       STUDIO_PORT: '18896'
       HF_HOME: ${{ github.workspace }}/hf-cache
-      # Force UTF-8 for stdio so Python tools (hf download, Studio
+      # Force UTF-8 for stdio so Python tools (hf download, Unsloth
       # CLI, etc.) can print Unicode characters like the success
       # checkmark "✓". Windows defaults to cp1252 / charmap and
       # any tool that prints "OK ✓" hits a UnicodeEncodeError.
@@ -121,7 +122,7 @@ jobs:
           # studio-windows-update-smoke.yml for the full rationale --
           # creating an empty studio/frontend/dist trips setup.ps1's
           # mtime-based staleness check into "frontend up to date, skip
-          # rebuild" and Studio boots with an empty dist directory.
+          # rebuild" and Unsloth boots with an empty dist directory.
           # Add-MpPreference accepts paths that do not yet exist.
           foreach ($p in @(
             "$env:USERPROFILE\.unsloth",
@@ -148,7 +149,7 @@ jobs:
           Set-Content -LiteralPath (Join-Path $appDir 'launch-studio.vbs') -Value 'WScript.Echo "legacy"' -Encoding Unicode
           Write-Host "seeded legacy launch-studio.vbs at $appDir"
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         # install.ps1 is the supported Windows installer. install.sh
         # has no Windows branch (apt-get / brew calls). The PS1
         # script's `Install-UnslothStudio @args` line at the bottom
@@ -205,7 +206,7 @@ jobs:
           echo "install.ps1 installed the Windows prebuilt llama.cpp:"
           cat "$INFO"
 
-      - name: Assert Studio launcher chain (no VBS, hidden PowerShell shortcut)
+      - name: Assert Unsloth launcher chain (no VBS, hidden PowerShell shortcut)
         # The shortcut launch path is otherwise untested here (the steps below
         # boot `unsloth studio` directly). Guard against re-introducing the VBS
         # that tripped Kaspersky HEUR:Trojan.VBS.Agent.gen and against the .lnk
@@ -234,7 +235,7 @@ jobs:
           }
           Write-Host "launcher chain OK (no VBS; hidden powershell over launch-studio.ps1)"
 
-      - name: Launch Studio via the shortcut and assert health
+      - name: Launch Unsloth via the shortcut and assert health
         # Run the exact command the .lnk stores (hidden PowerShell over
         # launch-studio.ps1) and confirm it brings the backend up. This is the
         # only step that proves the shortcut launch is not silently broken.
@@ -265,10 +266,10 @@ jobs:
             $owner = (Get-NetTCPConnection -LocalPort $foundPort -State Listen -ErrorAction Stop | Select-Object -First 1).OwningProcess
             if ($owner) { taskkill /PID $owner /T /F 2>$null | Out-Null }
           } catch {}
-          if (-not $foundPort) { throw "Studio did not become healthy when launched via the shortcut" }
-          Write-Host "Studio healthy on port $foundPort (launched via the shortcut)"
+          if (-not $foundPort) { throw "Unsloth did not become healthy when launched via the shortcut" }
+          Write-Host "Unsloth healthy on port $foundPort (launched via the shortcut)"
 
-      - name: Add Studio shim to GITHUB_PATH
+      - name: Add Unsloth shim to GITHUB_PATH
         # install.ps1 puts unsloth.exe at $StudioHome\bin\unsloth.exe
         # and adds that dir to the User PATH via the Windows registry.
         # Registry-level PATH updates don't propagate to a running
@@ -284,7 +285,7 @@ jobs:
           fi
           # GITHUB_PATH wants Windows-style paths; convert via cygpath.
           cygpath -w "$SHIM_DIR" >> "$GITHUB_PATH"
-          echo "Added Studio shim dir to PATH: $(cygpath -w "$SHIM_DIR")"
+          echo "Added Unsloth shim dir to PATH: $(cygpath -w "$SHIM_DIR")"
 
       - name: Install Playwright + Chromium
         # No --with-deps on Windows: that flag installs Linux apt
@@ -294,7 +295,7 @@ jobs:
           python -m pip install 'playwright>=1.45'
           python -m playwright install chromium
 
-      - name: Reset auth + boot Studio
+      - name: Reset auth + boot Unsloth
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -339,13 +340,17 @@ jobs:
           mkdir -p logs/playwright
           python tests/studio/playwright_chat_ui.py
 
-      - name: Stop Studio (chat-ui ends with Shutdown click; this is belt-and-suspenders)
+      - name: Stop Unsloth (chat-ui ends with Shutdown click; this is belt-and-suspenders)
         if: always()
         run: |
           kill "${STUDIO_PID}" 2>/dev/null || true
           sleep 2
 
-      - name: Reset auth + boot Studio for extra UI tests (port 18897)
+      - name: Edge permission controls
+        run: |
+          bash .github/scripts/run-studio-permission-browser.sh 18895 chromium msedge
+
+      - name: Reset auth + boot Unsloth for extra UI tests (port 18897)
         run: |
           unsloth studio reset-password
           mkdir -p logs
@@ -372,7 +377,7 @@ jobs:
           echo "STUDIO_EXTRA_OLD_PW=$OLD" >> "$GITHUB_ENV"
           echo "STUDIO_EXTRA_NEW_PW=$NEW" >> "$GITHUB_ENV"
 
-      - name: Drive Compare/Recipes/Export/Studio/Settings with Playwright
+      - name: Drive Compare/Recipes/Export/Unsloth/Settings with Playwright
         env:
           BASE_URL: http://127.0.0.1:18897
           STUDIO_OLD_PW: ${{ env.STUDIO_EXTRA_OLD_PW }}
@@ -386,7 +391,7 @@ jobs:
           mkdir -p logs/playwright_extra
           python tests/studio/playwright_extra_ui.py
 
-      - name: Stop second Studio
+      - name: Stop second Unsloth
         if: always()
         run: |
           kill "${STUDIO_EXTRA_PID}" 2>/dev/null || true
@@ -402,5 +407,7 @@ jobs:
             logs/studio_extra.log
             logs/install.log
             logs/playwright
+            logs/playwright-permissions-*
             logs/playwright_extra
+            logs/studio-permissions-*.log
           retention-days: 7
diff --git a/.github/workflows/studio-windows-update-smoke.yml b/.github/workflows/studio-windows-update-smoke.yml
index 5b92f1a3e0..42d74d47d2 100644
--- a/.github/workflows/studio-windows-update-smoke.yml
+++ b/.github/workflows/studio-windows-update-smoke.yml
@@ -5,19 +5,19 @@
 # studio-mac-update-smoke.yml. Verifies that on the FREE
 # windows-latest runner:
 #
-#   1. install.ps1 --local --no-torch installs Studio AND auto-fetches
+#   1. install.ps1 --local --no-torch installs Unsloth AND auto-fetches
 #      the prebuilt llama.cpp Windows binary (app-<tag>-windows-x64-cpu
 #      from unslothai/llama.cpp). Hitting the source-build fallback is
-#      treated as an Unsloth bug -- Studio must always pick the
+#      treated as an Unsloth bug -- Unsloth must always pick the
 #      prebuilt on Windows.
 #   2. unsloth studio update --local is idempotent. Two consecutive
 #      runs both report "prebuilt up to date and validated", no
 #      source-build fallback. The CLI's _find_setup_script picks
 #      setup.ps1 on Windows automatically.
-#   3. The installed Studio still boots and /api/health returns
+#   3. The installed Unsloth still boots and /api/health returns
 #      healthy after the update path.
 
-name: Windows Studio Update CI
+name: Windows Unsloth Update CI
 
 on:
   pull_request:
@@ -45,7 +45,7 @@ permissions:
 
 jobs:
   update-idempotency:
-    name: Studio Updating Tests
+    name: Unsloth Updating Tests
     runs-on: windows-latest
     timeout-minutes: 30
     defaults:
@@ -53,7 +53,7 @@ jobs:
         shell: bash
     env:
       # Force UTF-8 for stdio (Windows defaults to cp1252; hf
-      # download / Studio CLI print "✓" checkmarks and crash
+      # download / Unsloth CLI print "✓" checkmarks and crash
       # otherwise).
       PYTHONIOENCODING: utf-8
       PYTHONUTF8: '1'
@@ -90,7 +90,7 @@ jobs:
         #     reuses the existing Node with no download.
         #
         # (2) Defender. windows-latest's real-time scan opens / hashes
-        #     every file Studio writes during install (Vite output =
+        #     every file Unsloth writes during install (Vite output =
         #     thousands of small chunks, uv pip = wheel-extraction =
         #     thousands of small files). The latency dominates the
         #     200 s frontend build and the 90 s deps install. Adding
@@ -109,7 +109,7 @@ jobs:
           # setup.ps1 line 1281-1296's mtime-based "is the frontend
           # stale?" check into "up to date, skip rebuild", because the
           # newly-created dist's mtime is younger than every source
-          # file. Studio then boots with an empty dist and 500s on
+          # file. Unsloth then boots with an empty dist and 500s on
           # GET / with FileNotFoundError: dist\index.html. See run
           # 25546676715 / job 74984469728.
           # Add-MpPreference accepts paths that do not yet exist; the
@@ -129,7 +129,7 @@ jobs:
             }
           }
 
-      - name: Install Studio (--local, --no-torch)
+      - name: Install Unsloth (--local, --no-torch)
         shell: pwsh
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -168,7 +168,7 @@ jobs:
           echo "install.ps1 installed the Windows prebuilt llama.cpp:"
           cat "$INFO"
 
-      - name: Add Studio shim to GITHUB_PATH
+      - name: Add Unsloth shim to GITHUB_PATH
         run: |
           SHIM_DIR=~/.unsloth/studio/bin
           if [ ! -f "$SHIM_DIR/unsloth.exe" ]; then
@@ -212,7 +212,7 @@ jobs:
           grep -qE "prebuilt up to date and validated|prebuilt installed and validated" logs/update2.log
           echo "second update was clean"
 
-      - name: Boot Studio briefly to confirm the install is still usable
+      - name: Boot Unsloth briefly to confirm the install is still usable
         run: |
           mkdir -p logs
           UNSLOTH_API_ONLY=1 unsloth studio -H 127.0.0.1 -p 18891 \
@@ -239,13 +239,13 @@ jobs:
             sleep 1
           done
           if [ -z "$HEALTHY" ]; then
-            echo "Studio failed to come up after \`update\`"
+            echo "Unsloth failed to come up after \`update\`"
             tail -200 logs/studio.log
             kill "$PID" 2>/dev/null || true
             exit 1
           fi
           kill "$PID" 2>/dev/null || true
-          echo "post-update Studio /api/health OK"
+          echo "post-update Unsloth /api/health OK"
 
       - name: Uninstall and verify clean
         # Round-trip through scripts/uninstall.ps1 against the default
diff --git a/.github/workflows/wheel-smoke.yml b/.github/workflows/wheel-smoke.yml
index 3de3c33ca2..cdad617027 100644
--- a/.github/workflows/wheel-smoke.yml
+++ b/.github/workflows/wheel-smoke.yml
@@ -3,7 +3,7 @@
 
 # Builds the PyPI wheel from the PR branch, then verifies the built wheel
 # actually contains what we expect to ship and does NOT contain the broken
-# Studio bundle that 2026.5.1 published. This is the single workflow that
+# Unsloth bundle that 2026.5.1 published. This is the single workflow that
 # would have blocked the 2026.5.1 release before twine upload.
 #
 # Verified locally end-to-end against this branch:
@@ -12,7 +12,7 @@
 #       lockfile shipped, frontend dist shipped,
 #       no node_modules in wheel, no bun.lock in wheel,
 #       main bundle has unstable_Provider hits=1 (assistant-ui internals only).
-#   - Studio backend imports cleanly from the installed wheel with the
+#   - Unsloth backend imports cleanly from the installed wheel with the
 #     lightweight dep set below.
 
 name: Wheel CI
@@ -101,7 +101,7 @@ jobs:
               hits = data.count("unstable_Provider:")
               print(f"main bundle: {js[0]}")
               print(f"unstable_Provider hits: {hits} (>=4 indicates 2026.5.1 regression)")
-              checks["bundle has no Studio unstable_Provider call site"] = (hits < 4)
+              checks["bundle has no Unsloth unstable_Provider call site"] = (hits < 4)
 
               print()
               for k, v in checks.items():
@@ -109,7 +109,7 @@ jobs:
               sys.exit(0 if all(checks.values()) else 1)
           PY
 
-      - name: Studio backend import smoke
+      - name: Unsloth backend import smoke
         # Imports `studio.backend.main:app` from the freshly-installed wheel in
         # a clean venv. This catches the class of bug that 2026.5.1 shipped with:
         # frontend dist missing, package-lock.json missing, or the wheel's Python
@@ -125,7 +125,7 @@ jobs:
           /tmp/v/bin/pip install --no-deps dist/unsloth-*.whl
           # Run from /tmp so Python imports the installed package, not the source tree.
           cd /tmp
-          /tmp/v/bin/python -c "from studio.backend.main import app; print('Studio backend OK:', app.title)"
+          /tmp/v/bin/python -c "from studio.backend.main import app; print('Unsloth backend OK:', app.title)"
 
       - name: Upload wheel on failure
         if: failure()
diff --git a/README.md b/README.md
index ef45b91430..514454f985 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,7 @@ Unsloth Studio lets you run and train models locally.
 
 <p align="center">
   <a href="#-features">Features</a> •
+  <a href="#-unsloth-news">News</a> •
   <a href="#-install">Quickstart</a> •
   <a href="#-free-notebooks">Notebooks</a> •
   <a href="https://unsloth.ai/docs">Documentation</a>
@@ -47,15 +48,51 @@ Unsloth Studio (Beta) lets you run and train text, [audio](https://unsloth.ai/do
 * [Auto set inference settings](https://unsloth.ai/docs/new/studio/chat#auto-parameter-tuning) and customize chat templates.
 * We work directly with teams behind [gpt-oss](https://docs.unsloth.ai/new/gpt-oss-how-to-run-and-fine-tune#unsloth-fixes-for-gpt-oss), [Qwen3](https://www.reddit.com/r/LocalLLaMA/comments/1kaodxu/qwen3_unsloth_dynamic_ggufs_128k_context_bug_fixes/), [Llama 4](https://github.com/ggml-org/llama.cpp/pull/12889), [Mistral](https://huggingface.co/mistralai/Mistral-Medium-3.5-128B/discussions/18), [Gemma 1-3](https://news.ycombinator.com/item?id=39671146), and [Phi-4](https://unsloth.ai/blog/phi4), where we’ve fixed bugs that improve model accuracy.
 * Chat with images, audio, PDFs, code, DOCX and more. [Connect API providers](https://unsloth.ai/docs/integrations/connections) (OpenAI, Anthropic) or servers (vLLM, Ollama).
+* [**Compare any two models**](https://unsloth.ai/docs/new/studio/chat#model-arena) side by side with the same prompt.
+* **OpenAI/Anthropic-compatible APIs**: Serve local models through `/v1/chat/completions`, `/v1/responses` and `/v1/messages`.
+* **Connect local models to agents**: Use `unsloth start` with Claude Code, Codex, Hermes and more.
+* **Web/PDF search** can read PDF papers, manuals and other PDF results.
+* **GGUF hardware controls**: Choose GPUs/layers, offload MoE experts, use multi-GPU or Tensor Parallelism.
+* The opt-in **MCP control endpoint** lets AI clients manage models, training, recipes and exports.
 ### Training
-* Train and RL **500+ models** up to **2x faster** with up to **70% less VRAM**, with no accuracy loss.
-* Custom Triton and mathematical **kernels**. See some collabs we did with [PyTorch](https://unsloth.ai/docs/get-started/reinforcement-learning-rl-guide/fp8-reinforcement-learning) and [Hugging Face](https://unsloth.ai/docs/new/faster-moe).
+* Train and RL **500+ models** up to **2x faster** with **70% less VRAM**; MoE up to **12x faster**.
+* Train and run RL on [AMD GPUs](https://unsloth.ai/docs/basics/amd) across Windows, WSL and Linux.
 * **Data Recipes**: [Auto-create datasets](https://unsloth.ai/docs/new/studio/data-recipe) from **PDF, CSV, DOCX** etc. Edit data in a visual-node workflow.
-* **[Reinforcement Learning](https://unsloth.ai/docs/get-started/reinforcement-learning-rl-guide)** (RL): The most efficient [RL](https://unsloth.ai/docs/get-started/reinforcement-learning-rl-guide) library, using **80% less VRAM** for GRPO, [FP8](https://unsloth.ai/docs/get-started/reinforcement-learning-rl-guide/fp8-reinforcement-learning) etc.
-* Supports full fine-tuning, RL, pretraining, 4-bit, 16-bit and, FP8 training.
+* **[Reinforcement Learning](https://unsloth.ai/docs/get-started/reinforcement-learning-rl-guide)** uses **80% less VRAM** for GRPO, FP8 and vision RL, with 7x longer contexts.
+* [**Long-context training**](https://unsloth.ai/docs/new/3x-faster-training-packing): **3x faster**, 30% less VRAM and 500K+ context.
+* Supports LoRA/QLoRA, full fine-tuning, RL, pretraining, 4-bit, 16-bit and FP8.
+* Custom Triton and mathematical **kernels** built with PyTorch and Hugging Face.
 * **Observability**: Monitor training live, track loss and GPU usage and customize graphs.
 * [Multi-GPU](https://unsloth.ai/docs/basics/multi-gpu-training-with-unsloth) training is supported, with major improvements coming soon.
 
+## 🚀 Unsloth Start
+
+[Unsloth Start](https://unsloth.ai/docs/integrations/unsloth-start) connects [Claude Code](https://unsloth.ai/docs/basics/claude-code), [Codex](https://unsloth.ai/docs/basics/codex) and other agents to local models with one command.
+
+Start Unsloth, load a model, open your project folder, then run:
+
+```bash
+unsloth start claude
+```
+
+Replace `claude` with any supported agent:
+
+| Agent | Command |
+| --- | --- |
+| Claude Code | `unsloth start claude` |
+| OpenAI Codex | `unsloth start codex` |
+| Hermes Agent | `unsloth start hermes` |
+| OpenClaw | `unsloth start openclaw` |
+| OpenCode | `unsloth start opencode` |
+| Pi Coding Agent | `unsloth start pi` |
+
+Claude Code, Codex, OpenCode and Pi can keep their current model and use Unsloth as a local
+subagent:
+
+```bash
+unsloth start claude --as-subagent --model unsloth/model-GGUF:quant
+```
+
 ## 📥 Install
 Unsloth can be used in two ways: through **[Unsloth Studio](https://unsloth.ai/docs/new/studio/)**, the web UI, or through **Unsloth Core**, the code-based version. Each has different requirements.
 
@@ -65,7 +102,8 @@ Unsloth Studio (Beta) works on **Windows, Linux, WSL** and **macOS**.
 * **CPU:** Supported for Chat and Data Recipes currently
 * **NVIDIA:** Training works on RTX 30/40/50, Blackwell, DGX Spark, Station and more
 * **macOS:** Training, MLX and GGUF inference are ALL supported.
-* **AMD:** Chat + Data works. Train with [Unsloth Core](#unsloth-core-code-based). Studio support is out soon.
+* **AMD:** Training, RL, chat and deployment work on Windows, WSL and Linux. [Read the AMD guide](https://unsloth.ai/docs/basics/amd).
+* **Vulkan:** GGUF inference is supported on [compatible GPUs, including Intel GPUs](https://github.com/unslothai/unsloth/pull/5819).
 * **Multi-GPU:** Available now, with a major upgrade on the way
 
 #### macOS, Linux, WSL:
@@ -86,7 +124,7 @@ unsloth studio -p 8888
 ```
 For LAN or cloud access, add `-H 0.0.0.0` (raw port only; add `--cloudflare` for a public URL). By default, Unsloth is accessible only locally.
 
-To reach Studio over HTTPS, use `unsloth studio --secure`. Studio stays bound to localhost and is reached only through a free Cloudflare tunnel, which publishes it at a public `https://*.trycloudflare.com` URL (it fails closed if the tunnel can't start, so the raw port is never exposed). This makes Studio reachable from the internet, so anyone with the link and API key can use it and run code: keep your API key private (see Remote access below).
+To reach Unsloth over HTTPS, use `unsloth studio --secure`. Unsloth stays bound to localhost and is reached only through a free Cloudflare tunnel, which publishes it at a public `https://*.trycloudflare.com` URL (it fails closed if the tunnel can't start, so the raw port is never exposed). This makes Unsloth reachable from the internet, so anyone with the link and API key can use it and run code: keep your API key private (see Remote access below).
 
 #### Docker
 Use our [Docker image](https://hub.docker.com/r/unsloth/unsloth) ```unsloth/unsloth``` container. Run:
@@ -122,7 +160,7 @@ You can use the same Docker image as Unsloth Studio.
 
 #### AMD, Intel:
 For RTX 50x, B200, 6000 GPUs: `uv pip install unsloth --torch-backend=auto`. Read our guides for: [Blackwell](https://unsloth.ai/docs/blog/fine-tuning-llms-with-blackwell-rtx-50-series-and-unsloth) and [DGX Spark](https://unsloth.ai/docs/blog/fine-tuning-llms-with-nvidia-dgx-spark-and-unsloth). <br>
-To install Unsloth on **AMD** and **Intel** GPUs, follow our [AMD Guide](https://unsloth.ai/docs/get-started/install/amd) and [Intel Guide](https://unsloth.ai/docs/get-started/install/intel).
+To install Unsloth on **AMD** and **Intel** GPUs, follow our [AMD Guide](https://unsloth.ai/docs/basics/amd) and [Intel Guide](https://unsloth.ai/docs/get-started/install/intel).
 
 ## 📒 Free Notebooks
 
@@ -148,13 +186,20 @@ Read our [guide](https://unsloth.ai/docs/get-started/fine-tuning-llms-guide). Ad
 - See detailed documentation for Unsloth [here](https://unsloth.ai/docs)
 
 ## 🦥 Unsloth News
-- **Connections**: Connect any API provider (OpenAI, Anthropic) or server (vLLM, Ollama). [Guide](https://unsloth.ai/docs/integrations/connections)
-- **MTP**: Run Qwen3.6 MTP in Unsloth. MTP settings are autoset specific to your hardware. [Guide](https://unsloth.ai/docs/models/qwen3.6#mtp-guide)
-- **API inference endpoint**: Deploy and run local LLMs in Claude Code, Codex tools. [Guide](https://unsloth.ai/docs/basics/api)
-- **Qwen3.6**: Qwen3.6-35B-A3B can now be trained and run in Unsloth Studio. [Blog](https://unsloth.ai/docs/models/qwen3.6)
-- **Gemma 4**: Run and train Google’s new models directly in Unsloth. [Blog](https://unsloth.ai/docs/models/gemma-4)
+- **AMD training**: Train, run RL, chat and deploy on AMD GPUs across Windows, WSL and Linux. [Guide](https://unsloth.ai/docs/basics/amd)
+- **GGUF hardware controls**: Choose GPU/layer placement, offload MoE experts and use multi-GPU or Tensor Parallelism. [#6414](https://github.com/unslothai/unsloth/pull/6414)
+- **Local models for any agent**: Use `unsloth start` with Claude Code, Codex, Hermes, OpenCode, OpenClaw, Pi and more through Unsloth's OpenAI- and Anthropic-compatible APIs. [Guide](https://unsloth.ai/docs/basics/api)
+- **MCP control endpoint**: Let compatible clients manage models, training, recipes, checkpoints and exports. [#7191](https://github.com/unslothai/unsloth/pull/7191)
+- **Local inference reliability**: Resume long chats faster, recover stalled downloads and reuse existing GGUF files. [#7204](https://github.com/unslothai/unsloth/pull/7204) • [#6858](https://github.com/unslothai/unsloth/pull/6858) • [#7209](https://github.com/unslothai/unsloth/pull/7209)
+- **New models**: [Qwen-AgentWorld](https://huggingface.co/unsloth/Qwen-AgentWorld-35B-A3B-GGUF), [Ornith](https://huggingface.co/unsloth/models?search=ornith), [Kimi K2.7 Code](https://unsloth.ai/docs/models/kimi-k2.7-code) and [MiniMax M3](https://unsloth.ai/docs/models/minimax-m3)
+- **GLM-5.2**: Run Z.ai's 744B-parameter, 1M-context open model locally with Unsloth Dynamic GGUFs. [Guide](https://unsloth.ai/docs/models/glm-5.2)
+- **DeepSeek-V4**: Run DeepSeek-V4-Flash locally with corrected multi-turn and tool-calling behavior. [Guide](https://unsloth.ai/docs/models/deepseek-v4)
+- **DiffusionGemma**: Run and fine-tune Google's diffusion language model with 1.8x faster inference in Unsloth Studio. [Guide](https://unsloth.ai/docs/models/diffusiongemma)
+- **Qwen3.6**: Run and train Qwen3.6 with MTP for 1.4-2.2x faster inference and NVFP4 quants for supported GPUs. [Guide](https://unsloth.ai/docs/models/qwen3.6)
+- **Gemma 4**: Run and train Gemma 4 text, image and audio models with QAT, MTP, GGUF and MLX support. [Guide](https://unsloth.ai/docs/models/gemma-4)
+- **MCP servers**: Connect local models to files, apps, databases and external tools through Model Context Protocol. [Guide](https://unsloth.ai/docs/basics/mcp)
+- **Connections**: Mix local models with API providers (OpenAI, Anthropic) or servers (vLLM, Ollama) in the same interface. [Guide](https://unsloth.ai/docs/integrations/connections)
 - **Introducing Unsloth Studio**: our new web UI for running and training LLMs. [Blog](https://unsloth.ai/docs/new/studio)
-- **Qwen3.5** - 0.8B, 2B, 4B, 9B, 27B, 35-A3B, 112B-A10B are now supported. [Guide + notebooks](https://unsloth.ai/docs/models/qwen3.5/fine-tune)
 - Train **MoE LLMs 12x faster** with 35% less VRAM - DeepSeek, GLM, Qwen and gpt-oss. [Blog](https://unsloth.ai/docs/new/faster-moe)
 - **Embedding models**: Unsloth now supports ~1.8-3.3x faster embedding fine-tuning. [Blog](https://unsloth.ai/docs/new/embedding-finetuning) • [Notebooks](https://unsloth.ai/docs/get-started/unsloth-notebooks#embedding-models)
 - New **7x longer context RL** vs. all other setups, via our new batching algorithms. [Blog](https://unsloth.ai/docs/new/grpo-long-context)
@@ -208,7 +253,7 @@ unsloth studio -p 8888
 #### Remote access: `--secure` (HTTPS tunnel) vs raw port
 By default `unsloth studio` binds to `127.0.0.1` (this machine only). To reach it from another device, pick one of:
 
-- `--secure` (recommended): serve **only** through a free Cloudflare HTTPS link. Studio stays bound to localhost and the tunnel provides the public URL; it fails closed (does not start) if the tunnel can't come up, so the raw port is never exposed.
+- `--secure` (recommended): serve **only** through a free Cloudflare HTTPS link. Unsloth stays bound to localhost and the tunnel provides the public URL; it fails closed (does not start) if the tunnel can't come up, so the raw port is never exposed.
 ```bash
 unsloth studio --secure -p 8888
 ```
@@ -218,7 +263,7 @@ unsloth studio -H 0.0.0.0 -p 8888
 ```
 The Cloudflare tunnel is **off by default**: `-H 0.0.0.0` exposes the raw port only, not a public internet URL. Pair the wildcard bind with `--cloudflare` (`unsloth studio -H 0.0.0.0 --cloudflare`) to also publish a public `https://*.trycloudflare.com` link, or prefer `--secure` (above), which keeps the raw port private. `--cloudflare` has no effect on a loopback bind.
 
-The first time Studio is published on a public URL (`--secure` or `--cloudflare`) with the auto-generated admin password still in place, it asks for a new admin password in the terminal (masked input with confirmation) before the public link goes up. Without an attached terminal it warns instead and keeps the bootstrap deadline: Studio shuts down after `UNSLOTH_STUDIO_BOOTSTRAP_TIMEOUT` (default 1 hour) unless the password is changed in the web UI.
+The first time Unsloth is published on a public URL (`--secure` or `--cloudflare`) with the auto-generated admin password still in place, it asks for a new admin password in the terminal (masked input with confirmation) before the public link goes up. Without an attached terminal it warns instead and keeps the bootstrap deadline: Unsloth shuts down after `UNSLOTH_STUDIO_BOOTSTRAP_TIMEOUT` (default 1 hour) unless the password is changed in the web UI.
 
 For headless setups that cannot answer that prompt, set the initial admin password non-interactively with `--password` (only takes effect when no password is set yet; if one already exists it is a hard error, so rotate later with `unsloth studio reset-password`):
 
@@ -230,7 +275,7 @@ printf '%s\n' 'your-strong-password' | unsloth studio --secure --password -   #
 
 A literal `--password VALUE` is visible in the process list and shell history, so prefer the `UNSLOTH_STUDIO_PASSWORD` env var or `--password -` (stdin) for automation. This applies to any launch (public or a headless `-H 0.0.0.0` bind), and the password is set in the parent before the server binds, so it never reaches a re-executed child process.
 
-Server-side tools (web search, Python and terminal code execution) run as your user and are on by default. Anyone who can reach the server with the API key can run code on this machine, so keep your API key private and pass `--disable-tools` when exposing Studio.
+Server-side tools (web search, Python and terminal code execution) run as your user and are on by default. Anyone who can reach the server with the API key can run code on this machine, so keep your API key private and pass `--disable-tools` when exposing Unsloth.
 
 #### Advanced launch options
 Installer options can be passed as environment variables. On macOS, Linux and WSL place the variable after the pipe so the shell passes it to `sh`; on Windows set it with `$env:` before piping to `iex`.
@@ -243,7 +288,7 @@ curl -fsSL https://unsloth.ai/install.sh | UNSLOTH_NO_TORCH=1 sh
 $env:UNSLOTH_NO_TORCH=1; irm https://unsloth.ai/install.ps1 | iex
 ```
 
-Skip the post-install prompt that starts Studio (useful for automated installs):
+Skip the post-install prompt that starts Unsloth (useful for automated installs):
 ```bash
 curl -fsSL https://unsloth.ai/install.sh | UNSLOTH_SKIP_AUTOSTART=1 sh
 ```
@@ -279,9 +324,9 @@ UNSLOTH_NPM_REGISTRY=https://artifactory.example.com/api/npm/npm/ ./install.sh -
 ```powershell
 $env:UNSLOTH_NPM_REGISTRY='https://artifactory.example.com/api/npm/npm/'; .\install.ps1 --local
 ```
-It is threaded as `--registry` into the Studio frontend `npm`/`bun` installs; the supply-chain locks (7-day `min-release-age`, exact version pins) stay in force.
+It is threaded as `--registry` into the Unsloth frontend `npm`/`bun` installs; the supply-chain locks (7-day `min-release-age`, exact version pins) stay in force.
 
-Cap Studio's native CPU thread pools on high-core hosts: `UNSLOTH_CPU_THREADS=8 unsloth studio -p 8888`.
+Cap Unsloth's native CPU thread pools on high-core hosts: `UNSLOTH_CPU_THREADS=8 unsloth studio -p 8888`.
 
 #### Uninstall
 The recommended way to fully remove Unsloth Studio is the matching uninstall script for your OS. It stops any running servers, removes the install dir, the launcher data dir, the desktop shortcut, and any platform-specific entries (macOS `.app` bundle + Launch Services on Mac; Start Menu, `HKCU\Software\Unsloth` registry key and user `PATH` entries on Windows):
diff --git a/build.sh b/build.sh
index dc272f0de1..2a836e19d9 100644
--- a/build.sh
+++ b/build.sh
@@ -4,9 +4,9 @@
 
 set -euo pipefail
 
-# PyPI/Studio release publishing must use `./build.sh publish` (or an
-# equivalent stamp -> build -> verify-dist -> upload flow) so packaged Studio
-# artifacts include the display-only Studio release version.
+# PyPI/Unsloth release publishing must use `./build.sh publish` (or an
+# equivalent stamp -> build -> verify-dist -> upload flow) so packaged Unsloth
+# artifacts include the display-only Unsloth release version.
 
 # 1. Build frontend (Vite outputs to dist/)
 cd studio/frontend
@@ -87,7 +87,7 @@ cd ../..
 # 2. Clean old artifacts
 rm -rf build dist *.egg-info
 
-# 3. Stamp display-only Studio release metadata for packaged builds.
+# 3. Stamp display-only Unsloth release metadata for packaged builds.
 _STUDIO_BUILD_INFO="studio/backend/utils/_studio_release_build.py"
 _STUDIO_BUILD_INFO_BACKUP="$(mktemp)"
 cp "$_STUDIO_BUILD_INFO" "$_STUDIO_BUILD_INFO_BACKUP"
diff --git a/install.ps1 b/install.ps1
index c25d7e7b7f..9c91d4ba16 100644
--- a/install.ps1
+++ b/install.ps1
@@ -53,7 +53,8 @@ function Install-UnslothStudio {
         param([string]$TorchIndexUrl)
         if ($SkipTorch) { return "none" }
         if ([string]::IsNullOrWhiteSpace($TorchIndexUrl)) { return "none" }
-        $leaf = ($TorchIndexUrl.TrimEnd('/') -split '/')[-1].ToLowerInvariant()
+        # Drop query/fragment first so a token-authenticated pin classifies by family.
+        $leaf = (($TorchIndexUrl -split '[?#]', 2)[0].TrimEnd('/') -split '/')[-1].ToLowerInvariant()
         if (@("cpu", "cu118", "cu124", "cu126", "cu128", "cu130") -contains $leaf) { return $leaf }
         if ($leaf -match '^rocm[0-9]+\.[0-9]+$') { return $leaf }
         return "auto"
@@ -62,7 +63,8 @@ function Install-UnslothStudio {
     function Get-TauriGpuBranch {
         param([string]$TorchIndexFamily)
         if ($SkipTorch) { return "no_torch" }
-        if ($TorchIndexFamily -like "cu*") { return "cuda" }
+        # Require a digit after "cu" so /current or /custom isn't branded CUDA (parity ^cu[0-9]).
+        if ($TorchIndexFamily -match '^cu[0-9]') { return "cuda" }
         if ($TorchIndexFamily -like "rocm*") { return "rocm" }
         if ($TorchIndexFamily -eq "cpu") { return "cpu" }
         return "unknown"
@@ -176,7 +178,7 @@ function Install-UnslothStudio {
         $envOverride = $env:STUDIO_HOME.Trim()
     }
 
-    # Custom Studio roots are not supported with --tauri (desktop app still
+    # Custom Unsloth roots are not supported with --tauri (desktop app still
     # resolves %USERPROFILE%\.unsloth\studio). Pass through if override == legacy.
     if ($TauriMode -and $envOverride) {
         $_tauriOverride = $envOverride
@@ -467,22 +469,35 @@ function Install-UnslothStudio {
         }
     }
 
+    # Redact index-URL credentials (userinfo + ?query= + #fragment) from captured installer
+    # output before printing on failure; uv/pip errors echo the failing --index-url verbatim.
+    # Mirrors the other installers. Verbose mode streams uncaptured, so it isn't redacted.
+    function Redact-InstallOutput {
+        param([string]$Text)
+        if (-not $Text) { return $Text }
+        $Text = $Text -replace '(https?://)[^/@\s`]+@', '$1<redacted>@'
+        $Text = $Text -replace '([?&][^=\s&`]+)=[^&#\s`]+', '$1=<redacted>'
+        # A #token=... fragment is as sensitive as a query; URL-anchored.
+        return $Text -replace '(https?://[^\s`#]+)#[^\s`]+', '$1#<redacted>'
+    }
+
     # Run native commands quietly by default to match install.sh behavior.
     # Full command output is shown only when --verbose / UNSLOTH_VERBOSE=1.
     function Invoke-InstallCommand {
         param(
             [Parameter(Mandatory = $true)][ScriptBlock]$Command
         )
-        # Installer-pinned index installs (torch) must beat an inherited uv mirror
-        # (#6898): when the command pins an index, clear every uv index env var so
-        # it wins, then restore in finally. Other installs keep the user's mirror.
+        # Installer-pinned index installs (torch) must beat an inherited uv mirror (#6898):
+        # for --default-index, clear the uv index env vars (restore in finally) and set
+        # UV_NO_CONFIG=1 so a uv.toml/pyproject index can't outrank the CLI pin (uv 0.10).
         $savedUvIndex = $null
         if ($Command.ToString() -match '--default-index') {
             $savedUvIndex = @{}
-            foreach ($n in 'UV_DEFAULT_INDEX', 'UV_INDEX_URL', 'UV_INDEX', 'UV_EXTRA_INDEX_URL') {
+            foreach ($n in 'UV_DEFAULT_INDEX', 'UV_INDEX_URL', 'UV_INDEX', 'UV_EXTRA_INDEX_URL', 'UV_TORCH_BACKEND', 'UV_FIND_LINKS', 'UV_CONFIG_FILE', 'UV_NO_CONFIG') {
                 $savedUvIndex[$n] = [Environment]::GetEnvironmentVariable($n)
                 Remove-Item "Env:$n" -ErrorAction SilentlyContinue
             }
+            $env:UV_NO_CONFIG = '1'
         }
         $prevEap = $ErrorActionPreference
         $ErrorActionPreference = "Continue"
@@ -493,17 +508,23 @@ function Install-UnslothStudio {
                 # Merge stderr into stdout so progress/warning output stays visible
                 # without flipping $? on successful native commands (PS 5.1 treats
                 # stderr records as errors that set $? = $false even on exit code 0).
-                & $Command 2>&1 | Out-Host
+                # Redact per record: uv echoes index URLs (credentials and all) in
+                # its errors, and verbose mode must not bypass the quiet path's
+                # redaction. ForEach-Object/Out-Host leave $LASTEXITCODE untouched.
+                & $Command 2>&1 | ForEach-Object { Redact-InstallOutput "$_" } | Out-Host
             } else {
                 $output = & $Command 2>&1 | Out-String
                 if ($LASTEXITCODE -ne 0) {
-                    Write-Host $output -ForegroundColor Red
+                    Write-Host (Redact-InstallOutput $output) -ForegroundColor Red
                 }
             }
             return [int]$LASTEXITCODE
         } finally {
             $ErrorActionPreference = $prevEap
-            if ($savedUvIndex) { foreach ($n in $savedUvIndex.Keys) { if ($null -ne $savedUvIndex[$n]) { Set-Item "Env:$n" $savedUvIndex[$n] } } }
+            if ($savedUvIndex) {
+                Remove-Item "Env:UV_NO_CONFIG" -ErrorAction SilentlyContinue
+                foreach ($n in $savedUvIndex.Keys) { if ($null -ne $savedUvIndex[$n]) { Set-Item "Env:$n" $savedUvIndex[$n] } }
+            }
         }
     }
 
@@ -756,7 +777,7 @@ function Find-FreeLaunchPort {
     return `$null
 }
 
-# If Studio is already healthy on any expected port, just open it and exit.
+# If Unsloth is already healthy on any expected port, just open it and exit.
 `$existingPort = Find-HealthyStudioPort
 if (`$existingPort) {
     Start-Process "http://localhost:`$existingPort"
@@ -772,7 +793,7 @@ try {
         `$haveMutex = `$true
     }
     if (-not `$haveMutex) {
-        # Another launcher is already running; wait for it to bring Studio up
+        # Another launcher is already running; wait for it to bring Unsloth up
         `$deadline = (Get-Date).AddSeconds(`$timeoutSec)
         while ((Get-Date) -lt `$deadline) {
             `$port = Find-HealthyStudioPort
@@ -1395,13 +1416,82 @@ exit 0
             $suffix++
             $candidate = Join-Path $StudioHome "unsloth_studio.rollback.$stamp.$PID.$suffix"
         }
-        Move-Item -LiteralPath $ExistingDir -Destination $candidate -ErrorAction Stop
         $script:StudioVenvRollbackDir = $candidate
         $script:StudioVenvRollbackTarget = $ExistingDir
         $script:StudioVenvRollbackActive = $true
+        # Publish the rollback state before the atomic rename so interruption
+        # cannot land after Move-Item but before cleanup knows where the old venv went.
+        try {
+            Move-Item -LiteralPath $ExistingDir -Destination $candidate -ErrorAction Stop
+        } catch {
+            # A collision or ordinary rename failure leaves the original in place.
+            # Keep state active only when the rename happened before interruption.
+            if (Test-Path -LiteralPath $ExistingDir) {
+                $script:StudioVenvRollbackActive = $false
+                $script:StudioVenvRollbackDir = $null
+            }
+            throw
+        }
         substep "previous environment preserved for rollback"
     }
 
+    function Remove-StudioVenvTreeWithRetry {
+        param(
+            [Parameter(Mandatory = $true)][string]$Path,
+            [Parameter(Mandatory = $true)][string]$Label
+        )
+        $lastError = $null
+        for ($attempt = 1; $attempt -le 3; $attempt++) {
+            try {
+                Remove-Item -LiteralPath $Path -Recurse -Force -ErrorAction Stop
+            } catch {
+                $lastError = $_.Exception.Message
+            }
+            if (-not (Test-Path -LiteralPath $Path)) { return $true }
+            if ($attempt -lt 3) { Start-Sleep -Milliseconds (250 * $attempt) }
+        }
+        Write-Host "[WARN] Could not remove $Label at $Path" -ForegroundColor Yellow
+        if ($lastError) { Write-Host "       $lastError" -ForegroundColor Yellow }
+        return $false
+    }
+
+    function Test-StudioVenvRollbackMustBePreserved {
+        param([Parameter(Mandatory = $true)][System.IO.FileSystemInfo]$Rollback)
+        # Preserve anything outside the installer's timestamp.PID[.suffix] format.
+        if ($Rollback.Name -notmatch '^unsloth_studio\.rollback\.[0-9]{14}\.([0-9]+)(?:\.[0-9]+)?$') {
+            return $true
+        }
+        $ownerPid = 0
+        if (-not [int]::TryParse($Matches[1], [ref]$ownerPid)) { return $true }
+        if ($ownerPid -eq $PID) { return $true }
+        return $null -ne (Get-Process -Id $ownerPid -ErrorAction SilentlyContinue)
+    }
+
+    function Remove-StaleStudioVenvRollbacks {
+        try {
+            $rollbacks = @(
+                Get-ChildItem -LiteralPath $StudioHome -Directory -Force -ErrorAction Stop |
+                    Where-Object { $_.Name -like 'unsloth_studio.rollback.*' }
+            )
+        } catch {
+            Write-Host "[WARN] Could not inspect stale environment rollbacks in $StudioHome" -ForegroundColor Yellow
+            Write-Host "       $($_.Exception.Message)" -ForegroundColor Yellow
+            return
+        }
+        foreach ($rollback in $rollbacks) {
+            if (($rollback.Attributes -band [System.IO.FileAttributes]::ReparsePoint) -ne 0) {
+                Write-Host "[WARN] Refusing to remove rollback reparse point $($rollback.FullName)" -ForegroundColor Yellow
+                continue
+            }
+            # A concurrent installer may have moved its live venv aside. The PID
+            # in the generated name keeps this run from deleting its rescue copy.
+            if (Test-StudioVenvRollbackMustBePreserved -Rollback $rollback) { continue }
+            if (Remove-StudioVenvTreeWithRetry -Path $rollback.FullName -Label "stale environment rollback") {
+                substep "removed stale environment rollback $($rollback.Name)"
+            }
+        }
+    }
+
     function Restore-StudioVenvRollback {
         if (-not $script:StudioVenvRollbackActive) { return }
         $backup = $script:StudioVenvRollbackDir
@@ -1413,7 +1503,9 @@ exit 0
         substep "restoring previous environment after failed install..." "Yellow"
         try {
             if (Test-Path -LiteralPath $target) {
-                Remove-Item -LiteralPath $target -Recurse -Force -ErrorAction SilentlyContinue
+                if (-not (Remove-StudioVenvTreeWithRetry -Path $target -Label "incomplete environment")) {
+                    throw "Could not remove incomplete environment at $target"
+                }
             }
             Move-Item -LiteralPath $backup -Destination $target -Force -ErrorAction Stop
             substep "restored previous environment"
@@ -1428,17 +1520,21 @@ exit 0
     function Complete-StudioVenvRollback {
         if (-not $script:StudioVenvRollbackActive) { return }
         $backup = $script:StudioVenvRollbackDir
-        if ($backup -and (Test-Path -LiteralPath $backup)) {
-            Remove-Item -LiteralPath $backup -Recurse -Force -ErrorAction SilentlyContinue
-        }
+        # The replacement is committed. Disable restoration before deleting the
+        # backup so interruption cannot restore a partially deleted environment.
         $script:StudioVenvRollbackActive = $false
         $script:StudioVenvRollbackDir = $null
+        if ($backup -and (Test-Path -LiteralPath $backup)) {
+            Remove-StudioVenvTreeWithRetry -Path $backup -Label "environment rollback" | Out-Null
+        }
     }
 
+    $studioVenvReplacementCommitted = $false
+    try {
     if (Test-Path -LiteralPath $VenvPython) {
         # why: matching guard to the .venv branch below -- in env-mode
         # $StudioHome is a user-chosen workspace, so refuse to nuke an
-        # existing $StudioHome\unsloth_studio that lacks Studio sentinels.
+        # existing $StudioHome\unsloth_studio that lacks Unsloth sentinels.
         # -PathType Leaf rejects a directory at the sentinel path. Accept the
         # in-VENV ownership marker so partial-install retries are not blocked.
         if (
@@ -1449,7 +1545,7 @@ exit 0
         ) {
             Write-Host "[ERROR] $VenvDir already exists but does not look like an Unsloth Studio install." -ForegroundColor Red
             Write-Host "        Move it aside or choose an empty UNSLOTH_STUDIO_HOME." -ForegroundColor Yellow
-            throw "Refusing to delete non-Studio venv at $VenvDir"
+            throw "Refusing to delete non-Unsloth venv at $VenvDir"
         }
         # New layout already exists -- replace only after preserving rollback copy.
         substep "preserving existing environment for rollback..."
@@ -1468,7 +1564,7 @@ exit 0
         # workspace root (e.g. user's existing project Python venv).
         $OldVenv = Join-Path $StudioHome ".venv"
         $OldPy = Join-Path $OldVenv "Scripts\python.exe"
-        substep "found legacy Studio environment, validating..."
+        substep "found legacy Unsloth environment, validating..."
         $prevEAP2 = $ErrorActionPreference
         $ErrorActionPreference = "Continue"
         try {
@@ -1498,7 +1594,7 @@ exit 0
         # Skip in env-mode so we don't relocate the default-install venv into
         # the workspace root.
         $CwdVenv = Join-Path $env:USERPROFILE "unsloth_studio"
-        substep "found CWD-relative Studio environment, migrating to $VenvDir..."
+        substep "found CWD-relative Unsloth environment, migrating to $VenvDir..."
         Move-Item -LiteralPath $CwdVenv -Destination $VenvDir -Force
         substep "moved ~/unsloth_studio -> ~/.unsloth/studio/unsloth_studio"
         $_Migrated = $true
@@ -1517,7 +1613,7 @@ exit 0
         substep "$VenvDir"
     }
 
-    # Mark the freshly-created venv as Studio-owned so a partial install can be
+    # Mark the freshly-created venv as Unsloth-owned so a partial install can be
     # repaired by re-running install.ps1; the env-mode deletion guard above
     # accepts this marker as the primary sentinel.
     if (Test-Path -LiteralPath $VenvDir -PathType Container) {
@@ -1526,7 +1622,7 @@ exit 0
 
     # ── Helper: run amd-smi without triggering a UAC elevation prompt ──
     # amd-smi on Windows auto-elevates to read GPU/APU memory, surfacing a confusing
-    # DiskPart UAC prompt mid-install (Studio backend amd.py hits the same).
+    # DiskPart UAC prompt mid-install (Unsloth backend amd.py hits the same).
     # __COMPAT_LAYER=RunAsInvoker forces it (and helpers it spawns) to run
     # un-elevated; on failure the WMI name -> gfx fallback still resolves the arch.
     function Invoke-AmdSmiNoElevate {
@@ -1653,7 +1749,7 @@ exit 0
         function Test-HipinfoIsVenvInternal {
             param([AllowNull()][string]$HipinfoPath)
             if ([string]::IsNullOrWhiteSpace($HipinfoPath)) { return $false }
-            # Also derive the venv from the setup python + default Studio home, so
+            # Also derive the venv from the setup python + default Unsloth home, so
             # the venv hipInfo is caught when VenvDir/VIRTUAL_ENV are unset.
             $venvRoots = @()
             if ($env:VIRTUAL_ENV) { $venvRoots += $env:VIRTUAL_ENV }
@@ -1663,7 +1759,7 @@ exit 0
                 try { $venvRoots += (Split-Path -Parent (Split-Path -Parent $env:UNSLOTH_SETUP_PYTHON)) } catch {}
             }
             if ($env:USERPROFILE) { $venvRoots += (Join-Path $env:USERPROFILE ".unsloth\studio\unsloth_studio") }
-            # A custom Studio home (UNSLOTH_STUDIO_HOME / STUDIO_HOME alias) moves the
+            # A custom Unsloth home (UNSLOTH_STUDIO_HOME / STUDIO_HOME alias) moves the
             # venv off the default path; seed it too or its hipInfo escapes the filter.
             $studioHomeEnv = if (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_STUDIO_HOME)) { $env:UNSLOTH_STUDIO_HOME.Trim() } elseif (-not [string]::IsNullOrWhiteSpace($env:STUDIO_HOME)) { $env:STUDIO_HOME.Trim() } else { $null }
             if ($studioHomeEnv) {
@@ -1823,7 +1919,7 @@ exit 0
                 $nameArchTable = @(
                     @{ P = "9070 XT|9080";                                        A = "gfx1201" }  # RDNA 4 (RX 9070 XT / 9080)
                     @{ P = "9070|9060";                                           A = "gfx1200" }  # RDNA 4 (RX 9070 / 9060)
-                    @{ P = "8060S|8050S|8040S|Strix Halo|Ryzen AI Max|AI Max"; A = "gfx1151" }  # RDNA 3.5 (Strix Halo: Radeon 8060S/8050S/8040S iGPU, Ryzen AI Max+)
+                    @{ P = "8065S|8060S|8050S|8040S|Strix Halo|Ryzen AI Max|AI Max"; A = "gfx1151" }  # RDNA 3.5 (Strix Halo + Gorgon Halo: Radeon 8065S/8060S/8050S/8040S iGPU, Ryzen AI Max / Max+)
                     @{ P = "890M|880M|860M|840M|Strix Point|Krackan|HX 37[05]|AI 9 HX|AI 9 36[05]|AI 7 35[05]|AI 5 34[05]|AI 7 PRO 35|AI 5 33"; A = "gfx1150" }  # RDNA 3.5 (Strix/Krackan Point: Radeon 890M/880M iGPU, Ryzen AI 9 HX 370/375)
                     @{ P = "RX 7900|RX 7800|RX 7700(?!S)|PRO W7900|PRO W7800|PRO W7700"; A = "gfx1100" }  # RDNA 3 desktop/workstation (Navi 31)
                     @{ P = "RX 7600|RX 7700S|RX 7650|PRO W7600|PRO W7500|PRO V710"; A = "gfx1102" }  # RDNA 3 (Navi 33)
@@ -1942,7 +2038,7 @@ exit 0
         substep "       Ensure the ROCm compute driver is installed alongside the display driver:" "Yellow"
         substep "       https://rocm.docs.amd.com/en/latest/deploy/windows/index.html" "Yellow"
     } elseif ($ROCmGfxArch) {
-        # Known arch: Studio setup installs AMD's bundled-runtime ROCm PyTorch wheels
+        # Known arch: Unsloth setup installs AMD's bundled-runtime ROCm PyTorch wheels
         # (repo.amd.com), which ship their own runtime -- HIP SDK optional.
         step "gpu" "AMD ROCm ($ROCmGfxArch)" "Cyan"
         substep "Detected: $ROCmGpuLabel" "Cyan"
@@ -1960,10 +2056,31 @@ exit 0
     # On an AMD GPU (no NVIDIA), surface the optional WSL-ROCm driver hint.
     if (-not $HasNvidiaSmi -and ($ROCmGfxArch -or $ROCmGpuLabel)) { Show-AmdWslDriverHint }
 
+    # Trim trailing slashes from the URL PATH only, preserving ?query / #fragment: a whole-URL
+    # TrimEnd corrupts a token ending in "/", a single strip leaves .../cu128// empty. Shared.
+    function Trim-IndexPathSlashes {
+        param([string]$Url)
+        $value = $Url.Trim()
+        $idx = $value.IndexOfAny([char[]]@('?', '#'))
+        if ($idx -lt 0) {
+            return $value.TrimEnd('/')
+        }
+        return $value.Substring(0, $idx).TrimEnd('/') + $value.Substring($idx)
+    }
+
     # ── Choose the correct PyTorch index URL based on driver CUDA version ──
     # Mirrors Get-PytorchCudaTag in setup.ps1.
     function Get-TorchIndexUrl {
         $baseUrl = if ($env:UNSLOTH_PYTORCH_MIRROR) { $env:UNSLOTH_PYTORCH_MIRROR.TrimEnd('/') } else { "https://download.pytorch.org/whl" }
+        # Explicit pin -- skip ALL GPU probing (headless / CI / cross-install).
+        # UNSLOTH_TORCH_INDEX_URL wins (full URL, verbatim); _FAMILY is the leaf appended
+        # to the mirror base. Matches install.sh / install_python_stack.py.
+        if (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_TORCH_INDEX_URL)) {
+            return (Trim-IndexPathSlashes $env:UNSLOTH_TORCH_INDEX_URL)
+        }
+        if (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_TORCH_INDEX_FAMILY)) {
+            return "$baseUrl/$($env:UNSLOTH_TORCH_INDEX_FAMILY.Trim().Trim('/'))"
+        }
         if (-not $NvidiaSmiExe) { return "$baseUrl/cpu" }
         try {
             $output = Invoke-NvidiaSmiBounded $NvidiaSmiExe
@@ -1984,6 +2101,27 @@ exit 0
         return "$baseUrl/cu126"
     }
 
+    # Strip userinfo AND query/fragment so an authenticated pin never leaks. Shared with
+    # _strip_index_url_credentials (install.sh / py / setup.ps1).
+    function Remove-IndexUrlCredentials {
+        param([string]$Url)
+        # Ordinal, not culture-aware: on non-English locales (e.g. th-TH) linguistic
+        # IndexOf treats "://" as ignorable, mis-locates it, and crashes Substring (issue #7279).
+        $sep = $Url.IndexOf('://', [System.StringComparison]::Ordinal)
+        if ($sep -lt 0) { return $Url }
+        $scheme = $Url.Substring(0, $sep)
+        $rest = $Url.Substring($sep + 3)
+        # Drop query / fragment (may hold auth tokens).
+        $q = $rest.IndexOfAny([char[]]('?', '#'))
+        if ($q -ge 0) { $rest = $rest.Substring(0, $q) }
+        $slash = $rest.IndexOf('/', [System.StringComparison]::Ordinal)
+        $authority = if ($slash -ge 0) { $rest.Substring(0, $slash) } else { $rest }
+        $at = $authority.LastIndexOf('@', [System.StringComparison]::Ordinal)
+        $host_ = if ($at -ge 0) { $authority.Substring($at + 1) } else { $authority }
+        if ($slash -ge 0) { return "${scheme}://${host_}$($rest.Substring($slash))" }
+        return "${scheme}://${host_}"
+    }
+
     # ── Torch flavor helpers (to repair a stale CPU / wrong-CUDA wheel) ──
     # torch.__version__ -> flavor tag (cuXXX / rocm / cpu); untagged wheel = cpu,
     # matching setup.ps1's stale-venv parse.
@@ -2002,11 +2140,13 @@ exit 0
         param([string]$TorchIndexUrl, [string]$ROCmIndexUrl)
         if (-not [string]::IsNullOrWhiteSpace($ROCmIndexUrl)) { return 'rocm' }
         if ([string]::IsNullOrWhiteSpace($TorchIndexUrl)) { return $null }
-        $leaf = ($TorchIndexUrl.TrimEnd('/') -split '/')[-1].ToLowerInvariant()
+        # Drop query/fragment first so .../cu128?token=x classifies as cu128 (else it reinstalls every run).
+        $leaf = (($TorchIndexUrl -split '[?#]', 2)[0].TrimEnd('/') -split '/')[-1].ToLowerInvariant()
         if ($leaf -match '^cu\d+$') { return $leaf }
         if ($leaf -eq 'cpu')        { return 'cpu' }
         if ($leaf -match '^rocm')   { return 'rocm' }
-        if ($leaf -match '^gfx')    { return 'rocm' }
+        # gfx must be followed by a digit (an architecture leaf); gfx-private is custom.
+        if ($leaf -match '^gfx[0-9]') { return 'rocm' }
         return $null
     }
 
@@ -2041,6 +2181,10 @@ exit 0
         } catch { return $null }
     }
 
+    # An explicit pin is authoritative: the AMD ROCm reroute below must not rewrite it
+    # (e.g. a deliberate cpu pin on an AMD host).
+    $TorchIndexPinned = (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_TORCH_INDEX_URL)) -or `
+                        (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_TORCH_INDEX_FAMILY))
     $TorchIndexUrl = Get-TorchIndexUrl
 
     # ── GPU arch → newest compatible Windows ROCm wheel release ──
@@ -2052,13 +2196,19 @@ exit 0
     # Override with UNSLOTH_ROCM_WINDOWS_MIRROR for air-gapped / mirror installs.
     $ROCmIndexUrl = $null
     $ROCmTorchFloor = $null
-    if (($HasROCm -or $ROCmGfxArch) -and $TorchIndexUrl -like "*/cpu" -and -not $SkipTorch) {
+    $PinnedRocmVisionSpec = $null
+    $PinnedRocmAudioSpec = $null
+    if (-not $TorchIndexPinned -and ($HasROCm -or $ROCmGfxArch) -and $TorchIndexUrl -like "*/cpu" -and -not $SkipTorch) {
         $amdIndexBase = if ($env:UNSLOTH_ROCM_WINDOWS_MIRROR) { $env:UNSLOTH_ROCM_WINDOWS_MIRROR.TrimEnd('/') } else { "https://repo.amd.com/rocm/whl" }
         $archFamilyMap = @{
             "gfx1201" = "gfx120X-all"; "gfx1200" = "gfx120X-all"  # RDNA 4
             "gfx1151" = "gfx1151";     "gfx1150" = "gfx1150"       # RDNA 3.5 (Strix Halo/Point)
             "gfx1103" = "gfx110X-all"; "gfx1102" = "gfx110X-all"   # RDNA 3
             "gfx1101" = "gfx110X-all"; "gfx1100" = "gfx110X-all"
+            "gfx1036" = "gfx103X-all"; "gfx1035" = "gfx103X-all"   # RDNA 2 (RX 6000)
+            "gfx1034" = "gfx103X-all"; "gfx1033" = "gfx103X-all"
+            "gfx1032" = "gfx103X-all"; "gfx1031" = "gfx103X-all"
+            "gfx1030" = "gfx103X-all"
             "gfx90a"  = "gfx90a";      "gfx908"  = "gfx908"        # MI200/MI100
         }
         # gfx120X (RDNA 4) and gfx1151/gfx1150 (Strix) have a null-pointer bug in
@@ -2102,6 +2252,32 @@ exit 0
         }
     }
 
+    # A gfx*/rocm pin skips the auto-reroute above, but the generic CPU/CUDA install below
+    # would use torch>=2.4,<2.11 and pull a known-bad wheel on the gfx115x/gfx120x/rocm>=7.2
+    # indexes (the _grouped_mm bug). Route a pinned ROCm index through the ROCm path.
+    if ($TorchIndexPinned -and -not $ROCmIndexUrl -and -not $SkipTorch) {
+        $_pinLeaf = (($TorchIndexUrl -split '[?#]', 2)[0].TrimEnd('/') -split '/')[-1].ToLower()
+        $_pinRocm211 = $false
+        # Anchor ($) so a suffixed custom leaf (rocm7.2-private) falls through to verbatim.
+        if ($_pinLeaf -match '^rocm(\d+)\.(\d+)$') {
+            # Only KNOWN-2.11 rocm (rocm7.2) gets the floor. Matches Test-RocmKnown211Version.
+            $_pinRocm211 = ([int]$Matches[1] -eq 7 -and [int]$Matches[2] -eq 2)
+        }
+        # Only the 2.11-allowlist gfx arches need the floor; others publish <2.11 and stay bare.
+        $_pinGfx211 = @('gfx120x-all', 'gfx1151', 'gfx1150') -contains $_pinLeaf
+        if ($_pinGfx211 -or $_pinRocm211) {
+            $ROCmIndexUrl = $TorchIndexUrl
+            $ROCmTorchFloor = "torch>=2.11.0,<2.12.0"
+            $PinnedRocmVisionSpec = "torchvision>=0.26.0,<0.27.0"
+            $PinnedRocmAudioSpec = "torchaudio>=2.11.0,<2.12.0"
+            substep "pinned ROCm index ($_pinLeaf) -- enforcing $ROCmTorchFloor" "Cyan"
+        } elseif ($_pinLeaf -match '^gfx[0-9]' -or $_pinLeaf -match '^rocm[0-9]+(\.[0-9]+)?$') {
+            # Other gfx / older rocm (<=7.1) ship torch <2.11; route via the ROCm path with
+            # bare specs. Only EXACT rocm<digits>/gfx* are families; a suffixed leaf is verbatim.
+            $ROCmIndexUrl = $TorchIndexUrl
+        }
+    }
+
     if ($ROCmIndexUrl) {
         $TorchIndexFamily = "rocm"
     } else {
@@ -2164,14 +2340,14 @@ exit 0
     }
 
     if ($_Migrated) {
-        # Migrated env: force-reinstall unsloth+unsloth-zoo to ensure clean state
-        # in the new venv location, while preserving existing torch/CUDA
+        # Migrated env: force-reinstall unsloth+unsloth-zoo for a clean state, preserving
+        # existing torch/CUDA unless the flavor repair below re-lands it.
         Write-TauriLog "STEP" "Installing unsloth"
         substep "upgrading unsloth in migrated environment..."
         if ($SkipTorch) {
             # No-torch: install unsloth + unsloth-zoo with --no-deps, then
             # runtime deps (typer, safetensors, transformers, etc.) with --no-deps.
-            $baseInstallExit = Invoke-InstallCommandRetry -Label "install unsloth (migrated no-torch)" { uv pip install --python $VenvPython --no-deps --reinstall-package unsloth --reinstall-package unsloth-zoo "unsloth>=2026.7.3" "unsloth-zoo>=2026.7.3" }
+            $baseInstallExit = Invoke-InstallCommandRetry -Label "install unsloth (migrated no-torch)" { uv pip install --python $VenvPython --no-deps --reinstall-package unsloth --reinstall-package unsloth-zoo "unsloth>=2026.7.5" "unsloth-zoo>=2026.7.6" }
             if ($baseInstallExit -eq 0) {
                 # Resolve pydantic WITH deps so pip pins pydantic-core
                 # to the matching version (no-torch-runtime.txt below
@@ -2185,7 +2361,7 @@ exit 0
                 }
             }
         } else {
-            $baseInstallExit = Invoke-InstallCommandRetry -Label "install unsloth (migrated)" { uv pip install --python $VenvPython --reinstall-package unsloth --reinstall-package unsloth-zoo "unsloth>=2026.7.3" "unsloth-zoo>=2026.7.3" }
+            $baseInstallExit = Invoke-InstallCommandRetry -Label "install unsloth (migrated)" { uv pip install --python $VenvPython --reinstall-package unsloth --reinstall-package unsloth-zoo "unsloth>=2026.7.5" "unsloth-zoo>=2026.7.6" }
         }
         if ($baseInstallExit -ne 0) {
             Write-Host "[ERROR] Failed to install unsloth (exit code $baseInstallExit)" -ForegroundColor Red
@@ -2210,22 +2386,24 @@ exit 0
             substep "skipping PyTorch (--no-torch flag set)." "Yellow"
         } elseif ($ROCmIndexUrl) {
             Write-TauriLog "STEP" "Installing PyTorch (AMD ROCm Windows)"
-            substep "installing PyTorch from $ROCmIndexUrl..."
+            substep "installing PyTorch from $(Remove-IndexUrlCredentials $ROCmIndexUrl)..."
             $torchSpec = if ($ROCmTorchFloor) { $ROCmTorchFloor } else { "torch" }
             # Pin the companions to match $torchSpec; bare names can resolve an
             # ABI-incompatible torchvision/torchaudio on AMD's per-arch index.
-            $visionSpec = if ($ROCmGfxArch -and $torchvisionFloorMap.ContainsKey($ROCmGfxArch)) { $torchvisionFloorMap[$ROCmGfxArch] } else { "torchvision" }
-            $audioSpec = if ($ROCmGfxArch -and $torchaudioFloorMap.ContainsKey($ROCmGfxArch)) { $torchaudioFloorMap[$ROCmGfxArch] } else { "torchaudio" }
+            $visionSpec = if ($PinnedRocmVisionSpec) { $PinnedRocmVisionSpec } elseif ($ROCmGfxArch -and $torchvisionFloorMap -and $torchvisionFloorMap.ContainsKey($ROCmGfxArch)) { $torchvisionFloorMap[$ROCmGfxArch] } else { "torchvision" }
+            $audioSpec = if ($PinnedRocmAudioSpec) { $PinnedRocmAudioSpec } elseif ($ROCmGfxArch -and $torchaudioFloorMap -and $torchaudioFloorMap.ContainsKey($ROCmGfxArch)) { $torchaudioFloorMap[$ROCmGfxArch] } else { "torchaudio" }
             $torchInstallExit = Invoke-InstallCommandRetry -Label "install PyTorch (AMD ROCm)" { uv pip install --python $VenvPython --force-reinstall --default-index $ROCmIndexUrl $torchSpec $visionSpec $audioSpec }
             if ($torchInstallExit -ne 0) {
-                # Transient AMD-index failure: fall back to a CPU base so the install
-                # still completes; Studio setup retries ROCm afterwards.
-                substep "ROCm PyTorch install failed (exit $torchInstallExit); using a CPU base, Studio setup retries ROCm." "Yellow"
+                # Transient AMD-index failure: fall back to a CPU base (Unsloth setup retries
+                # ROCm). Use an explicit CPU index -- for a pinned ROCm index $TorchIndexUrl IS
+                # the ROCm mirror, so reusing it would just retry it.
+                $CpuFallbackIndexUrl = if ($env:UNSLOTH_PYTORCH_MIRROR) { "$($env:UNSLOTH_PYTORCH_MIRROR.TrimEnd('/'))/cpu" } else { "https://download.pytorch.org/whl/cpu" }
+                substep "ROCm PyTorch install failed (exit $torchInstallExit); using a CPU base, Unsloth setup retries ROCm." "Yellow"
                 # --force-reinstall: a failed ROCm install can leave an unpinned ROCm
                 # torch (e.g. 2.10.0+rocm on gfx110X/gfx90a) that still satisfies the CPU
                 # torch>= range, so without it uv would keep the ROCm build and only swap
                 # the companions -- a mismatched venv the flavor-repair block won't fix.
-                $torchInstallExit = Invoke-InstallCommandRetry -Label "install PyTorch (CPU fallback)" { uv pip install --python $VenvPython --force-reinstall "torch>=2.4,<2.11.0" torchvision torchaudio --default-index $TorchIndexUrl }
+                $torchInstallExit = Invoke-InstallCommandRetry -Label "install PyTorch (CPU fallback)" { uv pip install --python $VenvPython --force-reinstall "torch>=2.4,<2.11.0" "torchvision>=0.19,<0.26.0" "torchaudio>=2.4,<2.11.0" --default-index $CpuFallbackIndexUrl }
                 if ($torchInstallExit -ne 0) {
                     Write-Host "[ERROR] Failed to install PyTorch (ROCm and CPU base both failed, exit code $torchInstallExit)" -ForegroundColor Red
                     return (Exit-InstallFailure "Failed to install PyTorch (exit code $torchInstallExit)" $torchInstallExit)
@@ -2238,8 +2416,14 @@ exit 0
             }
         } else {
             Write-TauriLog "STEP" "Installing PyTorch"
-            substep "installing PyTorch ($TorchIndexUrl)..."
-            $torchInstallExit = Invoke-InstallCommandRetry -Label "install PyTorch" { uv pip install --python $VenvPython "torch>=2.4,<2.11.0" torchvision torchaudio --default-index $TorchIndexUrl }
+            substep "installing PyTorch ($(Remove-IndexUrlCredentials $TorchIndexUrl))..."
+            # Bound the companions to the capped torch on EVERY index, cu<digits>
+            # families included: torchaudio 2.11 dropped its exact torch pin from
+            # the wheel metadata, so a bare companion next to torch<2.11 can
+            # resolve a mismatched 2.11.0 build. Mirrors install.sh.
+            $_pinVisionSpec = "torchvision>=0.19,<0.26.0"
+            $_pinAudioSpec = "torchaudio>=2.4,<2.11.0"
+            $torchInstallExit = Invoke-InstallCommandRetry -Label "install PyTorch" { uv pip install --python $VenvPython "torch>=2.4,<2.11.0" $_pinVisionSpec $_pinAudioSpec --default-index $TorchIndexUrl }
             if ($torchInstallExit -ne 0) {
                 Write-Host "[ERROR] Failed to install PyTorch (exit code $torchInstallExit)" -ForegroundColor Red
                 return (Exit-InstallFailure "Failed to install PyTorch (exit code $torchInstallExit)" $torchInstallExit)
@@ -2251,7 +2435,7 @@ exit 0
         if ($SkipTorch) {
             # No-torch: install unsloth + unsloth-zoo with --no-deps, then
             # runtime deps (typer, safetensors, transformers, etc.) with --no-deps.
-            $baseInstallExit = Invoke-InstallCommandRetry -Label "install unsloth (no-torch)" { uv pip install --python $VenvPython --no-deps --upgrade-package unsloth --upgrade-package unsloth-zoo "unsloth>=2026.7.3" "unsloth-zoo>=2026.7.3" }
+            $baseInstallExit = Invoke-InstallCommandRetry -Label "install unsloth (no-torch)" { uv pip install --python $VenvPython --no-deps --upgrade-package unsloth --upgrade-package unsloth-zoo "unsloth>=2026.7.5" "unsloth-zoo>=2026.7.6" }
             if ($baseInstallExit -eq 0) {
                 # Same pydantic-with-deps trick as the migrated branch.
                 $baseInstallExit = Invoke-InstallCommandRetry -Label "install pydantic" { uv pip install --python $VenvPython pydantic }
@@ -2263,7 +2447,7 @@ exit 0
                 }
             }
         } elseif ($StudioLocalInstall) {
-            $baseInstallExit = Invoke-InstallCommandRetry -Label "install unsloth (local)" { uv pip install --python $VenvPython --upgrade-package unsloth "unsloth>=2026.7.3" "unsloth-zoo>=2026.7.3" }
+            $baseInstallExit = Invoke-InstallCommandRetry -Label "install unsloth (local)" { uv pip install --python $VenvPython --upgrade-package unsloth "unsloth>=2026.7.5" "unsloth-zoo>=2026.7.6" }
         } else {
             $baseInstallExit = Invoke-InstallCommandRetry -Label "install unsloth" { uv pip install --python $VenvPython --upgrade-package unsloth -- "$PackageName" }
         }
@@ -2291,7 +2475,7 @@ exit 0
         Write-TauriLog "STEP" "Installing unsloth"
         substep "installing unsloth (this may take a few minutes)..."
         if ($StudioLocalInstall) {
-            $baseInstallExit = Invoke-InstallCommandRetry -Label "install unsloth (auto torch backend)" { uv pip install --python $VenvPython "unsloth-zoo>=2026.7.3" "unsloth>=2026.7.3" --torch-backend=auto }
+            $baseInstallExit = Invoke-InstallCommandRetry -Label "install unsloth (auto torch backend)" { uv pip install --python $VenvPython "unsloth-zoo>=2026.7.6" "unsloth>=2026.7.5" --torch-backend=auto }
             if ($baseInstallExit -ne 0) {
                 Write-Host "[ERROR] Failed to install unsloth (exit code $baseInstallExit)" -ForegroundColor Red
                 return (Exit-InstallFailure "Failed to install unsloth (exit code $baseInstallExit)" $baseInstallExit)
@@ -2317,6 +2501,13 @@ exit 0
         }
     }
 
+    $installedPackageVersion = (& $VenvPython -c "from importlib.metadata import version; import sys; print(version(sys.argv[1]))" $PackageName 2>$null | Out-String).Trim()
+    if ($LASTEXITCODE -eq 0 -and $installedPackageVersion) {
+        step $PackageName "$installedPackageVersion installed"
+    } else {
+        substep "[WARN] installed $PackageName version could not be determined" "Yellow"
+    }
+
     # ── Enforce the installed torch flavor matches the detected GPU build ──
     # PEP 440 ignores the +cpu/+cuXXX/+rocm local label in a version range, so uv
     # keeps a stale torch==X+cpu against a CUDA index and setup.ps1 then loops on
@@ -2335,8 +2526,8 @@ exit 0
                     $rocmSpec = if ($ROCmTorchFloor) { $ROCmTorchFloor } else { "torch" }
                     # Pin companions like the fresh ROCm path (bare names can pull an
                     # ABI-incompatible torchvision/torchaudio from the per-arch index).
-                    $visionSpec = if ($ROCmGfxArch -and $torchvisionFloorMap.ContainsKey($ROCmGfxArch)) { $torchvisionFloorMap[$ROCmGfxArch] } else { "torchvision" }
-                    $audioSpec = if ($ROCmGfxArch -and $torchaudioFloorMap.ContainsKey($ROCmGfxArch)) { $torchaudioFloorMap[$ROCmGfxArch] } else { "torchaudio" }
+                    $visionSpec = if ($PinnedRocmVisionSpec) { $PinnedRocmVisionSpec } elseif ($ROCmGfxArch -and $torchvisionFloorMap -and $torchvisionFloorMap.ContainsKey($ROCmGfxArch)) { $torchvisionFloorMap[$ROCmGfxArch] } else { "torchvision" }
+                    $audioSpec = if ($PinnedRocmAudioSpec) { $PinnedRocmAudioSpec } elseif ($ROCmGfxArch -and $torchaudioFloorMap -and $torchaudioFloorMap.ContainsKey($ROCmGfxArch)) { $torchaudioFloorMap[$ROCmGfxArch] } else { "torchaudio" }
                     substep "PyTorch flavor mismatch (installed $installedTorchTag, need ROCm) -- reinstalling correct build..." "Yellow"
                     $torchFixExit = Invoke-InstallCommand { uv pip install --python $VenvPython --force-reinstall --default-index $ROCmIndexUrl $rocmSpec $visionSpec $audioSpec }
                     if ($torchFixExit -ne 0) {
@@ -2347,7 +2538,7 @@ exit 0
                 } elseif ($expectedTorchTag -ne 'rocm') {
                     # CUDA: stale +cpu (or wrong cuXXX) against a CUDA index -> reinstall triplet.
                     substep "PyTorch flavor mismatch (installed $installedTorchTag, need $expectedTorchTag) -- reinstalling correct build..." "Yellow"
-                    $torchFixExit = Invoke-InstallCommand { uv pip install --python $VenvPython "torch>=2.4,<2.11.0" torchvision torchaudio --default-index $TorchIndexUrl --reinstall-package torch --reinstall-package torchvision --reinstall-package torchaudio }
+                    $torchFixExit = Invoke-InstallCommand { uv pip install --python $VenvPython "torch>=2.4,<2.11.0" "torchvision>=0.19,<0.26.0" "torchaudio>=2.4,<2.11.0" --default-index $TorchIndexUrl --reinstall-package torch --reinstall-package torchvision --reinstall-package torchaudio }
                     if ($torchFixExit -ne 0) {
                         Write-Host "[ERROR] Failed to reinstall PyTorch with the correct CUDA build (exit code $torchFixExit)" -ForegroundColor Red
                         return (Exit-InstallFailure "Failed to reinstall PyTorch ($expectedTorchTag) (exit code $torchFixExit)" $torchFixExit)
@@ -2422,7 +2613,7 @@ exit 0
         Write-TauriLog "ERROR" "unsloth CLI was not installed correctly"
         Write-Host "[ERROR] unsloth CLI was not installed correctly." -ForegroundColor Red
         Write-Host "        Expected: $UnslothExe" -ForegroundColor Yellow
-        Write-Host "        This usually means an older unsloth version was installed that does not include the Studio CLI." -ForegroundColor Yellow
+        Write-Host "        This usually means an older unsloth version was installed that does not include the Unsloth CLI." -ForegroundColor Yellow
         Write-Host "        Try re-running the installer or see: https://github.com/unslothai/unsloth?tab=readme-ov-file#-quickstart" -ForegroundColor Yellow
         return (Exit-InstallFailure "unsloth CLI was not installed correctly")
     }
@@ -2533,7 +2724,7 @@ exit 0
         Write-Host "        Move or remove it manually, then re-run the installer." -ForegroundColor Yellow
         throw "Cannot create unsloth launcher: $ShimExe is a directory."
     }
-    # try/catch: if unsloth.exe is locked (Studio running), keep the old shim.
+    # try/catch: if unsloth.exe is locked (Unsloth running), keep the old shim.
     $shimUpdated = $false
     try {
         if (Test-Path -LiteralPath $ShimExe) { Remove-Item -LiteralPath $ShimExe -Force -ErrorAction Stop }
@@ -2551,7 +2742,7 @@ exit 0
         if (Test-Path -LiteralPath $ShimExe) {
             Write-Host "[WARN] Could not refresh unsloth launcher at $ShimExe." -ForegroundColor Yellow
             Write-Host "       This usually means a running 'unsloth studio' process still holds the file open." -ForegroundColor Yellow
-            Write-Host "       Close Studio and re-run the installer to pick up the latest launcher." -ForegroundColor Yellow
+            Write-Host "       Close Unsloth and re-run the installer to pick up the latest launcher." -ForegroundColor Yellow
             Write-Host "       Continuing with the existing launcher." -ForegroundColor Yellow
         } else {
             Write-Host "[WARN] Could not create unsloth launcher at $ShimExe" -ForegroundColor Yellow
@@ -2572,6 +2763,13 @@ exit 0
     }
     Refresh-SessionPath  # sync current session with registry
     Complete-StudioVenvRollback
+    $studioVenvReplacementCommitted = $true
+    Remove-StaleStudioVenvRollbacks
+    } finally {
+        if (-not $studioVenvReplacementCommitted) {
+            Restore-StudioVenvRollback
+        }
+    }
 
     # Env-mode session export AFTER Refresh-SessionPath; otherwise a legacy
     # User PATH entry (Machine > User > current $env:Path) would win.
@@ -2616,7 +2814,7 @@ exit 0
         # Diagnostic only; never block install on a probe failure.
     }
 
-    # In interactive terminals, ask the user before starting Studio unless the
+    # In interactive terminals, ask the user before starting Unsloth unless the
     # caller explicitly disabled the post-install prompt.
     # In non-interactive environments (CI, Docker) just print instructions.
     $IsInteractive = (-not $SkipAutostart) -and [Environment]::UserInteractive -and (-not [Console]::IsInputRedirected)
diff --git a/install.sh b/install.sh
index 4a3c4471fa..dface28918 100755
--- a/install.sh
+++ b/install.sh
@@ -97,7 +97,7 @@ if [ "$_VERBOSE" = true ]; then
     export UNSLOTH_VERBOSE=1
 fi
 
-# Custom Studio roots are not supported with --tauri (desktop app still
+# Custom Unsloth roots are not supported with --tauri (desktop app still
 # resolves ~/.unsloth/studio). Pass through if the override == legacy default.
 if [ "$TAURI_MODE" = true ]; then
     _tauri_override_var=""
@@ -159,18 +159,58 @@ run_maybe_quiet() {
     fi
 }
 
+# Trim trailing slashes from the URL PATH only, preserving ?query / #fragment: a whole-URL
+# strip corrupts a token ending in "/", a single strip leaves .../cu128// empty. Shared.
+_trim_index_path_slashes() {
+    _tips_v="$1"
+    case "$_tips_v" in
+        *[?#]*)
+            _tips_head="${_tips_v%%[?#]*}"
+            _tips_tail="${_tips_v#"$_tips_head"}"
+            ;;
+        *)
+            _tips_head="$_tips_v"
+            _tips_tail=""
+            ;;
+    esac
+    while [ -n "$_tips_head" ] && [ "${_tips_head%/}" != "$_tips_head" ]; do
+        _tips_head="${_tips_head%/}"
+    done
+    printf '%s%s' "$_tips_head" "$_tips_tail"
+}
+
+# Redact index-URL credentials (userinfo + ?query= + #fragment) from captured installer
+# output before printing on failure; uv/pip errors echo the failing --index-url verbatim.
+# Mirrors the other installers. Verbose mode streams uncaptured, so it isn't redacted.
+_redact_install_output() {
+    sed -E \
+        -e 's#(https?://)[^/@[:space:]`]+@#\1<redacted>@#g' \
+        -e 's#([?&][^=[:space:]&`]+)=[^&#[:space:]`]+#\1=<redacted>#g' \
+        -e 's|(https?://[^[:space:]`#]+)#[^[:space:]`]+|\1#<redacted>|g' \
+        "$@"
+}
+
 run_install_cmd() {
     _label="$1"
     shift
-    # Installer-pinned index installs (torch) must beat an inherited uv mirror
-    # (#6898): when we pass --default-index, neutralize every uv index env var so
-    # the pinned index wins. Other installs keep the user's mirror.
+    # Installer-pinned index installs (torch) must beat an inherited uv mirror (#6898):
+    # for --default-index, neutralize the uv index/backend/config vars (UV_TORCH_BACKEND
+    # redirects torch; UV_NO_CONFIG=1 + dropping UV_CONFIG_FILE stops a uv.toml/pyproject
+    # index outranking the CLI pin, uv 0.10).
     case " $* " in
-        *" --default-index "*) set -- env -u UV_DEFAULT_INDEX -u UV_INDEX_URL -u UV_INDEX -u UV_EXTRA_INDEX_URL "$@" ;;
+        *" --default-index "*) set -- env -u UV_DEFAULT_INDEX -u UV_INDEX_URL -u UV_INDEX -u UV_EXTRA_INDEX_URL -u UV_TORCH_BACKEND -u UV_FIND_LINKS -u UV_CONFIG_FILE UV_NO_CONFIG=1 "$@" ;;
     esac
     if _is_verbose; then
-        "$@" && return 0
-        _rc=$?
+        # Stream through the redactor: uv echoes index URLs (credentials and
+        # all) in its errors, and verbose mode previously bypassed the
+        # redaction the quiet path applies. The rc file preserves the
+        # command's exit code across the pipe without relying on pipefail
+        # (this script runs under plain sh).
+        _rcf=$(mktemp)
+        { "$@" 2>&1; printf '%s' "$?" > "$_rcf"; } | _redact_install_output
+        _rc=$(cat "$_rcf" 2>/dev/null || echo 1)
+        rm -f "$_rcf"
+        [ "${_rc:-1}" -eq 0 ] 2>/dev/null && return 0
         step "error" "$_label failed (exit code $_rc)" "$C_ERR" >&2
         return "$_rc"
     fi
@@ -178,7 +218,7 @@ run_install_cmd() {
     "$@" >"$_log" 2>&1 && { rm -f "$_log"; return 0; }
     _rc=$?
     step "error" "$_label failed (exit code $_rc)" "$C_ERR" >&2
-    cat "$_log" >&2
+    _redact_install_output "$_log" >&2
     rm -f "$_log"
     return $_rc
 }
@@ -257,7 +297,7 @@ _install_bnb_rocm() {
         fi
         _bnb_rc=$?
         if _is_verbose; then
-            cat "$_bnb_log" >&2
+            _redact_install_output "$_bnb_log" >&2
         fi
         rm -f "$_bnb_log"
         step "warning" "$_label (pre-release) failed (exit code $_bnb_rc)" "$C_WARN" >&2
@@ -310,6 +350,11 @@ _tauri_torch_index_family() {
         return
     fi
     _diag_url="${1:-}"
+    # Strip query/fragment AND a trailing slash before classifying (like _torch_index_url_leaf):
+    # a token isn't echoed into [TAURI:DIAG], and .../cu128/?token=x still classifies as cu128.
+    _diag_url="${_diag_url%%\?*}"
+    _diag_url="${_diag_url%%#*}"
+    _diag_url="${_diag_url%/}"
     case "$_diag_url" in
         */cu118) echo "cu118" ;;
         */cu124) echo "cu124" ;;
@@ -343,7 +388,8 @@ _tauri_gpu_branch() {
         return
     fi
     case "$_diag_family" in
-        cu*) echo "cuda" ;;
+        # Require a digit after cu so /current or /custom isn't branded CUDA (parity ^cu[0-9]).
+        cu[0-9]*) echo "cuda" ;;
         rocm*)
             if [ "$_diag_radeon" = true ]; then
                 echo "rocm_radeon"
@@ -429,14 +475,20 @@ _start_studio_venv_replacement() {
     _stamp=$(date +%Y%m%d%H%M%S 2>/dev/null || echo "time")
     _candidate="$STUDIO_HOME/unsloth_studio.rollback.$_stamp.$$"
     _suffix=0
-    while [ -e "$_candidate" ]; do
+    while [ -e "$_candidate" ] || [ -L "$_candidate" ]; do
         _suffix=$((_suffix + 1))
         _candidate="$STUDIO_HOME/unsloth_studio.rollback.$_stamp.$$.$_suffix"
     done
-    mv "$_existing_dir" "$_candidate"
     _VENV_ROLLBACK_DIR="$_candidate"
     _VENV_ROLLBACK_TARGET="$_existing_dir"
     _VENV_ROLLBACK_ACTIVE=true
+    # Publish the rollback state before the atomic rename so a signal cannot
+    # land after mv but before the exit handlers know where the old venv went.
+    if ! mv "$_existing_dir" "$_candidate"; then
+        _VENV_ROLLBACK_ACTIVE=false
+        _VENV_ROLLBACK_DIR=""
+        return 1
+    fi
     substep "previous environment preserved for rollback"
 }
 
@@ -457,13 +509,68 @@ _restore_studio_venv_replacement() {
     fi
 }
 
-_commit_studio_venv_replacement() {
-    [ "$_VENV_ROLLBACK_ACTIVE" = true ] || return 0
-    if [ -n "$_VENV_ROLLBACK_DIR" ] && [ -d "$_VENV_ROLLBACK_DIR" ]; then
-        rm -rf "$_VENV_ROLLBACK_DIR" || true
+_studio_venv_rollback_must_be_preserved() {
+    _rollback_name=${1##*/}
+    _rollback_metadata=${_rollback_name#unsloth_studio.rollback.}
+    _rollback_stamp=${_rollback_metadata%%.*}
+    _rollback_process=${_rollback_metadata#*.}
+    # Preserve anything outside the installer's timestamp.PID[.suffix] format.
+    [ "$_rollback_process" != "$_rollback_metadata" ] || return 0
+    case "$_rollback_stamp" in
+        time) ;;
+        ''|*[!0-9]*) return 0 ;;
+        *) [ "${#_rollback_stamp}" -eq 14 ] || return 0 ;;
+    esac
+    _rollback_pid=${_rollback_process%%.*}
+    case "$_rollback_pid" in
+        ''|*[!0-9]*) return 0 ;;
+    esac
+    _rollback_suffix=${_rollback_process#*.}
+    if [ "$_rollback_suffix" != "$_rollback_process" ]; then
+        case "$_rollback_suffix" in ''|*[!0-9]*) return 0 ;; esac
     fi
-    _VENV_ROLLBACK_ACTIVE=false
-    _VENV_ROLLBACK_DIR=""
+    kill -0 "$_rollback_pid" 2>/dev/null
+}
+
+_prune_stale_studio_venv_rollbacks() {
+    for _stale_rollback in "$STUDIO_HOME"/unsloth_studio.rollback.*; do
+        [ -d "$_stale_rollback" ] || continue
+        if [ -L "$_stale_rollback" ]; then
+            echo "⚠️  Refusing to remove rollback symlink $_stale_rollback" >&2
+            continue
+        fi
+        # A concurrent installer may have moved its live venv aside. The PID in
+        # the generated name keeps this successful run from deleting its rescue copy.
+        _studio_venv_rollback_must_be_preserved "$_stale_rollback" && continue
+        if rm -rf "$_stale_rollback"; then
+            substep "removed stale environment rollback ${_stale_rollback##*/}"
+        else
+            echo "⚠️  Could not remove stale environment rollback $_stale_rollback" >&2
+        fi
+    done
+}
+
+_commit_studio_venv_replacement() {
+    if [ "$_VENV_ROLLBACK_ACTIVE" = true ]; then
+        _rollback_to_remove="$_VENV_ROLLBACK_DIR"
+        # The new environment is already committed. Clear the restore state
+        # before deletion so an interrupt cannot replace it with a half-deleted backup.
+        _VENV_ROLLBACK_ACTIVE=false
+        _VENV_ROLLBACK_DIR=""
+        if [ -n "$_rollback_to_remove" ] && [ -d "$_rollback_to_remove" ]; then
+            if ! rm -rf "$_rollback_to_remove"; then
+                echo "⚠️  Could not remove environment rollback $_rollback_to_remove" >&2
+            fi
+        fi
+    fi
+    # Only prune older orphaned copies after the replacement has succeeded, so
+    # an interrupted install never discards the last known-good environment.
+    _prune_stale_studio_venv_rollbacks
+}
+
+_cleanup_install_temporaries() {
+    [ -n "${_UV_OVERRIDE_TMPDIR:-}" ] && rm -rf "$_UV_OVERRIDE_TMPDIR" 2>/dev/null || true
+    [ -n "${_UNSLOTH_TORCH_OVERRIDES:-}" ] && rm -f "$_UNSLOTH_TORCH_OVERRIDES" 2>/dev/null || true
 }
 
 _on_install_exit() {
@@ -471,13 +578,28 @@ _on_install_exit() {
     if [ "$_status" -ne 0 ]; then
         _restore_studio_venv_replacement
     fi
-    [ -n "${_UV_OVERRIDE_TMPDIR:-}" ] && rm -rf "$_UV_OVERRIDE_TMPDIR" 2>/dev/null || true
+    _cleanup_install_temporaries
     exit "$_status"
 }
-# Empty so an inherited value can never reach the trap's rm; only a temp dir
-# this script creates below (Apple Silicon, spaced path) is ever removed.
+
+_on_install_signal() {
+    _signal_status="$1"
+    # EXIT is disabled to avoid a second cleanup pass. Ignore further termination
+    # signals until the old environment is back in place.
+    trap - EXIT
+    trap '' HUP INT TERM
+    _restore_studio_venv_replacement
+    _cleanup_install_temporaries
+    exit "$_signal_status"
+}
+# Empty so an inherited value never reaches the trap's rm; only temp paths this
+# script creates below (spaced-path dir, torch-trio overrides) are removed.
 _UV_OVERRIDE_TMPDIR=""
+_UNSLOTH_TORCH_OVERRIDES=""
 trap _on_install_exit EXIT
+trap '_on_install_signal 129' HUP
+trap '_on_install_signal 130' INT
+trap '_on_install_signal 143' TERM
 
 # ── Helper: download a URL to a file (supports curl and wget) ──
 download() {
@@ -503,6 +625,36 @@ _is_pkg_installed() {
     esac
 }
 
+# ── Helper: human-readable apt distro label for the sudo package prompt (#6207) ──
+# Reads /etc/os-release so the Accept? prompt can say which distro we detected and
+# that packages come from that distro's official apt repos (not a tarball).
+_apt_distro_description() {
+    # Plain ( ... ) subshell — not $() — so case/;; stays bash-3.2-safe on macOS.
+    # Bash 3.2 misparses case arms inside command substitution and errors on `;;`.
+    (
+        if [ ! -r /etc/os-release ]; then
+            printf 'a debian-like system'
+            exit 0
+        fi
+        # shellcheck disable=SC1091
+        . /etc/os-release 2>/dev/null || true
+        if [ -n "${NAME:-}" ] && [ -n "${VERSION_ID:-}" ]; then
+            _ad_label="$NAME $VERSION_ID"
+        elif [ -n "${PRETTY_NAME:-}" ]; then
+            _ad_label="$PRETTY_NAME"
+        elif [ -n "${NAME:-}" ]; then
+            _ad_label="$NAME"
+        else
+            printf 'a debian-like system'
+            exit 0
+        fi
+        case " ${ID:-} ${ID_LIKE:-} " in
+            *" debian "*|*" ubuntu "*) _ad_label="${_ad_label} (debian-like)" ;;
+        esac
+        printf '%s' "$_ad_label"
+    )
+}
+
 # ── Helper: install packages via apt, escalating to sudo only if needed ──
 # Usage: _smart_apt_install pkg1 pkg2 pkg3 ...
 _smart_apt_install() {
@@ -533,11 +685,14 @@ _smart_apt_install() {
 
     # Step 3: Escalate -- need elevated permissions for remaining packages
     if command -v sudo >/dev/null 2>&1; then
+        _ad_desc="$(_apt_distro_description)"
         echo ""
         echo "    !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
         echo "    WARNING: We require sudo elevated permissions to install:"
         echo "    $_STILL_MISSING"
-        echo "    If you accept, we'll run sudo now, and it'll prompt your password."
+        echo "    Detected ${_ad_desc}."
+        echo "    If you accept, we'll run sudo apt-get to install these packages"
+        echo "    from your distro's official repositories (not a third-party tarball)."
         echo "    !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
         echo ""
         printf "    Accept? [Y/n] "
@@ -663,7 +818,7 @@ POLL_INTERVAL_SEC=0.25
 LOG_FILE="$DATA_DIR/studio.log"
 # why: in env-override mode multiple installs share an OS user; namespace the
 # lock and remember our own healthy port so we never attach to an unrelated
-# Studio listening on the global 8888..8908 range.
+# Unsloth listening on the global 8888..8908 range.
 LOCK_DIR="${XDG_RUNTIME_DIR:-/tmp}/unsloth-studio-launcher-$(id -u).lock"
 PORT_FILE=""
 # why: gate on the install-time mode (baked above) instead of the runtime env
@@ -734,7 +889,7 @@ _candidate_ports() {
 _find_healthy_port() {
     if [ -n "$PORT_FILE" ] && [ -f "$PORT_FILE" ]; then
         # why: env-mode installs only attach to a port we previously launched
-        # ourselves; never to a sibling Studio that happens to be healthy.
+        # ourselves; never to a sibling Unsloth that happens to be healthy.
         _p=$(cat "$PORT_FILE" 2>/dev/null || true)
         case "$_p" in
             ''|*[!0-9]*) ;;
@@ -901,7 +1056,7 @@ _acquire_lock() {
     # Lock dir exists -- check if owner is still alive
     _old_pid=$(cat "$LOCK_DIR/pid" 2>/dev/null || true)
     if [ -n "$_old_pid" ] && kill -0 "$_old_pid" 2>/dev/null; then
-        # Another launcher is running; wait for it to bring Studio up
+        # Another launcher is running; wait for it to bring Unsloth up
         _deadline=$(($(date +%s) + TIMEOUT_SEC))
         while [ "$(date +%s)" -lt "$_deadline" ]; do
             _port=$(_find_healthy_port) && {
@@ -1371,7 +1526,7 @@ WSLPS1_EOF
         # shortcut wasn't created; tell the user how to launch / re-enable it.
         if [ "$_css_created" -ne 1 ]; then
             substep "Couldn't create the Windows shortcut (WSL interop may be disabled)." "$C_WARN"
-            substep "  Launch Studio from Windows:  wsl -d \"$_css_distro\" -- bash -lc 'unsloth studio'" "$C_WARN"
+            substep "  Launch Unsloth from Windows:  wsl -d \"$_css_distro\" -- bash -lc 'unsloth studio'" "$C_WARN"
             substep "  (re-enable shortcuts: turn WSL interop back on, e.g. run 'wsl --shutdown' then reopen WSL.)" "$C_WARN"
         fi
     fi
@@ -1439,7 +1594,7 @@ if [ "$MAC_INTEL" = true ]; then
     echo ""
     echo "  NOTE: Intel Mac (x86_64) detected."
     echo "  PyTorch is unavailable for this platform (dropped Jan 2024)."
-    echo "  Studio will install in GGUF-only mode."
+    echo "  Unsloth will install in GGUF-only mode."
     echo "  Chat, inference via GGUF, and data recipes will work."
     echo "  Training requires Apple Silicon or Linux with GPU."
     echo ""
@@ -1573,6 +1728,12 @@ _has_usable_nvidia_gpu() {
 # the STUDIO_HOME mkdir/venv so the origin distro is untouched.
 _maybe_reroute_strixhalo_to_2404() {
     [ "${OS:-}" = "wsl" ] || return 0
+    # An explicit index pin skips every GPU-driven reroute (same contract as
+    # the later Radeon/Strix guard): the pin is honored in THIS distro rather
+    # than probing the GPU and switching distributions. Whitespace-only
+    # overrides do not gate (parity with get_torch_index_url).
+    _rr_pin=$(printf '%s' "${UNSLOTH_TORCH_INDEX_URL:-}${UNSLOTH_TORCH_INDEX_FAMILY:-}" | tr -d '[:space:]')
+    [ -n "$_rr_pin" ] && return 0
     [ "${SKIP_TORCH:-false}" = "false" ] || return 0
     [ "${UNSLOTH_SKIP_ROCM_WSL_SETUP:-0}" = "1" ] && return 0
     [ "${UNSLOTH_WSL_REROUTED:-0}" = "1" ] && return 0
@@ -1582,7 +1743,7 @@ _maybe_reroute_strixhalo_to_2404() {
     # CUDA_VISIBLE_DEVICES=""/-1 and the /proc/driver/nvidia fallback for PATH/timeout gaps.
     if _has_usable_nvidia_gpu; then return 0; fi
     # Strix APUs show in /proc/cpuinfo; discrete cards don't, so also try WMI. Either reroutes.
-    if ! grep -qiE 'Ryzen AI Max|Radeon 80[0-9]0S|Strix Halo' /proc/cpuinfo 2>/dev/null \
+    if ! grep -qiE 'Ryzen AI Max|Radeon 80[0-9][05]S|Strix Halo' /proc/cpuinfo 2>/dev/null \
        && ! _wsl_amd_gpu_name >/dev/null 2>&1; then
         return 0
     fi
@@ -1634,6 +1795,10 @@ _maybe_reroute_strixhalo_to_2404() {
     # Forward explicit ROCm-bootstrap consent (e.g. Tauri) so the child auto-enables the
     # GPU instead of falling back to the desktop-app prompt path.
     [ "${UNSLOTH_ROCM_WSL_AUTO:-0}" = "1" ] && _rr_exports="$_rr_exports; export UNSLOTH_ROCM_WSL_AUTO=1"
+    # Forward a pinned torch index into the rerouted distro; dropping it would
+    # silently revert the child install to auto-detection.
+    [ -n "${UNSLOTH_TORCH_INDEX_URL:-}" ] && _rr_exports="$_rr_exports; export UNSLOTH_TORCH_INDEX_URL=$(_rr_q "$UNSLOTH_TORCH_INDEX_URL")"
+    [ -n "${UNSLOTH_TORCH_INDEX_FAMILY:-}" ] && _rr_exports="$_rr_exports; export UNSLOTH_TORCH_INDEX_FAMILY=$(_rr_q "$UNSLOTH_TORCH_INDEX_FAMILY")"
     [ "$_SKIP_AUTOSTART" = true ] && _rr_exports="$_rr_exports; export UNSLOTH_SKIP_AUTOSTART=1"
     _rr_args=""
     [ "$PACKAGE_NAME" != "unsloth" ] && _rr_args="$_rr_args --package $(_rr_q "$PACKAGE_NAME")"
@@ -1671,7 +1836,7 @@ _maybe_reroute_strixhalo_to_2404() {
 _maybe_reroute_strixhalo_to_2404 || true
 
 # ── Check system dependencies ──
-# cmake/git are only needed to *build* llama.cpp from source. Studio downloads a
+# cmake/git are only needed to *build* llama.cpp from source. Unsloth downloads a
 # prebuilt by default, and setup.sh self-skips the source build when they're
 # absent -- so macOS doesn't block on cmake (requiring it would force a manual
 # Homebrew install). Linux keeps requiring them; its package manager has them.
@@ -1821,11 +1986,13 @@ tauri_log "STEP" "Creating virtual environment"
 mkdir -p "$STUDIO_HOME"
 
 _MIGRATED=false
+# Empty so an inherited value can never masquerade as a probed torch version.
+_PREV_TORCH_VER=""
 
 if [ -x "$VENV_DIR/bin/python" ]; then
     # why: matching guard to the .venv branch below -- in env-mode
     # $STUDIO_HOME is a user-chosen workspace, so refuse to nuke an
-    # existing $STUDIO_HOME/unsloth_studio that lacks Studio sentinels.
+    # existing $STUDIO_HOME/unsloth_studio that lacks Unsloth sentinels.
     # Accept the in-VENV ownership marker so partial-install retries are
     # not blocked. Sentinels must be regular files: -f follows symlinks
     # to files (the legitimate ln -s shim shape) but rejects directories
@@ -1838,6 +2005,12 @@ if [ -x "$VENV_DIR/bin/python" ]; then
         echo "       Move it aside or choose an empty UNSLOTH_STUDIO_HOME." >&2
         exit 1
     fi
+    # Record the existing venv's torch BEFORE the replacement moves it aside: a re-run
+    # rebuilds the venv for clean state, but must keep the torch release the user
+    # already has (see _previous_torch_pin below). Last line only: sitecustomize or
+    # import-hook noise on stdout must not corrupt the version.
+    _PREV_TORCH_VER=$("$VENV_DIR/bin/python" -c \
+        "import torch; print(torch.__version__)" 2>/dev/null | tail -n 1 || true)
     # New layout already exists — replace only after preserving rollback copy.
     substep "preserving existing environment for rollback..."
     _start_studio_venv_replacement "$VENV_DIR"
@@ -1846,7 +2019,7 @@ elif [ "$_STUDIO_HOME_REDIRECT" != "env" ] && [ -x "$STUDIO_HOME/.venv/bin/pytho
     # Skip in env-mode so we don't rm -rf an unrelated .venv at the
     # workspace root (e.g. user's existing project Python venv).
     # In no-torch mode, a missing torch package is expected; validate Python only.
-    substep "found legacy Studio environment, validating..."
+    substep "found legacy Unsloth environment, validating..."
     _legacy_ok=false
     if [ "$SKIP_TORCH" = true ]; then
         if "$STUDIO_HOME/.venv/bin/python" -c "import sys; print(sys.executable)" >/dev/null 2>&1; then
@@ -1903,7 +2076,7 @@ if [ ! -x "$VENV_DIR/bin/python" ]; then
     fi
 fi
 
-# Mark the freshly-created venv as Studio-owned so a partial install can be
+# Mark the freshly-created venv as Unsloth-owned so a partial install can be
 # repaired by re-running install.sh; the env-mode deletion guard above accepts
 # this marker as the primary sentinel.
 if [ -x "$VENV_DIR/bin/python" ]; then
@@ -1991,6 +2164,15 @@ if [ "$SKIP_TORCH" = false ] && [ "$OS" = "macos" ] && [ "$_ARCH" = "arm64" ]; t
         TORCH_CONSTRAINT="torch>=2.6,<2.11.0"
     fi
 fi
+# Companion (torchvision/torchaudio) constraints, bounded to torch's window.
+# torchaudio 2.11 dropped its exact torch pin, so a bare companion next to a
+# <2.11-capped torch resolves torchaudio 2.11 (verified: cpu leaf installed
+# torch 2.10.0+cpu with torchaudio 2.11.0+cpu). torchvision still exact-pins
+# torch and self-corrects, but is bounded for symmetry. Widened alongside the
+# cu* torch window below; the torch-2.11 AMD paths (rocm7.2 / per-gfx / Strix)
+# pin their own trio.
+TORCHVISION_CONSTRAINT="torchvision>=0.19,<0.26.0"
+TORCHAUDIO_CONSTRAINT="torchaudio>=2.4,<2.11.0"
 
 # ── Resolve repo root (for --local installs) ──
 _REPO_ROOT="$(cd "$(dirname "$0" 2>/dev/null || echo ".")" && pwd)"
@@ -2040,18 +2222,148 @@ _has_amd_rocm_gpu() {
          amd-smi list 2>/dev/null | awk '/^GPU[[:space:]]*[:\[][[:space:]]*[0-9]/{ found=1 } END{ exit !found }'; then
         return 0
     elif [ -e /dev/kfd ] && \
-         awk 'FNR==1{ gpu=0; amd=0 } /gpu_id/{ gpu=($2+0>0) } /vendor_id/{ amd=($2==4098) } \
-              gpu && amd { found=1 } END{ exit !found }' \
+         awk '/vendor_id/ && $2 == 4098 { found = 1 } END { exit !found }' \
              /sys/class/kfd/kfd/topology/nodes/*/properties 2>/dev/null; then
-        # vendor_id 4098 = 0x1002 (AMD). NVIDIA open kernel module (driver
-        # 560+) can register KFD topology nodes with non-zero gpu_id but
-        # vendor_id 4318 (0x10DE). Require AMD vendor to avoid misrouting
-        # NVIDIA-only hosts to the ROCm install path.
+        # vendor_id 4098 = 0x1002 (AMD) marks a GPU node: the KFD CPU node
+        # reports vendor_id 0, so any 4098 node is an AMD GPU. NVIDIA's open
+        # kernel module (driver 560+) registers KFD nodes as vendor_id 4318
+        # (0x10DE), so this never false-positives on NVIDIA-only hosts.
+        # The prior check also required a gpu_id line, but gpu_id is a SIBLING
+        # sysfs file, not a line in properties -- it never matched, so the
+        # fallback silently missed every ROCm-less AMD host (issue: fresh
+        # Arch/CachyOS boxes reporting "no GPU detected").
         return 0
     fi
     return 1
 }
 
+# Returns 0 if an AMD display GPU is on the PCI bus even when ROCm can't use it
+# (e.g. a Strix Halo iGPU with no /dev/kfd). Only sharpens the "no GPU detected"
+# hint. vendor 0x1002 = AMD/ATI; class 0x03* = display controller.
+_amd_gpu_present_via_pci() {
+    [ -d /sys/bus/pci/devices ] || return 1
+    for _pci_vendor in /sys/bus/pci/devices/*/vendor; do
+        [ -r "$_pci_vendor" ] || continue
+        read -r _v < "$_pci_vendor" 2>/dev/null || continue
+        [ "$_v" = "0x1002" ] || continue
+        _cls="${_pci_vendor%vendor}class"
+        [ -r "$_cls" ] || continue
+        read -r _c < "$_cls" 2>/dev/null || continue
+        case "$_c" in 0x03*) return 0 ;; esac
+    done
+    return 1
+}
+
+# Map a gfx arch to the AMD pip index family (mirrors install.ps1 $archFamilyMap).
+_amd_arch_index_family_for_gfx() {
+    case "$1" in
+        gfx1201|gfx1200) echo gfx120X-all ;;
+        gfx1151) echo gfx1151 ;;
+        gfx1150) echo gfx1150 ;;
+        gfx1103|gfx1102|gfx1101|gfx1100) echo gfx110X-all ;;
+        gfx1036|gfx1035|gfx1034|gfx1033|gfx1032|gfx1031|gfx1030) echo gfx103X-all ;;
+        gfx90a) echo gfx90a ;;
+        gfx908) echo gfx908 ;;
+        *) return 1 ;;
+    esac
+}
+
+# Map a GPU marketing name to gfx arch (kept in sync with install.ps1 nameArchTable).
+_infer_amd_gfx_arch_from_gpu_name() {
+    case "$1" in
+        *"9070 XT"*|*9080*) echo gfx1201 ;;
+        *9070*|*9060*) echo gfx1200 ;;
+        *"8065S"*|*"8060S"*|*"8050S"*|*"8040S"*|*"Strix Halo"*|*"Ryzen AI Max"*|*"AI Max"*) echo gfx1151 ;;
+        *"890M"*|*"880M"*|*"860M"*|*"840M"*|*"Strix Point"*|*"Krackan"*|*"HX 37"*|*"AI 9 HX"*|*"AI 9 36"*|*"AI 7 35"*|*"AI 5 34"*|*"AI 7 PRO 35"*|*"AI 5 33"*) echo gfx1150 ;;
+        *"RX 7600"*|*"RX 7700S"*|*"RX 7650"*|*"PRO W7600"*|*"PRO W7500"*|*"PRO V710"*) echo gfx1102 ;;
+        *"RX 7900"*|*"RX 7800"*|*"RX 7700"*|*"PRO W7900"*|*"PRO W7800"*|*"PRO W7700"*) echo gfx1100 ;;
+        *"780M"*|*"760M"*|*"740M"*|*"Phoenix"*|*"Hawk Point"*|*"Z1 Extreme"*|*"Z2 Extreme"*) echo gfx1103 ;;
+        *"RX 6900"*|*"RX 6800"*|*"RX 6750"*|*"RX 6700"*|*"PRO W6800"*|*"PRO W6900"*) echo gfx1030 ;;
+        *"RX 6650"*|*"RX 6600"*|*"PRO W6600"*|*"PRO W6650"*) echo gfx1032 ;;
+        *"RX 6500"*|*"RX 6400"*|*"RX 6300"*|*"PRO W6400"*|*"PRO W6500"*) echo gfx1034 ;;
+        *) return 1 ;;
+    esac
+}
+
+# Best-effort gfx inference when ROCm tools can't see the GPU (unslothai#7301).
+# Mirrors install.ps1 arch resolution on Windows ($HasROCm false, $ROCmGfxArch set).
+_infer_linux_amd_gfx_arch() {
+    if [ -n "${UNSLOTH_ROCM_GFX_ARCH:-}" ]; then
+        printf '%s\n' "$(printf '%s' "$UNSLOTH_ROCM_GFX_ARCH" | tr '[:upper:]' '[:lower:]')"
+        return 0
+    fi
+    # On WSL /proc/cpuinfo and lspci still report the host APU, but without the
+    # ROCDXG bridge (librocdxg over /dev/dxg) the AMD wheels can't reach the GPU;
+    # keep the CPU fallback there unless that runtime is present (the explicit
+    # override above still wins). Mirrors install_python_stack.py.
+    _gpu_evidence=""
+    if [ -e /dev/dxg ] || grep -qi microsoft /proc/version 2>/dev/null; then
+        for _d in /opt/rocm/lib /opt/rocm/lib64 /opt/rocm-*/lib /opt/rocm-*/lib64; do
+            { [ -e "$_d/librocdxg.so" ] || [ -e "$_d/librocdxg.so.1" ]; } && _rocdxg=1 && break
+        done
+        [ -n "${_rocdxg:-}" ] || return 1
+        # WSL enumerates no PCI display device; /dev/dxg + librocdxg IS the
+        # GPU evidence there.
+        _gpu_evidence=1
+    elif _amd_gpu_present_via_pci; then
+        _gpu_evidence=1
+    fi
+    # /proc/cpuinfo leaks the HOST CPU model into VMs/containers that received
+    # no AMD GPU, so the CPU-model text alone is not GPU evidence: require an
+    # AMD display device (PCI vendor 0x1002, class 0x03*) before trusting it.
+    # The lspci fallback below needs no gate; an AMD display line IS evidence.
+    if [ -n "$_gpu_evidence" ] && grep -qiE 'Ryzen AI Max|Radeon 80[0-9][05]S|Strix Halo' /proc/cpuinfo 2>/dev/null; then
+        echo gfx1151
+        return 0
+    fi
+    if [ -n "$_gpu_evidence" ] && grep -qiE '890M|880M|860M|840M|Strix Point|Krackan|HX 37[05]|AI 9 HX|AI 9 36[05]|AI 7 35[05]|AI 5 34[05]|AI 7 PRO 35|AI 5 33' /proc/cpuinfo 2>/dev/null; then
+        echo gfx1150
+        return 0
+    fi
+    if command -v lspci >/dev/null 2>&1; then
+        # A non-AMD controller can enumerate first (Intel/ASPEED before an AMD
+        # dGPU), so scan every display-class line and take the first AMD one
+        # that maps. The vendor guard is case-SENSITIVE (a -i "ATI" would match
+        # "CorporATIon" on every Intel/NVIDIA line); whole-line matching also
+        # survives the 0000: PCI domain prefix. Mirrors install_python_stack.py.
+        _amd_disp=$(lspci -nn 2>/dev/null | grep -E 'VGA compatible controller|3D controller|Display controller' | grep -E 'AMD|ATI' || true)
+        while IFS= read -r _ln; do
+            [ -n "$_ln" ] || continue
+            if _gfx=$(_infer_amd_gfx_arch_from_gpu_name "$_ln"); then
+                echo "$_gfx"
+                return 0
+            fi
+        done <<EOF
+$_amd_disp
+EOF
+    fi
+    return 1
+}
+
+# Reads the AMD gfx arch for wheel-index decisions: a user-set
+# UNSLOTH_ROCM_GFX_ARCH is authoritative (lowercased), else rocminfo, then
+# amd-smi. rocminfo/amd-smi honor ROCR/HIP_VISIBLE_DEVICES, so a container mask
+# (e.g. ROCR_VISIBLE_DEVICES=-1) would hide a GPU that the env-independent KFD
+# detection still sees -- the tool probes run with the masks cleared. Prints the
+# gfx token(s) or nothing when unreadable, and always returns 0 (a failing probe
+# as the last command would trip set -e in callers' assignments). Shared by
+# get_torch_index_url's gfx gate and the runtime-less reroute gate so the two
+# can never disagree on what "readable" means.
+_probe_amd_gfx_arch() {
+    _ensure_rocm_probe_env
+    _pg=$(printf '%s' "${UNSLOTH_ROCM_GFX_ARCH:-}" | tr '[:upper:]' '[:lower:]')
+    if [ -z "$_pg" ] && command -v rocminfo >/dev/null 2>&1; then
+        _pg=$( (unset ROCR_VISIBLE_DEVICES HIP_VISIBLE_DEVICES; rocminfo 2>/dev/null) | grep -oE 'gfx[1-9][0-9a-z]{2,3}' || true)
+    fi
+    if [ -z "$_pg" ] && command -v amd-smi >/dev/null 2>&1; then
+        _pg=$( (unset ROCR_VISIBLE_DEVICES HIP_VISIBLE_DEVICES; amd-smi list 2>/dev/null) | grep -oE 'gfx[1-9][0-9a-z]{2,3}' || true)
+        if [ -z "$_pg" ]; then
+            _pg=$( (unset ROCR_VISIBLE_DEVICES HIP_VISIBLE_DEVICES; amd-smi static --asic 2>/dev/null) | grep -oE 'gfx[1-9][0-9a-z]{2,3}' || true)
+        fi
+    fi
+    printf '%s\n' "$_pg"
+}
+
 # ── Detect GPU and choose PyTorch index URL ──
 # Mirrors Get-TorchIndexUrl in install.ps1.
 # On CPU-only machines this returns the cpu index, avoiding the solver
@@ -2059,6 +2371,24 @@ _has_amd_rocm_gpu() {
 get_torch_index_url() {
     _base="${UNSLOTH_PYTORCH_MIRROR:-https://download.pytorch.org/whl}"
     _base="${_base%/}"
+    # Explicit override -- skip ALL GPU probing (headless / container / CI / cross-install).
+    # UNSLOTH_TORCH_INDEX_URL wins (full URL, verbatim); _FAMILY is the leaf (cpu, cu128, ...)
+    # appended to the mirror base. Trim whitespace so a whitespace-only value is unset.
+    _url="${UNSLOTH_TORCH_INDEX_URL:-}"
+    _url="${_url#"${_url%%[![:space:]]*}"}"; _url="${_url%"${_url##*[![:space:]]}"}"
+    if [ -n "$_url" ]; then
+        # Trim trailing PATH slashes (a multi-slash path 404s on strict pip proxies) while
+        # preserving a ?query/#fragment token (a whole-URL strip would eat a "/"-ending token).
+        _url=$(_trim_index_path_slashes "$_url")
+        echo "$_url"; return
+    fi
+    _family="${UNSLOTH_TORCH_INDEX_FAMILY:-}"
+    _family="${_family#"${_family%%[![:space:]]*}"}"; _family="${_family%"${_family##*[![:space:]]}"}"
+    if [ -n "$_family" ]; then
+        while [ "${_family#/}" != "$_family" ]; do _family="${_family#/}"; done
+        while [ "${_family%/}" != "$_family" ]; do _family="${_family%/}"; done
+        echo "$_base/$_family"; return
+    fi
     # macOS: always CPU (no CUDA support)
     case "$(uname -s)" in Darwin) echo "$_base/cpu"; return ;; esac
     # Try nvidia-smi -- require the binary to actually list a usable GPU.
@@ -2087,6 +2417,29 @@ get_torch_index_url() {
         if ! _has_amd_rocm_gpu; then
             echo "$_base/cpu"; return
         fi
+        # A generic rocm index is only safe when the gfx arch is readable: the
+        # Strix reroute (gfx1150/1151 -> arch-specific index) learns gfx from
+        # rocminfo/amd-smi, so if those are missing OR do not enumerate the GPU, an
+        # unknown-arch box might be Strix and would get the broken _grouped_mm
+        # wheels. Probe via the shared helper (override first, then rocminfo/amd-smi
+        # with visibility masks cleared); if the arch is unreadable, never guess a
+        # rocm index. A KFD-only host whose arch is still inferable from hardware
+        # IDs (PCI/cpuinfo/lspci) returns the cpu index and lets the runtime-less
+        # reroute below upgrade it to AMD per-arch wheels -- the reroute gate uses
+        # this same probe, so the handoff can't misfire. Only when inference fails
+        # too is CPU final, with the actionable warning.
+        _amd_gfx_probe=$(_probe_amd_gfx_arch)
+        if [ -z "$_amd_gfx_probe" ]; then
+            if _amd_inferred_gfx=$(_infer_linux_amd_gfx_arch 2>/dev/null) && \
+               [ -n "$_amd_inferred_gfx" ] && \
+               _amd_arch_index_family_for_gfx "$_amd_inferred_gfx" >/dev/null 2>&1; then
+                echo "[WARN] AMD GPU detected but rocminfo/amd-smi can't read its gfx arch -- inferring $_amd_inferred_gfx from hardware IDs." >&2
+                echo "$_base/cpu"; return
+            fi
+            echo "[WARN] AMD GPU detected but its gfx arch can't be read (rocminfo/amd-smi missing or not enumerating the GPU) -- installing CPU-only PyTorch." >&2
+            echo "[WARN] For GPU PyTorch, install or repair rocminfo/amd-smi (e.g. sudo pacman -S rocm-hip-sdk) and re-run this installer." >&2
+            echo "$_base/cpu"; return
+        fi
         # AMD GPU confirmed -- detect ROCm version
         _rocm_tag=""
         _rocm_tag=$({ command -v amd-smi >/dev/null 2>&1 && \
@@ -2103,7 +2456,11 @@ get_torch_index_url() {
             { command -v rpm >/dev/null 2>&1 && \
                 ver="$(rpm -q --qf '%{VERSION}\n' rocm-core 2>/dev/null)" && \
                 [ -n "$ver" ] && \
-                printf '%s\n' "$ver" | awk -F'[.-]' '{print "rocm"$1"."$2; exit}'; }) 2>/dev/null
+                printf '%s\n' "$ver" | awk -F'[.-]' '{print "rocm"$1"."$2; exit}'; }) 2>/dev/null || _rocm_tag=""
+        # ^ || guard: when EVERY version source is missing (e.g. rocminfo present
+        # but rocm-core not installed, so dpkg-query/rpm exit 1), the whole ||
+        # chain fails and set -e would kill the installer BEFORE the actionable
+        # no-version WARN below -- exactly the fresh-install case it exists for.
         # Validate _rocm_tag: must match "rocmX.Y" with major >= 1
         case "$_rocm_tag" in
             rocm[1-9]*.[0-9]*) : ;;  # valid (major >= 1)
@@ -2139,12 +2496,27 @@ get_torch_index_url() {
             esac
             return
         fi
-        # AMD GPU confirmed by rocminfo/amd-smi but ROCm version could not be
-        # read from any source (amd-smi, /opt/rocm/.info/version, hipconfig,
-        # dpkg, rpm).  Warn explicitly rather than silently installing CPU PyTorch.
-        echo "[WARN] AMD GPU detected but ROCm version could not be determined -- falling back to CPU-only PyTorch" >&2
-        echo "[WARN] Ensure one of the following is accessible: amd-smi, hipconfig, /opt/rocm/.info/version, rocm-core package" >&2
-        echo "[WARN] To install ROCm: https://rocm.docs.amd.com/en/latest/deploy/linux/index.html" >&2
+        # AMD GPU confirmed (rocminfo/amd-smi or the KFD topology fallback) but
+        # no ROCm/HIP install was found to read the version from (amd-smi,
+        # /opt/rocm/.info/version, hipconfig, dpkg, rpm). This is the common
+        # fresh-install case: the GPU is real, but with no ROCm userspace the
+        # correct PyTorch build can't be selected. Warn with an actionable fix
+        # rather than silently installing CPU PyTorch.
+        # A user-set UNSLOTH_ROCM_GFX_ARCH seeded the probe above, so rocminfo/
+        # amd-smi may still be unable to see the GPU; when the named arch maps to
+        # a wheel family, the runtime-less reroute (gated on the override) will
+        # install the AMD per-arch wheels -- a CPU-only warning here would be
+        # false for that path. Defer like the inferable-arch branch does.
+        if [ -n "${UNSLOTH_ROCM_GFX_ARCH:-}" ] && \
+           _amd_arch_index_family_for_gfx "$_amd_gfx_probe" >/dev/null 2>&1; then
+            echo "[WARN] AMD GPU detected with no readable ROCm version, but UNSLOTH_ROCM_GFX_ARCH=$_amd_gfx_probe is set -- routing to AMD per-arch wheels." >&2
+            echo "$_base/cpu"; return
+        fi
+        echo "[WARN] AMD GPU detected, but no ROCm/HIP install was found to select the matching GPU PyTorch build -- falling back to CPU-only PyTorch." >&2
+        echo "[WARN] Install the ROCm/HIP SDK, then re-run this installer:" >&2
+        echo "[WARN]   Arch / CachyOS : sudo pacman -S rocm-hip-sdk" >&2
+        echo "[WARN]   other distros  : https://rocm.docs.amd.com/en/latest/deploy/linux/index.html" >&2
+        echo "[WARN] Minimum required for version detection: amd-smi, hipconfig, /opt/rocm/.info/version, or the rocm-core package." >&2
         echo "$_base/cpu"; return
     fi
     # Parse CUDA version from nvidia-smi output (POSIX-safe, no grep -P).
@@ -2187,16 +2559,155 @@ _torch_flavor_tag() {
     esac
 }
 
+# Final path segment of a wheel index URL ($1), lowercased, query/fragment stripped first
+# so a token-authenticated pin (.../cu128?token=x) classifies as cu128 (else it reinstalls
+# every update). Classification only. Shared with the py / ps1 leaf extractors.
+_torch_index_url_leaf() {
+    _tl_u="${1%%\?*}"
+    _tl_u="${_tl_u%%#*}"
+    # Strip ALL trailing slashes, not one: .../rocm7.2// must yield rocm7.2, not an empty leaf.
+    while [ -n "$_tl_u" ] && [ "${_tl_u%/}" != "$_tl_u" ]; do
+        _tl_u="${_tl_u%/}"
+    done
+    printf '%s' "${_tl_u##*/}" | tr '[:upper:]' '[:lower:]'
+}
+
+# True (exit 0) when a lowercased leaf is an EXACT pip ROCm family: rocm<digits>[.<digits>]
+# or a gfx ARCHITECTURE leaf (gfx followed by a digit: gfx90a, gfx1151, gfx120x-all). A leaf
+# that merely starts with rocm/gfx (rocm7.2-private, gfx-private) is a custom verbatim pin.
+# Matches the py / ps1 sides.
+_is_pip_rocm_family_leaf() {
+    case "$1" in
+        gfx[0-9]*) return 0 ;;
+        rocm[0-9]*)
+            # Exact rocm<digits>[.<digits>]: both major and minor must be non-empty all-digits
+            # (rocm7., rocm7.2.1, rocm7.2-private are all custom pins, not a family).
+            _rocm_rest="${1#rocm}"
+            case "$_rocm_rest" in
+                *.*.*) return 1 ;;
+                *.*)
+                    _rocm_minor="${_rocm_rest#*.}"
+                    case "${_rocm_rest%%.*}" in "" | *[!0-9]*) return 1 ;; esac
+                    case "$_rocm_minor" in "" | *[!0-9]*) return 1 ;; esac
+                    ;;
+                *[!0-9]*) return 1 ;;
+            esac
+            return 0
+            ;;
+        *) return 1 ;;
+    esac
+}
+
+# Whether release base $1 (X.Y[.Z...]) falls inside constraint window $2
+# ("torch>=A.B[.C],<D.E.F"). Compares at major.minor granularity, which is exact
+# for the windows this script uses (ceilings are always X.Y.0); a non-.0 ceiling
+# would only make this conservative (excludes the whole ceiling minor). Anything
+# unparseable answers "no" so the caller fails toward the supported range.
+_torch_release_in_window() {
+    _trw_con="$2"
+    case "$_trw_con" in
+        "torch>="*",<"*) ;;
+        *) echo "no"; return ;;
+    esac
+    _trw_floor="${_trw_con#torch>=}"; _trw_floor="${_trw_floor%%,*}"
+    _trw_ceil="${_trw_con##*,<}"
+    _v_maj="${1%%.*}";          _v_rest="${1#*.}";          _v_min="${_v_rest%%.*}"
+    _f_maj="${_trw_floor%%.*}"; _f_rest="${_trw_floor#*.}"; _f_min="${_f_rest%%.*}"
+    _c_maj="${_trw_ceil%%.*}";  _c_rest="${_trw_ceil#*.}";  _c_min="${_c_rest%%.*}"
+    for _trw_n in "$_v_maj" "$_v_min" "$_f_maj" "$_f_min" "$_c_maj" "$_c_min"; do
+        case "$_trw_n" in ''|*[!0-9]*) echo "no"; return ;; esac
+    done
+    if [ "$_v_maj" -gt "$_f_maj" ] || { [ "$_v_maj" -eq "$_f_maj" ] && [ "$_v_min" -ge "$_f_min" ]; }; then
+        if [ "$_v_maj" -lt "$_c_maj" ] || { [ "$_v_maj" -eq "$_c_maj" ] && [ "$_v_min" -lt "$_c_min" ]; }; then
+            echo "yes"
+            return
+        fi
+    fi
+    echo "no"
+}
+
+# Keep the previous venv's torch on a re-run: echo "torch==X.Y.Z" when the probed
+# version ($1) is inside the active constraint window ($2), else "". The RELEASE is kept
+# regardless of flavor tag; the pin installs from the freshly chosen index, so flavor
+# follows the machine (cpu <-> cuda, cu126 -> cu130, PyPI bare -> +cu130) while the
+# release follows the user. Gating on flavor was wrong: a PyPI torch reports a BARE
+# version (on Linux the PyPI wheel IS CUDA), misclassified "cpu", so a healthy 2.10 on a
+# cu130 host was moved to 2.11. Per-leaf floors still win (rocm7.2 / gfx >=2.11 for the
+# Strix _grouped_mm fix, out-of-window manual installs) and are never pinned; the caller's
+# _PREV_FALLBACK_CONSTRAINT installs the newest supported release when the index lacks the
+# exact one. Opt out with UNSLOTH_TORCH_UPGRADE=1.
+_previous_torch_pin() {
+    _ptp_ver="$1"
+    _ptp_con="$2"
+    [ -n "$_ptp_ver" ] || { echo ""; return; }
+    [ "${UNSLOTH_TORCH_UPGRADE:-0}" = "1" ] && { echo ""; return; }
+    _ptp_base="${_ptp_ver%%+*}"
+    # Base must be a plain numeric release (X.Y[.Z]); probe noise and
+    # nightly/dev/source builds (2.11.0.dev20250704, 2.9.0a0) must never
+    # become a pin -- no stable index carries them, so pinning would only
+    # print "keeping it" and then burn a doomed resolve before falling back.
+    case "$_ptp_base" in
+        *[!0-9.]* | *..* | .* | *.) echo ""; return ;;
+        [0-9]*.[0-9]*) ;;
+        *) echo ""; return ;;
+    esac
+    [ "$(_torch_release_in_window "$_ptp_base" "$_ptp_con")" = "yes" ] || { echo ""; return; }
+    echo "torch==$_ptp_base"
+}
+
+# Install torch from TORCH_INDEX_URL honoring a kept-release pin: with _PREV_TORCH_PIN
+# set, TORCH_CONSTRAINT is the exact previous release; fall back to the supported range
+# if the index lacks it (pruned mirror) rather than failing. Used by every --default-index
+# path (NVIDIA cu*, AMD rocm/gfx fallbacks, cpu/mac, ROCm repairs) so preservation is
+# uniform. Extra args (e.g. --force-reinstall) are passed through to uv.
+_install_torch_default_index() {
+    if [ -n "$_PREV_TORCH_PIN" ]; then
+        # Pair the companions with the kept torch minor: torchaudio no longer
+        # exact-pins torch in its metadata, so leaving it unconstrained resolves
+        # a newer mismatched build (a kept torch 2.9.0 pulled torchaudio 2.11.0).
+        _itdi_base="${_PREV_TORCH_PIN#torch==}"
+        _itdi_minor="${_itdi_base#*.}"
+        _itdi_minor="${_itdi_minor%%.*}"
+        _itdi_tv="torchvision"
+        _itdi_ta="torchaudio"
+        case "$_itdi_base" in
+            2.*)
+                _itdi_tv="torchvision==0.$((_itdi_minor + 15)).*"
+                _itdi_ta="torchaudio==2.${_itdi_minor}.*"
+                ;;
+        esac
+        if ! run_install_cmd_retry "install PyTorch (kept release)" uv pip install --python "$_VENV_PY" "$TORCH_CONSTRAINT" "$_itdi_tv" "$_itdi_ta" \
+            --default-index "$TORCH_INDEX_URL" "$@"; then
+            substep "[WARN] $_PREV_TORCH_PIN is not installable from $(_strip_index_url_credentials "$TORCH_INDEX_URL") -- installing the newest supported release instead" "$C_WARN"
+            TORCH_CONSTRAINT="$_PREV_FALLBACK_CONSTRAINT"
+            _PREV_TORCH_PIN=""
+            run_install_cmd_retry "install PyTorch" uv pip install --python "$_VENV_PY" "$TORCH_CONSTRAINT" "$TORCHVISION_CONSTRAINT" "$TORCHAUDIO_CONSTRAINT" \
+                --default-index "$TORCH_INDEX_URL" "$@"
+        fi
+    else
+        run_install_cmd_retry "install PyTorch" uv pip install --python "$_VENV_PY" "$TORCH_CONSTRAINT" "$TORCHVISION_CONSTRAINT" "$TORCHAUDIO_CONSTRAINT" \
+            --default-index "$TORCH_INDEX_URL" "$@"
+    fi
+}
+
 # Expected tag from the index leaf ($1): cuXXX / cpu / rocm (rocmX.Y and gfx* ->
 # rocm). Empty on an unknown leaf (odd mirror) so the repair safely no-ops.
 _expected_torch_flavor_tag() {
-    _u="${1%/}"
-    _leaf="${_u##*/}"
+    _leaf=$(_torch_index_url_leaf "$1")
     case "$_leaf" in
-        cu[0-9]*)   echo "$_leaf" ;;
-        cpu)        echo "cpu" ;;
-        rocm*|gfx*) echo "rocm" ;;
-        *)          echo "" ;;
+        cu[0-9]*)
+            # Exact cu + digits only; a cu*-suffixed leaf (cu128-private) -> "" (custom),
+            # else a correct +cu128 wheel is force-reinstalled every run.
+            case "${_leaf#cu}" in
+                *[!0-9]*) echo "" ;;
+                *)        echo "$_leaf" ;;
+            esac
+            ;;
+        cpu)          echo "cpu" ;;
+        # Exact rocm/gfx families only; a custom rocm*-suffixed leaf -> "" (custom).
+        *)
+            if _is_pip_rocm_family_leaf "$_leaf"; then echo "rocm"; else echo ""; fi
+            ;;
     esac
 }
 
@@ -2206,14 +2717,42 @@ _expected_torch_flavor_tag() {
 # fresh-install paths above already use -- so a stale wheel is auto-repairable.
 # Unknown/odd-mirror leaves -> no, so we warn rather than risk a wrong reinstall.
 _torch_index_repairable() {
-    _u="${1%/}"
-    _leaf="${_u##*/}"
+    _leaf=$(_torch_index_url_leaf "$1")
     case "$_leaf" in
-        cu[0-9]*|rocm[0-9]*|gfx*) echo "yes" ;;
-        *)                        echo "no" ;;
+        cu[0-9]*) echo "yes" ;;
+        # Only EXACT rocm/gfx families resolve via --default-index; a suffixed leaf is verbatim.
+        *)
+            if _is_pip_rocm_family_leaf "$_leaf"; then echo "yes"; else echo "no"; fi
+            ;;
     esac
 }
 
+# Remove credentials from a wheel index URL ($1) so an authenticated pin never leaks:
+# drops userinfo AND query/fragment; scheme/host/path stay exact. Shared with py / ps1.
+_strip_index_url_credentials() {
+    _sic_url="$1"
+    case "$_sic_url" in
+        *://*) ;;
+        *) printf '%s' "$_sic_url"; return ;;
+    esac
+    _sic_scheme="${_sic_url%%://*}"
+    _sic_rest="${_sic_url#*://}"
+    # Drop query / fragment (may hold auth tokens).
+    _sic_rest="${_sic_rest%%\?*}"
+    _sic_rest="${_sic_rest%%#*}"
+    _sic_auth="${_sic_rest%%/*}"
+    # Drop user:pass@ userinfo if present.
+    case "$_sic_auth" in
+        *@*) _sic_host="${_sic_auth##*@}" ;;
+        *)   _sic_host="$_sic_auth" ;;
+    esac
+    if [ "$_sic_auth" = "$_sic_rest" ]; then
+        printf '%s://%s' "$_sic_scheme" "$_sic_host"
+    else
+        printf '%s://%s/%s' "$_sic_scheme" "$_sic_host" "${_sic_rest#*/}"
+    fi
+}
+
 get_radeon_wheel_url() {
     # Only meaningful on Linux. Picks a repo.radeon.com base URL whose listing
     # contains torch wheels. Tries paths like rocm-rel-7.2.1/, rocm-rel-7.2/,
@@ -2335,7 +2874,7 @@ _pick_radeon_wheel() {
 # the installer -- always returns 0. Runs the idempotent helper (ROCm 7.2 +
 # librocdxg), then sources the env it persisted so detection finds the GPU.
 # Export the ROCm-on-WSL env into this process and persist it to /etc/profile.d
-# so non-login Studio/llama launches inherit it. Idempotent (writes only when
+# so non-login Unsloth/llama launches inherit it. Idempotent (writes only when
 # the drop-in is missing); no-op without librocdxg, so never fires off WSL.
 # /etc/profile.d is root-owned -- sudo-tee when not root, else ROCm vanishes
 # after this shell on a non-root reinstall. Best-effort either way.
@@ -2380,7 +2919,7 @@ _maybe_bootstrap_rocm_wsl() {
        rocminfo 2>/dev/null | awk '/Name:[[:space:]]*gfx[1-9]/ && !/generic/{found=1} END{exit !found}'; then
         # rocminfo may work only via the transient env _ensure_rocm_probe_env
         # just set, which dies with the installer. Persist the drop-in so login
-        # shells (Studio, llama.cpp) inherit it -- else a reinstall over an
+        # shells (Unsloth, llama.cpp) inherit it -- else a reinstall over an
         # existing /opt/rocm (uninstall keeps ROCm but drops it) loses the GPU.
         _persist_rocm_wsl_dropin
         return 0
@@ -2389,7 +2928,7 @@ _maybe_bootstrap_rocm_wsl() {
     [ -e /dev/dxg ] || return 0
     # Strix APUs show in /proc/cpuinfo (the CPU model); discrete cards don't, so also
     # ask the Windows host. Either signal suffices; the bootstrap detects arch from rocminfo.
-    if ! grep -qiE 'Ryzen AI Max|Radeon 80[0-9]0S|Strix Halo' /proc/cpuinfo 2>/dev/null \
+    if ! grep -qiE 'Ryzen AI Max|Radeon 80[0-9][05]S|Strix Halo' /proc/cpuinfo 2>/dev/null \
        && ! _wsl_amd_gpu_name >/dev/null 2>&1; then
         return 0
     fi
@@ -2402,7 +2941,7 @@ _maybe_bootstrap_rocm_wsl() {
             # shellcheck disable=SC1091
             . /etc/profile.d/unsloth-rocm-wsl.sh || true
         else
-            # librocdxg present but the env drop-in is gone (e.g. a Studio
+            # librocdxg present but the env drop-in is gone (e.g. an Unsloth
             # uninstall removed it while keeping shared ROCm). Restore the env.
             _persist_rocm_wsl_dropin
         fi
@@ -2459,10 +2998,88 @@ _maybe_bootstrap_rocm_wsl() {
     [ -n "$_rw_tmp" ] && rm -f "$_rw_tmp"
     return 0
 }
-_maybe_bootstrap_rocm_wsl || true
+# When the caller pins the wheel index (UNSLOTH_TORCH_INDEX_URL / _FAMILY), honour it
+# everywhere: skip the WSL ROCm bootstrap and the Radeon/Strix reroute below (which would
+# re-probe the GPU and overwrite the pin). Trim whitespace first (parity with
+# get_torch_index_url): a whitespace-only override is unset there, so must not flip this true.
+_torch_index_pinned=false
+_ti_url_trim="${UNSLOTH_TORCH_INDEX_URL:-}"
+_ti_url_trim="${_ti_url_trim#"${_ti_url_trim%%[![:space:]]*}"}"; _ti_url_trim="${_ti_url_trim%"${_ti_url_trim##*[![:space:]]}"}"
+_ti_family_trim="${UNSLOTH_TORCH_INDEX_FAMILY:-}"
+_ti_family_trim="${_ti_family_trim#"${_ti_family_trim%%[![:space:]]*}"}"; _ti_family_trim="${_ti_family_trim%"${_ti_family_trim##*[![:space:]]}"}"
+if [ -n "$_ti_url_trim" ] || [ -n "$_ti_family_trim" ]; then
+    _torch_index_pinned=true
+fi
+[ "$_torch_index_pinned" = true ] || _maybe_bootstrap_rocm_wsl || true
 
 TORCH_INDEX_URL=$(get_torch_index_url)
 
+# Linux: ROCm runtime missing but a supported AMD gfx arch is inferable (Strix Halo
+# in /proc/cpuinfo, lspci marketing name, UNSLOTH_ROCM_GFX_ARCH). Route to AMD's
+# per-arch wheels like install.ps1 does on Windows (unslothai#7301).
+# Gated on the runtime probes NOT naming a gfx: either no AMD GPU is detected at
+# all (_has_amd_rocm_gpu false), or the GPU is visible only through the
+# env-independent KFD topology while rocminfo/amd-smi can't read its arch
+# (KFD-only host, unslothai#7314 -- before the KFD detection fix these hosts
+# reached this reroute via the false branch, so the empty-probe condition
+# preserves that routing). A */cpu index chosen WITH a readable gfx
+# (unsupported/unreadable ROCm version, after its own warning) is a deliberate
+# fallback -- rerouting it would contradict that decision, and stays excluded
+# because the shared probe returns its gfx. An explicit UNSLOTH_ROCM_GFX_ARCH
+# override stays authoritative either way.
+if [ "$_torch_index_pinned" = false ] && [ "$SKIP_TORCH" = false ] && \
+   ! _has_usable_nvidia_gpu && \
+   { [ -n "${UNSLOTH_ROCM_GFX_ARCH:-}" ] || ! _has_amd_rocm_gpu || \
+     [ -z "$(_probe_amd_gfx_arch)" ]; } && \
+   case "$(uname -s)" in Linux) true ;; *) false ;; esac && \
+   case "$_ARCH" in x86_64|amd64) true ;; *) false ;; esac; then
+    # ROCm torch wheels are x86_64-only; get_torch_index_url returns CPU on other
+    # arches, so an inferred/overridden gfx must not reroute arm64 to AMD wheels.
+    case "$TORCH_INDEX_URL" in
+        */cpu)
+            _linux_inferred_gfx=$(_infer_linux_amd_gfx_arch 2>/dev/null || true)
+            if [ -n "$_linux_inferred_gfx" ]; then
+                _amd_family=$(_amd_arch_index_family_for_gfx "$_linux_inferred_gfx") || _amd_family=""
+                if [ -n "$_amd_family" ]; then
+                    _amd_mirror="${UNSLOTH_AMD_ROCM_MIRROR:-https://repo.amd.com/rocm/whl}"
+                    while [ "${_amd_mirror%/}" != "$_amd_mirror" ]; do
+                        _amd_mirror="${_amd_mirror%/}"
+                    done
+                    TORCH_INDEX_URL="${_amd_mirror}/${_amd_family}/"
+                    # Hand the inferred arch to setup.sh (llama.cpp): it re-probes
+                    # ROCm on its own, and on these runtime-less hosts its probes
+                    # find nothing, so without this it classifies the box as
+                    # non-ROCm and installs the CPU prebuilt while torch just got
+                    # AMD per-arch wheels. setup.sh and install_llama_prebuilt.py
+                    # both honor UNSLOTH_ROCM_GFX_ARCH, so exporting it is the
+                    # whole handoff (a user-set override re-exports unchanged).
+                    export UNSLOTH_ROCM_GFX_ARCH="$_linux_inferred_gfx"
+                    case "$_linux_inferred_gfx" in
+                        gfx1201|gfx1200|gfx1151|gfx1150)
+                            TORCH_CONSTRAINT="torch>=2.11.0,<2.12.0"
+                            TORCHVISION_CONSTRAINT="torchvision>=0.26.0,<0.27.0"
+                            TORCHAUDIO_CONSTRAINT="torchaudio>=2.11.0,<2.12.0"
+                            ;;
+                    esac
+                    echo "" >&2
+                    # KFD-only hosts reach this reroute with /dev/kfd present
+                    # (that's what detected them), so don't claim it's missing.
+                    if _has_amd_rocm_gpu; then
+                        echo "  [WARN] AMD GPU visible via the kernel driver (KFD) but rocminfo/amd-smi can't read its gfx arch; using $_linux_inferred_gfx." >&2
+                    else
+                        echo "  [WARN] ROCm runtime not visible (/dev/kfd, rocminfo, amd-smi) but $_linux_inferred_gfx inferred." >&2
+                    fi
+                    echo "  [WARN] Routing to AMD arch-specific wheels ($(_strip_index_url_credentials "$TORCH_INDEX_URL"))." >&2
+                    echo "  [WARN] These wheels bundle their own ROCm runtime; install the kernel stack for native compute:" >&2
+                    echo "  [WARN]   https://docs.unsloth.ai/get-started/install-and-update/amd" >&2
+                    echo "  [WARN] Tip: set UNSLOTH_ROCM_GFX_ARCH=$_linux_inferred_gfx to skip inference next time." >&2
+                    echo "" >&2
+                fi
+            fi
+            ;;
+    esac
+fi
+
 # Export the resolved torch backend ("cuda", "rocm", or "cpu") so that
 # downstream scripts (setup.sh -> install_python_stack.py) know what was
 # chosen here and can skip ROCm-specific repair steps on CUDA/CPU hosts.
@@ -2470,24 +3087,74 @@ TORCH_INDEX_URL=$(get_torch_index_url)
 # whose base path happens to contain "rocm" or "gfx" must not mislabel a
 # cu*/cpu index as ROCm (radeon repo URLs end in rocm-rel-X.Y/, Strix
 # overrides in gfxNNNN/, so the trailing slash is stripped first).
-_torch_index_leaf="${TORCH_INDEX_URL%/}"
+# Lowercase the leaf so every gfx*/rocm*/cu* arm matches regardless of case (canonical AMD
+# RDNA4 leaf is gfx120X-all). CUDA is branded only on a real cu[0-9]* leaf, so a mirror
+# leaf (/current) does NOT commit a CUDA backend; an unknown leaf leaves the var unset so
+# the stack probes the GPU. Query/fragment dropped first, then ALL trailing slashes (in
+# lockstep with the shared _torch_index_url_leaf extractor).
+_torch_index_leaf="${TORCH_INDEX_URL%%\?*}"
+_torch_index_leaf="${_torch_index_leaf%%#*}"
+# Strip ALL trailing slashes, not one: .../cu128// must yield cu128, not an empty leaf.
+while [ -n "$_torch_index_leaf" ] && [ "${_torch_index_leaf%/}" != "$_torch_index_leaf" ]; do
+    _torch_index_leaf="${_torch_index_leaf%/}"
+done
 _torch_index_leaf="${_torch_index_leaf##*/}"
+_torch_index_leaf=$(printf '%s' "$_torch_index_leaf" | tr '[:upper:]' '[:lower:]')
 case "$_torch_index_leaf" in
     rocm*|gfx*) export UNSLOTH_TORCH_BACKEND="rocm" ;;
     cpu)        export UNSLOTH_TORCH_BACKEND="cpu"  ;;
-    *)          export UNSLOTH_TORCH_BACKEND="cuda" ;;
+    cu[0-9]*)   export UNSLOTH_TORCH_BACKEND="cuda" ;;
+    # Unknown leaf (odd mirror, /current): unset so a stale inherited value can't leak and
+    # the stack probes the GPU.
+    *)          unset UNSLOTH_TORCH_BACKEND ;;
 esac
 
-# rocm7.2 ships torch 2.11.0 -- adjust the constraint to allow it.
-# All other ROCm tags and CUDA stay within <2.11.0.
-case "$TORCH_INDEX_URL" in
-    */rocm7.2) TORCH_CONSTRAINT="torch>=2.11.0,<2.12.0" ;;
+# Whether TORCH_INDEX_URL names an actual pip ROCm family (rocm<digit>* / gfx*), gating the
+# ROCm-only side effects below (AMD bitsandbytes, ROCm-torch repair). Digit-gated so a leaf
+# merely STARTING with "rocm" isn't force-repaired from the wrong path.
+if _is_pip_rocm_family_leaf "$_torch_index_leaf"; then
+    _torch_index_is_rocm_family=true
+else
+    _torch_index_is_rocm_family=false
+fi
+
+# rocm7.2 and the per-gfx indexes with the _grouped_mm <2.11 bug (gfx120X-all, gfx1151,
+# gfx1150) ship torch 2.11.0 -- raise the floor (also covers a pinned override that skipped
+# the Strix reroute). Pin the companions too: the per-gfx index publishes them independently
+# and a bare name can resolve a 2.12 ABI-mismatched wheel. Match on the FINAL leaf so a
+# custom mirror with a gfx/rocm7.2 path segment but a cu*/cpu family isn't forced.
+case "$_torch_index_leaf" in
+    rocm7.2|gfx120x-all|gfx1151|gfx1150)
+        TORCH_CONSTRAINT="torch>=2.11.0,<2.12.0"
+        TORCHVISION_CONSTRAINT="torchvision>=0.26.0,<0.27.0"
+        TORCHAUDIO_CONSTRAINT="torchaudio>=2.11.0,<2.12.0"
+        ;;
+    # CUDA cu12x/cu13x indexes ship torch 2.11.x: widen the ceiling to <2.12.0 (matches
+    # _CUDA_TORCH_PKG_SPEC) and widen the companions with it so the trio stays paired.
+    cu[0-9]*)
+        TORCH_CONSTRAINT="torch>=2.4,<2.12.0"
+        TORCHVISION_CONSTRAINT="torchvision>=0.19,<0.27.0"
+        TORCHAUDIO_CONSTRAINT="torchaudio>=2.4,<2.12.0"
+        ;;
 esac
 
+# A pinned custom/unknown-leaf index (/simple, /current, /cu128-private) has no curated
+# companion set, so bound torchvision/torchaudio to the same <2.11 range the Python path pins
+# (else a mirror with newer companions resolves a 2.12 ABI-mismatched wheel). Known families
+# keep their curated companions above (_expected_torch_flavor_tag returns "" only for custom).
+if [ "$_torch_index_pinned" = true ] && \
+   [ -z "$(_expected_torch_flavor_tag "$TORCH_INDEX_URL")" ]; then
+    TORCHVISION_CONSTRAINT="torchvision>=0.19,<0.26.0"
+    TORCHAUDIO_CONSTRAINT="torchaudio>=2.4,<2.11.0"
+fi
+
 # Auto-detect GPU for AMD ROCm based
 # get_torch_index_url must have chosen */rocm*
 # (gfx in rocminfo or amd-smi list). Then require rocminfo "Marketing Name:.*Radeon".
+# Skipped when the index is pinned: an explicit override must not be rerouted to the
+# Radeon/Strix repos by GPU probing.
 _amd_gpu_radeon=false
+if [ "$_torch_index_pinned" = false ]; then
 case "$TORCH_INDEX_URL" in
     */rocm*)
         if _has_amd_rocm_gpu && command -v rocminfo >/dev/null 2>&1 && \
@@ -2496,29 +3163,64 @@ case "$TORCH_INDEX_URL" in
         fi
         ;;
 esac
-# ── Strix Halo / Strix Point: force rocm7.2 wheels, bypass Radeon repo ───────
-# gfx1151 (Strix Halo) and gfx1150 (Strix Point) have a ROCm 7.1 driver bug
-# that causes a segfault in torch._grouped_mm (moe_utils.py line 167).
-# The Radeon repo now ships cp313 wheels for rocm-rel-7.1, so when
-# _amd_gpu_radeon=true the installer silently lands on the broken combo.
-# Detect these GPUs when TORCH_INDEX_URL is rocm7.1 and override to rocm7.2.
-case "$TORCH_INDEX_URL" in
-    */rocm7.1|*/rocm7.1.*)
+# 0 when a rocmX.Y index leaf ($1, the final path segment) is older than floor
+# $2.$3 (int compare, so rocm7.2 < rocm7.13). Non-rocm leaves (gfx*, cu*, cpu) and
+# non-numeric versions return 1. Leaf-based (like $_torch_index_leaf) so a mirror
+# base holding its own rocm token compares the family leaf, not the base path.
+_rocm_leaf_below() {
+    case "$1" in rocm[0-9]*.[0-9]*) : ;; *) return 1 ;; esac
+    _rb=${1#rocm}; _maj=${_rb%%.*}; _min=${_rb#*.}; _min=${_min%%.*}
+    case "$_maj$_min" in *[!0-9]*) return 1 ;; esac
+    if [ "$_maj" -lt "$2" ]; then return 0; fi
+    if [ "$_maj" -eq "$2" ] && [ "$_min" -lt "$3" ]; then return 0; fi
+    return 1
+}
+# ── Strix Halo / Strix Point: route to the AMD arch-specific index ───────────
+# gfx1151/gfx1150 need torch 2.11+rocm7.13 from repo.amd.com/rocm/whl/gfx<arch>/,
+# which carries AMD's real fixes (the rocm7.1 _grouped_mm segfault, moe_utils.py:167,
+# and later Strix kernel bugs). Every generic pytorch.org index below rocm7.13 lacks
+# them (and the Radeon repo can be offline, unslothai#7264), so reroute a detected
+# Strix GPU whenever the picked index is older than the arch build -- covers today's
+# rocm6.0-7.2 and any future 7.x < 7.13; rocm7.13+ already has the fixes, so leave it.
+case "$_torch_index_leaf" in
+    rocm[0-9]*)
         # Collect every gfx token in rocminfo / amd-smi enumeration order
         # (skip duplicates), then index by HIP_VISIBLE_DEVICES /
         # ROCR_VISIBLE_DEVICES so a mixed Strix iGPU + non-Strix dGPU box
         # where the user selected the dGPU does NOT get rerouted to the
         # Strix per-gfx index.
-        _gfx_all=""
-        if command -v rocminfo >/dev/null 2>&1; then
-            _gfx_all=$(rocminfo 2>/dev/null | grep -oE 'gfx[1-9][0-9a-z]{2,3}')
+        # || true on each probe: no gfx match makes grep exit 1, which under
+        # set -euo pipefail would abort the installer before the next fallback
+        # runs (now that the case matches every rocm* index, not just rocm7.1).
+        # A user-supplied UNSLOTH_ROCM_GFX_ARCH overrides probing (mirrors setup.sh
+        # and the display block), so a Strix override still reaches the arch index.
+        _gfx_all=$(printf '%s' "${UNSLOTH_ROCM_GFX_ARCH:-}" | tr '[:upper:]' '[:lower:]')
+        if [ -z "$_gfx_all" ] && command -v rocminfo >/dev/null 2>&1; then
+            _gfx_all=$(rocminfo 2>/dev/null | grep -oE 'gfx[1-9][0-9a-z]{2,3}' || true)
         fi
         if [ -z "$_gfx_all" ] && command -v amd-smi >/dev/null 2>&1; then
-            _gfx_all=$(amd-smi list 2>/dev/null | grep -oE 'gfx[1-9][0-9a-z]{2,3}')
+            _gfx_all=$(amd-smi list 2>/dev/null | grep -oE 'gfx[1-9][0-9a-z]{2,3}' || true)
             # PowerShell paths also probe `amd-smi static --asic`; mirror it
             # so a host with hipinfo-less amd-smi reports the gfx target.
             if [ -z "$_gfx_all" ]; then
-                _gfx_all=$(amd-smi static --asic 2>/dev/null | grep -oE 'gfx[1-9][0-9a-z]{2,3}')
+                _gfx_all=$(amd-smi static --asic 2>/dev/null | grep -oE 'gfx[1-9][0-9a-z]{2,3}' || true)
+            fi
+        fi
+        # get_torch_index_url reads the arch with ROCR/HIP masks cleared, so a
+        # mask hiding every agent (e.g. ROCR_VISIBLE_DEVICES=-1) still lands
+        # here on a generic rocm index; re-probe unmasked or a masked-out Strix
+        # box keeps the broken generic wheels. Partial masks never get here
+        # (they enumerate at least one agent above) and keep their selection.
+        # ${VAR+x} (not :-): a SET-but-empty mask also hides every agent and
+        # must trigger the re-probe too.
+        if [ -z "$_gfx_all" ] && [ -n "${ROCR_VISIBLE_DEVICES+x}${HIP_VISIBLE_DEVICES+x}" ]; then
+            if command -v rocminfo >/dev/null 2>&1; then
+                _gfx_all=$( (unset ROCR_VISIBLE_DEVICES HIP_VISIBLE_DEVICES; rocminfo 2>/dev/null) | grep -oE 'gfx[1-9][0-9a-z]{2,3}' || true)
+            fi
+            if [ -z "$_gfx_all" ] && command -v amd-smi >/dev/null 2>&1; then
+                _gfx_all=$( (unset ROCR_VISIBLE_DEVICES HIP_VISIBLE_DEVICES; amd-smi list 2>/dev/null) | grep -oE 'gfx[1-9][0-9a-z]{2,3}' || true)
+                [ -z "$_gfx_all" ] && \
+                    _gfx_all=$( (unset ROCR_VISIBLE_DEVICES HIP_VISIBLE_DEVICES; amd-smi static --asic 2>/dev/null) | grep -oE 'gfx[1-9][0-9a-z]{2,3}' || true)
             fi
         fi
         _runtime_gfx=""
@@ -2543,13 +3245,14 @@ case "$TORCH_INDEX_URL" in
         case "$_runtime_gfx" in
             gfx1151|gfx1150) _strix_gfx="$_runtime_gfx" ;;
         esac
-        if [ -n "$_strix_gfx" ]; then
+        # Skip rocm7.13+ generic indexes: they already ship the fixes, so the
+        # arch build (rocm7.13) would be a downgrade rather than a rescue.
+        if [ -n "$_strix_gfx" ] && _rocm_leaf_below "$_torch_index_leaf" 7 13; then
             echo "" >&2
-            echo "  [WARN] $_strix_gfx (Strix) + ROCm 7.1 detected -- known _grouped_mm segfault" >&2
-            echo "  [WARN] ROCm 7.1 wheels are broken for gfx1150/gfx1151 (moe_utils.py:167)" >&2
-            echo "  [WARN] Routing to AMD arch-specific index (torch 2.11+rocm7.13 has the real fix)" >&2
-            echo "  [WARN] Upgrade ROCm to 7.2+ to use the standard index:" >&2
-            echo "  [WARN]   https://rocm.docs.amd.com/en/latest/deploy/linux/index.html" >&2
+            echo "  [WARN] $_strix_gfx (Strix) detected -- routing to the AMD arch-specific index" >&2
+            echo "  [WARN] torch 2.11+rocm7.13 has AMD's real gfx1150/gfx1151 fixes (the ROCm 7.1" >&2
+            echo "  [WARN] _grouped_mm segfault, moe_utils.py:167, and later Strix kernel bugs)," >&2
+            echo "  [WARN] and is more reliable than the rocm7.2 index or an offline Radeon repo." >&2
             echo "" >&2
             # AMD's arch-specific index serves torch 2.11.0+rocm7.13.0 which has AMD's
             # actual fix for the gfx1151/gfx1150 _grouped_mm kernel bug -- preferred
@@ -2564,10 +3267,31 @@ case "$TORCH_INDEX_URL" in
             done
             TORCH_INDEX_URL="${_amd_strix_base}/${_strix_gfx}/"
             TORCH_CONSTRAINT="torch>=2.11.0,<2.12.0"
+            # Pin companions to 2.11 (per-gfx index publishes them independently).
+            TORCHVISION_CONSTRAINT="torchvision>=0.26.0,<0.27.0"
+            TORCHAUDIO_CONSTRAINT="torchaudio>=2.11.0,<2.12.0"
             _amd_gpu_radeon=false
         fi
         ;;
 esac
+fi  # _torch_index_pinned guard (Radeon + Strix reroute)
+# Re-run over an existing install: keep the previous venv's torch RELEASE; the fresh
+# index above supplies the right flavor for this machine. Evaluated HERE, after every
+# index/constraint decision including the Strix reroute, so the window checked is the
+# final one and a raised floor (rocm7.2 / Strix gfx) rejects an older release.
+# _PREV_FALLBACK_CONSTRAINT keeps the range so the install can fall back when the exact
+# release is not on the chosen index (mirrors may prune old wheels). Skipped for --no-torch.
+_PREV_TORCH_PIN=""
+_PREV_FALLBACK_CONSTRAINT="$TORCH_CONSTRAINT"
+if [ "$SKIP_TORCH" = false ]; then
+    _prev_pin=$(_previous_torch_pin "$_PREV_TORCH_VER" "$TORCH_CONSTRAINT")
+    if [ -n "$_prev_pin" ]; then
+        _PREV_TORCH_PIN="$_prev_pin"
+        TORCH_CONSTRAINT="$_prev_pin"
+        substep "existing install has torch $_PREV_TORCH_VER -- keeping it (set UNSLOTH_TORCH_UPGRADE=1 to get the newest release)"
+    fi
+fi
+
 _TAURI_TORCH_INDEX_FAMILY=$(_tauri_torch_index_family "$TORCH_INDEX_URL")
 if [ "$_amd_gpu_radeon" = true ] && [ "$SKIP_TORCH" = false ]; then
     _TAURI_TORCH_INDEX_FAMILY="radeon"
@@ -2617,7 +3341,7 @@ elif case "$TORCH_INDEX_URL" in */rocm*|*/gfx*) true ;; *) false ;; esac; then
         case "$_gpu_disp_mkt" in
             *"9070 XT"*|*9080*)                                                                            _gpu_disp_gfx="gfx1201" ;;  # RDNA 4
             *9070*|*9060*)                                                                                 _gpu_disp_gfx="gfx1200" ;;  # RDNA 4
-            *"8060S"*|*"8050S"*|*"8040S"*|*"Strix Halo"*|*"Ryzen AI Max"*|*"AI Max"*) _gpu_disp_gfx="gfx1151" ;;  # RDNA 3.5 (Strix Halo: Radeon 8060S/8050S/8040S iGPU, Ryzen AI Max+)
+            *"8065S"*|*"8060S"*|*"8050S"*|*"8040S"*|*"Strix Halo"*|*"Ryzen AI Max"*|*"AI Max"*) _gpu_disp_gfx="gfx1151" ;;  # RDNA 3.5 (Strix Halo + Gorgon Halo: Radeon 8065S/8060S/8050S/8040S iGPU, Ryzen AI Max / Max+)
             *"890M"*|*"880M"*|*"860M"*|*"840M"*|*"Strix Point"*|*"Krackan"*|*"HX 37"*|*"AI 9 HX"*|*"AI 9 36"*|*"AI 7 35"*|*"AI 5 34"*|*"AI 7 PRO 35"*|*"AI 5 33"*) _gpu_disp_gfx="gfx1150" ;;  # RDNA 3.5 (Strix/Krackan Point: Radeon 890M/880M iGPU, Ryzen AI 9 HX 370/375)
             *"RX 7600"*|*"RX 7700S"*|*"RX 7650"*|*"PRO W7600"*|*"PRO W7500"*|*"PRO V710"*)                  _gpu_disp_gfx="gfx1102" ;;  # RDNA 3 (Navi 33)
             *"RX 7900"*|*"RX 7800"*|*"RX 7700"*|*"PRO W7900"*|*"PRO W7800"*|*"PRO W7700"*)                  _gpu_disp_gfx="gfx1100" ;;  # RDNA 3 desktop / workstation (Navi 31)
@@ -2652,6 +3376,17 @@ elif case "$TORCH_INDEX_URL" in */rocm*|*/gfx*) true ;; *) false ;; esac; then
 elif [ "$OS" = "macos" ] && [ "$_ARCH" = "arm64" ]; then
     # Apple Silicon: PyTorch gets Metal (MPS) acceleration over unified memory, so not CPU-only.
     step "gpu" "Apple Silicon (Metal, unified memory)"
+elif _has_amd_rocm_gpu; then
+    if [ "$_torch_index_pinned" = true ]; then
+        # An explicit UNSLOTH_TORCH_INDEX_URL/_FAMILY pin skipped all probing;
+        # do not claim ROCm is unusable when a CPU/other index was requested.
+        step "gpu" "AMD GPU (torch index pinned: $_torch_index_leaf)" "$C_WARN"
+    else
+        # AMD GPU visible to the kernel but the torch index stayed CPU: no usable
+        # ROCm userspace to pick a wheel. "none" would repeat the false diagnosis
+        # this installer used to give.
+        step "gpu" "AMD GPU (no usable ROCm -- CPU fallback)" "$C_WARN"
+    fi
 else
     step "gpu" "none (CPU-only)" "$C_WARN"
 fi
@@ -2660,8 +3395,17 @@ fi
 case "$TORCH_INDEX_URL" in
     */cpu)
         if [ "$SKIP_TORCH" = false ] && [ "$OS" != "macos" ]; then
-            substep "No GPU detected -- installing CPU-only PyTorch." "$C_WARN"
-            if [ "$OS" = "wsl" ]; then
+            if [ "$_torch_index_pinned" = true ]; then
+                # An explicit CPU pin is a request, not a detection failure:
+                # skip the SDK guidance (ROCm may be perfectly healthy here).
+                substep "CPU-only PyTorch (index pinned via UNSLOTH_TORCH_INDEX_URL / _FAMILY)."
+            elif _has_amd_rocm_gpu; then
+                substep "AMD GPU detected, but no usable ROCm/HIP install -- installing CPU-only PyTorch." "$C_WARN"
+                substep "Install the ROCm/HIP SDK and re-run this installer for GPU PyTorch." "$C_WARN"
+            else
+                substep "No GPU detected -- installing CPU-only PyTorch." "$C_WARN"
+            fi
+            if [ "$OS" = "wsl" ] && [ "$_torch_index_pinned" = false ]; then
                 # WSL + no GPU detected (detection above found nothing). Common
                 # cause: an AMD GPU whose ROCm-on-WSL runtime isn't exposed yet --
                 # /dev/dxg present (graphics) but no ROCm runtime.
@@ -2688,6 +3432,13 @@ case "$TORCH_INDEX_URL" in
                 substep "  driver is current; or run unsloth/scripts/install_rocm_wsl_strixhalo.sh yourself."
             else
                 substep "AMD ROCm users: see https://docs.unsloth.ai/get-started/install-and-update/amd"
+                # Only when ROCm truly can't see the GPU: a detected-but-too-old
+                # ROCm (rocminfo works, wheels need 6.0+) has its own guidance.
+                if ! _has_amd_rocm_gpu && _amd_gpu_present_via_pci; then
+                    substep "An AMD GPU is on the PCI bus but ROCm cannot see it (no /dev/kfd," "$C_WARN"
+                    substep "  rocminfo, or amd-smi). Install the ROCm kernel stack so /dev/kfd exists;"
+                    substep "  Strix Halo (gfx1151/gfx1150) needs a recent kernel (6.11+) and ROCm 7.x."
+                fi
             fi
             substep "Re-run with --no-torch for GGUF-only (faster, no PyTorch):"
             substep "  curl -fsSL https://unsloth.ai/install.sh | sh -s -- --no-torch"
@@ -2697,7 +3448,7 @@ case "$TORCH_INDEX_URL" in
         if [ "$_amd_gpu_radeon" = true ]; then
             substep "wheels: repo.radeon.com (Radeon)"
         else
-            substep "wheels: $TORCH_INDEX_URL"
+            substep "wheels: $(_strip_index_url_credentials "$TORCH_INDEX_URL")"
         fi
         ;;
 esac
@@ -2705,9 +3456,46 @@ esac
 # ── Install unsloth directly into the venv (no activation needed) ──
 tauri_log "STEP" "Installing PyTorch"
 _VENV_PY="$VENV_DIR/bin/python"
+
+# A released unsloth wheel can pin an older torch (unsloth 2026.7.2 declares
+# torch<2.11.0); a with-deps PyPI resolve then downgrades the whole trio,
+# swapping the pinned +cuXXX/+rocm build for PyPI's default. The flavor guard
+# below misses this (PyPI's torch 2.10 default is itself cu128-flavored), so
+# freeze the trio via uv --overrides (overrides replace dependency requirements
+# during resolution) while unsloth's other deps resolve normally. Sets
+# _UNSLOTH_TORCH_OVERRIDES from the trio in the venv; every with-deps unsloth
+# install (migrated and fresh) must call this before resolving and rm it after.
+_build_unsloth_torch_overrides() {
+    _UNSLOTH_TORCH_OVERRIDES=""
+    [ "$SKIP_TORCH" = false ] || return 0
+    _torch_trio_pins=$("$_VENV_PY" -c "
+from importlib.metadata import version, PackageNotFoundError
+for _p in ('torch', 'torchvision', 'torchaudio'):
+    try:
+        print(_p + '==' + version(_p))
+    except PackageNotFoundError:
+        pass
+" 2>/dev/null) || _torch_trio_pins=""
+    case "$_torch_trio_pins" in
+        torch==*)
+            _UNSLOTH_TORCH_OVERRIDES=$(mktemp)
+            printf '%s\n' "$_torch_trio_pins" > "$_UNSLOTH_TORCH_OVERRIDES"
+            # The CLI --overrides flag replaces any UV_OVERRIDE env file (same
+            # uv setting; macOS arm64 exports one here), so fold its pins in.
+            # awk, not cat: it drops inherited torch-trio lines (uv intersects
+            # duplicate overrides, so a conflicting pin would make resolution
+            # unsatisfiable) and newline-terminates the last line so an
+            # unterminated file cannot join two requirements into one.
+            for _ov_file in ${UV_OVERRIDE:-}; do
+                [ -f "$_ov_file" ] && awk '!/^[[:space:]]*torch(vision|audio)?([[:space:]<>=!~;@[]|$)/' "$_ov_file" >> "$_UNSLOTH_TORCH_OVERRIDES"
+            done
+            ;;
+    esac
+}
+
 if [ "$_MIGRATED" = true ]; then
-    # Migrated env: force-reinstall unsloth+unsloth-zoo to ensure clean state
-    # in the new venv location, while preserving existing torch/CUDA
+    # Migrated env: force-reinstall unsloth+unsloth-zoo for a clean state, preserving
+    # existing torch/CUDA unless the ROCm repair below fires.
     substep "upgrading unsloth in migrated environment..."
     if [ "$SKIP_TORCH" = true ]; then
         # No-torch: install unsloth + unsloth-zoo with --no-deps (current
@@ -2716,7 +3504,7 @@ if [ "$_MIGRATED" = true ]; then
         # to prevent transitive torch resolution.
         run_install_cmd_retry "install unsloth (migrated no-torch)" uv pip install --python "$_VENV_PY" --no-deps \
             --reinstall-package unsloth --reinstall-package unsloth-zoo \
-            "unsloth>=2026.7.3" "unsloth-zoo>=2026.7.3"
+            "unsloth>=2026.7.5" "unsloth-zoo>=2026.7.6"
         # Resolve pydantic WITH deps so pip pins pydantic-core to the
         # matching version (no-torch-runtime.txt below is --no-deps).
         # All transitive deps are torch-free.
@@ -2729,9 +3517,13 @@ if [ "$_MIGRATED" = true ]; then
     else
         # Pin mlx-lm away from 0.31.3 here too: a curl-piped migration has no
         # overrides file, so UV_OVERRIDE is unset and this positional is the only cover.
+        _build_unsloth_torch_overrides
         run_install_cmd_retry "install unsloth (migrated)" uv pip install --python "$_VENV_PY" \
+            ${_UNSLOTH_TORCH_OVERRIDES:+--overrides "$_UNSLOTH_TORCH_OVERRIDES"} \
             --reinstall-package unsloth --reinstall-package unsloth-zoo \
-            "unsloth>=2026.7.3" "unsloth-zoo>=2026.7.3" ${_MLX_LM_EXCLUDE_ARG:-}
+            "unsloth>=2026.7.5" "unsloth-zoo>=2026.7.6" ${_MLX_LM_EXCLUDE_ARG:-}
+        [ -n "$_UNSLOTH_TORCH_OVERRIDES" ] && rm -f "$_UNSLOTH_TORCH_OVERRIDES"
+        _UNSLOTH_TORCH_OVERRIDES=""
     fi
     if [ "$STUDIO_LOCAL_INSTALL" = true ]; then
         substep "overlaying local repo (editable)..."
@@ -2744,21 +3536,14 @@ if [ "$_MIGRATED" = true ]; then
     # AMD ROCm: install bitsandbytes even in migrated environments so
     # existing ROCm installs gain the AMD bitsandbytes build without a
     # fresh reinstall.
-    if [ "$SKIP_TORCH" = false ]; then
-        case "$TORCH_INDEX_URL" in
-            */rocm*|*/gfx*)
-                _install_bnb_rocm "install bitsandbytes (AMD)" "$_VENV_PY"
-                # Repair ROCm torch if overwritten during migrated install
-                _has_hip=$("$_VENV_PY" -c "import torch; print(getattr(torch.version,'hip','') or '')" 2>/dev/null || true)
-                if [ -z "$_has_hip" ]; then
-                    substep "repairing ROCm torch (overwritten by dependency resolution)..."
-                    run_install_cmd_retry "repair ROCm torch" uv pip install --python "$_VENV_PY" \
-                        "$TORCH_CONSTRAINT" torchvision torchaudio \
-                        --default-index "$TORCH_INDEX_URL" \
-                        --force-reinstall
-                fi
-                ;;
-        esac
+    if [ "$SKIP_TORCH" = false ] && [ "$_torch_index_is_rocm_family" = true ]; then
+        _install_bnb_rocm "install bitsandbytes (AMD)" "$_VENV_PY"
+        # Repair ROCm torch if overwritten during migrated install
+        _has_hip=$("$_VENV_PY" -c "import torch; print(getattr(torch.version,'hip','') or '')" 2>/dev/null || true)
+        if [ -z "$_has_hip" ]; then
+            substep "repairing ROCm torch (overwritten by dependency resolution)..."
+            _install_torch_default_index --force-reinstall
+        fi
     fi
 elif [ -n "$TORCH_INDEX_URL" ]; then
     # Fresh: Step 1 - install torch from explicit index (skip when --no-torch or Intel Mac)
@@ -2820,7 +3605,42 @@ elif [ -n "$TORCH_INDEX_URL" ]; then
                 _ta_ver=$(_extract_version "$_ta_whl" "torchaudio")
 
                 _radeon_versions_match=false
-                if [ -n "$_torch_ver" ] && [ -n "$_tv_ver" ] && [ -n "$_ta_ver" ]; then
+                # Kept release (_PREV_TORCH_PIN) wins here too: pick its exact
+                # patch (else the newest patch of its minor) plus the paired
+                # vision/audio wheels. Any gap falls back to the newest-trio
+                # search below, mirroring _install_torch_default_index, so a
+                # rerun never drifts to another release nor below the kept one.
+                if [ -n "$_PREV_TORCH_PIN" ]; then
+                    _prev_kept_base="${_PREV_TORCH_PIN#torch==}"
+                    _prev_kept_minor="${_prev_kept_base#*.}"
+                    _prev_kept_minor="${_prev_kept_minor%%.*}"
+                    case "$_prev_kept_minor" in
+                        ''|*[!0-9]*) ;;
+                        *)
+                            _kept_torch=$(_pick_radeon_wheel "torch" "${_prev_kept_base}" 2>/dev/null) || _kept_torch=""
+                            [ -z "$_kept_torch" ] && { _kept_torch=$(_pick_radeon_wheel "torch" "2.${_prev_kept_minor}." 2>/dev/null) || _kept_torch=""; }
+                            _kept_tv=$(_pick_radeon_wheel "torchvision" "0.$((_prev_kept_minor + 15))." 2>/dev/null) || _kept_tv=""
+                            _kept_ta=$(_pick_radeon_wheel "torchaudio" "2.${_prev_kept_minor}." 2>/dev/null) || _kept_ta=""
+                            if [ -n "$_kept_torch" ] && [ -n "$_kept_tv" ] && [ -n "$_kept_ta" ]; then
+                                _torch_whl=$_kept_torch
+                                _tv_whl=$_kept_tv
+                                _ta_whl=$_kept_ta
+                                _tri_whl=""
+                                _radeon_versions_match=true
+                                # Say so when the listing pruned the exact patch
+                                # and a same-series build is installed instead.
+                                case "$(printf '%s' "${_kept_torch##*/}" | sed 's/%2[Bb]/+/g')" in
+                                    "torch-${_prev_kept_base}"[+-]*) ;;
+                                    *) substep "kept release ${_prev_kept_base} is not in the Radeon listing -- installing the closest 2.${_prev_kept_minor} series build instead" ;;
+                                esac
+                            else
+                                substep "[WARN] Radeon repo lacks a complete wheel set for kept $_PREV_TORCH_PIN -- installing the newest compatible set instead" "$C_WARN"
+                            fi
+                            ;;
+                    esac
+                fi
+                if [ "$_radeon_versions_match" != true ] && \
+                   [ -n "$_torch_ver" ] && [ -n "$_tv_ver" ] && [ -n "$_ta_ver" ]; then
                     _torch_minor=${_torch_ver#*.}
                     _ta_minor=${_ta_ver#*.}
                     _tv_minor=${_tv_ver#*.}
@@ -2877,10 +3697,8 @@ elif [ -n "$TORCH_INDEX_URL" ]; then
 
                 if [ -z "$_torch_whl" ] || [ -z "$_tv_whl" ] || [ -z "$_ta_whl" ] || \
                    [ "$_radeon_versions_match" != true ]; then
-                    substep "[WARN] Radeon repo lacks a compatible wheel set for this Python; falling back to ROCm index ($TORCH_INDEX_URL)" "$C_WARN"
-                    run_install_cmd_retry "install PyTorch" uv pip install --python "$_VENV_PY" \
-                        "$TORCH_CONSTRAINT" torchvision torchaudio \
-                        --default-index "$TORCH_INDEX_URL"
+                    substep "[WARN] Radeon repo lacks a compatible wheel set for this Python; falling back to ROCm index ($(_strip_index_url_credentials "$TORCH_INDEX_URL"))" "$C_WARN"
+                    _install_torch_default_index
                 else
                     substep "installing PyTorch from Radeon repo (${_RADEON_BASE_URL})..."
                     # Pass explicit wheel URLs so the matched trio is
@@ -2900,42 +3718,34 @@ elif [ -n "$TORCH_INDEX_URL" ]; then
                     fi
                 fi
             else
-                substep "[WARN] Radeon repo unavailable; falling back to ROCm index ($TORCH_INDEX_URL)" "$C_WARN"
-                run_install_cmd_retry "install PyTorch" uv pip install --python "$_VENV_PY" \
-                    "$TORCH_CONSTRAINT" torchvision torchaudio \
-                    --default-index "$TORCH_INDEX_URL"
+                substep "[WARN] Radeon repo unavailable; falling back to ROCm index ($(_strip_index_url_credentials "$TORCH_INDEX_URL"))" "$C_WARN"
+                _install_torch_default_index
             fi
         else
             substep "[WARN] Radeon GPU detected but could not detect full ROCm version; falling back to ROCm index" "$C_WARN"
-            run_install_cmd_retry "install PyTorch" uv pip install --python "$_VENV_PY" \
-                "$TORCH_CONSTRAINT" torchvision torchaudio \
-                --default-index "$TORCH_INDEX_URL"
+            _install_torch_default_index
         fi
     else
-        substep "installing PyTorch ($TORCH_INDEX_URL)..."
-        run_install_cmd_retry "install PyTorch" uv pip install --python "$_VENV_PY" "$TORCH_CONSTRAINT" torchvision torchaudio \
-            --default-index "$TORCH_INDEX_URL"
+        substep "installing PyTorch ($(_strip_index_url_credentials "$TORCH_INDEX_URL"))..."
+        _install_torch_default_index
     fi
     # AMD ROCm: install bitsandbytes (once, after torch, for all ROCm paths).
     # Gate on SKIP_TORCH=false so a user running with --no-torch on a ROCm
     # host stays in GGUF-only mode rather than pulling in bitsandbytes,
     # which is only useful once torch is present for training.
-    if [ "$SKIP_TORCH" = false ]; then
-        case "$TORCH_INDEX_URL" in
-            */rocm*|*/gfx*)
-                _install_bnb_rocm "install bitsandbytes (AMD)" "$_VENV_PY"
-                ;;
-        esac
+    if [ "$SKIP_TORCH" = false ] && [ "$_torch_index_is_rocm_family" = true ]; then
+        _install_bnb_rocm "install bitsandbytes (AMD)" "$_VENV_PY"
     fi
-    # Fresh: Step 2 - install unsloth, preserving pre-installed torch
+    # Fresh: Step 2 - install unsloth, preserving the torch Step 1 installed
     tauri_log "STEP" "Installing Unsloth"
     substep "installing unsloth (this may take a few minutes)..."
+    _build_unsloth_torch_overrides
     if [ "$SKIP_TORCH" = true ]; then
         # No-torch: install unsloth + unsloth-zoo with --no-deps, then
         # runtime deps (typer, safetensors, transformers, etc.) with --no-deps.
         run_install_cmd_retry "install unsloth (no-torch)" uv pip install --python "$_VENV_PY" --no-deps \
             --upgrade-package unsloth --upgrade-package unsloth-zoo \
-            "unsloth>=2026.7.3" "unsloth-zoo>=2026.7.3"
+            "unsloth>=2026.7.5" "unsloth-zoo>=2026.7.6"
         # Same pydantic-with-deps trick as the migrated branch.
         run_install_cmd_retry "install pydantic (with deps for compatible core)" \
             uv pip install --python "$_VENV_PY" pydantic
@@ -2953,7 +3763,8 @@ elif [ -n "$TORCH_INDEX_URL" ]; then
         fi
     elif [ "$STUDIO_LOCAL_INSTALL" = true ]; then
         run_install_cmd_retry "install unsloth (local)" uv pip install --python "$_VENV_PY" \
-            --upgrade-package unsloth "unsloth>=2026.7.3" "unsloth-zoo>=2026.7.3"
+            ${_UNSLOTH_TORCH_OVERRIDES:+--overrides "$_UNSLOTH_TORCH_OVERRIDES"} \
+            --upgrade-package unsloth "unsloth>=2026.7.5" "unsloth-zoo>=2026.7.6"
         substep "overlaying local repo (editable)..."
         run_install_cmd "overlay local repo" uv pip install --python "$_VENV_PY" -e "$_REPO_ROOT" --no-deps
         substep "overlaying unsloth-zoo from git main..."
@@ -2962,30 +3773,26 @@ elif [ -n "$TORCH_INDEX_URL" ]; then
             "unsloth-zoo @ git+https://github.com/unslothai/unsloth-zoo"
     else
         run_install_cmd_retry "install unsloth" uv pip install --python "$_VENV_PY" \
+            ${_UNSLOTH_TORCH_OVERRIDES:+--overrides "$_UNSLOTH_TORCH_OVERRIDES"} \
             --upgrade-package unsloth -- "$PACKAGE_NAME" ${_MLX_LM_EXCLUDE_ARG:-}
     fi
+    [ -n "$_UNSLOTH_TORCH_OVERRIDES" ] && rm -f "$_UNSLOTH_TORCH_OVERRIDES"
+    _UNSLOTH_TORCH_OVERRIDES=""
     # AMD ROCm: repair torch if the unsloth/unsloth-zoo install pulled in
     # CUDA torch from PyPI, overwriting the ROCm wheels installed in Step 1.
-    if [ "$SKIP_TORCH" = false ]; then
-        case "$TORCH_INDEX_URL" in
-            */rocm*|*/gfx*)
-                _has_hip=$("$_VENV_PY" -c "import torch; print(getattr(torch.version,'hip','') or '')" 2>/dev/null || true)
-                if [ -z "$_has_hip" ]; then
-                    substep "repairing ROCm torch (overwritten by dependency resolution)..."
-                    run_install_cmd_retry "repair ROCm torch" uv pip install --python "$_VENV_PY" \
-                        "$TORCH_CONSTRAINT" torchvision torchaudio \
-                        --default-index "$TORCH_INDEX_URL" \
-                        --force-reinstall
-                fi
-                ;;
-        esac
+    if [ "$SKIP_TORCH" = false ] && [ "$_torch_index_is_rocm_family" = true ]; then
+        _has_hip=$("$_VENV_PY" -c "import torch; print(getattr(torch.version,'hip','') or '')" 2>/dev/null || true)
+        if [ -z "$_has_hip" ]; then
+            substep "repairing ROCm torch (overwritten by dependency resolution)..."
+            _install_torch_default_index --force-reinstall
+        fi
     fi
 else
     # Fallback: GPU detection failed to produce a URL -- let uv resolve torch
     tauri_log "STEP" "Installing Unsloth"
     substep "installing unsloth (this may take a few minutes)..."
     if [ "$STUDIO_LOCAL_INSTALL" = true ]; then
-        run_install_cmd_retry "install unsloth (auto torch backend)" uv pip install --python "$_VENV_PY" "unsloth-zoo>=2026.7.3" "unsloth>=2026.7.3" --torch-backend=auto
+        run_install_cmd_retry "install unsloth (auto torch backend)" uv pip install --python "$_VENV_PY" "unsloth-zoo>=2026.7.6" "unsloth>=2026.7.5" --torch-backend=auto
         substep "overlaying local repo (editable)..."
         run_install_cmd "overlay local repo" uv pip install --python "$_VENV_PY" -e "$_REPO_ROOT" --no-deps
         substep "overlaying unsloth-zoo from git main..."
@@ -2997,6 +3804,15 @@ else
     fi
 fi
 
+_installed_package_version=$("$_VENV_PY" -c \
+    'from importlib.metadata import version; import sys; print(version(sys.argv[1]))' \
+    "$PACKAGE_NAME" 2>/dev/null || true)
+if [ -n "$_installed_package_version" ]; then
+    step "$PACKAGE_NAME" "$_installed_package_version installed"
+else
+    substep "[WARN] installed $PACKAGE_NAME version could not be determined" "$C_WARN"
+fi
+
 # ── Enforce the installed torch flavor matches the detected GPU build ──
 # PEP 440 ignores the +cpu/+cuXXX/+rocm local label in a version range, so uv
 # keeps a stale torch==X+cpu against a GPU index and the venv silently trains on
@@ -3014,9 +3830,7 @@ if [ "$SKIP_TORCH" = false ] && [ -n "${TORCH_INDEX_URL:-}" ]; then
         if [ -n "$_installed_torch_tag" ] && [ "$_installed_torch_tag" != "$_expected_torch_tag" ] \
            && [ "$(_torch_index_repairable "$TORCH_INDEX_URL")" = "yes" ]; then
             substep "PyTorch flavor mismatch (installed $_installed_torch_tag, need $_expected_torch_tag) -- reinstalling correct build..."
-            run_install_cmd "reinstall PyTorch ($_expected_torch_tag)" uv pip install --python "$_VENV_PY" \
-                "$TORCH_CONSTRAINT" torchvision torchaudio \
-                --default-index "$TORCH_INDEX_URL" \
+            _install_torch_default_index \
                 --reinstall-package torch --reinstall-package torchvision --reinstall-package torchaudio
             _installed_torch_ver=$("$_VENV_PY" -c "import torch; print(torch.__version__)" 2>/dev/null || true)
             _installed_torch_tag=""
@@ -3027,13 +3841,13 @@ if [ "$SKIP_TORCH" = false ] && [ -n "${TORCH_INDEX_URL:-}" ]; then
             substep "[WARN] PyTorch is CPU-only but a $_expected_torch_tag GPU build was expected for this machine." "$C_WARN"
             substep "[WARN] Training and GPU inference will run on CPU until this is fixed." "$C_WARN"
             substep "[WARN] Re-run this installer, or reinstall the GPU build manually:" "$C_WARN"
-            substep "[WARN]   uv pip install --python \"$_VENV_PY\" \"$TORCH_CONSTRAINT\" torchvision torchaudio --default-index $TORCH_INDEX_URL --reinstall-package torch --reinstall-package torchvision --reinstall-package torchaudio" "$C_WARN"
+            substep "[WARN]   uv pip install --python \"$_VENV_PY\" \"$TORCH_CONSTRAINT\" \"$TORCHVISION_CONSTRAINT\" \"$TORCHAUDIO_CONSTRAINT\" --default-index $(_strip_index_url_credentials "$TORCH_INDEX_URL") --reinstall-package torch --reinstall-package torchvision --reinstall-package torchaudio" "$C_WARN"
         fi
     fi
 fi
 
 # ── Run studio setup ──
-tauri_log "STEP" "Running Studio setup"
+tauri_log "STEP" "Running Unsloth setup"
 # When --local, use the repo's own setup.sh directly.
 # Otherwise, find it inside the installed package.
 SETUP_SH=""
@@ -3227,7 +4041,7 @@ printf "  ${C_TITLE}%s${C_RST}\n" "Unsloth Studio installed!"
 printf "  ${C_DIM}%s${C_RST}\n" "$RULE"
 echo ""
 
-# In interactive terminals, ask the user before starting Studio unless the
+# In interactive terminals, ask the user before starting Unsloth unless the
 # caller explicitly disabled the post-install prompt.
 # In non-interactive environments (Docker, CI, cloud-init) just print instructions.
 if [ "$_SKIP_AUTOSTART" != true ] && [ -t 1 ]; then
diff --git a/pyproject.toml b/pyproject.toml
index f8754d5143..f7da75b6d3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -25,7 +25,7 @@ classifiers = [
     "Topic :: Scientific/Engineering :: Artificial Intelligence",
 ]
 dependencies = [
-    "typer",
+    "typer>=0.12.0",
     "rich",
     "pydantic",
     "pyyaml",
@@ -42,7 +42,7 @@ version = {attr = "unsloth.models._utils.__version__"}
 include-package-data = true
 
 [tool.setuptools.package-data]
-unsloth_cli = ["codex_fallback_prompt.md"]
+unsloth_cli = ["codex_fallback_prompt.md", "pi_subagent.ts"]
 studio = [
     "*.sh",
     "*.ps1",
@@ -74,7 +74,7 @@ triton = [
 ]
 
 huggingfacenotorch = [
-    "unsloth_zoo>=2026.7.3",
+    "unsloth_zoo>=2026.7.6",
     "wheel>=0.42.0",
     "packaging",
     "numpy",
@@ -93,9 +93,20 @@ huggingfacenotorch = [
     "trl>=0.18.2,!=0.19.0,<=0.24.0",
     "sentence-transformers",
 ]
+# torchcodec backend for Gemma audio / datasets>=4 (#7225).
+# Pick the audio-torch* pin matching your torch minor (see TORCH_TORCHCODEC).
+audio-torch210 = [
+    "torchcodec>=0.10.0,<0.11.0 ; python_version >= '3.10'",
+]
+audio-torch290 = [
+    "torchcodec>=0.8.0,<0.10.0 ; python_version >= '3.10'",
+]
+audio-torch280 = [
+    "torchcodec>=0.6.0,<0.8.0 ; python_version >= '3.9'",
+]
 huggingface = [
     "unsloth[huggingfacenotorch]",
-    "unsloth_zoo>=2026.7.3",
+    "unsloth_zoo>=2026.7.6",
     "torchvision",
     "unsloth[triton]",
 ]
@@ -541,16 +552,19 @@ cu126-torch2100 = [
     "unsloth[huggingface]",
     "bitsandbytes>=0.45.5,!=0.46.0,!=0.48.0",
     "unsloth[cu126onlytorch2100]",
+    "unsloth[audio-torch210]",
 ]
 cu128-torch2100 = [
     "unsloth[huggingface]",
     "bitsandbytes>=0.45.5,!=0.46.0,!=0.48.0",
     "unsloth[cu128onlytorch2100]",
+    "unsloth[audio-torch210]",
 ]
 cu130-torch2100 = [
     "unsloth[huggingface]",
     "bitsandbytes>=0.45.5,!=0.46.0,!=0.48.0",
     "unsloth[cu130onlytorch2100]",
+    "unsloth[audio-torch210]",
 ]
 kaggle = [
     "unsloth[huggingface]",
@@ -589,7 +603,7 @@ colab-ampere-torch220 = [
     "flash-attn>=2.6.3 ; ('linux' in sys_platform)",
 ]
 colab-new = [
-    "unsloth_zoo>=2026.7.3",
+    "unsloth_zoo>=2026.7.6",
     "packaging",
     "tyro",
     "transformers>=4.51.3,!=4.52.0,!=4.52.1,!=4.52.2,!=4.52.3,!=4.53.0,!=4.54.0,!=4.55.0,!=4.55.1,!=4.57.0,!=4.57.4,!=4.57.5,!=5.0.0,!=5.1.0,<=5.5.0",
@@ -840,16 +854,19 @@ cu126-ampere-torch2100 = [
     "unsloth[huggingface]",
     "bitsandbytes>=0.45.5,!=0.46.0,!=0.48.0",
     "unsloth[cu126onlytorch2100]",
+    "unsloth[audio-torch210]",
 ]
 cu128-ampere-torch2100 = [
     "unsloth[huggingface]",
     "bitsandbytes>=0.45.5,!=0.46.0,!=0.48.0",
     "unsloth[cu128onlytorch2100]",
+    "unsloth[audio-torch210]",
 ]
 cu130-ampere-torch2100 = [
     "unsloth[huggingface]",
     "bitsandbytes>=0.45.5,!=0.46.0,!=0.48.0",
     "unsloth[cu130onlytorch2100]",
+    "unsloth[audio-torch210]",
 ]
 flashattentiontorch260abiFALSEcu12x = [
     "flash-attn @ https://github.com/Dao-AILab/flash-attention/releases/download/v2.7.4.post1/flash_attn-2.7.4.post1+cu12torch2.6cxx11abiFALSE-cp39-cp39-linux_x86_64.whl ; ('linux' in sys_platform) and python_version == '3.9'",
@@ -1134,7 +1151,8 @@ intelgputorch210 = [
     "torchvision @ https://download.pytorch.org/whl/xpu/torchvision-0.25.0%2Bxpu-cp313-cp313-win_amd64.whl#sha256=1c4b44b36a557f7381e3076fb8843366742238648441d607c8d049c6da0f8886 ; sys_platform == 'win32' and python_version == '3.13' and (platform_machine == 'AMD64' or platform_machine == 'x86_64')",
 ]
 intel-gpu-torch210 = [
-    "unsloth[intelgputorch210]"
+    "unsloth[intelgputorch210]",
+    "unsloth[audio-torch210]",
 ]
 intelgputorch2110 = [
     "unsloth_zoo[intelgpu]",
@@ -1288,6 +1306,7 @@ rocm72-torch2100 = [
     "torchvision @ https://repo.radeon.com/rocm/manylinux/rocm-rel-7.2/torchvision-0.25.0%2Brocm7.2.0.git82df5f59-cp311-cp311-linux_x86_64.whl ; platform_system == 'Linux' and python_version == '3.11' and platform_machine == 'x86_64'",
     "torchvision @ https://repo.radeon.com/rocm/manylinux/rocm-rel-7.2/torchvision-0.25.0%2Brocm7.2.0.git82df5f59-cp312-cp312-linux_x86_64.whl ; platform_system == 'Linux' and python_version == '3.12' and platform_machine == 'x86_64'",
     "torchvision @ https://repo.radeon.com/rocm/manylinux/rocm-rel-7.2/torchvision-0.25.0%2Brocm7.2.0.git82df5f59-cp313-cp313-linux_x86_64.whl ; platform_system == 'Linux' and python_version == '3.13' and platform_machine == 'x86_64'",
+    "unsloth[audio-torch210]",
 ]
 rocm711-torch2100 = [
     "unsloth[amd]",
@@ -1306,6 +1325,7 @@ rocm711-torch2100 = [
     "torchvision @ https://repo.radeon.com/rocm/manylinux/rocm-rel-7.1.1/torchvision-0.25.0%2Brocm7.1.1.git82df5f59-cp311-cp311-linux_x86_64.whl ; platform_system == 'Linux' and python_version == '3.11' and platform_machine == 'x86_64'",
     "torchvision @ https://repo.radeon.com/rocm/manylinux/rocm-rel-7.1.1/torchvision-0.25.0%2Brocm7.1.1.git82df5f59-cp312-cp312-linux_x86_64.whl ; platform_system == 'Linux' and python_version == '3.12' and platform_machine == 'x86_64'",
     "torchvision @ https://repo.radeon.com/rocm/manylinux/rocm-rel-7.1.1/torchvision-0.25.0%2Brocm7.1.1.git82df5f59-cp313-cp313-linux_x86_64.whl ; platform_system == 'Linux' and python_version == '3.13' and platform_machine == 'x86_64'",
+    "unsloth[audio-torch210]",
 ]
 
 [project.urls]
diff --git a/scripts/build_whisper_cpp.sh b/scripts/build_whisper_cpp.sh
new file mode 100755
index 0000000000..9f7e4d4ef3
--- /dev/null
+++ b/scripts/build_whisper_cpp.sh
@@ -0,0 +1,71 @@
+#!/bin/sh
+# Build whisper.cpp's whisper-server for Studio's GGUF dictation engine.
+#
+# Installs into the managed Studio home so the backend's binary discovery
+# (core/inference/stt_ggml_sidecar.py::find_whisper_server_binary) picks it up:
+#   <UNSLOTH_STUDIO_HOME>/whisper.cpp/build/bin/whisper-server   (custom home)
+#   ~/.unsloth/whisper.cpp/build/bin/whisper-server              (default)
+#
+# Usage:
+#   ./scripts/build_whisper_cpp.sh              # build the pinned tag
+#   WHISPER_CPP_TAG=v1.9.0 ./scripts/build_whisper_cpp.sh
+#
+# Requires: git, cmake, a C/C++ toolchain (the same prerequisites as a
+# llama.cpp source build). GPU backends are auto-detected by whisper.cpp's
+# CMake (Metal on macOS; set GGML_CUDA=1 to force a CUDA build on Linux).
+
+set -eu
+
+WHISPER_CPP_SOURCE="${WHISPER_CPP_SOURCE:-https://github.com/ggml-org/whisper.cpp}"
+WHISPER_CPP_TAG="${WHISPER_CPP_TAG:-v1.9.1}"
+
+STUDIO_HOME="${UNSLOTH_STUDIO_HOME:-${STUDIO_HOME:-}}"
+CUSTOM_STUDIO_HOME=false
+if [ -n "$STUDIO_HOME" ]; then
+    CUSTOM_STUDIO_HOME=true
+    INSTALL_DIR="$STUDIO_HOME/whisper.cpp"
+else
+    INSTALL_DIR="$HOME/.unsloth/whisper.cpp"
+fi
+
+command -v git >/dev/null 2>&1 || { echo "ERROR: git is required" >&2; exit 1; }
+command -v cmake >/dev/null 2>&1 || { echo "ERROR: cmake is required" >&2; exit 1; }
+
+# Same policy as studio/setup.sh's _assert_studio_owned_or_absent: never delete
+# a directory under a custom Studio home unless Studio itself created it (the
+# marker file below). Protects a user-managed whisper.cpp/src from rm -rf.
+STUDIO_OWNED_MARKER=".unsloth-studio-owned"
+if [ "$CUSTOM_STUDIO_HOME" = true ] && [ -e "$INSTALL_DIR" ] && \
+   [ ! -f "$INSTALL_DIR/$STUDIO_OWNED_MARKER" ]; then
+    echo "ERROR: $INSTALL_DIR already exists and is not marked as an Unsloth-owned whisper.cpp build tree." >&2
+    echo "       Move it aside or choose an empty UNSLOTH_STUDIO_HOME before re-running." >&2
+    exit 1
+fi
+
+echo "==> Building whisper.cpp ($WHISPER_CPP_TAG) into $INSTALL_DIR"
+mkdir -p "$INSTALL_DIR"
+: > "$INSTALL_DIR/$STUDIO_OWNED_MARKER"
+
+if [ ! -d "$INSTALL_DIR/src/.git" ]; then
+    rm -rf "$INSTALL_DIR/src"
+    git clone --depth 1 --branch "$WHISPER_CPP_TAG" "$WHISPER_CPP_SOURCE" "$INSTALL_DIR/src"
+else
+    git -C "$INSTALL_DIR/src" fetch --depth 1 origin "$WHISPER_CPP_TAG"
+    git -C "$INSTALL_DIR/src" checkout FETCH_HEAD
+fi
+
+CMAKE_FLAGS="-DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=OFF"
+if [ "${GGML_CUDA:-0}" = "1" ]; then
+    CMAKE_FLAGS="$CMAKE_FLAGS -DGGML_CUDA=ON"
+fi
+
+# shellcheck disable=SC2086
+cmake -S "$INSTALL_DIR/src" -B "$INSTALL_DIR/src/build" $CMAKE_FLAGS
+NCPU="$(getconf _NPROCESSORS_ONLN 2>/dev/null || echo 4)"
+cmake --build "$INSTALL_DIR/src/build" --config Release --target whisper-server -j"$NCPU"
+
+mkdir -p "$INSTALL_DIR/build/bin"
+cp "$INSTALL_DIR/src/build/bin/whisper-server" "$INSTALL_DIR/build/bin/whisper-server"
+
+echo "==> Installed $INSTALL_DIR/build/bin/whisper-server"
+"$INSTALL_DIR/build/bin/whisper-server" --help >/dev/null 2>&1 && echo "==> Binary runs OK"
diff --git a/scripts/install_rocm_wsl_strixhalo.sh b/scripts/install_rocm_wsl_strixhalo.sh
index aa560fc432..697aae933f 100644
--- a/scripts/install_rocm_wsl_strixhalo.sh
+++ b/scripts/install_rocm_wsl_strixhalo.sh
@@ -219,7 +219,7 @@ fi
 echo "${ROCM_DIR}/lib" | $SUDO tee /etc/ld.so.conf.d/rocm.conf >/dev/null
 $SUDO ldconfig
 
-# ── Step 4: persist environment (system-wide so Studio's worker inherits it) ──
+# ── Step 4: persist environment (system-wide so Unsloth's worker inherits it) ──
 say "Persisting ROCm-on-WSL environment"
 _envfile="/etc/profile.d/unsloth-rocm-wsl.sh"
 $SUDO tee "$_envfile" >/dev/null <<EOF
diff --git a/scripts/lockfile_supply_chain_audit.py b/scripts/lockfile_supply_chain_audit.py
index 66b48c094d..f9cf726dc1 100644
--- a/scripts/lockfile_supply_chain_audit.py
+++ b/scripts/lockfile_supply_chain_audit.py
@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 
-"""Lockfile supply-chain audit for the Studio frontend and Tauri shell.
+"""Lockfile supply-chain audit for the Unsloth frontend and Tauri shell.
 
 Runs BEFORE `npm ci` / `cargo fetch` in CI. Refuses to proceed when a
 lockfile contains patterns indicating supply-chain injection (npm
@@ -294,7 +294,7 @@ CARGO_REGISTRY_SOURCE = "registry+https://github.com/rust-lang/crates.io-index"
 
 # Cargo non-registry source allowlist: `(crate_name, exact_source_string)`.
 # Both must match verbatim; bumping the pinned SHA forces a re-review.
-# Studio's Tauri shell pulls `fix-path-env` from git because it is not
+# Unsloth's Tauri shell pulls `fix-path-env` from git because it is not
 # published to crates.io; commit c4c45d5 was reviewed when it landed.
 CARGO_SOURCE_ALLOWLIST: tuple[tuple[str, str], ...] = (
     (
diff --git a/scripts/notebook_validator.py b/scripts/notebook_validator.py
index c1be7a63a4..7bcee47c66 100644
--- a/scripts/notebook_validator.py
+++ b/scripts/notebook_validator.py
@@ -95,8 +95,8 @@ COLAB_ORACLE_BASE_URL = "https://raw.githubusercontent.com/googlecolab/backend-i
 # Source: pytorch/torchcodec compatibility matrix on its README.
 TORCH_TORCHCODEC: dict[str, set[str]] = {
     "2.10": {"0.10"},
-    "2.9": {"0.7", "0.8", "0.9"},
-    "2.8": {"0.6"},
+    "2.9": {"0.8", "0.9"},
+    "2.8": {"0.6", "0.7"},
     "2.7": {"0.3", "0.4", "0.5"},
     "2.6": {"0.2", "0.3"},
     "2.5": {"0.1", "0.2"},
diff --git a/scripts/scan_npm_packages.py b/scripts/scan_npm_packages.py
index 47b85147ca..6c83552727 100644
--- a/scripts/scan_npm_packages.py
+++ b/scripts/scan_npm_packages.py
@@ -62,7 +62,7 @@ REPO_ROOT = Path(__file__).resolve().parents[1]
 # Hard caps (deliberately conservative; npm tarballs in this repo are
 # all well under these limits, so a packaging spike is noticeable).
 # ─────────────────────────────────────────────────────────────────────
-# Caps calibrated against the real Studio frontend transitive closure:
+# Caps calibrated against the real Unsloth frontend transitive closure:
 #   - typescript.js is 9.1 MB (TS compiler bundled into one file)
 #   - mermaid 11.x dist/mermaid.js.map is ~12 MB (sourcemap)
 #   - lightningcss-linux-x64-{gnu,musl}.node is 10 MB
diff --git a/scripts/scan_packages_baseline.json b/scripts/scan_packages_baseline.json
index 929cc37bda..1c21f8da86 100644
--- a/scripts/scan_packages_baseline.json
+++ b/scripts/scan_packages_baseline.json
@@ -1,5 +1,5 @@
 {
-  "_comment": "scan_packages.py allowlist. Each entry is a CRITICAL/HIGH finding manually judged benign. Matched on (package, package-relative file, check, evidence_hash); evidence_hash is over the matched code with L<NN>: markers stripped, so version bumps and line shifts do not reopen an entry but changed code does. severity and evidence are for review only. Regenerate with --write-baseline AFTER reviewing every line.",
+  "_comment": "scan_packages.py allowlist (reviewed). Each entry is a CRITICAL/HIGH finding manually judged benign. Matched on (package, package-relative file, check, evidence_hash); evidence_hash is over the matched code with L<NN>: markers stripped, so version bumps and line shifts do not reopen an entry but changed code does. severity and evidence are for review only. Regenerate with --write-baseline AFTER reviewing every line.",
   "version": 1,
   "entries": [
     {
@@ -95,8 +95,8 @@
       "file": "fastapi/routing.py",
       "check": "C2 polling/beaconing loop detected",
       "severity": "CRITICAL",
-      "evidence": "L586:                                 while True: sha256:251135b5ebfdd1248916449f32262575e003ef64382501c65b7e4061d67bda45",
-      "evidence_hash": "365aef4449c8089753d9398417cd76ab762cef547d75db70d87bca9c0b550ab5"
+      "evidence": "L587:                                 while True: sha256:06c2c7f15d73bf192e5e3272c5ff5fcaeff7f6774fef5f4eca6ef473ae50e2b3",
+      "evidence_hash": "57acd497f404c203e4450d0580ad85aa8a33406e8d64ad06fbac6cf47d97b24d"
     },
     {
       "package": "fastmcp-slim",
@@ -303,8 +303,8 @@
       "file": "openai/_base_client.py",
       "check": "C2 polling/beaconing loop detected",
       "severity": "CRITICAL",
-      "evidence": "L264:         while True: sha256:95ca67e46d42354ae650abbdc5b0d97df8b0ed43187800bf40f5690c3901b94b",
-      "evidence_hash": "a57d8d15fed0bf04f9967dcc18a18b80bb19f4095675bccbb78ac0450d7fce14"
+      "evidence": "L274:         while True: sha256:90a38e5c1e26893c7c273354143612640e9a9c0f079d3e2b60612d79f24e80a6",
+      "evidence_hash": "1022e8e8649436ec64a98a9d9141d085452c49549fd2157b0278fc369a83ac66"
     },
     {
       "package": "openai",
@@ -319,8 +319,8 @@
       "file": "openai/auth/_workload.py",
       "check": "Accesses cloud metadata/IMDS AND makes network calls",
       "severity": "CRITICAL",
-      "evidence": "IMDS: L96:             url = \"http://169.254.169.254/metadata/identity/oauth2/token\" | L149:             url = \"http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/identity\"\nNetwork: L77:     http_client: httpx.Client | None = None, | L108:                 with httpx.Client() as client: | L133:     http_client: httpx.Client | None = None, | L155:                 with httpx.Client() as client: | L248:         with httpx.Client() as client:",
-      "evidence_hash": "1581d9f4a23393e9af23fbe5ef9f66807b22c5b5a3f1fe167254c9ebee108567"
+      "evidence": "IMDS: L97:             url = \"http://169.254.169.254/metadata/identity/oauth2/token\" | L150:             url = \"http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/identity\"\nNetwork: L78:     http_client: httpx.Client | None = None, | L109:                 with httpx.Client() as client: | L134:     http_client: httpx.Client | None = None, | L156:                 with httpx.Client() as client: | L251:         exchange_client = DefaultHttpx2Client(follow_redirects=False) if self._use_httpx2 else httpx.Client()",
+      "evidence_hash": "9717e51cb961dc14c458955d91a1e48e3753997346ecea0106bded3a8d64bfe0"
     },
     {
       "package": "openai",
@@ -343,8 +343,8 @@
       "file": "openai/resources/beta/responses/responses.py",
       "check": "C2 polling/beaconing loop detected",
       "severity": "CRITICAL",
-      "evidence": "L3999:         while True: sha256:df298b6eaf3416589b79f4ef283f8fb76e54d505bfda8840673f8e6419117e2e",
-      "evidence_hash": "10ce5cb5a7097fcff4042ddcfb4802edda60aa4b7b113c8b926a52ddb76f78c2"
+      "evidence": "L4000:         while True: sha256:f8ab538118daba9ec06e27399dbdc90a4521c3390e6a47a6348a1f180a83effd",
+      "evidence_hash": "31481ea83c687acc27144d72d3832d4fb98dd1c79fb5e0ddd85080de95997b9f"
     },
     {
       "package": "openai",
@@ -359,16 +359,16 @@
       "file": "openai/resources/realtime/realtime.py",
       "check": "C2 polling/beaconing loop detected",
       "severity": "CRITICAL",
-      "evidence": "L310:         while True: sha256:458198ff3d3f05870bf98c9564cbfd68c739e57b9bbe4120ed81e3eb6af74a05",
-      "evidence_hash": "a3165d21e46b3ce553795daeae53e8f80e8e89c5cb228e68e6dcaff54bca5a89"
+      "evidence": "L311:         while True: sha256:5b63313072aae9ca28677e03426513ccf12221e4f4e0ea6c31efbe09790633b5",
+      "evidence_hash": "05e1af469d651b51673763a7c4cdf759af9472fb627b7b470adc28cc237bd650"
     },
     {
       "package": "openai",
       "file": "openai/resources/responses/responses.py",
       "check": "C2 polling/beaconing loop detected",
       "severity": "CRITICAL",
-      "evidence": "L3950:         while True: sha256:1ce0b5a388c747945cdfda1a71b77afdfd03ae840d7aa9fa62f02eb00aa5e29f",
-      "evidence_hash": "6de300ebb5e6e17cb51c89cbcdf08515a44655182f0776f0908a9d1043ebbcd7"
+      "evidence": "L3951:         while True: sha256:d68ef896bf0743ca430cfacb9a3353da1f3b9c51c3a21b6450a07a32b55aa2ac",
+      "evidence_hash": "160eecdd79b521bffbe8476f782b69a0724c35d1b19376a7600807165fd54f9f"
     },
     {
       "package": "openai",
@@ -1545,6 +1545,78 @@
       "severity": "HIGH",
       "evidence": "Obfusc: L836:         code = compile(module, \"<werkzeug routing>\", \"exec\")\nExec: L736:         exec(code, globs, locs)",
       "evidence_hash": "5c0992c90f05c772abd94d00784f157de337e1f8567f8b3aee1b15e46c96cd5d"
+    },
+    {
+      "package": "unsloth-zoo",
+      "file": "tests/test_mlx_save_export_regressions.py",
+      "check": "Writes to /tmp and executes (staged dropper)",
+      "severity": "CRITICAL",
+      "evidence": "L165:         temporary_location=\"/tmp/ignored\", sha256:ab5c587f9ec31a0cc10ee55698ab133a417148d9d3f371bbc81b1e13fa119c13",
+      "evidence_hash": "93a11159147aad94f353ec4d2e0b8486b256abef88cd96d741813222cd32b138"
+    },
+    {
+      "package": "unsloth-zoo",
+      "file": "tests/test_vision_collator_audio.py",
+      "check": "Writes to /tmp and executes (staged dropper)",
+      "severity": "CRITICAL",
+      "evidence": "L111:         out = extract_audio_info(msgs({\"type\": \"audio\", key: \"/tmp/a.wav\"})) sha256:2efe23ffbe2b91b8403aec9b700736919b59e5ca770f8e1f5501651b44b7d398",
+      "evidence_hash": "d416b79dd17b24214f3f7653ac01354507d7bf0fc464dee30a4a4b8998f063ba"
+    },
+    {
+      "package": "openai",
+      "file": "openai/_base_client.py",
+      "check": "C2 polling/beaconing loop detected",
+      "severity": "CRITICAL",
+      "evidence": "L274:         while True: sha256:90a38e5c1e26893c7c273354143612640e9a9c0f079d3e2b60612d79f24e80a6",
+      "evidence_hash": "1022e8e8649436ec64a98a9d9141d085452c49549fd2157b0278fc369a83ac66"
+    },
+    {
+      "package": "openai",
+      "file": "openai/auth/_workload.py",
+      "check": "Accesses cloud metadata/IMDS AND makes network calls",
+      "severity": "CRITICAL",
+      "evidence": "IMDS: L97:             url = \"http://169.254.169.254/metadata/identity/oauth2/token\" | L150:             url = \"http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/identity\"\nNetwork: L78:     http_client: httpx.Client | None = None, | L109:                 with httpx.Client() as client: | L134:     http_client: httpx.Client | None = None, | L156:                 with httpx.Client() as client: | L251:         exchange_client = DefaultHttpx2Client(follow_redirects=False) if self._use_httpx2 else httpx.Client()",
+      "evidence_hash": "9717e51cb961dc14c458955d91a1e48e3753997346ecea0106bded3a8d64bfe0"
+    },
+    {
+      "package": "openai",
+      "file": "openai/resources/beta/responses/responses.py",
+      "check": "C2 polling/beaconing loop detected",
+      "severity": "CRITICAL",
+      "evidence": "L4000:         while True: sha256:f8ab538118daba9ec06e27399dbdc90a4521c3390e6a47a6348a1f180a83effd",
+      "evidence_hash": "31481ea83c687acc27144d72d3832d4fb98dd1c79fb5e0ddd85080de95997b9f"
+    },
+    {
+      "package": "openai",
+      "file": "openai/resources/realtime/realtime.py",
+      "check": "C2 polling/beaconing loop detected",
+      "severity": "CRITICAL",
+      "evidence": "L311:         while True: sha256:5b63313072aae9ca28677e03426513ccf12221e4f4e0ea6c31efbe09790633b5",
+      "evidence_hash": "05e1af469d651b51673763a7c4cdf759af9472fb627b7b470adc28cc237bd650"
+    },
+    {
+      "package": "openai",
+      "file": "openai/resources/responses/responses.py",
+      "check": "C2 polling/beaconing loop detected",
+      "severity": "CRITICAL",
+      "evidence": "L3951:         while True: sha256:d68ef896bf0743ca430cfacb9a3353da1f3b9c51c3a21b6450a07a32b55aa2ac",
+      "evidence_hash": "160eecdd79b521bffbe8476f782b69a0724c35d1b19376a7600807165fd54f9f"
+    },
+    {
+      "package": "unsloth-zoo",
+      "file": "tests/test_gemma4_forced_float32_ple_dtype.py",
+      "check": "Advanced obfuscation (marshal/compile/zlib) + exec/eval",
+      "severity": "HIGH",
+      "evidence": "Obfusc: L277:     compile(rewritten + _GEMMA4_PLE_CAST_HELPER, \"<gemma4-ple-generated>\", \"exec\") | L440:     compile(on, \"<gemma4-ple-append>\", \"exec\") | L468:     compile(generated, \"<gemma4-ple-crosspath>\", \"exec\")\nExec: L19:     exec(_GEMMA4_PLE_CAST_HELPER, namespace)",
+      "evidence_hash": "a85e24d8e7c431563cbd83b70f91a3b971abde0f37083d68e70984147960cc70"
+    },
+    {
+      "package": "unsloth-zoo",
+      "file": "tests/test_vision_collator_audio.py",
+      "check": "Writes to /tmp and executes (staged dropper)",
+      "severity": "CRITICAL",
+      "evidence": "L111:         out = extract_audio_info(msgs({\"type\": \"audio\", key: \"/tmp/a.wav\"})) sha256:022f81dd21acfc6a35a058de96132834c218404a9e37b3d09a7768a8c8f6c728",
+      "evidence_hash": "2d1e75446af120d9133a42aa8af426a839d3434d9dc109cc1d6c1b22ca1ddb75"
     }
   ]
 }
diff --git a/scripts/stamp_studio_release.py b/scripts/stamp_studio_release.py
index 7dab35ea8a..739f6d1063 100644
--- a/scripts/stamp_studio_release.py
+++ b/scripts/stamp_studio_release.py
@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Stamp and verify display-only Studio release metadata for builds."""
+"""Stamp and verify display-only Unsloth release metadata for builds."""
 
 from __future__ import annotations
 
@@ -50,7 +50,7 @@ MAX_VERSION_LENGTH = 64
 PLACEHOLDER = """# SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-\"\"\"Build-stamped Studio release metadata.
+\"\"\"Build-stamped Unsloth release metadata.
 
 Release builds may rewrite this module in the build workspace before creating
 Python artifacts. Keep the committed value neutral so source checkouts do not
@@ -145,7 +145,7 @@ def build_info_source(version: str | None) -> str:
     return f'''# SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Build-stamped Studio release metadata."""
+"""Build-stamped Unsloth release metadata."""
 
 STUDIO_RELEASE_VERSION = {literal}
 '''
@@ -168,7 +168,7 @@ def stamp(require_release: bool) -> int:
     version, source = resolve_version()
     if version is not None and not is_valid_version(version):
         print(
-            f"Invalid Studio release version from {source}: {version!r}",
+            f"Invalid Unsloth release version from {source}: {version!r}",
             file = sys.stderr,
         )
         return 2
@@ -196,9 +196,9 @@ def stamp(require_release: bool) -> int:
     if version is None:
         if require_release:
             print(
-                "No Studio release version available. Set "
+                "No Unsloth release version available. Set "
                 "UNSLOTH_STUDIO_RELEASE_VERSION, build from a GitHub tag, "
-                "or run from an exact local Studio release tag.",
+                "or run from an exact local Unsloth release tag.",
                 file = sys.stderr,
             )
             return 2
@@ -207,7 +207,7 @@ def stamp(require_release: bool) -> int:
         return 0
 
     _atomic_write_text(BUILD_INFO_PATH, build_info_source(version), encoding = "utf-8")
-    print(f"Stamping Studio release version {version} from {source}", file = sys.stderr)
+    print(f"Stamping Unsloth release version {version} from {source}", file = sys.stderr)
     print(version)
     return 0
 
@@ -233,7 +233,7 @@ def _read_sdist_member(path: Path) -> str | None:
 
 def verify_dist(expected: str, dist_dir: Path) -> int:
     if not is_valid_version(expected):
-        print(f"Invalid expected Studio release version: {expected!r}", file = sys.stderr)
+        print(f"Invalid expected Unsloth release version: {expected!r}", file = sys.stderr)
         return 2
 
     artifacts = list(dist_dir.glob("*.whl")) + list(dist_dir.glob("*.tar.gz"))
@@ -251,14 +251,14 @@ def verify_dist(expected: str, dist_dir: Path) -> int:
         if content is None:
             failures.append(f"{artifact.name}: missing {BUILD_INFO_SUFFIX}")
         elif expected_line not in content:
-            failures.append(f"{artifact.name}: Studio release version mismatch")
+            failures.append(f"{artifact.name}: Unsloth release version mismatch")
 
     if failures:
         for failure in failures:
             print(failure, file = sys.stderr)
         return 2
 
-    print(f"Verified Studio release version {expected} in {len(artifacts)} artifact(s)")
+    print(f"Verified Unsloth release version {expected} in {len(artifacts)} artifact(s)")
     return 0
 
 
diff --git a/scripts/uninstall.ps1 b/scripts/uninstall.ps1
index 88defb9ea0..9b6e6ebb86 100644
--- a/scripts/uninstall.ps1
+++ b/scripts/uninstall.ps1
@@ -83,7 +83,7 @@ function Uninstall-UnslothStudio {
         }
     }
 
-    # A path is a Studio-owned root iff one of install.ps1's sentinels exists:
+    # A path is an Unsloth-owned root iff one of install.ps1's sentinels exists:
     #   <root>\share\studio.conf, <root>\unsloth_studio\.unsloth-studio-owned,
     #   or <root>\bin\unsloth.exe.
     function _IsStudioRoot {
@@ -164,7 +164,7 @@ function Uninstall-UnslothStudio {
         return $p
     }
 
-    # Discover non-default Studio roots from env vars + studio.conf files.
+    # Discover non-default Unsloth roots from env vars + studio.conf files.
     # Mirrors install.ps1's precedence: UNSLOTH_STUDIO_HOME wins, STUDIO_HOME
     # is ignored when both are set, so uninstalling install A doesn't also
     # delete install B if the user has a stale STUDIO_HOME pointing at B.
@@ -207,7 +207,7 @@ function Uninstall-UnslothStudio {
 
     # Return $true iff the PID's image path lives under one of $KnownRoots.
     # Prevents killing an unrelated process that happens to listen on a stale
-    # Studio port.
+    # Unsloth port.
     function _PidUnderKnownRoot {
         param([int]$Pid_, [string[]]$KnownRoots)
         if (-not $KnownRoots -or $KnownRoots.Count -eq 0) { return $false }
@@ -223,8 +223,8 @@ function Uninstall-UnslothStudio {
         return $false
     }
 
-    # Stop a Studio backend whose port is recorded in <DataDir>\studio.port.
-    # Only kills if the listening PID's exe path is under a known Studio root.
+    # Stop an Unsloth backend whose port is recorded in <DataDir>\studio.port.
+    # Only kills if the listening PID's exe path is under a known Unsloth root.
     function _StopByPortFile {
         param([string]$PortFile, [string[]]$KnownRoots)
         if (-not (Test-Path -LiteralPath $PortFile -PathType Leaf)) { return }
@@ -372,7 +372,7 @@ function Uninstall-UnslothStudio {
             continue
         }
         if (-not (_IsStudioRoot $r)) {
-            _Substep "refusing to remove non-Studio path: $r" "Yellow"
+            _Substep "refusing to remove non-Unsloth path: $r" "Yellow"
             continue
         }
         _RemovePath $r
@@ -436,7 +436,7 @@ function Uninstall-UnslothStudio {
                     $entries = $rawPath -split ';'
                     $kept = New-Object System.Collections.ArrayList
                     $removedAny = $false
-                    # Only remove PATH entries that live inside a Studio root we
+                    # Only remove PATH entries that live inside an Unsloth root we
                     # actually own (default or env-mode). A literal substring
                     # match on `unsloth_studio` would clobber unrelated user
                     # virtualenvs that happen to share the name.
diff --git a/scripts/uninstall.sh b/scripts/uninstall.sh
index 31e851fcbb..957d2b7af2 100755
--- a/scripts/uninstall.sh
+++ b/scripts/uninstall.sh
@@ -12,7 +12,7 @@
 
 set -e
 
-# Stop a Studio server via its PID file (written by install.sh's _spawn_terminal).
+# Stop an Unsloth server via its PID file (written by install.sh's _spawn_terminal).
 _kill_pid_file() {
     _pid_file="$1"
     [ -f "$_pid_file" ] || return 0
@@ -47,7 +47,7 @@ _pkill_studio() {
     command -v pkill >/dev/null 2>&1 || return 0
 
     # Scope fallback patterns to the install roots we are removing so a
-    # different Studio install (different UNSLOTH_STUDIO_HOME) is not touched.
+    # different Unsloth install (different UNSLOTH_STUDIO_HOME) is not touched.
     _kill_roots="$HOME/.unsloth/studio"
     _roots_from_conf=$(_custom_studio_roots 2>/dev/null || true)
     [ -n "$_roots_from_conf" ] && _kill_roots="$_kill_roots
@@ -89,7 +89,7 @@ _remove_path() {
     fi
 }
 
-# Accept as Studio root only if Studio sentinels exist (matches install.sh's
+# Accept as Unsloth root only if Unsloth sentinels exist (matches install.sh's
 # env-mode ownership guard at install.sh:1358-1361). A bare unsloth_studio/
 # directory is NOT enough -- require the install-time owner marker so a user
 # directory that happens to contain a folder named "unsloth_studio" is safe.
@@ -175,8 +175,8 @@ _custom_studio_roots() {
     _from_conf "$HOME/.local/share/unsloth/studio.conf"
 }
 
-# Remove $HOME/.local/bin/unsloth only if it's a Studio-managed symlink.
-# Studio's install.sh writes this as a symlink into the studio venv
+# Remove $HOME/.local/bin/unsloth only if it's an Unsloth-managed symlink.
+# Unsloth's install.sh writes this as a symlink into the studio venv
 # (install.sh: `ln -sfn "$VENV_DIR/bin/unsloth" "$_shim_path"`). A
 # pip-installed `unsloth` CLI is a regular file — leave it alone to avoid
 # wiping an unrelated install.
@@ -206,7 +206,7 @@ _custom_studio_roots | while IFS= read -r _custom_root; do
         continue
     fi
     if ! _is_studio_root "$_custom_root"; then
-        echo "  refusing to remove non-Studio path: $_custom_root" >&2
+        echo "  refusing to remove non-Unsloth path: $_custom_root" >&2
         continue
     fi
     _remove_path "$_custom_root"
@@ -234,7 +234,7 @@ _remove_path "$HOME/.unsloth/rocm-smoketest"
 # Drop ~/.unsloth only if now empty (rmdir refuses non-empty, so user content is kept).
 rmdir "$HOME/.unsloth" 2>/dev/null || true
 _remove_path "$HOME/.local/share/unsloth"
-# CLI shim: only the symlink Studio created, never a pip-installed file.
+# CLI shim: only the symlink Unsloth created, never a pip-installed file.
 _remove_cli_shim
 
 echo "Removing desktop shortcut and launcher lock..."
diff --git a/studio/MCP.md b/studio/MCP.md
new file mode 100644
index 0000000000..127a85a116
--- /dev/null
+++ b/studio/MCP.md
@@ -0,0 +1,34 @@
+# Unsloth Studio MCP server
+
+Unsloth can expose a local MCP server so an MCP client can inspect models and
+GPU state, validate recipes, start or stop training, inspect recipe output, and
+export a loaded model.
+
+The server is disabled by default. Enable it for a local Unsloth process with:
+
+```bash
+UNSLOTH_STUDIO_ENABLE_MCP=1 \
+UNSLOTH_STUDIO_MCP_TOKEN='use-a-local-secret' \
+unsloth studio
+```
+
+The endpoint is `http://127.0.0.1:8888/mcp/` when Unsloth uses its default port
+(a request to `/mcp` redirects to the canonical `/mcp/`). Use the actual Unsloth
+port when it is configured differently.
+
+The high-impact tools are:
+
+- `studio_status` and `list_local_models` for discovery
+- `get_training_status`, `start_training`, `stop_training`, and `list_training_runs`
+- `validate_recipe`, `get_recipe_job_status`, and `get_recipe_job_dataset`
+- `load_checkpoint` and `export_gguf`
+
+`start_training` accepts the same fields as the Unsloth `TrainingStartRequest`.
+The request is validated by the existing Pydantic model before a subprocess is
+started. Export paths use the existing Unsloth validation as well.
+
+The endpoint always requires `UNSLOTH_STUDIO_MCP_TOKEN` and checks an exact
+Bearer token for both HTTP and WebSocket connections. Keep it on localhost
+unless the deployment has an authenticated reverse proxy. The MCP endpoint is
+intentionally opt-in because tools can consume GPU memory, write model
+artifacts, and stop active work.
\ No newline at end of file
diff --git a/studio/Unsloth_Studio_Colab.ipynb b/studio/Unsloth_Studio_Colab.ipynb
index 619395bd6d..612d739806 100644
--- a/studio/Unsloth_Studio_Colab.ipynb
+++ b/studio/Unsloth_Studio_Colab.ipynb
@@ -1,134 +1,145 @@
 {
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {
-    "id": "view-in-github",
-    "colab_type": "text"
-   },
-   "source": [
-    "<a href=\"https://colab.research.google.com/github/unslothai/unsloth/blob/main/studio/Unsloth_Studio_Colab.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/></a>"
-   ]
+  "cells": [
+    {
+      "cell_type": "markdown",
+      "metadata": {
+        "id": "view-in-github",
+        "colab_type": "text"
+      },
+      "source": [
+        "<a href=\"https://colab.research.google.com/github/unslothai/unsloth/blob/main/studio/Unsloth_Studio_Colab.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/></a>"
+      ]
+    },
+    {
+      "cell_type": "markdown",
+      "metadata": {
+        "id": "6b87de59"
+      },
+      "source": [
+        "To run this, press \"*Runtime*\" and press \"*Run all*\" on a **free** Tesla T4 Google Colab instance!\n",
+        "<div class=\"align-center\">\n",
+        "<a href=\"https://unsloth.ai/\"><img src=\"https://github.com/unslothai/unsloth/raw/main/images/unsloth%20new%20logo.png\" width=\"115\"></a>\n",
+        "<a href=\"https://discord.gg/unsloth\"><img src=\"https://github.com/unslothai/unsloth/raw/main/images/Discord button.png\" width=\"145\"></a>\n",
+        "<a href=\"https://unsloth.ai/docs/\"><img src=\"https://github.com/unslothai/unsloth/blob/main/images/documentation%20green%20button.png?raw=true\" width=\"125\"></a> Join Discord if you need help + ⭐ <i>Star us on <a href=\"https://github.com/unslothai/unsloth\">Github</a> </i> ⭐\n",
+        "</div>\n",
+        "\n",
+        "To install Unsloth Studio on your local device, follow [our guide](https://unsloth.ai/docs/new/unsloth-studio/install). Unsloth Studio is licensed [AGPL-3.0](https://github.com/unslothai/unsloth/blob/main/studio/LICENSE.AGPL-3.0).\n",
+        "\n",
+        "### Unsloth Studio\n",
+        "\n",
+        "Train and run open models with [**Unsloth Studio**](https://unsloth.ai/docs/new/unsloth-studio/start). NEW! Installation should now only take 2 mins!\n",
+        "\n",
+        "\n",
+        "We are actively working on making Unsloth Studio install on Colab T4 GPUs faster.\n",
+        "\n",
+        "[Features](https://unsloth.ai/docs/new/unsloth-studio#features) • [Quickstart](https://unsloth.ai/docs/new/unsloth-studio/start) • [Data Recipes](https://unsloth.ai/docs/new/unsloth-studio/data-recipe) • [Unsloth Chat](https://unsloth.ai/docs/new/unsloth-studio/chat) • [Export](https://unsloth.ai/docs/new/unsloth-studio/export)"
+      ],
+      "id": "6b87de59"
+    },
+    {
+      "cell_type": "markdown",
+      "metadata": {
+        "id": "e4206349"
+      },
+      "source": [
+        "<p align=\"left\"><img src=\"https://github.com/unslothai/unsloth/raw/main/studio/frontend/public/studio%20github%20landscape%20colab%20display.png\" width=\"600\"></p>"
+      ],
+      "id": "e4206349"
+    },
+    {
+      "cell_type": "markdown",
+      "metadata": {
+        "id": "27da2957"
+      },
+      "source": [
+        "### Setup: Clone repo and run setup"
+      ],
+      "id": "27da2957"
+    },
+    {
+      "cell_type": "code",
+      "metadata": {
+        "id": "27e68f91"
+      },
+      "source": "!git clone --depth 1 --branch main https://github.com/unslothai/unsloth.git\n%cd /content/unsloth\n!chmod +x studio/setup.sh && ./studio/setup.sh --local",
+      "execution_count": null,
+      "outputs": [],
+      "id": "27e68f91"
+    },
+    {
+      "cell_type": "markdown",
+      "metadata": {
+        "id": "3e1771a9"
+      },
+      "source": [
+        "### Start Unsloth Studio"
+      ],
+      "id": "3e1771a9"
+    },
+    {
+      "cell_type": "code",
+      "metadata": {
+        "id": "277e431e"
+      },
+      "source": [
+        "import sys\n",
+        "sys.path.insert(0, \"/content/unsloth/studio/backend\")\n",
+        "from colab import start\n",
+        "\n",
+        "# On Colab, start() auto-opens a Cloudflare link and prints admin login credentials.\n",
+        "# Use the Cloudflare link above the ready card to open Studio (in-cell iframes often stay blank).\n",
+        "start()\n",
+        "\n",
+        "# To skip the Cloudflare tunnel and try the in-notebook proxy iframe only:\n",
+        "# start(cloudflare=False)"
+      ],
+      "execution_count": null,
+      "outputs": [],
+      "id": "277e431e"
+    },
+    {
+      "cell_type": "markdown",
+      "metadata": {
+        "id": "f2b0c6a1"
+      },
+      "source": [
+        "And we're done! If you have any questions on Unsloth, we have a [Discord](https://discord.gg/unsloth) channel! If you find any bugs or want to keep updated with the latest LLM stuff, or need help, join projects etc, feel free to join our Discord!\n",
+        "\n",
+        "Some other resources:\n",
+        "1. Looking to use Unsloth locally? Read our [Installation Guide](https://unsloth.ai/docs/get-started/install) for details on installing Unsloth on Windows, Docker, AMD, Intel GPUs.\n",
+        "2. Learn how to do Reinforcement Learning with our [RL Guide and notebooks](https://unsloth.ai/docs/get-started/reinforcement-learning-rl-guide).\n",
+        "3. Read our guides and notebooks for [Text-to-speech (TTS)](https://unsloth.ai/docs/basics/text-to-speech-tts-fine-tuning) and [vision](https://unsloth.ai/docs/basics/vision-fine-tuning) model support.\n",
+        "4. Explore our [LLM Tutorials Directory](https://unsloth.ai/docs/models/tutorials-how-to-fine-tune-and-run-llms) to find dedicated guides for each model.\n",
+        "5. Need help with Inference? Read our [Inference & Deployment page](https://unsloth.ai/docs/basics/inference-and-deployment) for details on using vLLM, llama.cpp, Ollama etc.\n",
+        "\n",
+        "<div class=\"align-center\">\n",
+        "  <a href=\"https://unsloth.ai\"><img src=\"https://github.com/unslothai/unsloth/raw/main/images/unsloth%20new%20logo.png\" width=\"115\"></a>\n",
+        "  <a href=\"https://discord.gg/unsloth\"><img src=\"https://github.com/unslothai/unsloth/raw/main/images/Discord.png\" width=\"145\"></a>\n",
+        "  <a href=\"https://unsloth.ai/docs/\"><img src=\"https://github.com/unslothai/unsloth/blob/main/images/documentation%20green%20button.png?raw=true\" width=\"125\"></a>\n",
+        "\n",
+        "  Join Discord if you need help + ⭐️ <i>Star us on <a href=\"https://github.com/unslothai/unsloth\">Github</a> </i> ⭐️\n",
+        "\n",
+        "  <b>This notebook is licensed <a href=\"https://github.com/unslothai/unsloth/blob/main/studio/LICENSE.AGPL-3.0\">AGPL-3.0</a></b>\n",
+        "</div>"
+      ],
+      "id": "f2b0c6a1"
+    }
+  ],
+  "metadata": {
+    "accelerator": "GPU",
+    "colab": {
+      "gpuType": "T4",
+      "provenance": [],
+      "include_colab_link": true
+    },
+    "kernelspec": {
+      "display_name": "Python 3",
+      "name": "python3"
+    },
+    "language_info": {
+      "name": "python"
+    }
   },
-  {
-   "cell_type": "markdown",
-   "id": "6b87de59",
-   "metadata": {
-    "id": "6b87de59"
-   },
-   "source": [
-    "To run this, press \"*Runtime*\" and press \"*Run all*\" on a **free** Tesla T4 Google Colab instance!\n",
-    "<div class=\"align-center\">\n",
-    "<a href=\"https://unsloth.ai/\"><img src=\"https://github.com/unslothai/unsloth/raw/main/images/unsloth%20new%20logo.png\" width=\"115\"></a>\n",
-    "<a href=\"https://discord.gg/unsloth\"><img src=\"https://github.com/unslothai/unsloth/raw/main/images/Discord button.png\" width=\"145\"></a>\n",
-    "<a href=\"https://unsloth.ai/docs/\"><img src=\"https://github.com/unslothai/unsloth/blob/main/images/documentation%20green%20button.png?raw=true\" width=\"125\"></a> Join Discord if you need help + ⭐ <i>Star us on <a href=\"https://github.com/unslothai/unsloth\">Github</a> </i> ⭐\n",
-    "</div>\n",
-    "\n",
-    "To install Unsloth Studio on your local device, follow [our guide](https://unsloth.ai/docs/new/unsloth-studio/install). Unsloth Studio is licensed [AGPL-3.0](https://github.com/unslothai/unsloth/blob/main/studio/LICENSE.AGPL-3.0).\n",
-    "\n",
-    "### Unsloth Studio\n",
-    "\n",
-    "Train and run open models with [**Unsloth Studio**](https://unsloth.ai/docs/new/unsloth-studio/start). NEW! Installation should now only take 2 mins!\n",
-    "\n",
-    "\n",
-    "We are actively working on making Unsloth Studio install on Colab T4 GPUs faster.\n",
-    "\n",
-    "[Features](https://unsloth.ai/docs/new/unsloth-studio#features) • [Quickstart](https://unsloth.ai/docs/new/unsloth-studio/start) • [Data Recipes](https://unsloth.ai/docs/new/unsloth-studio/data-recipe) • [Studio Chat](https://unsloth.ai/docs/new/unsloth-studio/chat) • [Export](https://unsloth.ai/docs/new/unsloth-studio/export)"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "id": "e4206349",
-   "metadata": {
-    "id": "e4206349"
-   },
-   "source": [
-    "<p align=\"left\"><img src=\"https://github.com/unslothai/unsloth/raw/main/studio/frontend/public/studio%20github%20landscape%20colab%20display.png\" width=\"600\"></p>"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "id": "27da2957",
-   "metadata": {
-    "id": "27da2957"
-   },
-   "source": [
-    "### Setup: Clone repo and run setup"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "27e68f91",
-   "metadata": {
-    "id": "27e68f91"
-   },
-   "outputs": [],
-   "source": "!git clone --depth 1 --branch main https://github.com/unslothai/unsloth.git\n%cd /content/unsloth\n!chmod +x studio/setup.sh && ./studio/setup.sh --local"
-  },
-  {
-   "cell_type": "markdown",
-   "id": "3e1771a9",
-   "metadata": {
-    "id": "3e1771a9"
-   },
-   "source": [
-    "### Start Unsloth Studio"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "277e431e",
-   "metadata": {
-    "id": "277e431e"
-   },
-   "outputs": [],
-   "source": "import sys\nsys.path.insert(0, \"/content/unsloth/studio/backend\")\nfrom colab import start\n\n# Default: in-tab iframe only. start() blocks to keep the kernel alive.\nstart()\n\n# For a shareable Cloudflare link, replace start() above with:\n# start(cloudflare=True)"
-  },
-  {
-   "cell_type": "markdown",
-   "id": "f2b0c6a1",
-   "metadata": {
-    "id": "f2b0c6a1"
-   },
-   "source": [
-    "And we're done! If you have any questions on Unsloth, we have a [Discord](https://discord.gg/unsloth) channel! If you find any bugs or want to keep updated with the latest LLM stuff, or need help, join projects etc, feel free to join our Discord!\n",
-    "\n",
-    "Some other resources:\n",
-    "1. Looking to use Unsloth locally? Read our [Installation Guide](https://unsloth.ai/docs/get-started/install) for details on installing Unsloth on Windows, Docker, AMD, Intel GPUs.\n",
-    "2. Learn how to do Reinforcement Learning with our [RL Guide and notebooks](https://unsloth.ai/docs/get-started/reinforcement-learning-rl-guide).\n",
-    "3. Read our guides and notebooks for [Text-to-speech (TTS)](https://unsloth.ai/docs/basics/text-to-speech-tts-fine-tuning) and [vision](https://unsloth.ai/docs/basics/vision-fine-tuning) model support.\n",
-    "4. Explore our [LLM Tutorials Directory](https://unsloth.ai/docs/models/tutorials-how-to-fine-tune-and-run-llms) to find dedicated guides for each model.\n",
-    "5. Need help with Inference? Read our [Inference & Deployment page](https://unsloth.ai/docs/basics/inference-and-deployment) for details on using vLLM, llama.cpp, Ollama etc.\n",
-    "\n",
-    "<div class=\"align-center\">\n",
-    "  <a href=\"https://unsloth.ai\"><img src=\"https://github.com/unslothai/unsloth/raw/main/images/unsloth%20new%20logo.png\" width=\"115\"></a>\n",
-    "  <a href=\"https://discord.gg/unsloth\"><img src=\"https://github.com/unslothai/unsloth/raw/main/images/Discord.png\" width=\"145\"></a>\n",
-    "  <a href=\"https://unsloth.ai/docs/\"><img src=\"https://github.com/unslothai/unsloth/blob/main/images/documentation%20green%20button.png?raw=true\" width=\"125\"></a>\n",
-    "\n",
-    "  Join Discord if you need help + ⭐️ <i>Star us on <a href=\"https://github.com/unslothai/unsloth\">Github</a> </i> ⭐️\n",
-    "\n",
-    "  <b>This notebook is licensed <a href=\"https://github.com/unslothai/unsloth/blob/main/studio/LICENSE.AGPL-3.0\">AGPL-3.0</a></b>\n",
-    "</div>"
-   ]
-  }
- ],
- "metadata": {
-  "accelerator": "GPU",
-  "colab": {
-   "gpuType": "T4",
-   "provenance": [],
-   "include_colab_link": true
-  },
-  "kernelspec": {
-   "display_name": "Python 3",
-   "name": "python3"
-  },
-  "language_info": {
-   "name": "python"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 5
+  "nbformat": 4,
+  "nbformat_minor": 5
 }
\ No newline at end of file
diff --git a/studio/backend/assets/chat_templates/gemma-4-edge.jinja b/studio/backend/assets/chat_templates/gemma-4-edge.jinja
index 0266127233..74fa73ddd3 100644
--- a/studio/backend/assets/chat_templates/gemma-4-edge.jinja
+++ b/studio/backend/assets/chat_templates/gemma-4-edge.jinja
@@ -3,7 +3,7 @@
   Source: google/gemma-4-31B-it HF discussion/PR #118 (adds the preserve_thinking
   flag plus null-rendering, string-arguments validation, balanced turn tags, empty
   messages handling, and OpenAI image_url/input_audio aliases).
-  Studio-local changes vs PR #118:
+  Unsloth-local changes vs PR #118:
     1. preserve_thinking defaults to false (see SETUP block below).
     2. The empty "<|channel>thought\n<channel|>" block on enable_thinking=false is
        NOT emitted. Google ships a distinct template for E2B/E4B (google/gemma-4-E2B-it,
diff --git a/studio/backend/assets/chat_templates/gemma-4.jinja b/studio/backend/assets/chat_templates/gemma-4.jinja
index 65ab39df57..cc5f98065f 100644
--- a/studio/backend/assets/chat_templates/gemma-4.jinja
+++ b/studio/backend/assets/chat_templates/gemma-4.jinja
@@ -3,7 +3,7 @@
   Source: google/gemma-4-31B-it HF discussion/PR #118 (adds the preserve_thinking
   flag plus null-rendering, string-arguments validation, balanced turn tags, empty
   messages handling, and OpenAI image_url/input_audio aliases).
-  Studio-local change: preserve_thinking defaults to false (see SETUP block below).
+  Unsloth-local change: preserve_thinking defaults to false (see SETUP block below).
   Applied to unsloth/gemma-4-*-GGUF models so the embedded GGUF template does not
   need re-downloading. Keep in sync with upstream if PR #118 changes.
 -#}
diff --git a/studio/backend/assets/configs/full_finetune.yaml b/studio/backend/assets/configs/full_finetune.yaml
index e398515f61..98c45dd851 100644
--- a/studio/backend/assets/configs/full_finetune.yaml
+++ b/studio/backend/assets/configs/full_finetune.yaml
@@ -30,6 +30,7 @@ lora:
   vision_all_linear: false
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/lora_text.yaml b/studio/backend/assets/configs/lora_text.yaml
index 9cb6b8c700..6c6a4d8839 100644
--- a/studio/backend/assets/configs/lora_text.yaml
+++ b/studio/backend/assets/configs/lora_text.yaml
@@ -30,6 +30,7 @@ lora:
   vision_all_linear: false
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/default.yaml b/studio/backend/assets/configs/model_defaults/default.yaml
index 841e8ba166..e569031a31 100644
--- a/studio/backend/assets/configs/model_defaults/default.yaml
+++ b/studio/backend/assets/configs/model_defaults/default.yaml
@@ -33,6 +33,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/embedding/unsloth_Qwen3-Embedding-0.6B.yaml b/studio/backend/assets/configs/model_defaults/embedding/unsloth_Qwen3-Embedding-0.6B.yaml
index f7b49c75b7..7ac1c83e04 100644
--- a/studio/backend/assets/configs/model_defaults/embedding/unsloth_Qwen3-Embedding-0.6B.yaml
+++ b/studio/backend/assets/configs/model_defaults/embedding/unsloth_Qwen3-Embedding-0.6B.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/embedding/unsloth_all-MiniLM-L6-v2.yaml b/studio/backend/assets/configs/model_defaults/embedding/unsloth_all-MiniLM-L6-v2.yaml
index be7da0f624..4cab9e9f96 100644
--- a/studio/backend/assets/configs/model_defaults/embedding/unsloth_all-MiniLM-L6-v2.yaml
+++ b/studio/backend/assets/configs/model_defaults/embedding/unsloth_all-MiniLM-L6-v2.yaml
@@ -30,6 +30,7 @@ lora:
     - "query"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/embedding/unsloth_bge-m3.yaml b/studio/backend/assets/configs/model_defaults/embedding/unsloth_bge-m3.yaml
index d9e49bc0d5..c1f1c2a344 100644
--- a/studio/backend/assets/configs/model_defaults/embedding/unsloth_bge-m3.yaml
+++ b/studio/backend/assets/configs/model_defaults/embedding/unsloth_bge-m3.yaml
@@ -30,6 +30,7 @@ lora:
     - "value"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/embedding/unsloth_embeddinggemma-300m.yaml b/studio/backend/assets/configs/model_defaults/embedding/unsloth_embeddinggemma-300m.yaml
index c3422d399f..7828feae81 100644
--- a/studio/backend/assets/configs/model_defaults/embedding/unsloth_embeddinggemma-300m.yaml
+++ b/studio/backend/assets/configs/model_defaults/embedding/unsloth_embeddinggemma-300m.yaml
@@ -33,6 +33,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/embedding/unsloth_gte-modernbert-base.yaml b/studio/backend/assets/configs/model_defaults/embedding/unsloth_gte-modernbert-base.yaml
index 529a56a527..5a4028f15b 100644
--- a/studio/backend/assets/configs/model_defaults/embedding/unsloth_gte-modernbert-base.yaml
+++ b/studio/backend/assets/configs/model_defaults/embedding/unsloth_gte-modernbert-base.yaml
@@ -29,6 +29,7 @@ lora:
     - "Wqkv"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/ernie/unsloth_ERNIE-4.5-21B-A3B-PT.yaml b/studio/backend/assets/configs/model_defaults/ernie/unsloth_ERNIE-4.5-21B-A3B-PT.yaml
index 734115ec41..7645d11c98 100644
--- a/studio/backend/assets/configs/model_defaults/ernie/unsloth_ERNIE-4.5-21B-A3B-PT.yaml
+++ b/studio/backend/assets/configs/model_defaults/ernie/unsloth_ERNIE-4.5-21B-A3B-PT.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/ernie/unsloth_ERNIE-4.5-VL-28B-A3B-PT.yaml b/studio/backend/assets/configs/model_defaults/ernie/unsloth_ERNIE-4.5-VL-28B-A3B-PT.yaml
index 1032449e8c..b746235f1f 100644
--- a/studio/backend/assets/configs/model_defaults/ernie/unsloth_ERNIE-4.5-VL-28B-A3B-PT.yaml
+++ b/studio/backend/assets/configs/model_defaults/ernie/unsloth_ERNIE-4.5-VL-28B-A3B-PT.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/falcon/tiiuae_Falcon-H1-0.5B-Instruct.yaml b/studio/backend/assets/configs/model_defaults/falcon/tiiuae_Falcon-H1-0.5B-Instruct.yaml
index c8e5f35841..4964fea276 100644
--- a/studio/backend/assets/configs/model_defaults/falcon/tiiuae_Falcon-H1-0.5B-Instruct.yaml
+++ b/studio/backend/assets/configs/model_defaults/falcon/tiiuae_Falcon-H1-0.5B-Instruct.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_codegemma-7b-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_codegemma-7b-bnb-4bit.yaml
index 251409c29d..e5f3344356 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_codegemma-7b-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_codegemma-7b-bnb-4bit.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_functiongemma-270m-it.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_functiongemma-270m-it.yaml
index 89b1d7f938..71c61f383a 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_functiongemma-270m-it.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_functiongemma-270m-it.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-2-27b-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-2-27b-bnb-4bit.yaml
index e3292b5972..3fe29cd800 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-2-27b-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-2-27b-bnb-4bit.yaml
@@ -33,6 +33,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-2-2b.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-2-2b.yaml
index 98fe497912..cd4e3e0c4d 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-2-2b.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-2-2b.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-270m-it.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-270m-it.yaml
index bda5471643..97aa10e861 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-270m-it.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-270m-it.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-27b-it.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-27b-it.yaml
index 18392568bd..a1b1640fa2 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-27b-it.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-27b-it.yaml
@@ -29,6 +29,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-4b-it.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-4b-it.yaml
index 434ac41b46..dbf60f04d4 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-4b-it.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-4b-it.yaml
@@ -29,6 +29,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-4b-pt.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-4b-pt.yaml
index 5f0a7b26ce..54c7dd6cd4 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-4b-pt.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3-4b-pt.yaml
@@ -29,6 +29,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3n-E4B-it.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3n-E4B-it.yaml
index dd5ae51ab0..119440a585 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3n-E4B-it.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3n-E4B-it.yaml
@@ -29,6 +29,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3n-E4B.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3n-E4B.yaml
index e53e163a04..d08e5e9547 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3n-E4B.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-3n-E4B.yaml
@@ -29,6 +29,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-26B-A4B-it.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-26B-A4B-it.yaml
index ebe344e382..a266d7a39b 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-26B-A4B-it.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-26B-A4B-it.yaml
@@ -26,6 +26,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-26B-A4B.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-26B-A4B.yaml
index fb89a07133..970cac3259 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-26B-A4B.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-26B-A4B.yaml
@@ -26,6 +26,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-31B-it.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-31B-it.yaml
index 4a089992ac..5bba4ccdc0 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-31B-it.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-31B-it.yaml
@@ -26,6 +26,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-31B.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-31B.yaml
index ae7524b7c6..ac5c6eca22 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-31B.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-31B.yaml
@@ -26,6 +26,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E2B-it.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E2B-it.yaml
index 10c1abd8a5..68c2d35644 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E2B-it.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E2B-it.yaml
@@ -26,6 +26,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E2B.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E2B.yaml
index fb5c1d9dea..175f9c0f17 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E2B.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E2B.yaml
@@ -26,6 +26,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E4B-it.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E4B-it.yaml
index 189e5dc6b2..4f3834e7c0 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E4B-it.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E4B-it.yaml
@@ -26,6 +26,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E4B.yaml b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E4B.yaml
index aa51440b6a..d6d97f7e44 100644
--- a/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E4B.yaml
+++ b/studio/backend/assets/configs/model_defaults/gemma/unsloth_gemma-4-E4B.yaml
@@ -26,6 +26,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/gpt-oss/unsloth_gpt-oss-120b.yaml b/studio/backend/assets/configs/model_defaults/gpt-oss/unsloth_gpt-oss-120b.yaml
index e2d67bcb0b..4f1f54a4e6 100644
--- a/studio/backend/assets/configs/model_defaults/gpt-oss/unsloth_gpt-oss-120b.yaml
+++ b/studio/backend/assets/configs/model_defaults/gpt-oss/unsloth_gpt-oss-120b.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/gpt-oss/unsloth_gpt-oss-20b.yaml b/studio/backend/assets/configs/model_defaults/gpt-oss/unsloth_gpt-oss-20b.yaml
index aa436117a1..127700b53b 100644
--- a/studio/backend/assets/configs/model_defaults/gpt-oss/unsloth_gpt-oss-20b.yaml
+++ b/studio/backend/assets/configs/model_defaults/gpt-oss/unsloth_gpt-oss-20b.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/granite/unsloth_granite-4.0-350m-unsloth-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/granite/unsloth_granite-4.0-350m-unsloth-bnb-4bit.yaml
index 3f2cb84a94..2412b3accf 100644
--- a/studio/backend/assets/configs/model_defaults/granite/unsloth_granite-4.0-350m-unsloth-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/granite/unsloth_granite-4.0-350m-unsloth-bnb-4bit.yaml
@@ -37,6 +37,7 @@ lora:
     - "shared_mlp.output_linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/granite/unsloth_granite-4.0-h-micro.yaml b/studio/backend/assets/configs/model_defaults/granite/unsloth_granite-4.0-h-micro.yaml
index ab756fe764..81b59c4323 100644
--- a/studio/backend/assets/configs/model_defaults/granite/unsloth_granite-4.0-h-micro.yaml
+++ b/studio/backend/assets/configs/model_defaults/granite/unsloth_granite-4.0-h-micro.yaml
@@ -37,6 +37,7 @@ lora:
     - "shared_mlp.output_linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.2-11B-Vision-Instruct.yaml b/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.2-11B-Vision-Instruct.yaml
index 1a7a91e56f..6110d84a6c 100644
--- a/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.2-11B-Vision-Instruct.yaml
+++ b/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.2-11B-Vision-Instruct.yaml
@@ -29,6 +29,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.2-1B-Instruct.yaml b/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.2-1B-Instruct.yaml
index 7c7bb8dc3e..3c7fc7f238 100644
--- a/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.2-1B-Instruct.yaml
+++ b/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.2-1B-Instruct.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.2-3B-Instruct.yaml b/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.2-3B-Instruct.yaml
index f73b0c09b6..2b0977e435 100644
--- a/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.2-3B-Instruct.yaml
+++ b/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.2-3B-Instruct.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.3-70B-Instruct.yaml b/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.3-70B-Instruct.yaml
index ffefb29e24..1742c04a06 100644
--- a/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.3-70B-Instruct.yaml
+++ b/studio/backend/assets/configs/model_defaults/llama/unsloth_Llama-3.3-70B-Instruct.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/llama/unsloth_Meta-Llama-3.1-70B-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/llama/unsloth_Meta-Llama-3.1-70B-bnb-4bit.yaml
index cd986a6da1..f33726b0dd 100644
--- a/studio/backend/assets/configs/model_defaults/llama/unsloth_Meta-Llama-3.1-70B-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/llama/unsloth_Meta-Llama-3.1-70B-bnb-4bit.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/llama/unsloth_Meta-Llama-3.1-8B-Instruct-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/llama/unsloth_Meta-Llama-3.1-8B-Instruct-bnb-4bit.yaml
index 55dd3144c6..79b30bd758 100644
--- a/studio/backend/assets/configs/model_defaults/llama/unsloth_Meta-Llama-3.1-8B-Instruct-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/llama/unsloth_Meta-Llama-3.1-8B-Instruct-bnb-4bit.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/llama/unsloth_llama-3-8b-Instruct-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/llama/unsloth_llama-3-8b-Instruct-bnb-4bit.yaml
index 8c9cb07fb9..4ee9a5a8ed 100644
--- a/studio/backend/assets/configs/model_defaults/llama/unsloth_llama-3-8b-Instruct-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/llama/unsloth_llama-3-8b-Instruct-bnb-4bit.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/llama/unsloth_llama-3-8b-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/llama/unsloth_llama-3-8b-bnb-4bit.yaml
index 32441c5674..da20663688 100644
--- a/studio/backend/assets/configs/model_defaults/llama/unsloth_llama-3-8b-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/llama/unsloth_llama-3-8b-bnb-4bit.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/llasa/unsloth_Llasa-3B.yaml b/studio/backend/assets/configs/model_defaults/llasa/unsloth_Llasa-3B.yaml
index 6bba9c9633..30e4440afb 100644
--- a/studio/backend/assets/configs/model_defaults/llasa/unsloth_Llasa-3B.yaml
+++ b/studio/backend/assets/configs/model_defaults/llasa/unsloth_Llasa-3B.yaml
@@ -30,6 +30,7 @@ lora:
     - "v_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/mistral/unsloth_Magistral-Small-2509-unsloth-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/mistral/unsloth_Magistral-Small-2509-unsloth-bnb-4bit.yaml
index f9833ce705..9bb0a93e63 100644
--- a/studio/backend/assets/configs/model_defaults/mistral/unsloth_Magistral-Small-2509-unsloth-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/mistral/unsloth_Magistral-Small-2509-unsloth-bnb-4bit.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/mistral/unsloth_Ministral-3-3B-Instruct-2512.yaml b/studio/backend/assets/configs/model_defaults/mistral/unsloth_Ministral-3-3B-Instruct-2512.yaml
index 0ba857cd40..ded3607a14 100644
--- a/studio/backend/assets/configs/model_defaults/mistral/unsloth_Ministral-3-3B-Instruct-2512.yaml
+++ b/studio/backend/assets/configs/model_defaults/mistral/unsloth_Ministral-3-3B-Instruct-2512.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/mistral/unsloth_Mistral-Nemo-Base-2407-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/mistral/unsloth_Mistral-Nemo-Base-2407-bnb-4bit.yaml
index 3476f2dd6d..2ac72f1c88 100644
--- a/studio/backend/assets/configs/model_defaults/mistral/unsloth_Mistral-Nemo-Base-2407-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/mistral/unsloth_Mistral-Nemo-Base-2407-bnb-4bit.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/mistral/unsloth_Mistral-Small-Instruct-2409.yaml b/studio/backend/assets/configs/model_defaults/mistral/unsloth_Mistral-Small-Instruct-2409.yaml
index eda04d21f9..a087ced1f3 100644
--- a/studio/backend/assets/configs/model_defaults/mistral/unsloth_Mistral-Small-Instruct-2409.yaml
+++ b/studio/backend/assets/configs/model_defaults/mistral/unsloth_Mistral-Small-Instruct-2409.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/mistral/unsloth_Pixtral-12B-2409.yaml b/studio/backend/assets/configs/model_defaults/mistral/unsloth_Pixtral-12B-2409.yaml
index bcd0d20c8c..c9811f4f06 100644
--- a/studio/backend/assets/configs/model_defaults/mistral/unsloth_Pixtral-12B-2409.yaml
+++ b/studio/backend/assets/configs/model_defaults/mistral/unsloth_Pixtral-12B-2409.yaml
@@ -29,6 +29,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: false
diff --git a/studio/backend/assets/configs/model_defaults/mistral/unsloth_mistral-7b-instruct-v0.3-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/mistral/unsloth_mistral-7b-instruct-v0.3-bnb-4bit.yaml
index 34a033e32f..e3659d9fb0 100644
--- a/studio/backend/assets/configs/model_defaults/mistral/unsloth_mistral-7b-instruct-v0.3-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/mistral/unsloth_mistral-7b-instruct-v0.3-bnb-4bit.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/mistral/unsloth_mistral-7b-v0.3-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/mistral/unsloth_mistral-7b-v0.3-bnb-4bit.yaml
index 98105eaf38..ee17efc54d 100644
--- a/studio/backend/assets/configs/model_defaults/mistral/unsloth_mistral-7b-v0.3-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/mistral/unsloth_mistral-7b-v0.3-bnb-4bit.yaml
@@ -33,6 +33,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/other/OuteAI_Llama-OuteTTS-1.0-1B.yaml b/studio/backend/assets/configs/model_defaults/other/OuteAI_Llama-OuteTTS-1.0-1B.yaml
index 72b5b018e1..ef836b9b55 100644
--- a/studio/backend/assets/configs/model_defaults/other/OuteAI_Llama-OuteTTS-1.0-1B.yaml
+++ b/studio/backend/assets/configs/model_defaults/other/OuteAI_Llama-OuteTTS-1.0-1B.yaml
@@ -33,6 +33,7 @@ lora:
     - "v_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/other/Spark-TTS-0.5B_LLM.yaml b/studio/backend/assets/configs/model_defaults/other/Spark-TTS-0.5B_LLM.yaml
index d20751b0c7..c80fad35a8 100644
--- a/studio/backend/assets/configs/model_defaults/other/Spark-TTS-0.5B_LLM.yaml
+++ b/studio/backend/assets/configs/model_defaults/other/Spark-TTS-0.5B_LLM.yaml
@@ -38,6 +38,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/other/sesame_csm-1b.yaml b/studio/backend/assets/configs/model_defaults/other/sesame_csm-1b.yaml
index 8a80282a2a..034b5bd131 100644
--- a/studio/backend/assets/configs/model_defaults/other/sesame_csm-1b.yaml
+++ b/studio/backend/assets/configs/model_defaults/other/sesame_csm-1b.yaml
@@ -37,6 +37,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/other/unsloth_GLM-4.7-Flash.yaml b/studio/backend/assets/configs/model_defaults/other/unsloth_GLM-4.7-Flash.yaml
index a973c2d4e4..d1a226be79 100644
--- a/studio/backend/assets/configs/model_defaults/other/unsloth_GLM-4.7-Flash.yaml
+++ b/studio/backend/assets/configs/model_defaults/other/unsloth_GLM-4.7-Flash.yaml
@@ -35,6 +35,7 @@ lora:
     - "out_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/other/unsloth_LFM2-1.2B.yaml b/studio/backend/assets/configs/model_defaults/other/unsloth_LFM2-1.2B.yaml
index b0feafbd6e..1b8df5ced9 100644
--- a/studio/backend/assets/configs/model_defaults/other/unsloth_LFM2-1.2B.yaml
+++ b/studio/backend/assets/configs/model_defaults/other/unsloth_LFM2-1.2B.yaml
@@ -29,6 +29,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/other/unsloth_Nemotron-3-Nano-30B-A3B.yaml b/studio/backend/assets/configs/model_defaults/other/unsloth_Nemotron-3-Nano-30B-A3B.yaml
index 2c44c91eab..cecab7f083 100644
--- a/studio/backend/assets/configs/model_defaults/other/unsloth_Nemotron-3-Nano-30B-A3B.yaml
+++ b/studio/backend/assets/configs/model_defaults/other/unsloth_Nemotron-3-Nano-30B-A3B.yaml
@@ -37,6 +37,7 @@ lora:
     - "out_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/other/unsloth_PaddleOCR-VL.yaml b/studio/backend/assets/configs/model_defaults/other/unsloth_PaddleOCR-VL.yaml
index e1fbc08e4d..730be338cf 100644
--- a/studio/backend/assets/configs/model_defaults/other/unsloth_PaddleOCR-VL.yaml
+++ b/studio/backend/assets/configs/model_defaults/other/unsloth_PaddleOCR-VL.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/other/unsloth_answerdotai_ModernBERT-large.yaml b/studio/backend/assets/configs/model_defaults/other/unsloth_answerdotai_ModernBERT-large.yaml
index 2abdfd8ac3..a70ac0bd49 100644
--- a/studio/backend/assets/configs/model_defaults/other/unsloth_answerdotai_ModernBERT-large.yaml
+++ b/studio/backend/assets/configs/model_defaults/other/unsloth_answerdotai_ModernBERT-large.yaml
@@ -33,6 +33,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/other/unsloth_orpheus-3b-0.1-ft.yaml b/studio/backend/assets/configs/model_defaults/other/unsloth_orpheus-3b-0.1-ft.yaml
index 5a3c4abb48..90ead037f6 100644
--- a/studio/backend/assets/configs/model_defaults/other/unsloth_orpheus-3b-0.1-ft.yaml
+++ b/studio/backend/assets/configs/model_defaults/other/unsloth_orpheus-3b-0.1-ft.yaml
@@ -38,6 +38,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/other/unsloth_tinyllama-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/other/unsloth_tinyllama-bnb-4bit.yaml
index a6ce27620f..a97c557c31 100644
--- a/studio/backend/assets/configs/model_defaults/other/unsloth_tinyllama-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/other/unsloth_tinyllama-bnb-4bit.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/other/unsloth_whisper-large-v3.yaml b/studio/backend/assets/configs/model_defaults/other/unsloth_whisper-large-v3.yaml
index 050774a8cd..6855ed6a35 100644
--- a/studio/backend/assets/configs/model_defaults/other/unsloth_whisper-large-v3.yaml
+++ b/studio/backend/assets/configs/model_defaults/other/unsloth_whisper-large-v3.yaml
@@ -33,6 +33,7 @@ lora:
     - "v_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/phi/unsloth_Phi-3-medium-4k-instruct.yaml b/studio/backend/assets/configs/model_defaults/phi/unsloth_Phi-3-medium-4k-instruct.yaml
index c574714d78..1933fed2ba 100644
--- a/studio/backend/assets/configs/model_defaults/phi/unsloth_Phi-3-medium-4k-instruct.yaml
+++ b/studio/backend/assets/configs/model_defaults/phi/unsloth_Phi-3-medium-4k-instruct.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/phi/unsloth_Phi-3.5-mini-instruct.yaml b/studio/backend/assets/configs/model_defaults/phi/unsloth_Phi-3.5-mini-instruct.yaml
index e803c842b3..fda4e64158 100644
--- a/studio/backend/assets/configs/model_defaults/phi/unsloth_Phi-3.5-mini-instruct.yaml
+++ b/studio/backend/assets/configs/model_defaults/phi/unsloth_Phi-3.5-mini-instruct.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/phi/unsloth_Phi-4.yaml b/studio/backend/assets/configs/model_defaults/phi/unsloth_Phi-4.yaml
index 4de3d9437d..c3910e3e5b 100644
--- a/studio/backend/assets/configs/model_defaults/phi/unsloth_Phi-4.yaml
+++ b/studio/backend/assets/configs/model_defaults/phi/unsloth_Phi-4.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/imdatta0_tiny_qwen3_moe_2.8B_0.7B.yaml b/studio/backend/assets/configs/model_defaults/qwen/imdatta0_tiny_qwen3_moe_2.8B_0.7B.yaml
index bb75b3ce52..765ffee938 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/imdatta0_tiny_qwen3_moe_2.8B_0.7B.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/imdatta0_tiny_qwen3_moe_2.8B_0.7B.yaml
@@ -36,6 +36,7 @@ lora:
     - "gate_up_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2-7B.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2-7B.yaml
index c305d328c2..39b30e9cee 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2-7B.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2-7B.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2-VL-7B-Instruct.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2-VL-7B-Instruct.yaml
index 6cee3d0949..f97e525798 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2-VL-7B-Instruct.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2-VL-7B-Instruct.yaml
@@ -29,6 +29,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-1.5B-Instruct.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-1.5B-Instruct.yaml
index 20ba81df2c..e19b94ede2 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-1.5B-Instruct.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-1.5B-Instruct.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-7B.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-7B.yaml
index 9930786c24..982f54b32f 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-7B.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-7B.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-Coder-1.5B-Instruct.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-Coder-1.5B-Instruct.yaml
index 775c7ce08f..5242128004 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-Coder-1.5B-Instruct.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-Coder-1.5B-Instruct.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-Coder-14B-Instruct.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-Coder-14B-Instruct.yaml
index 856db0c1b3..3559b636c6 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-Coder-14B-Instruct.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-Coder-14B-Instruct.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-Coder-7B-Instruct-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-Coder-7B-Instruct-bnb-4bit.yaml
index 5900392547..3bc6d69afc 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-Coder-7B-Instruct-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-Coder-7B-Instruct-bnb-4bit.yaml
@@ -34,6 +34,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-VL-7B-Instruct-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-VL-7B-Instruct-bnb-4bit.yaml
index bd54b1d015..604b86dacd 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-VL-7B-Instruct-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen2.5-VL-7B-Instruct-bnb-4bit.yaml
@@ -29,6 +29,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-0.6B.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-0.6B.yaml
index 9feb6dcaae..daed4ebccb 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-0.6B.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-0.6B.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-14B-Base-unsloth-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-14B-Base-unsloth-bnb-4bit.yaml
index a40eace253..05eef89b88 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-14B-Base-unsloth-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-14B-Base-unsloth-bnb-4bit.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-14B.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-14B.yaml
index c130771c32..b4580e6d71 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-14B.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-14B.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-30B-A3B-Instruct-2507.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-30B-A3B-Instruct-2507.yaml
index 2fb3a95c30..2eceb7d0de 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-30B-A3B-Instruct-2507.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-30B-A3B-Instruct-2507.yaml
@@ -36,6 +36,7 @@ lora:
     - "gate_up_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-32B.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-32B.yaml
index 152f4ae06a..032091880c 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-32B.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-32B.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-4B-Instruct-2507.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-4B-Instruct-2507.yaml
index 94fe000708..e0e7f4ee3d 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-4B-Instruct-2507.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-4B-Instruct-2507.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-4B-Thinking-2507.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-4B-Thinking-2507.yaml
index 3c325485d2..bb463849ed 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-4B-Thinking-2507.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-4B-Thinking-2507.yaml
@@ -35,6 +35,7 @@ lora:
     - "down_proj"
   use_rslora: false
   use_loftq: false
+  use_dora: false
 
 logging:
   enable_wandb: false
diff --git a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-VL-8B-Instruct-unsloth-bnb-4bit.yaml b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-VL-8B-Instruct-unsloth-bnb-4bit.yaml
index 5b47c3bdd2..23e2b89dd0 100644
--- a/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-VL-8B-Instruct-unsloth-bnb-4bit.yaml
+++ b/studio/backend/assets/configs/model_defaults/qwen/unsloth_Qwen3-VL-8B-Instruct-unsloth-bnb-4bit.yaml
@@ -29,6 +29,7 @@ lora:
     - "all-linear"
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/assets/configs/vision_lora.yaml b/studio/backend/assets/configs/vision_lora.yaml
index 063a970316..a06f971523 100644
--- a/studio/backend/assets/configs/vision_lora.yaml
+++ b/studio/backend/assets/configs/vision_lora.yaml
@@ -30,6 +30,7 @@ lora:
   vision_all_linear: true
   use_rslora: false
   use_loftq: false
+  use_dora: false
   finetune_vision_layers: true
   finetune_language_layers: true
   finetune_attention_modules: true
diff --git a/studio/backend/auth/authentication.py b/studio/backend/auth/authentication.py
index b13cd1c851..dfb8fc513e 100644
--- a/studio/backend/auth/authentication.py
+++ b/studio/backend/auth/authentication.py
@@ -148,7 +148,7 @@ async def authenticated_via_api_key(
 ) -> bool:
     """True when the caller used an sk-unsloth API key, not a UI session JWT.
 
-    Lets routes treat programmatic API callers differently from the Studio UI
+    Lets routes treat programmatic API callers differently from the Unsloth UI
     (e.g. refuse a teardown the UI would allow).
     """
     return bool(credentials and credentials.credentials.startswith(API_KEY_PREFIX))
diff --git a/studio/backend/auth/bootstrap_timeout.py b/studio/backend/auth/bootstrap_timeout.py
index 728433dc54..97a8086f04 100644
--- a/studio/backend/auth/bootstrap_timeout.py
+++ b/studio/backend/auth/bootstrap_timeout.py
@@ -1,13 +1,13 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Auto-shutdown for an exposed first-run Studio whose admin password is unchanged.
+"""Auto-shutdown for an exposed first-run Unsloth whose admin password is unchanged.
 
 On a fresh install the seeded bootstrap admin password stays a valid login
 credential until first login changes it. When the web UI is put on the network
 (``--secure`` / ``0.0.0.0``) and nobody completes that first-login change within
-a deadline, tear Studio down so a fresh, unconfigured instance does not stay
-publicly reachable indefinitely. If the password was changed, Studio keeps
+a deadline, tear Unsloth down so a fresh, unconfigured instance does not stay
+publicly reachable indefinitely. If the password was changed, Unsloth keeps
 running.
 
 Scope: web UI launches only (never ``--api-only``, which authenticates by API
@@ -98,7 +98,7 @@ def enforce_bootstrap_password_deadline(
 ) -> bool:
     """Deadline handler: shut down iff the seeded admin password is still unchanged.
 
-    Returns True if it shut Studio down, False if it left it running (the
+    Returns True if it shut Unsloth down, False if it left it running (the
     password was changed in time).
     """
     try:
@@ -106,7 +106,7 @@ def enforce_bootstrap_password_deadline(
     except Exception:
         return False
     if not still_default:
-        return False  # password changed in time -> leave Studio running
+        return False  # password changed in time -> leave Unsloth running
 
     message = (
         "\nUnsloth Studio was exposed on the network but its default admin "
diff --git a/studio/backend/auth/storage.py b/studio/backend/auth/storage.py
index 9bb3ab5735..39fa691304 100644
--- a/studio/backend/auth/storage.py
+++ b/studio/backend/auth/storage.py
@@ -146,7 +146,7 @@ def get_connection() -> sqlite3.Connection:
             pass
     conn.row_factory = sqlite3.Row
     # WAL lets token reads run concurrently with refresh-token writes;
-    # busy_timeout bounds lock waits. Matches the other Studio SQLite stores.
+    # busy_timeout bounds lock waits. Matches the other Unsloth SQLite stores.
     # Set busy_timeout first: switching journal_mode needs a lock, so if a
     # refresh-token write already holds one, journal_mode=WAL raises SQLITE_BUSY;
     # with busy_timeout already in effect it waits instead of failing and leaving
@@ -305,8 +305,8 @@ def get_or_create_identity_secret() -> bytes:
 def compute_identity_proof(nonce: bytes, host: str, port: int) -> str:
     """HMAC-SHA256 proof that the caller holds this install's identity secret,
     bound to the loopback address and port the connection landed on. A proof
-    relayed from a Studio on a different address/port (a squatter proxying to the
-    real one, e.g. localhost resolving to ::1 while Studio is on 127.0.0.1) was
+    relayed from an Unsloth on a different address/port (a squatter proxying to the
+    real one, e.g. localhost resolving to ::1 while Unsloth is on 127.0.0.1) was
     computed for that other endpoint and won't match the one the client dialed."""
     try:
         host = ipaddress.ip_address(host).compressed  # normalise 127.0.0.1 / ::1 forms
diff --git a/studio/backend/auth/terminal_prompt.py b/studio/backend/auth/terminal_prompt.py
index 8491019ae9..925404f47d 100644
--- a/studio/backend/auth/terminal_prompt.py
+++ b/studio/backend/auth/terminal_prompt.py
@@ -2,14 +2,14 @@
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 """Interactive terminal prompt that forces a bootstrap password change before
-Studio is exposed on a public Cloudflare URL (``--secure`` / ``--cloudflare``).
+Unsloth is exposed on a public Cloudflare URL (``--secure`` / ``--cloudflare``).
 
 Masked input echoes one ``*`` per keystroke (unlike ``getpass``). Works on
 Windows (``msvcrt``) and Linux/macOS (``termios``). All output goes to stderr so
 redirected stdout never swallows the prompt.
 
 Mirrored for the CLI at ``unsloth_cli/commands/_password_prompt.py`` (the CLI
-cannot import the Studio backend package); keep the two in sync.
+cannot import the Unsloth backend package); keep the two in sync.
 """
 
 from __future__ import annotations
@@ -236,6 +236,10 @@ def prompt_for_password_change(
                 out.write(f"Password must be at least {min_length} characters; try again.\n")
                 out.flush()
                 continue
+            if any(ch.isspace() for ch in new_password):
+                out.write("Password cannot contain spaces; try again.\n")
+                out.flush()
+                continue
             if is_current_password(new_password):
                 out.write(
                     "New password must differ from the current bootstrap password; try again.\n"
@@ -252,7 +256,7 @@ def prompt_for_password_change(
             out.flush()
             return True
     except (KeyboardInterrupt, EOFError):
-        out.write("Password change aborted; not exposing Studio.\n")
+        out.write("Password change aborted; not exposing Unsloth.\n")
         out.flush()
         return False
 
diff --git a/studio/backend/cloudflare_tunnel.py b/studio/backend/cloudflare_tunnel.py
index ef7bacba67..78fce0c70a 100644
--- a/studio/backend/cloudflare_tunnel.py
+++ b/studio/backend/cloudflare_tunnel.py
@@ -1,13 +1,13 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Free Cloudflare quick tunnel for Studio's 0.0.0.0 launches.
+"""Free Cloudflare quick tunnel for Unsloth's 0.0.0.0 launches.
 
 The raw http://<ip>:<port> is often unreachable (https-vs-http, blocked ports,
 closed security groups); a cloudflared quick tunnel gives a free
 https://*.trycloudflare.com URL that works anywhere, with no account or domain.
 
-Best-effort throughout: any failure collapses to "no URL" and Studio keeps
+Best-effort throughout: any failure collapses to "no URL" and Unsloth keeps
 running. Stdlib only (back-end imports are lazy) so it is safe to import early.
 """
 
@@ -20,6 +20,7 @@ import shutil
 import subprocess
 import sys
 import threading
+import time
 from pathlib import Path
 from typing import Optional, Tuple
 
@@ -40,6 +41,22 @@ _RELEASE_BASE = "https://github.com/cloudflare/cloudflared/releases/latest/downl
 _READY_TIMEOUT = 15.0  # seconds to wait for the URL + a registered edge connection
 _DOWNLOAD_TIMEOUT = 60  # urlopen timeout for the one-time binary download
 
+# A registered edge connection does not mean the hostname resolves yet, so the
+# URL is fetched once before it is advertised.
+_PUBLIC_PROBE_PATH = "/api/health"
+_PUBLIC_PROBE_MARKER = "Unsloth UI Backend"
+# One deadline for DNS propagation + the health probe, bounding the startup stall.
+_PUBLIC_PROBE_TIMEOUT = 45.0
+_PUBLIC_PROBE_ATTEMPT_TIMEOUT = 5.0
+_PUBLIC_PROBE_RETRY_DELAY = 1.0
+
+# Wait for the hostname via DoH first: an early OS lookup negative-caches the
+# NXDOMAIN for up to 30 min.
+_DNS_POLL_DELAY = 2.0
+# Retry transient DoH failures, but give up fast when DoH is blocked outright.
+_DNS_MAX_DOH_ERRORS = 3
+_DOH_URL = "https://cloudflare-dns.com/dns-query?name={host}&type=A"
+
 
 def _windows_hidden_kwargs() -> dict:
     """Suppress a child console window on Windows; no-op elsewhere."""
@@ -95,7 +112,7 @@ def _cache_path() -> Optional[Path]:
 
 
 def find_cloudflared() -> Optional[str]:
-    """Locate an existing cloudflared: PATH first, then the Studio bin cache."""
+    """Locate an existing cloudflared: PATH first, then the Unsloth bin cache."""
     on_path = shutil.which("cloudflared")
     if on_path:
         return on_path
@@ -191,6 +208,59 @@ def ensure_cloudflared() -> Optional[str]:
         return None
 
 
+def _wait_for_dns(host: str, deadline: float) -> None:
+    import json
+    import urllib.request
+
+    errors = 0
+    while True:
+        answered = False
+        try:
+            req = urllib.request.Request(
+                _DOH_URL.format(host = host),
+                headers = {"Accept": "application/dns-json", "User-Agent": "unsloth-studio"},
+            )
+            with urllib.request.urlopen(req, timeout = 5) as response:
+                answered = bool(json.loads(response.read(65536)).get("Answer"))
+            errors = 0
+        except Exception:
+            errors += 1
+            if errors >= _DNS_MAX_DOH_ERRORS:
+                return
+        if answered:
+            return
+        remaining = deadline - time.monotonic()
+        if remaining <= 0:
+            return
+        time.sleep(min(_DNS_POLL_DELAY, remaining))
+
+
+def verify_public_url(url: str, timeout: float = _PUBLIC_PROBE_TIMEOUT) -> bool:
+    import json
+    import urllib.request
+    from urllib.parse import urlsplit
+
+    deadline = time.monotonic() + timeout
+    host = urlsplit(url).hostname
+    if host:
+        _wait_for_dns(host, deadline)
+
+    probe_url = f"{url.rstrip('/')}{_PUBLIC_PROBE_PATH}"
+    while True:
+        try:
+            req = urllib.request.Request(probe_url, headers = {"User-Agent": "unsloth-studio"})
+            with urllib.request.urlopen(req, timeout = _PUBLIC_PROBE_ATTEMPT_TIMEOUT) as response:
+                body = response.read(4096)
+            if json.loads(body).get("service") == _PUBLIC_PROBE_MARKER:
+                return True
+        except Exception:
+            pass
+        remaining = deadline - time.monotonic()
+        if remaining <= 0:
+            return False
+        time.sleep(min(_PUBLIC_PROBE_RETRY_DELAY, remaining))
+
+
 class CloudflareTunnel:
     """A cloudflared quick tunnel to http://localhost:<port>. Best-effort throughout.
 
@@ -309,7 +379,7 @@ class CloudflareTunnel:
             pass
 
 
-# Single serving process per Studio launch, so one module-level tunnel handle is
+# Single serving process per Unsloth launch, so one module-level tunnel handle is
 # enough; the lock guards the start/stop/shutdown races.
 _active_tunnel: Optional[CloudflareTunnel] = None
 _active_lock = threading.Lock()
@@ -322,11 +392,12 @@ def start_studio_tunnel(port: int, timeout: float = _READY_TIMEOUT) -> Optional[
     """Start a quick tunnel and return its public URL once it is actually
     serving, or None (best-effort).
 
-    Waits for cloudflared to both mint the URL and register an edge connection
-    before returning, so the caller never advertises a URL that yields Cloudflare
-    error 1033 (HTTP 530). If a URL is minted but no connection registers within
-    the window (e.g. quic is blocked on this network), retries once forcing the
-    http2 protocol. On any failure the tunnel is stopped and None is returned.
+    Waits for cloudflared to both mint the URL and register an edge connection,
+    then fetches /api/health over the public URL, so the caller never advertises
+    a link that yields Cloudflare error 1033 (HTTP 530) or an unresolvable host.
+    If a URL is minted but no connection registers within the window (e.g. quic
+    is blocked on this network), retries once forcing the http2 protocol. On any
+    failure the tunnel is stopped and None is returned.
     """
     global _active_tunnel, _shutdown_requested
     binary = ensure_cloudflared()
@@ -349,9 +420,13 @@ def start_studio_tunnel(port: int, timeout: float = _READY_TIMEOUT) -> Optional[
             prior, _active_tunnel = _active_tunnel, tunnel
         if prior is not None:
             prior.stop()
+        registered = False
         try:
             tunnel.start()
             url = tunnel.wait_for_ready(timeout)
+            registered = url is not None
+            if url and not verify_public_url(url):
+                url = None
         except Exception:
             url = None
         if url:
@@ -371,6 +446,9 @@ def start_studio_tunnel(port: int, timeout: float = _READY_TIMEOUT) -> Optional[
         # http2 will not help, so do not burn another window on it.
         if not saw_url:
             return None
+        # probe failure after registering is DNS propagation; http2 would not help
+        if registered:
+            return None
     return None
 
 
diff --git a/studio/backend/colab.py b/studio/backend/colab.py
index e04543b3aa..baa18a2fec 100644
--- a/studio/backend/colab.py
+++ b/studio/backend/colab.py
@@ -1,9 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""
-Colab helpers for Unsloth Studio. Uses Colab's built-in proxy.
-"""
+"""Colab helpers for Unsloth Studio. Uses Colab's built-in proxy."""
 
 from pathlib import Path
 import sys
@@ -22,11 +20,9 @@ logger = get_logger(__name__)
 
 
 def get_colab_url(port: int = 8888) -> str:
-    """
-    Get the Colab proxy URL for a port.
+    """Get the Colab proxy URL for a port.
 
-    Retries up to 3 times, validating the result is a real HTTPS Colab URL.
-    Falls back to http://localhost:{port} only when all attempts fail.
+    Retries 3x validating a real HTTPS Colab URL; falls back to localhost on failure.
     """
     import time as _time
 
@@ -55,28 +51,244 @@ def get_colab_url(port: int = 8888) -> str:
     return fallback
 
 
-def show_link(port: int = 8888, *, _url: "str | None" = None):
-    """Display a styled clickable link to the UI.
-
-    *_url* is an optional pre-fetched proxy URL; pass it to avoid a second eval_js round-trip.
-    """
-    from IPython.display import display, HTML
-
-    url = _url if _url is not None else get_colab_url(port)
-
-    # Truncated display URL; try/except so an odd URL shape still renders the link.
+def _short_colab_url(url: str, port: int) -> str:
+    """Truncated display form of a Colab proxy URL; falls back to the full URL."""
     try:
         port_prefix = f"{port}-"
         idx = url.index(port_prefix)
         next_dash = url.index("-", idx + len(port_prefix))
-        short_url = url[: next_dash + 1] + "..."
+        return url[: next_dash + 1] + "..."
     except (ValueError, IndexError):
-        short_url = url
+        return url
 
-    # Plain-text line so the URL shows even if HTML display fails.
-    logger.info(f"🌐 Unsloth Studio URL: {url}")
 
-    html = f"""
+def _is_colab_proxy_url(url: str, port: int) -> bool:
+    """True when *url* looks like a real Colab kernel proxy, not a localhost fallback."""
+    return bool(url and isinstance(url, str) and url.startswith("https://") and str(port) in url)
+
+
+def _is_colab_runtime() -> bool:
+    """True on a hosted Colab notebook kernel.
+
+    Reuses the backend's main Colab detector (``/content`` + Colab env / ``google.colab``)
+    instead of a single env var, which is not always present on hosted runtimes.
+    """
+    try:
+        from main import _IS_COLAB
+        return bool(_IS_COLAB)
+    except Exception:
+        return False
+
+
+def _colab_login_credentials_path() -> Path:
+    from auth.storage import DB_PATH
+    return DB_PATH.parent / ".colab_notebook_login"
+
+
+def _store_colab_login_credentials(username: str, password: str) -> None:
+    """Persist Colab admin credentials for notebook re-runs after interrupt."""
+    path = _colab_login_credentials_path()
+    try:
+        path.parent.mkdir(parents = True, exist_ok = True)
+        path.write_text(f"{username}\n{password}\n")
+        try:
+            import os
+            os.chmod(path, 0o600)
+        except OSError:
+            pass
+    except OSError as e:
+        logger.info(f"Could not persist Colab login credentials ({e}).")
+
+
+def _load_colab_login_credentials() -> "tuple[str, str] | None":
+    """Return stored Colab admin credentials from a previous ``start()`` run, if any."""
+    path = _colab_login_credentials_path()
+    try:
+        if not path.is_file():
+            return None
+        lines = path.read_text().splitlines()
+        if len(lines) >= 2 and lines[0] and lines[1]:
+            return lines[0], lines[1]
+    except OSError as e:
+        logger.info(f"Could not load Colab login credentials ({e}).")
+    return None
+
+
+def _clear_colab_login_credentials() -> None:
+    """Drop the cached Colab credentials once they no longer authenticate."""
+    path = _colab_login_credentials_path()
+    try:
+        path.unlink(missing_ok = True)
+    except OSError as e:
+        logger.info(f"Could not clear Colab login credentials ({e}).")
+
+
+def _colab_credentials_still_valid(username: str, password: str) -> bool:
+    """True when *password* still matches the stored admin hash.
+
+    Guards against redisplaying a cached first-run password after the user has
+    changed the admin password through the app, which would print credentials
+    that no longer authenticate to the current Cloudflare tunnel.
+    """
+    try:
+        from auth.storage import get_user_and_secret
+        from auth.hashing import verify_password
+    except Exception as e:
+        logger.info(f"Could not load auth to validate cached Colab credentials ({e}).")
+        return False
+    try:
+        row = get_user_and_secret(username)
+        if not row:
+            return False
+        salt, pwd_hash = row[0], row[1]
+        return bool(verify_password(password, salt, pwd_hash))
+    except Exception as e:
+        logger.info(f"Could not validate cached Colab credentials ({e}).")
+        return False
+
+
+def _colab_wants_cloudflare(cloudflare: "bool | None") -> bool:
+    """Resolve whether to open a Cloudflare tunnel.
+
+    ``None`` auto-enables on real Colab (the in-cell proxy embed is often blank);
+    pass ``False`` to opt out.
+    """
+    if cloudflare is not None:
+        return cloudflare
+    return _is_colab_runtime()
+
+
+def _finalize_colab_admin_password() -> "tuple[str, str] | None":
+    """Clear the bootstrap-password gate on Colab so Cloudflare tunnels can start.
+
+    Returns ``(username, password)`` for display in the notebook. On first run the
+    random admin password is finalized; on later runs (e.g. after interrupt) the
+    stored credentials are re-displayed so the Cloudflare link stays usable.
+    Anyone who can read this cell already controls the runtime.
+    """
+    if not _is_colab_runtime():
+        return None
+    try:
+        from auth.storage import (
+            DEFAULT_ADMIN_USERNAME,
+            ensure_default_admin,
+            generate_bootstrap_password,
+            get_bootstrap_password,
+            requires_password_change,
+            update_password,
+        )
+    except Exception as e:
+        logger.warning(
+            f"Could not load auth for Colab setup ({e}); Cloudflare link may be blocked."
+        )
+        return None
+
+    try:
+        ensure_default_admin()
+        username = DEFAULT_ADMIN_USERNAME
+        if not requires_password_change(username):
+            creds = _load_colab_login_credentials()
+            if creds is not None and _colab_credentials_still_valid(username, creds[1]):
+                return creds
+            # The admin password was changed through the app after the first run,
+            # so the cached copy is stale; drop it instead of printing dead credentials.
+            _clear_colab_login_credentials()
+            return None
+        password = get_bootstrap_password() or generate_bootstrap_password()
+        if not update_password(username, password):
+            logger.warning(
+                "Could not finalize Colab admin password; Cloudflare link may be blocked."
+            )
+            return None
+        _store_colab_login_credentials(username, password)
+        return username, password
+    except Exception as e:
+        logger.warning(
+            f"Could not finalize Colab admin password ({e}); Cloudflare link may be blocked."
+        )
+        return None
+
+
+def _colab_login_html(username: str, password: str) -> str:
+    """Notebook card with Colab admin credentials (shown once after auto-finalize)."""
+    return f"""
+    <div style="display: inline-block; padding: 20px; background: #ffffff; border: 2px solid #000000;
+                border-radius: 12px; margin: 10px 0; font-family: system-ui, -apple-system, sans-serif;">
+        <h2 style="color: #000000; margin: 0 0 12px 0; font-size: 22px; font-weight: 800;">
+            Unsloth Studio Login (Colab)
+        </h2>
+        <p style="color: #333333; margin: 0 0 12px 0; font-size: 14px; font-weight: bold;">
+            Log in to Studio with the Cloudflare link above using these credentials. This cell
+            is visible only in your notebook session.
+        </p>
+        <p style="color: #333333; margin: 0; font-size: 14px; font-family: monospace; font-weight: bold;">
+            Username: <code>{username}</code><br>
+            Password: <code>{password}</code>
+        </p>
+    </div>
+    """
+
+
+def _show_colab_login_credentials(username: str, password: str) -> None:
+    """Display Colab admin credentials in the notebook output."""
+    from IPython.display import HTML, display
+
+    logger.info(f"🔐 Unsloth Studio login — user: {username}")
+    display(HTML(_colab_login_html(username, password)))
+
+
+def _ready_card_html(
+    url: str,
+    port: int,
+    *,
+    has_cloudflare_link: bool = False,
+    cloudflare_requested: bool = False,
+) -> str:
+    """Branded ready card for the in-notebook Studio view.
+
+    Colab ``*.prod.colab.dev`` proxy URLs are session-scoped and 404 when opened as a
+    top-level tab or on another device, so never ``window.open`` them. On real Colab the
+    Cloudflare link is the supported entry point because in-cell proxy embeds often stay blank.
+    """
+    short_url = _short_colab_url(url, port)
+    if _is_colab_runtime() or _is_colab_proxy_url(url, port):
+        if has_cloudflare_link:
+            embed_note = (
+                "Open Studio with the Cloudflare link above. In-cell proxy previews on "
+                "current Colab often stay blank, so the tunnel link is the supported path."
+            )
+        elif cloudflare_requested:
+            embed_note = (
+                "Could not open a Cloudflare tunnel, so Studio may be unreachable on Colab. "
+                "Check the logs above and re-run this cell. Pass "
+                '<code style="background:#f3f3f3;padding:2px 6px;border-radius:4px;">'
+                "cloudflare=True</code> after fixing any tunnel errors."
+            )
+        else:
+            embed_note = (
+                "Colab proxy links cannot be opened in a new tab (they 404 outside this "
+                'notebook). Re-run with <code style="background:#f3f3f3;padding:2px 6px;'
+                'border-radius:4px;">start(cloudflare=True)</code> for a working link.'
+            )
+        return f"""
+    <div style="display: inline-block; padding: 20px; background: #ffffff; border: 2px solid #000000;
+                border-radius: 12px; margin: 10px 0; font-family: system-ui, -apple-system, sans-serif;">
+        <h2 style="color: #000000; margin: 0 0 12px 0; font-size: 26px; font-weight: 800;
+                   display: flex; align-items: center; gap: 12px;">
+            <img src="https://github.com/unslothai/unsloth/raw/main/studio/frontend/public/unsloth-gem.png"
+                 height="48" style="display:block;">
+            Unsloth Studio is Ready!
+        </h2>
+        <p style="color: #333333; margin: 0 0 8px 0; font-size: 15px; font-weight: bold;">
+            {embed_note}
+        </p>
+        <p style="color: #666666; margin: 16px 0 0 0; font-size: 13px; font-family: monospace; font-weight: bold;">
+            {short_url}
+        </p>
+    </div>
+    """
+
+    return f"""
     <div style="display: inline-block; padding: 20px; background: #ffffff; border: 2px solid #000000;
                 border-radius: 12px; margin: 10px 0; font-family: system-ui, -apple-system, sans-serif;">
         <h2 style="color: #000000; margin: 0 0 12px 0; font-size: 26px; font-weight: 800;
@@ -100,15 +312,52 @@ def show_link(port: int = 8888, *, _url: "str | None" = None):
         </p>
     </div>
     """
-    display(HTML(html))
+
+
+def show_link(
+    port: int = 8888,
+    *,
+    _url: "str | None" = None,
+    has_cloudflare_link: bool = False,
+    cloudflare_requested: bool = False,
+):
+    """Display a styled ready card for the UI.
+
+    Colab proxy URLs are informational only (no new-tab open; they 404 outside the cell);
+    non-proxy URLs keep a clickable open button. *_url* is an optional pre-fetched proxy
+    URL to avoid a second eval_js round-trip.
+    """
+    from IPython.display import display, HTML
+
+    url = _url if _url is not None else get_colab_url(port)
+    logger.info(f"🌐 Unsloth Studio URL: {url}")
+    display(
+        HTML(
+            _ready_card_html(
+                url,
+                port,
+                has_cloudflare_link = has_cloudflare_link,
+                cloudflare_requested = cloudflare_requested,
+            )
+        )
+    )
+
+
+def _warn_colab_cloudflare_missing(*, use_cloudflare: bool, cloudflare_url: "str | None") -> None:
+    """Log a prominent warning when Colab expected a tunnel but none was opened."""
+    if not use_cloudflare or cloudflare_url or not _is_colab_runtime():
+        return
+    logger.warning(
+        "Colab Cloudflare tunnel unavailable — Studio is unlikely to be reachable in this "
+        "notebook. Check the logs above for tunnel or auth errors, then re-run start()."
+    )
 
 
 def _bootstrap_password_pending() -> bool:
     """True while the default admin still owes a bootstrap-password change.
 
-    While pending, main.py injects that password into same-origin GETs, and a public
-    tunnel GET (no Origin) reads as same-origin, so sharing the link would leak admin
-    access. Fails safe to pending if the state cannot be read.
+    While pending, a public tunnel GET (no Origin) reads as same-origin and gets the
+    injected password, so sharing the link would leak admin access. Fails safe to pending.
     """
     try:
         from auth.storage import requires_password_change, DEFAULT_ADMIN_USERNAME
@@ -121,15 +370,14 @@ def _bootstrap_password_pending() -> bool:
 def start_cloudflare_tunnel(port: int) -> "str | None":
     """Open a shareable Cloudflare quick tunnel to localhost:*port*, or None.
 
-    run_server suppresses the tunnel on Colab by design, so we start it directly.
-    Refused while the bootstrap password is pending; any failure collapses to None
-    and the Colab proxy still works.
+    run_server suppresses the tunnel on Colab, so we start it directly. Refused while the
+    bootstrap password is pending; any failure collapses to None (Colab proxy still works).
     """
     if _bootstrap_password_pending():
         logger.warning(
             "Cloudflare link not started: the admin account still has its temporary "
             "bootstrap password, which is exposed to anyone who can load the page. "
-            "Open Studio in this tab, log in and change the admin password, then re-run "
+            "Open Unsloth in this tab, log in and change the admin password, then re-run "
             "start(cloudflare=True) to get the shareable link."
         )
         return None
@@ -152,9 +400,9 @@ def start_cloudflare_tunnel(port: int) -> "str | None":
 def _publish_cloudflare_url(cloudflare_url: "str | None") -> None:
     """Publish a directly-started tunnel URL onto app.state so /api/health advertises it.
 
-    run_server only sets this when it opens the tunnel itself, which it skips on Colab,
-    so we set it here. Otherwise the frontend's API examples fall back to an
-    unreachable server_url. Best-effort.
+    run_server sets this only when it opens the tunnel itself (skipped on Colab), so we
+    set it here; otherwise the frontend's API examples fall back to an unreachable
+    server_url. Best-effort.
     """
     if not cloudflare_url:
         return
@@ -183,8 +431,7 @@ def _stop_cloudflare_tunnel() -> None:
 def _is_studio_healthy(port: int, timeout: float = 2.0) -> bool:
     """True only if Unsloth Studio (not some other app) answers /api/health on *port*.
 
-    The service-marker check stops the reuse path reusing or tunneling a foreign
-    process that merely serves /api/health.
+    The service-marker check stops the reuse path reusing or tunneling a foreign process.
     """
     import json, urllib.request
     try:
@@ -203,7 +450,7 @@ def _shareable_link_html(cloudflare_url: str) -> str:
                    display: flex; align-items: center; gap: 12px;">
             <img src="https://github.com/unslothai/unsloth/raw/main/studio/frontend/public/unsloth-gem.png"
                  height="48" style="display:block;">
-            Shareable Studio Link is Ready!
+            Shareable Unsloth Link is Ready!
         </h2>
         <a href="{cloudflare_url}" onclick="var w=window.open(this.href,'_blank');if(!w){{return true;}}return false;"
            style="display: inline-flex; align-items: center; gap: 10px; padding: 14px 28px;
@@ -222,31 +469,45 @@ def _shareable_link_html(cloudflare_url: str) -> str:
     """
 
 
-def _show_and_embed(port: int, *, cloudflare_url: "str | None" = None):
-    """Render the Studio header + iframe for *port*, with a shareable-link card above
-    when *cloudflare_url* is set. Falls back to serve_kernel_port_as_iframe."""
-    url = get_colab_url(port)
-    logger.info(f"🌐 Unsloth Studio URL: {url}")
-    if cloudflare_url:
-        logger.info(f"🔗 Shareable Cloudflare link: {cloudflare_url}")
+# Height for serve_kernel_port_as_iframe (~82vh on a 1080p screen, clamped).
+_COLAB_IFRAME_HEIGHT = 900
 
+
+def _embed_kernel_port_iframe(port: int) -> bool:
+    """Embed Studio via Colab's native kernel-port iframe helper.
+
+    Only trusted on a real Colab runtime: colabtools can import ``google.colab`` and
+    queue browser-side JS without appending an iframe, so callers outside Colab must use
+    the HTML iframe path instead.
+    """
+    if not _is_colab_runtime():
+        return False
+    try:
+        from google.colab import output as colab_output
+    except ImportError:
+        return False
+    try:
+        colab_output.serve_kernel_port_as_iframe(
+            port,
+            height = _COLAB_IFRAME_HEIGHT,
+            width = "100%",
+        )
+        return True
+    except Exception as e:
+        logger.info(f"serve_kernel_port_as_iframe failed ({e}); trying HTML iframe.")
+        return False
+
+
+def _embed_html_iframe(url: str, port: int) -> bool:
+    """Fallback embed: raw HTML iframe when the Colab helper is unavailable."""
     try:
         from IPython.display import HTML, display
+    except ImportError:
+        return False
 
-        iframe_id = f"unsloth-studio-{port}"
-
-        # Truncated header URL — best-effort, falls back to full URL.
-        try:
-            port_prefix = f"{port}-"
-            idx = url.index(port_prefix)
-            next_dash = url.index("-", idx + len(port_prefix))
-            short_url = url[: next_dash + 1] + "..."
-        except (ValueError, IndexError):
-            short_url = url
-
-        if cloudflare_url:
-            display(HTML(_shareable_link_html(cloudflare_url)))
-
+    short_url = _short_colab_url(url, port)
+    iframe_id = f"unsloth-studio-{port}"
+    try:
         display(
             HTML(f"""
 <div style="font-family:system-ui,-apple-system,sans-serif;margin:8px 0;
@@ -266,41 +527,101 @@ def _show_and_embed(port: int, *, cloudflare_url: "str | None" = None):
 </div>
 """)
         )
-    except Exception:
-        # Fallback: Colab's built-in helper.
+        return True
+    except Exception as e:
+        logger.info(f"HTML iframe embed failed ({e}).")
+        return False
+
+
+def _show_and_embed(
+    port: int,
+    *,
+    cloudflare_url: "str | None" = None,
+    colab_login: "tuple[str, str] | None" = None,
+    cloudflare_requested: bool = False,
+):
+    """Render the Unsloth ready card + iframe for *port*.
+
+    Prefer Colab's ``serve_kernel_port_as_iframe`` on real Colab; raw HTML iframe is the
+    fallback. Cloudflare cards stay clickable.
+    """
+    url = get_colab_url(port)
+    logger.info(f"🌐 Unsloth Studio URL: {url}")
+    if cloudflare_url:
+        logger.info(f"🔗 Shareable Cloudflare link: {cloudflare_url}")
+
+    _warn_colab_cloudflare_missing(
+        use_cloudflare = cloudflare_requested,
+        cloudflare_url = cloudflare_url,
+    )
+
+    if cloudflare_url:
         try:
-            from google.colab import output as colab_output
-            colab_output.serve_kernel_port_as_iframe(port, height = 900, width = "100%")
-        except ImportError:
-            pass
+            from IPython.display import HTML, display
+            display(HTML(_shareable_link_html(cloudflare_url)))
+        except Exception as e:
+            logger.info(f"Could not render Cloudflare link card ({e}).")
+
+    if colab_login:
+        try:
+            _show_colab_login_credentials(*colab_login)
+        except Exception as e:
+            logger.info(f"Could not render Colab login card ({e}).")
+
+    try:
+        show_link(
+            port,
+            _url = url,
+            has_cloudflare_link = bool(cloudflare_url),
+            cloudflare_requested = cloudflare_requested,
+        )
+    except Exception as e:
+        logger.info(f"Could not render Unsloth link card ({e}).")
+
+    # On Colab with a working tunnel, skip the in-cell proxy embed (often blank).
+    if _is_colab_runtime() and cloudflare_url:
+        return
+
+    # Real Colab: kernel helper needs only the port (works when eval_js failed).
+    if _is_colab_runtime():
+        if _embed_kernel_port_iframe(port):
+            return
+    _embed_html_iframe(url, port)
 
 
-def start(port: int = 8888, *, cloudflare: bool = False):
+def start(port: int = 8888, *, cloudflare: "bool | None" = None):
     """Start Unsloth Studio in Colab and display the URL.
 
     Args:
         port: Port to bind/serve on.
-        cloudflare: Opt in to a shareable Cloudflare HTTPS link reachable from any
-            device (default OFF). It exposes Studio's login page beyond Colab, so it
-            stays an explicit opt-in; the default shows only the in-tab proxy iframe.
+        cloudflare: Shareable Cloudflare HTTPS link. ``None`` (default) auto-enables on
+            real Colab because the in-cell proxy embed is often blank; pass ``False`` to
+            skip the tunnel or ``True`` to force it on other runtimes.
 
     Usage:
-        start()                    # Colab-proxy iframe only (default)
-        start(cloudflare=True)     # also open a shareable Cloudflare link
+        start()                    # Cloudflare link on Colab (auto); proxy iframe elsewhere
+        start(cloudflare=False)    # Colab proxy iframe only (often blank on current Colab)
+        start(cloudflare=True)     # force Cloudflare link on any runtime
     """
     import time
 
     logger.info("🦥 Starting Unsloth Studio...")
+    use_cloudflare = _colab_wants_cloudflare(cloudflare)
 
-    # Fast path: Studio already running (cell re-run). Re-launching would collide on
-    # the port, so just re-show the link and iframe.
+    # Fast path: already running (cell re-run); re-show link/iframe instead of rebinding the port.
     if _is_studio_healthy(port):
-        logger.info(f"   Studio is already running on port {port} — reusing existing server.")
+        logger.info(f"   Unsloth is already running on port {port} — reusing existing server.")
         # try/finally: tear the tunnel down even if interrupted mid-start/render.
         try:
-            cf_url = start_cloudflare_tunnel(port) if cloudflare else None
+            colab_login = _finalize_colab_admin_password() if use_cloudflare else None
+            cf_url = start_cloudflare_tunnel(port) if use_cloudflare else None
             _publish_cloudflare_url(cf_url)
-            _show_and_embed(port, cloudflare_url = cf_url)
+            _show_and_embed(
+                port,
+                cloudflare_url = cf_url,
+                colab_login = colab_login,
+                cloudflare_requested = use_cloudflare,
+            )
             for _ in range(10000):
                 time.sleep(300)
                 print("=", end = "", flush = True)
@@ -313,7 +634,6 @@ def start(port: int = 8888, *, cloudflare: bool = False):
     logger.info("   Loading backend...")
     from run import run_server
 
-    # Auto-detect frontend path
     repo_root = Path(__file__).parent.parent
     frontend_path = repo_root / "frontend" / "dist"
 
@@ -323,8 +643,7 @@ def start(port: int = 8888, *, cloudflare: bool = False):
 
     logger.info("   Starting server...")
     try:
-        # cloudflare=False: this helper owns the tunnel (Colab's own
-        # start(cloudflare=...) drives it), so pin it off explicitly.
+        # cloudflare=False: this helper owns the tunnel (via start(cloudflare=...)), so pin it off.
         app = run_server(
             host = "0.0.0.0",
             port = port,
@@ -339,14 +658,12 @@ def start(port: int = 8888, *, cloudflare: bool = False):
         logger.error(f"❌ Unsloth Studio failed to start: {exc}")
         return
 
-    # run_server auto-increments the port if in use; read back the bound port so the
-    # proxy URL and iframe point at the right place.
+    # run_server may auto-increment the port; read back the bound port for the proxy URL/iframe.
     actual_port: int = getattr(getattr(app, "state", None), "server_port", None) or port
 
     logger.info(f"   Server started on port {actual_port}!")
 
-    # Poll health endpoint before showing the link — avoids the race where ready_event
-    # fires but the process hasn't finished binding.
+    # Poll health before showing the link: avoids the race where ready_event fires pre-bind.
     import urllib.request
 
     server_ready = False
@@ -365,12 +682,17 @@ def start(port: int = 8888, *, cloudflare: bool = False):
         )
         return
 
-    # Open the tunnel now the server is healthy, publish its URL for /api/health, and
-    # tear it down on interrupt (try/finally) rather than orphan the process.
+    # Server healthy: finalize Colab auth, open the tunnel, publish URL, tear down on interrupt.
     try:
-        cf_url = start_cloudflare_tunnel(actual_port) if cloudflare else None
+        colab_login = _finalize_colab_admin_password() if use_cloudflare else None
+        cf_url = start_cloudflare_tunnel(actual_port) if use_cloudflare else None
         _publish_cloudflare_url(cf_url)
-        _show_and_embed(actual_port, cloudflare_url = cf_url)
+        _show_and_embed(
+            actual_port,
+            cloudflare_url = cf_url,
+            colab_login = colab_login,
+            cloudflare_requested = use_cloudflare,
+        )
 
         # Keep kernel alive so the daemon server thread runs.
         for _ in range(10000):
diff --git a/studio/backend/core/data_recipe/jobs/manager.py b/studio/backend/core/data_recipe/jobs/manager.py
index 0e0044702e..135c9fccf6 100644
--- a/studio/backend/core/data_recipe/jobs/manager.py
+++ b/studio/backend/core/data_recipe/jobs/manager.py
@@ -27,7 +27,6 @@ from .constants import (
 )
 from .parse import apply_update, coerce_event, parse_log_message
 from .types import Job
-from .worker import run_job_process
 from loggers import get_logger
 
 logger = get_logger(__name__)
@@ -169,12 +168,18 @@ class JobManager:
                 native_path_secret_removed_for_child_start,
                 run_without_native_path_secret,
             )
+            from utils.hf_cache_settings import child_environment_for_spawn, get_hf_cache_paths
 
-            with native_path_secret_removed_for_child_start():
+            cache_env = get_hf_cache_paths().child_env({})
+
+            with (
+                child_environment_for_spawn(cache_env),
+                native_path_secret_removed_for_child_start(),
+            ):
                 mp_q = _CTX.Queue()
                 proc = _CTX.Process(
                     target = run_without_native_path_secret,
-                    args = (run_job_process,),
+                    args = ("core.data_recipe.jobs.worker", "run_job_process", cache_env),
                     kwargs = {"event_queue": mp_q, "recipe": recipe, "run": run_payload},
                     daemon = True,
                 )
diff --git a/studio/backend/core/data_recipe/jobs/parse.py b/studio/backend/core/data_recipe/jobs/parse.py
index 3be830d0e4..8c2e8a4d55 100644
--- a/studio/backend/core/data_recipe/jobs/parse.py
+++ b/studio/backend/core/data_recipe/jobs/parse.py
@@ -133,7 +133,7 @@ def parse_log_message(msg: str) -> ParsedUpdate | None:
                 source = "github",
                 status = "rate_limited",
                 retry_after_sec = seconds,
-                message = ("Waiting for GitHub rate limit. Studio will resume automatically."),
+                message = ("Waiting for GitHub rate limit. Unsloth will resume automatically."),
             ),
         )
 
@@ -147,7 +147,7 @@ def parse_log_message(msg: str) -> ParsedUpdate | None:
                 status = "rate_limited",
                 retry_after_sec = seconds,
                 message = (
-                    "Waiting for GitHub secondary rate limit. Studio will resume automatically."
+                    "Waiting for GitHub secondary rate limit. Unsloth will resume automatically."
                 ),
             ),
         )
@@ -161,7 +161,7 @@ def parse_log_message(msg: str) -> ParsedUpdate | None:
                 source = "github",
                 status = "rate_limited",
                 retry_after_sec = seconds,
-                message = ("Waiting for GitHub rate limit. Studio will resume automatically."),
+                message = ("Waiting for GitHub rate limit. Unsloth will resume automatically."),
             ),
         )
 
diff --git a/studio/backend/core/data_recipe/local_callable_validators.py b/studio/backend/core/data_recipe/local_callable_validators.py
index ebb1d39dfb..ffc81669ae 100644
--- a/studio/backend/core/data_recipe/local_callable_validators.py
+++ b/studio/backend/core/data_recipe/local_callable_validators.py
@@ -238,7 +238,7 @@ def _run_oxc_batch(
     if not node_executable:
         return _fallback_results(
             len(code_values),
-            "Node.js not found (install Node >= 20.19, or re-run Studio setup to provision it).",
+            "Node.js not found (install Node >= 20.19, or re-run Unsloth setup to provision it).",
         )
     try:
         tmp_dir = ensure_dir(oxc_validator_tmp_root())
diff --git a/studio/backend/core/data_recipe/service.py b/studio/backend/core/data_recipe/service.py
index 4647dc098d..9770e88b7f 100644
--- a/studio/backend/core/data_recipe/service.py
+++ b/studio/backend/core/data_recipe/service.py
@@ -280,8 +280,8 @@ def create_data_designer(recipe: dict[str, Any], *, artifact_path: str | None =
     from data_designer.interface.data_designer import DataDesigner  # pyright: ignore[reportMissingImports]
 
     if artifact_path is None:
-        # DataDesigner defaults to cwd/artifacts; packaged Studio can run with
-        # cwd=/, so keep default callers on Studio's writable recipe artifact root.
+        # DataDesigner defaults to cwd/artifacts; packaged Unsloth can run with
+        # cwd=/, so keep default callers on Unsloth's writable recipe artifact root.
         artifact_path = str(recipe_datasets_root())
 
     recipe = _strip_frontend_model_config_metadata(recipe)
diff --git a/studio/backend/core/export/export.py b/studio/backend/core/export/export.py
index c8be50b08b..1b24c46e65 100644
--- a/studio/backend/core/export/export.py
+++ b/studio/backend/core/export/export.py
@@ -1048,6 +1048,21 @@ class ExportBackend:
                     "Use the safetensors adapter instead.",
                     None,
                 )
+            # llama.cpp's convert_lora_to_gguf.py has no concept of DoRA's
+            # lora_magnitude_vector tensors: it only reads the standard
+            # lora_A/lora_B delta, so exporting a DoRA adapter would silently
+            # drop the magnitude rescaling and produce a GGUF LoRA file that
+            # loads fine but no longer matches the trained model.
+            _peft_config = getattr(self.current_model, "peft_config", {}).get("default")
+            if getattr(_peft_config, "use_dora", False):
+                return (
+                    False,
+                    "GGUF LoRA export is not supported for DoRA adapters: the GGUF LoRA "
+                    "format has no way to represent DoRA's magnitude vectors, so the "
+                    "exported file would silently lose the DoRA behavior. Use the "
+                    "safetensors adapter instead, or merge to a full GGUF model.",
+                    None,
+                )
             outtype = str(gguf_outtype).lower()
             if outtype not in _GGUF_LORA_OUTTYPES:
                 return (
diff --git a/studio/backend/core/export/orchestrator.py b/studio/backend/core/export/orchestrator.py
index 6d1a928f2e..aaf48615f0 100644
--- a/studio/backend/core/export/orchestrator.py
+++ b/studio/backend/core/export/orchestrator.py
@@ -230,16 +230,20 @@ class ExportOrchestrator:
             native_path_secret_removed_for_child_start,
             run_without_native_path_secret,
         )
+        from utils.hf_cache_settings import child_environment_for_spawn, get_hf_cache_paths
 
-        from .worker import run_export_process
+        cache_env = get_hf_cache_paths().child_env({})
 
-        with native_path_secret_removed_for_child_start():
+        with (
+            child_environment_for_spawn(cache_env),
+            native_path_secret_removed_for_child_start(),
+        ):
             self._cmd_queue = _CTX.Queue()
             self._resp_queue = _CTX.Queue()
 
             self._proc = _CTX.Process(
                 target = run_without_native_path_secret,
-                args = (run_export_process,),
+                args = ("core.export.worker", "run_export_process", cache_env),
                 kwargs = {
                     "cmd_queue": self._cmd_queue,
                     "resp_queue": self._resp_queue,
diff --git a/studio/backend/core/inference/__init__.py b/studio/backend/core/inference/__init__.py
index ad78157418..1491dfa749 100644
--- a/studio/backend/core/inference/__init__.py
+++ b/studio/backend/core/inference/__init__.py
@@ -11,7 +11,7 @@ subprocess and can be imported directly from .inference when needed.
 Public names are resolved lazily (PEP 562): importing this package -- or a
 dependency-light leaf like ``core.inference.chat_eos`` -- must NOT eagerly pull
 the orchestrator / llama_cpp import chain (httpx, subprocess plumbing, the ML
-backend and its Studio dependencies). Those load only when a public name is
+backend and its Unsloth dependencies). Those load only when a public name is
 actually accessed, so standalone helpers stay unit-testable without the full
 inference stack.
 """
diff --git a/studio/backend/core/inference/anthropic_compat.py b/studio/backend/core/inference/anthropic_compat.py
index 3c7a4cb182..34445cc58e 100644
--- a/studio/backend/core/inference/anthropic_compat.py
+++ b/studio/backend/core/inference/anthropic_compat.py
@@ -539,7 +539,7 @@ class AnthropicPassthroughEmitter:
 
         Only calls naming a tool in ``allowed_tools`` (the client's declared
         tools) are promoted; everything else streams as text exactly as before.
-        Never enabled for Studio's own tool loop.
+        Never enabled for Unsloth's own tool loop.
         """
         from core.inference.passthrough_healing import StreamToolCallHealer
 
diff --git a/studio/backend/core/inference/audio_codecs.py b/studio/backend/core/inference/audio_codecs.py
index 93c7da72cb..b59f2bcce0 100644
--- a/studio/backend/core/inference/audio_codecs.py
+++ b/studio/backend/core/inference/audio_codecs.py
@@ -76,8 +76,14 @@ class AudioCodecManager:
         if self._snac_model is not None:
             return
         from snac import SNAC
+        from utils.hf_cache_settings import active_hf_hub_cache
 
-        self._snac_model = SNAC.from_pretrained("hubertsiuzdak/snac_24khz").to(device).eval()
+        # Route weights to the selected cache; this can run in the main process.
+        self._snac_model = (
+            SNAC.from_pretrained("hubertsiuzdak/snac_24khz", cache_dir = active_hf_hub_cache())
+            .to(device)
+            .eval()
+        )
         logger.info("Loaded SNAC codec (24kHz)")
 
     def _load_bicodec(
diff --git a/studio/backend/core/inference/chat_template_helpers.py b/studio/backend/core/inference/chat_template_helpers.py
index 897db8262d..528c059fbc 100644
--- a/studio/backend/core/inference/chat_template_helpers.py
+++ b/studio/backend/core/inference/chat_template_helpers.py
@@ -10,10 +10,242 @@ native-chat-template fallback used by the transformers and MLX backends.
 import copy
 import json
 import logging
+from dataclasses import dataclass
 from typing import Optional
 
 _THINK_OPEN = "<think>"
 _THINK_CLOSE = "</think>"
+_GEMMA_CHANNEL_START = "<|channel>"
+_GEMMA_THOUGHT_OPEN = "<|channel>thought"
+_GEMMA_THOUGHT_CLOSE = "<channel|>"
+_GEMMA_TEMPLATE_OPENERS = (
+    _GEMMA_THOUGHT_OPEN + "\n",
+    _GEMMA_THOUGHT_OPEN + "\\n",
+    _GEMMA_THOUGHT_OPEN + _GEMMA_THOUGHT_CLOSE,
+)
+
+
+def _tokenizer_objects(tokenizer) -> tuple:
+    """Return a processor/tokenizer and its distinct nested tokenizer."""
+    if tokenizer is None:
+        return ()
+    nested = getattr(tokenizer, "tokenizer", None)
+    return (tokenizer,) if nested is None or nested is tokenizer else (tokenizer, nested)
+
+
+def _selected_template_strings_from_value(
+    template,
+    tools = None,
+    *,
+    prefer_tool_use: bool = True,
+) -> tuple[str, ...]:
+    """Return the named chat template matching HF's default selection rules."""
+    tools = tools or None
+    if isinstance(template, str):
+        return (template,)
+    if not isinstance(template, dict):
+        return ()
+    if prefer_tool_use and tools and isinstance(template.get("tool_use"), str):
+        return (template["tool_use"],)
+    if isinstance(template.get("default"), str):
+        return (template["default"],)
+    values = tuple(value for value in template.values() if isinstance(value, str))
+    return values if len(values) == 1 else ()
+
+
+def _selected_chat_template_strings(tokenizer, tools = None) -> tuple[str, ...]:
+    """Return the active chat template selected for this request."""
+    tools = tools or None
+    getter = getattr(tokenizer, "get_chat_template", None)
+    if callable(getter):
+        for kwargs in ({"chat_template": None, "tools": tools}, {"tools": tools}, {}):
+            try:
+                selected = getter(**kwargs)
+            except Exception:
+                continue
+            if isinstance(selected, str):
+                return (selected,)
+    # ProcessorMixin.apply_chat_template does not switch to "tool_use" implicitly;
+    # it uses "default" unless chat_template= names another template.
+    is_processor = getattr(tokenizer, "tokenizer", None) is not None and callable(
+        getattr(tokenizer, "apply_chat_template", None)
+    )
+    return _selected_template_strings_from_value(
+        getattr(tokenizer, "chat_template", None),
+        tools,
+        prefer_tool_use = not is_processor,
+    )
+
+
+def _detect_reasoning_channel_markers_from_templates(
+    templates: tuple[str, ...],
+) -> Optional[tuple[str, str]]:
+    """Return Gemma native reasoning markers only when a template emits them."""
+    if any(opener in template for template in templates for opener in _GEMMA_TEMPLATE_OPENERS):
+        return _GEMMA_THOUGHT_OPEN, _GEMMA_THOUGHT_CLOSE
+    return None
+
+
+def detect_reasoning_channel_markers(tokenizer, tools = None) -> Optional[tuple[str, str]]:
+    """Return native Gemma thought-channel markers supported by a tokenizer.
+
+    Detection uses the active chat template rather than model names or vocabulary
+    membership. Some models expose Gemma control tokens without using the native
+    thought-channel response protocol, and those must keep normal
+    ``skip_special_tokens`` streaming.
+    """
+    for obj in _tokenizer_objects(tokenizer):
+        templates = _selected_chat_template_strings(obj, tools)
+        if templates:
+            return _detect_reasoning_channel_markers_from_templates(templates)
+    return None
+
+
+def detect_reasoning_channel_markers_from_template(
+    template, tools = None
+) -> Optional[tuple[str, str]]:
+    """Return native Gemma thought-channel markers from a raw template value."""
+    return _detect_reasoning_channel_markers_from_templates(
+        _selected_template_strings_from_value(template, tools)
+    )
+
+
+def detect_reasoning_channel_markers_from_model_info(
+    tokenizer,
+    model_info: Optional[dict] = None,
+    tools = None,
+) -> Optional[tuple[str, str]]:
+    """Return reasoning markers from the active or cached native template."""
+    markers = detect_reasoning_channel_markers(tokenizer, tools = tools)
+    if markers is not None or not isinstance(model_info, dict):
+        return markers
+
+    native_templates = (
+        model_info.get("native_chat_template"),
+        (model_info.get("chat_template_info") or {}).get("template"),
+    )
+    for template in native_templates:
+        markers = detect_reasoning_channel_markers_from_template(template, tools)
+        if markers is not None:
+            return markers
+    return None
+
+
+@dataclass(frozen = True)
+class ChatTemplateRenderResult:
+    """Prompt plus response-protocol metadata selected by the renderer."""
+
+    prompt: str
+    reasoning_channel_markers: Optional[tuple[str, str]] = None
+
+
+def _split_partial_marker(text: str, marker: str) -> tuple[str, str]:
+    """Hold the longest suffix that may become ``marker`` in the next chunk."""
+    for length in range(min(len(text), len(marker) - 1), 0, -1):
+        if text.endswith(marker[:length]):
+            return text[:-length], text[-length:]
+    return text, ""
+
+
+class ReasoningChannelNormalizer:
+    """Incrementally convert one native reasoning channel to ``<think>``.
+
+    The parser follows mlx-vlm's streaming boundary behavior but emits Unsloth's
+    established canonical text contract. Only the configured opening and
+    closing markers are consumed; tool-call and other control markers remain
+    available to downstream parsers.
+    """
+
+    def __init__(self, opening_marker: str, closing_marker: str):
+        self._opening_marker = opening_marker
+        self._closing_marker = closing_marker
+        self._buffer = ""
+        self._in_reasoning = False
+        self._reasoning_done = False
+        self._skip_opening_newline = False
+
+    def feed(self, text: str) -> str:
+        """Consume a raw text delta and return the stable canonical delta."""
+        self._buffer += text or ""
+        output: list[str] = []
+        while self._buffer:
+            if self._reasoning_done:
+                output.append(self._buffer)
+                self._buffer = ""
+                break
+
+            if self._in_reasoning and self._skip_opening_newline:
+                if self._buffer.startswith("\n"):
+                    self._buffer = self._buffer[1:]
+                self._skip_opening_newline = False
+                if not self._buffer:
+                    break
+
+            marker = self._closing_marker if self._in_reasoning else self._opening_marker
+            index = self._buffer.find(marker)
+            if index < 0:
+                stable, self._buffer = _split_partial_marker(self._buffer, marker)
+                output.append(stable)
+                break
+
+            output.append(self._buffer[:index])
+            self._buffer = self._buffer[index + len(marker) :]
+            if self._in_reasoning:
+                output.append(_THINK_CLOSE)
+                self._in_reasoning = False
+                self._reasoning_done = True
+            else:
+                output.append(_THINK_OPEN)
+                self._in_reasoning = True
+                self._skip_opening_newline = True
+        return "".join(output)
+
+    def finish(self) -> str:
+        """Flush a naturally completed stream and close an open think block."""
+        output = self.drain()
+        if self._in_reasoning:
+            output += _THINK_CLOSE
+            self._in_reasoning = False
+            self._reasoning_done = True
+        return output
+
+    def drain(self) -> str:
+        """Flush buffered literal text without synthesizing a closing tag."""
+        output = self._buffer
+        self._buffer = ""
+        return output
+
+
+def normalize_reasoning_snapshots(
+    stream,
+    tokenizer = None,
+    cancel_event = None,
+    markers: Optional[tuple[str, str]] = None,
+    tools = None,
+):
+    """Normalize a prefix-monotonic cumulative text stream when supported."""
+    markers = markers or detect_reasoning_channel_markers(tokenizer, tools = tools)
+    if markers is None:
+        yield from stream
+        return
+
+    normalizer = ReasoningChannelNormalizer(*markers)
+    raw_output = ""
+    normalized_output = ""
+    for snapshot in stream:
+        if not snapshot.startswith(raw_output):
+            raise RuntimeError("Reasoning normalization requires cumulative text snapshots")
+        delta = normalizer.feed(snapshot[len(raw_output) :])
+        raw_output = snapshot
+        if delta:
+            normalized_output += delta
+            yield normalized_output
+
+    cancelled = cancel_event is not None and cancel_event.is_set()
+    tail = normalizer.drain() if cancelled else normalizer.finish()
+    if tail:
+        normalized_output += tail
+        yield normalized_output
 
 
 def detect_think_prefill(prompt: Optional[str], special_tokens = None) -> str:
@@ -166,7 +398,8 @@ def render_native_template(
     preserve_thinking: Optional[bool] = None,
     apply_fn = None,
     hf_token: Optional[str] = None,
-) -> Optional[str]:
+    return_metadata: bool = False,
+):
     """Render ``messages`` + ``tools`` with the model's NATIVE chat template.
 
     Some Unsloth override templates (e.g. ``mistral``, ``gemma-4``) do not emit
@@ -175,7 +408,9 @@ def render_native_template(
     tool-calling syntax. It is loaded straight from the repo (bypassing any
     override on the live tokenizer) and cached on ``model_info``. Returns the
     rendered prompt only if the native template actually emits the tools (render
-    differs with vs without tools); otherwise ``None``.
+    differs with vs without tools); otherwise ``None``. With ``return_metadata``,
+    returns ``ChatTemplateRenderResult`` so callers can stream with the response
+    protocol selected by this request's template.
 
     ``hf_token`` is the token the model was loaded with -- passed to the repo load
     so a gated/private model's native template can still be fetched (otherwise the
@@ -261,7 +496,16 @@ def render_native_template(
             exc,
         )
         return None
-    return with_tools if with_tools != no_tools else None
+    if with_tools == no_tools:
+        return None
+    if return_metadata:
+        return ChatTemplateRenderResult(
+            with_tools,
+            _detect_reasoning_channel_markers_from_templates(
+                _selected_template_strings_from_value(native_tpl, tools)
+            ),
+        )
+    return with_tools
 
 
 def render_with_native_template_fallback(
@@ -277,7 +521,8 @@ def render_with_native_template_fallback(
     preserve_thinking: Optional[bool] = None,
     apply_fn = None,
     hf_token: Optional[str] = None,
-) -> str:
+    return_metadata: bool = False,
+):
     """Return ``formatted_prompt``, swapping in a native-template render when an
     override template dropped the ``tools`` schema.
 
@@ -285,9 +530,27 @@ def render_with_native_template_fallback(
     them (detected by comparison, robust against tool names in the system prompt),
     re-render with the model's native template. Shared by the transformers and MLX
     backends so both advertise tools consistently. ``hf_token`` is forwarded so a
-    gated/private model's native template can still be fetched."""
+    gated/private model's native template can still be fetched. With
+    ``return_metadata``, returns the selected prompt plus reasoning-channel markers
+    for the exact template used by this request."""
+    live_markers = detect_reasoning_channel_markers(tokenizer, tools = tools)
+
+    def _result(prompt: str, markers = live_markers):
+        if return_metadata:
+            return ChatTemplateRenderResult(prompt, markers)
+        return prompt
+
     if not tools:
-        return formatted_prompt
+        # Gemma 4 can emit its native reasoning protocol even when a generation-time
+        # Unsloth override rendered a marker-free prompt. Preserve the live-verified
+        # no-tools thinking behavior without letting cached native metadata describe
+        # unrelated tool prompts that kept the active override.
+        markers = live_markers
+        if markers is None:
+            markers = detect_reasoning_channel_markers_from_model_info(
+                tokenizer, model_info, tools = None
+            )
+        return _result(formatted_prompt, markers)
     if apply_fn is None:
         apply_fn = apply_chat_template_for_generation
     # Probe whether the live template dropped the schema. A tools-requiring template
@@ -307,9 +570,9 @@ def render_with_native_template_fallback(
             active_model_name,
             exc,
         )
-        return formatted_prompt
+        return _result(formatted_prompt)
     if formatted_prompt != probe_no_tools:
-        return formatted_prompt  # template already emits the tools schema
+        return _result(formatted_prompt)  # template already emits the tools schema
     native_prompt = render_native_template(
         model_info = model_info,
         active_model_name = active_model_name,
@@ -320,6 +583,7 @@ def render_with_native_template_fallback(
         preserve_thinking = preserve_thinking,
         apply_fn = apply_fn,
         hf_token = hf_token,
+        return_metadata = return_metadata,
     )
     if native_prompt:
         logger.info(
@@ -328,4 +592,4 @@ def render_with_native_template_fallback(
             active_model_name,
         )
         return native_prompt
-    return formatted_prompt
+    return _result(formatted_prompt)
diff --git a/studio/backend/core/inference/chat_templates.py b/studio/backend/core/inference/chat_templates.py
index 58f63ff61b..04c0db6aae 100644
--- a/studio/backend/core/inference/chat_templates.py
+++ b/studio/backend/core/inference/chat_templates.py
@@ -4,13 +4,13 @@
 """Bundled chat-template selection for GGUF inference.
 
 Some shipped GGUF quants embed an older chat template. Rather than re-cutting and
-asking users to re-download every quant, Studio can override the embedded template
+asking users to re-download every quant, Unsloth can override the embedded template
 at llama-server launch time with a bundled, up-to-date Jinja template for known
 model families. The override is wired through the existing ``chat_template_override``
 -> ``--chat-template-file`` path in ``LlamaCppBackend.load_model``.
 
 Currently this covers ``unsloth/gemma-4-*-GGUF``, which gains the upstream PR #118
-``preserve_thinking`` flag (defaulted OFF here) so the Studio "Preserve thinking"
+``preserve_thinking`` flag (defaulted OFF here) so the Unsloth "Preserve thinking"
 toggle appears while staying disabled by default.
 """
 
diff --git a/studio/backend/core/inference/external_provider.py b/studio/backend/core/inference/external_provider.py
index 20312e067c..2debf946e9 100644
--- a/studio/backend/core/inference/external_provider.py
+++ b/studio/backend/core/inference/external_provider.py
@@ -473,7 +473,7 @@ def _apply_mistral_reasoning_controls(
 # handles every provider without storing credentials.
 def _create_shared_http_client() -> httpx.AsyncClient:
     # Unsupported env proxy schemes (socks:// etc) raise at construction and
-    # would crash Studio startup (#6090); retry ignoring env proxies instead.
+    # would crash Unsloth startup (#6090); retry ignoring env proxies instead.
     try:
         return httpx.AsyncClient()
     except (ImportError, ValueError) as exc:
@@ -858,7 +858,7 @@ class ExternalProviderClient:
         if not self._is_openai_compatible():
             # Gemini speaks its own native REST shape (contents/parts);
             # `_stream_gemini` translates request/response into the OpenAI
-            # Chat Completions chunk format the rest of Studio expects.
+            # Chat Completions chunk format the rest of Unsloth expects.
             # API ref: https://ai.google.dev/gemini-api/docs
             if self.provider_type == "gemini":
                 async for line in self._stream_gemini(
@@ -1706,7 +1706,7 @@ class ExternalProviderClient:
                 # Translate OpenAI multimodal parts -> Anthropic native shapes.
                 # - `image_url`     -> `{type:"image", source:...}`
                 # - `input_document` -> `{type:"document", source:...}`
-                #   (Studio extension; mirrors Anthropic's document block,
+                #   (Unsloth extension; mirrors Anthropic's document block,
                 #   which supports PDFs as base64 or URL per
                 #   https://platform.claude.com/docs/en/build-with-claude/vision)
                 anthropic_parts: list[dict[str, Any]] = []
@@ -1749,7 +1749,7 @@ class ExternalProviderClient:
                                 }
                             )
                     elif part.get("type") == "input_document":
-                        # Studio's normalised PDF/doc type (file_data data-URI or
+                        # Unsloth's normalised PDF/doc type (file_data data-URI or
                         # file_url) -> Anthropic's native `document` block.
                         url = part.get("file_url") or ""
                         data_uri = part.get("file_data") or ""
@@ -4704,7 +4704,7 @@ class ExternalProviderClient:
                                 {"type": "image_generation_call", "id": call_id}
                             )
                     elif part_type == "input_document":
-                        # Map Studio's `input_document` onto Responses' `input_file`.
+                        # Map Unsloth's `input_document` onto Responses' `input_file`.
                         # https://developers.openai.com/api/docs/guides/images-vision
                         file_url = part.get("file_url")
                         file_data = part.get("file_data")
@@ -6010,7 +6010,7 @@ class ExternalProviderClient:
             if not models and self.provider_type == "ollama":
                 models = await self._list_ollama_native_models()
             # Gemini's native /v1beta/models uses a different shape; repackage
-            # into the OpenAI-compatible one Studio expects.
+            # into the OpenAI-compatible one Unsloth expects.
             if not models and self.provider_type == "gemini":
                 models = self._parse_gemini_models(data)
             return models
@@ -6213,7 +6213,7 @@ def _friendly_provider_error_text(
     *,
     model: str | None = None,
 ) -> str:
-    """Rewrite common provider errors into actionable Studio copy."""
+    """Rewrite common provider errors into actionable Unsloth copy."""
     if status_code == 404 and model:
         lowered = raw_message.lower()
         if "not found" in lowered or "not_found" in lowered:
diff --git a/studio/backend/core/inference/inference.py b/studio/backend/core/inference/inference.py
index 172e9e5546..2f46470091 100644
--- a/studio/backend/core/inference/inference.py
+++ b/studio/backend/core/inference/inference.py
@@ -5,9 +5,10 @@
 
 from unsloth import FastLanguageModel, FastVisionModel
 from unsloth.chat_templates import get_chat_template
-from transformers import TextStreamer
+from transformers import TextIteratorStreamer, TextStreamer
 from peft import PeftModel, PeftModelForCausalLM
 
+import contextlib
 import json
 import sys
 import torch
@@ -32,6 +33,11 @@ from core.inference.chat_eos import (
     chat_eos_repair,
     resolve_chat_turn_end_eos_ids_using,
 )
+from core.inference.chat_template_helpers import (
+    ReasoningChannelNormalizer,
+    detect_reasoning_channel_markers,
+    detect_think_prefill,
+)
 from core.inference.presence_penalty import _make_presence_penalty_processor
 from io import StringIO
 import structlog
@@ -187,6 +193,53 @@ class HarmonyTextStreamer:
                     self._queue.put(new_content)
 
 
+class ReasoningTextIteratorStreamer(TextIteratorStreamer):
+    """TextIteratorStreamer that preserves native channel tokens until parsed."""
+
+    def __init__(
+        self,
+        tokenizer,
+        *,
+        markers: tuple[str, str],
+        skip_prompt: bool = True,
+        timeout: float = 0.2,
+        cancel_event = None,
+        **decode_kwargs,
+    ):
+        decode_kwargs["skip_special_tokens"] = False
+        super().__init__(tokenizer, skip_prompt = skip_prompt, timeout = timeout, **decode_kwargs)
+        self._normalizer = ReasoningChannelNormalizer(*markers)
+        self._cancel_event = cancel_event
+        self._aborted = False
+
+    def abort(self):
+        """Mark generation as failed so ``end`` drains without closing."""
+        self._aborted = True
+
+    def on_finalized_text(
+        self,
+        text: str,
+        stream_end: bool = False,
+    ):
+        """Queue canonical deltas, closing only on natural stream completion."""
+        delta = self._normalizer.feed(text)
+        if delta:
+            self.text_queue.put(delta, timeout = self.timeout)
+
+        if stream_end:
+            cancelled = self._aborted or (
+                self._cancel_event is not None and self._cancel_event.is_set()
+            )
+            tail = self._normalizer.drain() if cancelled else self._normalizer.finish()
+            if tail:
+                self.text_queue.put(tail, timeout = self.timeout)
+            self.text_queue.put(self.stop_signal, timeout = self.timeout)
+
+
+class _GenerationThreadError(RuntimeError):
+    """Generation worker failures that should propagate through stream routes."""
+
+
 class InferenceBackend:
     """Unified inference backend supporting text, vision, and LoRA models"""
 
@@ -836,6 +889,7 @@ class InferenceBackend:
         thread_id: Optional[str] = None,
         rag_scope: Optional[dict] = None,
         presence_penalty: float = 0.0,
+        reasoning_prefilled: bool = False,
     ):
         """Run an agentic tool loop on top of ``generate_chat_response``.
 
@@ -889,6 +943,7 @@ class InferenceBackend:
             session_id = session_id,
             thread_id = thread_id,
             rag_scope = rag_scope,
+            reasoning_prefilled = reasoning_prefilled,
         )
 
     def generate_chat_response(
@@ -960,8 +1015,7 @@ class InferenceBackend:
         thread can toggle adapters under the generation lock.
         """
         if not self.active_model_name:
-            yield "Error: No active model"
-            return
+            raise RuntimeError("No active model")
 
         model_info = self.models[self.active_model_name]
         is_vision = model_info.get("is_vision", False)
@@ -1049,6 +1103,7 @@ class InferenceBackend:
             template_messages = [{"role": "system", "content": system_prompt}] + messages
         else:
             template_messages = messages
+        reasoning_channel_markers_resolved = False
         try:
             if not (hasattr(tokenizer, "chat_template") and tokenizer.chat_template):
                 raise ValueError(
@@ -1058,6 +1113,7 @@ class InferenceBackend:
                     f"Please use a model that includes a chat template, or manually set "
                     f"one via tokenizer.chat_template before inference."
                 )
+            reasoning_channel_markers = None
             formatted_prompt = self._apply_chat_template_for_generation(
                 tokenizer,
                 template_messages,
@@ -1073,7 +1129,7 @@ class InferenceBackend:
                 render_with_native_template_fallback,
             )
 
-            formatted_prompt = render_with_native_template_fallback(
+            render_result = render_with_native_template_fallback(
                 formatted_prompt = formatted_prompt,
                 tokenizer = tokenizer,
                 model_info = model_info,
@@ -1085,13 +1141,19 @@ class InferenceBackend:
                 preserve_thinking = preserve_thinking,
                 apply_fn = self._apply_chat_template_for_generation,
                 hf_token = model_info.get("hf_token"),
+                return_metadata = True,
             )
+            formatted_prompt = render_result.prompt
+            reasoning_channel_markers = render_result.reasoning_channel_markers
+            reasoning_channel_markers_resolved = True
 
             logger.debug(f"Formatted prompt: {formatted_prompt[:200]}...")
         except Exception as e:
             logger.error(f"Error applying chat template: {e}")
             # Fall back to manual formatting
             formatted_prompt = self.format_chat_prompt(messages, system_prompt)
+            reasoning_channel_markers = None
+            reasoning_channel_markers_resolved = True
 
         # Step 3: generate
         yield from self.generate_stream(
@@ -1105,6 +1167,8 @@ class InferenceBackend:
             cancel_event = cancel_event,
             _adapter_state = _adapter_state,
             presence_penalty = presence_penalty,
+            reasoning_channel_markers = reasoning_channel_markers,
+            reasoning_channel_markers_resolved = reasoning_channel_markers_resolved,
         )
 
     def _generate_vision_response(
@@ -1190,21 +1254,27 @@ class InferenceBackend:
 
         # Stream with TextIteratorStreamer + background thread
         try:
-            from core.inference.chat_template_helpers import detect_think_prefill
-
             # Re-emit an open <think> prefill swallowed by skip_prompt (see
             # generate_stream).
             think_prefix = detect_think_prefill(
                 prompt_text, getattr(raw_tokenizer, "all_special_tokens", None)
             )
-            from transformers import TextIteratorStreamer
             import threading
 
-            streamer = TextIteratorStreamer(
+            streamer = self._make_text_streamer(
                 raw_tokenizer,
+                protocol_source = processor,
+                # The text-only VLM fallback above did not render with the
+                # processor template, so its native markers do not describe
+                # this request's response protocol.
+                reasoning_channel_markers = detect_reasoning_channel_markers(processor)
+                if image
+                else None,
+                reasoning_channel_markers_resolved = True,
                 skip_prompt = True,
-                skip_special_tokens = True,
                 timeout = 0.2,
+                cancel_event = cancel_event,
+                use_harmony = self._is_gpt_oss_model(),
             )
 
             generation_kwargs = dict(
@@ -1226,6 +1296,10 @@ class InferenceBackend:
                 )
                 if _pp is not None:
                     generation_kwargs["logits_processor"] = _pp
+            stopping_criteria = self._cancel_stopping_criteria(cancel_event)
+            if stopping_criteria is not None:
+                generation_kwargs["stopping_criteria"] = stopping_criteria
+            active_stop_token_ids = self._generation_stop_token_ids(model, generation_kwargs)
 
             err: dict[str, str] = {}
 
@@ -1235,6 +1309,8 @@ class InferenceBackend:
                         model.generate(**generation_kwargs)
                     except Exception as e:
                         err["msg"] = str(e)
+                        if hasattr(streamer, "abort"):
+                            streamer.abort()
                         logger.error(f"Vision generation error in thread: {e}")
                     finally:
                         try:
@@ -1251,12 +1327,17 @@ class InferenceBackend:
             if think_prefix:
                 yield think_prefix
             from queue import Empty
+            import time
 
             generation_complete = False
+            cancel_deadline = None
             try:
                 while True:
                     if cancel_event is not None and cancel_event.is_set():
-                        break
+                        if cancel_deadline is None:
+                            cancel_deadline = time.monotonic() + 10
+                        elif time.monotonic() >= cancel_deadline:
+                            break
                     try:
                         new_token = next(streamer)
                     except StopIteration:
@@ -1265,27 +1346,48 @@ class InferenceBackend:
                     except Empty:
                         if not thread.is_alive():
                             generation_complete = True
+                            output = yield from self._drain_streamer_tail(
+                                streamer, output, active_stop_token_ids
+                            )
+                            break
+                        if cancel_deadline is not None:
+                            remaining = cancel_deadline - time.monotonic()
+                            if remaining <= 0:
+                                break
+                            thread.join(timeout = remaining)
+                            if thread.is_alive():
+                                break
+                            generation_complete = True
+                            output = yield from self._drain_streamer_tail(
+                                streamer, output, active_stop_token_ids
+                            )
                             break
                         continue
                     if new_token:
-                        output += new_token
-                        cleaned = self._clean_generated_text(output)
+                        output, cleaned = self._append_stream_delta(
+                            output, new_token, active_stop_token_ids
+                        )
                         yield cleaned
             finally:
                 if cancel_event is not None and not generation_complete:
                     cancel_event.set()
-                thread.join(timeout = 10)
+                join_timeout = 10
+                if cancel_deadline is not None:
+                    join_timeout = max(0, cancel_deadline - time.monotonic())
+                thread.join(timeout = join_timeout)
                 if thread.is_alive():
                     logger.warning(
                         "Vision generation thread did not exit after cancel/join timeout"
                     )
 
             if err.get("msg"):
-                yield f"Error: {err['msg']}"
+                raise _GenerationThreadError(err["msg"])
 
+        except _GenerationThreadError:
+            raise
         except Exception as e:
             logger.error(f"Vision generation error: {e}")
-            yield f"Error: {str(e)}"
+            raise
 
     def generate_audio_input_response(
         self,
@@ -1410,11 +1512,13 @@ class InferenceBackend:
                     )
 
             if err.get("msg"):
-                yield f"Error: {err['msg']}"
+                raise _GenerationThreadError(err["msg"])
 
+        except _GenerationThreadError:
+            raise
         except Exception as e:
             logger.error(f"Audio input generation error: {e}")
-            yield f"Error: {str(e)}"
+            raise
 
     def generate_whisper_response(
         self,
@@ -1447,6 +1551,86 @@ class InferenceBackend:
         from utils.datasets import is_gpt_oss_model_name
         return is_gpt_oss_model_name(model_name or self.active_model_name or "")
 
+    def _make_text_streamer(
+        self,
+        tokenizer,
+        *,
+        protocol_source = None,
+        reasoning_channel_markers = None,
+        reasoning_channel_markers_resolved: bool = False,
+        skip_prompt: bool = True,
+        timeout: float = 0.2,
+        cancel_event = None,
+        use_harmony: bool = False,
+    ):
+        """Create the streamer matching this model's native response protocol."""
+        if use_harmony:
+            try:
+                return HarmonyTextStreamer(
+                    tokenizer,
+                    skip_prompt = skip_prompt,
+                    timeout = timeout,
+                )
+            except Exception as e:
+                logger.warning(f"HarmonyTextStreamer init failed, falling back: {e}")
+                return TextIteratorStreamer(
+                    tokenizer,
+                    skip_prompt = skip_prompt,
+                    skip_special_tokens = True,
+                    timeout = timeout,
+                )
+
+        markers = (
+            reasoning_channel_markers
+            if reasoning_channel_markers_resolved
+            else reasoning_channel_markers
+            or detect_reasoning_channel_markers(protocol_source or tokenizer)
+        )
+        if markers is not None:
+            return ReasoningTextIteratorStreamer(
+                tokenizer,
+                markers = markers,
+                skip_prompt = skip_prompt,
+                timeout = timeout,
+                cancel_event = cancel_event,
+            )
+        return TextIteratorStreamer(
+            tokenizer,
+            skip_prompt = skip_prompt,
+            skip_special_tokens = True,
+            timeout = timeout,
+        )
+
+    def _append_stream_delta(
+        self,
+        output: str,
+        new_token: str,
+        stop_token_ids = None,
+    ):
+        """Append a streamer delta and apply response-boundary cleanup."""
+        output += new_token
+        return output, self._clean_generated_text(output, stop_token_ids = stop_token_ids)
+
+    def _drain_streamer_tail(
+        self,
+        streamer,
+        output: str,
+        stop_token_ids = None,
+    ):
+        """Drain queued streamer text after the producer exits."""
+        while True:
+            try:
+                new_token = next(streamer)
+            except StopIteration:
+                return output
+            except Exception:
+                return output
+            if new_token:
+                output, cleaned = self._append_stream_delta(
+                    output, new_token, stop_token_ids = stop_token_ids
+                )
+                yield cleaned
+
     def generate_stream(
         self,
         prompt: str,
@@ -1459,6 +1643,8 @@ class InferenceBackend:
         cancel_event = None,
         _adapter_state = None,
         presence_penalty: float = 0.0,
+        reasoning_channel_markers = None,
+        reasoning_channel_markers_resolved: bool = False,
     ) -> Generator[str, None, None]:
         """Generate a streaming text response (text models only).
 
@@ -1467,8 +1653,7 @@ class InferenceBackend:
         ``presence_penalty`` matches the GGUF sampling path via a logits processor (0 disables it).
         """
         if not self.active_model_name:
-            yield "Error: No active model"
-            return
+            raise RuntimeError("No active model")
 
         model_info = self.models[self.active_model_name]
         model = model_info["model"]
@@ -1481,9 +1666,7 @@ class InferenceBackend:
         try:
             inputs = tokenizer(prompt, return_tensors = "pt").to(model.device)
 
-            from transformers import TextIteratorStreamer
             import threading
-            from core.inference.chat_template_helpers import detect_think_prefill
 
             # skip_prompt swallows an open <think> prefilled by the template;
             # re-emit it so the frontend can render the thinking block.
@@ -1494,30 +1677,16 @@ class InferenceBackend:
                 else detect_think_prefill(prompt, getattr(tokenizer, "all_special_tokens", None))
             )
 
-            # gpt-oss models: HarmonyTextStreamer parses the multi-channel
-            # harmony protocol into <think> tags
-            if self._is_gpt_oss_model():
-                try:
-                    streamer = HarmonyTextStreamer(
-                        tokenizer,
-                        skip_prompt = True,
-                        timeout = 0.2,
-                    )
-                except Exception as e:
-                    logger.warning(f"HarmonyTextStreamer init failed, falling back: {e}")
-                    streamer = TextIteratorStreamer(
-                        tokenizer,
-                        skip_prompt = True,
-                        skip_special_tokens = True,
-                        timeout = 0.2,
-                    )
-            else:
-                streamer = TextIteratorStreamer(
-                    tokenizer,
-                    skip_prompt = True,
-                    skip_special_tokens = True,
-                    timeout = 0.2,
-                )
+            streamer = self._make_text_streamer(
+                tokenizer,
+                protocol_source = model_info.get("tokenizer"),
+                reasoning_channel_markers = reasoning_channel_markers,
+                reasoning_channel_markers_resolved = reasoning_channel_markers_resolved,
+                skip_prompt = True,
+                timeout = 0.2,
+                cancel_event = cancel_event,
+                use_harmony = self._is_gpt_oss_model(),
+            )
 
             generation_kwargs = dict(
                 **inputs,
@@ -1535,27 +1704,16 @@ class InferenceBackend:
                 if tokenizer.pad_token_id is None
                 else tokenizer.pad_token_id,
             )
+            active_stop_token_ids = self._generation_stop_token_ids(model, generation_kwargs)
             # Presence penalty (GGUF parity); prompt_len excludes prompt tokens.
             _pp = _make_presence_penalty_processor(
                 presence_penalty, int(inputs["input_ids"].shape[1])
             )
             if _pp is not None:
                 generation_kwargs["logits_processor"] = _pp
-            if cancel_event is not None:
-                from transformers.generation.stopping_criteria import (
-                    StoppingCriteria,
-                    StoppingCriteriaList,
-                )
-                class _CancelCriteria(StoppingCriteria):
-                    def __init__(self, ev):
-                        self.ev = ev
-
-                    def __call__(self, input_ids, scores, **kwargs):
-                        return self.ev.is_set()
-
-                generation_kwargs["stopping_criteria"] = StoppingCriteriaList(
-                    [_CancelCriteria(cancel_event)]
-                )
+            stopping_criteria = self._cancel_stopping_criteria(cancel_event)
+            if stopping_criteria is not None:
+                generation_kwargs["stopping_criteria"] = stopping_criteria
 
             def generate_fn():
                 with self._generation_lock:
@@ -1565,6 +1723,8 @@ class InferenceBackend:
                         model.generate(**generation_kwargs)
                     except Exception as e:
                         err["msg"] = str(e)
+                        if hasattr(streamer, "abort"):
+                            streamer.abort()
                         logger.error(f"Generation error: {e}")
                     finally:
                         try:
@@ -1582,12 +1742,17 @@ class InferenceBackend:
             if think_prefix:
                 yield think_prefix
             from queue import Empty
+            import time
 
             generation_complete = False
+            cancel_deadline = None
             try:
                 while True:
                     if cancel_event is not None and cancel_event.is_set():
-                        break
+                        if cancel_deadline is None:
+                            cancel_deadline = time.monotonic() + 10
+                        elif time.monotonic() >= cancel_deadline:
+                            break
                     try:
                         new_token = next(streamer)
                     except StopIteration:
@@ -1596,11 +1761,27 @@ class InferenceBackend:
                     except Empty:
                         if not thread.is_alive():
                             generation_complete = True
+                            output = yield from self._drain_streamer_tail(
+                                streamer, output, active_stop_token_ids
+                            )
+                            break
+                        if cancel_deadline is not None:
+                            remaining = cancel_deadline - time.monotonic()
+                            if remaining <= 0:
+                                break
+                            thread.join(timeout = remaining)
+                            if thread.is_alive():
+                                break
+                            generation_complete = True
+                            output = yield from self._drain_streamer_tail(
+                                streamer, output, active_stop_token_ids
+                            )
                             break
                         continue
                     if new_token:
-                        output += new_token
-                        cleaned = self._clean_generated_text(output)
+                        output, cleaned = self._append_stream_delta(
+                            output, new_token, active_stop_token_ids
+                        )
                         yield cleaned
             finally:
                 # Set cancel_event only on early exit (user cancel), NOT on
@@ -1609,16 +1790,21 @@ class InferenceBackend:
                 # disrupt the next serialized request (e.g. compare mode).
                 if cancel_event is not None and not generation_complete:
                     cancel_event.set()
-                thread.join(timeout = 10)
+                join_timeout = 10
+                if cancel_deadline is not None:
+                    join_timeout = max(0, cancel_deadline - time.monotonic())
+                thread.join(timeout = join_timeout)
                 if thread.is_alive():
                     logger.warning("Generation thread did not exit after cancel/join timeout")
 
             if err.get("msg"):
-                yield f"Error: {err['msg']}"
+                raise _GenerationThreadError(err["msg"])
 
+        except _GenerationThreadError:
+            raise
         except Exception as e:
             logger.error(f"Error during generation: {e}")
-            yield f"Error: {str(e)}"
+            raise
 
     # ── Audio (TTS) Generation ────────────────────────────────────
 
@@ -1757,8 +1943,30 @@ class InferenceBackend:
             + text
             + "<|text_end|>\n<|audio_start|><|global_features_start|>\n"
         )
+
         with torch.inference_mode():
-            with torch.amp.autocast("cuda", dtype = model.dtype):
+            # Derive the autocast device from the loaded model, not from the
+            # global backend: a CPU-fallback DAC on an XPU/CUDA host must not
+            # open a GPU autocast context around CPU tensors.
+            device_type = (
+                model.device.type
+                if hasattr(model.device, "type")
+                else str(model.device).split(":", 1)[0]
+            )
+            # Clamp to autocast-supported backends so exotic devices
+            # (e.g. "meta" during accelerate offloaded loading) do not raise.
+            # MPS is autocast-supported since torch 2.3, keep it in the set.
+            if device_type not in ("cuda", "xpu", "mps", "cpu"):
+                device_type = "cpu"
+            # CPU and XPU autocast only accept bfloat16/float16. For a
+            # float32 model, skip autocast entirely to avoid raising or
+            # producing a warning on every generate call.
+            autocast_dtype_supported = model.dtype in (torch.bfloat16, torch.float16)
+            if device_type in ("cpu", "xpu") and not autocast_dtype_supported:
+                autocast_ctx = contextlib.nullcontext()
+            else:
+                autocast_ctx = torch.amp.autocast(device_type, dtype = model.dtype)
+            with autocast_ctx:
                 inputs = tokenizer([prompt], return_tensors = "pt").to(model.device)
                 generated = model.generate(
                     **inputs,
@@ -2107,8 +2315,42 @@ class InferenceBackend:
             return img.resize(new_size, Image.Resampling.LANCZOS)
         return img
 
-    def _clean_generated_text(self, text: str) -> str:
-        """Strip leaked special tokens using the tokenizer's own token list."""
+    def _generation_stop_token_ids(self, model, generation_kwargs: dict):
+        """Return the stop-token ids active for a ``generate`` call."""
+        if "eos_token_id" in generation_kwargs:
+            return generation_kwargs.get("eos_token_id")
+        generation_config = getattr(model, "generation_config", None)
+        eos_token_id = getattr(generation_config, "eos_token_id", None)
+        if eos_token_id is not None:
+            return eos_token_id
+        config = getattr(model, "config", None)
+        return getattr(config, "eos_token_id", None)
+
+    def _cancel_stopping_criteria(self, cancel_event):
+        """Build a Transformers stopping criteria list for user cancellation."""
+        if cancel_event is None:
+            return None
+        from transformers.generation.stopping_criteria import (
+            StoppingCriteria,
+            StoppingCriteriaList,
+        )
+
+        class _CancelCriteria(StoppingCriteria):
+            def __init__(self, ev):
+                self.ev = ev
+
+            def __call__(self, input_ids, scores, **kwargs):
+                return self.ev.is_set()
+
+        return StoppingCriteriaList([_CancelCriteria(cancel_event)])
+
+    def _clean_generated_text(
+        self,
+        text: str,
+        *,
+        stop_token_ids = None,
+    ) -> str:
+        """Strip leaked response-boundary tokens after streaming."""
         if self._is_gpt_oss_model():
             # HarmonyTextStreamer emits clean <think>...</think>. Strip any
             # harmony protocol tokens and other gpt-oss tokens (e.g.
@@ -2118,10 +2360,28 @@ class InferenceBackend:
             return text.strip()
 
         tokenizer = self.models.get(self.active_model_name, {}).get("tokenizer")
+        tokenizer = getattr(tokenizer, "tokenizer", tokenizer)
         if tokenizer:
-            for token in getattr(tokenizer, "all_special_tokens", []):
-                if token in text:
-                    text = text.replace(token, "")
+            if stop_token_ids is None:
+                stop_token_ids = self.models.get(self.active_model_name, {}).get(
+                    "chat_turn_end_eos_ids"
+                )
+            if isinstance(stop_token_ids, int):
+                stop_token_ids = (stop_token_ids,)
+            for token_id in stop_token_ids or ():
+                try:
+                    token = tokenizer.convert_ids_to_tokens(int(token_id))
+                except Exception:
+                    token = None
+                if isinstance(token, str) and token and text.endswith(token):
+                    text = text[: -len(token)]
+                elif (
+                    isinstance(token, str)
+                    and token
+                    and text.endswith("</think>")
+                    and text[: -len("</think>")].endswith(token)
+                ):
+                    text = text[: -len("</think>") - len(token)] + "</think>"
         return text.strip()
 
     def _load_chat_template_info(self, model_name: str):
diff --git a/studio/backend/core/inference/llama_cpp.py b/studio/backend/core/inference/llama_cpp.py
index 3e93a26787..1fe134c3f9 100644
--- a/studio/backend/core/inference/llama_cpp.py
+++ b/studio/backend/core/inference/llama_cpp.py
@@ -9,7 +9,9 @@ OpenAI-compatible /v1/chat/completions endpoint.
 
 import atexit
 import contextlib
+import functools
 import json
+import math
 import os
 import re
 import struct
@@ -21,12 +23,24 @@ import subprocess
 import sys
 import threading
 import time
+import uuid
 from pathlib import Path
-from typing import Callable, Collection, Generator, Iterable, List, Mapping, Optional, Union
+from typing import (
+    Callable,
+    Collection,
+    Generator,
+    Iterable,
+    List,
+    Literal,
+    Mapping,
+    Optional,
+    Union,
+)
 
 import httpx
 
 from core.inference.llama_server_args import (
+    _LAYER_OFFLOAD_FLAGS,
     _effective_tensor_parallel,
     _tensor_parallel_matches_loaded,
     extra_args_disable_mmproj,
@@ -115,7 +129,7 @@ LLAMA_SERVER_NOT_FOUND_DETAIL = (
 
 # llama-server can serve HTTP 200 while running a model entirely on CPU when a
 # GPU backend fails to init (#5807 / #5106 / #5830). Classify the startup log so
-# Studio can warn. Priority: explicit "offloaded N/M layers to GPU" counts
+# Unsloth can warn. Priority: explicit "offloaded N/M layers to GPU" counts
 # (authoritative), then GPU "model buffer size" lines (host-pinned _Host
 # excluded), then the "device_info:" device table (disconfirm only).
 _GPU_OFFLOAD_MARKERS = (
@@ -233,8 +247,60 @@ def _wsl_system_rocm_lib_dirs() -> "list[str]":
     return out
 
 
-# Plan-without-action re-prompt state (intent signal, caps, message) now lives
-# in tool_call_parser, imported above under its old aliases.
+def _bundled_hip_present(binary_dir: str) -> bool:
+    """True when a prebuilt bundle ships its own HIP backend library."""
+    if not binary_dir:
+        return False
+    try:
+        # Glob the version suffix (libggml-hip.so, .so.0, .so.0.11.1) the same
+        # way the installer's runtime health check matches libggml-hip.so*.
+        return any(Path(str(binary_dir)).glob("libggml-hip.so*"))
+    except OSError:
+        return False
+
+
+def _native_linux_system_rocm_lib_dirs(binary_dir: str = "") -> "list[str]":
+    """System ROCm lib dir(s) to prepend before a prebuilt's bundled HIP, on native Linux.
+
+    The bundled bare-metal HIP runtime can mismatch the host amdkfd driver and crash
+    in hsa_init(); prepending the whole system ROCm lib dir loads a driver-matched,
+    version-consistent stack (libhsa-runtime64 / libamdhip64 / librocblas) ahead of it.
+    The whole dir is deliberate: mixing the bundle's rocBLAS with a different-version
+    system HIP/ROCR risks missing symbols. UNSLOTH_LLAMA_NO_SYSTEM_ROCM=1 keeps the pure
+    bundle (for a host whose system ROCm lacks this arch); no-op on WSL / non-Linux.
+    """
+    if os.environ.get("UNSLOTH_LLAMA_NO_SYSTEM_ROCM") == "1":
+        return []
+    if sys.platform != "linux" or os.path.exists("/dev/dxg"):
+        return []
+    if not os.path.exists("/dev/kfd"):
+        return []
+    if not _bundled_hip_present(binary_dir):
+        return []
+    # Env-configured ROCm root first; /opt/rocm only as a fallback so a stale
+    # /opt/rocm doesn't shadow the driver-matching install these vars point at.
+    candidates = []
+    for var in ("HIP_PATH", "HIP_PATH_57", "ROCM_PATH"):
+        val = os.environ.get(var)
+        if val:
+            candidates.append(val)
+    candidates.append("/opt/rocm")
+    out: "list[str]" = []
+    seen: "set[str]" = set()
+    for base in candidates:
+        for lib_sub in ("lib", "lib64"):
+            d = os.path.join(base, lib_sub)
+            if d in seen:
+                continue
+            seen.add(d)
+            if os.path.exists(os.path.join(d, "libhsa-runtime64.so")) or os.path.exists(
+                os.path.join(d, "libhsa-runtime64.so.1")
+            ):
+                out.append(d)
+    return out
+
+
+# Plan-without-action re-prompt state now lives in tool_call_parser (imported above).
 
 # Default max_tokens to the effective context when known. The floor is high
 # enough for reasoning-heavy GGUFs and max_tokens-omitting API clients.
@@ -441,6 +507,23 @@ def _hf_offline_if_dns_dead():
             os.environ.pop("TRANSFORMERS_OFFLINE", None)
 
 
+try:
+    _SLOT_SAVE_MAX_BYTES = int(os.environ.get("UNSLOTH_SLOT_SAVE_MAX_BYTES") or (10 << 30))
+except ValueError:
+    _SLOT_SAVE_MAX_BYTES = 10 << 30
+
+# The idle loop holds the lifecycle gate across a slot save, so a newly arriving
+# request waits on the in-flight save's HTTP call. Bound it (was 120s) so a slow
+# or stuck save can't stall the next request for minutes; best-effort save just
+# falls back to a plain unload. Override with UNSLOTH_SLOT_SAVE_TIMEOUT (seconds).
+try:
+    _SLOT_SAVE_HTTP_TIMEOUT = float(os.environ.get("UNSLOTH_SLOT_SAVE_TIMEOUT") or 30.0)
+except ValueError:
+    _SLOT_SAVE_HTTP_TIMEOUT = 30.0
+if _SLOT_SAVE_HTTP_TIMEOUT <= 0:
+    _SLOT_SAVE_HTTP_TIMEOUT = 30.0
+
+
 def _swa_cache_path() -> Path:
     home = os.environ.get("UNSLOTH_STUDIO_HOME") or os.environ.get("STUDIO_HOME")
     base = Path(home) if home else Path.home() / ".unsloth" / "studio"
@@ -496,7 +579,14 @@ def _swa_entry_from_layer_types(lt) -> Optional[object]:
 def _fetch_swa_entry_from_hf(repo_id: str) -> Optional[object]:
     try:
         from huggingface_hub import hf_hub_download
-        cfg_path = hf_hub_download(repo_id, "config.json", repo_type = "model")
+        from utils.hf_cache_settings import active_hf_hub_cache
+
+        cfg_path = hf_hub_download(
+            repo_id,
+            "config.json",
+            repo_type = "model",
+            cache_dir = active_hf_hub_cache(),
+        )
         with open(cfg_path) as f:
             cfg = json.load(f)
     except Exception:
@@ -898,6 +988,7 @@ def _cached_hf_snapshot_file(
     filename: str,
     *,
     expected_size: Optional[int] = None,
+    cache_dir: Optional[str] = None,
 ) -> Optional[str]:
     """Return a cached snapshot file even when HF's current-ref probe misses it."""
     if not filename:
@@ -906,8 +997,22 @@ def _cached_hf_snapshot_file(
     if not parts or any(part in (".", "..") for part in parts):
         return None
     try:
-        from utils.models.model_config import _iter_hf_cache_snapshots
-        for snap in _iter_hf_cache_snapshots(repo_id):
+        if cache_dir is None:
+            from utils.models.model_config import _iter_hf_cache_snapshots
+            snapshots = _iter_hf_cache_snapshots(repo_id)
+        else:
+            from hub.utils.hf_cache_state import iter_active_repo_cache_dirs
+            snapshots = (
+                snapshot
+                for repo_dir in iter_active_repo_cache_dirs(
+                    "model",
+                    repo_id,
+                    root = Path(cache_dir),
+                )
+                for snapshot in (repo_dir / "snapshots").glob("*")
+                if snapshot.is_dir()
+            )
+        for snap in snapshots:
             candidate = snap.joinpath(*parts)
             if not candidate.is_file():
                 continue
@@ -999,6 +1104,293 @@ def _cached_colocated_split_main(
     return None
 
 
+def _cached_variant_resolution(repo_id: str, hf_variant: str) -> tuple[Optional[str], list[str]]:
+    """Find a cached main GGUF and its shards for a variant."""
+    candidate = next(_cached_variant_candidates(repo_id, hf_variant), None)
+    if candidate is None:
+        return None, []
+    _, main, shards, _ = candidate
+    return main, shards
+
+
+def _cached_variant_candidates(
+    repo_id: str,
+    hf_variant: str,
+    *,
+    require_mmproj: bool = False,
+) -> Generator[tuple[str, str, list[str], Path], None, None]:
+    """Yield complete cached variant copies in snapshot preference order."""
+    try:
+        from utils.models.model_config import _iter_hf_cache_snapshots
+        for snap in _iter_hf_cache_snapshots(repo_id):
+            cached_files = _gguf_snapshot_files(snap)
+            matches = _gguf_files_for_variant(cached_files, hf_variant)
+            if not matches:
+                continue
+            main = matches[0]
+            shards = _gguf_extra_shards(matches, main)
+            split = _SHARD_FULL_RE.match(main)
+            if split:
+                numbers = {
+                    int(match.group(2))
+                    for path in [main, *shards]
+                    if (match := _SHARD_FULL_RE.match(path))
+                }
+                if numbers != set(range(1, int(split.group(3)) + 1)):
+                    continue
+            main_path = snap.joinpath(*main.replace("\\", "/").split("/"))
+            if not main_path.is_file() or not _snapshot_has_all_shards(
+                str(main_path), main, shards, {}
+            ):
+                continue
+            if require_mmproj and not _pick_mmproj(cached_files):
+                continue
+            yield str(main_path), main, shards, snap
+    except Exception as e:
+        logger.debug(f"Cache lookup for variant failed: {e}")
+
+
+def _cached_candidate_matches_revision_size(
+    repo_id: str, candidate: tuple[str, str, list[str], Path], hf_token: Optional[str]
+) -> bool:
+    """Check cached byte sizes against the snapshot's own Hub revision.
+
+    A snapshot pointer is normally published only after its blob is complete.
+    When the old revision is still queryable, also compare every weight file's
+    size so a manually truncated cache entry is not treated as reusable. If
+    metadata cannot be reached, retain the cache's normal offline semantics.
+    """
+    main_path, main, shards, snap = candidate
+    paths = [main, *shards]
+    try:
+        from huggingface_hub import get_paths_info
+        infos = list(
+            get_paths_info(
+                repo_id,
+                paths,
+                revision = snap.name,
+                token = hf_token,
+            )
+        )
+    except Exception as e:
+        logger.debug(
+            "Could not size-check cached GGUF %s at revision %s: %s",
+            repo_id,
+            snap.name,
+            e,
+        )
+        return True
+
+    if not infos:
+        # The Hub answers an unknown (e.g. force-pushed away) revision with an
+        # empty result, not an error; treat it like unreachable metadata.
+        return True
+    expected_sizes = {info.path: info.size for info in infos if info.size is not None}
+    if any(path not in expected_sizes for path in paths):
+        return False
+    try:
+        if os.path.getsize(main_path) < expected_sizes[main]:
+            return False
+    except OSError:
+        return False
+    return _snapshot_has_all_shards(main_path, main, shards, expected_sizes)
+
+
+def _cached_complete_candidate(
+    repo_id: str, gguf_filename: Optional[str], shards: list[str]
+) -> Optional[tuple[str, str, list[str], Path]]:
+    """Return one complete exact-filename cache candidate with snapshot context."""
+    if not gguf_filename:
+        return None
+    if shards:
+        main_path = _cached_colocated_split_main(repo_id, gguf_filename, shards, {})
+    else:
+        m = _SHARD_FULL_RE.match(gguf_filename)
+        if m and int(m.group(3)) > 1:
+            return None
+        main_path = _cached_hf_snapshot_file(repo_id, gguf_filename)
+    if main_path is None:
+        return None
+    snap = _snapshot_dir_of(main_path)
+    if snap is None:
+        return None
+    return main_path, gguf_filename, shards, snap
+
+
+def cached_gguf_for_load(
+    hf_repo: str,
+    hf_variant: Optional[str],
+    *,
+    require_mmproj: bool = False,
+    verify_sizes: bool = False,
+    hf_token: Optional[str] = None,
+) -> Optional[str]:
+    """Return a cached GGUF that can be loaded without downloading."""
+    if not hf_variant:
+        return None
+    hf_repo = _resolve_repo_id_casing(hf_repo)
+    for candidate in _cached_variant_candidates(
+        hf_repo,
+        hf_variant,
+        require_mmproj = require_mmproj,
+    ):
+        if verify_sizes and not _cached_candidate_matches_revision_size(
+            hf_repo, candidate, hf_token
+        ):
+            continue
+        return candidate[0]
+    return None
+
+
+def _snapshot_dir_of(path: str) -> Optional[Path]:
+    """Return the HF cache snapshot containing path, if any."""
+    try:
+        p = Path(os.path.abspath(path))
+    except OSError:
+        return None
+    for ancestor in p.parents:
+        if ancestor.parent.name == "snapshots":
+            return ancestor
+    return None
+
+
+def _hub_cache_dir_for_snapshot_path(path: Optional[str]) -> Optional[str]:
+    """Return the HF Hub cache root that owns a snapshot-contained path."""
+    if not path:
+        return None
+    snapshot = _snapshot_dir_of(path)
+    if snapshot is None or snapshot.parent.name != "snapshots":
+        return None
+    return str(snapshot.parent.parent.parent)
+
+
+def _companion_snapshot_sibling(
+    near_path: str, pick: Callable[[list[str]], Optional[str]]
+) -> Optional[str]:
+    """Find a companion in the same snapshot as near_path."""
+    snap = _snapshot_dir_of(near_path)
+    if snap is None:
+        return None
+    try:
+        sibling = pick(_gguf_snapshot_files(snap))
+    except Exception:
+        return None
+    if not sibling:
+        return None
+    candidate = snap / sibling
+    return str(candidate) if candidate.is_file() else None
+
+
+def _pick_mmproj(candidates: list[str]) -> Optional[str]:
+    mmproj_files = sorted(
+        f for f in candidates if f.lower().endswith(".gguf") and "mmproj" in Path(f).name.lower()
+    )
+    if not mmproj_files:
+        return None
+    return next((f for f in mmproj_files if f.lower().endswith("-f16.gguf")), mmproj_files[0])
+
+
+def _hub_download_in_flight(hf_repo: str) -> bool:
+    try:
+        from hub.utils.download_registry import get_models_registry
+        return bool(get_models_registry().active_job_refs(hf_repo))
+    except Exception:
+        return False
+
+
+def _hub_download_blocks_gguf_load(
+    hf_repo: str,
+    hf_variant: Optional[str],
+    *,
+    require_mmproj: bool = False,
+    hf_token: Optional[str] = None,
+) -> bool:
+    """Whether an active Hub job makes this GGUF load unsafe.
+
+    Same-variant jobs can reclaim the stale snapshot a load would reuse, so
+    they always block. Other jobs block only when this load lacks a complete
+    cached copy and would write to the shared cache itself.
+    """
+    try:
+        from hub.utils.download_registry import get_models_registry
+
+        registry = get_models_registry()
+        if not registry.active_job_refs(hf_repo):
+            return False
+        if registry.has_active_variant(hf_repo, hf_variant):
+            return True
+    except Exception:
+        return False
+    return (
+        cached_gguf_for_load(
+            hf_repo,
+            hf_variant,
+            require_mmproj = require_mmproj,
+            verify_sizes = True,
+            hf_token = hf_token,
+        )
+        is None
+    )
+
+
+# Active GGUF loads by normalized repo ID.
+_LOADS_IN_FLIGHT: dict[str, int] = {}
+_LOADS_IN_FLIGHT_LOCK = threading.Lock()
+
+
+@contextlib.contextmanager
+def gguf_load_in_flight(hf_repo: Optional[str]):
+    """Track an HF GGUF load until the context exits."""
+    key = (hf_repo or "").strip().lower()
+    if not key:
+        yield
+        return
+    with _LOADS_IN_FLIGHT_LOCK:
+        _LOADS_IN_FLIGHT[key] = _LOADS_IN_FLIGHT.get(key, 0) + 1
+    try:
+        yield
+    finally:
+        with _LOADS_IN_FLIGHT_LOCK:
+            remaining = _LOADS_IN_FLIGHT.get(key, 1) - 1
+            if remaining <= 0:
+                _LOADS_IN_FLIGHT.pop(key, None)
+            else:
+                _LOADS_IN_FLIGHT[key] = remaining
+
+
+def hf_gguf_load_in_flight(hf_repo: str) -> bool:
+    """Return whether a GGUF load is active for hf_repo."""
+    key = (hf_repo or "").strip().lower()
+    if not key:
+        return False
+    with _LOADS_IN_FLIGHT_LOCK:
+        return _LOADS_IN_FLIGHT.get(key, 0) > 0
+
+
+def _with_gguf_load_marker(load: Callable):
+    """Keep an HF repo marked for the full synchronous load call."""
+
+    @functools.wraps(load)
+    def wrapped(self, *args, **kwargs):
+        hf_repo = kwargs.get("hf_repo")
+        with gguf_load_in_flight(hf_repo):
+            if hf_repo and _hub_download_blocks_gguf_load(
+                hf_repo,
+                kwargs.get("hf_variant"),
+                require_mmproj = bool(
+                    kwargs.get("is_vision")
+                    and not extra_args_disable_mmproj(kwargs.get("extra_args"))
+                ),
+                hf_token = kwargs.get("hf_token"),
+            ):
+                raise RuntimeError(
+                    f"'{hf_repo}' is currently being downloaded by the download manager"
+                )
+            return load(self, *args, **kwargs)
+
+    return wrapped
+
+
 def _gguf_extra_shards(files: Iterable[str], first_shard: str) -> list[str]:
     m = _SHARD_FULL_RE.match(first_shard)
     if not m:
@@ -1085,7 +1477,7 @@ def _kv_bytes_per_elem(cache_type: Optional[str]) -> float:
 
 def _env_main_cache_type_for_budget(env: Optional[Mapping[str, str]] = None) -> Optional[str]:
     """Heavier of the inherited LLAMA_ARG_CACHE_TYPE_K/_V env types when it
-    exceeds the f16 default, else None. Studio emits --cache-type only for the
+    exceeds the f16 default, else None. Unsloth emits --cache-type only for the
     param/extras path, so a heavier env (f32) would otherwise reach the child
     unbudgeted; quantized env types stay over-reserved by f16 (-> None)."""
     e = os.environ if env is None else env
@@ -1153,7 +1545,10 @@ def _extra_args_set_spec_type(extra_args: Optional[Iterable[str]]) -> bool:
     return _extra_args_set_any_flag(extra_args, {"--spec-type", "--spec-default"})
 
 
-_GPU_OFFLOAD_OVERRIDE_FLAGS = frozenset({"-ngl", "--gpu-layers", "--n-gpu-layers", "-fit", "--fit"})
+# Layer-offload override detection. Single-sourced from llama_server_args, which
+# also strips these (plus the MoE flags) from inherited extras; sharing the layer
+# set keeps detection and stripping from drifting.
+_GPU_OFFLOAD_OVERRIDE_FLAGS = _LAYER_OFFLOAD_FLAGS
 _THREAD_OVERRIDE_FLAGS = frozenset({"-t", "--threads"})
 
 
@@ -1404,7 +1799,7 @@ def _build_ngram_mod_flags(
     return []
 
 
-# Canonical Speculative Decoding modes exposed by the Studio chat UI.
+# Canonical Speculative Decoding modes exposed by the Unsloth chat UI.
 # Dropdown renders five (auto, mtp, ngram, mtp+ngram, off); the load API
 # also accepts legacy values the original Switch and external callers emit
 # (default, draft-mtp, ngram-mod, ngram-simple).
@@ -1453,7 +1848,7 @@ def _backfill_usage_from_timings(usage, timings):
     """Synthesize ``usage`` from llama-server's ``timings`` when the
     OpenAI-style usage block is missing or reports zero tokens.
 
-    The Studio chat UI computes generation t/s from
+    The Unsloth chat UI computes generation t/s from
     ``meta.usage.completion_tokens / totalStreamTime``. llama-server always
     populates ``timings.predicted_n`` (true decoded count) and
     ``timings.prompt_n``, but the final SSE chunk's ``usage`` can be absent
@@ -1526,7 +1921,7 @@ def _llama_lib_dir(binary: str) -> Path:
 def _is_external_link(path: Path) -> bool:
     """True when ``path`` is a --with-llama-cpp-dir local link: a POSIX symlink
     or a Windows directory junction / reparse point. Such a link resolves into
-    the user's own llama.cpp checkout, which Studio does not own."""
+    the user's own llama.cpp checkout, which Unsloth does not own."""
     try:
         if os.path.islink(path):
             return True
@@ -1617,6 +2012,21 @@ class LlamaCppBackend:
         self._cache_type_kv: Optional[str] = None
         # Whether --split-mode tensor was applied on the active load.
         self._tensor_parallel: bool = False
+        # GPU memory strategy applied on the active load ("auto"/"manual").
+        self._gpu_memory_mode: str = "auto"
+        # Manual-mode load options (echoed back so the UI round-trips them).
+        self._gpu_layers: int = -1
+        # MoE expert layers to keep on CPU (--n-cpu-moe); 0 = none.
+        self._n_cpu_moe: int = 0
+        # Relative model share per GPU (--tensor-split), in GPU order; None =
+        # default (llama.cpp splits by free VRAM).
+        self._tensor_split: Optional[List[float]] = None
+        # User-picked physical GPU indices (None = automatic selection).
+        self._gpu_ids: Optional[List[int]] = None
+        # RAW requested GPU pin, before the fit narrowed it. self._gpu_ids records the
+        # EFFECTIVE (fit-narrowed) pin for /status; dedupe compares this raw value so a
+        # [0, 1] narrowed to [0] and re-sent as [0, 1] still matches (#7239).
+        self._requested_gpu_ids: Optional[List[int]] = None
         # Layer load kept multi-GPU only to honor a downgraded tensor request, so a
         # later explicit tensor-off reloads instead of deduping to it (#6659).
         self._layer_preserves_tensor_intent: bool = False
@@ -1631,6 +2041,11 @@ class LlamaCppBackend:
         self._spec_draft_n_max: Optional[int] = None
         # KV-cache estimation fields (populated by _read_gguf_metadata)
         self._n_layers: Optional[int] = None
+        # MoE metadata (populated by _read_gguf_metadata): expert count (>0 =
+        # MoE) and leading dense-layer count (offsets --n-cpu-moe, which counts
+        # from layer 0). See the n_moe_layers property.
+        self._n_experts: Optional[int] = None
+        self._leading_dense_block_count: Optional[int] = None
         self._n_kv_heads: Optional[int] = None
         self._n_kv_heads_by_layer: Optional[list[int]] = None
         self._n_heads: Optional[int] = None
@@ -1682,7 +2097,7 @@ class LlamaCppBackend:
         # observes it (direct proxy endpoints, or nothing in flight).
         self._mtp_watchdog_thread: Optional[threading.Thread] = None
         self._mtp_watchdog_stop = threading.Event()
-        # True when the launch actually runs MTP+tensor (Studio- or user/env-driven);
+        # True when the launch actually runs MTP+tensor (Unsloth- or user/env-driven);
         # gates the probe, watchdog, and recovery so pass-through MTP is covered.
         self._mtp_runtime_fallback_active = False
         self._stdout_lines: list[str] = []
@@ -1692,6 +2107,12 @@ class LlamaCppBackend:
         self._llama_log_path: Optional[Path] = None
         self._cancel_event = threading.Event()
         self._api_key: Optional[str] = None
+        self._slot_save_dir: Optional[str] = None
+        self._slot_save_binary: Optional[tuple[str, int]] = None
+        # (gguf_identity, launch_fingerprint) snapshotted at load, so a later slot
+        # save can tell whether the model files were swapped on disk since load.
+        self._slot_loaded_identity: Optional[tuple] = None
+        self._prompt_cache_disabled: bool = False
         # True once a probe has completed; cleared on transient failure.
         self._is_audio: bool = False
         self._audio_type: Optional[str] = None
@@ -2051,6 +2472,119 @@ class LlamaCppBackend:
         """Whether --split-mode tensor is active on the loaded server."""
         return self._tensor_parallel
 
+    @property
+    def gpu_memory_mode(self) -> str:
+        """Active GPU memory strategy: 'auto' or 'manual' (gpu_layers < 0 = Auto/--fit, >= 0 = pinned)."""
+        return self._gpu_memory_mode
+
+    @property
+    def gpu_layers(self) -> int:
+        """Requested --gpu-layers for manual mode (-1 when not manual)."""
+        return self._gpu_layers
+
+    @property
+    def n_cpu_moe(self) -> int:
+        """MoE expert layers manual mode kept on CPU (--n-cpu-moe); 0 = none."""
+        return self._n_cpu_moe
+
+    @property
+    def tensor_split(self) -> Optional[List[float]]:
+        """Manual-mode relative model share per GPU (--tensor-split); None =
+        default (split by free VRAM)."""
+        return self._tensor_split
+
+    @property
+    def gpu_ids(self) -> Optional[List[int]]:
+        """User-picked physical GPU indices, or None for automatic selection."""
+        return self._gpu_ids
+
+    @property
+    def requested_gpu_ids(self) -> Optional[List[int]]:
+        """RAW requested GPU pin (before the fit narrowed it), or None for auto.
+        gpu_ids echoes the EFFECTIVE pin for /status."""
+        return self._requested_gpu_ids
+
+    def matches_gpu_ids(self, gpu_ids: Optional[List[int]]) -> bool:
+        """Whether a requested pin is already satisfied by the active runner.
+
+        A regular GGUF load may narrow the requested placement pool to the
+        smallest fitting subset. Accept both the original request and the
+        effective status-echoed subset so either can round-trip without a
+        needless reload. Diffusion drives one device and keeps its existing
+        lowest-device normalization.
+        """
+        if self._is_diffusion:
+            requested = [sorted(int(x) for x in gpu_ids)[0]] if gpu_ids else None
+            return requested == (self._gpu_ids or None)
+
+        requested = sorted(int(x) for x in gpu_ids) if gpu_ids else None
+        raw = self._requested_gpu_ids or None
+        effective = self._gpu_ids or None
+        return requested == raw or requested == effective
+
+    def _record_matching_gpu_request(self, gpu_ids: Optional[List[int]]) -> None:
+        """Adopt the caller's explicit pool after a full already-loaded match.
+
+        Matching an effective subset avoids a reload, but the incoming request
+        is still the user's latest placement intent. Record it so status and a
+        later reload do not restore GPUs the user just removed.
+        """
+        if self._is_diffusion:
+            self._requested_gpu_ids = [sorted(int(x) for x in gpu_ids)[0]] if gpu_ids else None
+        else:
+            self._requested_gpu_ids = sorted(int(x) for x in gpu_ids) if gpu_ids else None
+        if self._last_load_kwargs is not None:
+            self._last_load_kwargs["gpu_ids"] = (
+                list(self._requested_gpu_ids) if self._requested_gpu_ids else None
+            )
+
+    @property
+    def n_layers(self) -> Optional[int]:
+        """Model layer count (GGUF block_count), or None if unknown."""
+        return self._n_layers
+
+    @property
+    def n_moe_layers(self) -> int:
+        """Number of MoE expert layers (the --n-cpu-moe ceiling), 0 if not MoE.
+
+        block_count minus the leading dense layers (which carry no experts):
+        --n-cpu-moe counts from layer 0, so those dense layers are no-ops.
+        """
+        if not self._n_experts or not self._n_layers:
+            return 0
+        return max(0, self._n_layers - (self._leading_dense_block_count or 0))
+
+    @staticmethod
+    def _resolve_cpu_moe_flag(
+        n_cpu_moe: int, n_moe_layers: int, leading_dense: int
+    ) -> Optional[int]:
+        """The --n-cpu-moe value (absolute first-N layers), or None to omit it.
+
+        Clamps the requested count to the model's MoE layers, then offsets past
+        the leading dense layers (--n-cpu-moe counts from layer 0). Returns None
+        for nothing-to-offload (0 requested) or a non-MoE model.
+        """
+        if n_cpu_moe <= 0 or n_moe_layers <= 0:
+            return None
+        return leading_dense + min(n_cpu_moe, n_moe_layers)
+
+    @staticmethod
+    def _sanitize_tensor_split(tensor_split: Optional[List[float]]) -> List[float]:
+        """Per-GPU shares with negative and non-finite entries clamped to 0.
+
+        A direct caller's negative entry would launch a placement different
+        from the ratio the UI showed, and inf would pass a plain ``> 0`` total
+        gate and emit ``--tensor-split inf,...``. Returns [] for input that
+        can't be read as floats (the length gate at the call site then drops
+        the split).
+        """
+        try:
+            return [
+                x if math.isfinite(x) and x > 0.0 else 0.0 for x in (float(v) for v in tensor_split)
+            ]
+        except (TypeError, ValueError, OverflowError):
+            return []
+
     @property
     def layer_preserves_tensor_intent(self) -> bool:
         """True when a downgraded tensor request kept this layer load multi-GPU."""
@@ -2075,7 +2609,7 @@ class LlamaCppBackend:
 
     @staticmethod
     def _resolved_studio_root_and_is_legacy() -> "tuple[Optional[Path], bool]":
-        """Resolve the Studio install root and classify it as the legacy
+        """Resolve the Unsloth install root and classify it as the legacy
         ~/.unsloth/studio root vs. a custom (env/venv-inferred) root.
 
         Returns (resolved_root, is_legacy). On any import/resolution failure the
@@ -2247,15 +2781,18 @@ class LlamaCppBackend:
                 "found": False,
                 "mtp_token": None,
                 "supports_mtp": False,
+                "mtp_probe_inconclusive": True,
                 "ngram_mod_flavor": None,
                 "supports_ngram_mod": False,
                 "spec_draft_n_max_flag": None,
                 "supports_kv_unified": False,
                 "supports_fit_ctx": False,
+                "supports_fit_target": False,
                 "supports_cache_ram": False,
                 "supports_ctx_checkpoints": False,
                 "supports_no_cache_prompt": False,
                 "supports_metrics": False,
+                "supports_slot_save": False,
             }
         try:
             mtime = int(Path(bin_path).stat().st_mtime)
@@ -2271,10 +2808,15 @@ class LlamaCppBackend:
         spec_draft_n_max_flag: Optional[str] = None
         supports_kv_unified = False
         supports_fit_ctx = False
+        supports_fit_target = False
         supports_cache_ram = False
         supports_ctx_checkpoints = False
         supports_no_cache_prompt = False
         supports_metrics = False
+        supports_slot_save = False
+        saw_spec_type = False
+        probe_ok = False
+        help_text = ""
         try:
             probe_env = cls._llama_server_env_for_binary(bin_path)
             result = subprocess.run(
@@ -2286,6 +2828,7 @@ class LlamaCppBackend:
                 check = False,
                 env = probe_env,
             )
+            probe_ok = result.returncode == 0
             help_text = (result.stdout or "") + "\n" + (result.stderr or "")
             # Split into per-flag blocks (each --flag line + its indented
             # continuation), so the "argument has been removed" description
@@ -2330,17 +2873,19 @@ class LlamaCppBackend:
                     return False
                 return "argument has been removed" not in desc
 
-            # MTP token from the --spec-type line.
-            spec_line = ""
-            for line in help_text.splitlines():
-                if "--spec-type" in line:
-                    spec_line = line
-                    break
-            # PR #22673 used draft-mtp; later renamed to mtp.
-            if "draft-mtp" in spec_line:
-                mtp_token = "draft-mtp"
-            elif re.search(r"[|,\[]mtp[|,\]]", spec_line):
-                mtp_token = "mtp"
+            # MTP token from the full --spec-type help block (decl + indented
+            # continuation). First-line-only probing missed builds putting the
+            # enum on the next line (#7302). Prefer draft-mtp (PR #22673) over mtp.
+            spec_help = blocks.get("--spec-type") or ""
+            if not spec_help:
+                # Fallback: join --spec-type lines, avoiding incidental "mtp" in --help.
+                spec_help = "\n".join(
+                    line for line in help_text.splitlines() if "--spec-type" in line
+                )
+            mtp_token = cls._mtp_token_from_spec_help(spec_help)
+            # Only a resolved --spec-type block confirms missing MTP; empty/crash
+            # leaves saw_spec_type False so supports_mtp fails open.
+            saw_spec_type = bool(spec_help.strip()) and "--spec-type" in spec_help
 
             # ngram-mod flag flavor. Post-rename builds advertise both new
             # args (real) and legacy ones (stubs); pre-rename builds only
@@ -2368,30 +2913,67 @@ class LlamaCppBackend:
 
             supports_kv_unified = _is_real("--kv-unified")
             supports_fit_ctx = _is_real("--fit-ctx")
+            supports_fit_target = _is_real("--fit-target")
             supports_cache_ram = _is_real("--cache-ram")
             supports_ctx_checkpoints = _is_real("--ctx-checkpoints")
             supports_no_cache_prompt = _is_real("--no-cache-prompt")
             supports_metrics = _is_real("--metrics")
+            supports_slot_save = _is_real("--slot-save-path")
         except (OSError, subprocess.SubprocessError) as exc:
             logger.debug(f"llama-server --help probe failed: {exc}")
+            saw_spec_type = False
+            probe_ok = False
+            help_text = ""
+
+        help_nonempty = bool(help_text.strip())
+        # Confirmed only when a successful --help lists a --spec-type block with
+        # mtp/draft-mtp; nonempty --help without it is a definitive pre-spec
+        # binary; failed/empty probes stay inconclusive (#7302).
+        if saw_spec_type and probe_ok:
+            supports_mtp = mtp_token is not None
+            mtp_probe_inconclusive = False
+        elif help_nonempty and probe_ok:
+            supports_mtp = False
+            mtp_probe_inconclusive = False
+        else:
+            supports_mtp = False
+            mtp_probe_inconclusive = True
 
         info = {
             "found": True,
             "mtp_token": mtp_token,
-            "supports_mtp": mtp_token is not None,
+            "supports_mtp": supports_mtp,
+            "mtp_probe_inconclusive": mtp_probe_inconclusive,
             "ngram_mod_flavor": ngram_mod_flavor,
             "supports_ngram_mod": ngram_mod_flavor is not None,
             "spec_draft_n_max_flag": spec_draft_n_max_flag,
             "supports_kv_unified": supports_kv_unified,
             "supports_fit_ctx": supports_fit_ctx,
+            "supports_fit_target": supports_fit_target,
             "supports_cache_ram": supports_cache_ram,
             "supports_ctx_checkpoints": supports_ctx_checkpoints,
             "supports_no_cache_prompt": supports_no_cache_prompt,
             "supports_metrics": supports_metrics,
+            "supports_slot_save": supports_slot_save,
         }
         cls._capability_cache[cache_key] = info
         return info
 
+    @staticmethod
+    def _mtp_token_from_spec_help(spec_help: str) -> Optional[str]:
+        """Extract ``draft-mtp`` / ``mtp`` from a ``--spec-type`` help snippet.
+
+        Prefers ``draft-mtp`` (llama.cpp PR #22673) over the later bare ``mtp``
+        rename. Returns ``None`` when neither token appears as an enum value.
+        """
+        text = spec_help or ""
+        if "draft-mtp" in text:
+            return "draft-mtp"
+        # Bare `mtp` enum token (`|mtp|`, `,mtp,`, ...), not a substring.
+        if re.search(r"(?<![A-Za-z0-9_-])mtp(?![A-Za-z0-9_-])", text):
+            return "mtp"
+        return None
+
     # ── GPU allocation ────────────────────────────────────────────
 
     @staticmethod
@@ -2446,12 +3028,25 @@ class LlamaCppBackend:
         on the ordinal->physical mapping."""
         try:
             import torch
-            is_rocm = getattr(torch.version, "hip", None) is not None
+
+            # Same ROCm detection as _emit_child_gpu_visibility: AMD SDK wheels
+            # leave version.hip unset but encode "rocm" in __version__. The two
+            # must agree, else an inherited ROCR mask reads back as "no mask",
+            # ordinal 0 is labelled physical 0, and the child's new ROCR pin
+            # re-exposes the GPU the inherited mask was hiding.
+            is_rocm = (
+                getattr(torch.version, "hip", None) is not None
+                or "rocm" in getattr(torch, "__version__", "").lower()
+            )
         except Exception:
             is_rocm = False
         if is_rocm:
             hip_v = os.environ.get("HIP_VISIBLE_DEVICES")
-            rocr_v = os.environ.get("ROCR_VISIBLE_DEVICES")
+            # ROCR_VISIBLE_DEVICES is a Linux ROCr variable; Windows HIP has no
+            # ROCr layer, so a stray ROCR var there does not mask the runtime and
+            # must not be read as the ordinal->physical mapping (mirrors the
+            # Windows gate in _emit_child_gpu_visibility).
+            rocr_v = None if sys.platform == "win32" else os.environ.get("ROCR_VISIBLE_DEVICES")
             cvd = (
                 hip_v
                 if hip_v is not None
@@ -2468,6 +3063,103 @@ class LlamaCppBackend:
         except ValueError:
             return None
 
+    @staticmethod
+    def _emit_child_gpu_visibility(
+        env: dict,
+        pinned: str,
+        *,
+        prefer_rocr: bool = False,
+    ) -> None:
+        """Write the child's GPU visibility mask: CUDA, plus a ROCm mirror on AMD
+        (masking only CUDA_VISIBLE_DEVICES leaves an AMD child seeing every GPU).
+
+        Default: HIP_VISIBLE_DEVICES, clearing any inherited ROCR mask so the two
+        can't stack (ROCR re-indexes from 0, then a non-zero HIP pin points out of
+        range, HIP sees 0 devices, and llama.cpp falls back to CPU).
+
+        prefer_rocr masks at the ROCr/HSA layer instead (clearing HIP). A HIP mask
+        filters only AFTER the HSA runtime enumerates every agent, and that
+        enumeration segfaults at startup on a GPU the build has no kernels for
+        (e.g. a gfx1103 iGPU under a gfx110X prebuilt), before llama-server logs a
+        line. ROCR drops the device at the driver layer, consuming physical ids.
+        The CPU-only sentinel ("-1") has no portable ROCR spelling, so it keeps
+        the HIP mask. Windows keeps the HIP mask too: ROCR_VISIBLE_DEVICES is a
+        Linux ROCr variable (Windows HIP has no ROCr layer), so the ROCR pin
+        would be dead there while the cleared HIP mask stops selecting."""
+        env["CUDA_VISIBLE_DEVICES"] = pinned
+        try:
+            import torch as _torch
+
+            # torch.version.hip is set on ROCm, None on CUDA; AMD SDK wheels may
+            # leave it unset but encode "rocm" in __version__ (mirrors detect_hardware).
+            if (
+                getattr(_torch.version, "hip", None) is not None
+                or "rocm" in getattr(_torch, "__version__", "").lower()
+            ):
+                if prefer_rocr and pinned != "-1" and sys.platform != "win32":
+                    env["ROCR_VISIBLE_DEVICES"] = pinned
+                    env.pop("HIP_VISIBLE_DEVICES", None)
+                    # ROCR re-indexes the visible agents from 0, and with HIP
+                    # cleared HIP honours CUDA_VISIBLE_DEVICES -- so it must carry
+                    # the post-ROCR ordinals (0..N-1), not the physical ids, else a
+                    # non-zero pick points out of range and HIP sees 0 devices (the
+                    # same stacking the default path avoids by clearing ROCR).
+                    env["CUDA_VISIBLE_DEVICES"] = ",".join(
+                        str(i) for i in range(len(pinned.split(",")))
+                    )
+                else:
+                    env["HIP_VISIBLE_DEVICES"] = pinned
+                    env.pop("ROCR_VISIBLE_DEVICES", None)
+        except Exception as e:
+            logger.debug("Failed to set ROCm visibility env vars for child: %s", e)
+
+    @staticmethod
+    def _pin_visible_gpu_order_for_split(env: dict) -> None:
+        """Pin the child's GPU enumeration to the picker's order for a manual
+        ``--tensor-split`` across the whole visible set. CUDA's default
+        FASTEST_FIRST enumeration applies the shares to the wrong cards on
+        heterogeneous hosts (#5025), and CUDA_DEVICE_ORDER only fixes the
+        numbering base: an inherited numeric visibility mask ALSO defines
+        enumeration order, so a reordered parent mask (CUDA_VISIBLE_DEVICES=3,1)
+        would still hand the shares to the wrong cards. The UI built the split
+        positionally over get_backend_visible_gpu_info's device list (ascending
+        physical via nvidia-smi, inherited mask order on the torch fallback), so
+        re-emit the same set in that report order -- not an assumed ascending
+        sort. The visible set itself never changes. No mask, an empty mask, or a
+        UUID/MIG mask (which resolves to None) is left alone -- the multi-GPU
+        controls are hidden for the latter."""
+        env["CUDA_DEVICE_ORDER"] = "PCI_BUS_ID"
+        inherited = LlamaCppBackend._resolve_visible_physical_ids()
+        if not inherited:
+            return
+        order = None
+        try:
+            from utils.hardware import get_backend_visible_gpu_info
+            info = get_backend_visible_gpu_info()
+            if info.get("available") and info.get("index_kind") == "physical":
+                reported = [d["index"] for d in info.get("devices", [])]
+                if sorted(reported) == sorted(inherited):
+                    order = reported
+        except Exception as e:
+            logger.debug("Could not read reported GPU order for split pin: %s", e)
+        if order is None:
+            order = sorted(inherited)
+        # Re-emit at the layer that produced the mapping. A parent masked only
+        # via ROCR_VISIBLE_DEVICES hides agents at the driver layer, and the
+        # default HIP re-emission clears that mask -- HSA then enumerates every
+        # agent again and can segfault at startup on an unsupported GPU the
+        # parent was hiding (the crash prefer_rocr exists to avoid). Linux-only,
+        # mirroring _resolve_visible_physical_ids: on Windows a stray ROCR var
+        # is dead and was not the mapping's source.
+        prefer_rocr = (
+            sys.platform != "win32"
+            and env.get("HIP_VISIBLE_DEVICES") is None
+            and env.get("ROCR_VISIBLE_DEVICES") is not None
+        )
+        LlamaCppBackend._emit_child_gpu_visibility(
+            env, ",".join(str(i) for i in order), prefer_rocr = prefer_rocr
+        )
+
     @staticmethod
     def _amd_apu_wants_unified_memory(gpu_indices = None) -> bool:
         """True only for AMD unified-memory APUs (gfx1150/gfx1151), where
@@ -2963,7 +3655,7 @@ class LlamaCppBackend:
                 return
             prev = curr
 
-    # Free-VRAM fraction at which Studio pins the GPU directly instead of
+    # Free-VRAM fraction at which Unsloth pins the GPU directly instead of
     # deferring to ``--fit on``. 3% headroom: the compute buffer is now modelled in
     # the fit, so this only guards fragmentation + multi-GPU per-device CUDA context
     # (~2-3%); kept >= 3% as a floor (0.90 dropped 91-94% fits to CPU offload, #5106).
@@ -2984,6 +3676,20 @@ class LlamaCppBackend:
     # aborts a --split-mode tensor load, so it's dropped for the tensor attempt.
     _TENSOR_PARALLEL_KV_TYPES = frozenset({"f16", "bf16", "f32"})
 
+    # Main-model placement settings that Manual mode owns. They must not leak
+    # from Studio's parent environment into llama-server and silently override
+    # the command assembled from the current request. Draft-model placement is
+    # intentionally separate and remains available to speculative decoding.
+    _MANUAL_PLACEMENT_ENV_VARS = (
+        "LLAMA_ARG_CPU_MOE",
+        "LLAMA_ARG_N_CPU_MOE",
+        "LLAMA_ARG_N_GPU_LAYERS",
+        "LLAMA_ARG_TENSOR_SPLIT",
+        "LLAMA_ARG_FIT",
+        "LLAMA_ARG_FIT_TARGET",
+        "LLAMA_ARG_FIT_CTX",
+    )
+
     # (binary, mtime, model) that aborted on --split-mode tensor this process (#6415
     # geometry limit, e.g. MQA n_head_kv=1). Model-keyed so one model's abort doesn't
     # skip tensor for others; tensor is tried by default, recorded only on a real abort.
@@ -3114,6 +3820,9 @@ class LlamaCppBackend:
             lib_dirs.extend(_wsl_system_rocm_lib_dirs())
             if lib_dirs:
                 env.setdefault("HSA_ENABLE_DXG_DETECTION", "1")
+            # Native Linux AMD: system ROCm libs before the bundle's HIP runtime,
+            # which can be incompatible with the host amdkfd driver.
+            lib_dirs.extend(_native_linux_system_rocm_lib_dirs(binary_dir))
             lib_dirs.append(binary_dir)
             _arch = platform.machine()  # x86_64, aarch64, etc.
 
@@ -3148,6 +3857,12 @@ class LlamaCppBackend:
 
         return env
 
+    @classmethod
+    def _clear_manual_placement_env(cls, env: dict[str, str]) -> None:
+        """Remove inherited main-model placement owned by Manual mode."""
+        for name in cls._MANUAL_PLACEMENT_ENV_VARS:
+            env.pop(name, None)
+
     @staticmethod
     def _select_gpus(
         model_size_bytes: int,
@@ -3522,7 +4237,7 @@ class LlamaCppBackend:
             return total if total > 0 else None
         return draft_kv + weights + target_ctx_copy
 
-    _DEFAULT_N_UBATCH = 512  # llama.cpp --ubatch default; Studio does not override it
+    _DEFAULT_N_UBATCH = 512  # llama.cpp --ubatch default; Unsloth does not override it
     _COMPUTE_BUFFER_SAFETY = 1.15  # upper-bound margin on the compute-buffer estimate
     # Soft VRAM the modeled terms omit; charged to the fit budget on tight tiers (#6682).
     _CUDA_CONTEXT_RESERVE_BYTES = 320 * 1024 * 1024  # CUDA ctx + cuBLAS workspace (~330 MiB)
@@ -3662,7 +4377,7 @@ class LlamaCppBackend:
         n_ubatch: Optional[int] = None,
     ) -> tuple[Optional[list[int]], bool, int]:
         """Largest serving-slot count in [1, n_parallel) whose fully-on-GPU footprint fits,
-        so Studio keeps the model on GPU (-ngl -1) instead of --fit on, which offloads layers
+        so Unsloth keeps the model on GPU (-ngl -1) instead of --fit on, which offloads layers
         to host and collapses decode ~3x (oobabooga #6718). ``base_footprint_bytes`` is the
         slot-independent footprint (weights + soft overhead + MTP + context-linear compute,
         minus the folded compute buffer); each candidate re-adds the slot-sized compute buffer
@@ -3806,13 +4521,13 @@ class LlamaCppBackend:
         hf_repo: str,
         free_bytes: int,
         hf_token: Optional[str] = None,
-    ) -> Optional[tuple[str, int]]:
+    ) -> Optional[tuple[str, int, list[str]]]:
         """Find the smallest GGUF variant (including all shards) that fits.
 
         Groups split shards by variant prefix and sums their sizes (e.g.
         UD-Q4_K_XL with 9 shards of 50 GB each = 450 GB total).
 
-        Returns (first_shard_filename, total_size_bytes) or None.
+        Returns (first_shard_filename, total_size_bytes, extra_shards) or None.
         """
         try:
             from huggingface_hub import get_paths_info, list_repo_files
@@ -3848,9 +4563,13 @@ class LlamaCppBackend:
 
             # Smallest that fits
             variant_sizes.sort(key = lambda x: x[1])
-            for first_file, total_size, _ in variant_sizes:
+            for first_file, total_size, shard_files in variant_sizes:
                 if total_size > 0 and total_size <= free_bytes:
-                    return first_file, total_size
+                    return (
+                        first_file,
+                        total_size,
+                        [path for path in sorted(shard_files) if path != first_file],
+                    )
 
             return None
         except Exception:
@@ -3946,6 +4665,14 @@ class LlamaCppBackend:
             LlamaCppBackend._gguf_skip_value(f, atype)
         return None
 
+    @classmethod
+    def _gguf_path_is_diffusion(cls, gguf_path: str, model_identifier: str) -> bool:
+        """Classify a downloaded GGUF without mutating the active backend."""
+        probe = object.__new__(cls)
+        probe._model_identifier = model_identifier
+        probe._read_gguf_metadata(gguf_path)
+        return probe._is_diffusion
+
     def _read_gguf_metadata(self, gguf_path: str) -> None:
         """Read context_length, architecture params, and chat_template from a GGUF header.
 
@@ -3964,6 +4691,8 @@ class LlamaCppBackend:
         self._supports_preserve_thinking = False
         self._supports_tools = False
         self._n_layers = None
+        self._n_experts = None
+        self._leading_dense_block_count = None
         self._n_kv_heads = None
         self._n_kv_heads_by_layer = None
         self._n_heads = None
@@ -4053,6 +4782,8 @@ class LlamaCppBackend:
                                     arch_keys = {
                                         f"{arch}.context_length": "context_length",
                                         f"{arch}.block_count": "n_layers",
+                                        f"{arch}.expert_count": "n_experts",
+                                        f"{arch}.leading_dense_block_count": "leading_dense_block_count",
                                         f"{arch}.attention.head_count_kv": "n_kv_heads",
                                         f"{arch}.attention.head_count": "n_heads",
                                         f"{arch}.embedding_length": "embedding_length",
@@ -4134,7 +4865,7 @@ class LlamaCppBackend:
                 ]
 
             # Otherwise hand off to the resolver (cache / bootstrap / transformers / HF). Diffusion models
-            # skip it: they do not use Studio's SWA pattern and the resolver can raise for them.
+            # skip it: they do not use Unsloth's SWA pattern and the resolver can raise for them.
             if (
                 self._sliding_window_pattern is None
                 and self._sliding_window
@@ -4241,6 +4972,28 @@ class LlamaCppBackend:
 
         return None
 
+    @staticmethod
+    def _diffusion_gpu_arg(gpu_ids: Optional[List[int]], *, cpu_only: bool = False) -> str:
+        """Device token passed to the diffusion visual-server child.
+
+        The visual engine replaces its child's CUDA visibility mask with this
+        token, so an unpinned load must carry forward the first token from the
+        parent's mask rather than turning a parent-relative ordinal into a new
+        physical selection.
+        """
+        if gpu_ids:
+            return str(sorted(gpu_ids)[0])
+        if cpu_only:
+            return ""
+        if "DG_GPU" in os.environ:
+            return os.environ["DG_GPU"]
+        parent_mask = os.environ.get("CUDA_VISIBLE_DEVICES")
+        if parent_mask:
+            first = next((token.strip() for token in parent_mask.split(",") if token.strip()), "")
+            if first and first != "-1":
+                return first
+        return "0"
+
     def _start_diffusion_server(
         self,
         *,
@@ -4251,10 +5004,11 @@ class LlamaCppBackend:
         model_identifier: str,
         n_ctx: int,
         extra_args: Optional[List[str]],
+        gpu_ids: Optional[List[int]] = None,
     ) -> bool:
         """Launch the OpenAI-compat diffusion shim (which drives the on-device
         visual decoder) and wait for health. Presents the same /v1 + /health
-        interface as llama-server, so the rest of Studio is unchanged.
+        interface as llama-server, so the rest of Unsloth is unchanged.
         """
         assets = self._find_diffusion_assets()
         if assets is None:
@@ -4276,7 +5030,11 @@ class LlamaCppBackend:
         # CUDA_VISIBLE_DEVICES="" to force CPU serving. Keep the visual-server child
         # CPU-masked (empty --gpu) so the shim does not re-expose GPU 0 via its default.
         cpu_only = self._effective_gpu_count() == 0
-        gpu = "" if cpu_only else os.environ.get("DG_GPU", "0")
+        # Honor the GPU picker first: the diffusion runner takes a single device,
+        # so use the lowest selected GPU (matches the sorted set recorded below, so
+        # the device used == the echoed gpu_ids[0]). With no pick, fall back to the
+        # CPU-only mask, else DG_GPU / 0.
+        gpu = self._diffusion_gpu_arg(gpu_ids, cpu_only = cpu_only)
 
         cmd = list(shim_cmd) + [
             "--gguf",
@@ -4304,6 +5062,11 @@ class LlamaCppBackend:
             env.setdefault("UNSLOTH_ALLOW_CPU", "1")
         env["DG_VISUAL_BIN"] = visual_bin
         env["DG_GPU"] = gpu
+        if gpu_ids:
+            # The visual server remasks via CUDA_VISIBLE_DEVICES=<gpu>; pin PCI
+            # order (as the llama-server path does) so the picked physical id maps
+            # to the GPU the picker showed, not CUDA's default fastest-first order.
+            env["CUDA_DEVICE_ORDER"] = "PCI_BUS_ID"
         # The file-override shim imports its sibling visual_engine; put its dir on PYTHONPATH.
         # (The zoo-package shim is an installed module and needs no PYTHONPATH change.)
         if extra_pythonpath:
@@ -4326,7 +5089,7 @@ class LlamaCppBackend:
             logger.debug(f"Could not open diffusion runner log file: {e}")
 
         # The shim (and its visual server) die with this backend process, so a
-        # Studio crash/restart never orphans a GPU process.
+        # Unsloth crash/restart never orphans a GPU process.
         self._process = subprocess.Popen(
             cmd,
             stdout = subprocess.PIPE,
@@ -4349,6 +5112,26 @@ class LlamaCppBackend:
         self._model_identifier = model_identifier
         self._cache_type_kv = None
         self._gpu_offload_active = True
+        # Diffusion doesn't use the llama.cpp GPU-memory knobs; reset them to
+        # defaults (the picked device is still recorded below) so /load, /status
+        # and reload dedup don't report a previous GGUF's manual settings.
+        self._gpu_memory_mode = "auto"
+        self._gpu_layers = -1
+        self._n_cpu_moe = 0
+        self._tensor_split = None
+        # Diffusion is never tensor-parallel; clear any state left by a prior TP
+        # chat load (load_model phase 1 only kills the process, it doesn't run
+        # the unload reset) so /status doesn't misreport TP and an identical
+        # re-Apply doesn't reload against stale tensor-parallel state.
+        self._tensor_parallel = False
+        # The single-device runner records only the lowest selected GPU (chosen
+        # above), not the whole pick, and clears any explicit pin from a prior
+        # chat load; a multi-GPU list would misreport placement and mis-dedup.
+        self._gpu_ids = [sorted(gpu_ids)[0]] if gpu_ids else None
+        # The frontend prefers requested_gpu_ids when hydrating the picker.
+        # Diffusion uses only one device, so echo the collapsed effective pin,
+        # not unused members of the original request.
+        self._requested_gpu_ids = list(self._gpu_ids) if self._gpu_ids else None
         if hf_variant:
             self._hf_variant = hf_variant
         elif gguf_path:
@@ -4414,6 +5197,9 @@ class LlamaCppBackend:
         touching the shared one; defaults to the shared event.
         """
         cancel_event = cancel_event if cancel_event is not None else self._cancel_event
+        from utils.hf_cache_settings import get_hf_cache_paths
+
+        download_cache_dir = str(get_hf_cache_paths().hub_cache)
         try:
             import huggingface_hub  # noqa: F401 -- presence check only
         except ImportError:
@@ -4446,42 +5232,52 @@ class LlamaCppBackend:
             except Exception as e:
                 logger.warning(f"Could not list repo files: {e}")
 
-            # Offline: resolve variant -> filename from the local HF cache.
-            # The heuristic below assumes filenames echo the repo name, which
-            # breaks for e.g. Qwen3.6-27B-MTP-GGUF (no "MTP" in file). Match
-            # against the rel path (not just basename) so subdir layouts like
-            # ``BF16/foo.gguf`` are findable.
+            # Fall back to the local cache when the repo listing is unavailable.
             if not gguf_filename:
-                try:
-                    from utils.models.model_config import _iter_hf_cache_snapshots
-                    for snap in _iter_hf_cache_snapshots(hf_repo):
-                        cached_files = _gguf_snapshot_files(snap)
-                        matches = _gguf_files_for_variant(cached_files, hf_variant)
-                        if not matches:
-                            continue
-                        gguf_filename = matches[0]
-                        gguf_extra_shards = _gguf_extra_shards(matches, gguf_filename)
-                        logger.info(
-                            "Resolved variant %s -> %s from local HF cache",
-                            hf_variant,
-                            gguf_filename,
-                        )
-                        break
-                except Exception as e:
-                    logger.debug(f"Offline cache lookup for variant failed: {e}")
+                cached_name, cached_shards = _cached_variant_resolution(hf_repo, hf_variant)
+                if cached_name:
+                    gguf_filename = cached_name
+                    gguf_extra_shards = cached_shards
+                    logger.info(
+                        "Resolved variant %s -> %s from local HF cache",
+                        hf_variant,
+                        gguf_filename,
+                    )
 
             if not gguf_filename:
                 repo_name = hf_repo.split("/")[-1].replace("-GGUF", "")
                 gguf_filename = f"{repo_name}-{hf_variant}.gguf"
 
+        # Prefer the existing model. Updates use force=True to fetch a new revision.
+        if not force:
+            if hf_variant:
+                # Resolve by variant so a newer revision's filename does not hide
+                # the complete older copy. Size-check against that older snapshot's
+                # own revision when its metadata remains available.
+                cached_main = cached_gguf_for_load(
+                    hf_repo,
+                    hf_variant,
+                    verify_sizes = True,
+                    hf_token = hf_token,
+                )
+            else:
+                candidate = _cached_complete_candidate(hf_repo, gguf_filename, gguf_extra_shards)
+                cached_main = (
+                    candidate[0]
+                    if candidate is not None
+                    and _cached_candidate_matches_revision_size(hf_repo, candidate, hf_token)
+                    else None
+                )
+            if cached_main is not None:
+                logger.info(f"Reusing cached GGUF: {cached_main}")
+                return cached_main
+
         # Check disk space; fall back to a smaller variant if needed
         all_gguf_files = [gguf_filename] + gguf_extra_shards
-        expected_sizes: dict[str, int] = {}
         try:
             from huggingface_hub import get_paths_info, try_to_load_from_cache
 
             path_infos = list(get_paths_info(hf_repo, all_gguf_files, token = hf_token))
-            expected_sizes = {p.path: p.size for p in path_infos if p.size}
             total_bytes = sum((p.size or 0) for p in path_infos)
 
             # Subtract bytes already in the HF cache so we only preflight
@@ -4490,31 +5286,20 @@ class LlamaCppBackend:
             # cold whenever free disk is below the full weight footprint,
             # even though nothing needs downloading.
             already_cached_bytes = 0
-            # Cross-snapshot / case-variant cache reuse is offline-only (see the download
-            # path below); online, hf_hub_download fetches the current revision and
-            # resumes partials, so an old snapshot must not be counted as cached here or
-            # the preflight would under-count the download and skip the disk fallback.
+            # Count only files that can resume this download.
             offline = _hf_env_offline()
-            # A split GGUF whose shards are not co-located in a single snapshot is
-            # refetched as a whole set later, so it must not be counted as cached here.
-            split_needs_refetch = False
-            if offline and not force and gguf_extra_shards:
-                # Scan all snapshots for one that holds the whole set co-located, so a
-                # newer snapshot with only the first shard does not mask an older
-                # complete one and needlessly trip the disk fallback.
-                if (
-                    _cached_colocated_split_main(
-                        hf_repo, gguf_filename, gguf_extra_shards, expected_sizes
-                    )
-                    is None
-                ):
-                    split_needs_refetch = True
+            # Offline split sets are reusable only when every shard shares a snapshot.
+            split_needs_refetch = bool(offline and not force and gguf_extra_shards)
             if not force and not split_needs_refetch:
                 for p in path_infos:
                     if not p.size:
                         continue
                     try:
-                        cached_path = try_to_load_from_cache(hf_repo, p.path)
+                        cached_path = try_to_load_from_cache(
+                            hf_repo,
+                            p.path,
+                            cache_dir = download_cache_dir,
+                        )
                     except Exception:
                         cached_path = None
                     if (
@@ -4525,6 +5310,7 @@ class LlamaCppBackend:
                             hf_repo,
                             p.path,
                             expected_size = p.size,
+                            cache_dir = download_cache_dir,
                         )
                     if isinstance(cached_path, str) and os.path.exists(cached_path):
                         try:
@@ -4538,12 +5324,8 @@ class LlamaCppBackend:
             total_download_bytes = max(0, total_bytes - already_cached_bytes)
 
             if total_download_bytes > 0:
-                cache_dir = os.environ.get(
-                    "HF_HUB_CACHE",
-                    str(Path.home() / ".cache" / "huggingface" / "hub"),
-                )
-                Path(cache_dir).mkdir(parents = True, exist_ok = True)
-                free_bytes = shutil.disk_usage(cache_dir).free
+                Path(download_cache_dir).mkdir(parents = True, exist_ok = True)
+                free_bytes = shutil.disk_usage(download_cache_dir).free
 
                 total_gb = total_download_bytes / (1024**3)
                 free_gb = free_bytes / (1024**3)
@@ -4561,7 +5343,7 @@ class LlamaCppBackend:
                         # surface the disk shortfall for the requested variant.
                         raise RuntimeError(
                             f"Not enough disk space to download {gguf_filename}. "
-                            f"Only {free_gb:.1f} GB free in {cache_dir}"
+                            f"Only {free_gb:.1f} GB free in {download_cache_dir}"
                         )
                     smaller = self._find_smallest_fitting_variant(
                         hf_repo,
@@ -4569,36 +5351,30 @@ class LlamaCppBackend:
                         hf_token,
                     )
                     if smaller:
-                        fallback_file, fallback_size = smaller
+                        fallback_file, fallback_size, fallback_shards = smaller
                         logger.info(
                             f"Selected variant too large ({total_gb:.1f} GB), "
                             f"falling back to {fallback_file} ({fallback_size / (1024**3):.1f} GB)"
                         )
                         gguf_filename = fallback_file
-                        _m = _SHARD_RE.match(gguf_filename)
-                        _prefix = _m.group(1) if _m else None
-                        if _prefix:
-                            prefix_lower = _prefix.lower()
-                            gguf_extra_shards = sorted(
-                                f
-                                for f in all_gguf_files
-                                if f.lower().startswith(prefix_lower)
-                                and f != gguf_filename
-                                and not _is_companion_gguf_path(f)
+                        gguf_extra_shards = fallback_shards
+
+                        # The selected fallback is a new load target. Apply the
+                        # same any-revision reuse policy before starting a fetch.
+                        fallback_candidate = _cached_complete_candidate(
+                            hf_repo, gguf_filename, gguf_extra_shards
+                        )
+                        if fallback_candidate is not None and (
+                            _cached_candidate_matches_revision_size(
+                                hf_repo, fallback_candidate, hf_token
                             )
-                        else:
-                            gguf_extra_shards = []
-                        # Record the fallback's size so the later cache-reuse probe can
-                        # size-verify it; only for a single-file fallback, since
-                        # _find_smallest_fitting_variant returns the whole-variant size
-                        # and using that as the first shard's expected size would reject
-                        # a valid cached first shard of a split fallback.
-                        if not gguf_extra_shards:
-                            expected_sizes[fallback_file] = fallback_size
+                        ):
+                            logger.info(f"Reusing cached fallback GGUF: {fallback_candidate[0]}")
+                            return fallback_candidate[0]
                     else:
                         raise RuntimeError(
                             f"Not enough disk space to download any variant. "
-                            f"Only {free_gb:.1f} GB free in {cache_dir}"
+                            f"Only {free_gb:.1f} GB free in {download_cache_dir}"
                         )
         except RuntimeError:
             raise
@@ -4614,45 +5390,27 @@ class LlamaCppBackend:
                 raise RuntimeError("Cancelled")
             dl_start = time.monotonic()
             # Xet primary, HTTP fallback on stall; per-file so finished shards stay cached.
-            local_path = None
-            # Reuse a cached copy from another snapshot / case-variant repo dir only when
-            # offline. Online, fall through to hf_hub_download so its revision/etag check
-            # fetches the current file (and resumes a partial) instead of serving a stale
-            # same-name blob from an older revision.
-            if not force and _hf_env_offline():
-                if gguf_extra_shards:
-                    # A split GGUF must load every shard from one snapshot; reuse only a
-                    # snapshot that holds the whole set co-located, scanning past a newer
-                    # snapshot that has just the first shard while an older one is complete.
-                    local_path = _cached_colocated_split_main(
-                        hf_repo, gguf_filename, gguf_extra_shards, expected_sizes
-                    )
-                else:
-                    local_path = _cached_hf_snapshot_file(
-                        hf_repo,
-                        gguf_filename,
-                        expected_size = expected_sizes.get(gguf_filename),
-                    )
-            if local_path is None:
-                local_path = hf_hub_download_with_xet_fallback(
+            local_path = hf_hub_download_with_xet_fallback(
+                hf_repo,
+                gguf_filename,
+                hf_token,
+                cancel_event = cancel_event,
+                on_status = lambda m: logger.info(m),
+                force_download = force,
+                cache_dir = download_cache_dir,
+            )
+            for shard in gguf_extra_shards:
+                if cancel_event.is_set():
+                    raise RuntimeError("Cancelled")
+                logger.info(f"Resolving GGUF shard: {shard}")
+                hf_hub_download_with_xet_fallback(
                     hf_repo,
-                    gguf_filename,
+                    shard,
                     hf_token,
                     cancel_event = cancel_event,
-                    on_status = lambda m: logger.info(m),
                     force_download = force,
+                    cache_dir = download_cache_dir,
                 )
-                for shard in gguf_extra_shards:
-                    if cancel_event.is_set():
-                        raise RuntimeError("Cancelled")
-                    logger.info(f"Resolving GGUF shard: {shard}")
-                    hf_hub_download_with_xet_fallback(
-                        hf_repo,
-                        shard,
-                        hf_token,
-                        cancel_event = cancel_event,
-                        force_download = force,
-                    )
         except Exception as e:
             if isinstance(e, RuntimeError) and "Cancelled" in str(e):
                 raise
@@ -4675,10 +5433,12 @@ class LlamaCppBackend:
         pick: Callable[[list[str]], Optional[str]],
         label: str,
         cancel_event: Optional[threading.Event] = None,
+        near_path: Optional[str] = None,
     ) -> Optional[str]:
         """Resolve and fetch a companion GGUF (mmproj / MTP drafter) by name.
 
-        Tries the live repo file list, then the local HF cache snapshots
+        Prefers a companion co-located with ``near_path``'s cache snapshot,
+        then tries the live repo file list, then the local HF cache snapshots
         (offline, same fallback as _download_gguf), then hf_hub_download.
         Runs WITHOUT self._lock (like _download_gguf); honors _cancel_event so
         an /unload between the main download and here skips the fetch.
@@ -4688,6 +5448,23 @@ class LlamaCppBackend:
         if cancel_event.is_set():
             return None
 
+        # Keep companion files in the main GGUF's snapshot.
+        if near_path:
+            cached = _companion_snapshot_sibling(near_path, pick)
+            if cached:
+                logger.info("Reusing cached %s: %s", label, cached)
+                return cached
+
+        from utils.hf_cache_settings import get_hf_cache_paths
+
+        companion_cache_dir = _hub_cache_dir_for_snapshot_path(near_path) or str(
+            get_hf_cache_paths().hub_cache
+        )
+
+        if _hub_download_in_flight(hf_repo):
+            logger.info("Skipping %s download while a hub download is active", label)
+            return None
+
         target: Optional[str] = None
         from huggingface_hub import list_repo_files
 
@@ -4718,7 +5495,7 @@ class LlamaCppBackend:
         if target is None:
             try:
                 from utils.models.model_config import _iter_hf_cache_snapshots
-                for snap in _iter_hf_cache_snapshots(hf_repo):
+                for snap in _iter_hf_cache_snapshots(hf_repo, companion_cache_dir):
                     rel_files = _gguf_snapshot_files(snap)
                     target = pick(rel_files)
                     if target is not None:
@@ -4736,7 +5513,11 @@ class LlamaCppBackend:
         # hf_hub_download with hf_repo would miss the canonical file and silently
         # drop the companion. _cached_hf_snapshot_file scans every case variant.
         if _hf_env_offline():
-            cached = _cached_hf_snapshot_file(hf_repo, target)
+            cached = _cached_hf_snapshot_file(
+                hf_repo,
+                target,
+                cache_dir = companion_cache_dir,
+            )
             if cached:
                 logger.info("Resolved %s from local HF cache: %s", label, cached)
                 return cached
@@ -4749,6 +5530,7 @@ class LlamaCppBackend:
                 target,
                 hf_token,
                 cancel_event = cancel_event,
+                cache_dir = companion_cache_dir,
             )
         except Exception as e:
             logger.warning(f"Could not download {label}: {e}")
@@ -4760,36 +5542,31 @@ class LlamaCppBackend:
         hf_repo: str,
         hf_token: Optional[str] = None,
         cancel_event: Optional[threading.Event] = None,
+        near_path: Optional[str] = None,
     ) -> Optional[str]:
         """Download the mmproj (vision projection) file from a GGUF repo.
 
         Prefers mmproj-F16.gguf, else any mmproj*.gguf. Returns the local
         path, or None if none exists. ``cancel_event`` overrides
-        ``self._cancel_event`` (defaults to it).
+        ``self._cancel_event`` (defaults to it). ``near_path`` prefers a
+        copy co-located with the main GGUF's cache snapshot.
         """
 
-        def _pick_mmproj(candidates: list[str]) -> Optional[str]:
-            mmproj_files = sorted(
-                f
-                for f in candidates
-                if f.lower().endswith(".gguf") and "mmproj" in Path(f).name.lower()
-            )
-            if not mmproj_files:
-                return None
-            for f in mmproj_files:
-                if f.lower().endswith("-f16.gguf"):
-                    return f
-            return mmproj_files[0]
-
         return self._download_companion_gguf(
             hf_repo = hf_repo,
             hf_token = hf_token,
             pick = _pick_mmproj,
             label = "mmproj",
             cancel_event = cancel_event,
+            near_path = near_path,
         )
 
-    def _cached_repo_mtp_drafter(self, hf_repo: str) -> Optional[str]:
+    def _cached_repo_mtp_drafter(
+        self,
+        hf_repo: str,
+        *,
+        cache_dir: Optional[str] = None,
+    ) -> Optional[str]:
         """A drafter already in this repo's local HF cache, reused offline when a
         fresh copy can't be fetched. Prefers a repo-root ``mtp-*.gguf`` across all
         cached snapshots; else an existing ``MTP/`` copy (any precision -- the
@@ -4799,7 +5576,12 @@ class LlamaCppBackend:
 
             roots: list[Path] = []
             subdirs: list[Path] = []
-            for snap in _iter_hf_cache_snapshots(hf_repo):  # newest first
+            snapshots = (
+                _iter_hf_cache_snapshots(hf_repo)
+                if cache_dir is None
+                else _iter_hf_cache_snapshots(hf_repo, cache_dir)
+            )
+            for snap in snapshots:  # newest first
                 for f in sorted(_gguf_snapshot_files(snap)):
                     if _is_companion_gguf_path(f) and "mmproj" not in f.lower():
                         (roots if "/" not in f else subdirs).append(snap / f)
@@ -4817,6 +5599,7 @@ class LlamaCppBackend:
         *,
         hf_repo: str,
         hf_token: Optional[str] = None,
+        near_path: Optional[str] = None,
     ) -> Optional[str]:
         """Download the separate MTP drafter (speculative head) from a GGUF repo.
 
@@ -4828,16 +5611,6 @@ class LlamaCppBackend:
         are intentionally skipped. Returns the local path, or None.
         """
 
-        # Offline, reuse any drafter already on disk (a fresh copy can't be
-        # fetched). Online, _download_companion_gguf/hf_hub_download reuse the
-        # current cached file and refetch a changed one, so skip the probe here
-        # rather than pair new weights with a stale draft.
-        if _hf_env_offline():
-            cached = self._cached_repo_mtp_drafter(hf_repo)
-            if cached:
-                logger.info(f"Reusing cached MTP drafter (offline): {cached}")
-                return cached
-
         def _pick_mtp(candidates: list[str]) -> Optional[str]:
             # Root-level only: MTP/ subdir copies now share the mtp- prefix but
             # are explicit-selection, not auto-fetch (they'd sort ahead of root).
@@ -4850,11 +5623,31 @@ class LlamaCppBackend:
             )
             return mtp_files[0] if mtp_files else None
 
+        if near_path:
+            cached = _companion_snapshot_sibling(near_path, _pick_mtp)
+            if cached:
+                logger.info("Reusing cached MTP drafter: %s", cached)
+                return cached
+
+        # Offline, reuse any drafter already on disk (a fresh copy can't be
+        # fetched). Online, _download_companion_gguf/hf_hub_download reuse the
+        # current cached file and refetch a changed one, so skip the probe here
+        # rather than pair new weights with a stale draft.
+        if _hf_env_offline():
+            cached = self._cached_repo_mtp_drafter(
+                hf_repo,
+                cache_dir = _hub_cache_dir_for_snapshot_path(near_path),
+            )
+            if cached:
+                logger.info(f"Reusing cached MTP drafter (offline): {cached}")
+                return cached
+
         return self._download_companion_gguf(
             hf_repo = hf_repo,
             hf_token = hf_token,
             pick = _pick_mtp,
             label = "MTP drafter",
+            near_path = near_path,
         )
 
     def _resolve_launch_mmproj_path(
@@ -4980,7 +5773,7 @@ class LlamaCppBackend:
                 return (
                     f"'{arch}' is a diffusion (image-generation) GGUF, which "
                     "llama-server cannot run as a chat/completion model. Use "
-                    "Studio's Images page to generate with local diffusion "
+                    "Unsloth's Images page to generate with local diffusion "
                     "GGUFs such as FLUX and Qwen-Image."
                 )
             if is_ollama:
@@ -5262,6 +6055,24 @@ class LlamaCppBackend:
             and ("unknown" in text or "unsupported" in text or "not supported" in text)
         )
 
+    @staticmethod
+    def _mmproj_retry_failure_message(*, projector_confirmed: bool, detail: str) -> str:
+        """User-facing error when the text-only --mmproj strip retry also fails.
+
+        Confirmed projector-format mismatches keep the historical wording.
+        Bare signal crashes (common on some ROCm/driver paths) must not be
+        reported as "Vision projector incompatible" — that misled #7302.
+        """
+        if projector_confirmed:
+            return (
+                "Vision projector incompatible with this llama.cpp "
+                "build, and the text-only retry also failed: " + detail
+            )
+        return (
+            "Vision model failed to start (llama-server crashed with "
+            "--mmproj), and the text-only retry also failed: " + detail
+        )
+
     @staticmethod
     def _output_has_nonprojector_diagnostic(output: str) -> bool:
         """True when the output already names a concrete non-projector cause (out
@@ -5436,6 +6247,7 @@ class LlamaCppBackend:
         )
         self._stdout_thread.start()
 
+    @_with_gguf_load_marker
     def load_model(
         self,
         *,
@@ -5458,6 +6270,13 @@ class LlamaCppBackend:
         speculative_type: Optional[str] = None,
         spec_draft_n_max: Optional[int] = None,
         tensor_parallel: bool = False,
+        gpu_memory_mode: Literal["auto", "manual"] = "auto",
+        gpu_layers: int = -1,
+        n_cpu_moe: int = 0,
+        tensor_split: Optional[List[float]] = None,
+        # Explicit GPU placement pool (issue #7164). None/[] = auto-select;
+        # the fitter may pin the smallest subset of this pool that fits.
+        gpu_ids: Optional[List[int]] = None,
         n_threads: Optional[int] = None,
         n_gpu_layers: Optional[int] = None,  # caller compat, unused
         n_parallel: int = 1,
@@ -5490,6 +6309,14 @@ class LlamaCppBackend:
             "speculative_type": speculative_type,
             "spec_draft_n_max": spec_draft_n_max,
             "tensor_parallel": tensor_parallel,
+            # GPU-memory placement: replayed on respawn so a server SIGKILL'd by
+            # GPU/RAM pressure reloads onto the same devices with the same
+            # offload, not the auto defaults.
+            "gpu_memory_mode": gpu_memory_mode,
+            "gpu_layers": gpu_layers,
+            "n_cpu_moe": n_cpu_moe,
+            "tensor_split": list(tensor_split) if tensor_split is not None else None,
+            "gpu_ids": list(gpu_ids) if gpu_ids is not None else None,
             "n_threads": n_threads,
             "n_gpu_layers": n_gpu_layers,
             "n_parallel": n_parallel,
@@ -5516,6 +6343,11 @@ class LlamaCppBackend:
                 speculative_type = speculative_type,
                 spec_draft_n_max = spec_draft_n_max,
                 tensor_parallel = tensor_parallel,
+                gpu_memory_mode = gpu_memory_mode,
+                gpu_layers = gpu_layers,
+                n_cpu_moe = n_cpu_moe,
+                tensor_split = tensor_split,
+                gpu_ids = gpu_ids,
                 chat_template_override = chat_template_override,
                 extra_args = extra_args,
                 is_vision = is_vision,
@@ -5541,15 +6373,63 @@ class LlamaCppBackend:
 
             self._cancel_event.clear()
 
-            # ── Phase 1: kill old process (under lock, fast) ──────────
-            with self._lock:
-                self._kill_process()
-
             # Resolve llama-server now but defer a not-found error: a block-diffusion
             # GGUF uses the diffusion runner, and its arch is only known after the header.
             binary = self._find_llama_server_binary()
             is_vulkan_backend = self._is_vulkan_backend(binary)
 
+            # ── Vulkan-ordinal preflight (BEFORE the Phase 1 kill) ────────
+            # An explicit Vulkan pin the ggml probe never enumerated cannot be honored.
+            # Validate it ABOVE the kill so an invalid selection leaves the live model
+            # untouched: CUDA ids are range-checked at the route, but Vulkan ordinals are
+            # not, so a stale gpu_ids=[99] used to kill the server then 400, leaving
+            # nothing running (#7239). _get_gpu_memory needs only the binary (safe pre-
+            # download) and reuses the later fit's issubset logic. Guarded on a found
+            # Vulkan build + a pin so a deferred not-found stays deferred for diffusion.
+            if is_vulkan_backend and gpu_ids and binary:
+                _pf_wanted = {int(x) for x in gpu_ids}
+                _pf_probed = {g[0] for g in self._get_gpu_memory(binary)}
+                if not _pf_wanted.issubset(_pf_probed):
+                    raise ValueError(
+                        f"Requested Vulkan GPU ordinal(s) {sorted(_pf_wanted)} not "
+                        f"present. Available Vulkan devices: {sorted(_pf_probed)}."
+                    )
+
+            # A remote uncached GGUF may only reveal that it needs the
+            # single-device diffusion runner after download. On Vulkan, an
+            # explicit gpu_ids request cannot be mapped from ggml ordinals to
+            # that runner's CUDA physical index. Download and classify the main
+            # file before killing the healthy server so this late rejection is
+            # non-destructive. The Phase 2 call below reuses this cached path.
+            _preflight_model_path = None
+            if is_vulkan_backend and gpu_ids and hf_repo:
+                _resolved_repo = _resolve_repo_id_casing(hf_repo)
+                if _resolved_repo != hf_repo:
+                    logger.info(
+                        "Using cached repo_id casing '%s' for requested '%s'",
+                        _resolved_repo,
+                        hf_repo,
+                    )
+                    hf_repo = _resolved_repo
+                with _hf_offline_if_dns_dead():
+                    _preflight_model_path = self._download_gguf(
+                        hf_repo = hf_repo,
+                        hf_variant = hf_variant,
+                        hf_token = hf_token,
+                    )
+                if self._gguf_path_is_diffusion(_preflight_model_path, model_identifier):
+                    raise ValueError(
+                        "GPU selection (gpu_ids) is not supported for a DiffusionGemma "
+                        "GGUF on a Vulkan llama.cpp build: the diffusion runner selects "
+                        "its device by CUDA physical index, which has no defined mapping "
+                        "to ggml Vulkan device ordinals. Omit gpu_ids to use the default "
+                        "device."
+                    )
+
+            # ── Phase 1: kill old process (under lock, fast) ──────────
+            with self._lock:
+                self._kill_process()
+
             # ── Phase 2: download (NO lock held, so cancel can proceed) ──
             # mtp_draft_path arrives set for local Gemma loads (detected
             # sibling); for -hf loads it's None here and resolved just below.
@@ -5571,7 +6451,7 @@ class LlamaCppBackend:
                     )
                     hf_repo = _resolved_repo
                 with _hf_offline_if_dns_dead():
-                    model_path = self._download_gguf(
+                    model_path = _preflight_model_path or self._download_gguf(
                         hf_repo = hf_repo,
                         hf_variant = hf_variant,
                         hf_token = hf_token,
@@ -5581,6 +6461,7 @@ class LlamaCppBackend:
                         mmproj_path = self._download_mmproj(
                             hf_repo = hf_repo,
                             hf_token = hf_token,
+                            near_path = model_path,
                         )
                     # Auto-download the separate MTP drafter (e.g. Gemma) when
                     # the requested spec mode can use it. Repos with the head
@@ -5598,6 +6479,7 @@ class LlamaCppBackend:
                         mtp_draft_path = self._download_mtp(
                             hf_repo = hf_repo,
                             hf_token = hf_token,
+                            near_path = model_path,
                         )
             elif gguf_path:
                 if not Path(gguf_path).is_file():
@@ -5619,6 +6501,18 @@ class LlamaCppBackend:
             # Block-diffusion GGUFs (DiffusionGemma) cannot run on llama-server;
             # serve them with the diffusion runner (same OpenAI-compat interface).
             if self._is_diffusion:
+                # The diffusion runner pins its child by CUDA visibility mask, so a
+                # ggml Vulkan ordinal cannot be honored (wrong GPU / CPU fallback).
+                # Route and remote-download preflights reject before teardown; keep
+                # this as a final defense if classification ever disagrees.
+                if is_vulkan_backend and gpu_ids:
+                    raise ValueError(
+                        "GPU selection (gpu_ids) is not supported for a DiffusionGemma "
+                        "GGUF on a Vulkan llama.cpp build: the diffusion runner selects "
+                        "its device by CUDA physical index, which has no defined mapping "
+                        "to ggml Vulkan device ordinals. Omit gpu_ids to use the default "
+                        "device."
+                    )
                 # Not a tensor/layer GGUF: clear any preserved-fallback flag from a
                 # prior load (this path skips the command builder that clears it).
                 self._layer_preserves_tensor_intent = False
@@ -5634,6 +6528,7 @@ class LlamaCppBackend:
                         model_identifier = model_identifier,
                         n_ctx = n_ctx,
                         extra_args = extra_args,
+                        gpu_ids = gpu_ids,
                     )
 
             if not binary:
@@ -5695,6 +6590,59 @@ class LlamaCppBackend:
                 # use the same helper so a healthy env-driven tensor server matches.
                 split_mode_override = parse_split_mode_override(extra_args)
                 tensor_parallel = _effective_tensor_parallel(extra_args, tensor_parallel)
+                # gpu_layers=0 leaves nothing to split, yet --split-mode tensor or
+                # a per-GPU ratio still launches tensor mode -- and under the
+                # CPU-only mask below (no visible devices) that aborts the server
+                # instead of loading on CPU. Drop both here (nothing to split).
+                if gpu_memory_mode == "manual" and gpu_layers == 0:
+                    if tensor_parallel or tensor_split:
+                        logger.info(
+                            "Manual gpu_layers=0: dropping tensor split/parallel "
+                            "flags (nothing to split on the GPU)"
+                        )
+                    tensor_parallel = False
+                    tensor_split = None
+                # Record the requested strategy for /status and the load
+                # response. 'manual' has no fallback, so the request value is the
+                # value actually applied.
+                self._gpu_memory_mode = gpu_memory_mode
+                # The layer/MoE/split knobs apply only with an explicit offload
+                # (manual + gpu_layers >= 0); else record defaults so /status and
+                # /load don't report knobs the server never applied.
+                if gpu_memory_mode == "manual" and gpu_layers >= 0:
+                    self._gpu_layers = gpu_layers
+                    self._n_cpu_moe = n_cpu_moe
+                    self._tensor_split = tensor_split
+                else:
+                    self._gpu_layers = -1
+                    self._n_cpu_moe = 0
+                    self._tensor_split = None
+                self._gpu_ids = sorted(gpu_ids) if gpu_ids else None
+                # Manual offload skips the TP planner but still emits --split-mode
+                # tensor at launch; drop it when fewer than 2 GPUs are in use --
+                # tensor split is a no-op there and aborts on some architectures.
+                # Done before the cache-drop below so a quantized KV survives.
+                if (
+                    tensor_parallel
+                    and gpu_memory_mode == "manual"
+                    and gpu_layers >= 0
+                    and self._effective_gpu_count(sorted(gpu_ids) if gpu_ids else None) < 2
+                ):
+                    logger.info(
+                        "Tensor parallelism requested in manual mode but fewer "
+                        "than 2 GPUs are in use; ignoring (needs >= 2)."
+                    )
+                    tensor_parallel = False
+                # Drop TP for manual + Auto layers before the cache-drop below (like
+                # the <2-GPU guard above), so a requested quantized KV survives into
+                # the --fit load rather than being stripped for a tensor attempt.
+                if tensor_parallel and gpu_memory_mode == "manual" and gpu_layers < 0:
+                    logger.info(
+                        "Manual mode with Auto layers hands memory management to "
+                        "llama.cpp --fit, which is incompatible with tensor "
+                        "parallelism; ignoring the tensor split."
+                    )
+                    tensor_parallel = False
                 # Tensor mode aborts on a quantized KV cache, so drop it for the
                 # tensor attempt (and strip any inherited/explicit --cache-type
                 # that would re-impose it when appended last). Layer split does
@@ -5775,10 +6723,22 @@ class LlamaCppBackend:
                         "Vision-capable GGUF loaded without a usable mmproj; "
                         "image input will be disabled for this session"
                     )
+                # Seed before the try: the except (GPU-selection failure ->
+                # --fit on) falls through to the launch which reads this, and the
+                # probe that assigns it may throw first. Captured before manual
+                # empty `gpus` so the speculative defaults stay GPU-aware and the
+                # CPU-fallback check still knows GPUs were present.
+                _detected_gpus: list[tuple[int, int]] = []
                 model_size = None  # set in the fit try; used by the APU RAM guard
                 # Layer-fallback min GPUs; raised below on a tensor downgrade. Bound
                 # before the try so the --fit-on except path still has it (no UnboundLocal).
                 _layer_min_gpus = 1
+                # An explicit Vulkan ordinal absent from the ggml probe cannot be
+                # honored; flag it in the fit and reject after the try (raising inside
+                # would be swallowed into the --fit-on fallback). Bound before the try.
+                _vulkan_explicit_unmatched = False
+                _vulkan_requested_ids: list[int] = []
+                _vulkan_available_ordinals: list[int] = []
                 try:
                     gguf_size = self._get_gguf_size_bytes(model_path)
                     # Include GPU-loaded mmproj in the fit budget (#5825).
@@ -5791,7 +6751,41 @@ class LlamaCppBackend:
                     # Pass binary so a Vulkan build probes ggml's Vulkan ordinals.
                     _gpu_mem = self._get_gpu_memory(binary)
                     gpus = [(idx, free) for idx, free, _t in _gpu_mem]
+                    # Restrict the fit (and thus the layer plan + pin env) to the
+                    # selected GPUs; fail-open if none match so a stale UI choice
+                    # can't strand the load on CPU (issue #7164).
+                    if gpu_ids:
+                        # A Vulkan build indexes by ggml ordinal. An explicit ordinal
+                        # absent from the probe can't be pinned, so reject after the try
+                        # rather than fail-open onto a device the user didn't pick.
+                        _wanted_ids = {int(x) for x in gpu_ids}
+                        # Reject if ANY requested ordinal is absent, not only when none
+                        # match: [0, 99] against {0, 1} silently drops 99. Comparing the
+                        # full requested set (before filter narrows) still lets the fitter
+                        # pick a valid subset later -- that is narrowing, not absence.
+                        _probed_ordinals = {g[0] for g in gpus}
+                        if is_vulkan_backend and not _wanted_ids.issubset(_probed_ordinals):
+                            _vulkan_explicit_unmatched = True
+                            _vulkan_requested_ids = sorted(_wanted_ids)
+                            _vulkan_available_ordinals = sorted(_probed_ordinals)
+                        # Restrict the probed pool to the selection; fail-open (keep the
+                        # full pool) if none match so a stale UI choice can't strand the
+                        # load on CPU (issue #7164).
+                        _sel_gpus = [g for g in gpus if g[0] in _wanted_ids]
+                        gpus = _sel_gpus if _sel_gpus else gpus
                     total_by_idx = {idx: total for idx, _f, total in _gpu_mem}
+                    # GPU picker: restrict every mode to the chosen devices, so
+                    # auto selection only considers them and manual mask to
+                    # them (the env block below pins CUDA/HIP_VISIBLE_DEVICES).
+                    if gpu_ids:
+                        _picked = set(gpu_ids)
+                        gpus = [g for g in gpus if g[0] in _picked]
+
+                    # GPUs the model will run on -- captured before manual
+                    # empty `gpus` to bypass the planner. bool() drives the
+                    # GPU-aware speculative defaults; the list feeds the
+                    # CPU-fallback check.
+                    _detected_gpus = list(gpus)
 
                     def _gpu_usable(g, frac = _CTX_FIT_VRAM_FRACTION):
                         # Per-GPU usable budget for ranking: free - (1-frac)*total.
@@ -5823,6 +6817,44 @@ class LlamaCppBackend:
                     # GPU/VRAM-fit logic below may shrink it on limited HW.
                     max_available_ctx = self._context_length or effective_ctx
 
+                    # Manual + Auto layers (the Manual default): hand memory
+                    # management to llama.cpp's --fit. Emptying the probed GPU set
+                    # no-ops the selection/TP planning below, leaving gpu_indices
+                    # None (an explicit gpu_ids pick still pins below) and use_fit
+                    # True. An explicit context is honored (--fit optimizes around
+                    # it); 0 lets --fit size it.
+                    if gpu_memory_mode == "manual" and gpu_layers < 0:
+                        # Tensor parallelism was already dropped above (before the
+                        # cache-drop), so a quantized KV survives into this --fit load.
+                        gpus = []
+                        effective_ctx = requested_ctx if requested_ctx > 0 else 0
+                        original_ctx = effective_ctx
+                        # --fit aborts under --split-mode tensor; a raw extras
+                        # --split-mode/--tensor-split (appended last) would
+                        # otherwise reach llama-server. Strip it like the TP
+                        # downgrade does.
+                        extra_args = strip_split_mode_only(extra_args)
+                    elif gpu_memory_mode == "manual":
+                        # Manual offload (--gpu-layers + --fit off): no automatic
+                        # device masking (a gpu_ids pick still pins below) or
+                        # context cap -- the user owns both. tensor_parallel is
+                        # honored but skips the memory-based planner (gpus = []);
+                        # the toggle just emits --split-mode tensor (split by free
+                        # VRAM, or by the Split ratio if set).
+                        gpus = []
+                        effective_ctx = (
+                            requested_ctx if requested_ctx > 0 else (self._context_length or 0)
+                        )
+                        original_ctx = effective_ctx
+                        # Strip the user --split-mode when the toggle owns the split
+                        # (TP engaged -> Studio emits --split-mode tensor) or when the
+                        # user asked for tensor (which aborts on a single GPU even if
+                        # the manual <2-GPU guard downgraded TP). Otherwise keep their
+                        # non-tensor mode (row/none/layer) -- the toggle can't express
+                        # those.
+                        if tensor_parallel or split_mode_override == "tensor":
+                            extra_args = strip_split_mode_only(extra_args)
+
                     # Will MTP engage? If so, auto-fit reserves draft-model VRAM.
                     # Mirrors _build_speculative_flags: forced mtp/mtp+ngram always
                     # engage; auto only on an MTP model >= 3B; ngram/off never. A
@@ -5838,7 +6870,7 @@ class LlamaCppBackend:
                         and not bool(mtp_draft_path)
                     )
                     # LLAMA_ARG_SPEC_TYPE only reaches the child when neither extras
-                    # nor Studio emit a spec flag (mode "off", no user --spec-type),
+                    # nor Unsloth emit a spec flag (mode "off", no user --spec-type),
                     # since _build_speculative_flags emits one for every other mode.
                     # Consult the env for the reserve only then, else a stale MTP env
                     # would over-reserve.
@@ -5847,7 +6879,7 @@ class LlamaCppBackend:
                         if (not _extra_args_set_spec_type(extra_args) and _mtp_canonical == "off")
                         else {}
                     )
-                    # Extras can run MTP even when Studio suppresses its own emission.
+                    # Extras can run MTP even when Unsloth suppresses its own emission.
                     _user_mtp_via_extras = _extra_args_requests_mtp(extra_args, env = _spec_env)
                     # A non-MTP model-based draft mode (draft-simple/draft-eagle3) in
                     # extras also loads a separate draft model that needs reserving;
@@ -5910,10 +6942,13 @@ class LlamaCppBackend:
                     _extra_n_max = _extra_args_spec_draft_n_max(extra_args)
                     _mtp_eff_n_max = _extra_n_max if _extra_n_max is not None else spec_draft_n_max
                     if _mtp_eff_n_max is None:
-                        _mtp_eff_n_max = 2 if gpus else 3
+                        # _detected_gpus (not gpus) so manual -- which empty
+                        # gpus to bypass the planner -- keep the GPU draft depth the
+                        # launch flags also use, instead of the CPU default.
+                        _mtp_eff_n_max = 2 if _detected_gpus else 3
                     # Separate-drafter weights live on GPU (an embedded head is
                     # already in model_size). Size the drafter the launch loads, by
-                    # precedence: extras --model-draft (last-wins), else Studio's
+                    # precedence: extras --model-draft (last-wins), else Unsloth's
                     # emitted mtp_draft_path, else the env drafter. Sizing the wrong
                     # one would under-reserve and OOM.
                     _cli_draft_for_budget = _extra_args_mtp_draft_path(extra_args, env = {})
@@ -6048,7 +7083,8 @@ class LlamaCppBackend:
                     # honor it, cap only if it fits no combination. Auto (native):
                     # prefer fewer GPUs with reduced context (multi-GPU is slower).
                     gpu_indices, use_fit = None, True
-                    # Per-GPU weight proportions for tensor mode (None = even).
+                    # Per-GPU weight proportions for tensor mode (None lets
+                    # llama.cpp split by free VRAM).
                     tp_tensor_split: Optional[list[int]] = None
                     explicit_ctx = requested_ctx > 0
                     # Flat MTP reserve fraction: used only as the fallback when the
@@ -6123,7 +7159,12 @@ class LlamaCppBackend:
                     # GPUs below that reserve from the set up front (gpu_indices
                     # becomes the CUDA_VISIBLE_DEVICES mask, fully excluding them).
                     tp_gpus = gpus
-                    if tensor_parallel:
+                    # Manual mode owns the layer count and context, so it skips
+                    # the memory-based planner; its toggle still emits
+                    # --split-mode tensor below (split by free VRAM, or by the
+                    # Split ratio if set). auto plans here.
+                    plan_tp = tensor_parallel and gpu_memory_mode != "manual"
+                    if plan_tp:
                         # Deterministic per-device compute buffer (replicated on
                         # every device in tensor mode); flat fallback when dims
                         # are unavailable. _plan_tensor_parallel uses the same.
@@ -6142,7 +7183,7 @@ class LlamaCppBackend:
                         # free yet have no budget left.
                         tp_gpus = [g for g in gpus if _gpu_usable(g) >= reserve_mib]
 
-                    if tensor_parallel and len(tp_gpus) < 2:
+                    if plan_tp and len(tp_gpus) < 2:
                         # Tensor parallelism needs >= 2 usable GPUs. On a single
                         # GPU --split-mode tensor is a no-op; with 0 GPUs (CPU-only
                         # or probe failed) it must not reach llama-server; and a
@@ -6558,6 +7599,23 @@ class LlamaCppBackend:
                     tp_tensor_split = None
                     effective_ctx = requested_ctx  # fall back to original
 
+                # An unenumerated explicit Vulkan ordinal can't be pinned; fail loudly
+                # instead of fitting onto an unselected device. Clear the raw selection
+                # the early state-publish recorded so it never leaks into gpu_ids (#7239).
+                if _vulkan_explicit_unmatched:
+                    self._gpu_ids = None
+                    self._requested_gpu_ids = None
+                    raise ValueError(
+                        f"Requested Vulkan GPU ordinal(s) {_vulkan_requested_ids} not "
+                        f"present. Available Vulkan devices: {_vulkan_available_ordinals}."
+                    )
+
+                # GPU picker: when no narrower subset was chosen (manual, or
+                # a failed/file-size selection), pin the whole picked set so the
+                # model can't spill onto an unpicked GPU.
+                if gpu_ids and gpu_indices is None:
+                    gpu_indices = sorted(gpu_ids)
+
                 # Unified-memory APUs load weights into system RAM (under WSL the VM
                 # cap, not the ROCm-reported VRAM, is the real ceiling); refuse an
                 # oversize load the OS would otherwise kill mid-flight. Base model
@@ -6594,8 +7652,6 @@ class LlamaCppBackend:
                     model_path,
                     "--port",
                     str(self._port),
-                    "-c",
-                    str(effective_ctx) if effective_ctx > 0 else "0",
                     "--parallel",
                     str(n_parallel),
                     "--flash-attn",
@@ -6603,6 +7659,17 @@ class LlamaCppBackend:
                     # Error out at n_ctx instead of silently rotating the KV cache; frontend catches it and points the user at "Context Length".
                     "--no-context-shift",
                 ]
+                # A positive context is always passed (in auto-fit, --fit then
+                # optimizes the gpu-layer offload around it). When auto-fit has
+                # no explicit context, omit -c so --fit sizes it to fit VRAM:
+                # "-c 0" would instead pin the FULL native context (llama.cpp's
+                # -c handler sets fit_params_min_ctx = UINT32_MAX on value 0,
+                # disabling --fit's reduction). See gpu_memory_mode.
+                auto_fit = gpu_memory_mode == "manual" and gpu_layers < 0
+                if effective_ctx > 0:
+                    cmd.extend(["-c", str(effective_ctx)])
+                elif not auto_fit:
+                    cmd.extend(["-c", "0"])
 
                 # Report a clean public model id (matching GET /v1/models) rather
                 # than the raw -m path in llama-server's own /v1/models and the
@@ -6614,7 +7681,63 @@ class LlamaCppBackend:
                     cmd.extend(["--alias", _alias])
 
                 fully_gpu_offloaded = False
-                if use_fit:
+                # Set when a positional --tensor-split is emitted, so the env block
+                # can pin CUDA to PCI order even without a GPU subset (see below).
+                manual_tensor_split_emitted = False
+                if gpu_memory_mode == "manual" and gpu_layers >= 0:
+                    # Pin the user's layer count and disable auto-fit. --fit off
+                    # also means _ctx_integrity_flags must not add --fit-ctx.
+                    use_fit = False
+                    cmd.extend(["--gpu-layers", str(gpu_layers), "--fit", "off"])
+                    # Keep the first n_cpu_moe MoE layers' experts on CPU.
+                    moe_flag = self._resolve_cpu_moe_flag(
+                        n_cpu_moe,
+                        self.n_moe_layers,
+                        self._leading_dense_block_count or 0,
+                    )
+                    if moe_flag is not None:
+                        cmd.extend(["--n-cpu-moe", str(moe_flag)])
+                    elif n_cpu_moe:
+                        # Requested on a dense model: nothing was emitted, so
+                        # don't report a count llama-server never received.
+                        self._n_cpu_moe = 0
+                    # Distribute the model across GPUs by the user's per-GPU shares
+                    # (--tensor-split). Works with layer split and tensor
+                    # parallelism; --fit off means no fit/tensor abort. Only emit
+                    # when >1 GPU is in use AND the list length matches that count:
+                    # the field is hidden (not cleared) when the picker narrows to
+                    # one, and a direct caller can send a stale ratio for a different
+                    # GPU set. Studio drops any mismatch to the free-VRAM default
+                    # (llama.cpp would silently zero-pad a short list, or abort past
+                    # its 16-device cap).
+                    _split_gpus = self._effective_gpu_count(gpu_indices)
+                    if tensor_split and _split_gpus > 1:
+                        # An all-zero/non-positive sanitized split assigns nothing
+                        # anywhere, so fall through to the free-VRAM default in
+                        # that case.
+                        _sanitized_split = self._sanitize_tensor_split(tensor_split)
+                        _split_total = sum(_sanitized_split)
+                        if len(_sanitized_split) == _split_gpus and _split_total > 0:
+                            cmd.extend(
+                                ["--tensor-split", ",".join(f"{x:g}" for x in _sanitized_split)]
+                            )
+                            self._tensor_split = _sanitized_split
+                            manual_tensor_split_emitted = True
+                        else:
+                            logger.warning(
+                                "Dropping manual --tensor-split (%d entries for "
+                                "%d GPUs, sanitized total %s); llama.cpp's "
+                                "free-VRAM split applies instead",
+                                len(tensor_split),
+                                _split_gpus,
+                                _split_total,
+                            )
+                            self._tensor_split = None
+                    elif tensor_split:
+                        # Single effective GPU: the split is never emitted, so
+                        # don't report it as active via /status and /load.
+                        self._tensor_split = None
+                elif use_fit:
                     cmd.extend(["--fit", "on"])
                 elif gpu_indices is not None:
                     # Fits on selected GPU(s) -- force all layers on GPU. --fit off is
@@ -6628,10 +7751,31 @@ class LlamaCppBackend:
                 # when the binary advertises it (older/custom binaries may not).
                 if server_caps.get("supports_metrics"):
                     cmd.append("--metrics")
+                self._slot_save_dir = None
+                self._slot_save_binary = None
+                self._prompt_cache_disabled = False
+                if server_caps.get("supports_slot_save"):
+                    try:
+                        from utils.paths.storage_roots import (  # noqa: WPS433
+                            llama_slot_cache_root,
+                        )
+
+                        slot_dir = llama_slot_cache_root()
+                        slot_dir.mkdir(parents = True, exist_ok = True)
+                        # Saved KV encodes chat content; keep it from other local users.
+                        with contextlib.suppress(OSError):
+                            os.chmod(slot_dir, 0o700)
+                        cmd.extend(["--slot-save-path", str(slot_dir)])
+                        self._slot_save_dir = str(slot_dir)
+                        self._slot_save_binary = (binary, Path(binary).stat().st_mtime_ns)
+                    except OSError:
+                        self._slot_save_dir = None
+                        self._slot_save_binary = None
                 cmd.extend(
                     self._ctx_integrity_flags(
                         n_parallel,
                         use_fit,
+                        auto_fit,
                         requested_ctx,
                         effective_ctx,
                         server_caps,
@@ -6695,9 +7839,11 @@ class LlamaCppBackend:
                     self._cache_type_kv = None
 
                 # Tensor parallelism: split the model across GPUs by tensor
-                # rather than by layer. Multi-GPU only -- a no-op on a single
-                # GPU. Default (layer split) is left implicit by omitting the
-                # flag. See llama.cpp --split-mode.
+                # rather than by layer. The UI only offers it on multi-GPU; a
+                # direct single-GPU caller is redundant (supported archs no-op,
+                # unsupported ones abort and the /load path retries layer split).
+                # Default (layer split) is left implicit by omitting the flag.
+                # See llama.cpp --split-mode.
                 if tensor_parallel:
                     cmd.extend(["--split-mode", "tensor"])
                     if tp_tensor_split and len(tp_tensor_split) > 1:
@@ -6729,7 +7875,7 @@ class LlamaCppBackend:
                     extra_args = extra_args,
                     model_identifier = model_identifier,
                     model_path = model_path,
-                    gpus = bool(gpus),
+                    gpus = bool(_detected_gpus),
                     binary = binary,
                     mtp_draft_path = launch_mtp_draft_path,
                 )
@@ -6808,8 +7954,9 @@ class LlamaCppBackend:
                 else:
                     self._api_key = None
 
-                # Windows + full offload: disable KV checkpoints (WDDM/PCI-E
-                # overhead). CPU/partial offload keeps prompt caching. #5692.
+                # Windows + full offload: drop the host-RAM KV checkpoints that cause
+                # WDDM/PCI-E overhead, but keep prompt caching (in-VRAM prefix reuse) so
+                # a repeated prompt is not re-prefilled on every request. #5692.
                 if sys.platform == "win32" and full_offload_tuning_active:
                     unsupported_cache_flags: list[str] = []
                     if server_caps.get("supports_cache_ram"):
@@ -6820,24 +7967,54 @@ class LlamaCppBackend:
                         cmd.extend(["--ctx-checkpoints", "0"])
                     else:
                         unsupported_cache_flags.append("--ctx-checkpoints")
-                    if server_caps.get("supports_no_cache_prompt"):
-                        cmd.append("--no-cache-prompt")
-                    else:
-                        unsupported_cache_flags.append("--no-cache-prompt")
                     if unsupported_cache_flags:
                         logger.info(
                             "Skipping unsupported Windows cache flags for llama-server: %s",
                             ", ".join(unsupported_cache_flags),
                         )
 
-                # Vulkan pins via --device (a cmd arg, unlike the env-based
-                # CUDA/ROCm pin below), emitted BEFORE user extras so llama.cpp's
-                # last-wins parsing lets a user --device override Studio's pick.
-                if is_vulkan_backend and gpu_indices is not None:
-                    cmd += LlamaCppBackend._vulkan_pin_args(gpu_indices)
+                # Vulkan pins via --device (a cmd arg), before user extras so a user
+                # --device wins. Fall back to raw ids when the fit did not narrow.
+                _vulkan_pin_ids = gpu_indices if gpu_indices is not None else (gpu_ids or None)
+
+                # Record the pin actually applied (fit-narrowed gpu_indices, else the raw
+                # request) for the keep-warm loop, dedupe, and /status, so an explicit
+                # [0, 1] narrowed to [0] records [0] and /status never echoes an ordinal
+                # the child never saw. Auto selection (no gpu_ids) stays None (#7239).
+                if is_vulkan_backend:
+                    # Only record an EXPLICIT Vulkan pin: an auto pick still narrows +
+                    # pins below, but recording it would misreport an explicit pin and
+                    # make dedupe miss the loaded server; mirrors the CUDA/ROCm branch.
+                    self._gpu_ids = (
+                        sorted(int(x) for x in _vulkan_pin_ids)
+                        if (gpu_ids and _vulkan_pin_ids)
+                        else None
+                    )
+                elif gpu_ids:
+                    # Physical pin: the fit-selected subset when the fit ran, else the raw
+                    # user selection so an explicit choice is honoured even when the fit
+                    # could not size the model.
+                    _effective_pin_ids = (
+                        [int(x) for x in gpu_indices]
+                        if gpu_indices is not None
+                        else [int(x) for x in gpu_ids]
+                    )
+                    self._gpu_ids = (
+                        sorted(int(x) for x in _effective_pin_ids) if _effective_pin_ids else None
+                    )
+                else:
+                    self._gpu_ids = None
+
+                # Also record the RAW requested pin (before the fit narrowed it). Load
+                # dedupe compares this so a [0, 1] narrowed to [0] and re-sent as [0, 1]
+                # still matches, while /status keeps echoing the effective pin (#7239).
+                self._requested_gpu_ids = sorted(int(x) for x in gpu_ids) if gpu_ids else None
+
+                if is_vulkan_backend and _vulkan_pin_ids is not None:
+                    cmd += LlamaCppBackend._vulkan_pin_args(_vulkan_pin_ids)
 
                 # User pass-through args go last so llama.cpp's last-wins parsing
-                # lets the user override Studio's auto-set flags. Already
+                # lets the user override Unsloth's auto-set flags. Already
                 # validated by the route via validate_extra_args().
                 if extra_args:
                     cmd.extend(str(a) for a in extra_args)
@@ -6847,15 +8024,17 @@ class LlamaCppBackend:
 
                 # Library paths so llama-server finds its shared libs and CUDA DLLs.
                 env = self._llama_server_env_for_binary(binary)
+                if gpu_memory_mode == "manual":
+                    self._clear_manual_placement_env(env)
                 # Omitting --threads relies on llama.cpp's physical-core default, so
                 # drop an inherited LLAMA_ARG_THREADS that would otherwise feed the
                 # arg handler and silently force hardware_concurrency(). #5692
                 if "--threads" not in cmd:
                     env.pop("LLAMA_ARG_THREADS", None)
 
-                # Reconcile the inherited LLAMA_ARG_* env with Studio's final
+                # Reconcile the inherited LLAMA_ARG_* env with Unsloth's final
                 # decision: stripping CLI extras on a tensor->layer downgrade
-                # can't remove env vars, so the child could run a mode/KV Studio
+                # can't remove env vars, so the child could run a mode/KV Unsloth
                 # didn't budget.
                 if not tensor_parallel:
                     # Layer split: clear a non-layer inherited split mode (and any
@@ -6865,7 +8044,7 @@ class LlamaCppBackend:
                         env.pop("LLAMA_ARG_SPLIT_MODE", None)
                         env.pop("LLAMA_ARG_TENSOR_SPLIT", None)
                 else:
-                    # Studio owns the tensor split: it emits --tensor-split when it
+                    # Unsloth owns the tensor split: it emits --tensor-split when it
                     # picks an uneven one (CLI wins) and nothing when an even split
                     # is safe. Clear any inherited LLAMA_ARG_TENSOR_SPLIT so the even
                     # case can't be overridden by a stale env (the layer branch above
@@ -6901,32 +8080,48 @@ class LlamaCppBackend:
                         f"Data-center GPU detected: applied DC llama.cpp env tuning (multi_gpu={multi_gpu})"
                     )
 
-                # Pin to selected GPU(s). On ROCm, narrowing only
-                # CUDA_VISIBLE_DEVICES leaves an AMD child seeing the full set, so
-                # set HIP_VISIBLE_DEVICES too. Vulkan is pinned via --device
-                # (above), not here.
-                if gpu_indices is not None and not is_vulkan_backend:
-                    pinned = ",".join(str(i) for i in gpu_indices)
-                    env["CUDA_VISIBLE_DEVICES"] = pinned
-                    try:
-                        import torch as _torch
-                        if getattr(_torch.version, "hip", None) is not None:
-                            env["HIP_VISIBLE_DEVICES"] = pinned
-                            # Do NOT also set ROCR_VISIBLE_DEVICES to the same
-                            # value. ROCR_VISIBLE_DEVICES filters at the HSA/ROCr
-                            # layer and HIP_VISIBLE_DEVICES at the HIP layer, so
-                            # setting both with the same physical indices applies
-                            # the mask twice: ROCR reduces the visible set and
-                            # re-indexes it from 0, then HIP indexes into the
-                            # already-reduced set. A single non-zero pin (e.g.
-                            # "1") then points out of range at the HIP layer, HIP
-                            # enumerates 0 devices, and llama.cpp falls back to
-                            # CPU ("ggml_cuda_init: no ROCm-capable device is
-                            # detected"). The HIP mask alone narrows correctly;
-                            # clear any inherited ROCR mask so it can't double up.
-                            env.pop("ROCR_VISIBLE_DEVICES", None)
-                    except Exception as e:
-                        logger.debug("Failed to set ROCm visibility env vars for child: %s", e)
+                # Pin to selected GPU(s) (issue #7164; resolved above into gpu_indices).
+                # On ROCm, narrowing only CUDA_VISIBLE_DEVICES leaves the AMD child
+                # seeing the full set, so set HIP_VISIBLE_DEVICES too. Vulkan is pinned
+                # via --device (above), not here.
+                # A deliberate zero-offload load with no GPU companions runs
+                # entirely on CPU, yet a visible CUDA device still costs the child
+                # ~0.5 GB (context + compute scratch) that the CPU-only
+                # classification below reports as free. Hide the GPUs so the load
+                # is exactly what it claims: zero VRAM (verified: GPU stays at idle
+                # baseline and generation runs). Companion loads keep the normal
+                # masking, and a user device pin (in extras or an inherited
+                # LLAMA_ARG_DEVICE) keeps control of its own devices -- the child
+                # aborts on a pin it can't see. The draft-device forms count too:
+                # llama-server parses them even with no drafter loaded.
+                _cpu_only_zero_offload = (
+                    gpu_memory_mode == "manual"
+                    and gpu_layers == 0
+                    and not is_vulkan_backend
+                    and not self._zero_offload_keeps_gpu_visible(cmd, env)
+                )
+                if _cpu_only_zero_offload:
+                    self._emit_child_gpu_visibility(env, "-1")
+                elif gpu_indices is not None and not is_vulkan_backend:
+                    # When the user picked GPUs by index, align CUDA's ordering
+                    # with the PCI-bus order the picker enumerated (nvidia-smi),
+                    # so "GPU 1" in the UI is GPU 1 to llama.cpp -- not CUDA's
+                    # default FASTEST_FIRST order (#5025).
+                    if gpu_ids:
+                        env["CUDA_DEVICE_ORDER"] = "PCI_BUS_ID"
+                    # Mask on AMD at the ROCr/HSA layer: HIP-only masking still
+                    # enumerates every agent first, which segfaults on a deselected
+                    # unsupported GPU (e.g. gfx1103 iGPU under a gfx110X prebuilt).
+                    self._emit_child_gpu_visibility(
+                        env, ",".join(str(i) for i in gpu_indices), prefer_rocr = True
+                    )
+                elif manual_tensor_split_emitted and not is_vulkan_backend:
+                    # A manual per-GPU ratio across ALL GPUs (no explicit pick, so
+                    # no CUDA_VISIBLE_DEVICES mask above): the UI built the
+                    # --tensor-split list in ascending physical/PCI index order,
+                    # so pin the child's enumeration to that order too. The whole
+                    # visible set stays in use; only its ordering is fixed.
+                    self._pin_visible_gpu_order_for_split(env)
 
                 # Captured before any text-only fallback strips it from cmd.
                 launched_with_mmproj = "--mmproj" in cmd
@@ -6936,7 +8131,7 @@ class LlamaCppBackend:
                 # 'on') even when -ngl is explicit. That step has aborted on
                 # some ROCm hosts (ggml-cuda.cu ROCm error during worst-case
                 # estimation, e.g. MTP + mmproj models on gfx1151). When
-                # Studio's own VRAM math already placed the model
+                # Unsloth's own VRAM math already placed the model
                 # (use_fit=False), the step is redundant second-guessing --
                 # retry once with --fit off before declaring the load failed.
                 # Never retry when fit was requested (use_fit) or the caller
@@ -7019,7 +8214,7 @@ class LlamaCppBackend:
                             and _startup_crashed
                             and not _split_axis_crash
                         ):
-                            # We forced --fit off because Studio's (conservative) VRAM
+                            # We forced --fit off because Unsloth's (conservative) VRAM
                             # math placed the model fully on GPU. A startup crash here
                             # means that estimate was optimistic, so fall back to --fit
                             # on and let llama.cpp offload rather than fail the load.
@@ -7031,7 +8226,7 @@ class LlamaCppBackend:
                                 self._process.returncode,
                                 self._llama_log_path,
                             )
-                            # Flip Studio's own --fit off (added first, before any
+                            # Flip Unsloth's own --fit off (added first, before any
                             # user extra args) to on; a user's later --fit still wins
                             # by last-arg. Defensive: if absent, the default is already
                             # --fit on, so leave it.
@@ -7048,7 +8243,7 @@ class LlamaCppBackend:
                         ):
                             logger.warning(
                                 "llama-server crashed during startup (exit code %s) "
-                                "with the default memory-fit step enabled; Studio "
+                                "with the default memory-fit step enabled; Unsloth "
                                 "already verified the model fits, retrying once "
                                 "with --fit off. Crash log: %s",
                                 self._process.returncode,
@@ -7085,7 +8280,6 @@ class LlamaCppBackend:
                 self._effective_context_length = (
                     effective_ctx if effective_ctx > 0 else self._context_length
                 )
-                self._reconcile_effective_ctx_with_server()
                 self._max_context_length = (
                     max_available_ctx if max_available_ctx > 0 else self._effective_context_length
                 )
@@ -7128,7 +8322,7 @@ class LlamaCppBackend:
                         cmd = _fa_cmd
                         healthy = _spawn_and_wait(_fa_cmd, label = "-noflash")
 
-                # MTP from Studio's spec flags or the user's (extra_args
+                # MTP from Unsloth's spec flags or the user's (extra_args
                 # --spec-type / LLAMA_ARG_SPEC_TYPE). The env reaches the child
                 # only when neither emits a spec flag, so consult it only then.
                 _launch_spec_env: Mapping[str, str] = (
@@ -7252,24 +8446,34 @@ class LlamaCppBackend:
                     self._kill_process()
                     # The #6415 split-axis abort is latched earlier (first spawn).
                     # Skip if a cancel/unload is pending (mirrors the MTP guard).
+                    _projector_msg = self._is_projector_incompatibility(out)
+                    _signal_mmproj_guess = self._is_signal_crash(
+                        _crash_rc
+                    ) and not self._output_has_nonprojector_diagnostic(out)
                     if (
                         launched_with_mmproj
                         and not self._cancel_event.is_set()
-                        and (
-                            self._is_projector_incompatibility(out)
-                            or (
-                                self._is_signal_crash(_crash_rc)
-                                and not self._output_has_nonprojector_diagnostic(out)
-                            )
-                        )
+                        and (_projector_msg or _signal_mmproj_guess)
                     ):
-                        logger.warning(
-                            "llama-server could not load this model's vision "
-                            "projector (--mmproj). The installed llama.cpp build is "
-                            "likely too old for it. Loading text-only for this "
-                            "session; run 'unsloth studio update' to enable vision."
-                        )
+                        if _projector_msg:
+                            logger.warning(
+                                "llama-server could not load this model's vision "
+                                "projector (--mmproj). The installed llama.cpp build is "
+                                "likely too old for it. Loading text-only for this "
+                                "session; run 'unsloth studio update' to enable vision."
+                            )
+                        else:
+                            logger.warning(
+                                "llama-server crashed while loading this model's vision "
+                                "projector (--mmproj). Retrying text-only for this "
+                                "session; if this persists, run 'unsloth studio update' "
+                                "or check GPU/driver logs."
+                            )
                         cmd = self._strip_mmproj_args(_last_spawn_cmd)
+                        # This retry bypasses _spawn_and_wait, so refresh the
+                        # launched-argv snapshot itself -- the zero-offload
+                        # classification below must not see the stripped --mmproj.
+                        _last_spawn_cmd = list(cmd)
                         self._is_vision = False
                         self._mmproj_has_audio = False
                         self._start_llama_process(cmd, env)
@@ -7278,14 +8482,30 @@ class LlamaCppBackend:
                             # an OS-killed text-only retry still gets the OOM message.
                             _retry_rc = self._process.poll() if self._process is not None else None
                             self._kill_process()
+                            # If the text-only retry ALSO hard-crashed (a signal, not
+                            # OOM/timeout), the vision projector was never the cause:
+                            # llama-server is faulting during GPU/driver init. Say so
+                            # -- with the ROCm fix -- instead of blaming the mmproj.
+                            if self._is_signal_crash(_retry_rc):
+                                raise RuntimeError(
+                                    "llama-server crashed at startup on both the vision "
+                                    "and text-only attempts -- a GPU driver/runtime "
+                                    "initialization crash, not a model or vision-projector "
+                                    "problem. This often means an unsupported secondary "
+                                    "GPU; on AMD/ROCm, hide it with ROCR_VISIBLE_DEVICES "
+                                    "(e.g. ROCR_VISIBLE_DEVICES=0 exposes only the first "
+                                    "GPU) before launching Unsloth Studio."
+                                )
+                            _retry_detail = self._classify_llama_start_failure(
+                                "\n".join(self._stdout_lines[-50:]),
+                                gguf_path,
+                                self._model_identifier,
+                                _retry_rc,
+                            )
                             raise RuntimeError(
-                                "Vision projector incompatible with this llama.cpp "
-                                "build, and the text-only retry also failed: "
-                                + self._classify_llama_start_failure(
-                                    "\n".join(self._stdout_lines[-50:]),
-                                    gguf_path,
-                                    self._model_identifier,
-                                    _retry_rc,
+                                self._mmproj_retry_failure_message(
+                                    projector_confirmed = _projector_msg,
+                                    detail = _retry_detail,
                                 )
                             )
                     else:
@@ -7301,6 +8521,13 @@ class LlamaCppBackend:
                 self._healthy = True
                 self._commit_effective_parallel_slots(n_parallel)
 
+                # Server is up: adopt the real per-request context it allocated
+                # -- the length --fit chose, or a --parallel slot split -- so the
+                # reported context_length matches reality. (Querying /props
+                # before the spawn above always failed; the seeded value was the
+                # requested/native length.)
+                self._reconcile_effective_ctx_with_server()
+
                 # Commit caller intent only after _healthy=True so a failed start
                 # can't poison the next inheritance check. None keeps prior, []
                 # clears, list sets. Source records hf_variant for the route's
@@ -7315,18 +8542,31 @@ class LlamaCppBackend:
                 self._mtp_runtime_fallback_active = _mtp_active_for_launched_server
                 self._start_mtp_crash_watchdog()
 
-                # Catch silent CPU fallback when GPU was intended (#5106).
-                self._gpu_offload_active = self._classify_gpu_offload(
-                    gpu_indices is not None or use_fit, gpus or []
-                )
-                if self._gpu_offload_active is False:
+                # Catch silent CPU fallback when GPU was intended (#5106). Manual
+                # offload (no picker) leaves gpu_indices None and use_fit False, so
+                # include its GPU-layer intent; use the preserved probe since
+                # auto-layers/manual empty `gpus`. A deliberate zero-offload load
+                # classifies by its launched argv instead: the main model is
+                # CPU-only by construction and must read False (not None), or
+                # training needlessly unloads a server holding no VRAM.
+                _deliberate_cpu_only = gpu_memory_mode == "manual" and gpu_layers == 0
+                if _deliberate_cpu_only:
+                    self._gpu_offload_active = self._zero_offload_gpu_flag(
+                        _last_spawn_cmd, _detected_gpus, env
+                    )
+                else:
+                    self._gpu_offload_active = self._classify_gpu_offload(
+                        gpu_indices is not None or use_fit or gpu_memory_mode == "manual",
+                        _detected_gpus,
+                    )
+                if self._gpu_offload_active is False and not _deliberate_cpu_only:
                     logger.warning(
                         "llama-server appears to have loaded the model entirely "
-                        "on CPU even though Studio detected at least one GPU. "
+                        "on CPU even though Unsloth detected at least one GPU. "
                         "This usually means the prebuilt binary's GPU backend "
                         "failed to load -- on Windows, cudart64_X.dll / "
                         "cublas64_X.dll could not be resolved. Reinstall the "
-                        "Studio llama.cpp prebuilt or install a matching CUDA "
+                        "Unsloth llama.cpp prebuilt or install a matching CUDA "
                         "toolkit (issue unslothai/unsloth#5106).",
                     )
 
@@ -7362,6 +8602,15 @@ class LlamaCppBackend:
 
             if not self._healthy:
                 return False
+            # Snapshot the files the server actually loaded. If a GGUF shard or a
+            # LoRA/control-vector sidecar is swapped on disk afterwards while the
+            # old weights stay mapped, save_slots_for_resume() compares against
+            # this and refuses to persist KV that a reload could misapply.
+            if self._slot_save_dir:
+                self._slot_loaded_identity = (
+                    self._gguf_file_identity(self._gguf_path),
+                    self._slot_launch_fingerprint(),
+                )
             return True
 
     def _build_speculative_flags(
@@ -7486,18 +8735,29 @@ class LlamaCppBackend:
             caps = self.probe_server_capabilities(binary)
             mtp_token = caps.get("mtp_token") if caps else None
             if not mtp_token:
-                logger.warning(
-                    "Requested MTP speculative decoding but "
-                    "llama-server lacks --spec-type mtp/draft-mtp; "
-                    "run `unsloth studio update`. Loading without "
-                    "speculative decoding."
-                )
+                inconclusive = bool(caps.get("mtp_probe_inconclusive")) if caps else True
+                if inconclusive:
+                    logger.info(
+                        "Requested MTP speculative decoding but llama-server MTP "
+                        "capability probe was inconclusive; loading without "
+                        "speculative decoding."
+                    )
+                else:
+                    logger.warning(
+                        "Requested MTP speculative decoding but "
+                        "llama-server lacks --spec-type mtp/draft-mtp; "
+                        "run `unsloth studio update`. Loading without "
+                        "speculative decoding."
+                    )
                 # Override an inherited LLAMA_ARG_SPEC_TYPE=draft-mtp (CLI wins
                 # over env) so the child matches the binary-capability gate and
                 # the no-MTP budget, like the sibling no-head/non-MTP fallbacks.
                 flags.append("--spec-default")
                 self._speculative_type = "default"
-                self._spec_fallback_reason = "binary_no_mtp"
+                if inconclusive:
+                    self._spec_fallback_reason = None
+                else:
+                    self._spec_fallback_reason = "binary_no_mtp"
                 return False
             draft_n_max = _resolved_draft_n_max()
             n_max_flag = caps.get("spec_draft_n_max_flag") or "--spec-draft-n-max"
@@ -7623,7 +8883,7 @@ class LlamaCppBackend:
                 logger.info(
                     "Auto: MLA embedded-MTP model detected; llama.cpp's MLA/DSA "
                     "MTP path is slower than no speculation, so using ngram-mod "
-                    "instead. Override via the Studio Speculative Decoding "
+                    "instead. Override via the Unsloth Speculative Decoding "
                     "dropdown or UNSLOTH_MLA_MTP_ENABLED=1."
                 )
                 _emit_ngram_mod()
@@ -7651,7 +8911,7 @@ class LlamaCppBackend:
                     f"MTP GGUF detected but model size {_mtp_size_b:.1f}B "
                     "is below the 3B speedup threshold; using ngram-mod "
                     "only (zero-VRAM, no draft head). Override via "
-                    "--spec-type or the Studio Speculative Decoding "
+                    "--spec-type or the Unsloth Speculative Decoding "
                     "dropdown."
                 )
                 _emit_ngram_mod()
@@ -7682,6 +8942,11 @@ class LlamaCppBackend:
         gguf_path: Optional[str] = None,
         spec_draft_n_max: Optional[int] = None,
         tensor_parallel: bool = False,
+        gpu_memory_mode: Literal["auto", "manual"] = "auto",
+        gpu_layers: int = -1,
+        n_cpu_moe: int = 0,
+        tensor_split: Optional[List[float]] = None,
+        gpu_ids: Optional[List[int]] = None,
         mtp_draft_path: Optional[str] = None,
         preserve_multi_gpu_on_layer: bool = False,
     ) -> bool:
@@ -7738,6 +9003,32 @@ class LlamaCppBackend:
         ):
             return False
 
+        # The diffusion runner is mode-agnostic (always "auto", ignores the
+        # layer/MoE/split knobs), so a standing manual preference in the
+        # request must not force a needless reload -- only the GPU pick matters.
+        if not self._is_diffusion:
+            # A GPU-memory-mode flip (Unsloth / manual) must always reload.
+            if self._gpu_memory_mode != gpu_memory_mode:
+                return False
+            # Manual: a layer-count change always reloads (covers Auto(-1) <-> a
+            # pinned count); MoE/split only matter with an explicit offload.
+            if gpu_memory_mode == "manual" and (
+                self._gpu_layers != gpu_layers
+                or (
+                    gpu_layers >= 0
+                    and (
+                        self._n_cpu_moe != n_cpu_moe
+                        or (self._tensor_split or None) != (tensor_split or None)
+                    )
+                )
+            ):
+                return False
+        # A changed GPU pick must reload. Regular GGUF accepts either the raw
+        # requested placement pool or the effective status-echoed subset;
+        # diffusion compares its normalized single-device pick.
+        if not self.matches_gpu_ids(gpu_ids):
+            return False
+
         # Compare on the canonical requested mode. With --spec-type in
         # extra_args the backend stores None; mirror that here.
         if _extra_args_set_spec_type(extra_args):
@@ -7793,6 +9084,7 @@ class LlamaCppBackend:
             current = list(self._extra_args) if self._extra_args is not None else []
             if list(extra_args) != current:
                 return False
+        self._record_matching_gpu_request(gpu_ids)
         return True
 
     def _classify_gpu_offload(
@@ -7806,6 +9098,78 @@ class LlamaCppBackend:
             return None
         return classify_gpu_offload_lines(self._stdout_lines)
 
+    @staticmethod
+    def _cmd_has_gpu_companion(cmd: list, env: Optional[Mapping[str, str]] = None) -> bool:
+        """True when the argv/env carries a GPU companion: any --mmproj form, or
+        a drafter (Studio's --model-draft, the extras aliases, or the
+        LLAMA_ARG_SPEC_DRAFT_* env) -- these offload to the GPU regardless of
+        the main ``--gpu-layers``. A drafter explicitly forced to CPU
+        (--spec-draft-ngl 0 / --spec-draft-device cpu) doesn't count."""
+        if any(str(a).startswith("--mmproj") for a in cmd):
+            return True
+        if _extra_args_mtp_draft_path(cmd, env) is None:
+            return False
+        return not _extra_args_draft_offloaded_to_cpu(cmd, env)
+
+    @staticmethod
+    def _zero_offload_keeps_gpu_visible(cmd: list, env: Optional[Mapping[str, str]] = None) -> bool:
+        """Whether a zero-layer launch still has a reason to use visible GPUs.
+
+        Keep this shared by child masking and post-launch residency bookkeeping:
+        a device pin, surviving tensor mode, mmproj, or GPU drafter prevents the
+        launch from being a confirmed zero-VRAM server.
+        """
+        return (
+            LlamaCppBackend._cmd_has_gpu_device_pin(cmd, env)
+            or _effective_tensor_parallel(cmd, False, env)
+            or LlamaCppBackend._cmd_has_gpu_companion(cmd, env)
+        )
+
+    @staticmethod
+    def _cmd_has_gpu_device_pin(cmd: list, env: Optional[Mapping[str, str]] = None) -> bool:
+        """True when the effective main or draft ``--device`` pin names a GPU."""
+        main_flags = {"--device", "-dev"}
+        draft_flags = {"--spec-draft-device", "-devd", "--device-draft"}
+        last_main: Optional[str] = None
+        last_draft: Optional[str] = None
+        args = [str(arg) for arg in cmd]
+        for index, raw in enumerate(args):
+            flag, equals, inline = raw.partition("=")
+            if flag not in main_flags and flag not in draft_flags:
+                continue
+            value = inline if equals else (args[index + 1] if index + 1 < len(args) else "")
+            if flag in main_flags:
+                last_main = value
+            else:
+                last_draft = value
+        if last_main is None:
+            last_main = (env or {}).get("LLAMA_ARG_DEVICE")
+
+        def _names_gpu(value: Optional[str]) -> bool:
+            if value is None:
+                return False
+            devices = [item.strip().lower() for item in value.split(",") if item.strip()]
+            return not devices or any(item not in ("cpu", "none") for item in devices)
+
+        return _names_gpu(last_main) or _names_gpu(last_draft)
+
+    @staticmethod
+    def _zero_offload_gpu_flag(
+        spawn_cmd: list,
+        detected_gpus: list,
+        env: Optional[Mapping[str, str]] = None,
+    ) -> Optional[bool]:
+        """GPU-residency flag for a deliberate manual zero-offload load. The
+        main model is CPU-only by construction, but device pins, tensor mode,
+        mmproj, and GPU drafters can still make the server hold VRAM. The counted
+        offload classifier cannot see those allocations. This uses the same
+        predicate as the launch-time zero-VRAM mask; None means no GPU signal."""
+        if not detected_gpus:
+            return None
+        if LlamaCppBackend._is_vulkan_backend():
+            return True
+        return LlamaCppBackend._zero_offload_keeps_gpu_visible(spawn_cmd, env)
+
     def load_cancelled(self) -> bool:
         """True if a load was cancelled (e.g. via unload/_cancel_event) and not
         yet consumed by the next load_model. Lets the tensor->layer fallback
@@ -7838,6 +9202,10 @@ class LlamaCppBackend:
             self._effective_context_length = None
             self._max_context_length = None
             self._reset_effective_parallel_slots()
+            self._slot_save_dir = None
+            self._slot_save_binary = None
+            self._slot_loaded_identity = None
+            self._prompt_cache_disabled = False
             self._chat_template = None
             self._chat_template_override = None
             self._supports_reasoning = False
@@ -7848,12 +9216,22 @@ class LlamaCppBackend:
             self._supports_preserve_thinking = False
             self._supports_tools = False
             self._cache_type_kv = None
+            # GPU-pin state describes the active runner only; clear it so an explicit
+            # pin never leaks into the next (or diffusion) runner.
+            self._gpu_ids = None
+            self._requested_gpu_ids = None
             self._tensor_parallel = False
+            self._gpu_memory_mode = "auto"
+            self._gpu_layers = -1
+            self._n_cpu_moe = 0
+            self._tensor_split = None
             self._layer_preserves_tensor_intent = False
             self._speculative_type = None
             self._requested_spec_mode = None
             self._spec_draft_n_max = None
             self._n_layers = None
+            self._n_experts = None
+            self._leading_dense_block_count = None
             self._n_kv_heads = None
             self._n_kv_heads_by_layer = None
             self._n_heads = None
@@ -7916,6 +9294,10 @@ class LlamaCppBackend:
             # Clear healthy so a /load during the replacement's warm-up can't
             # short-circuit against the previous server's health (#5401).
             self._healthy = False
+            # Reset to unknown so the training guard treats the next (still
+            # loading) server as VRAM-resident rather than reading the killed
+            # server's stale zero-offload flag until the health probe reclassifies.
+            self._gpu_offload_active = None
             # Drives _wait_for_vram_settle in the next load_model; set in finally
             # so both in-process and frontend Apply paths record the kill.
             self._last_kill_monotonic = time.monotonic()
@@ -8029,7 +9411,7 @@ class LlamaCppBackend:
     def _pid_parent_is_alive(pid: int) -> bool:
         """True if the recorded server's parent is still running, i.e. the server is
         NOT orphaned. Lets the cross-session reap kill only a true orphan (parent
-        gone) and never a live server owned by a running Studio, regardless of which
+        gone) and never a live server owned by a running Unsloth, regardless of which
         process performs the sweep. Biased toward "alive" on uncertainty so a live
         server is never mistakenly reaped."""
         try:
@@ -8069,9 +9451,9 @@ class LlamaCppBackend:
     @classmethod
     def _reap_recorded_pid(cls) -> int:
         """Kill the exact llama-server PID recorded at spawn, but only when it is a
-        genuine orphan -- its parent (the Studio that spawned it) is gone. This is
+        genuine orphan -- its parent (the Unsloth that spawned it) is gone. This is
         the cross-session backstop the parent-death reaper (Job Object /
-        PR_SET_PDEATHSIG) cannot cover: an orphan left by an already-dead Studio
+        PR_SET_PDEATHSIG) cannot cover: an orphan left by an already-dead Unsloth
         (macOS, a best-effort failure, or a pre-existing orphan). Path-independent,
         so it also catches an orphan the install-root match would miss.
 
@@ -8128,7 +9510,7 @@ class LlamaCppBackend:
         """Kill orphaned llama-server processes started by studio.
 
         Only kills processes whose resolved binary lives under a known
-        Studio install dir (or matches an exact env-var override), to avoid
+        Unsloth install dir (or matches an exact env-var override), to avoid
         terminating unrelated llama-server instances. Mirrors every location
         _find_llama_server_binary() can return, so orphans from any
         supported install path are cleaned up.
@@ -8148,7 +9530,7 @@ class LlamaCppBackend:
         try:
             # -- Build the ownership allowlist --------------------------------
             # exact_binaries -- env var overrides (exact path match).
-            # install_roots  -- Studio-owned dir trees (binary must be under one).
+            # install_roots  -- Unsloth-owned dir trees (binary must be under one).
             install_roots: list[Path] = []
 
             # Env-mode custom root (mirrors _find_llama_server_binary).
@@ -8158,7 +9540,7 @@ class LlamaCppBackend:
                 install_roots.append(_resolved_sr / "llama.cpp")
 
             # Primary install dir (default mode only). Env-mode skips this so a
-            # custom-root Studio can't kill a default-install Studio's server.
+            # custom-root Unsloth can't kill a default-install Unsloth's server.
             if not _is_custom_root:
                 install_roots.append(Path.home() / ".unsloth" / "llama.cpp")
 
@@ -8232,7 +9614,7 @@ class LlamaCppBackend:
                         if not is_ours:
                             continue
 
-                        # A live parent means a running Studio (or the user's
+                        # A live parent means a running Unsloth (or the user's
                         # shell) still owns it -- not an orphan.
                         if LlamaCppBackend._pid_parent_is_alive(proc.info["pid"]):
                             continue
@@ -8312,7 +9694,7 @@ class LlamaCppBackend:
     def _fit_off_retry_eligible(cmd: "list[str]", use_fit: bool) -> bool:
         """Whether a llama-server startup crash may be retried with --fit off.
 
-        Only when Studio's own VRAM math placed the model (use_fit=False)
+        Only when Unsloth's own VRAM math placed the model (use_fit=False)
         and nothing on the command line set the fit mode explicitly
         (-fit / --fit, space- or equals-form). --fit-ctx / --fit-target /
         -fitc / -fitt tune the fit step but do not select the mode, so
@@ -8353,6 +9735,237 @@ class LlamaCppBackend:
             return False
         return True
 
+    def _slot_launch_fingerprint(self) -> tuple:
+        # KV validity keys on extra args, stat'd sidecar weights, effective ctx.
+        sidecars = []
+        for path in self._sidecar_weight_files():
+            try:
+                st = os.stat(path)
+                sidecars.append((path, st.st_size, st.st_mtime_ns))
+            except OSError:
+                sidecars.append((path, None, None))
+        return (
+            tuple(self._extra_args or ()),
+            tuple(sidecars),
+            self._requested_n_ctx,
+            self._effective_context_length,
+            getattr(self, "_cache_type_kv", None),
+            self.effective_parallel_slots,
+        )
+
+    def _gguf_file_identity(self, path) -> Optional[tuple]:
+        # (size, mtime_ns) per shard: a split GGUF keys KV validity on every sibling.
+        p = Path(path)
+        paths = [p]
+        m = _SHARD_FULL_RE.match(p.name)
+        if m:
+            prefix, _first, total = m.groups()
+            paths = [
+                p.with_name(f"{prefix}-{i:05d}-of-{total}{p.suffix}")
+                for i in range(1, int(total) + 1)
+            ]
+        try:
+            return tuple((sp.stat().st_size, sp.stat().st_mtime_ns) for sp in paths)
+        except OSError:
+            return None
+
+    _SIDECAR_WEIGHT_FLAGS = (
+        "--lora",
+        "--lora-scaled",
+        "--control-vector",
+        "--control-vector-scaled",
+    )
+
+    def _sidecar_weight_files(self) -> list[str]:
+        # llama.cpp: comma-separated paths, FNAME:SCALE on -scaled (older builds: FNAME SCALE).
+        args = [str(a).strip() for a in (self._extra_args or ())]
+        files: list[str] = []
+        for i, arg in enumerate(args):
+            flag, sep, inline = arg.partition("=")
+            if flag not in self._SIDECAR_WEIGHT_FLAGS:
+                continue
+            operand = inline if sep else (args[i + 1] if i + 1 < len(args) else "")
+            if not operand:
+                continue
+            candidates = [operand]
+            pieces = [p for p in operand.split(",") if p]
+            if len(pieces) > 1:
+                candidates.extend(pieces)
+            if flag.endswith("-scaled"):
+                for item in list(candidates):
+                    # ":<number>" tail is a scale; rpartition spares drive letters.
+                    head, colon, tail = item.rpartition(":")
+                    if not (colon and head):
+                        continue
+                    try:
+                        float(tail)
+                    except ValueError:
+                        continue
+                    candidates.append(head)
+            for cand in candidates:
+                if cand not in files:
+                    files.append(cand)
+        return files
+
+    def _prompt_cache_off(self) -> bool:
+        # Caching off makes restores useless; last prompt-cache flag wins, env only when unset.
+        last = None
+        for arg in self._extra_args or ():
+            flag = arg.strip().split("=", 1)[0]
+            if flag in ("--cache-prompt", "--no-cache-prompt"):
+                last = flag
+        if last is not None:
+            return last == "--no-cache-prompt"
+        if self._prompt_cache_disabled:
+            return True
+        if os.environ.get("LLAMA_ARG_NO_CACHE_PROMPT") is not None:
+            return True
+        env = (os.environ.get("LLAMA_ARG_CACHE_PROMPT") or "").strip().lower()
+        return env in {"off", "disabled", "false", "0"}
+
+    def save_slots_for_resume(
+        self, should_abort: Optional[Callable[[], bool]] = None
+    ) -> Optional[dict]:
+        if (
+            not self.is_loaded
+            or not self._slot_save_dir
+            or not self._gguf_path
+            or self._prompt_cache_off()
+        ):
+            return None
+        save_dir = Path(self._slot_save_dir)
+        gguf_stat = self._gguf_file_identity(self._gguf_path)
+        if gguf_stat is None:
+            return None
+        launch = self._slot_launch_fingerprint()
+        # If the GGUF or a sidecar was swapped on disk while the original weights
+        # stayed mapped, the live KV belongs to the old weights but a reload would
+        # load the new file. Persisting it would let restore misapply stale KV.
+        if self._slot_loaded_identity is not None and self._slot_loaded_identity != (
+            gguf_stat,
+            launch,
+        ):
+            logger.debug("Skipping slot save: model files changed on disk since load")
+            return None
+        try:
+            estimate = self._estimate_kv_cache_bytes(
+                self._effective_context_length or self._context_length or 0,
+                self._cache_type_kv,
+                n_parallel = self.effective_parallel_slots,
+            )
+            # Skip before writing anything when the estimate alone blows the cap,
+            # rather than fully writing a slot and discarding it afterwards.
+            if estimate > _SLOT_SAVE_MAX_BYTES:
+                logger.debug(
+                    "Skipping slot save: estimated %d bytes exceeds cap %d",
+                    estimate,
+                    _SLOT_SAVE_MAX_BYTES,
+                )
+                return None
+            # A 0 estimate means metadata was insufficient, not a zero-byte cache:
+            # a slot can still be many GiB, so demand room for the whole cap before
+            # trusting the post-write check.
+            required = (estimate if estimate > 0 else _SLOT_SAVE_MAX_BYTES) + (1 << 30)
+            if shutil.disk_usage(save_dir).free < required:
+                logger.debug("Skipping slot save: insufficient free disk")
+                return None
+        except Exception:
+            pass
+        token = uuid.uuid4().hex[:8]
+        entries: list[dict] = []
+        total_bytes = 0
+        for slot in range(self.effective_parallel_slots):
+            # A request pending mid-save waits on the gate; stop wasting its time.
+            if should_abort is not None and should_abort():
+                break
+            filename = f"resume-{token}-slot{slot}.bin"
+            path = save_dir / filename
+            try:
+                resp = httpx.post(
+                    f"{self.base_url}/slots/{slot}",
+                    params = {"action": "save"},
+                    json = {"filename": filename},
+                    headers = self._auth_headers,
+                    timeout = _SLOT_SAVE_HTTP_TIMEOUT,
+                    trust_env = False,
+                )
+            except Exception as e:
+                logger.debug(f"slot {slot} save failed: {e}")
+                with contextlib.suppress(OSError):
+                    path.unlink()
+                break
+            if resp.status_code != 200:
+                logger.debug(f"slot {slot} save returned HTTP {resp.status_code}")
+                with contextlib.suppress(OSError):
+                    path.unlink()
+                continue
+            try:
+                body = resp.json()
+                if not isinstance(body, dict):
+                    raise ValueError("slot save response was not a JSON object")
+                n_saved = int(body.get("n_saved") or 0)
+            except Exception as e:
+                # A 200 that still wrote a file but returns a malformed body must
+                # clean up like the transport/HTTP error paths above, or the file
+                # (which holds chat KV) is orphaned until the next startup sweep.
+                logger.debug(f"slot {slot} save returned an invalid response: {e}")
+                with contextlib.suppress(OSError):
+                    path.unlink()
+                continue
+            if n_saved <= 0:
+                with contextlib.suppress(OSError):
+                    path.unlink()
+                continue
+            # Account by the bytes actually on disk, not the server-reported
+            # count, so the cap holds even if a custom binary under-reports.
+            try:
+                n_written = path.stat().st_size
+            except OSError:
+                n_written = 0
+            total_bytes += n_written
+            entries.append({"id": slot, "filename": filename, "n_saved": n_saved})
+            if total_bytes > _SLOT_SAVE_MAX_BYTES:
+                break  # already over the cap; the discard below cleans up
+        if not entries:
+            return None
+        if total_bytes > _SLOT_SAVE_MAX_BYTES:
+            logger.debug(
+                "Discarding slot save: %d bytes exceeds cap %d",
+                total_bytes,
+                _SLOT_SAVE_MAX_BYTES,
+            )
+            for entry in entries:
+                with contextlib.suppress(OSError):
+                    (save_dir / entry["filename"]).unlink()
+            return None
+        return {
+            "dir": self._slot_save_dir,
+            "binary": self._slot_save_binary,
+            "gguf": str(self._gguf_path),
+            "gguf_stat": gguf_stat,
+            "launch": launch,
+            "slots": entries,
+        }
+
+    def restore_slots_for_resume(self, manifest: dict) -> None:
+        if not self.is_loaded or not self._slot_save_dir:
+            return
+        for entry in manifest.get("slots") or []:
+            try:
+                resp = httpx.post(
+                    f"{self.base_url}/slots/{int(entry['id'])}",
+                    params = {"action": "restore"},
+                    json = {"filename": str(entry["filename"])},
+                    headers = self._auth_headers,
+                    timeout = _SLOT_SAVE_HTTP_TIMEOUT,
+                    trust_env = False,
+                )
+            except Exception as e:
+                logger.debug(f"slot restore failed: {e}")
+                break
+            if resp.status_code != 200:
+                logger.debug(f"slot {entry.get('id')} restore returned HTTP {resp.status_code}")
+
     def _maybe_recover_from_mtp_crash(self, exc: Optional[BaseException] = None) -> bool:
         """Schedule one background reload without MTP after a mid-generation death.
 
@@ -8520,7 +10133,12 @@ class LlamaCppBackend:
 
     @staticmethod
     def _ctx_integrity_flags(
-        n_parallel: int, use_fit: bool, requested_ctx: int, effective_ctx: int, caps: dict
+        n_parallel: int,
+        use_fit: bool,
+        auto_fit: bool,
+        requested_ctx: int,
+        effective_ctx: int,
+        caps: dict,
     ) -> list[str]:
         """Flags that keep the per-request window equal to the advertised ctx.
 
@@ -8528,14 +10146,28 @@ class LlamaCppBackend:
         ``--kv-unified`` default, silently splitting ``-c`` into per-slot
         windows of ``-c / N``; restore the shared pool so one request can use
         the full context. With ``--fit on``, ``--fit-ctx`` floors the fit step
-        at an explicitly requested ctx (default floor is 4096) so it offloads
-        or fails instead of silently shrinking the window.
+        at an explicitly requested ctx so it offloads or fails instead of
+        silently shrinking the window. The 8192 auto-floor and the tighter
+        ``--fit-target`` margin apply only under Manual + Auto (``auto_fit``),
+        which omits ``-c``: on the legacy auto path ``-c 0`` already pins the
+        native window and ``--fit-ctx 8192`` would override it down to 8192.
         """
         flags: list[str] = []
         if n_parallel > 1 and caps.get("supports_kv_unified"):
             flags.append("--kv-unified")
-        if use_fit and requested_ctx > 0 and effective_ctx > 0 and caps.get("supports_fit_ctx"):
-            flags.extend(["--fit-ctx", str(effective_ctx)])
+        if use_fit and caps.get("supports_fit_ctx"):
+            if requested_ctx > 0 and effective_ctx > 0:
+                # Floor the fit step at the explicitly requested ctx.
+                flags.extend(["--fit-ctx", str(effective_ctx)])
+            elif auto_fit:
+                # Manual + Auto omits -c, so floor at 8192 so --fit doesn't
+                # shrink the window below a usable size.
+                flags.extend(["--fit-ctx", "8192"])
+        if use_fit and auto_fit and caps.get("supports_fit_target"):
+            # llama.cpp's --fit leaves 1 GiB free per device by default;
+            # tighten that to 512 MiB so it packs more of the model onto
+            # the GPU before spilling to system RAM.
+            flags.extend(["--fit-target", "512"])
         return flags
 
     def _query_server_n_ctx(self) -> Optional[int]:
@@ -8556,7 +10188,7 @@ class LlamaCppBackend:
             return None
 
     def _reconcile_effective_ctx_with_server(self) -> None:
-        """Adopt the server's real ``n_ctx`` when it is below Studio's value.
+        """Adopt the server's real ``n_ctx`` when it is below Unsloth's value.
 
         Keeps ``context_length`` (load response, status route, passthrough
         ``max_tokens`` ceiling) honest; clients sized to the requested value
@@ -8732,6 +10364,75 @@ class LlamaCppBackend:
         except Exception:
             logger.debug("Could not close httpx client", exc_info = True)
 
+    @staticmethod
+    def _install_cancel_aware_read(
+        client: "httpx.Client",
+        cancel_event: threading.Event,
+        response: Optional["httpx.Response"] = None,
+        poll_s: float = 0.2,
+    ) -> None:
+        """Wrap the httpcore stream so the reader interrupts its own blocked recv() on cancel.
+
+        A cross-thread socket shutdown wakes a parked recv() on POSIX but not on
+        Windows (Winsock), so read in short slices and poll cancel_event between them
+        (plain or TLS); slice timeouts are swallowed so a slow-but-alive stream survives.
+        httpcore snapshots request.extensions["timeout"]["read"] once at body start, so
+        given ``response`` we re-read the live value per call to honor the post-first-token
+        stall timeout instead of the long prefill timeout."""
+        import httpcore
+
+        def _live_read_timeout() -> Optional[float]:
+            if response is None:
+                return None
+            try:
+                ext = response.request.extensions.get("timeout")
+                if isinstance(ext, dict):
+                    value = ext.get("read")
+                    if isinstance(value, (int, float)):
+                        return float(value)
+            except Exception:
+                pass
+            return None
+
+        try:
+            pool = getattr(getattr(client, "_transport", None), "_pool", None)
+            for connection in list(getattr(pool, "_connections", []) or []):
+                inner = getattr(connection, "_connection", None)
+                stream = getattr(inner, "_network_stream", None)
+                if stream is None or getattr(stream, "_unsloth_cancel_wrapped", False):
+                    continue
+                orig_read = stream.read
+
+                def read(
+                    max_bytes,
+                    timeout = None,
+                    _orig = orig_read,
+                ):
+                    live = _live_read_timeout()
+                    effective = live if live is not None else timeout
+                    deadline = None if effective is None else time.monotonic() + effective
+                    while True:
+                        if cancel_event.is_set():
+                            raise httpcore.ReadError("stream cancelled by user")
+                        if deadline is None:
+                            step = poll_s
+                        else:
+                            remaining = deadline - time.monotonic()
+                            if remaining <= 0:
+                                raise httpcore.ReadTimeout("read operation timed out")
+                            step = min(poll_s, remaining)
+                        try:
+                            return _orig(max_bytes, timeout = step)
+                        except httpcore.ReadTimeout:
+                            if deadline is not None and time.monotonic() >= deadline:
+                                raise
+                            continue  # slow but alive: keep reading
+
+                stream.read = read
+                stream._unsloth_cancel_wrapped = True
+        except Exception:
+            logger.debug("Could not install cancel-aware read", exc_info = True)
+
     @staticmethod
     @contextlib.contextmanager
     def _stream_with_retry(
@@ -8789,6 +10490,11 @@ class LlamaCppBackend:
                 headers = headers,
             ) as response:
                 _response_ref[0] = response
+                if cancel_event is not None:
+                    # Portable mid-stream cancel: the reader polls cancel itself, so
+                    # Stop interrupts a stalled read where the watcher's Windows socket
+                    # shutdown does not. Pass response to honor the live stall timeout.
+                    LlamaCppBackend._install_cancel_aware_read(client, cancel_event, response)
                 if cancel_event is not None and cancel_event.is_set():
                     raise _LlamaStreamCancelled
                 yield response
diff --git a/studio/backend/core/inference/llama_keepwarm.py b/studio/backend/core/inference/llama_keepwarm.py
index 4ce663c3ce..3380ebf5f5 100644
--- a/studio/backend/core/inference/llama_keepwarm.py
+++ b/studio/backend/core/inference/llama_keepwarm.py
@@ -15,6 +15,7 @@ import asyncio
 import contextlib
 import threading
 import time
+from pathlib import Path
 
 from loggers import get_logger
 
@@ -30,6 +31,8 @@ _last_active = time.monotonic()
 # otherwise 503 against an empty backend can reload it (set on unload, cleared on
 # reload). Storing the quant means the reload restores the exact freed variant.
 _last_unloaded_model = None
+# Slot KV manifest saved by the idle unload; whoever pops it owns deleting its files.
+_kv_resume = None
 # Guards inflight bumps against the idle-check-then-unload race, and blocks new
 # inference from starting mid-swap. Process-wide, not per-loop: the backend slot is
 # shared across every event loop in the process, so a per-loop gate would let a
@@ -59,7 +62,7 @@ _INFERENCE_SUFFIXES = (
     "/messages/count_tokens",  # counts via the loaded tokenizer; protect like /messages
     "/embeddings",
     "/responses",
-    "/generate/stream",  # Studio's own streaming route on the same llama-server
+    "/generate/stream",  # Unsloth's own streaming route on the same llama-server
     "/audio/generate",  # direct GGUF TTS; can outlive the idle TTL
 )
 
@@ -161,11 +164,17 @@ def inference_lifecycle_gate():
     return _unload_gate()
 
 
-def note_model_loaded() -> None:
-    """Record a successful GGUF load: stamp activity and drop any reload stash so
-    a manual load clears it synchronously, not only on the next idle poll."""
+def note_model_loaded(backend = None) -> None:
+    """Stamp activity and synchronously drop any reload stash."""
     _note_activity()
+    resume = take_kv_resume()
     _set_last_unloaded(None)
+    if resume is None:
+        return
+    if backend is not None:
+        restore_kv_resume(backend, resume)
+    else:
+        _delete_resume_files(resume)
 
 
 def note_model_unloaded() -> None:
@@ -182,9 +191,81 @@ def get_last_unloaded_model():
 
 
 def _set_last_unloaded(value) -> None:
-    global _last_unloaded_model
+    global _last_unloaded_model, _kv_resume
+    stale = None
     with _lock:
         _last_unloaded_model = value
+        if value is None and _kv_resume is not None:
+            stale, _kv_resume = _kv_resume, None
+    if stale:
+        _delete_resume_files(stale)
+
+
+def _delete_resume_files(manifest) -> None:
+    try:
+        base = Path(manifest.get("dir") or "")
+        for entry in manifest.get("slots") or []:
+            with contextlib.suppress(OSError):
+                (base / str(entry.get("filename"))).unlink()
+    except Exception:
+        pass
+
+
+def _set_kv_resume(value) -> None:
+    global _kv_resume
+    stale = None
+    with _lock:
+        if _kv_resume is not None and _kv_resume is not value:
+            stale = _kv_resume
+        _kv_resume = value
+    if stale:
+        _delete_resume_files(stale)
+
+
+def take_kv_resume():
+    global _kv_resume
+    with _lock:
+        manifest, _kv_resume = _kv_resume, None
+        return manifest
+
+
+def purge_kv_resume() -> None:
+    resume = take_kv_resume()
+    if resume:
+        _delete_resume_files(resume)
+
+
+def restore_kv_resume(backend, manifest) -> None:
+    try:
+        gguf = manifest.get("gguf")
+        binary = manifest.get("binary")
+        current = getattr(backend, "_gguf_path", None)
+        same_gguf = bool(gguf and current) and Path(current).resolve() == Path(gguf).resolve()
+        if same_gguf:
+            # Same path is not enough: shards may have been rewritten meanwhile.
+            identity = getattr(backend, "_gguf_file_identity", None)
+            same_gguf = callable(identity) and identity(current) == manifest.get("gguf_stat")
+        if same_gguf:
+            # Nor the same file: launch overrides can invalidate KV numerics.
+            fingerprint = getattr(backend, "_slot_launch_fingerprint", None)
+            same_gguf = callable(fingerprint) and manifest.get("launch") == fingerprint()
+        if same_gguf and binary and binary == getattr(backend, "_slot_save_binary", None):
+            logger.info("Restoring saved slot KV onto the reloaded model")
+            backend.restore_slots_for_resume(manifest)
+    except Exception as exc:
+        logger.debug("slot restore after reload failed: %s", exc)
+    finally:
+        _delete_resume_files(manifest)
+
+
+def sweep_slot_save_dir() -> None:
+    try:
+        from utils.paths.storage_roots import llama_slot_cache_root
+        for path in llama_slot_cache_root().glob("resume-*.bin"):
+            with contextlib.suppress(OSError):
+                path.unlink()
+    except Exception:
+        pass
 
 
 class LlamaKeepWarmMiddleware:
@@ -266,7 +347,10 @@ def _loaded_identity(backend):
 
 async def idle_unload_loop(poll_seconds: float = 15.0) -> None:
     """Unload the loaded GGUF once idle past the configured TTL. Inert when off."""
-    from utils.openai_auto_switch_settings import get_auto_unload_idle_seconds
+    from utils.openai_auto_switch_settings import (
+        get_auto_unload_idle_seconds,
+        get_auto_unload_keep_kv,
+    )
 
     seen_model = None
     while True:
@@ -281,17 +365,47 @@ async def idle_unload_loop(poll_seconds: float = 15.0) -> None:
             # Track by (id, variant): a (re)loaded model -- including the same repo
             # at a different quant -- counts as activity so it survives one TTL
             # before its first request (loads bypass the activity middleware).
-            current = _loaded_identity(backend)
-            if current != seen_model:
-                seen_model = current
-                if current is not None:
-                    _note_activity()
-                    _set_last_unloaded(None)  # a model is loaded; drop stale stash
             async with _unload_gate():
+                # Purging the stash mid-reload would race the restore.
+                current = _loaded_identity(backend)
+                if current != seen_model:
+                    seen_model = current
+                    if current is not None:
+                        _note_activity()
+                        _set_last_unloaded(None)  # a model is loaded; drop stale stash
                 if backend.is_loaded and _is_idle(ttl):
                     freed = _loaded_identity(backend)
-                    await asyncio.to_thread(backend.unload_model)
+                    manifest = None
+                    if get_auto_unload_keep_kv():
+                        try:
+                            manifest = await asyncio.to_thread(
+                                backend.save_slots_for_resume,
+                                lambda: not _is_idle(ttl),
+                            )
+                        except Exception as exc:
+                            logger.debug("slot save before idle unload failed: %s", exc)
+                    # Re-read settings: the save can outlive a settings change.
+                    ttl = get_auto_unload_idle_seconds()
+                    if ttl <= 0 or not _is_idle(ttl):
+                        if manifest:
+                            _delete_resume_files(manifest)
+                        continue
+                    if manifest and not get_auto_unload_keep_kv():
+                        _delete_resume_files(manifest)
+                        manifest = None
+                    try:
+                        await asyncio.to_thread(backend.unload_model)
+                    except Exception:
+                        # Failed unload means nothing will stash the manifest.
+                        if manifest:
+                            _delete_resume_files(manifest)
+                        raise
                     _set_last_unloaded(freed)  # let an alias request reload it
+                    if manifest and freed:
+                        _set_kv_resume({"identity": freed, **manifest})
+                        logger.info("Idle auto-unload: saved slot KV for restore on reload")
+                    elif manifest:
+                        _delete_resume_files(manifest)
                     logger.info("Idle auto-unload: freed GGUF after %ss idle", ttl)
                     seen_model = None
         except Exception as exc:
diff --git a/studio/backend/core/inference/llama_server_args.py b/studio/backend/core/inference/llama_server_args.py
index f400d2ae40..7b42d2f40d 100644
--- a/studio/backend/core/inference/llama_server_args.py
+++ b/studio/backend/core/inference/llama_server_args.py
@@ -3,10 +3,10 @@
 
 """Boundary validator for user-supplied llama-server pass-through args.
 
-Reject only flags Studio manages (model identity, auth, network, parallel
+Reject only flags Unsloth manages (model identity, auth, network, parallel
 slots). Everything else (sampling, ``-c``, ``-ngl``, ``--flash-attn``,
 ``--cache-type-*``, ``--spec-*``, ``--jinja``, ...) is appended after
-Studio's auto-set flags so llama.cpp's last-wins parser lets the user override.
+Unsloth's auto-set flags so llama.cpp's last-wins parser lets the user override.
 
 Ref: https://github.com/ggml-org/llama.cpp/blob/master/tools/server/README.md
 """
@@ -22,12 +22,12 @@ _DENYLIST_GROUPS: tuple[frozenset[str], ...] = (
     # Parallel slots: owned by typer --parallel; a pass-through would desync
     # app.state.llama_parallel_slots from llama-server.
     frozenset({"-np", "--parallel", "--n-parallel"}),
-    # Model identity: Studio resolves it from LoadRequest; a second -m would
-    # load a different model than Studio thinks it loaded.
+    # Model identity: Unsloth resolves it from LoadRequest; a second -m would
+    # load a different model than Unsloth thinks it loaded.
     frozenset({"-m", "--model"}),
-    # Public model id: Studio sets a sanitized --alias so the OpenAI API never
+    # Public model id: Unsloth sets a sanitized --alias so the OpenAI API never
     # exposes the local .gguf path. A user-supplied alias is appended after
-    # Studio's and, with llama.cpp's last-wins parsing, would reintroduce the
+    # Unsloth's and, with llama.cpp's last-wins parsing, would reintroduce the
     # path leak this is meant to prevent.
     frozenset({"-a", "--alias"}),
     frozenset({"-mu", "--model-url"}),
@@ -39,14 +39,14 @@ _DENYLIST_GROUPS: tuple[frozenset[str], ...] = (
     frozenset({"-hft", "--hf-token"}),
     frozenset({"-mm", "--mmproj"}),
     frozenset({"-mmu", "--mmproj-url"}),
-    # Networking: Studio binds + proxies; retargeting orphans the proxy.
+    # Networking: Unsloth binds + proxies; retargeting orphans the proxy.
     frozenset({"--host"}),
     frozenset({"--port"}),
     frozenset({"--path"}),
     frozenset({"--api-prefix"}),
     frozenset({"--reuse-port"}),
-    # Auth / TLS: Studio terminates auth; upstream --api-key / TLS shadows
-    # Studio's key and breaks the proxy hop.
+    # Auth / TLS: Unsloth terminates auth; upstream --api-key / TLS shadows
+    # Unsloth's key and breaks the proxy hop.
     frozenset({"--api-key"}),
     frozenset({"--api-key-file"}),
     frozenset({"--ssl-key-file"}),
@@ -64,12 +64,14 @@ _DENYLIST_GROUPS: tuple[frozenset[str], ...] = (
     frozenset({"--models-max"}),
     frozenset({"--models-autoload", "--no-models-autoload"}),
     # Server-mode flips: --embedding / --rerank restrict llama-server to
-    # those endpoints, breaking Studio's /v1/chat/completions hop.
+    # those endpoints, breaking Unsloth's /v1/chat/completions hop.
     frozenset({"--embedding", "--embeddings"}),
     frozenset({"--rerank", "--reranking"}),
     # llama-server's own built-in tools flag would silently stack on top of
-    # Studio's --enable-tools / --disable-tools policy resolver.
+    # Unsloth's --enable-tools / --disable-tools policy resolver.
     frozenset({"--tools"}),
+    # Slot-state dir: Studio owns it for KV persistence across idle unload.
+    frozenset({"--slot-save-path"}),
 )
 
 _DENYLIST: frozenset[str] = frozenset().union(*_DENYLIST_GROUPS)
@@ -120,7 +122,7 @@ def validate_extra_args(args: Optional[Iterable[str]]) -> list[str]:
 
 
 def is_managed_flag(flag: str) -> bool:
-    """True if ``flag`` is Studio-managed. Normalises via ``_flag_name`` so
+    """True if ``flag`` is Unsloth-managed. Normalises via ``_flag_name`` so
     `-np8` / `--parallel=8` classify like the canonical tokens."""
     normalised = _flag_name(flag)
     return normalised is not None and normalised in _DENYLIST
@@ -142,7 +144,7 @@ _SPEC_FLAGS: frozenset[str] = frozenset(
         "--draft-min",
         "--draft-max",
         # MTP path (llama.cpp #22673). The drafter selectors (local --model-draft
-        # and HF --spec-draft-hf aliases) are Studio-managed since the separate-
+        # and HF --spec-draft-hf aliases) are Unsloth-managed since the separate-
         # drafter support (Gemma 4): an inherited copy must not last-wins-override
         # the auto-detected drafter. Explicit extras for the current load are never
         # stripped. The per-drafter tuning knobs (--spec-draft-type-*, -ngld,
@@ -179,25 +181,38 @@ _TEMPLATE_FLAGS: frozenset[str] = frozenset(
 # (--split-mode tensor). Pass-through stays allowed so users keep the
 # row/none/layer modes the toggle doesn't expose, but it's stripped on
 # inherit and reconciled into the round-tripped tensor_parallel state.
-# --tensor-split is coupled to the split mode and is stripped with it: Studio
+# --tensor-split is coupled to the split mode and is stripped with it: Unsloth
 # owns the tensor-mode split ratios, so an inherited/stale --tensor-split must
-# not last-wins-override Studio's computed asymmetric split.
+# not last-wins-override Unsloth's computed asymmetric split.
 _SPLIT_MODE_FLAGS: frozenset[str] = frozenset({"-sm", "--split-mode"})
 _TENSOR_SPLIT_FLAGS: frozenset[str] = frozenset({"-ts", "--tensor-split"})
 _SPLIT_SHADOWING_FLAGS: frozenset[str] = _SPLIT_MODE_FLAGS | _TENSOR_SPLIT_FLAGS
 
+# GPU-offload flags. Stripped only when the GPU Memory mode owns offload
+# (manual emits --fit / --gpu-layers / --n-cpu-moe); in auto, a user's
+# inherited -ngl is respected (the offload_overridden path), so this group is
+# opt-in, not default. Layer flags are shared with llama_cpp's override
+# detection; the MoE flags are strip-only (manual's --n-cpu-moe slider owns them).
+_LAYER_OFFLOAD_FLAGS: frozenset[str] = frozenset(
+    {"-ngl", "--gpu-layers", "--n-gpu-layers", "-fit", "--fit"}
+)
+_MOE_OFFLOAD_FLAGS: frozenset[str] = frozenset({"-ncmoe", "--n-cpu-moe", "-cmoe", "--cpu-moe"})
+_OFFLOAD_SHADOWING_FLAGS: frozenset[str] = _LAYER_OFFLOAD_FLAGS | _MOE_OFFLOAD_FLAGS
+
 _SHADOWING_FLAGS: frozenset[str] = (
     _CONTEXT_FLAGS | _CACHE_FLAGS | _SPEC_FLAGS | _TEMPLATE_FLAGS | _SPLIT_SHADOWING_FLAGS
 )
 
 # Shadowing flags that take no value -- strip the flag only, not the next token.
-_BOOLEAN_SHADOWING_FLAGS: frozenset[str] = frozenset({"--spec-default", "--jinja", "--no-jinja"})
+_BOOLEAN_SHADOWING_FLAGS: frozenset[str] = frozenset(
+    {"--spec-default", "--jinja", "--no-jinja", "-cmoe", "--cpu-moe"}
+)
 
 
 def parse_ctx_override(args: Optional[Iterable[str]]) -> Optional[int]:
     """Return the last user-supplied ``-c`` / ``--ctx-size`` value.
 
-    Mirrors llama.cpp's last-wins parsing for the one numeric knob Studio's
+    Mirrors llama.cpp's last-wins parsing for the one numeric knob Unsloth's
     load-time fit logic needs.
     """
     if not args:
@@ -286,7 +301,7 @@ def parse_cache_override(args: Optional[Iterable[str]]) -> Optional[str]:
     Mirrors parse_ctx_override but for cache type. Recognises both -ctk
     (key) and -ctv (value). When both flags appear, returns the last-wins
     value, treating key and value cache flags as the same setting because
-    Studio's KV estimate has a single cache_type_kv knob.
+    Unsloth's KV estimate has a single cache_type_kv knob.
     """
     return _last_flag_value(args, _CACHE_FLAGS)
 
@@ -341,7 +356,7 @@ def resolve_tensor_parallel(args: Optional[Iterable[str]], fallback_tensor_paral
 
 
 def _env_split_mode_is_tensor(env: Optional[Mapping[str, str]] = None) -> bool:
-    """True when the inherited LLAMA_ARG_SPLIT_MODE env selects tensor. Studio
+    """True when the inherited LLAMA_ARG_SPLIT_MODE env selects tensor. Unsloth
     emits --split-mode only on its tensor branch, so a tensor env on the layer
     path would run the child tensor-parallel unbudgeted; this flips the budget
     to tensor. Only tensor is heavier, so other modes are ignored."""
@@ -424,14 +439,22 @@ def strip_shadowing_flags(
     strip_spec: bool = True,
     strip_template: bool = True,
     strip_split_mode: bool = True,
+    strip_tensor_split: bool = False,
+    strip_offload: bool = False,
 ) -> list[str]:
-    """Strip flags that shadow first-class Studio settings.
+    """Strip flags that shadow first-class Unsloth settings.
 
     Used when inheriting a previous load's ``llama_extra_args`` so an
     inherited `-c 4096` can't override the current `max_seq_length`
     (same for cache / spec / template / split-mode). Each ``strip_*``
     toggle controls one group; the route only strips groups whose
     first-class field the caller actually supplied.
+
+    ``strip_split_mode`` removes both ``--split-mode`` and the coupled
+    ``--tensor-split`` (the Tensor Parallelism toggle owns the whole split).
+    ``strip_tensor_split`` removes ``--tensor-split`` *alone*, so manual mode can
+    replace an inherited per-GPU ratio while leaving the user's ``--split-mode``
+    row/none/layer choice intact.
     """
     shadowing: set[str] = set()
     if strip_context:
@@ -444,6 +467,10 @@ def strip_shadowing_flags(
         shadowing |= _TEMPLATE_FLAGS
     if strip_split_mode:
         shadowing |= _SPLIT_SHADOWING_FLAGS
+    if strip_tensor_split:
+        shadowing |= _TENSOR_SPLIT_FLAGS
+    if strip_offload:
+        shadowing |= _OFFLOAD_SHADOWING_FLAGS
 
     tokens = [str(a) for a in (args or [])]
     out: list[str] = []
diff --git a/studio/backend/core/inference/llama_stats.py b/studio/backend/core/inference/llama_stats.py
index 6047aedbc0..ab0d287e8c 100644
--- a/studio/backend/core/inference/llama_stats.py
+++ b/studio/backend/core/inference/llama_stats.py
@@ -5,7 +5,7 @@
 engine-stats log line (generation/prompt throughput, requests in flight).
 
 llama-server already computes these (it needs `--metrics`); this lifts them
-into Studio's structured log so the terminal shows serving health, not just
+into Unsloth's structured log so the terminal shows serving health, not just
 per-request access lines. Emitted only while there is activity.
 """
 
diff --git a/studio/backend/core/inference/local_model_resolver.py b/studio/backend/core/inference/local_model_resolver.py
index 002cafe2c8..9e3eaeda3f 100644
--- a/studio/backend/core/inference/local_model_resolver.py
+++ b/studio/backend/core/inference/local_model_resolver.py
@@ -130,7 +130,7 @@ def info_has_local_gguf(info) -> bool:
 def _build_index() -> dict[str, _LocalGgufEntry]:
     """Map normalized id/model_id/display_name -> local GGUF entry.
 
-    Scans the same roots Studio's model picker lists (./models, the active plus
+    Scans the same roots Unsloth's model picker lists (./models, the active plus
     legacy/default HF caches, LM Studio dirs, and user scan folders) so a named
     local model is never missed and silently served as the loaded one. Ollama's
     scanner is skipped: it creates symlinks as a side effect and this runs on the
@@ -146,6 +146,7 @@ def _build_index() -> dict[str, _LocalGgufEntry]:
         _is_hidden_model,
     )
     from utils.paths import legacy_hf_cache_dir, hf_default_cache_dir, lmstudio_model_dirs
+    from utils.hf_cache_settings import known_hf_hub_caches
 
     index: dict[str, _LocalGgufEntry] = {}
     seen_hf: set[str] = set()
@@ -174,7 +175,12 @@ def _build_index() -> dict[str, _LocalGgufEntry]:
     except Exception as exc:
         logger.debug("auto-switch: ./models scan failed: %s", exc)
     try:
-        for hf_dir in (_resolve_hf_cache_dir(), legacy_hf_cache_dir(), hf_default_cache_dir()):
+        for hf_dir in (
+            *known_hf_hub_caches(),
+            _resolve_hf_cache_dir(),
+            legacy_hf_cache_dir(),
+            hf_default_cache_dir(),
+        ):
             found += _scan_hf_once(hf_dir)
     except Exception as exc:
         logger.debug("auto-switch: HF cache scan failed: %s", exc)
@@ -199,9 +205,13 @@ def _build_index() -> dict[str, _LocalGgufEntry]:
         raw_id = getattr(info, "id", None)
         if not raw_id:
             continue
-        # Skip what Studio hides from its pickers (validation probe, RAG embed
+        # Skip what Unsloth hides from its pickers (validation probe, RAG embed
         # weights): not chat models, so never an auto-switch target.
-        if _is_hidden_model(raw_id, getattr(info, "path", None)):
+        if _is_hidden_model(
+            raw_id,
+            getattr(info, "model_id", None),
+            getattr(info, "path", None),
+        ):
             continue
         # Advertise a client-facing alias, not an absolute filesystem path.
         loader_id = _advertised_loader_id(info)
diff --git a/studio/backend/core/inference/mcp_client.py b/studio/backend/core/inference/mcp_client.py
index 6b5ce02216..0256df944e 100644
--- a/studio/backend/core/inference/mcp_client.py
+++ b/studio/backend/core/inference/mcp_client.py
@@ -906,7 +906,7 @@ def _call_stdio_tool(
     def _remaining() -> Optional[float]:
         return None if deadline is None else max(0.0, deadline - time.monotonic())
 
-    # Callers without a Studio session id must retain the former one-shot
+    # Callers without an Unsloth session id must retain the former one-shot
     # behavior: no browser/cookie/tool state can leak into another request.
     # Use an ephemeral key (and close it below) rather than the shared empty
     # scope that the persistent-session cache used previously.
diff --git a/studio/backend/core/inference/mlx_inference.py b/studio/backend/core/inference/mlx_inference.py
index 163ade10c4..d19c67a01a 100644
--- a/studio/backend/core/inference/mlx_inference.py
+++ b/studio/backend/core/inference/mlx_inference.py
@@ -8,14 +8,76 @@ instead of torch/transformers for model loading and generation.
 import json
 import os
 import threading
+from contextlib import contextmanager
 from typing import Optional, Generator
 from core.inference.message_content import content_to_text
 from core.inference.runtime_context import runtime_context_length
+from core.inference.chat_template_helpers import (
+    ReasoningChannelNormalizer,
+    normalize_reasoning_snapshots,
+)
 from loggers import get_logger
 
 logger = get_logger(__name__)
 
 
+def _mlx_adapter_modules(model):
+    """Return bypassable adapter entries and unsupported wrapper paths."""
+    adapters = []
+    unsupported = []
+    for path, module in model.named_modules():
+        if not path or not (hasattr(module, "lora_a") and hasattr(module, "lora_b")):
+            continue
+        base = getattr(module, "linear", None)
+        if base is None:
+            base = getattr(module, "embedding", None)
+        if base is None:
+            unsupported.append(path)
+        else:
+            adapters.append((path, module, base))
+    return adapters, unsupported
+
+
+@contextmanager
+def _temporary_mlx_adapter_state(model, use_adapter):
+    """Select base or adapter modules for one request, then restore the tree."""
+    if use_adapter is None:
+        yield
+        return
+    if isinstance(use_adapter, str):
+        raise NotImplementedError(
+            "Unsloth MLX: named adapter selection is not supported; use True for "
+            "the loaded adapter or False for the base model."
+        )
+    if use_adapter is not True and use_adapter is not False:
+        raise TypeError("Unsloth MLX: use_adapter must be None, True, False, or a string.")
+
+    adapters, unsupported = _mlx_adapter_modules(model)
+    if use_adapter is True:
+        if not adapters and not unsupported:
+            logger.warning("MLX adapter requested, but the active model has no adapter layers")
+        yield
+        return
+    if unsupported:
+        raise RuntimeError(
+            "Unsloth MLX: cannot disable adapter layers without their base modules: "
+            + ", ".join(unsupported[:5])
+        )
+    if not adapters:
+        yield
+        return
+
+    from mlx.utils import tree_unflatten
+
+    base_modules = tree_unflatten([(path, base) for path, _, base in adapters])
+    adapter_modules = tree_unflatten([(path, wrapper) for path, wrapper, _ in adapters])
+    try:
+        model.update_modules(base_modules)
+        yield
+    finally:
+        model.update_modules(adapter_modules)
+
+
 def _mlx_vlm_model_config(model):
     """Return the loaded MLX model config and its type, preferring whichever of
     config / _config actually carries a model_type."""
@@ -119,19 +181,27 @@ def _vlm_messages_have_tool_history(messages):
     )
 
 
-def _build_generation_stats(prompt_n, prompt_tps, gen_n, gen_tps):
+def _build_generation_stats(
+    prompt_n,
+    prompt_tps,
+    gen_n,
+    gen_tps,
+    cached_n = 0,
+):
     """Map mlx stream stats onto the usage/timings shape llama-server emits."""
     prompt_n = int(prompt_n or 0)
     gen_n = int(gen_n or 0)
+    cached_n = int(cached_n or 0)
     prompt_tps = float(prompt_tps or 0.0)
     gen_tps = float(gen_tps or 0.0)
     prompt_ms = (prompt_n / prompt_tps * 1000.0) if prompt_tps > 0 else 0.0
     predicted_ms = (gen_n / gen_tps * 1000.0) if gen_tps > 0 else 0.0
+    total_prompt_n = prompt_n + cached_n
     return {
         "usage": {
-            "prompt_tokens": prompt_n,
+            "prompt_tokens": total_prompt_n,
             "completion_tokens": gen_n,
-            "total_tokens": prompt_n + gen_n,
+            "total_tokens": total_prompt_n + gen_n,
         },
         "timings": {
             "prompt_n": prompt_n,
@@ -142,11 +212,123 @@ def _build_generation_stats(prompt_n, prompt_tps, gen_n, gen_tps):
             "predicted_ms": predicted_ms,
             "predicted_per_token_ms": (predicted_ms / gen_n) if gen_n > 0 else 0.0,
             "predicted_per_second": gen_tps,
-            "cache_n": 0,
+            "cache_n": cached_n,
         },
     }
 
 
+PROMPT_CACHE_ENTRIES = 6
+PROMPT_CACHE_MEMORY_FRACTION = 0.15
+PROMPT_CACHE_FALLBACK_BYTES = 2 * 1024**3
+
+
+def _mlx_prompt_cache_api():
+    try:
+        from mlx_lm.models.cache import (
+            LRUPromptCache,
+            can_trim_prompt_cache,
+            make_prompt_cache,
+            trim_prompt_cache,
+        )
+    except ImportError:
+        return None
+    return LRUPromptCache, make_prompt_cache, can_trim_prompt_cache, trim_prompt_cache
+
+
+def _prompt_cache_max_bytes(recommended_gb = None):
+    override = os.environ.get("UNSLOTH_MLX_PROMPT_CACHE_BYTES")
+    if override:
+        try:
+            return max(int(override), 0)
+        except ValueError:
+            logger.warning("Ignoring non-integer UNSLOTH_MLX_PROMPT_CACHE_BYTES=%r", override)
+    if recommended_gb:
+        return int(recommended_gb * 1e9 * PROMPT_CACHE_MEMORY_FRACTION)
+    return PROMPT_CACHE_FALLBACK_BYTES
+
+
+def _flatten_kv_entries(cache):
+    for entry in cache:
+        nested = getattr(entry, "caches", None)
+        if nested is None:
+            yield entry
+        else:
+            yield from _flatten_kv_entries(nested)
+
+
+def _kv_prefix_coverage(cache):
+    covered = None
+    for entry in _flatten_kv_entries(cache):
+        offset = getattr(entry, "offset", None)
+        if offset is None:
+            return None
+        if getattr(entry, "start_position", 0):
+            return None
+        window = getattr(entry, "max_size", None)
+        if window is not None and offset > window:
+            return None
+        if covered is None:
+            covered = offset
+        elif covered != offset:
+            return None
+    return covered
+
+
+class _MLXPromptCacheHistory:
+    def __init__(self, max_entries, max_bytes):
+        api = _mlx_prompt_cache_api()
+        if api is None:
+            raise RuntimeError("mlx-lm is too old for LRUPromptCache")
+        lru_cls, make, can_trim, trim = api
+        self._make_prompt_cache = make
+        self._can_trim = can_trim
+        self._trim = trim
+        self._max_bytes = max_bytes
+        self._lru = lru_cls(max_size = max_entries, max_bytes = max_bytes)
+
+    def fetch(self, model, key, tokens):
+        cache, rest = self._lru.fetch_nearest_cache(key, list(tokens))
+        if cache is not None:
+            if rest:
+                return cache, list(rest)
+            if self._can_trim(cache) and self._trim(cache, 1) == 1:
+                return cache, list(tokens[-1:])
+        if len(tokens) > 1:
+            head = list(tokens[:-1])
+            cache, rest = self._lru.fetch_nearest_cache(key, head)
+            if cache is not None:
+                covered = len(head) - len(rest)
+                return cache, list(tokens[covered:])
+        return self._make_prompt_cache(model), list(tokens)
+
+    def insert(self, key, tokens, cache):
+        # An over-budget entry evicts itself and every other conversation.
+        nbytes = sum(getattr(entry, "nbytes", 0) for entry in cache)
+        if nbytes > self._max_bytes:
+            logger.debug(
+                "MLX prompt cache: skipping %.2f GB entry over the %.2f GB budget",
+                nbytes / 1e9,
+                self._max_bytes / 1e9,
+            )
+            return
+        covered = _kv_prefix_coverage(cache)
+        if covered is None:
+            logger.debug("MLX prompt cache: skipping cache with unverifiable prefix coverage")
+            return
+        tokens = list(tokens)
+        if covered > len(tokens):
+            logger.debug(
+                "MLX prompt cache: cache covers %d tokens but only %d were tracked",
+                covered,
+                len(tokens),
+            )
+            return
+        tokens = tokens[:covered]
+        if not tokens:
+            return
+        self._lru.insert_cache(key, tokens, cache)
+
+
 def _mlx_distributed_rank_size(group = None):
     """Return ``(rank, world_size)`` for an optional MLX distributed group."""
     if group is None:
@@ -251,6 +433,55 @@ class MLXInferenceBackend:
         # Recorded for unload to release pinned memory back to the OS.
         self._memory_limits_applied = {}
 
+        self._prompt_cache_history = None
+        self._prompt_cache_unavailable = False
+
+    def _prompt_cache(self):
+        if self._prompt_cache_history is not None or self._prompt_cache_unavailable:
+            return self._prompt_cache_history
+        max_bytes = _prompt_cache_max_bytes(self._memory_limits_applied.get("recommended_gb"))
+        if max_bytes <= 0:
+            self._prompt_cache_unavailable = True
+            logger.info("MLX prompt cache disabled by budget")
+            return None
+        try:
+            self._prompt_cache_history = _MLXPromptCacheHistory(
+                PROMPT_CACHE_ENTRIES,
+                max_bytes,
+            )
+        except Exception as exc:
+            self._prompt_cache_unavailable = True
+            logger.info("MLX prompt cache unavailable (%s); prefilling every request", exc)
+            return None
+        logger.info(
+            "MLX prompt cache: %d entries, %.2f GB budget",
+            PROMPT_CACHE_ENTRIES,
+            max_bytes / 1e9,
+        )
+        return self._prompt_cache_history
+
+    def _clear_prompt_cache(self):
+        self._prompt_cache_history = None
+        self._prompt_cache_unavailable = False
+
+    def _prepare_prompt_cache(self, prompt, adapter_state):
+        history = self._prompt_cache()
+        if history is None:
+            return prompt, None, None, None, 0
+        try:
+            tokenizer = self._tokenizer
+            bos = getattr(tokenizer, "bos_token", None)
+            add_special_tokens = bos is None or not prompt.startswith(bos)
+            tokens = list(tokenizer.encode(prompt, add_special_tokens = add_special_tokens))
+            if not tokens:
+                return prompt, None, None, None, 0
+            key = f"{self.active_model_name}|{adapter_state!r}"
+            cache, rest = history.fetch(self._model, key, tokens)
+        except Exception as exc:
+            logger.debug("MLX prompt cache lookup failed: %s", exc)
+            return prompt, None, None, None, 0
+        return rest, cache, key, tokens, len(tokens) - len(rest)
+
     def _configure_memory_limits(self):
         """Apply Metal memory caps before loading a model.
 
@@ -473,6 +704,7 @@ class MLXInferenceBackend:
         self._distributed_world_size = 1
         if self.active_model_name == model_name:
             self.active_model_name = None
+        self._clear_prompt_cache()
         gc.collect()
         mx.clear_cache()
 
@@ -504,6 +736,7 @@ class MLXInferenceBackend:
         reasoning_effort = None,
         preserve_thinking = None,
         presence_penalty = 0.0,
+        _adapter_state = None,
     ) -> Generator[str, None, None]:
         if self._model is None:
             raise RuntimeError("No model loaded")
@@ -533,7 +766,7 @@ class MLXInferenceBackend:
                     break
 
         if self._is_vlm:
-            yield from self._generate_vlm(
+            stream = self._generate_vlm(
                 full_messages,
                 image,
                 temperature,
@@ -548,9 +781,10 @@ class MLXInferenceBackend:
                 reasoning_effort = reasoning_effort,
                 preserve_thinking = preserve_thinking,
                 presence_penalty = presence_penalty,
+                _adapter_state = _adapter_state,
             )
         else:
-            yield from self._generate_text(
+            stream = self._generate_text(
                 full_messages,
                 temperature,
                 top_p,
@@ -564,7 +798,9 @@ class MLXInferenceBackend:
                 reasoning_effort = reasoning_effort,
                 preserve_thinking = preserve_thinking,
                 presence_penalty = presence_penalty,
+                _adapter_state = _adapter_state,
             )
+        yield from stream
 
     def _generate_text(
         self,
@@ -582,6 +818,7 @@ class MLXInferenceBackend:
         reasoning_effort = None,
         preserve_thinking = None,
         presence_penalty = 0.0,
+        _adapter_state = None,
     ):
         from mlx_lm import stream_generate
         from mlx_lm.sample_utils import make_sampler, make_logits_processors
@@ -609,7 +846,7 @@ class MLXInferenceBackend:
         # probe and native render share a renderer. (VLM renders via the
         # processor for image tokens and is not wired here.)
         model_info = self.models.get(self.active_model_name, {})
-        prompt = render_with_native_template_fallback(
+        render_result = render_with_native_template_fallback(
             formatted_prompt = prompt,
             tokenizer = self._tokenizer,
             model_info = model_info,
@@ -620,17 +857,16 @@ class MLXInferenceBackend:
             reasoning_effort = reasoning_effort,
             preserve_thinking = preserve_thinking,
             hf_token = model_info.get("hf_token"),
+            return_metadata = True,
         )
+        prompt = render_result.prompt
+        reasoning_channel_markers = render_result.reasoning_channel_markers
 
         # An open <think> prefilled by the template lives in the prompt, not
         # the generated tokens; re-emit it so the frontend renders the block.
         think_prefix = detect_think_prefill(
             prompt, getattr(self._tokenizer, "all_special_tokens", None)
         )
-        # Emit it before the first token so the block renders during prefill.
-        if think_prefix:
-            yield think_prefix
-
         sampler = make_sampler(
             temp = temperature,
             top_p = top_p,
@@ -654,22 +890,45 @@ class MLXInferenceBackend:
         if not logits_processors:
             logits_processors = None
 
+        preserve_native_channels = reasoning_channel_markers is not None
         token_ids = []
-        logger.info(
-            "Generating: prompt_len=%d, max_tokens=%d, model=%s, tokenizer=%s",
-            len(prompt),
-            max_new_tokens,
-            type(self._model).__name__,
-            type(self._tokenizer).__name__,
+        normalizer = (
+            ReasoningChannelNormalizer(*reasoning_channel_markers)
+            if reasoning_channel_markers is not None
+            else None
         )
-        with self._generation_lock:
+        # MLX consumers diff cumulative snapshots. Keep a prompt-prefilled
+        # <think> prefix on every native-protocol snapshot just as the normal
+        # decoding path does below.
+        normalized_output = think_prefix
+        with self._generation_lock, _temporary_mlx_adapter_state(self._model, _adapter_state):
+            (
+                gen_prompt,
+                prompt_cache,
+                cache_key,
+                prompt_tokens,
+                cached_n,
+            ) = self._prepare_prompt_cache(prompt, _adapter_state)
+            logger.info(
+                "Generating: prompt_len=%d, cached=%d, max_tokens=%d, model=%s, tokenizer=%s",
+                len(prompt),
+                cached_n,
+                max_new_tokens,
+                type(self._model).__name__,
+                type(self._tokenizer).__name__,
+            )
             final_response = None
             try:
+                # Enter request-scoped model state before yielding any response.
+                if think_prefix:
+                    yield think_prefix
                 gen_kwargs = dict(
-                    prompt = prompt,
+                    prompt = gen_prompt,
                     max_tokens = max_new_tokens,
                     sampler = sampler,
                 )
+                if prompt_cache is not None:
+                    gen_kwargs["prompt_cache"] = prompt_cache
                 if logits_processors is not None:
                     gen_kwargs["logits_processors"] = logits_processors
                 for response in stream_generate(
@@ -679,14 +938,28 @@ class MLXInferenceBackend:
                 ):
                     final_response = response
                     token_ids.append(response.token)
-                    cumulative = self._tokenizer.decode(
-                        token_ids,
-                        skip_special_tokens = True,
-                    )
-                    yield think_prefix + cumulative
+                    if preserve_native_channels:
+                        piece = getattr(response, "text", None) or ""
+                        delta = normalizer.feed(piece)
+                        if delta:
+                            normalized_output += delta
+                            yield normalized_output
+                    else:
+                        cumulative = self._tokenizer.decode(
+                            token_ids,
+                            skip_special_tokens = True,
+                        )
+                        yield think_prefix + cumulative
 
                     if cancel_event and cancel_event.is_set():
                         break
+                if prompt_cache is not None and prompt_tokens is not None:
+                    history = self._prompt_cache_history
+                    if history is not None:
+                        try:
+                            history.insert(cache_key, prompt_tokens + token_ids, prompt_cache)
+                        except Exception as exc:
+                            logger.debug("MLX prompt cache insert failed: %s", exc)
             except Exception as e:
                 import traceback
                 logger.error("stream_generate failed:\n%s", traceback.format_exc())
@@ -699,7 +972,14 @@ class MLXInferenceBackend:
                         getattr(final_response, "prompt_tps", 0.0),
                         getattr(final_response, "generation_tokens", 0),
                         getattr(final_response, "generation_tps", 0.0),
+                        cached_n,
                     )
+        if normalizer is not None:
+            cancelled = cancel_event is not None and cancel_event.is_set()
+            tail = normalizer.drain() if cancelled else normalizer.finish()
+            if tail:
+                normalized_output += tail
+                yield normalized_output
 
     def _generate_vlm(
         self,
@@ -718,6 +998,7 @@ class MLXInferenceBackend:
         reasoning_effort = None,
         preserve_thinking = None,
         presence_penalty = 0.0,
+        _adapter_state = None,
     ):
         from mlx_vlm import stream_generate as vlm_stream
 
@@ -821,9 +1102,6 @@ class MLXInferenceBackend:
 
         # Re-emit an open <think> prefill from the prompt (see _generate_text).
         cumulative = detect_think_prefill(prompt, getattr(chat_target, "all_special_tokens", None))
-        # Emit it before the first token so the block renders during prefill.
-        if cumulative:
-            yield cumulative
         logger.info(
             "VLM generating: prompt_len=%d, has_image=%s",
             len(prompt),
@@ -858,31 +1136,46 @@ class MLXInferenceBackend:
         elif _rep_active:
             vlm_kwargs["repetition_penalty"] = float(repetition_penalty)
 
-        with self._generation_lock:
-            final_response = None
-            try:
-                for response in vlm_stream(
-                    self._model,
-                    self._processor,
-                    prompt,
-                    images,
-                    **vlm_kwargs,
-                ):
-                    final_response = response
-                    token_text = response.text if hasattr(response, "text") else str(response)
-                    cumulative += token_text
-                    yield cumulative
-                    if cancel_event and cancel_event.is_set():
-                        break
-            finally:
-                # mlx_vlm exposes the same stats fields as mlx_lm.
-                if final_response is not None:
-                    self.last_generation_stats = _build_generation_stats(
-                        getattr(final_response, "prompt_tokens", 0),
-                        getattr(final_response, "prompt_tps", 0.0),
-                        getattr(final_response, "generation_tokens", 0),
-                        getattr(final_response, "generation_tps", 0.0),
-                    )
+        def _stream_vlm_snapshots():
+            nonlocal cumulative
+            # Hold the generation lock AND the request-scoped adapter state for the
+            # whole stream so Base-vs-LoRA compare mode honors use_adapter and the
+            # wrapper tree is restored on completion, cancellation, or close.
+            with self._generation_lock, _temporary_mlx_adapter_state(self._model, _adapter_state):
+                final_response = None
+                try:
+                    # Emit any prefilled <think> block before the first token so the
+                    # UI renders it during prefill, matching _generate_text. Done
+                    # inside the adapter context so an unsupported request raises
+                    # before any output escapes.
+                    if cumulative:
+                        yield cumulative
+                    for response in vlm_stream(
+                        self._model,
+                        self._processor,
+                        prompt,
+                        images,
+                        **vlm_kwargs,
+                    ):
+                        final_response = response
+                        token_text = response.text if hasattr(response, "text") else str(response)
+                        cumulative += token_text
+                        yield cumulative
+                        if cancel_event and cancel_event.is_set():
+                            break
+                finally:
+                    # mlx_vlm exposes the same stats fields as mlx_lm.
+                    if final_response is not None:
+                        self.last_generation_stats = _build_generation_stats(
+                            getattr(final_response, "prompt_tokens", 0),
+                            getattr(final_response, "prompt_tps", 0.0),
+                            getattr(final_response, "generation_tokens", 0),
+                            getattr(final_response, "generation_tps", 0.0),
+                        )
+
+        yield from normalize_reasoning_snapshots(
+            _stream_vlm_snapshots(), chat_target, cancel_event, tools = tools
+        )
 
     def generate_with_adapter_control(
         self,
@@ -890,8 +1183,11 @@ class MLXInferenceBackend:
         cancel_event = None,
         **gen_kwargs,
     ) -> Generator[str, None, None]:
-        # MLX LoRA adapter toggling not yet supported; generate normally
-        yield from self.generate_chat_response(cancel_event = cancel_event, **gen_kwargs)
+        yield from self.generate_chat_response(
+            cancel_event = cancel_event,
+            _adapter_state = use_adapter,
+            **gen_kwargs,
+        )
 
     def reset_generation_state(self):
         import mlx.core as mx
diff --git a/studio/backend/core/inference/orchestrator.py b/studio/backend/core/inference/orchestrator.py
index c2082bc198..616384386d 100644
--- a/studio/backend/core/inference/orchestrator.py
+++ b/studio/backend/core/inference/orchestrator.py
@@ -27,7 +27,7 @@ import uuid
 from io import BytesIO
 from pathlib import Path
 from typing import Any, Generator, Optional, Tuple, Union
-from utils.hardware import prepare_gpu_selection
+from utils.hardware import get_device, prepare_gpu_selection
 
 # Re-exported from the shared helper so GGUF, training, and inference share one
 # type; kept importable here for backwards compatibility.
@@ -54,12 +54,36 @@ class GenStreamError(str):
     """A stream chunk carrying a real backend/generation error, not model text.
 
     Subclasses str so existing display/logging consumers are unaffected, while
-    callers that must abort a distributed run on error (raise_on_streamed_error)
-    can distinguish a real error from model output whose visible text starts with
-    "Error:" by checking isinstance(chunk, GenStreamError).
+    callers can distinguish a real error from model output whose visible text
+    starts with "Error:" by checking isinstance(chunk, GenStreamError).
     """
 
-    __slots__ = ()
+    __slots__ = ("public",)
+
+    def __new__(
+        cls,
+        value,
+        *,
+        public: bool = False,
+    ):
+        obj = str.__new__(cls, value)
+        obj.public = bool(public)
+        return obj
+
+
+class GenStreamErrorRaised(RuntimeError):
+    """Internal exception form of ``GenStreamError`` for generator boundaries."""
+
+    __slots__ = ("public",)
+
+    def __init__(
+        self,
+        value,
+        *,
+        public: bool = False,
+    ):
+        super().__init__(value)
+        self.public = bool(public)
 
 
 class InferenceOrchestrator:
@@ -193,10 +217,14 @@ class InferenceOrchestrator:
             native_path_secret_removed_for_child_start,
             run_without_native_path_secret,
         )
+        from utils.hf_cache_settings import child_environment_for_spawn, get_hf_cache_paths
 
-        from .worker import run_inference_process
+        cache_env = get_hf_cache_paths().child_env({})
 
-        with native_path_secret_removed_for_child_start():
+        with (
+            child_environment_for_spawn(cache_env),
+            native_path_secret_removed_for_child_start(),
+        ):
             self._cmd_queue = _CTX.Queue()
             self._resp_queue = _CTX.Queue()
             self._cancel_event = _CTX.Event()
@@ -204,7 +232,7 @@ class InferenceOrchestrator:
 
             self._proc = _CTX.Process(
                 target = run_without_native_path_secret,
-                args = (run_inference_process,),
+                args = ("core.inference.worker", "run_inference_process", cache_env),
                 kwargs = {
                     "cmd_queue": self._cmd_queue,
                     "resp_queue": self._resp_queue,
@@ -531,13 +559,19 @@ class InferenceOrchestrator:
         initial_resp_queue = self._resp_queue
         while True:
             if self._proc is not initial_proc or self._resp_queue is not initial_resp_queue:
-                yield GenStreamError(f"Error: {self._subprocess_crash_message(crash_context)}")
+                yield GenStreamError(
+                    f"Error: {self._subprocess_crash_message(crash_context)}",
+                    public = True,
+                )
                 return
             resp = read_one(read_timeout)
             if resp is None:
                 # Check subprocess health
                 if not self._ensure_subprocess_alive():
-                    yield GenStreamError(f"Error: {self._subprocess_crash_message(crash_context)}")
+                    yield GenStreamError(
+                        f"Error: {self._subprocess_crash_message(crash_context)}",
+                        public = True,
+                    )
                     return
                 continue
 
@@ -689,11 +723,11 @@ class InferenceOrchestrator:
         GPU work stays serialized; this only avoids orchestrator lock contention.
         """
         if not self._ensure_subprocess_alive():
-            yield GenStreamError("Error: Inference subprocess is not running")
+            yield GenStreamError("Error: Inference subprocess is not running", public = True)
             return
 
         if not self.active_model_name:
-            yield GenStreamError("Error: No active model")
+            yield GenStreamError("Error: No active model", public = True)
             return
         # Latch the target model so the recheck below can detect a switch that completed
         # between _start_dispatcher and mailbox registration (mirrors the locked path's
@@ -704,7 +738,7 @@ class InferenceOrchestrator:
         # so without this early-out a compare request would enqueue a generate on the
         # outgoing model and delay the switch.
         if self._unload_pending:
-            yield GenStreamError("Error: model is being unloaded")
+            yield GenStreamError("Error: model is being unloaded", public = True)
             return
 
         # Ensure the dispatcher runs. _start_dispatcher serializes concurrent starters under
@@ -776,7 +810,7 @@ class InferenceOrchestrator:
             # _stop_dispatcher joins the dispatcher, which itself takes that lock.
             if orphaned_dispatcher:
                 self._stop_dispatcher()
-            yield GenStreamError("Error: model is being unloaded")
+            yield GenStreamError("Error: model is being unloaded", public = True)
             return
 
         try:
@@ -978,6 +1012,8 @@ class InferenceOrchestrator:
             )
             sub_config["resolved_gpu_ids"] = resolved_gpu_ids
             sub_config["gpu_selection"] = gpu_selection
+            # Parent-detected backend for the worker's apply_gpu_ids().
+            sub_config["device_backend"] = get_device().value
 
             # Recheck the sidecar reservation BEFORE tearing the old worker down,
             # for REPAIRS only: an install holds this same lifecycle gate, so it
@@ -1376,6 +1412,7 @@ class InferenceOrchestrator:
         use_adapter: Optional[Union[bool, str]] = None,
         stats_holder: Optional[dict] = None,
         presence_penalty: float = 0.0,
+        reasoning_prefilled: bool = False,
         **_unused,
     ):
         """Run the safetensors agentic tool loop in the parent process,
@@ -1414,12 +1451,27 @@ class InferenceOrchestrator:
                 presence_penalty = presence_penalty,
             )
             if use_adapter is not None:
-                yield from self.generate_with_adapter_control(
+                stream = self.generate_with_adapter_control(
                     use_adapter = use_adapter,
                     **common_kwargs,
                 )
             else:
-                yield from self.generate_chat_response(**common_kwargs)
+                stream = self.generate_chat_response(**common_kwargs)
+            close_stream = False
+            try:
+                for chunk in stream:
+                    if isinstance(chunk, GenStreamError):
+                        close_stream = True
+                        raise GenStreamErrorRaised(str(chunk), public = chunk.public)
+                    yield chunk
+            finally:
+                if close_stream:
+                    close = getattr(stream, "close", None)
+                    if callable(close):
+                        try:
+                            close()
+                        except Exception:
+                            logger.debug("failed to close errored generation stream", exc_info = True)
 
         initial = list(messages)
         if system_prompt:
@@ -1441,6 +1493,7 @@ class InferenceOrchestrator:
             confirm_tool_calls = confirm_tool_calls,
             bypass_permissions = bypass_permissions,
             permission_mode = permission_mode,
+            reasoning_prefilled = reasoning_prefilled,
         )
 
     def generate_with_adapter_control(
@@ -1454,14 +1507,27 @@ class InferenceOrchestrator:
 
         Uses the dispatcher path (no _gen_lock) so compare-mode requests
         don't block each other; the subprocess serializes them via its
-        sequential command loop.
+        sequential command loop. Backend failures raise instead of becoming
+        assistant text.
         """
-        yield from self._generate_dispatched(
+        stream = self._generate_dispatched(
             use_adapter = use_adapter,
             cancel_event = cancel_event,
             stats_holder = stats_holder,
             **gen_kwargs,
         )
+        try:
+            for chunk in stream:
+                if isinstance(chunk, GenStreamError):
+                    # Preserve the public/operational flag so the route can surface
+                    # the real message (e.g. "model is being unloaded") instead of a
+                    # generic error. Mirrors the safetensors tool loop's _single_turn.
+                    raise GenStreamErrorRaised(str(chunk), public = chunk.public)
+                yield chunk
+        finally:
+            close = getattr(stream, "close", None)
+            if callable(close):
+                close()
 
     def _generate_inner(
         self,
@@ -1489,11 +1555,11 @@ class InferenceOrchestrator:
         readers don't consume each other's tokens off the shared resp_queue.
         """
         if not self._ensure_subprocess_alive():
-            yield GenStreamError("Error: Inference subprocess is not running")
+            yield GenStreamError("Error: Inference subprocess is not running", public = True)
             return
 
         if not self.active_model_name:
-            yield GenStreamError("Error: No active model")
+            yield GenStreamError("Error: No active model", public = True)
             return
         expected_model = self.active_model_name
 
@@ -1510,7 +1576,7 @@ class InferenceOrchestrator:
             # so we never generate on the wrong one.
             if self._unload_pending or self.active_model_name != expected_model:
                 # Won the lock handoff during a switch; don't start on the outgoing model.
-                yield GenStreamError("Error: model is being unloaded")
+                yield GenStreamError("Error: model is being unloaded", public = True)
                 return
             request_id = str(uuid.uuid4())
             image_b64 = self._pil_to_base64(image) if image is not None else None
@@ -1695,10 +1761,10 @@ class InferenceOrchestrator:
     ) -> Generator[str, None, None]:
         """Shared inner logic for audio input generation (Whisper + ASR)."""
         if not self._ensure_subprocess_alive():
-            yield GenStreamError("Error: Inference subprocess is not running")
+            yield GenStreamError("Error: Inference subprocess is not running", public = True)
             return
         if not self.active_model_name:
-            yield GenStreamError("Error: No active model")
+            yield GenStreamError("Error: No active model", public = True)
             return
         expected_model = self.active_model_name
 
@@ -1707,7 +1773,7 @@ class InferenceOrchestrator:
             # cleared or swapped the model while we waited.
             if self._unload_pending or self.active_model_name != expected_model:
                 # Won the lock handoff during a switch; don't start on the outgoing model.
-                yield GenStreamError("Error: model is being unloaded")
+                yield GenStreamError("Error: model is being unloaded", public = True)
                 return
             request_id = str(uuid.uuid4())
 
diff --git a/studio/backend/core/inference/passthrough_healing.py b/studio/backend/core/inference/passthrough_healing.py
index ed7c7ecfcf..e6da0a22b0 100644
--- a/studio/backend/core/inference/passthrough_healing.py
+++ b/studio/backend/core/inference/passthrough_healing.py
@@ -5,7 +5,7 @@
 
 With server-side tools disabled (``unsloth run --disable-tools``, every
 ``unsloth start`` coding agent), requests carrying the client's own ``tools``
-bypass Studio's tool loop and are relayed to/from llama-server verbatim. Small
+bypass Unsloth's tool loop and are relayed to/from llama-server verbatim. Small
 GGUF models often emit their tool calls as TEXT (``<tool_call>{...}</tool_call>``,
 Gemma ``<|tool_call>...``, ``<function=...>`` XML) instead of structured
 ``tool_calls`` -- on the passthrough that text reaches the agent as prose and
@@ -18,7 +18,7 @@ promotes calls whose function name exactly matches a declared tool. Promotion
 removes EXACTLY the promoted calls' markup spans (the parser reports them):
 undeclared calls, unparseable blocks, and suppressed alternate formats keep
 every byte and relay as text, so healing can never silently delete model
-output. Responses without a tool signal, requests without tools, and Studio's
+output. Responses without a tool signal, requests without tools, and Unsloth's
 own enable-tools loop are untouched. Per-request opt-out:
 ``auto_heal_tool_calls: false``. Process kill-switch:
 ``UNSLOTH_DISABLE_TOOL_CALL_HEALING=1``.
diff --git a/studio/backend/core/inference/pricing.py b/studio/backend/core/inference/pricing.py
index 3b611d3596..30fec47723 100644
--- a/studio/backend/core/inference/pricing.py
+++ b/studio/backend/core/inference/pricing.py
@@ -122,12 +122,12 @@ def calculate_cost(provider: str, model: str, usage: dict[str, Any]) -> dict[str
         "priced": bool(prices),
     }
 
-    # Accept raw (input_tokens/output_tokens) and Studio chat-style
+    # Accept raw (input_tokens/output_tokens) and Unsloth chat-style
     # (prompt_tokens/completion_tokens) envelopes. Cache buckets differ:
     #   raw Anthropic:    input_tokens EXCLUDES cache buckets
     #   raw OpenAI:       input_tokens INCLUDES cache_read
-    #   Studio Anthropic: prompt_tokens INCLUDES cache_creation + cache_read
-    #   Studio OpenAI:    prompt_tokens == raw input_tokens
+    #   Unsloth Anthropic: prompt_tokens INCLUDES cache_creation + cache_read
+    #   Unsloth OpenAI:    prompt_tokens == raw input_tokens
     # Clamp >=0 so corrupted payloads can't produce a negative bill.
     cache_creation = max(0, int(usage.get("cache_creation_input_tokens") or 0))
     cache_read_native_present = (
@@ -160,7 +160,7 @@ def calculate_cost(provider: str, model: str, usage: dict[str, Any]) -> dict[str
         output_tokens = max(0, int(usage.get("completion_tokens") or 0))
     if provider == "openai":
         # Cached tokens land on input_tokens_details (raw Responses) or
-        # prompt_tokens_details (Studio chat-style).
+        # prompt_tokens_details (Unsloth chat-style).
         for key in ("input_tokens_details", "prompt_tokens_details"):
             details = usage.get(key) or {}
             if isinstance(details, dict):
diff --git a/studio/backend/core/inference/providers.py b/studio/backend/core/inference/providers.py
index 5b72373c03..d3bffc2f3d 100644
--- a/studio/backend/core/inference/providers.py
+++ b/studio/backend/core/inference/providers.py
@@ -276,8 +276,9 @@ PROVIDER_REGISTRY: dict[str, dict[str, Any]] = {
         "auth_header": "Authorization",
         "auth_prefix": "Bearer ",
         "notes": (
-            "Local Ollama server. OpenAI-compatible /v1/chat/completions; "
-            "no API key. Surfaced via CUSTOM_PROVIDER_PRESETS in the frontend."
+            "Ollama server (local or cloud). OpenAI-compatible "
+            "/v1/chat/completions; API key optional (required by Ollama "
+            "cloud). Surfaced via CUSTOM_PROVIDER_PRESETS in the frontend."
         ),
         "hidden": True,
     },
diff --git a/studio/backend/core/inference/safetensors_agentic.py b/studio/backend/core/inference/safetensors_agentic.py
index 43b72110ff..40731de57b 100644
--- a/studio/backend/core/inference/safetensors_agentic.py
+++ b/studio/backend/core/inference/safetensors_agentic.py
@@ -50,6 +50,7 @@ from core.inference.tool_call_parser import (
 # pattern lists, so the safetensors streaming strip stays aligned with the parser.
 from core.tool_healing import (
     _REHEARSAL_TAIL_STRIP_RE,
+    _THINK_CLOSE_RE,
     _strip_bracket_tag_calls,
     _think_spans_outside_tool_markup,
     apply_tool_strip_patterns,
@@ -304,6 +305,45 @@ def _status_for_tool(tool_name: str, arguments: dict) -> str:
     return status_for_tool(tool_name, arguments)
 
 
+def _reprompt_intent_text(text: str, *, reasoning_prefilled: bool = False) -> str:
+    """Return visible answer text for the plan-without-action classifier.
+
+    Safetensors reasoning shares the cumulative text channel with the answer.
+    Forward-looking phrases inside ``<think>`` / ``[THINK]`` are private
+    planning, not a user-visible promise to call a tool. Match GGUF's behavior:
+    classify visible content when present and fall back to reasoning only for a
+    reasoning-only stall.
+    """
+    prefilled_reasoning = ""
+    if reasoning_prefilled:
+        close = _THINK_CLOSE_RE.search(text)
+        if close is None:
+            return text.strip()
+        prefilled_reasoning = text[: close.end()].strip()
+        text = text[close.end() :].strip()
+        if not text:
+            return prefilled_reasoning
+
+    spans = _think_spans_outside_tool_markup(text)
+    if not spans:
+        return text.strip()
+
+    visible: list[str] = []
+    reasoning: list[str] = []
+    cursor = 0
+    for start, end in spans:
+        visible.append(text[cursor:start])
+        reasoning.append(text[start:end])
+        cursor = end
+    visible.append(text[cursor:])
+
+    visible_text = "".join(visible).strip()
+    reasoning_text = "".join(reasoning).strip()
+    if visible_text:
+        return visible_text
+    return "\n".join(part for part in (prefilled_reasoning, reasoning_text) if part).strip()
+
+
 def _looks_like_enabled_bare_json(text: str, enabled_tool_names: Optional[set]) -> bool:
     """True when ``text`` opens with an ENABLED markerless bare-JSON call; an ordinary JSON answer returns False."""
     probe = strip_llama3_leading_sentinels(text.lstrip())
@@ -448,6 +488,7 @@ def run_safetensors_tool_loop(
     confirm_tool_calls: bool = False,
     bypass_permissions: bool = False,
     permission_mode: Optional[str] = None,
+    reasoning_prefilled: bool = False,
 ) -> Generator[dict, None, None]:
     """Drive an agentic tool loop on top of a cumulative-text generator.
 
@@ -954,9 +995,12 @@ def run_safetensors_tool_loop(
             if not safety_tc:
                 # Re-prompt once on plan-without-action, before any tool runs
                 # (GGUF loop parity). The retry is gated on nudge_tool_calls so
-                # Studio callers (which send True) always nudge, while API callers
+                # Unsloth callers (which send True) always nudge, while API callers
                 # who omit the flag keep today's no-reprompt behavior (opt-in).
-                stripped_answer = content_accum.strip()
+                intent_text = _reprompt_intent_text(
+                    content_accum,
+                    reasoning_prefilled = reasoning_prefilled,
+                )
                 if (
                     auto_heal_tool_calls
                     and nudge_tool_calls
@@ -965,7 +1009,7 @@ def run_safetensors_tool_loop(
                     and not rag_autoinjected
                     and not tool_denied
                     and not any(record.executed for record in tool_controller.history)
-                    and is_short_intent_without_action(stripped_answer)
+                    and is_short_intent_without_action(intent_text)
                 ):
                     reprompt_count += 1
                     logger.info(
@@ -973,9 +1017,9 @@ def run_safetensors_tool_loop(
                         "calling tools (%d chars)",
                         reprompt_count,
                         MAX_ACT_REPROMPTS,
-                        len(stripped_answer),
+                        len(intent_text),
                     )
-                    conversation.append({"role": "assistant", "content": stripped_answer})
+                    conversation.append({"role": "assistant", "content": intent_text})
                     tool_hint = " or ".join(_active_tool_names(active_tools)) or "an available tool"
                     conversation.append(
                         {
diff --git a/studio/backend/core/inference/sandbox_site/sitecustomize.py b/studio/backend/core/inference/sandbox_site/sitecustomize.py
index d655e8e35a..244fa95145 100644
--- a/studio/backend/core/inference/sandbox_site/sitecustomize.py
+++ b/studio/backend/core/inference/sandbox_site/sitecustomize.py
@@ -4,7 +4,7 @@
 """Sandbox-side compatibility shim for ChatGPT code-interpreter paths.
 
 Models habitually write to /mnt/data (or /mnt/outputs, /home/sandbox,
-/workspace), none of which exist in the Studio sandbox. This module sits on the
+/workspace), none of which exist in the Unsloth sandbox. This module sits on the
 sandbox subprocess PYTHONPATH (see ``tools._build_safe_env``), so it loads at
 interpreter startup in every sandboxed ``python`` run and any Python the
 ``terminal`` tool launches.
diff --git a/studio/backend/core/inference/stt_ggml_sidecar.py b/studio/backend/core/inference/stt_ggml_sidecar.py
new file mode 100644
index 0000000000..02b376dea5
--- /dev/null
+++ b/studio/backend/core/inference/stt_ggml_sidecar.py
@@ -0,0 +1,876 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""whisper.cpp (GGML/GGUF) speech-to-text sidecar for Studio dictation.
+
+Runs the same curated Whisper checkpoints as the Transformers sidecar
+(stt_sidecar.py) through whisper.cpp's `whisper-server`, ~2.5x faster at
+identical quality on Apple Silicon and CPU because its Metal/CPU kernels run
+the weights in f16 where PyTorch MPS requires fp32.
+
+Owns a single `whisper-server` subprocess bound to 127.0.0.1 on an ephemeral
+port; the model loads on demand, stays warm between dictations, and unloads
+after the same keep-alive as the Transformers sidecar. Curated GGML checkpoints
+are single files from `unslothai/whisper-*-GGUF`, downloaded directly rather
+than through the Model Hub (whose variant planner only handles `.gguf` chat
+layouts).
+
+Binary discovery mirrors `_find_llama_server_binary`: env override, then managed
+Studio home, then PATH. With no binary the engine is unavailable and dictation
+falls back to the Transformers sidecar; `scripts/build_whisper_cpp.sh` installs
+the binary.
+"""
+
+from __future__ import annotations
+
+import io
+import json
+import os
+import re
+import shutil
+import socket
+import subprocess
+import sys
+import threading
+import time
+import urllib.request
+import uuid
+import wave
+from contextlib import contextmanager
+from pathlib import Path
+from typing import Iterator, Optional
+
+from loggers import get_logger
+
+from core.inference.stt_sidecar import (
+    STT_KEEP_ALIVE_SECONDS,
+    SttAudioDecodeError,
+    SttLanguageError,
+    SttLoadCancelledError,
+    SttModelIdError,
+    SttModelNotDownloadedError,
+    SttUnavailableError,
+    _decode_audio_bounded,
+    _known_whisper_languages,
+    _TARGET_SAMPLE_RATE,
+    _training_active,
+    normalize_whisper_language,
+)
+from utils.prebuilt.child_env import isolate_home, scrub_env, wsl_system_rocm_lib_dirs
+from utils.prebuilt.runtime_libs import dedupe_existing_dirs
+from utils.prebuilt.whisper_layout import lookup_marker
+from utils.process_lifetime import adopt_pid, child_popen_kwargs, forget_pid
+
+logger = get_logger(__name__)
+
+# Curated GGML checkpoints, one repo per model. Keys match the Transformers
+# sidecar's ids so the frontend reuses one picker; values are the single file
+# inside each repo.
+GGML_STT_REPOS: dict[str, str] = {
+    "tiny": "unslothai/whisper-tiny-GGUF",
+    "base": "unslothai/whisper-base-GGUF",
+    "small": "unslothai/whisper-small-GGUF",
+    "large-v3-turbo": "unslothai/whisper-large-v3-turbo-GGUF",
+    "large-v3": "unslothai/whisper-large-v3-GGUF",
+}
+GGML_STT_MODELS: dict[str, str] = {
+    "tiny": "whisper-tiny.bin",
+    "base": "whisper-base.bin",
+    "small": "whisper-small.bin",
+    "large-v3-turbo": "whisper-large-v3-turbo.bin",
+    "large-v3": "whisper-large-v3.bin",
+}
+DEFAULT_GGML_STT_MODEL = "small"
+
+_SERVER_START_TIMEOUT_SECONDS = 120.0
+_TRANSCRIBE_TIMEOUT_SECONDS = 600.0
+
+
+class SttEngineUnavailableError(SttUnavailableError):
+    """whisper-server is not installed; the GGUF dictation engine is off."""
+
+
+def resolve_ggml_model_id(model: Optional[str]) -> str:
+    """Validate a curated GGML model id. Custom repos are not supported here."""
+    if model is None or not str(model).strip():
+        return DEFAULT_GGML_STT_MODEL
+    normalized = str(model).strip()
+    if normalized in GGML_STT_MODELS:
+        return normalized
+    raise SttModelIdError(
+        f"STT model '{model}' is not a curated GGUF dictation model. "
+        f"Choose one of: {', '.join(GGML_STT_MODELS)}."
+    )
+
+
+def _managed_whisper_cpp_dir() -> Path:
+    """`<STUDIO_HOME>/whisper.cpp` in custom mode, else `~/.unsloth/whisper.cpp`.
+
+    Mirrors `managed_node_dir` / `_find_llama_server_binary` so managed runtimes
+    share one parent directory.
+    """
+    legacy = Path.home() / ".unsloth" / "whisper.cpp"
+    try:
+        from utils.paths.storage_roots import studio_root
+
+        resolved = studio_root()
+        legacy_studio = Path.home() / ".unsloth" / "studio"
+        try:
+            is_legacy = resolved.resolve() == legacy_studio.resolve()
+        except (OSError, ValueError):
+            is_legacy = resolved == legacy_studio
+        return legacy if is_legacy else (resolved / "whisper.cpp")
+    except (ImportError, OSError, ValueError):
+        override = (
+            os.environ.get("UNSLOTH_STUDIO_HOME") or os.environ.get("STUDIO_HOME") or ""
+        ).strip()
+        if override:
+            try:
+                return Path(override).expanduser().resolve() / "whisper.cpp"
+            except (OSError, ValueError):
+                return Path(override).expanduser() / "whisper.cpp"
+        return legacy
+
+
+def find_whisper_server_binary() -> Optional[str]:
+    """Locate the whisper-server binary.
+
+    Search order:
+    1. WHISPER_SERVER_PATH environment variable (direct path to binary)
+    2. UNSLOTH_WHISPER_CPP_PATH env var (custom whisper.cpp install dir)
+    3. managed dir: <STUDIO_HOME or ~/.unsloth>/whisper.cpp/{,build/bin/}whisper-server
+    4. whisper-server on PATH
+    """
+    binary_name = "whisper-server.exe" if sys.platform == "win32" else "whisper-server"
+
+    def _layout_candidates(d: Path) -> list[Path]:
+        cands = [d / binary_name, d / "build" / "bin" / binary_name]
+        if sys.platform == "win32":
+            cands.append(d / "build" / "bin" / "Release" / binary_name)
+        return cands
+
+    env_path = os.environ.get("WHISPER_SERVER_PATH")
+    if env_path:
+        p = Path(env_path)
+        if _is_runnable(p):
+            return str(p)
+
+    custom_dir = os.environ.get("UNSLOTH_WHISPER_CPP_PATH")
+    if custom_dir:
+        for p in _layout_candidates(Path(custom_dir)):
+            if _is_runnable(p):
+                return str(p)
+
+    for p in _layout_candidates(_managed_whisper_cpp_dir()):
+        if _is_runnable(p):
+            return str(p)
+
+    return shutil.which(binary_name)
+
+
+def _is_runnable(p: Path) -> bool:
+    """A real whisper-server is an executable file. On Windows os.access(X_OK) is
+    effectively an existence check; on Unix it rejects a non-executable stub so a
+    half-written or wrong-mode file isn't mistaken for the server."""
+    return p.is_file() and (sys.platform == "win32" or os.access(p, os.X_OK))
+
+
+def _whisper_install_marker(binary: str) -> Optional[dict]:
+    """The prebuilt install marker above ``binary``, or None (source/custom builds)."""
+    return lookup_marker(binary).marker
+
+
+def slim_runtime_intact(binary: str) -> bool:
+    """True unless the marker says slim and the linked ggml runtime is missing
+    beside the server. New markers record the exact wired filenames
+    (linked_libraries), all of which must be present; legacy markers without the
+    field fall back to the per-OS core ggml name globs. A broken slim install
+    reads as engine-unavailable (reinstall via `unsloth studio update`), never a
+    crash at load."""
+    lookup = lookup_marker(binary)
+    marker = lookup.marker
+    if lookup.invalid or marker is None:
+        return not lookup.slim_collision
+    if not marker or marker.get("install_kind") != "slim":
+        return True
+    if lookup.authoritative:
+        valid = marker.get("component") == "whisper.cpp"
+        valid = valid and isinstance(marker.get("schema_version"), int)
+        valid = valid and all(
+            isinstance(marker.get(key), str) and marker[key]
+            for key in ("release_tag", "backend", "paired_llama_tag")
+        )
+        valid = valid and isinstance(marker.get("linked_libraries"), list)
+        valid = valid and bool(marker.get("linked_libraries"))
+        valid = valid and all(
+            isinstance(name, str) and name and Path(name).name == name
+            for name in marker["linked_libraries"]
+        )
+        if not valid:
+            return False
+    bin_dir = Path(binary).parent
+    linked = marker.get("linked_libraries")
+    if isinstance(linked, list) and linked and all(isinstance(name, str) for name in linked):
+        intact = all((bin_dir / name).is_file() for name in linked)
+    else:
+        if sys.platform == "win32":
+            required = ("ggml.dll", "ggml-base.dll")
+        elif sys.platform == "darwin":
+            required = ("libggml*.dylib", "libggml-base*.dylib")
+        else:
+            required = ("libggml.so*", "libggml-base.so*")
+        intact = all(any(p.is_file() for p in bin_dir.glob(pattern)) for pattern in required)
+    runtime_dirs = marker.get("linked_runtime_directories")
+    if intact and isinstance(runtime_dirs, list) and runtime_dirs:
+        intact = all(
+            isinstance(name, str)
+            and name
+            and (bin_dir / name).is_dir()
+            and any(path.is_file() for path in (bin_dir / name).rglob("*"))
+            for name in runtime_dirs
+        )
+    if intact and marker.get("backend") == "rocm":
+        expected_runtime_dirs = set() if sys.platform == "win32" else {"hipblaslt", "rocblas"}
+        intact = (
+            marker.get("runtime_wiring_version") == 2
+            and isinstance(runtime_dirs, list)
+            and set(runtime_dirs) == expected_runtime_dirs
+        )
+    if not intact:
+        logger.warning(
+            "slim whisper install is missing its linked ggml runtime at "
+            f"{bin_dir}; run `unsloth studio update` to reinstall it"
+        )
+    return intact
+
+
+def is_available() -> bool:
+    binary = find_whisper_server_binary()
+    if binary is None:
+        return False
+    if not slim_runtime_intact(binary):
+        return False
+    try:
+        import av  # noqa: F401
+    except Exception:
+        # No PyAV means every transcription 501s on decode.
+        return False
+    return True
+
+
+def ensure_engine_available() -> str:
+    binary = find_whisper_server_binary()
+    if binary is None:
+        raise SttEngineUnavailableError(
+            "The local transcription runtime is not installed. Run "
+            "`unsloth studio update` to install it."
+        )
+    if not slim_runtime_intact(binary):
+        raise SttEngineUnavailableError(
+            "The local transcription runtime is missing its paired ggml "
+            "libraries. Run `unsloth studio update` to reinstall it."
+        )
+    return binary
+
+
+# ---------------------------------------------------------------------------
+# whisper-server child-process environment
+# ---------------------------------------------------------------------------
+# Build the whisper-server env: prepend the binary dir (co-located libs win, and
+# a backstop where the loader ignores the rpath) and scrub secret-bearing vars the
+# binary never needs. On WSL2 ROCm the system HIP libs go first, since a bundle's
+# bare-metal HIP cannot drive /dev/dxg. A CUDA bundle ships libggml-cuda.so but not
+# libcudart/libcublas (paired with the user's PyTorch), so add the
+# CUDA-from-PyTorch runtime dirs the selection gated on, else the backend cannot
+# resolve a runtime that lives only in wheels. Mirrors llama's binary_env(); the
+# scrub/WSL/dedupe helpers live in utils.prebuilt.
+
+# Module-level aliases keep the historical patch points for tests and callers.
+_wsl_system_rocm_lib_dirs = wsl_system_rocm_lib_dirs
+_dedupe_existing_dirs = dedupe_existing_dirs
+
+
+def _whisper_server_child_env(binary: str) -> dict[str, str]:
+    """Env for the whisper-server subprocess: secrets scrubbed, home/profile vars
+    repointed at a managed scratch dir (a downloaded binary must not see the real
+    home's token caches), co-located libs on the loader path, WSL system HIP first
+    on WSL2 ROCm."""
+    env = scrub_env(os.environ)
+    isolate_home(env, str(_managed_whisper_cpp_dir() / ".child_home"))
+    bin_dir = str(Path(binary).parent)
+    # A CUDA bundle needs the CUDA-from-PyTorch wheel dirs so libcudart/libcublas
+    # resolve at launch when they live only in site-packages/nvidia/*/lib. Placed
+    # after bin_dir so co-located libs still win; empty for other bundles.
+    cuda_runtime_dirs: list[str] = []
+    bundle_dir = Path(bin_dir)
+    has_cuda_module = any(
+        path.is_file()
+        for pattern in ("libggml-cuda.so*", "ggml-cuda*.dll")
+        for path in bundle_dir.glob(pattern)
+    )
+    if has_cuda_module:
+        try:
+            from utils.prebuilt.runtime_libs import python_runtime_dirs
+            cuda_runtime_dirs = python_runtime_dirs()
+        except Exception:
+            cuda_runtime_dirs = []
+    if sys.platform == "win32":
+        var, lead = "PATH", [bin_dir, *cuda_runtime_dirs]
+    elif sys.platform == "darwin":
+        var, lead = "DYLD_LIBRARY_PATH", [bin_dir]
+    else:
+        var, lead = "LD_LIBRARY_PATH", [bin_dir, *cuda_runtime_dirs]
+        wsl_rocm = _wsl_system_rocm_lib_dirs()
+        if wsl_rocm:
+            lead = [*wsl_rocm, bin_dir, *cuda_runtime_dirs]
+            env.setdefault("HSA_ENABLE_DXG_DETECTION", "1")
+    existing = [p for p in env.get(var, "").split(os.pathsep) if p]
+    env[var] = os.pathsep.join(_dedupe_existing_dirs([*lead, *existing]))
+    return env
+
+
+# ---------------------------------------------------------------------------
+# Model file download (single files; deliberately outside the Model Hub flow)
+# ---------------------------------------------------------------------------
+
+
+def _cached_model_path(model_id: str) -> Optional[str]:
+    """Path of a fully downloaded GGML file in the shared HF cache, else None."""
+    from huggingface_hub import hf_hub_download
+    try:
+        return hf_hub_download(
+            repo_id = GGML_STT_REPOS[model_id],
+            filename = GGML_STT_MODELS[model_id],
+            local_files_only = True,
+        )
+    except Exception:
+        return None
+
+
+class _GgmlDownloadState:
+    """Tracks one background hf_hub_download of a curated GGML file."""
+
+    def __init__(self) -> None:
+        self._lock = threading.Lock()
+        self._thread: Optional[threading.Thread] = None
+        self._model_id: Optional[str] = None
+        self._error: Optional[str] = None
+        self._total_bytes: Optional[int] = None
+        self._etag: Optional[str] = None
+
+    def status(self) -> dict:
+        with self._lock:
+            downloading = self._thread is not None and self._thread.is_alive()
+            return {
+                "downloading": downloading,
+                "model": self._model_id if downloading else None,
+                "error": self._error,
+                "bytes_total": self._total_bytes if downloading else None,
+                "bytes_done": self._incomplete_bytes() if downloading else None,
+            }
+
+    def _incomplete_bytes(self) -> Optional[int]:
+        """Best-effort progress: size of the in-flight blob in the HF cache.
+
+        hf_hub_download writes ``blobs/<etag>.incomplete``; prefer this file's
+        etag, else the largest in-flight blob.
+        """
+        try:
+            from huggingface_hub.constants import HF_HUB_CACHE
+
+            # Caller may hold the non-reentrant self._lock; bare reads are safe.
+            model_id = self._model_id
+            if not model_id:
+                return None
+            repo_dir = (
+                Path(HF_HUB_CACHE)
+                / f"models--{GGML_STT_REPOS[model_id].replace('/', '--')}"
+                / "blobs"
+            )
+            if not repo_dir.is_dir():
+                return None
+            etag = self._etag
+            if etag:
+                target = repo_dir / f"{etag}.incomplete"
+                if target.is_file():
+                    return target.stat().st_size
+            sizes = [p.stat().st_size for p in repo_dir.glob("*.incomplete") if p.is_file()]
+            return max(sizes) if sizes else None
+        except Exception:
+            return None
+
+    def start(
+        self,
+        model_id: str,
+        hf_token: Optional[str] = None,
+    ) -> None:
+        model_id = resolve_ggml_model_id(model_id)
+        with self._lock:
+            if self._thread is not None and self._thread.is_alive():
+                if self._model_id == model_id:
+                    return
+                raise SttModelIdError(
+                    f"Another GGUF dictation model ('{self._model_id}') is still "
+                    "downloading; wait for it to finish."
+                )
+            self._model_id = model_id
+            self._error = None
+            self._total_bytes = None
+            self._etag = None
+            thread = threading.Thread(target = self._run, args = (model_id, hf_token), daemon = True)
+            self._thread = thread
+            thread.start()
+
+    def _run(self, model_id: str, hf_token: Optional[str]) -> None:
+        repo_id = GGML_STT_REPOS[model_id]
+        filename = GGML_STT_MODELS[model_id]
+        try:
+            from huggingface_hub import (
+                get_hf_file_metadata,
+                hf_hub_download,
+                hf_hub_url,
+            )
+            try:
+                # One HEAD request for the total and etag.
+                meta = get_hf_file_metadata(hf_hub_url(repo_id, filename), token = hf_token or None)
+                with self._lock:
+                    self._total_bytes = meta.size
+                    self._etag = meta.etag
+            except Exception:
+                pass
+            hf_hub_download(
+                repo_id = repo_id,
+                filename = filename,
+                token = hf_token or None,
+            )
+        except Exception as exc:
+            logger.warning("GGUF STT download failed for %s: %s", model_id, exc)
+            with self._lock:
+                self._error = f"Download failed for '{model_id}'."
+
+
+_download_state = _GgmlDownloadState()
+
+
+def start_model_download(model: Optional[str], hf_token: Optional[str] = None) -> None:
+    _download_state.start(resolve_ggml_model_id(model), hf_token)
+
+
+def download_status() -> dict:
+    return _download_state.status()
+
+
+# ---------------------------------------------------------------------------
+# WAV packaging
+# ---------------------------------------------------------------------------
+
+
+def _pcm_to_wav_bytes(decoded_audio) -> bytes:
+    """Wrap decoded float32 mono 16 kHz PCM into an in-memory 16-bit WAV."""
+    import numpy as np
+
+    clipped = np.clip(decoded_audio, -1.0, 1.0)
+    pcm16 = (clipped * 32767.0).astype("<i2")
+    buf = io.BytesIO()
+    with wave.open(buf, "wb") as w:
+        w.setnchannels(1)
+        w.setsampwidth(2)
+        w.setframerate(_TARGET_SAMPLE_RATE)
+        w.writeframes(pcm16.tobytes())
+    return buf.getvalue()
+
+
+# ---------------------------------------------------------------------------
+# Sidecar
+# ---------------------------------------------------------------------------
+
+
+class GgmlSttSidecar:
+    """Owns one whisper-server subprocess and proxies dictation to it."""
+
+    def __init__(self, keep_alive_seconds: float = STT_KEEP_ALIVE_SECONDS) -> None:
+        self._lock = threading.RLock()
+        self._process: Optional[subprocess.Popen] = None
+        self._port: Optional[int] = None
+        self._model_id: Optional[str] = None
+        self._idle_timer: Optional[threading.Timer] = None
+        self._idle_generation = 0
+        self._keep_alive_seconds = keep_alive_seconds
+        # Set while whisper-server starts so training admission can account for
+        # the accelerator memory it is about to bind. Read without the lock.
+        self._loading = False
+        # A still-starting whisper-server is cancellable so training can preempt
+        # it before it binds accelerator memory. Assigned inside self._lock but
+        # acted on without it: cancel_pending_load() runs while load() holds the
+        # lock, so the event is the source of truth and terminating the process
+        # is a best-effort fast path.
+        self._load_cancel_event: Optional[threading.Event] = None
+        self._starting_process: Optional[subprocess.Popen] = None
+        # Set before the updater waits for _lock, then kept set while it owns
+        # the lock and atomically replaces the managed install tree. New loads
+        # fail fast instead of starting a process from files being swapped.
+        self._update_in_progress = False
+
+    @property
+    def loaded_model(self) -> Optional[str]:
+        # Lock-free status read (like stt_sidecar.py): transcribe() holds
+        # self._lock for the whole inference call (up to
+        # _TRANSCRIBE_TIMEOUT_SECONDS), and status polls plus training admission
+        # must not block behind it. _process_alive() snapshots self._process
+        # before poll(), which subprocess guards with _waitpid_lock, so a
+        # concurrent unload is safe.
+        return self._model_id if self._process_alive() else None
+
+    @property
+    def device(self) -> Optional[str]:
+        return "whisper.cpp" if self._process_alive() else None
+
+    def is_loading(self) -> bool:
+        # True only while whisper-server is starting (seconds to bind its GPU
+        # backend); load() sets and clears the flag around that window.
+        return self._loading
+
+    @property
+    def keep_alive_seconds(self) -> float:
+        return self._keep_alive_seconds
+
+    def _process_alive(self) -> bool:
+        # Snapshot self._process once: a concurrent unload() nulls it under the
+        # lock, so lock-free readers would otherwise re-read None between the
+        # truthiness check and .poll().
+        process = self._process
+        return process is not None and process.poll() is None
+
+    # -- idle unload ------------------------------------------------------
+
+    def _cancel_idle_unload_locked(self) -> None:
+        self._idle_generation += 1
+        if self._idle_timer is not None:
+            self._idle_timer.cancel()
+            self._idle_timer = None
+
+    def _schedule_idle_unload_locked(self) -> None:
+        self._cancel_idle_unload_locked()
+        if not self._process_alive():
+            return
+        generation = self._idle_generation
+        timer = threading.Timer(self._keep_alive_seconds, self._idle_unload, args = (generation,))
+        timer.daemon = True
+        self._idle_timer = timer
+        timer.start()
+
+    def _idle_unload(self, generation: int) -> None:
+        with self._lock:
+            if generation != self._idle_generation:
+                return
+            logger.info("Unloading idle GGUF STT model %s", self._model_id)
+            self._release_locked()
+
+    # -- process lifecycle -------------------------------------------------
+
+    def _release_locked(self) -> None:
+        self._cancel_idle_unload_locked()
+        process = self._process
+        self._process = None
+        self._port = None
+        self._model_id = None
+        if process is not None and process.poll() is None:
+            process.terminate()
+            try:
+                process.wait(timeout = 10)
+            except subprocess.TimeoutExpired:
+                process.kill()
+                process.wait(timeout = 10)
+        if process is not None:
+            forget_pid(process.pid)
+
+    def unload(self) -> None:
+        with self._lock:
+            self._release_locked()
+
+    def _raise_if_update_in_progress(self) -> None:
+        if self._update_in_progress:
+            raise SttEngineUnavailableError(
+                "The local transcription runtime is being updated. Try dictation again shortly."
+            )
+
+    @contextmanager
+    def update_maintenance(self) -> Iterator[bool]:
+        """Block new loads while the managed whisper.cpp tree is replaced.
+
+        The flag is published before waiting for an existing transcription to
+        release ``_lock``. Holding that lock across the yielded installer phase
+        prevents Windows from relocking the executable and prevents every host
+        from starting a process against a partially swapped tree. The yielded
+        value records whether a warm model had to be unloaded.
+        """
+        self._update_in_progress = True
+        try:
+            with self._lock:
+                model_was_active = self._process_alive()
+                self._release_locked()
+                yield model_was_active
+        finally:
+            self._update_in_progress = False
+
+    def cancel_pending_load(self) -> bool:
+        # Preempt a starting whisper-server so training does not launch while it
+        # binds accelerator memory. load() holds self._lock for the whole startup,
+        # so act without the lock: signal abort and terminate the starting
+        # process. _wait_for_server observes the event and raises, then load()
+        # reaps the process and releases the lock.
+        if not self._loading:
+            return False
+        event = self._load_cancel_event
+        if event is None:
+            return False
+        event.set()
+        process = self._starting_process
+        if process is not None and process.poll() is None:
+            try:
+                process.terminate()
+            except Exception:
+                pass
+        return True
+
+    def wait_for_load_to_settle(self) -> None:
+        # load() holds self._lock across startup and cancel cleanup, so acquiring
+        # it blocks until a cancelled server is killed, reaped, and its
+        # accelerator memory released.
+        with self._lock:
+            pass
+
+    @staticmethod
+    def _reserve_free_port() -> tuple[socket.socket, int]:
+        """Bind an ephemeral port and keep the socket held.
+
+        The caller closes the reservation immediately before spawning
+        whisper-server, shrinking the window in which another local process
+        could bind the port. SO_REUSEADDR lets the child rebind right after.
+        """
+        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        s.bind(("127.0.0.1", 0))
+        return s, s.getsockname()[1]
+
+    def _ensure_model_downloaded(self, model_id: str) -> str:
+        path = _cached_model_path(model_id)
+        if path is None:
+            raise SttModelNotDownloadedError(
+                f"STT model '{model_id}' (GGUF) is not downloaded. "
+                "Download it in Settings, then Voice, before loading it."
+            )
+        return path
+
+    def load(self, model: Optional[str] = None) -> None:
+        """Start (or switch) whisper-server for the requested curated model."""
+        self._raise_if_update_in_progress()
+        model_id = resolve_ggml_model_id(model)
+        with self._lock:
+            self._raise_if_update_in_progress()
+            binary = ensure_engine_available()
+            if self._process_alive() and self._model_id == model_id:
+                self._schedule_idle_unload_locked()
+                return
+            model_path = self._ensure_model_downloaded(model_id)
+            self._release_locked()
+            reservation, port = self._reserve_free_port()
+            command = [binary, "-m", model_path, "--host", "127.0.0.1", "--port", str(port)]
+            marker = _whisper_install_marker(binary)
+            if _training_active():
+                # Keep whisper.cpp off the accelerator during training (like the
+                # Transformers sidecar's CPU choice) so a mid-training dictation
+                # cannot reclaim the VRAM training just freed.
+                command.append("--no-gpu")
+            elif marker is not None and marker.get("backend") == "cpu":
+                # A deliberate CPU install must stay CPU: the slim wiring links
+                # every llama ggml backend (including CUDA/ROCm), so without
+                # this flag a cpu-selected install would still grab the GPU.
+                command.append("--no-gpu")
+            logger.info(
+                "Starting whisper-server for STT model %s on 127.0.0.1:%s",
+                model_id,
+                port,
+            )
+            cancel_event = threading.Event()
+            self._load_cancel_event = cancel_event
+            self._loading = True
+            try:
+                # Release the reservation as late as possible: whisper-server
+                # binds the port moments after this close.
+                reservation.close()
+                process = subprocess.Popen(
+                    command,
+                    stdout = subprocess.DEVNULL,
+                    stderr = subprocess.DEVNULL,
+                    stdin = subprocess.DEVNULL,
+                    # Co-located GPU libs on the loader path (WSL system HIP first),
+                    # secrets scrubbed from the downloaded binary's env.
+                    env = _whisper_server_child_env(binary),
+                    # Die with Studio (Linux PDEATHSIG, Windows job) so a crash
+                    # never orphans a server holding the model.
+                    **child_popen_kwargs(),
+                )
+                self._starting_process = process
+                adopt_pid(process.pid)  # terminate_all backstop for graceful exits
+                try:
+                    self._wait_for_server(process, port, cancel_event)
+                except Exception:
+                    if process.poll() is None:
+                        process.kill()
+                        process.wait(timeout = 10)
+                    forget_pid(process.pid)
+                    raise
+                self._process = process
+                self._port = port
+                self._model_id = model_id
+                self._schedule_idle_unload_locked()
+            finally:
+                reservation.close()  # no-op when already released before spawn
+                self._loading = False
+                self._load_cancel_event = None
+                self._starting_process = None
+
+    @staticmethod
+    def _wait_for_server(
+        process: subprocess.Popen,
+        port: int,
+        cancel_event: Optional[threading.Event] = None,
+    ) -> None:
+        deadline = time.monotonic() + _SERVER_START_TIMEOUT_SECONDS
+        while time.monotonic() < deadline:
+            if cancel_event is not None and cancel_event.is_set():
+                raise SttLoadCancelledError(
+                    "GGUF STT model loading was cancelled so training could start."
+                )
+            if process.poll() is not None:
+                raise SttEngineUnavailableError(
+                    "The local transcription runtime exited before becoming "
+                    "ready; the model file may be corrupt or unsupported."
+                )
+            # Require a whisper-server-specific response twice, with the managed
+            # child alive around each probe. An arbitrary local process that won
+            # the bind race would otherwise be mistaken for the sidecar and
+            # receive the user's microphone audio.
+            if GgmlSttSidecar._probe_is_whisper_server(process, port) and (
+                GgmlSttSidecar._probe_is_whisper_server(process, port)
+            ):
+                return
+            time.sleep(0.2)
+        raise SttEngineUnavailableError("The local transcription runtime did not start in time.")
+
+    @staticmethod
+    def _probe_is_whisper_server(process: subprocess.Popen, port: int) -> bool:
+        """One readiness probe: our child is alive and the responder looks like
+        whisper.cpp's server (its index page and errors identify whisper)."""
+        if process.poll() is not None:
+            return False
+        try:
+            req = urllib.request.Request(f"http://127.0.0.1:{port}/", method = "GET")
+            with urllib.request.urlopen(req, timeout = 2) as response:
+                body = response.read(65536)
+        except Exception:
+            return False
+        if process.poll() is not None:
+            return False
+        return b"whisper" in body.lower()
+
+    # -- transcription ------------------------------------------------------
+
+    def transcribe(
+        self,
+        audio: bytes,
+        model: Optional[str] = None,
+        language: Optional[str] = None,
+        fast: bool = False,
+    ) -> dict:
+        """Transcribe encoded audio bytes via whisper-server.
+
+        Accepts any container PyAV can decode (same validation and caps as the
+        Transformers sidecar). Returns {text, language, duration, model}.
+        """
+        self._raise_if_update_in_progress()
+        ensure_engine_available()
+        model_id = resolve_ggml_model_id(model)
+        lang = normalize_whisper_language(language)
+        known_languages = _known_whisper_languages()
+        if lang is not None and known_languages is not None and lang not in known_languages:
+            raise SttLanguageError(
+                f"Language '{language}' is not supported by STT model '{model_id}'."
+            )
+        # Reject a missing model before decoding so a long clip does not burn CPU
+        # only to 409 (matches the Transformers sidecar's preflight).
+        self._ensure_model_downloaded(model_id)
+        decoded_audio = _decode_audio_bounded(audio)
+        wav_bytes = _pcm_to_wav_bytes(decoded_audio)
+        with self._lock:
+            try:
+                self.load(model_id)
+                text = self._post_inference(wav_bytes, lang, fast)
+            finally:
+                self._schedule_idle_unload_locked()
+        duration = (len(decoded_audio) / _TARGET_SAMPLE_RATE) if len(decoded_audio) else None
+        return {
+            "text": text,
+            "language": lang,
+            "duration": duration,
+            "model": model_id,
+        }
+
+    def _post_inference(self, wav_bytes: bytes, lang: Optional[str], fast: bool) -> str:
+        boundary = uuid.uuid4().hex
+        fields = {
+            "temperature": "0.0",
+            "response_format": "json",
+            # Match the Transformers sidecar: 5-way beam search, greedy for fast.
+            "beam_size": "1" if fast else "5",
+            "language": lang or "auto",
+        }
+        parts: list[bytes] = []
+        for name, value in fields.items():
+            parts.append(
+                (
+                    f"--{boundary}\r\nContent-Disposition: form-data; "
+                    f'name="{name}"\r\n\r\n{value}\r\n'
+                ).encode()
+            )
+        parts.append(
+            (
+                f"--{boundary}\r\nContent-Disposition: form-data; "
+                'name="file"; filename="dictation.wav"\r\n'
+                "Content-Type: audio/wav\r\n\r\n"
+            ).encode()
+            + wav_bytes
+            + b"\r\n"
+        )
+        parts.append(f"--{boundary}--\r\n".encode())
+        body = b"".join(parts)
+        req = urllib.request.Request(
+            f"http://127.0.0.1:{self._port}/inference",
+            data = body,
+            headers = {"Content-Type": f"multipart/form-data; boundary={boundary}"},
+        )
+        try:
+            with urllib.request.urlopen(req, timeout = _TRANSCRIBE_TIMEOUT_SECONDS) as resp:
+                payload = json.load(resp)
+        except SttAudioDecodeError:
+            raise
+        except Exception as exc:
+            raise SttEngineUnavailableError(
+                "The local transcription runtime did not answer the request."
+            ) from exc
+        text = payload.get("text")
+        if not isinstance(text, str):
+            raise SttAudioDecodeError("Could not decode the audio.")
+        # whisper.cpp joins segments with newlines; dictation wants one line.
+        return " ".join(part.strip() for part in text.splitlines() if part.strip()).strip()
+
+
+_sidecar: Optional[GgmlSttSidecar] = None
+
+
+def get_ggml_stt_sidecar() -> GgmlSttSidecar:
+    global _sidecar
+    if _sidecar is None:
+        _sidecar = GgmlSttSidecar()
+    return _sidecar
diff --git a/studio/backend/core/inference/stt_sidecar.py b/studio/backend/core/inference/stt_sidecar.py
new file mode 100644
index 0000000000..edf57c16e3
--- /dev/null
+++ b/studio/backend/core/inference/stt_sidecar.py
@@ -0,0 +1,1142 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""
+Standalone speech-to-text (STT) sidecar for dictation.
+
+Loads a Whisper model (via Transformers) in the backend process, separate from
+the chat model's inference subprocess, so dictation works with any chat model
+without evicting it. Curated defaults plus any Transformers-compatible Whisper
+repo; weights come through Studio's Model Hub and stay warm briefly between
+dictations. CUDA runs float16; MPS and CPU run float32.
+"""
+
+from __future__ import annotations
+
+import gc
+import hashlib
+import io
+import json
+import os
+import re
+import threading
+import uuid
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Optional
+
+from loggers import get_logger
+
+logger = get_logger(__name__)
+
+# Multilingual Whisper defaults: stable API/UI id -> Hub repository. A request
+# may instead pass a validated Hugging Face `owner/model` id.
+STT_MODELS: dict[str, str] = {
+    "tiny": "unsloth/whisper-tiny",
+    "base": "unsloth/whisper-base",
+    "small": "unsloth/whisper-small",
+    "large-v3-turbo": "unsloth/whisper-large-v3-turbo",
+    "large-v3": "unsloth/whisper-large-v3",
+}
+DEFAULT_STT_MODEL = "small"
+STT_KEEP_ALIVE_SECONDS = 5 * 60
+_HF_REPO_ID = re.compile(r"^[A-Za-z0-9][A-Za-z0-9._-]{0,95}/[A-Za-z0-9][A-Za-z0-9._-]{0,95}$")
+_HF_COMMIT_SHA = re.compile(r"^[0-9a-f]{40}$")
+
+# Bound decoded PCM length so a crafted upload cannot exhaust memory (callers
+# also cap the encoded bytes).
+_MAX_AUDIO_SECONDS = 30 * 60
+_TARGET_SAMPLE_RATE = 16000
+
+# Non-weight files WhisperProcessor/WhisperForConditionalGeneration may load.
+# Weight selection is built from pinned Hub metadata. A custom repo id is
+# attacker-controllable, so only safetensors weights are accepted: a
+# pytorch_model.bin is a pickle and executes code while Transformers
+# deserializes it (see utils/security/file_security.py), and this path skips
+# the malware gate the normal model loader applies.
+_STT_SNAPSHOT_SUPPORT_FILES = (
+    "config.json",
+    "generation_config.json",
+    "preprocessor_config.json",
+    "processor_config.json",
+    "tokenizer.json",
+    "tokenizer_config.json",
+    "vocab.json",
+    "merges.txt",
+    "normalizer.json",
+    "special_tokens_map.json",
+    "added_tokens.json",
+)
+_STT_SAFETENSORS_INDEX = "model.safetensors.index.json"
+_STT_SAFETENSORS_WEIGHTS = "model.safetensors"
+_STT_REVISION_RECORD_VERSION = 1
+
+
+@dataclass(frozen = True)
+class _SelectedHubFile:
+    path: str
+    size: int
+    blob_key: Optional[str]
+
+
+@dataclass(frozen = True)
+class _CachedSttSnapshot:
+    path: Optional[Path]
+    is_multilingual: Optional[bool]
+
+
+class SttUnavailableError(RuntimeError):
+    """The STT backend (PyTorch/Transformers or PyAV) is not installed."""
+
+
+class SttLoadCancelledError(RuntimeError):
+    """An in-flight STT model load was cancelled for training."""
+
+
+class SttModelNotDownloadedError(RuntimeError):
+    """The selected model is not complete in the shared Hub cache."""
+
+
+class SttModelIdError(ValueError):
+    """The requested custom model is not a valid Hugging Face repository id."""
+
+
+class SttModelCompatibilityError(ValueError):
+    """The requested repository is not a Transformers Whisper checkpoint."""
+
+
+class SttAudioDecodeError(ValueError):
+    """The uploaded bytes could not be decoded as audio."""
+
+
+class SttAudioTooLongError(ValueError):
+    """The decoded audio exceeds the bounded transcription duration."""
+
+
+class SttLanguageError(ValueError):
+    """The requested language is not supported by the selected STT model."""
+
+
+_WHISPER_LANGUAGE_ALIASES = {
+    # Legacy/browser BCP-47 primaries whose Whisper code differs.
+    "cmn": "zh",
+    "fil": "tl",
+    "in": "id",
+    "iw": "he",
+    "ji": "yi",
+    "nb": "no",
+    "nn": "no",
+}
+
+
+def normalize_whisper_language(language: Optional[str]) -> Optional[str]:
+    """Convert a BCP-47 locale into the short code Whisper expects."""
+    if not language:
+        return None
+    normalized = language.strip().replace("_", "-").lower()
+    if not normalized or normalized == "auto":
+        return None
+    primary = normalized.split("-", 1)[0]
+    return _WHISPER_LANGUAGE_ALIASES.get(primary, primary)
+
+
+def _known_whisper_languages() -> Optional[frozenset[str]]:
+    """Return Whisper's language codes without constructing/loading a model."""
+    try:
+        from transformers.models.whisper.tokenization_whisper import LANGUAGES
+    except Exception:
+        # Transformers unavailable or the constant moved: skip the check.
+        return None
+    return frozenset(LANGUAGES)
+
+
+def ensure_stt_available() -> None:
+    """Raise when the complete local Whisper backend cannot be imported."""
+    try:
+        import av  # noqa: F401
+        import torch  # noqa: F401
+        import transformers  # noqa: F401
+    except Exception as exc:
+        raise SttUnavailableError(
+            "Speech-to-text needs PyTorch, Transformers, and PyAV. "
+            "Run `unsloth studio update` to install them."
+        ) from exc
+
+
+def is_available() -> bool:
+    """True when the complete local Whisper backend can be imported."""
+    try:
+        ensure_stt_available()
+    except SttUnavailableError:
+        return False
+    return True
+
+
+def resolve_model_id(model: Optional[str]) -> str:
+    """Resolve a curated id or validate a custom Hugging Face repository."""
+    if not model:
+        return DEFAULT_STT_MODEL
+    normalized = model.strip()
+    if normalized in STT_MODELS:
+        return normalized
+    if _HF_REPO_ID.fullmatch(normalized):
+        return normalized
+    raise SttModelIdError(
+        "STT model must be one of Studio's defaults or a Hugging Face "
+        "repository in 'owner/model' form."
+    )
+
+
+def resolve_model_repo(model_id: str) -> str:
+    """Return the Hub repository for a curated or custom model id."""
+    resolved = resolve_model_id(model_id)
+    return STT_MODELS.get(resolved, resolved)
+
+
+def _is_whisper_config(config: object) -> bool:
+    """True when Hub/local config metadata identifies a Whisper ASR model."""
+    if not isinstance(config, dict):
+        return False
+    model_type = config.get("model_type")
+    if isinstance(model_type, str) and model_type.strip().lower() == "whisper":
+        return True
+    architectures = config.get("architectures")
+    return isinstance(architectures, list) and any(
+        isinstance(name, str) and name == "WhisperForConditionalGeneration"
+        for name in architectures
+    )
+
+
+def _read_json_object(path: Path) -> dict:
+    try:
+        with open(path, "r", encoding = "utf-8") as file:
+            value = json.load(file)
+        return value if isinstance(value, dict) else {}
+    except Exception:
+        return {}
+
+
+def _active_hf_hub_cache() -> Path:
+    """Return the active Hub cache while respecting runtime test overrides."""
+    explicit = (os.environ.get("HF_HUB_CACHE") or "").strip()
+    if explicit:
+        return Path(explicit).expanduser()
+    hf_home = (os.environ.get("HF_HOME") or "").strip()
+    if hf_home:
+        return Path(hf_home).expanduser() / "hub"
+    from huggingface_hub.constants import HF_HUB_CACHE
+
+    return Path(HF_HUB_CACHE)
+
+
+def _repo_cache_dir(repo: str) -> Path:
+    return _active_hf_hub_cache() / f"models--{repo.replace('/', '--')}"
+
+
+def _revision_record_path(repo: str) -> Path:
+    from utils.paths.storage_roots import cache_root
+    digest = hashlib.sha256(repo.encode("utf-8")).hexdigest()
+    return cache_root() / "stt-revisions" / f"{digest}.json"
+
+
+def _write_revision_record(repo: str, revision: str) -> None:
+    """Persist immutable identity only, never an HF-cache absolute path."""
+    if not _HF_COMMIT_SHA.fullmatch(revision):
+        return
+    path = _revision_record_path(repo)
+    tmp = path.with_name(f".{path.name}.tmp-{uuid.uuid4().hex[:8]}")
+    try:
+        path.parent.mkdir(parents = True, exist_ok = True)
+        with tmp.open("w", encoding = "utf-8") as handle:
+            json.dump(
+                {
+                    "version": _STT_REVISION_RECORD_VERSION,
+                    "repo": repo,
+                    "revision": revision,
+                },
+                handle,
+            )
+            handle.flush()
+            os.fsync(handle.fileno())
+        os.replace(tmp, path)
+    except OSError as exc:
+        logger.debug("Could not persist STT revision for %s: %s", repo, exc)
+        try:
+            tmp.unlink(missing_ok = True)
+        except OSError:
+            pass
+
+
+def _read_revision_record(repo: str) -> Optional[str]:
+    payload = _read_json_object(_revision_record_path(repo))
+    if payload.get("version") != _STT_REVISION_RECORD_VERSION or payload.get("repo") != repo:
+        return None
+    revision = payload.get("revision")
+    return revision if isinstance(revision, str) and _HF_COMMIT_SHA.fullmatch(revision) else None
+
+
+def _safe_snapshot_for_revision(repo: str, revision: str) -> Optional[Path]:
+    """Resolve a canonical SHA below this repository's active snapshots dir."""
+    if not _HF_COMMIT_SHA.fullmatch(revision):
+        return None
+    snapshots = _repo_cache_dir(repo) / "snapshots"
+    candidate = snapshots / revision
+    try:
+        snapshots_resolved = snapshots.resolve()
+        candidate_resolved = candidate.resolve()
+    except (OSError, RuntimeError):
+        return None
+    if snapshots_resolved not in candidate_resolved.parents or not candidate_resolved.is_dir():
+        return None
+    return candidate_resolved
+
+
+def _snapshot_usable(model_id: str, snapshot: Path) -> bool:
+    if not _snapshot_is_complete(snapshot):
+        return False
+    if model_id not in STT_MODELS:
+        return _is_whisper_config(_read_json_object(snapshot / "config.json"))
+    return True
+
+
+def _find_complete_cached_snapshot(model: Optional[str]) -> Optional[Path]:
+    """Find one complete local snapshot without contacting the Hub."""
+    model_id = resolve_model_id(model)
+    repo = resolve_model_repo(model_id)
+
+    recorded = _read_revision_record(repo)
+    if recorded:
+        snapshot = _safe_snapshot_for_revision(repo, recorded)
+        if snapshot is not None and _snapshot_usable(model_id, snapshot):
+            return snapshot
+
+    ref = _repo_cache_dir(repo) / "refs" / "main"
+    try:
+        revision = ref.read_text(encoding = "utf-8").strip()
+    except OSError:
+        revision = ""
+    snapshot = _safe_snapshot_for_revision(repo, revision)
+    if snapshot is not None and _snapshot_usable(model_id, snapshot):
+        _write_revision_record(repo, revision)
+        return snapshot
+
+    snapshots = _repo_cache_dir(repo) / "snapshots"
+    try:
+        revisions = sorted(
+            (
+                (path.stat().st_mtime_ns, path.name)
+                for path in snapshots.iterdir()
+                if path.is_dir() and _HF_COMMIT_SHA.fullmatch(path.name)
+            ),
+            reverse = True,
+        )
+    except OSError:
+        return None
+    for _mtime, revision in revisions:
+        snapshot = _safe_snapshot_for_revision(repo, revision)
+        if snapshot is not None and _snapshot_usable(model_id, snapshot):
+            _write_revision_record(repo, revision)
+            return snapshot
+    return None
+
+
+def _selected_file_from_sibling(sibling) -> _SelectedHubFile:
+    lfs = getattr(sibling, "lfs", None)
+    blob_key = getattr(lfs, "sha256", None) or getattr(sibling, "blob_id", None)
+    return _SelectedHubFile(
+        path = sibling.rfilename,
+        size = max(0, int(getattr(sibling, "size", 0) or 0)),
+        blob_key = blob_key if isinstance(blob_key, str) and blob_key else None,
+    )
+
+
+def _select_snapshot_files(info, load_index) -> tuple[_SelectedHubFile, ...]:
+    """Select support files and one complete safetensors weight set. Pickle
+    (pytorch_model.bin) weights are never selected: they are an RCE sink on a
+    custom repo id (see _STT_SNAPSHOT_SUPPORT_FILES)."""
+    siblings = {
+        sibling.rfilename: sibling
+        for sibling in (getattr(info, "siblings", None) or [])
+        if isinstance(getattr(sibling, "rfilename", None), str)
+    }
+    selected = {name for name in _STT_SNAPSHOT_SUPPORT_FILES if name in siblings}
+
+    index_name: Optional[str] = None
+    if _STT_SAFETENSORS_INDEX in siblings:
+        index_name = _STT_SAFETENSORS_INDEX
+    elif _STT_SAFETENSORS_WEIGHTS in siblings:
+        selected.add(_STT_SAFETENSORS_WEIGHTS)
+    else:
+        raise SttModelCompatibilityError(
+            "The STT repository has no safetensors model weights. Only safetensors "
+            "checkpoints are supported; convert the model with save_pretrained(safe_serialization=True)."
+        )
+
+    if index_name is not None:
+        weight_map = load_index(index_name).get("weight_map")
+        if not isinstance(weight_map, dict) or not weight_map:
+            raise SttModelCompatibilityError(f"Invalid checkpoint index '{index_name}'.")
+        shards = set(weight_map.values())
+        if not all(isinstance(shard, str) and shard in siblings for shard in shards):
+            raise SttModelCompatibilityError(f"Checkpoint index '{index_name}' has missing shards.")
+        # The index JSON is attacker-controlled: a safetensors index can name
+        # pytorch_model-*.bin shards, which Transformers still loads through
+        # torch.load (pickle) since it dispatches per shard by file extension.
+        # Require every shard to be safetensors so no pickle file is selected.
+        if not all(shard.endswith(".safetensors") for shard in shards):
+            raise SttModelCompatibilityError(
+                f"Checkpoint index '{index_name}' references non-safetensors shards."
+            )
+        selected.add(index_name)
+        selected.update(shards)
+
+    return tuple(_selected_file_from_sibling(siblings[name]) for name in sorted(selected))
+
+
+def validate_remote_model(model: Optional[str], hf_token: Optional[str] = None) -> dict:
+    """Verify a custom Hub repository is Whisper-compatible without downloading weights."""
+    model_id = resolve_model_id(model)
+    repo = resolve_model_repo(model_id)
+    if model_id in STT_MODELS:
+        return {"model": model_id, "repo": repo}
+
+    try:
+        from huggingface_hub import HfApi
+        info = HfApi(token = hf_token or False).model_info(
+            repo,
+            expand = ["config", "sha"],
+            timeout = 10,
+        )
+    except Exception as exc:
+        raise SttModelCompatibilityError(
+            f"Could not verify STT model '{model_id}'. "
+            "Check that the repository exists and your Hugging Face token can access it."
+        ) from exc
+
+    if not _is_whisper_config(getattr(info, "config", None)):
+        raise SttModelCompatibilityError(
+            f"STT model '{model_id}' is not a compatible Transformers Whisper model."
+        )
+    revision = getattr(info, "sha", None)
+    if not isinstance(revision, str) or not _HF_COMMIT_SHA.fullmatch(revision):
+        raise SttModelCompatibilityError(
+            f"Could not resolve an immutable revision for STT model '{model_id}'."
+        )
+    # The commit that was validated; the download pins to it so the repo cannot
+    # be swapped between validation and snapshot_download (TOCTOU).
+    return {"model": model_id, "repo": repo, "revision": revision}
+
+
+def _is_missing_local_model_error(exc: BaseException) -> bool:
+    """Recognize a local-cache-only miss by name/message, without importing HF
+    internals (tolerates huggingface_hub/Transformers moving the exception)."""
+    current: Optional[BaseException] = exc
+    seen: set[int] = set()
+    while current is not None and id(current) not in seen:
+        seen.add(id(current))
+        if type(current).__name__ in ("LocalEntryNotFoundError", "EntryNotFoundError"):
+            return True
+        message = str(current).lower()
+        if "local_files_only" in message or "does not appear to have a file" in message:
+            return True
+        current = current.__cause__ or current.__context__
+    return False
+
+
+def _snapshot_is_complete(snapshot: Path) -> bool:
+    """True when a cached snapshot holds every file loading needs.
+
+    An aborted download can leave only metadata behind, and an offline lookup
+    cannot know the repo's full file list, so verify config, preprocessor,
+    tokenizer, and weights directly. is_file() follows cache symlinks, so a
+    link from an interrupted blob download does not count.
+    """
+    # Safetensors only: a cached pytorch_model.bin is a pickle load path and is
+    # never treated as a usable snapshot (a repo shipping only pickle weights
+    # re-resolves and fails closed in _select_snapshot_files).
+    index = snapshot / _STT_SAFETENSORS_INDEX
+    if index.is_file():
+        # Sharded safetensors checkpoint: every shard must exist and be
+        # safetensors (a safe index naming .bin shards would still pickle-load
+        # them, matching the _select_snapshot_files guard).
+        weight_map = _read_json_object(index).get("weight_map")
+        if not isinstance(weight_map, dict) or not weight_map:
+            return False
+        shards = set(weight_map.values())
+        if not all(isinstance(shard, str) and shard.endswith(".safetensors") for shard in shards):
+            return False
+        has_weights = all((snapshot / shard).is_file() for shard in shards)
+    else:
+        has_weights = (snapshot / _STT_SAFETENSORS_WEIGHTS).is_file()
+    # WhisperProcessor needs the tokenizer: either the fast tokenizer.json or
+    # the slow vocab.json + merges.txt pair.
+    has_tokenizer = (snapshot / "tokenizer.json").is_file() or (
+        (snapshot / "vocab.json").is_file() and (snapshot / "merges.txt").is_file()
+    )
+    return (
+        has_weights
+        and has_tokenizer
+        and (snapshot / "config.json").is_file()
+        and (snapshot / "preprocessor_config.json").is_file()
+    )
+
+
+def is_model_downloaded(model: Optional[str]) -> bool:
+    """True when a usable Whisper snapshot exists in the local HF cache."""
+    try:
+        return _find_complete_cached_snapshot(model) is not None
+    except Exception:
+        return False
+
+
+class _SnapshotDownloadState:
+    """Tracks one background snapshot_download of a dictation repository.
+
+    Like stt_ggml_sidecar's tracker, but a Transformers checkpoint is a whole
+    repo, so progress is the byte count of its cache blobs.
+    """
+
+    def __init__(self) -> None:
+        self._lock = threading.Lock()
+        self._thread: Optional[threading.Thread] = None
+        self._model_id: Optional[str] = None
+        self._repo: Optional[str] = None
+        self._error: Optional[str] = None
+        self._total_bytes: Optional[int] = None
+        self._selected_files: tuple[_SelectedHubFile, ...] = ()
+        self._complete = False
+
+    def status(self) -> dict:
+        with self._lock:
+            downloading = self._thread is not None and self._thread.is_alive()
+            show_progress = downloading or self._complete
+            return {
+                "downloading": downloading,
+                "model": self._model_id if downloading else None,
+                "error": self._error,
+                "bytes_total": self._total_bytes if show_progress else None,
+                "bytes_done": self._blob_bytes() if show_progress else None,
+            }
+
+    def _blob_bytes(self) -> Optional[int]:
+        """Best-effort progress: bytes in the repo's HF cache blobs.
+
+        Counts only the selected support files and one selected weight format,
+        including in-progress ``.incomplete`` blobs.
+        """
+        try:
+            # Caller may hold the non-reentrant self._lock; a bare read is safe.
+            repo = self._repo
+            selected_files = self._selected_files
+            if not repo or not selected_files:
+                return None
+            blobs = _repo_cache_dir(repo) / "blobs"
+            if not blobs.is_dir():
+                return 0
+            done = 0
+            for selected in selected_files:
+                if not selected.blob_key:
+                    continue
+                complete = blobs / selected.blob_key
+                incomplete = blobs / f"{selected.blob_key}.incomplete"
+                candidate = complete if complete.is_file() else incomplete
+                if candidate.is_file():
+                    done += min(candidate.stat().st_size, selected.size)
+            total = self._total_bytes
+            return min(done, total) if total is not None else done
+        except Exception:
+            return None
+
+    def start(
+        self,
+        model_id: str,
+        hf_token: Optional[str] = None,
+        revision: Optional[str] = None,
+    ) -> None:
+        model_id = resolve_model_id(model_id)
+        with self._lock:
+            if self._thread is not None and self._thread.is_alive():
+                if self._model_id == model_id:
+                    return
+                raise SttModelIdError(
+                    f"Another dictation model ('{self._model_id}') is still "
+                    "downloading; wait for it to finish."
+                )
+            self._model_id = model_id
+            self._repo = resolve_model_repo(model_id)
+            self._error = None
+            self._total_bytes = None
+            self._selected_files = ()
+            self._complete = False
+            thread = threading.Thread(
+                target = self._run, args = (self._repo, hf_token, revision), daemon = True
+            )
+            self._thread = thread
+            thread.start()
+
+    def _run(
+        self,
+        repo: str,
+        hf_token: Optional[str],
+        revision: Optional[str] = None,
+    ) -> None:
+        try:
+            from huggingface_hub import HfApi, hf_hub_download, snapshot_download
+
+            info = HfApi(token = hf_token or None).model_info(
+                repo,
+                revision = revision,
+                files_metadata = True,
+                timeout = 30,
+            )
+            if not revision:
+                revision = getattr(info, "sha", None)
+            if not isinstance(revision, str) or not _HF_COMMIT_SHA.fullmatch(revision):
+                raise SttModelCompatibilityError(
+                    f"Could not resolve an immutable revision for STT model '{repo}'."
+                )
+
+            def load_index(filename: str) -> dict:
+                path = hf_hub_download(
+                    repo_id = repo,
+                    filename = filename,
+                    revision = revision,
+                    token = hf_token or None,
+                )
+                return _read_json_object(Path(path))
+
+            selected_files = _select_snapshot_files(info, load_index)
+            total = sum(selected.size for selected in selected_files)
+            with self._lock:
+                self._selected_files = selected_files
+                self._total_bytes = total or None
+            snapshot = Path(
+                snapshot_download(
+                    repo_id = repo,
+                    revision = revision,
+                    allow_patterns = [selected.path for selected in selected_files],
+                    token = hf_token or None,
+                )
+            )
+            if not _snapshot_is_complete(snapshot):
+                raise SttModelCompatibilityError(
+                    f"Downloaded STT snapshot for '{repo}' is incomplete."
+                )
+            _write_revision_record(repo, revision)
+            with self._lock:
+                self._complete = True
+        except Exception as exc:
+            logger.warning("STT snapshot download failed for %s: %s", repo, exc)
+            with self._lock:
+                self._error = f"Download failed for '{repo}'."
+
+
+_download_state = _SnapshotDownloadState()
+
+
+def start_model_download(
+    model: Optional[str],
+    hf_token: Optional[str] = None,
+    revision: Optional[str] = None,
+) -> None:
+    _download_state.start(resolve_model_id(model), hf_token, revision = revision)
+
+
+def download_status() -> dict:
+    return _download_state.status()
+
+
+def _training_active() -> bool:
+    try:
+        from core.training import get_training_backend
+        return bool(get_training_backend().is_training_active())
+    except Exception:
+        return False
+
+
+def _clear_device_cache(device: Optional[str]) -> None:
+    gc.collect()
+    try:
+        import torch
+        if device == "cuda":
+            torch.cuda.empty_cache()
+        elif device == "mps":
+            torch.mps.empty_cache()
+    except Exception:
+        pass
+
+
+def _pick_device():
+    """Return (device, torch_dtype) for the Whisper model.
+
+    CUDA uses float16. MPS and CPU use float32: Whisper's decoder is unstable in
+    float16 on MPS and degenerates into repeated tokens.
+    """
+    try:
+        import torch
+
+        # New loads use CPU during training; a resident GPU model may stay put
+        # when the training admission check confirms enough headroom.
+        training_active = _training_active()
+        if not training_active and torch.cuda.is_available():
+            return "cuda", torch.float16
+        if (
+            not training_active
+            and getattr(torch.backends, "mps", None) is not None
+            and torch.backends.mps.is_available()
+        ):
+            return "mps", torch.float32
+        return "cpu", torch.float32
+    except Exception as exc:
+        logger.debug("STT device detection failed, using CPU: %s", exc)
+        import torch
+        return "cpu", torch.float32
+
+
+def _decode_audio_bounded(audio: bytes):
+    """Decode to 16 kHz mono PCM without buffering unbounded audio.
+
+    A small, highly-compressed upload can expand far past the encoded request
+    limit once decoded, so decode frame-by-frame and enforce the sample cap as
+    frames arrive, then hand the array straight to Whisper.
+    """
+    try:
+        import av
+        import numpy as np
+        from av.error import FFmpegError, InvalidDataError
+    except ImportError as exc:
+        raise SttUnavailableError(
+            "Speech-to-text needs the PyAV package to decode audio. "
+            "Run `unsloth studio update` to install it."
+        ) from exc
+
+    max_samples = _MAX_AUDIO_SECONDS * _TARGET_SAMPLE_RATE
+    sample_count = 0
+    raw_buffer = io.BytesIO()
+    resampler = av.audio.resampler.AudioResampler(
+        format = "s16",
+        layout = "mono",
+        rate = _TARGET_SAMPLE_RATE,
+    )
+    # Group frames before resampling so short clips need one resampler call
+    # rather than one per codec frame.
+    fifo = av.audio.fifo.AudioFifo()
+
+    def write_frame(frame) -> None:
+        nonlocal sample_count
+        array = frame.to_ndarray()
+        sample_count += array.size
+        if sample_count > max_samples:
+            max_minutes = _MAX_AUDIO_SECONDS // 60
+            unit = "minute" if max_minutes == 1 else "minutes"
+            raise SttAudioTooLongError(f"Audio must be {max_minutes} {unit} or shorter.")
+        raw_buffer.write(array)
+
+    try:
+        with av.open(io.BytesIO(audio), mode = "r", metadata_errors = "ignore") as container:
+            if not container.streams.audio:
+                raise SttAudioDecodeError("Could not decode the audio.")
+            frames = iter(container.decode(audio = 0))
+            while True:
+                try:
+                    frame = next(frames)
+                except StopIteration:
+                    break
+                except InvalidDataError:
+                    # Skip a corrupt frame rather than fail the whole transcription.
+                    continue
+                frame.pts = None
+                fifo.write(frame)
+                if fifo.samples >= 500000:
+                    for resampled in resampler.resample(fifo.read()):
+                        write_frame(resampled)
+            if fifo.samples > 0:
+                for resampled in resampler.resample(fifo.read()):
+                    write_frame(resampled)
+            for resampled in resampler.resample(None):
+                write_frame(resampled)
+    except (SttAudioDecodeError, SttAudioTooLongError):
+        raise
+    except (FFmpegError, ValueError, RuntimeError) as exc:
+        raise SttAudioDecodeError("Could not decode the audio.") from exc
+    finally:
+        del fifo, resampler
+
+    if sample_count == 0:
+        raise SttAudioDecodeError("Could not decode the audio.")
+    decoded = np.frombuffer(raw_buffer.getbuffer(), dtype = np.int16).astype(np.float32)
+    decoded /= 32768.0
+    return decoded
+
+
+class WhisperSttSidecar:
+    """Lazily loaded Whisper model with idle eviction. Thread-safe."""
+
+    def __init__(self, keep_alive_seconds: float = STT_KEEP_ALIVE_SECONDS) -> None:
+        self._engine = None
+        self._model_id: Optional[str] = None
+        self._device: Optional[str] = None
+        self._lock = threading.RLock()
+        self._load_state_lock = threading.Lock()
+        self._loading = False
+        self._load_cancel_event: Optional[threading.Event] = None
+        self._keep_alive_seconds = max(0.0, keep_alive_seconds)
+        self._idle_timer: Optional[threading.Timer] = None
+        self._idle_generation = 0
+
+    @property
+    def loaded_model(self) -> Optional[str]:
+        return self._model_id
+
+    @property
+    def device(self) -> Optional[str]:
+        return self._device
+
+    def is_loading(self) -> bool:
+        with self._load_state_lock:
+            return self._loading
+
+    def cancel_pending_load(self) -> bool:
+        """Cancel a model load without waiting for the model lock."""
+        with self._load_state_lock:
+            event = self._load_cancel_event
+            if not self._loading or event is None:
+                return False
+            event.set()
+            return True
+
+    def wait_for_load_to_settle(self) -> None:
+        """Block until any in-flight load() has exited and freed its memory.
+
+        load() holds self._lock throughout, including the from_pretrained()/
+        .to(device) allocation and cancel cleanup, so acquiring the lock here
+        waits for that memory to be freed.
+        """
+        with self._lock:
+            pass
+
+    def _begin_load(self) -> threading.Event:
+        event = threading.Event()
+        with self._load_state_lock:
+            self._load_cancel_event = event
+            self._loading = True
+        return event
+
+    def _end_load(self, event: threading.Event) -> None:
+        with self._load_state_lock:
+            if self._load_cancel_event is event:
+                self._load_cancel_event = None
+                self._loading = False
+
+    @staticmethod
+    def _raise_if_load_cancelled(event: threading.Event) -> None:
+        if event.is_set():
+            raise SttLoadCancelledError("STT model loading was cancelled so training could start.")
+
+    @property
+    def keep_alive_seconds(self) -> float:
+        return self._keep_alive_seconds
+
+    def _cancel_idle_unload_locked(self) -> None:
+        self._idle_generation += 1
+        timer = self._idle_timer
+        self._idle_timer = None
+        if timer is not None:
+            timer.cancel()
+
+    def _schedule_idle_unload_locked(self) -> None:
+        self._cancel_idle_unload_locked()
+        if self._engine is None or self._keep_alive_seconds <= 0:
+            return
+        generation = self._idle_generation
+        timer = threading.Timer(
+            self._keep_alive_seconds,
+            self._idle_unload,
+            args = (generation,),
+        )
+        timer.daemon = True
+        self._idle_timer = timer
+        timer.start()
+
+    def _idle_unload(self, generation: int) -> None:
+        with self._lock:
+            if generation != self._idle_generation or self._engine is None:
+                return
+            logger.info("Unloading idle STT model %s", self._model_id)
+            self._release_engine_locked()
+
+    def _release_engine_locked(self) -> None:
+        self._cancel_idle_unload_locked()
+        engine = self._engine
+        device = self._device
+        self._engine = None
+        self._model_id = None
+        self._device = None
+        del engine
+        _clear_device_cache(device)
+
+    def _build_model(self, snapshot_path: str, device: str, dtype, cancel_event: threading.Event):
+        """Load a Whisper model + processor from the local Hub cache.
+
+        local_files_only keeps the Model Hub the only download path; a cache
+        miss raises so the caller can surface SttModelNotDownloadedError.
+        """
+        import torch
+        from transformers import WhisperForConditionalGeneration, WhisperProcessor
+
+        processor = None
+        model = None
+        try:
+            processor = WhisperProcessor.from_pretrained(snapshot_path, local_files_only = True)
+            self._raise_if_load_cancelled(cancel_event)
+            # use_safetensors forces the pickle-free load path even if a
+            # pytorch_model.bin somehow reached the cache; the selector and the
+            # completeness check already exclude pickle weights upstream.
+            model = WhisperForConditionalGeneration.from_pretrained(
+                snapshot_path, torch_dtype = dtype, local_files_only = True, use_safetensors = True
+            )
+            self._raise_if_load_cancelled(cancel_event)
+            model.to(torch.device(device))
+            self._raise_if_load_cancelled(cancel_event)
+            model.eval()
+            return model, processor
+        except SttLoadCancelledError:
+            model = None
+            processor = None
+            _clear_device_cache(device)
+            raise
+
+    def _ensure_model_downloaded(self, model_id: str) -> _CachedSttSnapshot:
+        """Validate the local snapshot before decode or model replacement.
+
+        Returns the checkpoint's multilingual flag when local metadata provides
+        it. Curated defaults are known multilingual.
+        """
+        model_id = resolve_model_id(model_id)
+        with self._lock:
+            if self._engine is not None and self._model_id == model_id:
+                resident_model = (
+                    self._engine[0] if isinstance(self._engine, (tuple, list)) else self._engine
+                )
+                generation_config = getattr(resident_model, "generation_config", None)
+                is_multilingual = getattr(generation_config, "is_multilingual", None)
+                return _CachedSttSnapshot(
+                    path = None,
+                    is_multilingual = is_multilingual if isinstance(is_multilingual, bool) else None,
+                )
+        snapshot_path = _find_complete_cached_snapshot(model_id)
+        if snapshot_path is None:
+            raise SttModelNotDownloadedError(
+                f"STT model '{model_id}' is not downloaded. "
+                "Download it in Settings, then Voice, before loading it."
+            )
+
+        if model_id in STT_MODELS:
+            return _CachedSttSnapshot(path = snapshot_path, is_multilingual = True)
+
+        if not _is_whisper_config(_read_json_object(snapshot_path / "config.json")):
+            raise SttModelCompatibilityError(
+                f"STT model '{model_id}' is not a compatible Transformers Whisper model."
+            )
+        generation_config = _read_json_object(snapshot_path / "generation_config.json")
+        is_multilingual = generation_config.get("is_multilingual")
+        if isinstance(is_multilingual, bool):
+            return _CachedSttSnapshot(path = snapshot_path, is_multilingual = is_multilingual)
+        if resolve_model_repo(model_id).lower().endswith(".en"):
+            return _CachedSttSnapshot(path = snapshot_path, is_multilingual = False)
+        return _CachedSttSnapshot(path = snapshot_path, is_multilingual = None)
+
+    def load(self, model: Optional[str] = None):
+        """Load (or switch to) a model, reusing it if already resident.
+
+        Returns a ``(model, processor)`` pair.
+        """
+        model_id = resolve_model_id(model)
+        with self._lock:
+            ensure_stt_available()
+            if self._engine is not None and self._model_id == model_id:
+                self._schedule_idle_unload_locked()
+                return self._engine
+            import torch
+
+            cancel_event = self._begin_load()
+            candidate = None
+            device: Optional[str] = None
+            try:
+                cached = self._ensure_model_downloaded(model_id)
+                snapshot_path = cached.path
+                if snapshot_path is None:
+                    raise SttModelNotDownloadedError(
+                        f"STT model '{model_id}' is not downloaded. "
+                        "Download it in Settings, then Voice, before loading it."
+                    )
+                self._raise_if_load_cancelled(cancel_event)
+                device, dtype = _pick_device()
+                self._release_engine_locked()
+                logger.info("Loading STT model %s (%s) on %s", model_id, snapshot_path, device)
+
+                def not_downloaded(cause: BaseException) -> SttModelNotDownloadedError:
+                    return SttModelNotDownloadedError(
+                        f"STT model '{model_id}' is not downloaded. "
+                        "Download it in Settings, then Voice, before loading it."
+                    )
+
+                retry_on_cpu = False
+                try:
+                    candidate = self._build_model(str(snapshot_path), device, dtype, cancel_event)
+                    self._raise_if_load_cancelled(cancel_event)
+                except SttLoadCancelledError:
+                    raise
+                except Exception as exc:
+                    if _is_missing_local_model_error(exc):
+                        raise not_downloaded(exc) from exc
+                    if device == "cpu":
+                        raise
+                    logger.warning("STT load on %s failed (%s); retrying on CPU", device, exc)
+                    retry_on_cpu = True
+                if retry_on_cpu:
+                    # Retry outside the handler: live exception state pins frames
+                    # referencing the partly loaded model, so leave it before
+                    # clearing the cache to release that memory.
+                    _clear_device_cache(device)
+                    try:
+                        candidate = self._build_model(
+                            str(snapshot_path),
+                            "cpu",
+                            torch.float32,
+                            cancel_event,
+                        )
+                        self._raise_if_load_cancelled(cancel_event)
+                    except SttLoadCancelledError:
+                        raise
+                    except Exception as cpu_exc:
+                        if _is_missing_local_model_error(cpu_exc):
+                            raise not_downloaded(cpu_exc) from cpu_exc
+                        raise
+                    device = "cpu"
+                with self._load_state_lock:
+                    self._raise_if_load_cancelled(cancel_event)
+                    self._engine = candidate
+                    self._model_id = model_id
+                    self._device = device
+                    self._load_cancel_event = None
+                    self._loading = False
+                self._schedule_idle_unload_locked()
+                logger.info("STT model %s ready on %s", model_id, device)
+                return self._engine
+            except SttLoadCancelledError:
+                candidate = None
+                self._release_engine_locked()
+                _clear_device_cache(device)
+                raise
+            finally:
+                self._end_load(cancel_event)
+
+    def _transcribe_decoded(self, model_id: str, decoded_audio, generate_kwargs: dict) -> str:
+        """Run Whisper on already-decoded 16 kHz mono PCM and return text.
+
+        Feeds a pre-decoded array so nothing here touches the Transformers audio
+        path (torchcodec/ffmpeg). Splits into 30s windows (Whisper's receptive
+        field); short clips take one pass.
+        """
+        import torch
+
+        model, processor = self.load(model_id)
+        effective_generate_kwargs = dict(generate_kwargs)
+        generation_config = getattr(model, "generation_config", None)
+        if getattr(generation_config, "is_multilingual", None) is False:
+            # English-only checkpoints fix language and task in their generation
+            # config, and Transformers rejects passing them here.
+            effective_generate_kwargs.pop("task", None)
+            effective_generate_kwargs.pop("language", None)
+        window = 30 * _TARGET_SAMPLE_RATE
+        target_dtype = getattr(model, "dtype", None)
+        parts: list[str] = []
+        with torch.no_grad():
+            for start in range(0, max(len(decoded_audio), 1), window):
+                segment = decoded_audio[start : start + window]
+                if segment.size == 0:
+                    continue
+                inputs = processor(
+                    segment,
+                    sampling_rate = _TARGET_SAMPLE_RATE,
+                    return_tensors = "pt",
+                )
+                features = inputs.input_features.to(model.device)
+                if target_dtype is not None:
+                    features = features.to(target_dtype)
+                generated = model.generate(features, **effective_generate_kwargs)
+                text = processor.batch_decode(generated, skip_special_tokens = True)
+                parts.append(text[0] if text else "")
+        return " ".join(part.strip() for part in parts if part.strip()).strip()
+
+    def transcribe(
+        self,
+        audio: bytes,
+        model: Optional[str] = None,
+        language: Optional[str] = None,
+        fast: bool = False,
+    ) -> dict:
+        """Transcribe encoded audio bytes to text.
+
+        Accepts any container PyAV can decode: wav, mp3, opus/webm, ogg,
+        m4a/aac. Returns {text, language, duration, model}.
+        """
+        # Reject a missing runtime up front, before the cache and bounded decode.
+        ensure_stt_available()
+        # A set language beats auto-detect. API takes BCP-47; Whisper wants short
+        # codes like en or fr.
+        lang = normalize_whisper_language(language)
+        # Pin the requested id: another request may switch the resident model
+        # mid-transcription, so sidecar state is not this request's identity.
+        model_id = resolve_model_id(model)
+        known_languages = _known_whisper_languages()
+        if lang is not None and known_languages is not None and lang not in known_languages:
+            raise SttLanguageError(
+                f"Language '{language}' is not supported by STT model '{model_id}'."
+            )
+        cached = self._ensure_model_downloaded(model_id)
+        if cached.is_multilingual is False and lang not in (None, "en"):
+            raise SttLanguageError(
+                f"Language '{language}' is not supported by English-only STT model '{model_id}'."
+            )
+        decoded_audio = _decode_audio_bounded(audio)
+        # condition_on_prev_tokens=False stops a fresh clip inheriting prior
+        # context, which causes runaway repeats.
+        generate_kwargs = {
+            "task": "transcribe",
+            "condition_on_prev_tokens": False,
+            "num_beams": 5,
+        }
+        if lang is not None:
+            generate_kwargs["language"] = lang
+        if fast:
+            # Short voiced clips: greedy decoding drops beam search for latency.
+            generate_kwargs["num_beams"] = 1
+        # Serialize inference with model switches and unloads.
+        with self._lock:
+            try:
+                text = self._transcribe_decoded(model_id, decoded_audio, generate_kwargs)
+            finally:
+                self._schedule_idle_unload_locked()
+        duration = (len(decoded_audio) / _TARGET_SAMPLE_RATE) if len(decoded_audio) else None
+        return {
+            "text": text,
+            "language": lang,
+            "duration": duration,
+            "model": model_id,
+        }
+
+    def unload(self) -> None:
+        with self._lock:
+            self._release_engine_locked()
+
+
+_sidecar: Optional[WhisperSttSidecar] = None
+
+
+def get_stt_sidecar() -> WhisperSttSidecar:
+    global _sidecar
+    if _sidecar is None:
+        _sidecar = WhisperSttSidecar()
+    return _sidecar
diff --git a/studio/backend/core/inference/tool_loop_controller.py b/studio/backend/core/inference/tool_loop_controller.py
index f7ed450d11..61643b5795 100644
--- a/studio/backend/core/inference/tool_loop_controller.py
+++ b/studio/backend/core/inference/tool_loop_controller.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Shared controller state for Studio local agentic tool loops.
+"""Shared controller state for Unsloth local agentic tool loops.
 
 This module is intentionally dependency-light: it owns only per-response
 ledger state and value objects used by the GGUF and safetensors loops.
diff --git a/studio/backend/core/inference/tools.py b/studio/backend/core/inference/tools.py
index 5fd57e1b2c..0ef6dd46cf 100644
--- a/studio/backend/core/inference/tools.py
+++ b/studio/backend/core/inference/tools.py
@@ -18,6 +18,7 @@ import queue
 import random
 import re
 import shlex
+import shutil
 import ssl
 import subprocess
 import sys
@@ -328,6 +329,7 @@ def _find_blocked_commands(command: str) -> set[str]:
 # Directory holding the sandbox ``sitecustomize.py`` shim (code-interpreter
 # path remap); placed on the sandboxed child's PYTHONPATH in _build_safe_env.
 _SANDBOX_SITE_DIR = os.path.join(os.path.dirname(os.path.abspath(__file__)), "sandbox_site")
+
 # ── "Approve for me" (permission_mode="auto") safety detection ──────────────
 # Auto mode pauses only calls classified here as potentially unsafe. The sandbox
 # and hard blocks (blocklist, rlimits) still apply at run time; this gate only
@@ -2491,18 +2493,127 @@ def is_potentially_unsafe_tool_call(name: str, arguments: dict) -> bool:
     return True
 
 
+def _canon_win_path(p: str) -> str:
+    """Canonical form for trust comparison: realpath (expands 8.3 aliases and
+    resolves junctions/symlinks) + normcase/normpath."""
+    return os.path.normcase(os.path.normpath(os.path.realpath(p)))
+
+
+def _augment_native_program_roots(roots: list[str]) -> list[str]:
+    """Add the native Program Files sibling for any x86 root by stripping the
+    `` (x86)`` suffix, so a 32-bit process (whose known-folder ids map only to
+    the x86 root) still trusts a 64-bit Git install."""
+    out = list(roots)
+    for root in roots:
+        base = root.rstrip("\\/")
+        if base.lower().endswith(" (x86)"):
+            native = base[: -len(" (x86)")]
+            if native and native not in out:
+                out.append(native)
+    return out
+
+
+def _windows_program_roots() -> list[str]:
+    """Program Files install roots, resolved ONLY from the Windows known-folder
+    API (SHGetKnownFolderPath). Fails closed (returns ``[]``) if the API is
+    unavailable: env vars (%ProgramFiles%, even %SystemDrive%) are caller-
+    overrideable and could relocate the trust boundary, so we never derive a
+    trusted root from them. On any real Windows host shell32 is present, so
+    this only returns empty in a broken/non-Windows environment where the
+    sandbox git-PATH feature is not needed anyway (#7317).
+    """
+    roots: list[str] = []
+    try:
+        import ctypes
+        from ctypes import wintypes
+
+        # FOLDERID_ProgramFiles, _ProgramFilesX86, _ProgramFilesX64. The X64
+        # id (Win10 1703+) yields the native root even from a 32-bit process,
+        # where the first two both map to Program Files (x86).
+        folder_ids = (
+            "{905e63b6-c1bf-494e-b29c-65b732d3d21a}",
+            "{7C5A40EF-A0FB-4BFC-874A-C0F2E0B9FA8E}",
+            "{6D809377-6AF0-444b-8957-A3773F02200E}",
+        )
+        _SHGet = ctypes.windll.shell32.SHGetKnownFolderPath
+        _CoTaskMemFree = ctypes.windll.ole32.CoTaskMemFree
+        for fid in folder_ids:
+            guid = ctypes.create_string_buffer(16)
+            ctypes.windll.ole32.CLSIDFromString(wintypes.LPCWSTR(fid), ctypes.byref(guid))
+            ptr = ctypes.c_wchar_p()
+            if _SHGet(ctypes.byref(guid), 0, None, ctypes.byref(ptr)) == 0:
+                if ptr.value:
+                    roots.append(ptr.value)
+                _CoTaskMemFree(ptr)
+    except Exception:
+        return []
+    return _augment_native_program_roots(roots)
+
+
+def _resolve_trusted_windows_git() -> tuple[str, str]:
+    """Find a git launcher in a TRUSTED Program Files dir. Returns
+    ``(canonical_dir, ext)`` or ``("", "")``.
+
+    ``shutil.which`` returns only the first PATH match, which may be an
+    untrusted user shim; scan the remaining PATH entries for a later trusted
+    Git so bare ``git`` still resolves (#7317).
+    """
+    exts = [e for e in (os.environ.get("PATHEXT") or ".EXE;.CMD;.BAT;.COM").split(os.pathsep)]
+    candidates: list[str] = []
+    primary = shutil.which("git")
+    if primary:
+        candidates.append(primary)
+    for entry in (os.environ.get("PATH") or "").split(os.pathsep):
+        entry = entry.strip().strip('"')
+        if not entry or not os.path.isabs(entry):
+            continue
+        for ext in exts:
+            cand = os.path.join(entry, "git" + ext)
+            if os.path.isfile(cand):
+                candidates.append(cand)
+    for git_exe in candidates:
+        git_dir = os.path.dirname(git_exe)
+        if os.path.isabs(git_dir) and _is_trusted_windows_program_dir(git_dir):
+            return os.path.realpath(git_dir), os.path.splitext(git_exe)[1].upper()
+    return "", ""
+
+
+def _is_trusted_windows_program_dir(path: str) -> bool:
+    """True when ``path`` sits under a system-managed Program Files root.
+
+    Only the Program Files roots are trusted (admin-writable only), resolved
+    via the known-folder API so an overridden env var cannot relocate them,
+    never ``%SystemRoot%`` (Git does not install there and it holds
+    world-writable subdirs like ``Windows\\Temp``). Per-user managers
+    (Scoop/Choco shims under the profile) are refused. Paths are canonicalized
+    so 8.3 aliases and junctions still resolve to their real root (#7317).
+    """
+    norm = _canon_win_path(path)
+    for root in _windows_program_roots():
+        root_norm = _canon_win_path(root)
+        if norm == root_norm or norm.startswith(root_norm + os.sep):
+            return True
+    return False
+
+
 def _build_safe_env(workdir: str) -> dict[str, str]:
     """Build a minimal, credential-free environment for sandboxed subprocesses.
 
     Whitelist-built from scratch (parent env NOT inherited): only PATH/HOME/
     TMPDIR/LANG/TERM/PYTHONIOENCODING/PYTHONPATH (+VIRTUAL_ENV or Windows
-    SystemRoot) reach the child; all credential vars (HF_TOKEN, AWS_*, etc.)
-    are absent. HOME points at the sandbox workdir so SDKs can't read the
+    SystemRoot and a minimal PATHEXT) reach the child; all credential vars
+    (HF_TOKEN, AWS_*, etc.) are absent. HOME points at the sandbox workdir so SDKs can't read the
     operator's cached creds. PYTHONPATH carries only the sandbox sitecustomize
     shim directory.
+
+    PATH starts with the Studio interpreter / venv and OS system dirs so
+    ``python``/``pip`` stay pinned. On Windows only, Git-for-Windows install
+    dirs from the host PATH are appended so bare ``git`` resolves (#7317).
+    User-writable host PATH entries (venv, ``node_modules/.bin``, etc.) are
+    never inherited — they could shadow auto-safe terminal commands.
     """
     # Start from the running interpreter's dir so 'python'/'pip' resolve to the
-    # same environment the Studio server runs in.
+    # same environment the Unsloth server runs in.
     exe_dir = os.path.dirname(sys.executable)
     path_entries = [exe_dir] if exe_dir else []
 
@@ -2519,6 +2630,20 @@ def _build_safe_env(workdir: str) -> dict[str, str]:
     else:
         path_entries.extend(["/usr/local/bin", "/usr/bin", "/bin"])
 
+    # Windows Git installs live outside System32; inherit the dir of the git
+    # the HOST shell resolves, but ONLY when it sits under a system install
+    # root (Program Files, windir). A user-writable dir (Scoop/Choco shims)
+    # is refused: it would let an attacker drop rg.exe/jq.exe beside git and
+    # have an auto-approved bare command execute it (#7317).
+    git_ext = ""
+    if sys.platform == "win32":
+        # Append the CANONICAL (realpath) trusted git dir, scanning past any
+        # untrusted user shim that sorts first on PATH; the canonical path
+        # cannot be retargeted via a junction after the trust check.
+        _trusted_git_dir, git_ext = _resolve_trusted_windows_git()
+        if _trusted_git_dir:
+            path_entries.append(_trusted_git_dir)
+
     # Deduplicate, preserving order.
     deduped = list(dict.fromkeys(p for p in path_entries if p))
 
@@ -2538,6 +2663,15 @@ def _build_safe_env(workdir: str) -> dict[str, str]:
     # Windows needs SystemRoot for Python/subprocess to work.
     if sys.platform == "win32":
         env["SystemRoot"] = os.environ.get("SystemRoot", r"C:\Windows")
+        # Restrict PATHEXT so cwd .BAT/.CMD cannot hijack bare names (#7317).
+        pathext = ".EXE;.COM"
+        if git_ext and git_ext not in (".EXE", ".COM"):
+            # Keep the host git launcher (e.g. a .CMD shim) resolvable.
+            pathext += ";" + git_ext
+        env["PATHEXT"] = pathext
+        # cmd/CreateProcess search cwd before PATH for bare names; disable so
+        # a workdir rg.exe/git.exe cannot shadow auto-approved commands.
+        env["NoDefaultCurrentDirectoryInExePath"] = "1"
     return env
 
 
@@ -2792,7 +2926,7 @@ def _bypass_preexec():
     """Minimal pre-exec for bypass exec: os.setsid() only.
 
     Required, not a restriction: _kill_process_tree does killpg(getpgid(child)),
-    so without a new session a timeout/cancel would kill the Studio server too.
+    so without a new session a timeout/cancel would kill the Unsloth server too.
     """
     try:
         os.setsid()
@@ -2800,13 +2934,13 @@ def _bypass_preexec():
         pass
 
 
-# Hardening the Studio parent is done once (PR_SET_DUMPABLE is process-global
+# Hardening the Unsloth parent is done once (PR_SET_DUMPABLE is process-global
 # and sticky); guarded so repeated bypass calls do not re-issue the prctl.
 _parent_proc_hardened = False
 
 
 def _harden_parent_against_proc_env_leak() -> bool:
-    """Make the Studio process's /proc/<pid>/environ unreadable to its children.
+    """Make the Unsloth process's /proc/<pid>/environ unreadable to its children.
 
     Stripping the child env is not enough on Linux: a bypassed same-UID child
     can read /proc/<getppid()>/environ to recover the parent's unfiltered
@@ -5482,7 +5616,7 @@ def _truncate(text: str, limit: int = _MAX_OUTPUT_CHARS) -> str:
 
 
 # ChatGPT code-interpreter path conventions models write out of habit; none
-# exist in the Studio sandbox, so a failure on one earns the retry hint.
+# exist in the Unsloth sandbox, so a failure on one earns the retry hint.
 _MISSING_PATH_PREFIXES = (
     "/mnt/data",
     "/mnt/outputs",
@@ -5688,7 +5822,7 @@ def _python_exec(
         # Close the /proc/<parent>/environ secret-recovery path first; if it
         # cannot be applied, fail closed rather than leak the parent environ.
         return (
-            "Execution error: could not harden the Studio process against "
+            "Execution error: could not harden the Unsloth process against "
             "/proc environment reads; refusing bypass execution."
         )
 
@@ -5833,7 +5967,7 @@ def _bash_exec(
         # Close the /proc/<parent>/environ secret-recovery path first; if it
         # cannot be applied, fail closed rather than leak the parent environ.
         return (
-            "Execution error: could not harden the Studio process against "
+            "Execution error: could not harden the Unsloth process against "
             "/proc environment reads; refusing bypass execution."
         )
 
diff --git a/studio/backend/core/inference/worker.py b/studio/backend/core/inference/worker.py
index e4628dcea8..367de196f7 100644
--- a/studio/backend/core/inference/worker.py
+++ b/studio/backend/core/inference/worker.py
@@ -513,20 +513,25 @@ def _handle_generate(backend, cmd: dict, resp_queue: Any, cancel_event) -> None:
 
         logger.info("Starting text generation for request_id=%s", request_id)
 
-        for cumulative_text in generator:
-            # cancel_event is an mp.Event — checked instantly, no queue polling.
-            if cancel_event.is_set():
-                logger.info("Generation cancelled for request %s", request_id)
-                break
+        try:
+            for cumulative_text in generator:
+                # cancel_event is an mp.Event — checked instantly, no queue polling.
+                if cancel_event.is_set():
+                    logger.info("Generation cancelled for request %s", request_id)
+                    break
 
-            _send_response(
-                resp_queue,
-                {
-                    "type": "token",
-                    "request_id": request_id,
-                    "text": cumulative_text,
-                },
-            )
+                _send_response(
+                    resp_queue,
+                    {
+                        "type": "token",
+                        "request_id": request_id,
+                        "text": cumulative_text,
+                    },
+                )
+        finally:
+            close = getattr(generator, "close", None)
+            if callable(close):
+                close()
 
         _send_response(
             resp_queue,
@@ -789,7 +794,7 @@ def run_inference_process(
         env = os.getenv("ENVIRONMENT_TYPE", "production"),
     )
 
-    apply_gpu_ids(config.get("resolved_gpu_ids"))
+    apply_gpu_ids(config.get("resolved_gpu_ids"), backend = config.get("device_backend"))
 
     model_name = config["model_name"]
 
diff --git a/studio/backend/core/rag/captioner.py b/studio/backend/core/rag/captioner.py
index 6d1512a770..8398506f21 100644
--- a/studio/backend/core/rag/captioner.py
+++ b/studio/backend/core/rag/captioner.py
@@ -6,7 +6,7 @@
 Both turn pixels into indexable text and are a no-op (never raise) without a loaded
 vision model. They reuse the chat model's vision endpoint, so it must be served with
 ``--ubatch-size`` >= one image's tokens (some encoders, e.g. Gemma, attend
-non-causally and abort otherwise); Studio's vision chat already requires this."""
+non-causally and abort otherwise); Unsloth's vision chat already requires this."""
 
 from __future__ import annotations
 
diff --git a/studio/backend/core/rag/config.py b/studio/backend/core/rag/config.py
index 2de32a68e4..f54d795731 100644
--- a/studio/backend/core/rag/config.py
+++ b/studio/backend/core/rag/config.py
@@ -87,6 +87,22 @@ def _names_gguf(model: str) -> bool:
     return "gguf" in re.split(r"[^a-z0-9]+", model.lower())
 
 
+def gguf_repo_for_embedding_model(model: str) -> str:
+    """GGUF repo for ``model``, honoring an explicit companion override."""
+    if "RAG_EMBED_GGUF_REPO" in os.environ:
+        return EMBED_GGUF_REPO
+    if model == DEFAULT_EMBEDDING_MODEL:
+        return EMBED_GGUF_REPO
+    if _names_gguf(model):
+        return model
+    return f"{model}-GGUF"
+
+
+def default_gguf_repo() -> str:
+    """GGUF companion for the env/default embedding model."""
+    return gguf_repo_for_embedding_model(EMBEDDING_MODEL)
+
+
 def effective_gguf_repo() -> str:
     """GGUF repo for the llama-server backend, tracking the effective model.
 
@@ -95,14 +111,7 @@ def effective_gguf_repo() -> str:
     ``-GGUF`` companion repo (the unsloth convention the default pair follows),
     or is used as-is when it already names a GGUF repo.
     """
-    if "RAG_EMBED_GGUF_REPO" in os.environ:
-        return EMBED_GGUF_REPO
-    model = effective_embedding_model()
-    if model == DEFAULT_EMBEDDING_MODEL:
-        return EMBED_GGUF_REPO
-    if _names_gguf(model):
-        return model
-    return f"{model}-GGUF"
+    return gguf_repo_for_embedding_model(effective_embedding_model())
 
 
 # llama-server backend only. F16 over Q8_0: faster (no per-block dequant for this
diff --git a/studio/backend/core/rag/embed_llama_server.py b/studio/backend/core/rag/embed_llama_server.py
index 46a282c939..facd989b27 100644
--- a/studio/backend/core/rag/embed_llama_server.py
+++ b/studio/backend/core/rag/embed_llama_server.py
@@ -10,7 +10,7 @@ Opt-in (``RAG_EMBED_BACKEND=llama-server``). Runs a dedicated
 Device is ``auto`` (GPU when present, else CPU, falling back to CPU if a GPU start
 fails); ``RAG_EMBED_DEVICE`` forces it. We call only llama_cpp's *static* helpers
 (no torch), copying the instance-coupled bits locally, since constructing a
-``LlamaCppBackend`` runs an ``__init__`` reaper that kills any Studio llama-server
+``LlamaCppBackend`` runs an ``__init__`` reaper that kills any Unsloth llama-server
 -- so each request re-spawns ours if it died (self-heal).
 """
 
@@ -188,7 +188,14 @@ class LlamaServerBackend:
         match = [f for f in files if variant in f.lower()] or files
         filename = sorted(match, key = len)[0]
         logger.info("resolving GGUF embedder %s/%s", repo, filename)
-        self._model_path = hf_hub_download(repo_id = repo, filename = filename, token = token)
+        from utils.hf_cache_settings import active_hf_hub_cache
+
+        self._model_path = hf_hub_download(
+            repo_id = repo,
+            filename = filename,
+            token = token,
+            cache_dir = active_hf_hub_cache(),
+        )
         self._model_repo = desired
         self._dim = None
         return self._model_path
diff --git a/studio/backend/core/rag/embeddings.py b/studio/backend/core/rag/embeddings.py
index b0ecedd593..3354585d2a 100644
--- a/studio/backend/core/rag/embeddings.py
+++ b/studio/backend/core/rag/embeddings.py
@@ -22,6 +22,7 @@ from typing import Callable
 
 from utils.hardware.hardware import DeviceType, get_device
 from utils.transformers_dtype import dtype_kwargs
+from utils.utils import hf_env_offline
 
 from . import config
 
@@ -39,7 +40,7 @@ _model = None
 _name: str | None = None
 
 
-# Studio device -> torch device string. Apple has no torch device -> CPU.
+# Unsloth device -> torch device string. Apple has no torch device -> CPU.
 _TORCH_DEVICE = {DeviceType.CUDA: "cuda", DeviceType.XPU: "xpu"}
 
 
@@ -103,9 +104,15 @@ def _st_module_subdirs(name: str, token: str | None) -> tuple[str, ...]:
         else:
             from huggingface_hub import hf_hub_download
             from huggingface_hub.utils import EntryNotFoundError
+            from utils.hf_cache_settings import active_hf_hub_cache
 
             try:
-                local = hf_hub_download(name, "modules.json", token = token or None)
+                local = hf_hub_download(
+                    name,
+                    "modules.json",
+                    token = token or None,
+                    cache_dir = active_hf_hub_cache(),
+                )
             except EntryNotFoundError:
                 return ()
             data = json.loads(open(local).read())
@@ -119,30 +126,55 @@ def _st_module_subdirs(name: str, token: str | None) -> tuple[str, ...]:
         return ()
 
 
-def _guard_model_security(name: str) -> None:
+def _guard_model_security(name: str, local_only: bool = False) -> None:
     """Refuse to load a repo HF flagged as unsafe: a poisoned pickle deserializes inside
     SentenceTransformer regardless of trust_remote_code. Defense in depth behind the
     /settings gate (a name can also arrive via env/default); local paths and unreachable
     scans fail open inside evaluate_file_security. Never bricks the embedder on a gate error.
+
+    ``local_only`` (offline) inspects the local cache; subdir probes are skipped (they'd hit the
+    network and hang, and the offline gate walks the whole snapshot anyway).
     """
     try:
         from utils.security import evaluate_file_security, security_load_subdirs
 
         token = _ambient_hf_token()
-        # Union the audio-model load roots with the ST module dirs so a flagged pickle
-        # directly under a Transformer module dir (0_Transformer/) blocks instead of
-        # passing as an unreferenced nested shard.
-        load_subdirs = tuple(
-            dict.fromkeys((*security_load_subdirs(name, token), *_st_module_subdirs(name, token)))
-        )
-        blocked = evaluate_file_security(name, hf_token = token, load_subdirs = load_subdirs).blocked
+        if local_only:
+            load_subdirs = ()
+        else:
+            # Union audio-model load roots with ST module dirs so a flagged pickle under a
+            # Transformer module dir blocks instead of passing as an unreferenced nested shard.
+            load_subdirs = tuple(
+                dict.fromkeys(
+                    (*security_load_subdirs(name, token), *_st_module_subdirs(name, token))
+                )
+            )
+        blocked = evaluate_file_security(
+            name, hf_token = token, load_subdirs = load_subdirs, local_only_load = local_only
+        ).blocked
     except Exception:
         return
     if blocked:
-        raise UnsafeEmbeddingModelError(
-            f"Embedding model {name!r} is flagged as unsafe by Hugging Face's security "
-            "scan; refusing to load. Set a different RAG embedding model."
+        reason = (
+            "has cached pickle weights that cannot be security-scanned offline and no "
+            "safetensors alternative"
+            if local_only
+            else "is flagged as unsafe by Hugging Face's security scan"
         )
+        raise UnsafeEmbeddingModelError(
+            f"Embedding model {name!r} {reason}; refusing to load. "
+            "Set a different RAG embedding model."
+        )
+
+
+def _st_accepts_local_files_only(st_cls) -> bool:
+    """Whether this SentenceTransformer version accepts local_files_only; passing it to an
+    older constructor raises, so gate on the signature."""
+    try:
+        import inspect
+        return "local_files_only" in inspect.signature(st_cls.__init__).parameters
+    except Exception:
+        return False
 
 
 def _get(model_name: str | None = None):
@@ -150,15 +182,35 @@ def _get(model_name: str | None = None):
     for a ~1.5x speedup at negligible accuracy loss."""
     global _model, _name
     name = model_name or config.effective_embedding_model()
+    # Capture offline state once so the gate and the load agree (no window where the gate is
+    # skipped as offline but the constructor then reaches the network).
+    local_only = hf_env_offline()
     with _lock:
         if _model is None or _name != name:
             _install_torchao_stub_once()
             from sentence_transformers import SentenceTransformer
+            from utils.hf_cache_settings import active_hf_hub_cache
 
             device = _device()
             logger.info("loading embedding model %s on %s", name, device)
-            _guard_model_security(name)
-            _model = SentenceTransformer(name, device = device, model_kwargs = dtype_kwargs("float16"))
+            _guard_model_security(name, local_only)
+            st_kwargs = dict(
+                device = device,
+                cache_folder = active_hf_hub_cache(),
+                model_kwargs = dtype_kwargs("float16"),
+            )
+            load_target = name
+            if local_only:
+                from utils.utils import hf_cache_snapshot_dir
+                snapshot = hf_cache_snapshot_dir(name)
+                if snapshot is not None:
+                    # Load from the local snapshot dir: a local path never touches the Hub, so
+                    # this is offline-safe on ANY sentence-transformers version (even ones
+                    # predating local_files_only).
+                    load_target = str(snapshot)
+                elif _st_accepts_local_files_only(SentenceTransformer):
+                    st_kwargs["local_files_only"] = True
+            _model = SentenceTransformer(load_target, **st_kwargs)
             _name = name
         return _model
 
diff --git a/studio/backend/core/rag/store.py b/studio/backend/core/rag/store.py
index f9128d1715..1165b6bb0e 100644
--- a/studio/backend/core/rag/store.py
+++ b/studio/backend/core/rag/store.py
@@ -158,6 +158,16 @@ def list_documents(conn: sqlite3.Connection, scope: str) -> list[dict]:
     return [dict(r) for r in rows]
 
 
+def list_all_documents(conn: sqlite3.Connection) -> list[dict]:
+    """Every uploaded document across all scopes (KBs, threads, projects)."""
+    rows = conn.execute(
+        "SELECT id, scope, kb_id, thread_id, project_id, filename, sha256, status, error, "
+        "num_chunks, stored_path, created_at "
+        "FROM documents ORDER BY created_at DESC"
+    ).fetchall()
+    return [dict(r) for r in rows]
+
+
 def get_document(conn: sqlite3.Connection, document_id: str) -> dict | None:
     row = conn.execute("SELECT * FROM documents WHERE id=?", (document_id,)).fetchone()
     return dict(row) if row else None
diff --git a/studio/backend/core/training/resume.py b/studio/backend/core/training/resume.py
index 2a4a198610..17183484c5 100644
--- a/studio/backend/core/training/resume.py
+++ b/studio/backend/core/training/resume.py
@@ -4,6 +4,8 @@
 """Helpers for validating resumable training outputs."""
 
 import json
+import pickletools
+import zipfile
 from pathlib import Path
 from typing import Optional
 
@@ -33,27 +35,164 @@ def _checkpoint_step(path: Path) -> int:
         return -1
 
 
-def get_resume_checkpoint_path(path_value: str) -> Optional[str]:
+_MODEL_FILES = (
+    "adapter_model.safetensors",
+    "adapter_model.bin",
+    "model.safetensors",
+    "pytorch_model.bin",
+)
+_MODEL_INDEXES = ("model.safetensors.index.json", "pytorch_model.bin.index.json")
+
+
+def _valid_state_file(path: Path, require_tensor: bool = True) -> bool:
+    try:
+        if not path.is_file() or path.stat().st_size == 0:
+            return False
+        if path.suffix == ".safetensors":
+            try:
+                from safetensors import SafetensorError, safe_open
+            except ImportError:
+                return False
+            try:
+                with safe_open(str(path), framework = "np") as state:
+                    return bool(state.keys())
+            except SafetensorError:
+                return False
+        if path.suffix in {".bin", ".pt"}:
+            with zipfile.ZipFile(path) as state:
+                infos = state.infolist()
+                names = [info.filename for info in infos]
+                data_name = next(
+                    (name for name in names if name == "data.pkl" or name.endswith("/data.pkl")),
+                    None,
+                )
+                if data_name is None:
+                    return False
+                data_prefix = data_name.removesuffix("data.pkl") + "data/"
+                operations = list(pickletools.genops(state.read(data_name)))
+                if not operations or operations[-1][0].name != "STOP":
+                    return False
+                if not require_tensor:
+                    return True
+                # Require a non-empty tensor record; a zero-byte one fails torch.load.
+                return any(
+                    info.filename.startswith(data_prefix)
+                    and not info.is_dir()
+                    and info.file_size > 0
+                    for info in infos
+                )
+        # Unrecognized state-file formats are not usable resume state.
+        return False
+    except (OSError, ValueError, zipfile.BadZipFile):
+        return False
+
+
+def _checkpoint_state(path: Path) -> Optional[int]:
+    try:
+        state = json.loads((path / "trainer_state.json").read_text(encoding = "utf-8"))
+        step = state.get("global_step") if isinstance(state, dict) else None
+    except (OSError, UnicodeDecodeError, json.JSONDecodeError):
+        return None
+    if isinstance(step, bool) or not isinstance(step, int) or step < 0:
+        return None
+    directory_step = _checkpoint_step(path)
+    return step if directory_step < 0 or step == directory_step else None
+
+
+_INDEX_SHARD_SUFFIX = {
+    "model.safetensors.index.json": ".safetensors",
+    "pytorch_model.bin.index.json": ".bin",
+}
+
+
+def _valid_indexed_shard(checkpoint: Path, shard: object, expected_suffix: str) -> bool:
+    # Shard must be a relative, in-format path contained in the checkpoint dir.
+    if not isinstance(shard, str) or not shard:
+        return False
+    if Path(shard).is_absolute() or Path(shard).suffix != expected_suffix:
+        return False
+    try:
+        root = checkpoint.resolve(strict = True)
+        candidate = (checkpoint / shard).resolve(strict = True)
+        candidate.relative_to(root)
+    except (OSError, ValueError):
+        return False
+    return _valid_state_file(candidate)
+
+
+def _has_model_state(path: Path) -> bool:
+    if any(_valid_state_file(path / name) for name in _MODEL_FILES):
+        return True
+    for name in _MODEL_INDEXES:
+        try:
+            index = json.loads((path / name).read_text(encoding = "utf-8"))
+            shards = set(index["weight_map"].values())
+        except (
+            AttributeError,
+            OSError,
+            KeyError,
+            TypeError,
+            UnicodeDecodeError,
+            json.JSONDecodeError,
+        ):
+            continue
+        expected_suffix = _INDEX_SHARD_SUFFIX[name]
+        if shards and all(_valid_indexed_shard(path, shard, expected_suffix) for shard in shards):
+            return True
+    return False
+
+
+def is_resume_checkpoint_valid(
+    path: Path,
+    expected_step: Optional[int] = None,
+    backend: Optional[str] = None,
+) -> bool:
+    step = _checkpoint_state(path) if path.is_dir() else None
+    step_valid = step is not None and (expected_step is None or step == expected_step)
+    if backend == "mlx":
+        valid_bundle = _valid_state_file(path / "adapters.safetensors") and _valid_state_file(
+            path / "optimizer_state.safetensors"
+        )
+    else:
+        valid_bundle = (
+            _has_model_state(path)
+            # optimizer/scheduler state can be validly tensor-free (e.g. SGD without
+            # momentum); _has_model_state still requires real model tensors.
+            and _valid_state_file(path / "optimizer.pt", require_tensor = False)
+            and _valid_state_file(path / "scheduler.pt", require_tensor = False)
+        )
+        if backend is None and not valid_bundle:
+            valid_bundle = _valid_state_file(path / "adapters.safetensors") and _valid_state_file(
+                path / "optimizer_state.safetensors"
+            )
+    return step_valid and valid_bundle
+
+
+def get_resume_checkpoint_path(
+    path_value: str, expected_step: Optional[int] = None
+) -> Optional[str]:
     path = resolve_output_dir(path_value)
     if not _is_under_outputs(path) or not path.is_dir():
         return None
-    if (path / "trainer_state.json").is_file():
+    if is_resume_checkpoint_valid(path, expected_step):
         return str(path)
 
-    checkpoints = [
-        child
-        for child in path.glob("checkpoint-*")
-        if child.is_dir() and (child / "trainer_state.json").is_file()
-    ]
-    if not checkpoints:
-        return None
-    return str(max(checkpoints, key = _checkpoint_step))
+    checkpoints = sorted(path.glob("checkpoint-*"), key = _checkpoint_step, reverse = True)
+    return next(
+        (
+            str(checkpoint)
+            for checkpoint in checkpoints
+            if _checkpoint_step(checkpoint) >= 0
+            and is_resume_checkpoint_valid(checkpoint, expected_step)
+        ),
+        None,
+    )
 
 
 def normalize_resume_output_dir(path_value: str) -> str:
     path = resolve_output_dir(path_value)
     if not _is_under_outputs(path):
-        raise ValueError("Resume checkpoint must be inside Studio outputs.")
+        raise ValueError("Resume checkpoint must be inside Unsloth outputs.")
     return str(path)
 
 
@@ -78,9 +217,17 @@ def _uses_s3_dataset(run: dict) -> bool:
 def can_resume_run(run: dict) -> bool:
     if run.get("resumed_later"):
         return False
+    # Set when a stop-and-save failed to write a current-step checkpoint.
+    if run.get("resume_blocked"):
+        return False
     if _uses_s3_dataset(run):
         return False
 
+    status = run.get("status")
+    if status == "error":
+        # A save-time crash can report final_step == total_steps with no artifacts; checkpoint state alone decides resumability.
+        return has_resume_state(run.get("output_dir"))
+
     final_step = run.get("final_step")
     total_steps = run.get("total_steps")
     has_remaining_steps = (
@@ -89,8 +236,4 @@ def can_resume_run(run: dict) -> bool:
         or total_steps <= 0
         or final_step < total_steps
     )
-    return (
-        run.get("status") == "stopped"
-        and has_remaining_steps
-        and has_resume_state(run.get("output_dir"))
-    )
+    return status == "stopped" and has_remaining_steps and has_resume_state(run.get("output_dir"))
diff --git a/studio/backend/core/training/trainer.py b/studio/backend/core/training/trainer.py
index 883a535a89..b858fe6f17 100644
--- a/studio/backend/core/training/trainer.py
+++ b/studio/backend/core/training/trainer.py
@@ -797,7 +797,7 @@ class UnslothTrainer:
                 )
                 logger.info("Loaded text model")
 
-            raise_if_offloaded(self.model, device_map, "Studio training")
+            raise_if_offloaded(self.model, device_map, "Unsloth training")
 
             if self.should_stop:
                 return False
@@ -891,6 +891,7 @@ class UnslothTrainer:
         use_gradient_checkpointing: str = "unsloth",
         use_rslora: bool = False,
         use_loftq: bool = False,
+        use_dora: bool = False,
         modules_to_save: list = None,
     ) -> bool:
         """
@@ -993,6 +994,7 @@ class UnslothTrainer:
                     use_gradient_checkpointing = use_gradient_checkpointing,
                     random_state = 3407,
                     use_rslora = use_rslora,
+                    use_dora = use_dora,
                     loftq_config = {"loftq_bits": 4, "loftq_iter": 1} if use_loftq else None,
                 )
                 # Audio VLM models support VLM-style layer selection
@@ -1023,6 +1025,7 @@ class UnslothTrainer:
                     use_gradient_checkpointing = use_gradient_checkpointing,
                     random_state = 3407,
                     use_rslora = use_rslora,
+                    use_dora = use_dora,
                     loftq_config = {"loftq_bits": 4, "loftq_iter": 1} if use_loftq else None,
                     task_type = None,
                 )
@@ -1042,6 +1045,7 @@ class UnslothTrainer:
                     use_gradient_checkpointing = use_gradient_checkpointing,
                     random_state = 3407,
                     use_rslora = use_rslora,
+                    use_dora = use_dora,
                     loftq_config = {"loftq_bits": 4, "loftq_iter": 1} if use_loftq else None,
                 )
 
@@ -1067,6 +1071,7 @@ class UnslothTrainer:
                     use_gradient_checkpointing = use_gradient_checkpointing,
                     random_state = 3407,
                     use_rslora = use_rslora,
+                    use_dora = use_dora,
                     loftq_config = {"loftq_bits": 4, "loftq_iter": 1} if use_loftq else None,
                     modules_to_save = modules_to_save,
                 )
@@ -1087,6 +1092,7 @@ class UnslothTrainer:
                     use_gradient_checkpointing = use_gradient_checkpointing,
                     random_state = 3407,
                     use_rslora = use_rslora,
+                    use_dora = use_dora,
                     loftq_config = {"loftq_bits": 4, "loftq_iter": 1} if use_loftq else None,
                     modules_to_save = modules_to_save,
                 )
@@ -1481,6 +1487,9 @@ class UnslothTrainer:
 
         SNAC_MODEL_NAME = "hubertsiuzdak/snac_24khz"
         SNAC_SAMPLE_RATE = 24000
+
+        # SNAC codec unvalidated on Intel XPU; keep the pre-PR CPU
+        # fallback for non-CUDA hosts.
         device = "cuda" if torch.cuda.is_available() else "cpu"
         max_length = self.max_seq_length or 2048
         tokenizer = self.tokenizer
@@ -1642,7 +1651,8 @@ class UnslothTrainer:
         del snac_model
 
         gc.collect()
-        torch.cuda.empty_cache()
+
+        clear_gpu_cache()
         self._cuda_audio_used = True
 
         if not processed_examples:
@@ -1669,6 +1679,8 @@ class UnslothTrainer:
         import numpy as np
         import torchaudio.transforms as T
 
+        # Spark-TTS BiCodec unvalidated on Intel XPU; keep the pre-PR CPU
+        # fallback for non-CUDA hosts.
         device = "cuda" if torch.cuda.is_available() else "cpu"
 
         # sparktts lives in the SparkAudio/Spark-TTS GitHub repo, not the HF model
@@ -1857,7 +1869,8 @@ class UnslothTrainer:
         del audio_tokenizer
 
         gc.collect()
-        torch.cuda.empty_cache()
+
+        clear_gpu_cache()
         self._cuda_audio_used = True
 
         if not processed_examples:
@@ -1894,6 +1907,8 @@ class UnslothTrainer:
         from datasets import Dataset as HFDataset
         from utils.paths import ensure_dir, tmp_root
 
+        # OuteTTS DAC/Whisper preprocess unvalidated on Intel XPU; keep the
+        # pre-PR CPU fallback for non-CUDA hosts.
         device = "cuda" if torch.cuda.is_available() else "cpu"
 
         # Clone OuteTTS repo (same as audio_codecs._load_dac)
@@ -2065,7 +2080,8 @@ class UnslothTrainer:
         del prompt_processor
 
         gc.collect()
-        torch.cuda.empty_cache()
+
+        clear_gpu_cache()
         self._cuda_audio_used = True
 
         if not processed_examples:
@@ -3425,15 +3441,19 @@ class UnslothTrainer:
                     logger.info(
                         f"CPT: using UnslothTrainer with embedding_learning_rate={embedding_lr}\n"
                     )
+                    cpt_args = _UnslothTrainingArguments(
+                        embedding_learning_rate = embedding_lr,
+                        **config_args,
+                    )
+                    if config_args.get("packing", False):
+                        cpt_args.packing_strategy = "wrapped"
+                        logger.info("CPT packing strategy: wrapped\n")
                     trainer_kwargs = {
                         "model": self.model,
                         "tokenizer": sft_tokenizer,
                         "train_dataset": dataset["dataset"],
                         "data_collator": data_collator,
-                        "args": _UnslothTrainingArguments(
-                            embedding_learning_rate = embedding_lr,
-                            **config_args,
-                        ),
+                        "args": cpt_args,
                     }
                     if eval_dataset is not None:
                         trainer_kwargs["eval_dataset"] = eval_dataset
diff --git a/studio/backend/core/training/training.py b/studio/backend/core/training/training.py
index 38f6b92f6d..8592dabbfe 100644
--- a/studio/backend/core/training/training.py
+++ b/studio/backend/core/training/training.py
@@ -30,7 +30,7 @@ from typing import Optional, Tuple, Any, Callable, Union, TYPE_CHECKING
 
 if TYPE_CHECKING:
     import matplotlib.pyplot as plt
-from utils.hardware import prepare_gpu_selection
+from utils.hardware import get_device, prepare_gpu_selection
 from utils.native_path_leases import (
     native_path_secret_removed_for_child_start,
     run_without_native_path_secret,
@@ -140,7 +140,7 @@ def should_use_mlx_training_backend(*, device: Optional[Any] = None) -> bool:
 
 
 def _build_training_worker_config(values: dict[str, Any]) -> dict[str, Any]:
-    """Build the normalized worker config shared by Studio and the CLI adapter."""
+    """Build the normalized worker config shared by Unsloth and the CLI adapter."""
     config = {
         "model_name": values["model_name"],
         "project_name": values.get("project_name"),
@@ -196,6 +196,7 @@ def _build_training_worker_config(values: dict[str, Any]) -> dict[str, Any]:
         "gradient_checkpointing": values.get("gradient_checkpointing", "unsloth"),
         "use_rslora": values.get("use_rslora", False),
         "use_loftq": values.get("use_loftq", False),
+        "use_dora": values.get("use_dora", False),
         "train_on_completions": values.get("train_on_completions", False),
         "finetune_vision_layers": values.get("finetune_vision_layers", True),
         "finetune_language_layers": values.get("finetune_language_layers", True),
@@ -219,6 +220,9 @@ def _build_training_worker_config(values: dict[str, Any]) -> dict[str, Any]:
             config[key] = values.get(key)
     if config["training_type"] == "Full Finetuning":
         config["load_in_4bit"] = False
+    # The parent's detected backend: the worker's apply_gpu_ids() targets the
+    # right visibility env var from this, without probing torch pre-mask.
+    config["device_backend"] = get_device().value
     return config
 
 
@@ -307,7 +311,7 @@ PLOT_HEIGHT = 3.5
 
 @dataclass
 class TrainingProgress:
-    """Shared training progress payload for Studio and backend-aware trainers."""
+    """Shared training progress payload for Unsloth and backend-aware trainers."""
 
     epoch: float = 0
     step: int = 0
@@ -328,7 +332,7 @@ class TrainingProgress:
 
 
 class _MLXTrainerAdapter:
-    """Adapts the legacy UnslothTrainer API to the shared Studio MLX worker path."""
+    """Adapts the legacy UnslothTrainer API to the shared Unsloth MLX worker path."""
 
     def __init__(self):
         self.model = None
@@ -452,6 +456,7 @@ class _MLXTrainerAdapter:
         use_gradient_checkpointing: Union[str, bool] = "unsloth",
         use_rslora: bool = False,
         use_loftq: bool = False,
+        use_dora: bool = False,
     ) -> bool:
         self._peft_config = {
             "use_lora": bool(use_lora),
@@ -462,6 +467,7 @@ class _MLXTrainerAdapter:
             "gradient_checkpointing": use_gradient_checkpointing,
             "use_rslora": bool(use_rslora),
             "use_loftq": bool(use_loftq),
+            "use_dora": bool(use_dora),
             "finetune_vision_layers": bool(finetune_vision_layers),
             "finetune_language_layers": bool(finetune_language_layers),
             "finetune_attention_modules": bool(finetune_attention_modules),
@@ -569,6 +575,7 @@ class _MLXTrainerAdapter:
             "gradient_checkpointing": "unsloth",
             "use_rslora": False,
             "use_loftq": False,
+            "use_dora": False,
             "finetune_vision_layers": True,
             "finetune_language_layers": True,
             "finetune_attention_modules": True,
@@ -754,6 +761,9 @@ class TrainingBackend:
     def __init__(self):
         # Subprocess state
         self._proc: Optional[mp.Process] = None
+        # True from the sidecar-swap handshake until the worker is recorded, so
+        # installs and STT loads treat the startup window as active.
+        self._spawn_in_progress: bool = False
         self._event_queue: Any = None
         self._stop_queue: Any = None
         self._pump_thread: Optional[threading.Thread] = None
@@ -761,6 +771,7 @@ class TrainingBackend:
         # Left True after an abnormal death so _ensure_pump_alive spots a crash.
         self._pump_running: bool = False
         self._lock = threading.Lock()
+        self._run_intent_lock = threading.RLock()
 
         # Stop watchdog: after a stop is requested, escalates to force_terminate()
         # if the worker does not exit on its own within a bounded time. The watched
@@ -773,6 +784,7 @@ class TrainingBackend:
         self._progress = TrainingProgress()
         self._should_stop = False
         self._cancel_requested = False  # True only for stop(save=False)
+        self._cancel_cleanup_output_dir: Optional[str] = None
 
         # Throttled training-status logging to the server log (not one line/step).
         self._last_progress_log_ts: float = 0.0
@@ -792,6 +804,8 @@ class TrainingBackend:
         # Job metadata
         self.current_job_id: Optional[str] = None
         self._output_dir: Optional[str] = None
+        self._resume_source_run_id: Optional[str] = None
+        self._terminal_finalize_payload: Optional[dict] = None
 
         # DB persistence
         self._metric_buffer: list[dict] = []
@@ -819,6 +833,7 @@ class TrainingBackend:
         job_id: str,
         *,
         before_spawn = None,
+        resume_source_run_id: Optional[str] = None,
         **kwargs,
     ) -> bool:
         """Spawn a subprocess to run the full training pipeline.
@@ -924,16 +939,21 @@ class TrainingBackend:
                 config["resolved_gpu_ids"] = resolved_gpu_ids
                 config["gpu_selection"] = gpu_selection
 
-            from .worker import run_training_process
+            from utils.hf_cache_settings import child_environment_for_spawn, get_hf_cache_paths
+
+            cache_env = get_hf_cache_paths().child_env({})
 
             try:
-                with native_path_secret_removed_for_child_start():
+                with (
+                    child_environment_for_spawn(cache_env),
+                    native_path_secret_removed_for_child_start(),
+                ):
                     event_queue = _CTX.Queue()
                     stop_queue = _CTX.Queue()
 
                     proc = _CTX.Process(
                         target = run_without_native_path_secret,
-                        args = (run_training_process,),
+                        args = ("core.training.worker", "run_training_process", cache_env),
                         kwargs = {
                             "event_queue": event_queue,
                             "stop_queue": stop_queue,
@@ -956,6 +976,7 @@ class TrainingBackend:
             self.current_job_id = job_id
             self._should_stop = False
             self._cancel_requested = False
+            self._cancel_cleanup_output_dir = None
             self._complete_seen.clear()
             self._progress = TrainingProgress(
                 is_training = True, status_message = "Initializing training..."
@@ -972,7 +993,10 @@ class TrainingBackend:
             self.eval_loss_history.clear()
             self.eval_step_history.clear()
             self.eval_enabled = False
-            self._output_dir = None
+            self._output_dir = config.get("output_dir") if resume_source_run_id else None
+            self._progress.output_dir = self._output_dir
+            self._resume_source_run_id = resume_source_run_id
+            self._terminal_finalize_payload = None
             self._metric_buffer.clear()
             self._run_finalized = False
             self._db_run_created = False
@@ -982,6 +1006,7 @@ class TrainingBackend:
             self._db_started_at = datetime.now(timezone.utc).isoformat()
             # Start each job Xet-first; keep config so a stall can respawn over HTTP.
             self._last_full_config = config
+            self._last_hf_cache_env = cache_env
             self._in_model_load = False
             self._xet_fallback_used = False
             self._needs_xet_respawn = False
@@ -990,6 +1015,17 @@ class TrainingBackend:
             # in history during model loading and a fast terminal worker can't race the
             # pump into a duplicate create/finalize. From here the pump only finalizes.
             self._ensure_db_run_created()
+            if resume_source_run_id and not self._db_run_created:
+                if proc.is_alive():
+                    proc.terminate()
+                proc.join(timeout = 5.0)
+                if proc.is_alive():
+                    proc.kill()
+                    proc.join(timeout = 2.0)
+                self._progress.is_training = False
+                self._progress.error = "Resume checkpoint is no longer available."
+                self._spawn_in_progress = False
+                return False
 
             # Assign handles and start the pump together under the lock so a concurrent
             # poll can't see a live _proc with no pump and spawn a duplicate.
@@ -1011,28 +1047,75 @@ class TrainingBackend:
 
     def stop_training(self, save: bool = True) -> bool:
         """Send stop signal to the training subprocess."""
-        self._should_stop = True
-        if not save:
-            self._cancel_requested = True
-        with self._lock:
-            if self._stop_queue is not None:
-                try:
-                    self._stop_queue.put({"type": "stop", "save": save})
-                except (OSError, ValueError):
-                    pass
-            # Update progress immediately for responsive UI.
-            self._progress.status_message = (
-                "Stopping training and saving checkpoint..." if save else "Cancelling training..."
-            )
-        # Guarantee the run finalizes even if the worker wedges after saving.
-        self._start_stop_watchdog(cancel = not save)
+        with self._run_intent_lock:
+            with self._lock:
+                run_id = self.current_job_id
+            if not save and run_id:
+                persist_error: Optional[Exception] = None
+                for attempt in range(_DB_FINALIZE_RETRIES):
+                    try:
+                        from storage.studio_db import mark_run_cancel_requested
+
+                        self._ensure_db_run_created()
+                        with self._lock:
+                            terminal_payload = self._terminal_finalize_payload
+                            if (
+                                terminal_payload
+                                and terminal_payload.get("expected_job_id") == run_id
+                            ):
+                                return False
+                            if not mark_run_cancel_requested(run_id):
+                                if self._db_run_created:
+                                    return False
+                                raise RuntimeError(
+                                    "Training run disappeared before cancellation persisted"
+                                )
+                            if self.current_job_id != run_id:
+                                return False
+                            self._should_stop = self._cancel_requested = True
+                            self._cancel_cleanup_output_dir = self._output_dir
+                            self._output_dir = self._progress.output_dir = None
+                        persist_error = None
+                        break
+                    except Exception as exc:
+                        persist_error = exc
+                        if attempt + 1 < _DB_FINALIZE_RETRIES:
+                            time.sleep(_DB_FINALIZE_RETRY_S)
+                if persist_error is not None:
+                    raise RuntimeError("Failed to persist Stop-without-Save") from persist_error
+            with self._lock:
+                if self.current_job_id != run_id:
+                    return False
+                if save or not run_id:
+                    self._should_stop = True
+                if not save and not run_id:
+                    self._cancel_requested = True
+                    self._cancel_cleanup_output_dir = self._output_dir
+                    self._output_dir = self._progress.output_dir = None
+                if self._stop_queue is not None:
+                    try:
+                        self._stop_queue.put({"type": "stop", "save": save})
+                    except (OSError, ValueError):
+                        pass
+                self._progress.status_message = (
+                    "Stopping training and saving checkpoint..."
+                    if save
+                    else "Cancelling training..."
+                )
+        self._start_stop_watchdog(cancel = not save, expected_job_id = run_id)
         return True
 
-    def _start_stop_watchdog(self, cancel: bool) -> None:
+    def _start_stop_watchdog(
+        self,
+        cancel: bool,
+        expected_job_id: Optional[str] = None,
+    ) -> None:
         """Start a daemon that force-terminates the worker if a requested stop does not
         exit on its own. No-op if no worker is alive or a live watchdog already watches
         this proc (a stale watchdog on an old proc never blocks a new run's watcher)."""
         with self._lock:
+            if expected_job_id is not None and self.current_job_id != expected_job_id:
+                return
             proc = self._proc
             if proc is None or not proc.is_alive():
                 return
@@ -1113,8 +1196,9 @@ class TrainingBackend:
         watched_job_id: Optional[str] = None,
     ) -> None:
         """Finalize parent state after a force-terminate so the UI leaves "Stopping..."
-        even if the worker is wedged in driver teardown; preserves output_dir so a saved
-        checkpoint is kept. No-ops if a new run already replaced the watched worker, so a
+        even if the worker is wedged in driver teardown; preserves output_dir on a save so
+        the checkpoint is kept, and clears it on a cancel (Stop without saving must not
+        offer resume/export). No-ops if a new run already replaced the watched worker, so a
         stale watchdog never marks a fresh run stopped or drops its handle.
 
         Supersession is checked on both the watched proc and job id: start_training sets
@@ -1134,7 +1218,18 @@ class TrainingBackend:
                 return  # a new run is already starting up; leave its state alone
             run_id = self.current_job_id  # == watched_job_id
             self._progress.is_training = False
-            self._progress.status_message = "Training stopped."
+        terminal_payload = self._terminal_finalize_kwargs()
+        status = terminal_payload["status"]
+        error_message = terminal_payload.get("error_message")
+        output_dir = terminal_payload["output_dir"]
+        clear_output_dir = terminal_payload["clear_output_dir"]
+        resume_blocked = bool(terminal_payload.get("resume_blocked"))
+        with self._lock:
+            if self.current_job_id != run_id:
+                return
+            self._progress.status_message = error_message or "Training stopped."
+            if error_message:
+                self._progress.error = error_message
         # Create the row if a start-time create failed (no-op otherwise; skips when the pump
         # is mid-create, in which case its create-then-finalize records the run instead).
         self._ensure_db_run_created()
@@ -1148,7 +1243,8 @@ class TrainingBackend:
             batch: list = []
             final_step = final_loss = duration = None
             loss_history: list = []
-            output_dir = self._output_dir
+            if clear_output_dir:
+                self._output_dir = self._progress.output_dir = None
             if claim:
                 self._run_finalized = True  # claim this run's finalize
                 batch = list(self._metric_buffer)
@@ -1161,7 +1257,17 @@ class TrainingBackend:
                 loss_history = list(self.loss_history)
         if claim:
             self._finish_stopped_run(
-                run_id, output_dir, batch, final_step, final_loss, duration, loss_history
+                run_id,
+                output_dir,
+                batch,
+                final_step,
+                final_loss,
+                duration,
+                loss_history,
+                status = status,
+                error_message = error_message,
+                clear_output_dir = clear_output_dir,
+                resume_blocked = resume_blocked,
             )
         with self._lock:
             if target_proc is None or self._proc is target_proc:
@@ -1176,6 +1282,10 @@ class TrainingBackend:
         final_loss: Optional[float],
         duration: Optional[float],
         loss_history: list,
+        status: str = "stopped",
+        error_message: Optional[str] = None,
+        clear_output_dir: bool = False,
+        resume_blocked: bool = False,
     ) -> None:
         """Record a force-stopped run finished by its captured id, from state snapshotted
         under the lock. insert_metrics_batch upserts and finish_run is an idempotent UPDATE,
@@ -1194,14 +1304,16 @@ class TrainingBackend:
                 sparkline = downsample(loss_history, 50)
                 finish_run(
                     id = run_id,
-                    status = "stopped",
+                    status = status,
                     ended_at = datetime.now(timezone.utc).isoformat(),
                     final_step = final_step,
                     final_loss = final_loss,
                     duration_seconds = duration,
                     loss_sparkline = _json.dumps(sparkline),
                     output_dir = output_dir,
-                    error_message = None,
+                    error_message = error_message,
+                    clear_output_dir = clear_output_dir,
+                    resume_blocked = resume_blocked,
                 )
                 return
             except Exception:
@@ -1231,7 +1343,7 @@ class TrainingBackend:
                 logger.info("Force-terminating training subprocess (pid=%s)", proc.pid)
                 proc.terminate()
             cancelled = self._cancel_requested
-            output_dir = self._output_dir
+            output_dir = self._cancel_cleanup_output_dir or self._output_dir
 
         if proc is not None:
             proc.join(timeout = 5.0)
@@ -1304,7 +1416,11 @@ class TrainingBackend:
         self._last_full_config = config
         logger.warning("Respawning training worker with HF_HUB_DISABLE_XET=1 after Xet stall")
 
-        from .worker import run_training_process
+        cache_env = getattr(self, "_last_hf_cache_env", None)
+        if not cache_env:
+            from utils.hf_cache_settings import get_hf_cache_paths
+            cache_env = get_hf_cache_paths().child_env({})
+        from utils.hf_cache_settings import child_environment_for_spawn
 
         # This run is active, so an install request 409s rather than proceeds: a reservation seen here
         # is transient (an aborting install or short lazy repair). Wait it out instead of stranding the
@@ -1336,12 +1452,15 @@ class TrainingBackend:
         # crashed respawn cannot wedge is_training_active until restart.
         try:
             try:
-                with native_path_secret_removed_for_child_start():
+                with (
+                    child_environment_for_spawn(cache_env),
+                    native_path_secret_removed_for_child_start(),
+                ):
                     event_queue = _CTX.Queue()
                     stop_queue = _CTX.Queue()
                     new_proc = _CTX.Process(
                         target = run_without_native_path_secret,
-                        args = (run_training_process,),
+                        args = ("core.training.worker", "run_training_process", cache_env),
                         kwargs = {
                             "event_queue": event_queue,
                             "stop_queue": stop_queue,
@@ -1595,17 +1714,60 @@ class TrainingBackend:
                             )
 
                 self._ensure_db_run_created()
-                self._finalize_run_in_db(
-                    status = "stopped" if self._should_stop else "error",
-                    error_message = None
-                    if self._should_stop
-                    else "Training process terminated unexpectedly",
-                )
+                terminal_payload = self._terminal_finalize_kwargs()
+                with self._lock:
+                    if terminal_payload["clear_output_dir"]:
+                        self._output_dir = self._progress.output_dir = None
+                    if terminal_payload.get("error_message"):
+                        self._progress.error = terminal_payload["error_message"]
+                        self._progress.status_message = terminal_payload["error_message"]
+                self._finalize_run_in_db(**terminal_payload)
             except Exception:
                 logger.exception("Training event pump: finalization after worker exit failed")
             self._pump_running = False
             return
 
+    def _has_current_resume_checkpoint(self, output_dir, step) -> bool:
+        # A valid checkpoint at the current step means the stop-and-save landed on
+        # disk even if the worker died before confirming it.
+        if not output_dir or not isinstance(step, int) or step <= 0:
+            return False
+        from core.training.resume import get_resume_checkpoint_path
+        return get_resume_checkpoint_path(output_dir, expected_step = step) is not None
+
+    def _terminal_finalize_kwargs(self) -> dict:
+        with self._lock:
+            job_id = self.current_job_id
+            payload = self._terminal_finalize_payload
+            if payload and payload.get("expected_job_id") == job_id:
+                return dict(payload)
+            cancel, stopped = self._cancel_requested, self._should_stop
+            output_dir = None if cancel else self._output_dir
+            step = self._progress.step
+            existing_error = self._progress.error
+        status, error, blocked = (
+            ("stopped", None, cancel)
+            if stopped
+            else (
+                "error",
+                existing_error or "Training process terminated unexpectedly",
+                False,
+            )
+        )
+        # Block only when no valid current-step checkpoint actually landed.
+        if stopped and not cancel and not self._has_current_resume_checkpoint(output_dir, step):
+            status = "error"
+            error = "Stop and Save ended before a valid current-step checkpoint was written."
+            blocked = True
+        return {
+            "status": status,
+            "error_message": error,
+            "output_dir": output_dir,
+            "clear_output_dir": cancel,
+            "resume_blocked": blocked,
+            "expected_job_id": job_id,
+        }
+
     def _handle_event(self, event: dict) -> None:
         """Apply a subprocess event to local state.
 
@@ -1764,6 +1926,15 @@ class TrainingBackend:
             elif etype == "eval_configured":
                 self.eval_enabled = True
 
+            elif etype == "output_dir":
+                event_output_dir = event.get("output_dir")
+                if self._cancel_requested:
+                    self._cancel_cleanup_output_dir = event_output_dir
+                    self._output_dir = self._progress.output_dir = None
+                else:
+                    self._output_dir = event_output_dir
+                    db_action = "persist_output_dir"
+
             elif etype == "status":
                 self._progress.status_message = event.get("message", "")
                 self._progress.is_training = True
@@ -1778,7 +1949,12 @@ class TrainingBackend:
                 self._complete_seen.set()
                 self._progress.is_training = False
                 self._progress.is_completed = not stopped
-                self._output_dir = event.get("output_dir")
+                event_output_dir = event.get("output_dir")
+                if self._cancel_requested:
+                    self._cancel_cleanup_output_dir = event_output_dir
+                    self._output_dir = None
+                else:
+                    self._output_dir = event_output_dir
                 self._progress.output_dir = self._output_dir
                 self._progress.status_message = msg
                 if not self._db_run_created and self.current_job_id and self._db_config:
@@ -1788,11 +1964,16 @@ class TrainingBackend:
                 db_action_kwargs = {
                     "status": "stopped" if stopped else "completed",
                     "output_dir": self._output_dir,
+                    "clear_output_dir": self._cancel_requested,
+                    "expected_job_id": self.current_job_id,
                 }
+                self._terminal_finalize_payload = dict(db_action_kwargs)
 
             elif etype == "error":
                 self._progress.is_training = False
                 self._progress.error = event.get("error", "Unknown error")
+                if self._cancel_requested:
+                    self._output_dir = self._progress.output_dir = None
                 logger.error("Training error: %s", event.get("error"))
                 stack = event.get("stack", "")
                 if stack:
@@ -1801,29 +1982,36 @@ class TrainingBackend:
                     db_action = "create_and_finalize"
                 else:
                     db_action = "finalize"
+                stop_save_failed = (
+                    self._should_stop
+                    and not self._cancel_requested
+                    and not self._has_current_resume_checkpoint(
+                        self._output_dir, self._progress.step
+                    )
+                )
                 db_action_kwargs = {
-                    "status": "stopped" if self._should_stop else "error",
+                    "status": "stopped"
+                    if self._should_stop
+                    and not stop_save_failed
+                    and not event.get("keep_error_status")
+                    else "error",
                     "error_message": event.get("error", "Unknown error"),
+                    "output_dir": self._output_dir,
+                    "clear_output_dir": self._cancel_requested,
+                    "resume_blocked": stop_save_failed or bool(event.get("resume_blocked")),
+                    "expected_job_id": self.current_job_id,
                 }
+                self._terminal_finalize_payload = dict(db_action_kwargs)
 
         # --- DB I/O outside the lock ---
         if db_action == "create_run":
-            try:
-                from storage.studio_db import create_run
-
-                create_run(
-                    id = db_action_kwargs["job_id"],
-                    model_name = db_action_kwargs["model_name"],
-                    dataset_name = db_action_kwargs["dataset_name"],
-                    config_json = db_action_kwargs["config_json"],
-                    started_at = db_action_kwargs["started_at"],
-                    total_steps = db_action_kwargs["total_steps"],
-                )
-                self._db_run_created = True
+            self._ensure_db_run_created()
+            if self._db_run_created:
                 if db_action_kwargs["total_steps"]:
                     self._db_total_steps_set = True
-            except Exception:
-                logger.warning("Failed to create DB run record", exc_info = True)
+                self._persist_output_dir()
+        elif db_action == "persist_output_dir":
+            self._persist_output_dir()
         elif db_action == "create_and_finalize":
             self._ensure_db_run_created()
             self._finalize_run_in_db(**db_action_kwargs)
@@ -1842,6 +2030,22 @@ class TrainingBackend:
         if etype == "progress":
             self._log_training_progress()
 
+    def _persist_output_dir(self) -> None:
+        with self._lock:
+            if (
+                not self._output_dir
+                or not self.current_job_id
+                or not self._db_run_created
+                or self._cancel_requested
+            ):
+                return
+            run_id, output_dir = self.current_job_id, self._output_dir
+        try:
+            from storage.studio_db import update_run_output_dir
+            update_run_output_dir(run_id, output_dir)
+        except Exception:
+            logger.warning("Failed to persist output_dir", exc_info = True)
+
     def _log_training_progress(self) -> None:
         """One throttled training-status line to the server log (the per-step stream
         still goes to the UI via SSE): first step, then at most every 30s, plus the
@@ -1875,6 +2079,7 @@ class TrainingBackend:
         caller create at a time, and ``_db_run_created`` is published only after
         ``create_run`` commits, so a concurrent finalize never runs ``finish_run`` against a
         not-yet-inserted row (a zero-row UPDATE that would leave the run stuck as running)."""
+        self._run_intent_lock.acquire()
         with self._lock:
             if (
                 self._db_run_created
@@ -1882,6 +2087,7 @@ class TrainingBackend:
                 or not self.current_job_id
                 or not self._db_config
             ):
+                self._run_intent_lock.release()
                 return
             self._db_create_in_progress = True  # only one caller creates
             job_id = self.current_job_id
@@ -1898,6 +2104,12 @@ class TrainingBackend:
                 or _s3_dataset_name(db_config.get("s3_dataset"))
                 or "unknown"
             )
+            with self._lock:
+                if self.current_job_id != job_id:
+                    return
+                output_dir = self._output_dir
+                cancel_requested = self._cancel_requested
+                resumed_from_run_id = self._resume_source_run_id
             create_run(
                 id = job_id,
                 model_name = db_config["model_name"],
@@ -1905,6 +2117,9 @@ class TrainingBackend:
                 config_json = _json.dumps(db_config),
                 started_at = started_at,
                 total_steps = total_steps,
+                output_dir = output_dir,
+                cancel_requested = cancel_requested,
+                resumed_from_run_id = resumed_from_run_id,
             )
             created = True
         except Exception:
@@ -1919,12 +2134,15 @@ class TrainingBackend:
                     if created:
                         self._db_run_created = True  # publish only after the insert commits
                     self._db_create_in_progress = False
+            self._run_intent_lock.release()
 
     def _finalize_run_in_db(
         self,
         status: str,
         error_message: Optional[str] = None,
         output_dir: Optional[str] = None,
+        clear_output_dir: bool = False,
+        resume_blocked: bool = False,
         expected_job_id: Optional[str] = None,
     ) -> None:
         """Flush remaining metrics and mark a run finished in the DB. Claims the finalize
@@ -1947,26 +2165,33 @@ class TrainingBackend:
             duration = self._progress.elapsed_seconds
             loss_history = list(self.loss_history)
         self._flush_metrics_to_db(run_id = run_id)
-        try:
-            from storage.studio_db import finish_run
-            from utils.downsample import downsample
+        for attempt in range(_DB_FINALIZE_RETRIES):
+            try:
+                from storage.studio_db import finish_run
+                from utils.downsample import downsample
 
-            sparkline = downsample(loss_history, 50)
-            finish_run(
-                id = run_id,
-                status = status,
-                ended_at = datetime.now(timezone.utc).isoformat(),
-                final_step = final_step,
-                final_loss = final_loss,
-                duration_seconds = duration,
-                loss_sparkline = _json.dumps(sparkline),
-                output_dir = output_dir,
-                error_message = error_message,
-            )
-        except Exception:
-            with self._lock:
-                self._run_finalized = False  # unclaim so a later flush can retry
-            logger.warning("Failed to finalize run in DB (status=%s)", status, exc_info = True)
+                finish_run(
+                    id = run_id,
+                    status = status,
+                    ended_at = datetime.now(timezone.utc).isoformat(),
+                    final_step = final_step,
+                    final_loss = final_loss,
+                    duration_seconds = duration,
+                    loss_sparkline = _json.dumps(downsample(loss_history, 50)),
+                    output_dir = output_dir,
+                    error_message = error_message,
+                    clear_output_dir = clear_output_dir,
+                    resume_blocked = resume_blocked,
+                )
+                return
+            except Exception:
+                if attempt + 1 < _DB_FINALIZE_RETRIES:
+                    time.sleep(_DB_FINALIZE_RETRY_S)
+                    continue
+                with self._lock:
+                    if self.current_job_id == run_id:
+                        self._run_finalized = False
+                logger.warning("Failed to finalize run in DB (status=%s)", status, exc_info = True)
 
     def _flush_metrics_to_db(self, run_id: Optional[str] = None) -> None:
         """Flush buffered metrics to the DB and update live progress. The target run id,
diff --git a/studio/backend/core/training/worker.py b/studio/backend/core/training/worker.py
index c52adbe8fa..03327d3320 100644
--- a/studio/backend/core/training/worker.py
+++ b/studio/backend/core/training/worker.py
@@ -90,6 +90,79 @@ _FAST_PATH_HOOKS_SKIP_ENV = "UNSLOTH_STUDIO_SKIP_FAST_PATH_HOOKS"
 # run_training_process() and isn't GC'd mid-run.
 _WINDOWS_ROCM_GROUPED_MM_LIB = None
 
+
+def _install_grouped_mm_cpu_fallback(torch_mod, logger, label):
+    """Register a Python mm/bmm fallback for torch._grouped_mm and return the Library.
+
+    RDNA4 (gfx1200/gfx1201) ships a null HIP _grouped_mm kernel on ROCm <= 7.12
+    (fixed in 7.13; ROCm/TheRock #5284). JitDecomp dispatches _grouped_mm to the
+    null kernel and crashes; overriding the CUDA dispatch key bypasses it. Shared
+    by the Windows and Linux ROCm guards. Keep the returned Library referenced so
+    the registration outlives the caller.
+    """
+    import warnings as _warnings
+
+    _gm_lib = torch_mod.library.Library("aten", "IMPL")
+
+    def _grouped_mm_safe_impl(
+        self,
+        mat2,
+        offs = None,
+        bias = None,
+        out_dtype = None,
+    ):
+        """Python mm/bmm fallback for _grouped_mm on gfx120X (null HIP kernel, ROCm <= 7.12)."""
+        _t = torch_mod
+        if offs is None:
+            # No offsets: 2-D -> mm, 3-D batched -> bmm (unconditional mm broke 3-D MoE).
+            if self.dim() == 3 and mat2.dim() == 3:
+                result = _t.bmm(self.contiguous(), mat2.contiguous())
+            elif self.dim() == 3 and mat2.dim() == 2:
+                result = _t.matmul(self.contiguous(), mat2.contiguous())
+            elif self.dim() == 2 and mat2.dim() == 3:
+                result = _t.matmul(self.contiguous(), mat2.contiguous())
+            else:
+                result = _t.mm(self.contiguous(), mat2.contiguous())
+        else:
+            # Grouped: offs[i] is the exclusive end-row of group i.
+            offs_list = offs.tolist()
+            pieces = []
+            prev = 0
+            for idx, end in enumerate(offs_list):
+                end = int(end)
+                a_part = self[prev:end].contiguous()
+                b_part = mat2[idx].contiguous() if mat2.dim() == 3 else mat2.contiguous()
+                pieces.append(_t.mm(a_part, b_part))
+                prev = end
+            # Include trailing rows not covered by offs.
+            if prev < self.shape[0]:
+                a_tail = self[prev:].contiguous()
+                b_tail = mat2[-1].contiguous() if mat2.dim() == 3 else mat2.contiguous()
+                pieces.append(_t.mm(a_tail, b_tail))
+            result = (
+                _t.cat(pieces, dim = 0)
+                if pieces
+                else _t.zeros(0, mat2.shape[-1], device = self.device, dtype = self.dtype)
+            )
+        if bias is not None:
+            result = result + bias
+        if out_dtype is not None:
+            result = result.to(out_dtype)
+        elif result.dtype != self.dtype:
+            result = result.to(self.dtype)
+        return result
+
+    with _warnings.catch_warnings():
+        _warnings.simplefilter("ignore")
+        _gm_lib.impl("_grouped_mm", _grouped_mm_safe_impl, "CUDA")
+    logger.info(
+        "%s: patched _grouped_mm CUDA dispatch (null HIP kernel on gfx120X, "
+        "ROCm <= 7.12 -- bypassed with Python mm fallback)",
+        label,
+    )
+    return _gm_lib
+
+
 # Subprocesses don't inherit os.add_dll_directory registrations. Replicate
 # main.py's Windows ROCm DLL setup so the first `import torch` finds
 # amdhip64.dll. Handles retained at module scope so they aren't GC'd.
@@ -702,8 +775,9 @@ def _rocm_classify_unified_memory(props: Any) -> tuple[str, bool]:
     3. Device-name substring match (last resort when all arch attrs absent;
        AMD SDK / Radeon wheels may not populate them):
          - gfx1150 Strix Point: ``Radeon 890M``, ``Radeon 880M``
-         - gfx1151 Strix Halo:  ``Radeon 8060S`` (Ryzen AI MAX+ 395),
-                                ``Radeon 8050S`` (cut-down SKU)
+         - gfx1151 Strix Halo / Gorgon Halo:  ``Radeon 8065S`` (Ryzen AI
+                                Max+ 495), ``Radeon 8060S`` (Ryzen AI MAX+
+                                395), ``Radeon 8050S`` (cut-down SKU)
     """
     gcn_arch = ""
     for _attr in ("gcnArchName", "gcn_arch_name", "arch_name", "gfx_arch_name"):
@@ -728,7 +802,11 @@ def _rocm_classify_unified_memory(props: Any) -> tuple[str, bool]:
     # Arch attrs absent — fall back to device-name matching.
     dev_lower = (getattr(props, "name", "") or "").lower()
     is_unified = (
-        "890m" in dev_lower or "880m" in dev_lower or "8060s" in dev_lower or "8050s" in dev_lower
+        "890m" in dev_lower
+        or "880m" in dev_lower
+        or "8065s" in dev_lower
+        or "8060s" in dev_lower
+        or "8050s" in dev_lower
     )
     return gcn_arch, is_unified
 
@@ -1100,7 +1178,7 @@ _MLX_VLM_RESIZED_IMAGE_LAYOUT_CACHE = {}
 
 
 def _mlx_vlm_resized_image_layout(processor = None) -> str | None:
-    """Return the numpy image layout expected after Studio-side VLM resizing."""
+    """Return the numpy image layout expected after Unsloth-side VLM resizing."""
     image_processor = getattr(processor, "image_processor", None)
     if image_processor is None:
         return None
@@ -1257,7 +1335,7 @@ _MLX_STUDIO_LR_SCHEDULERS = {"linear", "cosine", "constant"}
 
 
 # Fallback alias map mirroring unsloth_zoo._normalize_mlx_optimizer_name, used
-# only when mlx (Apple Silicon) is not importable so Studio config validation
+# only when mlx (Apple Silicon) is not importable so Unsloth config validation
 # still works on non-MLX hosts. The zoo function stays the source of truth.
 _MLX_STUDIO_ADAMW_ALIASES = frozenset(
     (
@@ -1309,7 +1387,7 @@ def _normalize_mlx_studio_scheduler(value):
 
 
 def _resolve_mlx_local_dataset_files(file_paths: list) -> list[str]:
-    """Resolve CLI paths and Studio local dataset uploads without importing the GPU trainer."""
+    """Resolve CLI paths and Unsloth local dataset uploads without importing the GPU trainer."""
     from utils.paths import resolve_dataset_path
 
     all_files: list[str] = []
@@ -1469,6 +1547,10 @@ def _run_mlx_training(event_queue, stop_queue, config):
         message = "LoftQ is not supported for MLX training yet."
         _send("error", error = message)
         raise NotImplementedError(message)
+    if config.get("use_dora"):
+        message = "DoRA is not supported for MLX training yet."
+        _send("error", error = message)
+        raise NotImplementedError(message)
     if config.get("is_embedding"):
         message = "Embedding model training is not supported for MLX training yet."
         _send("error", error = message)
@@ -1840,8 +1922,15 @@ def _run_mlx_training(event_queue, stop_queue, config):
     # Resolve to ~/.unsloth/studio/outputs/ so the export page finds it
     from utils.paths import ensure_dir
 
-    output_dir = _resolve_mlx_output_dir(config, model_name)
+    # Resume must land in the original run dir even when config lacks output_dir.
+    resume_dir = config.get("output_dir", "") or _output_dir_from_resume_checkpoint(
+        resume_from_checkpoint
+    )
+    output_dir = _resolve_mlx_output_dir(
+        {**config, "output_dir": resume_dir} if resume_dir else config, model_name
+    )
     ensure_dir(Path(output_dir))
+    _emit_output_dir(event_queue, output_dir)
 
     # ── 6. Create trainer ──
     eval_steps_val = config.get("eval_steps", 0) or 0
@@ -1912,7 +2001,7 @@ def _run_mlx_training(event_queue, stop_queue, config):
     if "max_grad_leaf_norm" in _supported_fields:
         mlx_config_kwargs["max_grad_leaf_norm"] = max_grad_leaf_norm
     if "append_eos" in _supported_fields:
-        # Studio SFT formatting owns rendered examples; raw/CPT text still
+        # Unsloth SFT formatting owns rendered examples; raw/CPT text still
         # needs MLX to append EOS like the CUDA raw-text path.
         mlx_config_kwargs["append_eos"] = bool(raw_text_mode)
 
@@ -2067,6 +2156,17 @@ def _run_mlx_training(event_queue, stop_queue, config):
 
     trainer.add_eval_callback(_on_eval)
 
+    _opt_ref = [None]
+    _orig_build_optimizer = getattr(trainer, "_build_optimizer", None)
+
+    if callable(_orig_build_optimizer):
+
+        def _capture_optimizer(total_steps):
+            _opt_ref[0] = _orig_build_optimizer(total_steps)
+            return _opt_ref[0]
+
+        trainer._build_optimizer = _capture_optimizer
+
     # ── 11. Run training ──
     gc.collect()
     mx.synchronize()
@@ -2082,31 +2182,58 @@ def _run_mlx_training(event_queue, stop_queue, config):
         trainer.save_model = _save_model
 
     # ── 12. Save and finalize ──
-    if trainer.stop_requested:
-        if not _stop_save[0]:
-            # Cancel (save=False): skip saving.
-            _send("complete", output_dir = None, status_message = "Training cancelled")
+    def _finish_tracking() -> None:
+        # Runs on every save/finalize exit so TB/W&B never leak on early return.
+        if tb_writer is not None:
+            try:
+                tb_writer.close()
+            except Exception:
+                pass
+        if wandb_run is not None:
+            try:
+                wandb_run.finish()
+            except Exception:
+                pass
+
+    def _stop_checkpoint_ok() -> bool:
+        if _write_mlx_stop_checkpoint(trainer, _opt_ref[0], output_dir):
+            return True
+        _send(
+            "error",
+            error = (
+                "Failed to save a resumable checkpoint after stop. "
+                "Model files were saved, but this run cannot be resumed."
+            ),
+            # A user stop finalizes as 'stopped'; keep this failure's error status so history explains it.
+            keep_error_status = True,
+            # Older checkpoints are stale; resuming would roll back past this stop.
+            resume_blocked = True,
+        )
+        return False
+
+    try:
+        if trainer.stop_requested:
+            if not _stop_save[0]:
+                # Cancel (save=False): skip saving.
+                _send("complete", output_dir = None, status_message = "Training cancelled")
+            else:
+                _send("status", status_message = "Saving stopped model...")
+                mx.synchronize()
+                trainer.save_model(output_dir)
+                # Stop-and-save promises a resumable checkpoint, not just model files.
+                if not _stop_checkpoint_ok():
+                    return
+                _send("complete", output_dir = output_dir, status_message = "Training stopped")
         else:
-            _send("status", status_message = "Saving stopped model...")
+            _send("status", status_message = "Saving model...")
             mx.synchronize()
             trainer.save_model(output_dir)
-            _send("complete", output_dir = output_dir, status_message = "Training stopped")
-    else:
-        _send("status", status_message = "Saving model...")
-        mx.synchronize()
-        trainer.save_model(output_dir)
-        _send("complete", output_dir = output_dir, status_message = "Training completed")
-
-    if tb_writer is not None:
-        try:
-            tb_writer.close()
-        except Exception:
-            pass
-    if wandb_run is not None:
-        try:
-            wandb_run.finish()
-        except Exception:
-            pass
+            # A save-stop can race the natural final save; it made the same promise.
+            if trainer.stop_requested and _stop_save[0] and not _stop_checkpoint_ok():
+                return
+            _send("complete", output_dir = output_dir, status_message = "Training completed")
+    finally:
+        _finish_tracking()
 
 
 def _is_current_process_apple_silicon() -> bool:
@@ -2121,7 +2248,7 @@ def run_mlx_training_process(
     config: dict,
     transformers_activated: bool = False,
 ) -> None:
-    """MLX worker entrypoint shared by Studio subprocesses and the CLI adapter."""
+    """MLX worker entrypoint shared by Unsloth subprocesses and the CLI adapter."""
     model_name = config["model_name"]
 
     backend_path = str(Path(__file__).resolve().parent.parent.parent)
@@ -2250,7 +2377,7 @@ def run_training_process(*, event_queue: Any, stop_queue: Any, config: dict) ->
         env = os.getenv("ENVIRONMENT_TYPE", "production"),
     )
 
-    apply_gpu_ids(config.get("resolved_gpu_ids"))
+    apply_gpu_ids(config.get("resolved_gpu_ids"), backend = config.get("device_backend"))
 
     model_name = config["model_name"]
 
@@ -2644,80 +2771,8 @@ def run_training_process(*, event_queue: Any, stop_queue: Any, config: dict) ->
             # so 7.13+ uses the real GPU kernel.
             if not _hip_ver_at_least(7, 13):
                 try:
-                    import warnings as _warnings
-
-                    _gm_lib = _torch_for_rocm.library.Library("aten", "IMPL")
-
-                    def _grouped_mm_safe_impl(
-                        self,
-                        mat2,
-                        offs = None,
-                        bias = None,
-                        out_dtype = None,
-                    ):
-                        """Python mm/bmm fallback for _grouped_mm on gfx1200 (null HIP kernel, ROCm ≤ 7.12)."""
-                        _t = _torch_for_rocm
-                        if offs is None:
-                            # No offsets: 2-D -> mm, 3-D batched -> bmm
-                            # (unconditional mm broke 3-D MoE).
-                            if self.dim() == 3 and mat2.dim() == 3:
-                                result = _t.bmm(self.contiguous(), mat2.contiguous())
-                            elif self.dim() == 3 and mat2.dim() == 2:
-                                # Broadcast 2-D mat2 across the batch dim.
-                                result = _t.matmul(self.contiguous(), mat2.contiguous())
-                            elif self.dim() == 2 and mat2.dim() == 3:
-                                # Broadcast 2-D self across batch via matmul.
-                                result = _t.matmul(self.contiguous(), mat2.contiguous())
-                            else:
-                                result = _t.mm(self.contiguous(), mat2.contiguous())
-                        else:
-                            # Grouped: offs[i] is the exclusive end-row of group i.
-                            offs_list = offs.tolist()
-                            pieces = []
-                            prev = 0
-                            for idx, end in enumerate(offs_list):
-                                end = int(end)
-                                a_part = self[prev:end].contiguous()
-                                if mat2.dim() == 3:
-                                    b_part = mat2[idx].contiguous()
-                                else:
-                                    b_part = mat2.contiguous()
-                                pieces.append(_t.mm(a_part, b_part))
-                                prev = end
-                            # Include trailing rows not covered by offs.
-                            if prev < self.shape[0]:
-                                a_tail = self[prev:].contiguous()
-                                b_tail = (
-                                    mat2[-1].contiguous() if mat2.dim() == 3 else mat2.contiguous()
-                                )
-                                pieces.append(_t.mm(a_tail, b_tail))
-                            result = (
-                                _t.cat(pieces, dim = 0)
-                                if pieces
-                                else _t.zeros(
-                                    0,
-                                    mat2.shape[-1],
-                                    device = self.device,
-                                    dtype = self.dtype,
-                                )
-                            )
-                        if bias is not None:
-                            result = result + bias
-                        if out_dtype is not None:
-                            result = result.to(out_dtype)
-                        elif result.dtype != self.dtype:
-                            result = result.to(self.dtype)
-                        return result
-
-                    with _warnings.catch_warnings():
-                        _warnings.simplefilter("ignore")
-                        _gm_lib.impl("_grouped_mm", _grouped_mm_safe_impl, "CUDA")
-
-                    _WINDOWS_ROCM_GROUPED_MM_LIB = _gm_lib  # prevent GC
-                    logger.info(
-                        "Windows ROCm: patched _grouped_mm CUDA dispatch "
-                        "(null HIP kernel on gfx1200, ROCm ≤ 7.12 — "
-                        "bypassed with Python mm fallback)"
+                    _WINDOWS_ROCM_GROUPED_MM_LIB = _install_grouped_mm_cpu_fallback(
+                        _torch_for_rocm, logger, "Windows ROCm"
                     )
                 except Exception as _patch_exc:
                     logger.warning(
@@ -2731,6 +2786,44 @@ def run_training_process(*, event_queue: Any, stop_queue: Any, config: dict) ->
                     "skipping Python fallback (AMD fixed gfx1200 null kernel in ROCm 7.13)"
                 )
 
+    # ── 1f-linux. Linux ROCm RDNA4 _grouped_mm null kernel ──
+    # The win32 guard above misses Linux: RDNA4 (gfx1200/gfx1201) hits the same null
+    # HIP _grouped_mm kernel at ROCm <= 7.12 (fixed 7.13, ROCm/TheRock #5284). Gate on
+    # arch + HIP < 7.13 so NVIDIA/CUDA and non-RDNA4 AMD are untouched; no-op if fixed.
+    if sys.platform.startswith("linux") and _hw.IS_ROCM:
+        try:
+            _torch_lin = sys.modules.get("torch")
+            if _torch_lin is not None and _torch_lin.cuda.is_available():
+                # Prefer torch.version.hip, else rocmX.Y from torch.__version__ (AMD
+                # SDK / Radeon wheels leave version.hip unset). Unknown version on a
+                # gfx120X build -> assume affected unless it is a post-fix rocmsdk wheel.
+                _hip_str = str(getattr(getattr(_torch_lin, "version", None), "hip", "") or "")
+                _ver = getattr(_torch_lin, "__version__", "").lower()
+                _m = re.match(r"(\d+)\.(\d+)", _hip_str) or re.search(r"rocm(\d+)\.(\d+)", _ver)
+                if _m:
+                    _hip_lt_713 = (int(_m.group(1)), int(_m.group(2))) < (7, 13)
+                else:
+                    _hip_lt_713 = "rocmsdk" not in _ver
+                # Scan every visible GPU (device_map="balanced" can place layers on a
+                # later RDNA4 card, so device 0 is not enough). Match gfx120X by arch,
+                # or by RX 9000 / R9700 name when the wheel omits gcnArchName.
+                _rdna4 = False
+                for _i in range(_torch_lin.cuda.device_count()):
+                    _props = _torch_lin.cuda.get_device_properties(_i)
+                    _lin_arch, _ = _rocm_classify_unified_memory(_props)
+                    _lin_name = (getattr(_props, "name", "") or "").lower()
+                    if _lin_arch.lower() in ("gfx1200", "gfx1201") or (
+                        not _lin_arch and re.search(r"rx\s*90[0-9]0|r9700", _lin_name)
+                    ):
+                        _rdna4 = True
+                        break
+                if _rdna4 and _hip_lt_713:
+                    _WINDOWS_ROCM_GROUPED_MM_LIB = _install_grouped_mm_cpu_fallback(
+                        _torch_lin, logger, "Linux ROCm gfx120X"
+                    )
+        except Exception as _gm_lin_exc:
+            logger.warning("Linux ROCm gfx120X: could not patch _grouped_mm: %s", _gm_lin_exc)
+
     # ── 1g. ROCm OOM guard ──
     # On ROCm, exhausting VRAM can hang the HIP driver instead of raising.
     # set_per_process_memory_fraction caps the allocator so PyTorch raises
@@ -2780,7 +2873,7 @@ def run_training_process(*, event_queue: Any, stop_queue: Any, config: dict) ->
                 )
                 # Unified Windows APUs: the WDDM budget is user-raisable, but
                 # nothing on the box says so -- users see "48 GB VRAM" on a
-                # 96 GB machine and assume a Studio bug. Say where the limit
+                # 96 GB machine and assume an Unsloth bug. Say where the limit
                 # comes from and how to raise it.
                 if _is_unified and sys.platform == "win32":
                     try:
@@ -3097,6 +3190,7 @@ def run_training_process(*, event_queue: Any, stop_queue: Any, config: dict) ->
                 use_gradient_checkpointing = config.get("gradient_checkpointing", "unsloth"),
                 use_rslora = config.get("use_rslora", False),
                 use_loftq = config.get("use_loftq", False),
+                use_dora = config.get("use_dora", False),
             )
         elif use_lora:
             _send_status(event_queue, "Configuring LoRA adapters...")
@@ -3113,6 +3207,7 @@ def run_training_process(*, event_queue: Any, stop_queue: Any, config: dict) ->
                 use_gradient_checkpointing = config.get("gradient_checkpointing", "unsloth"),
                 use_rslora = config.get("use_rslora", False),
                 use_loftq = config.get("use_loftq", False),
+                use_dora = config.get("use_dora", False),
             )
         else:
             _send_status(event_queue, "Preparing model for full finetuning...")
@@ -3177,6 +3272,7 @@ def run_training_process(*, event_queue: Any, stop_queue: Any, config: dict) ->
             )
         output_dir = str(resolve_output_dir(output_dir))
         ensure_dir(Path(output_dir))
+        _emit_output_dir(event_queue, output_dir)
 
         tensorboard_dir = config.get("tensorboard_dir")
         if config.get("enable_tensorboard", False):
@@ -3296,6 +3392,61 @@ def _send_status(event_queue: Any, message: str) -> None:
     )
 
 
+def _emit_output_dir(event_queue: Any, output_dir: str) -> None:
+    try:
+        event_queue.put({"type": "output_dir", "output_dir": output_dir, "ts": time.time()})
+    except Exception:
+        pass
+
+
+def _mlx_has_checkpoint_at_step(output_dir, step: int) -> bool:
+    if step <= 0:
+        return False
+    from core.training.resume import is_resume_checkpoint_valid
+    return is_resume_checkpoint_valid(
+        Path(output_dir) / f"checkpoint-{step}", expected_step = step, backend = "mlx"
+    )
+
+
+def _write_mlx_stop_checkpoint(trainer, optimizer, output_dir) -> bool:
+    """Write a full resume checkpoint for a stopped MLX run.
+
+    Returns True when a checkpoint for the current training step exists.
+    """
+    step = int(getattr(trainer, "_global_step", 0) or 0)
+    # A periodic save or a resumed run may already cover the current step.
+    if _mlx_has_checkpoint_at_step(output_dir, step):
+        return True
+    if step <= 0 or optimizer is None:
+        return False
+    ckpt_dir = Path(output_dir) / f"checkpoint-{step}"
+    if ckpt_dir.is_symlink():
+        # Refuse a symlinked dir: it could redirect writes outside output_dir.
+        logger.error("Refusing to write MLX stop checkpoint through symlink: %s", ckpt_dir)
+        return False
+    try:
+        ckpt_dir.mkdir(parents = True, exist_ok = True)
+        from unsloth_zoo.mlx.utils import (
+            save_optimizer_state,
+            save_trainable_adapters,
+            save_trainer_state,
+        )
+
+        save_trainable_adapters(trainer.model, str(ckpt_dir))
+        save_optimizer_state(optimizer, str(ckpt_dir))
+        save_trainer_state(
+            {
+                "global_step": step,
+                "train_loss_history": list(getattr(trainer, "_train_loss_history", [])),
+            },
+            str(ckpt_dir),
+        )
+        logger.info("Saved stop checkpoint to %s", ckpt_dir)
+    except Exception:
+        logger.exception("Failed to write stop checkpoint under %s", output_dir)
+    return _mlx_has_checkpoint_at_step(output_dir, step)
+
+
 def _run_embedding_training(event_queue: Any, stop_queue: Any, config: dict) -> None:
     """Self-contained embedding model training pipeline.
 
@@ -3485,6 +3636,7 @@ def _run_embedding_training(event_queue: Any, stop_queue: Any, config: dict) ->
                 use_gradient_checkpointing = gradient_checkpointing,
                 random_state = config.get("random_seed", 3407),
                 use_rslora = config.get("use_rslora", False),
+                use_dora = config.get("use_dora", False),
                 loftq_config = {"loftq_bits": 4, "loftq_iter": 1}
                 if config.get("use_loftq")
                 else None,
@@ -3660,6 +3812,7 @@ def _run_embedding_training(event_queue: Any, stop_queue: Any, config: dict) ->
             config.get("project_name"),
         )
     output_dir = str(resolve_output_dir(output_dir))
+    _emit_output_dir(event_queue, output_dir)
 
     num_epochs = config.get("num_epochs", 2)
     batch_size = config.get("batch_size", 256)
diff --git a/studio/backend/hub/routes/__init__.py b/studio/backend/hub/routes/__init__.py
index e9579635b0..7c5cfb9b3c 100644
--- a/studio/backend/hub/routes/__init__.py
+++ b/studio/backend/hub/routes/__init__.py
@@ -5,8 +5,10 @@
 
 from hub.routes.inventory import router as inventory_router
 from hub.routes.datasets import router as datasets_router
+from hub.routes.token import router as token_router
 
 __all__ = [
     "inventory_router",
     "datasets_router",
+    "token_router",
 ]
diff --git a/studio/backend/hub/routes/datasets.py b/studio/backend/hub/routes/datasets.py
index edf4f36ac0..7c7cc274d3 100644
--- a/studio/backend/hub/routes/datasets.py
+++ b/studio/backend/hub/routes/datasets.py
@@ -61,9 +61,11 @@ async def list_cached_datasets(current_subject: str = Depends(get_current_subjec
 
 @router.delete("/cached", response_model = DeleteCachedDatasetResponse)
 async def delete_cached_dataset(
-    repo_id: str = Body(..., embed = True), current_subject: str = Depends(get_current_subject)
+    repo_id: str = Body(..., embed = True),
+    cache_path: Optional[str] = Body(None, embed = True),
+    current_subject: str = Depends(get_current_subject),
 ):
-    return await cache_inventory.delete_cached_dataset_response(repo_id)
+    return await cache_inventory.delete_cached_dataset_response(repo_id, cache_path)
 
 
 @router.get("/download-progress", response_model = DownloadProgressResponse)
diff --git a/studio/backend/hub/routes/inventory.py b/studio/backend/hub/routes/inventory.py
index 4b6c179a2b..dc3e3641bc 100644
--- a/studio/backend/hub/routes/inventory.py
+++ b/studio/backend/hub/routes/inventory.py
@@ -28,6 +28,7 @@ from hub.schemas.inventory import (
     CachedModelsResponse,
     DeleteCachedModelResponse,
     GgufVariantsResponse,
+    HiddenModelsResponse,
     LocalModelListResponse,
     ModelsFolderResponse,
     RecommendedFoldersResponse,
@@ -214,6 +215,16 @@ async def list_cached_models(
     return await cache_inventory.list_cached_models_response(hf_token)
 
 
+@router.get("/hidden-models", response_model = HiddenModelsResponse)
+async def list_hidden_models(current_subject: str = Depends(get_current_subject)):
+    import asyncio
+
+    from routes.models import hidden_model_matchers
+
+    needles, exact_ids, exact_paths = await asyncio.to_thread(hidden_model_matchers)
+    return HiddenModelsResponse(needles = needles, exact_ids = exact_ids, exact_paths = exact_paths)
+
+
 @router.delete(
     "/delete-cached",
     response_model = DeleteCachedModelResponse,
@@ -222,7 +233,8 @@ async def list_cached_models(
 async def delete_cached_model(
     repo_id: str = Body(...),
     variant: Optional[str] = Body(None),
+    cache_path: Optional[str] = Body(None),
     hf_token: Optional[str] = Depends(get_hf_token),
     current_subject: str = Depends(get_current_subject),
 ):
-    return await deletion.delete_cached_model_response(repo_id, variant, hf_token)
+    return await deletion.delete_cached_model_response(repo_id, variant, hf_token, cache_path)
diff --git a/studio/backend/hub/routes/token.py b/studio/backend/hub/routes/token.py
new file mode 100644
index 0000000000..1b7ad733a2
--- /dev/null
+++ b/studio/backend/hub/routes/token.py
@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Hugging Face token validation endpoint."""
+
+from __future__ import annotations
+
+import asyncio
+from typing import Literal, Optional
+
+from fastapi import APIRouter, Depends, Request
+from pydantic import BaseModel
+
+from auth.authentication import get_current_subject
+from hub.dependencies import get_hf_token
+from utils.client_ip import client_ip
+from utils.hf_token_validation import validate_hf_token
+
+
+router = APIRouter()
+
+
+class HfTokenValidationResponse(BaseModel):
+    status: Literal["missing", "valid", "invalid", "rate_limited", "unavailable"]
+    retry_after_seconds: Optional[int] = None
+
+
+@router.post("/token/validate", response_model = HfTokenValidationResponse)
+async def validate_token(
+    request: Request,
+    hf_token: Optional[str] = Depends(get_hf_token),
+    current_subject: str = Depends(get_current_subject),
+):
+    if not hf_token:
+        return HfTokenValidationResponse(status = "missing")
+    result = await asyncio.to_thread(
+        validate_hf_token,
+        hf_token,
+        rate_key = f"{current_subject}:{client_ip(request)}",
+    )
+    return HfTokenValidationResponse(
+        status = result.status,
+        retry_after_seconds = result.retry_after_seconds,
+    )
diff --git a/studio/backend/hub/schemas/inventory.py b/studio/backend/hub/schemas/inventory.py
index ef95efe2f2..ca0f4658a3 100644
--- a/studio/backend/hub/schemas/inventory.py
+++ b/studio/backend/hub/schemas/inventory.py
@@ -99,6 +99,10 @@ class LocalModelInfo(BaseModel):
         None,
         description = "HF repo id for cached models, e.g. org/model",
     )
+    active_cache: Optional[bool] = Field(
+        None,
+        description = "Whether this HF entry belongs to the current download cache.",
+    )
     base_model: Optional[str] = Field(
         None,
         description = "Base model from adapter_config.json when this is an adapter",
@@ -160,6 +164,7 @@ class CachedRepoBase(BaseModel):
     repo_id: str
     size_bytes: int = 0
     cache_path: Optional[str] = None
+    last_modified: Optional[float] = None
     partial: bool = False
     partial_transport: Optional[str] = None
     inventory_id: Optional[str] = None
@@ -189,6 +194,12 @@ class CachedModelsResponse(BaseModel):
     cached: List[CachedModelRepo] = Field(default_factory = list)
 
 
+class HiddenModelsResponse(BaseModel):
+    needles: List[str] = Field(default_factory = list)
+    exact_ids: List[str] = Field(default_factory = list)
+    exact_paths: List[str] = Field(default_factory = list)
+
+
 class AddScanFolderRequest(BaseModel):
     """Request body for adding a custom scan folder."""
 
diff --git a/studio/backend/hub/services/datasets/cache_inventory.py b/studio/backend/hub/services/datasets/cache_inventory.py
index a180c9df58..c106b62ab7 100644
--- a/studio/backend/hub/services/datasets/cache_inventory.py
+++ b/studio/backend/hub/services/datasets/cache_inventory.py
@@ -20,12 +20,11 @@ from hub.utils import inventory_scan as hf_cache_scan
 from hub.utils.hf_cache_state import (
     purge_partial_repo,
     purge_repo_cache_dirs,
+    resolve_delete_target_root,
     resolve_destructive_case_matches,
 )
 from hub.utils.paths import (
-    hf_default_cache_dir,
     is_valid_repo_id as _is_valid_repo_id,
-    legacy_hf_cache_dir,
     resolve_cached_repo_id_case,
 )
 
@@ -43,38 +42,8 @@ def _collect_hf_cache_scans() -> tuple[list, set[str]]:
 
 
 def _hf_hub_cache_roots() -> list[Path]:
-    roots: list[Path] = []
-    seen: set[str] = set()
-
-    def _add(path: Optional[Path]) -> None:
-        if path is None or not path.is_dir():
-            return
-        try:
-            resolved = str(path.resolve())
-        except OSError:
-            return
-        if resolved in seen:
-            return
-        seen.add(resolved)
-        roots.append(path)
-
-    try:
-        from huggingface_hub.constants import HF_HUB_CACHE
-        _add(Path(HF_HUB_CACHE))
-    except Exception:
-        pass
-
-    hf_hub_cache = os.environ.get("HF_HUB_CACHE")
-    if hf_hub_cache:
-        _add(Path(hf_hub_cache).expanduser())
-
-    hf_home = os.environ.get("HF_HOME")
-    if hf_home:
-        _add(Path(hf_home).expanduser() / "hub")
-
-    _add(legacy_hf_cache_dir())
-    _add(hf_default_cache_dir())
-    return roots
+    from hub.utils.hf_cache_state import hf_cache_roots
+    return hf_cache_roots()
 
 
 def _repo_id_from_hub_dataset_dir(name: str) -> str | None:
@@ -207,6 +176,21 @@ def _repo_id_from_datasets_cache_dir(name: str) -> str | None:
     return repo_id if _is_valid_repo_id(repo_id) else None
 
 
+def _is_processed_dataset_cache_path(repo_id: str, cache_path: str) -> bool:
+    """True when *cache_path* is this repo's processed Arrow cache dir
+    (``<owner>___<repo>`` directly under an HF_DATASETS_CACHE root). Such rows
+    have no Hub ``datasets--`` layout, so they are deleted via the processed
+    path and must not be rejected as an invalid cache_path."""
+    try:
+        resolved = Path(cache_path).expanduser().resolve(strict = False)
+    except (OSError, RuntimeError, ValueError):
+        return False
+    if resolved.name.lower() != repo_id.replace("/", "___").lower():
+        return False
+    roots = {r.resolve(strict = False) for r in _hf_datasets_cache_roots()}
+    return resolved.parent.resolve(strict = False) in roots
+
+
 def _processed_dataset_cache_size(path: Path) -> int:
     total = 0
     try:
@@ -361,7 +345,7 @@ async def list_cached_datasets_response() -> dict:
         ) from exc
 
 
-async def delete_cached_dataset_response(repo_id: str) -> dict:
+async def delete_cached_dataset_response(repo_id: str, cache_path: Optional[str] = None) -> dict:
     """Remove a cached dataset repo from the HF cache."""
     if not _is_valid_repo_id(repo_id):
         raise HTTPException(status_code = 400, detail = "Invalid repo_id format")
@@ -373,22 +357,40 @@ async def delete_cached_dataset_response(repo_id: str) -> dict:
             detail = "Cancel the active download before deleting.",
         )
     try:
-        return await asyncio.to_thread(_delete_cached_dataset_blocking, repo_key)
+        return await asyncio.to_thread(_delete_cached_dataset_blocking, repo_key, cache_path)
     finally:
         downloads.registry.end_delete(repo_key)
         hf_cache_scan.invalidate_hf_cache_scans()
 
 
-def _delete_cached_dataset_blocking(repo_id: str) -> dict:
+def _delete_cached_dataset_blocking(repo_id: str, cache_path: Optional[str] = None) -> dict:
     scans, _seen_roots = _collect_hf_cache_scans()
 
-    candidate_entries = []
+    # Group this dataset's copies by owning cache root, then target exactly one
+    # cache so a delete never removes copies in other, previously selected caches.
+    owners: dict = {}
     for hf_cache in scans:
         for repo_info in hf_cache.repos:
             if str(repo_info.repo_type) != "dataset":
                 continue
-            if repo_info.repo_id.lower() == repo_id.lower():
-                candidate_entries.append((hf_cache, repo_info))
+            if repo_info.repo_id.lower() != repo_id.lower():
+                continue
+            try:
+                owner = Path(repo_info.repo_path).parent.resolve(strict = False)
+            except (OSError, RuntimeError, ValueError):
+                continue
+            owners.setdefault(owner, []).append((hf_cache, repo_info))
+
+    target_root = resolve_delete_target_root("dataset", repo_id, cache_path, owners.keys())
+    # A processed-only dataset row sends its Arrow cache path (<owner>___<repo>
+    # under HF_DATASETS_CACHE), which is not a Hub datasets-- dir, so
+    # resolve_delete_target_root returns None. Accept it and fall through to the
+    # processed-cache delete rather than rejecting a legitimate row.
+    if target_root is None and not (
+        cache_path and _is_processed_dataset_cache_path(repo_id, cache_path)
+    ):
+        raise HTTPException(status_code = 400, detail = "Invalid cache_path")
+    candidate_entries = owners.get(target_root, []) if target_root is not None else []
     matched_repo_ids = resolve_destructive_repo_ids(
         repo_id,
         [str(repo_info.repo_id) for _hf_cache, repo_info in candidate_entries],
@@ -414,7 +416,26 @@ def _delete_cached_dataset_blocking(repo_id: str) -> dict:
                 exc_info = True,
             )
 
-    processed_deleted, processed_failures = _delete_processed_dataset_cache(repo_id)
+    # Restrict the processed Arrow-cache delete to the selected cache's datasets
+    # root so it never removes copies under other cache homes. A processed
+    # cache_path scopes to its own root; a Hub target scopes to the datasets root
+    # sharing its cache home; an unspecified cache_path stays global (legacy).
+    processed_roots: Optional[set[Path]]
+    if not cache_path:
+        processed_roots = None
+    elif _is_processed_dataset_cache_path(repo_id, cache_path):
+        processed_roots = {Path(cache_path).expanduser().resolve(strict = False).parent}
+    else:
+        home = target_root.parent if target_root is not None else None
+        processed_roots = {
+            root.resolve(strict = False)
+            for root in _hf_datasets_cache_roots()
+            if home is not None and root.resolve(strict = False).parent == home
+        }
+
+    processed_deleted, processed_failures = _delete_processed_dataset_cache(
+        repo_id, only_roots = processed_roots
+    )
     failures.extend(processed_failures)
     if failures:
         raise HTTPException(
@@ -427,15 +448,23 @@ def _delete_cached_dataset_blocking(repo_id: str) -> dict:
 
     # ``scan_cache_dir()`` skips blob-only/corrupt repos the revision delete
     # can't touch, yet the fallback scanner shows them; purge the whole dir.
-    cache_purged = purge_repo_cache_dirs("dataset", repo_id)
-    partial_purged = purge_partial_repo("dataset", repo_id)
-    state_purged = download_manifest.purge_all_state_for_repo("dataset", repo_id) > 0
+    # Only for a Hub cache target; a processed-only path has no Hub dir/state.
+    cache_purged = partial_purged = state_purged = False
+    if target_root is not None:
+        cache_purged = purge_repo_cache_dirs("dataset", repo_id, root = target_root)
+        partial_purged = purge_partial_repo("dataset", repo_id, root = target_root)
+        state_purged = (
+            download_manifest.purge_all_state_for_repo("dataset", repo_id, hub_cache = target_root)
+            > 0
+        )
     if not (deleted or processed_deleted or cache_purged or partial_purged or state_purged):
         raise HTTPException(status_code = 404, detail = "Dataset not found in cache")
     return {"status": "deleted", "repo_id": repo_id}
 
 
-def _delete_processed_dataset_cache(repo_id: str) -> tuple[bool, list[str]]:
+def _delete_processed_dataset_cache(
+    repo_id: str, only_roots: Optional[set[Path]] = None
+) -> tuple[bool, list[str]]:
     import shutil
 
     target = repo_id.replace("/", "___")
@@ -443,6 +472,10 @@ def _delete_processed_dataset_cache(repo_id: str) -> tuple[bool, list[str]]:
     deleted = False
     failures: list[str] = []
     for root in _hf_datasets_cache_roots():
+        # Scope to the selected cache's datasets root(s): a delete must not remove
+        # processed copies living under other, previously selected cache homes.
+        if only_roots is not None and root.resolve(strict = False) not in only_roots:
+            continue
         try:
             entries = [
                 entry
diff --git a/studio/backend/hub/services/datasets/downloads.py b/studio/backend/hub/services/datasets/downloads.py
index 5efac562fa..b412a339e9 100644
--- a/studio/backend/hub/services/datasets/downloads.py
+++ b/studio/backend/hub/services/datasets/downloads.py
@@ -159,12 +159,18 @@ async def download_dataset_response(
 
     use_xet = download_lifecycle.resolve_effective_use_xet(body.use_xet)
     transport = download_lifecycle.resolve_transport(use_xet)
+    from utils.hf_cache_settings import get_hf_cache_paths
+
+    cache_paths = get_hf_cache_paths()
+    cache_env = cache_paths.child_env({})
 
     claimed, claim_state = _registry.claim(
         key,
         transport,
         repo_type = "dataset",
         repo_id = repo_id,
+        hub_cache = str(cache_paths.hub_cache),
+        xet_cache = str(cache_paths.xet_cache),
     )
     generation = _registry.current_generation(key)
     if not claimed:
@@ -176,7 +182,12 @@ async def download_dataset_response(
             "accepted": _registry.adoptable(key),
             "generation": generation,
         }
-    download_manifest.clear_cancel_marker("dataset", repo_id, None)
+    download_manifest.clear_cancel_marker(
+        "dataset",
+        repo_id,
+        None,
+        hub_cache = cache_paths.hub_cache,
+    )
 
     state = download_lifecycle.launch_worker(
         _registry,
@@ -185,6 +196,7 @@ async def download_dataset_response(
             ["--repo-id", repo_id, "--dataset"],
             hf_token,
             use_xet = use_xet,
+            cache_env = cache_env,
         ),
         hf_token = hf_token,
         label = repo_id,
diff --git a/studio/backend/hub/services/download_lifecycle.py b/studio/backend/hub/services/download_lifecycle.py
index e5d48872c1..8e14427a56 100644
--- a/studio/backend/hub/services/download_lifecycle.py
+++ b/studio/backend/hub/services/download_lifecycle.py
@@ -11,7 +11,7 @@ import sys
 import time
 import threading
 from pathlib import Path
-from typing import Callable, Optional
+from typing import Callable, Mapping, Optional
 
 from fastapi import HTTPException
 
@@ -57,6 +57,7 @@ def spawn_worker(
     *,
     use_xet: bool,
     protected_blob_hashes: Optional[frozenset[str]] = None,
+    cache_env: Optional[Mapping[str, str]] = None,
 ) -> subprocess.Popen:
     """Spawn the download worker.
 
@@ -68,7 +69,11 @@ def spawn_worker(
     """
     cwd = backend_dir()
     mode = download_registry.TRANSPORT_XET if use_xet else download_registry.TRANSPORT_HTTP
-    env = os.environ.copy()
+    from utils.hf_cache_settings import get_hf_cache_paths
+
+    env = get_hf_cache_paths().child_env()
+    if cache_env is not None:
+        env.update(cache_env)
     if protected_blob_hashes:
         env["UNSLOTH_PROTECTED_BLOB_HASHES"] = ",".join(sorted(protected_blob_hashes))
     else:
@@ -76,7 +81,7 @@ def spawn_worker(
     env["HF_HUB_DISABLE_PROGRESS_BARS"] = "1"
     env["HF_HUB_DISABLE_TELEMETRY"] = "1"
     env["HF_HUB_DISABLE_XET"] = "0" if use_xet else "1"
-    # No token in Studio settings: fall back to the backend's own HF_TOKEN so
+    # No token in Unsloth settings: fall back to the backend's own HF_TOKEN so
     # private repos stay downloadable (needed while inkling repos are private).
     if not hf_token:
         hf_token = os.environ.get("HF_TOKEN") or None
@@ -230,6 +235,7 @@ def finalize_worker_exit(
         (stderr_data or b"").decode("utf-8", "replace").strip(),
         hf_token = hf_token,
     )
+    metadata = registry.get_job_metadata(key)
     state = classify_exit(rc, cancel_requested = cancel_requested)
     if state == "complete":
         registry.set_job(key, "complete")
@@ -252,13 +258,13 @@ def finalize_worker_exit(
                     repo_type,
                     repo_id,
                     download_registry.variant_from_key(key),
+                    hub_cache = metadata.hub_cache if metadata is not None else None,
                 )
             except Exception as exc:
                 logger.debug(f"clear_cancel_marker failed for {repo_id} (rc=0): {exc}")
     elif state == "cancelled":
         # Read metadata before the terminal set_job so a concurrent eviction
         # can't drop it; the job key is the fallback variant label.
-        metadata = registry.get_job_metadata(key)
         registry.set_job(key, "cancelled")
         logger.info(f"{log_prefix} cancelled: {label} (rc={rc})")
         download_registry.persist_cancel_marker(
@@ -268,6 +274,7 @@ def finalize_worker_exit(
             if metadata is not None and metadata.variant
             else download_registry.variant_from_key(key),
             cancel_marker_transport or transport,
+            hub_cache = metadata.hub_cache if metadata is not None else None,
             logger = logger,
         )
     else:
@@ -303,6 +310,7 @@ def _set_retry_failure_state(
             metadata.transport
             if metadata is not None and metadata.transport
             else fallback_transport,
+            hub_cache = metadata.hub_cache if metadata is not None else None,
             logger = logger,
         )
     return state
@@ -371,6 +379,7 @@ def _try_http_retry(
             repo_type,
             repo_id,
             progress_blob_hashes,
+            root = Path(original_metadata.hub_cache) if original_metadata.hub_cache else None,
         )
         if progress_blob_hashes
         else 0
@@ -403,6 +412,8 @@ def _try_http_retry(
             generation = generation,
             replace_active = True,
             cancel_marker_transport = original_metadata.transport,
+            hub_cache = original_metadata.hub_cache,
+            xet_cache = original_metadata.xet_cache,
         )
         if claimed:
             break
@@ -446,11 +457,24 @@ def _try_http_retry(
         label,
     )
     try:
+        cache_env = (
+            {
+                "HF_HUB_CACHE": original_metadata.hub_cache,
+                "HF_XET_CACHE": original_metadata.xet_cache,
+            }
+            if original_metadata.hub_cache and original_metadata.xet_cache
+            else None
+        )
+        spawn_kwargs = {
+            "use_xet": False,
+            "protected_blob_hashes": peer_hashes or None,
+        }
+        if cache_env is not None:
+            spawn_kwargs["cache_env"] = cache_env
         proc = spawn_worker(
             args,
             hf_token,
-            use_xet = False,
-            protected_blob_hashes = peer_hashes or None,
+            **spawn_kwargs,
         )
     except Exception as exc:
         scrubbed = download_registry.scrub_secrets(str(exc), hf_token = hf_token)
diff --git a/studio/backend/hub/services/models/cache_inventory.py b/studio/backend/hub/services/models/cache_inventory.py
index 1f38af9381..807ec70991 100644
--- a/studio/backend/hub/services/models/cache_inventory.py
+++ b/studio/backend/hub/services/models/cache_inventory.py
@@ -31,12 +31,19 @@ from hub.services.models.common import (
     _is_checkpoint_weight_name,
     _is_gguf_filename,
     _is_main_gguf_filename,
+    _is_mmproj_filename,
     _is_transformers_safetensors_weight_name,
     _local_inventory_id,
-    _prefer_complete_larger,
     _runtime_for_format,
 )
 
+# Imported at module scope (not inside the per-repo scan loop) so a broken
+# import surfaces at startup instead of silently emptying the inventory: the
+# scan loop swallows per-repo exceptions and would drop every repo. Lives under
+# ``utils`` (not ``utils.models``) to avoid the eager model-config/checkpoint
+# imports in ``utils/models/__init__.py``.
+from utils.hidden_models import is_hidden_model
+
 logger = get_logger(__name__)
 
 _repo_size_cache: "OrderedDict[tuple[str, str, str], tuple[int, frozenset[str], float]]" = (
@@ -125,6 +132,39 @@ def _repo_has_gguf_files(repo_info) -> bool:
     return _repo_gguf_size_bytes(repo_info) > 0
 
 
+def _blob_mtime(file_obj) -> float:
+    ts = getattr(file_obj, "blob_last_modified", None)
+    if isinstance(ts, (int, float)) and ts > 0:
+        return float(ts)
+    blob_path = getattr(file_obj, "blob_path", None)
+    if blob_path:
+        try:
+            return float(Path(blob_path).stat().st_mtime)
+        except OSError:
+            pass
+    return 0.0
+
+
+def _repo_gguf_last_modified(repo_info) -> float:
+    latest = 0.0
+    for revision in repo_info.revisions:
+        for f in revision.files:
+            if _is_main_gguf_filename(f.file_name):
+                latest = max(latest, _blob_mtime(f))
+    return latest
+
+
+def _repo_has_mmproj(repo_info) -> bool:
+    # An mmproj file only makes a repo vision-capable when it is an actual GGUF
+    # projector; a non-GGUF sidecar (e.g. mmproj_config.json) does not, and the
+    # runtime's projector detection is GGUF-only.
+    return any(
+        _is_gguf_filename(f.file_name) and _is_mmproj_filename(f.file_name)
+        for revision in repo_info.revisions
+        for f in revision.files
+    )
+
+
 def _cached_repo_file_name(file_obj) -> str:
     file_path = getattr(file_obj, "file_path", None)
     if file_path:
@@ -209,24 +249,46 @@ def _repo_gguf_blob_map(repo_info, *, include_companions: bool = False) -> dict[
 def _prefer_cache_row(candidate: dict, existing: Optional[dict]) -> bool:
     if existing is None:
         return True
-    return _prefer_complete_larger(
-        bool(candidate.get("partial")),
-        int(candidate.get("size_bytes") or 0),
-        bool(existing.get("partial")),
-        int(existing.get("size_bytes") or 0),
-    )
+    candidate_partial = bool(candidate.get("partial"))
+    existing_partial = bool(existing.get("partial"))
+    if candidate_partial != existing_partial:
+        return not candidate_partial
+    candidate_active = bool(candidate.get("active_cache"))
+    existing_active = bool(existing.get("active_cache"))
+    if candidate_active != existing_active:
+        return candidate_active
+    return int(candidate.get("size_bytes") or 0) > int(existing.get("size_bytes") or 0)
 
 
 def _cache_inventory_fields(
     repo_id: str,
     model_format: ModelFormat,
     *,
+    repo_path: Optional[Path] = None,
+    snapshot_path: Optional[Path] = None,
+    active_hub_cache: Optional[Path] = None,
     partial: bool = False,
     requires_variant: bool = False,
 ) -> dict:
+    load_id = repo_id
+    active_cache = True
+    if repo_path is not None:
+        try:
+            if active_hub_cache is None:
+                from utils.hf_cache_settings import get_hf_cache_paths
+                active_hub_cache = get_hf_cache_paths().hub_cache
+            active_root = active_hub_cache.resolve(strict = False)
+            cached_root = repo_path.parent.resolve(strict = False)
+            if cached_root != active_root:
+                active_cache = False
+                load_id = str(snapshot_path or repo_path.resolve(strict = False))
+        except (OSError, RuntimeError, ValueError):
+            active_cache = False
+            load_id = str(snapshot_path or repo_path)
     return {
         "inventory_id": _local_inventory_id("cache", model_format, repo_id),
-        "load_id": repo_id,
+        "load_id": load_id,
+        "active_cache": active_cache,
         "model_format": model_format,
         "runtime": _runtime_for_format(model_format),
         "format_variant": None,
@@ -243,9 +305,19 @@ def invalidate_hf_cache_scans() -> None:
     hf_cache_scan.invalidate_hf_cache_scans()
 
 
+def _is_hidden_infra_repo(*values: str | None) -> bool:
+    """True for infra-only repos (the RAG embedder and the llama.cpp install
+    validation probe) that are cached as a side effect of Studio itself and are
+    not usable chat models."""
+    return is_hidden_model(*values)
+
+
 def _scan_cached_gguf() -> list[dict]:
     """Synchronous HF-cache disk walk for GGUF repos; runs in a worker thread."""
     cache_scans = all_hf_cache_scans()
+    from utils.hf_cache_settings import get_hf_cache_paths
+
+    active_hub_cache = get_hf_cache_paths().hub_cache
 
     seen_lower: dict[str, dict] = {}
     for hf_cache in cache_scans:
@@ -254,18 +326,33 @@ def _scan_cached_gguf() -> list[dict]:
                 if str(repo_info.repo_type) != "model":
                     continue
                 repo_id = repo_info.repo_id
+                repo_path = Path(repo_info.repo_path)
+                snapshot_path = _cached_model_snapshot_path(repo_path)
                 total_size = _repo_gguf_size_bytes(repo_info)
-                has_variant_state, variant_state_size = _gguf_variant_state_summary(repo_id)
+                has_variant_state, variant_state_size = _gguf_variant_state_summary(
+                    repo_id,
+                    hub_cache = repo_path.parent,
+                )
+                is_hidden_infra = _is_hidden_infra_repo(
+                    repo_id,
+                    str(repo_path),
+                    str(snapshot_path) if snapshot_path is not None else None,
+                )
+                # Hide infra repos unless the user downloaded a variant via
+                # the Hub; variant state only exists for user downloads.
+                if is_hidden_infra and not has_variant_state:
+                    continue
                 if total_size == 0 and not has_variant_state:
                     continue
                 partial = hf_cache_scan.is_gguf_repo_partial(
                     repo_id,
-                    Path(repo_info.repo_path),
+                    repo_path,
                 )
                 if total_size == 0 and not partial:
                     continue
                 key = repo_id.lower()
                 existing = seen_lower.get(key)
+                last_modified = _repo_gguf_last_modified(repo_info)
                 row = {
                     "repo_id": repo_id,
                     "size_bytes": max(total_size, variant_state_size),
@@ -275,16 +362,34 @@ def _scan_cached_gguf() -> list[dict]:
                     # per-variant detail lives on GgufVariantDetail.
                     "partial_transport": None,
                 }
+                last_modified = max(last_modified, (existing or {}).get("last_modified", 0.0))
+                if last_modified > 0:
+                    row["last_modified"] = last_modified
                 row.update(
                     _cache_inventory_fields(
                         repo_id,
                         "gguf",
+                        repo_path = repo_path,
+                        snapshot_path = snapshot_path,
+                        active_hub_cache = active_hub_cache,
                         partial = bool(row["partial"]),
                         requires_variant = True,
                     )
                 )
+                if _repo_has_mmproj(repo_info):
+                    row["capabilities"]["supports_vision"] = True
+                # Visible infra variants remain management-only.
+                if is_hidden_infra:
+                    row["capabilities"]["can_chat"] = False
                 if _prefer_cache_row(row, existing):
+                    if existing and existing["capabilities"].get("supports_vision"):
+                        row["capabilities"]["supports_vision"] = True
                     seen_lower[key] = row
+                else:
+                    if last_modified > existing.get("last_modified", 0.0):
+                        existing["last_modified"] = last_modified
+                    if row["capabilities"].get("supports_vision"):
+                        existing["capabilities"]["supports_vision"] = True
             except Exception as e:
                 repo_label = getattr(repo_info, "repo_id", "<unknown>")
                 logger.warning(f"Skipping cached GGUF repo {repo_label}: {e}")
@@ -312,13 +417,14 @@ class _CachedNonGgufPayload(NamedTuple):
     size_bytes: int
     has_runnable_weights: bool
     model_format: ModelFormat
+    last_modified: float
 
 
 def _repo_non_gguf_model_payload(repo_info) -> _CachedNonGgufPayload:
-    all_weight_blobs: dict[str, int] = {}
-    adapter_blobs: dict[str, int] = {}
-    safetensors_blobs: dict[str, int] = {}
-    checkpoint_blobs: dict[str, int] = {}
+    all_weight_blobs: dict[str, tuple[int, float]] = {}
+    adapter_blobs: dict[str, tuple[int, float]] = {}
+    safetensors_blobs: dict[str, tuple[int, float]] = {}
+    checkpoint_blobs: dict[str, tuple[int, float]] = {}
     has_config = False
     has_adapter_config = False
     has_adapter_weights = False
@@ -326,12 +432,15 @@ def _repo_non_gguf_model_payload(repo_info) -> _CachedNonGgufPayload:
     has_transformers_safetensors = False
     has_checkpoint = False
 
-    def _record_blob(target: dict[str, int], file_obj, rev_id: str, file_name: str) -> None:
+    def _record_blob(
+        target: dict[str, tuple[int, float]], file_obj, rev_id: str, file_name: str
+    ) -> None:
         blob_path = getattr(file_obj, "blob_path", None)
         size = int(file_obj.size_on_disk or 0)
         key = str(blob_path) if blob_path else f"{rev_id}:{file_name}"
-        target[key] = size
-        all_weight_blobs[key] = size
+        value = (size, _blob_mtime(file_obj))
+        target[key] = value
+        all_weight_blobs[key] = value
 
     for revision in repo_info.revisions:
         rev_id = getattr(revision, "commit_hash", None) or str(id(revision))
@@ -375,18 +484,19 @@ def _repo_non_gguf_model_payload(repo_info) -> _CachedNonGgufPayload:
         or "unknown"
     )
     if model_format == "adapter":
-        size_bytes = sum(adapter_blobs.values())
+        selected_blobs = adapter_blobs
     elif model_format == "safetensors":
-        size_bytes = sum(safetensors_blobs.values())
+        selected_blobs = safetensors_blobs
     elif model_format == "checkpoint":
-        size_bytes = sum(checkpoint_blobs.values())
+        selected_blobs = checkpoint_blobs
     else:
-        size_bytes = sum(all_weight_blobs.values())
+        selected_blobs = all_weight_blobs
 
     return _CachedNonGgufPayload(
-        size_bytes = size_bytes,
+        size_bytes = sum(size for size, _mtime in selected_blobs.values()),
         has_runnable_weights = model_format != "unknown",
         model_format = model_format,
+        last_modified = max((mtime for _size, mtime in selected_blobs.values()), default = 0.0),
     )
 
 
@@ -407,6 +517,19 @@ def _read_json_object(path: Path) -> dict:
         return {}
 
 
+def _is_whisper_model_config(config: object) -> bool:
+    if not isinstance(config, dict):
+        return False
+    model_type = config.get("model_type")
+    if isinstance(model_type, str) and model_type.strip().lower() == "whisper":
+        return True
+    architectures = config.get("architectures")
+    return isinstance(architectures, list) and any(
+        isinstance(name, str) and name == "WhisperForConditionalGeneration"
+        for name in architectures
+    )
+
+
 def _read_model_card_frontmatter(path: Path) -> dict:
     try:
         text = path.read_text(encoding = "utf-8")
@@ -437,6 +560,8 @@ def _cached_model_local_metadata(repo_path: Path) -> dict:
 
     result: dict = {}
     config = _read_json_object(snapshot / "config.json")
+    if _is_whisper_model_config(config):
+        result["_hidden_stt"] = True
     quant_method = (
         config.get("quantization_config", {}).get("quant_method")
         if isinstance(config.get("quantization_config"), dict)
@@ -463,11 +588,15 @@ def _cached_model_local_metadata(repo_path: Path) -> dict:
 def _scan_cached_models() -> list[dict]:
     """Synchronous HF-cache disk walk for non-GGUF model repos; runs in a worker thread."""
     cache_scans = all_hf_cache_scans()
+    from utils.hf_cache_settings import get_hf_cache_paths
+
+    active_hub_cache = get_hf_cache_paths().hub_cache
 
     seen_lower: dict[str, dict] = {}
     inspected = 0
     skipped_gguf = 0
     skipped_no_weights = 0
+    skipped_stt = 0
     for hf_cache in cache_scans:
         for repo_info in hf_cache.repos:
             inspected += 1
@@ -475,6 +604,15 @@ def _scan_cached_models() -> list[dict]:
                 if str(repo_info.repo_type) != "model":
                     continue
                 repo_id = repo_info.repo_id
+                repo_path = Path(repo_info.repo_path)
+                snapshot_path = _cached_model_snapshot_path(repo_path)
+                # The non-GGUF embedder has no variant downloads; always hide.
+                if _is_hidden_infra_repo(
+                    repo_id,
+                    str(repo_path),
+                    str(snapshot_path) if snapshot_path is not None else None,
+                ):
+                    continue
                 has_main_gguf = _repo_has_gguf_files(repo_info)
                 payload = _repo_non_gguf_model_payload(repo_info)
                 if payload.size_bytes == 0:
@@ -486,7 +624,10 @@ def _scan_cached_models() -> list[dict]:
                     continue
                 key = repo_id.lower()
                 existing = seen_lower.get(key)
-                repo_path = Path(repo_info.repo_path)
+                local_metadata = _cached_model_local_metadata(repo_path)
+                if local_metadata.pop("_hidden_stt", False):
+                    skipped_stt += 1
+                    continue
                 snapshot_partial = hf_cache_scan.is_snapshot_partial(
                     "model",
                     repo_id,
@@ -506,27 +647,40 @@ def _scan_cached_models() -> list[dict]:
                         if snapshot_partial
                         else None
                     ),
-                    **_cached_model_local_metadata(repo_path),
+                    **local_metadata,
                 }
+                last_modified = max(
+                    payload.last_modified,
+                    (existing or {}).get("last_modified", 0.0),
+                )
+                if last_modified > 0:
+                    row["last_modified"] = last_modified
                 row.update(
                     _cache_inventory_fields(
                         repo_id,
                         payload.model_format,
+                        repo_path = repo_path,
+                        snapshot_path = snapshot_path,
+                        active_hub_cache = active_hub_cache,
                         partial = bool(row["partial"]),
                     )
                 )
                 if _prefer_cache_row(row, existing):
                     seen_lower[key] = row
+                elif last_modified > existing.get("last_modified", 0.0):
+                    existing["last_modified"] = last_modified
             except Exception as e:
                 repo_label = getattr(repo_info, "repo_id", "<unknown>")
                 logger.warning(f"Skipping cached model repo {repo_label}: {e}")
                 continue
     cached = sorted(seen_lower.values(), key = lambda c: c["repo_id"])
     logger.info(
-        "Cached model scan: inspected=%d skipped_gguf=%d skipped_no_weights=%d returned=%d",
+        "Cached model scan: inspected=%d skipped_gguf=%d skipped_no_weights=%d "
+        "skipped_stt=%d returned=%d",
         inspected,
         skipped_gguf,
         skipped_no_weights,
+        skipped_stt,
         len(cached),
     )
     return cached
diff --git a/studio/backend/hub/services/models/common.py b/studio/backend/hub/services/models/common.py
index f381bffe9c..4c0e296fdc 100644
--- a/studio/backend/hub/services/models/common.py
+++ b/studio/backend/hub/services/models/common.py
@@ -150,7 +150,9 @@ def _prefer_complete_larger(
     return candidate_size_bytes > existing_size_bytes
 
 
-def _gguf_variant_state_summary(repo_id: str) -> tuple[bool, int]:
+def _gguf_variant_state_summary(
+    repo_id: str, *, hub_cache: Optional[str | Path] = None
+) -> tuple[bool, int]:
     """Whether GGUF variant-scoped state exists and its expected size; a cancelled/in-progress variant may have only manifests/markers/`.incomplete` blobs, which inventory needs to avoid a generic fallback row."""
     from hub.utils import download_manifest
 
@@ -159,10 +161,16 @@ def _gguf_variant_state_summary(repo_id: str) -> tuple[bool, int]:
     for variant, _path in download_manifest.iter_variant_manifests(
         "model",
         repo_id,
+        hub_cache = hub_cache,
     ):
         key = variant.lower()
         variant_keys.add(key)
-        manifest = download_manifest.read_manifest("model", repo_id, variant)
+        manifest = download_manifest.read_manifest(
+            "model",
+            repo_id,
+            variant,
+            hub_cache = hub_cache,
+        )
         if manifest is None:
             continue
         size_by_variant[key] = max(
@@ -172,6 +180,7 @@ def _gguf_variant_state_summary(repo_id: str) -> tuple[bool, int]:
     for variant, _path in download_manifest.iter_variant_markers(
         "model",
         repo_id,
+        hub_cache = hub_cache,
     ):
         variant_keys.add(variant.lower())
     return bool(variant_keys), sum(size_by_variant.values())
@@ -432,8 +441,13 @@ def _local_model_info(
     base_model_source: Optional[str] = None,
     adapter_type: Optional[str] = None,
     training_method: Optional[str] = None,
+    active_cache: Optional[bool] = None,
 ) -> LocalModelInfo:
-    load_id = model_id if source == "hf_cache" and model_id else str(load_path)
+    load_id = (
+        model_id
+        if source == "hf_cache" and model_id and active_cache is not False
+        else str(load_path)
+    )
     semantic_id = model_id or str(load_path)
     return LocalModelInfo(
         id = load_id,
@@ -445,6 +459,7 @@ def _local_model_info(
         ),
         load_id = load_id,
         model_id = model_id,
+        active_cache = active_cache if source == "hf_cache" else None,
         display_name = display_name or (scan_path.stem if scan_path.is_file() else scan_path.name),
         path = str(load_path),
         size_bytes = max(0, int(size_bytes or 0)),
@@ -476,6 +491,7 @@ def _classify_local_path(
     model_id: Optional[str] = None,
     updated_at: Optional[float] = None,
     partial: bool = False,
+    active_cache: Optional[bool] = None,
 ) -> list[LocalModelInfo]:
     load_path = load_path or scan_path
     files = (
@@ -512,6 +528,7 @@ def _classify_local_path(
                 requires_variant = scan_path.is_dir(),
                 format_variant = variant,
                 size_bytes = gguf_size_bytes,
+                active_cache = active_cache,
             )
         )
 
@@ -574,6 +591,7 @@ def _classify_local_path(
                 ),
                 adapter_type = adapter_type if model_format == "adapter" else None,
                 training_method = training_method if model_format == "adapter" else None,
+                active_cache = active_cache,
             )
         )
     elif not rows:
@@ -592,6 +610,7 @@ def _classify_local_path(
                 updated_at = updated_at,
                 partial = partial or trusted_hf_cache_repo,
                 size_bytes = size_bytes,
+                active_cache = active_cache,
             )
         )
 
diff --git a/studio/backend/hub/services/models/deletion.py b/studio/backend/hub/services/models/deletion.py
index 636a223d4e..c736908058 100644
--- a/studio/backend/hub/services/models/deletion.py
+++ b/studio/backend/hub/services/models/deletion.py
@@ -19,8 +19,10 @@ from hub.utils import inventory_scan as hf_cache_scan
 from hub.utils.gguf import extract_quant_label, extract_quant_token
 from hub.utils.hf_cache_state import (
     INCOMPLETE_SUFFIX,
+    iter_repo_cache_dirs,
     purge_partial_repo,
     purge_repo_cache_dirs,
+    resolve_delete_target_root,
 )
 from hub.utils.paths import (
     is_valid_gguf_variant as _is_valid_gguf_variant,
@@ -184,6 +186,7 @@ def _delete_gguf_variant_from_repos(
     hf_token: Optional[str],
     *,
     sibling_active: bool = False,
+    root: Optional[Path] = None,
 ) -> dict:
     failures: list[str] = []
     removed_snapshots = 0
@@ -265,6 +268,7 @@ def _delete_gguf_variant_from_repos(
         hf_token,
         extra_hashes = frozenset(completed_hashes),
         companions = not sibling_active,
+        root = root,
     )
     if incomplete_result.unresolved:
         raise HTTPException(
@@ -276,7 +280,7 @@ def _delete_gguf_variant_from_repos(
             ),
         )
 
-    state_purged = download_manifest.purge_state("model", repo_id, variant)
+    state_purged = download_manifest.purge_state("model", repo_id, variant, hub_cache = root)
     # Reclaim the empty quant folder so it stops 404ing on delete.
     removed_dirs, dir_failures = _remove_empty_variant_dirs(target_repos, variant)
     removed_snap_dirs, snap_dir_failures = _remove_empty_snapshot_dirs(target_repos)
@@ -316,6 +320,8 @@ def reclaim_replaced_gguf_variant(
     variant: str,
     keep_main_hashes: frozenset[str],
     hf_token: Optional[str] = None,
+    *,
+    hub_cache: Optional[str | Path] = None,
 ) -> dict:
     """Prune stale main-GGUF files for a variant after a replacement verified.
 
@@ -366,12 +372,22 @@ def reclaim_replaced_gguf_variant(
             "reason": "scan_failed",
         }
 
+    if hub_cache is None:
+        from utils.hf_cache_settings import get_hf_cache_paths
+        hub_cache = get_hf_cache_paths().hub_cache
+    try:
+        target_hub_cache = Path(hub_cache).expanduser().resolve(strict = False)
+    except (OSError, RuntimeError, ValueError):
+        target_hub_cache = Path(hub_cache).expanduser()
+
     candidate_repos = [
         repo_info
         for hf_cache in cache_scans
         for repo_info in hf_cache.repos
         if str(getattr(repo_info, "repo_type", "")) == "model"
         and str(getattr(repo_info, "repo_id", "")).lower() == repo_id.lower()
+        and getattr(repo_info, "repo_path", None)
+        and Path(repo_info.repo_path).parent.resolve(strict = False) == target_hub_cache
     ]
     try:
         matched_repo_ids = resolve_destructive_repo_ids(
@@ -493,10 +509,24 @@ def reclaim_replaced_gguf_variant(
 
 
 def _loaded_id_matches_repo(loaded_id: str, repo_id: str) -> bool:
-    """True when *loaded_id* is *repo_id* or a file within it; ``/``-boundary aware so ``org/model`` doesn't match sibling ``org/model-v2``."""
+    """Match a loaded repo ID or an on-disk path inside any copy of the repo."""
     rid = repo_id.lower()
     lid = loaded_id.lower()
-    return lid == rid or lid.startswith(f"{rid}/")
+    if lid == rid or lid.startswith(f"{rid}/"):
+        return True
+
+    try:
+        loaded_path = Path(loaded_id).expanduser().resolve(strict = False)
+    except (OSError, RuntimeError, ValueError):
+        return False
+    for repo_dir in iter_repo_cache_dirs("model", repo_id):
+        try:
+            resolved_repo = repo_dir.resolve(strict = False)
+            if loaded_path == resolved_repo or loaded_path.is_relative_to(resolved_repo):
+                return True
+        except (OSError, RuntimeError, ValueError):
+            continue
+    return False
 
 
 def _loaded_repo_variant_blocks_delete(
@@ -560,6 +590,7 @@ async def delete_cached_model_response(
     repo_id: str,
     variant: Optional[str] = None,
     hf_token: Optional[str] = None,
+    cache_path: Optional[str] = None,
 ):
     """Delete a cached model repo (or a specific GGUF variant) from the HF cache.
 
@@ -603,14 +634,19 @@ async def delete_cached_model_response(
         )
         raise HTTPException(status_code = 400, detail = detail)
     try:
-        return await asyncio.to_thread(_delete_cached_model_blocking, repo_id, variant, hf_token)
+        return await asyncio.to_thread(
+            _delete_cached_model_blocking, repo_id, variant, hf_token, cache_path
+        )
     finally:
         downloads.registry.end_delete(repo_key, variant)
         cache_inventory.invalidate_hf_cache_scans()
 
 
 def _delete_cached_model_blocking(
-    repo_id: str, variant: Optional[str], hf_token: Optional[str]
+    repo_id: str,
+    variant: Optional[str],
+    hf_token: Optional[str],
+    cache_path: Optional[str] = None,
 ) -> dict:
     try:
         # If a sibling quant is downloading concurrently, restrict this delete to
@@ -621,13 +657,26 @@ def _delete_cached_model_blocking(
 
         cache_scans = cache_inventory.all_hf_cache_scans()
 
-        candidate_entries = []
+        # A repo can live in several remembered caches. Group its copies by the
+        # cache root that owns each, then target exactly one cache so a delete
+        # never removes copies in other, previously selected caches.
+        owners: dict = {}
         for hf_cache in cache_scans:
             for repo_info in hf_cache.repos:
                 if str(repo_info.repo_type) != "model":
                     continue
-                if repo_info.repo_id.lower() == repo_id.lower():
-                    candidate_entries.append((hf_cache, repo_info))
+                if repo_info.repo_id.lower() != repo_id.lower():
+                    continue
+                try:
+                    owner = Path(repo_info.repo_path).parent.resolve(strict = False)
+                except (OSError, RuntimeError, ValueError):
+                    continue
+                owners.setdefault(owner, []).append((hf_cache, repo_info))
+
+        target_root = resolve_delete_target_root("model", repo_id, cache_path, owners.keys())
+        if target_root is None:
+            raise HTTPException(status_code = 400, detail = "Invalid cache_path")
+        candidate_entries = owners.get(target_root, [])
 
         matched_repo_ids = resolve_destructive_repo_ids(
             repo_id,
@@ -642,10 +691,15 @@ def _delete_cached_model_blocking(
 
         if not target_entries:
             if variant is None:
-                cache_purged = purge_repo_cache_dirs("model", repo_id) or purge_partial_repo(
-                    "model", repo_id
+                cache_purged = purge_repo_cache_dirs(
+                    "model", repo_id, root = target_root
+                ) or purge_partial_repo("model", repo_id, root = target_root)
+                state_purged = (
+                    download_manifest.purge_all_state_for_repo(
+                        "model", repo_id, hub_cache = target_root
+                    )
+                    > 0
                 )
-                state_purged = download_manifest.purge_all_state_for_repo("model", repo_id) > 0
                 if cache_purged or state_purged:
                     return {"status": "deleted", "repo_id": repo_id}
             if variant:
@@ -654,6 +708,7 @@ def _delete_cached_model_blocking(
                     variant,
                     hf_token,
                     companions = not sibling_active,
+                    root = target_root,
                 )
                 if incomplete_result.unresolved:
                     raise HTTPException(
@@ -668,6 +723,7 @@ def _delete_cached_model_blocking(
                     "model",
                     repo_id,
                     variant,
+                    hub_cache = target_root,
                 )
                 if incomplete_result.deleted > 0 or state_purged:
                     return {
@@ -684,6 +740,7 @@ def _delete_cached_model_blocking(
                 [repo for _cache, repo in target_entries],
                 hf_token,
                 sibling_active = sibling_active,
+                root = target_root,
             )
 
         deleted_revisions = False
@@ -702,9 +759,11 @@ def _delete_cached_model_blocking(
             delete_strategy.execute()
             deleted_revisions = True
 
-        cache_purged = purge_repo_cache_dirs("model", repo_id)
-        partial_purged = purge_partial_repo("model", repo_id)
-        state_purged = download_manifest.purge_all_state_for_repo("model", repo_id) > 0
+        cache_purged = purge_repo_cache_dirs("model", repo_id, root = target_root)
+        partial_purged = purge_partial_repo("model", repo_id, root = target_root)
+        state_purged = (
+            download_manifest.purge_all_state_for_repo("model", repo_id, hub_cache = target_root) > 0
+        )
 
         if not (deleted_revisions or cache_purged or partial_purged or state_purged):
             raise HTTPException(status_code = 404, detail = "No revisions found for model")
diff --git a/studio/backend/hub/services/models/downloads.py b/studio/backend/hub/services/models/downloads.py
index c2ffe7bffc..c93b21c082 100644
--- a/studio/backend/hub/services/models/downloads.py
+++ b/studio/backend/hub/services/models/downloads.py
@@ -60,12 +60,37 @@ def _job_status(
     return DownloadJobStatus(state = state, error = error, generation = generation)
 
 
+def _load_in_flight(repo_id: str) -> bool:
+    try:
+        from core.inference.llama_cpp import hf_gguf_load_in_flight
+        return hf_gguf_load_in_flight(repo_id)
+    except Exception:
+        return False
+
+
+def _load_in_flight_error(repo_id: str) -> HTTPException:
+    return HTTPException(
+        status_code = 409,
+        detail = (
+            f"A model load for '{repo_id}' is in progress and may be "
+            "downloading it. Wait for the load to finish (or cancel it), "
+            "then start the download."
+        ),
+    )
+
+
+def _reject_if_load_in_flight(repo_id: str) -> None:
+    if _load_in_flight(repo_id):
+        raise _load_in_flight_error(repo_id)
+
+
 def _spawn_download_worker(
     repo_id: str,
     variant: Optional[str],
     hf_token: Optional[str],
     use_xet: bool = True,
     protected_blob_hashes: Optional[frozenset[str]] = None,
+    cache_env: Optional[dict[str, str]] = None,
 ) -> subprocess.Popen:
     args = ["--repo-id", repo_id]
     if variant:
@@ -75,6 +100,7 @@ def _spawn_download_worker(
         hf_token,
         use_xet = use_xet,
         protected_blob_hashes = protected_blob_hashes,
+        cache_env = cache_env,
     )
 
 
@@ -89,6 +115,9 @@ async def download_model_response(body: DownloadModelRequest, hf_token: Optional
     # Canonicalize so two different-cased paste-ins share one job + cache dir.
     repo_id = await asyncio.to_thread(resolve_cached_repo_id_case, repo_id, repo_type = "model")
 
+    # Avoid concurrent writers to the same HF cache files.
+    _reject_if_load_in_flight(repo_id)
+
     variant = (body.gguf_variant or "").strip() or None
     if variant is not None and not _is_valid_gguf_variant(variant):
         raise HTTPException(
@@ -98,6 +127,10 @@ async def download_model_response(body: DownloadModelRequest, hf_token: Optional
     key = _download_job_key(repo_id, variant)
     use_xet = download_lifecycle.resolve_effective_use_xet(body.use_xet)
     transport = download_lifecycle.resolve_transport(use_xet)
+    from utils.hf_cache_settings import get_hf_cache_paths
+
+    cache_paths = get_hf_cache_paths()
+    cache_env = cache_paths.child_env({})
     variant_blob_hashes = frozenset()
     variant_progress_blob_hashes = frozenset()
     completed_baseline_bytes = 0
@@ -147,9 +180,14 @@ async def download_model_response(body: DownloadModelRequest, hf_token: Optional
         blob_hashes = variant_blob_hashes,
         progress_blob_hashes = variant_progress_blob_hashes,
         completed_baseline_bytes = completed_baseline_bytes,
+        admission_check = lambda: not _load_in_flight(repo_id),
+        hub_cache = str(cache_paths.hub_cache),
+        xet_cache = str(cache_paths.xet_cache),
     )
     generation = _registry.current_generation(key)
     if not claimed:
+        if claim_state == "admission_blocked":
+            raise _load_in_flight_error(repo_id)
         # claim_state is the blocking job's state. The client can attach only
         # when the blocker is this key's own in-flight job (adoptable); a
         # cross-variant conflict or in-progress delete is not accepted.
@@ -159,7 +197,12 @@ async def download_model_response(body: DownloadModelRequest, hf_token: Optional
             "accepted": _registry.adoptable(key),
             "generation": generation,
         }
-    download_manifest.clear_cancel_marker("model", repo_id, variant)
+    download_manifest.clear_cancel_marker(
+        "model",
+        repo_id,
+        variant,
+        hub_cache = cache_paths.hub_cache,
+    )
     # Blobs a concurrent same-repo variant is already writing (e.g. a shared
     # mmproj). The worker must not purge these during cache preparation.
     protected_blob_hashes = _registry.peer_blob_hashes(key) if variant else frozenset()
@@ -174,6 +217,7 @@ async def download_model_response(body: DownloadModelRequest, hf_token: Optional
             hf_token,
             use_xet = use_xet,
             protected_blob_hashes = protected_blob_hashes,
+            cache_env = cache_env,
         ),
         hf_token = hf_token,
         label = label,
diff --git a/studio/backend/hub/services/models/folder_browser.py b/studio/backend/hub/services/models/folder_browser.py
index d56b62c318..effb6a32ae 100644
--- a/studio/backend/hub/services/models/folder_browser.py
+++ b/studio/backend/hub/services/models/folder_browser.py
@@ -30,6 +30,7 @@ from hub.utils.paths import (
 )
 from utils.paths.external_media import (
     linux_run_media_mount_roots,
+    macos_volume_roots,
     windows_drive_roots,
 )
 from hub.services.models.common import _safe_is_dir
@@ -165,7 +166,7 @@ def _looks_like_model_dir(directory: Path) -> bool:
 def _build_browse_allowlist(
     media_roots: Optional[list[Path]] = None, drive_roots: Optional[list[Path]] = None
 ) -> list[Path]:
-    """Root directories the browser may walk (also seeds the suggestion chips): HOME, resolved HF cache dirs, Studio outputs/exports/root, registered scan folders, and well-known local-LLM dirs. Each is added only if it resolves to a real directory so the sandbox has no dead boundary.
+    """Root directories the browser may walk (also seeds the suggestion chips): HOME, resolved HF cache dirs, Unsloth outputs/exports/root, registered scan folders, and well-known local-LLM dirs. Each is added only if it resolves to a real directory so the sandbox has no dead boundary.
 
     *media_roots* / *drive_roots* let the caller pass already-probed
     removable-media and Windows drive roots so they aren't scanned again (a
@@ -187,7 +188,7 @@ def _build_browse_allowlist(
 
     _add(Path.home())
     if media_roots is None:
-        media_roots = linux_run_media_mount_roots()
+        media_roots = [*linux_run_media_mount_roots(), *macos_volume_roots()]
     if drive_roots is None:
         drive_roots = windows_drive_roots()
     for p in media_roots:
@@ -195,6 +196,12 @@ def _build_browse_allowlist(
     for p in drive_roots:
         _add(p)
     _add(_resolve_hf_cache_dir())
+    try:
+        from utils.hf_cache_settings import known_hf_cache_homes
+        for cache_home in known_hf_cache_homes():
+            _add(cache_home)
+    except Exception:  # noqa: BLE001 -- best-effort
+        pass
     try:
         _add(hf_default_cache_dir())
     except Exception:  # noqa: BLE001 -- best-effort
@@ -431,7 +438,7 @@ def browse_folders_response(
 
     # Probe removable-media and Windows drive roots once; the allowlist and
     # chips reuse the result so a disconnected mapped drive isn't scanned twice.
-    media_roots = linux_run_media_mount_roots()
+    media_roots = [*linux_run_media_mount_roots(), *macos_volume_roots()]
     drive_roots = windows_drive_roots()
     # Build the allowlist once -- the sandbox check and suggestion chips share
     # it so chips are always navigable.
diff --git a/studio/backend/hub/services/models/gguf_variants.py b/studio/backend/hub/services/models/gguf_variants.py
index 33f0297ff5..533fd2ca5a 100644
--- a/studio/backend/hub/services/models/gguf_variants.py
+++ b/studio/backend/hub/services/models/gguf_variants.py
@@ -9,6 +9,7 @@ import asyncio
 import threading
 import time
 from collections import OrderedDict
+from pathlib import Path
 from typing import NamedTuple, Optional
 
 from fastapi import HTTPException
@@ -22,6 +23,7 @@ from hub.utils.hf_errors import hf_error_status
 from hub.utils.hf_cache_state import (
     INCOMPLETE_SUFFIX,
     iter_destructive_repo_cache_dirs,
+    repo_cache_dir_name,
 )
 from hub.utils.gguf import (
     extract_quant_label,
@@ -233,8 +235,14 @@ def _manifest_variant_blob_hashes(
     variant: str,
     *,
     include_companions: bool = True,
+    repo_cache_dir: Optional[Path] = None,
 ) -> frozenset[str]:
-    manifest = download_manifest.read_manifest("model", repo_id, variant)
+    manifest = download_manifest.read_manifest(
+        "model",
+        repo_id,
+        variant,
+        hub_cache = repo_cache_dir.parent if repo_cache_dir is not None else None,
+    )
     if manifest is None:
         return frozenset()
     variant_key = variant.lower()
@@ -257,6 +265,7 @@ def gguf_variant_blob_hashes(
     *,
     include_companions: bool = True,
     allow_remote: bool = True,
+    repo_cache_dir: Optional[Path] = None,
 ) -> frozenset[str]:
     key = _variant_blob_hash_cache_key(
         repo_id,
@@ -271,9 +280,9 @@ def gguf_variant_blob_hashes(
         repo_id,
         variant,
         include_companions = include_companions,
+        repo_cache_dir = repo_cache_dir,
     )
     if hashes:
-        _variant_hash_cache_set(key, hashes)
         return hashes
     requirement_key = _variant_hash_cache_key(repo_id, variant, hf_token)
     requirement = _variant_requirement_cache_get(requirement_key)
@@ -287,11 +296,22 @@ def gguf_variant_blob_hashes(
     return frozenset()
 
 
-def _partial_transport_for_variant(repo_id: str, variant: str) -> Optional[str]:
-    return hf_cache_scan.partial_transport_for("model", repo_id, variant)
+def _partial_transport_for_variant(
+    repo_id: str,
+    variant: str,
+    repo_cache_dir: Optional[Path] = None,
+) -> Optional[str]:
+    return hf_cache_scan.partial_transport_for(
+        "model",
+        repo_id,
+        variant,
+        repo_cache_dir,
+    )
 
 
-def _local_main_gguf_blobs_by_quant(repo_id: str) -> dict[str, dict[str, set[str]]]:
+def _local_main_gguf_blobs_by_quant(
+    repo_id: str, repo_cache_dir: Optional[Path] = None
+) -> dict[str, dict[str, set[str]]]:
     """Map quant -> repo-relative expected GGUF filename -> cached blob hashes.
 
     Shared companions are copied into each main-quant bucket so update checks can
@@ -313,6 +333,14 @@ def _local_main_gguf_blobs_by_quant(repo_id: str) -> dict[str, dict[str, set[str
                 continue
             if str(getattr(repo_info, "repo_id", "")).lower() != target_lower:
                 continue
+            if repo_cache_dir is not None:
+                try:
+                    if Path(repo_info.repo_path).resolve(strict = False) != repo_cache_dir.resolve(
+                        strict = False
+                    ):
+                        continue
+                except (AttributeError, OSError, RuntimeError, ValueError):
+                    continue
             for path, hashes in cache_inventory._repo_gguf_blob_map(
                 repo_info,
                 include_companions = True,
@@ -388,6 +416,7 @@ def delete_variant_incomplete_blobs_result(
     *,
     extra_hashes: frozenset[str] = frozenset(),
     companions: bool = True,
+    root: Optional[Path] = None,
 ) -> VariantIncompleteDeleteResult:
     # With a sibling still downloading, ``companions=False`` keeps a shared mmproj
     # from being unlinked out from under it; the repo's last delete reclaims it.
@@ -409,8 +438,9 @@ def delete_variant_incomplete_blobs_result(
         )
     deleted = 0
     # Destructive iterator: only the exact-case match (or abort if ambiguous),
-    # so a case-variant sibling repo's partials are never unlinked.
-    for entry in iter_destructive_repo_cache_dirs("model", repo_id):
+    # so a case-variant sibling repo's partials are never unlinked. ``root`` scopes
+    # the purge to one cache so a delete never touches another cache's partials.
+    for entry in iter_destructive_repo_cache_dirs("model", repo_id, root = root):
         blobs_dir = entry / "blobs"
         if not blobs_dir.is_dir():
             continue
@@ -425,15 +455,37 @@ def delete_variant_incomplete_blobs_result(
     return VariantIncompleteDeleteResult(deleted = deleted, unresolved = False)
 
 
+def _repo_cache_dir_for_request(repo_id: str, local_path: Optional[str]) -> Path:
+    """Resolve the one Hub repo cache represented by this variant request."""
+    expected_name = repo_cache_dir_name("model", repo_id).lower()
+    if local_path:
+        try:
+            local = Path(local_path).expanduser().resolve(strict = False)
+            for candidate in (local, *local.parents):
+                if candidate.name.lower() == expected_name:
+                    return candidate
+        except (OSError, RuntimeError, ValueError):
+            pass
+    from utils.hf_cache_settings import get_hf_cache_paths
+
+    return get_hf_cache_paths().hub_cache / repo_cache_dir_name("model", repo_id)
+
+
 def _mark_empty_dir_cleanables(
-    repo_id: str, response: GgufVariantsResponse
+    repo_id: str,
+    response: GgufVariantsResponse,
+    repo_cache_dir: Optional[Path] = None,
 ) -> GgufVariantsResponse:
     """Surface empty leftover ``<quant>/`` folders (interrupted downloads) as
     partial so the UI can delete them -- on local/offline paths too, not just a
     remote listing. A listed quant is flipped to partial; an unlisted one is
     appended as a zero-byte cleanable entry."""
     try:
-        empty_labels = list_empty_gguf_variant_dirs(repo_id)
+        empty_labels = (
+            list_empty_gguf_variant_dirs(repo_id, root = repo_cache_dir.parent)
+            if repo_cache_dir is not None
+            else list_empty_gguf_variant_dirs(repo_id)
+        )
     except Exception as e:
         logger.warning(f"Failed to scan empty GGUF variant folders for {repo_id}: {e}")
         return response
@@ -468,6 +520,11 @@ async def get_gguf_variants_response(
     """
 
     def _compute() -> GgufVariantsResponse:
+        repo_cache_dir = (
+            None if is_local_path(repo_id) else _repo_cache_dir_for_request(repo_id, local_path)
+        )
+        hub_cache = repo_cache_dir.parent if repo_cache_dir is not None else None
+
         def _local_response(
             response_repo_id: str, variants, has_vision: bool
         ) -> GgufVariantsResponse:
@@ -511,6 +568,7 @@ async def get_gguf_variants_response(
                         partial_transport = _partial_transport_for_variant(
                             response_repo_id,
                             v.quant,
+                            repo_cache_dir,
                         ),
                     )
                     for v in variants
@@ -532,7 +590,7 @@ async def get_gguf_variants_response(
 
         local_only = prefer_local_cache or offline
         if local_only:
-            cached = list_gguf_variants_from_hf_cache(repo_id)
+            cached = list_gguf_variants_from_hf_cache(repo_id, root = hub_cache)
             if cached is not None:
                 variants, has_vision = cached
                 return _local_response(repo_id, variants, has_vision)
@@ -540,7 +598,7 @@ async def get_gguf_variants_response(
                 variants, has_vision = list_local_gguf_variants(local_path)
                 if variants or has_vision:
                     return _local_response(repo_id, variants, has_vision)
-            partial = list_partial_gguf_variants_from_state(repo_id)
+            partial = list_partial_gguf_variants_from_state(repo_id, hub_cache = hub_cache)
             if partial is not None:
                 variants, has_vision = partial
                 return _partial_local_response(repo_id, variants, has_vision)
@@ -560,11 +618,11 @@ async def get_gguf_variants_response(
         try:
             variants, has_vision, siblings = list_gguf_variants(repo_id, hf_token = hf_token)
         except Exception:
-            cached = list_gguf_variants_from_hf_cache(repo_id)
+            cached = list_gguf_variants_from_hf_cache(repo_id, root = hub_cache)
             if cached is not None:
                 variants, has_vision = cached
                 return _local_response(repo_id, variants, has_vision)
-            partial = list_partial_gguf_variants_from_state(repo_id)
+            partial = list_partial_gguf_variants_from_state(repo_id, hub_cache = hub_cache)
             if partial is not None:
                 variants, has_vision = partial
                 return _partial_local_response(repo_id, variants, has_vision)
@@ -581,7 +639,7 @@ async def get_gguf_variants_response(
         cached_filenames_by_snapshot: list[dict[str, int]] = []
         cached_quant_bytes_by_snapshot: list[dict[str, int]] = []
         if _is_valid_repo_id(repo_id):
-            for snap in iter_hf_cache_snapshots(repo_id):
+            for snap in iter_hf_cache_snapshots(repo_id, root = hub_cache):
                 try:
                     gguf_paths = list(_iter_gguf_paths(snap))
                 except (OSError, RuntimeError, ValueError) as e:
@@ -694,11 +752,20 @@ async def get_gguf_variants_response(
         partial_quants: set[str] = set()
         partial_quant_transports: dict[str, Optional[str]] = {}
         try:
-            incomplete_hashes = download_registry.incomplete_blob_hashes("model", repo_id)
+            incomplete_hashes = download_registry.incomplete_blob_hashes(
+                "model",
+                repo_id,
+                active_only = True,
+                root = hub_cache,
+            )
         except Exception as e:
             logger.warning(f"Failed to compute partial GGUF variants for {repo_id}: {e}")
             incomplete_hashes = set()
-        scan_snapshot_dir = hf_cache_scan.resolve_snapshot_dir_for_scan("model", repo_id)
+        scan_snapshot_dir = hf_cache_scan.resolve_snapshot_dir_for_scan(
+            "model",
+            repo_id,
+            repo_cache_dir,
+        )
         # Manifest + marker + main incomplete-blob check: catches variants whose
         # download was cancelled or whose expected shards are missing/undersized.
         for variant in variants:
@@ -711,6 +778,7 @@ async def get_gguf_variants_response(
                         variant.quant,
                         hf_token,
                         include_companions = False,
+                        repo_cache_dir = repo_cache_dir,
                     )
                 if hf_cache_scan.is_variant_partial(
                     repo_id,
@@ -718,11 +786,13 @@ async def get_gguf_variants_response(
                     scan_snapshot_dir,
                     incomplete_blob_hashes = incomplete_hashes,
                     variant_blob_hashes = variant_hashes,
+                    repo_cache_dir = repo_cache_dir,
                 ):
                     partial_quants.add(variant.quant)
                     partial_quant_transports[variant.quant] = _partial_transport_for_variant(
                         repo_id,
                         variant.quant,
+                        repo_cache_dir,
                     )
             except Exception as e:
                 logger.warning(
@@ -744,10 +814,14 @@ async def get_gguf_variants_response(
                     partial_quants.add(variant.quant)
                     partial_quant_transports.setdefault(
                         variant.quant,
-                        _partial_transport_for_variant(repo_id, variant.quant),
+                        _partial_transport_for_variant(
+                            repo_id,
+                            variant.quant,
+                            repo_cache_dir,
+                        ),
                     )
 
-        local_blobs_by_quant = _local_main_gguf_blobs_by_quant(repo_id)
+        local_blobs_by_quant = _local_main_gguf_blobs_by_quant(repo_id, repo_cache_dir)
 
         def _variant_detail(v) -> GgufVariantDetail:
             is_partial = v.quant in partial_quants
@@ -790,14 +864,20 @@ async def get_gguf_variants_response(
             if skip:
                 raise
             enriched = _mark_empty_dir_cleanables(
-                repo_id, GgufVariantsResponse(repo_id = repo_id, variants = [])
+                repo_id,
+                GgufVariantsResponse(repo_id = repo_id, variants = []),
+                _repo_cache_dir_for_request(repo_id, local_path),
             )
             if enriched.variants:
                 return enriched
             raise
         if skip:
             return response
-        return _mark_empty_dir_cleanables(repo_id, response)
+        return _mark_empty_dir_cleanables(
+            repo_id,
+            response,
+            _repo_cache_dir_for_request(repo_id, local_path),
+        )
 
     try:
         return await asyncio.to_thread(_compute_with_cleanables)
diff --git a/studio/backend/hub/services/models/local_inventory.py b/studio/backend/hub/services/models/local_inventory.py
index a3782efead..9cf260b157 100644
--- a/studio/backend/hub/services/models/local_inventory.py
+++ b/studio/backend/hub/services/models/local_inventory.py
@@ -36,6 +36,7 @@ from hub.utils.paths import (
 )
 from hub.services.models import common as model_common
 from hub.services.models.ollama import scan_ollama_dir
+from utils.hidden_models import is_hidden_model
 
 logger = get_logger(__name__)
 _MAX_MODELS_PER_CUSTOM_FOLDER = 200
@@ -105,11 +106,8 @@ def _is_model_directory_for_scan(path: Path, *, entry_limit: int | None) -> bool
 
 
 def _resolve_hf_cache_dir() -> Path:
-    try:
-        from huggingface_hub.constants import HF_HUB_CACHE
-        return Path(HF_HUB_CACHE)
-    except Exception:
-        return Path.home() / ".cache" / "huggingface" / "hub"
+    from utils.hf_cache_settings import get_hf_cache_paths
+    return get_hf_cache_paths().hub_cache
 
 
 def _scan_models_dir(
@@ -201,7 +199,12 @@ def _hf_repo_dir_has_content(repo_dir: Path) -> bool:
     return False
 
 
-def _scan_hf_cache(cache_dir: Path, *, entry_limit: int | None = None) -> List[LocalModelInfo]:
+def _scan_hf_cache(
+    cache_dir: Path,
+    *,
+    entry_limit: int | None = None,
+    active_cache: bool = True,
+) -> List[LocalModelInfo]:
     if not _safe_is_dir(cache_dir):
         return []
 
@@ -239,7 +242,10 @@ def _scan_hf_cache(cache_dir: Path, *, entry_limit: int | None = None) -> List[L
             repo_dir,
         )
         gguf_partial = hf_cache_scan.is_gguf_repo_partial(model_id, repo_dir)
-        has_gguf_variant_state, gguf_variant_state_size = _gguf_variant_state_summary(model_id)
+        has_gguf_variant_state, gguf_variant_state_size = _gguf_variant_state_summary(
+            model_id,
+            hub_cache = cache_dir,
+        )
         snapshot_partial_transport = (
             hf_cache_scan.partial_transport_for(
                 "model",
@@ -251,23 +257,25 @@ def _scan_hf_cache(cache_dir: Path, *, entry_limit: int | None = None) -> List[L
         )
         resolved = hf_cache_scan.resolve_hf_cache_realpath(repo_dir)
         scan_path = Path(resolved) if resolved else repo_dir
+        load_path = repo_dir if active_cache else scan_path
         # partial=False here; _apply_format_aware_partial below rewrites per-row
         # so a hybrid repo's gguf row doesn't taint its safetensors row.
         rows = _classify_local_path(
             scan_path,
             "hf_cache",
-            load_path = repo_dir,
+            load_path = load_path,
             display_name = model_id.split("/")[-1],
             model_id = model_id,
             updated_at = updated_at,
             partial = False,
+            active_cache = active_cache,
         )
         if not rows:
             if has_gguf_variant_state and gguf_partial:
                 rows = [
                     _local_model_info(
                         scan_path = repo_dir,
-                        load_path = repo_dir,
+                        load_path = load_path,
                         source = "hf_cache",
                         model_format = "gguf",
                         display_name = model_id.split("/")[-1],
@@ -276,6 +284,7 @@ def _scan_hf_cache(cache_dir: Path, *, entry_limit: int | None = None) -> List[L
                         partial = True,
                         requires_variant = True,
                         size_bytes = gguf_variant_state_size,
+                        active_cache = active_cache,
                     )
                 ]
             else:
@@ -284,13 +293,14 @@ def _scan_hf_cache(cache_dir: Path, *, entry_limit: int | None = None) -> List[L
                 rows = [
                     _local_model_info(
                         scan_path = repo_dir,
-                        load_path = repo_dir,
+                        load_path = load_path,
                         source = "hf_cache",
                         model_format = "unknown",
                         display_name = model_id.split("/")[-1],
                         model_id = model_id,
                         updated_at = updated_at,
                         partial = snapshot_partial or gguf_partial,
+                        active_cache = active_cache,
                     )
                 ]
         elif (
@@ -301,7 +311,7 @@ def _scan_hf_cache(cache_dir: Path, *, entry_limit: int | None = None) -> List[L
             rows.append(
                 _local_model_info(
                     scan_path = repo_dir,
-                    load_path = repo_dir,
+                    load_path = load_path,
                     source = "hf_cache",
                     model_format = "gguf",
                     display_name = model_id.split("/")[-1],
@@ -310,6 +320,7 @@ def _scan_hf_cache(cache_dir: Path, *, entry_limit: int | None = None) -> List[L
                     partial = True,
                     requires_variant = True,
                     size_bytes = gguf_variant_state_size,
+                    active_cache = active_cache,
                 )
             )
         rows = _apply_format_aware_partial(
@@ -514,14 +525,39 @@ async def _collect_models_from_default_sources(
     local_models += await _scan_source("HF cache", _scan_hf_cache, hf_cache_dir)
 
     if _safe_is_dir(legacy_hf) and legacy_hf.resolve() != hf_cache_dir.resolve():
-        local_models += await _scan_source("legacy HF cache", _scan_hf_cache, legacy_hf)
+        local_models += await _scan_source(
+            "legacy HF cache",
+            lambda path: _scan_hf_cache(path, active_cache = False),
+            legacy_hf,
+        )
 
     if (
         _safe_is_dir(hf_default)
         and hf_default.resolve() != hf_cache_dir.resolve()
         and hf_default.resolve() != legacy_hf.resolve()
     ):
-        local_models += await _scan_source("default HF cache", _scan_hf_cache, hf_default)
+        local_models += await _scan_source(
+            "default HF cache",
+            lambda path: _scan_hf_cache(path, active_cache = False),
+            hf_default,
+        )
+
+    from utils.hf_cache_settings import known_hf_hub_caches
+
+    seen_hf = {
+        os.path.normcase(str(path.resolve(strict = False)))
+        for path in (hf_cache_dir, legacy_hf, hf_default)
+    }
+    for previous_cache in known_hf_hub_caches():
+        key = os.path.normcase(str(previous_cache.resolve(strict = False)))
+        if key in seen_hf:
+            continue
+        seen_hf.add(key)
+        local_models += await _scan_source(
+            "previous HF cache",
+            lambda path: _scan_hf_cache(path, active_cache = False),
+            previous_cache,
+        )
 
     for lm_dir in lm_dirs:
         local_models += await _scan_source("LM Studio", _scan_lmstudio_dir, lm_dir)
@@ -542,7 +578,11 @@ def _scan_custom_folder(folder_path: Path) -> List[LocalModelInfo]:
                 limit = _MAX_MODELS_PER_CUSTOM_FOLDER,
                 entry_limit = _MAX_CUSTOM_FOLDER_ENTRIES,
             )
-            + _scan_hf_cache(folder_path, entry_limit = _MAX_CUSTOM_FOLDER_ENTRIES)
+            + _scan_hf_cache(
+                folder_path,
+                entry_limit = _MAX_CUSTOM_FOLDER_ENTRIES,
+                active_cache = False,
+            )
             + _scan_lmstudio_dir(folder_path, entry_limit = _MAX_CUSTOM_FOLDER_ENTRIES)
         )
         if m.model_format in supported_formats
@@ -609,12 +649,20 @@ def _dedupe_local_models(local_models: List[LocalModelInfo]) -> list[LocalModelI
             row_key = model.inventory_id or model.id
             key = f"{row_key}\x00custom" if model.source == "custom" else row_key
         existing = deduped.get(key)
-        if existing is None or _prefer_complete_larger(
-            model.partial,
-            model.size_bytes,
-            existing.partial,
-            existing.size_bytes,
-        ):
+        prefer_candidate = existing is None
+        if existing is not None:
+            if model.partial != existing.partial:
+                prefer_candidate = not model.partial
+            elif (model.active_cache is True) != (existing.active_cache is True):
+                prefer_candidate = model.active_cache is True
+            else:
+                prefer_candidate = _prefer_complete_larger(
+                    model.partial,
+                    model.size_bytes,
+                    existing.partial,
+                    existing.size_bytes,
+                )
+        if prefer_candidate:
             deduped[key] = model
     return sorted(
         deduped.values(),
@@ -623,6 +671,20 @@ def _dedupe_local_models(local_models: List[LocalModelInfo]) -> list[LocalModelI
     )
 
 
+def _filter_hidden_models(local_models: List[LocalModelInfo]) -> list[LocalModelInfo]:
+    """Remove infrastructure-only models from the shared local inventory."""
+    visible: list[LocalModelInfo] = []
+    for model in local_models:
+        resolved_cache_path = (
+            hf_cache_scan.resolve_hf_cache_realpath(Path(model.path))
+            if model.source == "hf_cache"
+            else None
+        )
+        if not is_hidden_model(model.id, model.model_id, model.path, resolved_cache_path):
+            visible.append(model)
+    return visible
+
+
 async def list_local_models_response(models_dir: str = "./models") -> LocalModelListResponse:
     """List local model candidates from every supported on-device source."""
     hf_cache_dir = _resolve_hf_cache_dir()
@@ -653,7 +715,7 @@ async def list_local_models_response(models_dir: str = "./models") -> LocalModel
             ollama_dirs,
         )
         local_models += await _collect_models_from_custom_folders()
-        models = _dedupe_local_models(local_models)
+        models = _dedupe_local_models(_filter_hidden_models(local_models))
 
         return LocalModelListResponse(
             models_dir = str(models_root),
diff --git a/studio/backend/hub/services/models/ollama.py b/studio/backend/hub/services/models/ollama.py
index 96a4114620..2ccdbb44f1 100644
--- a/studio/backend/hub/services/models/ollama.py
+++ b/studio/backend/hub/services/models/ollama.py
@@ -85,7 +85,7 @@ def _contained_link_path(link_dir: Path, link_name: str) -> Optional[Path]:
 
 
 def _ollama_links_dir(ollama_dir: Path) -> Optional[Path]:
-    """Writable directory for Ollama ``.gguf`` symlinks. Prefers ``<ollama_dir>/.studio_links/`` next to the blobs; falls back to Studio's cache (read-only system installs), then the temp dir (sandboxed installs)."""
+    """Writable directory for Ollama ``.gguf`` symlinks. Prefers ``<ollama_dir>/.studio_links/`` next to the blobs; falls back to Unsloth's cache (read-only system installs), then the temp dir (sandboxed installs)."""
 
     def _ensure_writable_dir(path: Path) -> Optional[Path]:
         try:
diff --git a/studio/backend/hub/services/snapshot_progress.py b/studio/backend/hub/services/snapshot_progress.py
index 1fdf05e2e5..c3db6fed7a 100644
--- a/studio/backend/hub/services/snapshot_progress.py
+++ b/studio/backend/hub/services/snapshot_progress.py
@@ -86,9 +86,20 @@ def _snapshot_complete_on_disk(
         return False
     if variant is None and hf_cache_scan.repo_cache_dir_has_incomplete_blobs(entry):
         return False
-    if download_manifest.has_cancel_marker(repo_type, repo_id, variant):
+    hub_cache = entry.parent
+    if download_manifest.has_cancel_marker(
+        repo_type,
+        repo_id,
+        variant,
+        hub_cache = hub_cache,
+    ):
         return False
-    manifest = download_manifest.read_manifest(repo_type, repo_id, variant)
+    manifest = download_manifest.read_manifest(
+        repo_type,
+        repo_id,
+        variant,
+        hub_cache = hub_cache,
+    )
     if manifest is None:
         return False
     return download_manifest.verify_against_disk(manifest, snapshot_dir).ok
@@ -118,6 +129,8 @@ def compute_snapshot_progress(
         0,
         int(getattr(metadata, "completed_baseline_bytes", 0) or 0),
     )
+    metadata_hub_cache = getattr(metadata, "hub_cache", None)
+    active_root = Path(metadata_hub_cache) if metadata_hub_cache else None
 
     expected_total = max(expected_bytes, 0)
     # Always resolve the revision's blob hashes so stale blobs from a superseded
@@ -134,11 +147,17 @@ def compute_snapshot_progress(
     count_finalized_unscoped = variant is None
 
     readings: list[tuple[int, int, Optional[str], bool]] = []
-    for entry in preferred_repo_cache_dirs(
-        repo_type,
-        repo_id,
-        force_active = force_active,
-    ):
+    cache_dirs = (
+        preferred_repo_cache_dirs(
+            repo_type,
+            repo_id,
+            force_active = force_active,
+            active_root = active_root,
+        )
+        if active_root is not None
+        else preferred_repo_cache_dirs(repo_type, repo_id, force_active = force_active)
+    )
+    for entry in cache_dirs:
         completed_bytes = 0
         in_progress_bytes = 0
         cache_path = hf_cache_scan.resolve_hf_cache_realpath(entry)
diff --git a/studio/backend/hub/tests/test_dataset_services.py b/studio/backend/hub/tests/test_dataset_services.py
index 4890714cd0..6aab07cc46 100644
--- a/studio/backend/hub/tests/test_dataset_services.py
+++ b/studio/backend/hub/tests/test_dataset_services.py
@@ -72,57 +72,115 @@ def test_dataset_cache_scan_merges_raw_and_processed_rows(monkeypatch):
     assert rows[0]["partial"] is False
 
 
-def test_delete_cached_dataset_attempts_all_roots_before_raising(monkeypatch):
+def test_delete_cached_dataset_scopes_delete_to_selected_root(monkeypatch, tmp_path):
+    """A dataset present in the active cache and a previously selected cache is
+    deleted only from the selected root, so the other cache's copy survives."""
     calls = []
-    purged_state = []
+    target_hub = tmp_path / "active" / "hub"
+    other_hub = tmp_path / "previous" / "hub"
+    for hub in (target_hub, other_hub):
+        (hub / "datasets--Org--Data").mkdir(parents = True)
 
     class _DeleteStrategy:
-        def __init__(self, label: str, fail: bool):
+        def __init__(self, label: str):
             self.label = label
-            self.fail = fail
 
         def execute(self):
             calls.append(self.label)
-            if self.fail:
-                raise RuntimeError(f"{self.label} failed")
 
-    class _Cache:
-        def __init__(self, label: str, fail: bool):
-            self.cache_dir = label
-            self.repos = [
+    def _cache(label: str, hub):
+        return SimpleNamespace(
+            cache_dir = label,
+            repos = [
                 SimpleNamespace(
                     repo_type = "dataset",
                     repo_id = "Org/Data",
+                    repo_path = str(hub / "datasets--Org--Data"),
                     revisions = [SimpleNamespace(commit_hash = f"{label}-rev")],
                 )
-            ]
-            self.fail = fail
-
-        def delete_revisions(self, *_revisions):
-            return _DeleteStrategy(self.cache_dir, self.fail)
+            ],
+            delete_revisions = lambda *_revs, _label = label: _DeleteStrategy(_label),
+        )
 
     monkeypatch.setattr(
         cache_inventory,
         "_collect_hf_cache_scans",
-        lambda: ([_Cache("first", True), _Cache("second", False)], set()),
+        lambda: ([_cache("active", target_hub), _cache("previous", other_hub)], set()),
     )
     monkeypatch.setattr(
         cache_inventory,
         "_delete_processed_dataset_cache",
-        lambda _repo_id: (True, []),
+        lambda _repo_id, **_kwargs: (False, []),
     )
     monkeypatch.setattr(
         cache_inventory.download_manifest,
         "purge_all_state_for_repo",
-        lambda *_args: purged_state.append(True) or 1,
+        lambda *_args, **_kwargs: 0,
+    )
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = target_hub),
+    )
+    monkeypatch.setattr(
+        "hub.utils.hf_cache_state.hf_cache_roots",
+        lambda: [target_hub, other_hub],
     )
 
-    with pytest.raises(HTTPException) as exc_info:
-        cache_inventory._delete_cached_dataset_blocking("Org/Data")
+    result = cache_inventory._delete_cached_dataset_blocking("Org/Data")
 
-    assert exc_info.value.status_code == 500
-    assert calls == ["first", "second"]
-    assert purged_state == []
+    assert result == {"status": "deleted", "repo_id": "Org/Data"}
+    # Only the selected (active) cache's revision is deleted; the previous
+    # cache's copy is never touched.
+    assert calls == ["active"]
+    assert not (target_hub / "datasets--Org--Data").exists()
+    assert (other_hub / "datasets--Org--Data").exists()
+
+
+def test_delete_processed_only_dataset_accepts_processed_cache_path(monkeypatch, tmp_path):
+    """A processed-only dataset row sends its Arrow cache path (<owner>___<repo>
+    under HF_DATASETS_CACHE), which is not a Hub datasets-- dir. The delete must
+    accept it and run the processed-cache delete instead of raising 400."""
+    datasets_root = tmp_path / "datasets"
+    processed_dir = datasets_root / "Org___Data"
+    processed_dir.mkdir(parents = True)
+
+    # No Hub-cache copy exists; only the processed Arrow cache holds this repo.
+    monkeypatch.setattr(cache_inventory, "_collect_hf_cache_scans", lambda: ([], set()))
+    monkeypatch.setattr(cache_inventory, "_hf_datasets_cache_roots", lambda: [datasets_root])
+    processed_calls: list[str] = []
+    monkeypatch.setattr(
+        cache_inventory,
+        "_delete_processed_dataset_cache",
+        lambda repo_id, **_kwargs: (processed_calls.append(repo_id) or True, []),
+    )
+
+    result = cache_inventory._delete_cached_dataset_blocking("Org/Data", str(processed_dir))
+
+    assert result == {"status": "deleted", "repo_id": "Org/Data"}
+    assert processed_calls == ["Org/Data"]
+
+
+def test_delete_processed_dataset_scopes_to_selected_root(monkeypatch, tmp_path):
+    """A dataset processed under two HF_DATASETS_CACHE roots is deleted only from
+    the selected root; the copy under the other cache home survives (real delete,
+    not stubbed)."""
+    selected_root = tmp_path / "selected" / "datasets"
+    other_root = tmp_path / "other" / "datasets"
+    for root in (selected_root, other_root):
+        (root / "Org___Data").mkdir(parents = True)
+
+    monkeypatch.setattr(cache_inventory, "_collect_hf_cache_scans", lambda: ([], set()))
+    monkeypatch.setattr(
+        cache_inventory, "_hf_datasets_cache_roots", lambda: [selected_root, other_root]
+    )
+
+    result = cache_inventory._delete_cached_dataset_blocking(
+        "Org/Data", str(selected_root / "Org___Data")
+    )
+
+    assert result == {"status": "deleted", "repo_id": "Org/Data"}
+    assert not (selected_root / "Org___Data").exists()  # the selected copy is deleted
+    assert (other_root / "Org___Data").exists()  # the other cache home is untouched
 
 
 def test_delete_cached_dataset_purges_blob_only_repo_dir(monkeypatch):
@@ -139,22 +197,22 @@ def test_delete_cached_dataset_purges_blob_only_repo_dir(monkeypatch):
     monkeypatch.setattr(
         cache_inventory,
         "_delete_processed_dataset_cache",
-        lambda _repo_id: (False, []),
+        lambda _repo_id, **_kwargs: (False, []),
     )
     monkeypatch.setattr(
         cache_inventory,
         "purge_repo_cache_dirs",
-        lambda _repo_type, repo_id: purged_dirs.append(repo_id) or True,
+        lambda _repo_type, repo_id, **_kwargs: purged_dirs.append(repo_id) or True,
     )
     monkeypatch.setattr(
         cache_inventory,
         "purge_partial_repo",
-        lambda *_args: False,
+        lambda *_args, **_kwargs: False,
     )
     monkeypatch.setattr(
         cache_inventory.download_manifest,
         "purge_all_state_for_repo",
-        lambda *_args: 0,
+        lambda *_args, **_kwargs: 0,
     )
 
     result = cache_inventory._delete_cached_dataset_blocking("Org/Data")
@@ -172,22 +230,22 @@ def test_delete_cached_dataset_absent_everywhere_raises_404(monkeypatch):
     monkeypatch.setattr(
         cache_inventory,
         "_delete_processed_dataset_cache",
-        lambda _repo_id: (False, []),
+        lambda _repo_id, **_kwargs: (False, []),
     )
     monkeypatch.setattr(
         cache_inventory,
         "purge_repo_cache_dirs",
-        lambda *_args: False,
+        lambda *_args, **_kwargs: False,
     )
     monkeypatch.setattr(
         cache_inventory,
         "purge_partial_repo",
-        lambda *_args: False,
+        lambda *_args, **_kwargs: False,
     )
     monkeypatch.setattr(
         cache_inventory.download_manifest,
         "purge_all_state_for_repo",
-        lambda *_args: 0,
+        lambda *_args, **_kwargs: 0,
     )
 
     with pytest.raises(HTTPException) as exc_info:
diff --git a/studio/backend/hub/tests/test_download_manifest_scoping.py b/studio/backend/hub/tests/test_download_manifest_scoping.py
new file mode 100644
index 0000000000..966eeaf0c2
--- /dev/null
+++ b/studio/backend/hub/tests/test_download_manifest_scoping.py
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import json
+from types import SimpleNamespace
+
+from hub.utils import download_manifest, state_dir
+
+
+def _write_manifest(path, payload):
+    path.parent.mkdir(parents = True, exist_ok = True)
+    path.write_text(json.dumps(payload), encoding = "utf-8")
+
+
+def test_purge_state_preserves_active_legacy_when_deleting_inactive_cache(monkeypatch, tmp_path):
+    """A scoped delete of an inactive cache must not erase the unscoped legacy
+    state, which _legacy_state_applies attributes to the active cache."""
+    active = tmp_path / "active" / "hub"
+    previous = tmp_path / "previous" / "hub"
+    for path in (active, previous):
+        path.mkdir(parents = True)
+
+    monkeypatch.setattr(state_dir, "cache_root", lambda: tmp_path / "state")
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = str(active)),
+    )
+
+    # Unowned legacy manifest -> belongs to the active cache.
+    legacy = state_dir.manifest_path("model", "Org/Model")
+    _write_manifest(legacy, {"version": 1})
+    # The inactive cache's own scoped copy is the one being deleted.
+    scoped = state_dir.manifest_path("model", "Org/Model", hub_cache = str(previous))
+    _write_manifest(scoped, {"version": 1, "hub_cache": str(previous)})
+
+    removed = download_manifest.purge_state("model", "Org/Model", hub_cache = str(previous))
+
+    assert removed is True
+    assert not scoped.is_file()  # the inactive cache's copy is gone
+    assert legacy.is_file()  # the active cache's legacy state survives
+
+
+def test_purge_state_removes_legacy_owned_by_the_deleted_cache(monkeypatch, tmp_path):
+    """A legacy file that recorded the deleted cache as its owner is purged."""
+    active = tmp_path / "active" / "hub"
+    previous = tmp_path / "previous" / "hub"
+    for path in (active, previous):
+        path.mkdir(parents = True)
+
+    monkeypatch.setattr(state_dir, "cache_root", lambda: tmp_path / "state")
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = str(active)),
+    )
+
+    legacy = state_dir.manifest_path("model", "Org/Model")
+    _write_manifest(legacy, {"version": 1, "hub_cache": str(previous)})
+
+    removed = download_manifest.purge_state("model", "Org/Model", hub_cache = str(previous))
+
+    assert removed is True
+    assert not legacy.is_file()  # owned by the deleted cache -> purged
diff --git a/studio/backend/hub/tests/test_empty_variant_folder.py b/studio/backend/hub/tests/test_empty_variant_folder.py
index 33bf6c6819..3ed8e69e0d 100644
--- a/studio/backend/hub/tests/test_empty_variant_folder.py
+++ b/studio/backend/hub/tests/test_empty_variant_folder.py
@@ -120,10 +120,16 @@ def _force_compute_to_raise(monkeypatch):
 
     monkeypatch.setattr(gguf_variants, "list_gguf_variants", _boom, raising = False)
     monkeypatch.setattr(
-        gguf_variants, "list_gguf_variants_from_hf_cache", lambda repo_id: None, raising = False
+        gguf_variants,
+        "list_gguf_variants_from_hf_cache",
+        lambda repo_id, root = None: None,
+        raising = False,
     )
     monkeypatch.setattr(
-        gguf_variants, "list_partial_gguf_variants_from_state", lambda repo_id: None, raising = False
+        gguf_variants,
+        "list_partial_gguf_variants_from_state",
+        lambda repo_id, hub_cache = None: None,
+        raising = False,
     )
 
 
@@ -133,7 +139,11 @@ def test_get_variants_surfaces_cleanable_when_metadata_fails(monkeypatch):
     import asyncio
 
     _force_compute_to_raise(monkeypatch)
-    monkeypatch.setattr(gguf_variants, "list_empty_gguf_variant_dirs", lambda repo_id: {"UD-IQ1_S"})
+    monkeypatch.setattr(
+        gguf_variants,
+        "list_empty_gguf_variant_dirs",
+        lambda repo_id, root = None: {"UD-IQ1_S"},
+    )
 
     resp = asyncio.run(
         gguf_variants.get_gguf_variants_response(
@@ -152,7 +162,11 @@ def test_get_variants_reraises_when_no_cleanable(monkeypatch):
     from fastapi import HTTPException
 
     _force_compute_to_raise(monkeypatch)
-    monkeypatch.setattr(gguf_variants, "list_empty_gguf_variant_dirs", lambda repo_id: set())
+    monkeypatch.setattr(
+        gguf_variants,
+        "list_empty_gguf_variant_dirs",
+        lambda repo_id, root = None: set(),
+    )
 
     try:
         asyncio.run(
diff --git a/studio/backend/hub/tests/test_model_services.py b/studio/backend/hub/tests/test_model_services.py
index 2c33e09b2b..fa5862a13c 100644
--- a/studio/backend/hub/tests/test_model_services.py
+++ b/studio/backend/hub/tests/test_model_services.py
@@ -2,6 +2,7 @@
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import asyncio
+import json
 import sys
 from pathlib import Path
 from types import SimpleNamespace
@@ -102,6 +103,236 @@ def test_big_endian_detection_ignores_model_name_be_token():
     )
 
 
+def _cached_model_row(tmp_path: Path, *, partial: bool, active_cache: bool | None, size_bytes: int):
+    path = tmp_path / f"cache-{active_cache}-{partial}-{size_bytes}"
+    return model_common._local_model_info(
+        scan_path = path,
+        load_path = path,
+        source = "hf_cache",
+        model_format = "safetensors",
+        model_id = "Org/Model",
+        partial = partial,
+        active_cache = active_cache,
+        size_bytes = size_bytes,
+    )
+
+
+@pytest.mark.parametrize("reverse", [False, True])
+def test_local_inventory_prefers_complete_previous_cache_copy(tmp_path, reverse):
+    active_partial = _cached_model_row(
+        tmp_path,
+        partial = True,
+        active_cache = True,
+        size_bytes = 20,
+    )
+    previous_complete = _cached_model_row(
+        tmp_path,
+        partial = False,
+        active_cache = False,
+        size_bytes = 10,
+    )
+    rows = [active_partial, previous_complete]
+    if reverse:
+        rows.reverse()
+
+    result = local_inventory._dedupe_local_models(rows)
+
+    assert result == [previous_complete]
+
+
+def test_local_inventory_compares_all_non_active_cache_copies(tmp_path):
+    inactive_partial = _cached_model_row(
+        tmp_path,
+        partial = True,
+        active_cache = False,
+        size_bytes = 20,
+    )
+    custom_complete = _cached_model_row(
+        tmp_path,
+        partial = False,
+        active_cache = None,
+        size_bytes = 10,
+    )
+
+    assert local_inventory._dedupe_local_models([inactive_partial, custom_complete]) == [
+        custom_complete
+    ]
+
+
+def test_local_inventory_prefers_active_cache_when_copies_are_equally_complete(tmp_path):
+    previous = _cached_model_row(
+        tmp_path,
+        partial = False,
+        active_cache = False,
+        size_bytes = 20,
+    )
+    active = _cached_model_row(
+        tmp_path,
+        partial = False,
+        active_cache = True,
+        size_bytes = 10,
+    )
+
+    assert local_inventory._dedupe_local_models([previous, active]) == [active]
+
+
+def test_loaded_repo_match_accepts_previous_cache_snapshot_path(monkeypatch, tmp_path):
+    repo_dir = tmp_path / "old-hub" / "models--Org--Model"
+    snapshot = repo_dir / "snapshots" / "revision"
+    snapshot.mkdir(parents = True)
+    monkeypatch.setattr(deletion, "iter_repo_cache_dirs", lambda *_args: iter([repo_dir]))
+
+    assert deletion._loaded_id_matches_repo(str(snapshot), "Org/Model") is True
+    assert deletion._loaded_id_matches_repo(str(snapshot / "model.gguf"), "Org/Model") is True
+    assert deletion._loaded_id_matches_repo(str(tmp_path / "other"), "Org/Model") is False
+
+
+def test_cached_inventory_loads_previous_cache_copy_by_snapshot(monkeypatch, tmp_path):
+    active_hub = tmp_path / "active-hub"
+    previous_repo = tmp_path / "previous-hub" / "models--Org--Model"
+    snapshot = previous_repo / "snapshots" / "revision"
+    snapshot.mkdir(parents = True)
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = active_hub),
+    )
+
+    fields = cache_inventory._cache_inventory_fields(
+        "Org/Model",
+        "safetensors",
+        repo_path = previous_repo,
+        snapshot_path = snapshot,
+    )
+
+    assert fields["load_id"] == str(snapshot)
+
+
+def test_cached_inventory_keeps_repo_id_for_active_cache(monkeypatch, tmp_path):
+    active_hub = tmp_path / "active-hub"
+    active_repo = active_hub / "models--Org--Model"
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = active_hub),
+    )
+
+    fields = cache_inventory._cache_inventory_fields(
+        "Org/Model",
+        "safetensors",
+        repo_path = active_repo,
+    )
+
+    assert fields["load_id"] == "Org/Model"
+
+
+def test_cached_inventory_prefers_active_copy_when_completeness_matches():
+    previous = {"partial": False, "active_cache": False, "size_bytes": 200}
+    active = {"partial": False, "active_cache": True, "size_bytes": 100}
+
+    assert cache_inventory._prefer_cache_row(active, previous) is True
+    assert cache_inventory._prefer_cache_row(previous, active) is False
+
+
+def test_cached_inventory_prefers_complete_copy_before_active_cache():
+    previous = {"partial": False, "active_cache": False, "size_bytes": 100}
+    active_partial = {"partial": True, "active_cache": True, "size_bytes": 200}
+
+    assert cache_inventory._prefer_cache_row(previous, active_partial) is True
+    assert cache_inventory._prefer_cache_row(active_partial, previous) is False
+
+
+def test_inventory_scans_every_dynamic_cache_root(monkeypatch, tmp_path):
+    first = tmp_path / "first-hub"
+    second = tmp_path / "second-hub"
+    unreadable = tmp_path / "unreadable-hub"
+    first.mkdir()
+    second.mkdir()
+    unreadable.mkdir()
+    scanned = []
+
+    monkeypatch.setattr(
+        inventory_scan,
+        "hf_cache_roots",
+        lambda: [first, unreadable, second],
+    )
+
+    def scan_cache(cache_dir):
+        path = Path(cache_dir)
+        scanned.append(path)
+        if path == unreadable:
+            raise PermissionError("unreadable")
+        return SimpleNamespace(cache_dir = cache_dir)
+
+    monkeypatch.setattr("huggingface_hub.scan_cache_dir", scan_cache)
+
+    result = inventory_scan._compute_all_hf_cache_scans()
+
+    assert scanned == [first, unreadable, second]
+    assert [Path(scan.cache_dir) for scan in result] == [first, second]
+
+
+def test_inventory_applies_download_state_to_its_owning_cache(monkeypatch, tmp_path):
+    state_root = tmp_path / "state"
+    cache_a = tmp_path / "cache-a"
+    cache_b = tmp_path / "cache-b"
+    repo_id = "Org/Model"
+    repo_name = "models--Org--Model"
+    repo_a = cache_a / repo_name
+    repo_b = cache_b / repo_name
+    snapshot_a = repo_a / "snapshots" / "revision"
+    snapshot_b = repo_b / "snapshots" / "revision"
+    snapshot_a.mkdir(parents = True)
+    snapshot_b.mkdir(parents = True)
+    (snapshot_a / "config.json").write_bytes(b"x")
+    (snapshot_b / "config.json").write_bytes(b"xx")
+
+    monkeypatch.setattr(state_dir, "cache_root", lambda: state_root)
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = cache_b),
+    )
+    assert download_manifest.write_manifest(
+        "model",
+        repo_id,
+        None,
+        [download_manifest.ExpectedFile(path = "config.json", size = 2)],
+        "http",
+        hub_cache = cache_a,
+    )
+
+    assert inventory_scan.is_snapshot_partial("model", repo_id, repo_a) is True
+    assert inventory_scan.is_snapshot_partial("model", repo_id, repo_b) is False
+    assert inventory_scan.partial_transport_for("model", repo_id, None, repo_a) == "http"
+    assert inventory_scan.partial_transport_for("model", repo_id, None, repo_b) is None
+
+
+def test_inventory_scopes_cancel_markers_to_their_owning_cache(monkeypatch, tmp_path):
+    state_root = tmp_path / "state"
+    cache_a = tmp_path / "cache-a"
+    cache_b = tmp_path / "cache-b"
+    repo_id = "Org/Model"
+    repo_name = "models--Org--Model"
+    repo_a = cache_a / repo_name
+    repo_b = cache_b / repo_name
+    repo_a.mkdir(parents = True)
+    repo_b.mkdir(parents = True)
+
+    monkeypatch.setattr(state_dir, "cache_root", lambda: state_root)
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = cache_b),
+    )
+    assert download_manifest.write_cancel_marker(
+        "model",
+        repo_id,
+        "Q4_K_M",
+        "xet",
+        hub_cache = cache_a,
+    )
+
+    assert inventory_scan.is_variant_partial(repo_id, "Q4_K_M", repo_cache_dir = repo_a) is True
+    assert inventory_scan.is_variant_partial(repo_id, "Q4_K_M", repo_cache_dir = repo_b) is False
+
+
 def test_list_local_gguf_variants_skips_big_endian_sibling(tmp_path):
     (tmp_path / "model-Q4_K_M-be.gguf").write_bytes(b"x" * 100)
     (tmp_path / "model-Q4_K_M.gguf").write_bytes(b"y" * 10)
@@ -163,8 +394,19 @@ def test_download_state_bounds_long_repo_variant_filenames(monkeypatch, tmp_path
         "http",
     )
 
-    marker_path = state_dir.marker_path("model", repo_id, variant)
-    manifest_path = state_dir.manifest_path("model", repo_id, variant)
+    hub_cache = download_manifest._canonical_hub_cache()
+    marker_path = state_dir.marker_path(
+        "model",
+        repo_id,
+        variant,
+        hub_cache = hub_cache,
+    )
+    manifest_path = state_dir.manifest_path(
+        "model",
+        repo_id,
+        variant,
+        hub_cache = hub_cache,
+    )
 
     assert marker_path is not None
     assert manifest_path is not None
@@ -181,6 +423,97 @@ def test_download_state_bounds_long_repo_variant_filenames(monkeypatch, tmp_path
     ]
 
 
+def test_download_state_isolated_across_hub_cache_switches(monkeypatch, tmp_path):
+    monkeypatch.setattr(state_dir, "cache_root", lambda: tmp_path)
+    cache_a = tmp_path / "cache-a"
+    cache_b = tmp_path / "cache-b"
+    selected = SimpleNamespace(hub_cache = cache_a)
+
+    from utils import hf_cache_settings
+
+    monkeypatch.setattr(hf_cache_settings, "get_hf_cache_paths", lambda: selected)
+    expected_a = [download_manifest.ExpectedFile(path = "a.gguf", size = 1)]
+    expected_b = [download_manifest.ExpectedFile(path = "b.gguf", size = 2)]
+
+    assert download_manifest.write_manifest("model", "Owner/Repo", "Q4_K_M", expected_a)
+    assert download_manifest.write_cancel_marker("model", "Owner/Repo", "Q4_K_M", "http")
+
+    selected.hub_cache = cache_b
+    assert download_manifest.write_manifest("model", "Owner/Repo", "Q4_K_M", expected_b)
+
+    manifest_b = download_manifest.read_manifest("model", "Owner/Repo", "Q4_K_M")
+    manifest_a = download_manifest.read_manifest(
+        "model",
+        "Owner/Repo",
+        "Q4_K_M",
+        hub_cache = cache_a,
+    )
+
+    assert manifest_b is not None and manifest_b.expected_files == tuple(expected_b)
+    assert manifest_a is not None and manifest_a.expected_files == tuple(expected_a)
+    assert not download_manifest.has_cancel_marker("model", "Owner/Repo", "Q4_K_M")
+    assert download_manifest.has_cancel_marker(
+        "model",
+        "Owner/Repo",
+        "Q4_K_M",
+        hub_cache = cache_a,
+    )
+    assert len(list((tmp_path / "hub-state" / "manifests").rglob("*.json"))) == 2
+
+
+def test_legacy_unscoped_download_state_falls_back_only_for_selected_cache(monkeypatch, tmp_path):
+    monkeypatch.setattr(state_dir, "cache_root", lambda: tmp_path)
+    cache_a = tmp_path / "cache-a"
+    cache_b = tmp_path / "cache-b"
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = cache_a),
+    )
+    manifest = state_dir.manifest_path("model", "Owner/Repo", "Q4_K_M")
+    marker = state_dir.marker_path("model", "Owner/Repo", "Q4_K_M")
+    assert manifest is not None and marker is not None
+    manifest.write_text(
+        json.dumps(
+            {
+                "version": 1,
+                "repo_id": "Owner/Repo",
+                "variant": "Q4_K_M",
+                "expected_files": [{"path": "model.gguf", "size": 10}],
+                "transport": "http",
+            }
+        ),
+        encoding = "utf-8",
+    )
+    marker.write_text(
+        json.dumps({"version": 1, "repo_id": "Owner/Repo", "variant": "Q4_K_M"}),
+        encoding = "utf-8",
+    )
+
+    assert download_manifest.read_manifest("model", "Owner/Repo", "Q4_K_M") is not None
+    assert download_manifest.has_cancel_marker("model", "Owner/Repo", "Q4_K_M")
+    assert list(download_manifest.iter_variant_manifests("model", "Owner/Repo")) == [
+        ("Q4_K_M", manifest)
+    ]
+    assert list(download_manifest.iter_variant_markers("model", "Owner/Repo")) == [
+        ("Q4_K_M", marker)
+    ]
+    assert (
+        download_manifest.read_manifest(
+            "model",
+            "Owner/Repo",
+            "Q4_K_M",
+            hub_cache = cache_b,
+        )
+        is None
+    )
+    assert not download_manifest.has_cancel_marker(
+        "model",
+        "Owner/Repo",
+        "Q4_K_M",
+        hub_cache = cache_b,
+    )
+
+
 class _RecordingLogger:
     def __init__(self):
         self.warnings = []
@@ -416,8 +749,15 @@ def test_cached_gguf_scan_includes_variant_state_without_completed_gguf(monkeypa
         "Q4_K_M",
         [download_manifest.ExpectedFile(path = "model-Q4_K_M.gguf", size = 4096)],
         "http",
+        hub_cache = repo_path.parent,
+    )
+    assert download_manifest.write_cancel_marker(
+        "model",
+        "Org/PartialGguf",
+        "Q4_K_M",
+        "http",
+        hub_cache = repo_path.parent,
     )
-    assert download_manifest.write_cancel_marker("model", "Org/PartialGguf", "Q4_K_M", "http")
     monkeypatch.setattr(
         cache_inventory,
         "all_hf_cache_scans",
@@ -439,6 +779,288 @@ def test_cached_gguf_scan_includes_variant_state_without_completed_gguf(monkeypa
     assert row["capabilities"]["requires_variant"] is True
 
 
+def test_cached_gguf_scan_hides_infra_repos_without_user_downloads(monkeypatch, tmp_path):
+    probe = _repo(
+        "ggml-org/models",
+        [_file("tinyllamas/stories260K.gguf", 1_200_000)],
+        tmp_path / "probe",
+    )
+    embedder = _repo(
+        "unsloth/bge-small-en-v1.5-GGUF",
+        [_file("bge-small-en-v1.5-f16.gguf", 60_000_000)],
+        tmp_path / "embedder",
+    )
+    chat = _repo("Org/Chat-GGUF", [_file("Q4_K_M.gguf", 100)], tmp_path / "chat")
+    monkeypatch.setattr(
+        cache_inventory,
+        "all_hf_cache_scans",
+        lambda: [SimpleNamespace(repos = [probe, embedder, chat])],
+    )
+    monkeypatch.setattr(
+        cache_inventory.hf_cache_scan,
+        "is_gguf_repo_partial",
+        lambda _repo_id, _path: False,
+    )
+
+    result = {"cached": cache_inventory._scan_cached_gguf()}
+
+    assert [row["repo_id"] for row in result["cached"]] == ["Org/Chat-GGUF"]
+
+
+def test_cached_gguf_scan_keeps_infra_repo_with_user_downloaded_variant(monkeypatch, tmp_path):
+    monkeypatch.setattr(state_dir, "cache_root", lambda: tmp_path / "state")
+    embedder = _repo(
+        "unsloth/bge-small-en-v1.5-GGUF",
+        [
+            _file("bge-small-en-v1.5-f16.gguf", 60_000_000),
+            _file("bge-small-en-v1.5-Q8_0.gguf", 35_000_000),
+        ],
+        tmp_path / "embedder",
+    )
+    # Variant manifests only exist for user Hub downloads, not auto-downloads.
+    assert download_manifest.write_manifest(
+        "model",
+        "unsloth/bge-small-en-v1.5-GGUF",
+        "Q8_0",
+        [download_manifest.ExpectedFile(path = "bge-small-en-v1.5-Q8_0.gguf", size = 35_000_000)],
+        "http",
+        hub_cache = Path(embedder.repo_path).parent,
+    )
+    monkeypatch.setattr(
+        cache_inventory,
+        "all_hf_cache_scans",
+        lambda: [SimpleNamespace(repos = [embedder])],
+    )
+    monkeypatch.setattr(
+        cache_inventory.hf_cache_scan,
+        "is_gguf_repo_partial",
+        lambda _repo_id, _path: False,
+    )
+
+    result = {"cached": cache_inventory._scan_cached_gguf()}
+
+    assert [row["repo_id"] for row in result["cached"]] == ["unsloth/bge-small-en-v1.5-GGUF"]
+    assert result["cached"][0]["capabilities"]["can_chat"] is False
+
+
+def test_cached_models_scan_hides_non_gguf_embedder(monkeypatch, tmp_path):
+    embedder_path = tmp_path / "hub" / "models--unsloth--bge-small-en-v1.5"
+    embedder_path.mkdir(parents = True)
+    embedder = _repo(
+        "unsloth/bge-small-en-v1.5",
+        [_file("config.json", 12), _file("model.safetensors", 130_000_000)],
+        embedder_path,
+    )
+    chat_path = tmp_path / "hub" / "models--Org--Chat"
+    chat_path.mkdir(parents = True)
+    chat = _repo(
+        "Org/Chat",
+        [_file("config.json", 12), _file("model.safetensors", 100)],
+        chat_path,
+    )
+    monkeypatch.setattr(
+        cache_inventory,
+        "all_hf_cache_scans",
+        lambda: [SimpleNamespace(repos = [embedder, chat])],
+    )
+    monkeypatch.setattr(
+        cache_inventory.hf_cache_scan,
+        "is_snapshot_partial",
+        lambda _kind, _repo_id, _path: False,
+    )
+
+    result = {"cached": cache_inventory._scan_cached_models()}
+
+    assert [row["repo_id"] for row in result["cached"]] == ["Org/Chat"]
+
+
+def test_cached_scans_hide_embedders_configured_by_cache_path(monkeypatch, tmp_path):
+    from core.rag import config as rag_config
+
+    gguf_path = tmp_path / "hub" / "models--Org--PathEmbedder-GGUF"
+    gguf_path.mkdir(parents = True)
+    gguf = _repo(
+        "Org/PathEmbedder-GGUF",
+        [_file("model-F16.gguf", 60_000_000)],
+        gguf_path,
+    )
+    model_path = tmp_path / "hub" / "models--Org--PathEmbedder"
+    model_path.mkdir(parents = True)
+    model = _repo(
+        "Org/PathEmbedder",
+        [_file("config.json", 12), _file("model.safetensors", 130_000_000)],
+        model_path,
+    )
+    monkeypatch.setattr(
+        rag_config,
+        "effective_embedding_model",
+        lambda: str(model_path),
+    )
+    monkeypatch.setattr(
+        rag_config,
+        "effective_gguf_repo",
+        lambda: str(gguf_path),
+    )
+    monkeypatch.setattr(
+        cache_inventory,
+        "all_hf_cache_scans",
+        lambda: [SimpleNamespace(repos = [gguf, model])],
+    )
+    monkeypatch.setattr(
+        cache_inventory.hf_cache_scan,
+        "is_gguf_repo_partial",
+        lambda _repo_id, _path: False,
+    )
+    monkeypatch.setattr(
+        cache_inventory.hf_cache_scan,
+        "is_snapshot_partial",
+        lambda _kind, _repo_id, _path: False,
+    )
+
+    assert cache_inventory._scan_cached_gguf() == []
+    assert cache_inventory._scan_cached_models() == []
+
+
+def test_cached_scans_hide_embedders_configured_by_snapshot_path(monkeypatch, tmp_path):
+    from core.rag import config as rag_config
+
+    gguf_path = tmp_path / "hub" / "models--Org--SnapshotEmbedder-GGUF"
+    gguf_snapshot = gguf_path / "snapshots" / "gguf-revision"
+    gguf_snapshot.mkdir(parents = True)
+    gguf = _repo(
+        "Org/SnapshotEmbedder-GGUF",
+        [_file("model-F16.gguf", 60_000_000)],
+        gguf_path,
+    )
+    model_path = tmp_path / "hub" / "models--Org--SnapshotEmbedder"
+    model_snapshot = model_path / "snapshots" / "model-revision"
+    model_snapshot.mkdir(parents = True)
+    model = _repo(
+        "Org/SnapshotEmbedder",
+        [_file("config.json", 12), _file("model.safetensors", 130_000_000)],
+        model_path,
+    )
+    monkeypatch.setattr(
+        rag_config,
+        "effective_embedding_model",
+        lambda: str(model_snapshot),
+    )
+    monkeypatch.setattr(
+        rag_config,
+        "effective_gguf_repo",
+        lambda: str(gguf_snapshot),
+    )
+    monkeypatch.setattr(
+        cache_inventory,
+        "all_hf_cache_scans",
+        lambda: [SimpleNamespace(repos = [gguf, model])],
+    )
+
+    def _resolve_snapshot(repo_path):
+        return str(
+            {
+                gguf_path: gguf_snapshot,
+                model_path: model_snapshot,
+            }.get(Path(repo_path), Path(repo_path))
+        )
+
+    monkeypatch.setattr(
+        cache_inventory.hf_cache_scan,
+        "resolve_hf_cache_realpath",
+        _resolve_snapshot,
+    )
+    monkeypatch.setattr(
+        cache_inventory.hf_cache_scan,
+        "is_gguf_repo_partial",
+        lambda _repo_id, _path: False,
+    )
+    monkeypatch.setattr(
+        cache_inventory.hf_cache_scan,
+        "is_snapshot_partial",
+        lambda _kind, _repo_id, _path: False,
+    )
+
+    assert cache_inventory._scan_cached_gguf() == []
+    assert cache_inventory._scan_cached_models() == []
+
+
+def test_cached_models_scan_keeps_unrelated_repo_with_custom_generic_embedder(
+    monkeypatch, tmp_path
+):
+    # A custom embedder with a generic basename ("org/model") must be hidden by
+    # EXACT repo-id match only. An unrelated cached chat model whose id merely
+    # contains "model" (e.g. "user/model-chat") must stay on device: substring
+    # basename matching used to drop real chat models from the inventory.
+    from core.rag import config as rag_config
+
+    monkeypatch.setattr(rag_config, "effective_embedding_model", lambda: "org/model")
+    monkeypatch.setattr(rag_config, "effective_gguf_repo", lambda: "org/model-GGUF")
+
+    def _model_repo(repo_id: str):
+        path = tmp_path / "hub" / f"models--{repo_id.replace('/', '--')}"
+        path.mkdir(parents = True)
+        return _repo(
+            repo_id,
+            [_file("config.json", 12), _file("model.safetensors", 100)],
+            path,
+        )
+
+    embedder = _model_repo("org/model")
+    chat = _model_repo("user/model-chat")
+    monkeypatch.setattr(
+        cache_inventory,
+        "all_hf_cache_scans",
+        lambda: [SimpleNamespace(repos = [embedder, chat])],
+    )
+    monkeypatch.setattr(
+        cache_inventory.hf_cache_scan,
+        "is_snapshot_partial",
+        lambda _kind, _repo_id, _path: False,
+    )
+
+    result = {"cached": cache_inventory._scan_cached_models()}
+
+    assert [row["repo_id"] for row in result["cached"]] == ["user/model-chat"]
+
+
+def test_cached_scans_hide_stale_default_embedder_after_custom_setting(monkeypatch, tmp_path):
+    from core.rag import config as rag_config
+
+    monkeypatch.setattr(rag_config, "effective_embedding_model", lambda: "org/custom")
+    monkeypatch.setattr(rag_config, "effective_gguf_repo", lambda: "org/custom-GGUF")
+
+    gguf = _repo(
+        "unsloth/bge-small-en-v1.5-GGUF",
+        [_file("bge-small-en-v1.5-f16.gguf", 60_000_000)],
+        tmp_path / "default-gguf",
+    )
+    weights_path = tmp_path / "hub" / "models--unsloth--bge-small-en-v1.5"
+    weights_path.mkdir(parents = True)
+    weights = _repo(
+        "unsloth/bge-small-en-v1.5",
+        [_file("config.json", 12), _file("model.safetensors", 130_000_000)],
+        weights_path,
+    )
+    monkeypatch.setattr(
+        cache_inventory,
+        "all_hf_cache_scans",
+        lambda: [SimpleNamespace(repos = [gguf, weights])],
+    )
+    monkeypatch.setattr(
+        cache_inventory.hf_cache_scan,
+        "is_gguf_repo_partial",
+        lambda _repo_id, _path: False,
+    )
+    monkeypatch.setattr(
+        cache_inventory.hf_cache_scan,
+        "is_snapshot_partial",
+        lambda _kind, _repo_id, _path: False,
+    )
+
+    assert cache_inventory._scan_cached_gguf() == []
+    assert cache_inventory._scan_cached_models() == []
+
+
 def test_gguf_variant_requirements_include_split_files_and_preferred_mmproj():
     requirements = gguf_variants._build_gguf_variant_requirements(
         [
@@ -925,6 +1547,7 @@ def test_gguf_progress_counts_completed_mmproj_with_expected_bytes(monkeypatch,
             ),
         ],
         "http",
+        hub_cache = entry.parent,
     )
 
     requirement = gguf_variants._GgufVariantRequirement(
@@ -1011,6 +1634,7 @@ def test_gguf_progress_subtracts_new_job_completed_baseline(monkeypatch, tmp_pat
             ),
         ],
         "http",
+        hub_cache = entry.parent,
     )
 
     requirement = gguf_variants._GgufVariantRequirement(
@@ -1181,6 +1805,7 @@ def test_gguf_progress_complete_on_disk_ignores_full_baseline(monkeypatch, tmp_p
             ),
         ],
         "http",
+        hub_cache = entry.parent,
     )
 
     requirement = gguf_variants._GgufVariantRequirement(
@@ -1580,8 +2205,15 @@ def test_hf_cache_scan_uses_gguf_partial_row_for_variant_state(monkeypatch, tmp_
         "Q4_K_M",
         [download_manifest.ExpectedFile(path = "model-Q4_K_M.gguf", size = 8192)],
         "http",
+        hub_cache = cache_dir,
+    )
+    assert download_manifest.write_cancel_marker(
+        "model",
+        "Org/PartialGguf",
+        "Q4_K_M",
+        "http",
+        hub_cache = cache_dir,
     )
-    assert download_manifest.write_cancel_marker("model", "Org/PartialGguf", "Q4_K_M", "http")
     monkeypatch.setattr(local_inventory, "_classify_local_path", lambda *_args, **_kwargs: [])
     monkeypatch.setattr(
         local_inventory.hf_cache_scan,
@@ -1610,6 +2242,63 @@ def test_hf_cache_scan_uses_gguf_partial_row_for_variant_state(monkeypatch, tmp_
     assert rows[0].capabilities.requires_variant is True
 
 
+def test_local_inventory_filters_custom_embedder_hf_cache_row(monkeypatch, tmp_path):
+    from core.rag import config as rag_config
+
+    monkeypatch.setattr(rag_config, "effective_embedding_model", lambda: "org/embedder")
+    monkeypatch.setattr(rag_config, "effective_gguf_repo", lambda: "org/embedder-GGUF")
+
+    def _row(repo_id: str):
+        repo_path = tmp_path / f"models--{repo_id.replace('/', '--')}"
+        return model_common._local_model_info(
+            scan_path = repo_path,
+            load_path = repo_path,
+            source = "hf_cache",
+            model_format = "safetensors",
+            model_id = repo_id,
+        )
+
+    rows = local_inventory._filter_hidden_models([_row("org/embedder"), _row("org/chat-model")])
+
+    assert [row.model_id for row in rows] == ["org/chat-model"]
+
+
+def test_local_inventory_filters_embedder_configured_by_snapshot_path(monkeypatch, tmp_path):
+    from core.rag import config as rag_config
+
+    embedder_path = tmp_path / "hub" / "models--org--embedder"
+    embedder_snapshot = embedder_path / "snapshots" / "revision"
+    embedder_snapshot.mkdir(parents = True)
+    chat_path = tmp_path / "hub" / "models--org--chat-model"
+    chat_path.mkdir(parents = True)
+    monkeypatch.setattr(
+        rag_config,
+        "effective_embedding_model",
+        lambda: str(embedder_snapshot),
+    )
+    monkeypatch.setattr(rag_config, "effective_gguf_repo", lambda: "org/embedder-GGUF")
+    monkeypatch.setattr(
+        local_inventory.hf_cache_scan,
+        "resolve_hf_cache_realpath",
+        lambda path: str(embedder_snapshot) if Path(path) == embedder_path else str(path),
+    )
+
+    def _row(repo_id: str, repo_path: Path):
+        return model_common._local_model_info(
+            scan_path = repo_path,
+            load_path = repo_path,
+            source = "hf_cache",
+            model_format = "safetensors",
+            model_id = repo_id,
+        )
+
+    rows = local_inventory._filter_hidden_models(
+        [_row("org/embedder", embedder_path), _row("org/chat-model", chat_path)]
+    )
+
+    assert [row.model_id for row in rows] == ["org/chat-model"]
+
+
 def test_model_download_job_helpers_preserve_idle_shape():
     key = downloads._download_job_key("Org/Model", None)
     status = downloads._job_status(key)
@@ -1779,7 +2468,7 @@ def test_gguf_variants_partial_marker_overrides_size_only_downloaded(monkeypatch
     monkeypatch.setattr(
         gguf_variants,
         "iter_hf_cache_snapshots",
-        lambda _repo_id: [snapshot],
+        lambda _repo_id, root = None: [snapshot],
     )
     monkeypatch.setattr(
         gguf_variants,
@@ -1798,6 +2487,70 @@ def test_gguf_variants_partial_marker_overrides_size_only_downloaded(monkeypatch
     assert result.variants[0].partial is True
 
 
+def test_gguf_variants_scopes_partial_state_to_requested_cache(monkeypatch, tmp_path):
+    async def _run_inline(fn, *args, **kwargs):
+        return fn(*args, **kwargs)
+
+    repo_id = "Org/SharedRepo"
+    repo_name = "models--Org--SharedRepo"
+    cache_a = tmp_path / "cache-a"
+    cache_b = tmp_path / "cache-b"
+    repo_a = cache_a / repo_name
+    snapshot_a = repo_a / "snapshots" / "revision"
+    snapshot_a.mkdir(parents = True)
+    (snapshot_a / "model-Q8_0.gguf").write_bytes(b"complete")
+    blobs_b = cache_b / repo_name / "blobs"
+    blobs_b.mkdir(parents = True)
+    (blobs_b / "q8-hash.incomplete").write_bytes(b"partial")
+
+    monkeypatch.setattr(state_dir, "cache_root", lambda: tmp_path / "state")
+    monkeypatch.setattr(gguf_variants.asyncio, "to_thread", _run_inline)
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = cache_b),
+    )
+    assert download_manifest.write_cancel_marker(
+        "model",
+        repo_id,
+        "Q8_0",
+        "http",
+        hub_cache = cache_b,
+    )
+    monkeypatch.setattr(
+        gguf_variants,
+        "list_gguf_variants",
+        lambda *_args, **_kwargs: (
+            [
+                SimpleNamespace(
+                    filename = "model-Q8_0.gguf",
+                    quant = "Q8_0",
+                    display_label = None,
+                    size_bytes = 8,
+                )
+            ],
+            False,
+            [
+                SimpleNamespace(
+                    rfilename = "model-Q8_0.gguf",
+                    size = 8,
+                    lfs = SimpleNamespace(sha256 = "q8-hash"),
+                )
+            ],
+        ),
+    )
+    monkeypatch.setattr(cache_inventory, "all_hf_cache_scans", lambda: [])
+
+    result = asyncio.run(
+        gguf_variants.get_gguf_variants_response(
+            repo_id,
+            local_path = str(repo_a),
+        )
+    )
+
+    assert result.variants[0].downloaded is True
+    assert result.variants[0].partial is False
+
+
 def test_download_registry_repo_keys_are_case_insensitive():
     registry = download_registry.DownloadRegistry()
 
@@ -2106,6 +2859,34 @@ def test_prepare_cache_for_transport_purges_only_requested_hashes(monkeypatch, t
     assert (blobs / "shared-mmproj.incomplete").exists()
 
 
+def test_prepare_cache_for_transport_uses_captured_root(monkeypatch, tmp_path):
+    cache_a = tmp_path / "cache-a"
+    cache_b = tmp_path / "cache-b"
+    repo_name = "models--Org--Repo"
+    partial_a = cache_a / repo_name / "blobs" / "blob.incomplete"
+    partial_b = cache_b / repo_name / "blobs" / "blob.incomplete"
+    partial_a.parent.mkdir(parents = True)
+    partial_b.parent.mkdir(parents = True)
+    partial_a.write_bytes(b"a")
+    partial_b.write_bytes(b"b")
+    monkeypatch.setattr(
+        download_registry,
+        "hf_cache_root",
+        lambda create = False, root = None: root or cache_b,
+    )
+
+    purged = download_registry.prepare_cache_for_transport(
+        "model",
+        "Org/Repo",
+        download_registry.TRANSPORT_HTTP,
+        root = cache_a,
+    )
+
+    assert purged == 1
+    assert not partial_a.exists()
+    assert partial_b.exists()
+
+
 def _vision_cache_root(monkeypatch, tmp_path):
     root = tmp_path / "hub"
     blobs = root / "models--Org--Vision" / "blobs"
@@ -2464,6 +3245,47 @@ def test_shutdown_skips_marker_for_worker_that_exits_cleanly(monkeypatch):
     assert markers == ["Org/Cut"]
 
 
+def test_orphan_reaper_uses_worker_cache_root_after_setting_changes(monkeypatch, tmp_path):
+    workers = tmp_path / "workers"
+    workers.mkdir()
+    cache_a = tmp_path / "cache-a" / "hub"
+    cache_b = tmp_path / "cache-b" / "hub"
+    partial = cache_a / "models--Org--Model" / "blobs" / "abc.incomplete"
+    partial.parent.mkdir(parents = True)
+    partial.write_bytes(b"partial")
+    cache_b.mkdir(parents = True)
+    monkeypatch.setattr(state_dir, "workers_dir", lambda: workers)
+    monkeypatch.setattr(download_registry, "_process_alive", lambda _pid: False)
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = cache_b),
+    )
+    markers = []
+    monkeypatch.setattr(
+        download_registry,
+        "persist_cancel_marker",
+        lambda *args, **kwargs: markers.append(args),
+    )
+    metadata = download_registry.DownloadMetadata(
+        repo_type = "model",
+        repo_id = "Org/Model",
+        variant = None,
+        transport = download_registry.TRANSPORT_HTTP,
+        hub_cache = str(cache_a),
+        xet_cache = str(tmp_path / "cache-a" / "xet"),
+    )
+    download_registry.write_worker_breadcrumb("org/model", 1234, metadata)
+    [breadcrumb] = list(workers.iterdir())
+    payload = json.loads(breadcrumb.read_text(encoding = "utf-8"))
+    assert payload["hub_cache"] == str(cache_a)
+    assert payload["xet_cache"] == str(tmp_path / "cache-a" / "xet")
+
+    download_registry.reap_orphan_workers()
+
+    assert markers == [("model", "Org/Model", None, "http")]
+    assert list(workers.iterdir()) == []
+
+
 def test_model_claim_register_cancel_uses_registry_marker_owner(monkeypatch):
     killed = []
 
@@ -2787,12 +3609,19 @@ def _build_variant_cache_repo(repo_dir, blob_specs, snapshot_links):
     return repo
 
 
-def _patch_variant_delete_side_effects(monkeypatch):
+def _patch_variant_delete_side_effects(monkeypatch, hub_cache = None):
     monkeypatch.setattr(
         deletion.download_manifest,
         "purge_state",
         lambda *_args, **_kwargs: False,
     )
+    # The repo under test lives in this cache; make it the active one so the
+    # delete scopes to it (default target root is the active hub cache).
+    if hub_cache is not None:
+        monkeypatch.setattr(
+            "utils.hf_cache_settings.get_hf_cache_paths",
+            lambda: SimpleNamespace(hub_cache = hub_cache),
+        )
 
 
 def test_snapshot_progress_filters_stale_blobs(monkeypatch, tmp_path):
@@ -2970,7 +3799,7 @@ def test_delete_variant_keeps_blob_shared_with_other_snapshot(monkeypatch, tmp_p
         "all_hf_cache_scans",
         lambda: [SimpleNamespace(repos = [repo])],
     )
-    _patch_variant_delete_side_effects(monkeypatch)
+    _patch_variant_delete_side_effects(monkeypatch, tmp_path)
 
     result = deletion._delete_cached_model_blocking("Org/Repo-GGUF", "Q4_K_M", None)
 
@@ -2997,7 +3826,7 @@ def test_delete_variant_unlinks_unshared_blob(monkeypatch, tmp_path):
         "all_hf_cache_scans",
         lambda: [SimpleNamespace(repos = [repo])],
     )
-    _patch_variant_delete_side_effects(monkeypatch)
+    _patch_variant_delete_side_effects(monkeypatch, tmp_path)
 
     result = deletion._delete_cached_model_blocking("Org/Repo-GGUF", "Q4_K_M", None)
 
@@ -3023,7 +3852,7 @@ def test_delete_variant_surfaces_locked_file_as_conflict(monkeypatch, tmp_path):
         "all_hf_cache_scans",
         lambda: [SimpleNamespace(repos = [repo])],
     )
-    _patch_variant_delete_side_effects(monkeypatch)
+    _patch_variant_delete_side_effects(monkeypatch, tmp_path)
 
     real_unlink = Path.unlink
 
diff --git a/studio/backend/hub/utils/download_manifest.py b/studio/backend/hub/utils/download_manifest.py
index 5366689296..ac0ccb5490 100644
--- a/studio/backend/hub/utils/download_manifest.py
+++ b/studio/backend/hub/utils/download_manifest.py
@@ -77,6 +77,7 @@ class Manifest:
     started_at: str
     expected_files: tuple[ExpectedFile, ...]
     transport: Optional[str] = None
+    hub_cache: Optional[str] = None
 
 
 @dataclass(frozen = True)
@@ -86,6 +87,78 @@ class VerifyResult:
     size_mismatched: tuple[str, ...]
 
 
+def _canonical_hub_cache(hub_cache: Optional[str | Path] = None) -> Optional[str]:
+    if hub_cache is None:
+        try:
+            from utils.hf_cache_settings import get_hf_cache_paths
+            hub_cache = get_hf_cache_paths().hub_cache
+        except Exception:
+            return None
+    try:
+        return str(Path(hub_cache).expanduser().resolve(strict = False))
+    except (OSError, RuntimeError, ValueError):
+        return str(hub_cache)
+
+
+def _read_state_payload(path: Path) -> Optional[dict]:
+    try:
+        data = json.loads(path.read_text(encoding = "utf-8"))
+    except (OSError, ValueError) as exc:
+        logger.debug("Could not read Hub state %s: %s", path, exc)
+        return None
+    return data if isinstance(data, dict) else None
+
+
+def _legacy_state_applies(
+    path: Path,
+    requested_hub_cache: Optional[str],
+    *,
+    fail_closed: bool = False,
+) -> bool:
+    """Whether an old unscoped state file belongs to the requested cache.
+
+    Transitional files that recorded their cache keep that ownership. Older
+    files with no ownership can only be attributed to the currently selected
+    cache, which matches the single-cache behavior under which they were
+    written without leaking them into remembered inactive caches.
+    """
+    data = _read_state_payload(path)
+    if data is not None:
+        recorded = data.get("hub_cache")
+        if isinstance(recorded, str) and recorded:
+            return _canonical_hub_cache(recorded) == requested_hub_cache
+    elif not fail_closed:
+        return False
+    return requested_hub_cache == _canonical_hub_cache()
+
+
+def _state_read_path(
+    path_factory,
+    repo_type: RepoType,
+    repo_id: str,
+    variant: Optional[str],
+    hub_cache: Optional[str | Path],
+    *,
+    fail_closed: bool = False,
+) -> Optional[Path]:
+    requested = _canonical_hub_cache(hub_cache)
+    scoped = path_factory(repo_type, repo_id, variant, hub_cache = requested)
+    try:
+        if scoped is not None and scoped.is_file():
+            return scoped
+    except OSError:
+        pass
+    legacy = path_factory(repo_type, repo_id, variant)
+    if legacy is None or legacy == scoped:
+        return None
+    try:
+        if not legacy.is_file():
+            return None
+    except OSError:
+        return None
+    return legacy if _legacy_state_applies(legacy, requested, fail_closed = fail_closed) else None
+
+
 def _atomic_write_json(path: Path, payload: dict) -> bool:
     # Per-write uuid suffix so a concurrent caller or a stale tmp from a
     # previous crash cannot collide with the in-flight write.
@@ -124,6 +197,8 @@ def write_manifest(
     variant: Optional[str],
     expected_files: Sequence[ExpectedFile],
     transport: Optional[str] = None,
+    *,
+    hub_cache: Optional[str | Path] = None,
 ) -> bool:
     """Write/overwrite the manifest for this triple. Best-effort.
 
@@ -131,7 +206,13 @@ def write_manifest(
     worst-case fallback is the pre-fix scanner behavior (one missed
     partial detection), which is no regression.
     """
-    path = manifest_path(repo_type, repo_id, variant)
+    recorded_hub_cache = _canonical_hub_cache(hub_cache)
+    path = manifest_path(
+        repo_type,
+        repo_id,
+        variant,
+        hub_cache = recorded_hub_cache,
+    )
     if path is None:
         return False
     payload = {
@@ -149,6 +230,7 @@ def write_manifest(
             for f in expected_files
         ],
         "transport": transport,
+        "hub_cache": recorded_hub_cache,
     }
     return _atomic_write_json(path, payload)
 
@@ -157,6 +239,8 @@ def read_manifest(
     repo_type: RepoType,
     repo_id: str,
     variant: Optional[str] = None,
+    *,
+    hub_cache: Optional[str | Path] = None,
 ) -> Optional[Manifest]:
     """Return the manifest if present and parseable; ``None`` otherwise.
 
@@ -171,15 +255,17 @@ def read_manifest(
     ``_MANIFEST_VERSION`` and widen this check) or live under a different
     filename, so an incompatible payload can never mis-classify rows.
     """
-    path = manifest_path(repo_type, repo_id, variant)
+    path = _state_read_path(
+        manifest_path,
+        repo_type,
+        repo_id,
+        variant,
+        hub_cache,
+    )
     if path is None or not path.is_file():
         return None
-    try:
-        data = json.loads(path.read_text(encoding = "utf-8"))
-    except (OSError, ValueError) as exc:
-        logger.debug("Could not read manifest %s: %s", path, exc)
-        return None
-    if not isinstance(data, dict):
+    data = _read_state_payload(path)
+    if data is None:
         return None
     if data.get("version") != _MANIFEST_VERSION:
         logger.debug(
@@ -216,6 +302,7 @@ def read_manifest(
         started_at = str(data.get("started_at", "")),
         expected_files = tuple(expected),
         transport = transport if transport in ("http", "xet") else None,
+        hub_cache = data.get("hub_cache") if isinstance(data.get("hub_cache"), str) else None,
     )
 
 
@@ -289,6 +376,8 @@ def write_cancel_marker(
     repo_id: str,
     variant: Optional[str] = None,
     transport: Optional[str] = None,
+    *,
+    hub_cache: Optional[str | Path] = None,
 ) -> bool:
     """Record that this triple was cancelled. Idempotent across repeated cancels.
 
@@ -296,7 +385,13 @@ def write_cancel_marker(
     inventory rows so the UI labels HTTP retries as continuable and XET
     retries as full redownloads. None is accepted for forward-compat.
     """
-    path = marker_path(repo_type, repo_id, variant)
+    recorded_hub_cache = _canonical_hub_cache(hub_cache)
+    path = marker_path(
+        repo_type,
+        repo_id,
+        variant,
+        hub_cache = recorded_hub_cache,
+    )
     if path is None:
         return False
     payload = {
@@ -306,6 +401,7 @@ def write_cancel_marker(
         "variant": variant,
         "transport": transport,
         "cancelled_at": datetime.now(timezone.utc).isoformat(),
+        "hub_cache": recorded_hub_cache,
     }
     return _atomic_write_json(path, payload)
 
@@ -314,6 +410,8 @@ def read_cancel_marker_transport(
     repo_type: RepoType,
     repo_id: str,
     variant: Optional[str] = None,
+    *,
+    hub_cache: Optional[str | Path] = None,
 ) -> Optional[str]:
     """Return the transport recorded in the cancel marker, or ``None`` if no
     marker exists or it is unreadable.
@@ -330,15 +428,17 @@ def read_cancel_marker_transport(
       ``None`` keeps the neutral "Retry" label.
     * Unknown future versions → ``None`` (unknown layout, unknown transport).
     """
-    path = marker_path(repo_type, repo_id, variant)
+    path = _state_read_path(
+        marker_path,
+        repo_type,
+        repo_id,
+        variant,
+        hub_cache,
+    )
     if path is None or not path.is_file():
         return None
-    try:
-        data = json.loads(path.read_text(encoding = "utf-8"))
-    except (OSError, ValueError) as exc:
-        logger.debug("Could not read cancel marker %s: %s", path, exc)
-        return None
-    if not isinstance(data, dict):
+    data = _read_state_payload(path)
+    if data is None:
         return None
     version = data.get("version")
     if version == _LEGACY_MARKER_VERSION:
@@ -351,10 +451,30 @@ def read_cancel_marker_transport(
     return None
 
 
+def _all_matching_state_paths(
+    parent: Optional[Path], repo_type: RepoType, repo_id: str, variant: Optional[str]
+) -> tuple[Path, ...]:
+    if parent is None:
+        return ()
+    legacy_path = (
+        manifest_path(repo_type, repo_id, variant)
+        if parent.name == "manifests"
+        else marker_path(repo_type, repo_id, variant)
+    )
+    if legacy_path is None:
+        return ()
+    try:
+        return tuple(path for path in parent.rglob(legacy_path.name) if path.is_file())
+    except OSError:
+        return ()
+
+
 def clear_cancel_marker(
     repo_type: RepoType,
     repo_id: str,
     variant: Optional[str] = None,
+    *,
+    hub_cache: Optional[str | Path] = None,
 ) -> None:
     """Remove the cancel marker for this triple if present.
 
@@ -362,31 +482,48 @@ def clear_cancel_marker(
     download-start (a fresh attempt supersedes prior cancel state) and
     again at successful completion (cleans up if the start clear failed).
     """
-    path = marker_path(repo_type, repo_id, variant)
-    if path is None:
-        return
-    try:
-        path.unlink(missing_ok = True)
-    except OSError as exc:
-        logger.debug("Could not clear cancel marker %s: %s", path, exc)
+    requested = _canonical_hub_cache(hub_cache)
+    path = marker_path(
+        repo_type,
+        repo_id,
+        variant,
+        hub_cache = requested,
+    )
+    legacy = marker_path(repo_type, repo_id, variant)
+    paths = [path]
+    if (
+        legacy is not None
+        and legacy != path
+        and _legacy_state_applies(legacy, requested, fail_closed = True)
+    ):
+        paths.append(legacy)
+    for target in paths:
+        if target is None:
+            continue
+        try:
+            target.unlink(missing_ok = True)
+        except OSError as exc:
+            logger.debug("Could not clear cancel marker %s: %s", target, exc)
 
 
 def has_cancel_marker(
     repo_type: RepoType,
     repo_id: str,
     variant: Optional[str] = None,
+    *,
+    hub_cache: Optional[str | Path] = None,
 ) -> bool:
-    """File-existence check only. Body is never read.
-
-    Fail-closed: a corrupt marker still returns ``True`` because the
-    file's existence is the signal (the user once cancelled this
-    triple, even if the body is unreadable).
-    """
-    path = marker_path(repo_type, repo_id, variant)
-    if path is None:
-        return False
+    """Return whether a cancel marker applies to the selected cache."""
+    path = _state_read_path(
+        marker_path,
+        repo_type,
+        repo_id,
+        variant,
+        hub_cache,
+        fail_closed = True,
+    )
     try:
-        return path.is_file()
+        return path is not None and path.is_file()
     except OSError:
         return False
 
@@ -395,48 +532,124 @@ def delete_manifest(
     repo_type: RepoType,
     repo_id: str,
     variant: Optional[str] = None,
+    *,
+    hub_cache: Optional[str | Path] = None,
 ) -> bool:
-    path = manifest_path(repo_type, repo_id, variant)
-    if path is None:
-        return False
-    try:
-        if not path.is_file():
-            return False
-        path.unlink()
-        return True
-    except OSError as exc:
-        logger.debug("Could not delete manifest %s: %s", path, exc)
-        return False
+    requested = _canonical_hub_cache(hub_cache)
+    path = manifest_path(
+        repo_type,
+        repo_id,
+        variant,
+        hub_cache = requested,
+    )
+    legacy = manifest_path(repo_type, repo_id, variant)
+    paths = [path]
+    if legacy is not None and legacy != path and _legacy_state_applies(legacy, requested):
+        paths.append(legacy)
+    removed = False
+    for target in paths:
+        if target is None:
+            continue
+        try:
+            if target.is_file():
+                target.unlink()
+                removed = True
+        except OSError as exc:
+            logger.debug("Could not delete manifest %s: %s", target, exc)
+    return removed
 
 
 def purge_state(
     repo_type: RepoType,
     repo_id: str,
     variant: Optional[str] = None,
+    *,
+    hub_cache: Optional[str | Path] = None,
 ) -> bool:
     """Remove manifest + cancel marker for this triple. Returns ``True``
-    when anything was present on disk before the call. Idempotent."""
-    marker_existed = has_cancel_marker(repo_type, repo_id, variant)
-    manifest_removed = delete_manifest(repo_type, repo_id, variant)
-    clear_cancel_marker(repo_type, repo_id, variant)
-    return marker_existed or manifest_removed
+    when anything was present on disk before the call. Idempotent.
+
+    With ``hub_cache`` set, only that cache's scoped state (plus any legacy
+    unscoped file that belongs to it) is removed, so purging one cache's copy
+    never clears another cache's resumable/cancel state."""
+    if hub_cache is None:
+        paths = (
+            *_all_matching_state_paths(manifests_dir(), repo_type, repo_id, variant),
+            *_all_matching_state_paths(cancelled_dir(), repo_type, repo_id, variant),
+        )
+    else:
+        requested = _canonical_hub_cache(hub_cache)
+        candidates = [
+            manifest_path(repo_type, repo_id, variant, hub_cache = hub_cache),
+            marker_path(repo_type, repo_id, variant, hub_cache = hub_cache),
+        ]
+        # Legacy unscoped state is shared: an unowned file belongs to the active
+        # cache (per _legacy_state_applies), so only purge it when it belongs to
+        # the cache being deleted -- else deleting an inactive cache would erase
+        # the active cache's resume/cancel state.
+        for path_factory in (manifest_path, marker_path):
+            legacy = path_factory(repo_type, repo_id, variant)
+            if legacy is not None and _legacy_state_applies(legacy, requested):
+                candidates.append(legacy)
+        paths = tuple(p for p in candidates if p is not None)
+    removed = False
+    for path in paths:
+        try:
+            if path.is_file():
+                path.unlink()
+                removed = True
+        except OSError as exc:
+            logger.debug("Could not purge Hub state %s: %s", path, exc)
+    return removed
 
 
-def purge_all_state_for_repo(repo_type: RepoType, repo_id: str) -> int:
+def purge_all_state_for_repo(
+    repo_type: RepoType,
+    repo_id: str,
+    *,
+    hub_cache: Optional[str | Path] = None,
+) -> int:
     """Remove the snapshot-level manifest + marker AND every variant-keyed
     manifest + marker for this repo. Used by the route delete handlers so
     scanner state never outlives the cache it described. Returns the count
-    of (repo, variant) triples that had any state on disk."""
+    of (repo, variant) triples that had any state on disk.
+
+    With ``hub_cache`` set, only that cache's scoped state (plus any legacy
+    unscoped file) is enumerated and removed, so deleting one cache's copy does
+    not clear another cache's resumable/cancel state."""
     removed = 0
-    if purge_state(repo_type, repo_id, None):
+    if purge_state(repo_type, repo_id, None, hub_cache = hub_cache):
         removed += 1
     variants: set[str] = set()
-    for variant, _ in iter_variant_manifests(repo_type, repo_id):
-        variants.add(variant)
-    for variant, _ in iter_variant_markers(repo_type, repo_id):
-        variants.add(variant)
+    prefix = variant_filename_prefix(repo_type, repo_id)
+    if hub_cache is None:
+        search = [(p, True) for p in (manifests_dir(), cancelled_dir()) if p is not None]
+    else:
+        # This cache's scoped dir (parent of its scoped path) plus the legacy
+        # unscoped base; glob (not rglob) so other caches' dirs are not swept.
+        search = []
+        for scoped, base in (
+            (manifest_path(repo_type, repo_id, None, hub_cache = hub_cache), manifests_dir()),
+            (marker_path(repo_type, repo_id, None, hub_cache = hub_cache), cancelled_dir()),
+        ):
+            if scoped is not None:
+                search.append((scoped.parent, False))
+            if base is not None:
+                search.append((base, False))
+    for parent, recursive in search:
+        try:
+            entries = tuple(
+                parent.rglob(f"{prefix}*.json") if recursive else parent.glob(f"{prefix}*.json")
+            )
+        except OSError:
+            continue
+        for entry in entries:
+            if not entry.is_file():
+                continue
+            fallback = entry.stem[len(prefix) :]
+            variants.add(_variant_from_state_file(entry, fallback))
     for variant in variants:
-        if purge_state(repo_type, repo_id, variant):
+        if purge_state(repo_type, repo_id, variant, hub_cache = hub_cache):
             removed += 1
     return removed
 
@@ -453,35 +666,83 @@ def _variant_from_state_file(path: Path, fallback: str) -> str:
 
 
 def _iter_variant_state_files(
-    parent: Optional[Path], repo_type: RepoType, repo_id: str
+    parent: Optional[Path],
+    repo_type: RepoType,
+    repo_id: str,
+    hub_cache: Optional[str | Path],
+    *,
+    cancel_markers: bool,
 ) -> Iterator[tuple[str, Path]]:
     if parent is None:
         return
-    prefix = variant_filename_prefix(repo_type, repo_id)
-    try:
-        entries = list(parent.iterdir())
-    except OSError:
+    path_factory = marker_path if cancel_markers else manifest_path
+    requested = _canonical_hub_cache(hub_cache)
+    scoped_probe = path_factory(
+        repo_type,
+        repo_id,
+        None,
+        hub_cache = requested,
+    )
+    if scoped_probe is None:
         return
-    for entry in entries:
-        if not entry.is_file() or not entry.name.endswith(".json"):
+    prefix = variant_filename_prefix(repo_type, repo_id)
+    seen: set[str] = set()
+    for directory, legacy in ((scoped_probe.parent, False), (parent, True)):
+        if legacy and directory == scoped_probe.parent:
             continue
-        stem = entry.name[: -len(".json")]
-        if not stem.lower().startswith(prefix):
+        try:
+            entries = list(directory.iterdir())
+        except OSError:
             continue
-        variant = stem[len(prefix) :]
-        if variant:
-            yield _variant_from_state_file(entry, variant), entry
+        for entry in entries:
+            if not entry.is_file() or not entry.name.endswith(".json"):
+                continue
+            stem = entry.name[: -len(".json")]
+            if not stem.lower().startswith(prefix) or entry.name in seen:
+                continue
+            if legacy and not _legacy_state_applies(
+                entry,
+                requested,
+                fail_closed = cancel_markers,
+            ):
+                continue
+            fallback = stem[len(prefix) :]
+            if fallback:
+                seen.add(entry.name)
+                yield _variant_from_state_file(entry, fallback), entry
 
 
-def iter_variant_manifests(repo_type: RepoType, repo_id: str) -> Iterator[tuple[str, Path]]:
+def iter_variant_manifests(
+    repo_type: RepoType,
+    repo_id: str,
+    *,
+    hub_cache: Optional[str | Path] = None,
+) -> Iterator[tuple[str, Path]]:
     """Yield (variant, manifest_path) for every variant-keyed manifest
     written for this repo. Used by is_gguf_repo_partial to enumerate all
     variants present on disk so the all-variants-broken gate can run."""
-    yield from _iter_variant_state_files(manifests_dir(), repo_type, repo_id)
+    yield from _iter_variant_state_files(
+        manifests_dir(),
+        repo_type,
+        repo_id,
+        hub_cache,
+        cancel_markers = False,
+    )
 
 
-def iter_variant_markers(repo_type: RepoType, repo_id: str) -> Iterator[tuple[str, Path]]:
+def iter_variant_markers(
+    repo_type: RepoType,
+    repo_id: str,
+    *,
+    hub_cache: Optional[str | Path] = None,
+) -> Iterator[tuple[str, Path]]:
     """Yield (variant, marker_path) for every variant-keyed cancel marker.
     Companion to iter_variant_manifests: catches variants cancelled
     before download-start ever wrote a manifest (very early failures)."""
-    yield from _iter_variant_state_files(cancelled_dir(), repo_type, repo_id)
+    yield from _iter_variant_state_files(
+        cancelled_dir(),
+        repo_type,
+        repo_id,
+        hub_cache,
+        cancel_markers = True,
+    )
diff --git a/studio/backend/hub/utils/download_registry.py b/studio/backend/hub/utils/download_registry.py
index 274038b292..9e2b7d1a6d 100644
--- a/studio/backend/hub/utils/download_registry.py
+++ b/studio/backend/hub/utils/download_registry.py
@@ -47,7 +47,7 @@ import time
 import weakref
 from dataclasses import dataclass, field, replace
 from pathlib import Path
-from typing import Iterator, Literal, Optional
+from typing import Callable, Iterator, Literal, Optional
 
 from loggers import get_logger
 
@@ -129,6 +129,8 @@ def write_worker_breadcrumb(key: str, pid: int, metadata: Optional["DownloadMeta
         "cancel_marker_transport": metadata.cancel_marker_transport
         if metadata is not None
         else None,
+        "hub_cache": metadata.hub_cache if metadata is not None else None,
+        "xet_cache": metadata.xet_cache if metadata is not None else None,
     }
     tmp = path.with_name(f".{path.name}.tmp-{pid}")
     try:
@@ -236,6 +238,7 @@ def _settle_orphaned_download(
     repo_id: Optional[str],
     variant: Optional[str],
     transport: Optional[str],
+    hub_cache: Optional[str] = None,
 ) -> None:
     """Persist a cancel marker for a reaped orphan still mid-download so the next
     launch settles it to a resumable "cancelled" state instead of a phantom-running
@@ -251,18 +254,42 @@ def _settle_orphaned_download(
         return
     from hub.utils import download_manifest
 
-    manifest = download_manifest.read_manifest(repo_type, repo_id, variant)
+    cache_root = Path(hub_cache) if isinstance(hub_cache, str) and hub_cache else None
+
+    manifest = download_manifest.read_manifest(
+        repo_type,
+        repo_id,
+        variant,
+        hub_cache = cache_root,
+    )
     if repo_type == "model" and variant and manifest is None:
         return
     if manifest is None:
-        if not has_active_incomplete_blobs(repo_type, repo_id):
+        if not has_active_incomplete_blobs(repo_type, repo_id, root = cache_root):
             return
     else:
-        if _manifest_verifies_against_active_cache(repo_type, repo_id, manifest):
+        if _manifest_verifies_against_active_cache(
+            repo_type,
+            repo_id,
+            manifest,
+            root = cache_root,
+        ):
             return
-        if not _manifest_has_active_incomplete_blobs(repo_type, repo_id, manifest):
+        if not _manifest_has_active_incomplete_blobs(
+            repo_type,
+            repo_id,
+            manifest,
+            root = cache_root,
+        ):
             return
-    persist_cancel_marker(repo_type, repo_id, variant, transport, logger = logger)
+    persist_cancel_marker(
+        repo_type,
+        repo_id,
+        variant,
+        transport,
+        hub_cache = hub_cache,
+        logger = logger,
+    )
 
 
 def reap_orphan_workers() -> None:
@@ -309,6 +336,7 @@ def reap_orphan_workers() -> None:
                 repo_id,
                 data.get("variant"),
                 data.get("cancel_marker_transport") or data.get("transport"),
+                data.get("hub_cache"),
             )
         except Exception as exc:
             logger.debug("Reaper failed for breadcrumb %s: %s", entry, exc)
@@ -355,8 +383,13 @@ def _purge_incomplete_blobs(
     return removed
 
 
-def _iter_active_snapshot_dirs(repo_type: str, repo_id: str) -> Iterator[Path]:
-    for entry in iter_active_repo_cache_dirs(repo_type, repo_id):
+def _iter_active_snapshot_dirs(
+    repo_type: str,
+    repo_id: str,
+    *,
+    root: Optional[Path] = None,
+) -> Iterator[Path]:
+    for entry in iter_active_repo_cache_dirs(repo_type, repo_id, root = root):
         snapshots_dir = entry / "snapshots"
         if not snapshots_dir.is_dir():
             continue
@@ -369,24 +402,41 @@ def _iter_active_snapshot_dirs(repo_type: str, repo_id: str) -> Iterator[Path]:
                 yield snapshot
 
 
-def _manifest_verifies_against_active_cache(repo_type: str, repo_id: str, manifest) -> bool:
+def _manifest_verifies_against_active_cache(
+    repo_type: str,
+    repo_id: str,
+    manifest,
+    *,
+    root: Optional[Path] = None,
+) -> bool:
     from hub.utils import download_manifest
-    for snapshot_dir in _iter_active_snapshot_dirs(repo_type, repo_id):
+    for snapshot_dir in _iter_active_snapshot_dirs(repo_type, repo_id, root = root):
         if download_manifest.verify_against_disk(manifest, snapshot_dir).ok:
             return True
     return False
 
 
-def _manifest_has_active_incomplete_blobs(repo_type: str, repo_id: str, manifest) -> bool:
+def _manifest_has_active_incomplete_blobs(
+    repo_type: str,
+    repo_id: str,
+    manifest,
+    *,
+    root: Optional[Path] = None,
+) -> bool:
     if not getattr(manifest, "variant", None):
-        return has_active_incomplete_blobs(repo_type, repo_id)
+        return has_active_incomplete_blobs(repo_type, repo_id, root = root)
     expected_hashes = frozenset(
         expected.sha256 for expected in manifest.expected_files if expected.sha256
     )
     if not expected_hashes:
-        return has_active_incomplete_blobs(repo_type, repo_id)
+        return has_active_incomplete_blobs(repo_type, repo_id, root = root)
     return bool(
-        incomplete_blob_hashes(repo_type, repo_id, active_only = True).intersection(expected_hashes)
+        incomplete_blob_hashes(
+            repo_type,
+            repo_id,
+            active_only = True,
+            root = root,
+        ).intersection(expected_hashes)
     )
 
 
@@ -459,6 +509,7 @@ def prepare_cache_for_transport(
     only_blob_hashes: Optional[frozenset[str]] = None,
     companion_blob_hashes: Optional[frozenset[str]] = None,
     protected_blob_hashes: Optional[frozenset[str]] = None,
+    root: Optional[Path] = None,
 ) -> int:
     """Guarantee any pre-existing ``.incomplete`` blobs are SAFE to resume under
     *mode*. Returns the number of partial blobs purged for untrusted provenance.
@@ -485,14 +536,13 @@ def prepare_cache_for_transport(
     they are excluded from every purge so a shared companion is never deleted
     mid-write.
 
-    Scope: only the active ``HF_HUB_CACHE`` root is inspected. That suffices for
-    resume safety because ``snapshot_download`` runs without a ``cache_dir``
-    override and so can only read or resume a ``.incomplete`` under this same
-    active root. Markers are written for the new mode before returning.
+    Scope: ``root`` selects the cache captured by the caller. It defaults to the
+    active ``HF_HUB_CACHE`` root for workers that inherit their cache through
+    the environment. Markers are written for the new mode before returning.
     """
     if mode not in VALID_TRANSPORTS:
         raise ValueError(f"Invalid transport mode: {mode!r}")
-    root = hf_cache_root(create = True)
+    root = hf_cache_root(create = True) if root is None else hf_cache_root(create = True, root = root)
     if root is None:
         return 0
     target = target_dir_name(repo_type, repo_id)
@@ -618,10 +668,11 @@ def incomplete_blob_hashes(
     repo_id: str,
     *,
     active_only: bool = False,
+    root: Optional[Path] = None,
 ) -> set[str]:
     out: set[str] = set()
     entries = (
-        iter_active_repo_cache_dirs(repo_type, repo_id)
+        iter_active_repo_cache_dirs(repo_type, repo_id, root = root)
         if active_only
         else iter_repo_cache_dirs(repo_type, repo_id)
     )
@@ -638,16 +689,24 @@ def incomplete_blob_hashes(
     return out
 
 
-def completed_blob_bytes(repo_type: str, repo_id: str, blob_hashes: frozenset[str]) -> int:
-    """Sum finalized blob bytes for *blob_hashes* in the active HF cache root.
+def completed_blob_bytes(
+    repo_type: str,
+    repo_id: str,
+    blob_hashes: frozenset[str],
+    *,
+    root: Optional[Path] = None,
+) -> int:
+    """Sum finalized blob bytes for *blob_hashes* in a single HF cache root.
 
-    A worker only writes to the active ``HF_HUB_CACHE`` root, so a baseline must
-    ignore legacy/default roots that ``snapshot_download`` won't reuse this run.
+    A worker only writes to its captured ``HF_HUB_CACHE`` root, so a baseline
+    must be scoped to that root (``root``), not re-resolved to whatever cache is
+    active now; otherwise a runtime cache switch makes the retry baseline count
+    bytes from the wrong disk.
     """
     if not blob_hashes:
         return 0
     total = 0
-    for entry in iter_active_repo_cache_dirs(repo_type, repo_id):
+    for entry in iter_active_repo_cache_dirs(repo_type, repo_id, root = root):
         blobs_dir = entry / "blobs"
         if not blobs_dir.is_dir():
             continue
@@ -712,6 +771,8 @@ class DownloadMetadata:
     # Bytes already complete before this job started; not counted as this run's
     # progress.
     completed_baseline_bytes: int = 0
+    hub_cache: Optional[str] = None
+    xet_cache: Optional[str] = None
 
 
 @dataclass(frozen = True)
@@ -752,6 +813,7 @@ def persist_cancel_marker(
     variant: Optional[str],
     transport: Optional[str],
     *,
+    hub_cache: Optional[str] = None,
     logger = logger,
 ) -> None:
     if not repo_type or not repo_id:
@@ -763,6 +825,7 @@ def persist_cancel_marker(
             repo_id,
             variant,
             transport = transport,
+            hub_cache = hub_cache,
         ):
             logger.debug("write_cancel_marker returned False for %s", repo_id)
     except Exception as exc:
@@ -971,6 +1034,7 @@ class DownloadRegistry:
                 metadata_to_persist.repo_id,
                 metadata_to_persist.variant,
                 metadata_to_persist.transport,
+                hub_cache = metadata_to_persist.hub_cache,
             )
         return False
 
@@ -1028,16 +1092,26 @@ class DownloadRegistry:
         blob_hashes: Optional[frozenset[str]] = None,
         progress_blob_hashes: Optional[frozenset[str]] = None,
         completed_baseline_bytes: int = 0,
+        admission_check: Optional[Callable[[], bool]] = None,
         generation: Optional[int] = None,
         replace_active: bool = False,
         metadata_transport: Optional[str] = None,
         cancel_marker_transport: Optional[str] = None,
+        hub_cache: Optional[str] = None,
+        xet_cache: Optional[str] = None,
     ) -> tuple[bool, str]:
         key = normalize_job_key(key)
         repo = _repo_of_key(key)
         requested_hashes = blob_hashes or frozenset()
         requested_progress_hashes = progress_blob_hashes or frozenset()
         with self._lock:
+            # Run the final external admission check while the registry lock is
+            # held, immediately before inspecting and publishing active state.
+            # The GGUF load path establishes its marker before calling
+            # its active-job probe, so either this claim observes that marker
+            # or the load's later probe observes this claim.
+            if admission_check is not None and not admission_check():
+                return False, "admission_blocked"
             deleting_scopes = self._deleting.get(repo)
             if deleting_scopes is not None and (
                 None in deleting_scopes or variant_from_key(key) in deleting_scopes
@@ -1098,6 +1172,8 @@ class DownloadRegistry:
                         0,
                         int(completed_baseline_bytes or 0),
                     ),
+                    hub_cache = hub_cache,
+                    xet_cache = xet_cache,
                 )
                 if cancel_marker_transport is not None:
                     self._cancel_marker_transports[key] = cancel_marker_transport
@@ -1222,6 +1298,23 @@ class DownloadRegistry:
                 )
             return refs
 
+    def has_active_variant(self, repo_id: str, variant: Optional[str]) -> bool:
+        """Whether an active model job targets this exact GGUF variant.
+
+        Scans the job table rather than only ``_repo_active`` so an XET-to-HTTP
+        retry handoff remains visible while it has temporarily released its
+        active slot.
+        """
+        repo_key = normalize_repo_key(repo_id)
+        target = (variant or "").strip().lower() or None
+        with self._lock:
+            for key, job in self._jobs.items():
+                if _repo_of_key(key) != repo_key or job.state not in _ACTIVE_STATES:
+                    continue
+                if self._active_job_variant_locked(key) == target:
+                    return True
+        return False
+
     def begin_delete(
         self,
         repo_id: str,
@@ -1361,6 +1454,7 @@ class DownloadRegistry:
                     metadata.repo_id,
                     metadata.variant,
                     metadata.cancel_marker_transport or metadata.transport,
+                    hub_cache = metadata.hub_cache,
                 )
         reaped: list[tuple[str, subprocess.Popen, Optional[DownloadMetadata]]] = []
         for key, proc, metadata in live:
@@ -1376,6 +1470,7 @@ class DownloadRegistry:
                         metadata.repo_id,
                         metadata.variant,
                         metadata.cancel_marker_transport or metadata.transport,
+                        hub_cache = metadata.hub_cache,
                     )
                 continue
             reaped.append((key, proc, metadata))
@@ -1396,6 +1491,7 @@ class DownloadRegistry:
                     metadata.repo_id,
                     metadata.variant,
                     metadata.cancel_marker_transport or metadata.transport,
+                    hub_cache = metadata.hub_cache,
                 )
 
 
diff --git a/studio/backend/hub/utils/gguf.py b/studio/backend/hub/utils/gguf.py
index 2e3de125f1..eb768db5d6 100644
--- a/studio/backend/hub/utils/gguf.py
+++ b/studio/backend/hub/utils/gguf.py
@@ -253,11 +253,16 @@ def _env_offline() -> bool:
     ) or os.environ.get("TRANSFORMERS_OFFLINE", "").lower() in ("1", "true", "yes")
 
 
-def iter_hf_cache_snapshots(repo_id: str):
-    from hub.utils.hf_cache_state import iter_repo_cache_dirs
+def iter_hf_cache_snapshots(repo_id: str, root: Optional[Path] = None):
+    from hub.utils.hf_cache_state import iter_active_repo_cache_dirs, iter_repo_cache_dirs
 
     snapshots: list[Path] = []
-    for repo_dir in iter_repo_cache_dirs("model", repo_id):
+    repo_dirs = (
+        iter_active_repo_cache_dirs("model", repo_id, root = root)
+        if root is not None
+        else iter_repo_cache_dirs("model", repo_id)
+    )
+    for repo_dir in repo_dirs:
         snapshots_dir = repo_dir / "snapshots"
         if not snapshots_dir.is_dir():
             continue
@@ -276,12 +281,17 @@ def iter_hf_cache_snapshots(repo_id: str):
     yield from snapshots
 
 
-def list_empty_gguf_variant_dirs(repo_id: str) -> set[str]:
+def list_empty_gguf_variant_dirs(repo_id: str, root: Optional[Path] = None) -> set[str]:
     """Quant labels present only as an EMPTY snapshot ``<quant>/`` folder (an
     interrupted split download); a quant with shards in any snapshot is excluded."""
     empty: dict[str, str] = {}
     nonempty: set[str] = set()
-    for snapshot in iter_hf_cache_snapshots(repo_id):
+    snapshots = (
+        iter_hf_cache_snapshots(repo_id, root = root)
+        if root is not None
+        else iter_hf_cache_snapshots(repo_id)
+    )
+    for snapshot in snapshots:
         try:
             entries = list(snapshot.iterdir())
         except OSError:
@@ -303,8 +313,15 @@ def list_empty_gguf_variant_dirs(repo_id: str) -> set[str]:
     return {label for key, label in empty.items() if key not in nonempty}
 
 
-def list_gguf_variants_from_hf_cache(repo_id: str) -> Optional[tuple[list[GgufVariantInfo], bool]]:
-    for snapshot in iter_hf_cache_snapshots(repo_id):
+def list_gguf_variants_from_hf_cache(
+    repo_id: str, root: Optional[Path] = None
+) -> Optional[tuple[list[GgufVariantInfo], bool]]:
+    snapshots = (
+        iter_hf_cache_snapshots(repo_id, root = root)
+        if root is not None
+        else iter_hf_cache_snapshots(repo_id)
+    )
+    for snapshot in snapshots:
         variants, has_vision = list_local_gguf_variants(str(snapshot))
         if variants or has_vision:
             return variants, has_vision
@@ -312,7 +329,7 @@ def list_gguf_variants_from_hf_cache(repo_id: str) -> Optional[tuple[list[GgufVa
 
 
 def list_partial_gguf_variants_from_state(
-    repo_id: str,
+    repo_id: str, hub_cache: Optional[Path] = None
 ) -> Optional[tuple[list[GgufVariantInfo], bool]]:
     """Reconstruct GGUF variants from download manifests/markers alone.
 
@@ -328,10 +345,26 @@ def list_partial_gguf_variants_from_state(
     # original-casing label over a lowercased cancel marker for the same variant.
     seen: set[str] = set()
     ordered: list[str] = []
-    for source in (
-        download_manifest.iter_variant_manifests("model", repo_id),
-        download_manifest.iter_variant_markers("model", repo_id),
-    ):
+    sources = (
+        (
+            download_manifest.iter_variant_manifests("model", repo_id),
+            download_manifest.iter_variant_markers("model", repo_id),
+        )
+        if hub_cache is None
+        else (
+            download_manifest.iter_variant_manifests(
+                "model",
+                repo_id,
+                hub_cache = hub_cache,
+            ),
+            download_manifest.iter_variant_markers(
+                "model",
+                repo_id,
+                hub_cache = hub_cache,
+            ),
+        )
+    )
+    for source in sources:
         for variant, _path in source:
             key = variant.lower()
             if key not in seen:
@@ -343,7 +376,16 @@ def list_partial_gguf_variants_from_state(
     variants: list[GgufVariantInfo] = []
     has_vision = False
     for variant in ordered:
-        manifest = download_manifest.read_manifest("model", repo_id, variant)
+        manifest = (
+            download_manifest.read_manifest("model", repo_id, variant)
+            if hub_cache is None
+            else download_manifest.read_manifest(
+                "model",
+                repo_id,
+                variant,
+                hub_cache = hub_cache,
+            )
+        )
         main_filename: Optional[str] = None
         size_bytes = 0
         companion_bytes = 0
diff --git a/studio/backend/hub/utils/hf_cache_state.py b/studio/backend/hub/utils/hf_cache_state.py
index 22c948b683..49a28c813c 100644
--- a/studio/backend/hub/utils/hf_cache_state.py
+++ b/studio/backend/hub/utils/hf_cache_state.py
@@ -29,12 +29,10 @@ def _safe_is_dir(path: Path) -> bool:
         return False
 
 
-def hf_cache_root(*, create: bool = False) -> Optional[Path]:
-    try:
-        from huggingface_hub import constants as hf_constants
-    except ImportError:
-        return None
-    root = Path(hf_constants.HF_HUB_CACHE)
+def hf_cache_root(*, create: bool = False, root: Optional[Path] = None) -> Optional[Path]:
+    from utils.hf_cache_settings import get_hf_cache_paths
+
+    root = root or get_hf_cache_paths().hub_cache
     if create:
         try:
             root.mkdir(parents = True, exist_ok = True)
@@ -46,6 +44,7 @@ def hf_cache_root(*, create: bool = False) -> Optional[Path]:
 
 def hf_cache_roots() -> list[Path]:
     from hub.utils.paths import hf_default_cache_dir, legacy_hf_cache_dir
+    from utils.hf_cache_settings import known_hf_hub_caches
 
     roots: list[Path] = []
     seen: set[str] = set()
@@ -62,7 +61,8 @@ def hf_cache_roots() -> list[Path]:
         seen.add(key)
         roots.append(path)
 
-    _add(hf_cache_root())
+    for configured in known_hf_hub_caches():
+        _add(configured)
     _add(legacy_hf_cache_dir())
     _add(hf_default_cache_dir())
     return roots
@@ -181,12 +181,22 @@ def iter_repo_cache_dirs(repo_type: str, repo_id: str) -> Iterator[Path]:
             continue
 
 
-def iter_destructive_repo_cache_dirs(repo_type: str, repo_id: str) -> Iterator[Path]:
+def iter_destructive_repo_cache_dirs(
+    repo_type: str,
+    repo_id: str,
+    *,
+    root: Optional[Path] = None,
+) -> Iterator[Path]:
     target = repo_cache_dir_name(repo_type, repo_id)
     folded_target = target.lower()
-    for root in hf_cache_roots():
+    if root is not None:
+        scoped = hf_cache_root(root = root)
+        bases = [scoped] if scoped is not None else []
+    else:
+        bases = hf_cache_roots()
+    for base in bases:
         try:
-            entries = [entry for entry in root.iterdir() if entry.name.lower() == folded_target]
+            entries = [entry for entry in base.iterdir() if entry.name.lower() == folded_target]
         except OSError:
             continue
         matched_names = resolve_destructive_case_matches(
@@ -200,8 +210,13 @@ def iter_destructive_repo_cache_dirs(repo_type: str, repo_id: str) -> Iterator[P
                 yield entry
 
 
-def iter_active_repo_cache_dirs(repo_type: str, repo_id: str) -> Iterator[Path]:
-    root = hf_cache_root()
+def iter_active_repo_cache_dirs(
+    repo_type: str,
+    repo_id: str,
+    *,
+    root: Optional[Path] = None,
+) -> Iterator[Path]:
+    root = hf_cache_root(root = root)
     if root is None:
         return
     target = target_dir_name(repo_type, repo_id)
@@ -218,12 +233,13 @@ def preferred_repo_cache_dirs(
     repo_id: str,
     *,
     force_active: bool = False,
+    active_root: Optional[Path] = None,
 ) -> list[Path]:
-    active_entries = list(iter_active_repo_cache_dirs(repo_type, repo_id))
+    active_entries = list(iter_active_repo_cache_dirs(repo_type, repo_id, root = active_root))
     if active_entries:
         return active_entries
     if force_active:
-        root = hf_cache_root()
+        root = hf_cache_root(root = active_root)
         if root is not None:
             canonical = repo_cache_dir_name(repo_type, repo_id)
             return [root / canonical]
@@ -237,8 +253,13 @@ def has_incomplete_blobs(repo_type: str, repo_id: str) -> bool:
     return False
 
 
-def has_active_incomplete_blobs(repo_type: str, repo_id: str) -> bool:
-    for entry in iter_active_repo_cache_dirs(repo_type, repo_id):
+def has_active_incomplete_blobs(
+    repo_type: str,
+    repo_id: str,
+    *,
+    root: Optional[Path] = None,
+) -> bool:
+    for entry in iter_active_repo_cache_dirs(repo_type, repo_id, root = root):
         if repo_cache_dir_has_incomplete_blobs(entry):
             return True
     return False
@@ -273,9 +294,14 @@ def _prune_empty_dirs(root: Path) -> bool:
     return removed
 
 
-def purge_partial_repo(repo_type: str, repo_id: str) -> bool:
+def purge_partial_repo(
+    repo_type: str,
+    repo_id: str,
+    *,
+    root: Optional[Path] = None,
+) -> bool:
     removed = False
-    for entry in iter_destructive_repo_cache_dirs(repo_type, repo_id):
+    for entry in iter_destructive_repo_cache_dirs(repo_type, repo_id, root = root):
         blobs_dir = entry / "blobs"
         if blobs_dir.is_dir():
             for blob in blobs_dir.iterdir():
@@ -290,9 +316,14 @@ def purge_partial_repo(repo_type: str, repo_id: str) -> bool:
     return removed
 
 
-def purge_repo_cache_dirs(repo_type: str, repo_id: str) -> bool:
+def purge_repo_cache_dirs(
+    repo_type: str,
+    repo_id: str,
+    *,
+    root: Optional[Path] = None,
+) -> bool:
     removed = False
-    for entry in iter_destructive_repo_cache_dirs(repo_type, repo_id):
+    for entry in iter_destructive_repo_cache_dirs(repo_type, repo_id, root = root):
         try:
             if entry.is_symlink() or not entry.is_dir():
                 continue
@@ -301,3 +332,59 @@ def purge_repo_cache_dirs(repo_type: str, repo_id: str) -> bool:
         except FileNotFoundError:
             continue
     return removed
+
+
+def scoped_delete_root(repo_type: str, repo_id: str, cache_path: Optional[str]) -> Optional[Path]:
+    """Resolve the single cache root a delete of this repo may touch.
+
+    Returns the active hub cache when *cache_path* is falsy, the owning cache
+    root when *cache_path* points inside a known cache, or ``None`` when
+    *cache_path* is set but not inside any known cache (caller should reject).
+    This keeps a delete of one inventory row from removing copies in other,
+    previously selected caches.
+    """
+    from utils.hf_cache_settings import get_hf_cache_paths
+
+    if not cache_path:
+        return Path(get_hf_cache_paths().hub_cache).resolve(strict = False)
+    try:
+        resolved = Path(cache_path).expanduser().resolve(strict = False)
+    except (OSError, RuntimeError, ValueError):
+        return None
+    expected = repo_cache_dir_name(repo_type, repo_id).lower()
+    repo_dir = next(
+        (
+            candidate
+            for candidate in (resolved, *resolved.parents)
+            if candidate.name.lower() == expected
+        ),
+        None,
+    )
+    if repo_dir is None:
+        return None
+    allowed = {r.resolve(strict = False) for r in hf_cache_roots()}
+    root = repo_dir.parent.resolve(strict = False)
+    return root if root in allowed else None
+
+
+def resolve_delete_target_root(
+    repo_type: str, repo_id: str, cache_path: Optional[str], owner_roots
+) -> Optional[Path]:
+    """Pick the single cache root a delete of this repo should target.
+
+    An explicit *cache_path* wins (``None`` when it is not a known cache, so the
+    caller can reject it). Otherwise prefer the active cache when it holds a
+    copy, else the sole cache that does -- so a model that lives only in a
+    previously selected cache stays deletable while other caches are untouched.
+    """
+    if cache_path:
+        return scoped_delete_root(repo_type, repo_id, cache_path)
+    from utils.hf_cache_settings import get_hf_cache_paths
+
+    active = Path(get_hf_cache_paths().hub_cache).resolve(strict = False)
+    roots = list(owner_roots)
+    if active in roots:
+        return active
+    if len(roots) == 1:
+        return roots[0]
+    return active
diff --git a/studio/backend/hub/utils/inventory_scan.py b/studio/backend/hub/utils/inventory_scan.py
index 57ad7f6655..058fdf9b65 100644
--- a/studio/backend/hub/utils/inventory_scan.py
+++ b/studio/backend/hub/utils/inventory_scan.py
@@ -36,7 +36,7 @@ from hub.utils.state_dir import RepoType
 from hub.utils.hf_cache_state import (
     INCOMPLETE_SUFFIX,
     has_incomplete_blobs,
-    hf_cache_root,
+    hf_cache_roots,
     iter_repo_cache_dirs,
     latest_snapshot_dir,
     repo_cache_dir_has_incomplete_blobs,
@@ -127,33 +127,13 @@ def all_hf_cache_scans() -> list:
 
 def _compute_all_hf_cache_scans() -> list:
     from huggingface_hub import scan_cache_dir
-    from hub.utils.paths import legacy_hf_cache_dir, hf_default_cache_dir
 
     scans: list = []
-    seen: set[str] = set()
-    try:
-        from huggingface_hub.constants import HF_HUB_CACHE
-
-        active = Path(HF_HUB_CACHE).resolve()
-        seen.add(str(active))
-        if active.is_dir():
-            scans.append(scan_cache_dir())
-    except Exception as exc:
-        logger.warning("Could not scan active HF cache: %s", exc)
-
-    for extra_fn in (legacy_hf_cache_dir, hf_default_cache_dir):
+    for cache_root in hf_cache_roots():
         try:
-            extra = extra_fn()
-            # is_dir()/resolve() can raise on an inaccessible path; skip it.
-            if not extra.is_dir():
-                continue
-            resolved = str(extra.resolve())
-            if resolved in seen:
-                continue
-            seen.add(resolved)
-            scans.append(scan_cache_dir(cache_dir = str(extra)))
+            scans.append(scan_cache_dir(cache_dir = str(cache_root)))
         except Exception as exc:
-            logger.warning("Could not scan HF cache %s: %s", extra_fn.__name__, exc)
+            logger.warning("Could not scan HF cache %s: %s", cache_root, exc)
     return scans
 
 
@@ -224,16 +204,8 @@ def _compose_partial(*signals: Callable[[], bool]) -> bool:
     return any(signal() for signal in signals)
 
 
-def _state_applies_to_repo_cache_dir(repo_cache_dir: Optional[Path]) -> bool:
-    if repo_cache_dir is None:
-        return True
-    root = hf_cache_root()
-    if root is None:
-        return False
-    try:
-        return repo_cache_dir.resolve().parent == root.resolve()
-    except OSError:
-        return False
+def _hub_cache_for_repo_dir(repo_cache_dir: Optional[Path]) -> Optional[Path]:
+    return repo_cache_dir.parent if repo_cache_dir is not None else None
 
 
 def _legacy_partial(
@@ -285,12 +257,24 @@ def _repo_cache_dir_has_non_gguf_broken_snapshot_symlinks(repo_cache_dir: Path)
     return False
 
 
-def _gguf_variant_manifest_blob_hashes(repo_id: str) -> frozenset[str]:
+def _gguf_variant_manifest_blob_hashes(
+    repo_id: str, repo_cache_dir: Optional[Path] = None
+) -> frozenset[str]:
     from hub.utils import download_manifest
 
     hashes: set[str] = set()
-    for variant, _path in download_manifest.iter_variant_manifests("model", repo_id):
-        manifest = download_manifest.read_manifest("model", repo_id, variant)
+    hub_cache = _hub_cache_for_repo_dir(repo_cache_dir)
+    for variant, _path in download_manifest.iter_variant_manifests(
+        "model",
+        repo_id,
+        hub_cache = hub_cache,
+    ):
+        manifest = download_manifest.read_manifest(
+            "model",
+            repo_id,
+            variant,
+            hub_cache = hub_cache,
+        )
         if manifest is None:
             continue
         for expected in manifest.expected_files:
@@ -315,7 +299,7 @@ def _snapshot_legacy_partial(
 ) -> bool:
     if repo_type != "model":
         return _legacy_partial(repo_type, repo_id, repo_cache_dir)
-    ignored_hashes = _gguf_variant_manifest_blob_hashes(repo_id)
+    ignored_hashes = _gguf_variant_manifest_blob_hashes(repo_id, repo_cache_dir)
     if repo_cache_dir is not None:
         return _repo_cache_dir_has_snapshot_legacy_partial(
             repo_cache_dir,
@@ -375,9 +359,12 @@ def _manifest_partial(
 ) -> bool:
     from hub.utils import download_manifest
 
-    if not _state_applies_to_repo_cache_dir(repo_cache_dir):
-        return False
-    manifest = download_manifest.read_manifest(repo_type, repo_id, variant)
+    manifest = download_manifest.read_manifest(
+        repo_type,
+        repo_id,
+        variant,
+        hub_cache = _hub_cache_for_repo_dir(repo_cache_dir),
+    )
     if manifest is None:
         return False
     resolved = (
@@ -452,10 +439,13 @@ def is_snapshot_partial(
     A manifest without a resolvable snapshot is partial: the worker got
     far enough to record expectations but did not leave a usable snapshot."""
     from hub.utils import download_manifest
-
-    state_applies = _state_applies_to_repo_cache_dir(repo_cache_dir)
     return _compose_partial(
-        lambda: state_applies and download_manifest.has_cancel_marker(repo_type, repo_id, None),
+        lambda: download_manifest.has_cancel_marker(
+            repo_type,
+            repo_id,
+            None,
+            hub_cache = _hub_cache_for_repo_dir(repo_cache_dir),
+        ),
         lambda: _snapshot_legacy_partial(repo_type, repo_id, repo_cache_dir),
         lambda: _manifest_partial(
             repo_type,
@@ -484,10 +474,13 @@ def is_variant_partial(
     caller is checking many variants of the same repo (see
     is_gguf_repo_partial for that usage)."""
     from hub.utils import download_manifest
-
-    state_applies = _state_applies_to_repo_cache_dir(repo_cache_dir)
     return _compose_partial(
-        lambda: state_applies and download_manifest.has_cancel_marker("model", repo_id, variant),
+        lambda: download_manifest.has_cancel_marker(
+            "model",
+            repo_id,
+            variant,
+            hub_cache = _hub_cache_for_repo_dir(repo_cache_dir),
+        ),
         lambda: bool(
             incomplete_blob_hashes
             and variant_blob_hashes
@@ -526,22 +519,38 @@ def is_gguf_repo_partial(repo_id: str, repo_cache_dir: Optional[Path] = None) ->
     from hub.utils import download_manifest
 
     has_legacy_partial = _legacy_partial("model", repo_id, repo_cache_dir)
-    state_applies = _state_applies_to_repo_cache_dir(repo_cache_dir)
     snapshot_dir = resolve_snapshot_dir_for_scan(
         "model",
         repo_id,
         repo_cache_dir,
     )
     variants: set[str] = set(_completed_gguf_variants(snapshot_dir))
-    if state_applies:
-        for variant, _path in download_manifest.iter_variant_manifests(
-            "model",
-            repo_id,
+    hub_cache = _hub_cache_for_repo_dir(repo_cache_dir)
+    for variant, _path in download_manifest.iter_variant_manifests(
+        "model",
+        repo_id,
+        hub_cache = hub_cache,
+    ):
+        if (
+            download_manifest.read_manifest(
+                "model",
+                repo_id,
+                variant,
+                hub_cache = hub_cache,
+            )
+            is not None
         ):
             variants.add(variant)
-        for variant, _path in download_manifest.iter_variant_markers(
+    for variant, _path in download_manifest.iter_variant_markers(
+        "model",
+        repo_id,
+        hub_cache = hub_cache,
+    ):
+        if download_manifest.has_cancel_marker(
             "model",
             repo_id,
+            variant,
+            hub_cache = hub_cache,
         ):
             variants.add(variant)
     if not variants:
@@ -576,14 +585,19 @@ def partial_transport_for(
     available."""
     from hub.utils import download_manifest
 
-    if not _state_applies_to_repo_cache_dir(repo_cache_dir):
-        return None
+    hub_cache = _hub_cache_for_repo_dir(repo_cache_dir)
     marker_transport = download_manifest.read_cancel_marker_transport(
         repo_type,
         repo_id,
         variant,
+        hub_cache = hub_cache,
     )
     if marker_transport is not None:
         return marker_transport
-    manifest = download_manifest.read_manifest(repo_type, repo_id, variant)
+    manifest = download_manifest.read_manifest(
+        repo_type,
+        repo_id,
+        variant,
+        hub_cache = hub_cache,
+    )
     return manifest.transport if manifest is not None else None
diff --git a/studio/backend/hub/utils/paths.py b/studio/backend/hub/utils/paths.py
index 5435202565..81621edcf9 100644
--- a/studio/backend/hub/utils/paths.py
+++ b/studio/backend/hub/utils/paths.py
@@ -277,12 +277,8 @@ def _memo_drop(memo_key: tuple[str, str]) -> None:
 
 
 def _hf_hub_cache_dir() -> Path:
-    try:
-        from huggingface_hub.constants import HF_HUB_CACHE
-        return Path(HF_HUB_CACHE)
-    except Exception as exc:
-        logger.debug("Could not read huggingface_hub HF_HUB_CACHE, using default: %s", exc)
-        return Path.home() / ".cache" / "huggingface" / "hub"
+    from utils.hf_cache_settings import get_hf_cache_paths
+    return get_hf_cache_paths().hub_cache
 
 
 def _hf_hub_cache_dirs() -> list[Path]:
@@ -300,7 +296,10 @@ def _hf_hub_cache_dirs() -> list[Path]:
         seen.add(key)
         roots.append(resolved)
 
-    _add(_hf_hub_cache_dir())
+    from utils.hf_cache_settings import known_hf_hub_caches
+
+    for configured in known_hf_hub_caches():
+        _add(configured)
     try:
         _add(legacy_hf_cache_dir())
         _add(hf_default_cache_dir())
diff --git a/studio/backend/hub/utils/state_dir.py b/studio/backend/hub/utils/state_dir.py
index 183e934724..4650b97381 100644
--- a/studio/backend/hub/utils/state_dir.py
+++ b/studio/backend/hub/utils/state_dir.py
@@ -3,14 +3,15 @@
 
 """Filesystem layout for Hub download state.
 
-State directory sits beside HF's cache (under Studio's own cache root)
+State directory sits beside HF's cache (under Unsloth's own cache root)
 so it survives ``huggingface-cli delete-cache`` and any other HF-side
 cache lifecycle. Two subdirectories:
 
     <studio cache>/hub-state/
-        manifests/   <key>.json   per-download expected-files manifest
-        cancelled/   <key>.json   per-download cancel marker
+        manifests/cache-<digest>/<key>.json   expected-files manifest
+        cancelled/cache-<digest>/<key>.json   cancel marker
 
+The cache digest isolates state for the same repo across selectable Hub caches.
 The ``<key>`` mirrors HF's cache dir naming while the resulting manifest,
 cancel-marker, and atomic-write temp filenames fit common filesystem basename
 limits. Very long repo IDs use a stable hash in the state key:
@@ -29,6 +30,7 @@ configuration failure.
 from __future__ import annotations
 
 import hashlib
+import os
 import re
 from pathlib import Path
 from typing import Literal, Optional, get_args
@@ -55,6 +57,7 @@ _STATE_EXTENSION = ".json"
 # _atomic_write_json writes ".<target>.tmp-<8hex>" beside the final file.
 _ATOMIC_WRITE_TMP_OVERHEAD = len(".") + len(".tmp-") + 8
 _MAX_VARIANT_FRAGMENT_LENGTH = 64
+_CACHE_SCOPE_DIGEST_LENGTH = 32
 
 
 def state_root() -> Optional[Path]:
@@ -130,13 +133,32 @@ def _entry_key(repo_type: RepoType, repo_id: str, variant: Optional[str]) -> str
     return f"{variant_filename_prefix(repo_type, repo_id)}{variant_fragment}"
 
 
+def _cache_scope(parent: Path, hub_cache: Optional[str | Path]) -> Optional[Path]:
+    if hub_cache is None:
+        return parent
+    normalized = os.path.normcase(str(Path(hub_cache).expanduser()))
+    digest = hashlib.sha256(normalized.encode("utf-8")).hexdigest()[:_CACHE_SCOPE_DIGEST_LENGTH]
+    scoped = parent / f"cache-{digest}"
+    try:
+        scoped.mkdir(parents = True, exist_ok = True)
+    except OSError as exc:
+        logger.debug("Could not create cache-scoped Hub state dir %s: %s", scoped, exc)
+        return None
+    return scoped
+
+
 def manifest_path(
     repo_type: RepoType,
     repo_id: str,
     variant: Optional[str] = None,
+    *,
+    hub_cache: Optional[str | Path] = None,
 ) -> Optional[Path]:
     """Path to the manifest file for this triple. May or may not exist."""
     parent = _subdir(_MANIFESTS_SUBDIR)
+    if parent is None:
+        return None
+    parent = _cache_scope(parent, hub_cache)
     if parent is None:
         return None
     return parent / f"{_entry_key(repo_type, repo_id, variant)}.json"
@@ -146,9 +168,14 @@ def marker_path(
     repo_type: RepoType,
     repo_id: str,
     variant: Optional[str] = None,
+    *,
+    hub_cache: Optional[str | Path] = None,
 ) -> Optional[Path]:
     """Path to the cancel-marker file for this triple. May or may not exist."""
     parent = _subdir(_CANCELLED_SUBDIR)
+    if parent is None:
+        return None
+    parent = _cache_scope(parent, hub_cache)
     if parent is None:
         return None
     return parent / f"{_entry_key(repo_type, repo_id, variant)}.json"
diff --git a/studio/backend/hub/workers/hf_download.py b/studio/backend/hub/workers/hf_download.py
index e45357d311..9ff394b009 100644
--- a/studio/backend/hub/workers/hf_download.py
+++ b/studio/backend/hub/workers/hf_download.py
@@ -661,6 +661,7 @@ def _download_gguf_variant(repo_id: str, variant: str, hf_token: str | None, mod
                 variant,
                 plan.main_hashes,
                 hf_token,
+                hub_cache = Path(snapshot_path).parents[2],
             )
         except Exception as e:
             print(
diff --git a/studio/backend/main.py b/studio/backend/main.py
index e64048dc00..5af25efa74 100644
--- a/studio/backend/main.py
+++ b/studio/backend/main.py
@@ -19,7 +19,7 @@ os.environ["PYTHONWARNINGS"] = "ignore"
 
 # Pin GPU index ordering to PCI bus id before any torch import creates a CUDA
 # context. Without this, torch/CUDA default to FASTEST_FIRST while nvidia-smi
-# (and Studio's VRAM probes) use PCI-bus order, so a GPU index chosen from
+# (and Unsloth's VRAM probes) use PCI-bus order, so a GPU index chosen from
 # nvidia-smi data can resolve to a different physical card via
 # CUDA_VISIBLE_DEVICES. setdefault so an explicit user override wins. See
 # utils/hardware/hardware.py for the full rationale; set here too so the entry
@@ -93,7 +93,7 @@ if sys.platform == "win32":
     # ── Windows AMD ROCm: make hipInfo.exe resolvable for subprocess probes ──
     # bitsandbytes' get_rocm_gpu_arch() runs `hipinfo.exe` via PATH at import
     # time; the AMD torch wheel ships it in the venv Scripts dir, which is on
-    # PATH only when the venv is activated -- Studio launches python directly.
+    # PATH only when the venv is activated -- Unsloth launches python directly.
     # Without this, every bitsandbytes import logs a scary (but harmless)
     # "Could not detect ROCm GPU architecture: [WinError 2]" ERROR + WARNING.
     # Gated on the file existing: only AMD ROCm wheels ship hipInfo.exe, so
@@ -252,7 +252,7 @@ def _read_studio_install_id() -> str:
 
     Returns "" when absent or not a 64-char lowercase-hex token; then
     /api/health emits "" and the launcher accepts any healthy backend.
-    Carries no install-path info (matters when Studio runs -H 0.0.0.0)."""
+    Carries no install-path info (matters when Unsloth runs -H 0.0.0.0)."""
     try:
         token = (_STUDIO_ROOT_RESOLVED / "share" / "studio_install_id").read_text().strip()
     except (OSError, ValueError):
@@ -289,6 +289,7 @@ from fastapi import Depends, FastAPI, HTTPException, Query, Request
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.staticfiles import StaticFiles
 from fastapi.responses import FileResponse, HTMLResponse, Response
+from starlette.middleware.gzip import GZipMiddleware
 from pathlib import Path
 from datetime import datetime
 
@@ -308,11 +309,14 @@ from routes import (
     training_router,
 )
 from routes.llama import router as llama_router
+from routes.whisper import router as whisper_router
 from routes.preview import router as preview_router
 from hub.routes import (
     inventory_router as hub_inventory_router,
     datasets_router as hub_datasets_router,
+    token_router as hub_token_router,
 )
+from picker.routes import templates_router as picker_templates_router
 from hub.schemas.downloads import TransportCapabilities
 from hub.utils.download_registry import (
     get_download_transport_capabilities,
@@ -434,7 +438,11 @@ def _run_llama_cpp_startup_probes(app: FastAPI) -> None:
         import structlog as _structlog
 
         _log = _structlog.get_logger(__name__)
-        if _caps.get("found") and not _caps.get("supports_mtp"):
+        if (
+            _caps.get("found")
+            and not _caps.get("supports_mtp")
+            and not _caps.get("mtp_probe_inconclusive")
+        ):
             _msg = (
                 "llama.cpp prebuilt lacks MTP support "
                 "(--spec-type mtp/draft-mtp). Run `unsloth studio update`. "
@@ -547,8 +555,9 @@ async def lifespan(app: FastAPI):
     threading.Thread(target = _warm_rag_embedder, daemon = True, name = "rag-embedder-warm").start()
 
     # Idle auto-unload loop (no-op unless the OpenAI auto-unload TTL is set).
-    from core.inference.llama_keepwarm import idle_unload_loop
+    from core.inference.llama_keepwarm import idle_unload_loop, sweep_slot_save_dir
 
+    sweep_slot_save_dir()
     app.state.idle_unload_task = asyncio.create_task(idle_unload_loop())
 
     # Initialize RSA key pair for API key encryption (external providers).
@@ -573,7 +582,7 @@ async def lifespan(app: FastAPI):
         print("DEFAULT ADMIN ACCOUNT CREATED")
         print(f"    username: {storage.DEFAULT_ADMIN_USERNAME}")
         print(f"    password saved to: {bootstrap_path}")
-        print("    Open the Studio UI to sign in and change it.")
+        print("    Open the Unsloth UI to sign in and change it.")
         print("=" * 60 + "\n")
     else:
         app.state.bootstrap_password = (
@@ -612,6 +621,22 @@ app = FastAPI(
     lifespan = lifespan,
 )
 
+# The MCP surface is opt-in because it can start GPU jobs and write model
+# artifacts. Mount it only when explicitly enabled by the Unsloth process.
+if os.environ.get("UNSLOTH_STUDIO_ENABLE_MCP") == "1":
+    from fastmcp.utilities.lifespan import combine_lifespans
+
+    from mcp_server import BearerTokenMiddleware, create_studio_mcp
+
+    _studio_mcp_app = create_studio_mcp().http_app(path = "/")
+    _studio_mcp_lifespan = _studio_mcp_app.lifespan
+    _mcp_token = os.environ.get("UNSLOTH_STUDIO_MCP_TOKEN")
+    if not _mcp_token:
+        raise RuntimeError("UNSLOTH_STUDIO_MCP_TOKEN is required when MCP is enabled")
+    _studio_mcp_app = BearerTokenMiddleware(_studio_mcp_app, _mcp_token)
+    app.router.lifespan_context = combine_lifespans(lifespan, _studio_mcp_lifespan)
+    app.mount("/mcp", _studio_mcp_app)
+
 from loggers.config import LogConfig
 from loggers.handlers import LoggingMiddleware
 
@@ -735,6 +760,8 @@ app.add_middleware(SecurityHeadersMiddleware)
 # headroom; non-upload routes keep the default body cap.
 import json as _json_for_413  # noqa: E402
 from utils.upload_limits import (  # noqa: E402
+    STT_AUDIO_JSON_MAX_BYTES,
+    STT_AUDIO_RAW_MAX_BYTES,
     UNSTRUCTURED_RECIPE_UPLOAD_MAX_BYTES,
     default_request_body_limit_bytes,
     upload_request_limit_bytes,
@@ -745,6 +772,7 @@ _BODY_PROTECTED_PREFIXES = (
     "/v1/completions",
     "/p/",
     "/api/inference",
+    "/api/picker",
     "/api/data-recipe",
     "/api/datasets",
     "/api/hub",
@@ -752,6 +780,7 @@ _BODY_PROTECTED_PREFIXES = (
     "/api/settings",
     "/api/train",
     "/api/export",
+    "/mcp",
 )
 _DATASET_UPLOAD_PASSTHROUGH_PREFIX = "/api/datasets/upload"
 _DATA_RECIPE_UNSTRUCTURED_UPLOAD_PASSTHROUGH_PREFIX = (
@@ -771,6 +800,14 @@ def _get_upload_passthrough_request_max_bytes(path: str) -> int:
     return default_request_body_limit_bytes()
 
 
+def _get_request_body_max_bytes(path: str) -> int:
+    if path.startswith("/api/inference/audio/transcribe/raw"):
+        return STT_AUDIO_RAW_MAX_BYTES
+    if path.startswith("/api/inference/audio/transcribe"):
+        return STT_AUDIO_JSON_MAX_BYTES
+    return default_request_body_limit_bytes()
+
+
 async def _send_411(send) -> None:
     payload = _json_for_413.dumps(
         {"detail": "Content-Length required for upload requests."},
@@ -813,12 +850,14 @@ class MaxBodyMiddleware:
         app,
         max_bytes_getter,
         protected_prefixes: tuple,
+        request_max_bytes_getter = None,
         upload_passthrough_prefixes: tuple = (),
         upload_passthrough_max_bytes_getter = None,
     ):
         self.app = app
         self.max_bytes_getter = max_bytes_getter
         self.protected_prefixes = protected_prefixes
+        self.request_max_bytes_getter = request_max_bytes_getter
         self.upload_passthrough_prefixes = upload_passthrough_prefixes
         self.upload_passthrough_max_bytes_getter = upload_passthrough_max_bytes_getter
 
@@ -835,6 +874,14 @@ class MaxBodyMiddleware:
         except Exception:
             return int(self.max_bytes_getter())
 
+    def _request_max_bytes(self, path: str) -> int:
+        if self.request_max_bytes_getter is None:
+            return int(self.max_bytes_getter())
+        try:
+            return int(self.request_max_bytes_getter(path))
+        except Exception:
+            return int(self.max_bytes_getter())
+
     async def __call__(self, scope, receive, send):
         if scope["type"] != "http":
             await self.app(scope, receive, send)
@@ -847,7 +894,7 @@ class MaxBodyMiddleware:
             await self.app(scope, receive, send)
             return
 
-        max_bytes = int(self.max_bytes_getter())
+        max_bytes = self._request_max_bytes(path)
         declared = None
         for name, value in scope.get("headers", []):
             if name == b"content-length":
@@ -912,6 +959,7 @@ app.add_middleware(
     MaxBodyMiddleware,
     max_bytes_getter = default_request_body_limit_bytes,
     protected_prefixes = _BODY_PROTECTED_PREFIXES,
+    request_max_bytes_getter = _get_request_body_max_bytes,
     upload_passthrough_prefixes = _BODY_UPLOAD_PASSTHROUGH_PREFIXES,
     upload_passthrough_max_bytes_getter = _get_upload_passthrough_request_max_bytes,
 )
@@ -956,7 +1004,7 @@ app.include_router(training_router, prefix = "/api/train", tags = ["training"])
 app.include_router(models_router, prefix = "/api/models", tags = ["models"])
 app.include_router(chat_history_router, prefix = "/api/chat", tags = ["chat"])
 app.include_router(inference_router, prefix = "/api/inference", tags = ["inference"])
-# Studio-only inference endpoints (cancel, etc.) are NOT exposed on the /v1
+# Unsloth-only inference endpoints (cancel, etc.) are NOT exposed on the /v1
 # OpenAI-compat prefix below.
 app.include_router(inference_studio_router, prefix = "/api/inference", tags = ["inference"])
 
@@ -970,11 +1018,14 @@ app.include_router(prompts_router, prefix = "/api/prompts", tags = ["prompts"])
 app.include_router(datasets_router, prefix = "/api/datasets", tags = ["datasets"])
 app.include_router(data_recipe_router, prefix = "/api/data-recipe", tags = ["data-recipe"])
 app.include_router(llama_router, prefix = "/api/llama", tags = ["llama"])
+app.include_router(whisper_router, prefix = "/api/whisper", tags = ["whisper"])
 app.include_router(export_router, prefix = "/api/export", tags = ["export"])
 app.include_router(rag_router, prefix = "/api/rag", tags = ["rag"])
 app.include_router(training_history_router, prefix = "/api/train", tags = ["training-history"])
 app.include_router(hub_inventory_router, prefix = "/api/hub", tags = ["hub"])
 app.include_router(hub_datasets_router, prefix = "/api/hub/datasets", tags = ["hub"])
+app.include_router(picker_templates_router, prefix = "/api/picker", tags = ["picker"])
+app.include_router(hub_token_router, prefix = "/api/hub", tags = ["hub"])
 
 # Re-wrap client-error responses on the /v1/* surface into OpenAI/Anthropic
 # error envelopes; non-/v1 paths keep FastAPI's default {"detail": ...} shape.
@@ -1063,7 +1114,7 @@ def studio_install_source(_current_subject: str = Depends(get_current_subject)):
 
 @app.get("/api/studio/update-status")
 def studio_update_status(_current_subject: str = Depends(get_current_subject)):
-    """Return source-aware manual update status for browser-served Studio."""
+    """Return source-aware manual update status for browser-served Unsloth."""
     return get_studio_update_status(UNSLOTH_VERSION)
 
 
@@ -1131,17 +1182,35 @@ def _get_cached_system_gpu_info(logger) -> dict[str, Any]:
             util = util_devices.get(idx, {})
 
             total_vram = util.get("vram_total_gb") or dev.get("memory_total_gb") or 0
-            used_vram = util.get("vram_used_gb") or 0
+            # Keep None (usage unknown, e.g. Windows ROCm perf counter) so the UI
+            # shows unknown, not a fabricated 0 used / full free.
+            used_vram = util.get("vram_used_gb")
 
             enriched_dev = dict(dev)
             enriched_dev["vram_used_gb"] = used_vram
-            enriched_dev["vram_free_gb"] = round(total_vram - used_vram, 2) if total_vram else 0
+            enriched_dev["vram_free_gb"] = (
+                round(total_vram - used_vram, 2) if total_vram and used_vram is not None else None
+            )
             enriched_dev["vram_utilization_pct"] = util.get("vram_utilization_pct")
             enriched_devices.append(enriched_dev)
 
+        # Whether GGUF loads accept an explicit gpu_ids pick: /load and
+        # /validate 400 picks on XPU hosts (no visibility mask speaks torch-xpu
+        # ordinals) and on Vulkan-only builds (--device pins ggml's own
+        # ordinals), so the picker must not offer them.
+        try:
+            from core.inference.llama_cpp import LlamaCppBackend
+            from utils.hardware import DeviceType, get_device
+            gpu_ids_supported = (
+                get_device() != DeviceType.XPU and not LlamaCppBackend._is_vulkan_backend()
+            )
+        except Exception as e:
+            logger.debug(f"Could not resolve gpu_ids support: {e}")
+            gpu_ids_supported = True
         gpu_info = {
             "available": visibility_info.get("available", False),
             "devices": enriched_devices,
+            "gguf_gpu_ids_supported": gpu_ids_supported,
         }
         _system_gpu_cache = (time.monotonic(), gpu_info)
         return gpu_info
@@ -1471,6 +1540,34 @@ def _should_inject_bootstrap(request: Request) -> bool:
     return _is_local_bootstrap_request(request)
 
 
+_IMMUTABLE_ASSET_CACHE_CONTROL = "public, max-age=31536000, immutable"
+
+
+class ImmutableStaticFiles(StaticFiles):
+    """Serve Vite's content-hashed assets without browser revalidation."""
+
+    def file_response(
+        self,
+        full_path,
+        stat_result,
+        scope,
+        status_code = 200,
+    ):
+        response = super().file_response(full_path, stat_result, scope, status_code)
+        response.headers["Cache-Control"] = _IMMUTABLE_ASSET_CACHE_CONTROL
+        return response
+
+
+class _AssetGZipMiddleware(GZipMiddleware):
+    """Serve range requests uncompressed; gzip + 206 mislabels Content-Range."""
+
+    async def __call__(self, scope, receive, send):
+        if scope["type"] == "http" and any(key == b"range" for key, _ in scope["headers"]):
+            await self.app(scope, receive, send)
+            return
+        await super().__call__(scope, receive, send)
+
+
 def setup_frontend(app: FastAPI, build_path: Path):
     """Mount frontend static files (optional)"""
     if not build_path.exists():
@@ -1478,7 +1575,12 @@ def setup_frontend(app: FastAPI, build_path: Path):
 
     assets_dir = build_path / "assets"
     if assets_dir.exists():
-        app.mount("/assets", StaticFiles(directory = assets_dir), name = "assets")
+        assets_app = _AssetGZipMiddleware(
+            ImmutableStaticFiles(directory = assets_dir),
+            minimum_size = 1024,
+            compresslevel = 6,
+        )
+        app.mount("/assets", assets_app, name = "assets")
 
     def _build_index_response(request: Request) -> Response:
         content = (build_path / "index.html").read_bytes()
diff --git a/studio/backend/mcp_server.py b/studio/backend/mcp_server.py
new file mode 100644
index 0000000000..e93490411d
--- /dev/null
+++ b/studio/backend/mcp_server.py
@@ -0,0 +1,259 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Curated MCP tools for driving an Unsloth Studio instance.
+
+The MCP surface deliberately wraps the existing Unsloth services instead of
+duplicating training or export logic. It is opt-in because several tools can
+start GPU work or write model artifacts.
+"""
+
+from __future__ import annotations
+
+import hmac
+from typing import Any
+
+from fastmcp import FastMCP
+
+
+class BearerTokenMiddleware:
+    """Require an exact bearer token when Unsloth MCP is exposed remotely."""
+
+    def __init__(self, app: Any, token: str) -> None:
+        if not token or not token.strip():
+            raise ValueError("Unsloth MCP bearer token must be a non-empty value")
+        if not token.isascii():
+            # A non-ASCII token cannot be sent in an HTTP header; reject it here.
+            raise ValueError("Unsloth MCP bearer token must contain ASCII characters only")
+        self.app = app
+        # Compare on raw header bytes: str hmac.compare_digest raises on non-ASCII
+        # input, which would surface as a 500 instead of a clean 401.
+        self.expected = token.encode("utf-8")
+
+    async def __call__(self, scope: dict[str, Any], receive: Any, send: Any) -> None:
+        scope_type = scope.get("type")
+        if scope_type not in ("http", "websocket"):
+            await self.app(scope, receive, send)
+            return
+
+        headers = dict(scope.get("headers", []))
+        raw_auth = headers.get(b"authorization", b"")
+        scheme, _, supplied = raw_auth.partition(b" ")
+        if scheme.lower() != b"bearer" or not hmac.compare_digest(supplied, self.expected):
+            await _send_unauthorized(send, scope_type)
+            return
+
+        await self.app(scope, receive, send)
+
+
+async def _send_unauthorized(send: Any, scope_type: str) -> None:
+    if scope_type == "websocket":
+        await send({"type": "websocket.close", "code": 4401})
+        return
+
+    await send(
+        {
+            "type": "http.response.start",
+            "status": 401,
+            "headers": [(b"content-type", b"application/json"), (b"www-authenticate", b"Bearer")],
+        }
+    )
+    await send(
+        {
+            "type": "http.response.body",
+            "body": b'{"detail":"MCP bearer token required"}',
+        }
+    )
+
+
+def _dump(value: Any) -> Any:
+    """Convert Pydantic responses to plain JSON values for MCP clients."""
+    if hasattr(value, "model_dump"):
+        return value.model_dump(mode = "json")
+    return value
+
+
+def _clamp(value: int, low: int, high: int) -> int:
+    """Clamp an MCP-supplied integer into an inclusive range.
+
+    MCP tools call the Unsloth route functions directly, which skips FastAPI's
+    Query(ge=, le=) validation, so we re-apply the same bounds here.
+    """
+    return max(low, min(value, high))
+
+
+def create_studio_mcp() -> FastMCP:
+    """Create the Unsloth MCP server and register the high-value tools."""
+    mcp = FastMCP(
+        "Unsloth Studio",
+        instructions = (
+            "Use read tools to inspect the local Unsloth state before starting GPU work. "
+            "Training and export tools can consume substantial VRAM and write files. "
+            "Never expose tokens or local paths from tool results unless the user asks."
+        ),
+    )
+
+    @mcp.tool
+    async def studio_status() -> dict[str, Any]:
+        """Return the current training, export, inference, and GPU state."""
+        from routes.export import get_export_status
+        from routes.inference import get_status as get_inference_status
+        from routes.training import get_training_status
+
+        from utils.hardware import get_gpu_utilization
+
+        training, export, inference = await _gather_status(
+            get_training_status(current_subject = "mcp"),
+            get_export_status(current_subject = "mcp"),
+            get_inference_status(current_subject = "mcp"),
+        )
+        return {
+            "training": _dump(training),
+            "export": _dump(export),
+            "inference": _dump(inference),
+            "hardware": get_gpu_utilization(),
+        }
+
+    @mcp.tool
+    async def list_local_models(models_dir: str = "./models") -> dict[str, Any]:
+        """List local and cached models available to Unsloth."""
+        from routes.models import list_local_models as list_models
+        return _dump(await list_models(models_dir = models_dir, current_subject = "mcp"))
+
+    @mcp.tool
+    async def get_training_status() -> dict[str, Any]:
+        """Read the active training job, phase, progress, and recent metrics."""
+        from routes.training import get_training_status as get_status
+        return _dump(await get_status(current_subject = "mcp"))
+
+    @mcp.tool
+    async def start_training(config: dict[str, Any]) -> dict[str, Any]:
+        """Start a validated Unsloth training job from a TrainingStartRequest-shaped object.
+
+        The config is validated by the same Pydantic model used by the Unsloth UI.
+        Call get_training_status first and do not start work while another job runs.
+        """
+        from models import TrainingStartRequest
+        from routes.training import start_training as start
+
+        request = TrainingStartRequest.model_validate(config)
+        # Pass via_api_key explicitly (a direct call leaves it a Depends object).
+        # MCP drives Unsloth like the UI session, so it coexists and frees VRAM.
+        return _dump(await start(request, current_subject = "mcp", via_api_key = False))
+
+    @mcp.tool
+    async def stop_training(save: bool = True) -> dict[str, Any]:
+        """Ask the active training process to stop at its next safe checkpoint."""
+        from routes.training import TrainingStopRequest, stop_training as stop
+        return _dump(await stop(TrainingStopRequest(save = save), current_subject = "mcp"))
+
+    @mcp.tool
+    async def list_training_runs(limit: int = 50, offset: int = 0) -> dict[str, Any]:
+        """List completed and stopped training runs, newest first."""
+        from routes.training_history import list_training_runs as list_runs
+
+        # Clamp here (direct call skips Query bounds); a negative LIMIT = no limit.
+        limit = _clamp(limit, 1, 200)
+        offset = max(0, offset)
+        return _dump(await list_runs(limit = limit, offset = offset, current_subject = "mcp"))
+
+    @mcp.tool
+    def validate_recipe(recipe: dict[str, Any]) -> dict[str, Any]:
+        """Validate a Data Recipe with the same validator used by Unsloth."""
+        from models.data_recipe import RecipePayload
+        from routes.data_recipe.validate import validate
+
+        return _dump(validate(RecipePayload(recipe = recipe)))
+
+    @mcp.tool
+    def get_recipe_job_status(job_id: str) -> dict[str, Any]:
+        """Read the status of a Data Recipe job."""
+        from routes.data_recipe.jobs import job_status
+        return _dump(job_status(job_id))
+
+    @mcp.tool
+    def get_recipe_job_dataset(
+        job_id: str,
+        limit: int = 20,
+        offset: int = 0,
+    ) -> dict[str, Any]:
+        """Read a bounded page of generated Data Recipe rows."""
+        from routes.data_recipe.jobs import job_dataset
+
+        # Clamp here (direct call skips FastAPI's Query bounds).
+        limit = _clamp(limit, 1, 500)
+        offset = max(0, offset)
+        return _dump(job_dataset(job_id, limit = limit, offset = offset))
+
+    @mcp.tool
+    async def load_checkpoint(
+        checkpoint_path: str,
+        max_seq_length: int = 2048,
+        load_in_4bit: bool = True,
+        trust_remote_code: bool = False,
+        approved_remote_code_fingerprint: str | None = None,
+        hf_token: str | None = None,
+    ) -> dict[str, Any]:
+        """Load a checkpoint into the export backend.
+
+        Export runs in its own subprocess and coexists with training and
+        inference; it does not unload them, so a load can fail with a clear
+        out-of-memory error if the GPU is already full. Pass hf_token to load a
+        gated checkpoint, and approved_remote_code_fingerprint to retry a
+        trust_remote_code load that was blocked pending review.
+        """
+        from models import LoadCheckpointRequest
+        from routes.export import load_checkpoint as load
+
+        request = LoadCheckpointRequest(
+            checkpoint_path = checkpoint_path,
+            max_seq_length = max_seq_length,
+            load_in_4bit = load_in_4bit,
+            trust_remote_code = trust_remote_code,
+            approved_remote_code_fingerprint = approved_remote_code_fingerprint,
+            hf_token = hf_token,
+        )
+        return _dump(await load(request, current_subject = "mcp"))
+
+    @mcp.tool
+    async def export_gguf(
+        save_directory: str,
+        quantization_method: str | list[str] = "Q4_K_M",
+        push_to_hub: bool = False,
+        repo_id: str | None = None,
+        hf_token: str | None = None,
+        imatrix: bool = False,
+        imatrix_path: str | None = None,
+    ) -> dict[str, Any]:
+        """Export the loaded model to GGUF using Unsloth's existing path validation.
+
+        quantization_method may be a single method or a list to produce several
+        GGUFs from one load. Pass hf_token when push_to_hub is set (the backend
+        rejects a Hub upload without it). Set imatrix (or imatrix_path) for the
+        IQ low-bit quants that require an importance matrix.
+        """
+        from models import ExportGGUFRequest
+        from routes.export import export_gguf as export
+
+        request = ExportGGUFRequest(
+            save_directory = save_directory,
+            quantization_method = quantization_method,
+            push_to_hub = push_to_hub,
+            repo_id = repo_id,
+            hf_token = hf_token,
+            imatrix = imatrix,
+            imatrix_path = imatrix_path,
+        )
+        return _dump(await export(request, current_subject = "mcp"))
+
+    return mcp
+
+
+async def _gather_status(*coroutines: Any) -> tuple[Any, ...]:
+    """Gather independent status calls without letting one optional backend fail all state."""
+    import asyncio
+
+    results = await asyncio.gather(*coroutines, return_exceptions = True)
+    return tuple(
+        {"error": str(result)} if isinstance(result, Exception) else result for result in results
+    )
diff --git a/studio/backend/models/inference.py b/studio/backend/models/inference.py
index 3ae974448e..1758efe515 100644
--- a/studio/backend/models/inference.py
+++ b/studio/backend/models/inference.py
@@ -18,6 +18,8 @@ from pydantic import (
     model_validator,
 )
 
+from picker.schemas import MAX_CHAT_TEMPLATE_BYTES
+
 
 class LoadRequest(BaseModel):
     """Request to load a model for inference"""
@@ -54,17 +56,37 @@ class LoadRequest(BaseModel):
     @field_validator("chat_template_override")
     @classmethod
     def normalize_blank_chat_template_override(cls, value: Optional[str]) -> Optional[str]:
-        if value is not None and value.strip() == "":
+        if value is None:
             return None
+        # Char count is a lower bound on UTF-8 byte length: reject an oversized
+        # template before spending work encoding it.
+        if len(value) > MAX_CHAT_TEMPLATE_BYTES:
+            raise ValueError(f"Chat template exceeds the {MAX_CHAT_TEMPLATE_BYTES}-byte limit.")
+        if value.strip() == "":
+            return None
+        if len(value.encode("utf-8")) > MAX_CHAT_TEMPLATE_BYTES:
+            raise ValueError(f"Chat template exceeds the {MAX_CHAT_TEMPLATE_BYTES}-byte limit.")
         return value
 
     cache_type_kv: Optional[str] = Field(
         None,
-        description = "KV cache data type for both K and V (e.g. 'f16', 'bf16', 'q8_0', 'q4_1', 'q5_1')",
+        description = (
+            "KV cache data type for both K and V "
+            "(e.g. 'f16', 'bf16', 'q8_0', 'q4_0', 'q4_1', 'q5_0', 'q5_1', 'iq4_nl', 'f32')"
+        ),
     )
     gpu_ids: Optional[List[int]] = Field(
         None,
-        description = "Physical GPU indices to use, for example [0, 1]. Omit or pass [] to use automatic selection. Explicit gpu_ids are unsupported when the parent CUDA_VISIBLE_DEVICES uses UUID/MIG entries. Not supported for GGUF models.",
+        description = (
+            "GPU placement pool, for example [0, 1]. Omit or pass [] to use "
+            "automatic selection. CUDA/ROCm and Intel XPU values are physical "
+            "GPU indices; Vulkan values are ggml device ordinals. Explicit "
+            "physical IDs are unsupported when the parent visibility mask uses "
+            "non-numeric or subdevice entries, including CUDA_VISIBLE_DEVICES "
+            "with UUID/MIG entries and ZE_AFFINITY_MASK with subdevice tokens "
+            "(for example '0.0,0.1') or FLAT-hierarchy tile handles. For GGUF "
+            "models the fitter may pin the smallest subset of this pool that fits."
+        ),
     )
     speculative_type: Optional[str] = Field(
         None,
@@ -100,12 +122,72 @@ class LoadRequest(BaseModel):
             "No effect on a single GPU. Ignored for non-GGUF models."
         ),
     )
+    gpu_memory_mode: Literal["auto", "manual"] = Field(
+        "auto",
+        description = (
+            "GPU memory strategy for GGUF models. 'auto' (default): Unsloth "
+            "selects GPUs and caps context to fit VRAM. 'manual': you own the "
+            "offload. Leave gpu_layers at -1 (Auto) to hand memory management to "
+            "llama.cpp's --fit (no device masking, no context auto-reduce, no "
+            "gpu-layer/tensor-split planning); set gpu_layers >= 0 to pin layers "
+            "and n_cpu_moe yourself (--fit off), with tensor_parallel still "
+            "applying (split by free VRAM unless tensor_split is set, no planner). "
+            "Ignored for non-GGUF."
+        ),
+    )
+    gpu_layers: int = Field(
+        -1,
+        ge = -1,
+        description = (
+            "Manual mode only: number of layers to offload to the GPU "
+            "(--gpu-layers, with --fit off). A value >= the model's layer count "
+            "offloads all of them. -1 = Auto: hand layer + context sizing to "
+            "llama.cpp's --fit. Ignored unless gpu_memory_mode is 'manual'."
+        ),
+    )
+    n_cpu_moe: int = Field(
+        0,
+        ge = 0,
+        description = (
+            "Manual mode only: keep the first N MoE expert layers on the CPU "
+            "(--n-cpu-moe) to save VRAM on MoE models. 0 = none, N = number of "
+            "MoE layers offloaded (the backend offsets past any leading dense "
+            "layers). Ignored unless gpu_memory_mode is 'manual' with gpu_layers >= 0."
+        ),
+    )
+    tensor_split: Optional[List[float]] = Field(
+        None,
+        description = (
+            "Manual mode only: relative share of the model per GPU (--tensor-split), "
+            "in the order of the GPUs in use, e.g. [2, 1] for 2:1. Omit it to let "
+            "llama.cpp use its default, which splits by free VRAM. Any list given is "
+            "passed through as-is, so send [1, 1] to force an even split. Ignored "
+            "unless gpu_memory_mode is 'manual' with gpu_layers >= 0."
+        ),
+    )
+
+    @field_validator("tensor_split")
+    @classmethod
+    def _reject_degenerate_tensor_split(cls, value: Optional[List[float]]) -> Optional[List[float]]:
+        # A negative / non-finite / all-zero split is silently dropped at launch
+        # (stored as None) yet still compared raw in the reload dedupe, so an
+        # identical Apply reloads forever. Reject it up front; [] = no split.
+        if not value:
+            return value
+        import math
+
+        if any((not math.isfinite(v)) or v < 0 for v in value):
+            raise ValueError("tensor_split entries must be finite and non-negative")
+        if sum(value) <= 0:
+            raise ValueError("tensor_split must have a positive total")
+        return value
+
     llama_extra_args: Optional[List[str]] = Field(
         None,
         description = (
             "Extra arguments forwarded verbatim to llama-server for GGUF models. "
             "One token per list entry, e.g. ['--top-k', '20', '--seed', '42']. "
-            "Studio-managed flags (model identity, port, context length, GPU placement, "
+            "Unsloth-managed flags (model identity, port, context length, GPU placement, "
             "auth, UI/server mode) are rejected. Ignored for non-GGUF models."
         ),
     )
@@ -117,6 +199,32 @@ class UnloadRequest(BaseModel):
     model_path: str = Field(..., description = "Model identifier to unload")
 
 
+class TranscribeRequest(BaseModel):
+    """Speech-to-text request for the dictation STT sidecar."""
+
+    audio: str = Field(..., description = "Base64-encoded audio (any common format)")
+    model: Optional[str] = Field(None, description = "STT model id; defaults server-side")
+    language: Optional[str] = Field(None, description = "BCP-47 language, or 'auto'/None to detect")
+    fast: bool = Field(
+        False,
+        description = "Use low-latency single-candidate decoding for dictation",
+    )
+    engine: Optional[str] = Field(
+        None,
+        description = "STT engine: 'transformers' (default) or 'gguf' (whisper.cpp)",
+    )
+
+
+class SttLoadRequest(BaseModel):
+    """Warm the STT sidecar with a model without transcribing."""
+
+    model: Optional[str] = Field(None, description = "STT model id; defaults server-side")
+    engine: Optional[str] = Field(
+        None,
+        description = "STT engine: 'transformers' (default) or 'gguf' (whisper.cpp)",
+    )
+
+
 class ValidateModelRequest(BaseModel):
     """Check whether an identifier resolves to a ModelConfig; does NOT load weights."""
 
@@ -133,11 +241,26 @@ class ValidateModelRequest(BaseModel):
     max_seq_length: int = Field(0, ge = 0, le = 1048576)
     load_in_4bit: bool = Field(True)
     gpu_ids: Optional[List[int]] = Field(None)
+    gpu_memory_mode: Literal["auto", "manual"] = Field(
+        "auto",
+        description = (
+            "GGUF GPU-memory strategy intended for the follow-up load. Manual "
+            "placement bypasses the training coexistence estimate: Auto layers "
+            "delegate fitting to llama.cpp, while explicit layers are user-owned."
+        ),
+    )
     include_context_length: bool = Field(
         False,
         description = "Also read the native context length from the local GGUF header. "
         "Opt-in so the normal load preflight doesn't pay for a cache scan it doesn't need.",
     )
+    include_chat_template: bool = Field(
+        False,
+        description = "Also read the embedded chat template from the local GGUF header, so a "
+        "native (picked / drag-drop) file's default template can be shown before it is loaded. "
+        "Opt-in and, like include_context_length, a metadata-only probe that skips the training "
+        "guard. Only the leased file's own embedded template is read, never sibling sidecars.",
+    )
 
 
 class TransformersUpgradeInfo(BaseModel):
@@ -151,13 +274,13 @@ class TransformersUpgradeInfo(BaseModel):
     )
     supported_in_pypi: bool = Field(
         False,
-        description = "True if the latest PyPI release ships this model_type; Studio can "
+        description = "True if the latest PyPI release ships this model_type; Unsloth can "
         "install it into a persistent sidecar after user consent.",
     )
     supported_in_main: bool = Field(
         False,
         description = "True if transformers GitHub main ships this model_type (dev-only; "
-        "not installable through Studio yet).",
+        "not installable through Unsloth yet).",
     )
 
 
@@ -188,6 +311,21 @@ class ValidateModelResponse(BaseModel):
         description = "Native training context length, read from the GGUF header when the file "
         "is already downloaded locally; None for non-GGUF, gated, or not-yet-downloaded models.",
     )
+    layer_count: Optional[int] = Field(
+        None,
+        description = "Total layer count (GGUF block_count), the manual gpu-layers ceiling, read "
+        "from the header alongside context_length; None when not read.",
+    )
+    moe_layer_count: Optional[int] = Field(
+        None,
+        description = "MoE expert-layer count (the manual --n-cpu-moe ceiling), read from the GGUF "
+        "header alongside context_length; 0 for dense models, None when not read.",
+    )
+    chat_template: Optional[str] = Field(
+        None,
+        description = "Embedded GGUF chat template, read from the header when include_chat_template "
+        "is set (native lease-backed picks); None for non-GGUF, over-cap, or not-read templates.",
+    )
     # Additive fields; the consuming consent dialog ships in a follow-up frontend PR.
     requires_transformers_upgrade: bool = Field(
         False,
@@ -307,7 +445,10 @@ class LoadResponse(BaseModel):
     )
     cache_type_kv: Optional[str] = Field(
         None,
-        description = "KV cache data type for K and V (e.g. 'f16', 'bf16', 'q8_0')",
+        description = (
+            "KV cache data type for K and V "
+            "(e.g. 'f16', 'bf16', 'q8_0', 'q4_0', 'q4_1', 'q5_0', 'q5_1', 'iq4_nl', 'f32')"
+        ),
     )
     chat_template: Optional[str] = Field(
         None,
@@ -333,6 +474,41 @@ class LoadResponse(BaseModel):
         False,
         description = "Whether tensor-parallel split (--split-mode tensor) is active.",
     )
+    gpu_memory_mode: Literal["auto", "manual"] = Field(
+        "auto",
+        description = "Active GPU memory strategy ('auto' or 'manual').",
+    )
+    gpu_layers: int = Field(
+        -1,
+        description = "Manual mode: requested --gpu-layers value (-1 = Auto/--fit, or when not manual).",
+    )
+    n_cpu_moe: int = Field(
+        0,
+        description = "Manual mode: MoE expert layers pinned to CPU (--n-cpu-moe); 0 = none.",
+    )
+    tensor_split: Optional[List[float]] = Field(
+        None,
+        description = "Manual mode: relative model share per GPU (--tensor-split); None = default (split by free VRAM).",
+    )
+    n_layers: Optional[int] = Field(
+        None,
+        description = "Model's layer count (GGUF block_count), for the manual gpu-layers ceiling.",
+    )
+    n_moe_layers: int = Field(
+        0,
+        description = "Model's MoE expert-layer count (the n_cpu_moe ceiling); 0 if not an MoE model.",
+    )
+    gpu_ids: Optional[List[int]] = Field(
+        None,
+        description = "Effective GPU indices the model is using after fit-time narrowing, or None for automatic selection.",
+    )
+    requested_gpu_ids: Optional[List[int]] = Field(
+        None,
+        description = (
+            "GPU placement pool requested by the user before fit-time narrowing, "
+            "or None for automatic selection."
+        ),
+    )
 
 
 class UnloadResponse(BaseModel):
@@ -432,7 +608,11 @@ class InferenceStatusResponse(BaseModel):
     )
     cache_type_kv: Optional[str] = Field(
         None,
-        description = "KV cache quantization dtype (e.g. 'q8_0'), or None for default",
+        description = (
+            "KV cache quantization dtype "
+            "(e.g. 'f16', 'bf16', 'q8_0', 'q4_0', 'q4_1', 'q5_0', 'q5_1', 'iq4_nl', 'f32'), "
+            "or None for default"
+        ),
     )
     chat_template: Optional[str] = Field(
         None, description = "Model's default chat template (Jinja2 source), if any"
@@ -461,6 +641,49 @@ class InferenceStatusResponse(BaseModel):
         False,
         description = "Whether tensor-parallel split (--split-mode tensor) is active.",
     )
+    gpu_memory_mode: Literal["auto", "manual"] = Field(
+        "auto",
+        description = "Active GPU memory strategy ('auto' or 'manual').",
+    )
+    gpu_layers: int = Field(
+        -1,
+        description = "Manual mode: requested --gpu-layers value (-1 = Auto/--fit, or when not manual).",
+    )
+    n_cpu_moe: int = Field(
+        0,
+        description = "Manual mode: MoE expert layers pinned to CPU (--n-cpu-moe); 0 = none.",
+    )
+    tensor_split: Optional[List[float]] = Field(
+        None,
+        description = "Manual mode: relative model share per GPU (--tensor-split); None = default (split by free VRAM).",
+    )
+    requested_context_length: Optional[int] = Field(
+        None,
+        description = (
+            "The n_ctx the active GGUF load was invoked with (0 = Auto). Lets the "
+            "UI re-seed a Manual + Auto-layers context pin on hydration, where "
+            "context_length only exposes the resolved value. None for non-GGUF."
+        ),
+    )
+    n_layers: Optional[int] = Field(
+        None,
+        description = "Model's layer count (GGUF block_count), for the manual gpu-layers ceiling.",
+    )
+    n_moe_layers: int = Field(
+        0,
+        description = "Model's MoE expert-layer count (the n_cpu_moe ceiling); 0 if not an MoE model.",
+    )
+    gpu_ids: Optional[List[int]] = Field(
+        None,
+        description = "Effective GPU indices the model is using after fit-time narrowing, or None for automatic selection.",
+    )
+    requested_gpu_ids: Optional[List[int]] = Field(
+        None,
+        description = (
+            "GPU placement pool requested by the user before fit-time narrowing, "
+            "or None for automatic selection."
+        ),
+    )
     llama_cpp_supports_mtp: bool = Field(
         True,
         description = (
@@ -533,7 +756,7 @@ class ImageContentPart(BaseModel):
 class InputDocumentContentPart(BaseModel):
     """Document (PDF / file) content part in a multimodal message.
 
-    Studio-normalised shape (file_data or file_url, plus optional filename/media_type).
+    Unsloth-normalised shape (file_data or file_url, plus optional filename/media_type).
     Mapped onto Anthropic ``document`` / OpenAI ``input_file`` for vision providers;
     dropped for non-vision providers.
     """
@@ -689,7 +912,7 @@ class ThinkingConfig(BaseModel):
     """Anthropic-compatible thinking/reasoning configuration.
     Use type='disabled' to turn off thinking, or type='enabled' to turn it on.
     Only type is read; extra fields (e.g. budget_tokens) are ignored, since
-    Studio sets provider thinking budgets itself.
+    Unsloth sets provider thinking budgets itself.
     """
 
     type: Literal["disabled", "enabled"] = "disabled"
@@ -748,7 +971,7 @@ class ChatCompletionRequest(BaseModel):
         None,
         description = (
             "OpenAI function-tool definitions. When provided without `enable_tools=true`, "
-            "Studio forwards the tools to the backend so the model returns structured "
+            "Unsloth forwards the tools to the backend so the model returns structured "
             "tool_calls for the client to execute (standard OpenAI function calling)."
         ),
     )
@@ -1160,7 +1383,7 @@ class ChatCompletionRequest(BaseModel):
             and (self.enable_tools is True or bool(self.mcp_enabled))
         ):
             # "Ask" gates every call, so a direct API caller that omits the legacy
-            # confirm flag must still hit the confirmation gate for Studio's own
+            # confirm flag must still hit the confirmation gate for Unsloth's own
             # tool loop. An explicit confirm_tool_calls=False wins over the mode
             # (mirrors _permission_mode_confirm and the Anthropic pre-switch guard),
             # so only self-enable when the flag is unset. Only self-enable when that
@@ -1168,7 +1391,7 @@ class ChatCompletionRequest(BaseModel):
             # (enable_tools / mcp_enabled) -- the router enters the loop on those
             # signals, not on enabled_tools alone (which merely filters which tools
             # run). A plain client-tool passthrough (client-supplied `tools` that
-            # Studio does not execute) must route verbatim, and external-provider
+            # Unsloth does not execute) must route verbatim, and external-provider
             # routing rejects confirm_tool_calls with tools, so skip the fold there.
             #
             # "auto" is deliberately NOT folded: it only prompts for a call the
diff --git a/studio/backend/models/models.py b/studio/backend/models/models.py
index 54e88fed58..df6725c9c9 100644
--- a/studio/backend/models/models.py
+++ b/studio/backend/models/models.py
@@ -178,6 +178,14 @@ class LocalModelInfo(BaseModel):
         None,
         description = "HF repo id for cached models, e.g. org/model",
     )
+    active_cache: Optional[bool] = Field(
+        None,
+        description = "Whether an HF model belongs to the current download cache.",
+    )
+    partial: bool = Field(
+        False,
+        description = "Whether the cached model has an incomplete download.",
+    )
     model_format: Optional[str] = Field(
         None,
         description = "Detected weights format ('gguf' when known). Lets the UI "
diff --git a/studio/backend/models/providers.py b/studio/backend/models/providers.py
index 5a75246c07..4238403e00 100644
--- a/studio/backend/models/providers.py
+++ b/studio/backend/models/providers.py
@@ -47,6 +47,14 @@ class ProviderCreate(BaseModel):
         None,
         description = "Custom base URL (overrides registry default). Omit to use the default.",
     )
+    models: list[str] = Field(
+        default_factory = list,
+        description = "Enabled model IDs for this connection",
+    )
+    available_models: list[str] = Field(
+        default_factory = list,
+        description = "Discovered catalog model IDs last fetched for this connection",
+    )
 
 
 class ProviderUpdate(BaseModel):
@@ -55,6 +63,11 @@ class ProviderUpdate(BaseModel):
     display_name: Optional[str] = Field(None, description = "New display name")
     base_url: Optional[str] = Field(None, description = "New base URL")
     is_enabled: Optional[bool] = Field(None, description = "Enable or disable this provider")
+    models: Optional[list[str]] = Field(None, description = "Enabled model IDs for this connection")
+    available_models: Optional[list[str]] = Field(
+        None,
+        description = "Discovered catalog model IDs last fetched for this connection",
+    )
 
 
 class ProviderResponse(BaseModel):
@@ -65,6 +78,14 @@ class ProviderResponse(BaseModel):
     display_name: str = Field(..., description = "User-chosen label")
     base_url: str = Field(..., description = "API base URL")
     is_enabled: bool = Field(True, description = "Whether this provider is enabled")
+    models: list[str] = Field(
+        default_factory = list,
+        description = "Enabled model IDs for this connection",
+    )
+    available_models: list[str] = Field(
+        default_factory = list,
+        description = "Discovered catalog model IDs last fetched for this connection",
+    )
     created_at: str = Field(..., description = "ISO 8601 creation timestamp")
     updated_at: str = Field(..., description = "ISO 8601 last-update timestamp")
 
diff --git a/studio/backend/models/training.py b/studio/backend/models/training.py
index ff815a2fa9..0aca5da72c 100644
--- a/studio/backend/models/training.py
+++ b/studio/backend/models/training.py
@@ -446,7 +446,7 @@ class TrainingStartRequest(BaseModel):
     random_seed: int = Field(
         3407,
         description = (
-            "Random seed; matches the Studio backend / MLX worker default "
+            "Random seed; matches the Unsloth backend / MLX worker default "
             "and unsloth's historical recommended value."
         ),
     )
@@ -470,6 +470,7 @@ class TrainingStartRequest(BaseModel):
     gradient_checkpointing: str = Field("", description = "Gradient checkpointing setting")
     use_rslora: bool = Field(False, description = "Use RSLoRA")
     use_loftq: bool = Field(False, description = "Use LoftQ")
+    use_dora: bool = Field(False, description = "Use DoRA")
     train_on_completions: bool = Field(False, description = "Train on completions only")
 
     # Vision-specific LoRA parameters
@@ -496,7 +497,15 @@ class TrainingStartRequest(BaseModel):
     # GPU selection
     gpu_ids: Optional[List[int]] = Field(
         None,
-        description = "Physical GPU indices to use, for example [0, 1]. Omit or pass [] to use automatic selection. Explicit gpu_ids are unsupported when the parent CUDA_VISIBLE_DEVICES uses UUID/MIG entries.",
+        description = (
+            "Physical GPU indices to use, for example [0, 1]. Omit or pass "
+            "[] to use automatic selection. Explicit gpu_ids are unsupported "
+            "when the parent visibility mask uses non-numeric or subdevice "
+            "entries -- this includes CUDA_VISIBLE_DEVICES with UUID/MIG "
+            "entries on NVIDIA, and ZE_AFFINITY_MASK with subdevice tokens "
+            "(e.g. '0.0,0.1') or FLAT-hierarchy (default) tile handles on "
+            "Intel XPU."
+        ),
     )
 
     # S3 dataset source configuration
@@ -505,6 +514,13 @@ class TrainingStartRequest(BaseModel):
         description = "S3 bucket configuration for loading datasets from AWS S3. Requires boto3 to be installed.",
     )
 
+    @field_validator("target_modules", mode = "before")
+    @classmethod
+    def _normalize_target_modules(cls, value: Any) -> Any:
+        # Sanitized non-LoRA history stores the unused value as null; treat it as a
+        # fresh request's omitted/default empty list on resume.
+        return [] if value is None else value
+
     @model_validator(mode = "after")
     def _validate_streaming_splits(self) -> "TrainingStartRequest":
         # Streaming load_dataset does not accept HF slice syntax (e.g. "train[:50%]"
@@ -530,6 +546,37 @@ class TrainingStartRequest(BaseModel):
             raise ValueError("Either num_epochs or max_steps must be > 0; both cannot be 0.")
         return self
 
+    @model_validator(mode = "after")
+    def _validate_lora_variant_flags(self) -> "TrainingStartRequest":
+        # The frontend only ever sends one of these and never under Full
+        # Finetuning, but a direct API/YAML/CLI caller can bypass that. Nothing
+        # downstream breaks (full finetune ignores them, MLX rejects use_dora/
+        # use_loftq outright), but reject early here for a clear error instead
+        # of a silently-ignored flag.
+        active = [
+            name
+            for name, enabled in (
+                ("use_rslora", self.use_rslora),
+                ("use_loftq", self.use_loftq),
+                ("use_dora", self.use_dora),
+            )
+            if enabled
+        ]
+        if len(active) > 1:
+            raise ValueError(
+                f"Only one LoRA variant may be enabled at a time; got {active}. "
+                "use_rslora, use_loftq, and use_dora are mutually exclusive."
+            )
+        # getattr, not self.training_type: model_construct() (used by tests that
+        # validate a single field in isolation) leaves required fields unset, and
+        # this is a mode="after" validator so it still runs on that partial instance.
+        if getattr(self, "training_type", None) == "Full Finetuning" and active:
+            raise ValueError(
+                f"{active[0]} requires an adapter method (LoRA/QLoRA or "
+                "Continued Pretraining); it has no effect under Full Finetuning."
+            )
+        return self
+
 
 class TrainingJobResponse(BaseModel):
     """Immediate response when training is initiated"""
diff --git a/studio/backend/picker/__init__.py b/studio/backend/picker/__init__.py
new file mode 100644
index 0000000000..32014236c6
--- /dev/null
+++ b/studio/backend/picker/__init__.py
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
diff --git a/studio/backend/picker/routes/__init__.py b/studio/backend/picker/routes/__init__.py
new file mode 100644
index 0000000000..c0e988c8bb
--- /dev/null
+++ b/studio/backend/picker/routes/__init__.py
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+from .templates import router as templates_router
+
+__all__ = ["templates_router"]
diff --git a/studio/backend/picker/routes/templates.py b/studio/backend/picker/routes/templates.py
new file mode 100644
index 0000000000..02b8bf7184
--- /dev/null
+++ b/studio/backend/picker/routes/templates.py
@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+from __future__ import annotations
+
+import asyncio
+from typing import Optional
+
+from fastapi import APIRouter, Body, Depends, Query
+
+from auth.authentication import get_current_subject
+from hub.dependencies import get_hf_token
+
+from ..schemas import (
+    MAX_CHAT_TEMPLATE_BYTES,
+    ModelTemplateResponse,
+    ValidateChatTemplateRequest,
+    ValidateChatTemplateResponse,
+)
+from ..service import read_default_chat_template, validate_chat_template
+
+router = APIRouter()
+
+
+@router.post("/validate-chat-template", response_model = ValidateChatTemplateResponse)
+async def validate_chat_template_route(
+    body: ValidateChatTemplateRequest = Body(...),
+    current_subject: str = Depends(get_current_subject),
+) -> ValidateChatTemplateResponse:
+    return await asyncio.to_thread(validate_chat_template, body.template)
+
+
+@router.get("/chat-template/{model_name:path}", response_model = ModelTemplateResponse)
+async def get_default_chat_template_route(
+    model_name: str,
+    gguf_variant: Optional[str] = Query(None),
+    hf_token: Optional[str] = Depends(get_hf_token),
+    current_subject: str = Depends(get_current_subject),
+) -> ModelTemplateResponse:
+    template = await asyncio.to_thread(
+        read_default_chat_template, model_name, hf_token, gguf_variant
+    )
+    if template is not None and len(template.encode("utf-8")) > MAX_CHAT_TEMPLATE_BYTES:
+        template = None
+    return ModelTemplateResponse(model_name = model_name, chat_template = template)
diff --git a/studio/backend/picker/schemas.py b/studio/backend/picker/schemas.py
new file mode 100644
index 0000000000..b4f956188f
--- /dev/null
+++ b/studio/backend/picker/schemas.py
@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+from typing import Optional
+
+from pydantic import BaseModel, Field, field_validator
+
+# Mirror the frontend's 64 KiB chat-template contract (per-model-config.ts) at
+# the API boundary so a direct caller cannot make Jinja parse an oversized
+# template. MaxBodyMiddleware only caps the whole request body, not this field.
+MAX_CHAT_TEMPLATE_BYTES = 65_536
+
+
+class ValidateChatTemplateRequest(BaseModel):
+    template: str = Field(default = "")
+
+    @field_validator("template")
+    @classmethod
+    def _enforce_template_size(cls, value: str) -> str:
+        if len(value.encode("utf-8")) > MAX_CHAT_TEMPLATE_BYTES:
+            raise ValueError(f"Chat template exceeds the {MAX_CHAT_TEMPLATE_BYTES}-byte limit.")
+        return value
+
+
+class ValidateChatTemplateResponse(BaseModel):
+    valid: bool
+    error: Optional[str] = None
+
+
+class ModelTemplateResponse(BaseModel):
+    model_name: str
+    chat_template: Optional[str] = None
diff --git a/studio/backend/picker/service.py b/studio/backend/picker/service.py
new file mode 100644
index 0000000000..ccf9c3e152
--- /dev/null
+++ b/studio/backend/picker/service.py
@@ -0,0 +1,432 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+from __future__ import annotations
+
+import json
+import logging
+import os
+import re
+from pathlib import Path
+from typing import Optional
+
+from hub.services.models.folder_browser import (
+    _build_browse_allowlist,
+    _is_path_inside_allowlist,
+)
+from hub.utils.gguf import extract_quant_label, iter_hf_cache_snapshots
+from utils.models.gguf_metadata import read_gguf_chat_template
+from utils.models.model_config import (
+    _extract_quant_label,
+    _is_big_endian_gguf_path,
+    _is_mmproj,
+    _is_mtp_drafter,
+)
+from utils.hf_cache_settings import active_hf_hub_cache
+from utils.paths.path_utils import (
+    is_local_path,
+    normalize_path,
+    resolve_cached_repo_id_case,
+)
+
+from .schemas import MAX_CHAT_TEMPLATE_BYTES, ValidateChatTemplateResponse
+
+logger = logging.getLogger(__name__)
+
+_VALID_REPO_ID = re.compile(r"^[A-Za-z0-9._-]+/[A-Za-z0-9._-]+$")
+
+
+def _is_valid_repo_id(repo_id: str) -> bool:
+    return bool(_VALID_REPO_ID.fullmatch(repo_id))
+
+
+_TOKENIZER_CONFIG_PATHS = ("tokenizer_config.json", "LLM/tokenizer_config.json")
+_JINJA_TEMPLATE_PATHS = ("chat_template.jinja", "LLM/chat_template.jinja")
+_PROCESSOR_TEMPLATE_PATHS = ("chat_template.json", "LLM/chat_template.json")
+
+# Cap sidecar reads so a malformed or hostile metadata file cannot exhaust memory
+# before its template is size-checked. The JSON envelope may exceed a bare template
+# (it carries other tokenizer metadata); the extracted template is still bounded by
+# MAX_CHAT_TEMPLATE_BYTES downstream.
+MAX_TEMPLATE_METADATA_BYTES = 4 * 1024 * 1024
+
+
+def _read_bounded_text(path: Path, limit: int) -> Optional[str]:
+    """Read at most `limit` bytes of UTF-8 text; None if larger or unreadable."""
+    try:
+        with path.open("rb") as f:
+            data = f.read(limit + 1)
+    except OSError:
+        return None
+    if len(data) > limit:
+        return None
+    try:
+        return data.decode("utf-8")
+    except UnicodeError:
+        return None
+
+
+def _leaf_inside_allowlist(path: Path, allow_roots: Optional[list[Path]]) -> bool:
+    # Block symlinked children from escaping the validated directory (realpath-checked).
+    # None = trusted caller (HF cache / remote download).
+    return allow_roots is None or _is_path_inside_allowlist(path, allow_roots)
+
+
+def validate_chat_template(template: str) -> ValidateChatTemplateResponse:
+    text = (template or "").strip()
+    if not text:
+        return ValidateChatTemplateResponse(valid = True, error = None)
+    # Import Jinja lazily: optional at runtime (e.g. GGUF-only installs), so a
+    # missing dependency must not crash API startup.
+    try:
+        from jinja2 import TemplateError
+        from jinja2.ext import Extension
+        from jinja2.sandbox import ImmutableSandboxedEnvironment
+    except ImportError:
+        return ValidateChatTemplateResponse(valid = True, error = None)
+
+    class _GenerationTag(Extension):
+        # Accept Transformers' {% generation %} assistant-mask tag so a pasted HF
+        # chat template validates (we only parse it).
+        tags = {"generation"}
+
+        def parse(self, parser):
+            next(parser.stream)
+            return parser.parse_statements(["name:endgeneration"], drop_needle = True)
+
+    try:
+        env = ImmutableSandboxedEnvironment(
+            trim_blocks = True,
+            lstrip_blocks = True,
+            extensions = ["jinja2.ext.loopcontrols", _GenerationTag],
+        )
+        env.parse(text)
+        return ValidateChatTemplateResponse(valid = True, error = None)
+    except TemplateError as exc:
+        message = getattr(exc, "message", None) or str(exc)
+        lineno = getattr(exc, "lineno", None)
+        if lineno:
+            message = f"Line {lineno}: {message}"
+        return ValidateChatTemplateResponse(valid = False, error = message)
+    except Exception as exc:
+        return ValidateChatTemplateResponse(valid = False, error = str(exc))
+
+
+def _chat_template_from_tokenizer_config(config: dict) -> Optional[str]:
+    if not isinstance(config, dict):
+        return None
+    raw = config.get("chat_template")
+    if isinstance(raw, str) and raw.strip():
+        return raw
+    if isinstance(raw, list):
+        fallback: Optional[str] = None
+        for entry in raw:
+            if not isinstance(entry, dict):
+                continue
+            template = entry.get("template")
+            if not isinstance(template, str):
+                continue
+            if entry.get("name") == "default":
+                return template
+            if fallback is None:
+                fallback = template
+        return fallback
+    return None
+
+
+def _chat_template_from_jinja_file(
+    dir_path: Path, allow_roots: Optional[list[Path]] = None
+) -> Optional[str]:
+    for rel in _JINJA_TEMPLATE_PATHS:
+        template_file = dir_path / rel
+        if not template_file.exists() or not _leaf_inside_allowlist(template_file, allow_roots):
+            continue
+        try:
+            if template_file.stat().st_size > MAX_CHAT_TEMPLATE_BYTES:
+                continue
+            template = template_file.read_text(encoding = "utf-8")
+        except Exception:
+            continue
+        if template.strip():
+            return template
+    return None
+
+
+def _chat_template_from_processor_payload(payload: object) -> Optional[str]:
+    # processor chat_template.json may be the template string itself or a
+    # {name: template} map, not only a tokenizer_config-shaped object.
+    if isinstance(payload, str):
+        return payload if payload.strip() else None
+    template = _chat_template_from_tokenizer_config(payload)  # type: ignore[arg-type]
+    if template:
+        return template
+    if isinstance(payload, dict):
+        # Named-template map: prefer "default", else the first non-empty entry
+        # (mirrors the tokenizer-config list fallback).
+        default = payload.get("default")
+        if isinstance(default, str) and default.strip():
+            return default
+        for value in payload.values():
+            if isinstance(value, str) and value.strip():
+                return value
+    return None
+
+
+def _chat_template_from_processor_json(
+    dir_path: Path, allow_roots: Optional[list[Path]] = None
+) -> Optional[str]:
+    for rel in _PROCESSOR_TEMPLATE_PATHS:
+        config_file = dir_path / rel
+        if not config_file.exists() or not _leaf_inside_allowlist(config_file, allow_roots):
+            continue
+        raw = _read_bounded_text(config_file, MAX_TEMPLATE_METADATA_BYTES)
+        if raw is None:
+            continue
+        try:
+            payload = json.loads(raw)
+        except Exception:
+            continue
+        template = _chat_template_from_processor_payload(payload)
+        if template:
+            return template
+    return None
+
+
+def _chat_template_from_tokenizer_dir(
+    dir_path: Path, allow_roots: Optional[list[Path]] = None
+) -> Optional[str]:
+    jinja = _chat_template_from_jinja_file(dir_path, allow_roots)
+    if jinja:
+        return jinja
+    for rel in _TOKENIZER_CONFIG_PATHS:
+        config_file = dir_path / rel
+        if not config_file.exists() or not _leaf_inside_allowlist(config_file, allow_roots):
+            continue
+        raw = _read_bounded_text(config_file, MAX_TEMPLATE_METADATA_BYTES)
+        if raw is None:
+            continue
+        try:
+            config = json.loads(raw)
+        except Exception:
+            continue
+        template = _chat_template_from_tokenizer_config(config)
+        if template:
+            return template
+    return _chat_template_from_processor_json(dir_path, allow_roots)
+
+
+_GGUF_SCAN_MAX_DEPTH = 2
+
+
+def _iter_ggufs(dir_path: Path) -> list[Path]:
+    if dir_path == dir_path.parent:
+        return []
+    root = str(dir_path)
+    found: list[Path] = []
+    for current, dirs, files in os.walk(root, followlinks = False):
+        rel = os.path.relpath(current, root)
+        depth = 0 if rel == os.curdir else rel.count(os.sep) + 1
+        if depth >= _GGUF_SCAN_MAX_DEPTH:
+            dirs[:] = []
+        for name in files:
+            if not name.lower().endswith(".gguf") or _is_mmproj(name):
+                continue
+            path = Path(current) / name
+            try:
+                rel = path.relative_to(dir_path).as_posix()
+            except ValueError:
+                rel = name
+            quant = _extract_quant_label(rel)
+            if _is_mtp_drafter(rel) or _is_big_endian_gguf_path(rel, quant):
+                continue
+            found.append(path)
+    return found
+
+
+def _variant_matches(relative_path: str, needle: str) -> bool:
+    quant = _extract_quant_label(relative_path).lower()
+    if quant == needle:
+        return True
+    if extract_quant_label(relative_path).lower() == needle:
+        return True
+    prefix = f"{needle}-"
+    if not quant.startswith(prefix):
+        return False
+    suffix = quant[len(prefix) :]
+    if not suffix.endswith("bpw"):
+        return False
+    value = suffix[:-3]
+    return bool(value) and value.replace(".", "", 1).isdigit()
+
+
+_GGUF_SPLIT_INDEX_RE = re.compile(r"-(\d{3,})-of-\d{3,}$", re.IGNORECASE)
+
+
+def _is_nonfirst_gguf_split(path: Path) -> bool:
+    match = _GGUF_SPLIT_INDEX_RE.search(path.stem)
+    return match is not None and int(match.group(1)) != 1
+
+
+def _find_gguf_in_dir(dir_path: Path, gguf_variant: Optional[str]) -> Optional[Path]:
+    try:
+        ggufs = sorted(_iter_ggufs(dir_path))
+    except OSError:
+        return None
+    if not ggufs:
+        return None
+    needle = (gguf_variant or "").strip().lower()
+    if needle:
+        for path in ggufs:
+            try:
+                relative = path.relative_to(dir_path).as_posix()
+            except ValueError:
+                relative = path.name
+            if _variant_matches(relative, needle):
+                return path
+        return None
+    candidates = [path for path in ggufs if not _is_nonfirst_gguf_split(path)] or ggufs
+    try:
+        return max(candidates, key = lambda path: path.stat().st_size)
+    except OSError:
+        return candidates[0]
+
+
+def _chat_template_from_dir(
+    dir_path: Path,
+    gguf_variant: Optional[str] = None,
+    allow_roots: Optional[list[Path]] = None,
+) -> Optional[str]:
+    def from_gguf() -> Optional[str]:
+        gguf = _find_gguf_in_dir(dir_path, gguf_variant)
+        if gguf is None or not _leaf_inside_allowlist(gguf, allow_roots):
+            return None
+        return read_gguf_chat_template(str(gguf))
+
+    # Sidecar tokenizer files (chat_template.jinja / tokenizer_config.json) are the
+    # author's maintained template and supersede the GGUF's possibly-stale embedded
+    # copy. The variant only picks the GGUF fallback, so tokenizer-first precedence
+    # holds whether or not a variant is given.
+    return _chat_template_from_tokenizer_dir(dir_path, allow_roots) or from_gguf()
+
+
+def read_default_chat_template(
+    model_name: str,
+    hf_token: Optional[str] = None,
+    gguf_variant: Optional[str] = None,
+) -> Optional[str]:
+    if not isinstance(model_name, str) or not model_name.strip():
+        return None
+    name = model_name.strip()
+
+    if is_local_path(name):
+        try:
+            target = Path(normalize_path(name)).expanduser()
+            allow_roots = _build_browse_allowlist()
+            if not _is_path_inside_allowlist(target, allow_roots):
+                logger.debug("Refused chat template read outside allowed folders: %s", name)
+                return None
+            if name.lower().endswith(".gguf"):
+                # Prefer a maintained sidecar next to the file over the GGUF's
+                # embedded copy (tokenizer-first precedence, as elsewhere).
+                sidecar = _chat_template_from_tokenizer_dir(target.parent, allow_roots)
+                if sidecar:
+                    return sidecar
+                return read_gguf_chat_template(str(target))
+            return _chat_template_from_dir(target, gguf_variant, allow_roots)
+        except Exception as exc:
+            logger.debug("Could not read local chat template for %s: %s", name, exc)
+            return None
+
+    if not _is_valid_repo_id(name):
+        return None
+
+    resolved = resolve_cached_repo_id_case(name)
+
+    try:
+        # Resolve within each cached revision, newest first. A revision's sidecar
+        # supersedes its own embedded GGUF copy, but must not override a newer
+        # revision, so precedence stays per-snapshot rather than global.
+        for snapshot in iter_hf_cache_snapshots(resolved):
+            template = _chat_template_from_dir(snapshot, gguf_variant)
+            if template:
+                return template
+    except Exception as exc:
+        logger.debug("Could not read cached chat template for %s: %s", resolved, exc)
+
+    try:
+        from huggingface_hub import HfApi, hf_hub_download
+
+        _api = HfApi()
+
+        def _remote_exceeds_cap(rel: str) -> bool:
+            # Best-effort: skip the download when the remote's advertised size
+            # exceeds the cap, so a maliciously large sidecar is never fetched.
+            try:
+                infos = _api.get_paths_info(resolved, [rel], repo_type = "model", token = hf_token)
+            except Exception:
+                return False
+            for info in infos:
+                size = getattr(info, "size", None)
+                if (
+                    getattr(info, "path", None) == rel
+                    and isinstance(size, int)
+                    and size > MAX_TEMPLATE_METADATA_BYTES
+                ):
+                    return True
+            return False
+
+        def _download_text(rel: str) -> Optional[str]:
+            if _remote_exceeds_cap(rel):
+                return None
+            try:
+                path = hf_hub_download(
+                    resolved,
+                    rel,
+                    token = hf_token,
+                    cache_dir = active_hf_hub_cache(),
+                )
+                return _read_bounded_text(Path(path), MAX_TEMPLATE_METADATA_BYTES)
+            except Exception:
+                return None
+
+        for rel in _JINJA_TEMPLATE_PATHS:
+            template = _download_text(rel)
+            if not template or not template.strip():
+                continue
+            # A raw Jinja sidecar is the whole template, so it must fit the route's
+            # response cap (the local path skips oversized .jinja too). Download stays
+            # bounded at MAX_TEMPLATE_METADATA_BYTES so a large JSON embedding a small
+            # template still extracts below, but an over-cap Jinja is dropped so the
+            # search falls through to the tokenizer/processor template.
+            if len(template.encode("utf-8")) > MAX_CHAT_TEMPLATE_BYTES:
+                continue
+            return template
+
+        for rel in _TOKENIZER_CONFIG_PATHS:
+            raw = _download_text(rel)
+            if not raw:
+                continue
+            try:
+                config = json.loads(raw)
+            except Exception:
+                continue
+            template = _chat_template_from_tokenizer_config(config)
+            if template:
+                return template
+
+        for rel in _PROCESSOR_TEMPLATE_PATHS:
+            raw = _download_text(rel)
+            if not raw:
+                continue
+            try:
+                payload = json.loads(raw)
+            except Exception:
+                continue
+            template = _chat_template_from_processor_payload(payload)
+            if template:
+                return template
+
+        return None
+    except Exception as exc:
+        logger.debug("Could not fetch chat template for %s: %s", resolved, exc)
+        return None
diff --git a/studio/backend/plugins/data-designer-github-repo-seed/README.md b/studio/backend/plugins/data-designer-github-repo-seed/README.md
index 346d94b305..44519496f5 100644
--- a/studio/backend/plugins/data-designer-github-repo-seed/README.md
+++ b/studio/backend/plugins/data-designer-github-repo-seed/README.md
@@ -4,7 +4,7 @@ A Data Designer seed-reader plugin for **Unsloth Studio** that scrapes real
 GitHub data (issues, pull requests, commits) from one or more repositories
 and hands it to the recipe pipeline as a seed dataset.
 
-Designed to ship with Studio as a default seed source so any user with a
+Designed to ship with Unsloth as a default seed source so any user with a
 GitHub token can build training datasets straight from live repos.
 
 ## What it does
@@ -64,7 +64,7 @@ sleeps until reset when the budget drops below a safety threshold.
 
 ## Install
 
-Shipped as a default Studio plugin. For development:
+Shipped as a default Unsloth plugin. For development:
 
 ```bash
 pip install -e .
diff --git a/studio/backend/plugins/data-designer-github-repo-seed/src/data_designer_github_repo_seed/__init__.py b/studio/backend/plugins/data-designer-github-repo-seed/src/data_designer_github_repo_seed/__init__.py
index 62ecb2e280..d4d46da370 100644
--- a/studio/backend/plugins/data-designer-github-repo-seed/src/data_designer_github_repo_seed/__init__.py
+++ b/studio/backend/plugins/data-designer-github-repo-seed/src/data_designer_github_repo_seed/__init__.py
@@ -3,4 +3,4 @@
 
 # Intentionally empty. Data-designer loads submodules lazily via qualified names
 # in plugin.py, so importing this package must not touch data_designer.engine.*
-# during Studio bootstrap (circular import).
+# during Unsloth bootstrap (circular import).
diff --git a/studio/backend/plugins/data-designer-github-repo-seed/src/data_designer_github_repo_seed/scraper.py b/studio/backend/plugins/data-designer-github-repo-seed/src/data_designer_github_repo_seed/scraper.py
index 637193e8b3..1af8133cc5 100644
--- a/studio/backend/plugins/data-designer-github-repo-seed/src/data_designer_github_repo_seed/scraper.py
+++ b/studio/backend/plugins/data-designer-github-repo-seed/src/data_designer_github_repo_seed/scraper.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Multi-repo GitHub scraper for the Studio seed plugin.
+"""Multi-repo GitHub scraper for the Unsloth seed plugin.
 
 Drives the GraphQL scraper in `scraper_impl/` per repo, capped via trial_limits
 to stop at `limit` items per resource. Then reads the per-resource JSONL shards
diff --git a/studio/backend/requirements/extras-no-deps.txt b/studio/backend/requirements/extras-no-deps.txt
index 5830a47789..3361af50dd 100644
--- a/studio/backend/requirements/extras-no-deps.txt
+++ b/studio/backend/requirements/extras-no-deps.txt
@@ -5,7 +5,7 @@ julius
 torchcodec==0.10.0
 snac
 
-# peft 0.19.0 causes export subprocess shutdown issues in Studio;
+# peft 0.19.0 causes export subprocess shutdown issues in Unsloth;
 # installing with --no-deps to avoid pulling in torch>=0.11.0
 peft==0.18.1
 
diff --git a/studio/backend/requirements/extras.txt b/studio/backend/requirements/extras.txt
index 1baf2b6f2d..1601ccbfae 100644
--- a/studio/backend/requirements/extras.txt
+++ b/studio/backend/requirements/extras.txt
@@ -10,6 +10,7 @@ omegaconf
 einx
 pyloudnorm
 openai-whisper
+av                               # PyAV: decode dictation audio (webm/opus/mp3/…) for the Whisper STT sidecar
 uroman                           # 4.0 MB - used for Outetts.
 MeCab                            # 19.9 MB - used for Outetts.
 inflect                          # number-to-words, required by OuteTTS
diff --git a/studio/backend/requirements/no-torch-runtime.txt b/studio/backend/requirements/no-torch-runtime.txt
index de321f80ed..847e89823b 100644
--- a/studio/backend/requirements/no-torch-runtime.txt
+++ b/studio/backend/requirements/no-torch-runtime.txt
@@ -7,7 +7,7 @@
 # (current PyPI metadata still declares torch as a hard dep).
 
 # unsloth direct deps (from pyproject.toml [project].dependencies)
-typer
+typer>=0.12.0
 # typer's full runtime dep tree. Required explicitly because this
 # file is installed with --no-deps. On Linux/Mac CI runners these
 # are often cached transitively; on a fresh windows-latest venv they
@@ -70,7 +70,7 @@ cut_cross_entropy
 pillow
 
 # RAG store + document parsing, mirroring studio.txt. Pinned here because
-# this file installs --no-deps; without them Studio runs with RAG disabled.
+# this file installs --no-deps; without them Unsloth runs with RAG disabled.
 sqlite-vec==0.1.9
 pymupdf==1.27.2.3
 # 0.3.x keeps pymupdf-layout (which pulls onnxruntime) an optional extra; the
diff --git a/studio/backend/requirements/single-env/constraints.txt b/studio/backend/requirements/single-env/constraints.txt
index 0ed2bf8b26..0a5619924a 100644
--- a/studio/backend/requirements/single-env/constraints.txt
+++ b/studio/backend/requirements/single-env/constraints.txt
@@ -4,7 +4,7 @@ transformers==4.57.6
 trl==0.23.1
 huggingface-hub==0.36.2
 
-# Studio stack
+# Unsloth stack
 datasets==4.3.0
 pyarrow==23.0.1
 
diff --git a/studio/backend/requirements/studio.txt b/studio/backend/requirements/studio.txt
index 6f4a5c3292..0c7503a5ca 100644
--- a/studio/backend/requirements/studio.txt
+++ b/studio/backend/requirements/studio.txt
@@ -1,4 +1,4 @@
-# Studio UI backend dependencies
+# Unsloth UI backend dependencies
 typer
 fastapi
 uvicorn
@@ -9,7 +9,7 @@ pandas
 nest_asyncio
 datasets==4.3.0
 pyjwt
-# gradio>=4.0.0                  # 148 MB - Studio uses React + FastAPI, not Gradio
+# gradio>=4.0.0                  # 148 MB - Unsloth uses React + FastAPI, not Gradio
 huggingface-hub==0.36.2
 structlog>=24.1.0
 diceware
diff --git a/studio/backend/routes/auth.py b/studio/backend/routes/auth.py
index c61c1a16e4..1acc48e3a3 100644
--- a/studio/backend/routes/auth.py
+++ b/studio/backend/routes/auth.py
@@ -338,11 +338,11 @@ def _clear_login_bucket(key: tuple[str, str]) -> None:
 # so FastAPI runs it in the threadpool rather than blocking the event loop.
 @router.get("/identity")
 def identity(nonce: str, request: Request) -> dict:
-    """Challenge-response proof this is the real local Studio: caller sends a nonce,
+    """Challenge-response proof this is the real local Unsloth: caller sends a nonce,
     gets HMAC(install identity secret, nonce, connection address + port).
     Unauthenticated and side-effect free; a process that can't read the same-user
     secret can't forge a proof, and binding to the address/port the connection
-    landed on stops a squatter relaying a proof from the real Studio elsewhere."""
+    landed on stops a squatter relaying a proof from the real Unsloth elsewhere."""
     try:
         raw = base64.urlsafe_b64decode(nonce)
     except Exception:
@@ -494,6 +494,11 @@ async def change_password(
             status_code = status.HTTP_401_UNAUTHORIZED,
             detail = "Current password is incorrect",
         )
+    if any(ch.isspace() for ch in payload.new_password):
+        raise HTTPException(
+            status_code = status.HTTP_400_BAD_REQUEST,
+            detail = "New password cannot contain spaces",
+        )
     if payload.current_password == payload.new_password:
         raise HTTPException(
             status_code = status.HTTP_400_BAD_REQUEST,
diff --git a/studio/backend/routes/chat_history.py b/studio/backend/routes/chat_history.py
index 7a27a58a52..6a0d49b47d 100644
--- a/studio/backend/routes/chat_history.py
+++ b/studio/backend/routes/chat_history.py
@@ -5,7 +5,7 @@
 Chat history API routes backed by studio.db.
 """
 
-from typing import Any, Literal, Optional
+from typing import Annotated, Any, Literal, Optional
 
 from fastapi import APIRouter, Depends, HTTPException, Query
 from pydantic import BaseModel, ConfigDict, Field, ValidationError
@@ -19,13 +19,16 @@ from storage.studio_db import (
     clear_chat_history,
     count_chat_threads,
     count_forks_for_message,
+    delete_chat_attachment,
     delete_chat_threads,
     delete_chat_project,
     ensure_chat_project_workspace,
     fork_chat_thread,
+    get_chat_attachment,
     get_chat_project,
     get_chat_thread,
     get_chat_message,
+    list_chat_attachments_page,
     list_chat_projects,
     list_chat_legacy_imports,
     list_chat_settings,
@@ -157,11 +160,26 @@ class ChatInferenceSettings(BaseModel):
     fastMode: Optional[bool] = None
 
 
+class ChatPresetLoadConfig(BaseModel):
+    model_config = ConfigDict(extra = "forbid")
+
+    customContextLength: Optional[int] = Field(default = None, gt = 0)
+    maxSeqLength: Optional[float] = None
+    kvCacheDtype: Optional[str] = None
+    speculativeType: Optional[str] = None
+    specDraftNMax: Optional[int] = Field(default = None, ge = 1, le = 16)
+    tensorParallel: Optional[bool] = None
+    gpuMemoryMode: Optional[Literal["manual"]] = None
+    gpuLayers: Optional[int] = None
+    nCpuMoe: Optional[int] = Field(default = None, ge = 0)
+
+
 class ChatPreset(BaseModel):
     model_config = ConfigDict(extra = "forbid")
 
     name: str
     params: ChatInferenceSettings
+    loadConfig: Optional[ChatPresetLoadConfig] = None
 
 
 class ChatSettingsPayload(BaseModel):
@@ -279,6 +297,131 @@ async def delete_threads(
     return {"status": "deleted"}
 
 
+@router.get("/attachments")
+def list_attachments(
+    limit: Annotated[int, Query(ge = 1, le = 100)] = 50,
+    offset: Annotated[int, Query(ge = 0)] = 0,
+    current_subject: str = Depends(get_current_subject),
+) -> dict:
+    """One bounded page of chat uploads for the settings Data tab."""
+    attachments, next_offset = list_chat_attachments_page(limit = limit, offset = offset)
+    return {"attachments": attachments, "nextOffset": next_offset}
+
+
+def _decode_attachment_base64(payload: str) -> bytes:
+    """Strict base64 decode of a stored payload.
+
+    Normalizes first: strips whitespace, fixes padding, accepts the URL-safe
+    alphabet. validate=False would silently drop bad characters and serve
+    corrupted bytes instead of failing, so raise 422 on anything else.
+    """
+    import base64
+
+    normalized = "".join(payload.split())
+    altchars = b"-_" if ("-" in normalized or "_" in normalized) else None
+    normalized += "=" * (-len(normalized) % 4)
+    try:
+        return base64.b64decode(normalized, altchars = altchars, validate = True)
+    except Exception as exc:  # noqa: BLE001 - corrupt stored payload
+        raise HTTPException(status_code = 422, detail = "Attachment data is corrupt") from exc
+
+
+_AUDIO_FORMAT_MEDIA_TYPES = {
+    "mp3": "audio/mpeg",
+    "wav": "audio/wav",
+    "ogg": "audio/ogg",
+    "flac": "audio/flac",
+}
+
+
+def _safe_image_media_type(media_type: str) -> str:
+    """Clamp a data-URL media type to something inert to render.
+
+    Imported chats store image parts verbatim, so the embedded type can be
+    text/html or image/svg+xml; echoing those would execute markup with the
+    app origin when opened. Anything not a plain raster type downloads as
+    bytes instead.
+    """
+    lowered = media_type.strip().lower()
+    if lowered.startswith("image/") and lowered != "image/svg+xml":
+        return lowered
+    return "application/octet-stream"
+
+
+@router.get("/attachments/{message_id}/{attachment_id}/file")
+def get_attachment_file(
+    message_id: str,
+    attachment_id: str,
+    current_subject: str = Depends(get_current_subject),
+):
+    """Serve one attachment's stored content: image or audio bytes, or
+    extracted text."""
+    import urllib.parse
+
+    from fastapi.responses import Response
+
+    attachment = get_chat_attachment(message_id, attachment_id)
+    if attachment is None:
+        raise HTTPException(status_code = 404, detail = "Attachment not found")
+
+    attachment_content_type = attachment.get("contentType")
+    texts: list[str] = []
+    for part in attachment.get("content") or []:
+        if not isinstance(part, dict):
+            continue
+        image = part.get("image")
+        if isinstance(image, str) and image[:5].lower() == "data:":
+            header, _, payload = image.partition(",")
+            media_type = _safe_image_media_type(
+                header[5:].split(";", 1)[0] or "application/octet-stream"
+            )
+            if "base64" not in header.lower():
+                # RFC 2397 non-base64 form stores percent-encoded bytes.
+                data = urllib.parse.unquote_to_bytes(payload)
+                return Response(content = data, media_type = media_type)
+            data = _decode_attachment_base64(payload)
+            return Response(content = data, media_type = media_type)
+        # Audio parts: the attachment adapter stores {data, format} with raw
+        # base64; compare chats store a bare base64 string.
+        audio = part.get("audio")
+        if isinstance(audio, dict) or (isinstance(audio, str) and audio):
+            if isinstance(audio, dict):
+                payload = audio.get("data")
+                audio_format = audio.get("format")
+            else:
+                payload = audio.rsplit(",", 1)[-1]
+                audio_format = None
+            if isinstance(payload, str) and payload:
+                data = _decode_attachment_base64(payload)
+                media_type = (
+                    attachment_content_type
+                    if isinstance(attachment_content_type, str)
+                    and attachment_content_type.startswith("audio/")
+                    else _AUDIO_FORMAT_MEDIA_TYPES.get(
+                        str(audio_format or "").lower(), "application/octet-stream"
+                    )
+                )
+                return Response(content = data, media_type = media_type)
+        text = part.get("text")
+        if isinstance(text, str) and text:
+            texts.append(text)
+    if texts:
+        return Response(content = "\n".join(texts), media_type = "text/plain; charset=utf-8")
+    raise HTTPException(status_code = 404, detail = "Attachment has no stored content")
+
+
+@router.delete("/attachments/{message_id}/{attachment_id}")
+def delete_attachment(
+    message_id: str,
+    attachment_id: str,
+    current_subject: str = Depends(get_current_subject),
+) -> dict:
+    """Remove one attachment from its chat message."""
+    if not delete_chat_attachment(message_id, attachment_id):
+        raise HTTPException(status_code = 404, detail = "Attachment not found")
+    return {"ok": True}
+
+
 @router.get("/projects", response_model = ChatProjectListResponse)
 async def list_projects(
     include_archived: bool = Query(False), current_subject: str = Depends(get_current_subject)
@@ -409,7 +552,7 @@ async def get_thread_message(
 
 
 @router.put("/threads/{thread_id}/messages/{message_id}", response_model = ChatMessage)
-async def save_thread_message(
+def save_thread_message(
     thread_id: str,
     message_id: str,
     payload: ChatMessage,
@@ -432,7 +575,7 @@ async def save_thread_message(
 
 
 @router.put("/threads/{thread_id}/messages", response_model = ChatMessageListResponse)
-async def replace_thread_messages(
+def replace_thread_messages(
     thread_id: str,
     payload: ChatMessageSyncRequest,
     current_subject: str = Depends(get_current_subject),
diff --git a/studio/backend/routes/data_recipe/jobs.py b/studio/backend/routes/data_recipe/jobs.py
index 59714380da..e870e8855e 100644
--- a/studio/backend/routes/data_recipe/jobs.py
+++ b/studio/backend/routes/data_recipe/jobs.py
@@ -37,7 +37,7 @@ def _resolve_local_v1_endpoint(request: Request) -> str:
 
     Resolution order:
       1. ``app.state.server_port`` (run.py, post-bind) - survives proxies/tunnels.
-      2. ``request.scope["server"]`` - when Studio starts outside ``run_server``.
+      2. ``request.scope["server"]`` - when Unsloth starts outside ``run_server``.
       3. parsed ``request.base_url`` - last resort for test fixtures.
     """
     port: Any = getattr(request.app.state, "server_port", None)
diff --git a/studio/backend/routes/datasets.py b/studio/backend/routes/datasets.py
index 46319ca2ba..331eb5e1e0 100644
--- a/studio/backend/routes/datasets.py
+++ b/studio/backend/routes/datasets.py
@@ -23,40 +23,6 @@ def _is_valid_repo_id(repo_id: str) -> bool:
     return bool(_VALID_REPO_ID.fullmatch(repo_id))
 
 
-_dataset_size_cache: dict[str, int] = {}
-
-
-def _get_dataset_size_cached(repo_id: str) -> int:
-    if repo_id in _dataset_size_cache:
-        return _dataset_size_cache[repo_id]
-    try:
-        from huggingface_hub import dataset_info as hf_dataset_info
-
-        info = hf_dataset_info(repo_id, token = None, files_metadata = True)
-        total = sum(s.size for s in info.siblings if getattr(s, "size", None))
-        _dataset_size_cache[repo_id] = total
-        return total
-    except Exception:
-        return 0
-
-
-def _resolve_hf_cache_realpath(repo_dir: Path) -> Optional[str]:
-    """Resolved realpath for a HF cache repo dir: most-recent snapshot, else cache root.
-
-    Mirrors routes/models.py; duplicated here to keep this module self-contained.
-    """
-    try:
-        snapshots_dir = repo_dir / "snapshots"
-        if snapshots_dir.is_dir():
-            snaps = [s for s in snapshots_dir.iterdir() if s.is_dir()]
-            if snaps:
-                latest = max(snaps, key = lambda s: s.stat().st_mtime)
-                return str(latest.resolve())
-        return str(repo_dir.resolve())
-    except Exception:
-        return None
-
-
 backend_path = Path(__file__).parent.parent.parent
 if str(backend_path) not in sys.path:
     sys.path.insert(0, str(backend_path))
@@ -64,6 +30,7 @@ if str(backend_path) not in sys.path:
 from utils.datasets import check_dataset_format
 from utils.upload_limits import get_upload_limit_bytes, get_upload_limit_label
 from auth.authentication import get_current_subject
+from hub.dependencies import get_hf_token
 
 router = APIRouter()
 logger = get_logger(__name__)
@@ -292,11 +259,13 @@ def _download_hf_metadata(*, repo_id: str, repo_files: list[str], token: str | N
 
     try:
         from huggingface_hub import hf_hub_download
+        from utils.hf_cache_settings import active_hf_hub_cache
         local_path = hf_hub_download(
             repo_id = repo_id,
             filename = metadata_file,
             repo_type = "dataset",
             token = token,
+            cache_dir = active_hf_hub_cache(),
         )
     except Exception as exc:
         logger.warning(f"Could not read HF dataset metadata for {repo_id}: {exc}")
@@ -485,7 +454,7 @@ async def upload_dataset(
 
     # Stream to disk in chunks to avoid holding the whole file in memory. The
     # route-level cap gives a clear training-dataset error and avoids leaving
-    # oversized partial files in the Studio uploads directory.
+    # oversized partial files in the Unsloth uploads directory.
     upload_limit_bytes = get_upload_limit_bytes()
     total_bytes = 0
     upload_complete = False
@@ -525,77 +494,15 @@ def list_local_datasets(
 @router.get("/download-progress")
 async def get_dataset_download_progress(
     repo_id: str = Query(..., description = "HuggingFace dataset repo ID, e.g. 'unsloth/LaTeX_OCR'"),
+    hf_token: Optional[str] = Depends(get_hf_token),
     current_subject: str = Depends(get_current_subject),
 ):
-    """Return download progress for a HuggingFace dataset repo.
-
-    Mirrors ``GET /api/models/download-progress`` but scans the
-    ``datasets--owner--name`` cache dir under HF_HUB_CACHE, where in-progress
-    download bytes are visible. Returns ``cache_path`` so the UI can show it.
-    """
-    _empty = {
-        "downloaded_bytes": 0,
-        "expected_bytes": 0,
-        "progress": 0,
-        "cache_path": None,
-    }
-    try:
-        if not _is_valid_repo_id(repo_id):
-            return _empty
-
-        from huggingface_hub import constants as hf_constants
-
-        cache_dir = Path(hf_constants.HF_HUB_CACHE)
-        target = f"datasets--{repo_id.replace('/', '--')}".lower()
-        completed_bytes = 0
-        in_progress_bytes = 0
-        cache_path: Optional[str] = None
-
-        if cache_dir.is_dir():
-            for entry in cache_dir.iterdir():
-                if entry.name.lower() != target:
-                    continue
-                cache_path = _resolve_hf_cache_realpath(entry)
-                blobs_dir = entry / "blobs"
-                if not blobs_dir.is_dir():
-                    break
-                for f in blobs_dir.iterdir():
-                    if not f.is_file():
-                        continue
-                    if f.name.endswith(".incomplete"):
-                        in_progress_bytes += f.stat().st_size
-                    else:
-                        completed_bytes += f.stat().st_size
-                break
-
-        downloaded_bytes = completed_bytes + in_progress_bytes
-        if downloaded_bytes == 0:
-            return {**_empty, "cache_path": cache_path}
-
-        expected_bytes = _get_dataset_size_cached(repo_id)
-        if expected_bytes <= 0:
-            return {
-                "downloaded_bytes": downloaded_bytes,
-                "expected_bytes": 0,
-                "progress": 0,
-                "cache_path": cache_path,
-            }
-
-        # 95% threshold (as in the model endpoint): HF blob dedup makes
-        # completed_bytes drift under expected_bytes; inter-file gaps look "done".
-        if completed_bytes >= expected_bytes * 0.95:
-            progress = 1.0
-        else:
-            progress = min(downloaded_bytes / expected_bytes, 0.99)
-        return {
-            "downloaded_bytes": downloaded_bytes,
-            "expected_bytes": expected_bytes,
-            "progress": round(progress, 3),
-            "cache_path": cache_path,
-        }
-    except Exception as e:
-        logger.warning(f"Error checking dataset download progress for {repo_id}: {e}")
-        return _empty
+    """Compatibility route backed by the shared multi-cache progress service."""
+    from hub.services.datasets import downloads
+    return await downloads.get_dataset_download_progress_response(
+        repo_id,
+        hf_token = hf_token,
+    )
 
 
 @router.post("/check-format", response_model = CheckFormatResponse)
diff --git a/studio/backend/routes/inference.py b/studio/backend/routes/inference.py
index 0541a81ff2..445a26f04d 100644
--- a/studio/backend/routes/inference.py
+++ b/studio/backend/routes/inference.py
@@ -13,13 +13,14 @@ from pathlib import Path
 from fastapi import APIRouter, Depends, HTTPException, Request, status
 from fastapi.responses import StreamingResponse, JSONResponse, Response
 from starlette.requests import ClientDisconnect
-from typing import Any, Callable, List, Optional, Union
+from typing import Any, Callable, List, Literal, Optional, Union
 import json
 import httpx
 from loggers import get_logger
 import asyncio
 import threading
 import weakref
+from contextlib import ExitStack
 
 
 import re as _re
@@ -28,6 +29,9 @@ import re as _re
 from utils.models import extract_model_size_b as _extract_model_size_b
 
 from utils.api_errors import openai_error_body, anthropic_error_body
+from utils.upload_limits import STT_AUDIO_B64_MAX_CHARS, STT_AUDIO_RAW_MAX_BYTES
+from hub.dependencies import get_hf_token
+from core.inference.orchestrator import GenStreamError, GenStreamErrorRaised
 from core.inference.llama_admission import (
     LlamaAdmissionCancelled,
     LlamaAdmissionConfig,
@@ -90,7 +94,7 @@ def _mlx_distributed_launch_detected() -> bool:
 def _install_httpcore_asyncgen_silencer() -> None:
     """Silence benign httpx/httpcore asyncgen GC noise on Python 3.13.
 
-    When Studio proxies a llama-server stream via httpx, the innermost
+    When Unsloth proxies a llama-server stream via httpx, the innermost
     ``HTTP11ConnectionByteStream.__aiter__`` async generator is finalised by
     the asyncgen GC hook on a task different from the one that opened it. Its
     ``aclose`` calls ``anyio.Lock.acquire`` → ``cancel_shielded_checkpoint``,
@@ -212,6 +216,14 @@ def _friendly_error(exc: Exception) -> str:
     return "An internal error occurred"
 
 
+def _friendly_gen_stream_error(value) -> str:
+    """Return a client-safe message for typed local generation errors."""
+    text = str(value)
+    if getattr(value, "public", False):
+        return text
+    return safe_error_detail(RuntimeError(text), fallback = "An internal error occurred.")
+
+
 def _friendly_upstream_error(text: str) -> str:
     """Rewrite a raw llama-server error body into an actionable message where we can.
 
@@ -219,14 +231,14 @@ def _friendly_upstream_error(text: str) -> str:
     parse grammar" / "failed to initialize samplers"). This surfaces to coding agents as
     a hard 400 on every tool-bearing turn. It is a llama-server limitation with some
     model/quant + tool-schema combinations, and recent llama.cpp builds handle the common
-    coding-agent tools, so point the user at updating Studio rather than the raw body.
+    coding-agent tools, so point the user at updating Unsloth rather than the raw body.
     """
     lowered = text.lower()
     if "failed to parse grammar" in lowered or "failed to initialize samplers" in lowered:
         return (
             "The model couldn't compile a tool-calling grammar for this request. This is a "
             "llama-server limitation with some model/quant and tool-schema combinations. "
-            "Update Studio (it installs the latest llama.cpp, which handles the common "
+            "Update Unsloth (it installs the latest llama.cpp, which handles the common "
             "coding-agent tools) or try a different GGUF model."
         )
     return f"llama-server error: {text}"
@@ -721,7 +733,7 @@ def _openai_passthrough_sse_line_terminal_state(raw_line: str) -> Optional[str]:
 
     Some llama-server builds can emit the logical final chunk (``finish_reason``)
     and optional usage chunk, then keep the HTTP stream open without sending the
-    OpenAI ``data: [DONE]`` sentinel. Classifying those chunks lets Studio close
+    OpenAI ``data: [DONE]`` sentinel. Classifying those chunks lets Unsloth close
     the client stream promptly while preserving an optional trailing usage chunk.
     """
     if not raw_line.startswith("data:"):
@@ -998,6 +1010,7 @@ try:
     from core.inference.llama_server_args import (
         _effective_tensor_parallel,
         _tensor_parallel_matches_loaded,
+        extra_args_disable_mmproj,
         parse_split_mode_override,
         resolve_tensor_parallel,
         strip_shadowing_flags,
@@ -1035,6 +1048,7 @@ except ImportError:
     from core.inference.llama_server_args import (
         _effective_tensor_parallel,
         _tensor_parallel_matches_loaded,
+        extra_args_disable_mmproj,
         parse_split_mode_override,
         resolve_tensor_parallel,
         strip_shadowing_flags,
@@ -1680,6 +1694,8 @@ async def _aiter_llama_stream_items(
 from models.inference import (
     LoadRequest,
     UnloadRequest,
+    TranscribeRequest,
+    SttLoadRequest,
     GenerateRequest,
     LoadResponse,
     LoadProgressResponse,
@@ -1766,7 +1782,7 @@ from core.inference.providers import get_base_url
 from core.inference.external_provider import ExternalProviderClient
 from core.inference.chat_templates import resolve_effective_chat_template_override
 from storage import providers_db
-from utils.utils import safe_error_detail, log_and_http_error
+from utils.utils import is_hf_authentication_error, safe_error_detail, log_and_http_error
 
 import io
 import base64
@@ -1774,7 +1790,7 @@ import numpy as np
 from datetime import date as _date
 
 router = APIRouter()
-# Studio-only router (not mounted on /v1 OpenAI-compat).
+# Unsloth-only router (not mounted on /v1 OpenAI-compat).
 studio_router = APIRouter()
 
 
@@ -1915,16 +1931,57 @@ async def artifact_preview_frame(allow_network: bool = False):
 _BARE_JSON_NAME_MARKER_RE = _re.compile(r'\{\s*\\?"(?:name|function)\\?"\s*:')
 
 
-def _detect_safetensors_features(backend, chat_template: Optional[str]) -> dict:
+def _detect_safetensors_features(
+    backend,
+    chat_template: Optional[str],
+    tools = None,
+) -> dict:
     """Classify reasoning/tool capabilities via the GGUF classifier so flags
     match across backends. gpt-oss is overridden: Harmony routes reasoning and
     tools through tokenizer channels, not template markup."""
     model_id = getattr(backend, "active_model_name", None)
+    feature_template = chat_template
+    try:
+        from core.inference.chat_template_helpers import _selected_template_strings_from_value
+        selected_templates = _selected_template_strings_from_value(chat_template, tools)
+        if selected_templates:
+            feature_template = selected_templates[0]
+    except Exception:
+        logger.debug("safetensors_named_template_selection_failed", exc_info = True)
     flags = detect_reasoning_flags(
-        chat_template,
+        feature_template,
         model_identifier = model_id,
         log_source = "safetensors",
     )
+    if not flags.get("supports_reasoning"):
+        try:
+            from core.inference.chat_template_helpers import (
+                detect_reasoning_channel_markers_from_template,
+            )
+
+            templates = [chat_template]
+            models = getattr(backend, "models", None)
+            model_info = (
+                models.get(model_id, {})
+                if isinstance(models, dict) and model_id is not None
+                else {}
+            )
+            if isinstance(model_info, dict):
+                templates.extend(
+                    (
+                        model_info.get("native_chat_template"),
+                        (model_info.get("chat_template_info") or {}).get("template"),
+                    )
+                )
+            if any(
+                detect_reasoning_channel_markers_from_template(template, tools = tools) is not None
+                for template in templates
+            ):
+                flags["supports_reasoning"] = True
+                flags["reasoning_always_on"] = True
+                logger.info("safetensors: model always reasons (native channel markers)")
+        except Exception:
+            logger.debug("safetensors_native_reasoning_marker_check_failed", exc_info = True)
     # Markers any supported parser recognises (template advertises tools but
     # uses none -> drop the pill). Reuse the parser's own signal list so this
     # gate never drifts (a hand-maintained copy lost the DeepSeek variants);
@@ -1938,9 +1995,9 @@ def _detect_safetensors_features(backend, chat_template: Optional[str]) -> dict:
     )
     if (
         flags.get("supports_tools")
-        and chat_template
-        and not any(m in chat_template for m in _PARSER_MARKERS)
-        and not _BARE_JSON_NAME_MARKER_RE.search(chat_template)
+        and isinstance(feature_template, str)
+        and not any(m in feature_template for m in _PARSER_MARKERS)
+        and not _BARE_JSON_NAME_MARKER_RE.search(feature_template)
     ):
         logger.info(
             "safetensors: template advertises tools but uses an "
@@ -2055,9 +2112,9 @@ def _effective_enable_tools(payload) -> Optional[bool]:
 
 
 def _explicit_studio_tool_loop_requested(payload) -> bool:
-    """True when the request itself asks Studio to execute local tools.
+    """True when the request itself asks Unsloth to execute local tools.
 
-    Process-wide CLI policy can default Studio's tool loop on for ordinary chat,
+    Process-wide CLI policy can default Unsloth's tool loop on for ordinary chat,
     but it must not steal OpenAI-compatible client tools or response_format
     requests from the llama-server passthrough path. A policy of ``False``
     (--disable-tools) vetoes even an explicit ``enable_tools: true`` ask.
@@ -2069,7 +2126,7 @@ def _explicit_studio_tool_loop_requested(payload) -> bool:
 
 
 def _permission_mode_confirm(payload) -> bool:
-    """Effective confirm-gate intent for Studio's own local tool loop.
+    """Effective confirm-gate intent for Unsloth's own local tool loop.
 
     Honors the documented default that an unset permission_mode behaves as
     "ask". An explicit confirm_tool_calls (True or False) wins; explicit
@@ -2091,7 +2148,7 @@ def _permission_mode_confirm(payload) -> bool:
 
 
 def _confirm_gate_needs_stream(payload) -> bool:
-    """Whether Studio's local tool-loop confirm gate still requires stream=true.
+    """Whether Unsloth's local tool-loop confirm gate still requires stream=true.
 
     The gate can only prompt while streaming, so a non-streaming request that will
     prompt must 400 up front. auto ("Approve for me") only prompts for a call the
@@ -3062,13 +3119,16 @@ def _normalise_settings_str(value: Optional[str]) -> Optional[str]:
 
 
 def _should_strip_split_mode(request: LoadRequest, backend_extra: Optional[list[str]]) -> bool:
-    """Whether an inherited --split-mode should be stripped on reload.
+    """Whether an inherited --split-mode (and its coupled --tensor-split) should
+    be stripped on reload.
 
     The binary Tensor Parallelism toggle can't carry --split-mode's row/none/
     layer modes, so only strip when the toggle overrides it: tensor being turned
     on, or the inherited mode is tensor (toggle turning it off). Non-tensor modes
-    survive. Shared by the inheritance strip and the already-loaded stale check
-    so they agree on what reload would do.
+    survive. A manual per-GPU ratio is handled by _should_strip_tensor_split,
+    which strips only --tensor-split so the inherited mode is kept. Shared by the
+    inheritance strip and the already-loaded stale check so they agree on what
+    reload would do.
     """
     fields_set = getattr(request, "model_fields_set", set())
     return "tensor_parallel" in fields_set and (
@@ -3076,6 +3136,25 @@ def _should_strip_split_mode(request: LoadRequest, backend_extra: Optional[list[
     )
 
 
+def _should_strip_tensor_split(request: LoadRequest) -> bool:
+    """Whether an inherited --tensor-split alone should be stripped on reload.
+
+    Manual explicit offload (gpu_layers >= 0) owns the per-GPU split: with a ratio
+    it emits its own --tensor-split (an inherited one, appended last, would
+    override it), and with the ratio cleared it wants llama.cpp's default
+    free-VRAM split. Either way an inherited --tensor-split must go, else the
+    cleared case silently keeps the stale ratio while status reports None.
+    Unlike _should_strip_split_mode this leaves --split-mode untouched, so a
+    user's row/none/layer mode survives a Studio split-ratio edit. When the
+    Tensor Parallelism toggle IS overriding the mode, _should_strip_split_mode
+    (called alongside this at every site) strips --split-mode anyway.
+    """
+    return (
+        getattr(request, "gpu_memory_mode", "auto") == "manual"
+        and getattr(request, "gpu_layers", -1) >= 0
+    )
+
+
 def _carry_preserved_tensor_intent(
     *, preserved: bool, same_model: bool, explicit_drop: bool
 ) -> bool:
@@ -3090,7 +3169,7 @@ def _is_explicit_tensor_drop(request: LoadRequest) -> bool:
     """True only when the request explicitly selects a non-tensor --split-mode (e.g.
     layer/row/none), a deliberate departure from a preserved tensor->layer fallback.
 
-    A bare tensor_parallel field is NOT a drop: the Studio UI always sends it and echoes
+    A bare tensor_parallel field is NOT a drop: the Unsloth UI always sends it and echoes
     the /load response's resolved value back, so after a fallback every reload carries
     tensor_parallel=false even though the user never changed it -- treating that as a drop
     would collapse the preserved multi-GPU placement on the next ctx/settings reload. An
@@ -3134,12 +3213,39 @@ def _request_matches_loaded_settings(
         else strip_shadowing_flags(
             backend_extra,
             strip_split_mode = _should_strip_split_mode(request, backend_extra),
+            strip_tensor_split = _should_strip_tensor_split(request),
+            strip_offload = request.gpu_memory_mode == "manual",
         )
     )
     if not _tensor_parallel_matches_loaded(
         effective_extra, request.tensor_parallel, llama_backend.tensor_parallel
     ):
         return False
+    # The diffusion runner is mode-agnostic (it always reports "auto" and ignores
+    # the layer/MoE/split knobs), so a standing manual preference in the request
+    # must not force a needless reload -- only the GPU pick matters.
+    if not llama_backend.is_diffusion:
+        if request.gpu_memory_mode != llama_backend.gpu_memory_mode:
+            return False
+        # Manual: a layer-count change always reloads; MoE/split only matter with
+        # an explicit offload (gpu_layers >= 0), so a leftover value under Auto
+        # must not force one. Mirrors LlamaCppBackend._already_in_target_state.
+        if request.gpu_memory_mode == "manual" and (
+            request.gpu_layers != llama_backend.gpu_layers
+            or (
+                request.gpu_layers >= 0
+                and (
+                    request.n_cpu_moe != llama_backend.n_cpu_moe
+                    or (request.tensor_split or None) != (llama_backend.tensor_split or None)
+                )
+            )
+        ):
+            return False
+    # A regular GGUF may narrow the requested placement pool. Accept either the
+    # original request or the effective status-echoed subset; diffusion keeps
+    # its single-device normalization.
+    if not llama_backend.matches_gpu_ids(request.gpu_ids):
+        return False
     # Preserved tensor->layer fallback (both report tensor=off, so the check above
     # matches): if the user now explicitly drops tensor intent, reload so placement
     # re-selects instead of keeping the all-GPU mask (#6659). The effective check
@@ -3182,14 +3288,17 @@ def _request_matches_loaded_settings(
     # contain any shadow flag, so the reload path strips them rather than
     # leaving a stale override in effect. (backend_extra computed above.)
     if request.llama_extra_args is None:
-        # Mirror the reload's conditional split-mode strip, so a preserved
-        # non-tensor mode (row/none/layer) isn't seen as stale and doesn't
-        # trigger a needless reload of a healthy server.
+        # Mirror the reload's conditional strips, so a preserved non-tensor mode
+        # (row/none/layer) isn't seen as stale and doesn't trigger a needless
+        # reload of a healthy server, while an inherited offload/ratio flag that
+        # the reload *would* strip is correctly seen as stale.
         if (
             backend_extra
             and strip_shadowing_flags(
                 backend_extra,
                 strip_split_mode = _should_strip_split_mode(request, backend_extra),
+                strip_tensor_split = _should_strip_tensor_split(request),
+                strip_offload = request.gpu_memory_mode == "manual",
             )
             != backend_extra
         ):
@@ -3296,9 +3405,8 @@ async def _acquire_swap_gate() -> None:
         await asyncio.sleep(0.02)
 
 
-# Counts in-flight auto-switch requests per (target, variant). The busy guard
-# subtracts same-target waiters so concurrent requests for one model load once
-# instead of each 409-ing the other.
+# Counts auto-switch requests queued to load each (target, variant). They are not
+# generating, so the drain wait below excludes them from the active inference count.
 _auto_switch_waiters: dict[tuple[str, str], int] = {}
 _auto_switch_waiters_guard = threading.Lock()
 
@@ -3316,35 +3424,31 @@ def _note_switch_waiter(key: tuple[str, str], delta: int) -> None:
             _auto_switch_waiters.pop(key, None)
 
 
-def _same_target_waiters(key: tuple[str, str]) -> int:
+def _switch_waiter_count() -> int:
     with _auto_switch_waiters_guard:
-        return _auto_switch_waiters.get(key, 0)
+        return sum(max(0, count) for count in _auto_switch_waiters.values())
 
 
-# A second waiter map keyed by the raw requested model, registered before the
-# (slow) resolve. The middleware counts a concurrent same-model request as
-# in-flight before it resolves and joins _auto_switch_waiters, so without this
-# the first request would see it as an unrelated request and 409.
-_auto_switch_request_waiters: dict[str, int] = {}
-_auto_switch_request_waiters_guard = threading.Lock()
+async def _wait_for_model_switch_idle(*, current_request_counted: bool) -> None:
+    """Wait until a model replacement cannot interrupt active inference.
 
-
-def _request_waiter_key(requested_model: str) -> str:
-    return requested_model.strip().lower()
-
-
-def _note_request_waiter(key: str, delta: int) -> None:
-    with _auto_switch_request_waiters_guard:
-        n = _auto_switch_request_waiters.get(key, 0) + delta
-        if n > 0:
-            _auto_switch_request_waiters[key] = n
-        else:
-            _auto_switch_request_waiters.pop(key, None)
-
-
-def _same_request_waiters(key: str) -> int:
-    with _auto_switch_request_waiters_guard:
-        return _auto_switch_request_waiters.get(key, 0)
+    The caller holds ``inference_lifecycle_gate``, which prevents new inference
+    from starting while existing requests drain. Auto-switch requests that have
+    resolved their targets are scheduler waiters, not active generations, so
+    exclude them to avoid a queue deadlock.
+    """
+    from core.inference.llama_keepwarm import other_inference_request_count
+    while True:
+        queued_switches = _switch_waiter_count()
+        if current_request_counted and queued_switches > 0:
+            queued_switches -= 1
+        active_others = other_inference_request_count(
+            current_request_counted = current_request_counted,
+            include_pending = False,
+        )
+        if active_others <= queued_switches:
+            return
+        await asyncio.sleep(0.02)
 
 
 def _llama_public_model_id(llama_backend, fallback: Optional[str] = None) -> Optional[str]:
@@ -3472,7 +3576,6 @@ async def _maybe_auto_switch_model(
     from core.inference.local_model_resolver import resolve_local_gguf
     from core.inference.llama_keepwarm import (
         get_last_unloaded_model,
-        other_inference_request_count,
         inference_lifecycle_gate,
     )
 
@@ -3493,12 +3596,7 @@ async def _maybe_auto_switch_model(
     if not auto_switch_on and get_auto_unload_idle_seconds() <= 0:
         return
 
-    # Register by the raw requested model before resolving (which can be slow):
-    # the middleware already counts a concurrent same-model request as in-flight,
-    # so the busy guard must know it shares this target even while it resolves.
-    request_key = _request_waiter_key(requested_model)
-    _note_request_waiter(request_key, 1)
-    try:
+    async def _resolve_and_switch() -> None:
         # Off the loop: a cold-cache rebuild walks several model dirs + HF caches.
         # With auto-switch off (or an omitted-model reload-only request), skip the
         # resolve so only the reload-stash path runs and no name is ever matched.
@@ -3596,6 +3694,7 @@ async def _maybe_auto_switch_model(
             )
         key = _switch_key(override_id, variant)
         _note_switch_waiter(key, 1)
+        waiter_noted = True
         try:
             async with _auto_switch_lock():
                 # The asyncio lock is per loop; add a process-wide gate so a swap on
@@ -3608,31 +3707,6 @@ async def _maybe_auto_switch_model(
                         if _already_serving():
                             _record_serving_alias()
                             return
-                        # Single slot: refuse a cross-model swap while another inference
-                        # request is active rather than killing its response. Requests
-                        # heading to this same target (by resolved id or raw name) are
-                        # excluded, so concurrent requests for one model load once. A
-                        # pending request is still in the middleware, not generating, so
-                        # it is not counted here.
-                        same_others = max(
-                            _same_target_waiters(key) - 1, _same_request_waiters(request_key) - 1, 0
-                        )
-                        others = other_inference_request_count(
-                            current_request_counted = True, include_pending = False
-                        )
-                        # Not gated on the GGUF being loaded: _load_model_impl also
-                        # tears down an active Unsloth backend before loading a GGUF,
-                        # so refuse whenever any other inference request is in flight.
-                        if others > same_others:
-                            raise HTTPException(
-                                status_code = 409,
-                                detail = openai_error_body(
-                                    "Cannot switch models while another inference request is in progress.",
-                                    status = 409,
-                                    code = "model_switch_busy",
-                                    param = "model",
-                                ),
-                            )
                         # Apply this model's saved launch flags so the swap honors the config.
                         override = get_model_override(override_id)
                         load_kwargs = {"model_path": target_id, "gguf_variant": variant}
@@ -3647,16 +3721,22 @@ async def _maybe_auto_switch_model(
                             LoadRequest(**load_kwargs),
                             fastapi_request,
                             current_subject,
+                            current_request_counted = True,
                         )
                         # Advertise the repo id (not the concrete load path) as the loaded
                         # model's public id and override key for /v1/models and idle stash.
                         get_llama_cpp_backend()._openai_advertised_id = override_id
                 finally:
+                    # Deregister before releasing the gate: otherwise a swap on another
+                    # loop counts this finished request as queued and unloads its model.
+                    _note_switch_waiter(key, -1)
+                    waiter_noted = False
                     _auto_switch_process_lock.release()
         finally:
-            _note_switch_waiter(key, -1)
-    finally:
-        _note_request_waiter(request_key, -1)
+            if waiter_noted:
+                _note_switch_waiter(key, -1)
+
+    await _resolve_and_switch()
 
 
 async def _auto_switch_from_request_body(request: Request, current_subject: str):
@@ -3808,6 +3888,113 @@ def _estimate_gguf_required_gb(
         return None
 
 
+def _classify_diffusion_gguf(config: ModelConfig) -> Optional[bool]:
+    """Classify a GGUF as diffusion, normal, or unknown before it is loaded.
+
+    ``None`` is important here: a remote GGUF whose header is not cached can
+    still be routed to the single-GPU diffusion runner after download. Default
+    placement keeps that unknown case guarded until the header is available.
+    """
+    identity = " ".join(
+        str(getattr(config, attr, "") or "") for attr in ("identifier", "gguf_hf_repo", "gguf_file")
+    ).lower()
+    # Name-only hint, used ONLY as a pre-download fallback, scoped to the
+    # DiffusionGemma runner family: a bare "diffusion" substring is common in
+    # ordinary text-model names/paths (e.g. "stable-diffusion-prompt"), and treating
+    # those as diffusion falsely rejects a valid Vulkan+gpu_ids GGUF (#7239). Normalize
+    # non-alphanumerics so "DiffusionGemma"/"diffusion-gemma" collapse to one token.
+    # The local header below stays authoritative.
+    name_says_diffusion = "diffusiongemma" in _re.sub(r"[^a-z0-9]+", "", identity)
+
+    try:
+        main = getattr(config, "gguf_file", None)
+        if not (main and Path(main).is_file()):
+            repo = getattr(config, "gguf_hf_repo", None)
+            variant = getattr(config, "gguf_variant", None)
+            if repo and variant:
+                from hub.utils.gguf import resolve_local_gguf_path
+                main = resolve_local_gguf_path(repo, variant)
+        if main and Path(main).is_file():
+            # The local GGUF header is authoritative (same probe the loader uses), so
+            # it can't be fooled by a "diffusion"-flavored name/path.
+            probe = LlamaCppBackend()
+            probe._read_gguf_metadata(str(main))
+            if probe.is_diffusion:
+                return True
+            # A decoded architecture proves a normal llama-server GGUF; no architecture
+            # means the probe was inconclusive, so fall through to the name hint below.
+            if getattr(probe, "_architecture", None):
+                return False
+    except Exception as e:
+        logger.debug("Could not identify diffusion GGUF for training guard: %s", e)
+
+    # Header unavailable (remote uncached) or inconclusive: True only for the
+    # DiffusionGemma name family; otherwise None keeps an unknown remote GGUF guarded
+    # as potentially diffusion until its header proves otherwise.
+    return True if name_says_diffusion else None
+
+
+async def _resolve_gguf_gpu_ids_for_request(
+    config: ModelConfig, gpu_ids: Optional[List[int]]
+) -> Optional[List[int]]:
+    """Resolve and fully validate an explicit GGUF GPU placement pool.
+
+    CUDA and ROCm use physical IDs. Vulkan uses ggml ordinals, so its device
+    existence check comes from the same ggml probe used by the loader. Both
+    /load and /validate call this before their training guard or any teardown.
+    """
+    if not gpu_ids:
+        return None
+
+    from utils.hardware import DeviceType, get_device
+    from utils.hardware.hardware import resolve_requested_gpu_ids
+
+    is_vulkan = LlamaCppBackend._is_vulkan_backend()
+    if get_device() == DeviceType.XPU and not is_vulkan:
+        raise HTTPException(
+            status_code = 400,
+            detail = (
+                "GPU selection (gpu_ids) is not supported on Intel XPU. "
+                "Omit gpu_ids to use all devices."
+            ),
+        )
+
+    if is_vulkan and _classify_diffusion_gguf(config) is True:
+        raise HTTPException(
+            status_code = 400,
+            detail = (
+                "GPU selection (gpu_ids) is not supported for a DiffusionGemma "
+                "GGUF on a Vulkan llama.cpp build: the diffusion runner selects "
+                "its device by CUDA physical index, which has no defined mapping "
+                "to ggml Vulkan device ordinals. Omit gpu_ids to use the default "
+                "device."
+            ),
+        )
+
+    try:
+        resolved = resolve_requested_gpu_ids(gpu_ids, is_vulkan = is_vulkan)
+    except ValueError as exc:
+        raise HTTPException(status_code = 400, detail = str(exc)) from exc
+
+    if is_vulkan and resolved:
+        binary = LlamaCppBackend._find_llama_server_binary()
+        if binary:
+            probed = {
+                gpu[0] for gpu in await asyncio.to_thread(LlamaCppBackend._get_gpu_memory, binary)
+            }
+            wanted = {int(gpu_id) for gpu_id in resolved}
+            if not wanted.issubset(probed):
+                raise HTTPException(
+                    status_code = 400,
+                    detail = (
+                        f"Requested Vulkan GPU ordinal(s) {sorted(wanted)} not "
+                        f"present. Available Vulkan devices: {sorted(probed)}."
+                    ),
+                )
+
+    return resolved
+
+
 def _guard_chat_load_against_training(
     config: ModelConfig,
     *,
@@ -3818,11 +4005,19 @@ def _guard_chat_load_against_training(
     requested_gpu_ids: Optional[List[int]],
     llama_extra_args: Optional[list[str]] = None,
     n_parallel: int = 1,
+    gpu_memory_mode: Literal["auto", "manual"] = "auto",
 ) -> None:
-    """Refuse loading a local chat model that would OOM an active training run.
+    """Protect active training from automatically placed chat-model loads.
+
     No-op when training is inactive or unknown. `load_in_4bit` must be the
-    effective quantization (see _effective_load_in_4bit). Raises HTTP 409 when the
-    model would not fit alongside training."""
+    effective quantization (see _effective_load_in_4bit). Manual chat-GGUF
+    placement is an explicit override: Auto layers delegate fitting to
+    llama.cpp's ``--fit`` and pinned layers are owned by the user, so neither is
+    estimated here. Diffusion is still guarded because its mode-agnostic runner
+    ignores those controls and uses one GPU. An unclassified GGUF is guarded as
+    potentially diffusion until its local header proves otherwise. Other loads
+    raise HTTP 409 when they would not fit beside training.
+    """
     from core.training import get_training_backend
     from routes.training_vram import can_load_chat_during_training
 
@@ -3834,6 +4029,29 @@ def _guard_chat_load_against_training(
         return
 
     is_gguf = bool(getattr(config, "is_gguf", False))
+    diffusion_kind = _classify_diffusion_gguf(config) if is_gguf else False
+    if is_gguf and gpu_memory_mode == "manual" and diffusion_kind is False:
+        return
+
+    # Vulkan GGUF pins are ggml ordinals, not CUDA physical IDs. Detect this
+    # before deriving a possible diffusion fallback device so an unknown remote
+    # GGUF never sends its ordinal through the CUDA single-device path.
+    is_vulkan = False
+    if is_gguf:
+        try:
+            is_vulkan = LlamaCppBackend._is_vulkan_backend()
+        except Exception as e:
+            logger.warning("Could not detect Vulkan backend for chat-load guard: %s", e)
+
+    diffusion_gpu = None
+    if is_gguf and diffusion_kind is not False and not (is_vulkan and requested_gpu_ids):
+        # Use the same token selection as the runner: an explicit pick wins,
+        # followed by DG_GPU, the first parent-visible token, then GPU 0.
+        diffusion_gpu = LlamaCppBackend._diffusion_gpu_arg(
+            requested_gpu_ids,
+            cpu_only = LlamaCppBackend._effective_gpu_count() == 0,
+        )
+
     required_override_gb = (
         _estimate_gguf_required_gb(
             config,
@@ -3853,7 +4071,9 @@ def _guard_chat_load_against_training(
         max_seq_length = max_seq_length,
         requested_gpu_ids = requested_gpu_ids,
         is_gguf = is_gguf,
+        is_vulkan = is_vulkan,
         required_override_gb = required_override_gb,
+        single_device_gpu = diffusion_gpu,
     )
     if ok:
         return
@@ -3881,6 +4101,98 @@ def _guard_chat_load_against_training(
     raise HTTPException(status_code = 409, detail = detail)
 
 
+def _resolve_inherited_extra_args(
+    request,
+    config: ModelConfig,
+    model_identifier: str,
+    extra_llama_args: Optional[list[str]],
+    effective_chat_template_override: Optional[str] = None,
+) -> Optional[list[str]]:
+    """Effective pass-through extras for a GGUF request that omitted the field:
+    the previous same-model load's extras, shadow-stripped, so a settings-Apply
+    reload (which does not round-trip the extras field) keeps them (#5401)."""
+    if getattr(request, "llama_extra_args", None) is not None:
+        return extra_llama_args
+    if not getattr(config, "is_gguf", False):
+        return extra_llama_args
+    llama_backend = get_llama_cpp_backend()
+    if not llama_backend.extra_args:
+        return extra_llama_args
+    # Inherit the previous load's extras (the chat-settings Apply path doesn't
+    # round-trip them; an explicit [] still clears). Gated on (model_identifier,
+    # hf_variant) to refuse cross-model pickup, and shadowing flags are
+    # stripped so an inherited override can't win the last-wins CLI
+    # parse against a freshly-supplied first-class field.
+    source = llama_backend.extra_args_source
+    # Compare against the resolved variant, not the request field: callers
+    # commonly omit gguf_variant for local ``.gguf`` paths and HF auto-pick
+    # flows. ``config.gguf_variant`` is the variant load_model was actually
+    # invoked with, so both sides of the comparison key off the same string.
+    resolved_variant = (config.gguf_variant or "").lower()
+    request_variant = (request.gguf_variant or "").lower()
+    stored_variant = (source[1] or "").lower() if source else ""
+    same_model = bool(source and source[0] and source[0].lower() == model_identifier.lower())
+    if request.gguf_variant:
+        variant_mismatch = request_variant != stored_variant
+    else:
+        variant_mismatch = bool(stored_variant and resolved_variant != stored_variant)
+    same_source = same_model and not variant_mismatch
+    if not same_source:
+        logger.info(
+            "Not inheriting llama_extra_args: stored args came from %s, loading %s",
+            source,
+            (model_identifier, resolved_variant),
+        )
+        # Cross-model: clear explicitly so the backend doesn't
+        # inherit via "no opinion" semantics.
+        extra_llama_args = []
+    else:
+        # Strip only the groups whose first-class field was set by the caller, so
+        # an inherited --chat-template-file survives an Apply that omits
+        # chat_template_override. A bundled family template (e.g. gemma-4) counts as
+        # a first-class template even when the request omits chat_template_override,
+        # so strip the inherited --chat-template-file then too -- else the stale arg
+        # (appended last) shadows the bundled template while Studio reports its caps.
+        fields_set = getattr(request, "model_fields_set", set())
+        stripped = strip_shadowing_flags(
+            llama_backend.extra_args,
+            strip_context = "max_seq_length" in fields_set,
+            strip_cache = "cache_type_kv" in fields_set,
+            strip_spec = ("speculative_type" in fields_set or "spec_draft_n_max" in fields_set),
+            strip_template = (
+                "chat_template_override" in fields_set
+                or effective_chat_template_override is not None
+            ),
+            strip_split_mode = _should_strip_split_mode(request, llama_backend.extra_args),
+            # manual + per-GPU ratio emits its own --tensor-split; drop
+            # an inherited one (appended last would override it) while
+            # keeping the user's --split-mode row/none/layer choice.
+            strip_tensor_split = _should_strip_tensor_split(request),
+            # manual emits its own --fit/--gpu-layers, so an inherited offload flag
+            # must not last-wins-override it. auto leaves a user's inherited -ngl
+            # alone. getattr: a validate request reuses this resolver, no offload fields.
+            strip_offload = getattr(request, "gpu_memory_mode", "auto") == "manual",
+        )
+        try:
+            extra_llama_args = validate_extra_args(stripped)
+        except ValueError:
+            # Shouldn't happen on already-validated args; degrade to
+            # no-extras rather than 400 if managed flags changed.
+            logger.warning(
+                "Stored llama_extra_args failed revalidation; loading without them: %s",
+                stripped,
+            )
+            extra_llama_args = []
+        else:
+            if extra_llama_args:
+                logger.info(
+                    "Inheriting llama_extra_args from previous "
+                    "load (same model, shadow-stripped): %s",
+                    extra_llama_args,
+                )
+    return extra_llama_args
+
+
 def _model_json_response(model, status_code: int = 200) -> Response:
     """Serialize a pydantic response once via pydantic-core.
 
@@ -3922,6 +4234,15 @@ def _maybe_unsupported_message(msg: str) -> str:
     return msg
 
 
+def _raise_if_sidecar_swap_in_progress() -> None:
+    from utils.transformers_version import sidecar_swap_in_progress
+    if sidecar_swap_in_progress():
+        raise HTTPException(
+            status_code = 409,
+            detail = "A transformers installation is in progress. Retry when it completes.",
+        )
+
+
 @router.post("/load", response_model = LoadResponse)
 async def load_model(
     request: LoadRequest,
@@ -3942,24 +4263,23 @@ async def load_model(
     # install can reserve while this request queues on the gate, so the pre-gate
     # check alone is only a fast path.
     from core.inference.llama_keepwarm import inference_lifecycle_gate
-    from utils.transformers_version import sidecar_swap_in_progress
 
-    _swap_409 = HTTPException(
-        status_code = 409,
-        detail = "A transformers installation is in progress. Retry when it completes.",
-    )
-    if sidecar_swap_in_progress():
-        raise _swap_409
+    _raise_if_sidecar_swap_in_progress()
     # Hold the lifecycle gate across the load so idle auto-unload can't unload the
     # model mid-load. Auto-switch calls _load_model_impl directly since it already
     # holds this gate.
     async with inference_lifecycle_gate():
-        if sidecar_swap_in_progress():
-            raise _swap_409
+        _raise_if_sidecar_swap_in_progress()
         return await _load_model_impl(request, fastapi_request, current_subject)
 
 
-async def _load_model_impl(request: LoadRequest, fastapi_request: Request, current_subject: str):
+async def _load_model_impl(
+    request: LoadRequest,
+    fastapi_request: Request,
+    current_subject: str,
+    *,
+    current_request_counted: bool = False,
+):
     from core.inference.llama_cpp import LlamaServerNotFoundError
 
     # A new load starts here; arm the progress throttle so this load's first
@@ -3968,6 +4288,7 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
 
     native_grant_backed = False
     model_log_label = request.model_path
+    gguf_load_stack = ExitStack()
     try:
         # Validate user pass-through args up front so a managed-flag collision
         # returns 400 before any model work.
@@ -3986,6 +4307,35 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
             None if request.llama_extra_args is None else extra_llama_args
         )
 
+        # Manual mode owns the offload flags: strip them from EXPLICIT extras
+        # too (the inherited path already does), or a last-wins --gpu-layers /
+        # --fit in extras re-enables GPU offload on a load status reports as
+        # CPU-only. Manual + per-GPU ratio owns --tensor-split the same way.
+        if request.gpu_memory_mode == "manual" and extra_llama_args:
+            _stripped_explicit = strip_shadowing_flags(
+                extra_llama_args,
+                strip_context = False,
+                strip_cache = False,
+                strip_spec = False,
+                strip_template = False,
+                strip_split_mode = False,
+                strip_tensor_split = _should_strip_tensor_split(request),
+                strip_offload = True,
+            )
+            if _stripped_explicit != extra_llama_args:
+                logger.info(
+                    "Manual GPU memory owns the offload flags; stripping them "
+                    "from explicit llama_extra_args: %s -> %s",
+                    extra_llama_args,
+                    _stripped_explicit,
+                )
+                extra_llama_args = _stripped_explicit
+
+        # Keep every downstream consumer on the normalized explicit list. In
+        # particular, the already-loaded comparator must not compare the raw
+        # request's managed offload flags against the stripped launch state.
+        request = request.model_copy(update = {"llama_extra_args": extra_llama_args})
+
         model_identifier, model_log_label, native_grant_backed = (
             _resolve_model_identifier_for_request(request, operation = "load-model")
         )
@@ -4028,6 +4378,7 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
                 # Skip if a prior audio probe failed -- let load_model retry.
                 and getattr(llama_backend, "_audio_probed", True)
             ):
+                llama_backend._record_matching_gpu_request(request.gpu_ids)
                 logger.info(
                     "Model already loaded (GGUF): "
                     f"{model_log_label} variant={request.gguf_variant or llama_backend.hf_variant}, skipping reload"
@@ -4067,6 +4418,14 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
                     speculative_type = llama_backend.requested_spec_mode,
                     spec_draft_n_max = llama_backend.spec_draft_n_max,
                     tensor_parallel = llama_backend.tensor_parallel,
+                    gpu_memory_mode = llama_backend.gpu_memory_mode,
+                    gpu_layers = llama_backend.gpu_layers,
+                    n_cpu_moe = llama_backend.n_cpu_moe,
+                    tensor_split = llama_backend.tensor_split,
+                    n_layers = llama_backend.n_layers,
+                    n_moe_layers = llama_backend.n_moe_layers,
+                    gpu_ids = llama_backend.gpu_ids,
+                    requested_gpu_ids = llama_backend.requested_gpu_ids,
                 )
         else:
             if (
@@ -4133,18 +4492,18 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
         # Normalize gpu_ids: empty list means auto-selection, same as None
         effective_gpu_ids = request.gpu_ids if request.gpu_ids else None
 
-        # Reject GGUF + gpu_ids first so the guard can't mask it with a VRAM 409.
-        if config.is_gguf and effective_gpu_ids is not None:
-            raise HTTPException(
-                status_code = 400,
-                detail = "gpu_ids is not supported for GGUF models yet.",
-            )
+        # Validate the full GGUF placement pool before the training guard so an
+        # invalid physical ID or Vulkan ordinal is a clean 400, not a masked VRAM
+        # 409. The same helper is used by /validate.
+        gguf_gpu_ids: Optional[List[int]] = None
+        if config.is_gguf:
+            gguf_gpu_ids = await _resolve_gguf_gpu_ids_for_request(config, effective_gpu_ids)
         if not config.is_gguf and _mlx_distributed_launch_detected():
             raise HTTPException(
                 status_code = 400,
                 detail = (
-                    "Studio does not support distributed MLX inference under "
-                    "mlx.launch. Use `mlx.launch ... unsloth chat` or run Studio "
+                    "Unsloth does not support distributed MLX inference under "
+                    "mlx.launch. Use `mlx.launch ... unsloth chat` or run Unsloth "
                     "without the distributed launcher."
                 ),
             )
@@ -4168,8 +4527,20 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
                     "architectures)"
                 )
 
-        # Refuse a load that would OOM active training, before the unload step below
-        # frees the resident model. Off-loop: guard does sync nvidia-smi / HF work.
+        # Inherit the previous same-model load's pass-through extras when this
+        # request omits the field (a settings-Apply reload doesn't round-trip
+        # them); shadow-stripped so an inherited flag can't override a
+        # first-class field the caller did set (#5401).
+        extra_llama_args = _resolve_inherited_extra_args(
+            request,
+            config,
+            model_identifier,
+            extra_llama_args,
+            effective_chat_template_override,
+        )
+
+        # Apply the training coexistence policy before the unload step below
+        # frees the resident model. Off-loop: the default-mode guard does sync work.
         await asyncio.to_thread(
             _guard_chat_load_against_training,
             config,
@@ -4180,6 +4551,7 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
             requested_gpu_ids = effective_gpu_ids,
             llama_extra_args = extra_llama_args,
             n_parallel = getattr(fastapi_request.app.state, "llama_parallel_slots", 1),
+            gpu_memory_mode = request.gpu_memory_mode,
         )
 
         # ── GGUF path: load via llama-server ──────────────────────
@@ -4187,8 +4559,41 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
             llama_backend = get_llama_cpp_backend()
             unsloth_backend = get_inference_backend()
 
-            # Unload any active Unsloth model to free VRAM (off the event loop:
-            # unload takes _gen_lock and can wait on an in-flight stream).
+            if config.gguf_hf_repo:
+                from core.inference.llama_cpp import gguf_load_in_flight
+                gguf_load_stack.enter_context(gguf_load_in_flight(config.gguf_hf_repo))
+
+            # Block cache writes that would race the download manager. This runs
+            # after pass-through argument inheritance so a carried --no-mmproj
+            # changes the companion requirement exactly as it does for the load.
+            if config.gguf_hf_repo:
+                from core.inference.llama_cpp import _hub_download_blocks_gguf_load
+                if await asyncio.to_thread(
+                    _hub_download_blocks_gguf_load,
+                    config.gguf_hf_repo,
+                    config.gguf_variant,
+                    require_mmproj = bool(
+                        config.is_vision and not extra_args_disable_mmproj(extra_llama_args)
+                    ),
+                    hf_token = request.hf_token,
+                ):
+                    raise HTTPException(
+                        status_code = 409,
+                        detail = (
+                            f"'{model_log_label}' is currently being downloaded "
+                            "by the download manager. Wait for the download to "
+                            "finish (or cancel it), then load the model."
+                        ),
+                    )
+
+            # Keep the resident model alive until every active generation finishes;
+            # the caller's lifecycle gate blocks new starts.
+            await _wait_for_model_switch_idle(current_request_counted = current_request_counted)
+            # A sidecar install can reserve the gate while inference drains, after the
+            # route-level checks above, so recheck before replacing either backend.
+            _raise_if_sidecar_swap_in_progress()
+
+            # Unload any active Unsloth model only after every hub conflict check.
             if unsloth_backend.active_model_name:
                 logger.info(
                     f"Unloading Unsloth model '{unsloth_backend.active_model_name}' before loading GGUF"
@@ -4197,84 +4602,6 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
                     unsloth_backend.unload_model, unsloth_backend.active_model_name
                 )
 
-            # Inherit llama_extra_args from the previous load when the request
-            # omits the field (the chat-settings Apply path doesn't round-trip
-            # them; explicit [] still clears). Gated on (model_identifier,
-            # hf_variant) to refuse cross-model pickup, and shadowing flags are
-            # stripped so an inherited override can't win the last-wins CLI
-            # parse against a freshly-supplied first-class field.
-            if request.llama_extra_args is None and llama_backend.extra_args:
-                source = llama_backend.extra_args_source
-                # Compare against the resolved variant, not the request
-                # field: callers commonly omit gguf_variant for local
-                # ``.gguf`` paths and HF auto-pick flows. ``config.gguf_
-                # variant`` is the variant load_model was actually
-                # invoked with (see the HF / local branches below), so
-                # both sides of the comparison key off the same string.
-                resolved_variant = (config.gguf_variant or "").lower()
-                request_variant = (request.gguf_variant or "").lower()
-                stored_variant = (source[1] or "").lower() if source else ""
-                same_model = bool(
-                    source and source[0] and source[0].lower() == model_identifier.lower()
-                )
-                if request.gguf_variant:
-                    variant_mismatch = request_variant != stored_variant
-                else:
-                    variant_mismatch = bool(stored_variant and resolved_variant != stored_variant)
-                same_source = same_model and not variant_mismatch
-                if not same_source:
-                    logger.info(
-                        "Not inheriting llama_extra_args: stored args came from %s, loading %s",
-                        source,
-                        (model_identifier, resolved_variant),
-                    )
-                    # Cross-model: clear explicitly so the backend doesn't
-                    # inherit via "no opinion" semantics.
-                    extra_llama_args = []
-                else:
-                    # Strip only the groups whose first-class field was set by
-                    # the caller, so an inherited --chat-template-file survives
-                    # an Apply that omits chat_template_override. A bundled family
-                    # template (e.g. the gemma-4 override) is an effective
-                    # first-class template setting even when the raw request
-                    # omits chat_template_override, so strip the inherited
-                    # --chat-template-file in that case too -- otherwise the stale
-                    # extra arg (appended last) shadows the bundled template while
-                    # Studio reports the bundled template's capabilities.
-                    fields_set = getattr(request, "model_fields_set", set())
-                    stripped = strip_shadowing_flags(
-                        llama_backend.extra_args,
-                        strip_context = "max_seq_length" in fields_set,
-                        strip_cache = "cache_type_kv" in fields_set,
-                        strip_spec = (
-                            "speculative_type" in fields_set or "spec_draft_n_max" in fields_set
-                        ),
-                        strip_template = (
-                            "chat_template_override" in fields_set
-                            or effective_chat_template_override is not None
-                        ),
-                        strip_split_mode = _should_strip_split_mode(
-                            request, llama_backend.extra_args
-                        ),
-                    )
-                    try:
-                        extra_llama_args = validate_extra_args(stripped)
-                    except ValueError:
-                        # Shouldn't happen on already-validated args; degrade to
-                        # no-extras rather than 400 if managed flags changed.
-                        logger.warning(
-                            "Stored llama_extra_args failed revalidation; loading without them: %s",
-                            stripped,
-                        )
-                        extra_llama_args = []
-                    else:
-                        if extra_llama_args:
-                            logger.info(
-                                "Inheriting llama_extra_args from previous "
-                                "load (same model, shadow-stripped): %s",
-                                extra_llama_args,
-                            )
-
             # Route to HF or local mode based on config. Run in a thread so the
             # event loop stays free for progress polling and other requests
             # during the (potentially long) GGUF download + llama-server start.
@@ -4290,7 +4617,13 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
                 cache_type_kv = request.cache_type_kv,
                 speculative_type = request.speculative_type,
                 spec_draft_n_max = request.spec_draft_n_max,
+                gpu_memory_mode = request.gpu_memory_mode,
+                gpu_layers = request.gpu_layers,
+                n_cpu_moe = request.n_cpu_moe,
+                tensor_split = request.tensor_split,
                 n_parallel = _n_parallel,
+                # Issue #7164: explicit GPU pin resolved to physical ids above.
+                gpu_ids = gguf_gpu_ids,
             )
             if config.gguf_hf_repo:
                 # HF mode: download via huggingface_hub then start llama-server
@@ -4414,7 +4747,7 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
             # Clear any idle-unload reload stash now, not only on the next poll.
             from core.inference.llama_keepwarm import note_model_loaded
 
-            note_model_loaded()
+            await asyncio.to_thread(note_model_loaded, llama_backend)
             # A plain load advertises its own identifier; auto-switch overwrites
             # this with the repo id right after _load_model_impl returns.
             llama_backend._openai_advertised_id = None
@@ -4457,6 +4790,14 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
                 speculative_type = llama_backend.requested_spec_mode,
                 spec_draft_n_max = llama_backend.spec_draft_n_max,
                 tensor_parallel = llama_backend.tensor_parallel,
+                gpu_memory_mode = llama_backend.gpu_memory_mode,
+                gpu_layers = llama_backend.gpu_layers,
+                n_cpu_moe = llama_backend.n_cpu_moe,
+                tensor_split = llama_backend.tensor_split,
+                n_layers = llama_backend.n_layers,
+                n_moe_layers = llama_backend.n_moe_layers,
+                gpu_ids = llama_backend.gpu_ids,
+                requested_gpu_ids = llama_backend.requested_gpu_ids,
             )
 
         # ── Standard path: load via Unsloth/transformers ──────────
@@ -4464,6 +4805,8 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
 
         # Unload any active GGUF model first
         llama_backend = get_llama_cpp_backend()
+        await _wait_for_model_switch_idle(current_request_counted = current_request_counted)
+        _raise_if_sidecar_swap_in_progress()
         if llama_backend.is_loaded:
             logger.info("Unloading GGUF model before loading Unsloth model")
             llama_backend.unload_model()
@@ -4639,13 +4982,15 @@ async def _load_model_impl(request: LoadRequest, fastapi_request: Request, curre
         logger.error(f"Error loading model: {e}", exc_info = True)
         msg = _maybe_unsupported_message(redacted_msg)
         raise HTTPException(status_code = 500, detail = f"Failed to load model: {msg}")
+    finally:
+        gguf_load_stack.close()
 
 
 def _requires_trust_remote_code_for_model(
     model_identifier: str, hf_token: Optional[str] = None
 ) -> bool:
     """Whether loading this model would execute custom repo code, so the consent
-    dialog must run first. True if the Studio YAML default enables
+    dialog must run first. True if the Unsloth YAML default enables
     ``trust_remote_code`` OR the raw config declares an ``auto_map`` (Hub/local,
     config.json or tokenizer_config.json). Reads raw JSON only; never imports
     model code."""
@@ -4713,7 +5058,9 @@ def _requires_security_review_for_model(
 
 @router.post("/validate", response_model = ValidateModelResponse)
 async def validate_model(
-    request: ValidateModelRequest, current_subject: str = Depends(get_current_subject)
+    request: ValidateModelRequest,
+    fastapi_request: Request = None,
+    current_subject: str = Depends(get_current_subject),
 ):
     """
     Lightweight validation endpoint for model identifiers.
@@ -4741,15 +5088,11 @@ async def validate_model(
                 detail = f"Invalid model identifier: {model_log_label}",
             )
 
-        # Refuse early (before the frontend unloads to load this) if it can't fit
-        # alongside training, using the same settings /load uses so they agree.
+        # Apply the same training coexistence policy as /load before the frontend
+        # unloads the current model.
         effective_gpu_ids = request.gpu_ids if request.gpu_ids else None
-        # Mirror /load: reject GGUF + gpu_ids before the guard so both return 400.
-        if config.is_gguf and effective_gpu_ids is not None:
-            raise HTTPException(
-                status_code = 400,
-                detail = "gpu_ids is not supported for GGUF models yet.",
-            )
+        if config.is_gguf:
+            await _resolve_gguf_gpu_ids_for_request(config, effective_gpu_ids)
         effective_load_in_4bit = _effective_load_in_4bit(config, request.load_in_4bit)
 
         # Both checks cover the [adapter, base] set (matching the scan route and workers):
@@ -4813,16 +5156,32 @@ async def validate_model(
                 latest_tier_active_for, config.identifier, request.hf_token
             ):
                 effective_load_in_4bit = False
-        # Off-loop: guard does sync nvidia-smi / HF work.
-        await asyncio.to_thread(
-            _guard_chat_load_against_training,
-            config,
-            model_identifier = model_identifier,
-            hf_token = request.hf_token,
-            load_in_4bit = effective_load_in_4bit,
-            max_seq_length = request.max_seq_length,
-            requested_gpu_ids = effective_gpu_ids,
-        )
+        # A metadata-only probe reads the GGUF header and allocates no VRAM, so the
+        # training guard must not refuse it. Real loads omit include_context_length /
+        # include_chat_template, and /load applies the guard again.
+        if not (request.include_context_length or request.include_chat_template):
+            # Match /load's inherited llama.cpp extras and parallel slot count so
+            # validation cannot pass a smaller estimate than the subsequent load.
+            effective_extra_args = _resolve_inherited_extra_args(
+                request, config, model_identifier, None
+            )
+            # Off-loop: guard does sync nvidia-smi / HF work.
+            await asyncio.to_thread(
+                _guard_chat_load_against_training,
+                config,
+                model_identifier = model_identifier,
+                hf_token = request.hf_token,
+                load_in_4bit = effective_load_in_4bit,
+                max_seq_length = request.max_seq_length,
+                requested_gpu_ids = effective_gpu_ids,
+                llama_extra_args = effective_extra_args,
+                n_parallel = (
+                    getattr(fastapi_request.app.state, "llama_parallel_slots", 1)
+                    if fastapi_request is not None
+                    else 1
+                ),
+                gpu_memory_mode = request.gpu_memory_mode,
+            )
 
         # A selected GGUF loads via llama.cpp: auto_map Python and root pickle weights in a
         # mixed repo are inert for this load, so gating on them is a false positive. Only
@@ -4836,10 +5195,21 @@ async def validate_model(
         # Native context length, read from the local GGUF header when present.
         # Lets the staged ("Load on selection" off) flow populate the context
         # slider before the GPU load; None until the file is downloaded.
+        # Staged header dims (one read): native context, total layer count, and
+        # MoE expert-layer count -- let the staged flow size the context, GPU-
+        # layers and manual --n-cpu-moe sliders before the load.
         context_length: Optional[int] = None
-        if request.include_context_length and is_gguf:
+        layer_count: Optional[int] = None
+        moe_layer_count: Optional[int] = None
+        chat_template: Optional[str] = None
+        # Both header probes read the same local GGUF, so resolve it once.
+        if (request.include_context_length or request.include_chat_template) and is_gguf:
             from hub.utils.gguf import resolve_local_gguf_path
-            from utils.models.gguf_metadata import read_gguf_context_length
+            from picker.schemas import MAX_CHAT_TEMPLATE_BYTES
+            from utils.models.gguf_metadata import (
+                read_gguf_chat_template,
+                read_gguf_staged_dims,
+            )
 
             # Best-effort: a header-read failure must never fail validation of an
             # otherwise-valid model (the outer except turns it into a 400).
@@ -4855,9 +5225,26 @@ async def validate_model(
                         model_identifier, request.gguf_variant
                     )
                 if local_gguf:
-                    context_length = read_gguf_context_length(local_gguf)
+                    if request.include_context_length:
+                        # Header walk reads tokenizer arrays (tens of ms); keep it
+                        # off the event loop.
+                        dims = await asyncio.to_thread(read_gguf_staged_dims, local_gguf)
+                        if dims:
+                            context_length = dims["context_length"]
+                            layer_count = dims["layer_count"]
+                            moe_layer_count = dims["moe_layer_count"]
+                    if request.include_chat_template:
+                        # Read only the leased GGUF's own embedded template (the copy
+                        # llama.cpp loads), never a sibling sidecar: the native grant
+                        # authorizes just this path, so neighbours would be scope escalation.
+                        raw_template = await asyncio.to_thread(read_gguf_chat_template, local_gguf)
+                        if (
+                            raw_template is not None
+                            and len(raw_template.encode("utf-8")) <= MAX_CHAT_TEMPLATE_BYTES
+                        ):
+                            chat_template = raw_template
             except Exception as e:
-                logger.debug("Context-length probe failed for %s: %s", model_log_label, e)
+                logger.debug("Header probe failed for %s: %s", model_log_label, e)
 
         return ValidateModelResponse(
             valid = True,
@@ -4872,6 +5259,9 @@ async def validate_model(
             requires_trust_remote_code = requires_trust_remote_code,
             requires_security_review = requires_security_review,
             context_length = context_length,
+            layer_count = layer_count,
+            moe_layer_count = moe_layer_count,
+            chat_template = chat_template,
             requires_transformers_upgrade = transformers_upgrade is not None,
             transformers_upgrade = transformers_upgrade,
         )
@@ -4884,6 +5274,14 @@ async def validate_model(
         raise HTTPException(status_code = 400, detail = str(e))
     except Exception as e:
         redacted_msg = redact_native_paths(str(e))
+        if is_hf_authentication_error(e):
+            raise HTTPException(
+                status_code = 400,
+                detail = (
+                    "Hugging Face authentication failed. Check or clear the token "
+                    "in Settings, and confirm access to this gated repository."
+                ),
+            )
         if _is_unsupported_nvfp4_inference_error(redacted_msg):
             logger.warning(
                 "NVFP4 inference is not supported yet while validating '%s'",
@@ -5278,7 +5676,7 @@ async def confirm_tool_call(
 
 @studio_router.get("/monitor")
 async def get_api_monitor(current_subject: str = Depends(get_current_subject)):
-    """Return recent OpenAI-compatible API activity for Studio."""
+    """Return recent OpenAI-compatible API activity for Unsloth."""
     active_model = _monitor_active_model()
     active_requests = api_monitor.active_count(subject = current_subject)
     if active_requests:
@@ -5392,6 +5790,10 @@ async def generate_stream(
                 if chunk is _DONE:
                     completed = True
                     break
+                if isinstance(chunk, GenStreamError):
+                    yield f"data: {json.dumps({'error': _friendly_gen_stream_error(chunk)})}\n\n"
+                    yield "data: [DONE]\n\n"
+                    return
                 yield f"data: {json.dumps({'content': chunk})}\n\n"
             if completed:
                 yield "data: [DONE]\n\n"
@@ -5405,6 +5807,7 @@ async def generate_stream(
             backend.reset_generation_state()
             logger.error(f"Error during generation: {e}", exc_info = True)
             yield f"data: {json.dumps({'error': _friendly_error(e)})}\n\n"
+            yield "data: [DONE]\n\n"
         finally:
             await _stop_local_disconnect_cancel_watcher(disconnect_watcher)
             if not completed and not cancel_event.is_set():
@@ -5432,10 +5835,15 @@ async def get_status(current_subject: str = Depends(get_current_subject)):
         try:
             _bin = type(llama_backend)._find_llama_server_binary()
             _caps = type(llama_backend).probe_server_capabilities(_bin)
-            _supports_mtp = bool(_caps.get("supports_mtp", False))
+            # Fail open on inconclusive probes: False means a definitive
+            # "binary lacks MTP" to API consumers.
+            _supports_mtp = bool(
+                _caps.get("supports_mtp", False)
+                or (_caps.get("found", False) and _caps.get("mtp_probe_inconclusive", False))
+            )
         except Exception:
             _bin = None
-            _supports_mtp = True  # fail open
+            _supports_mtp = False  # no usable binary: MTP genuinely unavailable
         try:
             from utils.llama_cpp_freshness import check_prebuilt_freshness
             _freshness = check_prebuilt_freshness(_bin)
@@ -5461,7 +5869,7 @@ async def get_status(current_subject: str = Depends(get_current_subject)):
                 _display_model_id = os.path.basename(_model_id)
             _inference_cfg = load_inference_config(_model_id) if _model_id else None
             _audio_type = getattr(llama_backend, "_audio_type", None)
-            # Don't surface Studio's auto-applied bundled family template (e.g. the
+            # Don't surface Unsloth's auto-applied bundled family template (e.g. the
             # gemma-4 override) as a user-authored override: the frontend adopts
             # status.chat_template_override as editable state and would otherwise
             # re-send it as an explicit override for a later, unrelated model. Only
@@ -5506,6 +5914,15 @@ async def get_status(current_subject: str = Depends(get_current_subject)):
                 speculative_type = llama_backend.requested_spec_mode,
                 spec_draft_n_max = llama_backend.spec_draft_n_max,
                 tensor_parallel = llama_backend.tensor_parallel,
+                gpu_memory_mode = llama_backend.gpu_memory_mode,
+                gpu_layers = llama_backend.gpu_layers,
+                n_cpu_moe = llama_backend.n_cpu_moe,
+                tensor_split = llama_backend.tensor_split,
+                requested_context_length = llama_backend.requested_n_ctx,
+                n_layers = llama_backend.n_layers,
+                n_moe_layers = llama_backend.n_moe_layers,
+                gpu_ids = llama_backend.gpu_ids,
+                requested_gpu_ids = llama_backend.requested_gpu_ids,
                 llama_cpp_supports_mtp = _supports_mtp,
                 spec_fallback_reason = llama_backend.spec_fallback_reason,
                 llama_cpp_prebuilt_stale = _stale,
@@ -5670,6 +6087,7 @@ async def generate_audio(
         # Advertised repo id after an auto-switch load, else a clean public id,
         # never the absolute .gguf path.
         model_name = _llama_public_model_id(llama_backend)
+        _audio_model_id = getattr(llama_backend, "model_identifier", None) or model_name
         gen = lambda: llama_backend.generate_audio_response(
             text = text,
             audio_type = llama_backend._audio_type,
@@ -5688,6 +6106,7 @@ async def generate_audio(
         if not model_info.get("is_audio"):
             raise HTTPException(status_code = 400, detail = "Active model is not an audio model.")
         model_name = public_model_id(backend.active_model_name)
+        _audio_model_id = getattr(backend, "active_model_name", None) or model_name
         gen = lambda: backend.generate_audio_response(
             text = text,
             temperature = payload.temperature,
@@ -5699,6 +6118,13 @@ async def generate_audio(
             use_adapter = payload.use_adapter,
         )
 
+    # Apply per-model recommended sampling + any operator UNSLOTH_SAMPLING_* pin before
+    # generating, so `unsloth run --temperature` (and the other pins) and per-model
+    # recommendations reach audio (TTS) generation too, not just chat. The gen lambdas read
+    # payload.* lazily at call time, so filling here takes effect; this covers both the direct
+    # /audio/generate route and the chat-completions audio branches that delegate here.
+    _fill_recommended_sampling_openai(payload, _audio_model_id)
+
     try:
         wav_bytes, sample_rate = await asyncio.to_thread(gen)
     except Exception as e:
@@ -5726,6 +6152,342 @@ async def generate_audio(
     )
 
 
+# =====================================================================
+# Speech-to-text (STT) sidecar  (/audio/transcribe, /audio/stt/*)
+# =====================================================================
+
+
+def _resolve_stt_engine(engine: Optional[str]) -> str:
+    """Normalize the requested STT engine name; default is Transformers."""
+    normalized = (engine or "transformers").strip().lower()
+    if normalized in ("", "transformers", "whisper"):
+        return "transformers"
+    if normalized in ("gguf", "ggml", "whisper_cpp", "whisper.cpp"):
+        return "gguf"
+    raise HTTPException(
+        status_code = 422,
+        detail = f"Unknown STT engine '{engine}'. Use 'transformers' or 'gguf'.",
+    )
+
+
+def _resolve_serving_stt_engine(engine: Optional[str]) -> str:
+    """Resolve the engine that will actually serve a model.
+
+    whisper.cpp (gguf) only accepts curated ids, which Transformers serves too,
+    so when whisper-server is not installed (the common case: `unsloth studio
+    update` does not yet build it) fall back to Transformers instead of 501-ing
+    on every recording. Used for download/load/transcribe; unload targets a
+    specific engine via _resolve_stt_engine.
+    """
+    resolved = _resolve_stt_engine(engine)
+    if resolved == "gguf":
+        from core.inference import stt_ggml_sidecar
+        if not stt_ggml_sidecar.is_available():
+            return "transformers"
+    return resolved
+
+
+def _stt_sidecar_for(engine: str):
+    if engine == "gguf":
+        from core.inference.stt_ggml_sidecar import get_ggml_stt_sidecar
+        return get_ggml_stt_sidecar()
+    from core.inference.stt_sidecar import get_stt_sidecar
+    return get_stt_sidecar()
+
+
+@studio_router.get("/audio/stt/status")
+async def stt_status(
+    model: Optional[str] = None, current_subject: str = Depends(get_current_subject)
+):
+    """Report STT availability and which model, if any, is resident.
+
+    ``model`` extends the Transformers ``downloaded_models`` check to a
+    custom Hugging Face repository beyond the curated defaults.
+    """
+    from core.inference import stt_ggml_sidecar, stt_sidecar
+    from core.inference.stt_sidecar import (
+        DEFAULT_STT_MODEL,
+        STT_MODELS,
+        get_stt_sidecar,
+        is_available,
+    )
+
+    sidecar = get_stt_sidecar()
+    ggml = stt_ggml_sidecar.get_ggml_stt_sidecar()
+    transformers_downloaded = [
+        model_id for model_id in STT_MODELS if stt_sidecar.is_model_downloaded(model_id)
+    ]
+    if model and model not in STT_MODELS and stt_sidecar.is_model_downloaded(model):
+        transformers_downloaded.append(model)
+    return JSONResponse(
+        content = {
+            "available": is_available(),
+            "loaded_model": sidecar.loaded_model,
+            "loading": sidecar.is_loading(),
+            "device": sidecar.device,
+            "keep_alive_seconds": sidecar.keep_alive_seconds,
+            "default_model": DEFAULT_STT_MODEL,
+            "models": list(STT_MODELS.keys()),
+            # Transformers engine, same shape as "gguf" below so clients read
+            # either generically. Top-level fields above kept for old clients.
+            "transformers": {
+                "available": is_available(),
+                "loaded_model": sidecar.loaded_model,
+                "loading": sidecar.is_loading(),
+                "device": sidecar.device,
+                "keep_alive_seconds": sidecar.keep_alive_seconds,
+                "default_model": DEFAULT_STT_MODEL,
+                "models": list(STT_MODELS.keys()),
+                "downloaded_models": transformers_downloaded,
+                "download": stt_sidecar.download_status(),
+            },
+            # whisper.cpp (GGUF) engine.
+            "gguf": {
+                "available": stt_ggml_sidecar.is_available(),
+                "loaded_model": ggml.loaded_model,
+                "loading": ggml.is_loading(),
+                "device": ggml.device,
+                "keep_alive_seconds": ggml.keep_alive_seconds,
+                "default_model": stt_ggml_sidecar.DEFAULT_GGML_STT_MODEL,
+                "models": list(stt_ggml_sidecar.GGML_STT_MODELS.keys()),
+                "downloaded_models": [
+                    model_id
+                    for model_id in stt_ggml_sidecar.GGML_STT_MODELS
+                    if stt_ggml_sidecar._cached_model_path(model_id) is not None
+                ],
+                "download": stt_ggml_sidecar.download_status(),
+            },
+        }
+    )
+
+
+@studio_router.post("/audio/stt/download")
+async def stt_download(
+    payload: SttLoadRequest,
+    current_subject: str = Depends(get_current_subject),
+    hf_token: Optional[str] = Depends(get_hf_token),
+):
+    """Start a background download of a dictation model.
+
+    Both engines download directly (a GGML checkpoint is a single file the Model
+    Hub's GGUF variant planner cannot express; a Transformers checkpoint is a
+    whole snapshot). Progress is reported by /audio/stt/status.
+    """
+    from core.inference import stt_ggml_sidecar, stt_sidecar
+    from core.inference.stt_sidecar import (
+        SttModelCompatibilityError,
+        SttModelIdError,
+        validate_remote_model,
+    )
+
+    engine = _resolve_serving_stt_engine(payload.engine)
+    module = stt_ggml_sidecar if engine == "gguf" else stt_sidecar
+    try:
+        # Transformers accepts custom `owner/model` repos, so confirm the repo is
+        # a Whisper checkpoint (metadata-only) before snapshot_download pulls a
+        # possibly-large non-STT repo into the shared cache. Curated ids
+        # short-circuit; GGUF only accepts curated ids, so it needs no check.
+        if engine != "gguf":
+            validated = await asyncio.to_thread(validate_remote_model, payload.model, hf_token)
+            # Pin the download to the commit that was just validated so the
+            # repo cannot be swapped between validation and snapshot_download.
+            await asyncio.to_thread(
+                module.start_model_download,
+                payload.model,
+                hf_token,
+                validated.get("revision"),
+            )
+        else:
+            await asyncio.to_thread(module.start_model_download, payload.model, hf_token)
+    except SttModelIdError as e:
+        raise HTTPException(status_code = 422, detail = str(e))
+    except SttModelCompatibilityError as e:
+        raise HTTPException(status_code = 422, detail = str(e))
+    return JSONResponse(content = module.download_status())
+
+
+@studio_router.post("/audio/stt/load")
+async def stt_load(payload: SttLoadRequest, current_subject: str = Depends(get_current_subject)):
+    """Load the selected STT model after the user starts local dictation."""
+    from core.inference.stt_sidecar import (
+        SttLoadCancelledError,
+        SttModelCompatibilityError,
+        SttModelIdError,
+        SttModelNotDownloadedError,
+        SttUnavailableError,
+        get_stt_sidecar,
+    )
+
+    sidecar = _stt_sidecar_for(_resolve_serving_stt_engine(payload.engine))
+    try:
+        await asyncio.to_thread(sidecar.load, payload.model)
+    except SttModelNotDownloadedError as e:
+        raise HTTPException(status_code = 409, detail = str(e))
+    except SttUnavailableError as e:
+        raise HTTPException(status_code = 501, detail = str(e))
+    except SttLoadCancelledError as e:
+        raise HTTPException(status_code = 409, detail = str(e))
+    except SttModelIdError as e:
+        raise HTTPException(status_code = 422, detail = str(e))
+    except SttModelCompatibilityError as e:
+        raise HTTPException(status_code = 422, detail = str(e))
+    except Exception as e:
+        logger.error(f"STT load error: {e}", exc_info = True)
+        raise HTTPException(status_code = 500, detail = safe_error_detail(e))
+    return JSONResponse(content = {"loaded_model": sidecar.loaded_model, "device": sidecar.device})
+
+
+@studio_router.post("/audio/stt/validate")
+async def stt_validate(
+    payload: SttLoadRequest,
+    current_subject: str = Depends(get_current_subject),
+    hf_token: Optional[str] = Depends(get_hf_token),
+):
+    """Verify a Hub repository is a Whisper checkpoint before downloading it."""
+    from core.inference.stt_sidecar import (
+        SttModelCompatibilityError,
+        SttModelIdError,
+        validate_remote_model,
+    )
+
+    try:
+        result = await asyncio.to_thread(validate_remote_model, payload.model, hf_token)
+    except (SttModelIdError, SttModelCompatibilityError) as e:
+        raise HTTPException(status_code = 422, detail = str(e))
+    return JSONResponse(content = result)
+
+
+@studio_router.post("/audio/stt/unload")
+async def stt_unload(
+    engine: Optional[str] = None, current_subject: str = Depends(get_current_subject)
+):
+    """Release the local STT model when dictation is idle.
+
+    Without an engine, both sidecars unload so an engine switch in Voice
+    settings always frees whichever backend was resident.
+    """
+    if engine is None:
+        engines = ["transformers", "gguf"]
+    else:
+        # Use the serving resolver: a "gguf" pick without whisper-server is
+        # actually served by the Transformers fallback, so unload must target
+        # that same engine or the resident model is never freed.
+        engines = [_resolve_serving_stt_engine(engine)]
+    # Attempt every engine even if one raises, so failing to unload one never
+    # skips freeing the other (both can be resident after a switch).
+    failed: list[str] = []
+    for name in engines:
+        try:
+            await asyncio.to_thread(_stt_sidecar_for(name).unload)
+        except Exception as exc:  # noqa: BLE001 - report after attempting all engines
+            logger.warning("Failed to unload STT engine '%s': %s", name, exc)
+            failed.append(name)
+    if failed:
+        raise HTTPException(
+            status_code = 500,
+            detail = f"Failed to unload STT engine(s): {', '.join(failed)}",
+        )
+    return JSONResponse(content = {"loaded_model": None, "device": None})
+
+
+async def _transcribe_audio_bytes(
+    raw: bytes,
+    model: Optional[str],
+    language: Optional[str],
+    fast: bool,
+    engine: Optional[str] = None,
+) -> JSONResponse:
+    """Run STT for already-decoded request bytes."""
+    from core.inference.stt_sidecar import (
+        SttAudioDecodeError,
+        SttAudioTooLongError,
+        SttLanguageError,
+        SttLoadCancelledError,
+        SttModelCompatibilityError,
+        SttModelIdError,
+        SttModelNotDownloadedError,
+        SttUnavailableError,
+    )
+
+    if not raw:
+        raise HTTPException(status_code = 400, detail = "Audio is empty.")
+    if len(raw) > _MAX_AUDIO_RAW_BYTES:
+        raise HTTPException(status_code = 413, detail = "Audio is too large.")
+
+    sidecar = _stt_sidecar_for(_resolve_serving_stt_engine(engine))
+    try:
+        result = await asyncio.to_thread(
+            sidecar.transcribe,
+            raw,
+            model,
+            language,
+            fast,
+        )
+    except SttUnavailableError as e:
+        raise HTTPException(status_code = 501, detail = str(e))
+    except SttLoadCancelledError as e:
+        raise HTTPException(status_code = 409, detail = str(e))
+    except SttModelNotDownloadedError as e:
+        raise HTTPException(status_code = 409, detail = str(e))
+    except SttModelIdError as e:
+        raise HTTPException(status_code = 422, detail = str(e))
+    except SttModelCompatibilityError as e:
+        raise HTTPException(status_code = 422, detail = str(e))
+    except SttLanguageError as e:
+        raise HTTPException(status_code = 422, detail = str(e))
+    except SttAudioTooLongError as e:
+        raise HTTPException(status_code = 413, detail = str(e))
+    except SttAudioDecodeError as e:
+        raise HTTPException(status_code = 400, detail = str(e))
+    except Exception as e:
+        logger.error(f"Transcription error: {e}", exc_info = True)
+        raise HTTPException(status_code = 500, detail = safe_error_detail(e))
+    return JSONResponse(content = result)
+
+
+@studio_router.post("/audio/transcribe")
+async def transcribe_audio(
+    payload: TranscribeRequest, current_subject: str = Depends(get_current_subject)
+):
+    """Transcribe dictation audio to text via the STT sidecar.
+
+    Runs alongside the chat model without evicting it, so any model (including
+    text-only ones) can be driven by voice.
+    """
+    b64 = payload.audio or ""
+    if not b64:
+        raise HTTPException(status_code = 400, detail = "No audio provided.")
+    if len(b64) > _MAX_AUDIO_B64_CHARS:
+        raise HTTPException(status_code = 413, detail = "Audio is too large.")
+    try:
+        raw = base64.b64decode(b64, validate = True)
+    except Exception:
+        raise HTTPException(status_code = 400, detail = "Audio is not valid base64.")
+    return await _transcribe_audio_bytes(
+        raw, payload.model, payload.language, payload.fast, payload.engine
+    )
+
+
+@studio_router.post("/audio/transcribe/raw")
+async def transcribe_audio_raw(
+    request: Request,
+    model: Optional[str] = None,
+    language: Optional[str] = None,
+    fast: bool = False,
+    engine: Optional[str] = None,
+    current_subject: str = Depends(get_current_subject),
+):
+    """Transcribe a raw audio body without base64 or JSON conversion overhead."""
+    chunks: list[bytes] = []
+    size = 0
+    async for chunk in request.stream():
+        size += len(chunk)
+        if size > _MAX_AUDIO_RAW_BYTES:
+            raise HTTPException(status_code = 413, detail = "Audio is too large.")
+        chunks.append(chunk)
+    return await _transcribe_audio_bytes(b"".join(chunks), model, language, fast, engine)
+
+
 # =====================================================================
 # OpenAI-Compatible Chat Completions  (/chat/completions)
 # =====================================================================
@@ -5767,8 +6529,8 @@ def _decode_audio_base64(b64: str) -> np.ndarray:
 # cap the encoded length to bound the upload. _MAX_AUDIO_SECONDS additionally
 # bounds the *decoded* length, since a small compressed file (opus/flac/etc.)
 # can expand to a far larger PCM array than the encoded-size cap implies.
-_MAX_AUDIO_RAW_BYTES = 25 * 1024 * 1024
-_MAX_AUDIO_B64_CHARS = _MAX_AUDIO_RAW_BYTES * 4 // 3
+_MAX_AUDIO_RAW_BYTES = STT_AUDIO_RAW_MAX_BYTES
+_MAX_AUDIO_B64_CHARS = STT_AUDIO_B64_MAX_CHARS
 _MAX_AUDIO_SECONDS = 30 * 60
 _WAV_HEADER_BYTES = 44
 _MIN_TRANSCODE_AUDIO_SAMPLE_RATE = 8000
@@ -6086,7 +6848,7 @@ def _build_external_messages(
              metadata; strip it for providers that can't parse the unknown key.
           2. Marked server-side builtin cards (`_server_tool: true` on a
              canonical builtin name, or a Gemini `native_part` payload) are
-             Studio-internal tool cards from a prior native Gemini turn;
+             Unsloth-internal tool cards from a prior native Gemini turn;
              forwarding them to OpenAI / Anthropic / custom OAI-compat gateways
              sends an orphan `tool_calls` entry (no matching tool declaration,
              often no matching `role="tool"` reply) that can be rejected. We
@@ -6654,6 +7416,51 @@ async def delete_openai_container(
         await client.close()
 
 
+def _fill_recommended_sampling_openai(payload, model_id) -> None:
+    """Apply per-model recommended sampling (and any operator UNSLOTH_SAMPLING_* pin) to a
+    ChatCompletionRequest in place.
+
+    Only the sampling fields the client did NOT explicitly send (tracked via
+    ``model_fields_set``) are overwritten, so a client that sets a field stays byte-identical
+    unless an operator pins it. Fields with neither a recommendation nor a pin keep their
+    existing (schema-default) value.
+    """
+    from utils.inference.inference_config import resolve_effective_sampling, SAMPLING_FIELD_NAMES
+
+    explicit = {
+        f: (getattr(payload, f) if f in payload.model_fields_set else None)
+        for f in SAMPLING_FIELD_NAMES
+    }
+    effective = resolve_effective_sampling(model_id, explicit)
+    for field, value in effective.items():
+        setattr(payload, field, value)
+
+
+# /v1/completions is proxied to llama-server verbatim; its repetition knob is "repeat_penalty",
+# and every other sampling field keeps its name (mirrors _build_passthrough_payload).
+_COMPLETIONS_SAMPLING_BODY_KEY = {"repetition_penalty": "repeat_penalty"}
+
+
+def _fill_recommended_sampling_completions(body: dict, model_id) -> None:
+    """Apply per-model recommended sampling (and any operator UNSLOTH_SAMPLING_* pin) to a raw
+    ``/v1/completions`` body in place, so the legacy (non-chat) endpoint honors the same pins as
+    ``/v1/chat/completions``.
+
+    Unlike :func:`_fill_recommended_sampling_openai`, which fills a ChatCompletionRequest whose
+    schema already carries per-field defaults, this body is proxied to llama-server as-is. A field
+    with no operator pin, client value, or per-model recommendation is therefore left untouched
+    (``fill_defaults = False``) so llama-server keeps its own default rather than being forced onto
+    this schema's value. llama-server names the repetition knob ``repeat_penalty``, so read and
+    write that alias for the client-sent value and any pin.
+    """
+    from utils.inference.inference_config import resolve_effective_sampling, SAMPLING_FIELD_NAMES
+
+    explicit = {f: body.get(_COMPLETIONS_SAMPLING_BODY_KEY.get(f, f)) for f in SAMPLING_FIELD_NAMES}
+    effective = resolve_effective_sampling(model_id, explicit, fill_defaults = False)
+    for field, value in effective.items():
+        body[_COMPLETIONS_SAMPLING_BODY_KEY.get(field, field)] = value
+
+
 @router.post("/chat/completions")
 async def openai_chat_completions(
     payload: ChatCompletionRequest,
@@ -6697,7 +7504,7 @@ async def openai_chat_completions(
     if payload.provider_id or payload.provider_type:
         # External provider: this request won't touch the local GGUF, so drop it
         # from the keep-warm count or its in-flight stream would falsely block a
-        # concurrent local auto-switch with model_switch_busy.
+        # concurrent local model switch from proceeding.
         from core.inference.llama_keepwarm import untrack_current_request
 
         untrack_current_request(request.scope)
@@ -6772,7 +7579,7 @@ async def openai_chat_completions(
         # is invalid and must not evict the resident model first.
         #
         # Enter the local-loop arm exactly when the passthrough router below would
-        # run Studio's own tool loop. That gate is `_tools_on or _mcp_allowed`
+        # run Unsloth's own tool loop. That gate is `_tools_on or _mcp_allowed`
         # (see the use_tools block): _effective_enable_tools (which lets a
         # process-wide --enable-tools policy force the loop on) plus mcp_enabled
         # honoring --disable-tools, and tool_choice="none" disabling it unless the
@@ -6797,7 +7604,7 @@ async def openai_chat_completions(
             or bool(payload.openai_code_exec_container_id)
             or bool(payload.anthropic_code_exec_container_id)
             # A JSON-schema response_format is guided-decoding structured output the
-            # router forwards to the llama-server passthrough, not Studio's tool
+            # router forwards to the llama-server passthrough, not Unsloth's tool
             # loop, so a --enable-tools policy must not 400 it as a local-confirm
             # request under ask/auto.
             or bool(_extract_response_format(payload))
@@ -6874,7 +7681,7 @@ async def openai_chat_completions(
     using_gguf = llama_backend.is_loaded
 
     # OpenAI-SDK clients send ``chat_template_kwargs`` via ``extra_body``, which
-    # the SDK spreads into the request body at the top level. Studio's
+    # the SDK spreads into the request body at the top level. Unsloth's
     # ChatCompletionRequest has ``extra="allow"`` so pydantic stashes them in
     # ``model_extra``, but downstream generators consume the typed
     # ``payload.enable_thinking``. Lift ``enable_thinking`` from the extra-body
@@ -6983,6 +7790,13 @@ async def openai_chat_completions(
             completion_id = f"chatcmpl-{uuid.uuid4().hex[:12]}"
             created = int(time.time())
 
+            # Apply recommended sampling + operator pins to the omitted fields before generating,
+            # so audio-input (non-whisper) generation honors `unsloth run --temperature` and
+            # per-model recommendations like chat does. Whisper (ASR) ignores these fields.
+            _fill_recommended_sampling_openai(
+                payload, getattr(backend, "active_model_name", None) or model_name
+            )
+
             def audio_input_generate():
                 if model_info.get("audio_type") == "whisper":
                     return backend.generate_whisper_response(
@@ -7028,6 +7842,13 @@ async def openai_chat_completions(
                             chunk_text = await asyncio.to_thread(next, gen, _DONE)
                             if chunk_text is _DONE:
                                 break
+                            if isinstance(chunk_text, GenStreamError):
+                                _msg = _friendly_gen_stream_error(chunk_text)
+                                api_monitor.fail(monitor_id, _msg)
+                                yield _openai_stream_error_sse(
+                                    {"error": {"message": _msg, "type": "server_error"}}
+                                )
+                                return
                             if chunk_text:
                                 api_monitor.append_reply(monitor_id, chunk_text)
                                 yield _chat_content_chunk(
@@ -7043,8 +7864,11 @@ async def openai_chat_completions(
                         raise
                     except Exception as e:
                         logger.error(f"Error during audio input streaming: {e}", exc_info = True)
-                        api_monitor.fail(monitor_id, _friendly_error(e))
-                        yield f"data: {json.dumps({'error': {'message': _friendly_error(e), 'type': 'server_error'}})}\n\n"
+                        _msg = _friendly_error(e)
+                        api_monitor.fail(monitor_id, _msg)
+                        yield _openai_stream_error_sse(
+                            {"error": {"message": _msg, "type": "server_error"}}
+                        )
                     finally:
                         await _stop_local_disconnect_cancel_watcher(disconnect_watcher)
                         _tracker.__exit__(None, None, None)
@@ -7061,7 +7885,15 @@ async def openai_chat_completions(
                 )
             else:
                 try:
-                    full_text = "".join(audio_input_generate())
+                    full_text = ""
+                    for chunk_text in audio_input_generate():
+                        if isinstance(chunk_text, GenStreamError):
+                            _msg = _friendly_gen_stream_error(chunk_text)
+                            api_monitor.fail(monitor_id, _msg)
+                            raise HTTPException(status_code = 500, detail = _msg)
+                        full_text += chunk_text
+                except HTTPException:
+                    raise
                 except Exception as e:
                     api_monitor.fail(monitor_id, _friendly_error(e))
                     raise
@@ -7108,9 +7940,21 @@ async def openai_chat_completions(
             ),
         )
 
+    # Apply per-model recommended sampling (and any operator UNSLOTH_SAMPLING_* pin) to the
+    # fields the client omitted, so agents and API clients get the model's tuned defaults
+    # unless they set the field explicitly. Placed after external-provider routing (which
+    # returned above) so only local llama-server / transformers requests are touched, and it
+    # covers both the passthrough and non-passthrough branches below since both read payload.*.
+    _reco_model_id = (
+        getattr(llama_backend, "model_identifier", None)
+        if using_gguf
+        else getattr(backend, "active_model_name", None)
+    ) or model_name
+    _fill_recommended_sampling_openai(payload, _reco_model_id)
+
     # ── Standard OpenAI function-calling pass-through (GGUF only) ────
     # When a client (opencode / Claude Code via OpenAI compat / Cursor /
-    # Continue / ...) sends standard OpenAI `tools` without Studio's
+    # Continue / ...) sends standard OpenAI `tools` without Unsloth's
     # `enable_tools` shorthand, forward the request to llama-server
     # verbatim so structured `tool_calls` flow back to the client. This
     # branch runs BEFORE `_extract_content_parts` because that helper is
@@ -7133,7 +7977,7 @@ async def openai_chat_completions(
     _has_tool_catalog = bool(payload.tools and len(payload.tools) > 0)
     _has_active_tool_catalog = _has_tool_catalog and payload.tool_choice != "none"
     _has_client_tool_contract = _has_active_tool_catalog or _has_tool_messages
-    # The Studio tool loop needs a tool-capable backend, so a request that asks
+    # The Unsloth tool loop needs a tool-capable backend, so a request that asks
     # for it on a backend that can't run it (DiffusionGemma forces supports_tools
     # off) must not steal client tools from the passthrough (#6851).
     _studio_tool_loop_requested = (
@@ -7329,7 +8173,7 @@ async def openai_chat_completions(
                 use_tools = False
 
         if use_tools:
-            # permission_mode ask/auto require the confirm gate for Studio's own
+            # permission_mode ask/auto require the confirm gate for Unsloth's own
             # tool loop. The request validator self-enables confirm only for
             # request-level tool signals (enable_tools/enabled_tools/mcp_enabled);
             # when a CLI policy (--enable-tools) forces the loop on without those,
@@ -8605,19 +9449,33 @@ async def openai_chat_completions(
     # Classify capability flags from the loaded template.
     _sf_model_info = backend.models.get(backend.active_model_name, {})
     _sf_tpl = (_sf_model_info.get("chat_template_info") or {}).get("template")
-    _sf_features = _detect_safetensors_features(backend, _sf_tpl)
-
-    # GGUF parity: enable_thinking templates prefill an unclosed <think>; split into
-    # reasoning_content deltas so the UI renders the block for safetensors and MLX.
-    _sf_parse_think = bool(
-        _sf_features.get("supports_reasoning") or _sf_features.get("reasoning_always_on")
+    # Named templates may expose native reasoning only in their ``tool_use``
+    # branch. Use a truthy placeholder for Unsloth-managed tools, whose concrete
+    # schemas are selected below, and the request schemas for client passthrough.
+    _sf_server_tool_intent = bool(
+        _effective_enable_tools(payload) or _explicit_studio_tool_loop_requested(payload)
     )
-    # Prefilled-open only for prefill styles with thinking on; gpt-oss uses the normal mode.
-    _sf_reasoning_prefilled = _sf_reasoning_prefill_mode(
-        _sf_features,
-        payload.enable_thinking,
-        _sf_tpl,
-        reasoning_effort = payload.reasoning_effort,
+    _sf_template_tools = payload.tools if payload.tool_choice != "none" else None
+    if not _sf_template_tools and _sf_server_tool_intent:
+        _sf_template_tools = ({},)
+
+    def _sf_response_protocol(tools = None):
+        features = _detect_safetensors_features(backend, _sf_tpl, tools = tools)
+        parse_think = bool(
+            features.get("supports_reasoning") or features.get("reasoning_always_on")
+        )
+        reasoning_prefilled = _sf_reasoning_prefill_mode(
+            features,
+            payload.enable_thinking,
+            _sf_tpl,
+            reasoning_effort = payload.reasoning_effort,
+        )
+        return features, parse_think, reasoning_prefilled
+
+    # GGUF parity: split canonical <think> output into reasoning_content. The
+    # selected template branch must match whether this request renders tools.
+    _sf_features, _sf_parse_think, _sf_reasoning_prefilled = _sf_response_protocol(
+        _sf_template_tools
     )
 
     def _new_sf_reasoning_extractor():
@@ -8671,7 +9529,7 @@ async def openai_chat_completions(
             _sf_use_tools = False
 
     if _sf_use_tools:
-        # permission_mode ask/auto require the confirm gate for Studio's own tool
+        # permission_mode ask/auto require the confirm gate for Unsloth's own tool
         # loop; when a CLI policy (--enable-tools) forces the loop on without a
         # request-level tool signal, derive confirm here so the mode still gates
         # the call (matching the GGUF path). off/full never prompt.
@@ -8767,6 +9625,7 @@ async def openai_chat_completions(
                 permission_mode = payload.permission_mode,
                 use_adapter = payload.use_adapter,
                 stats_holder = _sf_stats_holder,
+                reasoning_prefilled = _sf_reasoning_prefilled,
             )
 
         _sf_tool_sentinel = object()
@@ -8826,6 +9685,18 @@ async def openai_chat_completions(
                     _sf_next_task = None
                     if event is _sf_tool_sentinel:
                         break
+                    if isinstance(event, GenStreamError):
+                        backend.reset_generation_state()
+                        _msg = _friendly_gen_stream_error(event)
+                        api_monitor.fail(monitor_id, _msg)
+                        yield _openai_stream_error_sse(
+                            {"error": {"message": _msg, "type": "server_error"}}
+                        )
+                        return
+                    if not isinstance(event, dict):
+                        raise RuntimeError(
+                            f"Invalid safetensors tool event: {type(event).__name__}"
+                        )
 
                     if event["type"] == "heartbeat":
                         # Tool-execution wrapper heartbeat -> SSE keepalive.
@@ -8913,6 +9784,11 @@ async def openai_chat_completions(
                 backend.reset_generation_state()
                 api_monitor.finish(monitor_id, "cancelled")
                 raise
+            except GenStreamErrorRaised as exc:
+                backend.reset_generation_state()
+                _msg = _friendly_gen_stream_error(exc)
+                api_monitor.fail(monitor_id, _msg)
+                yield _openai_stream_error_sse({"error": {"message": _msg, "type": "server_error"}})
             except Exception:
                 backend.reset_generation_state()
                 # Generic wire message; full trace stays in the log (CWE-209:
@@ -8962,6 +9838,15 @@ async def openai_chat_completions(
                 for event in gen:
                     if cancel_event.is_set():
                         break
+                    if isinstance(event, GenStreamError):
+                        raise HTTPException(
+                            status_code = 500,
+                            detail = _friendly_gen_stream_error(event),
+                        )
+                    if not isinstance(event, dict):
+                        raise RuntimeError(
+                            f"Invalid safetensors tool event: {type(event).__name__}"
+                        )
                     if event.get("type") == "content":
                         full_text = _strip_tool_xml_for_display(
                             event.get("text", ""),
@@ -9002,6 +9887,15 @@ async def openai_chat_completions(
             backend.reset_generation_state()
             api_monitor.finish(monitor_id, "cancelled")
             raise
+        except GenStreamErrorRaised as exc:
+            backend.reset_generation_state()
+            _msg = _friendly_gen_stream_error(exc)
+            api_monitor.fail(monitor_id, _msg)
+            raise HTTPException(status_code = 500, detail = _msg)
+        except HTTPException as exc:
+            backend.reset_generation_state()
+            api_monitor.fail(monitor_id, str(exc.detail))
+            raise
         except Exception:
             backend.reset_generation_state()
             # CWE-209: generic detail; full trace in log.
@@ -9088,6 +9982,12 @@ async def openai_chat_completions(
         else:
             gen_kwargs["tools"] = payload.tools
 
+    # The potential tool context above is needed before server/client routing is
+    # known. This standard path now has the exact schemas that will be rendered,
+    # so resolve reasoning parsing again to keep empty registries, forced-tool
+    # misses, and tool_choice="none" on the marker-free template branch.
+    _, _sf_parse_think, _sf_reasoning_prefilled = _sf_response_protocol(gen_kwargs.get("tools"))
+
     # Request-scoped usage/timings receptacle (filled at gen_done).
     stats_holder: dict = {}
 
@@ -9168,6 +10068,14 @@ async def openai_chat_completions(
                     _next_task = None
                     if cumulative is _DONE:
                         break
+                    if isinstance(cumulative, GenStreamError):
+                        backend.reset_generation_state()
+                        _msg = _friendly_gen_stream_error(cumulative)
+                        api_monitor.fail(monitor_id, _msg)
+                        yield _openai_stream_error_sse(
+                            {"error": {"message": _msg, "type": "server_error"}}
+                        )
+                        return
                     if await request.is_disconnected():
                         cancel_event.set()
                         backend.reset_generation_state()
@@ -9274,6 +10182,13 @@ async def openai_chat_completions(
                 backend.reset_generation_state()
                 api_monitor.finish(monitor_id, "cancelled")
                 raise
+            except GenStreamErrorRaised as exc:
+                # Adapter-controlled (compare-mode) backend failure. Honor the
+                # public flag so operational errors surface their real message.
+                backend.reset_generation_state()
+                _msg = _friendly_gen_stream_error(exc)
+                api_monitor.fail(monitor_id, _msg)
+                yield _openai_stream_error_sse({"error": {"message": _msg, "type": "server_error"}})
             except Exception as e:
                 backend.reset_generation_state()
                 logger.error(f"Error during OpenAI streaming: {e}", exc_info = True)
@@ -9317,6 +10232,11 @@ async def openai_chat_completions(
         try:
             full_text = ""
             for token in generate():
+                if isinstance(token, GenStreamError):
+                    backend.reset_generation_state()
+                    _msg = _friendly_gen_stream_error(token)
+                    api_monitor.fail(monitor_id, _msg)
+                    raise HTTPException(status_code = 500, detail = _msg)
                 full_text = token
 
             # Split prefilled <think> reasoning (GGUF parity); also covers MLX via
@@ -9415,6 +10335,15 @@ async def openai_chat_completions(
             api_monitor.finish(monitor_id)
             return _model_json_response(response)
 
+        except HTTPException:
+            raise
+        except GenStreamErrorRaised as exc:
+            # Adapter-controlled (compare-mode) backend failure. Honor the public
+            # flag so operational errors surface their real message.
+            backend.reset_generation_state()
+            _msg = _friendly_gen_stream_error(exc)
+            api_monitor.fail(monitor_id, _msg)
+            raise HTTPException(status_code = 500, detail = _msg)
         except Exception as e:
             backend.reset_generation_state()
             logger.error(f"Error during OpenAI completion: {e}", exc_info = True)
@@ -9800,6 +10729,10 @@ async def openai_completions(request: Request, current_subject: str = Depends(ge
         if _resolved_max_tokens is not None
         else (llama_backend.context_length or _DEFAULT_MAX_TOKENS_FLOOR)
     )
+    # Apply per-model recommended sampling and any operator UNSLOTH_SAMPLING_* pin to the raw
+    # body so /v1/completions honors the same pins as /v1/chat/completions; it is otherwise a
+    # verbatim proxy that would keep llama-server's defaults for every omitted sampling field.
+    _fill_recommended_sampling_completions(body, getattr(llama_backend, "model_identifier", None))
     target_url = f"{llama_backend.base_url}/v1/completions"
     is_stream = body.get("stream", False)
     prompt_text = _flatten_monitor_prompt(body.get("prompt", ""))
@@ -10758,6 +11691,9 @@ async def _responses_stream(
             detail = "Image provided but current GGUF model does not support vision.",
         )
 
+    # Streaming /v1/responses builds the passthrough body directly (bypassing
+    # openai_chat_completions), so apply recommended sampling here too.
+    _fill_recommended_sampling_openai(chat_req, getattr(llama_backend, "model_identifier", None))
     body = _build_openai_passthrough_body(
         chat_req, backend_ctx = llama_backend.context_length, llama_backend = llama_backend
     )
@@ -11860,7 +12796,7 @@ def _anthropic_requested_studio_tools(tools: Optional[list]) -> set[str]:
 def _select_anthropic_server_tools(
     all_tools: list[dict], requested_studio_tools: set[str], enabled_tools: Optional[list[str]]
 ) -> list[dict]:
-    """Select Studio tools requested through Anthropic tools and extensions."""
+    """Select Unsloth tools requested through Anthropic tools and extensions."""
     if not requested_studio_tools and enabled_tools is None:
         return all_tools
 
@@ -12099,7 +13035,7 @@ async def anthropic_messages(
             ),
         )
 
-    # Reject an unsupported confirm-gated permission mode for Studio's own
+    # Reject an unsupported confirm-gated permission mode for Unsloth's own
     # ("server") Anthropic tools before the switch, mirroring the malformed- and
     # mixed-tool checks above. ask always wants a per-call pause this passthrough
     # cannot offer, so it 400s whenever server tools are selected. auto only needs
@@ -12189,14 +13125,28 @@ async def anthropic_messages(
     # endpoint matches /v1/chat/completions.
     _has_image = _normalize_anthropic_openai_images(openai_messages, llama_backend.is_vision)
 
-    temperature = payload.temperature if payload.temperature is not None else 0.6
-    top_p = payload.top_p if payload.top_p is not None else 0.95
-    top_k = payload.top_k if payload.top_k is not None else 20
-    min_p = payload.min_p if payload.min_p is not None else 0.01
-    repetition_penalty = (
-        payload.repetition_penalty if payload.repetition_penalty is not None else 1.0
+    # Fill omitted sampling fields with the per-model recommendation (or an operator
+    # UNSLOTH_SAMPLING_* pin); an explicit client value wins unless the operator pinned it.
+    # Anthropic sampling fields are Optional, so None already marks "client omitted".
+    from utils.inference.inference_config import resolve_effective_sampling
+
+    _anthropic_sampling = resolve_effective_sampling(
+        getattr(llama_backend, "model_identifier", None) or model_name,
+        {
+            "temperature": payload.temperature,
+            "top_p": payload.top_p,
+            "top_k": payload.top_k,
+            "min_p": payload.min_p,
+            "repetition_penalty": payload.repetition_penalty,
+            "presence_penalty": payload.presence_penalty,
+        },
     )
-    presence_penalty = payload.presence_penalty if payload.presence_penalty is not None else 0.0
+    temperature = _anthropic_sampling["temperature"]
+    top_p = _anthropic_sampling["top_p"]
+    top_k = _anthropic_sampling["top_k"]
+    min_p = _anthropic_sampling["min_p"]
+    repetition_penalty = _anthropic_sampling["repetition_penalty"]
+    presence_penalty = _anthropic_sampling["presence_penalty"]
     stop = payload.stop_sequences or None
 
     # Translate Anthropic tool_choice to OpenAI format for llama-server. Falls
@@ -12588,11 +13538,11 @@ async def _anthropic_tool_stream(
                     ends_on_tool_use = True
                 elif etype == "tool_end":
                     tool_blocks_emitted += 1
-                    # A tool_end means Studio executed the tool server-side, so
+                    # A tool_end means Unsloth executed the tool server-side, so
                     # the response no longer ends on a pending client action.
                     # Without this, a server tool that produces no trailing text
                     # would be mislabeled stop_reason "tool_use", telling the
-                    # client to run a tool Studio already ran.
+                    # client to run a tool Unsloth already ran.
                     ends_on_tool_use = False
                 elif etype == "content" and event.get("text"):
                     ends_on_tool_use = False
@@ -13508,7 +14458,7 @@ def _openai_messages_for_passthrough(payload) -> list[dict]:
     structured ``tool_calls``. Content-parts images already in the list are
     left untouched.
 
-    When a client uses Studio's legacy ``image_base64`` top-level field, the
+    When a client uses Unsloth's legacy ``image_base64`` top-level field, the
     image is re-encoded to PNG (llama-server's stb_image has limited format
     support) and spliced into the last user message as an OpenAI ``image_url``
     content part so vision + function-calling requests work transparently.
@@ -13642,7 +14592,7 @@ def _build_openai_passthrough_body(
 ) -> dict:
     """Assemble the llama-server request body from a ChatCompletionRequest.
 
-    Only known OpenAI / llama-server fields are forwarded, so Studio-specific
+    Only known OpenAI / llama-server fields are forwarded, so Unsloth-specific
     extensions (``enable_tools``, ``enabled_tools``, ``session_id``, ...) never
     leak to the backend.
     """
@@ -13892,7 +14842,7 @@ async def _openai_passthrough_stream_admitted(
     admission_lease: LlamaAdmissionLease,
     tracker,
 ):
-    """Streaming client-side pass-through after Studio granted an upstream slot.
+    """Streaming client-side pass-through after Unsloth granted an upstream slot.
 
     Forwards the client's OpenAI function-calling request to llama-server and
     relays the SSE stream back with minimal normalization (reasoning-only
diff --git a/studio/backend/routes/llama.py b/studio/backend/routes/llama.py
index 540647e3bc..84b89ad7d5 100644
--- a/studio/backend/routes/llama.py
+++ b/studio/backend/routes/llama.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""llama.cpp prebuilt update endpoints.
+"""llama.cpp prebuilt update endpoints -- the single main update item.
 
 GET  /api/llama/update-status  -> is a newer prebuilt available + job state
 POST /api/llama/update         -> download + atomically swap to the latest
@@ -9,13 +9,19 @@ POST /api/llama/update         -> download + atomically swap to the latest
 Detection reuses utils.llama_cpp_freshness; the swap reuses
 install_llama_prebuilt.py via utils.llama_cpp_update. Both fail open so the UI
 never blocks on a missing marker / offline GitHub.
+
+whisper.cpp updates piggyback here: the status payload carries a whisper
+sub-status (update_available is the llama OR whisper union) and the apply job
+chains a whisper phase after the llama phase when whisper is behind, with a
+per-phase breakdown in job.phases. All pre-existing top-level fields keep
+their shape, so older clients keep working unchanged.
 """
 
 from __future__ import annotations
 
 import asyncio
 import threading
-from typing import Optional
+from typing import Literal, Optional
 
 from fastapi import APIRouter, Depends, Query
 from pydantic import BaseModel, Field
@@ -38,6 +44,31 @@ class LlamaUpdateJob(BaseModel):
     progress: Optional[float] = Field(None, description = "0..1 while running, 1 on success.")
     started_at: Optional[str] = None
     finished_at: Optional[str] = None
+    phases: Optional[dict] = Field(
+        None,
+        description = (
+            "Per-phase breakdown of a chained llama+whisper job "
+            "(name -> state/progress/to_tag/...); None for pre-chaining jobs."
+        ),
+    )
+
+
+class WhisperSubStatus(BaseModel):
+    """The whisper piggyback inside the llama update item."""
+
+    update_available: bool = Field(
+        False, description = "True when the chained apply would run a whisper phase."
+    )
+    installed_tag: Optional[str] = None
+    latest_tag: Optional[str] = None
+    update_size_bytes: Optional[int] = None
+    skip_reason: Optional[str] = Field(
+        None,
+        description = (
+            "Why the whisper phase would be skipped "
+            "(up_to_date | local_link | source_build | not_installed | ...)."
+        ),
+    )
 
 
 class LlamaUpdateStatusResponse(BaseModel):
@@ -46,7 +77,18 @@ class LlamaUpdateStatusResponse(BaseModel):
         description = "True when the install came from an Unsloth prebuilt (has a marker).",
     )
     update_available: bool = Field(
-        False, description = "True when the latest release is genuinely newer than the install."
+        False,
+        description = (
+            "True when an update would do something: llama.cpp is behind OR the "
+            "whisper piggyback is behind."
+        ),
+    )
+    llama_update_available: bool = Field(
+        False, description = "True when the latest llama.cpp release is newer than the install."
+    )
+    update_component: Optional[Literal["llama", "whisper"]] = Field(
+        None,
+        description = "Component whose versions the combined update banner should display.",
     )
     stale: bool = Field(
         False, description = "Update available AND install older than the staleness threshold."
@@ -62,6 +104,9 @@ class LlamaUpdateStatusResponse(BaseModel):
     update_size_bytes: Optional[int] = Field(
         None, description = "Download size of the prebuilt Update would fetch, in bytes."
     )
+    whisper: Optional[WhisperSubStatus] = Field(
+        None, description = "Whisper piggyback sub-status; None when the probe is unavailable."
+    )
     job: LlamaUpdateJob = Field(default_factory = LlamaUpdateJob)
 
 
diff --git a/studio/backend/routes/mcp_servers.py b/studio/backend/routes/mcp_servers.py
index 71f0fd2874..dc018d163a 100644
--- a/studio/backend/routes/mcp_servers.py
+++ b/studio/backend/routes/mcp_servers.py
@@ -82,7 +82,7 @@ def _validate_url(url: str) -> str:
         if _looks_like_command(trimmed):
             detail = (
                 "Local commands aren't enabled on this server. To allow them, "
-                "set UNSLOTH_STUDIO_ALLOW_STDIO_MCP=1 and restart Studio, or use "
+                "set UNSLOTH_STUDIO_ALLOW_STDIO_MCP=1 and restart Unsloth, or use "
                 "an http:// or https:// URL instead."
             )
         else:
diff --git a/studio/backend/routes/models.py b/studio/backend/routes/models.py
index b8526c75e7..ed83a12f48 100644
--- a/studio/backend/routes/models.py
+++ b/studio/backend/routes/models.py
@@ -59,59 +59,51 @@ def _safe_is_dir(path) -> bool:
         return False
 
 
-# Hub repo id shape ("owner/name", no leading separator); anything else is
-# treated as a local filesystem path.
-_HF_REPO_ID_RE = re.compile(r"^[A-Za-z0-9][\w.\-]*/[\w.\-]+$")
+# Shared with the hub inventory scans; keep the private aliases so existing
+# importers stay valid. ``_HF_REPO_ID_RE`` is the Hub repo id shape ("owner/name");
+# anything else is treated as a local filesystem path.
+from utils.hidden_models import (
+    _HF_REPO_ID_RE,
+    _existing_resolved_path,
+    _safe_resolve,
+    is_hidden_model as _is_hidden_model,
+)
 
 
-def _is_hidden_model(*values: str | None) -> bool:
-    """True if any id/path is the RAG embedding model (EMBEDDING_MODEL or
-    EMBED_GGUF_REPO basename) or the llama.cpp install validation probe
-    (ggml-org/models / stories260K), so pickers hide them (GGUF and non-GGUF).
-    None are usable chat models; the probe can be cached as a side effect of
-    installing the prebuilt llama-server and otherwise sorts smallest, so it
-    would be auto-selected. A local-path embedder is matched by exact resolved
-    path only: a generic basename like "model" must not substring-hide
-    unrelated chat models."""
+def hidden_model_matchers() -> tuple[list[str], list[str], list[str]]:
+    """Substring needles, exact repo ids, and exact resolved paths identifying
+    infra models (the RAG embedder and the llama.cpp install validation probe)
+    that pickers hide. Served by the ``/api/hub/hidden-models`` endpoint. A
+    configured HF-repo embedder is published as its exact lowercased repo id
+    (mirroring ``utils.hidden_models.is_hidden_model``) and a local-path
+    embedder as its exact resolved path only: a generic basename like "model"
+    must not substring-hide unrelated chat models."""
     from core.rag import config as rag_config
 
     needles = [
-        # The validation probe's repo (matches the cached repo id) and its exact
-        # filename (matches the on-disk path). The filename carries the .gguf so
-        # it does not hide unrelated repos like ``user/stories260K-finetune-GGUF``.
+        # The validation probe's repo and its exact filename. The filename carries
+        # .gguf so it won't hide unrelated repos like ``user/stories260K-finetune-GGUF``.
         "ggml-org/models",
         "stories260k.gguf",
     ]
+    exact_ids: list[str] = []
     exact_paths: list[str] = []
     for model in (
         rag_config.effective_embedding_model(),
         rag_config.effective_gguf_repo(),
     ):
-        if _HF_REPO_ID_RE.match(model):
-            needles.append(model.split("/")[-1].lower())
+        # Resolve an existing local path before the repo-id regex: a local embedder
+        # shaped like "models/embedder" is an exact path, not a Hub repo id.
+        existing_path = _existing_resolved_path(model)
+        if existing_path:
+            exact_paths.append(existing_path.lower())
+        elif _HF_REPO_ID_RE.match(model):
+            exact_ids.append(model.lower())
         else:
             resolved = _safe_resolve(Path(model).expanduser())
             if resolved:
                 exact_paths.append(resolved.lower())
-    for v in values:
-        if not v:
-            continue
-        low = v.lower()
-        if any(n in low for n in needles):
-            return True
-        if exact_paths:
-            resolved = _safe_resolve(Path(v).expanduser())
-            if resolved and resolved.lower() in exact_paths:
-                return True
-    return False
-
-
-def _safe_resolve(path: Path) -> Optional[str]:
-    """resolve() to a string, or None when the path is inaccessible."""
-    try:
-        return str(path.resolve())
-    except OSError:
-        return None
+    return needles, exact_ids, exact_paths
 
 
 backend_path = Path(__file__).parent.parent.parent
@@ -138,6 +130,7 @@ try:
         _pick_best_gguf,
         _extract_quant_label,
         _is_big_endian_gguf_path,
+        _is_mtp_drafter,
         is_audio_input_type,
     )
     from core.inference import get_inference_backend
@@ -170,6 +163,7 @@ except ImportError:
         _pick_best_gguf,
         _extract_quant_label,
         _is_big_endian_gguf_path,
+        _is_mtp_drafter,
         is_audio_input_type,
     )
     from core.inference import get_inference_backend
@@ -230,11 +224,8 @@ def derive_model_type(
 
 def _resolve_hf_cache_dir() -> Path:
     """Resolve local HF cache root used by hub downloads."""
-    try:
-        from huggingface_hub.constants import HF_HUB_CACHE
-        return Path(HF_HUB_CACHE)
-    except Exception:
-        return Path.home() / ".cache" / "huggingface" / "hub"
+    from utils.hf_cache_settings import get_hf_cache_paths
+    return get_hf_cache_paths().hub_cache
 
 
 def _is_model_directory(d: Path) -> bool:
@@ -376,10 +367,12 @@ def _scan_models_dir(models_dir: Path, *, limit: int | None = None) -> List[Loca
     return found
 
 
-def _scan_hf_cache(cache_dir: Path) -> List[LocalModelInfo]:
+def _scan_hf_cache(cache_dir: Path, *, active_cache: bool = True) -> List[LocalModelInfo]:
     if not cache_dir.exists() or not cache_dir.is_dir():
         return []
 
+    from hub.utils import inventory_scan as hf_cache_scan
+
     found: List[LocalModelInfo] = []
     for repo_dir in cache_dir.glob("models--*"):
         if not repo_dir.is_dir():
@@ -395,13 +388,21 @@ def _scan_hf_cache(cache_dir: Path) -> List[LocalModelInfo]:
         except OSError:
             updated_at = None
 
+        partial = hf_cache_scan.is_snapshot_partial("model", model_id, repo_dir)
+        partial = partial or hf_cache_scan.is_gguf_repo_partial(model_id, repo_dir)
+
+        load_id = model_id
+        if not active_cache:
+            load_id = _resolve_hf_cache_realpath(repo_dir) or str(repo_dir.resolve())
         found.append(
             LocalModelInfo(
-                id = model_id,
+                id = load_id,
                 model_id = model_id,
                 display_name = model_id.split("/")[-1],
-                path = str(repo_dir),
+                path = load_id if not active_cache else str(repo_dir),
                 source = "hf_cache",
+                active_cache = active_cache,
+                partial = partial,
                 updated_at = updated_at,
             ),
         )
@@ -544,7 +545,7 @@ def _ollama_links_dir(ollama_dir: Path) -> Optional[Path]:
     """Return a writable directory for Ollama ``.gguf`` symlinks.
 
     Prefers ``<ollama_dir>/.studio_links/`` so links sit next to their
-    blobs; falls back to a per-ollama-dir namespace under Studio's cache
+    blobs; falls back to a per-ollama-dir namespace under Unsloth's cache
     when the models dir is read-only (common for system installs).
     """
     from utils.paths.storage_roots import cache_root
@@ -555,7 +556,7 @@ def _ollama_links_dir(ollama_dir: Path) -> Optional[Path]:
         return primary
     except OSError as e:
         logger.debug(
-            "Ollama dir %s not writable for .studio_links (%s); falling back to Studio cache",
+            "Ollama dir %s not writable for .studio_links (%s); falling back to Unsloth cache",
             ollama_dir,
             e,
         )
@@ -594,7 +595,7 @@ def _scan_ollama_dir(ollama_dir: Path, limit: Optional[int] = None) -> List[Loca
     model, keyed by a short hash of the manifest path, so
     ``detect_mmproj_file`` only sees that model's projector). Links are
     symlinks when possible, else hardlinks; the link dir is
-    ``.studio_links/`` when writable, else Studio's cache.
+    ``.studio_links/`` when writable, else Unsloth's cache.
     """
     manifests_root = ollama_dir / "manifests"
     if not manifests_root.is_dir():
@@ -782,26 +783,34 @@ def collect_local_models(models_root: Path) -> List[LocalModelInfo]:
         legacy_hf_cache_dir,
         lmstudio_model_dirs,
     )
+    from utils.hf_cache_settings import known_hf_hub_caches
 
     hf_cache_dir = _resolve_hf_cache_dir()
     legacy_hf = legacy_hf_cache_dir()
     hf_default = hf_default_cache_dir()
     lm_dirs = lmstudio_model_dirs()
 
-    local_models = _scan_models_dir(models_root) + _scan_hf_cache(hf_cache_dir)
-
-    # Resolve once; an inaccessible aux cache must skip that scan, not 500.
-    hf_cache_real = _safe_resolve(hf_cache_dir)
-    legacy_real = _safe_resolve(legacy_hf)
-    default_real = _safe_resolve(hf_default)
-
-    # Scan legacy Unsloth HF cache for backward compatibility.
-    if _safe_is_dir(legacy_hf) and legacy_real != hf_cache_real:
-        local_models += _scan_hf_cache(legacy_hf)
-
-    # Scan HF system default cache (may differ under env overrides).
-    if _safe_is_dir(hf_default) and default_real != hf_cache_real and default_real != legacy_real:
-        local_models += _scan_hf_cache(hf_default)
+    local_models = _scan_models_dir(models_root)
+    active_cache_real = _safe_resolve(hf_cache_dir)
+    active_cache_key = os.path.normcase(active_cache_real) if active_cache_real else None
+    seen_hf: set[str] = set()
+    for cache_dir in (
+        hf_cache_dir,
+        *known_hf_hub_caches(),
+        legacy_hf,
+        hf_default,
+    ):
+        cache_real = _safe_resolve(cache_dir)
+        if cache_real is None:
+            continue
+        cache_key = os.path.normcase(str(cache_real))
+        if cache_key in seen_hf:
+            continue
+        seen_hf.add(cache_key)
+        local_models += _scan_hf_cache(
+            cache_dir,
+            active_cache = cache_key == active_cache_key,
+        )
 
     # Scan LM Studio directories.
     for lm_dir in lm_dirs:
@@ -823,7 +832,7 @@ def collect_local_models(models_root: Path) -> List[LocalModelInfo]:
                 m
                 for m in (
                     _scan_models_dir(folder_path, limit = _MAX_MODELS_PER_FOLDER)
-                    + _scan_hf_cache(folder_path)
+                    + _scan_hf_cache(folder_path, active_cache = False)
                     + _scan_lmstudio_dir(folder_path)
                 )
                 if not any(p in (".studio_links", "ollama_links") for p in Path(m.path).parts)
@@ -844,16 +853,26 @@ def collect_local_models(models_root: Path) -> List[LocalModelInfo]:
     # even when the model is also in the HF cache.
     deduped: dict[str, LocalModelInfo] = {}
     for model in local_models:
-        key = f"{model.id}\x00custom" if model.source == "custom" else model.id
-        if key not in deduped:
+        semantic_id = model.model_id if model.source == "hf_cache" and model.model_id else model.id
+        key = f"{semantic_id}\x00custom" if model.source == "custom" else semantic_id
+        existing = deduped.get(key)
+        prefer_model = existing is None
+        if existing is not None and model.source == existing.source == "hf_cache":
+            if model.partial != existing.partial:
+                prefer_model = not model.partial
+            elif bool(model.active_cache) != bool(existing.active_cache):
+                prefer_model = bool(model.active_cache)
+            else:
+                prefer_model = (model.updated_at or 0) > (existing.updated_at or 0)
+        if prefer_model:
             deduped[key] = model
 
     models = sorted(
         deduped.values(),
-        key = lambda item: (item.updated_at or 0),
+        key = lambda item: item.updated_at or 0,
         reverse = True,
     )
-    return [m for m in models if not _is_hidden_model(m.id, m.path)]
+    return [m for m in models if not _is_hidden_model(m.id, m.model_id, m.path)]
 
 
 @router.get("/local", response_model = LocalModelListResponse)
@@ -1194,7 +1213,7 @@ def _build_browse_allowlist(
     """Return the root directories the folder browser may walk.
 
     The same list seeds the sidebar suggestion chips, so chip targets are
-    always reachable. Roots: HOME, resolved HF cache dirs, Studio's
+    always reachable. Roots: HOME, resolved HF cache dirs, Unsloth's
     outputs/exports/studio root, registered scan folders, and well-known
     local-LLM dirs (LM Studio, Ollama, ``~/models``); each added only if
     it resolves to a real directory.
@@ -1208,10 +1227,7 @@ def _build_browse_allowlist(
         legacy_hf_cache_dir,
         well_known_model_dirs,
     )
-    from utils.paths.external_media import (
-        linux_run_media_mount_roots,
-        windows_drive_roots,
-    )
+    from utils.paths import external_media
     from storage.studio_db import list_scan_folders
 
     candidates: list[Path] = []
@@ -1228,9 +1244,12 @@ def _build_browse_allowlist(
 
     _add(Path.home())
     if media_roots is None:
-        media_roots = linux_run_media_mount_roots()
+        media_roots = [
+            *external_media.linux_run_media_mount_roots(),
+            *external_media.macos_volume_roots(),
+        ]
     if drive_roots is None:
-        drive_roots = windows_drive_roots()
+        drive_roots = external_media.windows_drive_roots()
     for p in media_roots:
         _add(p)
     for p in drive_roots:
@@ -1486,7 +1505,7 @@ def browse_folders(
             "Directory to list. If omitted, defaults to the current user's "
             "home directory. Tilde (`~`) and relative paths are expanded. "
             "Must resolve inside the allowlist of browseable roots (HOME, "
-            "HF cache, Studio dirs, registered scan folders, well-known "
+            "HF cache, Unsloth dirs, registered scan folders, well-known "
             "model dirs)."
         ),
     ),
@@ -1508,10 +1527,7 @@ def browse_folders(
     then hidden (if ``show_hidden=true``).
     """
     from utils.paths import hf_default_cache_dir, well_known_model_dirs
-    from utils.paths.external_media import (
-        linux_run_media_mount_roots,
-        windows_drive_roots,
-    )
+    from utils.paths import external_media
     from storage.studio_db import (
         contains_sensitive_path_component,
         is_denied_system_path,
@@ -1520,8 +1536,11 @@ def browse_folders(
 
     # Probe removable-media and Windows drive roots once; the allowlist and
     # chips reuse the result so a disconnected mapped drive isn't scanned twice.
-    media_roots = linux_run_media_mount_roots()
-    drive_roots = windows_drive_roots()
+    media_roots = [
+        *external_media.linux_run_media_mount_roots(),
+        *external_media.macos_volume_roots(),
+    ]
+    drive_roots = external_media.windows_drive_roots()
     # Build once; the sandbox check and suggestion chips share it.
     allowed_roots = _build_browse_allowlist(media_roots, drive_roots)
 
@@ -1797,9 +1816,11 @@ def _get_model_size_bytes(model_name: str, hf_token: Optional[str] = None) -> Op
 async def get_model_config(
     model_name: str,
     hf_token: Optional[str] = Query(None),
+    header_hf_token: Optional[str] = Depends(get_hf_token),
     current_subject: str = Depends(get_current_subject),
 ):
     """Get configuration for a specific model (wraps load_model_defaults)."""
+    hf_token = _normalize_hf_token(header_hf_token) or _normalize_hf_token(hf_token)
     try:
         if not is_local_path(model_name):
             resolved = resolve_cached_repo_id_case(model_name)
@@ -2038,19 +2059,19 @@ async def discard_remote_code_download(
 
     # Never delete a model that is loaded for inference.
     try:
+        from hub.services.models.deletion import _loaded_id_matches_repo
         from routes.inference import get_llama_cpp_backend
+
         llama_backend = get_llama_cpp_backend()
         if llama_backend.is_loaded and llama_backend.model_identifier:
-            loaded = llama_backend.model_identifier.lower()
-            if loaded == model_name.lower() or loaded.startswith(model_name.lower()):
+            if _loaded_id_matches_repo(llama_backend.model_identifier, model_name):
                 return {"deleted": False, "reason": "loaded"}
     except Exception:
         pass
     try:
         inference_backend = get_inference_backend()
         if inference_backend.active_model_name:
-            active = inference_backend.active_model_name.lower()
-            if active == model_name.lower() or active.startswith(model_name.lower()):
+            if _loaded_id_matches_repo(inference_backend.active_model_name, model_name):
                 return {"deleted": False, "reason": "loaded"}
     except Exception:
         pass
@@ -2251,15 +2272,15 @@ async def delete_finetuned_model(
     gguf_variant: Optional[str] = Body(None),
     current_subject: str = Depends(get_current_subject),
 ):
-    """Delete a Studio-trained or exported model from disk.
+    """Delete an Unsloth-trained or exported model from disk.
 
-    Only paths under Studio's outputs/exports roots are accepted.
+    Only paths under Unsloth's outputs/exports roots are accepted.
     Exported GGUF entries can delete one quant variant at a time.
     """
     if source not in {"training", "exported"}:
         raise HTTPException(
             status_code = 400,
-            detail = "Only trained or exported Studio models can be deleted",
+            detail = "Only trained or exported Unsloth models can be deleted",
         )
 
     if not model_path or not model_path.strip():
@@ -2291,14 +2312,14 @@ async def delete_finetuned_model(
         if not _is_path_under_lexically(delete_path, allowed_root):
             raise HTTPException(
                 status_code = 400,
-                detail = "Model path is outside Studio storage",
+                detail = "Model path is outside Unsloth storage",
             )
         if export_type == "gguf" and gguf_variant:
             target_path = delete_path.resolve()
             if not _is_path_under(target_path, allowed_root):
                 raise HTTPException(
                     status_code = 400,
-                    detail = "Model path is outside Studio storage",
+                    detail = "Model path is outside Unsloth storage",
                 )
         else:
             target_path = delete_path
@@ -2311,7 +2332,7 @@ async def delete_finetuned_model(
     if should_check_resolved_path and not _is_path_under(target_path, allowed_root):
         raise HTTPException(
             status_code = 400,
-            detail = "Model path is outside Studio storage",
+            detail = "Model path is outside Unsloth storage",
         )
     if target_path == allowed_root:
         raise HTTPException(
@@ -2518,6 +2539,7 @@ async def get_lora_base_model(lora_path: str, current_subject: str = Depends(get
 async def check_vision_model(
     model_name: str,
     hf_token: Optional[str] = Query(None),
+    header_hf_token: Optional[str] = Depends(get_hf_token),
     current_subject: str = Depends(get_current_subject),
 ):
     """
@@ -2525,6 +2547,7 @@ async def check_vision_model(
 
     This endpoint wraps the backend is_vision_model function.
     """
+    hf_token = _normalize_hf_token(header_hf_token) or _normalize_hf_token(hf_token)
     try:
         logger.info(f"Checking if vision model: {model_name}")
         # Authenticate so a gated/private VLM classifies correctly (else 404 -> non-vision).
@@ -2550,6 +2573,7 @@ async def check_vision_model(
 async def check_embedding_model(
     model_name: str,
     hf_token: Optional[str] = Query(None),
+    header_hf_token: Optional[str] = Depends(get_hf_token),
     current_subject: str = Depends(get_current_subject),
 ):
     """
@@ -2557,6 +2581,7 @@ async def check_embedding_model(
 
     This endpoint wraps the backend is_embedding_model function.
     """
+    hf_token = _normalize_hf_token(header_hf_token) or _normalize_hf_token(hf_token)
     try:
         logger.info(f"Checking if embedding model: {model_name}")
         is_embedding = is_embedding_model(model_name, hf_token = hf_token)
@@ -2588,13 +2613,10 @@ def _read_native_context_length(repo_id: str, is_local: bool) -> Optional[int]:
         if is_local:
             roots = [Path(repo_id)]
         else:
-            from huggingface_hub import constants as hf_constants
-
+            from hub.utils.hf_cache_state import iter_repo_cache_dirs
             if not _is_valid_repo_id(repo_id):
                 return None
-            cache_dir = Path(hf_constants.HF_HUB_CACHE)
-            target = f"models--{repo_id.replace('/', '--')}".lower()
-            roots = [e for e in cache_dir.iterdir() if e.name.lower() == target]
+            roots = list(iter_repo_cache_dirs("model", repo_id))
 
         for root in roots:
             for f in _iter_gguf_paths(root):
@@ -2620,47 +2642,32 @@ def _resolve_quant_gguf(repo_id: str, quant: str, is_local: bool) -> tuple[Optio
     Q8_0 weights). Never raises.
     """
     try:
-        from utils.models.model_config import (
-            _extract_quant_label,
-            _is_big_endian_gguf_path,
-            _is_mtp_drafter,
-        )
-
         if is_local:
             roots = [Path(repo_id)]
         else:
-            from huggingface_hub import constants as hf_constants
+            from hub.utils.hf_cache_state import iter_repo_cache_dirs
 
             if not _is_valid_repo_id(repo_id):
                 return None, 0
-            cache_dir = Path(hf_constants.HF_HUB_CACHE)
-            target = f"models--{repo_id.replace('/', '--')}".lower()
             roots = []
-            for entry in cache_dir.iterdir():
-                if entry.name.lower() == target:
-                    snaps = entry / "snapshots"
-                    if snaps.is_dir():
-                        roots.extend(s for s in snaps.iterdir() if s.is_dir())
+            for entry in iter_repo_cache_dirs("model", repo_id):
+                snaps = entry / "snapshots"
+                if snaps.is_dir():
+                    roots.extend(s for s in snaps.iterdir() if s.is_dir())
 
-        want = quant.lower().replace("-", "").replace("_", "")
+        want = _normalized_quant_label(quant)
         best_total = 0
         best_first: Optional[str] = None
         for root in roots:
             matches: list[tuple[str, Path]] = []
             total = 0
             for f in _iter_gguf_paths(root):
-                if _is_mmproj_filename(f.name):
-                    continue
                 try:
                     rel = f.relative_to(root).as_posix()
                 except ValueError:
                     rel = f.name
-                if _is_mtp_drafter(rel):
-                    continue
-                q = _extract_quant_label(rel)
-                if _is_big_endian_gguf_path(rel, q):
-                    continue
-                if q.lower().replace("-", "").replace("_", "") != want:
+                q = _main_variant_gguf_label(rel)
+                if q is None or _normalized_quant_label(q) != want:
                     continue
                 try:
                     total += f.stat().st_size
@@ -2685,7 +2692,10 @@ async def get_kv_cache_estimate(
     repo_id: str = Query(..., description = "HF repo ID or local path"),
     quant: str = Query(..., description = "Quantization label (e.g. Q4_K_M)"),
     n_ctx: int = Query(..., ge = 1, description = "Context length to size the KV cache for"),
-    cache_type_kv: Optional[str] = Query(None, description = "KV cache dtype (e.g. q8_0)"),
+    cache_type_kv: Optional[str] = Query(
+        None,
+        description = "KV cache dtype (e.g. q8_0, q4_0, q5_0, iq4_nl, f32)",
+    ),
     current_subject: str = Depends(get_current_subject),
 ):
     """Estimate KV cache + weight bytes for a downloaded GGUF at n_ctx.
@@ -2746,6 +2756,8 @@ async def get_gguf_variants(
     repo_id: str = Query(
         ..., description = "HuggingFace repo ID (e.g. 'unsloth/gemma-3-4b-it-GGUF')"
     ),
+    prefer_local_cache: bool = False,
+    local_path: Optional[str] = None,
     hf_token: Optional[str] = Query(None, description = "HuggingFace token for private repos"),
     hf_token_header: Optional[str] = Depends(get_hf_token),
     current_subject: str = Depends(get_current_subject),
@@ -2757,9 +2769,16 @@ async def get_gguf_variants(
 
         response = await hub_gguf_variants.get_gguf_variants_response(
             repo_id,
+            prefer_local_cache = prefer_local_cache,
+            local_path = local_path,
             hf_token = hf_token,
         )
-        local = is_local_path(repo_id)
+        context_model = (
+            local_path
+            if prefer_local_cache and local_path and is_local_path(local_path)
+            else repo_id
+        )
+        local = is_local_path(context_model)
 
         return GgufVariantsResponse(
             repo_id = response.repo_id,
@@ -2778,7 +2797,11 @@ async def get_gguf_variants(
             ],
             has_vision = response.has_vision,
             default_variant = response.default_variant,
-            context_length = _read_native_context_length(repo_id, is_local = local),
+            # The header walk reads tokenizer arrays on dense models (tens of
+            # ms per uncached file); keep it off the event loop.
+            context_length = await asyncio.to_thread(
+                _read_native_context_length, context_model, is_local = local
+            ),
         )
     except HTTPException:
         raise
@@ -2795,69 +2818,17 @@ async def get_gguf_download_progress(
     repo_id: str = Query(..., description = "HuggingFace repo ID"),
     variant: str = Query("", description = "Quantization variant (e.g. UD-TQ1_0)"),
     expected_bytes: int = Query(0, description = "Expected total download size in bytes"),
+    hf_token: Optional[str] = Depends(get_hf_token),
     current_subject: str = Depends(get_current_subject),
 ):
-    """Download progress from cached GGUF files for a specific variant.
-
-    Tracks completed shards in snapshots and in-progress (.incomplete)
-    downloads in the blobs directory.
-    """
-    try:
-        if not _is_valid_repo_id(repo_id):
-            return {
-                "downloaded_bytes": 0,
-                "expected_bytes": expected_bytes,
-                "progress": 0,
-            }
-
-        from huggingface_hub import constants as hf_constants
-
-        cache_dir = Path(hf_constants.HF_HUB_CACHE)
-        target = f"models--{repo_id.replace('/', '--')}".lower()
-        variant_lower = variant.lower().replace("-", "").replace("_", "")
-        downloaded_bytes = 0
-        in_progress_bytes = 0
-        for entry in cache_dir.iterdir():
-            if entry.name.lower() == target:
-                # Completed .gguf files for this variant in snapshots.
-                # Exclude mmproj so a vision adapter can't satisfy a same-label
-                # main variant (e.g. mmproj-F16 vs an F16 weight).
-                for f in _iter_gguf_paths(entry):
-                    if _is_mmproj_filename(f.name):
-                        continue
-                    rel = f.relative_to(entry).as_posix()
-                    quant = _extract_quant_label(rel)
-                    if _is_big_endian_gguf_path(rel, quant):
-                        continue
-                    rel_key = rel.lower().replace("-", "").replace("_", "")
-                    if not variant_lower or variant_lower in rel_key:
-                        try:
-                            downloaded_bytes += f.stat().st_size
-                        except OSError:
-                            continue  # broken symlink / unreadable: skip
-                # In-progress (.incomplete) downloads in blobs.
-                blobs_dir = entry / "blobs"
-                if blobs_dir.is_dir():
-                    for f in blobs_dir.iterdir():
-                        if f.is_file() and f.name.endswith(".incomplete"):
-                            try:
-                                in_progress_bytes += f.stat().st_size
-                            except OSError:
-                                continue
-                break
-
-        total_progress_bytes = downloaded_bytes + in_progress_bytes
-        progress = min(total_progress_bytes / expected_bytes, 0.99) if expected_bytes > 0 else 0
-        # Report 1.0 only when all bytes are in completed files.
-        if expected_bytes > 0 and downloaded_bytes >= expected_bytes:
-            progress = 1.0
-        return {
-            "downloaded_bytes": total_progress_bytes,
-            "expected_bytes": expected_bytes,
-            "progress": round(progress, 3),
-        }
-    except Exception:
-        return {"downloaded_bytes": 0, "expected_bytes": expected_bytes, "progress": 0}
+    """Compatibility route backed by the shared multi-cache progress service."""
+    from hub.services.models import downloads
+    return await downloads.get_gguf_download_progress_response(
+        repo_id,
+        variant = variant,
+        expected_bytes = expected_bytes,
+        hf_token = hf_token,
+    )
 
 
 def _resolve_hf_cache_realpath(repo_dir: Path) -> Optional[str]:
@@ -2882,98 +2853,12 @@ def _resolve_hf_cache_realpath(repo_dir: Path) -> Optional[str]:
 @router.get("/download-progress")
 async def get_download_progress(
     repo_id: str = Query(..., description = "HuggingFace repo ID"),
+    hf_token: Optional[str] = Depends(get_hf_token),
     current_subject: str = Depends(get_current_subject),
 ):
-    """Return download progress for any HuggingFace model repo.
-
-    Checks the local HF cache for completed blobs and in-progress
-    (.incomplete) downloads. Gets the expected total size from the HF API
-    on the first call, then caches it for later polls. Also returns
-    ``cache_path``: the realpath of the snapshot dir (or cache repo root
-    if no snapshot yet) so the UI can show where weights live on disk.
-    """
-    _empty = {
-        "downloaded_bytes": 0,
-        "expected_bytes": 0,
-        "progress": 0,
-        "cache_path": None,
-    }
-    try:
-        if not _is_valid_repo_id(repo_id):
-            return _empty
-
-        from huggingface_hub import constants as hf_constants
-
-        cache_dir = Path(hf_constants.HF_HUB_CACHE)
-        target = f"models--{repo_id.replace('/', '--')}".lower()
-        completed_bytes = 0
-        in_progress_bytes = 0
-        cache_path: Optional[str] = None
-
-        for entry in cache_dir.iterdir():
-            if entry.name.lower() != target:
-                continue
-            cache_path = _resolve_hf_cache_realpath(entry)
-            blobs_dir = entry / "blobs"
-            if not blobs_dir.is_dir():
-                break
-            for f in blobs_dir.iterdir():
-                if not f.is_file():
-                    continue
-                if f.name.endswith(".incomplete"):
-                    in_progress_bytes += f.stat().st_size
-                else:
-                    completed_bytes += f.stat().st_size
-            break
-
-        downloaded_bytes = completed_bytes + in_progress_bytes
-        if downloaded_bytes == 0:
-            return {**_empty, "cache_path": cache_path}
-
-        expected_bytes = _get_repo_size_cached(repo_id)
-        if expected_bytes <= 0:
-            # Total unknown; report bytes only, no percentage.
-            return {
-                "downloaded_bytes": downloaded_bytes,
-                "expected_bytes": 0,
-                "progress": 0,
-                "cache_path": cache_path,
-            }
-
-        # 95% threshold (blob dedup can skew completed_bytes). Do NOT
-        # treat "no .incomplete files" as done: HF downloads sequentially,
-        # so none exist between files even when far from finished.
-        if completed_bytes >= expected_bytes * 0.95:
-            progress = 1.0
-        else:
-            progress = min(downloaded_bytes / expected_bytes, 0.99)
-        return {
-            "downloaded_bytes": downloaded_bytes,
-            "expected_bytes": expected_bytes,
-            "progress": round(progress, 3),
-            "cache_path": cache_path,
-        }
-    except Exception as e:
-        logger.warning(f"Error checking download progress for {repo_id}: {e}")
-        return _empty
-
-
-_repo_size_cache: dict[str, int] = {}
-
-
-def _get_repo_size_cached(repo_id: str) -> int:
-    if repo_id in _repo_size_cache:
-        return _repo_size_cache[repo_id]
-    try:
-        from huggingface_hub import model_info as hf_model_info
-
-        info = hf_model_info(repo_id, token = None, files_metadata = True)
-        total = sum(s.size for s in info.siblings if s.size)
-        _repo_size_cache[repo_id] = total
-        return total
-    except Exception as e:
-        logger.warning(f"Failed to get repo size for {repo_id}: {e}")
-        return 0
+    """Compatibility route backed by the shared multi-cache progress service."""
+    from hub.services.models import downloads
+    return await downloads.get_download_progress_response(repo_id, hf_token = hf_token)
 
 
 def _repo_in_any_hf_cache(model_name: str) -> bool:
@@ -2986,25 +2871,13 @@ def _repo_in_any_hf_cache(model_name: str) -> bool:
     would delete a model they did not download via the scan. Mirrors the cache set in
     ``_all_hf_cache_scans`` but only probes for the one repo dir (cheap, no full scan).
     """
-    from utils.paths import (
-        hf_default_cache_dir,
-        legacy_hf_cache_dir,
-        resolve_cached_repo_id_case,
-    )
+    from utils.paths import resolve_cached_repo_id_case
 
     dirname = f"models--{resolve_cached_repo_id_case(model_name).replace('/', '--')}"
     dirname_lower = dirname.lower()
-    candidates = []
-    try:
-        from huggingface_hub.constants import HF_HUB_CACHE
-        candidates.append(Path(HF_HUB_CACHE))
-    except Exception:
-        pass
-    for fn in (legacy_hf_cache_dir, hf_default_cache_dir):
-        try:
-            candidates.append(fn())
-        except Exception:
-            continue
+    from hub.utils.hf_cache_state import hf_cache_roots
+
+    candidates = hf_cache_roots()
     # resolve_cached_repo_id_case only normalizes the ACTIVE cache, but discard deletes
     # case-insensitively across all caches, so detect case-insensitively too -- else a
     # pre-existing case-variant repo is misreported as scan-created and deleted on decline.
@@ -3028,38 +2901,8 @@ def _all_hf_cache_scans():
     broken symlink, OS-redirected ~/.cache) is skipped, not fatal, so the
     Downloaded list never blanks out and downloads never leak into Recommended.
     """
-    from huggingface_hub import scan_cache_dir
-    from utils.paths import legacy_hf_cache_dir, hf_default_cache_dir
-
-    scans = []
-    # Guard the active cache too: degrade to "no downloads" instead of raising.
-    try:
-        scans.append(scan_cache_dir())
-    except Exception as exc:
-        logger.warning("Could not scan active HF cache: %s", exc)
-
-    seen: set[str] = set()
-    try:
-        # Resolve the active cache dir for dedup.
-        from huggingface_hub.constants import HF_HUB_CACHE
-        seen.add(str(Path(HF_HUB_CACHE).resolve()))
-    except Exception:
-        pass
-
-    for extra_fn in (legacy_hf_cache_dir, hf_default_cache_dir):
-        try:
-            extra = extra_fn()
-            # is_dir()/resolve() can raise on an inaccessible path; skip it.
-            if not extra.is_dir():
-                continue
-            resolved = str(extra.resolve())
-            if resolved in seen:
-                continue
-            seen.add(resolved)
-            scans.append(scan_cache_dir(cache_dir = str(extra)))
-        except Exception as exc:
-            logger.warning("Could not scan HF cache %s: %s", extra_fn.__name__, exc)
-    return scans
+    from hub.utils.inventory_scan import all_hf_cache_scans
+    return all_hf_cache_scans()
 
 
 def _is_gguf_filename(name: str) -> bool:
@@ -3078,6 +2921,22 @@ def _is_main_gguf_filename(name: str) -> bool:
     return _is_gguf_filename(name) and not _is_mmproj_filename(name)
 
 
+def _main_variant_gguf_label(rel_path: str) -> Optional[str]:
+    name = rel_path.rsplit("/", 1)[-1]
+    if not _is_main_gguf_filename(name):
+        return None
+    if _is_mtp_drafter(rel_path):
+        return None
+    label = _extract_quant_label(rel_path)
+    if _is_big_endian_gguf_path(rel_path, label):
+        return None
+    return label
+
+
+def _normalized_quant_label(label: str) -> str:
+    return label.lower().replace("-", "").replace("_", "")
+
+
 def _repo_has_mmproj(repo_info) -> bool:
     """True if the repo ships a GGUF vision adapter (mmproj), so it can
     take image inputs. Cheap: scans already-listed file names only."""
@@ -3170,7 +3029,9 @@ async def list_cached_gguf(current_subject: str = Depends(get_current_subject)):
                     if repo_info.repo_type != "model":
                         continue
                     repo_id = repo_info.repo_id
-                    if _is_hidden_model(repo_id):
+                    # Pass the snapshot path too so the config check also hides
+                    # custom Whisper checkpoints, not just curated repo ids.
+                    if _is_hidden_model(repo_id, str(repo_info.repo_path)):
                         continue
                     total_size = _repo_gguf_size_bytes(repo_info)
                     if total_size == 0:
@@ -3227,7 +3088,9 @@ async def list_cached_models(
                     if repo_info.repo_type != "model":
                         continue
                     repo_id = repo_info.repo_id
-                    if _is_hidden_model(repo_id):
+                    # Pass the snapshot path too so the config check also hides
+                    # custom Whisper checkpoints, not just curated repo ids.
+                    if _is_hidden_model(repo_id, str(repo_info.repo_path)):
                         continue
                     if _repo_has_gguf_files(repo_info):
                         continue
@@ -3285,124 +3148,177 @@ async def list_cached_models(
 async def delete_cached_model(
     repo_id: str = Body(...),
     variant: Optional[str] = Body(None),
+    cache_path: Optional[str] = Body(None),
+    hf_token: Optional[str] = Depends(get_hf_token),
     current_subject: str = Depends(get_current_subject),
 ):
-    """Delete a cached model repo (or a specific GGUF variant) from the HF cache.
+    """Compatibility route backed by the shared multi-cache deletion service."""
+    from hub.services.models import deletion
+    return await deletion.delete_cached_model_response(repo_id, variant, hf_token, cache_path)
 
-    With *variant*, only GGUF files matching that quant label are removed
-    (e.g. ``UD-Q4_K_XL``); otherwise the whole repo is deleted. Refuses
-    if the model is currently loaded for inference.
-    """
+
+def _resolve_cached_model_path(repo_id: str, variant: Optional[str]) -> Path:
+    """Absolute path of a cached repo (newest snapshot dir) or, with *variant*,
+    that quant's main GGUF file (first split of a sharded quant). Paths come
+    from the HF cache scan only, so callers can't probe arbitrary paths."""
+    cache_scans = _all_hf_cache_scans()
+
+    matching_repos = []
+    for hf_cache in cache_scans:
+        for repo_info in hf_cache.repos:
+            if repo_info.repo_type != "model":
+                continue
+            if repo_info.repo_id.lower() == repo_id.lower():
+                matching_repos.append(repo_info)
+    if not matching_repos:
+        raise HTTPException(status_code = 404, detail = "Model not found in cache")
+
+    if variant:
+        want = _normalized_quant_label(variant)
+        candidate_revisions = sorted(
+            (rev for repo_info in matching_repos for rev in repo_info.revisions),
+            key = lambda rev: getattr(rev, "last_modified", 0) or 0,
+            reverse = True,
+        )
+        for rev in candidate_revisions:
+            snapshot = getattr(rev, "snapshot_path", None)
+            matches = []
+            for f in rev.files:
+                p = Path(f.file_path)
+                rel = f.file_name
+                if snapshot:
+                    try:
+                        rel = p.relative_to(snapshot).as_posix()
+                    except ValueError:
+                        pass
+                label = _main_variant_gguf_label(rel)
+                if label is None or _normalized_quant_label(label) != want:
+                    continue
+                if p.exists() or p.is_symlink():
+                    matches.append((rel, p))
+            if matches:
+                # Path-sorted so a sharded quant deterministically yields its first split.
+                return sorted(matches, key = lambda m: m[0].lower())[0][1]
+        raise HTTPException(
+            status_code = 404,
+            detail = f"Variant {variant} not found in cache for {repo_id}",
+        )
+
+    def repo_size(repo_info) -> int:
+        gguf_size = _repo_gguf_size_bytes(repo_info)
+        if gguf_size > 0:
+            return gguf_size
+        return sum(
+            (getattr(f, "size_on_disk", None) or 0)
+            for rev in repo_info.revisions
+            for f in rev.files
+        )
+
+    def repo_last_modified(repo_info) -> float:
+        return max(
+            (getattr(rev, "last_modified", 0) or 0 for rev in repo_info.revisions),
+            default = 0,
+        )
+
+    target_repo = max(
+        matching_repos,
+        key = lambda repo_info: (repo_size(repo_info), repo_last_modified(repo_info)),
+    )
+
+    # Whole repo: the newest revision's snapshot dir holds the visible files.
+    revisions = sorted(
+        (rev for rev in target_repo.revisions if getattr(rev, "snapshot_path", None)),
+        key = lambda rev: getattr(rev, "last_modified", 0) or 0,
+        reverse = True,
+    )
+    for rev in revisions:
+        p = Path(rev.snapshot_path)
+        if p.exists():
+            return p
+    p = Path(target_repo.repo_path)
+    if p.exists():
+        return p
+    raise HTTPException(status_code = 404, detail = "Cached model path not found")
+
+
+def _wsl_reveal_in_explorer(path: Path) -> bool:
+    import subprocess
+
+    from utils.paths.path_utils import _IS_WSL
+
+    if not _IS_WSL:
+        return False
+    try:
+        windows_path = subprocess.run(
+            ["wslpath", "-w", str(path)],
+            capture_output = True,
+            text = True,
+            check = True,
+            timeout = 10,
+        ).stdout.strip()
+        if not windows_path:
+            return False
+        argument = f"/select,{windows_path}" if path.is_file() else windows_path
+        subprocess.Popen(["explorer.exe", argument])
+        return True
+    except (OSError, subprocess.SubprocessError):
+        return False
+
+
+def _reveal_in_file_manager(path: Path) -> None:
+    """Open the OS file manager with *path* selected (best effort per platform)."""
+    import subprocess
+
+    target = str(path)
+    if sys.platform == "darwin":
+        cmd = ["open", "-R", target] if path.is_file() else ["open", target]
+        subprocess.Popen(cmd)
+    elif os.name == "nt":
+        if path.is_file():
+            subprocess.Popen(["explorer", f"/select,{target}"])
+        else:
+            os.startfile(target)  # noqa: S606 - local user's own file manager
+    elif not _wsl_reveal_in_explorer(path):
+        # No cross-desktop "select file" standard on Linux; open the directory.
+        directory = target if path.is_dir() else str(path.parent)
+        subprocess.Popen(["xdg-open", directory])
+
+
+class CachedModelPathResponse(BaseModel):
+    path: str
+    is_dir: bool
+
+
+@router.get("/cached-model-path", response_model = CachedModelPathResponse)
+async def get_cached_model_path(
+    repo_id: str = Query(..., description = "HuggingFace repo ID"),
+    variant: str = Query("", description = "Quantization variant (empty for whole repo)"),
+    current_subject: str = Depends(get_current_subject),
+):
+    """Absolute on-disk path of a cached repo or one of its GGUF variants."""
     if not _is_valid_repo_id(repo_id):
         raise HTTPException(status_code = 400, detail = "Invalid repo_id format")
+    path = await asyncio.to_thread(_resolve_cached_model_path, repo_id, variant.strip() or None)
+    return {"path": str(path), "is_dir": path.is_dir()}
 
-    # Refuse if the model is currently loaded.
+
+@router.post("/reveal-cached-model")
+async def reveal_cached_model(
+    repo_id: str = Body(...),
+    variant: Optional[str] = Body(None),
+    current_subject: str = Depends(get_current_subject),
+):
+    """Reveal a cached repo (or one GGUF variant's file) in the OS file manager."""
+    if not _is_valid_repo_id(repo_id):
+        raise HTTPException(status_code = 400, detail = "Invalid repo_id format")
+    variant = (variant or "").strip() or None
+    path = await asyncio.to_thread(_resolve_cached_model_path, repo_id, variant)
     try:
-        from routes.inference import get_llama_cpp_backend
-        llama_backend = get_llama_cpp_backend()
-        if llama_backend.is_loaded and llama_backend.model_identifier:
-            loaded_id = llama_backend.model_identifier.lower()
-            if loaded_id == repo_id.lower() or loaded_id.startswith(repo_id.lower()):
-                raise HTTPException(
-                    status_code = 400,
-                    detail = "Unload the model before deleting",
-                )
-    except HTTPException:
-        raise
-    except Exception:
-        pass
-
-    try:
-        inference_backend = get_inference_backend()
-        if inference_backend.active_model_name:
-            active = inference_backend.active_model_name.lower()
-            if active == repo_id.lower() or active.startswith(repo_id.lower()):
-                raise HTTPException(
-                    status_code = 400,
-                    detail = "Unload the model before deleting",
-                )
-    except HTTPException:
-        raise
-    except Exception:
-        pass
-
-    try:
-        cache_scans = _all_hf_cache_scans()
-
-        target_repo = None
-        for hf_cache in cache_scans:
-            for repo_info in hf_cache.repos:
-                if repo_info.repo_type != "model":
-                    continue
-                if repo_info.repo_id.lower() == repo_id.lower():
-                    target_repo = repo_info
-                    break
-            if target_repo is not None:
-                break
-
-        if target_repo is None:
-            raise HTTPException(status_code = 404, detail = "Model not found in cache")
-
-        # ── Per-variant GGUF deletion ────────────────────────────
-        if variant:
-            deleted_bytes = 0
-            deleted_count = 0
-            for rev in target_repo.revisions:
-                for f in rev.files:
-                    if not _is_gguf_filename(f.file_name):
-                        continue
-                    quant = _extract_quant_label(f.file_name)
-                    if quant.lower() != variant.lower():
-                        continue
-                    # Delete the blob (data) and the snapshot symlink.
-                    try:
-                        blob = Path(f.blob_path)
-                        snap = Path(f.file_path)
-                        size = blob.stat().st_size if blob.exists() else 0
-                        if snap.exists() or snap.is_symlink():
-                            snap.unlink()
-                        if blob.exists():
-                            blob.unlink()
-                        deleted_bytes += size
-                        deleted_count += 1
-                    except Exception as e:
-                        logger.warning(f"Failed to delete {f.file_name}: {e}")
-
-            if deleted_count == 0:
-                raise HTTPException(
-                    status_code = 404,
-                    detail = f"Variant {variant} not found in cache for {repo_id}",
-                )
-
-            freed_mb = deleted_bytes / (1024 * 1024)
-            logger.info(
-                f"Deleted {deleted_count} file(s) for {repo_id} variant {variant}: "
-                f"{freed_mb:.1f} MB freed"
-            )
-            return {"status": "deleted", "repo_id": repo_id, "variant": variant}
-
-        # ── Full repo deletion ───────────────────────────────────
-        revision_hashes = [rev.commit_hash for rev in target_repo.revisions]
-        if not revision_hashes:
-            raise HTTPException(status_code = 404, detail = "No revisions found for model")
-
-        delete_strategy = hf_cache.delete_revisions(*revision_hashes)
-        logger.info(
-            f"Deleting cached model {repo_id}: "
-            f"{delete_strategy.expected_freed_size_str} will be freed"
-        )
-        delete_strategy.execute()
-
-        return {"status": "deleted", "repo_id": repo_id}
-
-    except HTTPException:
-        raise
+        await asyncio.to_thread(_reveal_in_file_manager, path)
     except Exception as e:
-        logger.error(f"Error deleting cached model {repo_id}: {e}", exc_info = True)
-        raise HTTPException(
-            status_code = 500,
-            detail = "Failed to delete cached model",
-        )
+        logger.error(f"Failed to reveal {path}: {e}")
+        raise HTTPException(status_code = 500, detail = "Failed to open file manager")
+    return {"status": "ok", "path": str(path)}
 
 
 @router.get("/checkpoints", response_model = CheckpointListResponse)
@@ -3456,7 +3372,7 @@ _EXPORT_SIZE_CACHE: dict[str, tuple[int, int, str]] = {}
 
 
 def _is_sizable_local_path(model: str) -> bool:
-    """True only for local paths under a Studio data root.
+    """True only for local paths under an Unsloth data root.
 
     Containment is decided lexically (no filesystem access) before the path is
     touched, then the path is symlink-resolved and re-checked so a symlink
diff --git a/studio/backend/routes/providers.py b/studio/backend/routes/providers.py
index 5a55c9b0bb..4e7e53f2f0 100644
--- a/studio/backend/routes/providers.py
+++ b/studio/backend/routes/providers.py
@@ -47,6 +47,20 @@ logger = structlog.get_logger(__name__)
 router = APIRouter()
 
 
+def _provider_response(row: dict) -> ProviderResponse:
+    return ProviderResponse(
+        id = row["id"],
+        provider_type = row["provider_type"],
+        display_name = row["display_name"],
+        base_url = row["base_url"],
+        is_enabled = bool(row["is_enabled"]),
+        models = row.get("models") or [],
+        available_models = row.get("available_models") or [],
+        created_at = row["created_at"],
+        updated_at = row["updated_at"],
+    )
+
+
 # ── Public key for API key encryption ─────────────────────────────
 
 
@@ -89,18 +103,7 @@ async def get_pricing_snapshot(current_subject: str = Depends(get_current_subjec
 async def list_provider_configs(current_subject: str = Depends(get_current_subject)):
     """List all saved provider configurations."""
     rows = providers_db.list_providers()
-    return [
-        ProviderResponse(
-            id = row["id"],
-            provider_type = row["provider_type"],
-            display_name = row["display_name"],
-            base_url = row["base_url"],
-            is_enabled = bool(row["is_enabled"]),
-            created_at = row["created_at"],
-            updated_at = row["updated_at"],
-        )
-        for row in rows
-    ]
+    return [_provider_response(row) for row in rows]
 
 
 @router.post("/", response_model = ProviderResponse, status_code = 201)
@@ -124,18 +127,12 @@ async def create_provider_config(
         provider_type = payload.provider_type,
         display_name = payload.display_name,
         base_url = base_url,
+        models = payload.models,
+        available_models = payload.available_models,
     )
 
     row = providers_db.get_provider(provider_id)
-    return ProviderResponse(
-        id = row["id"],
-        provider_type = row["provider_type"],
-        display_name = row["display_name"],
-        base_url = row["base_url"],
-        is_enabled = bool(row["is_enabled"]),
-        created_at = row["created_at"],
-        updated_at = row["updated_at"],
-    )
+    return _provider_response(row)
 
 
 @router.put("/{provider_id}", response_model = ProviderResponse)
@@ -154,20 +151,14 @@ async def update_provider_config(
         display_name = payload.display_name,
         base_url = payload.base_url,
         is_enabled = payload.is_enabled,
+        models = payload.models,
+        available_models = payload.available_models,
     )
     if not updated:
         raise HTTPException(status_code = 400, detail = "No fields to update")
 
     row = providers_db.get_provider(provider_id)
-    return ProviderResponse(
-        id = row["id"],
-        provider_type = row["provider_type"],
-        display_name = row["display_name"],
-        base_url = row["base_url"],
-        is_enabled = bool(row["is_enabled"]),
-        created_at = row["created_at"],
-        updated_at = row["updated_at"],
-    )
+    return _provider_response(row)
 
 
 @router.delete("/{provider_id}", status_code = 204)
diff --git a/studio/backend/routes/rag.py b/studio/backend/routes/rag.py
index e20fea74a3..392a4e0d02 100644
--- a/studio/backend/routes/rag.py
+++ b/studio/backend/routes/rag.py
@@ -318,6 +318,39 @@ def list_project_documents(project_id: str, subject: str = Depends(get_current_s
         conn.close()
 
 
+@router.get("/documents")
+def list_all_uploaded_documents(subject: str = Depends(get_current_subject)) -> dict:
+    """Every uploaded file across chats, projects, and knowledge bases (settings
+    Data tab)."""
+    _require_rag()
+    conn = rag_db.get_connection()
+    try:
+        docs = store.list_all_documents(conn)
+        kb_names = {kb["id"]: kb["name"] for kb in store.list_kbs(conn)}
+    finally:
+        conn.close()
+
+    from storage.studio_db import list_chat_projects
+
+    project_names = {p["id"]: p["name"] for p in list_chat_projects(include_archived = True)}
+
+    out = []
+    for doc in docs:
+        view = _doc_view(doc)
+        stored_path = doc.get("stored_path")
+        size = None
+        if stored_path:
+            try:
+                size = os.path.getsize(stored_path)
+            except OSError:
+                size = None
+        view["sizeBytes"] = size
+        view["kbName"] = kb_names.get(doc.get("kb_id"))
+        view["projectName"] = project_names.get(doc.get("project_id"))
+        out.append(view)
+    return {"documents": out}
+
+
 @router.delete("/documents/{document_id}")
 def delete_document(document_id: str, subject: str = Depends(get_current_subject)) -> dict:
     _require_rag()
@@ -424,8 +457,10 @@ _CONTENT_TYPES = {
     ".txt": "text/plain; charset=utf-8",
     ".md": "text/markdown; charset=utf-8",
     ".markdown": "text/markdown; charset=utf-8",
-    ".html": "text/html; charset=utf-8",
-    ".htm": "text/html; charset=utf-8",
+    # Served as plain text, never text/html: an uploaded HTML document rendered
+    # same-origin would execute its scripts with access to the app's storage.
+    ".html": "text/plain; charset=utf-8",
+    ".htm": "text/plain; charset=utf-8",
     ".docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
 }
 
diff --git a/studio/backend/routes/settings.py b/studio/backend/routes/settings.py
index 1ddfc0eacb..fef18a9145 100644
--- a/studio/backend/routes/settings.py
+++ b/studio/backend/routes/settings.py
@@ -10,6 +10,7 @@ from pydantic import BaseModel, ConfigDict, Field, field_validator
 
 from auth.authentication import get_current_subject
 from auth.storage import rotate_preview_link_secret
+from core.rag.config import default_gguf_repo, effective_gguf_repo
 from loggers import get_logger
 from utils.utils import safe_error_detail, log_and_http_error
 from utils.personalization_settings import (
@@ -35,9 +36,10 @@ from utils.helper_precache_settings import (
 )
 from utils.coding_agents import CODING_AGENTS, detect_installed_coding_agents
 from utils.openai_auto_switch_settings import (
-    DEFAULT_AUTO_UNLOAD_IDLE_SECONDS,
+    DEFAULT_AUTO_UNLOAD_KEEP_KV,
     DEFAULT_OPENAI_AUTO_SWITCH_ENABLED,
     get_auto_unload_idle_seconds,
+    get_auto_unload_keep_kv,
     get_model_overrides,
     get_openai_auto_switch_enabled,
     get_stored_auto_unload_idle_seconds,
@@ -58,6 +60,7 @@ from utils.embedding_model_settings import (
     set_rag_embedding_model,
     validate_embedding_model,
 )
+from utils.hf_cache_settings import cache_status, get_hf_cache_paths, set_hf_cache_home
 
 router = APIRouter()
 
@@ -87,9 +90,28 @@ class HelperPrecacheResponse(BaseModel):
     disabled_by_env: bool
 
 
+class HuggingFaceCachePayload(BaseModel):
+    cache_home: Optional[str] = Field(default = None, max_length = 4096)
+
+
+class HuggingFaceCacheResponse(BaseModel):
+    cache_home: str
+    hub_cache: str
+    xet_cache: str
+    source: Literal["default", "studio", "environment"]
+    editable: bool
+    is_custom: bool
+    available: bool
+    writable: bool
+    free_bytes: Optional[int] = None
+    environment_variable: Optional[str] = None
+
+
 class OpenAIAutoSwitchPayload(BaseModel):
     enabled: bool
-    auto_unload_idle_seconds: int = Field(default = DEFAULT_AUTO_UNLOAD_IDLE_SECONDS, ge = 0)
+    # None leaves the stored value untouched (partial updates can't clobber it).
+    auto_unload_idle_seconds: Optional[int] = Field(default = None, ge = 0)
+    auto_unload_keep_kv: Optional[bool] = None
 
 
 class OpenAIAutoSwitchResponse(BaseModel):
@@ -100,6 +122,7 @@ class OpenAIAutoSwitchResponse(BaseModel):
     # UNSLOTH_MODEL_IDLE_TTL set and nothing stored, this is true even while enabled
     # is false, so the UI can show idle-unload as active instead of "needs enable".
     idle_unload_active: bool = False
+    auto_unload_keep_kv: bool = DEFAULT_AUTO_UNLOAD_KEEP_KV
 
 
 class ModelOverridePayload(BaseModel):
@@ -130,6 +153,30 @@ def _helper_precache_response(enabled: bool | None = None) -> HelperPrecacheResp
     )
 
 
+def _hugging_face_cache_response() -> HuggingFaceCacheResponse:
+    return HuggingFaceCacheResponse(**cache_status(get_hf_cache_paths()))
+
+
+@router.get("/hugging-face-cache", response_model = HuggingFaceCacheResponse)
+def get_hugging_face_cache(
+    current_subject: str = Depends(get_current_subject),
+) -> HuggingFaceCacheResponse:
+    return _hugging_face_cache_response()
+
+
+@router.put("/hugging-face-cache", response_model = HuggingFaceCacheResponse)
+def update_hugging_face_cache(
+    payload: HuggingFaceCachePayload, current_subject: str = Depends(get_current_subject)
+) -> HuggingFaceCacheResponse:
+    try:
+        set_hf_cache_home(payload.cache_home)
+    except RuntimeError as exc:
+        raise HTTPException(status_code = 409, detail = str(exc)) from exc
+    except ValueError as exc:
+        raise HTTPException(status_code = 400, detail = str(exc)) from exc
+    return _hugging_face_cache_response()
+
+
 @router.get("/upload-limit", response_model = UploadLimitResponse)
 def get_upload_limit(current_subject: str = Depends(get_current_subject)) -> UploadLimitResponse:
     return _upload_limit_response(get_upload_limit_mb())
@@ -197,6 +244,7 @@ def get_openai_auto_switch(
         enabled = get_openai_auto_switch_enabled(),
         auto_unload_idle_seconds = get_stored_auto_unload_idle_seconds(),
         idle_unload_active = get_auto_unload_idle_seconds() > 0,
+        auto_unload_keep_kv = get_auto_unload_keep_kv(),
     )
 
 
@@ -205,8 +253,8 @@ def update_openai_auto_switch(
     payload: OpenAIAutoSwitchPayload, current_subject: str = Depends(get_current_subject)
 ) -> OpenAIAutoSwitchResponse:
     try:
-        enabled, idle_seconds = set_openai_auto_switch(
-            payload.enabled, payload.auto_unload_idle_seconds
+        enabled, idle_seconds, keep_kv = set_openai_auto_switch(
+            payload.enabled, payload.auto_unload_idle_seconds, payload.auto_unload_keep_kv
         )
     except ValueError as exc:
         raise log_and_http_error(
@@ -216,10 +264,16 @@ def update_openai_auto_switch(
             event = "settings.update_openai_auto_switch_failed",
             log = logger,
         ) from exc
+    idle_unload_active = get_auto_unload_idle_seconds() > 0
+    if not keep_kv or not idle_unload_active:
+        # Keep-KV off or idle unload disabled: drop already-saved chat context too.
+        from core.inference.llama_keepwarm import purge_kv_resume
+        purge_kv_resume()
     return OpenAIAutoSwitchResponse(
         enabled = enabled,
         auto_unload_idle_seconds = idle_seconds,
-        idle_unload_active = get_auto_unload_idle_seconds() > 0,
+        idle_unload_active = idle_unload_active,
+        auto_unload_keep_kv = keep_kv,
     )
 
 
@@ -263,14 +317,18 @@ class EmbeddingModelPayload(BaseModel):
 
 class EmbeddingModelResponse(BaseModel):
     embedding_model: str
+    embedding_gguf_repo: str
     default_embedding_model: str
+    default_embedding_gguf_repo: str
     is_custom: bool
 
 
 def _embedding_model_response() -> EmbeddingModelResponse:
     return EmbeddingModelResponse(
         embedding_model = get_rag_embedding_model(),
+        embedding_gguf_repo = effective_gguf_repo(),
         default_embedding_model = default_embedding_model(),
+        default_embedding_gguf_repo = default_gguf_repo(),
         is_custom = get_stored_embedding_model() is not None,
     )
 
@@ -400,6 +458,11 @@ def update_embedding_model(
             log = logger,
         ) from exc
     hf_token = (payload.hf_token or "").strip() or None
+    from utils.utils import hf_env_offline
+
+    # Offline, both the Hub malware scan and the is-embedding check are unreachable and degrade
+    # to the local cache below; capture the state once.
+    local_only_load = hf_env_offline()
     # The env/default model needs no verification; saving it is a no-op override.
     # A local GGUF on the llama-server backend is accepted as-is: it is exactly
     # what the backend loads, and HF metadata cannot verify a local path.
@@ -423,26 +486,41 @@ def update_embedding_model(
         # Fall back to the loader's own token so a gated/private repo is actually scanned
         # (a token-less scan fails open for exactly the repo that would still load).
         scan_token = hf_token or _ambient_hf_token()
-        # Include the ST module dirs (0_Transformer/) so a flagged pickle directly under
-        # one blocks instead of passing as an unreferenced nested shard.
-        load_subdirs = tuple(
-            dict.fromkeys(
-                (
-                    *security_load_subdirs(model, scan_token),
-                    *_st_module_subdirs(model, scan_token),
+        # Offline: subdir probes would hit the network and hang; the offline gate walks the
+        # whole cached snapshot, so no load-subdir hints are needed.
+        if local_only_load:
+            load_subdirs = ()
+        else:
+            # Include ST module dirs (0_Transformer/) so a flagged pickle directly under one
+            # blocks instead of passing as an unreferenced nested shard.
+            load_subdirs = tuple(
+                dict.fromkeys(
+                    (
+                        *security_load_subdirs(model, scan_token),
+                        *_st_module_subdirs(model, scan_token),
+                    )
                 )
             )
-        )
-        if evaluate_file_security(model, hf_token = scan_token, load_subdirs = load_subdirs).blocked:
+        if evaluate_file_security(
+            model,
+            hf_token = scan_token,
+            load_subdirs = load_subdirs,
+            local_only_load = local_only_load,
+        ).blocked:
             # 403, not 409: the client routes every 409 into the forceable "save anyway"
             # flow, but this block is a hard, non-forceable security refusal.
-            raise HTTPException(
-                status_code = 403,
+            if local_only_load:
+                detail = (
+                    f"{model!r} has cached pickle weights that cannot be security-scanned "
+                    "offline and no safetensors alternative, so it cannot be used as the "
+                    "embedding model. Re-download it with safetensors weights while online."
+                )
+            else:
                 detail = (
                     f"{model!r} is flagged as unsafe by Hugging Face's security scan and "
                     "cannot be used as the embedding model."
-                ),
-            )
+                )
+            raise HTTPException(status_code = 403, detail = detail)
     if model != default_embedding_model() and not payload.force and not is_local_gguf:
         from core.rag import config as rag_config
 
@@ -452,15 +530,28 @@ def update_embedding_model(
         # which would wrongly 409 a valid online GGUF embedder.
         gguf_named = _llama_backend_active() and rag_config._names_gguf(model)
         if not gguf_named and not is_embedding_model(model, hf_token = hf_token):
-            raise HTTPException(
-                status_code = 409,
-                detail = (
-                    f"Could not verify {model!r} as an embedding model on "
-                    "Hugging Face (it may be the wrong model type, gated, or "
-                    "you may be offline)."
-                ),
-            )
-        gguf_error = _local_gguf_backend_error(model) or _hf_gguf_backend_error(model, hf_token)
+            # Offline, is_embedding_model can only confirm the ST layout (modules.json); a
+            # transformers-native embedder (e.g. gte-modernbert) is unverifiable without Hub
+            # metadata. If already cached and loadable, accept it rather than raising a 409 that
+            # online would not (ST can load any cached encoder). Uncached -> 409.
+            from utils.utils import hf_cache_snapshot_is_loadable
+
+            # Require a genuinely loadable cache (config + weights), not just a resolved refs/main,
+            # so a metadata-only partial cache still gets the forceable 409.
+            offline_cached = local_only_load and hf_cache_snapshot_is_loadable(model)
+            if not offline_cached:
+                raise HTTPException(
+                    status_code = 409,
+                    detail = (
+                        f"Could not verify {model!r} as an embedding model on "
+                        "Hugging Face (it may be the wrong model type, gated, or "
+                        "you may be offline)."
+                    ),
+                )
+        # The Hub GGUF probe (list_repo_files) can hang offline; skip it. Local check stays.
+        gguf_error = _local_gguf_backend_error(model)
+        if gguf_error is None and not local_only_load:
+            gguf_error = _hf_gguf_backend_error(model, hf_token)
         if gguf_error:
             raise HTTPException(status_code = 409, detail = gguf_error)
     set_rag_embedding_model(model)
diff --git a/studio/backend/routes/training.py b/studio/backend/routes/training.py
index d53e8f2bbc..8be4283415 100644
--- a/studio/backend/routes/training.py
+++ b/studio/backend/routes/training.py
@@ -109,7 +109,9 @@ async def get_hardware_utilization(current_subject: str = Depends(get_current_su
 @router.get("/hardware/visible")
 async def get_visible_hardware_utilization(current_subject: str = Depends(get_current_subject)):
     from utils.hardware import get_visible_gpu_utilization
-    return get_visible_gpu_utilization()
+
+    # Off the event loop: the ROCm fallbacks shell out (Windows perf counters, sysfs) and the System view polls this route.
+    return await asyncio.to_thread(get_visible_gpu_utilization)
 
 
 @router.post("/start")
@@ -127,9 +129,9 @@ async def start_training(
     try:
         logger.info(f"Starting training job with model: {request.model_name}")
 
-        # When Studio is driven as an inference API (API-key auth), refuse to start
+        # When Unsloth is driven as an inference API (API-key auth), refuse to start
         # training while a request is in flight: training frees VRAM by unloading
-        # the chat model, which would kill the stream. The Studio UI (session auth)
+        # the chat model, which would kill the stream. The Unsloth UI (session auth)
         # still starts training and coexists/frees VRAM as before. (A mixed UI+API
         # session is not yet special-cased.)
         if via_api_key is True:
@@ -139,7 +141,7 @@ async def start_training(
                     status_code = 409,
                     detail = (
                         "Cannot start training over the API while an inference request is in "
-                        "progress. Wait for it to finish, or start training from the Studio UI."
+                        "progress. Wait for it to finish, or start training from the Unsloth UI."
                     ),
                 )
 
@@ -196,6 +198,7 @@ async def start_training(
                 request.local_eval_datasets, "Local eval dataset"
             )
         resume_output_dir: Optional[str] = None
+        resume_run: Optional[dict] = None
         if request.resume_from_checkpoint:
             try:
                 resume_output_dir = normalize_resume_output_dir(request.resume_from_checkpoint)
@@ -208,7 +211,7 @@ async def start_training(
             if not resume_run or not can_resume_run(resume_run):
                 raise HTTPException(
                     status_code = 400,
-                    detail = "Resume checkpoint must belong to a stopped run with saved trainer state.",
+                    detail = "Resume checkpoint must belong to a stopped or errored run with complete saved trainer state.",
                 )
             resume_checkpoint = get_resume_checkpoint_path(resume_output_dir)
             if not resume_checkpoint:
@@ -329,6 +332,7 @@ async def start_training(
             else "unsloth",
             "use_rslora": request.use_rslora,
             "use_loftq": request.use_loftq,
+            "use_dora": request.use_dora,
             "train_on_completions": request.train_on_completions,
             "finetune_vision_layers": request.finetune_vision_layers,
             "finetune_language_layers": request.finetune_language_layers,
@@ -412,53 +416,39 @@ async def start_training(
             try:
                 from routes.training_vram import (
                     can_keep_chat_during_training,
-                    free_chat_models_for_training,
-                    summarize_resident_chat,
+                    coordinate_models_for_training,
                 )
 
-                resident = summarize_resident_chat()
-                if not resident["any"]:
-                    return
-                if resident.get("loading"):
-                    # In-flight load can't be sized -> free rather than risk OOM.
-                    freed = free_chat_models_for_training(reason = "chat model still loading")
-                    logger.info("Freed in-flight chat load for training: %s", freed)
-                    return
-                keep, info = can_keep_chat_during_training(
-                    model_name = training_kwargs["model_name"],
-                    hf_token = training_kwargs["hf_token"],
-                    training_type = training_kwargs["training_type"],
-                    load_in_4bit = training_kwargs["load_in_4bit"],
-                    batch_size = training_kwargs["batch_size"],
-                    max_seq_length = training_kwargs["max_seq_length"],
-                    lora_rank = training_kwargs["lora_r"],
-                    target_modules = training_kwargs["target_modules"],
-                    gradient_checkpointing = training_kwargs["gradient_checkpointing"],
-                    optimizer = training_kwargs["optim"],
-                    gpu_ids = training_kwargs["gpu_ids"],
-                )
-                if keep:
-                    logger.info(
-                        "Keeping chat model(s) loaded during training "
-                        "(free ~%s GB, needs ~%s GB): %s",
-                        info.get("usable_gb"),
-                        info.get("required_gb"),
-                        resident,
+                def _can_keep_resident_models():
+                    return can_keep_chat_during_training(
+                        model_name = training_kwargs["model_name"],
+                        hf_token = training_kwargs["hf_token"],
+                        training_type = training_kwargs["training_type"],
+                        load_in_4bit = training_kwargs["load_in_4bit"],
+                        batch_size = training_kwargs["batch_size"],
+                        max_seq_length = training_kwargs["max_seq_length"],
+                        lora_rank = training_kwargs["lora_r"],
+                        target_modules = training_kwargs["target_modules"],
+                        gradient_checkpointing = training_kwargs["gradient_checkpointing"],
+                        optimizer = training_kwargs["optim"],
+                        gpu_ids = training_kwargs["gpu_ids"],
                     )
-                else:
-                    freed = free_chat_models_for_training(
-                        reason = "insufficient VRAM to run training alongside chat",
-                    )
-                    logger.info("Freed chat model(s) for training: %s", freed)
+
+                freed = coordinate_models_for_training(_can_keep_resident_models)
+                if freed:
+                    logger.info("Freed models for training: %s", freed)
             except Exception as e:
-                logger.warning("Chat/training VRAM coordination failed; proceeding: %s", e)
+                logger.warning("Inference/training memory coordination failed; proceeding: %s", e)
 
         # The hook runs only once start guards pass -> VRAM freed iff training starts.
         from utils.transformers_version import SidecarSwapInProgress
 
         try:
             success = backend.start_training(
-                job_id = job_id, before_spawn = _free_vram_for_training, **training_kwargs
+                job_id = job_id,
+                before_spawn = _free_vram_for_training,
+                resume_source_run_id = resume_run["id"] if resume_run else None,
+                **training_kwargs,
             )
         except SidecarSwapInProgress as exc:
             # Expected loss of the race against a sidecar install: a retryable
@@ -521,7 +511,10 @@ async def stop_training(
                 status = "idle", message = "No training job is currently running"
             )
 
-        backend.stop_training(save = body.save)
+        if not backend.stop_training(save = body.save):
+            return TrainingStopResponse(
+                status = "idle", message = "No training job is currently running"
+            )
 
         return TrainingStopResponse(
             status = "stopped",
@@ -637,9 +630,9 @@ async def get_training_status(current_subject: str = Depends(get_current_subject
                 "loss": getattr(progress, "loss", None),
                 "learning_rate": getattr(progress, "learning_rate", None),
             }
-            output_dir = getattr(backend, "_output_dir", None)
-            if output_dir:
-                details["output_dir"] = output_dir
+            # Always present: an explicit null tells the client to drop a cached
+            # path (stop without save clears the run's output_dir).
+            details["output_dir"] = getattr(backend, "_output_dir", None) or None
 
         # Metric history for chart recovery after SSE reconnection.
         metric_history = None
diff --git a/studio/backend/routes/training_vram.py b/studio/backend/routes/training_vram.py
index fb361d3359..8ddda11b1e 100644
--- a/studio/backend/routes/training_vram.py
+++ b/studio/backend/routes/training_vram.py
@@ -1,15 +1,13 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""VRAM coordination between chat/inference and training.
+"""Memory coordination between inference and training.
 
-Decides, from live free VRAM, whether a resident chat model can stay loaded
-during training or must be unloaded, and unloads it across all backends
-(HF/MLX orchestrator + llama.cpp GGUF server). In the route layer because the
-GGUF accessor lives in routes/inference.py; backends are imported lazily.
+Uses live free VRAM to keep resident chat and STT models when they fit. STT is
+evicted before chat when training needs memory.
 """
 
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any, Callable, Dict, List, Optional, Tuple
 
 from loggers import get_logger
 
@@ -77,6 +75,37 @@ def summarize_resident_chat() -> Dict[str, Any]:
     }
 
 
+def summarize_resident_stt() -> Dict[str, Any]:
+    """Report the resident dictation model (either engine). Never raises."""
+    try:
+        from core.inference.stt_ggml_sidecar import get_ggml_stt_sidecar
+        from core.inference.stt_sidecar import get_stt_sidecar
+
+        sidecar = get_stt_sidecar()
+        model = sidecar.loaded_model
+        device = sidecar.device
+        loading = sidecar.is_loading()
+        # whisper.cpp holds GPU memory via its subprocess, and both engines can be
+        # live at once (engine switch or direct /audio/stt/load). Always fold the
+        # GGUF sidecar in: a resident Transformers model must not mask a GGUF
+        # server still binding its backend, or admission lets training launch into
+        # that startup and OOM.
+        ggml = get_ggml_stt_sidecar()
+        if not model:
+            model = ggml.loaded_model
+            device = device or ggml.device
+        loading = loading or ggml.is_loading()
+        return {
+            "model": model,
+            "device": device,
+            "loading": loading,
+            "any": bool(model or loading),
+        }
+    except Exception as e:
+        logger.warning("Could not inspect STT sidecar: %s", e)
+        return {"model": None, "device": None, "loading": False, "any": False}
+
+
 def can_keep_chat_during_training(
     *,
     model_name: str,
@@ -106,8 +135,8 @@ def can_keep_chat_during_training(
             resolve_requested_gpu_ids,
         )
 
-        if get_device() != DeviceType.CUDA:
-            return False, {"mode": "non_cuda", "reason": "non_cuda"}
+        if get_device() not in (DeviceType.CUDA, DeviceType.XPU):
+            return False, {"mode": "non_accelerator", "reason": "non_accelerator"}
 
         # Full finetuning runs in 16-bit, so ignore the 4-bit request or we under-count.
         effective_4bit = False if training_type == "Full Finetuning" else load_in_4bit
@@ -196,16 +225,24 @@ def can_load_chat_during_training(
     max_seq_length: int,
     requested_gpu_ids: Optional[List[int]],
     is_gguf: bool = False,
+    is_vulkan: bool = False,
     required_override_gb: Optional[float] = None,
+    single_device_gpu: Optional[str] = None,
 ) -> Tuple[bool, Dict[str, Any]]:
     """Decide if a NEW chat model can load without OOMing active training (inverse
     of can_keep_chat_during_training: training is already resident, so size the
     chat model against the free VRAM that remains). Sizes/places it the same way
     the loader will: HF auto reuses auto_select_gpu_ids; HF explicit requires an
     even-share per-GPU floor for device_map="balanced"; GGUF sizes from
-    required_override_gb over the visible pool. `load_in_4bit` must be effective
-    (LoRA can flip 4-bit -> 16-bit). Non-CUDA allows the load; default-deny on any
-    CUDA case it can't size, so a load never OOMs training."""
+    required_override_gb over the visible pool. A Vulkan GGUF selection picks by ggml
+    Vulkan ordinal (separate index space from CUDA ids), so its requested_gpu_ids is
+    NOT resolved against the CUDA set (which would raise -> invalid_gpu_ids -> bypass
+    the OOM check); conservatively size an N-device request against the least-free
+    N visible GPUs instead.
+    ``single_device_gpu`` is the exact physical device token selected by a
+    single-device runner. `load_in_4bit` must be effective (LoRA can flip 4-bit
+    -> 16-bit). CPU/MLX allows the load; default-deny on any CUDA/XPU case it
+    can't size, so a load never OOMs training."""
     try:
         from utils.hardware import (
             DeviceType,
@@ -216,8 +253,8 @@ def can_load_chat_during_training(
             resolve_requested_gpu_ids,
         )
 
-        if get_device() != DeviceType.CUDA:
-            return True, {"mode": "non_cuda", "reason": "non_cuda"}
+        if get_device() not in (DeviceType.CUDA, DeviceType.XPU):
+            return True, {"mode": "non_accelerator", "reason": "non_accelerator"}
 
         est_kwargs = dict(
             hf_token = hf_token or None,
@@ -226,6 +263,11 @@ def can_load_chat_during_training(
             max_seq_length = max_seq_length or 2048,
         )
 
+        # A Vulkan GGUF selection uses ggml Vulkan ordinals, not CUDA physical ids;
+        # size it against the full visible pool (GGUF self-placement) rather than
+        # resolving ordinals against the CUDA parent-visible set.
+        vulkan_gguf = is_gguf and is_vulkan
+
         # HF auto: reuse the loader's selector; fits iff its pick clears the margin.
         if not requested_gpu_ids and not is_gguf:
             _selected, meta = auto_select_gpu_ids(model_name, **est_kwargs)
@@ -251,26 +293,62 @@ def can_load_chat_during_training(
             }
 
         # Explicit GPUs, or GGUF: size directly and check live free VRAM.
+        if requested_gpu_ids and vulkan_gguf:
+            mode = "gguf_vulkan"
+        elif single_device_gpu is not None:
+            mode = "single_device"
+        elif is_gguf:
+            mode = "gguf"
+        else:
+            mode = "explicit"
         required_gb = required_override_gb
         if required_gb is None:
             required_gb, _meta = estimate_required_model_memory_gb(model_name, **est_kwargs)
         if required_gb is None:
-            mode = "explicit" if requested_gpu_ids else "gguf"
             return False, {"mode": mode, "reason": "estimate_unavailable"}
 
         free_by_index = _free_vram_by_index(get_visible_gpu_utilization().get("devices", []))
-        if requested_gpu_ids:
+        if requested_gpu_ids and vulkan_gguf:
+            # Vulkan ordinals cannot be mapped to CUDA physical indices. Budget
+            # the least-free N visible cards for an N-device request. If that
+            # conservative subset fits, any physical mapping of the ordinals
+            # fits, without collapsing a multi-GPU request to one card.
+            visible_free = list(free_by_index.values())
+            if not visible_free:
+                return False, {"mode": "gguf_vulkan", "reason": "no_visible_gpus"}
+            n_pins = min(len(requested_gpu_ids), len(visible_free))
+            free_vals = sorted(visible_free)[:n_pins]
+        elif single_device_gpu is not None:
+            token = str(single_device_gpu).strip()
+            if not token:
+                # Empty token = a CPU-only single-device runner (e.g. a CPU
+                # diffusion GGUF): it uses no GPU VRAM, so it never threatens
+                # active training and can always load.
+                return True, {"mode": "single_device", "reason": "cpu_only"}
+            try:
+                selected_gpu = int(token)
+                if selected_gpu < 0:
+                    raise ValueError
+            except (TypeError, ValueError):
+                # A non-numeric device token (e.g. a CUDA UUID / MIG handle)
+                # can't be mapped to a free-VRAM index, but the runner still
+                # drives ONE device. Size against the worst-case visible device
+                # (min free), never the aggregate pool, so a single-device load
+                # is never OK'd on capacity it can't use and OOMs training.
+                free_vals = [min(free_by_index.values())] if free_by_index else []
+            else:
+                free_vals = [free_by_index.get(selected_gpu, 0.0)]
+        elif requested_gpu_ids:
             # Invalid ids -> load_model 400s first, so don't block; missing id = 0.
             try:
                 resolved = resolve_requested_gpu_ids(requested_gpu_ids)
             except ValueError:
-                return True, {"mode": "explicit", "reason": "invalid_gpu_ids"}
+                return True, {"mode": mode, "reason": "invalid_gpu_ids"}
             free_vals = [free_by_index.get(i, 0.0) for i in resolved]
-            mode = "explicit"
         else:
-            # GGUF: llama.cpp picks the GPU(s); any visible GPU is a candidate.
+            # GGUF self-placement / auto Vulkan (no requested ids): llama.cpp picks
+            # the GPU(s), so any visible GPU is a candidate -> size the whole pool.
             free_vals = list(free_by_index.values())
-            mode = "gguf"
 
         if not free_vals:
             return False, {"mode": mode, "reason": "no_visible_gpus"}
@@ -340,3 +418,110 @@ def free_chat_models_for_training(reason: str) -> List[str]:
         logger.warning("Could not unload GGUF chat model: %s", e)
 
     return freed
+
+
+def free_stt_model_for_training(reason: str) -> List[str]:
+    """Unload the dictation model(s) before training. Never raises.
+
+    The Transformers and GGUF sidecars are freed under independent exception
+    boundaries so a failure unloading one backend never skips freeing the other
+    (both can hold accelerator memory at once after an engine switch).
+    """
+    freed: List[str] = []
+    try:
+        from core.inference.stt_sidecar import get_stt_sidecar
+        sidecar = get_stt_sidecar()
+        if sidecar.is_loading() and sidecar.cancel_pending_load():
+            logger.info("Cancelling STT model load for training (%s)", reason)
+            # The loader may still be in from_pretrained()/.to(device) holding
+            # VRAM; wait for it to observe the cancel and release first.
+            sidecar.wait_for_load_to_settle()
+            # A load that finished before seeing the cancel leaves a resident
+            # model; unload it so training gets the memory back.
+            if sidecar.loaded_model:
+                sidecar.unload()
+            freed.append("stt:loading")
+        else:
+            model = sidecar.loaded_model
+            if model:
+                logger.info("Unloading STT model '%s' for training (%s)", model, reason)
+                sidecar.unload()
+                freed.append(f"stt:{model}")
+    except Exception as e:
+        logger.warning("Could not unload Transformers STT model: %s", e)
+
+    # Check the GGUF sidecar even after a cancelled/failed Transformers unload;
+    # both engines can hold memory at once (engine switch or direct load).
+    try:
+        from core.inference.stt_ggml_sidecar import get_ggml_stt_sidecar
+        ggml = get_ggml_stt_sidecar()
+        if ggml.is_loading() and ggml.cancel_pending_load():
+            logger.info("Cancelling GGUF STT model load for training (%s)", reason)
+            # whisper-server may still be binding its backend; wait for the
+            # cancelled startup to be killed and reaped before training claims
+            # the memory (loaded_model stays unset until it is ready).
+            ggml.wait_for_load_to_settle()
+            if ggml.loaded_model:
+                ggml.unload()
+            freed.append("stt:gguf-loading")
+        else:
+            ggml_model = ggml.loaded_model
+            if ggml_model:
+                logger.info("Unloading GGUF STT model '%s' for training (%s)", ggml_model, reason)
+                ggml.unload()
+                freed.append(f"stt:{ggml_model}")
+    except Exception as e:
+        logger.warning("Could not unload GGUF STT model: %s", e)
+
+    return freed
+
+
+def coordinate_models_for_training(
+    can_keep: Callable[[], Tuple[bool, Dict[str, Any]]],
+) -> List[str]:
+    """Keep resident models when they fit, evicting STT before chat."""
+    resident_chat = summarize_resident_chat()
+    resident_stt = summarize_resident_stt()
+    if not resident_chat["any"] and not resident_stt["any"]:
+        return []
+
+    if resident_chat.get("loading"):
+        freed = free_stt_model_for_training(reason = "chat model still loading")
+        freed += free_chat_models_for_training(reason = "chat model still loading")
+        return freed
+
+    freed: List[str] = []
+    if resident_stt.get("loading"):
+        released_stt = free_stt_model_for_training(reason = "STT model still loading")
+        freed += released_stt
+        resident_stt = (
+            {"model": None, "device": None, "loading": False, "any": False}
+            if released_stt
+            else summarize_resident_stt()
+        )
+        if not resident_chat["any"] and not resident_stt["any"]:
+            return freed
+
+    keep, info = can_keep()
+    if keep:
+        logger.info(
+            "Keeping resident models loaded during training (free ~%s GB, needs ~%s GB): %s",
+            info.get("usable_gb"),
+            info.get("required_gb"),
+            {"chat": resident_chat, "stt": resident_stt},
+        )
+        return freed
+
+    if resident_stt["any"]:
+        freed += free_stt_model_for_training(reason = "insufficient training memory")
+        if not resident_chat["any"]:
+            return freed
+        keep, _info = can_keep()
+        if keep:
+            logger.info("Keeping chat model loaded after freeing STT: %s", resident_chat)
+            return freed
+
+    freed += free_chat_models_for_training(
+        reason = "insufficient VRAM to run training alongside chat",
+    )
+    return freed
diff --git a/studio/backend/routes/whisper.py b/studio/backend/routes/whisper.py
new file mode 100644
index 0000000000..08a8f269ec
--- /dev/null
+++ b/studio/backend/routes/whisper.py
@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""whisper.cpp prebuilt status endpoint.
+
+GET  /api/whisper/update-status  -> is a newer prebuilt available + job state
+
+Detection reuses utils.whisper_cpp_freshness and fails open so the UI never
+blocks on a missing marker / offline GitHub. There is no whisper-only update
+trigger: whisper updates piggyback on the single main update item
+(POST /api/llama/update chains a whisper phase when whisper is behind).
+"""
+
+from __future__ import annotations
+
+import asyncio
+from typing import Optional
+
+from fastapi import APIRouter, Depends, Query
+from pydantic import BaseModel, Field
+
+from auth.authentication import get_current_subject
+from utils.whisper_cpp_update import get_update_status
+
+router = APIRouter()
+
+
+class WhisperUpdateJob(BaseModel):
+    state: str = Field("idle", description = "idle | running | success | error")
+    message: str = ""
+    from_tag: Optional[str] = None
+    to_tag: Optional[str] = None
+    reload_required: Optional[bool] = None
+    error: Optional[str] = None
+    progress: Optional[float] = Field(None, description = "0..1 while running, 1 on success.")
+    started_at: Optional[str] = None
+    finished_at: Optional[str] = None
+
+
+class WhisperUpdateStatusResponse(BaseModel):
+    supported: bool = Field(
+        False,
+        description = "True when the install came from an Unsloth prebuilt (has a marker).",
+    )
+    update_available: bool = Field(
+        False, description = "True when the latest release is genuinely newer than the install."
+    )
+    stale: bool = Field(
+        False, description = "Update available AND install older than the staleness threshold."
+    )
+    installed_tag: Optional[str] = None
+    latest_tag: Optional[str] = None
+    published_repo: Optional[str] = None
+    installed_at_utc: Optional[str] = None
+    age_days: Optional[int] = None
+    source_build: bool = Field(
+        False, description = "True when there is no marker (source build) but a prebuilt is offered."
+    )
+    update_size_bytes: Optional[int] = Field(
+        None, description = "Download size of the prebuilt an update would fetch, in bytes."
+    )
+    job: WhisperUpdateJob = Field(default_factory = WhisperUpdateJob)
+
+
+@router.get("/update-status", response_model = WhisperUpdateStatusResponse)
+async def whisper_update_status(
+    force_refresh: bool = Query(
+        False, description = "Bypass the 24h release cache for an explicit check."
+    ),
+    current_subject: str = Depends(get_current_subject),
+) -> WhisperUpdateStatusResponse:
+    # Off the event loop: detection may probe the host and read GitHub.
+    status = await asyncio.to_thread(get_update_status, force_refresh = force_refresh)
+    return WhisperUpdateStatusResponse(**status)
diff --git a/studio/backend/run.py b/studio/backend/run.py
index 56b9c78343..d9569c46f6 100644
--- a/studio/backend/run.py
+++ b/studio/backend/run.py
@@ -232,7 +232,7 @@ def _working_local_url(port: int) -> "str | None":
 def _localhost_ipv6_mismatch_url(bind_host: str, port: int) -> "str | None":
     """Return the IPv4 loopback URL when localhost won't reach 127.0.0.1.
 
-    Local Studio binds to 127.0.0.1. Where localhost resolves to IPv6 only (::1),
+    Local Unsloth binds to 127.0.0.1. Where localhost resolves to IPv6 only (::1),
     http://localhost:<port> fails (or hits a different process on ::1) even though
     http://127.0.0.1:<port> works. Return the IPv4 URL for the caller to surface.
     """
@@ -243,7 +243,7 @@ def _localhost_ipv6_mismatch_url(bind_host: str, port: int) -> "str | None":
 
     ipv4_url = f"http://127.0.0.1:{port}"
 
-    # Only warn once Studio is confirmed answering on IPv4 loopback.
+    # Only warn once Unsloth is confirmed answering on IPv4 loopback.
     if _working_local_url(port) != ipv4_url:
         return None
 
@@ -265,7 +265,7 @@ def _localhost_ipv6_mismatch_url(bind_host: str, port: int) -> "str | None":
             if host == "::1":
                 has_ipv6_loopback = True
 
-    # A connection to ::1 is NOT evidence Studio is reachable there: Studio binds
+    # A connection to ::1 is NOT evidence Unsloth is reachable there: Unsloth binds
     # 127.0.0.1 only, so anything on ::1 is a different process. Dual-stack
     # localhost is fine (browsers fall back to 127.0.0.1), so only the IPv6-only
     # case strands the user.
@@ -287,7 +287,7 @@ def _stdout_color_ok() -> bool:
 
 
 def _print_localhost_ipv6_mismatch_warning(local_url: str, port: int) -> None:
-    """Warn that localhost points at ::1 while Studio is bound to 127.0.0.1."""
+    """Warn that localhost points at ::1 while Unsloth is bound to 127.0.0.1."""
     use_color = _stdout_color_ok()
     warn_c = "\033[38;5;215;1m" if use_color else ""
     reset = "\033[0m" if use_color else ""
@@ -303,7 +303,7 @@ def _print_localhost_ipv6_mismatch_warning(local_url: str, port: int) -> None:
 def _verify_global_reachability(display_host: str, port: int) -> None:
     """Probe check-host.net to confirm display_host:port is reachable from the
     public internet. Synchronous so output lands between the banner URLs and the
-    stop hint. Bounded at ~15s; failures swallowed (verifier failing != Studio
+    stop hint. Bounded at ~15s; failures swallowed (verifier failing != Unsloth
     failing). Only meaningful for a wildcard bind."""
     global _public_reachable
     # Reset to "unknown" each run; set True/False only when the probe decides.
@@ -563,15 +563,15 @@ def _print_cloudflare_line(secure: bool = False, loopback_host: str = "127.0.0.1
                     "  Cloudflare tunnel: ON. This Cloudflare URL is PUBLIC, and the "
                     "raw port is also publicly reachable. --no-cloudflare disables "
                     f"only the Cloudflare URL; bind {loopback_host} or close firewall "
-                    "access to keep Studio private.",
+                    "access to keep Unsloth private.",
                     warn,
                 )
             else:
                 _emit(
                     "  Cloudflare tunnel: ON. This is a PUBLIC internet URL: anyone "
-                    "who has it can reach this Studio. Relaunch with --no-cloudflare "
+                    "who has it can reach this Unsloth. Relaunch with --no-cloudflare "
                     f"to disable the Cloudflare URL; bind {loopback_host} or close "
-                    "firewall access to keep Studio private.",
+                    "firewall access to keep Unsloth private.",
                     warn,
                 )
         return
@@ -580,12 +580,12 @@ def _print_cloudflare_line(secure: bool = False, loopback_host: str = "127.0.0.1
             _emit(
                 "  Cloudflare tunnel: requested but failed to start. The raw port is "
                 "still reachable from the public internet (see the reachability check "
-                "above): anyone who can reach it can access this Studio.",
+                "above): anyone who can reach it can access this Unsloth.",
                 warn,
             )
         elif _public_reachable is False:
             _emit(
-                "  Cloudflare tunnel: requested but failed to start. Studio is reachable "
+                "  Cloudflare tunnel: requested but failed to start. Unsloth is reachable "
                 "on your local network only (no public link).",
                 warn,
             )
@@ -593,7 +593,7 @@ def _print_cloudflare_line(secure: bool = False, loopback_host: str = "127.0.0.1
             _emit(
                 "  Cloudflare tunnel: requested but failed to start. There is no "
                 "Cloudflare public link. Raw port reachability was not verified; "
-                f"bind {loopback_host} or close firewall access to keep Studio private.",
+                f"bind {loopback_host} or close firewall access to keep Unsloth private.",
                 warn,
             )
     elif _cloudflare_flag:
@@ -601,19 +601,19 @@ def _print_cloudflare_line(secure: bool = False, loopback_host: str = "127.0.0.1
             _emit(
                 "  Cloudflare tunnel: OFF for this mode. The raw port is still "
                 "reachable from the public internet (see the reachability check above): "
-                "anyone who can reach it can access this Studio.",
+                "anyone who can reach it can access this Unsloth.",
                 warn,
             )
         elif _public_reachable is False:
             _emit(
-                "  Cloudflare tunnel: OFF for this mode. Studio is reachable on your "
+                "  Cloudflare tunnel: OFF for this mode. Unsloth is reachable on your "
                 "local network only (no public link)."
             )
         else:
             _emit(
                 "  Cloudflare tunnel: OFF for this mode. There is no Cloudflare public "
                 "link. Raw port reachability was not verified; "
-                f"bind {loopback_host} or close firewall access to keep Studio private.",
+                f"bind {loopback_host} or close firewall access to keep Unsloth private.",
                 warn,
             )
     elif _cloudflare_flag is False or _cloudflare_flag is None:
@@ -624,12 +624,12 @@ def _print_cloudflare_line(secure: bool = False, loopback_host: str = "127.0.0.1
                 f"  Cloudflare tunnel: OFF ({_reason}). The raw port is still "
                 "reachable from the public internet (see the reachability check above): "
                 "pass --cloudflare to also expose a public Cloudflare HTTPS link, or "
-                f"bind {loopback_host} to keep Studio private.",
+                f"bind {loopback_host} to keep Unsloth private.",
                 warn,
             )
         elif _public_reachable is False:
             _emit(
-                f"  Cloudflare tunnel: OFF ({_reason}). Studio is reachable on your "
+                f"  Cloudflare tunnel: OFF ({_reason}). Unsloth is reachable on your "
                 "local network only. Pass --cloudflare to expose a public "
                 "Cloudflare HTTPS link."
             )
@@ -638,7 +638,7 @@ def _print_cloudflare_line(secure: bool = False, loopback_host: str = "127.0.0.1
                 f"  Cloudflare tunnel: OFF ({_reason}). There is no Cloudflare "
                 "public link. Raw port reachability was not verified; pass --cloudflare "
                 "to expose a public Cloudflare HTTPS link, or "
-                f"bind {loopback_host} or close firewall access to keep Studio private.",
+                f"bind {loopback_host} or close firewall access to keep Unsloth private.",
                 warn,
             )
 
@@ -674,7 +674,7 @@ def _is_port_free(host: str, port: int) -> bool:
 
     For a ``0.0.0.0`` wildcard host, also check whether anything is listening on
     ``127.0.0.1`` (and ``::1`` when IPv6 exists): an SSH tunnel may hold loopback
-    while the wildcard bind succeeds, making Studio unreachable via ``localhost``.
+    while the wildcard bind succeeds, making Unsloth unreachable via ``localhost``.
     """
     import socket
 
@@ -1087,7 +1087,7 @@ def _terminal_password_gate(
 ) -> Tuple[bool, bool]:
     """Force a terminal password change before the public tunnel goes up.
 
-    When the tunnel is about to publish Studio and the seeded admin password was
+    When the tunnel is about to publish Unsloth and the seeded admin password was
     never changed, ask for a new one (masked, confirmed) before any public URL
     exists. The CLI normally does this before re-exec'ing the backend; this is
     the backstop for direct `python run.py` launches and older-CLI installs.
@@ -1147,7 +1147,7 @@ def _terminal_password_gate(
         )
         if not deadline_arms:
             print(
-                "Refusing to publish Studio on a public Cloudflare URL: the "
+                "Refusing to publish Unsloth on a public Cloudflare URL: the "
                 "default admin password was never changed, no terminal is "
                 "attached to change it here, and the bootstrap shutdown "
                 "deadline does not apply to this launch (api-only, or "
@@ -1163,11 +1163,11 @@ def _terminal_password_gate(
         # terminal-attached run / reset-password instead of reading it from disk.
         print(
             "  WARNING: the default admin password is still active while "
-            "Studio is about to be published on a public Cloudflare URL, and "
+            "Unsloth is about to be published on a public Cloudflare URL, and "
             "no terminal is attached to change it here. The public page will "
             "NOT auto-fill the bootstrap credential. Set a new password by "
             "running `unsloth studio` locally with a terminal attached, or "
-            "`unsloth studio reset-password`. Studio shuts down after the "
+            "`unsloth studio reset-password`. Unsloth shuts down after the "
             "bootstrap deadline (UNSLOTH_STUDIO_BOOTSTRAP_TIMEOUT, default 1h) "
             "unless the password is changed.",
             file = sys.stderr,
@@ -1222,7 +1222,7 @@ def _apply_supplied_password(password_value: "Optional[str]") -> None:
     _auth_storage.ensure_default_admin()
     if not _auth_storage.requires_password_change(_admin):
         print(
-            "Error: a Studio admin password is already set; --password only sets "
+            "Error: an Unsloth admin password is already set; --password only sets "
             "the initial password. Run `unsloth studio reset-password` first.",
             file = sys.stderr,
             flush = True,
@@ -1244,6 +1244,13 @@ def _apply_supplied_password(password_value: "Optional[str]") -> None:
             flush = True,
         )
         sys.exit(1)
+    if any(ch.isspace() for ch in supplied):
+        print(
+            "Error: password cannot contain spaces; not starting.",
+            file = sys.stderr,
+            flush = True,
+        )
+        sys.exit(1)
     if _is_current_password(supplied):
         print(
             "Error: the new password must differ from the current bootstrap "
@@ -1337,7 +1344,7 @@ def run_server(
             pass
 
     # Persist a session log + native-crash stacks BEFORE importing main, so
-    # even import-time failures leave evidence on disk. Field report: Studio
+    # even import-time failures leave evidence on disk. Field report: Unsloth
     # "terminates without a warning" -- a native crash in the GPU runtime
     # kills the process with no Python traceback, and a desktop-shortcut
     # console closes before anything can be read. Console-only logging made
@@ -1354,11 +1361,23 @@ def run_server(
     if secure:
         os.environ["UNSLOTH_SECURE"] = "1"
 
-    import nest_asyncio
-
-    nest_asyncio.apply()
-
     import asyncio
+
+    # nest_asyncio is for Colab/IPython, where the main thread already runs a loop
+    # the blocking waits below would collide with. Apply it only with a loop running
+    # (a plain CLI start has nothing to nest) and only on Python <= 3.13: on 3.14+
+    # its global Task patch leaves asyncio.current_task() None (tracking moved into
+    # C), which also breaks the background uvicorn loop and 500s every request. It
+    # is archived upstream, so no 3.14 fix is coming; skip it there.
+    if sys.version_info < (3, 14):
+        try:
+            asyncio.get_running_loop()
+        except RuntimeError:
+            pass
+        else:
+            import nest_asyncio
+            nest_asyncio.apply()
+
     from threading import Thread, Event
     import uvicorn
 
@@ -1394,7 +1413,7 @@ def run_server(
     ensure_studio_directories()
 
     logger.info(
-        "Ensured Studio directories in %.1fms",
+        "Ensured Unsloth directories in %.1fms",
         (time.perf_counter() - boot_started) * 1000,
     )
 
@@ -1443,7 +1462,7 @@ def run_server(
                 installer_bin = home / "unsloth_studio" / "bin" / "unsloth"
             tried_lines = "\n".join(f"  - {p}" for p in attempted) or "  (none)"
             raise SystemExit(
-                "[ERROR] Studio frontend build not found.\n"
+                "[ERROR] Unsloth frontend build not found.\n"
                 f"Tried:\n{tried_lines}\n"
                 "\n"
                 "Likely cause: another 'unsloth' on PATH is shadowing the "
@@ -1545,7 +1564,7 @@ def run_server(
     )
     if not _pw_proceed:
         print(
-            "Not starting Studio; set a new admin password first, or launch "
+            "Not starting Unsloth; set a new admin password first, or launch "
             "without --secure/--cloudflare.",
             file = sys.stderr,
             flush = True,
@@ -1683,7 +1702,7 @@ def run_server(
                 logger = logger,
             )
             logger.info(
-                "Studio will shut down in %ds unless the default admin password is changed.",
+                "Unsloth will shut down in %ds unless the default admin password is changed.",
                 _bootstrap_timeout,
             )
     except Exception as e:  # best-effort: never block startup on the timeout
@@ -1741,11 +1760,11 @@ def _build_arg_parser():
         "--cloudflare",
         action = argparse.BooleanOptionalAction,
         default = None,
-        help = "Expose Studio on a PUBLIC internet URL via a free Cloudflare HTTPS "
+        help = "Expose Unsloth on a PUBLIC internet URL via a free Cloudflare HTTPS "
         "tunnel, for non-api-only wildcard binds (0.0.0.0 or ::). Off by default; "
         "pass --cloudflare to enable it (--secure implies it), --no-cloudflare to "
         "force it off. It does not change a raw wildcard bind. If the admin "
-        "password was never changed, Studio asks for a new one in the terminal "
+        "password was never changed, Unsloth asks for a new one in the terminal "
         "before publishing the URL.",
     )
     parser.add_argument(
@@ -1755,7 +1774,7 @@ def _build_arg_parser():
         help = "Expose ONLY a Cloudflare HTTPS link: bind localhost and fail closed "
         "if the tunnel can't start. Without it, --no-secure also serves the raw "
         "0.0.0.0 port, which is reachable from anywhere on the network. If the "
-        "admin password was never changed, Studio asks for a new one in the "
+        "admin password was never changed, Unsloth asks for a new one in the "
         "terminal before publishing the URL.",
     )
     # Back-compat: accept --not-secure as a hidden alias for --no-secure.
diff --git a/studio/backend/startup_banner.py b/studio/backend/startup_banner.py
index ea951a4325..9ec7a4f91c 100644
--- a/studio/backend/startup_banner.py
+++ b/studio/backend/startup_banner.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Terminal banner for Studio startup.
+"""Terminal banner for Unsloth startup.
 
 Stdlib only -- safe to import without the rest of the backend.
 """
@@ -172,7 +172,7 @@ def print_studio_access_banner(
                     secondary,
                 ),
                 style(
-                    "  Only on trusted networks -- anyone who reaches this machine can use Studio.",
+                    "  Only on trusted networks -- anyone who reaches this machine can use Unsloth.",
                     secondary,
                 ),
             ]
diff --git a/studio/backend/storage/providers_db.py b/studio/backend/storage/providers_db.py
index 07165cbe70..e6f40c5030 100644
--- a/studio/backend/storage/providers_db.py
+++ b/studio/backend/storage/providers_db.py
@@ -6,8 +6,12 @@
 Same pattern as studio_db.py (module-level functions, raw sqlite3, WAL,
 per-function connections). API keys are NOT stored here: they live only in
 the browser (localStorage) and are sent encrypted per-request.
+
+Enabled model selections and discovered catalog IDs are stored server-side so
+remote Studio clients see the same connection state (#7281).
 """
 
+import json
 import logging
 import sqlite3
 import threading
@@ -22,6 +26,33 @@ _schema_lock = threading.Lock()
 _schema_ready = False
 
 
+def _encode_models_json(models: Optional[list[str]]) -> str:
+    if not models:
+        return "[]"
+    return json.dumps([str(model).strip() for model in models if str(model).strip()])
+
+
+def _decode_models_json(raw: Optional[str]) -> list[str]:
+    if not raw:
+        return []
+    try:
+        parsed = json.loads(raw)
+    except json.JSONDecodeError:
+        return []
+    if not isinstance(parsed, list):
+        return []
+    return [str(model).strip() for model in parsed if str(model).strip()]
+
+
+def _row_models(row: sqlite3.Row) -> tuple[list[str], list[str]]:
+    return (
+        _decode_models_json(row["models_json"] if "models_json" in row.keys() else None),
+        _decode_models_json(
+            row["available_models_json"] if "available_models_json" in row.keys() else None
+        ),
+    )
+
+
 def _ensure_schema(conn: sqlite3.Connection) -> None:
     """Create the llm_providers table if absent. Called once per process."""
     conn.execute("PRAGMA journal_mode=WAL")
@@ -38,6 +69,13 @@ def _ensure_schema(conn: sqlite3.Connection) -> None:
         )
         """
     )
+    existing_cols = {row[1] for row in conn.execute("PRAGMA table_info(llm_providers)").fetchall()}
+    if "models_json" not in existing_cols:
+        conn.execute("ALTER TABLE llm_providers ADD COLUMN models_json TEXT NOT NULL DEFAULT '[]'")
+    if "available_models_json" not in existing_cols:
+        conn.execute(
+            "ALTER TABLE llm_providers ADD COLUMN available_models_json TEXT NOT NULL DEFAULT '[]'"
+        )
 
 
 def get_connection() -> sqlite3.Connection:
@@ -59,17 +97,37 @@ def get_connection() -> sqlite3.Connection:
     return conn
 
 
-def create_provider(id: str, provider_type: str, display_name: str, base_url: str) -> None:
+def create_provider(
+    id: str,
+    provider_type: str,
+    display_name: str,
+    base_url: str,
+    models: Optional[list[str]] = None,
+    available_models: Optional[list[str]] = None,
+) -> None:
     """Insert a new provider configuration."""
     now = datetime.now(timezone.utc).isoformat()
     conn = get_connection()
     try:
         conn.execute(
             """
-            INSERT INTO llm_providers (id, provider_type, display_name, base_url, created_at, updated_at)
-            VALUES (?, ?, ?, ?, ?, ?)
+            INSERT INTO llm_providers (
+                id, provider_type, display_name, base_url,
+                models_json, available_models_json,
+                created_at, updated_at
+            )
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?)
             """,
-            (id, provider_type, display_name, base_url, now, now),
+            (
+                id,
+                provider_type,
+                display_name,
+                base_url,
+                _encode_models_json(models),
+                _encode_models_json(available_models),
+                now,
+                now,
+            ),
         )
         conn.commit()
     finally:
@@ -81,6 +139,8 @@ def update_provider(
     display_name: Optional[str] = None,
     base_url: Optional[str] = None,
     is_enabled: Optional[bool] = None,
+    models: Optional[list[str]] = None,
+    available_models: Optional[list[str]] = None,
 ) -> bool:
     """Update fields on an existing provider. Returns True if a row was updated."""
     updates = []
@@ -94,6 +154,12 @@ def update_provider(
     if is_enabled is not None:
         updates.append("is_enabled = ?")
         params.append(1 if is_enabled else 0)
+    if models is not None:
+        updates.append("models_json = ?")
+        params.append(_encode_models_json(models))
+    if available_models is not None:
+        updates.append("available_models_json = ?")
+        params.append(_encode_models_json(available_models))
     if not updates:
         return False
     updates.append("updated_at = ?")
@@ -128,7 +194,13 @@ def get_provider(id: str) -> Optional[dict]:
     conn = get_connection()
     try:
         row = conn.execute("SELECT * FROM llm_providers WHERE id = ?", (id,)).fetchone()
-        return dict(row) if row else None
+        if not row:
+            return None
+        data = dict(row)
+        models, available_models = _row_models(row)
+        data["models"] = models
+        data["available_models"] = available_models
+        return data
     finally:
         conn.close()
 
@@ -138,6 +210,13 @@ def list_providers() -> list[dict]:
     conn = get_connection()
     try:
         rows = conn.execute("SELECT * FROM llm_providers ORDER BY created_at").fetchall()
-        return [dict(row) for row in rows]
+        providers: list[dict] = []
+        for row in rows:
+            data = dict(row)
+            models, available_models = _row_models(row)
+            data["models"] = models
+            data["available_models"] = available_models
+            providers.append(data)
+        return providers
     finally:
         conn.close()
diff --git a/studio/backend/storage/studio_db.py b/studio/backend/storage/studio_db.py
index 4e0c711b69..6972e7b7ff 100644
--- a/studio/backend/storage/studio_db.py
+++ b/studio/backend/storage/studio_db.py
@@ -7,6 +7,7 @@ Like auth/storage.py (module-level functions, raw sqlite3, per-function
 connections) plus WAL mode and PRAGMA foreign_keys = ON for CASCADE deletes.
 """
 
+import hashlib
 import json
 import logging
 import os
@@ -100,6 +101,7 @@ _schema_lock = threading.Lock()
 _schema_ready = False
 _SQLITE_IN_CHUNK_SIZE = 900
 _PROJECT_WORKSPACE_SUBDIRS = ("sandbox",)
+_CHAT_ATTACHMENT_INVENTORY_VERSION = 1
 
 
 def _project_slug(name: str) -> str:
@@ -190,13 +192,18 @@ def _ensure_schema(conn: sqlite3.Connection) -> None:
             error_message TEXT,
             duration_seconds REAL,
             loss_sparkline TEXT,
-            display_name TEXT
+            display_name TEXT,
+            resume_blocked INTEGER NOT NULL DEFAULT 0
         )
         """
     )
     existing_cols = {row[1] for row in conn.execute("PRAGMA table_info(training_runs)").fetchall()}
     if "display_name" not in existing_cols:
         conn.execute("ALTER TABLE training_runs ADD COLUMN display_name TEXT")
+    if "resume_blocked" not in existing_cols:
+        conn.execute(
+            "ALTER TABLE training_runs ADD COLUMN resume_blocked INTEGER NOT NULL DEFAULT 0"
+        )
     conn.execute(
         """
         CREATE TABLE IF NOT EXISTS training_metrics (
@@ -313,6 +320,141 @@ def _ensure_schema(conn: sqlite3.Connection) -> None:
         )
         """
     )
+    tombstone_schema = """
+        CREATE TABLE chat_attachment_tombstones (
+            thread_id TEXT NOT NULL REFERENCES chat_threads(id) ON DELETE CASCADE,
+            message_id TEXT NOT NULL,
+            attachment_id TEXT NOT NULL,
+            deleted_at INTEGER NOT NULL,
+            PRIMARY KEY(thread_id, message_id, attachment_id)
+        ) WITHOUT ROWID
+    """
+    tombstone_table = conn.execute(
+        """
+        SELECT 1 FROM sqlite_master
+        WHERE type = 'table' AND name = 'chat_attachment_tombstones'
+        """
+    ).fetchone()
+    if tombstone_table is None:
+        conn.execute(tombstone_schema)
+    else:
+        tombstone_columns = {
+            row[1] for row in conn.execute("PRAGMA table_info(chat_attachment_tombstones)")
+        }
+        tombstone_fk_targets = {
+            row[2] for row in conn.execute("PRAGMA foreign_key_list(chat_attachment_tombstones)")
+        }
+        if "thread_id" not in tombstone_columns or "chat_threads" not in tombstone_fk_targets:
+            # The first implementation cascaded through chat_messages, which
+            # erased deletion knowledge during pruneMissing. Rebuild once,
+            # retaining every tombstone whose owning thread still exists.
+            conn.execute("SAVEPOINT migrate_chat_attachment_tombstones")
+            try:
+                conn.execute(
+                    "ALTER TABLE chat_attachment_tombstones "
+                    "RENAME TO chat_attachment_tombstones_legacy"
+                )
+                conn.execute(tombstone_schema)
+                if "thread_id" in tombstone_columns:
+                    conn.execute(
+                        """
+                        INSERT OR IGNORE INTO chat_attachment_tombstones
+                            (thread_id, message_id, attachment_id, deleted_at)
+                        SELECT legacy.thread_id, legacy.message_id,
+                               legacy.attachment_id, legacy.deleted_at
+                        FROM chat_attachment_tombstones_legacy legacy
+                        JOIN chat_threads thread ON thread.id = legacy.thread_id
+                        """
+                    )
+                else:
+                    conn.execute(
+                        """
+                        INSERT OR IGNORE INTO chat_attachment_tombstones
+                            (thread_id, message_id, attachment_id, deleted_at)
+                        SELECT message.thread_id, legacy.message_id,
+                               legacy.attachment_id, legacy.deleted_at
+                        FROM chat_attachment_tombstones_legacy legacy
+                        JOIN chat_messages message ON message.id = legacy.message_id
+                        """
+                    )
+                conn.execute("DROP TABLE chat_attachment_tombstones_legacy")
+                conn.execute("RELEASE SAVEPOINT migrate_chat_attachment_tombstones")
+            except Exception:
+                conn.execute("ROLLBACK TO SAVEPOINT migrate_chat_attachment_tombstones")
+                conn.execute("RELEASE SAVEPOINT migrate_chat_attachment_tombstones")
+                raise
+    conn.execute(
+        """
+        CREATE TABLE IF NOT EXISTS chat_attachment_inventory (
+            message_id TEXT NOT NULL REFERENCES chat_messages(id) ON DELETE CASCADE,
+            attachment_id TEXT NOT NULL,
+            name TEXT NOT NULL,
+            type TEXT,
+            content_type TEXT,
+            size_bytes INTEGER,
+            PRIMARY KEY(message_id, attachment_id)
+        ) WITHOUT ROWID
+        """
+    )
+    conn.execute(
+        """
+        CREATE TABLE IF NOT EXISTS chat_attachment_inventory_state (
+            singleton INTEGER NOT NULL PRIMARY KEY CHECK(singleton = 1),
+            inventory_version INTEGER NOT NULL DEFAULT 0,
+            dirty INTEGER NOT NULL DEFAULT 1,
+            backfilled_at INTEGER NOT NULL
+        )
+        """
+    )
+    inventory_state_columns = {
+        row[1] for row in conn.execute("PRAGMA table_info(chat_attachment_inventory_state)")
+    }
+    if "inventory_version" not in inventory_state_columns:
+        conn.execute(
+            "ALTER TABLE chat_attachment_inventory_state "
+            "ADD COLUMN inventory_version INTEGER NOT NULL DEFAULT 0"
+        )
+    if "dirty" not in inventory_state_columns:
+        conn.execute(
+            "ALTER TABLE chat_attachment_inventory_state "
+            "ADD COLUMN dirty INTEGER NOT NULL DEFAULT 1"
+        )
+    conn.execute(
+        """
+        CREATE TRIGGER IF NOT EXISTS chat_attachment_inventory_dirty_insert
+        AFTER INSERT ON chat_messages
+        BEGIN
+            INSERT INTO chat_attachment_inventory_state
+                (singleton, inventory_version, dirty, backfilled_at)
+            VALUES (1, 0, 1, 0)
+            ON CONFLICT(singleton) DO UPDATE SET dirty = 1;
+        END
+        """
+    )
+    conn.execute(
+        """
+        CREATE TRIGGER IF NOT EXISTS chat_attachment_inventory_dirty_update
+        AFTER UPDATE ON chat_messages
+        BEGIN
+            INSERT INTO chat_attachment_inventory_state
+                (singleton, inventory_version, dirty, backfilled_at)
+            VALUES (1, 0, 1, 0)
+            ON CONFLICT(singleton) DO UPDATE SET dirty = 1;
+        END
+        """
+    )
+    conn.execute(
+        """
+        CREATE TRIGGER IF NOT EXISTS chat_attachment_inventory_dirty_delete
+        AFTER DELETE ON chat_messages
+        BEGIN
+            INSERT INTO chat_attachment_inventory_state
+                (singleton, inventory_version, dirty, backfilled_at)
+            VALUES (1, 0, 1, 0)
+            ON CONFLICT(singleton) DO UPDATE SET dirty = 1;
+        END
+        """
+    )
     conn.execute(
         "CREATE INDEX IF NOT EXISTS idx_chat_threads_model_type_created_at ON chat_threads(model_type, created_at)"
     )
@@ -391,6 +533,21 @@ def _ensure_schema(conn: sqlite3.Connection) -> None:
     conn.execute(
         "CREATE INDEX IF NOT EXISTS idx_prompt_lists_created_at ON prompt_lists(created_at)"
     )
+    inventory_state = conn.execute(
+        """
+        SELECT inventory_version, dirty
+        FROM chat_attachment_inventory_state
+        WHERE singleton = 1
+        """
+    ).fetchone()
+    if (
+        inventory_state is None
+        or inventory_state["inventory_version"] != _CHAT_ATTACHMENT_INVENTORY_VERSION
+        or inventory_state["dirty"]
+    ):
+        _rebuild_chat_attachment_inventory(conn)
+        _mark_chat_attachment_inventory_clean(conn)
+    conn.commit()
 
 
 def _prompt_entry_from_row(row: sqlite3.Row) -> dict:
@@ -582,16 +739,43 @@ def create_run(
     config_json: str,
     started_at: str,
     total_steps: Optional[int],
+    *,
+    output_dir: Optional[str] = None,
+    cancel_requested: bool = False,
+    resumed_from_run_id: Optional[str] = None,
 ) -> None:
     conn = get_connection()
     try:
         conn.execute(
             """
-            INSERT INTO training_runs (id, model_name, dataset_name, config_json, started_at, total_steps)
-            VALUES (?, ?, ?, ?, ?, ?)
+            INSERT INTO training_runs (
+                id, model_name, dataset_name, config_json, started_at, total_steps,
+                output_dir, resume_blocked
+            )
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?)
             """,
-            (id, model_name, dataset_name, config_json, started_at, total_steps),
+            (
+                id,
+                model_name,
+                dataset_name,
+                config_json,
+                started_at,
+                total_steps,
+                None if cancel_requested else output_dir,
+                int(cancel_requested),
+            ),
         )
+        if resumed_from_run_id:
+            claimed = conn.execute(
+                """
+                UPDATE training_runs SET resume_blocked = 1
+                WHERE id = ? AND status IN ('stopped', 'error')
+                  AND output_dir = ? AND resume_blocked = 0
+                """,
+                (resumed_from_run_id, output_dir),
+            )
+            if claimed.rowcount != 1:
+                raise RuntimeError("Resume source is no longer available")
         conn.commit()
     finally:
         conn.close()
@@ -634,6 +818,8 @@ def finish_run(
     loss_sparkline: Optional[str] = None,
     output_dir: Optional[str] = None,
     error_message: Optional[str] = None,
+    clear_output_dir: bool = False,
+    resume_blocked: bool = False,
 ) -> None:
     conn = get_connection()
     try:
@@ -641,9 +827,16 @@ def finish_run(
             """
             UPDATE training_runs
             SET status = ?, ended_at = ?, final_step = ?, final_loss = ?,
-                duration_seconds = ?, loss_sparkline = ?, output_dir = ?,
-                error_message = ?
-            WHERE id = ?
+                duration_seconds = ?, loss_sparkline = ?,
+                output_dir = CASE
+                    WHEN resume_blocked = 1 OR ? = 1 THEN NULL
+                    WHEN ? IS NOT NULL THEN ?
+                    WHEN ? IN ('error', 'stopped') THEN output_dir
+                    ELSE NULL
+                END,
+                error_message = ?,
+                resume_blocked = CASE WHEN resume_blocked = 1 OR ? = 1 THEN 1 ELSE ? END
+            WHERE id = ? AND status = 'running'
             """,
             (
                 status,
@@ -652,8 +845,13 @@ def finish_run(
                 final_loss,
                 duration_seconds,
                 loss_sparkline,
+                int(clear_output_dir),
                 output_dir,
+                output_dir,
+                status,
                 error_message,
+                int(clear_output_dir),
+                int(resume_blocked),
                 id,
             ),
         )
@@ -713,6 +911,38 @@ def update_run_display_name(id: str, display_name: Optional[str]) -> None:
         conn.close()
 
 
+def update_run_output_dir(id: str, output_dir: Optional[str]) -> None:
+    conn = get_connection()
+    try:
+        conn.execute(
+            """
+            UPDATE training_runs SET output_dir = ?
+            WHERE id = ? AND status = 'running' AND resume_blocked = 0
+            """,
+            (output_dir, id),
+        )
+        conn.commit()
+    finally:
+        conn.close()
+
+
+def mark_run_cancel_requested(id: str) -> bool:
+    """Clear resume/export state only while the exact run is still active."""
+    conn = get_connection()
+    try:
+        cursor = conn.execute(
+            """
+            UPDATE training_runs SET output_dir = NULL, resume_blocked = 1
+            WHERE id = ? AND status = 'running'
+            """,
+            (id,),
+        )
+        conn.commit()
+        return cursor.rowcount > 0
+    finally:
+        conn.close()
+
+
 def list_runs(limit: int = 50, offset: int = 0) -> dict:
     conn = get_connection()
     try:
@@ -722,15 +952,15 @@ def list_runs(limit: int = 50, offset: int = 0) -> dict:
             SELECT r.id, r.status, r.model_name, r.dataset_name, r.started_at,
                    r.ended_at, r.total_steps, r.final_step, r.final_loss,
                    r.output_dir, r.duration_seconds, r.error_message,
-                   r.loss_sparkline, r.display_name, r.config_json,
+                   r.loss_sparkline, r.display_name, r.config_json, r.resume_blocked,
                    CASE
-                       WHEN r.status = 'stopped'
+                       WHEN r.status IN ('stopped', 'error')
                             AND r.output_dir IS NOT NULL
                             AND EXISTS (
                                 SELECT 1
                                 FROM training_runs newer
                                 WHERE newer.output_dir = r.output_dir
-                                  AND newer.status IN ('stopped', 'completed')
+                                  AND newer.status IN ('stopped', 'completed', 'error', 'running')
                                   AND newer.started_at > r.started_at
                             )
                        THEN 1 ELSE 0
@@ -765,13 +995,13 @@ def get_run(id: str) -> Optional[dict]:
             """
             SELECT r.*,
                    CASE
-                       WHEN r.status = 'stopped'
+                       WHEN r.status IN ('stopped', 'error')
                             AND r.output_dir IS NOT NULL
                             AND EXISTS (
                                 SELECT 1
                                 FROM training_runs newer
                                 WHERE newer.output_dir = r.output_dir
-                                  AND newer.status IN ('stopped', 'completed')
+                                  AND newer.status IN ('stopped', 'completed', 'error', 'running')
                                   AND newer.started_at > r.started_at
                             )
                        THEN 1 ELSE 0
@@ -806,12 +1036,12 @@ def get_resumable_run_by_output_dir(output_dir: str) -> Optional[dict]:
                    0 AS resumed_later
             FROM training_runs r
             WHERE r.output_dir = ?
-              AND r.status = 'stopped'
+              AND r.status IN ('stopped', 'error')
               AND NOT EXISTS (
                   SELECT 1
                   FROM training_runs newer
                   WHERE newer.output_dir = r.output_dir
-                    AND newer.status IN ('stopped', 'completed')
+                    AND newer.status IN ('stopped', 'completed', 'error', 'running')
                     AND newer.started_at > r.started_at
               )
             ORDER BY r.started_at DESC
@@ -914,8 +1144,12 @@ def cleanup_orphaned_runs() -> None:
         conn.execute(
             """
             UPDATE training_runs
-            SET status = 'error',
-                error_message = 'Server restarted during training',
+            SET status = CASE WHEN resume_blocked = 1 THEN 'stopped' ELSE 'error' END,
+                error_message = CASE
+                    WHEN resume_blocked = 1 THEN NULL
+                    ELSE 'Server restarted during training'
+                END,
+                output_dir = CASE WHEN resume_blocked = 1 THEN NULL ELSE output_dir END,
                 ended_at = ?
             WHERE status = 'running'
             """,
@@ -1219,7 +1453,14 @@ def delete_chat_threads(ids: list[str]) -> None:
         return
     conn = get_connection()
     try:
+        conn.execute("BEGIN IMMEDIATE")
+        _ensure_chat_attachment_inventory_current(conn)
+        conn.executemany(
+            "DELETE FROM chat_attachment_tombstones WHERE thread_id = ?",
+            [(id,) for id in ids],
+        )
         conn.executemany("DELETE FROM chat_threads WHERE id = ?", [(id,) for id in ids])
+        _mark_chat_attachment_inventory_clean(conn)
         conn.commit()
     finally:
         conn.close()
@@ -1228,7 +1469,11 @@ def delete_chat_threads(ids: list[str]) -> None:
 def clear_chat_history() -> None:
     conn = get_connection()
     try:
+        conn.execute("BEGIN IMMEDIATE")
+        _ensure_chat_attachment_inventory_current(conn)
+        conn.execute("DELETE FROM chat_attachment_tombstones")
         conn.execute("DELETE FROM chat_threads")
+        _mark_chat_attachment_inventory_clean(conn)
         conn.commit()
     finally:
         conn.close()
@@ -1354,6 +1599,7 @@ def delete_chat_project(id: str, delete_files: bool = False) -> Optional[dict]:
     conn = get_connection()
     try:
         conn.execute("BEGIN IMMEDIATE")
+        _ensure_chat_attachment_inventory_current(conn)
         row = conn.execute("SELECT * FROM chat_projects WHERE id = ?", (id,)).fetchone()
         if row is None:
             conn.rollback()
@@ -1361,6 +1607,7 @@ def delete_chat_project(id: str, delete_files: bool = False) -> Optional[dict]:
         project = _chat_project_from_row(row)
         conn.execute("DELETE FROM chat_threads WHERE project_id = ?", (id,))
         conn.execute("DELETE FROM chat_projects WHERE id = ?", (id,))
+        _mark_chat_attachment_inventory_clean(conn)
         conn.commit()
         if delete_files:
             _delete_project_workspace(project)
@@ -1483,15 +1730,285 @@ def _recompute_chat_thread_updated_at(conn: sqlite3.Connection, thread_id: str)
     )
 
 
+_CONTENT_PART_ID_PREFIX = "content-part-sha256-"
+_URI_SCHEME_RE = re.compile(r"^[A-Za-z][A-Za-z0-9+.-]*:")
+
+
+def _is_locally_stored_blob(value: str) -> bool:
+    """True for data URIs or bare base64, never external/blob URI references."""
+    candidate = value.lstrip()
+    if not candidate:
+        return False
+    if candidate[:5].lower() == "data:":
+        return True
+    if candidate.startswith(("//", "\\\\")):
+        return False
+    return _URI_SCHEME_RE.match(candidate) is None
+
+
+def _managed_content_part_payload(part: dict) -> Optional[tuple[str, Any]]:
+    """Return the locally stored blob payload used to identify a content part."""
+    image = part.get("image")
+    if isinstance(image, str) and image[:5].lower() == "data:":
+        return "image", image
+
+    audio = part.get("audio")
+    if isinstance(audio, str) and _is_locally_stored_blob(audio):
+        return "audio", audio
+    if isinstance(audio, dict):
+        data = audio.get("data")
+        if isinstance(data, str) and _is_locally_stored_blob(data):
+            return "audio", audio
+    return None
+
+
+def _content_part_id(part: dict) -> Optional[str]:
+    """Stable managed id derived from blob data, without mutating inference content."""
+    payload = _managed_content_part_payload(part)
+    if payload is None:
+        return None
+    canonical = json.dumps(
+        payload,
+        ensure_ascii = False,
+        separators = (",", ":"),
+        sort_keys = True,
+    ).encode("utf-8")
+    return f"{_CONTENT_PART_ID_PREFIX}{hashlib.sha256(canonical).hexdigest()}"
+
+
+def _chat_attachment_tombstones_for_messages(
+    conn: sqlite3.Connection, thread_id: str, message_ids: list[str]
+) -> dict[str, set[str]]:
+    tombstones = {message_id: set() for message_id in message_ids}
+    unique_ids = list(dict.fromkeys(message_ids))
+    for start in range(0, len(unique_ids), _SQLITE_IN_CHUNK_SIZE):
+        chunk = unique_ids[start : start + _SQLITE_IN_CHUNK_SIZE]
+        placeholders = ",".join("?" for _ in chunk)
+        rows = conn.execute(
+            f"""
+            SELECT message_id, attachment_id
+            FROM chat_attachment_tombstones
+            WHERE thread_id = ? AND message_id IN ({placeholders})
+            """,
+            (thread_id, *chunk),
+        ).fetchall()
+        for row in rows:
+            tombstones[row["message_id"]].add(row["attachment_id"])
+    return tombstones
+
+
+def _reconcile_chat_message_uploads(message: dict, tombstones: set[str]) -> dict:
+    """Strip uploads previously deleted through the Data tab from a stale write."""
+    if not tombstones:
+        return message
+
+    reconciled = dict(message)
+    attachments = message.get("attachments")
+    if isinstance(attachments, list):
+        reconciled["attachments"] = [
+            attachment
+            for attachment in attachments
+            if not (isinstance(attachment, dict) and str(attachment.get("id") or "") in tombstones)
+        ]
+
+    content = message.get("content")
+    if isinstance(content, list):
+        reconciled["content"] = [
+            part
+            for part in content
+            if not (isinstance(part, dict) and (_content_part_id(part) or "") in tombstones)
+        ]
+    return reconciled
+
+
+def _chat_attachment_metadata_text(value, fallback: Optional[str] = None) -> Optional[str]:
+    """Keep untyped legacy/import metadata safe for SQLite binding."""
+    if value is None:
+        return fallback
+    if isinstance(value, str):
+        return value or fallback
+    if isinstance(value, (bool, int, float)):
+        return str(value)
+    # Objects and arrays are not useful display metadata and sqlite3 rejects
+    # binding them directly.
+    return fallback
+
+
+def _chat_attachment_inventory_entries(
+    attachments_json: Optional[str],
+    content_json: Optional[str],
+    tombstones: Optional[set[str]] = None,
+) -> list[dict]:
+    tombstones = tombstones or set()
+    attachments = _json_loads(attachments_json, None)
+    if not isinstance(attachments, list):
+        attachments = []
+    attachments = [
+        attachment
+        for attachment in attachments
+        if isinstance(attachment, dict) and attachment.get("id")
+    ]
+    attachments.extend(_content_part_attachments(content_json))
+
+    entries: list[dict] = []
+    seen: set[str] = set()
+    for attachment in attachments:
+        attachment_id = str(attachment["id"])
+        if attachment_id in seen or attachment_id in tombstones:
+            continue
+        seen.add(attachment_id)
+        entries.append(
+            {
+                "id": attachment_id,
+                "name": _chat_attachment_metadata_text(attachment.get("name"), "attachment"),
+                "type": _chat_attachment_metadata_text(attachment.get("type")),
+                "contentType": _chat_attachment_metadata_text(attachment.get("contentType")),
+                "sizeBytes": _chat_attachment_size_bytes(attachment),
+            }
+        )
+    return entries
+
+
+def _replace_chat_attachment_inventory(
+    conn: sqlite3.Connection,
+    message_id: str,
+    attachments_json: Optional[str],
+    content_json: Optional[str],
+    tombstones: Optional[set[str]] = None,
+) -> None:
+    conn.execute("DELETE FROM chat_attachment_inventory WHERE message_id = ?", (message_id,))
+    entries = _chat_attachment_inventory_entries(
+        attachments_json,
+        content_json,
+        tombstones,
+    )
+    conn.executemany(
+        """
+        INSERT INTO chat_attachment_inventory
+            (message_id, attachment_id, name, type, content_type, size_bytes)
+        VALUES (?, ?, ?, ?, ?, ?)
+        """,
+        [
+            (
+                message_id,
+                entry["id"],
+                entry["name"],
+                entry["type"],
+                entry["contentType"],
+                entry["sizeBytes"],
+            )
+            for entry in entries
+        ],
+    )
+
+
+def _mark_chat_attachment_inventory_clean(conn: sqlite3.Connection) -> None:
+    conn.execute(
+        """
+        INSERT INTO chat_attachment_inventory_state
+            (singleton, inventory_version, dirty, backfilled_at)
+        VALUES (1, ?, 0, ?)
+        ON CONFLICT(singleton) DO UPDATE SET
+            inventory_version = excluded.inventory_version,
+            dirty = 0,
+            backfilled_at = excluded.backfilled_at
+        """,
+        (
+            _CHAT_ATTACHMENT_INVENTORY_VERSION,
+            int(datetime.now(timezone.utc).timestamp() * 1000),
+        ),
+    )
+
+
+def _rebuild_chat_attachment_inventory(conn: sqlite3.Connection) -> None:
+    """Rebuild after schema upgrade or a write from an older Studio build."""
+    conn.execute("DELETE FROM chat_attachment_inventory")
+    tombstones: dict[tuple[str, str], set[str]] = {}
+    for row in conn.execute(
+        "SELECT thread_id, message_id, attachment_id FROM chat_attachment_tombstones"
+    ).fetchall():
+        tombstones.setdefault((row["thread_id"], row["message_id"]), set()).add(
+            row["attachment_id"]
+        )
+    rows = conn.execute(
+        "SELECT id, thread_id, attachments_json, content_json FROM chat_messages"
+    ).fetchall()
+    for row in rows:
+        _replace_chat_attachment_inventory(
+            conn,
+            row["id"],
+            row["attachments_json"],
+            row["content_json"],
+            tombstones.get((row["thread_id"], row["id"]), set()),
+        )
+
+
+def _ensure_chat_attachment_inventory_current(conn: sqlite3.Connection) -> None:
+    state = conn.execute(
+        """
+        SELECT inventory_version, dirty
+        FROM chat_attachment_inventory_state
+        WHERE singleton = 1
+        """
+    ).fetchone()
+    if (
+        state is not None
+        and state["inventory_version"] == _CHAT_ATTACHMENT_INVENTORY_VERSION
+        and not state["dirty"]
+    ):
+        return
+
+    owns_transaction = not conn.in_transaction
+    if owns_transaction:
+        conn.execute("BEGIN IMMEDIATE")
+    try:
+        state = conn.execute(
+            """
+            SELECT inventory_version, dirty
+            FROM chat_attachment_inventory_state
+            WHERE singleton = 1
+            """
+        ).fetchone()
+        if (
+            state is None
+            or state["inventory_version"] != _CHAT_ATTACHMENT_INVENTORY_VERSION
+            or state["dirty"]
+        ):
+            _rebuild_chat_attachment_inventory(conn)
+            _mark_chat_attachment_inventory_clean(conn)
+        if owns_transaction:
+            conn.commit()
+    except Exception:
+        if owns_transaction:
+            conn.rollback()
+        raise
+
+
 def upsert_chat_message(message: dict) -> dict:
     conn = get_connection()
     try:
         conn.execute("BEGIN IMMEDIATE")
+        _ensure_chat_attachment_inventory_current(conn)
         _raise_if_chat_message_thread_conflicts(
             conn,
             message["threadId"],
             [message["id"]],
         )
+        tombstones = _chat_attachment_tombstones_for_messages(
+            conn,
+            message["threadId"],
+            [message["id"]],
+        )
+        reconciled = _reconcile_chat_message_uploads(
+            message,
+            tombstones.get(message["id"], set()),
+        )
+        content_json = json.dumps(reconciled.get("content", []))
+        attachments_json = (
+            json.dumps(reconciled.get("attachments"))
+            if reconciled.get("attachments") is not None
+            else None
+        )
         conn.execute(
             """
             INSERT INTO chat_messages
@@ -1507,23 +2024,32 @@ def upsert_chat_message(message: dict) -> dict:
             WHERE excluded.thread_id = chat_messages.thread_id
             """,
             (
-                message["id"],
-                message["threadId"],
-                message.get("parentId"),
-                message["role"],
-                json.dumps(message.get("content", [])),
-                json.dumps(message.get("attachments"))
-                if message.get("attachments") is not None
+                reconciled["id"],
+                reconciled["threadId"],
+                reconciled.get("parentId"),
+                reconciled["role"],
+                content_json,
+                attachments_json,
+                json.dumps(reconciled.get("metadata"))
+                if reconciled.get("metadata") is not None
                 else None,
-                json.dumps(message.get("metadata"))
-                if message.get("metadata") is not None
-                else None,
-                int(message["createdAt"]),
+                int(reconciled["createdAt"]),
             ),
         )
-        _bump_chat_thread_updated_at(conn, message["threadId"], int(message["createdAt"]))
+        _replace_chat_attachment_inventory(
+            conn,
+            reconciled["id"],
+            attachments_json,
+            content_json,
+        )
+        _bump_chat_thread_updated_at(
+            conn,
+            reconciled["threadId"],
+            int(reconciled["createdAt"]),
+        )
+        _mark_chat_attachment_inventory_clean(conn)
         conn.commit()
-        return message
+        return reconciled
     except Exception:
         conn.rollback()
         raise
@@ -1539,13 +2065,28 @@ def sync_chat_messages(
     conn = get_connection()
     try:
         conn.execute("BEGIN IMMEDIATE")
+        _ensure_chat_attachment_inventory_current(conn)
         _raise_if_chat_message_thread_conflicts(
             conn,
             thread_id,
             [m["id"] for m in messages],
         )
-        if prune_missing:
-            conn.execute("DELETE FROM chat_messages WHERE thread_id = ?", (thread_id,))
+        tombstones = _chat_attachment_tombstones_for_messages(
+            conn,
+            thread_id,
+            [m["id"] for m in messages],
+        )
+        reconciled_messages = [
+            _reconcile_chat_message_uploads(m, tombstones.get(m["id"], set())) for m in messages
+        ]
+        serialized_messages = [
+            (
+                m,
+                json.dumps(m.get("content", [])),
+                json.dumps(m.get("attachments")) if m.get("attachments") is not None else None,
+            )
+            for m in reconciled_messages
+        ]
         conn.executemany(
             """
             INSERT INTO chat_messages
@@ -1566,20 +2107,46 @@ def sync_chat_messages(
                     thread_id,
                     m.get("parentId"),
                     m["role"],
-                    json.dumps(m.get("content", [])),
-                    json.dumps(m.get("attachments")) if m.get("attachments") is not None else None,
+                    content_json,
+                    attachments_json,
                     json.dumps(m.get("metadata")) if m.get("metadata") is not None else None,
                     int(m["createdAt"]),
                 )
-                for m in messages
+                for m, content_json, attachments_json in serialized_messages
             ],
         )
-        if prune_missing:
-            _recompute_chat_thread_updated_at(conn, thread_id)
-        elif messages:
-            _bump_chat_thread_updated_at(
-                conn, thread_id, max(int(m["createdAt"]) for m in messages)
+        for m, content_json, attachments_json in serialized_messages:
+            _replace_chat_attachment_inventory(
+                conn,
+                m["id"],
+                attachments_json,
+                content_json,
             )
+        if prune_missing:
+            retained_ids = {m["id"] for m in reconciled_messages}
+            existing_ids = {
+                row["id"]
+                for row in conn.execute(
+                    "SELECT id FROM chat_messages WHERE thread_id = ?",
+                    (thread_id,),
+                ).fetchall()
+            }
+            missing_ids = sorted(existing_ids - retained_ids)
+            for start in range(0, len(missing_ids), _SQLITE_IN_CHUNK_SIZE):
+                chunk = missing_ids[start : start + _SQLITE_IN_CHUNK_SIZE]
+                placeholders = ",".join("?" for _ in chunk)
+                conn.execute(
+                    f"DELETE FROM chat_messages WHERE thread_id = ? AND id IN ({placeholders})",
+                    (thread_id, *chunk),
+                )
+            _recompute_chat_thread_updated_at(conn, thread_id)
+        elif reconciled_messages:
+            _bump_chat_thread_updated_at(
+                conn,
+                thread_id,
+                max(int(m["createdAt"]) for m in reconciled_messages),
+            )
+        _mark_chat_attachment_inventory_clean(conn)
         conn.commit()
         return list_chat_messages(thread_id)
     except ChatMessageConflictError:
@@ -1613,6 +2180,7 @@ def fork_chat_thread(
     conn = get_connection()
     try:
         conn.execute("BEGIN IMMEDIATE")
+        _ensure_chat_attachment_inventory_current(conn)
         src = conn.execute(
             "SELECT * FROM chat_threads WHERE id = ?", (source_thread_id,)
         ).fetchone()
@@ -1686,6 +2254,14 @@ def fork_chat_thread(
                 for row in ancestry
             ],
         )
+        for row in ancestry:
+            _replace_chat_attachment_inventory(
+                conn,
+                id_map[row["id"]],
+                row["attachments_json"],
+                row["content_json"],
+            )
+        _mark_chat_attachment_inventory_clean(conn)
         conn.commit()
         thread_row = conn.execute(
             "SELECT * FROM chat_threads WHERE id = ?", (new_thread_id,)
@@ -1744,6 +2320,279 @@ def get_chat_message(thread_id: str, message_id: str) -> Optional[dict]:
         conn.close()
 
 
+def _blob_part_base64_len(part: dict) -> int:
+    """Base64 payload length of an image or audio content part, or 0."""
+    image = part.get("image")
+    if isinstance(image, str) and image[:5].lower() == "data:":
+        return len(image.rsplit(",", 1)[-1])
+    audio = part.get("audio")
+    if isinstance(audio, str) and _is_locally_stored_blob(audio):
+        return len(audio.rsplit(",", 1)[-1])
+    if isinstance(audio, dict):
+        data = audio.get("data")
+        if isinstance(data, str) and _is_locally_stored_blob(data):
+            return len(data)
+    return 0
+
+
+def _chat_attachment_size_bytes(attachment: dict) -> Optional[int]:
+    """Approximate stored size of one attachment's content parts.
+
+    Image and audio parts hold base64 payloads (decoded bytes ~= 3/4 of the
+    encoded length); text parts count their character length. None when there
+    is no sizable content (e.g. a stripped/legacy attachment).
+    """
+    total = 0
+    found = False
+    for part in attachment.get("content") or []:
+        if not isinstance(part, dict):
+            continue
+        blob_len = _blob_part_base64_len(part)
+        if blob_len > 0:
+            total += (blob_len * 3) // 4
+            found = True
+            continue
+        text = part.get("text")
+        if isinstance(text, str) and text:
+            total += len(text.encode("utf-8", errors = "ignore"))
+            found = True
+    return total if found else None
+
+
+def _content_part_attachments(content_json: Optional[str]) -> list[dict]:
+    """Managed local blobs stored in content_json, with stable payload ids.
+
+    Exact duplicate blobs intentionally share one inventory id. Deleting that
+    id removes every identical copy, avoiding ambiguous index-based addressing.
+    """
+    content = _json_loads(content_json, None)
+    if not isinstance(content, list):
+        return []
+    out: list[dict] = []
+    seen: set[str] = set()
+    for part in content:
+        if not isinstance(part, dict):
+            continue
+        attachment_id = _content_part_id(part)
+        payload = _managed_content_part_payload(part)
+        if attachment_id is None or payload is None or attachment_id in seen:
+            continue
+        seen.add(attachment_id)
+        kind, value = payload
+        content_type = None
+        if kind == "image" and isinstance(value, str):
+            content_type = value[5:].split(";", 1)[0].split(",", 1)[0] or None
+        out.append(
+            {
+                "id": attachment_id,
+                "type": kind,
+                "name": "Chat image" if kind == "image" else "Chat audio",
+                "contentType": content_type,
+                "content": [part],
+            }
+        )
+    return out
+
+
+def list_chat_attachments_page(
+    limit: int = 50, offset: int = 0
+) -> tuple[list[dict], Optional[int]]:
+    """One bounded page from the normalized attachment inventory."""
+    if not 1 <= limit <= 100:
+        raise ValueError("limit must be between 1 and 100")
+    if offset < 0:
+        raise ValueError("offset must be non-negative")
+
+    conn = get_connection()
+    try:
+        _ensure_chat_attachment_inventory_current(conn)
+        rows = conn.execute(
+            """
+            SELECT i.attachment_id, i.name, i.type, i.content_type,
+                   i.size_bytes, m.id AS message_id, m.thread_id,
+                   m.created_at, t.title AS thread_title, t.pair_id
+            FROM chat_attachment_inventory i
+            JOIN chat_messages m ON m.id = i.message_id
+            LEFT JOIN chat_threads t ON t.id = m.thread_id
+            ORDER BY m.created_at DESC, m.id ASC, i.attachment_id ASC
+            LIMIT ? OFFSET ?
+            """,
+            (limit + 1, offset),
+        ).fetchall()
+    finally:
+        conn.close()
+
+    has_more = len(rows) > limit
+    page_rows = rows[:limit]
+    attachments = [
+        {
+            "id": row["attachment_id"],
+            "messageId": row["message_id"],
+            "threadId": row["thread_id"],
+            "pairId": row["pair_id"],
+            "threadTitle": row["thread_title"],
+            "name": row["name"],
+            "type": row["type"],
+            "contentType": row["content_type"],
+            "sizeBytes": row["size_bytes"],
+            "createdAt": row["created_at"],
+        }
+        for row in page_rows
+    ]
+    return attachments, offset + limit if has_more else None
+
+
+def list_chat_attachments() -> list[dict]:
+    """Compatibility helper returning the full normalized inventory."""
+    attachments: list[dict] = []
+    offset = 0
+    while True:
+        page, next_offset = list_chat_attachments_page(limit = 100, offset = offset)
+        attachments.extend(page)
+        if next_offset is None:
+            return attachments
+        offset = next_offset
+
+
+def get_chat_attachment(message_id: str, attachment_id: str) -> Optional[dict]:
+    """One attachment record (full content) from a message, or None."""
+    conn = get_connection()
+    try:
+        row = conn.execute(
+            """
+            SELECT message.attachments_json, message.content_json,
+                   EXISTS(
+                       SELECT 1 FROM chat_attachment_tombstones tombstone
+                       WHERE tombstone.thread_id = message.thread_id
+                         AND tombstone.message_id = message.id
+                         AND tombstone.attachment_id = ?
+                   ) AS tombstoned
+            FROM chat_messages message
+            WHERE message.id = ?
+            """,
+            (attachment_id, message_id),
+        ).fetchone()
+    finally:
+        conn.close()
+    if row is None or row["tombstoned"]:
+        return None
+    attachments = _json_loads(row["attachments_json"], None)
+    if isinstance(attachments, list):
+        for attachment in attachments:
+            if isinstance(attachment, dict) and str(attachment.get("id") or "") == attachment_id:
+                return attachment
+    if attachment_id.startswith(_CONTENT_PART_ID_PREFIX):
+        for attachment in _content_part_attachments(row["content_json"]):
+            if attachment["id"] == attachment_id:
+                return attachment
+    return None
+
+
+def _record_chat_attachment_tombstone(
+    conn: sqlite3.Connection, thread_id: str, message_id: str, attachment_id: str
+) -> None:
+    conn.execute(
+        """
+        INSERT INTO chat_attachment_tombstones
+            (thread_id, message_id, attachment_id, deleted_at)
+        VALUES (?, ?, ?, ?)
+        ON CONFLICT(thread_id, message_id, attachment_id) DO UPDATE SET
+            deleted_at = excluded.deleted_at
+        """,
+        (
+            thread_id,
+            message_id,
+            attachment_id,
+            int(datetime.now(timezone.utc).timestamp() * 1000),
+        ),
+    )
+
+
+def delete_chat_attachment(message_id: str, attachment_id: str) -> bool:
+    """Remove one stored upload from a message.
+
+    The tombstone is retained while the thread exists, so pruning and later
+    recreating the same message id cannot restore the deleted upload. If an
+    ordinary attachment id collides with a content-blob id, both are deleted as
+    one managed item.
+    """
+    conn = get_connection()
+    try:
+        conn.execute("BEGIN IMMEDIATE")
+        _ensure_chat_attachment_inventory_current(conn)
+        row = conn.execute(
+            """
+            SELECT thread_id, attachments_json, content_json
+            FROM chat_messages WHERE id = ?
+            """,
+            (message_id,),
+        ).fetchone()
+        if row is None:
+            conn.rollback()
+            return False
+
+        attachments = _json_loads(row["attachments_json"], None)
+        updated_attachments_json = row["attachments_json"]
+        deleted_attachment = False
+        if isinstance(attachments, list):
+            remaining_attachments = [
+                attachment
+                for attachment in attachments
+                if not (
+                    isinstance(attachment, dict)
+                    and str(attachment.get("id") or "") == attachment_id
+                )
+            ]
+            deleted_attachment = len(remaining_attachments) != len(attachments)
+            if deleted_attachment:
+                updated_attachments_json = json.dumps(remaining_attachments)
+
+        content = _json_loads(row["content_json"], None)
+        updated_content_json = row["content_json"]
+        deleted_content = False
+        if attachment_id.startswith(_CONTENT_PART_ID_PREFIX) and isinstance(content, list):
+            remaining_content = [
+                part
+                for part in content
+                if not (isinstance(part, dict) and _content_part_id(part) == attachment_id)
+            ]
+            deleted_content = len(remaining_content) != len(content)
+            if deleted_content:
+                updated_content_json = json.dumps(remaining_content)
+
+        if not deleted_attachment and not deleted_content:
+            conn.rollback()
+            return False
+        conn.execute(
+            """
+            UPDATE chat_messages
+            SET attachments_json = ?, content_json = ?
+            WHERE id = ?
+            """,
+            (updated_attachments_json, updated_content_json, message_id),
+        )
+        _record_chat_attachment_tombstone(
+            conn,
+            row["thread_id"],
+            message_id,
+            attachment_id,
+        )
+        _replace_chat_attachment_inventory(
+            conn,
+            message_id,
+            updated_attachments_json,
+            updated_content_json,
+        )
+        _mark_chat_attachment_inventory_clean(conn)
+        conn.commit()
+        return True
+    except Exception:
+        conn.rollback()
+        raise
+    finally:
+        conn.close()
+
+
 def list_chat_messages_for_threads(thread_ids: list[str]) -> list[dict]:
     if not thread_ids:
         return []
diff --git a/studio/backend/tests/conftest.py b/studio/backend/tests/conftest.py
index b0b9ee309c..c2216104a3 100644
--- a/studio/backend/tests/conftest.py
+++ b/studio/backend/tests/conftest.py
@@ -101,13 +101,13 @@ def studio_server(request):
 
 @pytest.fixture
 def base_url(studio_server):
-    """Base URL for the e2e Studio server (from ``studio_server``)."""
+    """Base URL for the e2e Unsloth server (from ``studio_server``)."""
     return studio_server[0]
 
 
 @pytest.fixture
 def api_key(studio_server):
-    """API key for the e2e Studio server (from ``studio_server``)."""
+    """API key for the e2e Unsloth server (from ``studio_server``)."""
     return studio_server[1]
 
 
diff --git a/studio/backend/tests/test_amd_apu_unified_memory.py b/studio/backend/tests/test_amd_apu_unified_memory.py
index 4df9e85b30..9fd8260bf2 100644
--- a/studio/backend/tests/test_amd_apu_unified_memory.py
+++ b/studio/backend/tests/test_amd_apu_unified_memory.py
@@ -91,7 +91,7 @@ class TestApuRamShortfall:
     """On a unified-memory APU the weights load into system RAM, so a model
     larger than available RAM (the field case: a 64.6 GB GGUF on a WSL VM capped
     well below the ROCm-reported APU budget) must be refused before spawning,
-    not left to OOM-kill the Studio process."""
+    not left to OOM-kill the Unsloth process."""
 
     def test_field_case_wsl_cap_refuses(self):
         # 64.6 GB weights, ~46 GB available (WSL VM): refuse with guidance.
diff --git a/studio/backend/tests/test_anthropic_compaction.py b/studio/backend/tests/test_anthropic_compaction.py
index 1528eebe8b..acc0acc2e0 100644
--- a/studio/backend/tests/test_anthropic_compaction.py
+++ b/studio/backend/tests/test_anthropic_compaction.py
@@ -4,7 +4,7 @@
 """Unit tests for Anthropic server-side context compaction wiring.
 
 Compaction is a beta (header ``compact-2026-01-12``) gated to Opus 4.6/4.7,
-Sonnet 4.6, and Mythos preview. When enabled, Studio attaches
+Sonnet 4.6, and Mythos preview. When enabled, Unsloth attaches
 ``context_management.edits[{type:"compact_20260112", trigger:{type:"input_tokens",
 value:N}}]``; the 50k-token minimum is clamped up so the request doesn't 400.
 
diff --git a/studio/backend/tests/test_anthropic_fast_mode_edge.py b/studio/backend/tests/test_anthropic_fast_mode_edge.py
index dd69d77590..03f5d1c0eb 100644
--- a/studio/backend/tests/test_anthropic_fast_mode_edge.py
+++ b/studio/backend/tests/test_anthropic_fast_mode_edge.py
@@ -330,7 +330,7 @@ def test_refusal_chunk_is_proper_openai_delta_shape(monkeypatch):
 
 
 def test_refusal_tool_event_chunk_shape(monkeypatch):
-    """Drop signal rides a Studio `_toolEvent` envelope (delta={},
+    """Drop signal rides an Unsloth `_toolEvent` envelope (delta={},
     finish_reason=null); the frontend latches on
     `_toolEvent.type == "anthropic_refusal"`."""
     _, lines = _capture(monkeypatch, sse = _refusal_sse(), model = "claude-opus-4-7")
@@ -409,7 +409,7 @@ def _fast_speed_sse(model: str = "claude-opus-4-7", speed: str = "fast") -> byte
 
 
 def test_usage_speed_propagates_to_final_usage_chunk_fast(monkeypatch):
-    """``usage.speed == "fast"`` from upstream must reach the Studio usage chunk."""
+    """``usage.speed == "fast"`` from upstream must reach the Unsloth usage chunk."""
     _, lines = _capture(monkeypatch, sse = _fast_speed_sse(speed = "fast"))
     usage_lines = [l for l in lines if l.startswith("data: ") and '"usage"' in l]
     assert usage_lines, lines
@@ -428,7 +428,7 @@ def test_usage_speed_propagates_to_final_usage_chunk_standard(monkeypatch):
 
 
 def test_usage_speed_absent_when_anthropic_does_not_report(monkeypatch):
-    """Studio must not invent ``usage.speed`` when upstream omits it."""
+    """Unsloth must not invent ``usage.speed`` when upstream omits it."""
     _, lines = _capture(monkeypatch)
     parsed = [
         json.loads(l[len("data: ") :]) for l in lines if l.startswith("data: ") and '"usage"' in l
diff --git a/studio/backend/tests/test_anthropic_messages.py b/studio/backend/tests/test_anthropic_messages.py
index 3b0ea37372..9ccc3f44dd 100644
--- a/studio/backend/tests/test_anthropic_messages.py
+++ b/studio/backend/tests/test_anthropic_messages.py
@@ -1418,7 +1418,7 @@ class TestNormalizeAnthropicOpenAIImages:
 
 
 # =====================================================================
-# Studio-tool alias detection (/v1/messages tool routing)
+# Unsloth-tool alias detection (/v1/messages tool routing)
 # =====================================================================
 
 
@@ -1436,7 +1436,7 @@ class TestAnthropicRequestedStudioTools:
 
     def test_client_tool_named_python_is_not_misclassified(self):
         # input_schema is the client-tool discriminator; its presence must
-        # prevent the name from being treated as a Studio alias.
+        # prevent the name from being treated as an Unsloth alias.
         tools = [
             {
                 "name": "python",
@@ -1747,9 +1747,9 @@ class TestAnthropicMessagesToolRouting:
         assert "name" in exc.value.detail
 
     def test_alias_named_client_tool_without_schema_rejected_with_400(self, monkeypatch):
-        # Regression: a typo'd client tool whose name collides with a Studio
+        # Regression: a typo'd client tool whose name collides with an Unsloth
         # alias (e.g. a custom "python" tool missing input_schema) must
-        # surface a 400, not silently switch into Studio's built-in python
+        # surface a 400, not silently switch into Unsloth's built-in python
         # execution.
         _mock_backend(monkeypatch)
         payload = _basic_payload(tools = [{"name": "python"}])
@@ -1770,7 +1770,7 @@ class TestAnthropicMessagesToolRouting:
 
     def test_disable_tools_policy_overrides_server_tool_alias(self, monkeypatch):
         # CLI `unsloth run --disable-tools` sets policy=False. A request with
-        # a Studio server-tool alias must NOT enter the agentic loop then.
+        # an Unsloth server-tool alias must NOT enter the agentic loop then.
         backend = _mock_backend(monkeypatch)
         set_tool_policy(False)
         payload = _basic_payload(
diff --git a/studio/backend/tests/test_audio_sampling_fill.py b/studio/backend/tests/test_audio_sampling_fill.py
new file mode 100644
index 0000000000..efea18b83e
--- /dev/null
+++ b/studio/backend/tests/test_audio_sampling_fill.py
@@ -0,0 +1,90 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Audio (TTS) generation applies recommended sampling + operator pins, like chat.
+
+Regression guard for the fix that moved the sampling fill ahead of the audio generators: a
+prior version resolved sampling only after the audio branches returned, so `unsloth run
+--temperature` (UNSLOTH_SAMPLING_*) and per-model recommendations never reached audio
+generation. These exercise the transformers TTS path of ``generate_audio`` (the direct
+``/audio/generate`` route, which the chat-completions audio branches also delegate to).
+"""
+
+import asyncio
+
+import pytest
+
+import routes.inference as inference_route
+from models.inference import ChatCompletionRequest
+from utils.inference import inference_config as ic
+
+
+class _FakeLlama:
+    # is_loaded False forces the transformers (non-GGUF) TTS branch in generate_audio.
+    is_loaded = False
+    _is_audio = False
+
+
+class _FakeTransformersBackend:
+    def __init__(self):
+        self.active_model_name = "some/custom-tts"
+        self.models = {"some/custom-tts": {"is_audio": True}}
+        self.captured = {}
+
+    def generate_audio_response(self, **kwargs):
+        self.captured.update(kwargs)
+        return (b"RIFFfake", 24000)
+
+
+@pytest.fixture(autouse = True)
+def _isolate(monkeypatch):
+    ic._recommended_sampling.cache_clear()
+    for field in ic.SAMPLING_FIELD_NAMES:
+        monkeypatch.delenv(ic._SAMPLING_FIELDS[field][0], raising = False)
+    yield
+    ic._recommended_sampling.cache_clear()
+
+
+def _run_generate_audio(
+    monkeypatch,
+    *,
+    recommended = None,
+    temperature = None,
+):
+    backend = _FakeTransformersBackend()
+    monkeypatch.setattr(inference_route, "get_llama_cpp_backend", lambda: _FakeLlama())
+    monkeypatch.setattr(inference_route, "get_inference_backend", lambda: backend)
+
+    async def _noop_switch(*a, **k):
+        return None
+
+    monkeypatch.setattr(inference_route, "_maybe_auto_switch_model", _noop_switch)
+
+    # Recommendation source == the Chat UI's .inference block.
+    monkeypatch.setattr(ic, "load_inference_config", lambda mid: dict(recommended or {}))
+    ic._recommended_sampling.cache_clear()
+
+    kwargs = {"model": "some/custom-tts", "messages": [{"role": "user", "content": "hi"}]}
+    if temperature is not None:
+        kwargs["temperature"] = temperature
+    payload = ChatCompletionRequest(**kwargs)
+
+    asyncio.run(inference_route.generate_audio(payload, request = None, current_subject = "t"))
+    return backend.captured
+
+
+def test_audio_uses_recommended_sampling_when_omitted(monkeypatch):
+    captured = _run_generate_audio(monkeypatch, recommended = {"temperature": 1.0, "top_k": 64})
+    assert captured["temperature"] == 1.0
+    assert captured["top_k"] == 64
+
+
+def test_audio_operator_pin_overrides_client(monkeypatch):
+    monkeypatch.setenv("UNSLOTH_SAMPLING_TEMPERATURE", "0.9")
+    captured = _run_generate_audio(monkeypatch, recommended = {"temperature": 1.0}, temperature = 0.2)
+    assert captured["temperature"] == 0.9  # operator pin wins even over an explicit client value
+
+
+def test_audio_client_explicit_preserved(monkeypatch):
+    captured = _run_generate_audio(monkeypatch, recommended = {"temperature": 1.0}, temperature = 0.2)
+    assert captured["temperature"] == 0.2  # explicit client value preserved over recommendation
diff --git a/studio/backend/tests/test_cached_gguf_routes.py b/studio/backend/tests/test_cached_gguf_routes.py
index d4a7cae208..6f2c672002 100644
--- a/studio/backend/tests/test_cached_gguf_routes.py
+++ b/studio/backend/tests/test_cached_gguf_routes.py
@@ -66,6 +66,66 @@ def test_iter_gguf_paths_matches_extension_case_insensitively(tmp_path):
     assert result == ["Q4_K_M.gguf", "Q8_0.GGUF"]
 
 
+def test_legacy_hf_scan_uses_snapshot_path_for_inactive_cache(tmp_path):
+    repo = tmp_path / "models--Org--Model"
+    snapshot = repo / "snapshots" / "revision"
+    snapshot.mkdir(parents = True)
+
+    [row] = models_route._scan_hf_cache(tmp_path, active_cache = False)
+
+    assert row.model_id == "Org/Model"
+    assert row.id == str(snapshot.resolve())
+    assert row.path == str(snapshot.resolve())
+
+
+def test_collect_local_models_scans_previous_cache(monkeypatch, tmp_path):
+    active = tmp_path / "active"
+    previous = tmp_path / "previous"
+    active.mkdir()
+    snapshot = previous / "models--Org--Previous" / "snapshots" / "revision"
+    snapshot.mkdir(parents = True)
+
+    monkeypatch.setattr(models_route, "_resolve_hf_cache_dir", lambda: active)
+    monkeypatch.setattr("utils.paths.legacy_hf_cache_dir", lambda: tmp_path / "legacy")
+    monkeypatch.setattr("utils.paths.hf_default_cache_dir", lambda: tmp_path / "default")
+    monkeypatch.setattr("utils.paths.lmstudio_model_dirs", lambda: [])
+    monkeypatch.setattr("utils.hf_cache_settings.known_hf_hub_caches", lambda: [active, previous])
+    monkeypatch.setattr("storage.studio_db.list_scan_folders", lambda: [])
+
+    rows = models_route.collect_local_models(tmp_path / "models")
+
+    previous_row = next(row for row in rows if row.model_id == "Org/Previous")
+    assert previous_row.id == str(snapshot.resolve())
+
+
+def test_collect_local_models_prefers_complete_previous_copy(monkeypatch, tmp_path):
+    active = tmp_path / "active"
+    previous = tmp_path / "previous"
+    active_partial = active / "models--Org--Model" / "blobs" / "abc.incomplete"
+    active_partial.parent.mkdir(parents = True)
+    active_partial.write_bytes(b"partial")
+    snapshot = previous / "models--Org--Model" / "snapshots" / "revision"
+    snapshot.mkdir(parents = True)
+    (snapshot / "model.safetensors").write_bytes(b"complete")
+
+    monkeypatch.setattr(models_route, "_resolve_hf_cache_dir", lambda: active)
+    monkeypatch.setattr("utils.paths.legacy_hf_cache_dir", lambda: tmp_path / "legacy")
+    monkeypatch.setattr("utils.paths.hf_default_cache_dir", lambda: tmp_path / "default")
+    monkeypatch.setattr("utils.paths.lmstudio_model_dirs", lambda: [])
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.known_hf_hub_caches",
+        lambda: [active, previous],
+    )
+    monkeypatch.setattr("storage.studio_db.list_scan_folders", lambda: [])
+
+    rows = models_route.collect_local_models(tmp_path / "models")
+
+    [row] = [row for row in rows if row.model_id == "Org/Model"]
+    assert row.id == str(snapshot.resolve())
+    assert row.partial is False
+    assert row.active_cache is False
+
+
 def test_list_cached_gguf_includes_non_suffix_repo_when_cache_contains_gguf(monkeypatch, tmp_path):
     repo = _repo(
         "HauhauCS/Gemma-4-E4B-Uncensored-HauhauCS-Aggressive",
@@ -120,12 +180,217 @@ def test_is_hidden_model_hides_validation_probe_everywhere():
     assert models_route._is_hidden_model(
         None, "/hf/models--ggml-org--models/snapshots/abc/tinyllamas/stories260K.gguf"
     )
+    # A Windows-style snapshot path must match too, even on a POSIX interpreter
+    # (the filename check splits on both separators).
+    assert models_route._is_hidden_model(
+        r"C:\Users\u\.cache\huggingface\hub\models--ggml-org--models\snapshots\abc\tinyllamas\stories260K.gguf"
+    )
     assert not models_route._is_hidden_model("unsloth/gemma-3-270m-it-GGUF")
     # The exact-filename needle must not hide a real repo that merely
     # references stories260K in its name.
     assert not models_route._is_hidden_model("user/stories260K-finetune-GGUF")
 
 
+def test_is_hidden_model_hides_dictation_models(tmp_path):
+    assert models_route._is_hidden_model("unsloth/whisper-tiny")
+    assert models_route._is_hidden_model("unsloth/whisper-base")
+    assert models_route._is_hidden_model("unsloth/whisper-small")
+    assert models_route._is_hidden_model("unsloth/whisper-large-v3-turbo")
+    assert models_route._is_hidden_model(
+        "/hf/models--unsloth--whisper-large-v3/snapshots/abc/model.safetensors"
+    )
+    assert not models_route._is_hidden_model("user/whisper-finetune")
+    assert not models_route._is_hidden_model(
+        "C:\\cache\\models--unsloth--whisper-small-finetune\\model.safetensors"
+    )
+    custom = tmp_path / "custom-whisper"
+    custom.mkdir()
+    (custom / "config.json").write_text(
+        '{"model_type": "whisper", "architectures": ["WhisperForConditionalGeneration"]}'
+    )
+    (custom / "model.safetensors").write_bytes(b"weights")
+    assert models_route._is_hidden_model(
+        "user/custom-checkpoint",
+        str(custom / "model.safetensors"),
+    )
+    named_only = tmp_path / "whisper-finetune"
+    named_only.mkdir()
+    (named_only / "config.json").write_text('{"model_type": "llama"}')
+    assert not models_route._is_hidden_model("user/whisper-finetune", str(named_only))
+
+
+def test_list_cached_models_hides_custom_whisper_by_config(monkeypatch, tmp_path):
+    # Regression: the legacy /cached-models picker must pass the snapshot path so
+    # the config check hides a custom (non-curated) Whisper checkpoint; a bare
+    # repo id cannot ("user/whisper-finetune" is not in the curated set).
+    repo_path = tmp_path / "models--user--whisper-finetune"
+    snap = repo_path / "snapshots" / "abc"
+    snap.mkdir(parents = True)
+    (snap / "config.json").write_text(
+        '{"model_type": "whisper", "architectures": ["WhisperForConditionalGeneration"]}'
+    )
+    (snap / "model.safetensors").write_bytes(b"weights")
+
+    captured: list = []
+    real_hidden = models_route._is_hidden_model
+
+    def spy(*values):
+        captured.append(values)
+        return real_hidden(*values)
+
+    monkeypatch.setattr(models_route, "_is_hidden_model", spy)
+    repo = _repo(
+        "user/whisper-finetune",
+        [SimpleNamespace(file_name = "model.safetensors", size_on_disk = 10)],
+        repo_path,
+    )
+    monkeypatch.setattr(
+        models_route, "_all_hf_cache_scans", lambda: [SimpleNamespace(repos = [repo])]
+    )
+
+    result = asyncio.run(
+        models_route.list_cached_models(current_subject = "test-user", hf_token = None)
+    )
+    # The route passed the snapshot path (not just the repo id) ...
+    assert any(str(repo_path) in values for values in captured)
+    # ... so the custom Whisper checkpoint is hidden from the chat picker.
+    assert result["cached"] == []
+
+
+def test_is_hidden_model_matches_repo_ids_exactly(monkeypatch):
+    """A custom embedder with a generic basename is hidden by EXACT repo-id
+    match only, so unrelated cached repos that merely contain the basename stay
+    visible. Regression: substring basename matching hid real chat models like
+    ``user/model-chat`` from the On Device inventory."""
+    from core.rag import config as rag_config
+
+    monkeypatch.setattr(rag_config, "effective_embedding_model", lambda: "org/model")
+    monkeypatch.setattr(rag_config, "effective_gguf_repo", lambda: "org/model-GGUF")
+
+    # The exact embedder repo and its GGUF companion are hidden.
+    assert models_route._is_hidden_model("org/model")
+    assert models_route._is_hidden_model("org/model-GGUF")
+    # Unrelated repos that merely contain "model" must NOT be hidden.
+    assert not models_route._is_hidden_model("user/model-chat")
+    assert not models_route._is_hidden_model("org/model-instruct")
+    assert not models_route._is_hidden_model("acme/remodelled-chat")
+    # The validation probe stays hidden regardless of embedder config.
+    assert models_route._is_hidden_model("ggml-org/models")
+
+
+def test_is_hidden_model_matches_repo_derived_local_paths(monkeypatch):
+    """Match exact repo-derived cache and LM Studio paths."""
+    from core.rag import config as rag_config
+
+    monkeypatch.setattr(rag_config, "effective_embedding_model", lambda: "org/model")
+    monkeypatch.setattr(rag_config, "effective_gguf_repo", lambda: "org/model-GGUF")
+
+    assert models_route._is_hidden_model(
+        "/cache/models--org--model/snapshots/abc/model.safetensors"
+    )
+    assert models_route._is_hidden_model(
+        r"C:\Users\u\.cache\huggingface\hub\models--org--model-GGUF\snapshots\abc"
+    )
+    assert models_route._is_hidden_model("/lm-studio/org/model-GGUF/model-Q8_0.gguf")
+    assert not models_route._is_hidden_model("/lm-studio/user/model-chat/model-Q8_0.gguf")
+    assert not models_route._is_hidden_model("/cache/models--org--model-instruct")
+
+
+def test_is_hidden_model_prefers_existing_relative_path(monkeypatch, tmp_path):
+    """Prefer an existing relative path over repo-id syntax."""
+    from core.rag import config as rag_config
+
+    embedder = tmp_path / "models" / "embedder"
+    embedder.mkdir(parents = True)
+    monkeypatch.chdir(tmp_path)
+    monkeypatch.setattr(rag_config, "effective_embedding_model", lambda: "models/embedder")
+    monkeypatch.setattr(rag_config, "effective_gguf_repo", lambda: "org/embedder-GGUF")
+
+    assert models_route._is_hidden_model(str(embedder))
+
+
+def test_is_hidden_model_keeps_stale_default_embedder_hidden(monkeypatch):
+    """Keep default embedders hidden after a settings change."""
+    from core.rag import config as rag_config
+
+    monkeypatch.setattr(rag_config, "effective_embedding_model", lambda: "org/custom")
+    monkeypatch.setattr(rag_config, "effective_gguf_repo", lambda: "org/custom-GGUF")
+
+    assert models_route._is_hidden_model("unsloth/bge-small-en-v1.5")
+    assert models_route._is_hidden_model("unsloth/bge-small-en-v1.5-GGUF")
+    assert models_route._is_hidden_model("/models/bge-small-en-v1.5")
+    assert models_route._is_hidden_model("/models/bge-small-en-v1.5-F16.gguf")
+    assert models_route._is_hidden_model(r"C:\models\bge-small-en-v1.5-Q8_0.gguf")
+    # Repo IDs still use exact matching, and similar local basenames must have
+    # a real separator after the static default name.
+    assert not models_route._is_hidden_model("user/bge-small-en-v1.5-chat")
+    assert not models_route._is_hidden_model("/models/bge-small-en-v1.50")
+
+
+def test_is_hidden_model_keeps_env_default_hidden_after_override(monkeypatch):
+    """A persisted override must not expose the deployment's env default."""
+    from core.rag import config as rag_config
+
+    monkeypatch.delenv("RAG_EMBED_GGUF_REPO", raising = False)
+    monkeypatch.setattr(rag_config, "EMBEDDING_MODEL", "org/env-default")
+    monkeypatch.setattr(rag_config, "effective_embedding_model", lambda: "org/custom")
+    monkeypatch.setattr(rag_config, "effective_gguf_repo", lambda: "org/custom-GGUF")
+
+    assert models_route._is_hidden_model("org/env-default")
+    assert models_route._is_hidden_model("org/env-default-GGUF")
+    assert models_route._is_hidden_model("org/custom")
+    assert models_route._is_hidden_model("org/custom-GGUF")
+    assert not models_route._is_hidden_model("org/env-default-chat")
+
+
+def test_hidden_models_importable_without_heavy_model_stack():
+    """The hub cache scanner imports ``is_hidden_model`` at module scope, so it
+    must not drag in ``utils/models/__init__`` (the model-config + checkpoint
+    stack). Verify in a clean interpreter that importing the helper touches
+    neither ``utils.models`` nor those heavy submodules, and still classifies
+    the probe."""
+    import os
+    import subprocess
+    import textwrap
+
+    backend = Path(__file__).resolve().parents[1]
+    code = textwrap.dedent(
+        """
+        import sys
+
+        class _Blocker:
+            _blocked = (
+                "utils.models",
+                "utils.models.model_config",
+                "utils.models.checkpoints",
+            )
+
+            def find_spec(self, name, path=None, target=None):
+                if name in self._blocked:
+                    raise ImportError("blocked heavy import: " + name)
+                return None
+
+        sys.meta_path.insert(0, _Blocker())
+        from utils.hidden_models import is_hidden_model
+
+        loaded = sorted(m for m in sys.modules if m.startswith("utils.models"))
+        assert not loaded, loaded
+        assert is_hidden_model("ggml-org/models") is True
+        assert is_hidden_model("unsloth/gemma-3-270m-it-GGUF") is False
+        print("HIDDEN_MODELS_IMPORT_OK")
+        """
+    )
+    env = dict(os.environ, PYTHONPATH = str(backend))
+    proc = subprocess.run(
+        [sys.executable, "-c", code],
+        capture_output = True,
+        text = True,
+        env = env,
+    )
+    assert proc.returncode == 0, proc.stderr
+    assert "HIDDEN_MODELS_IMPORT_OK" in proc.stdout
+
+
 def test_list_cached_gguf_hides_llama_validation_probe(monkeypatch, tmp_path):
     """The ggml-org/models / stories260K install validation probe can land in
     the HF cache as a side effect of installing the prebuilt llama-server.
@@ -434,33 +699,14 @@ def _gfile(name: str, size: int, mtime: float) -> SimpleNamespace:
     )
 
 
-def test_all_hf_cache_scans_survives_inaccessible_aux_cache(monkeypatch, tmp_path):
-    """An unreadable auxiliary cache (e.g. an inaccessible
-    ``~/.cache/huggingface/hub``) must be skipped, not abort the scan.
-    Regression guard for ``extra.is_dir()`` raising and wiping the response.
-    """
-    import huggingface_hub
-    import utils.paths as paths_mod
+def test_all_hf_cache_scans_uses_shared_inventory(monkeypatch, tmp_path):
+    from hub.utils import inventory_scan
 
     active = SimpleNamespace(
         repos = [_repo("Org/Active", [_file("Q4_K_M.gguf", 5_000)], tmp_path / "active")]
     )
 
-    def _fake_scan(cache_dir = None):
-        if cache_dir is None:
-            return active
-        raise AssertionError("auxiliary scan should have been skipped")
-
-    class _Boom:
-        def is_dir(self):
-            raise PermissionError(13, "Permission denied")
-
-        def resolve(self):
-            raise PermissionError(13, "Permission denied")
-
-    monkeypatch.setattr(huggingface_hub, "scan_cache_dir", _fake_scan)
-    monkeypatch.setattr(paths_mod, "legacy_hf_cache_dir", lambda: _Boom())
-    monkeypatch.setattr(paths_mod, "hf_default_cache_dir", lambda: _Boom())
+    monkeypatch.setattr(inventory_scan, "all_hf_cache_scans", lambda: [active])
 
     scans = models_route._all_hf_cache_scans()
     assert scans == [active]
@@ -547,13 +793,17 @@ def test_gguf_variants_mmproj_does_not_mark_quant_downloaded(monkeypatch, tmp_pa
         "list_gguf_variants",
         lambda repo_id, hf_token = None: (variants, True, []),
     )
-    monkeypatch.setattr(GV, "_local_main_gguf_blobs_by_quant", lambda _repo_id: {})
+    monkeypatch.setattr(
+        GV,
+        "_local_main_gguf_blobs_by_quant",
+        lambda _repo_id, repo_cache_dir = None: {},
+    )
 
     snap = tmp_path / "models--org--repo" / "snapshots" / "rev"
     snap.mkdir(parents = True)
     (snap / "model-Q4_K_M.gguf").write_bytes(b"x" * 10_000)  # real weight, fully present
     (snap / "mmproj-F16.gguf").write_bytes(b"y" * 20_000)  # mmproj adapter, label "F16"
-    monkeypatch.setattr(GV, "iter_hf_cache_snapshots", lambda _repo_id: [snap])
+    monkeypatch.setattr(GV, "iter_hf_cache_snapshots", lambda _repo_id, root = None: [snap])
 
     result = asyncio.run(
         models_route.get_gguf_variants(
@@ -566,6 +816,52 @@ def test_gguf_variants_mmproj_does_not_mark_quant_downloaded(monkeypatch, tmp_pa
     assert flags["F16"] is False
 
 
+def test_gguf_variants_route_scopes_local_probe_to_selected_cache(monkeypatch, tmp_path):
+    snapshot = tmp_path / "inactive" / "models--org--repo" / "snapshots" / "rev"
+    snapshot.mkdir(parents = True)
+    calls = []
+
+    async def scoped_variants(repo_id, **kwargs):
+        calls.append((repo_id, kwargs))
+        return SimpleNamespace(
+            repo_id = repo_id,
+            variants = [],
+            has_vision = False,
+            default_variant = None,
+        )
+
+    context_calls = []
+    monkeypatch.setattr(GV, "get_gguf_variants_response", scoped_variants)
+    monkeypatch.setattr(
+        models_route,
+        "_read_native_context_length",
+        lambda model, *, is_local: context_calls.append((model, is_local)) or 8192,
+    )
+
+    result = asyncio.run(
+        models_route.get_gguf_variants(
+            repo_id = "org/repo",
+            prefer_local_cache = True,
+            local_path = str(snapshot),
+            hf_token = None,
+            current_subject = "test-user",
+        )
+    )
+
+    assert calls == [
+        (
+            "org/repo",
+            {
+                "prefer_local_cache": True,
+                "local_path": str(snapshot),
+                "hf_token": None,
+            },
+        )
+    ]
+    assert context_calls == [(str(snapshot), True)]
+    assert result.context_length == 8192
+
+
 def test_gguf_variants_ignore_big_endian_siblings(monkeypatch, tmp_path):
     siblings = [
         SimpleNamespace(rfilename = "model-Q4_K_M-be.gguf", size = 100),
@@ -587,12 +883,16 @@ def test_gguf_variants_ignore_big_endian_siblings(monkeypatch, tmp_path):
             siblings,
         ),
     )
-    monkeypatch.setattr(GV, "_local_main_gguf_blobs_by_quant", lambda _repo_id: {})
+    monkeypatch.setattr(
+        GV,
+        "_local_main_gguf_blobs_by_quant",
+        lambda _repo_id, repo_cache_dir = None: {},
+    )
 
     snap = tmp_path / "models--org--repo" / "snapshots" / "rev"
     snap.mkdir(parents = True)
     (snap / "model-Q4_K_M.gguf").write_bytes(b"x" * 10)
-    monkeypatch.setattr(GV, "iter_hf_cache_snapshots", lambda _repo_id: [snap])
+    monkeypatch.setattr(GV, "iter_hf_cache_snapshots", lambda _repo_id, root = None: [snap])
 
     result = asyncio.run(
         models_route.get_gguf_variants(
@@ -619,12 +919,16 @@ def test_gguf_variants_cached_big_endian_does_not_satisfy_variant(monkeypatch, t
         "list_gguf_variants",
         lambda repo_id, hf_token = None: (variants, False, []),
     )
-    monkeypatch.setattr(GV, "_local_main_gguf_blobs_by_quant", lambda _repo_id: {})
+    monkeypatch.setattr(
+        GV,
+        "_local_main_gguf_blobs_by_quant",
+        lambda _repo_id, repo_cache_dir = None: {},
+    )
 
     snap = tmp_path / "models--org--repo" / "snapshots" / "rev"
     snap.mkdir(parents = True)
     (snap / "model-Q4_K_M-be.gguf").write_bytes(b"x" * 10)
-    monkeypatch.setattr(GV, "iter_hf_cache_snapshots", lambda _repo_id: [snap])
+    monkeypatch.setattr(GV, "iter_hf_cache_snapshots", lambda _repo_id, root = None: [snap])
 
     result = asyncio.run(
         models_route.get_gguf_variants(
@@ -635,66 +939,82 @@ def test_gguf_variants_cached_big_endian_does_not_satisfy_variant(monkeypatch, t
     assert result.variants[0].downloaded is False
 
 
-def test_gguf_download_progress_excludes_mmproj(monkeypatch, tmp_path):
-    """A cached mmproj adapter must not count toward a same-label main
-    variant's download progress (mmproj-F16 vs an F16 weight)."""
-    import huggingface_hub.constants as hf_constants
+def test_legacy_gguf_progress_delegates_to_shared_service(monkeypatch):
+    calls = []
 
-    monkeypatch.setattr(hf_constants, "HF_HUB_CACHE", str(tmp_path))
-    snap = tmp_path / "models--org--repo" / "snapshots" / "rev"
-    snap.mkdir(parents = True)
-    (snap / "mmproj-F16.gguf").write_bytes(b"y" * 20_000)  # only the adapter on disk
+    async def shared(repo_id, *, variant, expected_bytes, hf_token):
+        calls.append((repo_id, variant, expected_bytes, hf_token))
+        return {"downloaded_bytes": 10, "expected_bytes": 20, "progress": 0.5}
 
-    result = asyncio.run(
-        models_route.get_gguf_download_progress(
-            repo_id = "org/repo",
-            variant = "F16",
-            expected_bytes = 20_000,
-            current_subject = "test-user",
-        )
+    monkeypatch.setattr(
+        "hub.services.models.downloads.get_gguf_download_progress_response",
+        shared,
     )
 
-    assert result["downloaded_bytes"] == 0
-    assert result["progress"] == 0
-
-
-def test_gguf_download_progress_excludes_big_endian_sibling(monkeypatch, tmp_path):
-    import huggingface_hub.constants as hf_constants
-
-    monkeypatch.setattr(hf_constants, "HF_HUB_CACHE", str(tmp_path))
-    snap = tmp_path / "models--org--repo" / "snapshots" / "rev"
-    snap.mkdir(parents = True)
-    (snap / "model-Q4_K_M-be.gguf").write_bytes(b"y" * 20_000)
-
     result = asyncio.run(
         models_route.get_gguf_download_progress(
             repo_id = "org/repo",
             variant = "Q4_K_M",
-            expected_bytes = 20_000,
+            expected_bytes = 20,
+            hf_token = "token",
             current_subject = "test-user",
         )
     )
 
-    assert result["downloaded_bytes"] == 0
-    assert result["progress"] == 0
+    assert result["progress"] == 0.5
+    assert calls == [("org/repo", "Q4_K_M", 20, "token")]
 
 
-def test_gguf_download_progress_counts_quant_subdir(monkeypatch, tmp_path):
-    import huggingface_hub.constants as hf_constants
+def test_legacy_model_progress_delegates_to_shared_service(monkeypatch):
+    calls = []
 
-    monkeypatch.setattr(hf_constants, "HF_HUB_CACHE", str(tmp_path))
-    snap = tmp_path / "models--org--repo" / "snapshots" / "rev" / "Q4_K_M"
-    snap.mkdir(parents = True)
-    (snap / "foo.gguf").write_bytes(b"x" * 20_000)
+    async def shared(repo_id, *, hf_token):
+        calls.append((repo_id, hf_token))
+        return {"downloaded_bytes": 10, "expected_bytes": 20, "progress": 0.5}
+
+    monkeypatch.setattr(
+        "hub.services.models.downloads.get_download_progress_response",
+        shared,
+    )
 
     result = asyncio.run(
-        models_route.get_gguf_download_progress(
+        models_route.get_download_progress(
             repo_id = "org/repo",
-            variant = "Q4_K_M",
-            expected_bytes = 20_000,
+            hf_token = "token",
             current_subject = "test-user",
         )
     )
 
-    assert result["downloaded_bytes"] == 20_000
-    assert result["progress"] == 1.0
+    assert result["progress"] == 0.5
+    assert calls == [("org/repo", "token")]
+
+
+def test_legacy_delete_delegates_to_shared_service(monkeypatch):
+    calls = []
+
+    async def shared(
+        repo_id,
+        variant,
+        hf_token,
+        cache_path = None,
+    ):
+        calls.append((repo_id, variant, hf_token, cache_path))
+        return {"status": "deleted", "repo_id": repo_id}
+
+    monkeypatch.setattr(
+        "hub.services.models.deletion.delete_cached_model_response",
+        shared,
+    )
+
+    result = asyncio.run(
+        models_route.delete_cached_model(
+            repo_id = "org/repo",
+            variant = None,
+            cache_path = "/data/hf/hub",
+            hf_token = "token",
+            current_subject = "test-user",
+        )
+    )
+
+    assert result == {"status": "deleted", "repo_id": "org/repo"}
+    assert calls == [("org/repo", None, "token", "/data/hf/hub")]
diff --git a/studio/backend/tests/test_change_password_policy.py b/studio/backend/tests/test_change_password_policy.py
new file mode 100644
index 0000000000..c73e9ed839
--- /dev/null
+++ b/studio/backend/tests/test_change_password_policy.py
@@ -0,0 +1,75 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import asyncio
+import importlib.util
+import sys
+from pathlib import Path
+
+import pytest
+from fastapi import HTTPException
+
+_BACKEND_ROOT = Path(__file__).resolve().parents[1]
+if str(_BACKEND_ROOT) not in sys.path:
+    sys.path.insert(0, str(_BACKEND_ROOT))
+
+from models.auth import ChangePasswordRequest  # noqa: E402
+
+# Load routes/auth.py directly so collection does not execute routes/__init__.py,
+# which pulls in the heavy training/models/inference routers.
+_route_path = _BACKEND_ROOT / "routes" / "auth.py"
+_spec = importlib.util.spec_from_file_location("_change_password_route", _route_path)
+assert _spec is not None and _spec.loader is not None
+auth_routes = importlib.util.module_from_spec(_spec)
+_spec.loader.exec_module(auth_routes)
+
+
+@pytest.fixture
+def _user(monkeypatch):
+    monkeypatch.setattr(
+        auth_routes.storage,
+        "get_user_and_secret",
+        lambda username: ("salt", "hash", "jwt-secret", False),
+    )
+    monkeypatch.setattr(
+        auth_routes.hashing,
+        "verify_password",
+        lambda password, salt, pwd_hash: password == "bootstrap-pw",
+    )
+
+
+def _change(new_password):
+    payload = ChangePasswordRequest(
+        current_password = "bootstrap-pw",
+        new_password = new_password,
+    )
+    return asyncio.run(auth_routes.change_password(payload, None, "unsloth"))
+
+
+def test_rejects_whitespace_only_password(_user):
+    with pytest.raises(HTTPException) as excinfo:
+        _change(" " * 8)
+    assert excinfo.value.status_code == 400
+    assert "spaces" in excinfo.value.detail
+
+
+def test_rejects_tabs_and_spaces_password(_user):
+    with pytest.raises(HTTPException) as excinfo:
+        _change(" \t \t \t \t ")
+    assert excinfo.value.status_code == 400
+
+
+def test_rejects_password_containing_spaces(_user):
+    with pytest.raises(HTTPException) as excinfo:
+        _change("correct horse battery")
+    assert excinfo.value.status_code == 400
+    assert "spaces" in excinfo.value.detail
+
+
+def test_allows_password_without_spaces(_user, monkeypatch):
+    monkeypatch.setattr(auth_routes.storage, "update_password", lambda *args, **kwargs: True)
+    monkeypatch.setattr(auth_routes, "create_access_token", lambda subject: "at")
+    monkeypatch.setattr(auth_routes, "create_refresh_token", lambda subject: "rt")
+    token = _change("correct-horse-battery")
+    assert token.access_token == "at"
+    assert token.must_change_password is False
diff --git a/studio/backend/tests/test_chat_attachments.py b/studio/backend/tests/test_chat_attachments.py
new file mode 100644
index 0000000000..459587ca9e
--- /dev/null
+++ b/studio/backend/tests/test_chat_attachments.py
@@ -0,0 +1,634 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import base64
+import json
+import os
+import sqlite3
+import sys
+
+import pytest
+from fastapi import HTTPException
+
+_backend = os.path.join(os.path.dirname(__file__), "..")
+sys.path.insert(0, _backend)
+
+from routes import chat_history
+from storage import studio_db
+from utils.paths import studio_db_path
+
+PNG_BYTES = base64.b64decode(
+    "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg=="
+)
+PNG_DATA_URL = "data:image/png;base64," + base64.b64encode(PNG_BYTES).decode("ascii")
+
+
+def _reset_studio_db(tmp_path, monkeypatch):
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    monkeypatch.setenv("UNSLOTH_STUDIO_PROJECTS_HOME", str(tmp_path / "Projects"))
+    monkeypatch.setattr(studio_db, "_schema_ready", False)
+
+
+def _thread(
+    thread_id: str = "thread-1",
+    title: str = "Test Chat",
+    pair_id: str | None = None,
+) -> dict:
+    return {
+        "id": thread_id,
+        "title": title,
+        "modelType": "base",
+        "modelId": "test-model",
+        "pairId": pair_id,
+        "archived": False,
+        "createdAt": 1_700_000_000_000,
+    }
+
+
+def _message(
+    message_id: str,
+    created_at: int = 1_700_000_000_000,
+    attachments = None,
+    thread_id: str = "thread-1",
+) -> dict:
+    message = {
+        "id": message_id,
+        "threadId": thread_id,
+        "parentId": None,
+        "role": "user",
+        "content": [{"type": "text", "text": "hello"}],
+        "createdAt": created_at,
+    }
+    if attachments is not None:
+        message["attachments"] = attachments
+    return message
+
+
+def _image_attachment(attachment_id: str = "att-1", name: str = "photo.png") -> dict:
+    return {
+        "id": attachment_id,
+        "type": "image",
+        "name": name,
+        "contentType": "image/png",
+        "content": [{"type": "image", "image": PNG_DATA_URL}],
+        "status": {"type": "complete"},
+    }
+
+
+def _seed(
+    tmp_path,
+    monkeypatch,
+    attachments,
+    message_id: str = "msg-1",
+):
+    _reset_studio_db(tmp_path, monkeypatch)
+    studio_db.upsert_chat_thread(_thread())
+    studio_db.upsert_chat_message(_message(message_id, attachments = attachments))
+
+
+def _set_raw_attachments_json(message_id: str, raw: str) -> None:
+    conn = sqlite3.connect(studio_db_path())
+    try:
+        conn.execute(
+            "UPDATE chat_messages SET attachments_json = ? WHERE id = ?",
+            (raw, message_id),
+        )
+        conn.commit()
+    finally:
+        conn.close()
+
+
+def _raw_attachments_json(message_id: str):
+    conn = sqlite3.connect(studio_db_path())
+    try:
+        row = conn.execute(
+            "SELECT attachments_json FROM chat_messages WHERE id = ?",
+            (message_id,),
+        ).fetchone()
+        return row[0] if row is not None else None
+    finally:
+        conn.close()
+
+
+# ---------------------------------------------------------------------------
+# Storage: list_chat_attachments
+# ---------------------------------------------------------------------------
+
+
+def test_list_chat_attachments_empty_db(tmp_path, monkeypatch):
+    _reset_studio_db(tmp_path, monkeypatch)
+    assert studio_db.list_chat_attachments() == []
+
+
+def test_list_chat_attachments_round_trip(tmp_path, monkeypatch):
+    _seed(tmp_path, monkeypatch, [_image_attachment()])
+    records = studio_db.list_chat_attachments()
+    assert len(records) == 1
+    record = records[0]
+    assert record["id"] == "att-1"
+    assert record["messageId"] == "msg-1"
+    assert record["threadId"] == "thread-1"
+    assert record["threadTitle"] == "Test Chat"
+    assert record["name"] == "photo.png"
+    assert record["type"] == "image"
+    assert record["contentType"] == "image/png"
+    assert record["createdAt"] == 1_700_000_000_000
+    # Base64 length estimate is within padding error of the decoded size.
+    assert abs(record["sizeBytes"] - len(PNG_BYTES)) <= 2
+
+
+def test_list_chat_attachments_counts_text_utf8(tmp_path, monkeypatch):
+    text = "héllo wörld é世界"
+    attachment = {
+        "id": "att-txt",
+        "type": "document",
+        "name": "notes.txt",
+        "content": [{"type": "text", "text": text}],
+    }
+    _seed(tmp_path, monkeypatch, [attachment])
+    records = studio_db.list_chat_attachments()
+    assert records[0]["sizeBytes"] == len(text.encode("utf-8"))
+
+
+def test_list_chat_attachments_no_content_size_is_none(tmp_path, monkeypatch):
+    attachment = {"id": "att-empty", "name": "ghost.bin", "content": []}
+    _seed(tmp_path, monkeypatch, [attachment])
+    records = studio_db.list_chat_attachments()
+    assert records[0]["sizeBytes"] is None
+    assert records[0]["name"] == "ghost.bin"
+
+
+def test_list_chat_attachments_defaults_missing_name(tmp_path, monkeypatch):
+    attachment = {"id": "att-noname", "content": []}
+    _seed(tmp_path, monkeypatch, [attachment])
+    assert studio_db.list_chat_attachments()[0]["name"] == "attachment"
+
+
+def test_list_chat_attachments_sanitizes_structured_metadata(tmp_path, monkeypatch):
+    attachment = {
+        "id": "att-weird",
+        "name": {"nested": "name"},
+        "type": ["image"],
+        "contentType": {"mime": "image/png"},
+        "content": [],
+    }
+    _seed(tmp_path, monkeypatch, [attachment])
+    record = studio_db.list_chat_attachments()[0]
+    assert record["name"] == "attachment"
+    assert record["type"] is None
+    assert record["contentType"] is None
+
+
+def test_list_chat_attachments_skips_malformed_rows(tmp_path, monkeypatch):
+    _reset_studio_db(tmp_path, monkeypatch)
+    studio_db.upsert_chat_thread(_thread())
+    for i, raw in enumerate(
+        [
+            "not json at all",
+            '{"id": "att-obj"}',
+            "null",
+            "[]",
+            '[{"noid": true}, "just a string", 42]',
+            '[{"id": ""}]',
+        ]
+    ):
+        message_id = f"msg-bad-{i}"
+        studio_db.upsert_chat_message(_message(message_id))
+        _set_raw_attachments_json(message_id, raw)
+    studio_db.upsert_chat_message(_message("msg-good", attachments = [_image_attachment("att-ok")]))
+    records = studio_db.list_chat_attachments()
+    assert [r["id"] for r in records] == ["att-ok"]
+
+
+def test_list_chat_attachments_orders_newest_first(tmp_path, monkeypatch):
+    _reset_studio_db(tmp_path, monkeypatch)
+    studio_db.upsert_chat_thread(_thread())
+    studio_db.upsert_chat_message(
+        _message("msg-old", 1_700_000_000_000, [_image_attachment("att-old")])
+    )
+    studio_db.upsert_chat_message(
+        _message("msg-new", 1_700_000_100_000, [_image_attachment("att-new")])
+    )
+    assert [r["id"] for r in studio_db.list_chat_attachments()] == ["att-new", "att-old"]
+
+
+def test_list_chat_attachments_survives_missing_thread_row(tmp_path, monkeypatch):
+    _reset_studio_db(tmp_path, monkeypatch)
+    studio_db.upsert_chat_thread(_thread())
+    studio_db.upsert_chat_message(_message("msg-1", attachments = [_image_attachment()]))
+    conn = sqlite3.connect(studio_db_path())
+    try:
+        conn.execute("DELETE FROM chat_threads WHERE id = 'thread-1'")
+        conn.commit()
+    finally:
+        conn.close()
+    records = studio_db.list_chat_attachments()
+    assert len(records) == 1
+    assert records[0]["threadTitle"] is None
+
+
+def test_list_chat_attachments_includes_compare_pair_id(tmp_path, monkeypatch):
+    _reset_studio_db(tmp_path, monkeypatch)
+    studio_db.upsert_chat_thread(_thread(pair_id = "pair-1"))
+    studio_db.upsert_chat_message(_message("msg-compare", attachments = [_image_attachment()]))
+    record = studio_db.list_chat_attachments()[0]
+    assert record["threadId"] == "thread-1"
+    assert record["pairId"] == "pair-1"
+
+
+def test_list_chat_attachments_gone_after_thread_delete(tmp_path, monkeypatch):
+    _seed(tmp_path, monkeypatch, [_image_attachment()])
+    studio_db.delete_chat_threads(["thread-1"])
+    assert studio_db.list_chat_attachments() == []
+
+
+# ---------------------------------------------------------------------------
+# Storage: get_chat_attachment / delete_chat_attachment
+# ---------------------------------------------------------------------------
+
+
+def test_get_chat_attachment_found_and_missing(tmp_path, monkeypatch):
+    _seed(tmp_path, monkeypatch, [_image_attachment()])
+    attachment = studio_db.get_chat_attachment("msg-1", "att-1")
+    assert attachment is not None
+    assert attachment["content"][0]["image"] == PNG_DATA_URL
+    assert studio_db.get_chat_attachment("msg-1", "att-missing") is None
+    assert studio_db.get_chat_attachment("msg-missing", "att-1") is None
+
+
+def test_delete_chat_attachment_keeps_others(tmp_path, monkeypatch):
+    _seed(
+        tmp_path,
+        monkeypatch,
+        [_image_attachment("att-1"), _image_attachment("att-2", "other.png")],
+    )
+    assert studio_db.delete_chat_attachment("msg-1", "att-1") is True
+    assert studio_db.get_chat_attachment("msg-1", "att-1") is None
+    assert studio_db.get_chat_attachment("msg-1", "att-2") is not None
+    assert [r["id"] for r in studio_db.list_chat_attachments()] == ["att-2"]
+
+
+def test_delete_last_chat_attachment_stores_empty_list(tmp_path, monkeypatch):
+    _seed(tmp_path, monkeypatch, [_image_attachment()])
+    assert studio_db.delete_chat_attachment("msg-1", "att-1") is True
+    # '[]' rather than NULL: a NULL attachments field reads back as missing
+    # and triggers the legacy IndexedDB backfill, resurrecting the deleted
+    # attachment on the next chat load.
+    assert _raw_attachments_json("msg-1") == "[]"
+    assert studio_db.list_chat_attachments() == []
+    # The message itself must survive with its content intact.
+    message = studio_db.get_chat_message("thread-1", "msg-1")
+    assert message is not None
+    assert message["content"] == [{"type": "text", "text": "hello"}]
+    assert message["attachments"] == []
+
+
+def test_delete_chat_attachment_missing_targets(tmp_path, monkeypatch):
+    _seed(tmp_path, monkeypatch, [_image_attachment()])
+    assert studio_db.delete_chat_attachment("msg-missing", "att-1") is False
+    assert studio_db.delete_chat_attachment("msg-1", "att-missing") is False
+    _set_raw_attachments_json("msg-1", "not json")
+    assert studio_db.delete_chat_attachment("msg-1", "att-1") is False
+
+
+# ---------------------------------------------------------------------------
+# Routes: /attachments endpoints (real storage, direct calls)
+# ---------------------------------------------------------------------------
+
+
+def test_list_attachments_route(tmp_path, monkeypatch):
+    _seed(tmp_path, monkeypatch, [_image_attachment()])
+    result = chat_history.list_attachments(current_subject = "unsloth")
+    assert [a["id"] for a in result["attachments"]] == ["att-1"]
+
+
+def test_attachment_file_serves_image_bytes(tmp_path, monkeypatch):
+    _seed(tmp_path, monkeypatch, [_image_attachment()])
+    response = chat_history.get_attachment_file("msg-1", "att-1", current_subject = "unsloth")
+    assert response.body == PNG_BYTES
+    assert response.media_type == "image/png"
+
+
+def test_attachment_file_tolerates_whitespace_in_base64(tmp_path, monkeypatch):
+    encoded = base64.b64encode(PNG_BYTES).decode("ascii")
+    wrapped = "\n".join(encoded[i : i + 8] for i in range(0, len(encoded), 8))
+    attachment = _image_attachment()
+    attachment["content"] = [{"type": "image", "image": "data:image/png;base64," + wrapped}]
+    _seed(tmp_path, monkeypatch, [attachment])
+    response = chat_history.get_attachment_file("msg-1", "att-1", current_subject = "unsloth")
+    assert response.body == PNG_BYTES
+
+
+def test_attachment_file_corrupt_base64_is_422(tmp_path, monkeypatch):
+    attachment = _image_attachment()
+    attachment["content"] = [{"type": "image", "image": "data:image/png;base64,%%%"}]
+    _seed(tmp_path, monkeypatch, [attachment])
+    with pytest.raises(HTTPException) as excinfo:
+        chat_history.get_attachment_file("msg-1", "att-1", current_subject = "unsloth")
+    assert excinfo.value.status_code == 422
+
+
+def test_attachment_file_accepts_urlsafe_base64(tmp_path, monkeypatch):
+    data = bytes(range(251, 256)) * 3  # encodes to characters remapped by urlsafe
+    payload = base64.urlsafe_b64encode(data).decode("ascii")
+    assert "-" in payload or "_" in payload
+    attachment = _image_attachment()
+    attachment["content"] = [{"type": "image", "image": "data:image/png;base64," + payload}]
+    _seed(tmp_path, monkeypatch, [attachment])
+    response = chat_history.get_attachment_file("msg-1", "att-1", current_subject = "unsloth")
+    assert response.body == data
+
+
+def test_attachment_file_accepts_missing_padding(tmp_path, monkeypatch):
+    payload = base64.b64encode(PNG_BYTES).decode("ascii").rstrip("=")
+    attachment = _image_attachment()
+    attachment["content"] = [{"type": "image", "image": "data:image/png;base64," + payload}]
+    _seed(tmp_path, monkeypatch, [attachment])
+    response = chat_history.get_attachment_file("msg-1", "att-1", current_subject = "unsloth")
+    assert response.body == PNG_BYTES
+
+
+def test_attachment_file_serves_percent_encoded_data_url(tmp_path, monkeypatch):
+    attachment = _image_attachment()
+    attachment["content"] = [{"type": "image", "image": "data:text/plain,hello%20world"}]
+    _seed(tmp_path, monkeypatch, [attachment])
+    response = chat_history.get_attachment_file("msg-1", "att-1", current_subject = "unsloth")
+    assert response.body == b"hello world"
+    # Non-image data URL types are clamped so markup never renders same-origin.
+    assert response.media_type == "application/octet-stream"
+
+
+def test_attachment_file_serves_text_parts(tmp_path, monkeypatch):
+    attachment = {
+        "id": "att-txt",
+        "type": "document",
+        "name": "notes.txt",
+        "content": [
+            {"type": "text", "text": "first"},
+            {"type": "text", "text": "second"},
+        ],
+    }
+    _seed(tmp_path, monkeypatch, [attachment])
+    response = chat_history.get_attachment_file("msg-1", "att-txt", current_subject = "unsloth")
+    assert response.body.decode("utf-8") == "first\nsecond"
+    assert response.media_type.startswith("text/plain")
+
+
+def test_attachment_file_no_content_is_404(tmp_path, monkeypatch):
+    _seed(tmp_path, monkeypatch, [{"id": "att-empty", "name": "ghost", "content": []}])
+    with pytest.raises(HTTPException) as excinfo:
+        chat_history.get_attachment_file("msg-1", "att-empty", current_subject = "unsloth")
+    assert excinfo.value.status_code == 404
+
+
+def test_attachment_file_missing_message_is_404(tmp_path, monkeypatch):
+    _reset_studio_db(tmp_path, monkeypatch)
+    with pytest.raises(HTTPException) as excinfo:
+        chat_history.get_attachment_file("nope", "att-1", current_subject = "unsloth")
+    assert excinfo.value.status_code == 404
+
+
+def test_attachment_file_non_data_url_image_is_404(tmp_path, monkeypatch):
+    attachment = _image_attachment()
+    attachment["content"] = [{"type": "image", "image": "https://example.com/a.png"}]
+    _seed(tmp_path, monkeypatch, [attachment])
+    with pytest.raises(HTTPException) as excinfo:
+        chat_history.get_attachment_file("msg-1", "att-1", current_subject = "unsloth")
+    assert excinfo.value.status_code == 404
+
+
+def test_attachment_file_defaults_media_type(tmp_path, monkeypatch):
+    payload = base64.b64encode(b"raw-bytes").decode("ascii")
+    attachment = _image_attachment()
+    attachment["content"] = [{"type": "image", "image": "data:;base64," + payload}]
+    _seed(tmp_path, monkeypatch, [attachment])
+    response = chat_history.get_attachment_file("msg-1", "att-1", current_subject = "unsloth")
+    assert response.body == b"raw-bytes"
+    assert response.media_type == "application/octet-stream"
+
+
+def test_attachment_file_svg_media_type(tmp_path, monkeypatch):
+    svg = b"<svg xmlns='http://www.w3.org/2000/svg'/>"
+    payload = base64.b64encode(svg).decode("ascii")
+    attachment = _image_attachment()
+    attachment["content"] = [{"type": "image", "image": "data:image/svg+xml;base64," + payload}]
+    _seed(tmp_path, monkeypatch, [attachment])
+    response = chat_history.get_attachment_file("msg-1", "att-1", current_subject = "unsloth")
+    assert response.body == svg
+    # SVG can carry scripts, so it downloads as bytes instead of rendering.
+    assert response.media_type == "application/octet-stream"
+
+
+def test_delete_attachment_route_then_404(tmp_path, monkeypatch):
+    _seed(tmp_path, monkeypatch, [_image_attachment()])
+    result = chat_history.delete_attachment("msg-1", "att-1", current_subject = "unsloth")
+    assert result == {"ok": True}
+    with pytest.raises(HTTPException) as excinfo:
+        chat_history.delete_attachment("msg-1", "att-1", current_subject = "unsloth")
+    assert excinfo.value.status_code == 404
+
+
+# ---------------------------------------------------------------------------
+# Audio attachments (adapter {data, format} and compare-chat bare base64)
+# ---------------------------------------------------------------------------
+
+WAV_BYTES = b"RIFF$\x00\x00\x00WAVEfmt \x10\x00\x00\x00\x01\x00\x01\x00"
+WAV_B64 = base64.b64encode(WAV_BYTES).decode("ascii")
+
+
+def _audio_attachment(attachment_id: str = "att-audio") -> dict:
+    return {
+        "id": attachment_id,
+        "type": "file",
+        "name": "clip.wav",
+        "contentType": "audio/wav",
+        "content": [{"type": "audio", "audio": {"data": WAV_B64, "format": "wav"}}],
+        "status": {"type": "complete"},
+    }
+
+
+def test_audio_attachment_lists_with_size(tmp_path, monkeypatch):
+    _seed(tmp_path, monkeypatch, [_audio_attachment()])
+    records = studio_db.list_chat_attachments()
+    assert len(records) == 1
+    assert records[0]["id"] == "att-audio"
+    assert abs(records[0]["sizeBytes"] - len(WAV_BYTES)) <= 2
+
+
+def test_audio_attachment_file_serves_bytes(tmp_path, monkeypatch):
+    _seed(tmp_path, monkeypatch, [_audio_attachment()])
+    response = chat_history.get_attachment_file("msg-1", "att-audio", current_subject = "unsloth")
+    assert response.body == WAV_BYTES
+    assert response.media_type == "audio/wav"
+
+
+def test_audio_attachment_media_type_from_format(tmp_path, monkeypatch):
+    attachment = _audio_attachment()
+    attachment["contentType"] = None
+    attachment["content"] = [{"type": "audio", "audio": {"data": WAV_B64, "format": "mp3"}}]
+    _seed(tmp_path, monkeypatch, [attachment])
+    response = chat_history.get_attachment_file("msg-1", "att-audio", current_subject = "unsloth")
+    assert response.media_type == "audio/mpeg"
+
+
+def test_audio_attachment_corrupt_payload_is_422(tmp_path, monkeypatch):
+    attachment = _audio_attachment()
+    attachment["content"] = [{"type": "audio", "audio": {"data": "%%%", "format": "wav"}}]
+    _seed(tmp_path, monkeypatch, [attachment])
+    with pytest.raises(HTTPException) as excinfo:
+        chat_history.get_attachment_file("msg-1", "att-audio", current_subject = "unsloth")
+    assert excinfo.value.status_code == 422
+
+
+# ---------------------------------------------------------------------------
+# Compare-chat uploads stored as message content parts
+# ---------------------------------------------------------------------------
+
+
+def _compare_message(message_id: str = "msg-cmp") -> dict:
+    return {
+        "id": message_id,
+        "threadId": "thread-1",
+        "parentId": None,
+        "role": "user",
+        "content": [
+            {"type": "image", "image": PNG_DATA_URL},
+            {"type": "audio", "audio": WAV_B64},
+            {"type": "text", "text": "compare these"},
+        ],
+        "createdAt": 1_700_000_000_000,
+    }
+
+
+def _seed_compare(tmp_path, monkeypatch):
+    _reset_studio_db(tmp_path, monkeypatch)
+    studio_db.upsert_chat_thread(_thread())
+    studio_db.upsert_chat_message(_compare_message())
+
+
+_CONTENT_PART_PREFIX = "content-part-sha256-"
+
+
+def _content_part_id_for(message_id: str, kind: str) -> str:
+    """Resolve the stable content-hash id for a message's stored blob.
+
+    Content-part ids are SHA-256 hashes of the blob payload, not array
+    indices, so tests look them up from the listing instead of hardcoding an
+    index that would shift when an earlier part is deleted.
+    """
+    for record in studio_db.list_chat_attachments():
+        if record["messageId"] == message_id and record["type"] == kind:
+            return record["id"]
+    raise AssertionError(f"no {kind} content-part upload for {message_id}")
+
+
+def test_content_part_uploads_are_listed(tmp_path, monkeypatch):
+    _seed_compare(tmp_path, monkeypatch)
+    records = studio_db.list_chat_attachments()
+    # Ids are stable content hashes, not array indices.
+    assert all(r["id"].startswith(_CONTENT_PART_PREFIX) for r in records)
+    assert {r["type"] for r in records} == {"image", "audio"}
+    image = next(r for r in records if r["type"] == "image")
+    assert image["contentType"] == "image/png"
+    assert abs(image["sizeBytes"] - len(PNG_BYTES)) <= 2
+    audio = next(r for r in records if r["type"] == "audio")
+    assert audio["type"] == "audio"
+
+
+def test_content_part_file_serves_image_bytes(tmp_path, monkeypatch):
+    _seed_compare(tmp_path, monkeypatch)
+    image_id = _content_part_id_for("msg-cmp", "image")
+    response = chat_history.get_attachment_file("msg-cmp", image_id, current_subject = "unsloth")
+    assert response.body == PNG_BYTES
+    assert response.media_type == "image/png"
+
+
+def test_content_part_delete_keeps_text(tmp_path, monkeypatch):
+    _seed_compare(tmp_path, monkeypatch)
+    image_id = _content_part_id_for("msg-cmp", "image")
+    assert studio_db.delete_chat_attachment("msg-cmp", image_id) is True
+    message = studio_db.get_chat_message("thread-1", "msg-cmp")
+    types = [p["type"] for p in message["content"]]
+    assert types == ["audio", "text"]
+    # The surviving audio blob keeps its own stable hash id after the delete.
+    remaining = studio_db.list_chat_attachments()
+    assert [r["type"] for r in remaining] == ["audio"]
+    assert remaining[0]["id"].startswith(_CONTENT_PART_PREFIX)
+    assert remaining[0]["id"] != image_id
+
+
+def test_content_part_delete_rejects_non_blob(tmp_path, monkeypatch):
+    _seed_compare(tmp_path, monkeypatch)
+    # The text part is not a stored upload, so it never gets an id: only the
+    # image and audio blobs are addressable.
+    assert len(studio_db.list_chat_attachments()) == 2
+    # A well-formed but unknown content-hash id, and malformed ids, all no-op.
+    assert studio_db.delete_chat_attachment("msg-cmp", _CONTENT_PART_PREFIX + "0" * 64) is False
+    assert studio_db.delete_chat_attachment("msg-cmp", "content-part-99") is False
+    assert studio_db.delete_chat_attachment("msg-cmp", "content-part-x") is False
+
+
+def test_text_only_messages_not_listed_as_uploads(tmp_path, monkeypatch):
+    _reset_studio_db(tmp_path, monkeypatch)
+    studio_db.upsert_chat_thread(_thread())
+    # The word "image" inside text must not create phantom upload rows.
+    message = _message("msg-txt")
+    message["content"] = [{"type": "text", "text": 'discussing an "image" and "audio" here'}]
+    studio_db.upsert_chat_message(message)
+    assert studio_db.list_chat_attachments() == []
+
+
+def test_remote_image_urls_are_not_listed_as_uploads(tmp_path, monkeypatch):
+    _reset_studio_db(tmp_path, monkeypatch)
+    studio_db.upsert_chat_thread(_thread())
+    message = _message("msg-remote")
+    message["content"] = [
+        {"type": "image", "image": "https://example.com/cat.png"},
+        {"type": "text", "text": "look at this"},
+    ]
+    studio_db.upsert_chat_message(message)
+    # No stored bytes: nothing to list, open, or delete.
+    assert studio_db.list_chat_attachments() == []
+    assert studio_db.get_chat_attachment("msg-remote", "content-part-0") is None
+    assert studio_db.delete_chat_attachment("msg-remote", "content-part-0") is False
+    stored = studio_db.get_chat_message("thread-1", "msg-remote")
+    assert [p["type"] for p in stored["content"]] == ["image", "text"]
+
+
+def test_html_data_url_serves_as_octet_stream(tmp_path, monkeypatch):
+    _reset_studio_db(tmp_path, monkeypatch)
+    studio_db.upsert_chat_thread(_thread())
+    html_b64 = base64.b64encode(b"<script>alert(1)</script>").decode()
+    message = _message("msg-html")
+    message["content"] = [
+        {"type": "image", "image": f"data:text/html;base64,{html_b64}"},
+    ]
+    studio_db.upsert_chat_message(message)
+    attachment_id = _content_part_id_for("msg-html", "image")
+    response = chat_history.get_attachment_file(
+        "msg-html", attachment_id, current_subject = "unsloth"
+    )
+    # Never echo a script-capable media type back under the app origin.
+    assert response.media_type == "application/octet-stream"
+    assert response.body == b"<script>alert(1)</script>"
+
+
+def test_svg_data_url_serves_as_octet_stream(tmp_path, monkeypatch):
+    _reset_studio_db(tmp_path, monkeypatch)
+    studio_db.upsert_chat_thread(_thread())
+    svg_b64 = base64.b64encode(b"<svg onload='x'/>").decode()
+    message = _message("msg-svg")
+    message["content"] = [
+        {"type": "image", "image": f"data:image/svg+xml;base64,{svg_b64}"},
+    ]
+    studio_db.upsert_chat_message(message)
+    attachment_id = _content_part_id_for("msg-svg", "image")
+    response = chat_history.get_attachment_file("msg-svg", attachment_id, current_subject = "unsloth")
+    assert response.media_type == "application/octet-stream"
+
+
+def test_png_data_url_keeps_its_media_type(tmp_path, monkeypatch):
+    _seed_compare(tmp_path, monkeypatch)
+    image_id = _content_part_id_for("msg-cmp", "image")
+    response = chat_history.get_attachment_file("msg-cmp", image_id, current_subject = "unsloth")
+    assert response.media_type == "image/png"
diff --git a/studio/backend/tests/test_chat_history_routes.py b/studio/backend/tests/test_chat_history_routes.py
index a60ac700bf..896bf1a6cd 100644
--- a/studio/backend/tests/test_chat_history_routes.py
+++ b/studio/backend/tests/test_chat_history_routes.py
@@ -91,6 +91,28 @@ def test_chat_settings_payload_accepts_fast_mode_presets():
     assert dumped["customPresets"][0]["params"]["fastMode"] is True
 
 
+def test_chat_settings_payload_accepts_preset_load_config():
+    payload = chat_history.ChatSettingsPayload.model_validate(
+        {
+            "customPresets": [
+                {
+                    "name": "GGUF preset",
+                    "params": {"temperature": 0.7, "maxTokens": 512},
+                    "loadConfig": {
+                        "customContextLength": 256,
+                        "kvCacheDtype": "q8_0",
+                        "tensorParallel": False,
+                    },
+                },
+            ],
+        }
+    )
+
+    dumped = payload.model_dump(exclude_unset = True)
+    assert dumped["customPresets"][0]["loadConfig"]["customContextLength"] == 256
+    assert dumped["customPresets"][0]["loadConfig"]["kvCacheDtype"] == "q8_0"
+
+
 def test_chat_settings_payload_accepts_nudge_tool_calls():
     # extra="forbid" 400s PUT /api/chat/settings on unknown keys, so the
     # frontend's persisted nudgeToolCalls needs a payload field (like
diff --git a/studio/backend/tests/test_chat_load_during_training.py b/studio/backend/tests/test_chat_load_during_training.py
index 63dba8579c..f1d973f004 100644
--- a/studio/backend/tests/test_chat_load_during_training.py
+++ b/studio/backend/tests/test_chat_load_during_training.py
@@ -168,11 +168,15 @@ class TestCanLoadGGUF(_GpuCacheResetMixin, unittest.TestCase):
         devices,
         required_override = None,
         estimate = None,
+        single_device_gpu = None,
+        gpu_ids = None,
+        is_vulkan = False,
     ):
         with (
             patch("utils.hardware.get_device", return_value = DeviceType.CUDA),
             patch("utils.hardware.estimate_required_model_memory_gb", return_value = (estimate, {})),
             patch("utils.hardware.get_visible_gpu_utilization", return_value = {"devices": devices}),
+            patch("utils.hardware.resolve_requested_gpu_ids", return_value = gpu_ids),
             patch("utils.hardware.auto_select_gpu_ids") as auto_mock,
         ):
             ok, info = tv.can_load_chat_during_training(
@@ -180,9 +184,11 @@ class TestCanLoadGGUF(_GpuCacheResetMixin, unittest.TestCase):
                 hf_token = None,
                 load_in_4bit = True,
                 max_seq_length = 0,
-                requested_gpu_ids = None,
+                requested_gpu_ids = gpu_ids,
                 is_gguf = True,
+                is_vulkan = is_vulkan,
                 required_override_gb = required_override,
+                single_device_gpu = single_device_gpu,
             )
         return ok, info, auto_mock
 
@@ -198,6 +204,117 @@ class TestCanLoadGGUF(_GpuCacheResetMixin, unittest.TestCase):
         ok, _, _ = self._run(devices = _devices((0, 80, 35), (1, 80, 70)), required_override = 20.0)
         self.assertTrue(ok)
 
+    def test_no_per_gpu_floor_for_gguf_with_explicit_gpu_ids(self):
+        # gpu_ids narrows llama.cpp's candidate pool but does not turn its
+        # self-placement into HF device_map="balanced". The uneven selected
+        # pair therefore keeps the aggregate GGUF check without an even-share
+        # floor on the nearly-full card.
+        ok, info, _ = self._run(
+            devices = _devices((0, 80, 35), (1, 80, 70), (2, 80, 0)),
+            required_override = 20.0,
+            gpu_ids = [0, 1],
+        )
+        self.assertTrue(ok)
+        self.assertEqual(info["mode"], "gguf")
+
+    def test_single_device_uses_selected_gpu(self):
+        # The model needs 27 GB with headroom. GPU 0 has 45 GB free, while an
+        # unrelated training-heavy GPU 1 has only 10 GB free.
+        ok, info, _ = self._run(
+            devices = _devices((0, 80, 35), (1, 80, 70)),
+            required_override = 20.0,
+            single_device_gpu = "0",
+        )
+        self.assertTrue(ok)
+        self.assertEqual(info["usable_gb"], 45.0)
+
+        blocked, blocked_info, _ = self._run(
+            devices = _devices((0, 80, 35), (1, 80, 70)),
+            required_override = 20.0,
+            single_device_gpu = "1",
+        )
+        self.assertFalse(blocked)
+        self.assertEqual(blocked_info["usable_gb"], 10.0)
+
+    def test_vulkan_pin_takes_precedence_over_unknown_diffusion_fallback(self):
+        # An uncached GGUF can carry a speculative single-device fallback while
+        # its explicit pin is actually a ggml Vulkan ordinal. Never interpret
+        # that ordinal as the same-numbered CUDA physical device.
+        ok, info, _ = self._run(
+            devices = _devices((0, 80, 0), (1, 80, 78)),
+            required_override = 20.0,
+            single_device_gpu = "0",
+            gpu_ids = [0],
+            is_vulkan = True,
+        )
+        self.assertFalse(ok)
+        self.assertEqual(info["mode"], "gguf_vulkan")
+        self.assertEqual(info["usable_gb"], 2.0)
+
+    def test_vulkan_multi_gpu_guard_counts_requested_devices(self):
+        # The ordinal mapping is unknown, so use the least-free two visible
+        # cards for a two-device request. Their aggregate capacity is still
+        # available instead of collapsing the request to one card.
+        ok, info, _ = self._run(
+            devices = _devices((0, 80, 70), (1, 80, 70), (2, 80, 0)),
+            required_override = 10.0,
+            gpu_ids = [0, 1],
+            is_vulkan = True,
+        )
+        self.assertTrue(ok)
+        self.assertEqual(info["mode"], "gguf_vulkan")
+        self.assertEqual(info["usable_gb"], 18.5)
+
+    def test_single_device_unresolved_token_sizes_against_worst_device(self):
+        # A non-numeric device token (a CUDA UUID / MIG handle) can't map to a
+        # free-VRAM index. The runner still drives ONE device, so size against the
+        # worst-case visible device (min free), not the aggregate pool: one GPU
+        # with 80 GB free vs a 20 GB model -> allow.
+        ok, info, _ = self._run(
+            devices = _devices((0, 80, 0)),
+            required_override = 20.0,
+            single_device_gpu = "GPU-uuid",
+        )
+        self.assertTrue(ok)
+        self.assertEqual(info["mode"], "single_device")
+        self.assertNotIn("reason", info)
+
+    def test_single_device_unresolved_token_refuses_when_worst_device_full(self):
+        # Same UUID fallback, worst-case device nearly full (2 GB for a 20 GB
+        # model) -> refuse (default-deny), not on an unresolved-token technicality.
+        ok, info, _ = self._run(
+            devices = _devices((0, 80, 78)),
+            required_override = 20.0,
+            single_device_gpu = "GPU-uuid",
+        )
+        self.assertFalse(ok)
+        self.assertNotEqual(info.get("reason"), "unresolved_gpu_id")
+
+    def test_single_device_unresolved_token_uses_min_free_not_aggregate(self):
+        # The single-device runner uses ONE device but we can't tell which from a
+        # UUID token. Sizing against the aggregate pool would let a 20 GB model
+        # "fit" 160 GB of pooled free VRAM while landing on a 2 GB card and OOMing
+        # training. Min-free (2 GB) is the safe worst case -> refuse.
+        ok, info, _ = self._run(
+            devices = _devices((0, 80, 78), (1, 80, 0), (2, 80, 0)),
+            required_override = 20.0,
+            single_device_gpu = "GPU-uuid",
+        )
+        self.assertFalse(ok)
+        self.assertEqual(info["mode"], "single_device")
+
+    def test_single_device_cpu_token_allows(self):
+        # An empty device token = a CPU-only single-device runner (CPU diffusion
+        # GGUF): it uses no GPU VRAM, so it never threatens training -> allow
+        # regardless of how full the GPUs are.
+        ok, info, _ = self._run(
+            devices = _devices((0, 80, 78)),
+            required_override = 20.0,
+            single_device_gpu = "",
+        )
+        self.assertTrue(ok)
+        self.assertEqual(info["reason"], "cpu_only")
+
     def test_estimate_unavailable_refuses(self):
         # No override and the estimator can't size it -> default-deny.
         ok, info, _ = self._run(devices = _devices((0, 80, 0)), required_override = None, estimate = None)
@@ -209,7 +326,7 @@ class TestCanLoadGGUF(_GpuCacheResetMixin, unittest.TestCase):
 
 
 class TestCanLoadMisc(_GpuCacheResetMixin, unittest.TestCase):
-    def test_non_cuda_allows(self):
+    def test_non_accelerator_allows(self):
         with patch("utils.hardware.get_device", return_value = DeviceType.MLX):
             ok, info = tv.can_load_chat_during_training(
                 model_name = "m",
@@ -219,7 +336,30 @@ class TestCanLoadMisc(_GpuCacheResetMixin, unittest.TestCase):
                 requested_gpu_ids = None,
             )
         self.assertTrue(ok)
-        self.assertEqual(info["mode"], "non_cuda")
+        self.assertEqual(info["mode"], "non_accelerator")
+
+    def test_xpu_overcommit_is_refused(self):
+        # XPU must NOT get the blanket non-accelerator allow: an oversized
+        # chat model during resident training is refused, like CUDA.
+        with (
+            patch("utils.hardware.get_device", return_value = DeviceType.XPU),
+            patch(
+                "utils.hardware.auto_select_gpu_ids",
+                return_value = (
+                    None,
+                    {"selection_mode": "auto", "required_gb": 50.0, "usable_gb": 4.0},
+                ),
+            ),
+        ):
+            ok, info = tv.can_load_chat_during_training(
+                model_name = "m",
+                hf_token = None,
+                load_in_4bit = True,
+                max_seq_length = 0,
+                requested_gpu_ids = None,
+            )
+        self.assertFalse(ok)
+        self.assertNotEqual(info.get("mode"), "non_accelerator")
 
     def test_no_visible_gpus_refuses(self):
         # GGUF with an empty device list -> no candidate GPU -> default-deny.
@@ -309,6 +449,8 @@ class TestChatLoadGuardRoute(unittest.TestCase):
         captured = None,
         training_active,
         decision,
+        gpu_memory_mode = "auto",
+        requested_gpu_ids = None,
     ):
         config = config or SimpleNamespace(is_gguf = False, is_lora = False, path = None)
         with _stub_guard_deps(
@@ -320,7 +462,8 @@ class TestChatLoadGuardRoute(unittest.TestCase):
                 hf_token = None,
                 load_in_4bit = True,
                 max_seq_length = 0,
-                requested_gpu_ids = None,
+                requested_gpu_ids = requested_gpu_ids,
+                gpu_memory_mode = gpu_memory_mode,
             )
 
     def test_noop_when_training_inactive(self):
@@ -332,6 +475,99 @@ class TestChatLoadGuardRoute(unittest.TestCase):
     def test_allows_when_fits(self):
         self._guard(training_active = True, decision = (True, {"mode": "auto"}))
 
+    def test_diffusion_detection_uses_name_before_download(self):
+        config = SimpleNamespace(
+            identifier = "unsloth/DiffusionGemma-GGUF",
+            gguf_hf_repo = "unsloth/DiffusionGemma-GGUF",
+            gguf_file = None,
+        )
+        self.assertTrue(self.route._classify_diffusion_gguf(config))
+
+    def test_uncached_gguf_classification_remains_unknown(self):
+        config = SimpleNamespace(
+            identifier = "owner/renamed-model",
+            gguf_hf_repo = "owner/renamed-model",
+            gguf_variant = "Q4_K_M",
+            gguf_file = None,
+        )
+        self.assertIsNone(self.route._classify_diffusion_gguf(config))
+
+    def test_diffusion_detection_reuses_loader_metadata_probe(self):
+        import tempfile
+
+        seen = []
+
+        class _Probe:
+            is_diffusion = False
+            _architecture = None
+
+            def _read_gguf_metadata(self, path):
+                seen.append(path)
+                self.is_diffusion = True
+
+        with tempfile.TemporaryDirectory() as d:
+            model = Path(d) / "renamed.gguf"
+            model.write_bytes(b"GGUF")
+            config = SimpleNamespace(identifier = "local", gguf_file = str(model))
+            with patch.object(self.route, "LlamaCppBackend", _Probe):
+                self.assertTrue(self.route._classify_diffusion_gguf(config))
+        self.assertEqual(seen, [str(model)])
+
+    def test_local_chat_gguf_classification_is_definitive(self):
+        import tempfile
+        class _Probe:
+            is_diffusion = False
+            _architecture = "llama"
+
+            def _read_gguf_metadata(self, _path):
+                pass
+
+        with tempfile.TemporaryDirectory() as d:
+            model = Path(d) / "renamed.gguf"
+            model.write_bytes(b"GGUF")
+            config = SimpleNamespace(identifier = "local", gguf_file = str(model))
+            with patch.object(self.route, "LlamaCppBackend", _Probe):
+                self.assertFalse(self.route._classify_diffusion_gguf(config))
+
+    def test_manual_known_normal_gguf_bypasses_training_estimate(self):
+        captured = []
+        config = SimpleNamespace(is_gguf = True)
+        with patch.object(self.route, "_classify_diffusion_gguf", return_value = False) as classify:
+            self._guard(
+                config = config,
+                captured = captured,
+                training_active = True,
+                decision = (False, {"reason": "must not run"}),
+                gpu_memory_mode = "manual",
+                requested_gpu_ids = [1, 3],
+            )
+        classify.assert_called_once_with(config)
+        self.assertEqual(captured, [])
+
+    def test_manual_diffusion_keeps_single_device_training_guard(self):
+        captured = []
+        config = SimpleNamespace(is_gguf = True)
+        with (
+            patch.object(self.route, "_classify_diffusion_gguf", return_value = True),
+            patch.object(self.route, "_estimate_gguf_required_gb", return_value = 12.5),
+            patch.object(
+                self.route.LlamaCppBackend,
+                "_effective_gpu_count",
+                return_value = 2,
+            ),
+        ):
+            self._guard(
+                config = config,
+                captured = captured,
+                training_active = True,
+                decision = (True, {"mode": "single_device"}),
+                gpu_memory_mode = "manual",
+                requested_gpu_ids = [3, 1],
+            )
+        self.assertEqual(len(captured), 1)
+        self.assertEqual(captured[0]["single_device_gpu"], "1")
+        self.assertEqual(captured[0]["requested_gpu_ids"], [3, 1])
+
     def test_refuses_with_headroom_number(self):
         info = {"required_gb": 30.0, "usable_gb": 6.0, "needed_gb": 39.0, "mode": "auto"}
         with self.assertRaises(HTTPException) as exc:
@@ -467,36 +703,189 @@ class TestValidateRefusesDuringTraining(unittest.TestCase):
         self.assertEqual(captured[0]["load_in_4bit"], False)
         self.assertEqual(captured[0]["max_seq_length"], 4096)
 
-    def test_rejects_gguf_with_gpu_ids_before_guard(self):
-        # /validate must mirror /load's GGUF + gpu_ids 400, before the VRAM guard.
+    def test_validate_forwards_manual_gpu_memory_mode_to_guard(self):
         from models.inference import ValidateModelRequest
 
-        request = ValidateModelRequest(model_path = "x.gguf", gpu_ids = [0])
+        request = ValidateModelRequest(
+            model_path = "unsloth/model-GGUF",
+            gguf_variant = "Q4_K_M",
+            gpu_memory_mode = "manual",
+        )
         cfg = SimpleNamespace(
-            identifier = "x.gguf",
-            display_name = "x",
+            identifier = "unsloth/model-GGUF",
+            display_name = "model-GGUF",
             is_gguf = True,
             is_lora = False,
             is_vision = False,
             path = None,
             base_model = None,
         )
-        captured = []
+        captured = {}
         with (
             patch.object(
                 self.route,
                 "_resolve_model_identifier_for_request",
-                return_value = ("x.gguf", "x.gguf", False),
+                return_value = ("unsloth/model-GGUF", "unsloth/model-GGUF", False),
             ),
             patch.object(self.route.ModelConfig, "from_identifier", return_value = cfg),
             patch.object(self.route, "load_inference_config", return_value = {}),
-            _stub_guard_deps(training_active = True, decision = (True, {}), captured = captured),
+            patch.object(
+                self.route,
+                "_guard_chat_load_against_training",
+                lambda config, **kw: captured.update(kw),
+            ),
         ):
-            with self.assertRaises(HTTPException) as exc:
-                asyncio.run(self.route.validate_model(request, current_subject = "u"))
-        self.assertEqual(exc.exception.status_code, 400)
-        self.assertIn("gpu_ids is not supported for GGUF", exc.exception.detail)
-        self.assertEqual(captured, [])  # guard never reached
+            asyncio.run(self.route.validate_model(request, current_subject = "u"))
+        self.assertEqual(captured.get("gpu_memory_mode"), "manual")
+
+    def test_validate_forwards_inherited_extras_and_parallel_to_guard(self):
+        # Regression: /load resolves inherited same-model extras and passes the
+        # real slot count to the guard; validate must do the same, else it sizes
+        # a smaller estimate (no inherited -c/--model-draft, n_parallel=1) and
+        # /load then 409s after the frontend has already unloaded.
+        from models.inference import ValidateModelRequest
+
+        request = ValidateModelRequest(model_path = "unsloth/Qwen3-1.7B", max_seq_length = 4096)
+        cfg = SimpleNamespace(
+            identifier = "unsloth/Qwen3-1.7B",
+            display_name = "Qwen3-1.7B",
+            is_gguf = False,
+            is_lora = False,
+            is_vision = False,
+            path = None,
+            base_model = None,
+        )
+        captured = {}
+        with (
+            patch.object(
+                self.route,
+                "_resolve_model_identifier_for_request",
+                return_value = ("unsloth/Qwen3-1.7B", "unsloth/Qwen3-1.7B", False),
+            ),
+            patch.object(self.route.ModelConfig, "from_identifier", return_value = cfg),
+            patch.object(self.route, "load_inference_config", return_value = {}),
+            patch.object(self.route, "_resolve_inherited_extra_args", return_value = ["-c", "32768"]),
+            patch.object(
+                self.route,
+                "_guard_chat_load_against_training",
+                lambda config, **kw: captured.update(kw),
+            ),
+        ):
+            asyncio.run(self.route.validate_model(request, current_subject = "u"))
+        self.assertEqual(captured.get("llama_extra_args"), ["-c", "32768"])
+        self.assertIn("n_parallel", captured)
+
+    def test_metadata_probe_skips_training_guard(self):
+        # A header-only probe (include_context_length) allocates no VRAM, so the
+        # training guard must not run -- else the staging GPU-layers / MoE sliders
+        # it feeds are hidden exactly when a during-training user needs them.
+        from models.inference import ValidateModelRequest
+
+        request = ValidateModelRequest(
+            model_path = "unsloth/Qwen3-1.7B",
+            max_seq_length = 4096,
+            include_context_length = True,
+        )
+        cfg = SimpleNamespace(
+            identifier = "unsloth/Qwen3-1.7B",
+            display_name = "Qwen3-1.7B",
+            is_gguf = False,
+            is_lora = False,
+            is_vision = False,
+            path = None,
+            base_model = None,
+        )
+        guard_called = []
+        with (
+            patch.object(
+                self.route,
+                "_resolve_model_identifier_for_request",
+                return_value = ("unsloth/Qwen3-1.7B", "unsloth/Qwen3-1.7B", False),
+            ),
+            patch.object(self.route.ModelConfig, "from_identifier", return_value = cfg),
+            patch.object(self.route, "load_inference_config", return_value = {}),
+            patch.object(
+                self.route,
+                "_guard_chat_load_against_training",
+                lambda *a, **kw: guard_called.append(True),
+            ),
+        ):
+            asyncio.run(self.route.validate_model(request, current_subject = "u"))
+        self.assertEqual(guard_called, [])
+
+    def _validate_gguf_template(
+        self,
+        *,
+        template,
+        canonical_path = "/picked/model.gguf",
+    ):
+        # Drive validate_model for a native lease-backed GGUF template probe and
+        # capture what the embedded-template reader was called with.
+        from models.inference import ValidateModelRequest
+
+        request = ValidateModelRequest(
+            model_path = "model.gguf",
+            gguf_variant = "Q4_K_M",
+            native_path_lease = "signed-lease",
+            include_chat_template = True,
+        )
+        cfg = SimpleNamespace(
+            identifier = canonical_path,
+            display_name = "model.gguf",
+            is_gguf = True,
+            is_lora = False,
+            is_vision = False,
+            gguf_file = canonical_path,
+            path = None,
+            base_model = None,
+        )
+        import utils.models.gguf_metadata as gguf_meta
+
+        seen = {}
+
+        def _fake_read(path):
+            seen["path"] = path
+            return template
+
+        guard_called = []
+        with (
+            patch.object(
+                self.route,
+                "_resolve_model_identifier_for_request",
+                return_value = (canonical_path, "model.gguf", True),
+            ),
+            patch.object(self.route.ModelConfig, "from_identifier", return_value = cfg),
+            patch.object(self.route, "load_inference_config", return_value = {}),
+            patch.object(gguf_meta, "read_gguf_chat_template", _fake_read),
+            patch.object(
+                self.route,
+                "_guard_chat_load_against_training",
+                lambda *a, **kw: guard_called.append(True),
+            ),
+        ):
+            resp = asyncio.run(self.route.validate_model(request, current_subject = "u"))
+        return resp, seen, guard_called
+
+    def test_include_chat_template_reads_leased_gguf_embedded_template(self):
+        # The picker chat-template GET has no lease plumbing, so a native picked
+        # GGUF surfaces its default template through this lease-aware probe: the
+        # embedded template is read from the granted canonical path and returned.
+        resp, seen, _ = self._validate_gguf_template(template = "{{ messages }}")
+        self.assertEqual(resp.chat_template, "{{ messages }}")
+        # Read strictly the leased file's own embedded template, never a sibling
+        # sidecar: the grant authorizes just this one path.
+        self.assertEqual(seen["path"], "/picked/model.gguf")
+
+    def test_include_chat_template_skips_training_guard(self):
+        # A template-only probe allocates no VRAM, so like include_context_length
+        # it must not be refused by the training guard.
+        _, _, guard_called = self._validate_gguf_template(template = "{{ messages }}")
+        self.assertEqual(guard_called, [])
+
+    def test_include_chat_template_over_cap_is_dropped(self):
+        from picker.schemas import MAX_CHAT_TEMPLATE_BYTES
+        resp, _, _ = self._validate_gguf_template(template = "a" * (MAX_CHAT_TEMPLATE_BYTES + 1))
+        self.assertIsNone(resp.chat_template)
 
 
 # ── _estimate_gguf_required_gb (sizes the same weights the loader loads) ──────
diff --git a/studio/backend/tests/test_cloudflare_tunnel.py b/studio/backend/tests/test_cloudflare_tunnel.py
index bb51cabf76..2094d15066 100644
--- a/studio/backend/tests/test_cloudflare_tunnel.py
+++ b/studio/backend/tests/test_cloudflare_tunnel.py
@@ -403,11 +403,234 @@ def test_reader_ignores_api_endpoint_failure_line():
     assert t.error == "cloudflared exited before emitting a tunnel URL"
 
 
+# ── public reachability probe ────────────────────────────────────────
+
+
+class _FakeResponse:
+    def __init__(self, body):
+        self._body = body
+
+    def read(self, size = -1):
+        return self._body
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *exc):
+        return False
+
+
+def _patch_urlopen(monkeypatch, handler):
+    import urllib.request
+    monkeypatch.setattr(urllib.request, "urlopen", lambda req, timeout = None: handler(req))
+
+
+@pytest.fixture(autouse = True)
+def _stub_dns_wait(monkeypatch, request):
+    if request.node.name.startswith("test_verify_public_url"):
+        monkeypatch.setattr(ct, "_wait_for_dns", lambda *a, **kw: None)
+
+
+def test_wait_for_dns_polls_until_answer(monkeypatch):
+    calls = []
+
+    def handler(req):
+        calls.append(req.full_url)
+        if len(calls) < 3:
+            return _FakeResponse(b'{"Status":3}')
+        return _FakeResponse(b'{"Status":0,"Answer":[{"data":"104.16.0.1"}]}')
+
+    _patch_urlopen(monkeypatch, handler)
+    monkeypatch.setattr(ct.time, "sleep", lambda _s: None)
+    ct._wait_for_dns("words.trycloudflare.com", ct.time.monotonic() + 5)
+    assert len(calls) == 3
+    assert "name=words.trycloudflare.com" in calls[0]
+
+
+def test_wait_for_dns_gives_up_at_deadline(monkeypatch):
+    _patch_urlopen(monkeypatch, lambda req: _FakeResponse(b'{"Status":3}'))
+    monkeypatch.setattr(ct.time, "sleep", lambda _s: None)
+    ct._wait_for_dns("words.trycloudflare.com", ct.time.monotonic() + 0.05)
+
+
+def test_wait_for_dns_retries_transient_doh_error(monkeypatch):
+    calls = []
+
+    def handler(req):
+        calls.append(req.full_url)
+        if len(calls) < 3:
+            raise OSError("transient")
+        return _FakeResponse(b'{"Status":0,"Answer":[{"data":"104.16.0.1"}]}')
+
+    _patch_urlopen(monkeypatch, handler)
+    monkeypatch.setattr(ct.time, "sleep", lambda _s: None)
+    ct._wait_for_dns("words.trycloudflare.com", ct.time.monotonic() + 5)
+    assert len(calls) == 3
+
+
+def test_wait_for_dns_bails_on_persistent_doh_errors(monkeypatch):
+    calls = []
+
+    def handler(req):
+        calls.append(req.full_url)
+        raise OSError("blocked")
+
+    _patch_urlopen(monkeypatch, handler)
+    monkeypatch.setattr(ct.time, "sleep", lambda _s: None)
+    ct._wait_for_dns("words.trycloudflare.com", ct.time.monotonic() + 5)
+    assert len(calls) == ct._DNS_MAX_DOH_ERRORS
+
+
+def test_verify_public_url_accepts_studio_marker(monkeypatch):
+    seen = {}
+
+    def handler(req):
+        seen["url"] = req.full_url
+        return _FakeResponse(b'{"status":"healthy","service":"Unsloth UI Backend"}')
+
+    _patch_urlopen(monkeypatch, handler)
+    assert ct.verify_public_url("https://words.trycloudflare.com") is True
+    assert seen["url"] == "https://words.trycloudflare.com/api/health"
+
+
+def test_verify_public_url_waits_for_dns_first(monkeypatch):
+    order = []
+    monkeypatch.setattr(ct, "_wait_for_dns", lambda host, deadline: order.append(("dns", host)))
+
+    def handler(req):
+        order.append(("probe", req.full_url))
+        return _FakeResponse(b'{"service":"Unsloth UI Backend"}')
+
+    _patch_urlopen(monkeypatch, handler)
+    assert ct.verify_public_url("https://words.trycloudflare.com") is True
+    assert order[0] == ("dns", "words.trycloudflare.com")
+    assert order[1][0] == "probe"
+
+
+def test_verify_public_url_dns_wait_and_probe_share_deadline(monkeypatch):
+    # An exhausted DNS wait leaves the probe a single attempt, not a fresh window.
+    calls = []
+    monkeypatch.setattr(ct, "_wait_for_dns", lambda host, deadline: None)
+
+    def handler(req):
+        calls.append(req.full_url)
+        raise OSError("unreachable")
+
+    _patch_urlopen(monkeypatch, handler)
+    assert ct.verify_public_url("https://words.trycloudflare.com", timeout = 0) is False
+    assert len(calls) == 1
+
+
+def test_verify_public_url_retries_then_succeeds(monkeypatch):
+    calls = []
+
+    def handler(req):
+        calls.append(req.full_url)
+        if len(calls) < 3:
+            raise OSError("Name or service not known")
+        return _FakeResponse(b'{"service":"Unsloth UI Backend"}')
+
+    _patch_urlopen(monkeypatch, handler)
+    monkeypatch.setattr(ct.time, "sleep", lambda _s: None)
+    assert ct.verify_public_url("https://words.trycloudflare.com") is True
+    assert len(calls) == 3
+
+
+def test_verify_public_url_rejects_unreachable_host(monkeypatch):
+    def handler(req):
+        raise OSError("Name or service not known")
+
+    _patch_urlopen(monkeypatch, handler)
+    monkeypatch.setattr(ct.time, "sleep", lambda _s: None)
+    assert ct.verify_public_url("https://words.trycloudflare.com", timeout = 0.05) is False
+
+
+def test_verify_public_url_rejects_foreign_responder(monkeypatch):
+    # e.g. a Cloudflare error page: no service marker in the body.
+    _patch_urlopen(monkeypatch, lambda req: _FakeResponse(b"<html>error 1033</html>"))
+    monkeypatch.setattr(ct.time, "sleep", lambda _s: None)
+    assert ct.verify_public_url("https://words.trycloudflare.com", timeout = 0.05) is False
+
+
+@pytest.fixture(autouse = True)
+def _stub_public_probe(monkeypatch, request):
+    # start_studio_tunnel tests use fake hostnames; keep them off the network.
+    if not request.node.name.startswith("test_start_studio_tunnel"):
+        return
+    monkeypatch.setattr(ct, "verify_public_url", lambda url, **kw: True)
+
+
 def test_start_studio_tunnel_no_binary(monkeypatch):
     monkeypatch.setattr(ct, "ensure_cloudflared", lambda: None)
     assert ct.start_studio_tunnel(8080) is None
 
 
+def test_start_studio_tunnel_drops_url_that_is_not_publicly_reachable(monkeypatch):
+    attempts = []
+
+    class _Stub:
+        def __init__(
+            self,
+            port,
+            binary,
+            protocol = None,
+        ):
+            self.url = None
+            attempts.append(protocol)
+
+        def start(self):
+            self.url = "https://words.trycloudflare.com"
+
+        def wait_for_ready(self, timeout):
+            return self.url
+
+        def stop(self):
+            pass
+
+    monkeypatch.setattr(ct, "ensure_cloudflared", lambda: "/bin/cloudflared")
+    monkeypatch.setattr(ct, "CloudflareTunnel", _Stub)
+    monkeypatch.setattr(ct, "verify_public_url", lambda url, **kw: False)
+    assert ct.start_studio_tunnel(8080) is None
+    assert attempts == [None]
+    assert ct._active_tunnel is None
+
+
+def test_start_studio_tunnel_returns_url_once_probe_passes(monkeypatch):
+    probed = []
+
+    class _Stub:
+        def __init__(
+            self,
+            port,
+            binary,
+            protocol = None,
+        ):
+            self.url = None
+            self.protocol = protocol
+
+        def start(self):
+            self.url = "https://words.trycloudflare.com"
+
+        def wait_for_ready(self, timeout):
+            return self.url
+
+        def stop(self):
+            pass
+
+    def _probe(url, **kw):
+        probed.append(url)
+        return True
+
+    monkeypatch.setattr(ct, "ensure_cloudflared", lambda: "/bin/cloudflared")
+    monkeypatch.setattr(ct, "CloudflareTunnel", _Stub)
+    monkeypatch.setattr(ct, "verify_public_url", _probe)
+    try:
+        assert ct.start_studio_tunnel(8080) == "https://words.trycloudflare.com"
+        assert probed == ["https://words.trycloudflare.com"]
+    finally:
+        ct.stop_studio_tunnel()
+
+
 def test_start_studio_tunnel_registers_before_wait(monkeypatch):
     # The tunnel must be visible to stop_studio_tunnel() during the readiness
     # wait, else a shutdown in that window orphans cloudflared.
diff --git a/studio/backend/tests/test_colab_embed.py b/studio/backend/tests/test_colab_embed.py
new file mode 100644
index 0000000000..dae0c7dae0
--- /dev/null
+++ b/studio/backend/tests/test_colab_embed.py
@@ -0,0 +1,479 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Regression coverage for Colab iframe embedding (#7344)."""
+
+import sys
+import types
+from types import SimpleNamespace
+from unittest.mock import MagicMock, patch
+
+import colab
+
+
+def _mock_google_colab_modules(colab_mod):
+    """Mock ``google`` and ``google.colab`` for environments without Google packages."""
+    google_mod = types.ModuleType("google")
+    google_mod.colab = colab_mod
+    return {"google": google_mod, "google.colab": colab_mod}
+
+
+def test_short_colab_url_truncates_proxy_host():
+    url = "https://8888-gpu-a100-s-kkb-usc1f0-9hzedjcxrlu8-f.us-central1-0.prod.colab.dev/"
+    assert colab._short_colab_url(url, 8888) == "https://8888-gpu-..."
+
+
+def test_short_colab_url_falls_back_on_unexpected_shape():
+    assert colab._short_colab_url("https://example.com", 8888) == "https://example.com"
+
+
+def test_is_colab_proxy_url_requires_https_proxy():
+    assert colab._is_colab_proxy_url("https://8888-test.prod.colab.dev/", 8888) is True
+    assert colab._is_colab_proxy_url("http://localhost:8888", 8888) is False
+    assert colab._is_colab_proxy_url("http://127.0.0.1:8888", 8888) is False
+
+
+def test_ready_card_html_does_not_open_colab_proxy_in_new_tab():
+    """Colab proxy hosts 404 as top-level tabs (#7349 reporter); never window.open them."""
+    html = colab._ready_card_html("https://8888-test.prod.colab.dev/", 8888)
+    assert "window.open" not in html
+    assert 'href="https://8888-test.prod.colab.dev/"' not in html
+    assert "start(cloudflare=True)" in html
+
+
+def test_ready_card_html_points_to_cloudflare_when_link_ready(monkeypatch):
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    html = colab._ready_card_html(
+        "https://8888-test.prod.colab.dev/",
+        8888,
+        has_cloudflare_link = True,
+    )
+    assert "Cloudflare link above" in html
+
+
+def test_ready_card_html_warns_when_cloudflare_tunnel_missing(monkeypatch):
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    html = colab._ready_card_html(
+        "https://8888-test.prod.colab.dev/",
+        8888,
+        cloudflare_requested = True,
+    )
+    assert "Could not open a Cloudflare tunnel" in html
+
+
+def test_warn_colab_cloudflare_missing_logs_on_colab_without_tunnel(monkeypatch):
+    warnings: list[str] = []
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    monkeypatch.setattr(colab.logger, "warning", lambda msg, **kwargs: warnings.append(msg))
+    colab._warn_colab_cloudflare_missing(use_cloudflare = True, cloudflare_url = None)
+    assert warnings
+    assert "Cloudflare tunnel unavailable" in warnings[0]
+
+
+def test_warn_colab_cloudflare_missing_skips_when_tunnel_ready(monkeypatch, caplog):
+    import logging
+
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    with caplog.at_level(logging.WARNING):
+        colab._warn_colab_cloudflare_missing(
+            use_cloudflare = True,
+            cloudflare_url = "https://share.trycloudflare.com",
+        )
+    assert "Cloudflare tunnel unavailable" not in caplog.text
+
+
+def test_is_colab_runtime_uses_backend_colab_detector(monkeypatch):
+    fake_main = types.ModuleType("main")
+    fake_main._IS_COLAB = True
+    monkeypatch.setitem(sys.modules, "main", fake_main)
+    assert colab._is_colab_runtime() is True
+    fake_main._IS_COLAB = False
+    assert colab._is_colab_runtime() is False
+
+
+def test_ready_card_html_uses_cloudflare_hint_on_colab_runtime_localhost(monkeypatch):
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    html = colab._ready_card_html("http://localhost:8888", 8888)
+    assert "window.open" not in html
+    assert "start(cloudflare=True)" in html
+
+
+def test_ready_card_html_keeps_open_button_for_localhost_outside_colab(monkeypatch):
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: False)
+    html = colab._ready_card_html("http://localhost:8888", 8888)
+    assert "window.open" in html
+    assert 'href="http://localhost:8888"' in html
+    assert "Open Unsloth Studio" in html
+
+
+def test_embed_kernel_port_iframe_uses_colab_helper(monkeypatch):
+    colab_output = MagicMock()
+    google_colab = SimpleNamespace(output = colab_output)
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    with patch.dict("sys.modules", _mock_google_colab_modules(google_colab)):
+        assert colab._embed_kernel_port_iframe(8888) is True
+    colab_output.serve_kernel_port_as_iframe.assert_called_once_with(
+        8888,
+        height = colab._COLAB_IFRAME_HEIGHT,
+        width = "100%",
+    )
+
+
+def test_embed_kernel_port_iframe_returns_false_without_colab():
+    with patch.dict("sys.modules", _mock_google_colab_modules(None)):
+        assert colab._embed_kernel_port_iframe(8888) is False
+
+
+def test_embed_kernel_port_iframe_skips_colabtools_without_runtime(monkeypatch):
+    """colabtools can queue JS without appending an iframe; only trust the helper on Colab."""
+    colab_output = MagicMock()
+    google_colab = SimpleNamespace(output = colab_output)
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: False)
+    with patch.dict("sys.modules", _mock_google_colab_modules(google_colab)):
+        assert colab._embed_kernel_port_iframe(8888) is False
+    colab_output.serve_kernel_port_as_iframe.assert_not_called()
+
+
+def test_show_and_embed_prefers_kernel_port_iframe(monkeypatch):
+    calls: list[str] = []
+
+    monkeypatch.setattr(colab, "get_colab_url", lambda port: f"https://{port}-test.prod.colab.dev/")
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    monkeypatch.setattr(
+        colab,
+        "show_link",
+        lambda port,
+        *,
+        _url = None,
+        has_cloudflare_link = False,
+        cloudflare_requested = False: calls.append("show_link"),
+    )
+    monkeypatch.setattr(
+        colab,
+        "_embed_kernel_port_iframe",
+        lambda port: calls.append("kernel_iframe") or True,
+    )
+    monkeypatch.setattr(
+        colab,
+        "_embed_html_iframe",
+        lambda url, port: calls.append("html_iframe") or True,
+    )
+
+    colab._show_and_embed(8888)
+
+    assert calls == ["show_link", "kernel_iframe"]
+
+
+def test_show_and_embed_falls_back_to_html_iframe(monkeypatch):
+    calls: list[str] = []
+
+    monkeypatch.setattr(colab, "get_colab_url", lambda port: f"https://{port}-test.prod.colab.dev/")
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: False)
+    monkeypatch.setattr(
+        colab,
+        "show_link",
+        lambda port, *, _url = None, has_cloudflare_link = False: None,
+    )
+    monkeypatch.setattr(colab, "_embed_kernel_port_iframe", lambda port: False)
+    monkeypatch.setattr(
+        colab,
+        "_embed_html_iframe",
+        lambda url, port: calls.append((url, port)) or True,
+    )
+
+    colab._show_and_embed(8888)
+
+    assert calls == [("https://8888-test.prod.colab.dev/", 8888)]
+
+
+def test_colab_wants_cloudflare_auto_enables_on_runtime(monkeypatch):
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    assert colab._colab_wants_cloudflare(None) is True
+    assert colab._colab_wants_cloudflare(True) is True
+    assert colab._colab_wants_cloudflare(False) is False
+
+
+def test_colab_wants_cloudflare_defaults_off_outside_runtime(monkeypatch):
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: False)
+    assert colab._colab_wants_cloudflare(None) is False
+    assert colab._colab_wants_cloudflare(True) is True
+
+
+def test_finalize_colab_admin_password_skips_outside_runtime(monkeypatch):
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: False)
+    assert colab._finalize_colab_admin_password() is None
+
+
+def test_finalize_colab_admin_password_clears_bootstrap_gate(monkeypatch):
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    monkeypatch.setattr(colab, "_load_colab_login_credentials", lambda: None)
+    stored: list[tuple[str, str]] = []
+    monkeypatch.setattr(
+        colab,
+        "_store_colab_login_credentials",
+        lambda username, password: stored.append((username, password)),
+    )
+
+    storage = SimpleNamespace(
+        DEFAULT_ADMIN_USERNAME = "unsloth",
+        ensure_default_admin = MagicMock(),
+        get_bootstrap_password = MagicMock(return_value = "alpha-beta-gamma"),
+        generate_bootstrap_password = MagicMock(return_value = "alpha-beta-gamma"),
+        requires_password_change = MagicMock(return_value = True),
+        update_password = MagicMock(return_value = True),
+    )
+    auth_pkg = types.ModuleType("auth")
+    auth_pkg.storage = storage
+    with patch.dict("sys.modules", {"auth": auth_pkg, "auth.storage": storage}):
+        result = colab._finalize_colab_admin_password()
+
+    assert result == ("unsloth", "alpha-beta-gamma")
+    storage.ensure_default_admin.assert_called_once()
+    storage.update_password.assert_called_once_with("unsloth", "alpha-beta-gamma")
+    assert stored == [("unsloth", "alpha-beta-gamma")]
+
+
+def test_start_skips_finalize_when_cloudflare_disabled(monkeypatch):
+    import time
+
+    finalize_calls: list[str] = []
+    monkeypatch.setattr(colab, "_is_studio_healthy", lambda port: True)
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    monkeypatch.setattr(
+        colab,
+        "_finalize_colab_admin_password",
+        lambda: finalize_calls.append("finalize") or ("unsloth", "secret"),
+    )
+    monkeypatch.setattr(
+        colab, "start_cloudflare_tunnel", lambda port: "https://share.trycloudflare.com"
+    )
+    monkeypatch.setattr(colab, "_publish_cloudflare_url", lambda url: None)
+    monkeypatch.setattr(colab, "_show_and_embed", lambda port, **kwargs: None)
+    monkeypatch.setattr(colab, "_stop_cloudflare_tunnel", lambda: None)
+    monkeypatch.setattr(time, "sleep", lambda _: (_ for _ in ()).throw(KeyboardInterrupt))
+
+    colab.start(cloudflare = False)
+
+    assert finalize_calls == []
+
+
+def test_finalize_colab_admin_password_redisplay_on_rerun(monkeypatch):
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    monkeypatch.setattr(
+        colab,
+        "_load_colab_login_credentials",
+        lambda: ("unsloth", "saved-pass"),
+    )
+    monkeypatch.setattr(colab, "_colab_credentials_still_valid", lambda username, password: True)
+
+    storage = SimpleNamespace(
+        DEFAULT_ADMIN_USERNAME = "unsloth",
+        ensure_default_admin = MagicMock(),
+        get_bootstrap_password = MagicMock(),
+        generate_bootstrap_password = MagicMock(),
+        requires_password_change = MagicMock(return_value = False),
+        update_password = MagicMock(),
+    )
+    auth_pkg = types.ModuleType("auth")
+    auth_pkg.storage = storage
+    with patch.dict("sys.modules", {"auth": auth_pkg, "auth.storage": storage}):
+        result = colab._finalize_colab_admin_password()
+
+    assert result == ("unsloth", "saved-pass")
+    storage.update_password.assert_not_called()
+
+
+def test_finalize_colab_admin_password_drops_stale_cached_credentials(monkeypatch):
+    """After an in-app password change the cached first-run password no longer
+    authenticates, so it must not be redisplayed (#7349 Codex review)."""
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    monkeypatch.setattr(
+        colab,
+        "_load_colab_login_credentials",
+        lambda: ("unsloth", "stale-pass"),
+    )
+    monkeypatch.setattr(colab, "_colab_credentials_still_valid", lambda username, password: False)
+    cleared: list[bool] = []
+    monkeypatch.setattr(colab, "_clear_colab_login_credentials", lambda: cleared.append(True))
+
+    storage = SimpleNamespace(
+        DEFAULT_ADMIN_USERNAME = "unsloth",
+        ensure_default_admin = MagicMock(),
+        get_bootstrap_password = MagicMock(),
+        generate_bootstrap_password = MagicMock(),
+        requires_password_change = MagicMock(return_value = False),
+        update_password = MagicMock(),
+    )
+    auth_pkg = types.ModuleType("auth")
+    auth_pkg.storage = storage
+    with patch.dict("sys.modules", {"auth": auth_pkg, "auth.storage": storage}):
+        result = colab._finalize_colab_admin_password()
+
+    assert result is None
+    assert cleared == [True]
+    storage.update_password.assert_not_called()
+
+
+def test_colab_credentials_still_valid_matches_stored_hash(monkeypatch):
+    from auth.hashing import hash_password
+
+    salt, pwd_hash = hash_password("right-pass")
+    storage = SimpleNamespace(
+        get_user_and_secret = MagicMock(return_value = (salt, pwd_hash, "jwt", False)),
+    )
+    with patch.dict("sys.modules", {"auth.storage": storage}):
+        assert colab._colab_credentials_still_valid("unsloth", "right-pass") is True
+        assert colab._colab_credentials_still_valid("unsloth", "wrong-pass") is False
+
+
+def test_colab_credentials_still_valid_false_when_user_missing(monkeypatch):
+    storage = SimpleNamespace(get_user_and_secret = MagicMock(return_value = None))
+    with patch.dict("sys.modules", {"auth.storage": storage}):
+        assert colab._colab_credentials_still_valid("unsloth", "any") is False
+
+
+def test_colab_login_html_includes_credentials():
+    html = colab._colab_login_html("unsloth", "alpha-beta-gamma-delta")
+    assert "unsloth" in html
+    assert "alpha-beta-gamma-delta" in html
+
+
+def test_show_and_embed_renders_cloudflare_before_colab_login(monkeypatch):
+    displayed: list[str] = []
+    ipython_display = SimpleNamespace(
+        HTML = lambda html: SimpleNamespace(html = html),
+        display = lambda html: displayed.append(html.html),
+    )
+
+    monkeypatch.setattr(colab, "get_colab_url", lambda port: "https://8888-test.prod.colab.dev/")
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    monkeypatch.setattr(
+        colab,
+        "show_link",
+        lambda port, *, _url = None, has_cloudflare_link = False, cloudflare_requested = False: None,
+    )
+    monkeypatch.setattr(colab, "_embed_kernel_port_iframe", lambda port: True)
+    with patch.dict("sys.modules", {"IPython.display": ipython_display}):
+        colab._show_and_embed(
+            8888,
+            cloudflare_url = "https://share.trycloudflare.com",
+            colab_login = ("unsloth", "secret-pass"),
+        )
+
+    assert len(displayed) == 2
+    assert "share.trycloudflare.com" in displayed[0]
+    assert "secret-pass" in displayed[1]
+
+
+def test_show_and_embed_skips_iframe_on_colab_when_cloudflare_ready(monkeypatch):
+    calls: list[str] = []
+
+    monkeypatch.setattr(colab, "get_colab_url", lambda port: f"https://{port}-test.prod.colab.dev/")
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    monkeypatch.setattr(
+        colab,
+        "show_link",
+        lambda port, *, _url = None, has_cloudflare_link = False, cloudflare_requested = False: None,
+    )
+    monkeypatch.setattr(
+        colab,
+        "_embed_kernel_port_iframe",
+        lambda port: calls.append("kernel_iframe") or True,
+    )
+    monkeypatch.setattr(
+        colab,
+        "_embed_html_iframe",
+        lambda url, port: calls.append("html_iframe") or True,
+    )
+
+    colab._show_and_embed(8888, cloudflare_url = "https://share.trycloudflare.com")
+
+    assert calls == []
+
+
+def test_show_and_embed_uses_kernel_helper_on_colab_runtime_despite_localhost(monkeypatch):
+    calls: list[str] = []
+
+    monkeypatch.setattr(colab, "get_colab_url", lambda port: f"http://localhost:{port}")
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+
+    monkeypatch.setattr(
+        colab,
+        "show_link",
+        lambda port,
+        *,
+        _url = None,
+        has_cloudflare_link = False,
+        cloudflare_requested = False: calls.append("show_link"),
+    )
+    monkeypatch.setattr(
+        colab,
+        "_embed_kernel_port_iframe",
+        lambda port: calls.append("kernel_iframe") or True,
+    )
+    monkeypatch.setattr(
+        colab,
+        "_embed_html_iframe",
+        lambda url, port: calls.append("html_iframe") or True,
+    )
+
+    colab._show_and_embed(8888)
+
+    assert calls == ["show_link", "kernel_iframe"]
+
+
+def test_show_and_embed_skips_kernel_helper_for_localhost_outside_colab(monkeypatch):
+    calls: list[str] = []
+
+    monkeypatch.setattr(colab, "get_colab_url", lambda port: f"http://localhost:{port}")
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: False)
+
+    monkeypatch.setattr(
+        colab,
+        "show_link",
+        lambda port,
+        *,
+        _url = None,
+        has_cloudflare_link = False,
+        cloudflare_requested = False: calls.append("show_link"),
+    )
+    monkeypatch.setattr(
+        colab,
+        "_embed_kernel_port_iframe",
+        lambda port: calls.append("kernel_iframe") or True,
+    )
+    monkeypatch.setattr(
+        colab,
+        "_embed_html_iframe",
+        lambda url, port: calls.append("html_iframe") or True,
+    )
+
+    colab._show_and_embed(8888)
+
+    assert calls == ["show_link", "html_iframe"]
+
+
+def test_show_and_embed_still_embeds_when_show_link_fails(monkeypatch):
+    calls: list[str] = []
+
+    monkeypatch.setattr(colab, "get_colab_url", lambda port: f"https://{port}-test.prod.colab.dev/")
+    monkeypatch.setattr(colab, "_is_colab_runtime", lambda: True)
+    monkeypatch.setattr(
+        colab,
+        "show_link",
+        lambda port, *, _url = None: (_ for _ in ()).throw(RuntimeError("no display")),
+    )
+    monkeypatch.setattr(
+        colab,
+        "_embed_kernel_port_iframe",
+        lambda port: calls.append("kernel_iframe") or True,
+    )
+    monkeypatch.setattr(
+        colab,
+        "_embed_html_iframe",
+        lambda url, port: calls.append("html_iframe") or True,
+    )
+
+    colab._show_and_embed(8888)
+
+    assert calls == ["kernel_iframe"]
diff --git a/studio/backend/tests/test_combined_update.py b/studio/backend/tests/test_combined_update.py
new file mode 100644
index 0000000000..b96d3d030c
--- /dev/null
+++ b/studio/backend/tests/test_combined_update.py
@@ -0,0 +1,735 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Hermetic tests for the combined llama+whisper update item.
+
+llama.cpp is the single main update item; whisper.cpp piggybacks on it. These
+pin the union status (update_available = llama behind OR whisper behind), the
+chained apply (llama phase first, whisper phase only when behind), the failure
+policy (llama failure aborts; whisper failure keeps the llama partial success),
+the silent whisper skips, and the backward-compatible payload shape.
+"""
+
+from __future__ import annotations
+
+import json
+import sys
+import time
+from pathlib import Path
+
+import pytest
+
+_BACKEND = Path(__file__).resolve().parents[1]
+if str(_BACKEND) not in sys.path:
+    sys.path.insert(0, str(_BACKEND))
+
+import utils.llama_cpp_freshness as freshness  # noqa: E402
+import utils.llama_cpp_update as upd  # noqa: E402
+import utils.whisper_cpp_freshness as wfresh  # noqa: E402
+import utils.whisper_cpp_update as wupd  # noqa: E402
+
+MARKER = "UNSLOTH_PREBUILT_INFO.json"
+WHISPER_MARKER = "UNSLOTH_WHISPER_PREBUILT_INFO.json"
+
+# The top-level status and job fields that predate the whisper piggyback; the
+# combined payload must stay an exact superset so current UI code keeps working.
+LEGACY_STATUS_FIELDS = {
+    "supported",
+    "update_available",
+    "stale",
+    "installed_tag",
+    "latest_tag",
+    "published_repo",
+    "installed_at_utc",
+    "age_days",
+    "source_build",
+    "update_size_bytes",
+    "job",
+}
+LEGACY_JOB_FIELDS = {
+    "state",
+    "message",
+    "from_tag",
+    "to_tag",
+    "reload_required",
+    "error",
+    "progress",
+    "started_at",
+    "finished_at",
+}
+
+
+class _FakeInstallerPopen:
+    """Stands in for the streamed llama installer process."""
+
+    def __init__(
+        self,
+        cmd,
+        *,
+        returncode = 0,
+        lines = None,
+        on_start = None,
+        **kwargs,
+    ):
+        if on_start is not None:
+            on_start(list(cmd))
+        self.returncode = returncode
+        self.stdout = iter(lines or [])
+
+    def wait(self):
+        return self.returncode
+
+    def kill(self):
+        pass
+
+
+def _patch_llama_installer(
+    monkeypatch,
+    *,
+    returncode = 0,
+    lines = None,
+    on_start = None,
+):
+    # Only intercept the installer invocation: importing routes.inference inside
+    # the worker can Popen unrelated host probes (ldconfig etc).
+    def _popen(cmd, **kw):
+        is_installer = any("install_llama_prebuilt" in str(part) for part in cmd)
+        return _FakeInstallerPopen(
+            cmd,
+            returncode = returncode if is_installer else 0,
+            lines = lines if is_installer else None,
+            on_start = on_start if is_installer else None,
+        )
+
+    monkeypatch.setattr(upd.subprocess, "Popen", _popen)
+
+
+def _write_llama_install(dir_: Path, tag: str) -> str:
+    """Create a fake llama prebuilt install and return the llama-server path."""
+    bin_dir = dir_ / "build" / "bin"
+    bin_dir.mkdir(parents = True, exist_ok = True)
+    binary = bin_dir / "llama-server"
+    binary.write_text("stub")
+    (dir_ / MARKER).write_text(
+        json.dumps(
+            {
+                "tag": tag,
+                "release_tag": tag,
+                "published_repo": "unslothai/llama.cpp",
+                "installed_at_utc": "2020-01-01T00:00:00Z",
+            }
+        )
+    )
+    return str(binary)
+
+
+def _write_whisper_install(
+    dir_: Path,
+    tag: str,
+    backend: str = "cpu",
+) -> str:
+    """Create a fake whisper prebuilt install and return the whisper-server path."""
+    bin_dir = dir_ / "build" / "bin"
+    bin_dir.mkdir(parents = True, exist_ok = True)
+    binary = bin_dir / "whisper-server"
+    binary.write_text("stub")
+    (dir_ / WHISPER_MARKER).write_text(
+        json.dumps(
+            {
+                "release_tag": tag,
+                "upstream_tag": tag.split("-")[0],
+                "published_repo": "unslothai/whisper.cpp",
+                "backend": backend,
+                "installed_at_utc": "2020-01-01T00:00:00Z",
+            }
+        )
+    )
+    return str(binary)
+
+
+@pytest.fixture(autouse = True)
+def _clean_state(monkeypatch, tmp_path):
+    freshness.reset_caches()
+    wfresh.reset_caches()
+    upd._reset_job_for_tests()
+    upd._resolve_memo.clear()
+    wupd._resolve_memo.clear()
+    monkeypatch.setattr(freshness, "_cache_dir", lambda: tmp_path / ".llama_cache")
+    monkeypatch.setattr(wfresh, "_cache_dir", lambda: tmp_path / ".whisper_cache")
+    for var in (
+        "LLAMA_SERVER_PATH",
+        "UNSLOTH_LLAMA_CPP_PATH",
+        "WHISPER_SERVER_PATH",
+        "UNSLOTH_WHISPER_CPP_PATH",
+    ):
+        monkeypatch.delenv(var, raising = False)
+    # Never hit the network in these tests.
+    monkeypatch.setattr(freshness, "_fetch_latest_release_tag", lambda repo, timeout = 5.0: None)
+    monkeypatch.setattr(wfresh, "_fetch_latest_release_tag", lambda repo, timeout = 5.0: None)
+    yield
+    freshness.reset_caches()
+    wfresh.reset_caches()
+    upd._reset_job_for_tests()
+    upd._resolve_memo.clear()
+    wupd._resolve_memo.clear()
+
+
+def _setup_llama(
+    monkeypatch,
+    tmp_path,
+    *,
+    installed = "b9493",
+    latest = "b9518",
+):
+    """Marker-managed llama install; behind when installed != latest."""
+    install_dir = tmp_path / "llama.cpp"
+    binary = _write_llama_install(install_dir, installed)
+    monkeypatch.setattr(upd, "_find_binary", lambda: binary)
+    monkeypatch.setattr(upd, "_installer_script", lambda: tmp_path / "install_llama_prebuilt.py")
+    monkeypatch.setattr(freshness, "_fetch_latest_release_tag", lambda repo, timeout = 5.0: latest)
+    return install_dir
+
+
+def _setup_whisper(
+    monkeypatch,
+    tmp_path,
+    *,
+    installed = "v1.9.1-unsloth.1",
+    latest = "v1.9.2-unsloth.1",
+):
+    """Marker-managed whisper install; behind when latest is newer."""
+    install_dir = tmp_path / "whisper.cpp"
+    binary = _write_whisper_install(install_dir, installed)
+    monkeypatch.setattr(wupd, "_find_binary", lambda: binary)
+    monkeypatch.setattr(wupd, "_installer_script", lambda: tmp_path / "install_whisper_prebuilt.py")
+    monkeypatch.setattr(wfresh, "_fetch_latest_release_tag", lambda repo, timeout = 5.0: latest)
+    return install_dir
+
+
+def _patch_whisper_phase(
+    monkeypatch,
+    events,
+    *,
+    to_tag = "v1.9.2-unsloth.1",
+    error = None,
+):
+    """Record whisper phase runs without touching a real installer."""
+
+    def _run(phase, set_progress):
+        events.append("whisper")
+        if error is not None:
+            raise RuntimeError(error)
+        set_progress(0.5)
+        return {
+            "to_tag": to_tag,
+            "reload_required": False,
+            "message": f"Updated whisper.cpp to {to_tag}.",
+        }
+
+    monkeypatch.setattr(wupd, "run_chained_phase", _run)
+
+
+def _wait_for_job():
+    deadline = time.time() + 10
+    while time.time() < deadline:
+        with upd._job_lock:
+            job = dict(upd._job)
+        if job["state"] in ("success", "error"):
+            return job
+        time.sleep(0.05)
+    with upd._job_lock:
+        return dict(upd._job)
+
+
+# --- status: the single item folds whisper in ---
+
+
+def test_status_payload_is_exact_superset_of_legacy_fields(monkeypatch, tmp_path):
+    _setup_llama(monkeypatch, tmp_path)
+    _setup_whisper(monkeypatch, tmp_path)
+    st = upd.get_update_status(force_refresh = True)
+    assert LEGACY_STATUS_FIELDS <= set(st)
+    assert LEGACY_JOB_FIELDS <= set(st["job"])
+    # The new fields ride alongside, never replacing the legacy ones.
+    assert st["llama_update_available"] is True
+    assert st["whisper"]["update_available"] is True
+    assert st["whisper"]["latest_tag"] == "v1.9.2-unsloth.1"
+    assert st["update_component"] == "llama"
+
+
+def test_status_union_whisper_only_surfaces_update(monkeypatch, tmp_path):
+    # llama current, whisper behind: the single item still shows an update.
+    _setup_llama(monkeypatch, tmp_path, installed = "b9518", latest = "b9518")
+    _setup_whisper(monkeypatch, tmp_path)
+    st = upd.get_update_status(force_refresh = True)
+    assert st["llama_update_available"] is False
+    assert st["whisper"]["update_available"] is True
+    assert st["update_available"] is True
+    assert st["update_component"] == "whisper"
+    assert st["installed_tag"] == "b9518"
+    assert st["latest_tag"] == "b9518"
+    assert st["whisper"]["installed_tag"] == "v1.9.1-unsloth.1"
+    assert st["whisper"]["latest_tag"] == "v1.9.2-unsloth.1"
+
+
+def test_status_whisper_current_does_not_flip_union(monkeypatch, tmp_path):
+    _setup_llama(monkeypatch, tmp_path, installed = "b9518", latest = "b9518")
+    _setup_whisper(monkeypatch, tmp_path, installed = "v1.9.2-unsloth.1", latest = "v1.9.2-unsloth.1")
+    st = upd.get_update_status(force_refresh = True)
+    assert st["update_available"] is False
+    assert st["whisper"]["skip_reason"] == "up_to_date"
+    assert st["update_component"] is None
+
+
+def test_status_survives_whisper_probe_failure(monkeypatch, tmp_path):
+    # The piggyback fails open: llama status still works without a whisper probe.
+    _setup_llama(monkeypatch, tmp_path)
+
+    def _boom(*, force_refresh = False):
+        raise RuntimeError("probe exploded")
+
+    monkeypatch.setattr(wupd, "chained_phase_plan", _boom)
+    st = upd.get_update_status(force_refresh = True)
+    assert st["update_available"] is True
+    assert st["whisper"] is None
+
+
+# --- whisper chained_phase_plan: silent skips ---
+
+
+def test_whisper_plan_skips_local_link(monkeypatch, tmp_path):
+    monkeypatch.setattr(wupd, "_find_binary", lambda: str(tmp_path / "whisper-server"))
+    monkeypatch.setattr(wupd, "_active_install_is_local_link", lambda b: True)
+    plan = wupd.chained_phase_plan()
+    assert plan["update_available"] is False
+    assert plan["skip_reason"] == "local_link"
+    assert plan["phase"] is None
+
+
+def test_whisper_plan_skips_source_build(monkeypatch, tmp_path):
+    binary = tmp_path / "whisper.cpp" / "build" / "bin" / "whisper-server"
+    binary.parent.mkdir(parents = True)
+    binary.write_text("stub")  # no marker
+    monkeypatch.setattr(wupd, "_find_binary", lambda: str(binary))
+    plan = wupd.chained_phase_plan()
+    assert plan["skip_reason"] == "source_build"
+    assert plan["phase"] is None
+
+
+def test_whisper_update_targets_canonical_root_when_inner_marker_exists(tmp_path):
+    install_dir = tmp_path / "whisper.cpp"
+    binary = install_dir / "build" / "bin" / "whisper-server"
+    binary.parent.mkdir(parents = True)
+    binary.write_text("stub")
+    (install_dir / WHISPER_MARKER).write_text("{}")
+    (binary.parent / WHISPER_MARKER).write_text("{}")
+    assert wupd._install_dir_for(str(binary)) == install_dir
+
+
+def test_whisper_plan_skips_when_not_installed(monkeypatch):
+    monkeypatch.setattr(wupd, "_find_binary", lambda: None)
+    plan = wupd.chained_phase_plan()
+    assert plan["skip_reason"] == "not_installed"
+    assert plan["phase"] is None
+
+
+def test_whisper_plan_eligible_when_behind(monkeypatch, tmp_path):
+    install_dir = _setup_whisper(monkeypatch, tmp_path)
+    script = tmp_path / "install_whisper_prebuilt.py"
+    script.write_text("stub")
+    plan = wupd.chained_phase_plan(force_refresh = True)
+    assert plan["update_available"] is True
+    assert plan["skip_reason"] is None
+    assert plan["phase"]["install_dir"] == install_dir
+    assert plan["phase"]["repo"] == "unslothai/whisper.cpp"
+    assert plan["phase"]["backend"] == "cpu"
+    # Pin to the exact release the freshness check offered: unpinned, the
+    # installer's download-host /releases/latest pointer can lag published_at
+    # and reinstall an older build in a loop.
+    assert plan["phase"]["pin_release_tag"] == "v1.9.2-unsloth.1"
+
+
+def test_whisper_plan_requires_a_repairable_pair_for_slim_installs(monkeypatch, tmp_path):
+    install_dir = _setup_whisper(monkeypatch, tmp_path)
+    marker_path = install_dir / WHISPER_MARKER
+    marker = json.loads(marker_path.read_text())
+    marker["install_kind"] = "slim"
+    marker_path.write_text(json.dumps(marker))
+    wfresh.reset_caches()
+    monkeypatch.setattr(
+        wupd,
+        "_resolve_prebuilt_for_host",
+        lambda **kwargs: {"prebuilt_available": False},
+    )
+
+    plan = wupd.chained_phase_plan(force_refresh = True)
+    assert plan["update_available"] is False
+    assert plan["skip_reason"] == "paired_llama_unavailable"
+
+    repaired = wupd.chained_phase_plan(
+        force_refresh = True,
+        paired_llama_will_update = True,
+    )
+    assert repaired["update_available"] is True
+    assert repaired["phase"] is not None
+
+
+def test_whisper_phase_pins_installer_to_checked_release(monkeypatch, tmp_path):
+    calls = []
+    monkeypatch.setattr(
+        wupd._flow,
+        "stream_installer",
+        lambda cmd, env, **kw: calls.append(cmd),
+    )
+    monkeypatch.setattr(wupd, "reset_caches", lambda **kw: None)
+    monkeypatch.setattr(wupd, "latest_published_release", lambda repo, **kw: "v9")
+    install_dir = tmp_path / "whisper.cpp"
+    binary = _write_whisper_install(install_dir, "v9")
+    monkeypatch.setattr(wupd, "_find_binary", lambda: binary)
+    wupd.run_chained_phase(
+        {
+            "install_dir": install_dir,
+            "repo": "unslothai/whisper.cpp",
+            "asset": None,
+            "backend": "cpu",
+            "script": tmp_path / "install_whisper_prebuilt.py",
+            "pin_release_tag": "v9",
+        },
+        lambda f: None,
+    )
+    cmd = calls[0]
+    assert "--published-release-tag" in cmd
+    assert cmd[cmd.index("--published-release-tag") + 1] == "v9"
+
+
+def test_whisper_phase_exit_2_is_a_failed_phase(monkeypatch, tmp_path):
+    # No install occurred, so incompatibility must remain an actionable job
+    # error instead of producing a false success toast and hiding the banner.
+    def _raise_exit_2(cmd, env, **kw):
+        raise wupd._flow.InstallerExit(2, "installer exited 2: incompatible release")
+
+    monkeypatch.setattr(wupd._flow, "stream_installer", _raise_exit_2)
+    install_dir = tmp_path / "whisper.cpp"
+    binary = _write_whisper_install(install_dir, "v1")
+    monkeypatch.setattr(wupd, "_find_binary", lambda: binary)
+    with pytest.raises(wupd._flow.InstallerExit) as exc_info:
+        wupd.run_chained_phase(
+            {
+                "install_dir": install_dir,
+                "repo": "unslothai/whisper.cpp",
+                "asset": None,
+                "backend": "cpu",
+                "script": tmp_path / "install_whisper_prebuilt.py",
+                "pin_release_tag": None,
+            },
+            lambda f: None,
+        )
+    assert exc_info.value.returncode == 2
+
+
+def test_llama_update_survives_unavailable_whisper_module(monkeypatch, tmp_path):
+    import builtins
+
+    llama_dir = _setup_llama(monkeypatch, tmp_path)
+    monkeypatch.setattr(upd, "_whisper_chain_status", lambda **kw: None)
+    _patch_llama_installer(
+        monkeypatch,
+        on_start = lambda cmd: _write_llama_install(llama_dir, "b9518"),
+    )
+    real_import = builtins.__import__
+
+    def guarded_import(
+        name,
+        globals = None,
+        locals = None,
+        fromlist = (),
+        level = 0,
+    ):
+        if name == "utils" and "whisper_cpp_update" in fromlist:
+            raise AssertionError("whisper module was re-imported after its failed probe")
+        return real_import(name, globals, locals, fromlist, level)
+
+    monkeypatch.setattr(builtins, "__import__", guarded_import)
+
+    # A failed optional whisper probe must not be followed by an unconditional
+    # import. The valid llama phase still starts and completes.
+    assert upd.start_update()["started"] is True
+    job = _wait_for_job()
+    assert job["state"] == "success", job
+    assert job["phases"]["llama"]["state"] == "success"
+    assert job["phases"]["whisper"]["state"] == "skipped"
+    assert job["phases"]["whisper"]["reason"] == "unavailable"
+
+
+def test_macos_status_uses_compatible_resolver_release(monkeypatch, tmp_path):
+    _setup_whisper(
+        monkeypatch,
+        tmp_path,
+        installed = "v1.9.1-unsloth.1",
+        latest = "v1.9.2-unsloth.1",
+    )
+    monkeypatch.setattr(wupd.sys, "platform", "darwin")
+    monkeypatch.setattr(
+        wupd,
+        "_resolve_prebuilt_for_host",
+        lambda **kw: {
+            "prebuilt_available": True,
+            "release_tag": "v1.9.1-unsloth.1",
+        },
+    )
+
+    status = wupd.get_update_status(force_refresh = True)
+    assert status["latest_tag"] == "v1.9.1-unsloth.1"
+    assert status["update_available"] is False
+    assert status["stale"] is False
+
+
+def test_whisper_phase_integrity_failure_is_not_swallowed(monkeypatch, tmp_path):
+    def _raise_exit_1(cmd, env, **kw):
+        raise wupd._flow.InstallerExit(1, "installer exited 1: checksum mismatch")
+
+    monkeypatch.setattr(wupd._flow, "stream_installer", _raise_exit_1)
+    install_dir = tmp_path / "whisper.cpp"
+    binary = _write_whisper_install(install_dir, "v1")
+    monkeypatch.setattr(wupd, "_find_binary", lambda: binary)
+    with pytest.raises(wupd._flow.InstallerExit, match = "checksum mismatch"):
+        wupd.run_chained_phase(
+            {
+                "install_dir": install_dir,
+                "repo": "unslothai/whisper.cpp",
+                "asset": None,
+                "backend": "cpu",
+                "script": tmp_path / "install_whisper_prebuilt.py",
+                "pin_release_tag": None,
+            },
+            lambda f: None,
+        )
+
+
+# --- apply: the chained job ---
+
+
+def test_apply_runs_llama_then_whisper(monkeypatch, tmp_path):
+    llama_dir = _setup_llama(monkeypatch, tmp_path)
+    _setup_whisper(monkeypatch, tmp_path)
+    (tmp_path / "install_whisper_prebuilt.py").write_text("stub")
+
+    events = []
+    _patch_llama_installer(
+        monkeypatch,
+        on_start = lambda cmd: (events.append("llama"), _write_llama_install(llama_dir, "b9518")),
+    )
+    _patch_whisper_phase(monkeypatch, events)
+
+    res = upd.start_update()
+    assert res["started"] is True, res
+    job = _wait_for_job()
+    assert job["state"] == "success", job
+    assert events == ["llama", "whisper"]  # llama phase strictly first
+    assert job["phases"]["llama"]["state"] == "success"
+    assert job["phases"]["llama"]["to_tag"] == "b9518"
+    assert job["phases"]["whisper"]["state"] == "success"
+    assert job["phases"]["whisper"]["to_tag"] == "v1.9.2-unsloth.1"
+    # Legacy top-level fields keep their llama meaning.
+    assert job["from_tag"] == "b9493"
+    assert job["to_tag"] == "b9518"
+    assert "Updated llama.cpp to b9518." in job["message"]
+    assert "Updated whisper.cpp to v1.9.2-unsloth.1." in job["message"]
+    assert job["progress"] == 1.0
+    assert LEGACY_JOB_FIELDS <= set(job)
+
+
+def test_apply_llama_only_when_whisper_current(monkeypatch, tmp_path):
+    llama_dir = _setup_llama(monkeypatch, tmp_path)
+    _setup_whisper(monkeypatch, tmp_path, installed = "v1.9.2-unsloth.1", latest = "v1.9.2-unsloth.1")
+
+    events = []
+    _patch_llama_installer(
+        monkeypatch,
+        on_start = lambda cmd: (events.append("llama"), _write_llama_install(llama_dir, "b9518")),
+    )
+    _patch_whisper_phase(monkeypatch, events)
+
+    assert upd.start_update()["started"] is True
+    job = _wait_for_job()
+    assert job["state"] == "success", job
+    assert events == ["llama"]
+    assert job["phases"]["whisper"]["state"] == "skipped"
+    assert job["phases"]["whisper"]["reason"] == "up_to_date"
+
+
+def test_apply_whisper_only_noops_llama(monkeypatch, tmp_path):
+    # llama current + whisper behind: the same single apply runs, with the llama
+    # phase a cheap already-matches no-op and the whisper phase doing the work.
+    _setup_llama(monkeypatch, tmp_path, installed = "b9518", latest = "b9518")
+    _setup_whisper(monkeypatch, tmp_path)
+    (tmp_path / "install_whisper_prebuilt.py").write_text("stub")
+
+    events = []
+    _patch_llama_installer(monkeypatch, on_start = lambda cmd: events.append("llama"))
+    _patch_whisper_phase(monkeypatch, events)
+
+    res = upd.start_update()
+    assert res["started"] is True, res
+    job = _wait_for_job()
+    assert job["state"] == "success", job
+    assert events == ["whisper"]  # the llama installer never ran
+    # The legacy job-level to_tag means "llama tag"; a whisper-only round
+    # leaves it unset so the UI never reports a llama update that never ran.
+    assert job["to_tag"] is None
+    assert job["phases"]["llama"]["state"] == "skipped"
+    assert job["phases"]["llama"]["reason"] == "up_to_date"
+    assert job["phases"]["whisper"]["state"] == "success"
+    assert "Updated whisper.cpp to v1.9.2-unsloth.1." in job["message"]
+
+
+def test_whisper_reload_never_raises_job_reload_flag(monkeypatch, tmp_path):
+    # A whisper-only update that had to unload a warm sidecar reports
+    # reload_required on its phase, but the JOB flag stays down: the chat
+    # frontend resyncs (and clears the local checkpoint) off the job flag,
+    # which must mean "the llama server changed", not "the sidecar restarted".
+    _setup_llama(monkeypatch, tmp_path, installed = "b9518", latest = "b9518")
+    _setup_whisper(monkeypatch, tmp_path)
+    (tmp_path / "install_whisper_prebuilt.py").write_text("stub")
+
+    def _whisper_phase(phase, set_progress):
+        return {
+            "to_tag": "v1.9.2-unsloth.1",
+            "reload_required": True,
+            "message": "Updated whisper.cpp to v1.9.2-unsloth.1.",
+        }
+
+    monkeypatch.setattr(wupd, "run_chained_phase", _whisper_phase)
+    assert upd.start_update()["started"] is True
+    job = _wait_for_job()
+    assert job["state"] == "success", job
+    assert job["phases"]["whisper"]["reload_required"] is True
+    assert not job["reload_required"]
+
+
+def test_apply_refuses_when_both_current(monkeypatch, tmp_path):
+    _setup_llama(monkeypatch, tmp_path, installed = "b9518", latest = "b9518")
+    _setup_whisper(monkeypatch, tmp_path, installed = "v1.9.2-unsloth.1", latest = "v1.9.2-unsloth.1")
+    res = upd.start_update()
+    assert res["started"] is False
+    assert res["reason"] == "up_to_date"
+
+
+def test_apply_llama_failure_aborts_before_whisper(monkeypatch, tmp_path):
+    _setup_llama(monkeypatch, tmp_path)
+    _setup_whisper(monkeypatch, tmp_path)
+    (tmp_path / "install_whisper_prebuilt.py").write_text("stub")
+
+    events = []
+    _patch_llama_installer(monkeypatch, returncode = 2, lines = ["boom: disk full\n"])
+    _patch_whisper_phase(monkeypatch, events)
+
+    assert upd.start_update()["started"] is True
+    job = _wait_for_job()
+    assert job["state"] == "error", job
+    assert "boom" in (job["error"] or "")
+    assert events == []  # whisper never attempted
+    assert job["phases"]["llama"]["state"] == "error"
+    assert job["phases"]["whisper"]["state"] == "skipped"
+    assert job["phases"]["whisper"]["reason"] == "aborted"
+    assert job["message"] == "llama.cpp update failed."
+
+
+def test_apply_whisper_failure_keeps_llama_partial_success(monkeypatch, tmp_path):
+    llama_dir = _setup_llama(monkeypatch, tmp_path)
+    _setup_whisper(monkeypatch, tmp_path)
+    (tmp_path / "install_whisper_prebuilt.py").write_text("stub")
+
+    # An active model makes the llama phase report reload_required.
+    import threading
+    from types import ModuleType
+
+    class _FakeBackend:
+        def __init__(self):
+            self._serial_load_lock = threading.Lock()
+            self._llama_update_in_progress = False
+            self.is_active = True
+
+        def unload_model(self):
+            self.is_active = False
+
+    backend = _FakeBackend()
+    routes_pkg = ModuleType("routes")
+    routes_pkg.__path__ = []
+    inference_mod = ModuleType("routes.inference")
+    inference_mod.get_llama_cpp_backend = lambda: backend
+    monkeypatch.setitem(sys.modules, "routes", routes_pkg)
+    monkeypatch.setitem(sys.modules, "routes.inference", inference_mod)
+
+    events = []
+    _patch_llama_installer(
+        monkeypatch,
+        on_start = lambda cmd: (events.append("llama"), _write_llama_install(llama_dir, "b9518")),
+    )
+    _patch_whisper_phase(monkeypatch, events, error = "whisper installer exploded")
+
+    assert upd.start_update()["started"] is True
+    job = _wait_for_job()
+    assert job["state"] == "error", job
+    assert events == ["llama", "whisper"]
+    # The message says both halves: llama landed, whisper did not.
+    assert "Updated llama.cpp to b9518." in job["message"]
+    assert "whisper.cpp update failed." in job["message"]
+    assert "whisper installer exploded" in (job["error"] or "")
+    # The llama phase's reload_required survives the whisper failure.
+    assert job["reload_required"] is True
+    assert job["to_tag"] == "b9518"
+    assert job["phases"]["llama"]["state"] == "success"
+    assert job["phases"]["whisper"]["state"] == "error"
+
+
+def test_apply_skips_whisper_local_link_silently(monkeypatch, tmp_path):
+    llama_dir = _setup_llama(monkeypatch, tmp_path)
+    _setup_whisper(monkeypatch, tmp_path)
+    monkeypatch.setattr(wupd, "_active_install_is_local_link", lambda b: True)
+
+    events = []
+    _patch_llama_installer(
+        monkeypatch,
+        on_start = lambda cmd: (events.append("llama"), _write_llama_install(llama_dir, "b9518")),
+    )
+    _patch_whisper_phase(monkeypatch, events)
+
+    assert upd.start_update()["started"] is True
+    job = _wait_for_job()
+    assert job["state"] == "success", job
+    assert events == ["llama"]
+    assert job["phases"]["whisper"]["state"] == "skipped"
+    assert job["phases"]["whisper"]["reason"] == "local_link"
+    assert job["message"] == "Updated llama.cpp to b9518."
+
+
+def test_chained_progress_windows(monkeypatch, tmp_path):
+    # The llama phase fills roughly the first 0.7 slice and whisper the rest.
+    llama_dir = _setup_llama(monkeypatch, tmp_path)
+    _setup_whisper(monkeypatch, tmp_path)
+    (tmp_path / "install_whisper_prebuilt.py").write_text("stub")
+
+    seen = {}
+
+    def _whisper_phase(phase, set_progress):
+        with upd._job_lock:
+            seen["at_whisper_start"] = upd._job["progress"]
+        set_progress(0.5)
+        with upd._job_lock:
+            seen["mid_whisper"] = upd._job["progress"]
+        return {"to_tag": "v1.9.2-unsloth.1", "reload_required": False, "message": "ok"}
+
+    monkeypatch.setattr(wupd, "run_chained_phase", _whisper_phase)
+    _patch_llama_installer(
+        monkeypatch,
+        lines = ["Downloading app.tar.gz: 100.0% (35.0 MiB/35.0 MiB) at 9.0 MiB/s\n"],
+        on_start = lambda cmd: _write_llama_install(llama_dir, "b9518"),
+    )
+
+    assert upd.start_update()["started"] is True
+    job = _wait_for_job()
+    assert job["state"] == "success", job
+    assert seen["at_whisper_start"] == pytest.approx(0.7)
+    assert seen["mid_whisper"] == pytest.approx(0.7 + 0.5 * 0.3)
+    assert job["progress"] == 1.0
diff --git a/studio/backend/tests/test_compute_buffer.py b/studio/backend/tests/test_compute_buffer.py
index 8408f8203d..3e95acc98d 100644
--- a/studio/backend/tests/test_compute_buffer.py
+++ b/studio/backend/tests/test_compute_buffer.py
@@ -152,7 +152,7 @@ class TestFallback:
 
 
 class TestParallel1Default:
-    """At Studio's default --parallel 1 the buffer is negligible in pipeline."""
+    """At Unsloth's default --parallel 1 the buffer is negligible in pipeline."""
 
     def test_default_n_parallel(self):
         est = _backend()._estimate_compute_buffer_bytes() / MIB
diff --git a/studio/backend/tests/test_consent_gate.py b/studio/backend/tests/test_consent_gate.py
index 804221ec7e..181e0c9fad 100644
--- a/studio/backend/tests/test_consent_gate.py
+++ b/studio/backend/tests/test_consent_gate.py
@@ -873,6 +873,7 @@ class TestScannerCoversAllExecutableCode:
             repo,
             fn,
             token = None,
+            cache_dir = None,
         ):
             if fn == "config.json":
                 import json
@@ -899,6 +900,7 @@ class TestScannerCoversAllExecutableCode:
             repo,
             fn,
             token = None,
+            cache_dir = None,
         ):
             import json
             import tempfile
@@ -932,6 +934,7 @@ class TestScannerCoversAllExecutableCode:
             repo,
             fn,
             token = None,
+            cache_dir = None,
         ):
             import json
             import tempfile
@@ -972,6 +975,7 @@ class TestScannerCoversAllExecutableCode:
             repo,
             fn,
             token = None,
+            cache_dir = None,
         ):
             import json
             import tempfile
@@ -1008,6 +1012,7 @@ class TestScannerCoversAllExecutableCode:
             repo,
             fn,
             token = None,
+            cache_dir = None,
         ):
             import json
             import tempfile
@@ -1037,6 +1042,7 @@ class TestScannerCoversAllExecutableCode:
             repo,
             fn,
             token = None,
+            cache_dir = None,
         ):
             import json
             import tempfile
@@ -1079,6 +1085,7 @@ class TestScannerCoversAllExecutableCode:
             repo,
             fn,
             token = None,
+            cache_dir = None,
         ):
             import json
             import tempfile
@@ -1120,6 +1127,7 @@ class TestScannerCoversAllExecutableCode:
             repo,
             fn,
             token = None,
+            cache_dir = None,
         ):
             import json
             import tempfile
@@ -1182,6 +1190,7 @@ class TestScannerCoversAllExecutableCode:
             repo,
             fn,
             token = None,
+            cache_dir = None,
         ):
             import json
             import tempfile
diff --git a/studio/backend/tests/test_cpu_threads.py b/studio/backend/tests/test_cpu_threads.py
index 2930c9f081..9d8795b6c0 100644
--- a/studio/backend/tests/test_cpu_threads.py
+++ b/studio/backend/tests/test_cpu_threads.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Tests for Studio's early CPU thread-pool configuration."""
+"""Tests for Unsloth's early CPU thread-pool configuration."""
 
 import ast
 import os
@@ -30,7 +30,7 @@ def test_cpu_thread_cap_seeds_native_pool_limits():
     }
 
 
-# Explicit per-library values win over the Studio knob via setdefault.
+# Explicit per-library values win over the Unsloth knob via setdefault.
 def test_cpu_thread_cap_preserves_runtime_specific_override():
     env = {"UNSLOTH_CPU_THREADS": "4", "OMP_NUM_THREADS": "2"}
 
diff --git a/studio/backend/tests/test_cuda_torch_spec.py b/studio/backend/tests/test_cuda_torch_spec.py
new file mode 100644
index 0000000000..928cef787e
--- /dev/null
+++ b/studio/backend/tests/test_cuda_torch_spec.py
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Tests for _CUDA_TORCH_PKG_SPEC in install_python_stack.py.
+
+The CUDA repair path installs the torch trio from an exclusive --index-url (no
+PyPI fallback), so these pinned ranges decide which torch the venv gets. The
+upper bound is locked to the 2.11.x family to match the base image and rocm7.2
+spec and to keep the companions off a torch-2.12 wheel that would ABI-mismatch.
+"""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+import pytest
+from packaging.requirements import Requirement
+
+# install_python_stack.py lives at repo_root/studio/install_python_stack.py
+_INSTALL_SCRIPT = Path(__file__).resolve().parents[2] / "install_python_stack.py"
+
+
+def _load_module(monkeypatch):
+    """(Re-)import and return install_python_stack (mirrors test_torchao_select)."""
+    sys.modules.pop("install_python_stack", None)
+    monkeypatch.syspath_prepend(str(_INSTALL_SCRIPT.parent))
+    import install_python_stack
+
+    return install_python_stack
+
+
+def _spec_of(pkg_spec: str):
+    """Parse 'torch>=2.4,<2.12.0' into a packaging SpecifierSet."""
+    return Requirement(pkg_spec).specifier
+
+
+@pytest.mark.parametrize(
+    "index, allowed, rejected",
+    [
+        # torch: 2.11.x allowed (matches base image); 2.12.x excluded.
+        (0, ["2.11.0", "2.11.2", "2.10.0", "2.4.0"], ["2.12.0", "2.3.0", "1.13.1"]),
+        # torchvision: 0.26.x (torch 2.11 companion) allowed; 0.27.x (torch 2.12) out.
+        (1, ["0.26.0", "0.26.1", "0.19.0"], ["0.27.0", "0.18.0"]),
+        # torchaudio: same 2.11.x window as torch.
+        (2, ["2.11.0", "2.10.0", "2.4.0"], ["2.12.0", "2.3.0"]),
+    ],
+)
+def test_cuda_spec_bounds(monkeypatch, index, allowed, rejected):
+    mod = _load_module(monkeypatch)
+    spec = _spec_of(mod._CUDA_TORCH_PKG_SPEC[index])
+    for v in allowed:
+        assert spec.contains(v, prereleases = True), f"{v} should satisfy {spec}"
+    for v in rejected:
+        assert not spec.contains(v, prereleases = True), f"{v} should not satisfy {spec}"
+
+
+def test_cuda_spec_matches_rocm72_upper_bound(monkeypatch):
+    """CUDA and rocm7.2 target the same torch 2.11.x family, so their upper
+    bounds must stay in lockstep (bump both together at 2.12.x)."""
+    mod = _load_module(monkeypatch)
+    rocm72 = mod._ROCM_TORCH_PKG_SPECS["rocm7.2"]
+
+    def _upper(pkg_spec: str) -> str:
+        for clause in _spec_of(pkg_spec):
+            if clause.operator == "<":
+                return clause.version
+        raise AssertionError(f"no upper bound in {pkg_spec!r}")
+
+    for cuda_pkg, rocm_pkg in zip(mod._CUDA_TORCH_PKG_SPEC, rocm72, strict = True):
+        assert _upper(cuda_pkg) == _upper(
+            rocm_pkg
+        ), f"CUDA {cuda_pkg!r} upper bound must match rocm7.2 {rocm_pkg!r}"
diff --git a/studio/backend/tests/test_embedding_model_security_gate.py b/studio/backend/tests/test_embedding_model_security_gate.py
index 940b35d7ba..a6c18bd8de 100644
--- a/studio/backend/tests/test_embedding_model_security_gate.py
+++ b/studio/backend/tests/test_embedding_model_security_gate.py
@@ -52,6 +52,16 @@ def client(monkeypatch):
     monkeypatch.setattr(settings, "_resolves_as_local_gguf", lambda m: False)
     monkeypatch.setattr(settings, "get_rag_embedding_model", lambda: saved.get("model", ""))
     monkeypatch.setattr(settings, "get_stored_embedding_model", lambda: saved.get("model"))
+    monkeypatch.setattr(
+        settings,
+        "effective_gguf_repo",
+        lambda: f"{saved.get('model', 'unsloth/default-embed')}-GGUF",
+    )
+    monkeypatch.setattr(
+        settings,
+        "default_gguf_repo",
+        lambda: "unsloth/default-embed-GGUF",
+    )
 
     app = FastAPI()
     app.include_router(settings.router)
@@ -96,6 +106,56 @@ def test_hard_block_uses_non_forceable_status(client, monkeypatch):
     assert unverified.status_code == 409
 
 
+def test_offline_cached_non_st_model_is_accepted(client, monkeypatch):
+    # Offline, a cached transformers-native embedder (no modules.json) is unverifiable via HF
+    # metadata, but ST can load any cached encoder, so accept it (no 409).
+    c, saved = client
+    monkeypatch.setitem(sys.modules, "utils.security", _security_stub(blocked = False))
+    monkeypatch.setenv("HF_HUB_OFFLINE", "1")
+    import utils.models as _models
+    import utils.utils as _uu
+
+    monkeypatch.setattr(_models, "is_embedding_model", lambda *a, **k: False)
+    monkeypatch.setattr(_uu, "hf_cache_snapshot_is_loadable", lambda name: True)
+    r = c.put("/embedding-model", json = {"embedding_model": "acme/gte-modernbert"})
+    assert r.status_code == 200
+    assert saved.get("model") == "acme/gte-modernbert"
+
+
+def test_offline_partial_or_uncached_model_still_409(client, monkeypatch):
+    # Offline but not loadable (uncached or metadata-only partial cache): keep the forceable
+    # 409, since the cache-only load would fail anyway.
+    c, _saved = client
+    monkeypatch.setitem(sys.modules, "utils.security", _security_stub(blocked = False))
+    monkeypatch.setenv("HF_HUB_OFFLINE", "1")
+    import utils.models as _models
+    import utils.utils as _uu
+
+    monkeypatch.setattr(_models, "is_embedding_model", lambda *a, **k: False)
+    monkeypatch.setattr(_uu, "hf_cache_snapshot_is_loadable", lambda name: False)
+    r = c.put("/embedding-model", json = {"embedding_model": "acme/uncached-embedder"})
+    assert r.status_code == 409
+
+
+def test_offline_skips_remote_gguf_probe(client, monkeypatch):
+    # Offline + llama backend: the remote GGUF probe (list_repo_files) must be skipped so a
+    # dead-DNS session cannot hang.
+    c, _saved = client
+    monkeypatch.setenv("HF_HUB_OFFLINE", "1")
+    monkeypatch.setattr(settings, "_llama_backend_active", lambda: True)
+    monkeypatch.setattr(settings, "_local_gguf_backend_error", lambda model: None)
+
+    def _boom(*a, **k):
+        raise AssertionError("hit the network for the GGUF probe")
+
+    monkeypatch.setattr(settings, "_hf_gguf_backend_error", _boom)
+    import utils.models as _models
+
+    monkeypatch.setattr(_models, "is_embedding_model", lambda *a, **k: True)
+    r = c.put("/embedding-model", json = {"embedding_model": "acme/embedder"})
+    assert r.status_code == 200
+
+
 def test_llama_backend_skips_the_st_pickle_scan(monkeypatch):
     # On the llama-server backend the embedder loads GGUF (inert), not the ST repo's
     # pickle, so a flagged ST repo with a clean GGUF companion must not be rejected here.
@@ -257,6 +317,13 @@ def test_clean_repo_saves_under_force(client, monkeypatch):
     r = c.put("/embedding-model", json = {"embedding_model": "acme/clean-embed", "force": True})
     assert r.status_code == 200
     assert saved.get("model") == "acme/clean-embed"
+    assert r.json() == {
+        "embedding_model": "acme/clean-embed",
+        "embedding_gguf_repo": "acme/clean-embed-GGUF",
+        "default_embedding_model": "unsloth/default-embed",
+        "default_embedding_gguf_repo": "unsloth/default-embed-GGUF",
+        "is_custom": True,
+    }
 
 
 def test_load_sink_refuses_flagged_model(monkeypatch):
diff --git a/studio/backend/tests/test_embedding_model_settings.py b/studio/backend/tests/test_embedding_model_settings.py
index 3be4af0e32..bcf3ded71c 100644
--- a/studio/backend/tests/test_embedding_model_settings.py
+++ b/studio/backend/tests/test_embedding_model_settings.py
@@ -53,3 +53,10 @@ def test_custom_model_overrides_default_and_derives_gguf(settings_store, monkeyp
 
     assert ems.reset_rag_embedding_model() == rag_config.EMBEDDING_MODEL
     assert ems.get_stored_embedding_model() is None
+
+
+def test_env_default_derives_its_gguf_companion(monkeypatch):
+    monkeypatch.delenv("RAG_EMBED_GGUF_REPO", raising = False)
+    monkeypatch.setattr(rag_config, "EMBEDDING_MODEL", "org/env-default-embedder")
+
+    assert rag_config.default_gguf_repo() == "org/env-default-embedder-GGUF"
diff --git a/studio/backend/tests/test_export_absolute_paths.py b/studio/backend/tests/test_export_absolute_paths.py
index 761ea08e3f..5097f9f53a 100644
--- a/studio/backend/tests/test_export_absolute_paths.py
+++ b/studio/backend/tests/test_export_absolute_paths.py
@@ -158,6 +158,7 @@ def _install_lightweight_backend_stubs(monkeypatch):
     utils_model_config._pick_best_gguf = lambda variants: variants[0] if variants else None
     utils_model_config._extract_quant_label = lambda value: value
     utils_model_config._is_big_endian_gguf_path = lambda *args, **kwargs: False
+    utils_model_config._is_mtp_drafter = lambda *args, **kwargs: False
     utils_model_config.is_audio_input_type = lambda *args, **kwargs: None
     monkeypatch.setitem(
         sys.modules,
diff --git a/studio/backend/tests/test_file_security.py b/studio/backend/tests/test_file_security.py
index b4c8f5d242..e02c33a0f1 100644
--- a/studio/backend/tests/test_file_security.py
+++ b/studio/backend/tests/test_file_security.py
@@ -165,6 +165,23 @@ def test_skips_local_path():
     assert "local" in d.reason
 
 
+def test_scans_inactive_hf_cache_snapshot_path(tmp_path):
+    # An inactive HF cache loads by snapshot path; the gate must recover the repo id +
+    # commit from models--org--repo/snapshots/<rev> and scan that exact commit, not exempt
+    # it and not fall back to the default branch (an older commit may hold a dropped pickle).
+    snapshot = tmp_path / "models--evil--repo" / "snapshots" / "deadbeef"
+    snapshot.mkdir(parents = True)
+    status = {
+        "scansDone": True,
+        "filesWithIssues": [{"path": "pytorch_model.bin", "level": "unsafe"}],
+    }
+    with _patch_status(status) as model_info:
+        d = evaluate_file_security(str(snapshot))
+    assert d.blocked is True
+    assert model_info.call_args.args[0] == "evil/repo"
+    assert model_info.call_args.kwargs["revision"] == "deadbeef"
+
+
 def test_remote_gguf_named_repo_is_still_scanned():
     # Only LOCAL paths skip the Hub scan, so a remote .gguf repo is still scanned and a
     # poisoned pickle smuggled into it is blocked.
diff --git a/studio/backend/tests/test_frontend_resolution.py b/studio/backend/tests/test_frontend_resolution.py
index c3e0524a30..7ac2717aae 100644
--- a/studio/backend/tests/test_frontend_resolution.py
+++ b/studio/backend/tests/test_frontend_resolution.py
@@ -218,7 +218,7 @@ def test_systemexit_message_contains_actionable_fixes(tmp_path, monkeypatch):
         installer_bin = home / "unsloth_studio" / "bin" / "unsloth"
     tried_lines = "\n".join(f"  - {p}" for p in attempted)
     message = (
-        "[ERROR] Studio frontend build not found.\n"
+        "[ERROR] Unsloth frontend build not found.\n"
         f"Tried:\n{tried_lines}\n"
         "\n"
         "Likely cause: another 'unsloth' on PATH is shadowing the "
diff --git a/studio/backend/tests/test_gemini_provider.py b/studio/backend/tests/test_gemini_provider.py
index 85ceb04d27..c6ffa798d0 100644
--- a/studio/backend/tests/test_gemini_provider.py
+++ b/studio/backend/tests/test_gemini_provider.py
@@ -768,7 +768,7 @@ def test_cached_content_pass_through(monkeypatch):
 
 
 def test_boolean_caching_does_not_set_cached_content(monkeypatch):
-    """Studio's existing True/False signals shouldn't fabricate a cache id."""
+    """Unsloth's existing True/False signals shouldn't fabricate a cache id."""
     captured = _capture_body(monkeypatch, enable_prompt_caching = True)
     assert "cachedContent" not in captured["body"]
 
@@ -2613,7 +2613,7 @@ def test_gemini_native_skips_orphan_function_response_for_native_part_replay(mon
 
 def test_gemini_native_part_falls_back_to_args_google(monkeypatch):
     """Round 27: a direct OpenAI-compat API caller (or imported third-party
-    thread) cannot use Studio's non-standard `tool_calls[].extra_content`
+    thread) cannot use Unsloth's non-standard `tool_calls[].extra_content`
     field, so the native_part payload round-trips through `function.arguments`
     as `{"google": {"native_part": {...}}}`. The synthetic-builtin detector
     recognizes that location, but the replay branch was only reading from
diff --git a/studio/backend/tests/test_gemma4_chat_template_override.py b/studio/backend/tests/test_gemma4_chat_template_override.py
index f726741aa5..9fb24a4cf6 100644
--- a/studio/backend/tests/test_gemma4_chat_template_override.py
+++ b/studio/backend/tests/test_gemma4_chat_template_override.py
@@ -3,7 +3,7 @@
 
 """Auto-override of the chat template for ``unsloth/gemma-4-*-GGUF``.
 
-Studio ships a bundled ``gemma-4.jinja`` (PR #118 based, ``preserve_thinking``
+Unsloth ships a bundled ``gemma-4.jinja`` (PR #118 based, ``preserve_thinking``
 defaulted off) and applies it to gemma-4 GGUF loads via the existing
 ``chat_template_override`` -> ``--chat-template-file`` path, so users do not need
 to re-download quants. Pins the family matcher, the resolver precedence, the
diff --git a/studio/backend/tests/test_gguf_load_cache_reuse.py b/studio/backend/tests/test_gguf_load_cache_reuse.py
new file mode 100644
index 0000000000..6d1fac980b
--- /dev/null
+++ b/studio/backend/tests/test_gguf_load_cache_reuse.py
@@ -0,0 +1,803 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Tests for cached GGUF reuse and load/download exclusion.
+
+No GPU, network, or subprocesses are required.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import sys
+import threading
+import types as _types
+from pathlib import Path
+from unittest.mock import patch
+
+import pytest
+
+
+_BACKEND_DIR = str(Path(__file__).resolve().parent.parent)
+if _BACKEND_DIR not in sys.path:
+    sys.path.insert(0, _BACKEND_DIR)
+
+# Stub optional dependencies before importing the modules under test.
+_loggers_stub = _types.ModuleType("loggers")
+_loggers_stub.get_logger = lambda name: __import__("logging").getLogger(name)
+sys.modules.setdefault("loggers", _loggers_stub)
+
+_structlog_stub = _types.ModuleType("structlog")
+sys.modules.setdefault("structlog", _structlog_stub)
+
+try:
+    import httpx  # noqa: F401
+except ImportError:
+    _httpx_stub = _types.ModuleType("httpx")
+    for _exc_name in (
+        "ConnectError",
+        "TimeoutException",
+        "ReadTimeout",
+        "ReadError",
+        "RemoteProtocolError",
+        "CloseError",
+        "HTTPError",
+        "RequestError",
+        "HTTPStatusError",
+    ):
+        setattr(_httpx_stub, _exc_name, type(_exc_name, (Exception,), {}))
+    _httpx_stub.Response = type("Response", (), {})
+    _httpx_stub.Request = type("Request", (), {})
+
+    class _FakeTimeout:
+        def __init__(self, *a, **kw):
+            pass
+
+    _httpx_stub.Timeout = _FakeTimeout
+    _httpx_stub.Client = type(
+        "Client",
+        (),
+        {
+            "__init__": lambda self, **kw: None,
+            "__enter__": lambda self: self,
+            "__exit__": lambda self, *a: None,
+        },
+    )
+    sys.modules.setdefault("httpx", _httpx_stub)
+
+
+from huggingface_hub import constants as hf_constants
+
+from core.inference.llama_cpp import (
+    LlamaCppBackend,
+    cached_gguf_for_load,
+    gguf_load_in_flight,
+    hf_gguf_load_in_flight,
+)
+
+
+REPO = "unsloth/gemma-test-GGUF"
+VARIANT = "UD-Q4_K_XL"
+MAIN = f"gemma-test-{VARIANT}.gguf"
+
+
+def _build_cache(
+    root: Path,
+    repo_id: str,
+    files: dict[str, int],
+    *,
+    snapshot_sha: str = "a" * 40,
+) -> Path:
+    """Create ``$root/models--<repo>/snapshots/<sha>/<rel>`` for each entry."""
+    repo_dir = root / f"models--{repo_id.replace('/', '--')}"
+    (repo_dir / "blobs").mkdir(parents = True, exist_ok = True)
+    snap = repo_dir / "snapshots" / snapshot_sha
+    snap.mkdir(parents = True, exist_ok = True)
+    for rel, size in files.items():
+        full = snap / rel
+        full.parent.mkdir(parents = True, exist_ok = True)
+        full.write_bytes(b"\0" * size)
+    return snap
+
+
+@pytest.fixture
+def hf_cache(tmp_path, monkeypatch):
+    monkeypatch.setattr(hf_constants, "HF_HUB_CACHE", str(tmp_path))
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: _types.SimpleNamespace(hub_cache = tmp_path),
+    )
+    monkeypatch.delenv("HF_HUB_OFFLINE", raising = False)
+    monkeypatch.delenv("TRANSFORMERS_OFFLINE", raising = False)
+    return tmp_path
+
+
+def _fail_download(*_args, **_kwargs):
+    raise AssertionError("must reuse the cached GGUF instead of downloading")
+
+
+def _fail_get_paths_info(*_args, **_kwargs):
+    raise AssertionError("cached reuse must return before the sizing preflight")
+
+
+class TestLoadReusesCachedCopy:
+    def test_download_uses_selected_cache_for_lookup_preflight_and_write(
+        self, tmp_path, monkeypatch
+    ):
+        backend = LlamaCppBackend()
+        selected = tmp_path / "selected" / "hub"
+        startup = tmp_path / "startup" / "hub"
+        monkeypatch.setattr(hf_constants, "HF_HUB_CACHE", str(startup))
+        monkeypatch.setattr(
+            "utils.hf_cache_settings.get_hf_cache_paths",
+            lambda: _types.SimpleNamespace(hub_cache = selected),
+        )
+        seen = {"lookups": [], "disk": [], "downloads": []}
+
+        def cached_lookup(
+            repo_id,
+            filename,
+            *,
+            cache_dir = None,
+            **_kwargs,
+        ):
+            seen["lookups"].append((repo_id, filename, cache_dir))
+            return None
+
+        def disk_usage(path):
+            seen["disk"].append(str(path))
+            return _types.SimpleNamespace(free = 1024)
+
+        def download(repo_id, filename, _token, **kwargs):
+            seen["downloads"].append((repo_id, filename, kwargs.get("cache_dir")))
+            return str(selected / filename)
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [MAIN]),
+            patch(
+                "huggingface_hub.get_paths_info",
+                lambda _repo, paths, **_kwargs: [
+                    _types.SimpleNamespace(path = path, size = 4) for path in paths
+                ],
+            ),
+            patch("huggingface_hub.try_to_load_from_cache", cached_lookup),
+            patch("core.inference.llama_cpp.shutil.disk_usage", disk_usage),
+            patch(
+                "core.inference.llama_cpp.hf_hub_download_with_xet_fallback",
+                download,
+            ),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT)
+
+        assert out == str(selected / MAIN)
+        assert seen == {
+            "lookups": [(REPO, MAIN, str(selected))],
+            "disk": [str(selected)],
+            "downloads": [(REPO, MAIN, str(selected))],
+        }
+
+    def test_online_reuse_after_revision_bump(self, hf_cache):
+        """A new repo revision does not replace a complete cached model."""
+        backend = LlamaCppBackend()
+        snap = _build_cache(hf_cache, REPO, {MAIN: 4})
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [MAIN]),
+            patch("huggingface_hub.get_paths_info", _fail_get_paths_info),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", _fail_download),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT)
+
+        assert out == str(snap / MAIN)
+
+    def test_reuse_size_check_uses_cached_snapshot_revision(self, hf_cache):
+        """Current-revision size changes do not invalidate an older complete copy."""
+        backend = LlamaCppBackend()
+        snap = _build_cache(hf_cache, REPO, {MAIN: 4})
+        revisions: list[str | None] = []
+
+        def fake_get_paths_info(
+            _repo,
+            paths,
+            *,
+            revision = None,
+            token = None,
+        ):
+            revisions.append(revision)
+            size = 4 if revision == snap.name else 8
+            return [_types.SimpleNamespace(path = path, size = size) for path in paths]
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [MAIN]),
+            patch("huggingface_hub.get_paths_info", fake_get_paths_info),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", _fail_download),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT)
+
+        assert out == str(snap / MAIN)
+        assert revisions == [snap.name]
+
+    def test_reuse_when_cached_revision_vanished_from_hub(self, hf_cache):
+        """The Hub answers an unknown revision with an empty result, not an error."""
+        backend = LlamaCppBackend()
+        snap = _build_cache(hf_cache, REPO, {MAIN: 4})
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [MAIN]),
+            patch("huggingface_hub.get_paths_info", lambda *_a, **_k: []),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", _fail_download),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT)
+
+        assert out == str(snap / MAIN)
+
+    def test_truncated_cached_file_is_not_reused(self, hf_cache):
+        backend = LlamaCppBackend()
+        _build_cache(hf_cache, REPO, {MAIN: 4})
+        downloaded: list[str] = []
+
+        def fake_get_paths_info(
+            _repo,
+            paths,
+            *,
+            revision = None,
+            token = None,
+        ):
+            return [_types.SimpleNamespace(path = path, size = 8) for path in paths]
+
+        def fake_download(
+            repo_id,
+            filename,
+            token = None,
+            **_kwargs,
+        ):
+            downloaded.append(filename)
+            return f"/fake/{repo_id}/{filename}"
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [MAIN]),
+            patch("huggingface_hub.get_paths_info", fake_get_paths_info),
+            patch("huggingface_hub.try_to_load_from_cache", lambda *_a, **_k: None),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", fake_download),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT)
+
+        assert downloaded == [MAIN]
+        assert out == f"/fake/{REPO}/{MAIN}"
+
+    def test_truncated_cached_split_shard_is_not_reused(self, hf_cache):
+        backend = LlamaCppBackend()
+        shard1 = f"gemma-test-{VARIANT}-00001-of-00002.gguf"
+        shard2 = f"gemma-test-{VARIANT}-00002-of-00002.gguf"
+        _build_cache(hf_cache, REPO, {shard1: 8, shard2: 4})
+        downloaded: list[str] = []
+
+        def fake_get_paths_info(
+            _repo,
+            paths,
+            *,
+            revision = None,
+            token = None,
+        ):
+            return [_types.SimpleNamespace(path = path, size = 8) for path in paths]
+
+        def fake_download(
+            repo_id,
+            filename,
+            token = None,
+            **_kwargs,
+        ):
+            downloaded.append(filename)
+            return f"/fake/{repo_id}/{filename}"
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [shard1, shard2]),
+            patch("huggingface_hub.get_paths_info", fake_get_paths_info),
+            patch("huggingface_hub.try_to_load_from_cache", lambda *_a, **_k: None),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", fake_download),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT)
+
+        assert downloaded == [shard1, shard2]
+        assert out == f"/fake/{REPO}/{shard1}"
+
+    def test_online_reuse_when_reupload_renamed_the_file(self, hf_cache):
+        """A renamed variant still reuses its cached file."""
+        backend = LlamaCppBackend()
+        old_name = f"gemma-test-old-{VARIANT}.gguf"
+        snap = _build_cache(hf_cache, REPO, {old_name: 4})
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [MAIN]),
+            patch("huggingface_hub.get_paths_info", _fail_get_paths_info),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", _fail_download),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT)
+
+        assert out == str(snap / old_name)
+
+    def test_downloads_when_nothing_cached(self, hf_cache):
+        backend = LlamaCppBackend()
+        downloaded: list[str] = []
+
+        def fake_download(
+            repo_id,
+            filename,
+            token = None,
+            **_kwargs,
+        ):
+            downloaded.append(filename)
+            return f"/fake/{repo_id}/{filename}"
+
+        def fake_get_paths_info(
+            _repo_id,
+            paths,
+            token = None,
+        ):
+            return [_types.SimpleNamespace(path = p, size = 1) for p in paths if p is not None]
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [MAIN]),
+            patch("huggingface_hub.get_paths_info", fake_get_paths_info),
+            patch("huggingface_hub.try_to_load_from_cache", lambda *_a, **_k: None),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", fake_download),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT)
+
+        assert downloaded == [MAIN]
+        assert out == f"/fake/{REPO}/{MAIN}"
+
+    def test_force_redownloads_despite_cache(self, hf_cache):
+        """A forced download ignores a complete cached copy."""
+        backend = LlamaCppBackend()
+        _build_cache(hf_cache, REPO, {MAIN: 4})
+        downloaded: list[str] = []
+
+        def fake_download(
+            repo_id,
+            filename,
+            token = None,
+            **kwargs,
+        ):
+            assert kwargs.get("force_download") is True
+            downloaded.append(filename)
+            return f"/fake/{repo_id}/{filename}"
+
+        def fake_get_paths_info(
+            _repo_id,
+            paths,
+            token = None,
+        ):
+            return [_types.SimpleNamespace(path = p, size = 1) for p in paths if p is not None]
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [MAIN]),
+            patch("huggingface_hub.get_paths_info", fake_get_paths_info),
+            patch("huggingface_hub.try_to_load_from_cache", lambda *_a, **_k: None),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", fake_download),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT, force = True)
+
+        assert downloaded == [MAIN]
+        assert out == f"/fake/{REPO}/{MAIN}"
+
+    def test_split_reused_only_when_colocated(self, hf_cache):
+        backend = LlamaCppBackend()
+        shard1 = f"gemma-test-{VARIANT}-00001-of-00002.gguf"
+        shard2 = f"gemma-test-{VARIANT}-00002-of-00002.gguf"
+        snap = _build_cache(hf_cache, REPO, {shard1: 4, shard2: 4})
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [shard1, shard2]),
+            patch("huggingface_hub.get_paths_info", _fail_get_paths_info),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", _fail_download),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT)
+
+        assert out == str(snap / shard1)
+
+    def test_partial_split_set_downloads(self, hf_cache):
+        """A partial split set is not reused."""
+        backend = LlamaCppBackend()
+        shard1 = f"gemma-test-{VARIANT}-00001-of-00002.gguf"
+        shard2 = f"gemma-test-{VARIANT}-00002-of-00002.gguf"
+        _build_cache(hf_cache, REPO, {shard1: 4})
+        downloaded: list[str] = []
+
+        def fake_download(
+            repo_id,
+            filename,
+            token = None,
+            **_kwargs,
+        ):
+            downloaded.append(filename)
+            return f"/fake/{repo_id}/{filename}"
+
+        def fake_get_paths_info(
+            _repo_id,
+            paths,
+            token = None,
+        ):
+            return [_types.SimpleNamespace(path = p, size = 4) for p in paths if p is not None]
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [shard1, shard2]),
+            patch("huggingface_hub.get_paths_info", fake_get_paths_info),
+            patch("huggingface_hub.try_to_load_from_cache", lambda *_a, **_k: None),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", fake_download),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT)
+
+        assert downloaded == [shard1, shard2]
+        assert out == f"/fake/{REPO}/{shard1}"
+
+    def test_reuse_prefers_newest_snapshot_after_update(self, hf_cache):
+        """Loads prefer the newest complete snapshot."""
+        import os
+
+        backend = LlamaCppBackend()
+        old_snap = _build_cache(hf_cache, REPO, {MAIN: 4}, snapshot_sha = "a" * 40)
+        new_snap = _build_cache(hf_cache, REPO, {MAIN: 6}, snapshot_sha = "b" * 40)
+        os.utime(old_snap, (1_000_000, 1_000_000))
+        os.utime(new_snap, (2_000_000, 2_000_000))
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [MAIN]),
+            patch("huggingface_hub.get_paths_info", _fail_get_paths_info),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", _fail_download),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT)
+
+        assert out == str(new_snap / MAIN)
+
+    def test_low_disk_fallback_reuses_cached_copy(self, hf_cache):
+        backend = LlamaCppBackend()
+        fallback = "gemma-test-Q2_K.gguf"
+        snap = _build_cache(hf_cache, REPO, {fallback: 4})
+
+        def fake_get_paths_info(
+            _repo,
+            paths,
+            *,
+            revision = None,
+            token = None,
+        ):
+            size = 4 if revision == snap.name else 100
+            return [_types.SimpleNamespace(path = path, size = size) for path in paths]
+
+        with (
+            patch("huggingface_hub.list_repo_files", lambda *_a, **_k: [MAIN]),
+            patch("huggingface_hub.get_paths_info", fake_get_paths_info),
+            patch("huggingface_hub.try_to_load_from_cache", lambda *_a, **_k: None),
+            patch("shutil.disk_usage", lambda *_a, **_k: _types.SimpleNamespace(free = 10)),
+            patch.object(
+                backend,
+                "_find_smallest_fitting_variant",
+                lambda *_a, **_k: (fallback, 4, []),
+            ),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", _fail_download),
+        ):
+            out = backend._download_gguf(hf_repo = REPO, hf_variant = VARIANT)
+
+        assert out == str(snap / fallback)
+
+    def test_companion_prefers_main_snapshot_sibling(self, hf_cache):
+        """A cached mmproj is reused from the main model's snapshot."""
+        backend = LlamaCppBackend()
+        snap = _build_cache(hf_cache, REPO, {MAIN: 4, "mmproj-F16.gguf": 2})
+
+        def _fail_list(*_args, **_kwargs):
+            raise AssertionError("snapshot sibling must resolve without a repo listing")
+
+        with patch("huggingface_hub.list_repo_files", _fail_list):
+            out = backend._download_mmproj(hf_repo = REPO, near_path = str(snap / MAIN))
+
+        assert out == str(snap / "mmproj-F16.gguf")
+
+    def test_companion_finds_snapshot_through_hf_symlink(self, hf_cache):
+        backend = LlamaCppBackend()
+        snap = _build_cache(hf_cache, REPO, {})
+        blobs = snap.parent.parent / "blobs"
+        main_blob = blobs / "main"
+        mmproj_blob = blobs / "mmproj"
+        main_blob.write_bytes(b"main")
+        mmproj_blob.write_bytes(b"mmproj")
+        try:
+            (snap / MAIN).symlink_to(main_blob)
+            (snap / "mmproj-F16.gguf").symlink_to(mmproj_blob)
+        except OSError as exc:
+            pytest.skip(f"symlinks unavailable: {exc}")
+
+        with patch("huggingface_hub.list_repo_files", _fail_download):
+            out = backend._download_mmproj(hf_repo = REPO, near_path = str(snap / MAIN))
+
+        assert out == str(snap / "mmproj-F16.gguf")
+
+    def test_companion_does_not_download_during_hub_job(self, hf_cache):
+        backend = LlamaCppBackend()
+        snap = _build_cache(hf_cache, REPO, {MAIN: 4})
+        registry = _types.SimpleNamespace(active_job_refs = lambda _repo: [object()])
+
+        with (
+            patch("huggingface_hub.list_repo_files", _fail_download),
+            patch("hub.utils.download_registry.get_models_registry", lambda: registry),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", _fail_download),
+        ):
+            out = backend._download_mmproj(hf_repo = REPO, near_path = str(snap / MAIN))
+
+        assert out is None
+
+
+class TestCachedGgufForLoadProbe:
+    def test_complete_copy_found(self, hf_cache):
+        snap = _build_cache(hf_cache, REPO, {MAIN: 4})
+        assert cached_gguf_for_load(REPO, VARIANT) == str(snap / MAIN)
+
+    def test_absent_copy_is_none(self, hf_cache):
+        assert cached_gguf_for_load(REPO, VARIANT) is None
+
+    def test_partial_split_is_none(self, hf_cache):
+        shard1 = f"gemma-test-{VARIANT}-00001-of-00002.gguf"
+        _build_cache(hf_cache, REPO, {shard1: 4})
+        assert cached_gguf_for_load(REPO, VARIANT) is None
+
+    def test_partial_new_snapshot_does_not_hide_complete_split(self, hf_cache):
+        import os
+
+        shard1 = f"gemma-test-{VARIANT}-00001-of-00002.gguf"
+        shard2 = f"gemma-test-{VARIANT}-00002-of-00002.gguf"
+        old = _build_cache(
+            hf_cache,
+            REPO,
+            {shard1: 4, shard2: 4},
+            snapshot_sha = "a" * 40,
+        )
+        new = _build_cache(hf_cache, REPO, {shard1: 4}, snapshot_sha = "b" * 40)
+        os.utime(old, (1_000_000, 1_000_000))
+        os.utime(new, (2_000_000, 2_000_000))
+
+        assert cached_gguf_for_load(REPO, VARIANT) == str(old / shard1)
+
+    def test_split_requires_every_declared_shard(self, hf_cache):
+        shard1 = f"gemma-test-{VARIANT}-00001-of-00003.gguf"
+        shard2 = f"gemma-test-{VARIANT}-00002-of-00003.gguf"
+        _build_cache(hf_cache, REPO, {shard1: 4, shard2: 4})
+
+        assert cached_gguf_for_load(REPO, VARIANT) is None
+
+    def test_required_mmproj_must_share_main_snapshot(self, hf_cache):
+        snap = _build_cache(hf_cache, REPO, {MAIN: 4})
+        assert cached_gguf_for_load(REPO, VARIANT) == str(snap / MAIN)
+        assert cached_gguf_for_load(REPO, VARIANT, require_mmproj = True) is None
+
+        (snap / "mmproj-F16.gguf").write_bytes(b"mmproj")
+        assert cached_gguf_for_load(REPO, VARIANT, require_mmproj = True) == str(snap / MAIN)
+
+    def test_required_mmproj_scans_past_newer_main_only_snapshot(self, hf_cache):
+        import os
+
+        old = _build_cache(
+            hf_cache,
+            REPO,
+            {MAIN: 4, "mmproj-F16.gguf": 2},
+            snapshot_sha = "a" * 40,
+        )
+        new = _build_cache(hf_cache, REPO, {MAIN: 4}, snapshot_sha = "b" * 40)
+        os.utime(old, (1_000_000, 1_000_000))
+        os.utime(new, (2_000_000, 2_000_000))
+
+        assert cached_gguf_for_load(REPO, VARIANT, require_mmproj = True) == str(old / MAIN)
+
+
+class TestLoadHubDownloadExclusion:
+    def test_in_flight_marker_counts_and_normalizes_case(self):
+        assert not hf_gguf_load_in_flight(REPO)
+        with gguf_load_in_flight(REPO):
+            assert hf_gguf_load_in_flight(REPO.upper())
+            with gguf_load_in_flight(REPO.lower()):
+                assert hf_gguf_load_in_flight(REPO)
+            assert hf_gguf_load_in_flight(REPO)
+        assert not hf_gguf_load_in_flight(REPO)
+
+    def test_marker_noops_for_local_loads(self):
+        with gguf_load_in_flight(None):
+            assert not hf_gguf_load_in_flight("")
+
+    def test_marker_cleared_on_exception(self):
+        with pytest.raises(RuntimeError):
+            with gguf_load_in_flight(REPO):
+                raise RuntimeError("boom")
+        assert not hf_gguf_load_in_flight(REPO)
+
+    def test_hub_download_refused_while_load_in_flight(self):
+        from fastapi import HTTPException
+
+        from hub.schemas.downloads import DownloadModelRequest
+        from hub.services.models import downloads as dl
+
+        body = DownloadModelRequest(repo_id = REPO, gguf_variant = VARIANT)
+        with (
+            patch.object(dl, "resolve_cached_repo_id_case", lambda repo_id, repo_type: repo_id),
+            gguf_load_in_flight(REPO),
+        ):
+            with pytest.raises(HTTPException) as exc_info:
+                asyncio.run(dl.download_model_response(body))
+
+        assert exc_info.value.status_code == 409
+        assert "load" in exc_info.value.detail.lower()
+
+    def test_hub_download_rechecks_marker_before_claim(self):
+        from fastapi import HTTPException
+
+        from hub.schemas.downloads import DownloadModelRequest
+        from hub.services.models import downloads as dl
+
+        scope = None
+
+        def mark_load(*_args, **_kwargs):
+            nonlocal scope
+            if scope is None:
+                scope = gguf_load_in_flight(REPO)
+                scope.__enter__()
+            return frozenset()
+
+        class _Registry:
+            def claim(self, *_args, admission_check, **_kwargs):
+                assert admission_check() is False
+                return False, "admission_blocked"
+
+            def current_generation(self, _key):
+                return 0
+
+        registry = _Registry()
+        body = DownloadModelRequest(repo_id = REPO, gguf_variant = VARIANT)
+        try:
+            with (
+                patch.object(dl, "resolve_cached_repo_id_case", lambda repo_id, repo_type: repo_id),
+                patch.object(dl.gguf_variants, "gguf_variant_blob_hashes", mark_load),
+                patch.object(dl, "_registry", registry),
+            ):
+                with pytest.raises(HTTPException) as exc_info:
+                    asyncio.run(dl.download_model_response(body))
+        finally:
+            if scope is not None:
+                scope.__exit__(None, None, None)
+
+        assert exc_info.value.status_code == 409
+
+    def test_registry_admission_check_prevents_claim(self):
+        from hub.utils.download_registry import DownloadRegistry, TRANSPORT_HTTP
+
+        registry = DownloadRegistry()
+        claimed, state = registry.claim(
+            f"{REPO}::{VARIANT}",
+            TRANSPORT_HTTP,
+            repo_type = "model",
+            repo_id = REPO,
+            variant = VARIANT,
+            admission_check = lambda: False,
+        )
+
+        assert claimed is False
+        assert state == "admission_blocked"
+        assert registry.active_jobs(REPO) == {}
+
+    def test_same_variant_job_stays_visible_during_retry_handoff(self):
+        from hub.utils.download_registry import DownloadRegistry, TRANSPORT_XET
+        from core.inference.llama_cpp import _hub_download_blocks_gguf_load
+
+        registry = DownloadRegistry()
+        key = f"{REPO}::{VARIANT}"
+        claimed, _ = registry.claim(
+            key,
+            TRANSPORT_XET,
+            repo_type = "model",
+            repo_id = REPO,
+            variant = VARIANT,
+        )
+        assert claimed is True
+        assert registry.has_active_variant(REPO, VARIANT.lower()) is True
+
+        registry.release_active_slot(key)
+
+        assert registry.active_jobs(REPO) == {}
+        assert registry.active_job_refs(REPO)
+        assert registry.has_active_variant(REPO, VARIANT) is True
+        with (
+            patch("hub.utils.download_registry.get_models_registry", lambda: registry),
+            patch(
+                "core.inference.llama_cpp.cached_gguf_for_load",
+                side_effect = AssertionError("same-variant jobs must block before cache reuse"),
+            ),
+        ):
+            assert _hub_download_blocks_gguf_load(REPO, VARIANT) is True
+
+        registry.set_job(key, "complete")
+        assert registry.has_active_variant(REPO, VARIANT) is False
+
+    def test_other_variant_job_still_allows_complete_cached_load(self):
+        from core.inference.llama_cpp import _hub_download_blocks_gguf_load
+        from hub.utils.download_registry import DownloadRegistry, TRANSPORT_HTTP
+
+        registry = DownloadRegistry()
+        registry.claim(
+            f"{REPO}::Q8_0",
+            TRANSPORT_HTTP,
+            repo_type = "model",
+            repo_id = REPO,
+            variant = "Q8_0",
+        )
+        with (
+            patch("hub.utils.download_registry.get_models_registry", lambda: registry),
+            patch(
+                "core.inference.llama_cpp.cached_gguf_for_load",
+                return_value = "/cached/model.gguf",
+            ) as cached_probe,
+        ):
+            assert _hub_download_blocks_gguf_load(REPO, VARIANT) is False
+
+        cached_probe.assert_called_once_with(
+            REPO,
+            VARIANT,
+            require_mmproj = False,
+            verify_sizes = True,
+            hf_token = None,
+        )
+
+    def test_cancelled_request_keeps_marker_until_load_thread_finishes(self):
+        from core.inference.llama_cpp import _with_gguf_load_marker
+
+        started = threading.Event()
+        release = threading.Event()
+        finished = threading.Event()
+
+        class FakeBackend:
+            @_with_gguf_load_marker
+            def load_model(self, *, hf_repo):
+                started.set()
+                release.wait(timeout = 2)
+                finished.set()
+                return True
+
+        async def scenario():
+            with patch(
+                "core.inference.llama_cpp._hub_download_blocks_gguf_load",
+                return_value = False,
+            ):
+                task = asyncio.create_task(
+                    asyncio.to_thread(FakeBackend().load_model, hf_repo = REPO)
+                )
+                assert await asyncio.to_thread(started.wait, 1)
+                task.cancel()
+                with pytest.raises(asyncio.CancelledError):
+                    await task
+                assert hf_gguf_load_in_flight(REPO)
+
+                release.set()
+                assert await asyncio.to_thread(finished.wait, 1)
+                for _ in range(100):
+                    if not hf_gguf_load_in_flight(REPO):
+                        break
+                    await asyncio.sleep(0.001)
+                assert not hf_gguf_load_in_flight(REPO)
+
+        asyncio.run(scenario())
+
+    def test_load_marker_precedes_hub_guard_and_unload(self):
+        source = (Path(__file__).resolve().parent.parent / "routes" / "inference.py").read_text()
+        gguf_branch = source[source.index("if config.is_gguf:") :]
+
+        # The gguf_load_in_flight marker must be entered before the hub-download
+        # guard and the unload so a concurrent load can't race the download
+        # manager. The llama_extra_args inheritance that used to sit between the
+        # marker and the guard now runs in _guard_chat_load_against_training, ahead
+        # of the GGUF branch, so it is no longer a landmark inside this slice.
+        assert (
+            gguf_branch.index("enter_context(gguf_load_in_flight")
+            < gguf_branch.index("_hub_download_blocks_gguf_load")
+            < gguf_branch.index("unsloth_backend.unload_model")
+        )
+        llama_source = (
+            Path(__file__).resolve().parent.parent / "core" / "inference" / "llama_cpp.py"
+        ).read_text()
+        assert "@_with_gguf_load_marker\n    def load_model(" in llama_source
diff --git a/studio/backend/tests/test_gguf_metadata.py b/studio/backend/tests/test_gguf_metadata.py
index a5be07f8e3..ec0330ce05 100644
--- a/studio/backend/tests/test_gguf_metadata.py
+++ b/studio/backend/tests/test_gguf_metadata.py
@@ -15,6 +15,7 @@ from utils.models.gguf_metadata import (
     pairing_score,
     read_gguf_context_length,
     read_gguf_general_metadata,
+    read_gguf_staged_dims,
     read_mmproj_audio_capability,
 )
 
@@ -153,6 +154,78 @@ def test_context_length_ignores_foreign_arch_key(tmp_path: Path):
     assert read_gguf_context_length(str(p)) is None
 
 
+# --- read_gguf_staged_dims (one pass: context + layer + moe counts) ----
+
+
+def test_staged_dims_none_for_missing_or_non_gguf(tmp_path: Path):
+    assert read_gguf_staged_dims(str(tmp_path / "nope.gguf")) is None
+    p = tmp_path / "garbage.gguf"
+    p.write_bytes(b"not a gguf at all")
+    assert read_gguf_staged_dims(str(p)) is None
+
+
+def test_staged_dims_moe_with_leading_dense(tmp_path: Path):
+    # GLM-4.7-Flash shape: context + total layers + MoE layers in one read.
+    p = _write_synthetic_gguf(
+        tmp_path / "glm.gguf",
+        {"general.architecture": "deepseek2"},
+        extra_uint32 = {
+            "deepseek2.context_length": 202752,
+            "deepseek2.block_count": 47,
+            "deepseek2.expert_count": 64,
+            "deepseek2.leading_dense_block_count": 1,
+        },
+    )
+    assert read_gguf_staged_dims(str(p)) == {
+        "context_length": 202752,
+        "layer_count": 47,
+        "moe_layer_count": 46,
+    }
+
+
+def test_staged_dims_dense_model(tmp_path: Path):
+    # Dense: layer_count present, moe_layer_count 0 (slider hidden).
+    p = _write_synthetic_gguf(
+        tmp_path / "dense.gguf",
+        {"general.architecture": "qwen3"},
+        extra_uint32 = {"qwen3.context_length": 40960, "qwen3.block_count": 36},
+    )
+    assert read_gguf_staged_dims(str(p)) == {
+        "context_length": 40960,
+        "layer_count": 36,
+        "moe_layer_count": 0,
+    }
+
+
+def test_staged_dims_all_moe_no_leading_dense(tmp_path: Path):
+    # Experts present, no leading_dense key -> every block is a MoE layer.
+    p = _write_synthetic_gguf(
+        tmp_path / "moe.gguf",
+        {"general.architecture": "qwen35moe"},
+        extra_uint32 = {"qwen35moe.block_count": 40, "qwen35moe.expert_count": 256},
+    )
+    assert read_gguf_staged_dims(str(p)) == {
+        "context_length": None,
+        "layer_count": 40,
+        "moe_layer_count": 40,
+    }
+
+
+def test_staged_dims_uint64_block_count(tmp_path: Path):
+    # block_count stored as uint64 (vtype 10) still parses; moe == block_count.
+    p = _write_synthetic_gguf(
+        tmp_path / "moe64.gguf",
+        {"general.architecture": "gpt-oss"},
+        extra_uint32 = {"gpt-oss.expert_count": 32},
+        extra_uint64 = {"gpt-oss.block_count": 24},
+    )
+    assert read_gguf_staged_dims(str(p)) == {
+        "context_length": None,
+        "layer_count": 24,
+        "moe_layer_count": 24,
+    }
+
+
 def test_context_length_read_from_uint64(tmp_path: Path):
     # Some models store context_length as a uint64 (vtype 10).
     p = _write_synthetic_gguf(
diff --git a/studio/backend/tests/test_gpu_memory_mode.py b/studio/backend/tests/test_gpu_memory_mode.py
new file mode 100644
index 0000000000..271a882b11
--- /dev/null
+++ b/studio/backend/tests/test_gpu_memory_mode.py
@@ -0,0 +1,1156 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Backend contract for the GPU Memory mode dropdown.
+
+The dropdown threads a single ``gpu_memory_mode`` ("auto" | "manual") from the
+chat UI through the load request. "manual" lets the user own the offload: with
+``gpu_layers < 0`` (Auto, the default) it hands all memory management to
+llama.cpp's ``--fit on`` (no CUDA/HIP device masking, no context auto-reduce, no
+gpu-layer or tensor-split planning); with ``gpu_layers >= 0`` it pins the layers
+and MoE offload itself (``--fit off``). These tests pin:
+
+  * the pydantic request/response/status contract (snake_case key, default
+    "auto", unknown values rejected),
+  * the backend ``gpu_memory_mode`` property and its reset on unload,
+  * the ``_already_in_target_state`` reload-detection branch, and
+  * that the manual + Auto-layers branch in ``load_model`` empties the probed
+    GPU set and drops tensor parallelism so the selection below no-ops, while
+    the explicit-offload branch emits ``--gpu-layers`` / ``--fit off``.
+"""
+
+from __future__ import annotations
+
+import inspect
+import sys
+import types as _types
+from pathlib import Path
+
+import pytest
+
+_BACKEND_DIR = str(Path(__file__).resolve().parent.parent)
+if _BACKEND_DIR not in sys.path:
+    sys.path.insert(0, _BACKEND_DIR)
+
+# Same external-dep stubs as the other llama_cpp unit tests so importing
+# the backend doesn't drag in structlog / httpx / loggers.
+_loggers_stub = _types.ModuleType("loggers")
+_loggers_stub.get_logger = lambda name: __import__("logging").getLogger(name)
+sys.modules.setdefault("loggers", _loggers_stub)
+
+_structlog_stub = _types.ModuleType("structlog")
+_structlog_stub.get_logger = lambda *a, **k: __import__("logging").getLogger("stub")
+sys.modules.setdefault("structlog", _structlog_stub)
+
+# httpx is a real, installed backend dependency: import it so the genuine module
+# is in sys.modules. A hand-rolled stub here is inevitably incomplete and, since
+# setdefault installs it before real httpx loads, would poison a combined pytest
+# run -- routes/inference references httpx.Response (and other attrs) at def time.
+import httpx  # noqa: F401
+
+from core.inference import llama_cpp as llama_cpp_module
+from core.inference.llama_cpp import LlamaCppBackend
+from models.inference import (
+    InferenceStatusResponse,
+    LoadRequest,
+    LoadResponse,
+)
+
+
+# ── Pydantic contract (snake_case key, default "auto") ───────────────
+
+
+def test_load_request_defaults_gpu_memory_mode_auto():
+    assert LoadRequest(model_path = "owner/repo").gpu_memory_mode == "auto"
+
+
+def test_load_request_round_trips_json_key():
+    req = LoadRequest.model_validate({"model_path": "owner/repo", "gpu_memory_mode": "manual"})
+    assert req.gpu_memory_mode == "manual"
+    assert req.model_dump()["gpu_memory_mode"] == "manual"
+
+
+def test_load_request_rejects_unknown_mode():
+    with pytest.raises(ValueError):
+        LoadRequest(model_path = "owner/repo", gpu_memory_mode = "bogus")
+
+
+@pytest.mark.parametrize("model_cls", [LoadResponse, InferenceStatusResponse])
+def test_response_models_emit_gpu_memory_mode(model_cls):
+    if model_cls is LoadResponse:
+        default = model_cls(
+            status = "loaded",
+            model = "owner/repo",
+            display_name = "repo",
+            inference = {},
+        )
+        manual = model_cls(
+            status = "loaded",
+            model = "owner/repo",
+            display_name = "repo",
+            inference = {},
+            gpu_memory_mode = "manual",
+        )
+    else:
+        default = model_cls()
+        manual = model_cls(gpu_memory_mode = "manual")
+    assert default.model_dump()["gpu_memory_mode"] == "auto"
+    assert manual.model_dump()["gpu_memory_mode"] == "manual"
+
+
+# ── Backend property + reset ─────────────────────────────────────────
+
+
+class _FakeProcess:
+    """Stand-in for subprocess.Popen so _kill_process is a no-op."""
+
+    def terminate(self):
+        pass
+
+    def wait(self, timeout = None):
+        return 0
+
+    def kill(self):
+        pass
+
+    def poll(self):
+        return 0
+
+
+def test_gpu_memory_mode_property_defaults_auto():
+    assert LlamaCppBackend().gpu_memory_mode == "auto"
+
+
+def test_gpu_memory_mode_property_reflects_field():
+    backend = LlamaCppBackend()
+    backend._gpu_memory_mode = "manual"
+    assert backend.gpu_memory_mode == "manual"
+
+
+def test_unload_resets_gpu_memory_mode():
+    backend = LlamaCppBackend()
+    backend._process = _FakeProcess()
+    backend._gpu_memory_mode = "manual"
+    backend.unload_model()
+    assert backend.gpu_memory_mode == "auto"
+
+
+# ── _already_in_target_state reload-detection branch ─────────────────
+
+
+def _loaded_backend(gpu_memory_mode: str) -> LlamaCppBackend:
+    backend = LlamaCppBackend()
+    backend._process = _FakeProcess()  # is_loaded only checks "is not None"
+    backend._healthy = True
+    backend._model_identifier = "owner/repo"
+    backend._hf_variant = "Q4_K_M"
+    backend._requested_n_ctx = 8192
+    backend._cache_type_kv = None
+    backend._requested_spec_mode = "auto"
+    backend._chat_template_override = None
+    backend._is_vision = False
+    backend._extra_args = None
+    backend._gguf_path = None
+    backend._gpu_memory_mode = gpu_memory_mode
+    return backend
+
+
+def _target_state(backend: LlamaCppBackend, gpu_memory_mode: str) -> bool:
+    return backend._already_in_target_state(
+        gguf_path = None,
+        model_identifier = "owner/repo",
+        hf_variant = "Q4_K_M",
+        n_ctx = 8192,
+        cache_type_kv = None,
+        speculative_type = "auto",
+        chat_template_override = None,
+        extra_args = None,
+        is_vision = False,
+        gpu_memory_mode = gpu_memory_mode,
+    )
+
+
+@pytest.mark.parametrize("mode", ["auto", "manual"])
+def test_already_in_target_state_matches_same_mode(mode):
+    assert _target_state(_loaded_backend(mode), mode) is True
+
+
+@pytest.mark.parametrize("loaded,requested", [("auto", "manual"), ("manual", "auto")])
+def test_already_in_target_state_reloads_on_mode_change(loaded, requested):
+    # Flipping the dropdown either direction must force a reload so the command
+    # is rebuilt with/without the Unsloth GPU masking.
+    assert _target_state(_loaded_backend(loaded), requested) is False
+
+
+def test_already_in_target_state_ignores_mode_for_diffusion():
+    # The diffusion runner is mode-agnostic (always "auto"), so a standing manual
+    # preference must not force a needless reload.
+    backend = _loaded_backend("auto")
+    backend._is_diffusion = True
+    assert _target_state(backend, "manual") is True
+
+
+# ── load_model: manual + Auto layers bypasses Unsloth GPU management ──
+
+
+def _load_model_source() -> str:
+    return inspect.getsource(llama_cpp_module.LlamaCppBackend.load_model)
+
+
+def test_auto_layers_branch_empties_gpus_and_drops_tensor_parallel():
+    # Emptying the probed set makes the selection / TP planning below no-op, so
+    # gpu_indices stays None and use_fit True (--fit on).
+    src = _load_model_source()
+    gate = src.find('if gpu_memory_mode == "manual" and gpu_layers < 0:')
+    assert gate != -1, "load_model must branch on manual + Auto layers (gpu_layers < 0)"
+    block = src[gate : gate + 1400]
+    assert "gpus = []" in block, "Auto-layers branch must empty the probed GPU set"
+    # --fit aborts under --split-mode tensor, so a raw-extras split-mode is stripped.
+    assert "strip_split_mode_only(extra_args)" in block
+    assert "requested_ctx if requested_ctx > 0 else 0" in block
+    # The branch sits before GPU selection assigns gpu_indices; --fit on is its emission.
+    assert gate < src.find("gpu_indices, use_fit = None, True")
+    assert 'cmd.extend(["--fit", "on"])' in src
+    # TP drops for this path, but at a guard BEFORE the quantized-KV cache-drop, so
+    # a requested quantized cache survives into the --fit load.
+    tp_drop = src.find('if tensor_parallel and gpu_memory_mode == "manual" and gpu_layers < 0:')
+    assert tp_drop != -1, "manual + Auto layers must drop tensor_parallel"
+    assert "tensor_parallel = False" in src[tp_drop : tp_drop + 400]
+    cache_drop = src.find("Tensor parallelism requires a non-quantized KV cache")
+    assert cache_drop != -1
+    assert (
+        tp_drop < cache_drop
+    ), "TP must drop before the cache-drop so a quantized KV survives --fit"
+
+
+def test_auto_layers_never_sends_ctx_size_zero():
+    # Sending "-c 0" sets fit_params_min_ctx = UINT32_MAX in llama.cpp, pinning
+    # the full native context and disabling --fit's reduction. So the base cmd
+    # must never carry -c, "-c 0" is emitted only outside the Auto-layers (--fit)
+    # case, and a positive context is passed through (which --fit optimizes
+    # layers around).
+    src = _load_model_source()
+    base_start = src.find("cmd = [")
+    base_end = src.find("\n                ]", base_start)
+    base_block = src[base_start:base_end]
+    assert '"-c"' not in base_block, "-c must be conditional, not in the base cmd list"
+    assert 'cmd.extend(["-c", str(effective_ctx)])' in src, "positive ctx must pass -c"
+    assert 'auto_fit = gpu_memory_mode == "manual" and gpu_layers < 0' in src
+    zero = src.find('cmd.extend(["-c", "0"])')
+    assert zero != -1, '"-c 0" emission must exist outside the Auto-layers case'
+    guard = src.rfind("elif not auto_fit:", 0, zero)
+    assert guard != -1 and zero - guard < 120, '"-c 0" must sit under the not-auto_fit guard'
+
+
+def test_manual_mode_clears_inherited_main_model_placement_env():
+    env = {name: "inherited" for name in LlamaCppBackend._MANUAL_PLACEMENT_ENV_VARS}
+    env["LLAMA_ARG_N_GPU_LAYERS_DRAFT"] = "7"
+    env["UNRELATED"] = "kept"
+
+    LlamaCppBackend._clear_manual_placement_env(env)
+
+    assert not (set(env) & set(LlamaCppBackend._MANUAL_PLACEMENT_ENV_VARS))
+    assert env["LLAMA_ARG_N_GPU_LAYERS_DRAFT"] == "7"
+    assert env["UNRELATED"] == "kept"
+
+
+def test_load_model_sanitizes_manual_env_after_building_child_env():
+    src = _load_model_source()
+    env_build = src.find("env = self._llama_server_env_for_binary(binary)")
+    env_clear = src.find("self._clear_manual_placement_env(env)", env_build)
+    launch = src.find("subprocess.Popen", env_build)
+    assert env_build != -1
+    assert env_build < env_clear < launch
+
+
+# ── Manual offload (--gpu-layers + --fit off + --n-cpu-moe) ───────────
+
+
+def test_load_request_accepts_manual():
+    req = LoadRequest(
+        model_path = "owner/repo",
+        gpu_memory_mode = "manual",
+        gpu_layers = 20,
+        n_cpu_moe = 8,
+        tensor_split = [2, 1],
+    )
+    assert req.gpu_memory_mode == "manual"
+    assert req.gpu_layers == 20
+    assert req.n_cpu_moe == 8
+    assert req.tensor_split == [2, 1]
+
+
+def test_load_request_manual_defaults():
+    req = LoadRequest(model_path = "owner/repo")
+    assert req.gpu_layers == -1
+    assert req.n_cpu_moe == 0
+    assert req.tensor_split is None
+
+
+@pytest.mark.parametrize("bad", [[0, 0], [-1, 2], [float("inf"), 1], [float("nan"), 1]])
+def test_load_request_rejects_degenerate_tensor_split(bad):
+    # A negative/non-finite/all-zero split is dropped at launch but compared raw
+    # in the reload dedupe, so it would reload forever -- reject it up front.
+    with pytest.raises(ValueError):
+        LoadRequest(model_path = "owner/repo", tensor_split = bad)
+
+
+@pytest.mark.parametrize("good", [[2, 1], [1, 1], [], None])
+def test_load_request_accepts_valid_tensor_split(good):
+    assert LoadRequest(model_path = "owner/repo", tensor_split = good).tensor_split == good
+
+
+def test_route_normalizes_explicit_extras_before_reload_dedupe():
+    route_src = (Path(_BACKEND_DIR) / "routes" / "inference.py").read_text(encoding = "utf-8")
+    load_impl = route_src[route_src.index("async def _load_model_impl") :]
+    strip = load_impl.index("_stripped_explicit = strip_shadowing_flags")
+    normalize = load_impl.index(
+        'request = request.model_copy(update = {"llama_extra_args": extra_llama_args})'
+    )
+    dedupe = load_impl.index("and _request_matches_loaded_settings(")
+    assert strip < normalize < dedupe
+
+
+@pytest.mark.parametrize("model_cls", [LoadResponse, InferenceStatusResponse])
+def test_response_models_emit_manual_fields(model_cls):
+    if model_cls is LoadResponse:
+        obj = model_cls(
+            status = "loaded",
+            model = "owner/repo",
+            display_name = "repo",
+            inference = {},
+            gpu_memory_mode = "manual",
+            gpu_layers = 20,
+            n_cpu_moe = 8,
+            tensor_split = [2, 1],
+            n_layers = 32,
+            n_moe_layers = 32,
+        )
+    else:
+        obj = model_cls(
+            gpu_memory_mode = "manual",
+            gpu_layers = 20,
+            n_cpu_moe = 8,
+            tensor_split = [2, 1],
+            n_layers = 32,
+            n_moe_layers = 32,
+        )
+    dumped = obj.model_dump()
+    assert dumped["gpu_memory_mode"] == "manual"
+    assert dumped["gpu_layers"] == 20
+    assert dumped["n_cpu_moe"] == 8
+    assert dumped["tensor_split"] == [2, 1]
+    assert dumped["n_layers"] == 32
+    assert dumped["n_moe_layers"] == 32
+
+
+def test_manual_properties_default_and_reflect_and_reset():
+    backend = LlamaCppBackend()
+    assert backend.gpu_layers == -1 and backend.n_cpu_moe == 0
+    assert backend.tensor_split is None
+    backend._gpu_layers = 20
+    backend._n_cpu_moe = 8
+    backend._tensor_split = [2, 1]
+    assert backend.gpu_layers == 20 and backend.n_cpu_moe == 8
+    assert backend.tensor_split == [2, 1]
+    backend._process = _FakeProcess()
+    backend.unload_model()
+    assert backend.gpu_layers == -1 and backend.n_cpu_moe == 0
+    assert backend.tensor_split is None
+
+
+def test_n_moe_layers_property():
+    # 0 for a dense model (hides the slider); block_count for all-MoE;
+    # block_count - leading_dense otherwise (GLM-4.7-Flash: 47 - 1 -> 46).
+    b = LlamaCppBackend()
+    b._n_layers = 36
+    b._n_experts = None
+    assert b.n_moe_layers == 0
+    b._n_experts = 128
+    b._leading_dense_block_count = None
+    assert b.n_moe_layers == 36
+    b._n_layers = 47
+    b._leading_dense_block_count = 1
+    assert b.n_moe_layers == 46
+
+
+def _target_state_manual(
+    backend,
+    *,
+    gpu_layers,
+    n_cpu_moe,
+    tensor_split = None,
+):
+    return backend._already_in_target_state(
+        gguf_path = None,
+        model_identifier = "owner/repo",
+        hf_variant = "Q4_K_M",
+        n_ctx = 8192,
+        cache_type_kv = None,
+        speculative_type = "auto",
+        chat_template_override = None,
+        extra_args = None,
+        is_vision = False,
+        gpu_memory_mode = "manual",
+        gpu_layers = gpu_layers,
+        n_cpu_moe = n_cpu_moe,
+        tensor_split = tensor_split,
+    )
+
+
+def test_manual_reloads_on_gpu_layers_or_n_cpu_moe_or_split_change():
+    backend = _loaded_backend("manual")
+    backend._gpu_layers = 20
+    backend._n_cpu_moe = 0
+    backend._tensor_split = None
+    # Same knobs -> no reload.
+    assert _target_state_manual(backend, gpu_layers = 20, n_cpu_moe = 0) is True
+    # Changed layer count -> reload.
+    assert _target_state_manual(backend, gpu_layers = 16, n_cpu_moe = 0) is False
+    # Changed MoE offload -> reload.
+    assert _target_state_manual(backend, gpu_layers = 20, n_cpu_moe = 8) is False
+    # Added a GPU split -> reload.
+    assert _target_state_manual(backend, gpu_layers = 20, n_cpu_moe = 0, tensor_split = [2, 1]) is False
+    # Same GPU split -> no reload.
+    backend._tensor_split = [2, 1]
+    assert _target_state_manual(backend, gpu_layers = 20, n_cpu_moe = 0, tensor_split = [2, 1]) is True
+
+
+def test_auto_layers_reload_tracks_only_gpu_layers():
+    # Under Auto (gpu_layers < 0) the MoE/split knobs don't apply, so a leftover
+    # request value must not reload -- only a gpu_layers change (Auto -> pinned) does.
+    backend = _loaded_backend("manual")
+    backend._gpu_layers = -1
+    backend._n_cpu_moe = 0
+    backend._tensor_split = None
+    # Same Auto, leftover MoE/split in the request -> still no reload.
+    assert _target_state_manual(backend, gpu_layers = -1, n_cpu_moe = 8, tensor_split = [2, 1]) is True
+    # Auto -> explicit offload reloads.
+    assert _target_state_manual(backend, gpu_layers = 20, n_cpu_moe = 0) is False
+
+
+def test_manual_offload_emits_gpu_layers_fit_off_and_n_cpu_moe():
+    src = _load_model_source()
+    gate = src.find('elif gpu_memory_mode == "manual":')
+    assert gate != -1, "load_model must have an explicit-offload manual branch"
+    block = src[gate : gate + 700]
+    # Empties the probed set (skips the planner) but keeps the user's TP choice
+    # (only the Auto-layers branch above drops TP).
+    assert "gpus = []" in block
+    assert "tensor_parallel = False" not in block
+    # The cmd emits the layer count with fit disabled, gated on gpu_layers >= 0.
+    assert 'if gpu_memory_mode == "manual" and gpu_layers >= 0:' in src
+    assert 'cmd.extend(["--gpu-layers", str(gpu_layers), "--fit", "off"])' in src
+    # MoE offload uses --n-cpu-moe via _resolve_cpu_moe_flag (tested behaviorally below).
+    assert "_resolve_cpu_moe_flag(" in src
+    assert 'cmd.extend(["--n-cpu-moe", str(moe_flag)])' in src
+    # A count requested on a dense model is never emitted, so it must also be
+    # dropped from the recorded state -- else /status and /load report a count
+    # llama-server never received (same rule as the tensor-split drop below).
+    moe_emit = src.find('cmd.extend(["--n-cpu-moe", str(moe_flag)])')
+    assert "elif n_cpu_moe:" in src[moe_emit : moe_emit + 300]
+    assert "self._n_cpu_moe = 0" in src[moe_emit : moe_emit + 300]
+    # The offload path forces use_fit False so --fit-ctx is never added under --fit off.
+    emit = src.find('cmd.extend(["--gpu-layers", str(gpu_layers), "--fit", "off"])')
+    assert "use_fit = False" in src[src.rfind("\n", 0, emit) - 200 : emit + 80]
+
+
+def test_status_reports_requested_context_length():
+    # The hydration path re-seeds a Manual+Auto context pin from the REQUESTED
+    # n_ctx (0 = Auto); context_length only exposes the resolved value.
+    assert "requested_context_length" in InferenceStatusResponse.model_fields
+    s = InferenceStatusResponse(requested_context_length = 8192)
+    assert s.model_dump()["requested_context_length"] == 8192
+    assert InferenceStatusResponse().model_dump()["requested_context_length"] is None
+    # The /status route must actually wire it from the backend (a declared-but-
+    # never-populated field would leave hydration silently reverting the pin).
+    from pathlib import Path as _P
+
+    route_src = (_P(_BACKEND_DIR) / "routes" / "inference.py").read_text(encoding = "utf-8")
+    assert "requested_context_length = llama_backend.requested_n_ctx" in route_src
+
+
+def test_manual_offload_emits_tensor_split():
+    # The offload path emits --tensor-split from the per-GPU shares, only when
+    # provided, with >1 GPU in use, AND matching that count (a stale ratio on a
+    # narrowed picker or a mismatched direct-API list must not emit -- llama-
+    # server aborts on a split/GPU-count mismatch).
+    src = _load_model_source()
+    assert "if tensor_split and _split_gpus > 1:" in src
+    # Emit only on a length match AND a positive sanitized total: a mismatched
+    # or all-zero split aborts llama-server / assigns nothing, so it's dropped.
+    # The emitted list is the sanitized one (clamping tested behaviorally below).
+    assert "_sanitized_split = self._sanitize_tensor_split(tensor_split)" in src
+    assert "if len(_sanitized_split) == _split_gpus and _split_total > 0:" in src
+    assert '"--tensor-split"' in src
+    # Joined as a comma list (e.g. "2,1") within the explicit-offload cmd branch.
+    gate = src.find('if gpu_memory_mode == "manual" and gpu_layers >= 0:')
+    nxt = src.find("elif use_fit:", gate)
+    assert '","' in src[gate:nxt] and "tensor_split" in src[gate:nxt]
+    # A split with a single effective GPU is never emitted, so it must also be
+    # dropped from the recorded state -- else /status and /load report a ratio
+    # llama-server never received and the dedupe baseline preserves it.
+    assert "elif tensor_split:" in src[gate:nxt]
+    drop = src.find("elif tensor_split:", gate, nxt)
+    assert "self._tensor_split = None" in src[drop : drop + 250]
+
+
+def test_sanitize_tensor_split_clamps_negative_and_non_finite():
+    # Negative entries would launch a placement different from the ratio the
+    # UI showed; inf passes a plain > 0 total gate and would emit
+    # "--tensor-split inf,..." (llama.cpp normalizes shares by the running
+    # total, so an inf poisons the shares from that entry on). Both clamp to 0.
+    sanitize = LlamaCppBackend._sanitize_tensor_split
+    assert sanitize([2, 1]) == [2.0, 1.0]
+    assert sanitize([-1, 2]) == [0.0, 2.0]
+    assert sanitize([float("inf"), 1]) == [0.0, 1.0]
+    assert sanitize([float("nan"), 1]) == [0.0, 1.0]
+    # All-zero survives sanitization; the call site's total gate drops it.
+    assert sanitize([0, 0]) == [0.0, 0.0]
+    # Unreadable input -> []; the call site's length gate drops it.
+    assert sanitize(["x", 1]) == []
+    assert sanitize([10**400, 1]) == []
+
+
+def test_zero_offload_mask_honors_device_pin_spellings():
+    # A user device pin must keep the GPUs visible: llama-server aborts on a
+    # pin it can't see ('error: invalid device'). The pin can arrive as
+    # --device or its -dev alias, as the draft forms (parsed even with no
+    # drafter loaded), or as an inherited LLAMA_ARG_DEVICE env var.
+    load_src = _load_model_source()
+    assert "self._zero_offload_keeps_gpu_visible(cmd, env)" in load_src
+    block = inspect.getsource(LlamaCppBackend._cmd_has_gpu_device_pin)
+    for flag in (
+        '"--device"',
+        '"-dev"',
+        '"--spec-draft-device"',
+        '"-devd"',
+        '"--device-draft"',
+    ):
+        assert flag in block
+    assert '"LLAMA_ARG_DEVICE"' in block
+
+
+def test_resolve_cpu_moe_flag():
+    # Clamp the requested MoE-layer count to the model's MoE layers, then offset
+    # past leading dense layers (--n-cpu-moe counts from layer 0).
+    R = LlamaCppBackend._resolve_cpu_moe_flag
+    assert R(0, 40, 0) is None  # nothing requested
+    assert R(8, 0, 0) is None  # dense model (no MoE layers)
+    assert R(8, 40, 0) == 8  # all-MoE: direct
+    assert R(100, 40, 0) == 40  # clamp to the MoE layer count
+    # GLM-4.7-Flash (deepseek2): block_count 47, leading_dense 1, n_moe 46.
+    assert R(5, 46, 1) == 6  # offset past the 1 dense layer
+    assert R(46, 46, 1) == 47  # all MoE on CPU == block_count
+
+
+def test_manual_allows_tensor_parallel_via_split_mode():
+    # Manual offload keeps the user's TP choice but skips the memory-based planner
+    # (plan_tp excludes manual, so its empty gpu set can't downgrade TP). The
+    # --split-mode tensor emission gates on tensor_parallel alone, so manual
+    # reaches it -- with tp_tensor_split None it's an even split (no
+    # --tensor-split). --fit off means no fit/tensor abort.
+    src = _load_model_source()
+    assert 'plan_tp = tensor_parallel and gpu_memory_mode != "manual"' in src
+    assert "if plan_tp:" in src
+    assert "if plan_tp and len(tp_gpus) < 2:" in src
+    sm = src.find('cmd.extend(["--split-mode", "tensor"])')
+    assert sm != -1, "TP must emit --split-mode tensor"
+    guard = src.rfind("if tensor_parallel:", 0, sm)
+    assert guard != -1 and sm - guard < 200, "split-mode gates on tensor_parallel"
+    # The tensor-split is only emitted for a planned (non-even) split, which
+    # manual never produces, so manual stays an even split.
+    assert "if tp_tensor_split and len(tp_tensor_split) > 1:" in src
+
+
+def test_fit_sets_target_margin():
+    # Manual + Auto (auto_fit) tightens the per-device VRAM margin to 512 MiB.
+    caps = {"supports_fit_target": True}
+    flags = LlamaCppBackend._ctx_integrity_flags(1, True, True, 0, 0, caps)
+    assert flags[flags.index("--fit-target") + 1] == "512"
+    # Not emitted on the legacy auto path (fit on but not auto_fit): -c 0 pins
+    # native there, so the tighter margin must not ride along.
+    assert "--fit-target" not in LlamaCppBackend._ctx_integrity_flags(1, True, False, 0, 0, caps)
+    # Not emitted when fit is off.
+    assert "--fit-target" not in LlamaCppBackend._ctx_integrity_flags(1, False, False, 0, 0, caps)
+    # Not emitted when the binary lacks support.
+    assert "--fit-target" not in LlamaCppBackend._ctx_integrity_flags(
+        1, True, True, 0, 0, {"supports_fit_target": False}
+    )
+
+
+# ── GPU picker (gpu_ids -> CUDA_VISIBLE_DEVICES) ─────────────────────
+
+
+def test_load_request_accepts_gpu_ids():
+    req = LoadRequest(model_path = "owner/repo", gpu_ids = [1, 0])
+    assert req.gpu_ids == [1, 0]
+    assert LoadRequest(model_path = "owner/repo").gpu_ids is None
+
+
+@pytest.mark.parametrize("model_cls", [LoadResponse, InferenceStatusResponse])
+def test_response_models_emit_gpu_ids(model_cls):
+    if model_cls is LoadResponse:
+        obj = model_cls(
+            status = "loaded",
+            model = "m",
+            display_name = "m",
+            inference = {},
+            gpu_ids = [1],
+            requested_gpu_ids = [1, 2],
+        )
+    else:
+        obj = model_cls(gpu_ids = [1], requested_gpu_ids = [1, 2])
+    assert obj.model_dump()["gpu_ids"] == [1]
+    assert obj.model_dump()["requested_gpu_ids"] == [1, 2]
+
+
+def test_gguf_load_and_status_responses_include_requested_gpu_pool():
+    route_src = (Path(_BACKEND_DIR) / "routes" / "inference.py").read_text(encoding = "utf-8")
+    assert route_src.count("requested_gpu_ids = llama_backend.requested_gpu_ids") == 3
+
+
+def test_gpu_ids_property_default_and_reset():
+    backend = LlamaCppBackend()
+    assert backend.gpu_ids is None
+    backend._gpu_ids = [0, 1]
+    assert backend.gpu_ids == [0, 1]
+    backend._process = _FakeProcess()
+    backend.unload_model()
+    assert backend.gpu_ids is None
+
+
+def _target_state_gpu_ids(backend, gpu_ids):
+    return backend._already_in_target_state(
+        gguf_path = None,
+        model_identifier = "owner/repo",
+        hf_variant = "Q4_K_M",
+        n_ctx = 8192,
+        cache_type_kv = None,
+        speculative_type = "auto",
+        chat_template_override = None,
+        extra_args = None,
+        is_vision = False,
+        gpu_ids = gpu_ids,
+    )
+
+
+def test_gpu_ids_reload_detection_is_order_insensitive():
+    backend = _loaded_backend("auto")
+    backend._gpu_ids = [0, 1]
+    # A real non-narrowed load records the raw request too; the non-diffusion
+    # dedupe now compares that raw pin (#7239). Set it to match the effective pin
+    # (no narrowing) so this exercises the order-insensitive comparison.
+    backend._requested_gpu_ids = [0, 1]
+    # Same set, different order -> no reload.
+    assert _target_state_gpu_ids(backend, [1, 0]) is True
+    # Different set -> reload.
+    assert _target_state_gpu_ids(backend, [0]) is False
+    # Dropping the pick (auto) -> reload.
+    assert _target_state_gpu_ids(backend, None) is False
+
+
+def test_gpu_ids_reload_detection_accepts_raw_and_effective_pin():
+    backend = _loaded_backend("auto")
+    backend._requested_gpu_ids = [0, 1]
+    backend._gpu_ids = [0]
+    backend._last_load_kwargs = {"gpu_ids": [0, 1], "model_identifier": "owner/repo"}
+
+    # The original request still matches after the fitter narrows it.
+    assert _target_state_gpu_ids(backend, [1, 0]) is True
+    assert backend.requested_gpu_ids == [0, 1]
+    # The status response echoes the effective pin, which must also round-trip.
+    # Treat the incoming subset as the latest intent so status and a future
+    # reload do not restore GPU 1 after the user removed it.
+    assert _target_state_gpu_ids(backend, [0]) is True
+    assert backend.requested_gpu_ids == [0]
+    assert backend._last_load_kwargs == {"gpu_ids": [0], "model_identifier": "owner/repo"}
+    # A genuinely different placement pool still reloads.
+    assert _target_state_gpu_ids(backend, [1]) is False
+    assert _target_state_gpu_ids(backend, None) is False
+
+
+def test_gpu_ids_reload_detection_collapses_diffusion_to_single_device():
+    # The diffusion runner drives only its single lowest device, so the backend
+    # records [lowest]. A later multi-GPU request that still resolves to that
+    # same lowest device must dedupe (no needless reload); a request whose lowest
+    # device moves, or that drops the pick, must reload.
+    backend = _loaded_backend("auto")
+    backend._is_diffusion = True
+    backend._gpu_ids = [1]  # loaded on the lowest of an earlier [3, 1] pick
+    assert _target_state_gpu_ids(backend, [3, 1]) is True
+    assert backend.requested_gpu_ids == [1]
+    assert _target_state_gpu_ids(backend, [1]) is True
+    # Lowest device changes (2, not 1) -> reload.
+    assert _target_state_gpu_ids(backend, [3, 2]) is False
+    # Dropping the pick (auto) -> reload.
+    assert _target_state_gpu_ids(backend, None) is False
+
+
+def test_remote_vulkan_diffusion_preflight_runs_before_teardown(monkeypatch):
+    def _mark_diffusion(probe, path):
+        assert path == "/cache/model.gguf"
+        probe._is_diffusion = True
+
+    monkeypatch.setattr(LlamaCppBackend, "_read_gguf_metadata", _mark_diffusion)
+    assert LlamaCppBackend._gguf_path_is_diffusion("/cache/model.gguf", "owner/model") is True
+
+    src = inspect.getsource(llama_cpp_module.LlamaCppBackend.load_model)
+    preflight = src.index("_preflight_model_path = self._download_gguf(")
+    teardown = src.index("# ── Phase 1: kill old process")
+    assert preflight < teardown
+    assert "model_path = _preflight_model_path or self._download_gguf(" in src
+
+
+def test_remote_vulkan_diffusion_rejection_keeps_active_server(monkeypatch):
+    backend = LlamaCppBackend()
+    killed = []
+    monkeypatch.setattr(backend, "_find_llama_server_binary", lambda **_kwargs: "/bin/llama")
+    monkeypatch.setattr(backend, "_is_vulkan_backend", lambda _binary = None: True)
+    monkeypatch.setattr(backend, "_get_gpu_memory", lambda _binary = None: [(0, 1024, 2048)])
+    monkeypatch.setattr(
+        backend,
+        "_download_gguf",
+        lambda **_kwargs: "/cache/diffusion.gguf",
+    )
+    monkeypatch.setattr(backend, "_gguf_path_is_diffusion", lambda *_args: True)
+    monkeypatch.setattr(backend, "_kill_process", lambda: killed.append(True))
+    monkeypatch.setattr(
+        llama_cpp_module,
+        "_resolve_repo_id_casing",
+        lambda repo: repo,
+    )
+    monkeypatch.setattr(
+        llama_cpp_module,
+        "_hf_offline_if_dns_dead",
+        lambda: __import__("contextlib").nullcontext(),
+    )
+
+    with pytest.raises(ValueError, match = "DiffusionGemma"):
+        backend.load_model(
+            hf_repo = "owner/model",
+            hf_variant = "Q4_K_M",
+            model_identifier = "owner/model",
+            gpu_ids = [0],
+        )
+
+    assert killed == []
+
+
+def test_start_diffusion_server_resets_tensor_parallel():
+    # A prior tensor-parallel chat load leaves self._tensor_parallel True (load_model
+    # phase 1 only kills the process, it skips the unload reset). Diffusion is never
+    # TP, so startup must clear it -- else /status misreports TP and an identical
+    # diffusion re-Apply reloads against stale tensor-parallel state.
+    src = inspect.getsource(llama_cpp_module.LlamaCppBackend._start_diffusion_server)
+    assert "self._tensor_parallel = False" in src
+    assert "self._requested_gpu_ids = list(self._gpu_ids) if self._gpu_ids else None" in src
+
+
+def test_route_matches_loaded_settings_uses_shared_gpu_pin_matcher():
+    # Route-level and backend race dedupe must share one normalization path so
+    # raw, effective, and diffusion pins cannot drift apart.
+    route_src = (Path(_BACKEND_DIR) / "routes" / "inference.py").read_text(encoding = "utf-8")
+    match_impl = route_src[route_src.index("def _request_matches_loaded_settings") :]
+    assert "if not llama_backend.matches_gpu_ids(request.gpu_ids):" in match_impl
+    assert "llama_backend._record_matching_gpu_request(request.gpu_ids)" in match_impl
+
+
+# ── Manual tensor split: child enumeration pinned to the picker's order ──────
+
+
+def _patch_split_pin_env(monkeypatch, *, inherited, reported):
+    """Point the pin helper at a fake inherited mask and picker report.
+    ``reported`` None = enumeration unavailable (falls back to ascending)."""
+    import utils.hardware as hw
+
+    monkeypatch.setattr(
+        LlamaCppBackend, "_resolve_visible_physical_ids", staticmethod(lambda: inherited)
+    )
+    info = (
+        {"available": False}
+        if reported is None
+        else {
+            "available": True,
+            "index_kind": "physical",
+            "devices": [{"index": i} for i in reported],
+        }
+    )
+    monkeypatch.setattr(hw, "get_backend_visible_gpu_info", lambda: info)
+
+
+def test_split_pin_reorders_inherited_numeric_mask(monkeypatch):
+    # Parent CUDA_VISIBLE_DEVICES=3,1 makes the child enumerate dev0=phys3, but
+    # nvidia-smi reported the picker's list ascending -- the mask must be
+    # re-emitted in that order or the per-GPU shares land on the wrong cards.
+    _patch_split_pin_env(monkeypatch, inherited = [3, 1], reported = [1, 3])
+    env = {"CUDA_VISIBLE_DEVICES": "3,1"}
+    LlamaCppBackend._pin_visible_gpu_order_for_split(env)
+    assert env["CUDA_DEVICE_ORDER"] == "PCI_BUS_ID"
+    assert env["CUDA_VISIBLE_DEVICES"] == "1,3"
+
+
+def test_split_pin_keeps_mask_order_when_picker_reported_it(monkeypatch):
+    # Torch-fallback enumeration (no nvidia-smi) reports devices in inherited
+    # mask order, so the picker's split list follows the mask -- the pin must
+    # keep that order, not re-sort it into a mismatch.
+    _patch_split_pin_env(monkeypatch, inherited = [3, 1], reported = [3, 1])
+    env = {"CUDA_VISIBLE_DEVICES": "3,1"}
+    LlamaCppBackend._pin_visible_gpu_order_for_split(env)
+    assert env["CUDA_VISIBLE_DEVICES"] == "3,1"
+
+
+def test_split_pin_falls_back_to_ascending_without_report(monkeypatch):
+    # Enumeration unavailable: ascending physical is the best guess (it matches
+    # the dominant nvidia-smi report order).
+    _patch_split_pin_env(monkeypatch, inherited = [3, 1], reported = None)
+    env = {"CUDA_VISIBLE_DEVICES": "3,1"}
+    LlamaCppBackend._pin_visible_gpu_order_for_split(env)
+    assert env["CUDA_VISIBLE_DEVICES"] == "1,3"
+
+
+def test_split_pin_without_mask_only_sets_pci_order(monkeypatch):
+    # No inherited mask (or a UUID/MIG one resolving to None): enumeration order
+    # is fully fixed by CUDA_DEVICE_ORDER, so no mask is written.
+    _patch_split_pin_env(monkeypatch, inherited = None, reported = None)
+    env = {}
+    LlamaCppBackend._pin_visible_gpu_order_for_split(env)
+    assert env == {"CUDA_DEVICE_ORDER": "PCI_BUS_ID"}
+
+
+def test_split_pin_mirrors_hip_mask_on_rocm(monkeypatch):
+    # ROCm with the mask sourced from HIP: the pin must land in
+    # HIP_VISIBLE_DEVICES too, and an inherited ROCR mask is cleared so the
+    # mask can't apply twice (ROCR re-indexes, then HIP would index into the
+    # already-reduced set).
+    _patch_split_pin_env(monkeypatch, inherited = [3, 1], reported = [1, 3])
+    _rocm_torch_stub(monkeypatch)
+    env = {
+        "CUDA_VISIBLE_DEVICES": "3,1",
+        "HIP_VISIBLE_DEVICES": "3,1",
+        "ROCR_VISIBLE_DEVICES": "3,1",
+    }
+    LlamaCppBackend._pin_visible_gpu_order_for_split(env)
+    assert env["CUDA_VISIBLE_DEVICES"] == "1,3"
+    assert env["HIP_VISIBLE_DEVICES"] == "1,3"
+    assert "ROCR_VISIBLE_DEVICES" not in env
+
+
+def test_split_pin_preserves_inherited_rocr_mask(monkeypatch):
+    # Mask sourced from ROCR alone (e.g. an AMD SDK parent): the pin must
+    # re-emit at the ROCr layer, not swap to HIP -- clearing ROCR re-exposes
+    # every agent to HSA enumeration, which can segfault at startup on an
+    # unsupported GPU the parent mask was hiding (#7272 review). CUDA carries
+    # the post-ROCR ordinals, mirroring the prefer_rocr emission.
+    _patch_split_pin_env(monkeypatch, inherited = [3, 1], reported = [1, 3])
+    _rocm_torch_stub(monkeypatch)
+    env = {"ROCR_VISIBLE_DEVICES": "3,1"}
+    LlamaCppBackend._pin_visible_gpu_order_for_split(env)
+    assert env["ROCR_VISIBLE_DEVICES"] == "1,3"
+    assert env["CUDA_VISIBLE_DEVICES"] == "0,1"
+    assert "HIP_VISIBLE_DEVICES" not in env
+
+
+def test_split_pin_keeps_hip_on_windows_despite_stray_rocr(monkeypatch):
+    # On Windows the ROCR var is dead (no ROCr layer) and the resolver never
+    # reads it, so a stray value must not flip the pin to the ROCR emission:
+    # the HIP mask is the only effective selector there.
+    _patch_split_pin_env(monkeypatch, inherited = [3, 1], reported = [1, 3])
+    torch_stub = _types.ModuleType("torch")
+    torch_stub.version = _types.SimpleNamespace(hip = "6.0")
+    monkeypatch.setitem(sys.modules, "torch", torch_stub)
+    monkeypatch.setattr(sys, "platform", "win32")
+    env = {"CUDA_VISIBLE_DEVICES": "3,1", "ROCR_VISIBLE_DEVICES": "9"}
+    LlamaCppBackend._pin_visible_gpu_order_for_split(env)
+    assert env["CUDA_VISIBLE_DEVICES"] == "1,3"
+    assert env["HIP_VISIBLE_DEVICES"] == "1,3"
+    assert "ROCR_VISIBLE_DEVICES" not in env
+
+
+def _rocm_torch_stub(monkeypatch):
+    torch_stub = _types.ModuleType("torch")
+    torch_stub.version = _types.SimpleNamespace(hip = "6.0")
+    monkeypatch.setitem(sys.modules, "torch", torch_stub)
+    # prefer_rocr is Linux-only (ROCR is an ROCr variable); pin the platform so
+    # these Linux-behaviour tests also pass on a Windows dev box.
+    monkeypatch.setattr(sys, "platform", "linux")
+
+
+def test_subset_pin_masks_via_rocr_on_rocm(monkeypatch):
+    # A GPU-subset pin must exclude the rest at the ROCr/HSA layer: HIP masking
+    # still enumerates every agent first, which segfaults the build on an
+    # unsupported deselected GPU (e.g. a gfx1103 iGPU under a gfx110X prebuilt).
+    # ROCR drops it at the driver layer; only one mask is set (HIP cleared).
+    _rocm_torch_stub(monkeypatch)
+    env = {"HIP_VISIBLE_DEVICES": "9"}  # stale/inherited HIP mask must not survive
+    LlamaCppBackend._emit_child_gpu_visibility(env, "0", prefer_rocr = True)
+    assert env["ROCR_VISIBLE_DEVICES"] == "0"
+    assert env["CUDA_VISIBLE_DEVICES"] == "0"
+    assert "HIP_VISIBLE_DEVICES" not in env
+
+
+def test_prefer_rocr_remaps_cuda_to_post_rocr_ordinals(monkeypatch):
+    # ROCR re-indexes the visible agents from 0, and HIP (cleared here) falls back
+    # to CUDA_VISIBLE_DEVICES -- so on the prefer_rocr path CUDA must carry the
+    # post-ROCR ordinals, not the physical ids, else a non-zero pick indexes out
+    # of range and the child sees no GPU and drops to CPU (#7272 review).
+    _rocm_torch_stub(monkeypatch)
+    # Single non-zero GPU: ROCR keeps the physical id, CUDA becomes ordinal 0.
+    env = {}
+    LlamaCppBackend._emit_child_gpu_visibility(env, "1", prefer_rocr = True)
+    assert env["ROCR_VISIBLE_DEVICES"] == "1"
+    assert env["CUDA_VISIBLE_DEVICES"] == "0"
+    assert "HIP_VISIBLE_DEVICES" not in env
+    # Multi-GPU subset: ROCR keeps the physical ids, CUDA is the 0-based ordinals.
+    env = {}
+    LlamaCppBackend._emit_child_gpu_visibility(env, "1,3", prefer_rocr = True)
+    assert env["ROCR_VISIBLE_DEVICES"] == "1,3"
+    assert env["CUDA_VISIBLE_DEVICES"] == "0,1"
+    assert "HIP_VISIBLE_DEVICES" not in env
+
+
+def test_subset_pin_default_still_uses_hip_and_clears_rocr(monkeypatch):
+    # Without prefer_rocr the masking is unchanged: HIP narrows, inherited ROCR
+    # is cleared so the two can't double-mask.
+    _rocm_torch_stub(monkeypatch)
+    env = {"ROCR_VISIBLE_DEVICES": "0,1"}
+    LlamaCppBackend._emit_child_gpu_visibility(env, "1")
+    assert env["HIP_VISIBLE_DEVICES"] == "1"
+    assert "ROCR_VISIBLE_DEVICES" not in env
+
+
+def test_cpu_only_pin_keeps_hip_even_with_prefer_rocr(monkeypatch):
+    # The CPU-only sentinel never routes through ROCR (no portable "hide all"
+    # spelling); it hides every GPU via HIP.
+    _rocm_torch_stub(monkeypatch)
+    env = {}
+    LlamaCppBackend._emit_child_gpu_visibility(env, "-1", prefer_rocr = True)
+    assert env["HIP_VISIBLE_DEVICES"] == "-1"
+    assert "ROCR_VISIBLE_DEVICES" not in env
+
+
+def _amd_sdk_torch_stub(monkeypatch):
+    # AMD SDK wheel: torch.version.hip is None but __version__ encodes rocm.
+    torch_stub = _types.ModuleType("torch")
+    torch_stub.version = _types.SimpleNamespace(hip = None)
+    torch_stub.__version__ = "2.9.1+rocm7.2.1"
+    monkeypatch.setitem(sys.modules, "torch", torch_stub)
+    monkeypatch.setattr(sys, "platform", "linux")
+
+
+def test_prefer_rocr_falls_back_to_hip_on_windows(monkeypatch):
+    # ROCR_VISIBLE_DEVICES is a Linux ROCr variable (Windows HIP has no ROCr
+    # layer), so on Windows ROCm prefer_rocr must keep the HIP mask or a nonzero
+    # pick loses its only effective selector (#7272 review).
+    torch_stub = _types.ModuleType("torch")
+    torch_stub.version = _types.SimpleNamespace(hip = "6.0")
+    monkeypatch.setitem(sys.modules, "torch", torch_stub)
+    monkeypatch.setattr(sys, "platform", "win32")
+    env = {"ROCR_VISIBLE_DEVICES": "9"}
+    LlamaCppBackend._emit_child_gpu_visibility(env, "1", prefer_rocr = True)
+    assert env["HIP_VISIBLE_DEVICES"] == "1"
+    assert env["CUDA_VISIBLE_DEVICES"] == "1"
+    assert "ROCR_VISIBLE_DEVICES" not in env
+
+
+def test_amd_sdk_wheel_hip_none_still_masks_rocr(monkeypatch):
+    # An AMD SDK wheel leaves torch.version.hip unset but has "rocm" in __version__.
+    # It must still get the ROCR mask, else only CUDA_VISIBLE_DEVICES is set and an
+    # unsupported iGPU keeps enumerating and can crash llama-server.
+    _amd_sdk_torch_stub(monkeypatch)
+    env = {"HIP_VISIBLE_DEVICES": "9"}
+    LlamaCppBackend._emit_child_gpu_visibility(env, "0", prefer_rocr = True)
+    assert env["ROCR_VISIBLE_DEVICES"] == "0"
+    assert "HIP_VISIBLE_DEVICES" not in env
+
+
+def test_cuda_wheel_hip_none_gets_no_rocm_mask(monkeypatch):
+    # A CUDA wheel (hip=None, no "rocm" in __version__) must NOT get a HIP/ROCR mask
+    # -- only CUDA_VISIBLE_DEVICES -- so the version-string check can't false-positive.
+    torch_stub = _types.ModuleType("torch")
+    torch_stub.version = _types.SimpleNamespace(hip = None)
+    torch_stub.__version__ = "2.9.1+cu124"
+    monkeypatch.setitem(sys.modules, "torch", torch_stub)
+    env = {}
+    LlamaCppBackend._emit_child_gpu_visibility(env, "0", prefer_rocr = True)
+    assert env["CUDA_VISIBLE_DEVICES"] == "0"
+    assert "ROCR_VISIBLE_DEVICES" not in env
+    assert "HIP_VISIBLE_DEVICES" not in env
+
+
+def test_resolve_physical_ids_reads_rocr_on_amd_sdk_wheel(monkeypatch):
+    # _resolve_visible_physical_ids must use the same ROCm detection as
+    # _emit_child_gpu_visibility: on an AMD SDK wheel (hip=None, rocm in
+    # __version__) an inherited ROCR mask IS the ordinal->physical mapping.
+    # Reading it as "no mask" labels ordinal 0 as physical 0 and the child's
+    # ROCR pin then re-exposes the GPU the mask was hiding (#7272 review).
+    _amd_sdk_torch_stub(monkeypatch)
+    for var in ("HIP_VISIBLE_DEVICES", "CUDA_VISIBLE_DEVICES"):
+        monkeypatch.delenv(var, raising = False)
+    monkeypatch.setenv("ROCR_VISIBLE_DEVICES", "1")
+    assert LlamaCppBackend._resolve_visible_physical_ids() == [1]
+
+
+def test_resolve_physical_ids_ignores_rocr_on_cuda_wheel(monkeypatch):
+    # A CUDA wheel (hip=None, no "rocm") keeps CUDA-only semantics: a stray
+    # ROCR var must not be read as the mask.
+    torch_stub = _types.ModuleType("torch")
+    torch_stub.version = _types.SimpleNamespace(hip = None)
+    torch_stub.__version__ = "2.9.1+cu124"
+    monkeypatch.setitem(sys.modules, "torch", torch_stub)
+    for var in ("HIP_VISIBLE_DEVICES", "CUDA_VISIBLE_DEVICES"):
+        monkeypatch.delenv(var, raising = False)
+    monkeypatch.setenv("ROCR_VISIBLE_DEVICES", "1")
+    assert LlamaCppBackend._resolve_visible_physical_ids() is None
+
+
+def test_resolve_physical_ids_ignores_rocr_on_windows(monkeypatch):
+    # ROCR_VISIBLE_DEVICES is a Linux ROCr variable: Windows HIP has no ROCr
+    # layer, so a stray ROCR var there does not mask the runtime. Reading it as
+    # the ordinal->physical mapping would label ordinal 0 with a stale ROCR id
+    # while the runtime still enumerates every adapter, so auto-selection could
+    # budget one card and pin another (#7272 review). HIP must still be honoured.
+    torch_stub = _types.ModuleType("torch")
+    torch_stub.version = _types.SimpleNamespace(hip = None)
+    torch_stub.__version__ = "2.9.1+rocm7.2.1"  # AMD SDK wheel
+    monkeypatch.setitem(sys.modules, "torch", torch_stub)
+    monkeypatch.setattr(sys, "platform", "win32")
+    for var in ("HIP_VISIBLE_DEVICES", "CUDA_VISIBLE_DEVICES"):
+        monkeypatch.delenv(var, raising = False)
+    monkeypatch.setenv("ROCR_VISIBLE_DEVICES", "1")
+    assert LlamaCppBackend._resolve_visible_physical_ids() is None
+    # HIP precedence is unchanged on Windows.
+    monkeypatch.setenv("HIP_VISIBLE_DEVICES", "1")
+    assert LlamaCppBackend._resolve_visible_physical_ids() == [1]
+
+
+# ── Diffusion single-device selection ───────────────────────────────────────
+
+
+def test_diffusion_gpu_arg_uses_lowest_explicit_physical_id(monkeypatch):
+    monkeypatch.setenv("CUDA_VISIBLE_DEVICES", "3,1")
+    monkeypatch.setenv("DG_GPU", "7")
+    assert LlamaCppBackend._diffusion_gpu_arg([3, 1]) == "1"
+
+
+def test_diffusion_gpu_arg_preserves_parent_mask_order(monkeypatch):
+    monkeypatch.delenv("DG_GPU", raising = False)
+    monkeypatch.setenv("CUDA_VISIBLE_DEVICES", "3,1")
+    assert LlamaCppBackend._diffusion_gpu_arg(None) == "3"
+
+
+def test_diffusion_gpu_arg_honors_override_and_cpu_mask(monkeypatch):
+    monkeypatch.setenv("DG_GPU", "GPU-abc")
+    assert LlamaCppBackend._diffusion_gpu_arg(None) == "GPU-abc"
+    assert LlamaCppBackend._diffusion_gpu_arg(None, cpu_only = True) == ""
+
+
+# ── Deliberate zero-offload (manual gpu_layers=0): training-skip flag ─────────
+
+
+def test_zero_offload_flag_false_without_companions():
+    # CPU-only by construction: False lets training skip unloading a server that
+    # holds no VRAM.
+    cmd = ["llama-server", "-m", "model.gguf", "--gpu-layers", "0", "--fit", "off"]
+    assert LlamaCppBackend._zero_offload_gpu_flag(cmd, [(0, 8000, 24000)], {}) is False
+
+
+@pytest.mark.parametrize(
+    "companion",
+    ["--mmproj", "--model-draft", "-md", "--spec-draft-model", "-hfd"],
+)
+def test_zero_offload_flag_true_with_companion(companion):
+    # mmproj / a drafter offload to GPU regardless of --gpu-layers, so the
+    # server still holds VRAM and training must unload it. Drafter detection
+    # reuses the extras parser, so pass-through aliases count too.
+    cmd = ["llama-server", "-m", "model.gguf", "--gpu-layers", "0", companion, "x.gguf"]
+    assert LlamaCppBackend._zero_offload_gpu_flag(cmd, [(0, 8000, 24000)], {}) is True
+
+
+def test_zero_offload_flag_true_with_inline_companion_forms():
+    cmd = ["llama-server", "-m", "model.gguf", "--spec-draft-model=x.gguf"]
+    assert LlamaCppBackend._zero_offload_gpu_flag(cmd, [(0, 8000, 24000)], {}) is True
+    cmd = ["llama-server", "-m", "model.gguf", "--mmproj=proj.gguf"]
+    assert LlamaCppBackend._zero_offload_gpu_flag(cmd, [(0, 8000, 24000)], {}) is True
+
+
+def test_zero_offload_flag_true_with_env_drafter():
+    cmd = ["llama-server", "-m", "model.gguf", "--gpu-layers", "0"]
+    env = {"LLAMA_ARG_SPEC_DRAFT_MODEL": "x.gguf"}
+    assert LlamaCppBackend._zero_offload_gpu_flag(cmd, [(0, 8000, 24000)], env) is True
+
+
+@pytest.mark.parametrize(
+    "device_args",
+    [
+        ["--device", "CUDA0"],
+        ["--device=CUDA0"],
+        ["-dev", "CUDA0"],
+        ["--spec-draft-device", "CUDA0"],
+        ["--device-draft=CUDA0"],
+    ],
+)
+def test_zero_offload_flag_true_with_device_pin(device_args):
+    cmd = ["llama-server", "-m", "model.gguf", "--gpu-layers", "0", *device_args]
+    assert LlamaCppBackend._zero_offload_gpu_flag(cmd, [(0, 8000, 24000)], {}) is True
+
+
+def test_zero_offload_flag_true_with_env_device_pin():
+    cmd = ["llama-server", "-m", "model.gguf", "--gpu-layers", "0"]
+    env = {"LLAMA_ARG_DEVICE": "CUDA0"}
+    assert LlamaCppBackend._zero_offload_gpu_flag(cmd, [(0, 8000, 24000)], env) is True
+
+
+@pytest.mark.parametrize(
+    ("device_args", "env"),
+    [
+        (["--device", "cpu"], {}),
+        (["--device=none"], {}),
+        (["--spec-draft-device", "cpu"], {}),
+        ([], {"LLAMA_ARG_DEVICE": "none"}),
+        (["--device", "CUDA0", "--device", "cpu"], {}),
+    ],
+)
+def test_zero_offload_flag_false_with_cpu_device_pin(device_args, env):
+    cmd = ["llama-server", "-m", "model.gguf", "--gpu-layers", "0", *device_args]
+    assert LlamaCppBackend._zero_offload_gpu_flag(cmd, [(0, 8000, 24000)], env) is False
+
+
+def test_zero_offload_flag_true_with_surviving_tensor_mode():
+    cmd = ["llama-server", "-m", "model.gguf", "--gpu-layers", "0", "--split-mode", "tensor"]
+    assert LlamaCppBackend._zero_offload_gpu_flag(cmd, [(0, 8000, 24000)], {}) is True
+
+
+def test_zero_offload_flag_true_for_unmasked_vulkan(monkeypatch):
+    monkeypatch.setattr(LlamaCppBackend, "_is_vulkan_backend", staticmethod(lambda: True))
+    cmd = ["llama-server", "-m", "model.gguf", "--gpu-layers", "0"]
+    assert LlamaCppBackend._zero_offload_gpu_flag(cmd, [(0, 8000, 24000)], {}) is True
+
+
+def test_zero_offload_flag_none_without_gpus():
+    cmd = ["llama-server", "-m", "model.gguf", "--gpu-layers", "0"]
+    assert LlamaCppBackend._zero_offload_gpu_flag(cmd, [], {}) is None
+
+
+def test_cmd_has_gpu_companion_detection():
+    # The env mask for CPU-only zero-offload loads keys off this scan: any
+    # --mmproj form or a drafter (flag aliases / env) keeps the GPUs visible.
+    has = LlamaCppBackend._cmd_has_gpu_companion
+    assert has(["llama-server", "-m", "m.gguf"], {}) is False
+    assert has(["llama-server", "--mmproj", "p.gguf"], {}) is True
+    assert has(["llama-server", "--mmproj=p.gguf"], {}) is True
+    assert has(["llama-server", "-md", "d.gguf"], {}) is True
+    assert has(["llama-server"], {"LLAMA_ARG_SPEC_DRAFT_MODEL": "d.gguf"}) is True
+
+
+def test_cmd_companion_ignores_cpu_forced_drafter():
+    # A CPU-pinned drafter holds no VRAM: the zero-offload mask may hide the GPUs
+    # and training may leave the server alone.
+    has = LlamaCppBackend._cmd_has_gpu_companion
+    cmd = ["llama-server", "-md", "d.gguf", "--spec-draft-ngl", "0"]
+    assert has(cmd, {}) is False
+    cmd = ["llama-server", "-md", "d.gguf", "--spec-draft-device", "cpu"]
+    assert has(cmd, {}) is False
+    # mmproj still counts even alongside a CPU drafter.
+    cmd = ["llama-server", "-md", "d.gguf", "--spec-draft-ngl", "0", "--mmproj", "p.gguf"]
+    assert has(cmd, {}) is True
diff --git a/studio/backend/tests/test_gpu_selection.py b/studio/backend/tests/test_gpu_selection.py
index 69ad560788..3dab7ef368 100644
--- a/studio/backend/tests/test_gpu_selection.py
+++ b/studio/backend/tests/test_gpu_selection.py
@@ -119,7 +119,8 @@ class TestResolveRequestedGpuIds(_GpuCacheResetMixin, unittest.TestCase):
             patch("utils.hardware.hardware.get_physical_gpu_count", return_value = 8),
         ):
             with self.assertRaisesRegex(
-                ValueError, "unsupported when CUDA_VISIBLE_DEVICES uses UUID/MIG"
+                ValueError,
+                "unsupported when CUDA_VISIBLE_DEVICES uses non-numeric or subdevice",
             ):
                 resolve_requested_gpu_ids([1])
 
@@ -130,6 +131,26 @@ class TestResolveRequestedGpuIds(_GpuCacheResetMixin, unittest.TestCase):
         ):
             self.assertEqual(resolve_requested_gpu_ids([]), [1, 3])
 
+    def test_vulkan_ordinals_bypass_cuda_parent_visible_validation(self):
+        # Vulkan build on a CPU-only torch host: no CUDA parent-visible set and a
+        # zero physical count, yet a valid Vulkan ordinal must not be rejected as
+        # a CUDA physical id (issue #7239).
+        with (
+            patch.dict(os.environ, {}, clear = True),
+            patch("utils.hardware.hardware.get_physical_gpu_count", return_value = 0),
+        ):
+            # As a CUDA physical id, [0] is outside the empty parent-visible set.
+            with self.assertRaises(ValueError):
+                resolve_requested_gpu_ids([0])
+            # As Vulkan ordinals, [0] and [0, 1] pass through unchanged.
+            self.assertEqual(resolve_requested_gpu_ids([0], is_vulkan = True), [0])
+            self.assertEqual(resolve_requested_gpu_ids([0, 1], is_vulkan = True), [0, 1])
+            # Malformed ordinals are still rejected.
+            with self.assertRaisesRegex(ValueError, "duplicate GPU IDs"):
+                resolve_requested_gpu_ids([0, 0], is_vulkan = True)
+            with self.assertRaisesRegex(ValueError, "non-negative"):
+                resolve_requested_gpu_ids([-1], is_vulkan = True)
+
     def test_apply_gpu_ids_only_updates_cuda_visible_devices(self):
         with patch.dict(
             os.environ,
@@ -846,14 +867,20 @@ class TestPreSpawnGpuResolution(_GpuCacheResetMixin, unittest.TestCase):
 
 
 class TestRouteErrors(unittest.TestCase):
-    def test_prepare_gpu_selection_rejects_gpu_ids_on_non_cuda_backend(self):
+    def test_prepare_gpu_selection_rejects_gpu_ids_on_non_accelerator_backend(self):
         with patch("utils.hardware.hardware.get_device", return_value = DeviceType.CPU):
             with self.assertRaises(ValueError) as exc_info:
                 prepare_gpu_selection([0], model_name = "unsloth/test")
 
-        self.assertIn("only supported on CUDA devices", str(exc_info.exception))
+        self.assertIn("only supported on CUDA and Intel XPU", str(exc_info.exception))
+
+    def test_inference_route_resolves_gguf_gpu_ids(self):
+        # GGUF gpu_ids are now supported: /load routes them through the same
+        # resolution as non-GGUF loads (rejecting only genuinely invalid ids with
+        # the resolver's actionable message) rather than a blanket "not supported"
+        # reject, so /validate can stay consistent with /load (#7239).
+        import utils.hardware.hardware as hardware_mod
 
-    def test_inference_route_rejects_gpu_ids_for_gguf(self):
         inference_route = _load_route_module(
             "inference_route_module_for_gguf_gpu_ids_test",
             "routes/inference.py",
@@ -874,12 +901,188 @@ class TestRouteErrors(unittest.TestCase):
             has_audio_input = False,
         )
 
+        def _fake_resolve(ids, is_vulkan = False):
+            raise ValueError("SENTINEL requested GPUs are outside the parent-visible set")
+
+        with (
+            patch.object(
+                inference_route,
+                "ModelConfig",
+                SimpleNamespace(from_identifier = lambda **_kwargs: model_config),
+            ),
+            # Patch both the package re-export and the defining module so the stub
+            # fires no matter which import path the route uses.
+            patch("utils.hardware.resolve_requested_gpu_ids", _fake_resolve),
+            patch.object(hardware_mod, "resolve_requested_gpu_ids", _fake_resolve),
+            patch.object(
+                inference_route,
+                "_guard_chat_load_against_training",
+                return_value = None,
+            ),
+            patch.object(inference_route.asyncio, "to_thread", new = _inline_to_thread),
+            patch.object(inference_route, "_hf_offline_if_dns_dead", nullcontext),
+        ):
+            with self.assertRaises(HTTPException) as exc_info:
+                asyncio.run(
+                    inference_route._load_model_impl(
+                        request,
+                        SimpleNamespace(
+                            app = SimpleNamespace(
+                                state = SimpleNamespace(llama_parallel_slots = 1),
+                            ),
+                        ),
+                        current_subject = "test-user",
+                    )
+                )
+
+        # The selection was routed through resolution (not the old blanket reject).
+        self.assertEqual(exc_info.exception.status_code, 400)
+        self.assertIn("SENTINEL", exc_info.exception.detail)
+        self.assertNotIn("not supported for GGUF", exc_info.exception.detail)
+
+    def test_load_rejects_unavailable_vulkan_ordinal_before_training_guard(self):
+        inference_route = _load_route_module(
+            "inference_route_module_for_vulkan_preflight_test",
+            "routes/inference.py",
+        )
+        request = LoadRequest(model_path = "unsloth/test.gguf", gpu_ids = [99])
+        model_config = SimpleNamespace(
+            is_gguf = True,
+            is_lora = False,
+            gguf_hf_repo = None,
+            gguf_file = "/tmp/test.gguf",
+            gguf_mmproj_file = None,
+            gguf_variant = None,
+            identifier = "unsloth/test.gguf",
+            display_name = "unsloth/test.gguf",
+            is_vision = False,
+            is_audio = False,
+            audio_type = None,
+            has_audio_input = False,
+        )
+
+        with (
+            patch.object(
+                inference_route,
+                "ModelConfig",
+                SimpleNamespace(from_identifier = lambda **_kwargs: model_config),
+            ),
+            patch("utils.hardware.get_device", return_value = DeviceType.CUDA),
+            patch.object(inference_route, "_classify_diffusion_gguf", return_value = None),
+            patch.object(
+                inference_route.LlamaCppBackend,
+                "_is_vulkan_backend",
+                return_value = True,
+            ),
+            patch.object(
+                inference_route.LlamaCppBackend,
+                "_find_llama_server_binary",
+                return_value = "/tmp/llama-server",
+            ),
+            patch.object(
+                inference_route.LlamaCppBackend,
+                "_get_gpu_memory",
+                return_value = [(0, 8 * 1024**3, 16 * 1024**3)],
+            ),
+            patch.object(
+                inference_route,
+                "_guard_chat_load_against_training",
+                return_value = None,
+            ) as training_guard,
+            patch.object(inference_route.asyncio, "to_thread", new = _inline_to_thread),
+            patch.object(inference_route, "_hf_offline_if_dns_dead", nullcontext),
+        ):
+            with self.assertRaises(HTTPException) as exc_info:
+                asyncio.run(
+                    inference_route._load_model_impl(
+                        request,
+                        SimpleNamespace(
+                            app = SimpleNamespace(
+                                state = SimpleNamespace(llama_parallel_slots = 1),
+                            ),
+                        ),
+                        current_subject = "test-user",
+                    )
+                )
+
+        self.assertEqual(exc_info.exception.status_code, 400)
+        self.assertIn("Vulkan GPU ordinal(s) [99]", exc_info.exception.detail)
+        training_guard.assert_not_called()
+
+    def test_vulkan_ordinals_are_allowed_on_xpu_hosts(self):
+        import utils.hardware.hardware as hardware_mod
+
+        inference_route = _load_route_module(
+            "inference_route_module_for_xpu_vulkan_test",
+            "routes/inference.py",
+        )
+        config = SimpleNamespace(is_gguf = True)
+
+        with (
+            patch("utils.hardware.get_device", return_value = DeviceType.XPU),
+            patch.object(
+                inference_route.LlamaCppBackend,
+                "_is_vulkan_backend",
+                return_value = True,
+            ),
+            patch.object(inference_route, "_classify_diffusion_gguf", return_value = False),
+            patch.object(hardware_mod, "resolve_requested_gpu_ids", return_value = [0, 1]),
+            patch.object(
+                inference_route.LlamaCppBackend,
+                "_find_llama_server_binary",
+                return_value = None,
+            ),
+        ):
+            resolved = asyncio.run(
+                inference_route._resolve_gguf_gpu_ids_for_request(config, [1, 0])
+            )
+
+        self.assertEqual(resolved, [0, 1])
+
+    def test_inference_route_validates_gpu_ids_for_gguf(self):
+        # gpu_ids is now SUPPORTED for GGUF (the GPU picker), but still
+        # validated: a rejected pick surfaces as a clean 400, not the old
+        # "not supported for GGUF" rejection. Patch the validator so the test
+        # is deterministic regardless of the host's (or a prior test's) GPU env.
+        import utils.hardware.hardware as hardware_mod
+
+        inference_route = _load_route_module(
+            "inference_route_module_for_gguf_gpu_ids_test2",
+            "routes/inference.py",
+        )
+        request = LoadRequest(model_path = "unsloth/test.gguf", gpu_ids = [0, 1])
+        model_config = SimpleNamespace(
+            is_gguf = True,
+            is_lora = False,
+            gguf_hf_repo = None,
+            gguf_file = "/tmp/test.gguf",
+            gguf_mmproj_file = None,
+            gguf_variant = None,
+            identifier = "unsloth/test.gguf",
+            display_name = "unsloth/test.gguf",
+            is_vision = False,
+            is_audio = False,
+            audio_type = None,
+            has_audio_input = False,
+        )
+
         with (
             patch.object(
                 inference_route,
                 "ModelConfig",
                 SimpleNamespace(from_identifier = lambda **_kwargs: model_config),
             ),
+            # Patch both the package re-export and the defining module so the stub
+            # fires no matter which import path the route uses.
+            patch(
+                "utils.hardware.resolve_requested_gpu_ids",
+                side_effect = ValueError("Invalid gpu_ids [0, 1]: rejected by test"),
+            ),
+            patch.object(
+                hardware_mod,
+                "resolve_requested_gpu_ids",
+                side_effect = ValueError("Invalid gpu_ids [0, 1]: rejected by test"),
+            ),
             patch.object(
                 inference_route,
                 "_guard_chat_load_against_training",
@@ -901,8 +1104,11 @@ class TestRouteErrors(unittest.TestCase):
                     )
                 )
 
+        # The validator's ValueError becomes a clean 400 (not the removed
+        # "not supported for GGUF" rejection).
         self.assertEqual(exc_info.exception.status_code, 400)
-        self.assertIn("GGUF", exc_info.exception.detail)
+        self.assertIn("gpu_ids", exc_info.exception.detail.lower())
+        self.assertNotIn("not supported", exc_info.exception.detail.lower())
 
     def test_training_route_returns_400_for_invalid_gpu_ids(self):
         training_route = _load_route_module(
@@ -1425,18 +1631,61 @@ class TestAutoSelectWithNoneRequired(_GpuCacheResetMixin, unittest.TestCase):
         self.assertEqual(metadata["selection_mode"], "fallback_all")
 
 
-class TestXpuRejection(_GpuCacheResetMixin, unittest.TestCase):
-    def test_auto_select_returns_non_cuda_for_xpu(self):
-        with patch("utils.hardware.hardware.get_device", return_value = DeviceType.XPU):
+class TestXpuSelection(_GpuCacheResetMixin, unittest.TestCase):
+    def test_auto_select_supports_xpu(self):
+        with (
+            patch("utils.hardware.hardware.get_device", return_value = DeviceType.XPU),
+            patch(
+                "utils.hardware.hardware.estimate_required_model_memory_gb",
+                return_value = (1.0, {}),
+            ),
+            patch(
+                "utils.hardware.hardware.get_visible_gpu_utilization",
+                return_value = {
+                    "devices": [
+                        {"index": 0, "vram_total_gb": 8, "vram_used_gb": 1},
+                    ]
+                },
+            ),
+            patch(
+                "utils.hardware.hardware._get_parent_visible_gpu_spec",
+                return_value = {
+                    "raw": None,
+                    "numeric_ids": [0],
+                    "supports_explicit_gpu_ids": True,
+                },
+            ),
+            patch(
+                "utils.hardware.hardware.get_parent_visible_gpu_ids",
+                return_value = [0],
+            ),
+        ):
             selected, metadata = auto_select_gpu_ids("unsloth/test")
 
-        self.assertIsNone(selected)
-        self.assertEqual(metadata["selection_mode"], "non_cuda")
+        self.assertEqual(selected, [0])
+        self.assertEqual(metadata["selection_mode"], "auto")
 
-    def test_prepare_gpu_selection_rejects_explicit_ids_on_xpu(self):
-        with patch("utils.hardware.hardware.get_device", return_value = DeviceType.XPU):
-            with self.assertRaisesRegex(ValueError, "only supported on CUDA"):
-                prepare_gpu_selection([0], model_name = "unsloth/test")
+    def test_prepare_gpu_selection_accepts_explicit_ids_on_xpu(self):
+        with (
+            patch("utils.hardware.hardware.get_device", return_value = DeviceType.XPU),
+            patch(
+                "utils.hardware.hardware._get_parent_visible_gpu_spec",
+                return_value = {
+                    "raw": "0",
+                    "numeric_ids": [0],
+                    "supports_explicit_gpu_ids": True,
+                },
+            ),
+            patch(
+                "utils.hardware.hardware.get_parent_visible_gpu_ids",
+                return_value = [0],
+            ),
+            patch("utils.hardware.hardware.get_physical_gpu_count", return_value = 1),
+        ):
+            selected, metadata = prepare_gpu_selection([0], model_name = "unsloth/test")
+
+        self.assertEqual(selected, [0])
+        self.assertEqual(metadata["selection_mode"], "explicit")
 
 
 class TestEstimateFp16ModelSizeBytesPrefersLocalWeights(unittest.TestCase):
diff --git a/studio/backend/tests/test_gpu_selection_sandbox.py b/studio/backend/tests/test_gpu_selection_sandbox.py
index 733933271b..ba6d057123 100644
--- a/studio/backend/tests/test_gpu_selection_sandbox.py
+++ b/studio/backend/tests/test_gpu_selection_sandbox.py
@@ -294,13 +294,13 @@ class TestAutoSelectGpuIds(unittest.TestCase):
             # 35GB (first) + 30*0.85 (second) = 60.5GB > 50GB
             self.assertEqual(len(selected), 2)
 
-    def test_non_cuda_returns_none(self):
+    def test_non_accelerator_returns_none(self):
         from utils.hardware.hardware import auto_select_gpu_ids
         import utils.hardware.hardware as hw
         with patch.object(hw, "get_device", return_value = hw.DeviceType.CPU):
             selected, meta = auto_select_gpu_ids("test/model")
             self.assertIsNone(selected)
-            self.assertEqual(meta["selection_mode"], "non_cuda")
+            self.assertEqual(meta["selection_mode"], "non_accelerator")
 
 
 class TestGetDeviceMap(unittest.TestCase):
diff --git a/studio/backend/tests/test_hf_cache_settings.py b/studio/backend/tests/test_hf_cache_settings.py
new file mode 100644
index 0000000000..1875d61809
--- /dev/null
+++ b/studio/backend/tests/test_hf_cache_settings.py
@@ -0,0 +1,290 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+from __future__ import annotations
+
+import os
+import sys
+import threading
+import time
+from pathlib import Path
+
+import pytest
+
+_BACKEND_DIR = str(Path(__file__).resolve().parent.parent)
+if _BACKEND_DIR not in sys.path:
+    sys.path.insert(0, _BACKEND_DIR)
+
+from hub.services.models.common import _local_model_info
+from utils import hf_cache_settings
+from utils import native_path_leases
+
+
+@pytest.fixture()
+def settings_store(monkeypatch, tmp_path):
+    store = {}
+    monkeypatch.setattr(hf_cache_settings, "_EXPLICIT_CACHE_ENV", {})
+    monkeypatch.setenv("XDG_CACHE_HOME", str(tmp_path / "xdg"))
+    monkeypatch.setattr(
+        "storage.studio_db.get_app_setting",
+        lambda key, fallback = None: store.get(key, fallback),
+    )
+    monkeypatch.setattr(
+        "storage.studio_db.upsert_app_settings",
+        lambda values: store.update(values) or values,
+    )
+    return store
+
+
+def test_studio_cache_switch_is_live_and_keeps_history(settings_store, tmp_path):
+    first = tmp_path / "external-a" / "huggingface"
+    second = tmp_path / "external-b" / "huggingface"
+    first.parent.mkdir()
+    second.parent.mkdir()
+
+    selected = hf_cache_settings.set_hf_cache_home(str(first))
+    assert selected.hub_cache == first / "hub"
+    assert selected.xet_cache == first / "xet"
+    assert selected.child_env({}) == {
+        "HF_HUB_CACHE": str(first / "hub"),
+        "HF_XET_CACHE": str(first / "xet"),
+    }
+
+    hf_cache_settings.set_hf_cache_home(str(second))
+    assert settings_store[hf_cache_settings.CACHE_HISTORY_SETTING_KEY] == [str(first)]
+    assert first / "hub" in hf_cache_settings.known_hf_hub_caches()
+
+    reset = hf_cache_settings.set_hf_cache_home(None)
+    assert reset.source == "default"
+    assert second in hf_cache_settings.known_hf_cache_homes()
+
+
+def test_environment_cache_is_read_only(monkeypatch, tmp_path):
+    custom = tmp_path / "managed"
+    monkeypatch.setattr(
+        hf_cache_settings,
+        "_EXPLICIT_CACHE_ENV",
+        {"HF_HOME": str(custom)},
+    )
+    paths = hf_cache_settings.get_hf_cache_paths()
+    assert paths.source == "environment"
+    assert paths.editable is False
+    assert paths.hub_cache == custom / "hub"
+    with pytest.raises(RuntimeError, match = "environment variable"):
+        hf_cache_settings.set_hf_cache_home(str(tmp_path / "other"))
+
+
+def test_explicit_hub_cache_is_the_displayed_location(monkeypatch, tmp_path):
+    custom_hub = tmp_path / "models-cache"
+    custom_hub.mkdir()
+    monkeypatch.setattr(
+        hf_cache_settings,
+        "_EXPLICIT_CACHE_ENV",
+        {"HF_HUB_CACHE": str(custom_hub)},
+    )
+
+    paths = hf_cache_settings.get_hf_cache_paths()
+    status = hf_cache_settings.cache_status(paths)
+
+    assert paths.cache_home == custom_hub
+    assert paths.hub_cache == custom_hub
+    assert status["cache_home"] == str(custom_hub)
+    assert status["available"] is True
+    assert custom_hub / "hub" not in hf_cache_settings.known_hf_hub_caches()
+
+
+def test_explicit_hub_cache_display_wins_over_hf_home(monkeypatch, tmp_path):
+    hf_home = tmp_path / "hf-home"
+    custom_hub = tmp_path / "other-disk" / "models-cache"
+    hf_home.mkdir()
+    custom_hub.mkdir(parents = True)
+    monkeypatch.setattr(
+        hf_cache_settings,
+        "_EXPLICIT_CACHE_ENV",
+        {"HF_HOME": str(hf_home), "HF_HUB_CACHE": str(custom_hub)},
+    )
+
+    paths = hf_cache_settings.get_hf_cache_paths()
+
+    assert paths.cache_home == custom_hub
+    assert paths.hub_cache == custom_hub
+    assert paths.xet_cache == hf_home / "xet"
+    assert custom_hub / "hub" not in hf_cache_settings.known_hf_hub_caches()
+    assert hf_home / "hub" in hf_cache_settings.known_hf_hub_caches()
+
+
+def test_xet_only_override_keeps_model_cache_editable(settings_store, monkeypatch, tmp_path):
+    xet_cache = tmp_path / "chunks"
+    stored = tmp_path / "stored-cache"
+    settings_store[hf_cache_settings.CACHE_HOME_SETTING_KEY] = str(stored)
+    monkeypatch.setattr(
+        hf_cache_settings,
+        "_EXPLICIT_CACHE_ENV",
+        {"HF_XET_CACHE": str(xet_cache)},
+    )
+
+    paths = hf_cache_settings.get_hf_cache_paths()
+
+    assert paths.cache_home == stored
+    assert paths.hub_cache == stored / "hub"
+    assert paths.xet_cache == xet_cache
+    assert paths.editable is True
+
+    selected = tmp_path / "selected-cache"
+    selected.parent.mkdir(exist_ok = True)
+    updated = hf_cache_settings.set_hf_cache_home(str(selected))
+    assert updated.hub_cache == selected / "hub"
+    assert updated.xet_cache == xet_cache
+
+
+def test_worker_environment_is_applied_before_import(monkeypatch, tmp_path):
+    hub = str(tmp_path / "hub")
+    xet = str(tmp_path / "xet")
+    observed = {}
+
+    class Module:
+        @staticmethod
+        def run():
+            import os
+            return os.environ["HF_HUB_CACHE"], os.environ["HF_XET_CACHE"]
+
+    def fake_import(name):
+        import os
+
+        observed["name"] = name
+        observed["hub"] = os.environ.get("HF_HUB_CACHE")
+        return Module
+
+    monkeypatch.setattr(native_path_leases.importlib, "import_module", fake_import)
+    result = native_path_leases.run_without_native_path_secret(
+        "fake.worker",
+        "run",
+        {"HF_HUB_CACHE": hub, "HF_XET_CACHE": xet},
+    )
+    assert observed == {"name": "fake.worker", "hub": hub}
+    assert result == (hub, xet)
+
+
+def test_spawn_environment_is_applied_then_restored(monkeypatch, tmp_path):
+    hub = str(tmp_path / "hub")
+    xet = str(tmp_path / "xet")
+    monkeypatch.setenv("HF_HUB_CACHE", "parent-hub")
+    monkeypatch.delenv("HF_XET_CACHE", raising = False)
+
+    with hf_cache_settings.child_environment_for_spawn({"HF_HUB_CACHE": hub, "HF_XET_CACHE": xet}):
+        import os
+        assert os.environ["HF_HUB_CACHE"] == hub
+        assert os.environ["HF_XET_CACHE"] == xet
+
+    assert os.environ["HF_HUB_CACHE"] == "parent-hub"
+    assert "HF_XET_CACHE" not in os.environ
+
+
+def test_spawn_environment_supports_nested_contexts(monkeypatch):
+    monkeypatch.setenv("HF_HUB_CACHE", "parent")
+
+    with hf_cache_settings.child_environment_for_spawn({"HF_HUB_CACHE": "outer"}):
+        assert os.environ["HF_HUB_CACHE"] == "outer"
+        with hf_cache_settings.child_environment_for_spawn({"HF_HUB_CACHE": "inner"}):
+            assert os.environ["HF_HUB_CACHE"] == "inner"
+        assert os.environ["HF_HUB_CACHE"] == "outer"
+
+    assert os.environ["HF_HUB_CACHE"] == "parent"
+
+
+def test_spawn_environment_serializes_threads(monkeypatch):
+    monkeypatch.setenv("HF_HUB_CACHE", "parent")
+    first_entered = threading.Event()
+    release_first = threading.Event()
+    observations: list[tuple[str, str]] = []
+
+    def first():
+        with hf_cache_settings.child_environment_for_spawn({"HF_HUB_CACHE": "first"}):
+            observations.append(("first", os.environ["HF_HUB_CACHE"]))
+            first_entered.set()
+            assert release_first.wait(timeout = 2)
+
+    def second():
+        assert first_entered.wait(timeout = 2)
+        with hf_cache_settings.child_environment_for_spawn({"HF_HUB_CACHE": "second"}):
+            observations.append(("second", os.environ["HF_HUB_CACHE"]))
+
+    first_thread = threading.Thread(target = first)
+    second_thread = threading.Thread(target = second)
+    first_thread.start()
+    second_thread.start()
+    assert first_entered.wait(timeout = 2)
+    time.sleep(0.02)
+    assert observations == [("first", "first")]
+    release_first.set()
+    first_thread.join(timeout = 2)
+    second_thread.join(timeout = 2)
+
+    assert observations == [("first", "first"), ("second", "second")]
+    assert os.environ["HF_HUB_CACHE"] == "parent"
+
+
+def test_cache_switch_invalidates_inventory(settings_store, tmp_path, monkeypatch):
+    invalidations = []
+    monkeypatch.setattr(
+        "hub.utils.inventory_scan.invalidate_hf_cache_scans",
+        lambda: invalidations.append(True),
+    )
+    selected = tmp_path / "external" / "huggingface"
+    selected.parent.mkdir()
+
+    hf_cache_settings.set_hf_cache_home(str(selected))
+
+    assert invalidations == [True]
+
+
+def test_cache_validation_write_tests_hub_and_xet(settings_store, tmp_path, monkeypatch):
+    selected = tmp_path / "external" / "huggingface"
+    selected.parent.mkdir()
+    tested = []
+    real_named_temporary_file = hf_cache_settings.tempfile.NamedTemporaryFile
+
+    def recording_write_test(*args, **kwargs):
+        tested.append(Path(kwargs["dir"]))
+        return real_named_temporary_file(*args, **kwargs)
+
+    monkeypatch.setattr(
+        hf_cache_settings.tempfile,
+        "NamedTemporaryFile",
+        recording_write_test,
+    )
+
+    hf_cache_settings.set_hf_cache_home(str(selected))
+
+    assert tested == [selected / "hub", selected / "xet"]
+
+
+def test_cache_validation_rejects_unwritable_child(settings_store, tmp_path, monkeypatch):
+    selected = tmp_path / "external" / "huggingface"
+    selected.parent.mkdir()
+
+    def reject_hub(*args, **kwargs):
+        if Path(kwargs["dir"]).name == "hub":
+            raise PermissionError("read-only")
+        raise AssertionError("xet should not be tested after hub fails")
+
+    monkeypatch.setattr(hf_cache_settings.tempfile, "NamedTemporaryFile", reject_hub)
+
+    with pytest.raises(ValueError, match = "permission"):
+        hf_cache_settings.set_hf_cache_home(str(selected))
+
+
+def test_inactive_cache_model_loads_from_snapshot_path(tmp_path):
+    snapshot = tmp_path / "snapshots" / "revision"
+    snapshot.mkdir(parents = True)
+    row = _local_model_info(
+        scan_path = snapshot,
+        load_path = snapshot,
+        source = "hf_cache",
+        model_format = "safetensors",
+        model_id = "org/model",
+        active_cache = False,
+    )
+    assert row.model_id == "org/model"
+    assert row.active_cache is False
+    assert row.load_id == str(snapshot)
diff --git a/studio/backend/tests/test_hf_token_validation.py b/studio/backend/tests/test_hf_token_validation.py
new file mode 100644
index 0000000000..31b30fc37d
--- /dev/null
+++ b/studio/backend/tests/test_hf_token_validation.py
@@ -0,0 +1,165 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Focused coverage for cached, rate-limited HF token validation."""
+
+from __future__ import annotations
+
+from pathlib import Path
+import sys
+
+import httpx
+import pytest
+
+
+_BACKEND_DIR = str(Path(__file__).resolve().parent.parent)
+if _BACKEND_DIR not in sys.path:
+    sys.path.insert(0, _BACKEND_DIR)
+
+import utils.hf_token_validation as validation
+
+
+@pytest.fixture(autouse = True)
+def _reset_validation_state():
+    validation.reset_hf_token_validation_state()
+    yield
+    validation.reset_hf_token_validation_state()
+
+
+def test_cached_token_does_not_spend_another_attempt(monkeypatch):
+    calls = []
+
+    def _check(token):
+        calls.append(token)
+        return validation.TokenValidationResult(status = "valid")
+
+    monkeypatch.setattr(validation, "_check_remote", _check)
+    first = validation.validate_hf_token("hf_valid", rate_key = "user:ip")
+    second = validation.validate_hf_token("hf_valid", rate_key = "user:ip")
+
+    assert first.status == second.status == "valid"
+    assert calls == ["hf_valid"]
+
+
+def test_three_uncached_attempts_per_hour(monkeypatch):
+    monkeypatch.setattr(
+        validation,
+        "_check_remote",
+        lambda _token: validation.TokenValidationResult(status = "invalid"),
+    )
+
+    for index in range(3):
+        result = validation.validate_hf_token(f"hf_bad_{index}", rate_key = "user:ip")
+        assert result.status == "invalid"
+
+    limited = validation.validate_hf_token("hf_bad_4", rate_key = "user:ip")
+    assert limited.status == "rate_limited"
+    assert limited.retry_after_seconds is not None
+    assert limited.retry_after_seconds > 0
+
+    other_user = validation.validate_hf_token("hf_other", rate_key = "other:ip")
+    assert other_user.status == "invalid"
+
+
+def test_window_rolls_forward(monkeypatch):
+    clock = {"now": 100.0}
+    monkeypatch.setattr(validation.time, "monotonic", lambda: clock["now"])
+    monkeypatch.setattr(validation, "_MAX_ATTEMPTS", 1)
+    monkeypatch.setattr(validation, "_WINDOW_SECONDS", 10.0)
+    monkeypatch.setattr(
+        validation,
+        "_check_remote",
+        lambda _token: validation.TokenValidationResult(status = "invalid"),
+    )
+
+    assert validation.validate_hf_token("hf_a", rate_key = "user:ip").status == "invalid"
+    assert validation.validate_hf_token("hf_b", rate_key = "user:ip").status == "rate_limited"
+    clock["now"] += 11.0
+    assert validation.validate_hf_token("hf_b", rate_key = "user:ip").status == "invalid"
+
+
+@pytest.mark.parametrize(
+    ("status_code", "expected"),
+    [(200, "valid"), (401, "invalid"), (429, "rate_limited"), (500, "unavailable")],
+)
+def test_remote_status_classification(monkeypatch, status_code, expected):
+    response = httpx.Response(
+        status_code,
+        request = httpx.Request("GET", "https://huggingface.co/api/whoami-v2"),
+        headers = {"Retry-After": "42"} if status_code == 429 else None,
+    )
+
+    class _Session:
+        def get(self, url, *, headers, timeout):
+            assert url == "https://huggingface.co/api/whoami-v2"
+            assert headers["authorization"] == "Bearer hf_test"
+            assert timeout == validation._REMOTE_TIMEOUT_SECONDS
+            return response
+
+    monkeypatch.setattr(validation, "get_session", lambda: _Session())
+    result = validation._check_remote("hf_test")
+    assert result.status == expected
+    if status_code == 429:
+        assert result.retry_after_seconds == 42
+
+
+def test_wrapped_http_401_is_invalid(monkeypatch):
+    response = httpx.Response(
+        401,
+        request = httpx.Request("GET", "https://huggingface.co/api/whoami-v2"),
+    )
+
+    class _Session:
+        def get(self, _url, **_kwargs):
+            error = RuntimeError("Invalid user token.")
+            error.response = response
+            raise error
+
+    monkeypatch.setattr(validation, "get_session", lambda: _Session())
+    assert validation._check_remote("hf_test").status == "invalid"
+
+
+def test_remote_timeout_is_bounded_and_unavailable(monkeypatch):
+    class _Session:
+        def get(self, _url, *, headers, timeout):
+            assert headers["authorization"] == "Bearer hf_test"
+            assert timeout == validation._REMOTE_TIMEOUT_SECONDS
+            raise TimeoutError("timed out")
+
+    monkeypatch.setattr(validation, "get_session", lambda: _Session())
+    assert validation._check_remote("hf_test").status == "unavailable"
+
+
+def test_raw_token_is_not_retained(monkeypatch):
+    monkeypatch.setattr(
+        validation,
+        "_check_remote",
+        lambda _token: validation.TokenValidationResult(status = "valid"),
+    )
+    token = "hf_do_not_store_this_value"
+    validation.validate_hf_token(token, rate_key = "user:ip")
+
+    assert token not in repr(validation._cache)
+    assert token not in repr(validation._attempts)
+
+
+def test_unexpected_remote_exception_releases_singleflight(monkeypatch):
+    calls = 0
+    monkeypatch.setattr(validation, "_INFLIGHT_WAIT_SECONDS", 0.0)
+
+    def _check(_token):
+        nonlocal calls
+        calls += 1
+        if calls == 1:
+            raise RuntimeError("unexpected failure")
+        return validation.TokenValidationResult(status = "valid")
+
+    monkeypatch.setattr(validation, "_check_remote", _check)
+
+    with pytest.raises(RuntimeError, match = "unexpected failure"):
+        validation.validate_hf_token("hf_test", rate_key = "user:ip")
+
+    result = validation.validate_hf_token("hf_test", rate_key = "user:ip")
+    assert result.status == "valid"
+    assert calls == 2
+    assert validation._inflight == {}
diff --git a/studio/backend/tests/test_hf_xet_fallback.py b/studio/backend/tests/test_hf_xet_fallback.py
index 2fff744b64..a037ea2579 100644
--- a/studio/backend/tests/test_hf_xet_fallback.py
+++ b/studio/backend/tests/test_hf_xet_fallback.py
@@ -1,10 +1,10 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Tests for the Studio shim over the shared unsloth_zoo Xet -> HTTP fallback.
+"""Tests for the Unsloth shim over the shared unsloth_zoo Xet -> HTTP fallback.
 
 The transport-policy matrix is tested once in unsloth_zoo; here we assert only the
-Studio seam: re-exporting the shared API and injecting the marker-aware
+Unsloth seam: re-exporting the shared API and injecting the marker-aware
 prepare_cache_for_transport on the HTTP retry. CPU-only, no network, no real subprocess.
 """
 
@@ -69,7 +69,7 @@ def test_child_should_disable_xet_truth_table():
 
 
 def test_shim_injects_studio_prepare_on_http_retry(monkeypatch):
-    """A Xet stall retries over HTTP and the shim runs Studio's marker-aware
+    """A Xet stall retries over HTTP and the shim runs Unsloth's marker-aware
     ``prepare_cache_for_transport(..., 'http')`` before the retry."""
     _requires_shared()
     for var in ("UNSLOTH_DISABLE_XET", "UNSLOTH_STABLE_DOWNLOADS", "HF_HUB_DISABLE_XET"):
@@ -101,17 +101,27 @@ def test_shim_injects_studio_prepare_on_http_retry(monkeypatch):
     prepared = []
     monkeypatch.setattr(
         "hub.utils.download_registry.prepare_cache_for_transport",
-        lambda repo_type, repo_id, mode, *a, **k: prepared.append((repo_type, repo_id, mode)),
+        lambda repo_type, repo_id, mode, *a, **k: prepared.append(
+            (repo_type, repo_id, mode, k.get("root"))
+        ),
     )
 
-    out = xf.hf_hub_download_with_xet_fallback(DL_REPO, FILE, None)
+    selected_cache = "/captured/hub"
+    out = xf.hf_hub_download_with_xet_fallback(
+        DL_REPO,
+        FILE,
+        None,
+        cache_dir = selected_cache,
+    )
     assert out == "/cache/model.gguf"
     assert seen_disable_xet == [False, True]  # Xet first, then HTTP
-    assert prepared == [("model", DL_REPO, "http")], "shim must run Studio's marker-aware prep"
+    assert prepared == [
+        ("model", DL_REPO, "http", Path(selected_cache))
+    ], "shim must prepare the cache captured by the download"
 
 
 def test_shim_snapshot_injects_studio_prepare(monkeypatch):
-    """The snapshot wrapper forwards Studio's marker-aware prep, like the file wrapper."""
+    """The snapshot wrapper forwards Unsloth's marker-aware prep, like the file wrapper."""
     captured = {}
 
     def fake_snapshot(repo_id, **kwargs):
@@ -120,14 +130,26 @@ def test_shim_snapshot_injects_studio_prepare(monkeypatch):
         return "/tmp/snap-dir"
 
     monkeypatch.setattr(xf, "_shared_snapshot_download_with_xet_fallback", fake_snapshot)
-    out = xf.snapshot_download_with_xet_fallback("org/model")
+    selected_cache = "/captured/hub"
+    out = xf.snapshot_download_with_xet_fallback(
+        "org/model",
+        cache_dir = selected_cache,
+    )
     assert out == "/tmp/snap-dir"
     assert captured["repo_id"] == "org/model"
-    assert captured["prepare_for_http_fn"] is xf._studio_prepare_for_http
+    prepared = []
+    monkeypatch.setattr(
+        "hub.utils.download_registry.prepare_cache_for_transport",
+        lambda repo_type, repo_id, mode, *a, **k: prepared.append(
+            (repo_type, repo_id, mode, k.get("root"))
+        ),
+    )
+    captured["prepare_for_http_fn"]("model", "org/model")
+    assert prepared == [("model", "org/model", "http", Path(selected_cache))]
 
 
 def test_degrades_gracefully_without_shared_helper(monkeypatch):
-    """On an older unsloth_zoo lacking the shared helper, the shim still imports (Studio
+    """On an older unsloth_zoo lacking the shared helper, the shim still imports (Unsloth
     boots) and exposes stub API doing plain HF downloads with the watchdog disabled."""
     import importlib
 
@@ -206,7 +228,7 @@ def test_degrades_gracefully_without_shared_helper(monkeypatch):
 def test_degrades_when_unsloth_zoo_entirely_absent():
     """When unsloth_zoo is absent entirely, the import raises
     ModuleNotFoundError(name='unsloth_zoo') (top-level package). Guard that the shim still
-    degrades and does not re-raise, breaking every Studio import that pulls it in."""
+    degrades and does not re-raise, breaking every Unsloth import that pulls it in."""
     import importlib
 
     class _BlockZoo:
@@ -248,7 +270,7 @@ def test_degrades_when_unsloth_zoo_entirely_absent():
 
 def test_degrades_when_shared_helper_import_raises_importerror():
     """unsloth_zoo can be installed yet fail to import when torch is missing (llama.cpp/GGUF-only
-    Studio), raising ImportError not ModuleNotFoundError. The shim must degrade for that too."""
+    Unsloth), raising ImportError not ModuleNotFoundError. The shim must degrade for that too."""
     import importlib
 
     class _BlockWithImportError:
@@ -329,7 +351,7 @@ def test_retries_under_light_gpu_init_when_import_fails(monkeypatch):
         # with it set); accessing DownloadStallError drives it via __getattr__.
         stall_error = degraded.DownloadStallError
         assert seen_env == [None, "1"], seen_env
-        # Both attempts raised -> Studio still boots in degraded mode.
+        # Both attempts raised -> Unsloth still boots in degraded mode.
         assert issubclass(stall_error, RuntimeError)
         # The env override must not leak past the load.
         assert os.environ.get("UNSLOTH_ZOO_DISABLE_GPU_INIT") is None
diff --git a/studio/backend/tests/test_identity.py b/studio/backend/tests/test_identity.py
index 1e84ddef35..712348f7ca 100644
--- a/studio/backend/tests/test_identity.py
+++ b/studio/backend/tests/test_identity.py
@@ -3,7 +3,7 @@
 
 """Tests for the server identity handshake (`GET /api/auth/identity`).
 
-The endpoint lets a client confirm an endpoint is really this Studio install
+The endpoint lets a client confirm an endpoint is really this Unsloth install
 before sending it a credential: the client sends a random nonce and checks the
 returned HMAC against one computed from the install identity secret. A process
 that cannot read this same-user secret cannot forge a matching proof.
diff --git a/studio/backend/tests/test_index_bootstrap_origin_extra.py b/studio/backend/tests/test_index_bootstrap_origin_extra.py
index feda88c14c..e1c52a653e 100644
--- a/studio/backend/tests/test_index_bootstrap_origin_extra.py
+++ b/studio/backend/tests/test_index_bootstrap_origin_extra.py
@@ -26,7 +26,7 @@ def _build_request(
 
 
 def test_is_same_origin_request_ipv6_loopback_same_origin():
-    """Studio supports ``-H ::1`` binds; netloc is ``[::1]:8902``. Bare
+    """Unsloth supports ``-H ::1`` binds; netloc is ``[::1]:8902``. Bare
     ``partition(":")`` mis-parses the bracketed form and would refuse the
     bootstrap on legitimate same-origin navigation.
     """
diff --git a/studio/backend/tests/test_install_resolve_prebuilt.py b/studio/backend/tests/test_install_resolve_prebuilt.py
index e97ca47717..02ccc68b11 100644
--- a/studio/backend/tests/test_install_resolve_prebuilt.py
+++ b/studio/backend/tests/test_install_resolve_prebuilt.py
@@ -200,14 +200,9 @@ def _gpu_linux_host(caps):
     )
 
 
-def test_host_is_blackwell_includes_datacenter_parts():
-    assert ilp._host_is_blackwell(_gpu_linux_host(["10.0"])) is True  # B200 sm_100
-    assert ilp._host_is_blackwell(_gpu_linux_host(["10.3"])) is True  # B300 sm_103
-    assert ilp._host_is_blackwell(_gpu_linux_host(["12.0"])) is True  # RTX 50 sm_120
-    assert ilp._host_is_blackwell(_gpu_linux_host(["12.1"])) is True  # DGX Spark sm_121
-    assert ilp._host_is_blackwell(_gpu_linux_host(["9.0"])) is False  # Hopper
-    assert ilp._host_is_blackwell(_gpu_linux_host(["8.0"])) is False  # Ampere
-    assert ilp._host_is_blackwell(_gpu_linux_host(["9.0", "10.0"])) is True  # highest cap wins
+# _host_is_blackwell / _blackwell_min_toolkit_for_host are prebuilt_core
+# re-exports; their value tables moved verbatim to
+# tests/studio/install/test_prebuilt_core.py.
 
 
 def _linux_cuda_artifact(runtime_line, supported_sms, min_sm, max_sm, profile):
@@ -285,16 +280,6 @@ def test_drop_blackwell_incapable_windows_cuda_applies_to_datacenter():
     assert [a.name for a in kept] == [cuda13.name]
 
 
-def test_blackwell_min_toolkit_is_sm_aware():
-    # Family floor is 12.8; sm_103/sm_121 (no native target before 12.9) lift it.
-    f = ilp._blackwell_min_toolkit_for_host
-    assert f(_gpu_linux_host(["10.0"])) == (12, 8)  # B200
-    assert f(_gpu_linux_host(["12.0"])) == (12, 8)  # RTX 50
-    assert f(_gpu_linux_host(["10.3"])) == (12, 9)  # B300
-    assert f(_gpu_linux_host(["12.1"])) == (12, 9)  # DGX Spark
-    assert f(_gpu_linux_host(["10.0", "10.3"])) == (12, 9)  # max across SMs wins
-
-
 def test_sm103_host_drops_cuda128_windows_build():
     # B300 (sm_103) needs cuda-12.9: a legacy win-cuda-12.8 build must be dropped.
     host = _host(
@@ -445,6 +430,101 @@ def test_route_to_vulkan_prebuilt_cpu_fallback_wins():
     assert routed is host
 
 
+@pytest.mark.parametrize("cpu_flag", ["--cpu-fallback", "--force-cpu"])
+def test_resolve_prebuilt_cpu_fallback_overrides_intel_vulkan(monkeypatch, capsys, cpu_flag):
+    """Either CPU flag via CLI must suppress Vulkan even on an Intel GPU host: both
+    drop GPU detection (--force-cpu additionally persists, on the install path)."""
+    monkeypatch.setattr(
+        ilp,
+        "detect_host",
+        lambda: _host(is_linux = True, is_x86_64 = True, has_intel_gpu = True),
+    )
+    seen = {}
+
+    def _resolver(tag, host, repo, published_release_tag):
+        seen["host"] = host
+        seen["repo"] = repo
+        raise ilp.PrebuiltFallback("no asset")
+
+    monkeypatch.setattr(ilp, "resolve_simple_install_release_plans", _resolver)
+    monkeypatch.setattr(
+        sys,
+        "argv",
+        [
+            "install_llama_prebuilt.py",
+            "--resolve-prebuilt",
+            "latest",
+            cpu_flag,
+            "--output-format",
+            "json",
+        ],
+    )
+    assert ilp.main() == ilp.EXIT_SUCCESS
+    # The CPU flag must suppress Intel GPU, route to fork (not upstream Vulkan)
+    assert seen["host"].has_intel_gpu is False
+    assert seen["repo"] == FORK
+
+
+@pytest.mark.parametrize(
+    "flags, expect_force, expect_persist",
+    [
+        ([], False, False),
+        # Automatic/transient last resort (arm64 GPU-build recovery): drops GPU but
+        # does NOT persist, so a later update heals to a GPU bundle (#6097).
+        (["--cpu-fallback"], True, False),
+        # Deliberate CPU-only (UNSLOTH_LLAMA_CPP_BACKEND=cpu): drops GPU AND persists so
+        # the updater re-asserts it and never revives the Intel iGPU crash (#7213).
+        (["--force-cpu"], True, True),
+        (["--cpu-fallback", "--force-cpu"], True, True),
+    ],
+)
+def test_cli_cpu_flags_thread_force_and_persist(
+    monkeypatch, tmp_path, flags, expect_force, expect_persist
+):
+    captured = {}
+    monkeypatch.setattr(ilp, "install_prebuilt", lambda **kw: captured.update(kw))
+    monkeypatch.setattr(
+        sys,
+        "argv",
+        ["install_llama_prebuilt.py", "--install-dir", str(tmp_path / "llama.cpp"), *flags],
+    )
+    assert ilp.main() == ilp.EXIT_SUCCESS
+    assert captured["force_cpu"] is expect_force
+    assert captured["persist_force_cpu"] is expect_persist
+
+
+@pytest.mark.parametrize(
+    "existing, requested, expected",
+    [
+        # A deliberate --force-cpu on top of a naturally-installed CPU bundle (same
+        # asset, install skipped) must still flip the marker to true (#7213).
+        (False, True, True),
+        (None, True, True),
+        # No spurious writes when already in sync, and a released force syncs down.
+        (True, True, True),
+        (False, False, False),
+        (True, False, False),
+    ],
+)
+def test_sync_marker_force_cpu(tmp_path, existing, requested, expected):
+    marker = {"tag": "b9585", "asset": "llama-b9585-bin-ubuntu-x64.tar.gz"}
+    if existing is not None:
+        marker["force_cpu"] = existing
+    marker_path = tmp_path / "UNSLOTH_PREBUILT_INFO.json"
+    marker_path.write_text(json.dumps(marker))
+    ilp.sync_marker_force_cpu(tmp_path, requested)
+    written = json.loads(marker_path.read_text())
+    assert written["force_cpu"] is expected
+    # Unrelated fields are preserved.
+    assert written["asset"] == "llama-b9585-bin-ubuntu-x64.tar.gz"
+
+
+def test_sync_marker_force_cpu_missing_marker_is_noop(tmp_path):
+    # No marker (or unreadable) must not crash the reuse path.
+    ilp.sync_marker_force_cpu(tmp_path, True)
+    assert not (tmp_path / "UNSLOTH_PREBUILT_INFO.json").exists()
+
+
 def test_route_to_vulkan_prebuilt_hidden_nvidia_not_rerouted():
     # A mixed NVIDIA+Intel host that hid NVIDIA (CUDA_VISIBLE_DEVICES=""/-1):
     # physical NVIDIA present but not usable. Must NOT auto-route to Vulkan, or
diff --git a/studio/backend/tests/test_install_whisper_prebuilt_checksums.py b/studio/backend/tests/test_install_whisper_prebuilt_checksums.py
new file mode 100644
index 0000000000..19bece9d0c
--- /dev/null
+++ b/studio/backend/tests/test_install_whisper_prebuilt_checksums.py
@@ -0,0 +1,231 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Trust-anchor tests for install_whisper_prebuilt.py.
+
+Whisper verifies each download against the release's own
+whisper-prebuilt-sha256.json checksum index (the same model as
+install_llama_prebuilt.py), not a committed pins file. These pin the index
+parser, the fail-closed behaviour when an asset is not covered, the
+tampered-manifest guard, and the newest-release resolution.
+"""
+
+from __future__ import annotations
+
+import importlib
+import sys
+from pathlib import Path
+
+import pytest
+
+_studio = Path(__file__).resolve().parent.parent.parent
+if str(_studio) not in sys.path:
+    sys.path.insert(0, str(_studio))
+
+iwp = importlib.import_module("install_whisper_prebuilt")
+
+if not hasattr(iwp, "parse_release_checksums"):
+    pytest.skip("checksum-model symbols not present - check branch", allow_module_level = True)
+
+_A = "0" * 64
+_B = "1" * 64
+_TAG = "v1.9.1-unsloth.1"
+_REPO = "unslothai/whisper.cpp"
+
+
+def _index(**overrides) -> dict:
+    payload = {
+        "schema_version": 1,
+        "component": "whisper.cpp",
+        "release_tag": _TAG,
+        "upstream_tag": "v1.9.1",
+        "artifacts": {
+            "whisper-v1.9.1-unsloth.1-linux-x64-cpu.tar.gz": {"sha256": _A},
+            "whisper-v1.9.1-unsloth.1-linux-x64-cuda12-portable.tar.gz": {"sha256": _B},
+        },
+    }
+    payload.update(overrides)
+    return payload
+
+
+# parse_release_checksums / expected_sha256_for are prebuilt_core re-exports;
+# their valid/fail-closed matrix is asserted against the real whisper
+# descriptor in tests/studio/install/test_prebuilt_core.py. The download-host
+# fast-path tests below still route through this module's parse wrapper.
+
+# release tag resolution.
+
+
+def test_resolve_release_tag_explicit_override_passthrough():
+    assert iwp.resolve_release_tag(_REPO, published_release_tag = "v1.9.1-unsloth.2") == (
+        "v1.9.1-unsloth.2"
+    )
+
+
+def test_resolve_release_tag_resolves_newest_when_no_override(monkeypatch):
+    monkeypatch.setattr(iwp, "resolve_newest_release_tag", lambda repo: "v9.9.9-unsloth.9")
+    assert iwp.resolve_release_tag(_REPO, published_release_tag = None) == "v9.9.9-unsloth.9"
+
+
+def test_resolve_newest_release_tag_picks_latest_published(monkeypatch):
+    releases = [
+        {"tag_name": "v1.9.1-unsloth.1", "published_at": "2026-01-01T00:00:00Z"},
+        {"tag_name": "v1.9.1-unsloth.3", "published_at": "2026-03-01T00:00:00Z"},
+        {"tag_name": "v1.9.1-unsloth.2", "published_at": "2026-02-01T00:00:00Z"},
+        {"tag_name": "draft", "published_at": "2026-09-01T00:00:00Z", "draft": True},
+        {"tag_name": "pre", "published_at": "2026-09-01T00:00:00Z", "prerelease": True},
+    ]
+    monkeypatch.setattr(iwp, "fetch_json", lambda url: releases)
+    assert iwp.resolve_newest_release_tag(_REPO) == "v1.9.1-unsloth.3"
+
+
+def test_resolve_newest_release_tag_none_published_fails_closed(monkeypatch):
+    monkeypatch.setattr(iwp, "fetch_json", lambda url: [{"tag_name": "d", "draft": True}])
+    with pytest.raises(iwp.PrebuiltFallback):
+        iwp.resolve_newest_release_tag(_REPO)
+
+
+def test_pins_symbols_are_gone():
+    # The committed-pins trust model was removed in favour of llama's runtime index.
+    for gone in ("load_pins", "pins_path", "resolve_expected_sha256", "PINS_FILENAME"):
+        assert not hasattr(iwp, gone), f"{gone} should have been removed"
+
+
+# Download-host fast path (resolve + fetch the JSON assets with no GitHub API).
+
+_CPU_ASSET = "whisper-v1.9.1-unsloth.1-linux-x64-cpu.tar.gz"
+
+
+def _manifest() -> dict:
+    return {
+        "schema_version": 1,
+        "component": "whisper.cpp",
+        "upstream_tag": "v1.9.1",
+        "artifacts": [{"asset": _CPU_ASSET, "os": "linux", "arch": "x64", "backend": "cpu"}],
+    }
+
+
+def _no_api(monkeypatch):
+    """Fail loudly if any code path touches api.github.com."""
+
+    def _boom(*a, **k):
+        raise AssertionError("api.github.com was used on the fast path")
+
+    monkeypatch.setattr(iwp, "fetch_json", _boom)
+    monkeypatch.setattr(iwp, "github_release", _boom)
+    monkeypatch.setattr(iwp, "fetch_release_bundle", _boom)
+
+
+def test_fetch_release_for_install_prefers_download_host(monkeypatch):
+    _no_api(monkeypatch)
+    monkeypatch.setattr(iwp, "_download_host_latest_release_tag", lambda repo: _TAG)
+
+    def _dhj(url):
+        if url.endswith(iwp.SHA256_ASSET_NAME):
+            return _index()
+        if url.endswith(iwp.MANIFEST_ASSET_NAME):
+            return _manifest()
+        raise AssertionError(f"unexpected url {url}")
+
+    monkeypatch.setattr(iwp, "_download_host_json", _dhj)
+    bundle, checks = iwp.fetch_release_for_install(_REPO, published_release_tag = None)
+    assert bundle.release_tag == _TAG
+    assert checks[_CPU_ASSET] == _A
+    # asset_urls point at the download host (github.com), not the API.
+    assert bundle.asset_urls[iwp.SHA256_ASSET_NAME].startswith(
+        f"https://github.com/{_REPO}/releases/"
+    )
+    assert bundle.asset_urls[_CPU_ASSET].startswith(
+        f"https://github.com/{_REPO}/releases/download/"
+    )
+    walked = iwp._fetch_release_candidate(_REPO, _TAG)
+    assert iwp.SHA256_ASSET_NAME in walked.asset_urls
+    assert _CPU_ASSET in walked.asset_urls
+
+
+def test_fetch_release_for_install_explicit_tag_skips_the_head(monkeypatch):
+    # An explicit tag needs no /releases/latest HEAD: resolving it must not call it.
+    monkeypatch.setattr(
+        iwp,
+        "_download_host_latest_release_tag",
+        lambda repo: (_ for _ in ()).throw(AssertionError("HEAD used for an explicit tag")),
+    )
+    monkeypatch.setattr(
+        iwp,
+        "_download_host_json",
+        lambda url: _index() if url.endswith(iwp.SHA256_ASSET_NAME) else _manifest(),
+    )
+    _no_api(monkeypatch)
+    bundle, checks = iwp.fetch_release_for_install(_REPO, published_release_tag = _TAG)
+    assert bundle.release_tag == _TAG
+
+
+def test_fetch_release_for_install_falls_back_to_api(monkeypatch):
+    # Fast path returns None (e.g. a 404) -> the API path resolves the release.
+    monkeypatch.setattr(iwp, "_resolve_release_via_download_host", lambda repo, tag: None)
+    sentinel = iwp.ReleaseBundle(repo = _REPO, release_tag = _TAG, manifest = _manifest(), asset_urls = {})
+    monkeypatch.setattr(iwp, "resolve_release_tag", lambda repo, *, published_release_tag: _TAG)
+    monkeypatch.setattr(iwp, "fetch_release_bundle", lambda repo, tag: sentinel)
+    monkeypatch.setattr(iwp, "fetch_release_checksums", lambda bundle: {_CPU_ASSET: _A})
+    bundle, checks = iwp.fetch_release_for_install(_REPO, published_release_tag = None)
+    assert bundle is sentinel
+    assert checks == {_CPU_ASSET: _A}
+
+
+def test_resolve_via_download_host_sha_404_returns_none(monkeypatch):
+    import urllib.error
+
+    monkeypatch.setattr(iwp, "_download_host_latest_release_tag", lambda repo: _TAG)
+
+    def _dhj(url):
+        raise urllib.error.HTTPError(url, 404, "not found", {}, None)
+
+    monkeypatch.setattr(iwp, "_download_host_json", _dhj)
+    assert iwp._resolve_release_via_download_host(_REPO, None) is None
+
+
+def test_resolve_via_download_host_tag_mismatch_returns_none(monkeypatch):
+    # A checksum index whose self-reported release_tag disagrees is rejected (None).
+    monkeypatch.setattr(iwp, "_download_host_latest_release_tag", lambda repo: _TAG)
+    monkeypatch.setattr(
+        iwp, "_download_host_json", lambda url: _index(release_tag = "v1.9.1-unsloth.2")
+    )
+    assert iwp._resolve_release_via_download_host(_REPO, None) is None
+
+
+def test_download_host_latest_release_tag_parses_redirect(monkeypatch):
+    class _Resp:
+        def __enter__(self):
+            return self
+
+        def __exit__(self, *a):
+            return False
+
+        def geturl(self):
+            return f"https://github.com/{_REPO}/releases/tag/{_TAG}"
+
+    class _Opener:
+        def open(
+            self,
+            req,
+            timeout = None,
+        ):
+            return _Resp()
+
+    monkeypatch.setattr(iwp, "_URL_OPENER", _Opener())
+    assert iwp._download_host_latest_release_tag(_REPO) == _TAG
+
+
+def test_download_host_latest_release_tag_404_returns_none(monkeypatch):
+    import urllib.error
+
+    class _Opener:
+        def open(
+            self,
+            req,
+            timeout = None,
+        ):
+            raise urllib.error.HTTPError(req.full_url, 404, "nf", {}, None)
+
+    monkeypatch.setattr(iwp, "_URL_OPENER", _Opener())
+    assert iwp._download_host_latest_release_tag(_REPO) is None
diff --git a/studio/backend/tests/test_linux_external_media_paths.py b/studio/backend/tests/test_linux_external_media_paths.py
index b735bd1132..8373cdd6bb 100644
--- a/studio/backend/tests/test_linux_external_media_paths.py
+++ b/studio/backend/tests/test_linux_external_media_paths.py
@@ -254,8 +254,10 @@ def test_legacy_browse_allowlist_includes_linux_run_media_mounts(monkeypatch, tm
     )
     fake_external_media = SimpleNamespace(
         linux_run_media_mount_roots = lambda: [media_root],
+        macos_volume_roots = lambda: [],
         windows_drive_roots = lambda: [],
     )
+    fake_paths.external_media = fake_external_media
     fake_studio_db = SimpleNamespace(
         list_scan_folders = lambda: [],
         contains_sensitive_path_component = studio_db.contains_sensitive_path_component,
diff --git a/studio/backend/tests/test_llama_cpp_context_fit.py b/studio/backend/tests/test_llama_cpp_context_fit.py
index d3a10df8ca..2a4f6d19d2 100644
--- a/studio/backend/tests/test_llama_cpp_context_fit.py
+++ b/studio/backend/tests/test_llama_cpp_context_fit.py
@@ -567,7 +567,7 @@ class TestClassifyGpuOffload:
         assert inst._classify_gpu_offload(False, []) is None
 
     def test_user_did_not_intend_gpu_returns_none(self):
-        # Studio called start_llama_server without expecting GPU; don't warn.
+        # Unsloth called start_llama_server without expecting GPU; don't warn.
         inst = self._backend(
             [
                 "load_tensors:   CPU_Mapped model buffer size = 21000.0 MiB",
diff --git a/studio/backend/tests/test_llama_cpp_mmproj_fallback.py b/studio/backend/tests/test_llama_cpp_mmproj_fallback.py
index 04d4aac9e1..4332a440a5 100644
--- a/studio/backend/tests/test_llama_cpp_mmproj_fallback.py
+++ b/studio/backend/tests/test_llama_cpp_mmproj_fallback.py
@@ -222,7 +222,7 @@ class TestFlashAttnOff:
         assert _flash_off(["llama-server", "-fa=on"]) == ["llama-server", "-fa=off"]
 
     def test_flips_every_occurrence_last_wins(self):
-        # extra_args can re-enable FA after Studio's flag; llama.cpp is last-wins,
+        # extra_args can re-enable FA after Unsloth's flag; llama.cpp is last-wins,
         # so one leftover 'on' would re-crash the retry. Every enable must flip.
         cmd = ["llama-server", "--flash-attn", "on", "--mmproj", "/p", "--flash-attn", "on"]
         out = _flash_off(cmd)
@@ -234,7 +234,7 @@ class TestFlashAttnOff:
         assert _flash_off(["llama-server", "--flash-attn=off"]) is None
 
     def test_none_when_user_off_wins_last(self):
-        # User appended 'off' after Studio's 'on'; effective (last-wins) is off,
+        # User appended 'off' after Unsloth's 'on'; effective (last-wins) is off,
         # so there is nothing to retry.
         assert _flash_off(["llama-server", "--flash-attn", "on", "--flash-attn", "off"]) is None
 
@@ -335,3 +335,24 @@ class TestRetryContract:
     def test_external_kill_skips_flash_attn_retry(self):
         # SIGKILL (-9, OOM killer) is not a program fault: no FA-off retry.
         assert _signal_crash(-9) is False
+
+
+class TestMmprojRetryFailureMessage:
+    """#7302: bare mmproj crashes must not be reported as projector-format."""
+
+    def test_confirmed_projector_keeps_historical_wording(self):
+        msg = LlamaCppBackend._mmproj_retry_failure_message(
+            projector_confirmed = True,
+            detail = "llama-server failed to start",
+        )
+        assert msg.startswith("Vision projector incompatible with this llama.cpp")
+        assert "llama-server failed to start" in msg
+
+    def test_bare_crash_does_not_claim_projector_incompatibility(self):
+        msg = LlamaCppBackend._mmproj_retry_failure_message(
+            projector_confirmed = False,
+            detail = "llama-server failed to start. Check that the GGUF file is valid",
+        )
+        assert "Vision projector incompatible" not in msg
+        assert "crashed with --mmproj" in msg
+        assert "GGUF file is valid" in msg
diff --git a/studio/backend/tests/test_llama_cpp_mtp_detection.py b/studio/backend/tests/test_llama_cpp_mtp_detection.py
index 3f9d2a8f50..27c1b17a85 100644
--- a/studio/backend/tests/test_llama_cpp_mtp_detection.py
+++ b/studio/backend/tests/test_llama_cpp_mtp_detection.py
@@ -9,6 +9,7 @@ the _already_in_target_state mirror that prevents needless reloads.
 
 from __future__ import annotations
 
+import ast
 import inspect
 import os
 import struct
@@ -345,10 +346,62 @@ def test_windows_full_offload_flags_use_current_llama_server_args():
     stale_checkpoint_flag = "--checkpoint-" + "every-n-tokens"
     assert '"--cache-ram"' in src
     assert '"--ctx-checkpoints"' in src
-    assert '"--no-cache-prompt"' in src
+    # Prompt caching stays on (in-VRAM prefix reuse); #5692 only needed the host-RAM
+    # checkpoints (--cache-ram / --ctx-checkpoints) disabled, not prompt reuse.
+    assert '"--no-cache-prompt"' not in src
     assert stale_checkpoint_flag not in src
 
 
+# Backend-wide guard: Unsloth must never inject --no-cache-prompt into a llama-server
+# command. It disables in-VRAM prompt-prefix reuse, re-prefilling every repeated prompt
+# (#5692 only needed --cache-ram / --ctx-checkpoints off; #7260 dropped the stray flag).
+# Detecting it (_is_real) or honouring a user-supplied one (_prompt_cache_off) is fine.
+_NO_CACHE_PROMPT_FLAG = "--no-cache-prompt"
+_LIST_MUTATORS = frozenset({"append", "extend", "insert"})
+
+
+def _has_flag_literal(node: ast.AST) -> bool:
+    return any(
+        isinstance(n, ast.Constant) and n.value == _NO_CACHE_PROMPT_FLAG for n in ast.walk(node)
+    )
+
+
+def _no_cache_prompt_injections(source: str, filename: str) -> list[tuple[str, int]]:
+    """(file, lineno) for each spot adding --no-cache-prompt to a list."""
+    hits: list[tuple[str, int]] = []
+    for node in ast.walk(ast.parse(source, filename = filename)):
+        # cmd.append/extend/insert(... flag ...) or cmd += [... flag ...]
+        if (
+            isinstance(node, ast.Call)
+            and isinstance(node.func, ast.Attribute)
+            and node.func.attr in _LIST_MUTATORS
+            and any(_has_flag_literal(a) for a in node.args)
+        ) or (
+            isinstance(node, ast.AugAssign)
+            and isinstance(node.op, ast.Add)
+            and _has_flag_literal(node.value)
+        ):
+            hits.append((filename, node.lineno))
+    return hits
+
+
+def test_unsloth_never_injects_no_cache_prompt_into_any_command():
+    root = Path(_BACKEND_DIR)
+    files = [p for p in root.rglob("*.py") if "tests" not in p.relative_to(root).parts]
+    violations: list[tuple[str, int]] = []
+    for path in files:
+        try:
+            violations += _no_cache_prompt_injections(path.read_text(encoding = "utf-8"), str(path))
+        except (OSError, UnicodeDecodeError, SyntaxError):
+            continue
+    assert files, "no backend source files were scanned"
+    assert violations == [], (
+        "Unsloth must never add --no-cache-prompt to a llama-server command "
+        "(it disables prompt-prefix reuse); detecting or honouring a user-supplied "
+        f"one is fine. Offending sites: {violations}"
+    )
+
+
 def test_load_model_sets_threads_once():
     src = inspect.getsource(LlamaCppBackend.load_model)
     assert src.count('cmd.extend(["--threads", str(') == 1
@@ -584,7 +637,9 @@ def test_probe_server_capabilities_uses_binary_library_env(tmp_path, monkeypatch
     def fake_run(cmd, **kwargs):
         captured["cmd"] = cmd
         captured["env"] = kwargs.get("env")
-        return _types.SimpleNamespace(stdout = "--spec-type none,mtp,ngram-simple\n", stderr = "")
+        return _types.SimpleNamespace(
+            stdout = "--spec-type none,mtp,ngram-simple\n", stderr = "", returncode = 0
+        )
 
     monkeypatch.setattr("core.inference.llama_cpp.subprocess.run", fake_run)
 
@@ -625,6 +680,95 @@ def test_probe_server_capabilities_reports_outdated_binary(tmp_path):
     assert caps["found"] is True
     assert caps["mtp_token"] is None
     assert caps["supports_mtp"] is False
+    assert caps["mtp_probe_inconclusive"] is False
+
+
+@_NEEDS_BASH
+def test_probe_server_capabilities_reads_mtp_from_multiline_help(tmp_path):
+    # Enum on the indented line: first-line-only probing falsely reported
+    # "lacks MTP" (#7302).
+    fake = _make_fake_llama_server(
+        tmp_path / "llama-server",
+        "--spec-type TYPE\n"
+        "                                        speculative decoding type\n"
+        "                                        (none,draft-simple,draft-mtp,ngram-mod)\n",
+    )
+    _clear_caps_cache()
+    caps = LlamaCppBackend.probe_server_capabilities(str(fake))
+    assert caps["mtp_token"] == "draft-mtp"
+    assert caps["supports_mtp"] is True
+    assert caps["mtp_probe_inconclusive"] is False
+
+
+@_NEEDS_BASH
+def test_probe_server_capabilities_empty_help_fails_open(tmp_path):
+    # --help prints nothing: must not claim the prebuilt lacks MTP (#7302).
+    fake = tmp_path / "llama-server"
+    fake.write_text("#!/usr/bin/env bash\nexit 0\n")
+    fake.chmod(0o755)
+    _clear_caps_cache()
+    caps = LlamaCppBackend.probe_server_capabilities(str(fake))
+    assert caps["found"] is True
+    assert caps["mtp_token"] is None
+    assert caps["supports_mtp"] is False
+    assert caps["mtp_probe_inconclusive"] is True
+
+
+@_NEEDS_BASH
+def test_probe_server_capabilities_no_spec_type_is_definitive(tmp_path):
+    # Nonempty --help without --spec-type: pre-spec binary, not inconclusive.
+    fake = _make_fake_llama_server(
+        tmp_path / "llama-server",
+        "--gpu-layers N\n  GPU layers to offload\n",
+    )
+    _clear_caps_cache()
+    caps = LlamaCppBackend.probe_server_capabilities(str(fake))
+    assert caps["found"] is True
+    assert caps["mtp_token"] is None
+    assert caps["supports_mtp"] is False
+    assert caps["mtp_probe_inconclusive"] is False
+
+
+@_NEEDS_BASH
+def test_probe_server_capabilities_failed_help_with_output_is_inconclusive(tmp_path):
+    fake = tmp_path / "llama-server"
+    fake.write_text(
+        "#!/usr/bin/env bash\n"
+        'if [ "$1" = "--help" ]; then\n'
+        "  echo 'illegal instruction'\n"
+        "  exit 1\n"
+        "fi\n"
+    )
+    fake.chmod(0o755)
+    _clear_caps_cache()
+    caps = LlamaCppBackend.probe_server_capabilities(str(fake))
+    assert caps["found"] is True
+    assert caps["supports_mtp"] is False
+    assert caps["mtp_probe_inconclusive"] is True
+
+
+@_NEEDS_BASH
+def test_probe_server_capabilities_crash_on_help_fails_open(tmp_path):
+    fake = tmp_path / "llama-server"
+    fake.write_text("#!/usr/bin/env bash\nkill -SEGV $$\n")
+    fake.chmod(0o755)
+    _clear_caps_cache()
+    caps = LlamaCppBackend.probe_server_capabilities(str(fake))
+    assert caps["found"] is True
+    assert caps["mtp_token"] is None
+    assert caps["supports_mtp"] is False
+    assert caps["mtp_probe_inconclusive"] is True
+
+
+def test_mtp_token_from_spec_help_prefers_draft_mtp():
+    assert (
+        LlamaCppBackend._mtp_token_from_spec_help("--spec-type none,draft-mtp,mtp,ngram-mod")
+        == "draft-mtp"
+    )
+    assert LlamaCppBackend._mtp_token_from_spec_help("--spec-type [none|mtp|ngram-cache]") == "mtp"
+    assert LlamaCppBackend._mtp_token_from_spec_help("--spec-type none,ngram-mod") is None
+    # No incidental substring matches.
+    assert LlamaCppBackend._mtp_token_from_spec_help("prompt cache") is None
 
 
 def test_probe_server_capabilities_handles_missing_binary():
@@ -632,6 +776,7 @@ def test_probe_server_capabilities_handles_missing_binary():
     caps = LlamaCppBackend.probe_server_capabilities("/no/such/llama-server")
     assert caps["found"] is False
     assert caps["supports_mtp"] is False
+    assert caps["mtp_probe_inconclusive"] is True
     assert caps["supports_cache_ram"] is False
     assert caps["supports_ctx_checkpoints"] is False
     assert caps["supports_no_cache_prompt"] is False
@@ -741,6 +886,25 @@ def test_probe_reports_windows_cache_flags_absent_for_older_binary(tmp_path):
     assert caps["supports_no_cache_prompt"] is False
 
 
+@_NEEDS_BASH
+def test_probe_detects_slot_save_path(tmp_path):
+    fake = _make_fake_llama_server(
+        tmp_path / "llama-server",
+        "--slot-save-path PATH  path to save slot kv cache\n--threads N\n",
+    )
+    _clear_caps_cache()
+    caps = LlamaCppBackend.probe_server_capabilities(str(fake))
+    assert caps["supports_slot_save"] is True
+
+
+@_NEEDS_BASH
+def test_probe_reports_slot_save_absent_for_older_binary(tmp_path):
+    fake = _make_fake_llama_server(tmp_path / "llama-server", "--threads N\n")
+    _clear_caps_cache()
+    caps = LlamaCppBackend.probe_server_capabilities(str(fake))
+    assert caps["supports_slot_save"] is False
+
+
 def test_build_ngram_mod_flags_new():
     flags = _build_ngram_mod_flags({"ngram_mod_flavor": "new"})
     assert flags == [
@@ -1014,7 +1178,7 @@ def test_already_in_target_state_2b_falls_back_to_ngram_below_threshold(monkeypa
     )
 
 
-# usage backfill from timings (Studio UI t/s widget fix).
+# usage backfill from timings (Unsloth UI t/s widget fix).
 
 
 def test_backfill_usage_from_timings_fills_when_completion_tokens_zero():
@@ -1104,12 +1268,14 @@ def _resolver_backend(
     *,
     ngram_supported = True,
     mtp_token = "draft-mtp",
+    mtp_probe_inconclusive = False,
 ):
     """Backend with a deterministic probe so the resolver is hermetic."""
     fake = {
         "found": True,
         "mtp_token": mtp_token,
         "supports_mtp": bool(mtp_token),
+        "mtp_probe_inconclusive": mtp_probe_inconclusive,
         "ngram_mod_flavor": "new" if ngram_supported else None,
         "supports_ngram_mod": bool(ngram_supported),
         "spec_draft_n_max_flag": "--spec-draft-n-max",
@@ -1606,7 +1772,7 @@ def test_reload_forced_mtp_bounces_auto_mla():
     )
 
 
-# ── Full named-repo resolver matrix (the shipping Studio families) ─────
+# ── Full named-repo resolver matrix (the shipping Unsloth families) ─────
 #
 # Locks auto / off / forced-mtp routing for every Qwen3.5 (MTP + plain) and
 # gemma-4 (regular + QAT) GGUF repo, including the giant MoEs that stay
@@ -1807,6 +1973,24 @@ def test_spec_fallback_reason_set_when_binary_lacks_mtp(monkeypatch):
     assert backend.spec_fallback_reason == "binary_no_mtp"
 
 
+def test_spec_fallback_reason_none_when_mtp_probe_inconclusive(monkeypatch):
+    backend = _resolver_backend(
+        monkeypatch,
+        mtp_token = None,
+        mtp_probe_inconclusive = True,
+    )
+    backend._build_speculative_flags(
+        speculative_type = "mtp",
+        spec_draft_n_max = None,
+        extra_args = None,
+        model_identifier = _MTP_MODEL,
+        model_path = None,
+        gpus = True,
+        binary = "/fake/llama-server",
+    )
+    assert backend.spec_fallback_reason is None
+
+
 def test_spec_fallback_reason_none_when_mtp_engages(monkeypatch):
     backend = _resolver_backend(monkeypatch)
     backend._build_speculative_flags(
diff --git a/studio/backend/tests/test_llama_cpp_no_context_shift.py b/studio/backend/tests/test_llama_cpp_no_context_shift.py
index 10b1dc7ff6..662c918305 100644
--- a/studio/backend/tests/test_llama_cpp_no_context_shift.py
+++ b/studio/backend/tests/test_llama_cpp_no_context_shift.py
@@ -5,7 +5,7 @@
 
 With llama-server's default context-shift behavior, the UI cannot tell the user
 the KV cache was rotated -- earlier turns silently vanish from the conversation.
-The Studio backend always passes ``--no-context-shift`` so the server returns a
+The Unsloth backend always passes ``--no-context-shift`` so the server returns a
 clean error instead, and the chat adapter can point the user at the
 ``Context Length`` input in the settings panel.
 
@@ -118,9 +118,17 @@ def test_flag_sits_inside_the_base_cmd_list():
         "conditional branch -- otherwise some code paths would still "
         "run with silent context shift enabled."
     )
-    # Pin that it sits next to -c / --ctx so the grouping makes sense.
-    assert '"-c"' in block
     assert '"--flash-attn"' in block
+    # -c is emitted in the conditional right after the base list, not inside
+    # it: auto-fit (--fit on with no pinned context) must omit -c entirely,
+    # because "-c 0" pins the full native context and disables --fit's
+    # VRAM-based sizing. Pin that it still sits next to the base block so the
+    # context grouping stays intact.
+    after = rest[end_rel : end_rel + 1000]
+    assert '"-c"' in after, (
+        "-c must still be emitted in the conditional immediately after the "
+        "base cmd list (omitted only in auto-fit, where --fit sizes context)."
+    )
 
 
 def _iter_lines_with_offset(text: str):
diff --git a/studio/backend/tests/test_llama_cpp_props_readback.py b/studio/backend/tests/test_llama_cpp_props_readback.py
index 316956325f..fe1e67edad 100644
--- a/studio/backend/tests/test_llama_cpp_props_readback.py
+++ b/studio/backend/tests/test_llama_cpp_props_readback.py
@@ -4,7 +4,7 @@
 """Tests for the post-launch /props context readback.
 
 llama-server's memory-fit step or --parallel slot split can allocate less
-context than the requested -c while Studio keeps advertising the requested
+context than the requested -c while Unsloth keeps advertising the requested
 value; clients sized to it then die on exceed_context_size_error 400s.
 ``_reconcile_effective_ctx_with_server`` must adopt the server's real
 ``default_generation_settings.n_ctx`` whenever it is smaller.
@@ -223,33 +223,48 @@ _CAPS_NONE = {"supports_kv_unified": False, "supports_fit_ctx": False}
 
 def test_kv_unified_added_for_multi_slot():
     """Explicit --parallel N disables llama-server's auto-slots kv-unified
-    default, splitting -c into per-slot windows of -c/N; Studio must restore
+    default, splitting -c into per-slot windows of -c/N; Unsloth must restore
     the shared pool so one request can use the full advertised context."""
-    flags = LlamaCppBackend._ctx_integrity_flags(4, False, 98304, 98304, _CAPS_ALL)
+    flags = LlamaCppBackend._ctx_integrity_flags(4, False, False, 98304, 98304, _CAPS_ALL)
     assert "--kv-unified" in flags
 
 
 def test_kv_unified_skipped_for_single_slot_or_old_build():
     assert "--kv-unified" not in LlamaCppBackend._ctx_integrity_flags(
-        1, False, 98304, 98304, _CAPS_ALL
+        1, False, False, 98304, 98304, _CAPS_ALL
     )
     assert "--kv-unified" not in LlamaCppBackend._ctx_integrity_flags(
-        4, False, 98304, 98304, _CAPS_NONE
+        4, False, False, 98304, 98304, _CAPS_NONE
     )
 
 
 def test_fit_ctx_floors_explicit_request_under_fit():
-    flags = LlamaCppBackend._ctx_integrity_flags(1, True, 98304, 98304, _CAPS_ALL)
+    # An explicit requested ctx floors --fit-ctx at that value on any --fit
+    # path, including legacy auto (auto_fit False).
+    flags = LlamaCppBackend._ctx_integrity_flags(1, True, False, 98304, 98304, _CAPS_ALL)
     assert flags[flags.index("--fit-ctx") + 1] == "98304"
 
 
-def test_fit_ctx_skipped_without_fit_or_explicit_ctx_or_support():
+def test_fit_ctx_skipped_without_fit_or_support():
+    # No --fit on -> no --fit-ctx.
     assert "--fit-ctx" not in LlamaCppBackend._ctx_integrity_flags(
-        1, False, 98304, 98304, _CAPS_ALL
+        1, False, False, 98304, 98304, _CAPS_ALL
     )
-    assert "--fit-ctx" not in LlamaCppBackend._ctx_integrity_flags(1, True, 0, 262144, _CAPS_ALL)
+    # --fit on but the binary doesn't support --fit-ctx.
     assert "--fit-ctx" not in LlamaCppBackend._ctx_integrity_flags(
-        1, True, 98304, 98304, _CAPS_NONE
+        1, True, True, 98304, 98304, _CAPS_NONE
+    )
+
+
+def test_fit_ctx_floors_auto_request_at_8192_only_under_auto_fit():
+    # Manual + Auto (auto_fit) floors the auto window at 8192 so --fit can't
+    # shrink it to a tiny size.
+    flags = LlamaCppBackend._ctx_integrity_flags(1, True, True, 0, 262144, _CAPS_ALL)
+    assert flags[flags.index("--fit-ctx") + 1] == "8192"
+    # Legacy auto (fit on but not auto_fit) emits -c 0 to pin native, so the
+    # 8192 floor must NOT ride along and override that pin.
+    assert "--fit-ctx" not in LlamaCppBackend._ctx_integrity_flags(
+        1, True, False, 0, 262144, _CAPS_ALL
     )
 
 
diff --git a/studio/backend/tests/test_llama_cpp_slot_resume.py b/studio/backend/tests/test_llama_cpp_slot_resume.py
new file mode 100644
index 0000000000..8b20c952c4
--- /dev/null
+++ b/studio/backend/tests/test_llama_cpp_slot_resume.py
@@ -0,0 +1,494 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import os
+from types import SimpleNamespace
+
+import core.inference.llama_cpp as llama_cpp
+from core.inference.llama_cpp import LlamaCppBackend
+
+
+def _resume_backend(tmp_path, n_slots = 1):
+    backend = LlamaCppBackend()
+    backend._healthy = True
+    # No-op lifecycle methods so the atexit cleanup can kill the fake quietly.
+    backend._process = SimpleNamespace(
+        poll = lambda: None,
+        terminate = lambda: None,
+        wait = lambda *a, **k: 0,
+        kill = lambda: None,
+        pid = 0,
+    )
+    backend._port = 8081
+    backend._slot_save_dir = str(tmp_path)
+    backend._slot_save_binary = ("/bin/llama-server", 1)
+    (tmp_path / "model.gguf").write_bytes(b"gguf")
+    backend._gguf_path = str(tmp_path / "model.gguf")
+    backend._effective_parallel_slots = n_slots
+    backend._estimate_kv_cache_bytes = lambda *a, **k: 0
+    return backend
+
+
+def _fake_disk(monkeypatch, free = 1 << 40):
+    monkeypatch.setattr(llama_cpp.shutil, "disk_usage", lambda _p: SimpleNamespace(free = free))
+
+
+class _Resp:
+    def __init__(
+        self,
+        status_code = 200,
+        body = None,
+    ):
+        self.status_code = status_code
+        self._body = body or {}
+
+    def json(self):
+        return self._body
+
+
+def test_save_returns_none_when_slot_save_disabled(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path)
+    backend._slot_save_dir = None
+    monkeypatch.setattr(
+        llama_cpp.httpx,
+        "post",
+        lambda *a, **k: (_ for _ in ()).throw(AssertionError),
+        raising = False,
+    )
+    assert backend.save_slots_for_resume() is None
+
+
+def test_save_skipped_when_prompt_cache_disabled(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path)
+    backend._prompt_cache_disabled = True
+    monkeypatch.setattr(
+        llama_cpp.httpx,
+        "post",
+        lambda *a, **k: (_ for _ in ()).throw(AssertionError),
+        raising = False,
+    )
+    assert backend.save_slots_for_resume() is None
+
+
+def test_save_skipped_when_insufficient_free_disk(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path)
+    backend._estimate_kv_cache_bytes = lambda *a, **k: 1 << 40
+    _fake_disk(monkeypatch, free = 1 << 20)
+    monkeypatch.setattr(
+        llama_cpp.httpx,
+        "post",
+        lambda *a, **k: (_ for _ in ()).throw(AssertionError),
+        raising = False,
+    )
+    assert backend.save_slots_for_resume() is None
+
+
+def test_save_collects_manifest_across_slots(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path, n_slots = 2)
+    _fake_disk(monkeypatch)
+    calls = []
+
+    def fake_post(url, **kwargs):
+        calls.append((url, kwargs["params"], kwargs["json"]))
+        return _Resp(200, {"n_saved": 40, "n_written": 100})
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    manifest = backend.save_slots_for_resume()
+    assert manifest is not None
+    assert manifest["dir"] == str(tmp_path)
+    assert manifest["binary"] == ("/bin/llama-server", 1)
+    assert manifest["gguf"] == str(tmp_path / "model.gguf")
+    st = os.stat(manifest["gguf"])
+    assert manifest["gguf_stat"] == ((st.st_size, st.st_mtime_ns),)
+    assert manifest["launch"] == backend._slot_launch_fingerprint()
+    assert [e["id"] for e in manifest["slots"]] == [0, 1]
+    assert all(e["n_saved"] == 40 for e in manifest["slots"])
+    assert [c[1] for c in calls] == [{"action": "save"}] * 2
+    assert "/slots/0" in calls[0][0] and "/slots/1" in calls[1][0]
+
+
+def test_save_unlinks_empty_slot_and_returns_none(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path)
+    _fake_disk(monkeypatch)
+
+    def fake_post(url, **kwargs):
+        (tmp_path / kwargs["json"]["filename"]).write_bytes(b"")
+        return _Resp(200, {"n_saved": 0, "n_written": 0})
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    assert backend.save_slots_for_resume() is None
+    assert list(tmp_path.glob("resume-*.bin")) == []  # empty-slot file removed
+
+
+def test_save_cap_breach_discards_all_files(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path, n_slots = 2)
+    _fake_disk(monkeypatch)
+    monkeypatch.setattr(llama_cpp, "_SLOT_SAVE_MAX_BYTES", 150)
+
+    def fake_post(url, **kwargs):
+        (tmp_path / kwargs["json"]["filename"]).write_bytes(b"x" * 100)
+        return _Resp(200, {"n_saved": 40, "n_written": 100})
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    assert backend.save_slots_for_resume() is None  # 200 bytes > 150 cap
+    assert list(tmp_path.glob("resume-*.bin")) == []
+
+
+def test_save_transport_error_aborts_remaining_slots(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path, n_slots = 3)
+    _fake_disk(monkeypatch)
+    calls = []
+
+    def fake_post(url, **kwargs):
+        calls.append(url)
+        raise OSError("connection refused")
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    assert backend.save_slots_for_resume() is None
+    assert len(calls) == 1  # no retries against a dead server
+
+
+def test_save_transport_error_unlinks_partial_file(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path)
+    _fake_disk(monkeypatch)
+
+    def fake_post(url, **kwargs):
+        (tmp_path / kwargs["json"]["filename"]).write_bytes(b"partial")
+        raise OSError("timed out")
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    assert backend.save_slots_for_resume() is None
+    assert list(tmp_path.glob("resume-*.bin")) == []
+
+
+def test_fingerprint_tracks_lora_sidecar_rewrite(tmp_path):
+    backend = _resume_backend(tmp_path)
+    adapter = tmp_path / "adapter.gguf"
+    adapter.write_bytes(b"v1")
+    backend._extra_args = ["--lora", str(adapter)]
+
+    before = backend._slot_launch_fingerprint()
+    adapter.write_bytes(b"v2-different")  # re-exported adapter, same path
+    assert backend._slot_launch_fingerprint() != before
+
+    backend._extra_args = [f"--lora={adapter}"]
+    assert backend._sidecar_weight_files() == [str(adapter)]
+    backend._extra_args = ["--lora-scaled", str(adapter), "0.5"]
+    assert backend._sidecar_weight_files() == [str(adapter)]
+    backend._extra_args = ["--control-vector", str(adapter), "--threads", "4"]
+    assert backend._sidecar_weight_files() == [str(adapter)]
+
+
+def test_sidecar_files_parse_csv_and_colon_scale(tmp_path):
+    backend = _resume_backend(tmp_path)
+    a, b = tmp_path / "a.gguf", tmp_path / "b.gguf"
+
+    backend._extra_args = ["--lora", f"{a},{b}"]
+    files = backend._sidecar_weight_files()
+    assert str(a) in files and str(b) in files
+
+    backend._extra_args = ["--lora-scaled", f"{a}:0.5"]
+    assert str(a) in backend._sidecar_weight_files()
+
+    backend._extra_args = ["--control-vector-scaled", f"{a}:1.0,{b}:2.0"]
+    files = backend._sidecar_weight_files()
+    assert str(a) in files and str(b) in files
+
+    # Windows drive letter must not be mistaken for a scale separator.
+    backend._extra_args = ["--lora-scaled", "C:\\adapters\\a.gguf:0.75"]
+    assert "C:\\adapters\\a.gguf" in backend._sidecar_weight_files()
+    backend._extra_args = ["--lora", "C:\\adapters\\a.gguf"]
+    assert backend._sidecar_weight_files() == ["C:\\adapters\\a.gguf"]
+
+
+def test_fingerprint_tracks_colon_scaled_adapter_rewrite(tmp_path):
+    backend = _resume_backend(tmp_path)
+    adapter = tmp_path / "adapter.gguf"
+    adapter.write_bytes(b"v1")
+    backend._extra_args = ["--lora-scaled", f"{adapter}:0.5"]
+
+    before = backend._slot_launch_fingerprint()
+    adapter.write_bytes(b"v2-different")  # re-exported adapter, same path
+    assert backend._slot_launch_fingerprint() != before
+
+
+def test_fingerprint_tracks_effective_context_length(tmp_path):
+    backend = _resume_backend(tmp_path)
+    backend._effective_context_length = 8192
+
+    before = backend._slot_launch_fingerprint()
+    backend._effective_context_length = 4096  # auto-fit landed smaller on reload
+    assert backend._slot_launch_fingerprint() != before
+
+
+def test_gguf_file_identity_covers_split_shards(tmp_path):
+    backend = _resume_backend(tmp_path)
+    first = tmp_path / "m-00001-of-00002.gguf"
+    second = tmp_path / "m-00002-of-00002.gguf"
+    first.write_bytes(b"a")
+    second.write_bytes(b"bb")
+
+    before = backend._gguf_file_identity(str(first))
+    st1, st2 = os.stat(first), os.stat(second)
+    assert before == ((st1.st_size, st1.st_mtime_ns), (st2.st_size, st2.st_mtime_ns))
+
+    second.write_bytes(b"rewritten")  # sibling changes, primary untouched
+    after = backend._gguf_file_identity(str(first))
+    assert after is not None and after != before
+    assert after[0] == before[0]  # primary shard unchanged
+
+    second.unlink()
+    assert backend._gguf_file_identity(str(first)) is None  # missing shard
+
+
+def test_save_skipped_when_user_disabled_prompt_cache(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path)
+    backend._extra_args = ["--no-cache-prompt"]
+    monkeypatch.setattr(
+        llama_cpp.httpx,
+        "post",
+        lambda *a, **k: (_ for _ in ()).throw(AssertionError),
+        raising = False,
+    )
+    assert backend.save_slots_for_resume() is None
+
+
+def test_save_skipped_when_env_disables_prompt_cache(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path)
+    monkeypatch.setenv("LLAMA_ARG_CACHE_PROMPT", "0")
+    monkeypatch.setattr(
+        llama_cpp.httpx,
+        "post",
+        lambda *a, **k: (_ for _ in ()).throw(AssertionError),
+        raising = False,
+    )
+    assert backend.save_slots_for_resume() is None
+    monkeypatch.delenv("LLAMA_ARG_CACHE_PROMPT")
+    monkeypatch.setenv("LLAMA_ARG_NO_CACHE_PROMPT", "1")  # legacy negative form
+    assert backend.save_slots_for_resume() is None
+
+
+def test_explicit_cache_prompt_flag_overrides_env(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path)
+    monkeypatch.setenv("LLAMA_ARG_CACHE_PROMPT", "0")
+    backend._extra_args = ["--cache-prompt"]  # CLI wins over env in llama.cpp
+    _fake_disk(monkeypatch)
+    monkeypatch.setattr(
+        llama_cpp.httpx,
+        "post",
+        lambda *a, **k: _Resp(200, {"n_saved": 1, "n_written": 1}),
+        raising = False,
+    )
+    assert backend.save_slots_for_resume() is not None
+
+
+def test_user_cache_prompt_overrides_studio_no_cache_flag(monkeypatch, tmp_path):
+    # User extras follow Studio's flags, so an explicit --cache-prompt wins.
+    backend = _resume_backend(tmp_path)
+    backend._prompt_cache_disabled = True
+    backend._extra_args = ["--cache-prompt"]
+    _fake_disk(monkeypatch)
+    monkeypatch.setattr(
+        llama_cpp.httpx,
+        "post",
+        lambda *a, **k: _Resp(200, {"n_saved": 1, "n_written": 1}),
+        raising = False,
+    )
+    assert backend.save_slots_for_resume() is not None
+    # Last flag wins when both appear in extras.
+    backend._extra_args = ["--cache-prompt", "--no-cache-prompt"]
+    assert backend.save_slots_for_resume() is None
+
+
+def test_save_stops_writing_once_cap_exceeded(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path, n_slots = 3)
+    _fake_disk(monkeypatch)
+    monkeypatch.setattr(llama_cpp, "_SLOT_SAVE_MAX_BYTES", 150)
+    calls = []
+
+    def fake_post(url, **kwargs):
+        calls.append(url)
+        (tmp_path / kwargs["json"]["filename"]).write_bytes(b"x" * 100)
+        return _Resp(200, {"n_saved": 1, "n_written": 100})
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    assert backend.save_slots_for_resume() is None
+    assert len(calls) == 2  # cap blown after slot 1; slot 2 never attempted
+    assert list(tmp_path.glob("resume-*.bin")) == []
+
+
+def test_save_aborts_between_slots_when_no_longer_idle(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path, n_slots = 3)
+    _fake_disk(monkeypatch)
+    calls = []
+
+    def fake_post(url, **kwargs):
+        calls.append(url)
+        return _Resp(200, {"n_saved": 5, "n_written": 10})
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    aborts = iter([False, True, True])
+    manifest = backend.save_slots_for_resume(should_abort = lambda: next(aborts))
+    assert len(calls) == 1  # slots 1 and 2 skipped
+    assert manifest is not None
+    assert [e["id"] for e in manifest["slots"]] == [0]
+
+
+def test_save_non_200_slot_is_skipped_but_others_kept(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path, n_slots = 2)
+    _fake_disk(monkeypatch)
+
+    def fake_post(url, **kwargs):
+        if "/slots/0" in url:
+            return _Resp(500)
+        return _Resp(200, {"n_saved": 5, "n_written": 10})
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    manifest = backend.save_slots_for_resume()
+    assert manifest is not None
+    assert [e["id"] for e in manifest["slots"]] == [1]
+
+
+def test_restore_posts_each_slot_and_tolerates_failures(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path)
+    calls = []
+
+    def fake_post(url, **kwargs):
+        calls.append((url, kwargs["params"], kwargs["json"]))
+        return _Resp(500 if "/slots/0" in url else 200, {"n_restored": 5})
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    backend.restore_slots_for_resume(
+        {
+            "slots": [
+                {"id": 0, "filename": "resume-a-slot0.bin", "n_saved": 5},
+                {"id": 1, "filename": "resume-a-slot1.bin", "n_saved": 5},
+            ]
+        }
+    )
+    assert [c[1] for c in calls] == [{"action": "restore"}] * 2
+    assert calls[0][2] == {"filename": "resume-a-slot0.bin"}
+
+
+def test_restore_transport_error_stops_early(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path)
+    calls = []
+
+    def fake_post(url, **kwargs):
+        calls.append(url)
+        raise OSError("connection refused")
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    backend.restore_slots_for_resume(
+        {"slots": [{"id": 0, "filename": "a.bin"}, {"id": 1, "filename": "b.bin"}]}
+    )
+    assert len(calls) == 1
+
+
+def test_save_deletes_orphan_on_malformed_response(monkeypatch, tmp_path):
+    # A 200 that writes a file but returns a non-numeric counter must be cleaned
+    # up like any other save failure, not left orphaned holding chat KV.
+    backend = _resume_backend(tmp_path)
+    _fake_disk(monkeypatch)
+
+    def fake_post(url, **kwargs):
+        (tmp_path / kwargs["json"]["filename"]).write_bytes(b"chat-kv")
+        return _Resp(200, {"n_saved": "not-an-int"})
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    assert backend.save_slots_for_resume() is None
+    assert list(tmp_path.glob("resume-*.bin")) == []
+
+
+def test_save_deletes_orphan_on_non_dict_response(monkeypatch, tmp_path):
+    backend = _resume_backend(tmp_path)
+    _fake_disk(monkeypatch)
+
+    def fake_post(url, **kwargs):
+        (tmp_path / kwargs["json"]["filename"]).write_bytes(b"chat-kv")
+        return _Resp(200, ["unexpected", "list"])
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    assert backend.save_slots_for_resume() is None
+    assert list(tmp_path.glob("resume-*.bin")) == []
+
+
+def test_save_cap_uses_actual_file_size_not_reported_bytes(monkeypatch, tmp_path):
+    # A binary under-reporting n_written must not slip past the disk cap: the
+    # cap is enforced against the bytes actually on disk.
+    backend = _resume_backend(tmp_path)
+    _fake_disk(monkeypatch)
+    monkeypatch.setattr(llama_cpp, "_SLOT_SAVE_MAX_BYTES", 150)
+
+    def fake_post(url, **kwargs):
+        (tmp_path / kwargs["json"]["filename"]).write_bytes(b"x" * 200)
+        return _Resp(200, {"n_saved": 5, "n_written": 1})  # under-reported
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    assert backend.save_slots_for_resume() is None  # 200 real bytes > 150 cap
+    assert list(tmp_path.glob("resume-*.bin")) == []
+
+
+def test_save_skipped_when_estimate_exceeds_cap(monkeypatch, tmp_path):
+    # An estimate over the cap skips before writing any slot at all.
+    backend = _resume_backend(tmp_path)
+    backend._estimate_kv_cache_bytes = lambda *a, **k: 1 << 40
+    monkeypatch.setattr(llama_cpp, "_SLOT_SAVE_MAX_BYTES", 1 << 20)
+    _fake_disk(monkeypatch)
+    monkeypatch.setattr(
+        llama_cpp.httpx,
+        "post",
+        lambda *a, **k: (_ for _ in ()).throw(AssertionError),
+        raising = False,
+    )
+    assert backend.save_slots_for_resume() is None
+
+
+def test_save_skipped_when_model_file_changed_since_load(monkeypatch, tmp_path):
+    # The GGUF/sidecars were swapped on disk after the server loaded them, so the
+    # live KV belongs to the old weights: refuse to persist it (no POST at all).
+    backend = _resume_backend(tmp_path)
+    backend._slot_loaded_identity = ((("stale", 0),), ())  # != current identity
+    _fake_disk(monkeypatch)
+    monkeypatch.setattr(
+        llama_cpp.httpx,
+        "post",
+        lambda *a, **k: (_ for _ in ()).throw(AssertionError),
+        raising = False,
+    )
+    assert backend.save_slots_for_resume() is None
+
+
+def test_save_proceeds_when_load_identity_matches(monkeypatch, tmp_path):
+    # Matching load-time snapshot: the save runs normally.
+    backend = _resume_backend(tmp_path)
+    backend._slot_loaded_identity = (
+        backend._gguf_file_identity(backend._gguf_path),
+        backend._slot_launch_fingerprint(),
+    )
+    _fake_disk(monkeypatch)
+
+    def fake_post(url, **kwargs):
+        (tmp_path / kwargs["json"]["filename"]).write_bytes(b"kv")
+        return _Resp(200, {"n_saved": 5, "n_written": 2})
+
+    monkeypatch.setattr(llama_cpp.httpx, "post", fake_post, raising = False)
+    manifest = backend.save_slots_for_resume()
+    assert manifest is not None
+    assert [e["id"] for e in manifest["slots"]] == [0]
+
+
+def test_save_skipped_when_estimate_unavailable_and_low_disk(monkeypatch, tmp_path):
+    # A 0 estimate means metadata was insufficient, not a zero-byte cache: the save
+    # must demand room for the whole cap, not just 1 GiB, on a low-disk host.
+    backend = _resume_backend(tmp_path)
+    backend._estimate_kv_cache_bytes = lambda *a, **k: 0  # metadata unavailable
+    monkeypatch.setattr(llama_cpp, "_SLOT_SAVE_MAX_BYTES", 8 << 30)  # 8 GiB cap
+    _fake_disk(monkeypatch, free = 2 << 30)  # 2 GiB free < 8 + 1 GiB required
+    monkeypatch.setattr(
+        llama_cpp.httpx,
+        "post",
+        lambda *a, **k: (_ for _ in ()).throw(AssertionError),
+        raising = False,
+    )
+    assert backend.save_slots_for_resume() is None
diff --git a/studio/backend/tests/test_llama_cpp_stall_timeout.py b/studio/backend/tests/test_llama_cpp_stall_timeout.py
new file mode 100644
index 0000000000..da36f75e8e
--- /dev/null
+++ b/studio/backend/tests/test_llama_cpp_stall_timeout.py
@@ -0,0 +1,125 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Regression test for the post-first-token stall timeout in the cancel-aware read.
+
+httpcore snapshots ``request.extensions["timeout"]["read"]`` once at body start, so
+when ``_iter_text_cancellable`` lowers it after the first token, a one-token-then-silent
+server hangs for the full prefill window. The fix re-reads the live extensions timeout
+per call; a fake clock and always-silent stream check the read gives up after the live
+stall timeout, not the stale prefill one.
+"""
+
+from __future__ import annotations
+
+import inspect
+import sys
+import threading
+import types as _types
+from pathlib import Path
+
+import pytest
+
+_BACKEND_DIR = str(Path(__file__).resolve().parent.parent)
+if _BACKEND_DIR not in sys.path:
+    sys.path.insert(0, _BACKEND_DIR)
+
+# Mirror sibling tests' stubbing so the module imports without fastapi.
+_loggers_stub = _types.ModuleType("loggers")
+_loggers_stub.get_logger = lambda name: __import__("logging").getLogger(name)
+sys.modules.setdefault("loggers", _loggers_stub)
+sys.modules.setdefault("structlog", _types.ModuleType("structlog"))
+
+import httpcore  # noqa: E402
+
+from core.inference import llama_cpp as llama_cpp_mod  # noqa: E402
+from core.inference.llama_cpp import LlamaCppBackend  # noqa: E402
+
+_PREFILL_TIMEOUT = 1200.0  # what httpcore snapshots from the prefill timeout
+_STALL_TIMEOUT = 120.0  # the post-first-token stall timeout the wrapper must honor
+
+
+class _Obj:
+    pass
+
+
+def _install(response, clock, silent_stream):
+    """Wire fake client/pool so _install_cancel_aware_read finds the stream; return the wrapped stream.read."""
+    inner = _Obj()
+    inner._network_stream = silent_stream
+    connection = _Obj()
+    connection._connection = inner
+    pool = _Obj()
+    pool._connections = [connection]
+    transport = _Obj()
+    transport._pool = pool
+    client = _Obj()
+    client._transport = transport
+
+    cancel_event = threading.Event()  # never set: we test the stall path, not cancel
+    sig = inspect.signature(LlamaCppBackend._install_cancel_aware_read)
+    if "response" in sig.parameters:
+        # Fixed signature: wrapper reads the live extensions timeout.
+        LlamaCppBackend._install_cancel_aware_read(client, cancel_event, response)
+    else:
+        # Pre-fix signature: no response, so the stall assertion fails (proves the bug).
+        LlamaCppBackend._install_cancel_aware_read(client, cancel_event)
+    return silent_stream.read
+
+
+def test_stall_timeout_honored_after_first_token(monkeypatch):
+    clock = {"t": 0.0}
+    monkeypatch.setattr(llama_cpp_mod.time, "monotonic", lambda: clock["t"])
+
+    # One token then silence: every read times out, advancing fake time by its timeout.
+    def silent_read(max_bytes, timeout = None):
+        clock["t"] += timeout if timeout is not None else 0.0
+        raise httpcore.ReadTimeout("slice timed out on silence")
+
+    stream = _Obj()
+    stream.read = silent_read
+
+    # First token seen: the live read timeout is lowered to the stall timeout.
+    request = _Obj()
+    request.extensions = {"timeout": {"read": _STALL_TIMEOUT}}
+    response = _Obj()
+    response.request = request
+
+    wrapped_read = _install(response, clock, stream)
+
+    # httpcore still passes the stale prefill timeout it snapshotted at body start.
+    with pytest.raises(httpcore.ReadTimeout):
+        wrapped_read(65536, timeout = _PREFILL_TIMEOUT)
+
+    # Must give up ~stall timeout after the last token, not the prefill window.
+    assert clock["t"] <= _STALL_TIMEOUT * 1.5, (
+        f"stall timeout not honored: waited {clock['t']}s "
+        f"(expected ~{_STALL_TIMEOUT}s, not {_PREFILL_TIMEOUT}s)"
+    )
+    assert clock["t"] >= _STALL_TIMEOUT * 0.5
+
+
+def test_prefill_timeout_used_when_no_live_override(monkeypatch):
+    """Without a lowered live timeout, the wrapper honors the passed prefill timeout, so the normal first-token wait is unchanged."""
+    clock = {"t": 0.0}
+    monkeypatch.setattr(llama_cpp_mod.time, "monotonic", lambda: clock["t"])
+
+    def silent_read(max_bytes, timeout = None):
+        clock["t"] += timeout if timeout is not None else 0.0
+        raise httpcore.ReadTimeout("slice timed out on silence")
+
+    stream = _Obj()
+    stream.read = silent_read
+
+    # No timeout extension: wrapper falls back to httpcore's passed timeout.
+    request = _Obj()
+    request.extensions = {}
+    response = _Obj()
+    response.request = request
+
+    wrapped_read = _install(response, clock, stream)
+
+    with pytest.raises(httpcore.ReadTimeout):
+        wrapped_read(65536, timeout = _PREFILL_TIMEOUT)
+
+    assert clock["t"] >= _PREFILL_TIMEOUT * 0.9
diff --git a/studio/backend/tests/test_llama_cpp_tool_loop.py b/studio/backend/tests/test_llama_cpp_tool_loop.py
index bd2c008589..e99e227d40 100644
--- a/studio/backend/tests/test_llama_cpp_tool_loop.py
+++ b/studio/backend/tests/test_llama_cpp_tool_loop.py
@@ -122,7 +122,7 @@ def _structured_tool_call(tool_name: str, arguments: dict, call_id: str) -> list
 def test_structured_tool_call_after_visible_preface_is_executed(monkeypatch):
     """llama-server may emit content first and then native delta.tool_calls.
 
-    Studio must not drop that tool call after it has streamed the preface.
+    Unsloth must not drop that tool call after it has streamed the preface.
     """
 
     tool_call_id = "call_render_late"
diff --git a/studio/backend/tests/test_llama_cpp_update.py b/studio/backend/tests/test_llama_cpp_update.py
index 83ea07a066..9e23242b97 100644
--- a/studio/backend/tests/test_llama_cpp_update.py
+++ b/studio/backend/tests/test_llama_cpp_update.py
@@ -83,6 +83,7 @@ def _write_install(
     repo: str = "unslothai/llama.cpp",
     asset: str | None = None,
     release_tag: str | None = None,
+    force_cpu: bool | None = None,
 ) -> str:
     """Create a fake prebuilt install and return the llama-server path."""
     bin_dir = dir_ / "build" / "bin"
@@ -99,6 +100,8 @@ def _write_install(
     }
     if asset is not None:
         marker["asset"] = asset
+    if force_cpu is not None:
+        marker["force_cpu"] = force_cpu
     (dir_ / MARKER).write_text(json.dumps(marker))
     return str(binary)
 
@@ -116,6 +119,9 @@ def _clean_state(monkeypatch, tmp_path):
     monkeypatch.delenv("UNSLOTH_LLAMA_CPP_PATH", raising = False)
     # Never hit the network in these tests.
     monkeypatch.setattr(freshness, "_fetch_latest_release_tag", lambda repo, timeout = 5.0: None)
+    # Keep the whisper piggyback out of the llama-only tests: no host probe, no
+    # whisper phase (test_combined_update.py covers the chained flow).
+    monkeypatch.setattr(upd, "_whisper_chain_status", lambda **kwargs: None)
     yield
     freshness.reset_caches()
     upd._reset_job_for_tests()
@@ -493,6 +499,47 @@ def test_start_update_preserves_vulkan_via_env(monkeypatch, tmp_path):
     assert popen_kwargs["env"]["UNSLOTH_FORCE_VULKAN"] == "1"
 
 
+@pytest.mark.parametrize(
+    "force_cpu, expect_flag",
+    [
+        # A deliberate CPU install (marker force_cpu=True) re-asserts --force-cpu on
+        # update so detect_host on a GPU host cannot re-route and revive the crash
+        # (#7213); --force-cpu also re-persists the flag for the next update.
+        (True, True),
+        # A transient fallback (or a legacy marker without the flag) stays free to
+        # heal to a GPU bundle (#6097).
+        (False, False),
+        (None, False),
+    ],
+)
+def test_start_update_cpu_fallback_preserved_by_flag(monkeypatch, tmp_path, force_cpu, expect_flag):
+    asset = "llama-b9493-bin-ubuntu-x64.tar.gz"
+    install_dir = tmp_path / "llama.cpp"
+    binary = _write_install(install_dir, "b9493", asset = asset, force_cpu = force_cpu)
+    monkeypatch.setattr(upd, "_find_binary", lambda: binary)
+    monkeypatch.setattr(upd, "_installer_script", lambda: tmp_path / "install_llama_prebuilt.py")
+    monkeypatch.setattr(freshness, "_fetch_latest_release_tag", lambda repo, timeout = 5.0: "b9518")
+
+    captured: dict = {}
+
+    def _on_start(cmd):
+        captured["cmd"] = cmd
+        _write_install(install_dir, "b9518", asset = asset, force_cpu = force_cpu)
+
+    _patch_installer_popen(monkeypatch, lines = ["installed\n"], on_start = _on_start)
+
+    assert upd.start_update()["started"] is True
+    deadline = time.time() + 10
+    while time.time() < deadline:
+        job = upd.get_update_status()["job"]
+        if job["state"] in ("success", "error"):
+            break
+        time.sleep(0.05)
+    assert job["state"] == "success", job
+    assert ("--force-cpu" in captured["cmd"]) is expect_flag
+    assert "--cpu-fallback" not in captured["cmd"]
+
+
 def test_start_update_reports_full_release_tag(monkeypatch, tmp_path):
     install_dir = tmp_path / "llama.cpp"
     binary = _write_install(install_dir, "b9595")
@@ -676,7 +723,7 @@ def test_install_cmd_rocm_marker_forwards_gfx(monkeypatch, tmp_path):
     assert "--rocm-gfx" in cmd
     assert cmd[cmd.index("--rocm-gfx") + 1] == "gfx110x"
     assert "--has-rocm" not in cmd
-    assert "--cpu-fallback" not in cmd
+    assert "--force-cpu" not in cmd
     assert "--simple-policy" not in cmd
     assert "--published-repo" in cmd and "unslothai/llama.cpp" in cmd
 
@@ -690,17 +737,17 @@ def test_install_cmd_fork_rocm_marker_forwards_has_rocm(monkeypatch, tmp_path):
 
 
 def test_install_cmd_ggml_cpu_marker_has_no_cpu_fallback(monkeypatch, tmp_path):
-    # Legacy CPU installs recorded a ggml-org marker (new installs use the fork).
-    # Re-running into the same install-dir/repo reproduces the same CPU bundle;
-    # --cpu-fallback (which force-drops GPU detection) is reserved for setup.sh's
-    # arm64 rescue and must not appear here.
+    # Legacy CPU installs recorded a ggml-org marker (new installs use the fork) with
+    # no force_cpu field. Re-running into the same install-dir/repo reproduces the same
+    # CPU bundle; --force-cpu (the persisted-CPU re-assert) must not appear for a marker
+    # that never recorded a deliberate CPU choice, so it can still heal to GPU (#6097).
     cmd = _capture_install_cmd(
         monkeypatch,
         tmp_path,
         repo = "ggml-org/llama.cpp",
         asset = "llama-b9334-bin-ubuntu-x64.tar.gz",
     )
-    assert "--cpu-fallback" not in cmd
+    assert "--force-cpu" not in cmd
     assert "--rocm-gfx" not in cmd
     assert "--has-rocm" not in cmd
     assert "--simple-policy" not in cmd
@@ -714,7 +761,7 @@ def test_install_cmd_cuda_marker_minimal_and_backward_compatible(monkeypatch, tm
     assert "--simple-policy" not in cmd
     assert "--rocm-gfx" not in cmd
     assert "--has-rocm" not in cmd
-    assert "--cpu-fallback" not in cmd
+    assert "--force-cpu" not in cmd
 
 
 def test_install_cmd_pins_offered_release_tag(monkeypatch, tmp_path):
diff --git a/studio/backend/tests/test_llama_cpp_wait_for_health.py b/studio/backend/tests/test_llama_cpp_wait_for_health.py
index 82c5b4931a..423c3dd009 100644
--- a/studio/backend/tests/test_llama_cpp_wait_for_health.py
+++ b/studio/backend/tests/test_llama_cpp_wait_for_health.py
@@ -224,7 +224,7 @@ class TestRetryLogFilenameUnique:
 class TestFitOffRetryEligible:
     """Gate for the one-shot --fit off startup-crash retry.
 
-    Retry only when Studio's own VRAM math placed the model and nothing
+    Retry only when Unsloth's own VRAM math placed the model and nothing
     on the command line chose the fit mode explicitly."""
 
     def test_eligible_for_plain_ngl_launch(self):
diff --git a/studio/backend/tests/test_llama_cpp_wait_for_vram_settle.py b/studio/backend/tests/test_llama_cpp_wait_for_vram_settle.py
index d0213f6079..b28df7ec3f 100644
--- a/studio/backend/tests/test_llama_cpp_wait_for_vram_settle.py
+++ b/studio/backend/tests/test_llama_cpp_wait_for_vram_settle.py
@@ -346,7 +346,7 @@ def test_helper_is_static_method_callable_off_class():
 
 def test_kill_orphaned_servers_returns_count():
     """The reaper reports how many owned orphans it killed, so __init__ can
-    arm the settle wait. Only Studio-owned llama-server procs count."""
+    arm the settle wait. Only Unsloth-owned llama-server procs count."""
     import os
 
     mypid = os.getpid()
@@ -376,7 +376,7 @@ def test_kill_orphaned_servers_returns_count():
         patch.object(LlamaCppBackend, "_pid_parent_is_alive", staticmethod(lambda pid: False)),
     ):
         n = LlamaCppBackend._kill_orphaned_servers()
-    assert n == 1, "only the Studio-owned orphan should be counted"
+    assert n == 1, "only the Unsloth-owned orphan should be counted"
     assert killed == [mypid + 1]
 
     # No owned orphans -> zero, so __init__ leaves the cold-start sentinel.
@@ -392,8 +392,8 @@ def test_kill_orphaned_servers_returns_count():
 
 
 def test_kill_orphaned_servers_spares_live_parent():
-    """A Studio-owned llama-server whose parent is still running is not an
-    orphan (a live Studio or the user's shell owns it) and must never be
+    """An Unsloth-owned llama-server whose parent is still running is not an
+    orphan (a live Unsloth or the user's shell owns it) and must never be
     killed; only the true orphan (parent gone) is reaped."""
     import os
 
@@ -548,7 +548,7 @@ def test_record_then_reap_round_trip_identity_matches(tmp_path):
 
 
 def test_reap_recorded_pid_spares_live_server(tmp_path):
-    """A recorded server whose parent is still alive (the running Studio) is NEVER
+    """A recorded server whose parent is still alive (the running Unsloth) is NEVER
     reaped, and its pidfile is kept. This is the finding-3 guard: a helper backend
     constructed in-process must not kill the active chat server. Uses the REAL
     _pid_parent_is_alive (the child's parent is this live test process)."""
diff --git a/studio/backend/tests/test_llama_cpp_windows_nvidia_path.py b/studio/backend/tests/test_llama_cpp_windows_nvidia_path.py
index 957de4bad6..489d9eb8d1 100644
--- a/studio/backend/tests/test_llama_cpp_windows_nvidia_path.py
+++ b/studio/backend/tests/test_llama_cpp_windows_nvidia_path.py
@@ -3,7 +3,7 @@
 
 """Tests for the Windows pip-nvidia DLL dir resolver.
 
-Studio installs torch with bundled CUDA wheels (nvidia-cuda-runtime-cu13,
+Unsloth installs torch with bundled CUDA wheels (nvidia-cuda-runtime-cu13,
 nvidia-cublas-cu13, etc.) and the prebuilt llama-server.exe must find those
 DLLs at runtime to load CUDA. Mirrors the Linux LD_LIBRARY_PATH block.
 See unslothai/unsloth#5106.
diff --git a/studio/backend/tests/test_llama_route.py b/studio/backend/tests/test_llama_route.py
index 0ecfeee018..cc450d55cc 100644
--- a/studio/backend/tests/test_llama_route.py
+++ b/studio/backend/tests/test_llama_route.py
@@ -100,6 +100,21 @@ def test_status_response_exposes_update_size_bytes():
     assert rl.LlamaUpdateStatusResponse(**without).model_dump()["update_size_bytes"] is None
 
 
+def test_status_response_exposes_update_component():
+    model = rl.LlamaUpdateStatusResponse(
+        supported = True,
+        update_available = True,
+        llama_update_available = False,
+        update_component = "whisper",
+        whisper = {
+            "update_available": True,
+            "installed_tag": "v1",
+            "latest_tag": "v2",
+        },
+    )
+    assert model.model_dump()["update_component"] == "whisper"
+
+
 def test_status_handler_runs_off_event_loop(monkeypatch):
     seen = {}
 
diff --git a/studio/backend/tests/test_llama_server_args.py b/studio/backend/tests/test_llama_server_args.py
index deeb228026..fa4ba71791 100644
--- a/studio/backend/tests/test_llama_server_args.py
+++ b/studio/backend/tests/test_llama_server_args.py
@@ -75,7 +75,7 @@ validate_extra_args = _lsa.validate_extra_args
         # Reasoning controls
         ["--reasoning-format", "deepseek"],
         ["-rea", "auto"],
-        # Soft-managed: user flags last-wins over Studio's auto-set version.
+        # Soft-managed: user flags last-wins over Unsloth's auto-set version.
         # --parallel / -np / --n-parallel are hard-denied (KV-cache + slot
         # count would desync); use `unsloth studio run --parallel N` instead.
         ["-c", "131072"],
@@ -150,7 +150,7 @@ def test_non_flag_token_passes_through():
         "--mmproj",
         "-mmu",
         "--mmproj-url",
-        # Networking (Studio binds + proxies)
+        # Networking (Unsloth binds + proxies)
         "--host",
         "--port",
         "--path",
@@ -176,13 +176,15 @@ def test_non_flag_token_passes_through():
         "--models-autoload",
         "--no-models-autoload",
         # Server-mode flips: --embedding / --rerank restrict llama-server to
-        # those endpoints and break Studio's chat hop.
+        # those endpoints and break Unsloth's chat hop.
         "--embedding",
         "--embeddings",
         "--rerank",
         "--reranking",
-        # llama-server's own --tools clashes with Studio's tool policy.
+        # llama-server's own --tools clashes with Unsloth's tool policy.
         "--tools",
+        # Slot-state dir: Studio owns it for KV persistence across idle unload.
+        "--slot-save-path",
     ],
 )
 def test_denylist_rejects_all_aliases(denied):
@@ -194,7 +196,7 @@ def test_denylist_rejects_all_aliases(denied):
     "args,offending",
     [
         # Pass-through --parallel would last-wins-override the real slot
-        # count while Studio's KV-cache fit + llama_parallel_slots stay at
+        # count while Unsloth's KV-cache fit + llama_parallel_slots stay at
         # the typer value -- plan vs. process disagree.
         (["--parallel", "8"], "--parallel"),
         (["--parallel=8"], "--parallel"),
@@ -224,6 +226,16 @@ def test_denylist_rejects_equals_form():
         validate_extra_args(["--port=9000"])
 
 
+def test_slot_save_path_is_managed_in_all_forms():
+    for args in (["--slot-save-path", "/tmp/x"], ["--slot-save-path=/tmp/x"], ["--slot-save-path"]):
+        with pytest.raises(ValueError, match = "--slot-save-path"):
+            validate_extra_args(args)
+    assert is_managed_flag("--slot-save-path") is True
+    assert is_managed_flag("--slot-save-path=/tmp/x") is True
+    # --slots (read-only diagnostics endpoint) stays a user choice.
+    assert is_managed_flag("--slots") is False
+
+
 @pytest.mark.parametrize(
     "padded",
     [" --parallel", "--parallel ", "\t--parallel", "  -np", "-np \n", "-np\t"],
@@ -656,7 +668,7 @@ def test_extra_args_disable_mmproj_last_wins():
 
 
 def test_strip_shadowing_flags_drops_model_draft_with_spec():
-    # --model-draft (and aliases) are Studio-managed since the separate
+    # --model-draft (and aliases) are Unsloth-managed since the separate
     # MTP drafter support: an inherited copy must not last-wins-override
     # the auto-detected drafter.
     out = strip_shadowing_flags(
@@ -681,7 +693,7 @@ def test_strip_shadowing_flags_drops_model_draft_with_spec():
 )
 def test_strip_shadowing_flags_drops_hf_drafter_selectors_with_spec(selector):
     # HF drafter selectors must reset on inherit like local --model-draft, or a
-    # stale inherited HF drafter last-wins over Studio's re-derived spec choice.
+    # stale inherited HF drafter last-wins over Unsloth's re-derived spec choice.
     out = strip_shadowing_flags(
         selector + ["--top-k", "20"],
         strip_context = False,
@@ -747,6 +759,34 @@ def test_strip_shadowing_flags_defaults_strip_split_mode_too():
     assert strip_shadowing_flags(["--split-mode", "tensor"]) == []
 
 
+def test_strip_offload_is_opt_in_and_covers_moe():
+    base = dict(
+        strip_context = False,
+        strip_cache = False,
+        strip_spec = False,
+        strip_template = False,
+        strip_split_mode = False,
+    )
+    # Default: offload (incl. MoE) flags are NOT stripped.
+    assert strip_shadowing_flags(["--n-cpu-moe", "8", "--top-k", "20"], **base) == [
+        "--n-cpu-moe",
+        "8",
+        "--top-k",
+        "20",
+    ]
+    # Opt-in strips layer AND MoE offload flags (value-aware), keeps the rest.
+    assert strip_shadowing_flags(
+        ["--n-cpu-moe", "8", "--gpu-layers", "33", "--fit", "off", "--top-k", "20"],
+        **base,
+        strip_offload = True,
+    ) == ["--top-k", "20"]
+    # Boolean --cpu-moe drops the flag only, not the following value.
+    assert strip_shadowing_flags(["--cpu-moe", "--seed", "-1"], **base, strip_offload = True) == [
+        "--seed",
+        "-1",
+    ]
+
+
 @pytest.mark.parametrize(
     "args",
     [
@@ -769,7 +809,7 @@ def test_strip_split_mode_only_preserves_none_and_empty():
 
 def test_strip_shadowing_flags_drops_tensor_split_with_split_mode():
     # --tensor-split is coupled to the split mode: stripped together so a stale
-    # ratio can't override Studio's computed tensor split. Other flags survive.
+    # ratio can't override Unsloth's computed tensor split. Other flags survive.
     out = strip_shadowing_flags(
         ["--split-mode", "row", "--tensor-split", "1,1", "--top-k", "20"],
         strip_context = False,
@@ -796,6 +836,23 @@ def test_strip_split_mode_only_drops_tensor_split_too():
     assert strip_split_mode_only(["-sm=tensor", "-ts=3,1"]) == []
 
 
+def test_strip_tensor_split_alone_preserves_split_mode():
+    # Manual mode emits its own --tensor-split, so an inherited ratio is dropped
+    # -- but the user's --split-mode row/none/layer choice (which the manual
+    # ratio toggle can't express) must survive. strip_tensor_split removes only
+    # the ratio, unlike strip_split_mode which removes the whole group.
+    out = strip_shadowing_flags(
+        ["--split-mode", "row", "--tensor-split", "1,1", "--top-k", "20"],
+        strip_context = False,
+        strip_cache = False,
+        strip_spec = False,
+        strip_template = False,
+        strip_split_mode = False,
+        strip_tensor_split = True,
+    )
+    assert out == ["--split-mode", "row", "--top-k", "20"]
+
+
 def test_strip_shadowing_flags_keeps_model_draft_without_spec():
     out = strip_shadowing_flags(
         ["--model-draft", "/custom/mtp.gguf"],
diff --git a/studio/backend/tests/test_local_llama_cpp_link.py b/studio/backend/tests/test_local_llama_cpp_link.py
index c78c029d91..79c9977c84 100644
--- a/studio/backend/tests/test_local_llama_cpp_link.py
+++ b/studio/backend/tests/test_local_llama_cpp_link.py
@@ -4,7 +4,7 @@
 """Behavioral tests for the --with-llama-cpp-dir 'unmanaged local link' contract.
 
 When the canonical llama.cpp dir is a symlink (POSIX) / junction (Windows) to a
-user's own checkout, Studio must treat it as externally managed:
+user's own checkout, Unsloth must treat it as externally managed:
   - the in-app updater must not offer or apply a prebuilt over the link
   - orphan cleanup must not kill a llama-server the user launched from that tree
 
@@ -21,6 +21,13 @@ from utils import llama_cpp_update as u
 from core.inference.llama_cpp import LlamaCppBackend
 
 
+@pytest.fixture(autouse = True)
+def _no_whisper_piggyback(monkeypatch):
+    # Keep the whisper piggyback probe off the host: these tests exercise the
+    # llama local-link contract only.
+    monkeypatch.setattr(u, "_whisper_chain_status", lambda **kwargs: None)
+
+
 def _make_link(link: Path, target: Path) -> None:
     """Create a directory junction (Windows) / symlink (POSIX); neither needs
     elevation."""
@@ -67,7 +74,7 @@ def test_active_install_is_local_link(tmp_path: Path) -> None:
     binary = str(link / _server_subpath())
     assert u._active_install_is_local_link(binary) is True
 
-    # A plain (non-link) llama.cpp dir is Studio-managed, not a local link.
+    # A plain (non-link) llama.cpp dir is Unsloth-managed, not a local link.
     plain = tmp_path / "plain" / "llama.cpp"
     plain.mkdir(parents = True)
     assert u._active_install_is_local_link(str(plain / _server_subpath())) is False
diff --git a/studio/backend/tests/test_mcp_server.py b/studio/backend/tests/test_mcp_server.py
new file mode 100644
index 0000000000..71792605ae
--- /dev/null
+++ b/studio/backend/tests/test_mcp_server.py
@@ -0,0 +1,290 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import asyncio
+import sys
+import types
+
+import pytest
+
+from mcp_server import BearerTokenMiddleware, _clamp, _dump, create_studio_mcp
+
+
+def _get_tool(name):
+    tools = asyncio.run(create_studio_mcp().list_tools())
+    return {tool.name: tool for tool in tools}[name]
+
+
+def test_studio_mcp_registers_control_plane_tools():
+    tools = asyncio.run(create_studio_mcp().list_tools())
+
+    assert {tool.name for tool in tools} == {
+        "studio_status",
+        "list_local_models",
+        "get_training_status",
+        "start_training",
+        "stop_training",
+        "list_training_runs",
+        "validate_recipe",
+        "get_recipe_job_status",
+        "get_recipe_job_dataset",
+        "load_checkpoint",
+        "export_gguf",
+    }
+
+
+def test_dump_serializes_pydantic_values():
+    class Response:
+        def model_dump(self, *, mode):
+            assert mode == "json"
+            return {"ok": True}
+
+    assert _dump(Response()) == {"ok": True}
+    assert _dump({"already": "json"}) == {"already": "json"}
+
+
+def test_bearer_token_middleware_rejects_wrong_token():
+    events = []
+
+    async def app(scope, receive, send):
+        events.append("app")
+
+    async def send(message):
+        events.append(message)
+
+    middleware = BearerTokenMiddleware(app, "secret")
+    asyncio.run(
+        middleware(
+            {"type": "http", "headers": [(b"authorization", b"Bearer wrong")]},
+            None,
+            send,
+        )
+    )
+
+    assert events[0]["status"] == 401
+    assert "app" not in events
+
+
+def test_bearer_token_middleware_closes_unauthorized_websocket():
+    events = []
+
+    async def app(scope, receive, send):
+        events.append("app")
+
+    async def send(message):
+        events.append(message)
+
+    middleware = BearerTokenMiddleware(app, "secret")
+    asyncio.run(
+        middleware(
+            {"type": "websocket", "headers": []},
+            None,
+            send,
+        )
+    )
+
+    assert events == [{"type": "websocket.close", "code": 4401}]
+
+
+def test_bearer_token_middleware_rejects_non_ascii_authorization():
+    # A non-ASCII bearer value must produce a clean 401, not a 500. Comparing on
+    # bytes avoids the str hmac.compare_digest TypeError on non-ASCII input.
+    events = []
+
+    async def app(scope, receive, send):
+        events.append("app")
+
+    async def send(message):
+        events.append(message)
+
+    middleware = BearerTokenMiddleware(app, "secret")
+    asyncio.run(
+        middleware(
+            {"type": "http", "headers": [(b"authorization", b"Bearer \xff\xff")]},
+            None,
+            send,
+        )
+    )
+
+    assert events[0]["status"] == 401
+    assert "app" not in events
+
+
+def test_bearer_token_middleware_accepts_correct_token():
+    events = []
+
+    async def app(scope, receive, send):
+        events.append("app")
+
+    async def send(message):
+        events.append(message)
+
+    middleware = BearerTokenMiddleware(app, "secret")
+    asyncio.run(
+        middleware(
+            {"type": "http", "headers": [(b"authorization", b"Bearer secret")]},
+            None,
+            send,
+        )
+    )
+
+    assert events == ["app"]
+
+
+def test_bearer_token_middleware_requires_non_empty_token():
+    async def app(scope, receive, send):
+        pass
+
+    for bad in ("", "   "):
+        with pytest.raises(ValueError):
+            BearerTokenMiddleware(app, bad)
+
+
+def test_bearer_token_middleware_rejects_non_ascii_token():
+    async def app(scope, receive, send):
+        pass
+
+    # non-ASCII tokens cannot be transmitted in an HTTP header by a standard
+    # client, so they are rejected at construction instead of locking out.
+    for bad in ("töken", "\U0001f600"):
+        with pytest.raises(ValueError):
+            BearerTokenMiddleware(app, bad)
+
+
+def test_bearer_token_middleware_passes_through_non_http_scopes():
+    events = []
+
+    async def app(scope, receive, send):
+        events.append("app")
+
+    async def send(message):
+        events.append(message)
+
+    middleware = BearerTokenMiddleware(app, "secret")
+    asyncio.run(middleware({"type": "lifespan"}, None, send))
+
+    assert events == ["app"]
+
+
+def test_clamp_restricts_to_inclusive_bounds():
+    assert _clamp(5, 1, 200) == 5
+    assert _clamp(-10, 1, 200) == 1
+    assert _clamp(10_000, 1, 200) == 200
+    assert _clamp(0, 1, 500) == 1
+    assert _clamp(1_000, 1, 500) == 500
+
+
+def test_export_and_checkpoint_tools_expose_forwarded_fields():
+    export_props = set(_get_tool("export_gguf").parameters["properties"])
+    assert {"hf_token", "imatrix", "imatrix_path"} <= export_props
+
+    checkpoint_props = set(_get_tool("load_checkpoint").parameters["properties"])
+    assert {"hf_token", "approved_remote_code_fingerprint"} <= checkpoint_props
+
+
+def _stub_module(monkeypatch, name, **attrs):
+    module = types.ModuleType(name)
+    for key, value in attrs.items():
+        setattr(module, key, value)
+    if "." in name:
+        module.__path__ = []  # mark package-like so submodule imports resolve
+    monkeypatch.setitem(sys.modules, name, module)
+    return module
+
+
+def test_export_gguf_forwards_hf_token_and_imatrix(monkeypatch):
+    captured = {}
+
+    class FakeExportGGUFRequest:
+        def __init__(self, **kwargs):
+            captured.update(kwargs)
+
+    async def fake_export(request, current_subject):
+        return {"current_subject": current_subject}
+
+    _stub_module(monkeypatch, "models", ExportGGUFRequest = FakeExportGGUFRequest)
+    _stub_module(monkeypatch, "routes")
+    _stub_module(monkeypatch, "routes.export", export_gguf = fake_export)
+
+    tool = _get_tool("export_gguf")
+    result = asyncio.run(
+        tool.fn(
+            save_directory = "/tmp/out",
+            quantization_method = ["Q4_K_M", "Q8_0"],
+            push_to_hub = True,
+            repo_id = "me/model",
+            hf_token = "hf_secret",
+            imatrix = True,
+            imatrix_path = "/tmp/imatrix.dat",
+        )
+    )
+
+    assert captured["hf_token"] == "hf_secret"
+    assert captured["imatrix"] is True
+    assert captured["imatrix_path"] == "/tmp/imatrix.dat"
+    assert captured["quantization_method"] == ["Q4_K_M", "Q8_0"]
+    assert result["current_subject"] == "mcp"
+
+
+def test_load_checkpoint_forwards_token_and_fingerprint(monkeypatch):
+    captured = {}
+
+    class FakeLoadCheckpointRequest:
+        def __init__(self, **kwargs):
+            captured.update(kwargs)
+
+    async def fake_load(request, current_subject):
+        return {"current_subject": current_subject}
+
+    _stub_module(monkeypatch, "models", LoadCheckpointRequest = FakeLoadCheckpointRequest)
+    _stub_module(monkeypatch, "routes")
+    _stub_module(monkeypatch, "routes.export", load_checkpoint = fake_load)
+
+    tool = _get_tool("load_checkpoint")
+    asyncio.run(
+        tool.fn(
+            checkpoint_path = "/tmp/ckpt",
+            approved_remote_code_fingerprint = "sha256:abc",
+            hf_token = "hf_secret",
+        )
+    )
+
+    assert captured["hf_token"] == "hf_secret"
+    assert captured["approved_remote_code_fingerprint"] == "sha256:abc"
+
+
+def test_list_training_runs_clamps_pagination(monkeypatch):
+    captured = {}
+
+    async def fake_list_runs(limit, offset, current_subject):
+        captured["limit"] = limit
+        captured["offset"] = offset
+        return {"ok": True}
+
+    _stub_module(monkeypatch, "routes")
+    _stub_module(monkeypatch, "routes.training_history", list_training_runs = fake_list_runs)
+
+    tool = _get_tool("list_training_runs")
+    asyncio.run(tool.fn(limit = 10_000, offset = -5))
+
+    assert captured["limit"] == 200
+    assert captured["offset"] == 0
+
+
+def test_get_recipe_job_dataset_clamps_pagination(monkeypatch):
+    captured = {}
+
+    def fake_job_dataset(job_id, limit, offset):
+        captured["limit"] = limit
+        captured["offset"] = offset
+        return {"ok": True}
+
+    _stub_module(monkeypatch, "routes")
+    _stub_module(monkeypatch, "routes.data_recipe")
+    _stub_module(monkeypatch, "routes.data_recipe.jobs", job_dataset = fake_job_dataset)
+
+    tool = _get_tool("get_recipe_job_dataset")  # this tool is synchronous
+    tool.fn(job_id = "job-1", limit = -1, offset = -9)
+
+    assert captured["limit"] == 1
+    assert captured["offset"] == 0
diff --git a/studio/backend/tests/test_mcp_servers.py b/studio/backend/tests/test_mcp_servers.py
index 6432ffb8e1..c5c37f098f 100644
--- a/studio/backend/tests/test_mcp_servers.py
+++ b/studio/backend/tests/test_mcp_servers.py
@@ -577,7 +577,7 @@ def test_clear_oauth_tokens_swallows_constructor_errors(tmp_path, monkeypatch):
 
 def test_tool_xml_parser_handles_hyphenated_function_names():
     """Hyphenated tool names like `mcp__srv__list-issues` must parse, else the
-    model can call the tool but Studio can't dispatch."""
+    model can call the tool but Unsloth can't dispatch."""
     from core.inference.tool_call_parser import parse_tool_calls_from_text
 
     calls = parse_tool_calls_from_text(
diff --git a/studio/backend/tests/test_mcp_stdio_improvements.py b/studio/backend/tests/test_mcp_stdio_improvements.py
index b0bfd45135..745c2cc447 100644
--- a/studio/backend/tests/test_mcp_stdio_improvements.py
+++ b/studio/backend/tests/test_mcp_stdio_improvements.py
@@ -188,7 +188,7 @@ def test_validate_url_allows_url_in_argument(monkeypatch):
 
 
 # ── P6: Data Recipe stdio path obeys the same host gate ─────────────
-# build_mcp_providers needs the Studio-only data_designer plugin; skip if absent.
+# build_mcp_providers needs the Unsloth-only data_designer plugin; skip if absent.
 
 _STDIO_RECIPE = {
     "mcp_providers": [
diff --git a/studio/backend/tests/test_middleware.py b/studio/backend/tests/test_middleware.py
index 11aeee6d77..36061b5375 100644
--- a/studio/backend/tests/test_middleware.py
+++ b/studio/backend/tests/test_middleware.py
@@ -14,6 +14,7 @@ import pytest
 from fastapi import FastAPI, HTTPException, Request
 from fastapi.responses import Response
 from fastapi.testclient import TestClient
+from starlette.middleware.gzip import GZipMiddleware
 
 
 _BACKEND_ROOT = Path(__file__).resolve().parents[1]
@@ -33,6 +34,7 @@ def main_module():
 def _make_protected_app(
     max_bytes: int,
     main_module,
+    request_max_bytes_getter = None,
     upload_passthrough_prefixes: tuple = (),
     upload_passthrough_max_bytes_getter = None,
 ):
@@ -40,7 +42,13 @@ def _make_protected_app(
     app.add_middleware(
         main_module.MaxBodyMiddleware,
         max_bytes_getter = lambda: max_bytes,
-        protected_prefixes = ("/v1/chat/completions", "/api/settings", "/api/train"),
+        protected_prefixes = (
+            "/v1/chat/completions",
+            "/api/inference",
+            "/api/settings",
+            "/api/train",
+        ),
+        request_max_bytes_getter = request_max_bytes_getter,
         upload_passthrough_prefixes = upload_passthrough_prefixes,
         upload_passthrough_max_bytes_getter = upload_passthrough_max_bytes_getter,
     )
@@ -67,6 +75,10 @@ def _make_protected_app(
                 total += len(chunk)
         return {"ok": True, "chunks": chunks, "total": total}
 
+    @app.post("/api/inference/audio/transcribe/raw")
+    async def transcribe_raw(request: Request):
+        return {"ok": True, "total": len(await request.body())}
+
     @app.get("/api/train/status")
     async def status_get():
         return {"ok": True, "get": True}
@@ -96,6 +108,43 @@ class TestMaxBodyMiddleware:
         assert r.status_code == 200
         assert r.json()["unprotected"] is True
 
+    def test_route_specific_cap_overrides_default(self, main_module):
+        app = _make_protected_app(
+            4096,
+            main_module,
+            request_max_bytes_getter = lambda path: (
+                128 if path.endswith("/transcribe/raw") else 4096
+            ),
+        )
+        c = TestClient(app)
+
+        rejected = c.post(
+            "/api/inference/audio/transcribe/raw",
+            content = b"x" * 129,
+        )
+        accepted = c.post(
+            "/api/inference/audio/transcribe/raw",
+            content = b"x" * 128,
+        )
+
+        assert rejected.status_code == 413
+        assert accepted.status_code == 200
+        assert accepted.json()["total"] == 128
+
+    def test_stt_routes_use_audio_specific_caps(self, main_module):
+        from utils.upload_limits import (
+            STT_AUDIO_JSON_MAX_BYTES,
+            STT_AUDIO_RAW_MAX_BYTES,
+        )
+        assert (
+            main_module._get_request_body_max_bytes("/api/inference/audio/transcribe/raw")
+            == STT_AUDIO_RAW_MAX_BYTES
+        )
+        assert (
+            main_module._get_request_body_max_bytes("/api/inference/audio/transcribe")
+            == STT_AUDIO_JSON_MAX_BYTES
+        )
+
     def test_settings_put_body_over_cap_rejected(self, main_module):
         app = _make_protected_app(1024, main_module)
         c = TestClient(app)
@@ -471,6 +520,71 @@ class TestSecurityHeadersMiddleware:
         assert b"server" in names
 
 
+class TestFrontendAssets:
+    def test_hashed_assets_are_compressed_and_cached(self, tmp_path, main_module):
+        content = b"export const value = 'responsive';\n" * 200
+        (tmp_path / "page-abc123.js").write_bytes(content)
+        app = FastAPI()
+        assets_app = GZipMiddleware(
+            main_module.ImmutableStaticFiles(directory = tmp_path),
+            minimum_size = 1024,
+            compresslevel = 6,
+        )
+        app.mount("/assets", assets_app, name = "assets")
+
+        response = TestClient(app).get(
+            "/assets/page-abc123.js",
+            headers = {"Accept-Encoding": "gzip"},
+        )
+
+        assert response.status_code == 200
+        assert response.content == content
+        assert response.headers["content-encoding"] == "gzip"
+        assert response.headers["cache-control"] == (main_module._IMMUTABLE_ASSET_CACHE_CONTROL)
+        assert "accept-encoding" in response.headers["vary"].lower()
+
+    def test_asset_revalidation_keeps_immutable_cache_header(self, tmp_path, main_module):
+        (tmp_path / "page-abc123.js").write_text("export {};", encoding = "utf-8")
+        app = FastAPI()
+        app.mount(
+            "/assets",
+            main_module.ImmutableStaticFiles(directory = tmp_path),
+            name = "assets",
+        )
+        client = TestClient(app)
+        first = client.get("/assets/page-abc123.js")
+
+        response = client.get(
+            "/assets/page-abc123.js",
+            headers = {"If-None-Match": first.headers["etag"]},
+        )
+
+        assert response.status_code == 304
+        assert response.headers["cache-control"] == (main_module._IMMUTABLE_ASSET_CACHE_CONTROL)
+
+    def test_range_request_is_not_compressed(self, tmp_path, main_module):
+        content = b"export const value = 'responsive';\n" * 200
+        (tmp_path / "page-abc123.js").write_bytes(content)
+        app = FastAPI()
+        assets_app = main_module._AssetGZipMiddleware(
+            main_module.ImmutableStaticFiles(directory = tmp_path),
+            minimum_size = 1024,
+            compresslevel = 6,
+        )
+        app.mount("/assets", assets_app, name = "assets")
+
+        response = TestClient(app).get(
+            "/assets/page-abc123.js",
+            headers = {"Accept-Encoding": "gzip", "Range": "bytes=0-99"},
+        )
+
+        assert response.status_code == 206
+        assert response.headers.get("content-encoding") != "gzip"
+        assert response.headers["content-range"] == f"bytes 0-99/{len(content)}"
+        assert response.content == content[:100]
+        assert response.headers["cache-control"] == (main_module._IMMUTABLE_ASSET_CACHE_CONTROL)
+
+
 # /api/health auth gate
 
 
diff --git a/studio/backend/tests/test_mlx_inference_backend.py b/studio/backend/tests/test_mlx_inference_backend.py
index 29fbb45158..d49a2281a0 100644
--- a/studio/backend/tests/test_mlx_inference_backend.py
+++ b/studio/backend/tests/test_mlx_inference_backend.py
@@ -2,6 +2,7 @@
 
 import sys
 import types
+from contextlib import contextmanager
 from types import SimpleNamespace
 
 import pytest
@@ -40,12 +41,16 @@ class _DummyModel:
 def _install_fake_mlx(monkeypatch):
     mlx_pkg = types.ModuleType("mlx")
     mlx_core = types.ModuleType("mlx.core")
+    mlx_utils = types.ModuleType("mlx.utils")
     mlx_core.metal = _DummyMetal()
     mlx_core.set_wired_limit = _DummyMX.set_wired_limit
     mlx_core.device_info = _DummyMX.device_info
+    mlx_utils.tree_unflatten = dict
     mlx_pkg.core = mlx_core
+    mlx_pkg.utils = mlx_utils
     monkeypatch.setitem(sys.modules, "mlx", mlx_pkg)
     monkeypatch.setitem(sys.modules, "mlx.core", mlx_core)
+    monkeypatch.setitem(sys.modules, "mlx.utils", mlx_utils)
 
 
 def _install_fake_fast_mlx(monkeypatch, calls):
@@ -68,6 +73,99 @@ def _install_fake_fast_mlx(monkeypatch, calls):
     monkeypatch.setitem(sys.modules, "unsloth_zoo.mlx.loader", mlx_loader)
 
 
+class _AdapterTree:
+    def __init__(self, modules):
+        self.modules = dict(modules)
+
+    def named_modules(self):
+        return list(self.modules.items())
+
+    def update_modules(self, modules):
+        self.modules.update(modules)
+
+
+def test_temporary_mlx_adapter_state_bypasses_and_restores_wrappers(monkeypatch):
+    _install_fake_mlx(monkeypatch)
+    from core.inference.mlx_inference import _temporary_mlx_adapter_state
+
+    base = object()
+    wrapper = SimpleNamespace(lora_a = object(), lora_b = object(), linear = base, m = object())
+    model = _AdapterTree({"model.layers.0.proj": wrapper})
+
+    with pytest.raises(RuntimeError, match = "generation failed"):
+        with _temporary_mlx_adapter_state(model, False):
+            assert model.modules["model.layers.0.proj"] is base
+            raise RuntimeError("generation failed")
+    assert model.modules["model.layers.0.proj"] is wrapper
+
+
+def test_temporary_mlx_adapter_state_validates_requests():
+    from core.inference.mlx_inference import _temporary_mlx_adapter_state
+
+    wrapper = SimpleNamespace(lora_a = object(), lora_b = object(), embedding = object())
+    model = _AdapterTree({"embed_tokens": wrapper})
+    with _temporary_mlx_adapter_state(model, True):
+        assert model.modules["embed_tokens"] is wrapper
+    with pytest.raises(NotImplementedError, match = "named adapter"):
+        with _temporary_mlx_adapter_state(model, "other"):
+            pass
+
+    base_model = _AdapterTree({"proj": object()})
+    with _temporary_mlx_adapter_state(base_model, None):
+        pass
+    with _temporary_mlx_adapter_state(base_model, True):
+        pass
+
+    unsupported = _AdapterTree({"proj": SimpleNamespace(lora_a = object(), lora_b = object())})
+    with _temporary_mlx_adapter_state(unsupported, True):
+        pass
+    with pytest.raises(RuntimeError, match = "without their base modules"):
+        with _temporary_mlx_adapter_state(unsupported, False):
+            pass
+
+
+def test_temporary_mlx_adapter_state_uses_real_mlx_module_tree():
+    nn = pytest.importorskip("mlx.nn")
+    pytest.importorskip("mlx_lm")
+    from mlx_lm.models.switch_layers import SwitchLinear
+    from mlx_lm.tuner.dora import DoRALinear
+    from mlx_lm.tuner.lora import LoRAEmbedding, LoRALinear, LoRASwitchLinear
+
+    from core.inference.mlx_inference import _temporary_mlx_adapter_state
+
+    class _Layer(nn.Module):
+        def __init__(self):
+            super().__init__()
+            quantized = nn.QuantizedLinear.from_linear(nn.Linear(32, 32), group_size = 32, bits = 4)
+            self.quantized_proj = LoRALinear.from_base(quantized)
+            self.dora_proj = DoRALinear.from_base(nn.Linear(4, 4))
+
+    class _Model(nn.Module):
+        def __init__(self):
+            super().__init__()
+            self.layers = [_Layer()]
+            self.embed_tokens = LoRAEmbedding.from_base(nn.Embedding(16, 4))
+            self.experts = LoRASwitchLinear.from_base(SwitchLinear(4, 4, 2))
+
+    model = _Model()
+    wrappers = {
+        path: module
+        for path, module in model.named_modules()
+        if hasattr(module, "lora_a") and hasattr(module, "lora_b")
+    }
+    bases = {
+        path: getattr(module, "linear", getattr(module, "embedding", None))
+        for path, module in wrappers.items()
+    }
+
+    with _temporary_mlx_adapter_state(model, False):
+        live = dict(model.named_modules())
+        assert all(live[path] is base for path, base in bases.items())
+
+    restored = dict(model.named_modules())
+    assert all(restored[path] is wrapper for path, wrapper in wrappers.items())
+
+
 def test_mlx_inference_text_load_forwards_studio_settings(monkeypatch):
     _install_fake_mlx(monkeypatch)
     calls = []
@@ -138,7 +236,7 @@ def test_mlx_inference_vlm_lora_uses_unsloth_loader_without_native_adapter_rewri
     _install_fake_fast_mlx(monkeypatch, calls)
 
     def _native_vlm_load(*_args, **_kwargs):
-        raise AssertionError("Studio MLX VLM inference must use FastMLXModel")
+        raise AssertionError("Unsloth MLX VLM inference must use FastMLXModel")
 
     mlx_vlm = types.ModuleType("mlx_vlm")
     mlx_vlm.load = _native_vlm_load
@@ -333,10 +431,87 @@ def test_mlx_generate_chat_response_accepts_template_kwargs():
         ), f"{name!r} must default to None so existing callers stay valid"
 
 
+def test_mlx_vlm_reemits_think_prefill_inside_adapter_context(monkeypatch):
+    """A prefilled <think> block must be re-emitted as the first VLM snapshot,
+    inside the adapter context (so unsupported requests still raise first), so
+    the UI renders the thinking block during prefill and a pre-first-token
+    cancel does not drop it. Mirrors _generate_text."""
+    from core.inference import mlx_inference
+
+    MLXInferenceBackend = mlx_inference.MLXInferenceBackend
+
+    order = []
+
+    @contextmanager
+    def _adapter_state(_model, state):
+        assert backend._generation_lock.locked()
+        order.append("adapter_enter")
+        try:
+            yield
+        finally:
+            order.append("adapter_exit")
+
+    monkeypatch.setattr(mlx_inference, "_temporary_mlx_adapter_state", _adapter_state)
+    monkeypatch.setattr(
+        "core.inference.chat_template_helpers.detect_think_prefill",
+        lambda *_a, **_k: "<think>\n",
+    )
+
+    prompt_utils = SimpleNamespace(
+        MODEL_CONFIG = {"deepseek_vl_v2": object()},
+        apply_chat_template = lambda *_a, **_k: "<image> model-aware",
+    )
+    mlx_vlm = types.ModuleType("mlx_vlm")
+    mlx_vlm.prompt_utils = prompt_utils
+
+    def _vlm_stream(*_a, **_k):
+        # The prefill must have been emitted before any generated token.
+        assert order[-1] == "adapter_enter"
+        yield SimpleNamespace(text = "ok", prompt_tokens = 3, generation_tokens = 1)
+
+    mlx_vlm.stream_generate = _vlm_stream
+    monkeypatch.setitem(sys.modules, "mlx_vlm", mlx_vlm)
+    monkeypatch.setattr(
+        "core.inference.chat_template_helpers.apply_chat_template_for_generation",
+        lambda _t, _m, **_k: "<image> model-aware",
+    )
+
+    backend = MLXInferenceBackend()
+    backend._model = SimpleNamespace(config = {"model_type": "deepseek_vl_v2"})
+    backend._processor = SimpleNamespace(tokenizer = SimpleNamespace())
+    args = ([{"role": "user", "content": [{"type": "image"}]}], object(), 0, 1, 0, 0, 1, 1, None)
+
+    gen = backend._generate_vlm(*args, _adapter_state = False)
+    # First snapshot is the prefill alone, emitted after entering the adapter context.
+    assert next(gen) == "<think>\n"
+    assert order == ["adapter_enter"]
+    # Subsequent snapshots are cumulative (prefill + generated text).
+    assert next(gen) == "<think>\nok"
+    gen.close()
+    assert order == ["adapter_enter", "adapter_exit"]
+
+
 def test_mlx_vlm_generation_selects_renderer_by_capability(monkeypatch):
-    from core.inference.mlx_inference import MLXInferenceBackend
+    from core.inference import mlx_inference
+
+    MLXInferenceBackend = mlx_inference.MLXInferenceBackend
 
     calls = {"generic": [], "model": [], "stream": []}
+    adapter_events = []
+    adapter_active = {"value": False}
+
+    @contextmanager
+    def _adapter_state(_model, state):
+        assert backend._generation_lock.locked()
+        adapter_events.append(("enter", state))
+        adapter_active["value"] = True
+        try:
+            yield
+        finally:
+            adapter_active["value"] = False
+            adapter_events.append(("exit", state))
+
+    monkeypatch.setattr(mlx_inference, "_temporary_mlx_adapter_state", _adapter_state)
     state = {"generic": "serialized", "model": "<image> model-aware"}
     prompt_utils = SimpleNamespace(
         MODEL_CONFIG = {"deepseek_vl_v2": object()},
@@ -346,10 +521,13 @@ def test_mlx_vlm_generation_selects_renderer_by_capability(monkeypatch):
     )
     mlx_vlm = types.ModuleType("mlx_vlm")
     mlx_vlm.prompt_utils = prompt_utils
-    mlx_vlm.stream_generate = lambda *_args, **kwargs: (
-        calls["stream"].append((_args, kwargs))
-        or iter([SimpleNamespace(text = "ok", prompt_tokens = 3, generation_tokens = 1)])
-    )
+
+    def _vlm_stream(*args, **kwargs):
+        assert adapter_active["value"]
+        calls["stream"].append((args, kwargs))
+        yield SimpleNamespace(text = "ok", prompt_tokens = 3, generation_tokens = 1)
+
+    mlx_vlm.stream_generate = _vlm_stream
     monkeypatch.setitem(sys.modules, "mlx_vlm", mlx_vlm)
 
     def generic(_target, _messages, **kwargs):
@@ -369,7 +547,11 @@ def test_mlx_vlm_generation_selects_renderer_by_capability(monkeypatch):
     backend._processor = SimpleNamespace(tokenizer = SimpleNamespace())
     args = ([{"role": "user", "content": [{"type": "image"}]}], object(), 0, 1, 0, 0, 1, 1, None)
     tools = [{"function": {"name": "search"}}]
-    assert list(backend._generate_vlm(*args)) == ["ok"]
+    generator = backend._generate_vlm(*args, _adapter_state = False)
+    assert next(generator) == "ok"
+    assert adapter_active["value"] and backend._generation_lock.locked()
+    generator.close()
+    assert adapter_events == [("enter", False), ("exit", False)]
     assert calls["model"][0]["num_images"] == 1
     assert calls["stream"][0][0][2] == "<image> model-aware"
     with pytest.raises(RuntimeError, match = "dropping requested tools"):
@@ -449,7 +631,10 @@ def test_mlx_generate_text_forwards_kwargs_into_template_helper(monkeypatch):
     """Mac text path must route through apply_chat_template_for_generation so
     reasoning / tool kwargs reach the tokenizer."""
     _install_fake_mlx(monkeypatch)
-    from core.inference.mlx_inference import MLXInferenceBackend
+    from core.inference import mlx_inference
+
+    MLXInferenceBackend = mlx_inference.MLXInferenceBackend
+    real_adapter_state = mlx_inference._temporary_mlx_adapter_state
 
     # The text path renders once with tools, then the native-template fallback makes a second no-
     # tools probe call (tools=None) to detect whether the template dropped the schema.
@@ -474,11 +659,31 @@ def test_mlx_generate_text_forwards_kwargs_into_template_helper(monkeypatch):
     mlx_lm_sample.make_sampler = lambda **_kw: object()
     mlx_lm_sample.make_logits_processors = lambda **_kw: None
 
+    adapter_events = []
+    adapter_active = {"value": False}
+    stream_state = {"fail": False}
+
+    @contextmanager
+    def _adapter_state(_model, state):
+        assert backend._generation_lock.locked()
+        adapter_events.append(("enter", state))
+        adapter_active["value"] = True
+        try:
+            yield
+        finally:
+            adapter_active["value"] = False
+            adapter_events.append(("exit", state))
+
+    monkeypatch.setattr(mlx_inference, "_temporary_mlx_adapter_state", _adapter_state)
+
     class _Resp:
         def __init__(self, tok):
             self.token = tok
 
     def _stream_generate(_model, _tokenizer, **_kw):
+        assert adapter_active["value"]
+        if stream_state["fail"]:
+            raise RuntimeError("generation failed")
         yield _Resp(1)
 
     mlx_lm_pkg.stream_generate = _stream_generate
@@ -500,17 +705,45 @@ def test_mlx_generate_text_forwards_kwargs_into_template_helper(monkeypatch):
     backend._tokenizer = _Tok()
     backend._is_vlm = False
 
-    out = list(
-        backend.generate_chat_response(
-            messages = [{"role": "user", "content": "ping"}],
-            tools = [{"function": {"name": "web_search"}}],
-            enable_thinking = True,
-            reasoning_effort = "medium",
-            preserve_thinking = True,
-            max_new_tokens = 1,
-        )
+    generator = backend.generate_with_adapter_control(
+        use_adapter = False,
+        messages = [{"role": "user", "content": "ping"}],
+        tools = [{"function": {"name": "web_search"}}],
+        enable_thinking = True,
+        reasoning_effort = "medium",
+        preserve_thinking = True,
+        max_new_tokens = 1,
     )
-    assert out == ["hi"]
+    assert next(generator) == "hi"
+    assert adapter_active["value"] and backend._generation_lock.locked()
+    generator.close()
+    assert adapter_events == [("enter", False), ("exit", False)]
+    stream_state["fail"] = True
+    with pytest.raises(RuntimeError, match = "generation failed"):
+        list(
+            backend.generate_with_adapter_control(
+                use_adapter = False,
+                messages = [{"role": "user", "content": "ping"}],
+                max_new_tokens = 1,
+            )
+        )
+    assert adapter_events[-2:] == [("enter", False), ("exit", False)]
+    assert not backend._generation_lock.locked()
+
+    monkeypatch.setattr(mlx_inference, "_temporary_mlx_adapter_state", real_adapter_state)
+    monkeypatch.setattr(
+        "core.inference.chat_template_helpers.detect_think_prefill",
+        lambda *_args, **_kwargs: "<think>",
+    )
+    stream_state["fail"] = False
+    named = backend.generate_with_adapter_control(
+        use_adapter = "named",
+        messages = [{"role": "user", "content": "ping"}],
+        max_new_tokens = 1,
+    )
+    with pytest.raises(NotImplementedError, match = "named adapter"):
+        next(named)
+    assert not adapter_active["value"] and not backend._generation_lock.locked()
     # The toggled kwargs must reach the chat-template helper on the real render
     # (one of the calls carries the tools; the fallback probe passes tools=None).
     tool_renders = [
@@ -523,3 +756,579 @@ def test_mlx_generate_text_forwards_kwargs_into_template_helper(monkeypatch):
     assert render["kwargs"]["enable_thinking"] is True
     assert render["kwargs"]["reasoning_effort"] == "medium"
     assert render["kwargs"]["preserve_thinking"] is True
+
+
+def test_mlx_text_normalizes_native_reasoning_and_close_releases_lock(monkeypatch):
+    _install_fake_mlx(monkeypatch)
+    from core.inference.mlx_inference import MLXInferenceBackend
+
+    monkeypatch.setattr(
+        "core.inference.chat_template_helpers.apply_chat_template_for_generation",
+        lambda *_args, **_kwargs: "prompt",
+        raising = True,
+    )
+    monkeypatch.setattr(
+        "core.inference.chat_template_helpers.render_with_native_template_fallback",
+        lambda formatted_prompt, **_kwargs: SimpleNamespace(
+            prompt = formatted_prompt,
+            reasoning_channel_markers = ("<|channel>thought\n", "<channel|>"),
+        ),
+        raising = True,
+    )
+
+    mlx_lm_pkg = types.ModuleType("mlx_lm")
+    mlx_lm_sample = types.ModuleType("mlx_lm.sample_utils")
+    mlx_lm_sample.make_sampler = lambda **_kw: object()
+    mlx_lm_sample.make_logits_processors = lambda **_kw: None
+
+    class _Resp:
+        def __init__(self, text, tok):
+            self.text = text
+            self.token = tok
+
+    def _stream_generate(_model, _tokenizer, **_kw):
+        yield _Resp("<|channel>thought\n", 10)
+        yield _Resp("r", 11)
+        yield _Resp("<channel|>", 12)
+        yield _Resp("a", 13)
+
+    mlx_lm_pkg.stream_generate = _stream_generate
+    monkeypatch.setitem(sys.modules, "mlx_lm", mlx_lm_pkg)
+    monkeypatch.setitem(sys.modules, "mlx_lm.sample_utils", mlx_lm_sample)
+
+    backend = MLXInferenceBackend()
+    backend._model = object()
+    backend._tokenizer = SimpleNamespace(all_special_tokens = [])
+    backend._is_vlm = False
+
+    assert list(
+        backend.generate_chat_response(
+            messages = [{"role": "user", "content": "ping"}],
+            max_new_tokens = 4,
+        )
+    ) == ["<think>", "<think>r", "<think>r</think>", "<think>r</think>a"]
+
+    gen = backend.generate_chat_response(
+        messages = [{"role": "user", "content": "ping"}],
+        max_new_tokens = 4,
+    )
+    assert next(gen) == "<think>"
+    assert backend._generation_lock.locked()
+    gen.close()
+    assert not backend._generation_lock.locked()
+
+
+def test_mlx_text_native_metadata_preserves_prefilled_think_snapshots(monkeypatch):
+    _install_fake_mlx(monkeypatch)
+    from core.inference.mlx_inference import MLXInferenceBackend
+
+    monkeypatch.setattr(
+        "core.inference.chat_template_helpers.apply_chat_template_for_generation",
+        lambda *_args, **_kwargs: "prompt<think>\n",
+        raising = True,
+    )
+    monkeypatch.setattr(
+        "core.inference.chat_template_helpers.render_with_native_template_fallback",
+        lambda formatted_prompt, **_kwargs: SimpleNamespace(
+            prompt = formatted_prompt,
+            reasoning_channel_markers = ("<|channel>thought", "<channel|>"),
+        ),
+        raising = True,
+    )
+
+    mlx_lm_pkg = types.ModuleType("mlx_lm")
+    mlx_lm_sample = types.ModuleType("mlx_lm.sample_utils")
+    mlx_lm_sample.make_sampler = lambda **_kw: object()
+    mlx_lm_sample.make_logits_processors = lambda **_kw: None
+
+    class _Resp:
+        def __init__(self, text, tok):
+            self.text = text
+            self.token = tok
+
+    def _stream_generate(_model, _tokenizer, **_kw):
+        yield _Resp("reason", 10)
+        yield _Resp("</think>", 11)
+        yield _Resp("answer", 12)
+
+    mlx_lm_pkg.stream_generate = _stream_generate
+    monkeypatch.setitem(sys.modules, "mlx_lm", mlx_lm_pkg)
+    monkeypatch.setitem(sys.modules, "mlx_lm.sample_utils", mlx_lm_sample)
+
+    backend = MLXInferenceBackend()
+    backend._model = object()
+    backend._tokenizer = SimpleNamespace(all_special_tokens = [])
+    backend._is_vlm = False
+
+    snapshots = list(
+        backend.generate_chat_response(
+            messages = [{"role": "user", "content": "ping"}],
+            max_new_tokens = 3,
+        )
+    )
+    assert snapshots == [
+        "<think>\n",
+        "<think>\nreason",
+        "<think>\nreason</think>",
+        "<think>\nreason</think>answer",
+    ]
+    assert all(current.startswith(previous) for previous, current in zip(snapshots, snapshots[1:]))
+
+
+def test_mlx_vlm_normalizes_native_reasoning_channels(monkeypatch):
+    _install_fake_mlx(monkeypatch)
+    from core.inference.mlx_inference import MLXInferenceBackend
+
+    monkeypatch.setattr(
+        "core.inference.chat_template_helpers.apply_chat_template_for_generation",
+        lambda *_args, **_kwargs: "prompt",
+        raising = True,
+    )
+
+    mlx_vlm_pkg = types.ModuleType("mlx_vlm")
+
+    class _Resp:
+        def __init__(self, text, tok):
+            self.text = text
+            self.token = tok
+
+    def _stream_generate(_model, _processor, _prompt, _images, **_kw):
+        yield _Resp("<|channel>thought\n", 10)
+        yield _Resp("vision", 11)
+        yield _Resp("<channel|>", 12)
+        yield _Resp(" answer", 13)
+
+    mlx_vlm_pkg.stream_generate = _stream_generate
+    monkeypatch.setitem(sys.modules, "mlx_vlm", mlx_vlm_pkg)
+
+    backend = MLXInferenceBackend()
+    backend._model = SimpleNamespace(config = SimpleNamespace())
+    backend._processor = SimpleNamespace(
+        chat_template = "<|channel>thought\n...<channel|>",
+        all_special_tokens = [],
+        apply_chat_template = lambda *_args, **_kwargs: "prompt",
+    )
+    backend._is_vlm = True
+
+    assert list(
+        backend.generate_chat_response(
+            messages = [{"role": "user", "content": "describe"}],
+            image = object(),
+            max_new_tokens = 4,
+        )
+    ) == [
+        "<think>",
+        "<think>vision",
+        "<think>vision</think>",
+        "<think>vision</think> answer",
+    ]
+
+
+class _FakeLRUPromptCache:
+    def __init__(
+        self,
+        max_size = 10,
+        max_bytes = 1 << 63,
+    ):
+        self.max_size = max_size
+        self.max_bytes = max_bytes
+        self.entries = {}
+
+    def fetch_nearest_cache(self, key, tokens):
+        import copy
+
+        stored = self.entries.get(key, {})
+        exact = stored.get(tuple(tokens))
+        if exact is not None:
+            return copy.deepcopy(exact), []
+        best = None
+        for candidate, cache in stored.items():
+            if len(candidate) < len(tokens) and tuple(tokens[: len(candidate)]) == candidate:
+                if best is None or len(candidate) > len(best[0]):
+                    best = (candidate, cache)
+        if best is not None:
+            return copy.deepcopy(best[1]), list(tokens[len(best[0]) :])
+        return None, list(tokens)
+
+    def insert_cache(
+        self,
+        key,
+        tokens,
+        prompt_cache,
+        *,
+        cache_type = "assistant",
+    ):
+        import copy
+        self.entries.setdefault(key, {})[tuple(tokens)] = copy.deepcopy(prompt_cache)
+
+
+class _FakeCacheEntry:
+    def __init__(
+        self,
+        offset = 0,
+        nbytes = 1,
+    ):
+        self.offset = offset
+        self.nbytes = nbytes
+
+
+def _install_fake_prompt_cache_api(monkeypatch, trimmable = True):
+    from core.inference import mlx_inference
+
+    def _make_prompt_cache(_model):
+        return [_FakeCacheEntry()]
+
+    def _can_trim_prompt_cache(_cache):
+        return trimmable
+
+    def _trim_prompt_cache(cache, num):
+        cache[0].offset = max(cache[0].offset - num, 0)
+        return num
+
+    monkeypatch.setattr(
+        mlx_inference,
+        "_mlx_prompt_cache_api",
+        lambda: (
+            _FakeLRUPromptCache,
+            _make_prompt_cache,
+            _can_trim_prompt_cache,
+            _trim_prompt_cache,
+        ),
+    )
+
+
+def test_mlx_prompt_cache_max_bytes_budget(monkeypatch):
+    from core.inference.mlx_inference import (
+        PROMPT_CACHE_FALLBACK_BYTES,
+        PROMPT_CACHE_MEMORY_FRACTION,
+        _prompt_cache_max_bytes,
+    )
+
+    monkeypatch.delenv("UNSLOTH_MLX_PROMPT_CACHE_BYTES", raising = False)
+    assert _prompt_cache_max_bytes(None) == PROMPT_CACHE_FALLBACK_BYTES
+    assert _prompt_cache_max_bytes(20.0) == int(20.0 * 1e9 * PROMPT_CACHE_MEMORY_FRACTION)
+
+    monkeypatch.setenv("UNSLOTH_MLX_PROMPT_CACHE_BYTES", "4096")
+    assert _prompt_cache_max_bytes(20.0) == 4096
+    monkeypatch.setenv("UNSLOTH_MLX_PROMPT_CACHE_BYTES", "0")
+    assert _prompt_cache_max_bytes(20.0) == 0
+    monkeypatch.setenv("UNSLOTH_MLX_PROMPT_CACHE_BYTES", "not-a-number")
+    assert _prompt_cache_max_bytes(20.0) == int(20.0 * 1e9 * PROMPT_CACHE_MEMORY_FRACTION)
+
+
+def test_mlx_prompt_cache_never_returns_empty_remainder(monkeypatch):
+    _install_fake_prompt_cache_api(monkeypatch)
+    from core.inference.mlx_inference import _MLXPromptCacheHistory
+
+    history = _MLXPromptCacheHistory(6, 1 << 30)
+    tokens = list(range(10))
+    cache, rest = history.fetch(object(), "key", tokens)
+    assert len(rest) == 10
+    cache[0].offset = len(tokens)
+    history.insert("key", tokens, cache)
+
+    _cache, rest = history.fetch(object(), "key", tokens)
+    assert rest == tokens[-1:]
+
+    longer = tokens + [99, 100]
+    _cache, rest = history.fetch(object(), "key", longer)
+    assert rest == [99, 100]
+
+    _install_fake_prompt_cache_api(monkeypatch, trimmable = False)
+    history = _MLXPromptCacheHistory(6, 1 << 30)
+    cache, _rest = history.fetch(object(), "key", tokens)
+    cache[0].offset = len(tokens)
+    history.insert("key", tokens, cache)
+    _cache, rest = history.fetch(object(), "key", tokens)
+    assert rest == tokens, "untrimmable entry must not be reused"
+
+
+def test_mlx_prompt_cache_key_isolates_adapter_state(monkeypatch):
+    _install_fake_prompt_cache_api(monkeypatch)
+    _install_fake_mlx(monkeypatch)
+    from core.inference.mlx_inference import MLXInferenceBackend
+
+    class _Tok:
+        bos_token = None
+
+        def encode(
+            self,
+            text,
+            add_special_tokens = True,
+        ):
+            return [ord(c) for c in text]
+
+    backend = MLXInferenceBackend()
+    backend._model = object()
+    backend._tokenizer = _Tok()
+    backend.active_model_name = "model-a"
+
+    prompt = "shared prefix"
+    _rest, cache, key, tokens, cached = backend._prepare_prompt_cache(prompt, True)
+    assert cached == 0
+    cache[0].offset = len(tokens)
+    backend._prompt_cache_history.insert(key, tokens, cache)
+
+    _rest, _cache, _key, _tokens, cached_same = backend._prepare_prompt_cache(prompt, True)
+    assert cached_same > 0
+    _rest, _cache, _key, _tokens, cached_flipped = backend._prepare_prompt_cache(prompt, False)
+    assert cached_flipped == 0
+
+
+def _install_fake_text_stack(
+    monkeypatch,
+    token_map,
+    captured,
+    markers = None,
+):
+    import types as _types
+
+    from core.inference import mlx_inference
+
+    _install_fake_mlx(monkeypatch)
+    monkeypatch.setattr(
+        mlx_inference,
+        "_temporary_mlx_adapter_state",
+        lambda _model, _state: __import__("contextlib").nullcontext(),
+    )
+    monkeypatch.setattr(
+        "core.inference.chat_template_helpers.apply_chat_template_for_generation",
+        lambda _tok, messages, **_kw: messages[-1]["content"],
+    )
+    monkeypatch.setattr(
+        "core.inference.chat_template_helpers.render_with_native_template_fallback",
+        lambda formatted_prompt, **_kw: SimpleNamespace(
+            prompt = formatted_prompt,
+            reasoning_channel_markers = markers,
+        ),
+    )
+    monkeypatch.setattr(
+        "core.inference.chat_template_helpers.detect_think_prefill",
+        lambda *_a, **_kw: "",
+    )
+
+    class _Resp:
+        def __init__(self, token, processed):
+            self.token = token
+            self.text = f"<{token}>"
+            self.prompt_tokens = processed
+            self.prompt_tps = 10.0
+            self.generation_tokens = 1
+            self.generation_tps = 5.0
+
+    def _stream_generate(_model, _tokenizer, **kwargs):
+        captured.append(kwargs)
+        processed = len(kwargs["prompt"])
+        cache = kwargs.get("prompt_cache")
+        if cache is not None:
+            cache[0].offset += processed
+        for token in token_map["generated"]:
+            if cache is not None:
+                cache[0].offset += 1
+            yield _Resp(token, processed)
+
+    mlx_lm_pkg = _types.ModuleType("mlx_lm")
+    mlx_lm_pkg.stream_generate = _stream_generate
+    mlx_lm_sample = _types.ModuleType("mlx_lm.sample_utils")
+    mlx_lm_sample.make_sampler = lambda **_kw: object()
+    mlx_lm_sample.make_logits_processors = lambda **_kw: []
+    monkeypatch.setitem(sys.modules, "mlx_lm", mlx_lm_pkg)
+    monkeypatch.setitem(sys.modules, "mlx_lm.sample_utils", mlx_lm_sample)
+
+    class _Tok:
+        bos_token = None
+        chat_template = "x"
+
+        def encode(
+            self,
+            text,
+            add_special_tokens = True,
+        ):
+            return list(token_map[text])
+
+        def decode(
+            self,
+            ids,
+            skip_special_tokens = False,
+        ):
+            return "".join(str(i) for i in ids)
+
+    from core.inference.mlx_inference import MLXInferenceBackend
+
+    backend = MLXInferenceBackend()
+    backend._model = object()
+    backend._tokenizer = _Tok()
+    backend._is_vlm = False
+    backend.active_model_name = "model-a"
+    return backend
+
+
+def _run_turn(backend, prompt):
+    list(
+        backend.generate_chat_response(
+            messages = [{"role": "user", "content": prompt}],
+            max_new_tokens = 4,
+        )
+    )
+
+
+def test_mlx_text_reuses_prompt_cache_on_the_next_turn(monkeypatch):
+    _install_fake_prompt_cache_api(monkeypatch)
+    captured = []
+    token_map = {
+        "P1": [1, 2, 3],
+        "P2": [1, 2, 3, 7, 8, 9, 10],
+        "generated": [7, 8],
+    }
+    backend = _install_fake_text_stack(monkeypatch, token_map, captured)
+
+    _run_turn(backend, "P1")
+    assert captured[0]["prompt"] == [1, 2, 3]
+    assert "prompt_cache" in captured[0]
+    assert backend.last_generation_stats["timings"]["cache_n"] == 0
+
+    _run_turn(backend, "P2")
+    assert captured[1]["prompt"] == [9, 10], "turn two should prefill only the new tail"
+
+    stats = backend.last_generation_stats
+    assert stats["timings"]["cache_n"] == 5
+    assert stats["timings"]["prompt_n"] == 2
+    assert stats["usage"]["prompt_tokens"] == 7
+
+
+def test_mlx_text_without_lru_prompt_cache_prefills_the_full_prompt(monkeypatch):
+    from core.inference import mlx_inference
+
+    monkeypatch.setattr(mlx_inference, "_mlx_prompt_cache_api", lambda: None)
+    captured = []
+    token_map = {"P1": [1, 2, 3], "generated": [7]}
+    backend = _install_fake_text_stack(monkeypatch, token_map, captured)
+
+    _run_turn(backend, "P1")
+    assert captured[0]["prompt"] == "P1"
+    assert "prompt_cache" not in captured[0]
+    assert backend.last_generation_stats["timings"]["cache_n"] == 0
+
+
+def test_mlx_text_tracks_tokens_on_the_native_reasoning_path(monkeypatch):
+    _install_fake_prompt_cache_api(monkeypatch)
+    captured = []
+    token_map = {"P1": [1, 2, 3], "P2": [1, 2, 3, 7, 8, 9], "generated": [7, 8]}
+    backend = _install_fake_text_stack(monkeypatch, token_map, captured, markers = ("<a>", "</a>"))
+
+    _run_turn(backend, "P1")
+    _run_turn(backend, "P2")
+    assert captured[1]["prompt"] == [9]
+
+
+def test_mlx_presence_penalty_latches_the_first_decode_step():
+    mx = pytest.importorskip("mlx.core")
+    import numpy as np
+
+    from core.inference.mlx_inference import _make_mlx_presence_penalty_processor
+
+    processor = _make_mlx_presence_penalty_processor(2.0)
+    logits = mx.zeros((1, 5))
+    out = processor(mx.array([3]), logits)
+    assert np.array_equal(np.array(out), np.zeros((1, 5))), "prompt must not be penalized"
+    out = processor(mx.array([3, 1]), mx.zeros((1, 5)))
+    penalized = np.array(out)[0]
+    assert penalized[1] == -2.0
+    assert penalized[3] == 0.0
+
+
+def test_mlx_prompt_cache_survives_reset_but_not_unload(monkeypatch):
+    _install_fake_prompt_cache_api(monkeypatch)
+    _install_fake_mlx(monkeypatch)
+    sys.modules["mlx.core"].clear_cache = lambda: None
+    from core.inference.mlx_inference import MLXInferenceBackend
+
+    backend = MLXInferenceBackend()
+    backend.active_model_name = "model-a"
+    history = backend._prompt_cache()
+    assert history is not None
+
+    backend.reset_generation_state()
+    assert backend._prompt_cache_history is history
+
+    backend.unload_model("model-a")
+    assert backend._prompt_cache_history is None
+
+
+def test_mlx_prompt_cache_skips_entries_over_budget(monkeypatch):
+    _install_fake_prompt_cache_api(monkeypatch)
+    from core.inference.mlx_inference import _MLXPromptCacheHistory
+
+    history = _MLXPromptCacheHistory(6, 1000)
+    history.insert("key", [1, 2, 3], [_FakeCacheEntry(offset = 3, nbytes = 400)])
+    assert len(history._lru.entries.get("key", {})) == 1
+
+    history.insert("key", list(range(50)), [_FakeCacheEntry(offset = 50, nbytes = 5000)])
+    stored = history._lru.entries.get("key", {})
+    assert tuple([1, 2, 3]) in stored
+    assert tuple(range(50)) not in stored
+
+
+def test_mlx_prompt_cache_keys_on_what_the_kv_covers(monkeypatch):
+    _install_fake_prompt_cache_api(monkeypatch)
+    from core.inference.mlx_inference import _MLXPromptCacheHistory
+
+    class _Entry:
+        def __init__(
+            self,
+            offset,
+            nbytes = 1,
+        ):
+            self.offset = offset
+            self.nbytes = nbytes
+
+    history = _MLXPromptCacheHistory(6, 1 << 30)
+
+    history.insert("key", list(range(10)), [_Entry(offset = 8)])
+    assert tuple(range(8)) in history._lru.entries["key"]
+    assert tuple(range(10)) not in history._lru.entries["key"]
+
+    history.insert("other", list(range(4)), [_Entry(offset = 9)])
+    assert "other" not in history._lru.entries
+
+
+def test_mlx_prompt_cache_only_stores_verifiable_prefix_coverage(monkeypatch):
+    mx = pytest.importorskip("mlx.core")
+    from mlx_lm.models.cache import CacheList, ChunkedKVCache, KVCache, RotatingKVCache
+
+    _install_fake_prompt_cache_api(monkeypatch)
+    from core.inference.mlx_inference import _kv_prefix_coverage, _MLXPromptCacheHistory
+
+    def feed(entry, n):
+        for _ in range(n):
+            block = mx.zeros((1, 2, 1, 4), dtype = mx.float16)
+            entry.update_and_fetch(block, block)
+        mx.eval(entry.state)
+        return entry
+
+    plain = feed(KVCache(), 30)
+    unwrapped = feed(RotatingKVCache(max_size = 100, keep = 2), 30)
+    wrapped = feed(RotatingKVCache(max_size = 10, keep = 2), 30)
+    chunked = feed(ChunkedKVCache(chunk_size = 8), 30)
+    slid = feed(ChunkedKVCache(chunk_size = 8), 30)
+    slid.maybe_trim_front()
+
+    assert _kv_prefix_coverage([plain]) == 30
+    assert _kv_prefix_coverage([unwrapped]) == 30
+    assert _kv_prefix_coverage([chunked]) == 30
+    assert wrapped.offset == 30 and wrapped.state[0].shape[2] == 10
+    assert _kv_prefix_coverage([wrapped]) is None
+    assert slid.start_position > 0
+    assert _kv_prefix_coverage([slid]) is None
+    assert _kv_prefix_coverage([CacheList(feed(KVCache(), 30), feed(KVCache(), 30))]) == 30
+    assert _kv_prefix_coverage([CacheList(feed(KVCache(), 30), wrapped)]) is None
+    assert _kv_prefix_coverage([feed(KVCache(), 30), feed(KVCache(), 29)]) is None
+    assert _kv_prefix_coverage([]) is None
+
+    history = _MLXPromptCacheHistory(6, 1 << 40)
+    for unsafe in (wrapped, slid):
+        history.insert("key", list(range(30)), [unsafe])
+    assert "key" not in history._lru.entries
+
+    history.insert("key", list(range(30)), [plain])
+    assert tuple(range(30)) in history._lru.entries["key"]
diff --git a/studio/backend/tests/test_mlx_repair.py b/studio/backend/tests/test_mlx_repair.py
index 365cc46410..47a695ccbd 100644
--- a/studio/backend/tests/test_mlx_repair.py
+++ b/studio/backend/tests/test_mlx_repair.py
@@ -103,7 +103,7 @@ def test_repair_install_pins_transformers_and_cleans_up(monkeypatch):
     assert mr.attempt_mlx_repair() is True
     cmd = captured["cmd"]
     # transformers is pinned via a constraint file so the mlx install cannot
-    # upgrade it underneath Studio, and the temp constraint file is cleaned up.
+    # upgrade it underneath Unsloth, and the temp constraint file is cleaned up.
     assert "--constraint" in cmd
     assert "--upgrade" in cmd
     reinstall_pairs = set(zip(cmd, cmd[1:]))
@@ -123,7 +123,7 @@ def test_install_requires_prebuilt_wheels(monkeypatch):
     # A source distribution's PEP 517 build backend runs arbitrary code at install
     # time, before the post-install stack check. The unattended self-heal must
     # require pre-built wheels so a malicious resolver-selected sdist cannot execute
-    # during ordinary Studio startup. mlx/mlx-metal ship wheels only and
+    # during ordinary Unsloth startup. mlx/mlx-metal ship wheels only and
     # mlx-lm/mlx-vlm publish py3-none-any wheels, so a healthy self-heal still works.
     pytest.importorskip("transformers")
     captured = {}
@@ -143,7 +143,7 @@ def test_install_requires_prebuilt_wheels(monkeypatch):
 
 
 def test_install_env_drops_secrets_and_source_redirects(monkeypatch):
-    # The unattended self-heal must not hand resolver/build code the full Studio
+    # The unattended self-heal must not hand resolver/build code the full Unsloth
     # environment: secrets and package-source redirects are dropped, while the
     # variables uv genuinely needs are forwarded.
     monkeypatch.setenv("HF_TOKEN", "secret-hf")
diff --git a/studio/backend/tests/test_mlx_stop_checkpoint.py b/studio/backend/tests/test_mlx_stop_checkpoint.py
new file mode 100644
index 0000000000..d4a00cc6c8
--- /dev/null
+++ b/studio/backend/tests/test_mlx_stop_checkpoint.py
@@ -0,0 +1,137 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Regression tests for MLX stop-and-save checkpoint handling."""
+
+import importlib.util
+import json
+import sys
+import types
+from pathlib import Path
+
+import numpy as np
+from safetensors.numpy import save_file
+
+
+_BACKEND = Path(__file__).resolve().parents[1]
+
+
+def _load_worker_module():
+    spec = importlib.util.spec_from_file_location(
+        "training_worker_under_test",
+        _BACKEND / "core" / "training" / "worker.py",
+    )
+    module = importlib.util.module_from_spec(spec)
+    assert spec.loader is not None
+    spec.loader.exec_module(module)
+    return module
+
+
+worker = _load_worker_module()
+
+
+class _FakeTrainer:
+    def __init__(self, step: int):
+        self._global_step = step
+        self._train_loss_history = []
+        self.model = object()
+
+
+def _write_checkpoint(out: Path, step: int) -> Path:
+    checkpoint = out / f"checkpoint-{step}"
+    checkpoint.mkdir(parents = True, exist_ok = True)
+    (checkpoint / "trainer_state.json").write_text(
+        json.dumps({"global_step": step}), encoding = "utf-8"
+    )
+    save_file({"weight": np.ones(1, dtype = np.float32)}, checkpoint / "adapters.safetensors")
+    save_file(
+        {"state": np.ones(1, dtype = np.float32)},
+        checkpoint / "optimizer_state.safetensors",
+    )
+    return checkpoint
+
+
+def test_mlx_has_checkpoint_at_step_requires_complete_state(tmp_path):
+    out = tmp_path / "outputs" / "run_x"
+    _write_checkpoint(out, 5)
+
+    assert worker._mlx_has_checkpoint_at_step(out, 5) is True
+
+
+def test_write_mlx_stop_checkpoint_returns_true_when_current_step_checkpoint_exists(tmp_path):
+    out = tmp_path / "outputs" / "run_x"
+    _write_checkpoint(out, 5)
+
+    assert worker._write_mlx_stop_checkpoint(_FakeTrainer(step = 5), object(), out) is True
+
+
+def test_write_mlx_stop_checkpoint_writes_current_step_when_only_older_checkpoint_exists(
+    tmp_path, monkeypatch
+):
+    out = tmp_path / "outputs" / "run_x"
+    _write_checkpoint(out, 5)
+
+    saved_steps: list[int] = []
+
+    def _save_state(_value, path, name):
+        save_file({"state": np.ones(1, dtype = np.float32)}, Path(path, name))
+
+    def _save_trainer_state(state, ckpt_dir, **_kwargs):
+        Path(ckpt_dir, "trainer_state.json").write_text(json.dumps(state), encoding = "utf-8")
+        saved_steps.append(int(state["global_step"]))
+
+    fake_utils = types.SimpleNamespace(
+        save_trainable_adapters = lambda model, path: _save_state(
+            model, path, "adapters.safetensors"
+        ),
+        save_optimizer_state = lambda optimizer, path: _save_state(
+            optimizer, path, "optimizer_state.safetensors"
+        ),
+        save_trainer_state = _save_trainer_state,
+    )
+    monkeypatch.setitem(sys.modules, "unsloth_zoo.mlx.utils", fake_utils)
+
+    assert worker._write_mlx_stop_checkpoint(_FakeTrainer(step = 10), object(), out) is True
+    assert saved_steps == [10]
+    assert (out / "checkpoint-10" / "trainer_state.json").is_file()
+
+
+def test_write_mlx_stop_checkpoint_returns_false_without_optimizer(tmp_path):
+    out = tmp_path / "outputs" / "run_x"
+    out.mkdir(parents = True)
+
+    assert worker._write_mlx_stop_checkpoint(_FakeTrainer(step = 5), None, out) is False
+
+
+def test_write_mlx_stop_checkpoint_rejects_incomplete_current_checkpoint(tmp_path):
+    out = tmp_path / "outputs" / "run_x"
+    ckpt = out / "checkpoint-5"
+    ckpt.mkdir(parents = True)
+    (ckpt / "trainer_state.json").write_text('{"global_step": 5}', encoding = "utf-8")
+
+    assert worker._write_mlx_stop_checkpoint(_FakeTrainer(step = 5), None, out) is False
+
+
+def test_write_mlx_stop_checkpoint_ignores_stale_checkpoint_without_optimizer(tmp_path):
+    # An older checkpoint does not cover the current step, so this still fails.
+    out = tmp_path / "outputs" / "run_x"
+    _write_checkpoint(out, 5)
+
+    assert worker._write_mlx_stop_checkpoint(_FakeTrainer(step = 10), None, out) is False
+
+
+def test_write_mlx_stop_checkpoint_returns_false_when_save_fails(tmp_path, monkeypatch):
+    out = tmp_path / "outputs" / "run_x"
+    out.mkdir(parents = True)
+
+    def _boom(*_args, **_kwargs):
+        raise RuntimeError("save failed")
+
+    fake_utils = types.SimpleNamespace(
+        save_trainable_adapters = _boom,
+        save_optimizer_state = lambda *_a, **_k: None,
+        save_trainer_state = lambda *_a, **_k: None,
+    )
+    monkeypatch.setitem(sys.modules, "unsloth_zoo.mlx.utils", fake_utils)
+
+    assert worker._write_mlx_stop_checkpoint(_FakeTrainer(step = 5), object(), out) is False
diff --git a/studio/backend/tests/test_model_picker_regression.py b/studio/backend/tests/test_model_picker_regression.py
new file mode 100644
index 0000000000..f38a4d0b8d
--- /dev/null
+++ b/studio/backend/tests/test_model_picker_regression.py
@@ -0,0 +1,232 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Regression guards for the model-picker per-model-config feature (the set of
+bugs that got the predecessor PR reverted). Pure-function / validation checks
+only, so they run on CPU in the backend pytest job with no model download.
+
+Covers, at the backend layer:
+  - infra-model hiding: the RAG embedder (bge-small-en-v1.5) and the llama.cpp
+    install-validation probe (ggml-org/models / stories260K) stay hidden, while
+    normal chat repos are not hidden;
+  - the HF token is honored from the dedicated header with the query string as a
+    fallback, never the other way around;
+  - the chat-template byte caps reject oversized overrides (both the char-count
+    fast path and the UTF-8 byte path) and the sidecar reader is size-bounded.
+"""
+
+from __future__ import annotations
+
+import sys
+import types
+
+import pytest
+
+# Keep this test runnable without the optional structlog dependency (mirrors
+# tests/test_cached_gguf_routes.py), since importing routes.models pulls it in.
+if "structlog" not in sys.modules:
+
+    class _DummyLogger:
+        def __getattr__(self, _name):
+            return lambda *args, **kwargs: None
+
+    sys.modules["structlog"] = types.SimpleNamespace(
+        BoundLogger = _DummyLogger,
+        get_logger = lambda *args, **kwargs: _DummyLogger(),
+    )
+
+import routes.models as models_route
+from core.rag import config as rag_config
+from hub.dependencies import get_hf_token
+from models.inference import LoadRequest
+from picker.schemas import MAX_CHAT_TEMPLATE_BYTES
+from picker.service import _read_bounded_text
+from utils.hidden_models import is_hidden_model
+
+
+@pytest.fixture(autouse = True)
+def _pin_default_embedder(monkeypatch):
+    """Pin the effective embedder to Studio's static default so hiding is
+    deterministic and cannot depend on ambient RAG config / env."""
+    default = "unsloth/bge-small-en-v1.5"
+    monkeypatch.setattr(rag_config, "EMBEDDING_MODEL", default, raising = False)
+    monkeypatch.setattr(rag_config, "effective_embedding_model", lambda: default)
+    monkeypatch.setattr(rag_config, "effective_gguf_repo", lambda: default)
+    monkeypatch.setattr(rag_config, "default_gguf_repo", lambda: default)
+
+
+# --------------------------------------------------------------------------- #
+# Infra-model hiding (the "infra models resurfaced in the picker" regression)  #
+# --------------------------------------------------------------------------- #
+
+
+@pytest.mark.parametrize(
+    "value",
+    [
+        "ggml-org/models",  # the probe repo id
+        "unsloth/bge-small-en-v1.5",  # the RAG embedder repo
+        "unsloth/bge-small-en-v1.5-GGUF",  # its GGUF companion
+        "/root/.cache/huggingface/hub/x/stories260K.gguf",  # probe on disk
+        "/root/.cache/x/Stories260K.GGUF",  # case-insensitive
+        r"C:\\models\\stories260K.gguf",  # windows-style path
+        "/opt/models/bge-small-en-v1.5",  # embedder basename folder
+        "/opt/models/bge-small-en-v1.5-Q8_0.gguf",  # suffixed local weight
+    ],
+)
+def test_infra_models_are_hidden(value):
+    assert is_hidden_model(value) is True
+
+
+@pytest.mark.parametrize(
+    "value",
+    [
+        "unsloth/gemma-3-270m-it-GGUF",  # a normal small chat GGUF
+        "unsloth/Qwen3-0.6B",  # a normal non-GGUF chat model
+        "user/stories260K-finetune-GGUF",  # repo id merely contains "stories260k"
+        "user/model-chat",  # generic repo must not be hidden
+        "meta-llama/Llama-3.1-8B-Instruct",
+    ],
+)
+def test_normal_models_are_not_hidden(value):
+    assert is_hidden_model(value) is False
+
+
+def test_is_hidden_model_ignores_empty_values():
+    assert is_hidden_model(None) is False
+    assert is_hidden_model("") is False
+    assert is_hidden_model(None, "", "unsloth/gemma-3-270m-it-GGUF") is False
+
+
+def test_hidden_model_matchers_expose_probe_needles():
+    needles, exact_ids, _exact_paths = models_route.hidden_model_matchers()
+    lowered = [n.lower() for n in needles]
+    assert "ggml-org/models" in lowered
+    assert "stories260k.gguf" in lowered
+    # The configured embedder is exposed as an exact repo id, never as a
+    # basename needle that would substring-hide unrelated chat models.
+    assert "bge-small-en-v1.5" not in lowered
+    assert "unsloth/bge-small-en-v1.5" in exact_ids
+
+
+def test_hidden_model_matchers_custom_repo_publishes_exact_ids(monkeypatch):
+    monkeypatch.setattr(rag_config, "effective_embedding_model", lambda: "org/model")
+    monkeypatch.setattr(rag_config, "effective_gguf_repo", lambda: "org/model-GGUF")
+    needles, exact_ids, exact_paths = models_route.hidden_model_matchers()
+    assert needles == ["ggml-org/models", "stories260k.gguf"]
+    assert "org/model" in exact_ids
+    assert "org/model-gguf" in exact_ids
+    assert exact_paths == []
+
+
+def test_hidden_model_matchers_local_owner_name_path_is_exact_path(monkeypatch, tmp_path):
+    # A local embedder shaped like owner/name that exists on disk must be an
+    # exact resolved path, not a Hub repo id (mirroring is_hidden_model), so the
+    # local row stays hidden instead of showing as a chat model.
+    (tmp_path / "models" / "embedder").mkdir(parents = True)
+    monkeypatch.chdir(tmp_path)
+    monkeypatch.setattr(rag_config, "effective_embedding_model", lambda: "models/embedder")
+    monkeypatch.setattr(rag_config, "effective_gguf_repo", lambda: "ggml-org/models")
+    _needles, exact_ids, exact_paths = models_route.hidden_model_matchers()
+    resolved = str((tmp_path / "models" / "embedder").resolve()).lower()
+    assert resolved in exact_paths
+    assert "models/embedder" not in exact_ids
+
+
+# --------------------------------------------------------------------------- #
+# HF token via header, query string only as a fallback (the token-leak fix)    #
+# --------------------------------------------------------------------------- #
+
+
+def test_get_hf_token_strips_and_returns():
+    assert get_hf_token("  hf_abc ") == "hf_abc"
+
+
+@pytest.mark.parametrize("value", [None, "", "   ", "\n\t"])
+def test_get_hf_token_blank_is_none(value):
+    assert get_hf_token(value) is None
+
+
+@pytest.mark.parametrize(
+    "value,expected",
+    [("  hf_x ", "hf_x"), ("", None), ("   ", None), (None, None), (1234, None)],
+)
+def test_normalize_hf_token(value, expected):
+    assert models_route._normalize_hf_token(value) == expected
+
+
+def test_header_token_wins_over_query():
+    header, query = "hf_header", "hf_query"
+    resolved = models_route._normalize_hf_token(header) or models_route._normalize_hf_token(query)
+    assert resolved == "hf_header"
+
+
+def test_query_token_is_fallback_when_header_absent():
+    resolved = models_route._normalize_hf_token(None) or models_route._normalize_hf_token(
+        "hf_query"
+    )
+    assert resolved == "hf_query"
+
+
+# --------------------------------------------------------------------------- #
+# Chat-template byte caps (the unbounded-template hardening)                    #
+# --------------------------------------------------------------------------- #
+
+
+def _load_request(**overrides):
+    data = {"model_path": "unsloth/test-model-GGUF", "gguf_variant": "Q4_K_M"}
+    data.update(overrides)
+    return LoadRequest.model_validate(data)
+
+
+def test_blank_chat_template_override_normalizes_to_none():
+    assert _load_request(chat_template_override = "   \n\t").chat_template_override is None
+
+
+def test_nonblank_chat_template_override_preserved_verbatim():
+    template = "  {{ messages }}  "
+    assert _load_request(chat_template_override = template).chat_template_override == template
+
+
+def test_chat_template_at_byte_limit_is_accepted():
+    template = "a" * MAX_CHAT_TEMPLATE_BYTES  # exactly the limit, 1 byte/char
+    assert (
+        len(_load_request(chat_template_override = template).chat_template_override)
+        == MAX_CHAT_TEMPLATE_BYTES
+    )
+
+
+def test_chat_template_over_char_limit_is_rejected():
+    with pytest.raises(Exception):  # pydantic ValidationError wrapping ValueError
+        _load_request(chat_template_override = "a" * (MAX_CHAT_TEMPLATE_BYTES + 1))
+
+
+def test_chat_template_over_byte_limit_is_rejected():
+    # Char count stays under the limit but UTF-8 bytes exceed it (3 bytes/char),
+    # so only the byte-count branch can catch this.
+    multibyte = "€" * (MAX_CHAT_TEMPLATE_BYTES // 2)  # euro sign, 3 bytes each
+    assert len(multibyte) <= MAX_CHAT_TEMPLATE_BYTES
+    assert len(multibyte.encode("utf-8")) > MAX_CHAT_TEMPLATE_BYTES
+    with pytest.raises(Exception):
+        _load_request(chat_template_override = multibyte)
+
+
+def test_read_bounded_text_reads_within_limit(tmp_path):
+    p = tmp_path / "t.json"
+    p.write_text("hello", encoding = "utf-8")
+    assert _read_bounded_text(p, 16) == "hello"
+
+
+def test_read_bounded_text_rejects_over_limit(tmp_path):
+    p = tmp_path / "big.json"
+    p.write_bytes(b"x" * 100)
+    assert _read_bounded_text(p, 50) is None
+
+
+def test_read_bounded_text_at_limit_is_read(tmp_path):
+    p = tmp_path / "exact.json"
+    p.write_bytes(b"x" * 50)
+    assert _read_bounded_text(p, 50) == "x" * 50
+
+
+def test_read_bounded_text_missing_file_is_none(tmp_path):
+    assert _read_bounded_text(tmp_path / "nope.json", 50) is None
diff --git a/studio/backend/tests/test_model_update_robustness.py b/studio/backend/tests/test_model_update_robustness.py
index edf55812e2..d84f8c94a7 100644
--- a/studio/backend/tests/test_model_update_robustness.py
+++ b/studio/backend/tests/test_model_update_robustness.py
@@ -112,13 +112,21 @@ def patch_hub_gguf(monkeypatch):
             blob_ids = [local_blob],
             gguf_files = {"model-Q4_K_M.gguf": 1000},
         )
+        monkeypatch.setattr(
+            "utils.hf_cache_settings.get_hf_cache_paths",
+            lambda: SimpleNamespace(hub_cache = tmp_path),
+        )
         monkeypatch.setattr(
             GV,
             "list_gguf_variants",
             lambda r, hf_token = None: (_variants(), False, [remote_sibling]),
             raising = True,
         )
-        monkeypatch.setattr(GV, "iter_hf_cache_snapshots", lambda _repo_id: [snap])
+        monkeypatch.setattr(
+            GV,
+            "iter_hf_cache_snapshots",
+            lambda _repo_id, root = None: [snap],
+        )
         monkeypatch.setattr(
             CI,
             "all_hf_cache_scans",
@@ -217,6 +225,10 @@ def test_variant_update_check_detects_companion_only_update(
             companion_path: 100,
         },
     )
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = tmp_path),
+    )
     siblings = [
         patch_hub_gguf.sibling("model-Q4_K_M.gguf", 1000, "mainsha"),
         patch_hub_gguf.sibling(companion_path, 100, "new-companion"),
@@ -227,7 +239,11 @@ def test_variant_update_check_detects_companion_only_update(
         lambda r, hf_token = None: (_variants(), has_vision, siblings),
         raising = True,
     )
-    monkeypatch.setattr(GV, "iter_hf_cache_snapshots", lambda _repo_id: [snap])
+    monkeypatch.setattr(
+        GV,
+        "iter_hf_cache_snapshots",
+        lambda _repo_id, root = None: [snap],
+    )
     monkeypatch.setattr(
         CI,
         "all_hf_cache_scans",
@@ -314,6 +330,7 @@ def test_cached_model_scan_keeps_local_safetensors_repo(monkeypatch, tmp_path):
                         file_name = "model.safetensors",
                         size_on_disk = 100,
                         blob_path = str(repo_path / "blobs" / "modelsha"),
+                        blob_last_modified = 3_000.0,
                     ),
                 ]
             )
@@ -336,6 +353,98 @@ def test_cached_model_scan_keeps_local_safetensors_repo(monkeypatch, tmp_path):
     assert rows[0]["repo_id"] == "Org/SafeTensorRepo"
     assert rows[0]["model_format"] == "safetensors"
     assert rows[0]["size_bytes"] == 100
+    assert rows[0]["last_modified"] == 3_000.0
+
+
+def test_cached_gguf_scan_keeps_download_timestamp(monkeypatch, tmp_path):
+    repo_path = tmp_path / "models--Org--GgufRepo"
+    repo = SimpleNamespace(
+        repo_id = "Org/GgufRepo",
+        repo_type = "model",
+        repo_path = repo_path,
+        revisions = [
+            SimpleNamespace(
+                files = [
+                    SimpleNamespace(
+                        file_name = "model-Q4_K_M.gguf",
+                        size_on_disk = 100,
+                        blob_path = None,
+                        blob_last_modified = 5_000.0,
+                    ),
+                ]
+            )
+        ],
+    )
+    monkeypatch.setattr(
+        CI,
+        "all_hf_cache_scans",
+        lambda: [SimpleNamespace(repos = [repo])],
+    )
+    monkeypatch.setattr(
+        CI.hf_cache_scan,
+        "is_gguf_repo_partial",
+        lambda *args, **kwargs: False,
+    )
+    monkeypatch.setattr(
+        CI,
+        "_gguf_variant_state_summary",
+        lambda _repo_id, **_kwargs: (False, 0),
+    )
+
+    rows = CI._scan_cached_gguf()
+
+    assert len(rows) == 1
+    assert rows[0]["repo_id"] == "Org/GgufRepo"
+    assert rows[0]["model_format"] == "gguf"
+    assert rows[0]["size_bytes"] == 100
+    assert rows[0]["last_modified"] == 5_000.0
+
+
+def test_cached_model_scan_hides_custom_whisper_repo(monkeypatch, tmp_path):
+    repo_path = tmp_path / "models--Org--CustomWhisper"
+    snapshot = repo_path / "snapshots" / ("a" * 40)
+    snapshot.mkdir(parents = True)
+    (snapshot / "config.json").write_text(
+        '{"model_type": "whisper", "architectures": ["WhisperForConditionalGeneration"]}'
+    )
+    repo = SimpleNamespace(
+        repo_id = "Org/CustomWhisper",
+        repo_type = "model",
+        repo_path = repo_path,
+        revisions = [
+            SimpleNamespace(
+                files = [
+                    SimpleNamespace(
+                        file_name = "config.json",
+                        size_on_disk = 10,
+                        blob_path = None,
+                    ),
+                    SimpleNamespace(
+                        file_name = "model.safetensors",
+                        size_on_disk = 100,
+                        blob_path = str(repo_path / "blobs" / "modelsha"),
+                    ),
+                ]
+            )
+        ],
+    )
+    monkeypatch.setattr(
+        CI,
+        "all_hf_cache_scans",
+        lambda: [SimpleNamespace(repos = [repo])],
+    )
+    monkeypatch.setattr(
+        CI,
+        "_cached_model_snapshot_path",
+        lambda _repo_path: snapshot,
+    )
+    monkeypatch.setattr(
+        CI.hf_cache_scan,
+        "is_snapshot_partial",
+        lambda *args, **kwargs: False,
+    )
+
+    assert CI._scan_cached_models() == []
 
 
 # ── hf_hub_download_with_xet_fallback force_download bypass (X2/F2) ───
@@ -584,7 +693,12 @@ def test_reclaim_replaced_gguf_variant_prunes_old_revision_only(monkeypatch, tmp
     invalidated = []
     monkeypatch.setattr(CI, "invalidate_hf_cache_scans", lambda: invalidated.append(True))
 
-    result = D.reclaim_replaced_gguf_variant(repo_id, "Q4_K_M", frozenset({"NEWsha"}))
+    result = D.reclaim_replaced_gguf_variant(
+        repo_id,
+        "Q4_K_M",
+        frozenset({"NEWsha"}),
+        hub_cache = tmp_path,
+    )
 
     assert result["removed_snapshots"] == 1
     assert result["deleted_blobs"] == 1
@@ -631,8 +745,85 @@ def test_reclaim_replaced_gguf_variant_keeps_no_symlink_current_file(monkeypatch
     monkeypatch.setattr(CI, "all_hf_cache_scans", lambda: [SimpleNamespace(repos = [repo_info])])
     monkeypatch.setattr(CI, "invalidate_hf_cache_scans", lambda: None)
 
-    result = D.reclaim_replaced_gguf_variant(repo_id, "Q4_K_M", frozenset({"REMOTEsha256"}))
+    result = D.reclaim_replaced_gguf_variant(
+        repo_id,
+        "Q4_K_M",
+        frozenset({"REMOTEsha256"}),
+        hub_cache = tmp_path,
+    )
 
     assert snap.exists() is True  # the current file must survive
     assert result["removed_snapshots"] == 0
     assert result["deleted_blobs"] == 0
+
+
+def test_reclaim_replaced_gguf_variant_only_mutates_worker_cache(monkeypatch, tmp_path):
+    repo_id = "org/repo-GGUF"
+    cache_a = tmp_path / "cache-a"
+    cache_b = tmp_path / "cache-b"
+
+    def cached_repo(cache_dir, revision):
+        repo_path = cache_dir / "models--org--repo-GGUF"
+        snap = repo_path / "snapshots" / revision / "model-Q4_K_M.gguf"
+        blob = repo_path / "blobs" / "OLDsha"
+        snap.parent.mkdir(parents = True, exist_ok = True)
+        blob.parent.mkdir(parents = True, exist_ok = True)
+        blob.write_bytes(b"old")
+        snap.symlink_to(blob)
+        return (
+            SimpleNamespace(
+                repo_id = repo_id,
+                repo_type = "model",
+                repo_path = repo_path,
+                revisions = [
+                    SimpleNamespace(
+                        files = [
+                            SimpleNamespace(
+                                file_name = snap.name,
+                                file_path = str(snap),
+                                blob_path = str(blob),
+                            )
+                        ]
+                    )
+                ],
+            ),
+            snap,
+            blob,
+        )
+
+    repo_a, snap_a, blob_a = cached_repo(cache_a, "a" * 40)
+    repo_b, snap_b, blob_b = cached_repo(cache_b, "b" * 40)
+    monkeypatch.setattr(
+        CI,
+        "all_hf_cache_scans",
+        lambda: [SimpleNamespace(repos = [repo_a]), SimpleNamespace(repos = [repo_b])],
+    )
+    monkeypatch.setattr(CI, "invalidate_hf_cache_scans", lambda: None)
+
+    result = D.reclaim_replaced_gguf_variant(
+        repo_id,
+        "Q4_K_M",
+        frozenset({"NEWsha"}),
+        hub_cache = cache_b,
+    )
+
+    assert result["removed_snapshots"] == 1
+    assert snap_b.exists() is False
+    assert blob_b.exists() is False
+    assert snap_a.exists() is True
+    assert blob_a.exists() is True
+
+
+def _mmproj_repo(*file_names: str):
+    return SimpleNamespace(
+        revisions = [SimpleNamespace(files = [SimpleNamespace(file_name = n) for n in file_names])]
+    )
+
+
+def test_repo_has_mmproj_requires_gguf_projector():
+    # A non-GGUF sidecar whose name merely contains "mmproj" must NOT mark the
+    # repo vision-capable; the runtime's projector detection is GGUF-only.
+    assert CI._repo_has_mmproj(_mmproj_repo("model-Q4_K_M.gguf", "mmproj_config.json")) is False
+    assert CI._repo_has_mmproj(_mmproj_repo("model-Q4_K_M.gguf", "README-mmproj.md")) is False
+    # A real GGUF projector still marks the repo vision-capable.
+    assert CI._repo_has_mmproj(_mmproj_repo("model-Q4_K_M.gguf", "mmproj-F16.gguf")) is True
diff --git a/studio/backend/tests/test_models_get_model_config_case_resolution.py b/studio/backend/tests/test_models_get_model_config_case_resolution.py
index 12f6c497ab..a50765898b 100644
--- a/studio/backend/tests/test_models_get_model_config_case_resolution.py
+++ b/studio/backend/tests/test_models_get_model_config_case_resolution.py
@@ -84,7 +84,7 @@ def test_repo_in_any_hf_cache_matches_case_variant_in_legacy_cache(tmp_path, mon
     # covers the active cache; discard deletes case-insensitively, so detection must too,
     # else a decline deletes a pre-existing user repo).
     import utils.paths as paths_pkg
-    import huggingface_hub.constants as hf_constants
+    import hub.utils.paths as hub_paths
 
     active = tmp_path / "active"
     legacy = tmp_path / "legacy"
@@ -96,9 +96,12 @@ def test_repo_in_any_hf_cache_matches_case_variant_in_legacy_cache(tmp_path, mon
 
     # No active-cache variant; case resolution is a no-op here.
     monkeypatch.setattr(paths_pkg, "resolve_cached_repo_id_case", lambda name: name)
-    monkeypatch.setattr(paths_pkg, "legacy_hf_cache_dir", lambda: legacy)
-    monkeypatch.setattr(paths_pkg, "hf_default_cache_dir", lambda: default)
-    monkeypatch.setattr(hf_constants, "HF_HUB_CACHE", str(active))
+    monkeypatch.setattr(hub_paths, "legacy_hf_cache_dir", lambda: legacy)
+    monkeypatch.setattr(hub_paths, "hf_default_cache_dir", lambda: default)
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.known_hf_hub_caches",
+        lambda: [active],
+    )
 
     assert models_route._repo_in_any_hf_cache("unsloth/foo") is True
     # Absent from every cache -> reported absent.
diff --git a/studio/backend/tests/test_mtp_drafter_companion.py b/studio/backend/tests/test_mtp_drafter_companion.py
index 86e528ae67..02230632b6 100644
--- a/studio/backend/tests/test_mtp_drafter_companion.py
+++ b/studio/backend/tests/test_mtp_drafter_companion.py
@@ -328,6 +328,7 @@ def test_download_mtp_prefers_root_over_new_scheme_copies(monkeypatch):
         pick,
         label,
         cancel_event = None,
+        near_path = None,
     ):
         captured["pick"] = pick
         return None
@@ -428,6 +429,32 @@ def test_download_mtp_reuse_follows_snapshot_order_offline(tmp_path, monkeypatch
     assert got is not None and Path(got).parent.parent.name == "newest"
 
 
+def test_download_mtp_prefers_main_snapshot_offline(tmp_path, monkeypatch):
+    import utils.models.model_config as mc
+    from core.inference.llama_cpp import LlamaCppBackend
+
+    monkeypatch.setenv("HF_HUB_OFFLINE", "1")
+    snapshots = tmp_path / "models--unsloth--gemma" / "snapshots"
+    old = snapshots / "old"
+    new = snapshots / "new"
+    old.mkdir(parents = True)
+    new.mkdir(parents = True)
+    main = old / "gemma-UD-Q4_K_XL.gguf"
+    old_drafter = old / "mtp-gemma.gguf"
+    new_drafter = new / "mtp-gemma.gguf"
+    main.write_bytes(b"main")
+    old_drafter.write_bytes(b"old")
+    new_drafter.write_bytes(b"new")
+    monkeypatch.setattr(mc, "_iter_hf_cache_snapshots", lambda _repo: [new, old])
+
+    got = LlamaCppBackend()._download_mtp(
+        hf_repo = "unsloth/gemma-GGUF",
+        near_path = str(main),
+    )
+
+    assert got == str(old_drafter)
+
+
 def test_download_mtp_online_skips_cache_reuse(tmp_path, monkeypatch):
     # Online, do not reuse a cached copy: go to the download path so a changed
     # drafter is refetched (hf_hub_download checks the current revision).
@@ -447,6 +474,7 @@ def test_download_mtp_online_skips_cache_reuse(tmp_path, monkeypatch):
         pick,
         label,
         cancel_event = None,
+        near_path = None,
     ):
         reached["hit"] = True
         return None
diff --git a/studio/backend/tests/test_mtp_vram_budget.py b/studio/backend/tests/test_mtp_vram_budget.py
index 0efbbf596d..694d60cfc6 100644
--- a/studio/backend/tests/test_mtp_vram_budget.py
+++ b/studio/backend/tests/test_mtp_vram_budget.py
@@ -502,7 +502,7 @@ class TestExtraArgsMtpDetection:
         assert _extra_args_mtp_draft_path([], env = dict(os.environ)) == "/large.gguf"
 
     def test_load_model_gates_env_spec_type_on_off_mode(self):
-        # LLAMA_ARG_SPEC_TYPE only reaches the child when Studio emits no spec
+        # LLAMA_ARG_SPEC_TYPE only reaches the child when Unsloth emits no spec
         # flag (UI mode "off", no user --spec-type); otherwise the emitted
         # --spec-type/--spec-default overrides the env, so the reserve must not
         # consult it or a stale MTP env over-reserves (Finding F3). Whitespace-
@@ -530,8 +530,8 @@ class TestExtraArgsMtpDetection:
 
     def test_load_model_drafter_budget_precedence(self):
         # The budget sizes the drafter the launch actually loads: CLI extras win,
-        # then Studio's emitted mtp_draft_path (overrides LLAMA_ARG_SPEC_DRAFT_MODEL),
-        # then the env drafter -- not the env before Studio's (reviewer.py R3).
+        # then Unsloth's emitted mtp_draft_path (overrides LLAMA_ARG_SPEC_DRAFT_MODEL),
+        # then the env drafter -- not the env before Unsloth's (reviewer.py R3).
         compact = "".join(inspect.getsource(LlamaCppBackend.load_model).split())
         assert "_cli_draft_for_budget=_extra_args_mtp_draft_path(extra_args,env={})" in compact
         assert "_env_draft_for_budget=_extra_args_mtp_draft_path([],env=os.environ)" in compact
@@ -732,7 +732,7 @@ class TestExtraArgsMtpDetection:
         assert _extra_args_n_ubatch([], env = {"LLAMA_ARG_UBATCH": "notint"}) is None
 
     def test_env_main_cache_type_for_budget(self):
-        # The child inherits LLAMA_ARG_CACHE_TYPE_K/_V, but Studio emits no
+        # The child inherits LLAMA_ARG_CACHE_TYPE_K/_V, but Unsloth emits no
         # --cache-type when neither param nor extras set it -> a heavier env
         # main KV (f32) must be adopted so the reserve matches the child.
         assert _env_main_cache_type_for_budget(env = {}) is None
@@ -765,7 +765,7 @@ class TestExtraArgsMtpDetection:
         assert "cache_type_kv=_env_main_cache_type_for_budget()" in compact
 
     def test_env_split_mode_is_tensor(self):
-        # The child inherits LLAMA_ARG_SPLIT_MODE, but Studio emits --split-mode
+        # The child inherits LLAMA_ARG_SPLIT_MODE, but Unsloth emits --split-mode
         # only on its tensor branch -> a tensor env must flip the budget so the
         # heavier per-device compute buffer is reserved (not layer overhead).
         assert _env_split_mode_is_tensor(env = {}) is False
@@ -918,7 +918,7 @@ class TestExtraArgsMtpDetection:
         # Cluster A: when the final decision is layer split, an inherited
         # non-layer LLAMA_ARG_SPLIT_MODE (and paired LLAMA_ARG_TENSOR_SPLIT) must
         # be popped from the child env so the child cannot run tensor/row/none
-        # against Studio's layer budget. Whitespace-stripped for formatter.
+        # against Unsloth's layer budget. Whitespace-stripped for formatter.
         compact = "".join(inspect.getsource(LlamaCppBackend.load_model).split())
         assert 'env.get("LLAMA_ARG_SPLIT_MODE")' in compact
         assert '_inherited_sm!="layer"' in compact
@@ -936,10 +936,10 @@ class TestExtraArgsMtpDetection:
         assert "env.pop(_ct_var,None)" in compact
 
     def test_load_model_clears_tensor_split_env_in_tensor_mode(self):
-        # review run3 #2: Studio owns the tensor split. When it emits no
+        # review run3 #2: Unsloth owns the tensor split. When it emits no
         # --tensor-split (even split), a stale inherited LLAMA_ARG_TENSOR_SPLIT must
         # be cleared in the TENSOR branch too (not just the layer downgrade), or the
-        # child runs a split Studio didn't budget. The else (tensor) branch pops it.
+        # child runs a split Unsloth didn't budget. The else (tensor) branch pops it.
         src = inspect.getsource(LlamaCppBackend.load_model)
         compact = "".join(src.split())
         # appears in both the layer branch and the tensor branch.
@@ -1005,14 +1005,14 @@ def test_qwen36_class_regression_picks_lower_ctx_with_mtp():
 
 def test_mtp_draft_budget_prefers_user_extras_drafter():
     # A user --model-draft in extras is appended last and wins at launch, so the
-    # VRAM budget must size it first; then Studio's emitted mtp_draft_path (which
+    # VRAM budget must size it first; then Unsloth's emitted mtp_draft_path (which
     # overrides LLAMA_ARG_SPEC_DRAFT_MODEL), then the env drafter (load_model is too
     # entangled to drive end-to-end; assert the precedence at the source level).
     # Whitespace-stripped so the check survives any formatter line-wrapping.
     compact = "".join(inspect.getsource(LlamaCppBackend.load_model).split())
-    # CLI extras sized first (env={} so the env doesn't pre-empt Studio's drafter).
+    # CLI extras sized first (env={} so the env doesn't pre-empt Unsloth's drafter).
     assert "_cli_draft_for_budget=_extra_args_mtp_draft_path(extra_args,env={})" in compact
-    # Order: CLI extras, then Studio's mtp_draft_path, then the env drafter.
+    # Order: CLI extras, then Unsloth's mtp_draft_path, then the env drafter.
     assert "_cli_draft_for_budgetor_studio_draft_for_budgetor_env_draft_for_budget" in compact
-    # The env must not be consulted before Studio's resolved drafter.
+    # The env must not be consulted before Unsloth's resolved drafter.
     assert "_extra_args_mtp_draft_path(extra_args)ormtp_draft_path" not in compact
diff --git a/studio/backend/tests/test_multimodal_document.py b/studio/backend/tests/test_multimodal_document.py
index 5cd7c876cc..b347c4aef8 100644
--- a/studio/backend/tests/test_multimodal_document.py
+++ b/studio/backend/tests/test_multimodal_document.py
@@ -3,7 +3,7 @@
 
 """Tests for PDF / document attachment translation on external providers.
 
-Studio adds a normalised `input_document` content part on
+Unsloth adds a normalised `input_document` content part on
 ChatCompletionRequest so the frontend needn't know the per-provider
 attachment shape:
 
diff --git a/studio/backend/tests/test_nudge_tool_calls_wiring.py b/studio/backend/tests/test_nudge_tool_calls_wiring.py
index e03fd0c7d7..82a6543aeb 100644
--- a/studio/backend/tests/test_nudge_tool_calls_wiring.py
+++ b/studio/backend/tests/test_nudge_tool_calls_wiring.py
@@ -3,7 +3,7 @@
 
 """Wiring guard for the plan-without-action ``nudge_tool_calls`` policy.
 
-Decided policy: the re-prompt is ALWAYS ON for the Studio inference paths
+Decided policy: the re-prompt is ALWAYS ON for the Unsloth inference paths
 (safetensors, GGUF/llama_cpp, MLX) and OPT-IN for the API (/v1 OpenAI-compat +
 Anthropic-compat, controlled by the request's ``nudge_tool_calls``, default off).
 
@@ -16,7 +16,7 @@ Mechanism (verified here without loading a model):
     opt-in), while the GGUF loop keeps its pre-existing default-on behaviour
     (``None`` keeps nudging) so an omitted flag never disables GGUF;
   * the API request models default the flag to ``None`` (opt-in / off);
-  * the Studio-facing routes forward the request's flag, and the Studio frontend
+  * the Unsloth-facing routes forward the request's flag, and the Unsloth frontend
     sends ``nudge_tool_calls: true`` -- exercised behaviourally in
     ``test_safetensors_tool_loop.py`` and ``test_llama_cpp_tool_loop.py``.
 """
@@ -87,7 +87,7 @@ def test_api_request_models_default_the_flag_off():
 
 
 def test_studio_routes_forward_the_request_flag():
-    # The Studio chat frontend posts to /v1/chat/completions and /v1/messages
+    # The Unsloth chat frontend posts to /v1/chat/completions and /v1/messages
     # with nudge_tool_calls=true; the route handlers forward the request value
     # (external API clients that omit it fall back to the opt-in default).
     from routes import inference as routes_inference
diff --git a/studio/backend/tests/test_offline_embedding_minimal.py b/studio/backend/tests/test_offline_embedding_minimal.py
new file mode 100644
index 0000000000..ccc6b5f76a
--- /dev/null
+++ b/studio/backend/tests/test_offline_embedding_minimal.py
@@ -0,0 +1,942 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Offline RAG embedding-model handling (issue #6817).
+
+Offline the studio must never call the Hub (a DNS-dead session hangs on retries). Using a fake
+HF cache under a temp HF_HUB_CACHE, assert that offline: is_embedding_model classifies from the
+cached modules.json without the Hub; the file-security gate fails CLOSED on an unscanned pickle
+weight with no safetensors alternative and allows an inert cache; the embedder threads
+local_files_only into the load. Online behavior is unchanged (bounded timeout + cache fallback).
+"""
+
+import sys
+import types
+from pathlib import Path
+from types import SimpleNamespace
+from unittest.mock import patch
+
+import pytest
+
+from utils.security import evaluate_file_security
+from utils.utils import (
+    hf_cache_snapshot_dir,
+    hf_cache_snapshot_is_loadable,
+    hf_env_offline,
+    st_repo_id_candidates,
+)
+
+# Minimal sentence-transformers modules.json (the marker the gate keys on).
+MODULES_JSON = (
+    '[{"idx": 0, "name": "0", "path": "", "type": "sentence_transformers.models.Transformer"}]'
+)
+
+
+def _modules_json(*paths):
+    """modules.json listing one Transformer module per path (a load root)."""
+    import json
+    return json.dumps(
+        [
+            {
+                "idx": i,
+                "name": str(i),
+                "path": p,
+                "type": "sentence_transformers.models.Transformer",
+            }
+            for i, p in enumerate(paths)
+        ]
+    )
+
+
+_COMMIT = "0123456789abcdef0123456789abcdef01234567"
+
+
+def _fs_case_sensitive(root):
+    """Whether root's filesystem is case-sensitive (Linux yes; macOS/Windows usually no). The gate
+    mirrors the loader, whose file lookups follow the same rule, so some cases only exist on one."""
+    probe = Path(root) / "_case_probe"
+    probe.write_text("x")
+    try:
+        return not (Path(root) / "_CASE_PROBE").exists()
+    finally:
+        probe.unlink()
+
+
+def _requires_case_sensitive_fs(root):
+    if not _fs_case_sensitive(root):
+        pytest.skip("requires a case-sensitive filesystem")
+
+
+def _requires_case_insensitive_fs(root):
+    if _fs_case_sensitive(root):
+        pytest.skip("requires a case-insensitive filesystem")
+
+
+def _make_cache(
+    root,
+    repo_id,
+    files,
+    commit = _COMMIT,
+):
+    """Build a canonical HF-cache snapshot (refs/main + snapshots/<commit>/) for repo_id under
+    root from {relpath: contents}; returns the snapshot dir."""
+    from huggingface_hub.file_download import repo_folder_name
+
+    repo_dir = Path(root) / repo_folder_name(repo_id = repo_id, repo_type = "model")
+    (repo_dir / "refs").mkdir(parents = True, exist_ok = True)
+    (repo_dir / "refs" / "main").write_text(commit)
+    snapshot = repo_dir / "snapshots" / commit
+    snapshot.mkdir(parents = True, exist_ok = True)
+    for rel, contents in files.items():
+        path = snapshot / rel
+        path.parent.mkdir(parents = True, exist_ok = True)
+        path.write_text(contents)
+    return snapshot
+
+
+def _no_network():
+    """Patch model_info to fail loudly if any offline path reaches the network."""
+    return patch("huggingface_hub.model_info", side_effect = AssertionError("hit the network"))
+
+
+def _is_embedding_model(*args, **kwargs):
+    from utils.models.model_config import is_embedding_model
+    return is_embedding_model(*args, **kwargs)
+
+
+@pytest.fixture
+def hf_cache(tmp_path, monkeypatch):
+    """Point the HF cache at a fresh temp dir.
+
+    get_hf_cache_paths() reads an import-time env snapshot, not live os.environ,
+    so point it (and thus active_hf_hub_cache + the snapshot lookup's selected
+    root) at this temp cache too."""
+    root = tmp_path / "hub"
+    root.mkdir()
+    monkeypatch.setenv("HF_HOME", str(tmp_path))
+    monkeypatch.setenv("HF_HUB_CACHE", str(root))
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = root),
+    )
+    return root
+
+
+@pytest.fixture(autouse = True)
+def _clean_env(monkeypatch):
+    """Start each test online with an empty detection cache; offline tests opt in."""
+    monkeypatch.delenv("HF_HUB_OFFLINE", raising = False)
+    monkeypatch.delenv("TRANSFORMERS_OFFLINE", raising = False)
+    from utils.models import model_config as mc
+
+    mc._embedding_detection_cache.clear()
+    yield
+    mc._embedding_detection_cache.clear()
+
+
+# ── hf_env_offline ───────────────────────────────────────────────
+
+
+@pytest.mark.parametrize("value", ["1", "true", "TRUE", "yes", "on", "  On  "])
+def test_hf_env_offline_true(monkeypatch, value):
+    monkeypatch.setenv("HF_HUB_OFFLINE", value)
+    assert hf_env_offline() is True
+
+
+@pytest.mark.parametrize("value", ["0", "false", "no", "off", ""])
+def test_hf_env_offline_false(monkeypatch, value):
+    monkeypatch.setenv("HF_HUB_OFFLINE", value)
+    assert hf_env_offline() is False
+
+
+def test_hf_env_offline_honors_transformers_flag(monkeypatch):
+    monkeypatch.setenv("TRANSFORMERS_OFFLINE", "1")
+    assert hf_env_offline() is True
+
+
+def test_hf_env_offline_default_false():
+    assert hf_env_offline() is False
+
+
+# ── st_repo_id_candidates ────────────────────────────────────────
+
+
+def test_candidates_slashless_adds_st_alias():
+    assert st_repo_id_candidates("all-MiniLM-L6-v2") == [
+        "all-MiniLM-L6-v2",
+        "sentence-transformers/all-MiniLM-L6-v2",
+    ]
+
+
+def test_candidates_with_org_is_verbatim():
+    assert st_repo_id_candidates("org/model") == ["org/model"]
+
+
+def test_candidates_empty_name():
+    assert st_repo_id_candidates("   ") == []
+
+
+# ── hf_cache_snapshot_dir ────────────────────────────────────────
+
+
+def test_snapshot_dir_resolves_active_commit(hf_cache):
+    snapshot = _make_cache(hf_cache, "org/emb", {"modules.json": MODULES_JSON})
+    assert hf_cache_snapshot_dir("org/emb") == snapshot
+
+
+def test_snapshot_dir_none_when_uncached(hf_cache):
+    assert hf_cache_snapshot_dir("org/missing") is None
+
+
+def test_snapshot_dir_uses_st_alias_for_slashless(hf_cache):
+    snapshot = _make_cache(
+        hf_cache, "sentence-transformers/all-MiniLM-L6-v2", {"modules.json": MODULES_JSON}
+    )
+    assert hf_cache_snapshot_dir("all-MiniLM-L6-v2") == snapshot
+
+
+def test_snapshot_dir_none_when_snapshot_missing(hf_cache):
+    from huggingface_hub.file_download import repo_folder_name
+
+    repo_dir = hf_cache / repo_folder_name(repo_id = "org/broken", repo_type = "model")
+    (repo_dir / "refs").mkdir(parents = True)
+    (repo_dir / "refs" / "main").write_text("deadbeef")  # no snapshots/deadbeef dir
+    assert hf_cache_snapshot_dir("org/broken") is None
+
+
+def test_snapshot_dir_expands_env_vars_in_cache_path(tmp_path, monkeypatch):
+    # An unexpanded $VAR in HF_HUB_CACHE must resolve where the loader looks.
+    real = tmp_path / "hub"
+    real.mkdir()
+    monkeypatch.setenv("MY_HF_CACHE", str(real))
+    monkeypatch.setenv("HF_HUB_CACHE", "$MY_HF_CACHE")
+    monkeypatch.delenv("HF_HOME", raising = False)
+    monkeypatch.delenv("SENTENCE_TRANSFORMERS_HOME", raising = False)
+    snapshot = _make_cache(real, "org/emb", {"modules.json": MODULES_JSON})
+    assert hf_cache_snapshot_dir("org/emb") == snapshot
+
+
+def test_snapshot_dir_uses_sentence_transformers_home(tmp_path, monkeypatch):
+    # ST uses SENTENCE_TRANSFORMERS_HOME as its cache_folder, so the gate must inspect it too.
+    st_home = tmp_path / "st_home"
+    st_home.mkdir()
+    monkeypatch.setenv("SENTENCE_TRANSFORMERS_HOME", str(st_home))
+    monkeypatch.delenv("HF_HUB_CACHE", raising = False)
+    monkeypatch.delenv("HF_HOME", raising = False)
+    snapshot = _make_cache(st_home, "org/emb", {"modules.json": MODULES_JSON})
+    assert hf_cache_snapshot_dir("org/emb") == snapshot
+
+
+def test_snapshot_dir_prefers_selected_cache_over_st_home(tmp_path, monkeypatch):
+    # The RAG loader passes cache_folder=active_hf_hub_cache(), which overrides
+    # SENTENCE_TRANSFORMERS_HOME, so the snapshot + offline security lookup must
+    # search the selected cache even when ST_HOME points elsewhere. Otherwise the
+    # gate scans a cache the model never loads from and a pickle weight in the
+    # selected cache slips through.
+    st_home = tmp_path / "st_home"
+    st_home.mkdir()
+    selected = tmp_path / "hub"
+    selected.mkdir()
+    monkeypatch.setenv("SENTENCE_TRANSFORMERS_HOME", str(st_home))
+    monkeypatch.delenv("HF_HUB_CACHE", raising = False)
+    monkeypatch.delenv("HF_HOME", raising = False)
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = selected),
+    )
+    snapshot = _make_cache(selected, "org/emb", {"modules.json": MODULES_JSON})  # only in selected
+    assert hf_cache_snapshot_dir("org/emb") == snapshot
+
+
+def test_snapshot_is_loadable_with_config_and_weights(hf_cache):
+    _make_cache(hf_cache, "org/emb", {"config.json": "{}", "model.safetensors": "x"})
+    assert hf_cache_snapshot_is_loadable("org/emb") is True
+
+
+def test_snapshot_is_not_loadable_when_metadata_only(hf_cache):
+    # A partial cache (refs/main resolves but no weights) is not loadable.
+    _make_cache(hf_cache, "org/partial", {"config.json": "{}", "modules.json": MODULES_JSON})
+    assert hf_cache_snapshot_is_loadable("org/partial") is False
+
+
+def test_snapshot_is_not_loadable_when_uncached(hf_cache):
+    assert hf_cache_snapshot_is_loadable("org/missing") is False
+
+
+def test_gate_blocks_pickle_in_sentence_transformers_home(tmp_path, monkeypatch):
+    # A pickle under SENTENCE_TRANSFORMERS_HOME must still fail closed offline.
+    st_home = tmp_path / "st_home"
+    st_home.mkdir()
+    monkeypatch.setenv("SENTENCE_TRANSFORMERS_HOME", str(st_home))
+    monkeypatch.delenv("HF_HUB_CACHE", raising = False)
+    monkeypatch.delenv("HF_HOME", raising = False)
+    _make_cache(st_home, "org/pk", {"config.json": "{}", "pytorch_model.bin": "x"})
+    with _no_network():
+        assert evaluate_file_security("org/pk", local_only_load = True).blocked is True
+
+
+# ── is_embedding_model: offline (no network) ─────────────────────
+
+
+def test_offline_true_for_cached_st_model(hf_cache, monkeypatch):
+    monkeypatch.setenv("HF_HUB_OFFLINE", "1")
+    _make_cache(hf_cache, "org/emb", {"modules.json": MODULES_JSON, "config.json": "{}"})
+    with _no_network():
+        assert _is_embedding_model("org/emb") is True
+
+
+def test_offline_false_for_cached_non_st_model(hf_cache, monkeypatch):
+    monkeypatch.setenv("HF_HUB_OFFLINE", "1")
+    _make_cache(hf_cache, "org/plain", {"config.json": "{}", "model.safetensors": "x"})
+    with _no_network():
+        assert _is_embedding_model("org/plain") is False
+
+
+def test_offline_false_when_uncached(hf_cache, monkeypatch):
+    monkeypatch.setenv("TRANSFORMERS_OFFLINE", "1")
+    with _no_network():
+        assert _is_embedding_model("org/missing") is False
+
+
+def test_offline_slashless_resolves_via_alias(hf_cache, monkeypatch):
+    monkeypatch.setenv("HF_HUB_OFFLINE", "1")
+    _make_cache(hf_cache, "sentence-transformers/all-MiniLM-L6-v2", {"modules.json": MODULES_JSON})
+    with _no_network():
+        assert _is_embedding_model("all-MiniLM-L6-v2") is True
+
+
+def test_offline_ignores_stale_online_memo(hf_cache, monkeypatch):
+    # An online lookup memoizes True for an UNCACHED repo (tags say embedding, no weights). Once
+    # offline, is_embedding_model must reclassify from the empty cache and return False, not the
+    # stale online True that would make settings accept a repo _get() cannot load.
+    with patch(
+        "huggingface_hub.model_info",
+        side_effect = lambda *a, **k: SimpleNamespace(
+            tags = ["sentence-transformers"], pipeline_tag = None
+        ),
+    ):
+        assert _is_embedding_model("org/uncached-emb") is True  # memoized True online
+
+    monkeypatch.setenv("HF_HUB_OFFLINE", "1")
+    with _no_network():
+        assert _is_embedding_model("org/uncached-emb") is False  # recomputed from empty cache
+
+
+def test_offline_recomputes_after_cache_materializes(hf_cache, monkeypatch):
+    # Because the offline branch never records a memo, once an uncached repo's snapshot
+    # materializes (another process populates the cache) the next call re-reports True.
+    monkeypatch.setenv("HF_HUB_OFFLINE", "1")
+    with _no_network():
+        assert _is_embedding_model("org/later") is False  # uncached
+        _make_cache(hf_cache, "org/later", {"modules.json": MODULES_JSON})
+        assert _is_embedding_model("org/later") is True  # cache now present, no stale negative
+
+
+# ── is_embedding_model: online (bounded + fallback) ──────────────
+
+
+def test_online_passes_bounded_timeout(hf_cache):
+    seen = {}
+
+    def _mi(
+        name,
+        token = None,
+        timeout = None,
+        **kw,
+    ):
+        seen["timeout"] = timeout
+        return SimpleNamespace(tags = ["sentence-transformers"], pipeline_tag = None)
+
+    with patch("huggingface_hub.model_info", side_effect = _mi):
+        assert _is_embedding_model("org/emb") is True
+    assert seen["timeout"] == 15.0
+
+
+def test_online_error_falls_back_to_cache_marker(hf_cache):
+    _make_cache(hf_cache, "org/emb", {"modules.json": MODULES_JSON})
+    with patch("huggingface_hub.model_info", side_effect = RuntimeError("dns dead")):
+        assert _is_embedding_model("org/emb") is True
+
+
+def test_online_error_without_cache_returns_false(hf_cache):
+    with patch("huggingface_hub.model_info", side_effect = RuntimeError("dns dead")):
+        assert _is_embedding_model("org/missing") is False
+
+
+# ── evaluate_file_security: offline fail-closed gate ─────────────
+
+
+def _offline_decision(name):
+    return evaluate_file_security(name, local_only_load = True)
+
+
+def test_gate_allows_safetensors_only(hf_cache):
+    _make_cache(hf_cache, "org/st", {"modules.json": MODULES_JSON, "model.safetensors": "x"})
+    with _no_network():
+        assert _offline_decision("org/st").blocked is False
+
+
+def test_gate_blocks_pickle_without_safetensors(hf_cache):
+    _make_cache(hf_cache, "org/pk", {"config.json": "{}", "pytorch_model.bin": "x"})
+    with _no_network():
+        decision = _offline_decision("org/pk")
+    assert decision.blocked is True
+    assert any(u["path"] == "pytorch_model.bin" for u in decision.unsafe_files)
+
+
+def test_gate_allows_pickle_with_safetensors_sibling(hf_cache):
+    _make_cache(hf_cache, "org/both", {"pytorch_model.bin": "x", "model.safetensors": "y"})
+    with _no_network():
+        assert _offline_decision("org/both").blocked is False
+
+
+def test_gate_blocks_sharded_pickle(hf_cache):
+    _make_cache(
+        hf_cache,
+        "org/shard",
+        {
+            "pytorch_model-00001-of-00002.bin": "a",
+            "pytorch_model-00002-of-00002.bin": "b",
+        },
+    )
+    with _no_network():
+        assert _offline_decision("org/shard").blocked is True
+
+
+def test_gate_blocks_indexed_pickle_shard_in_subdirectory(hf_cache):
+    # from_pretrained follows weight_map paths relative to the root index, so these nested shards
+    # are deserialized even though they are not direct children of the load root (iterdir misses
+    # them). The online gate blocks index-referenced subdir pickles; the offline gate must too.
+    _make_cache(
+        hf_cache,
+        "org/indexed-shard",
+        {
+            "pytorch_model.bin.index.json": (
+                '{"weight_map": {"layer.weight": "shards/pytorch_model-00001-of-00001.bin"}}'
+            ),
+            "shards/pytorch_model-00001-of-00001.bin": "pickle",
+        },
+    )
+    with _no_network():
+        decision = _offline_decision("org/indexed-shard")
+    assert decision.blocked is True
+    assert any(
+        u["path"] == "shards/pytorch_model-00001-of-00001.bin" for u in decision.unsafe_files
+    )
+
+
+def test_gate_blocks_indexed_pickle_shard_with_nonstandard_stem(hf_cache):
+    # The index tells the loader to deserialize this file, so a pickle EXTENSION is enough -- the
+    # shard's stem need not match the on-disk weight-name heuristic (which only guesses bare files).
+    _make_cache(
+        hf_cache,
+        "org/indexed-odd",
+        {
+            "pytorch_model.bin.index.json": '{"weight_map": {"w": "shards/evil-00001-of-00001.bin"}}',
+            "shards/evil-00001-of-00001.bin": "pickle",
+        },
+    )
+    with _no_network():
+        decision = _offline_decision("org/indexed-odd")
+    assert decision.blocked is True
+    assert any(u["path"] == "shards/evil-00001-of-00001.bin" for u in decision.unsafe_files)
+
+
+def test_gate_blocks_safetensors_index_pointing_to_pickle_shard(hf_cache):
+    # load_state_dict picks safetensors vs torch.load by each shard's own suffix, so a
+    # model.safetensors.index.json that maps a weight to a .bin shard still deserializes it. The
+    # index's own existence must not suppress the shard it names.
+    _make_cache(
+        hf_cache,
+        "org/st-index-pickle",
+        {
+            "model.safetensors.index.json": (
+                '{"weight_map": {"w": "shards/pytorch_model-00001-of-00001.bin"}}'
+            ),
+            "shards/pytorch_model-00001-of-00001.bin": "pickle",
+        },
+    )
+    with _no_network():
+        decision = _offline_decision("org/st-index-pickle")
+    assert decision.blocked is True
+    assert any(
+        u["path"] == "shards/pytorch_model-00001-of-00001.bin" for u in decision.unsafe_files
+    )
+
+
+def test_gate_blocks_indexed_shard_with_no_pickle_extension(hf_cache):
+    # Transformers torch.loads any indexed shard not ending in .safetensors, so an unconventional
+    # extensionless name is still a deserialization target.
+    _make_cache(
+        hf_cache,
+        "org/indexed-noext",
+        {
+            "pytorch_model.bin.index.json": '{"weight_map": {"w": "shards/payload"}}',
+            "shards/payload": "pickle",
+        },
+    )
+    with _no_network():
+        decision = _offline_decision("org/indexed-noext")
+    assert decision.blocked is True
+    assert any(u["path"] == "shards/payload" for u in decision.unsafe_files)
+
+
+_UPPER_INDEX_FILES = {
+    "PYTORCH_MODEL.BIN.INDEX.JSON": (
+        '{"weight_map": {"w": "shards/pytorch_model-00001-of-00001.bin"}}'
+    ),
+    "shards/pytorch_model-00001-of-00001.bin": "pickle",
+}
+
+
+def test_gate_blocks_uppercase_index_on_case_insensitive_fs(hf_cache):
+    # On a case-insensitive volume (Windows/macOS) from_pretrained opens an oddly-cased index when it
+    # requests the canonical lowercase name, so the loader-mirror lookup resolves it and blocks.
+    _requires_case_insensitive_fs(hf_cache)
+    _make_cache(hf_cache, "org/upper-index", _UPPER_INDEX_FILES)
+    with _no_network():
+        decision = _offline_decision("org/upper-index")
+    assert decision.blocked is True
+    assert any(
+        u["path"] == "shards/pytorch_model-00001-of-00001.bin" for u in decision.unsafe_files
+    )
+
+
+def test_gate_allows_uppercase_index_on_case_sensitive_fs(hf_cache):
+    # On a case-sensitive FS from_pretrained's os.path.isfile of the canonical lowercase name misses
+    # the uppercase artifact and never loads its shard, so the gate must not over-block it.
+    _requires_case_sensitive_fs(hf_cache)
+    _make_cache(hf_cache, "org/upper-index", _UPPER_INDEX_FILES)
+    with _no_network():
+        assert _offline_decision("org/upper-index").blocked is False
+
+
+def test_gate_blocks_indexed_shard_named_with_backslash(hf_cache):
+    # On POSIX a backslash is a literal filename char, so from_pretrained joins the raw weight_map
+    # value and deserializes a file actually named "dir\payload.bin"; the gate must probe it verbatim.
+    import os
+
+    if os.sep != "/":
+        pytest.skip("backslash is a path separator off POSIX")
+    _make_cache(
+        hf_cache,
+        "org/backslash",
+        {
+            "pytorch_model.bin.index.json": '{"weight_map": {"w": "dir\\\\payload.bin"}}',
+            "dir\\payload.bin": "pickle",
+        },
+    )
+    with _no_network():
+        decision = _offline_decision("org/backslash")
+    assert decision.blocked is True
+    assert any(u["path"] == "dir\\payload.bin" for u in decision.unsafe_files)
+
+
+def test_gate_blocks_indexed_shard_with_uppercase_safetensors_suffix(hf_cache):
+    # load_state_dict's endswith(".safetensors") is case-sensitive, so a shard named payload.SAFETENSORS
+    # falls to torch.load. The gate must classify shard suffixes case-sensitively to match it.
+    _make_cache(
+        hf_cache,
+        "org/upper-suffix",
+        {
+            "pytorch_model.bin.index.json": '{"weight_map": {"w": "shards/payload.SAFETENSORS"}}',
+            "shards/payload.SAFETENSORS": "pickle",
+        },
+    )
+    with _no_network():
+        decision = _offline_decision("org/upper-suffix")
+    assert decision.blocked is True
+    assert any(u["path"] == "shards/payload.SAFETENSORS" for u in decision.unsafe_files)
+
+
+def test_gate_allows_stale_safetensors_index_beside_direct_safetensors(hf_cache):
+    # A complete direct model.safetensors is selected before either index, so a stale
+    # model.safetensors.index.json referencing a .bin shard never deserializes -> must not block.
+    _make_cache(
+        hf_cache,
+        "org/direct-plus-stale-index",
+        {
+            "model.safetensors": "tensors",
+            "model.safetensors.index.json": (
+                '{"weight_map": {"w": "shards/pytorch_model-00001-of-00001.bin"}}'
+            ),
+            "shards/pytorch_model-00001-of-00001.bin": "pickle",
+        },
+    )
+    with _no_network():
+        assert _offline_decision("org/direct-plus-stale-index").blocked is False
+
+
+def test_gate_blocks_pytorch_index_with_uppercase_safetensors_decoy(hf_cache):
+    # On a case-sensitive FS, from_pretrained asks for the canonical lowercase model.safetensors, does
+    # not find an uppercase decoy, and selects the pytorch index instead. The decoy must not suppress.
+    _requires_case_sensitive_fs(hf_cache)
+    _make_cache(
+        hf_cache,
+        "org/upper-decoy",
+        {
+            "MODEL.SAFETENSORS": "decoy",
+            "pytorch_model.bin.index.json": (
+                '{"weight_map": {"w": "shards/pytorch_model-00001-of-00001.bin"}}'
+            ),
+            "shards/pytorch_model-00001-of-00001.bin": "pickle",
+        },
+    )
+    with _no_network():
+        decision = _offline_decision("org/upper-decoy")
+    assert decision.blocked is True
+    assert any(
+        u["path"] == "shards/pytorch_model-00001-of-00001.bin" for u in decision.unsafe_files
+    )
+
+
+def test_gate_blocks_direct_pickle_with_uppercase_safetensors_decoy(hf_cache):
+    # Same decoy against a direct pytorch_model.bin: the loader selects the pickle, so the uppercase
+    # safetensors must not suppress it on a case-sensitive FS.
+    _requires_case_sensitive_fs(hf_cache)
+    _make_cache(
+        hf_cache,
+        "org/upper-decoy-direct",
+        {"MODEL.SAFETENSORS": "decoy", "pytorch_model.bin": "pickle"},
+    )
+    with _no_network():
+        decision = _offline_decision("org/upper-decoy-direct")
+    assert decision.blocked is True
+    assert any(u["path"] == "pytorch_model.bin" for u in decision.unsafe_files)
+
+
+def test_gate_blocks_indexed_pickle_shard_in_module_subdir(hf_cache):
+    # A weight index inside a sentence-transformers module load root points at a nested pickle shard.
+    _make_cache(
+        hf_cache,
+        "org/mod-indexed",
+        {
+            "modules.json": _modules_json("0_Transformer"),
+            "0_Transformer/pytorch_model.bin.index.json": (
+                '{"weight_map": {"w": "shards/pytorch_model-00001-of-00001.bin"}}'
+            ),
+            "0_Transformer/shards/pytorch_model-00001-of-00001.bin": "pickle",
+        },
+    )
+    with _no_network():
+        decision = _offline_decision("org/mod-indexed")
+    assert decision.blocked is True
+    assert any(
+        u["path"] == "0_Transformer/shards/pytorch_model-00001-of-00001.bin"
+        for u in decision.unsafe_files
+    )
+
+
+def test_gate_allows_indexed_pickle_shard_with_safetensors_sibling(hf_cache):
+    # A base model.safetensors makes the loader ignore the pickle index entirely, so it must not
+    # block (mirrors the direct-file safetensors-sibling suppression).
+    _make_cache(
+        hf_cache,
+        "org/indexed-both",
+        {
+            "pytorch_model.bin.index.json": (
+                '{"weight_map": {"w": "shards/pytorch_model-00001-of-00001.bin"}}'
+            ),
+            "shards/pytorch_model-00001-of-00001.bin": "pickle",
+            "model.safetensors": "y",
+        },
+    )
+    with _no_network():
+        assert _offline_decision("org/indexed-both").blocked is False
+
+
+def test_gate_allows_indexed_safetensors_shard_in_subdirectory(hf_cache):
+    # A safetensors index lists inert shards -- following it must never block (guards against a
+    # scanner that flags every indexed shard regardless of format).
+    _make_cache(
+        hf_cache,
+        "org/st-indexed",
+        {
+            "model.safetensors.index.json": (
+                '{"weight_map": {"w": "shards/model-00001-of-00001.safetensors"}}'
+            ),
+            "shards/model-00001-of-00001.safetensors": "tensors",
+        },
+    )
+    with _no_network():
+        assert _offline_decision("org/st-indexed").blocked is False
+
+
+def test_gate_blocks_on_index_path_traversal(hf_cache):
+    # A weight_map entry escaping the snapshot via ".." is abnormal/hostile -> fail closed.
+    _make_cache(
+        hf_cache,
+        "org/escape",
+        {"pytorch_model.bin.index.json": '{"weight_map": {"w": "../../../../etc/evil.bin"}}'},
+    )
+    with _no_network():
+        assert _offline_decision("org/escape").blocked is True
+
+
+def test_gate_allows_symlinked_sharded_safetensors(tmp_path, monkeypatch):
+    # Real HF caches store snapshot files as symlinks into blobs/. A resolve()-based containment
+    # check would escape the snapshot and false-block every sharded model; the lexical gate must not.
+    import hashlib
+    import os
+
+    from huggingface_hub.file_download import repo_folder_name
+
+    root = tmp_path / "hub"
+    root.mkdir()
+    monkeypatch.setenv("HF_HOME", str(tmp_path))
+    monkeypatch.setenv("HF_HUB_CACHE", str(root))
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: SimpleNamespace(hub_cache = root),
+    )
+    repo_dir = root / repo_folder_name(repo_id = "org/sym", repo_type = "model")
+    (repo_dir / "refs").mkdir(parents = True)
+    (repo_dir / "refs" / "main").write_text(_COMMIT)
+    blobs = repo_dir / "blobs"
+    blobs.mkdir()
+    snapshot = repo_dir / "snapshots" / _COMMIT
+    (snapshot / "shards").mkdir(parents = True)
+
+    def _blobbed(rel, content):
+        digest = hashlib.sha256(content.encode()).hexdigest()
+        (blobs / digest).write_text(content)
+        target = snapshot / rel
+        target.parent.mkdir(parents = True, exist_ok = True)
+        target.symlink_to(os.path.relpath(blobs / digest, target.parent))
+
+    _blobbed("config.json", "{}")
+    _blobbed(
+        "model.safetensors.index.json",
+        '{"weight_map": {"w": "shards/model-00001-of-00001.safetensors"}}',
+    )
+    _blobbed("shards/model-00001-of-00001.safetensors", "tensors")
+    with _no_network():
+        assert _offline_decision("org/sym").blocked is False
+
+
+def test_gate_allows_index_without_weight_map(hf_cache):
+    # An index whose top-level JSON has no dict weight_map lets the loader resolve no shards, so it
+    # must not crash or block on its own (only inert safetensors are cached here).
+    _make_cache(
+        hf_cache,
+        "org/no-wm",
+        {"model.safetensors.index.json": "[]", "model.safetensors": "x"},
+    )
+    with _no_network():
+        assert _offline_decision("org/no-wm").blocked is False
+
+
+def test_gate_allows_nothing_cached(hf_cache):
+    with _no_network():
+        assert _offline_decision("org/missing").blocked is False
+
+
+def test_gate_allows_gguf_only(hf_cache):
+    _make_cache(hf_cache, "org/gg", {"model.gguf": "x"})
+    with _no_network():
+        assert _offline_decision("org/gg").blocked is False
+
+
+def test_gate_blocks_pickle_in_module_subdir(hf_cache):
+    # 0_Transformer is a module load root (listed in modules.json), so its pickle blocks.
+    _make_cache(
+        hf_cache,
+        "org/mod",
+        {"modules.json": _modules_json("0_Transformer"), "0_Transformer/pytorch_model.bin": "x"},
+    )
+    with _no_network():
+        assert _offline_decision("org/mod").blocked is True
+
+
+def test_gate_allows_pickle_in_subdir_with_safetensors(hf_cache):
+    _make_cache(
+        hf_cache,
+        "org/mod2",
+        {
+            "modules.json": _modules_json("0_Transformer"),
+            "0_Transformer/pytorch_model.bin": "x",
+            "0_Transformer/model.safetensors": "y",
+        },
+    )
+    with _no_network():
+        assert _offline_decision("org/mod2").blocked is False
+
+
+def test_gate_allows_unreferenced_nested_pickle(hf_cache):
+    # A pickle in a dir NOT referenced by modules.json (e.g. nemo/) is never deserialized, so it
+    # must not block the offline load (matches the online gate).
+    _make_cache(
+        hf_cache,
+        "org/aux",
+        {
+            "modules.json": MODULES_JSON,  # Transformer at the root only
+            "model.safetensors": "w",
+            "nemo/pytorch_model.bin": "x",
+        },
+    )
+    with _no_network():
+        assert _offline_decision("org/aux").blocked is False
+
+
+def test_gate_blocks_adapter_pickle_without_safetensors(hf_cache):
+    _make_cache(hf_cache, "org/ad", {"config.json": "{}", "adapter_model.bin": "x"})
+    with _no_network():
+        decision = _offline_decision("org/ad")
+    assert decision.blocked is True
+    assert any(u["path"] == "adapter_model.bin" for u in decision.unsafe_files)
+
+
+def test_gate_allows_adapter_pickle_with_adapter_safetensors(hf_cache):
+    _make_cache(hf_cache, "org/ad2", {"adapter_model.bin": "x", "adapter_model.safetensors": "y"})
+    with _no_network():
+        assert _offline_decision("org/ad2").blocked is False
+
+
+def test_gate_blocks_base_pickle_with_only_adapter_safetensors_decoy(hf_cache):
+    # A decoy adapter_model.safetensors must NOT suppress a base pytorch_model.bin (the base
+    # loader would still deserialize the unscanned pickle).
+    _make_cache(hf_cache, "org/decoy", {"pytorch_model.bin": "x", "adapter_model.safetensors": "y"})
+    with _no_network():
+        assert _offline_decision("org/decoy").blocked is True
+
+
+def test_gate_blocks_adapter_pickle_with_only_base_safetensors_decoy(hf_cache):
+    # Symmetric: a base model.safetensors must NOT suppress an adapter_model.bin.
+    _make_cache(hf_cache, "org/decoy2", {"adapter_model.bin": "x", "model.safetensors": "y"})
+    with _no_network():
+        assert _offline_decision("org/decoy2").blocked is True
+
+
+def test_gate_reports_snapshot_relative_path(hf_cache):
+    _make_cache(
+        hf_cache,
+        "org/mod3",
+        {"modules.json": _modules_json("0_Transformer"), "0_Transformer/pytorch_model.bin": "x"},
+    )
+    with _no_network():
+        decision = _offline_decision("org/mod3")
+    assert decision.blocked is True
+    assert any(u["path"] == "0_Transformer/pytorch_model.bin" for u in decision.unsafe_files)
+
+
+# ── evaluate_file_security: online path unchanged ────────────────
+
+
+def test_online_default_blocks_unsafe():
+    status = {
+        "scansDone": True,
+        "filesWithIssues": [{"path": "pytorch_model.bin", "level": "unsafe"}],
+    }
+    with patch(
+        "huggingface_hub.model_info",
+        side_effect = lambda *a, **k: SimpleNamespace(security_repo_status = status),
+    ):
+        assert evaluate_file_security("org/x").blocked is True
+
+
+def test_online_default_allows_clean():
+    status = {"scansDone": True, "filesWithIssues": []}
+    with patch(
+        "huggingface_hub.model_info",
+        side_effect = lambda *a, **k: SimpleNamespace(security_repo_status = status),
+    ):
+        assert evaluate_file_security("org/x").blocked is False
+
+
+# ── embeddings guard + loader ────────────────────────────────────
+
+
+def test_guard_offline_blocks_pickle_only(hf_cache):
+    from core.rag.embeddings import UnsafeEmbeddingModelError, _guard_model_security
+    _make_cache(hf_cache, "org/pk", {"config.json": "{}", "pytorch_model.bin": "x"})
+    with _no_network():
+        with pytest.raises(UnsafeEmbeddingModelError):
+            _guard_model_security("org/pk", local_only = True)
+
+
+def test_guard_offline_allows_safetensors(hf_cache):
+    from core.rag.embeddings import _guard_model_security
+    _make_cache(hf_cache, "org/st", {"modules.json": MODULES_JSON, "model.safetensors": "x"})
+    with _no_network():
+        _guard_model_security("org/st", local_only = True)  # must not raise
+
+
+def _install_fake_sentence_transformers(monkeypatch, captured):
+    class FakeSentenceTransformer:
+        def __init__(
+            self,
+            name,
+            *,
+            device = None,
+            model_kwargs = None,
+            local_files_only = False,
+            **kw,
+        ):
+            captured["name"] = name
+            captured["device"] = device
+            captured["local_files_only"] = local_files_only
+
+    module = types.ModuleType("sentence_transformers")
+    module.SentenceTransformer = FakeSentenceTransformer
+    monkeypatch.setitem(sys.modules, "sentence_transformers", module)
+
+
+def test_get_offline_loads_from_local_snapshot(hf_cache, monkeypatch):
+    from core.rag import embeddings
+
+    snapshot = _make_cache(
+        hf_cache, "org/st", {"modules.json": MODULES_JSON, "model.safetensors": "x"}
+    )
+    # TRANSFORMERS_OFFLINE only: a cached model loads from its local snapshot dir (a local path,
+    # never the Hub), offline-safe on ANY sentence-transformers version.
+    monkeypatch.setenv("TRANSFORMERS_OFFLINE", "1")
+    monkeypatch.delenv("HF_HUB_OFFLINE", raising = False)
+    monkeypatch.setattr(embeddings, "_model", None, raising = False)
+    monkeypatch.setattr(embeddings, "_name", None, raising = False)
+    monkeypatch.setattr(embeddings, "_install_torchao_stub_once", lambda: None)
+    monkeypatch.setattr(embeddings, "_device", lambda: "cpu")
+    captured = {}
+    _install_fake_sentence_transformers(monkeypatch, captured)
+    with _no_network():
+        embeddings._get("org/st")
+    assert captured["name"] == str(snapshot)
+
+
+def test_get_offline_uncached_uses_local_files_only(tmp_path, monkeypatch):
+    from core.rag import embeddings
+
+    empty = tmp_path / "hub"
+    empty.mkdir()
+    monkeypatch.setenv("HF_HUB_CACHE", str(empty))
+    monkeypatch.delenv("HF_HOME", raising = False)
+    monkeypatch.delenv("SENTENCE_TRANSFORMERS_HOME", raising = False)
+    monkeypatch.setenv("TRANSFORMERS_OFFLINE", "1")
+    monkeypatch.delenv("HF_HUB_OFFLINE", raising = False)
+    monkeypatch.setattr(embeddings, "_model", None, raising = False)
+    monkeypatch.setattr(embeddings, "_name", None, raising = False)
+    monkeypatch.setattr(embeddings, "_install_torchao_stub_once", lambda: None)
+    monkeypatch.setattr(embeddings, "_device", lambda: "cpu")
+    # No cache -> repo-id load forced cache-only (fails fast offline, not a hang).
+    monkeypatch.setattr(embeddings, "_guard_model_security", lambda name, local_only = False: None)
+    captured = {}
+    _install_fake_sentence_transformers(monkeypatch, captured)
+    embeddings._get("org/uncached-xyz")
+    assert captured["name"] == "org/uncached-xyz"
+    assert captured["local_files_only"] is True
+
+
+def test_get_online_omits_local_files_only(monkeypatch):
+    from core.rag import embeddings
+
+    monkeypatch.delenv("HF_HUB_OFFLINE", raising = False)
+    monkeypatch.delenv("TRANSFORMERS_OFFLINE", raising = False)
+    monkeypatch.setattr(embeddings, "_model", None, raising = False)
+    monkeypatch.setattr(embeddings, "_name", None, raising = False)
+    monkeypatch.setattr(embeddings, "_install_torchao_stub_once", lambda: None)
+    monkeypatch.setattr(embeddings, "_device", lambda: "cpu")
+    # Isolate the loader wiring from the online guard's network calls.
+    monkeypatch.setattr(embeddings, "_guard_model_security", lambda name, local_only = False: None)
+    captured = {}
+    _install_fake_sentence_transformers(monkeypatch, captured)
+    embeddings._get("org/online")
+    assert captured["local_files_only"] is False
diff --git a/studio/backend/tests/test_offline_gguf_cache_fallback.py b/studio/backend/tests/test_offline_gguf_cache_fallback.py
index e24e2ca451..d1e61d0546 100644
--- a/studio/backend/tests/test_offline_gguf_cache_fallback.py
+++ b/studio/backend/tests/test_offline_gguf_cache_fallback.py
@@ -119,10 +119,21 @@ def _build_cache(
     return snap
 
 
+def _symlink_or_skip(link: Path, target: Path) -> None:
+    try:
+        link.symlink_to(target)
+    except OSError as exc:
+        pytest.skip(f"symlinks unavailable: {exc}")
+
+
 @pytest.fixture
 def hf_cache(tmp_path, monkeypatch):
     """Point ``huggingface_hub.constants.HF_HUB_CACHE`` at a temp dir."""
     monkeypatch.setattr(hf_constants, "HF_HUB_CACHE", str(tmp_path))
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.get_hf_cache_paths",
+        lambda: _types.SimpleNamespace(hub_cache = tmp_path),
+    )
     return tmp_path
 
 
@@ -220,6 +231,10 @@ class TestGgufVariantFileResolution:
             return f"/fake/{repo_id}/{filename}"
 
         monkeypatch.setattr(hf_constants, "HF_HUB_CACHE", str(tmp_path))
+        monkeypatch.setattr(
+            "utils.hf_cache_settings.get_hf_cache_paths",
+            lambda: _types.SimpleNamespace(hub_cache = tmp_path),
+        )
         with (
             patch(
                 "huggingface_hub.list_repo_files",
@@ -244,9 +259,7 @@ class TestGgufVariantFileResolution:
     def test_download_reuses_older_snapshot_when_current_ref_snapshot_is_partial(
         self, monkeypatch, hf_cache
     ):
-        # Cross-snapshot reuse is an offline-resilience path: online, hf_hub_download
-        # resumes the partial current-ref download and revalidates the revision instead
-        # of serving an older snapshot's same-name blob.
+        # Keep coverage for offline reuse; online reuse is tested separately.
         monkeypatch.setenv("HF_HUB_OFFLINE", "1")
         backend = LlamaCppBackend()
         repo = "unsloth/vision-GGUF"
@@ -292,8 +305,7 @@ class TestGgufVariantFileResolution:
     def test_download_reuses_cached_gguf_when_lowercase_partial_cache_shadows_it(
         self, monkeypatch, hf_cache
     ):
-        # Case-variant cross-dir reuse is offline-only; online the canonical repo id
-        # resolves up front and hf_hub_download fetches the current revision.
+        # Keep coverage for case-insensitive offline cache lookup.
         monkeypatch.setenv("HF_HUB_OFFLINE", "1")
         backend = LlamaCppBackend()
         canonical_repo = "unsloth/gemma-4-E2B-it-GGUF"
@@ -348,45 +360,26 @@ class TestGgufVariantFileResolution:
         assert out == str(snap / gguf_file)
         assert seen_repos
 
-    def test_download_online_does_not_reuse_old_snapshot(self, monkeypatch, hf_cache):
-        # Online, an older same-name snapshot must not be served (it may be a stale
-        # revision); hf_hub_download is called so the current revision is fetched and
-        # its etag revalidated.
+    def test_download_online_reuses_complete_cached_snapshot(self, monkeypatch, hf_cache):
+        # Loads reuse complete cached models across repo revisions.
         monkeypatch.delenv("HF_HUB_OFFLINE", raising = False)
         backend = LlamaCppBackend()
         repo = "unsloth/vision-GGUF"
-        _build_cache(hf_cache, repo, {"model-UD-Q4_K_XL.gguf": 4}, snapshot_sha = "a" * 40)
-        downloaded: list[str] = []
+        snap = _build_cache(hf_cache, repo, {"model-UD-Q4_K_XL.gguf": 4}, snapshot_sha = "a" * 40)
 
-        def fake_get_paths_info(
-            _repo_id,
-            paths,
-            token = None,
-        ):
-            return [_types.SimpleNamespace(path = p, size = 4) for p in paths if p]
-
-        def fake_download(
-            repo_id,
-            filename,
-            token = None,
-            **kwargs,
-        ):
-            downloaded.append(filename)
-            return f"/fresh/{filename}"
+        def fail_download(*_args, **_kwargs):
+            raise AssertionError("must reuse the cached GGUF instead of downloading")
 
         with (
             patch(
                 "huggingface_hub.list_repo_files",
                 lambda *_a, **_k: ["model-UD-Q4_K_XL.gguf"],
             ),
-            patch("huggingface_hub.get_paths_info", fake_get_paths_info),
-            patch("huggingface_hub.try_to_load_from_cache", lambda *_a, **_k: None),
-            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", fake_download),
+            patch("core.inference.llama_cpp.hf_hub_download_with_xet_fallback", fail_download),
         ):
             out = backend._download_gguf(hf_repo = repo, hf_variant = "UD-Q4_K_XL")
 
-        assert downloaded == ["model-UD-Q4_K_XL.gguf"]
-        assert out == "/fresh/model-UD-Q4_K_XL.gguf"
+        assert out == str(snap / "model-UD-Q4_K_XL.gguf")
 
     def test_download_reuses_older_snapshot_when_offline_env_is_true(self, monkeypatch, hf_cache):
         # HF_HUB_OFFLINE accepts truthy spellings beyond "1" (true/yes/on); the offline
@@ -449,6 +442,40 @@ class TestGgufVariantFileResolution:
 
         assert out == str(snap / "mmproj-F16.gguf")
 
+    def test_download_companion_uses_selected_cache_not_import_time_default(
+        self, monkeypatch, tmp_path
+    ):
+        monkeypatch.setenv("HF_HUB_OFFLINE", "1")
+        import_time_cache = tmp_path / "import-time-cache"
+        selected_cache = tmp_path / "selected-cache"
+        monkeypatch.setattr(hf_constants, "HF_HUB_CACHE", str(import_time_cache))
+        monkeypatch.setattr(
+            "utils.hf_cache_settings.get_hf_cache_paths",
+            lambda: _types.SimpleNamespace(hub_cache = selected_cache),
+        )
+        repo = "unsloth/vision-GGUF"
+        snap = _build_cache(selected_cache, repo, {"mmproj-F16.gguf": 4})
+        backend = LlamaCppBackend()
+
+        offline_error = type("OfflineModeIsEnabled", (Exception,), {})
+
+        def fail_list(*_args, **_kwargs):
+            raise offline_error("offline")
+
+        def fail_download(*_args, **_kwargs):
+            raise AssertionError("selected-cache companion must not download")
+
+        with (
+            patch("huggingface_hub.list_repo_files", fail_list),
+            patch(
+                "core.inference.llama_cpp.hf_hub_download_with_xet_fallback",
+                fail_download,
+            ),
+        ):
+            out = backend._download_mmproj(hf_repo = repo)
+
+        assert out == str(snap / "mmproj-F16.gguf")
+
     def test_download_includes_uppercase_split_gguf_shards(self, monkeypatch, tmp_path):
         backend = LlamaCppBackend()
         downloaded: list[str] = []
@@ -475,6 +502,10 @@ class TestGgufVariantFileResolution:
             return f"/fake/{repo_id}/{filename}"
 
         monkeypatch.setattr(hf_constants, "HF_HUB_CACHE", str(tmp_path))
+        monkeypatch.setattr(
+            "utils.hf_cache_settings.get_hf_cache_paths",
+            lambda: _types.SimpleNamespace(hub_cache = tmp_path),
+        )
         with (
             patch("huggingface_hub.list_repo_files", lambda *_a, **_k: files),
             patch("huggingface_hub.get_paths_info", fake_get_paths_info),
@@ -919,7 +950,7 @@ class TestHfOfflineIfDnsDead:
             assert "HF_HUB_OFFLINE" not in os.environ
 
     def test_user_set_hf_hub_offline_is_preserved(self, dns, clean_offline_env, monkeypatch):
-        # User explicitly set offline before launching Studio.
+        # User explicitly set offline before launching Unsloth.
         monkeypatch.setenv("HF_HUB_OFFLINE", "1")
         dns.fail()
         with _hf_offline_if_dns_dead() as did_set:
@@ -1106,7 +1137,7 @@ class TestListLocalGgufVariantsSubdir:
         target.write_bytes(b"\0" * 20)
 
         out = _find_local_gguf_by_variant(str(tmp_path), "Q4_K_M")
-        assert out == str(target.resolve())
+        assert out == str(target.absolute())
 
     def test_find_local_gguf_by_variant_skips_big_endian_only_match(self, tmp_path):
         from utils.models.model_config import _find_local_gguf_by_variant
@@ -1116,6 +1147,57 @@ class TestListLocalGgufVariantsSubdir:
 
         assert _find_local_gguf_by_variant(str(tmp_path), "Q4_K_M") is None
 
+    def test_find_local_gguf_by_variant_keeps_split_symlink_name(self, tmp_path):
+        from utils.models.model_config import _find_local_gguf_by_variant
+
+        blobs = tmp_path / "blobs"
+        blobs.mkdir()
+        snap = tmp_path / "snapshots" / "rev" / "BF16"
+        snap.mkdir(parents = True)
+        (tmp_path / "snapshots" / "rev" / "config.json").write_text("{}")
+        for i, sha in enumerate(("aa" * 32, "bb" * 32), start = 1):
+            (blobs / sha).write_bytes(b"\0" * 10)
+            _symlink_or_skip(snap / f"model-BF16-0000{i}-of-00002.gguf", blobs / sha)
+
+        out = _find_local_gguf_by_variant(str(tmp_path / "snapshots" / "rev"), "BF16")
+        assert out is not None
+        assert Path(out).name == "model-BF16-00001-of-00002.gguf"
+
+    def test_detect_gguf_model_keeps_split_symlink_name(self, tmp_path):
+        from utils.models.model_config import detect_gguf_model
+
+        blobs = tmp_path / "blobs"
+        blobs.mkdir()
+        snap = tmp_path / "snapshots" / "rev"
+        snap.mkdir(parents = True)
+        for i, (sha, size) in enumerate((("cc" * 32, 10), ("dd" * 32, 20)), start = 1):
+            (blobs / sha).write_bytes(b"\0" * size)
+            _symlink_or_skip(snap / f"model-BF16-0000{i}-of-00002.gguf", blobs / sha)
+
+        out = detect_gguf_model(str(snap))
+        assert out is not None
+        assert Path(out).name == "model-BF16-00001-of-00002.gguf"
+
+    def test_lone_split_symlink_uses_colocated_target_shards(self, tmp_path):
+        from utils.models.model_config import _find_local_gguf_by_variant, detect_gguf_model
+
+        target_dir = tmp_path / "external" / "BF16"
+        target_dir.mkdir(parents = True)
+        target = target_dir / "model-BF16-00001-of-00002.gguf"
+        target.write_bytes(b"\0" * 10)
+        (target_dir / "model-BF16-00002-of-00002.gguf").write_bytes(b"\0" * 10)
+
+        local = tmp_path / "local"
+        local.mkdir()
+        (local / "config.json").write_text("{}")
+        link = local / target.name
+        _symlink_or_skip(link, target)
+
+        expected = str(target.absolute())
+        assert _find_local_gguf_by_variant(str(local), "BF16") == expected
+        assert detect_gguf_model(str(local)) == expected
+        assert detect_gguf_model(str(link)) == expected
+
     def test_model_config_variant_ignores_big_endian_sibling(self, tmp_path):
         from utils.models.model_config import ModelConfig
 
diff --git a/studio/backend/tests/test_offline_inference_parent.py b/studio/backend/tests/test_offline_inference_parent.py
index 71331220d6..bd0014ea64 100644
--- a/studio/backend/tests/test_offline_inference_parent.py
+++ b/studio/backend/tests/test_offline_inference_parent.py
@@ -139,7 +139,7 @@ class TestLoraDetectOffline:
 
         monkeypatch.setenv("HF_HUB_OFFLINE", "1")
 
-        # Studio catches Exception broadly; pin that the call still happens
+        # Unsloth catches Exception broadly; pin that the call still happens
         # (so cached LoRAs aren't missed) and returns fast via the mock.
         class _OfflineModeIsEnabled(Exception):
             pass
diff --git a/studio/backend/tests/test_openai_auto_switch.py b/studio/backend/tests/test_openai_auto_switch.py
index d02a2a4f7e..9c6c20e6b6 100644
--- a/studio/backend/tests/test_openai_auto_switch.py
+++ b/studio/backend/tests/test_openai_auto_switch.py
@@ -8,6 +8,7 @@ tests/test_gguf_completion_usage.py.
 """
 
 import asyncio
+import os
 
 import pytest
 
@@ -18,6 +19,10 @@ from utils import openai_auto_switch_settings as settings
 
 
 class _FakeBackend:
+    effective_parallel_slots = 1
+    _slot_save_binary = None
+    _gguf_path = None
+
     def __init__(
         self,
         loaded_id = None,
@@ -29,6 +34,22 @@ class _FakeBackend:
         self.hf_variant = hf_variant
         self._openai_advertised_id = advertised_id
 
+    def save_slots_for_resume(self, should_abort = None):
+        return None
+
+    def restore_slots_for_resume(self, manifest):
+        return None
+
+    def _slot_launch_fingerprint(self):
+        return ((), None, None, 1)
+
+    def _gguf_file_identity(self, path):
+        try:
+            st = os.stat(path)
+        except OSError:
+            return None
+        return ((st.st_size, st.st_mtime_ns),)
+
 
 class _LoadRecorder:
     """Stand-in for the load route: records calls and simulates a load."""
@@ -47,16 +68,27 @@ class _LoadRecorder:
         request,
         fastapi_request,
         current_subject = None,
+        *,
+        current_request_counted = False,
     ):
+        # Mirror the production load boundary before recording any replacement.
+        await inference_route._wait_for_model_switch_idle(
+            current_request_counted = current_request_counted
+        )
         self.calls.append(request)
         if self.fail:
             from fastapi import HTTPException
             raise HTTPException(status_code = 503, detail = "load failed")
         self.backend.model_identifier = request.model_path
+        self.backend.hf_variant = getattr(request, "gguf_variant", None)
+        self.backend._gguf_path = request.model_path
         self.backend.is_loaded = True
         # Mirror _load_model_impl: a load advertises its own id until the
         # auto-switch caller overwrites it with the repo id.
         self.backend._openai_advertised_id = None
+        from core.inference import llama_keepwarm as kw
+
+        kw.note_model_loaded(self.backend)
         return None
 
 
@@ -68,7 +100,6 @@ def _wire(monkeypatch, *, enabled, resolves_to, backend, recorder):
     # gate that auto-switch already owns, so it calls the impl directly).
     monkeypatch.setattr(inference_route, "_load_model_impl", recorder)
     monkeypatch.setattr(inference_route, "_auto_switch_waiters", {})
-    monkeypatch.setattr(inference_route, "_auto_switch_request_waiters", {})
 
 
 def _run_hook(model = "some/model"):
@@ -446,6 +477,75 @@ def test_idle_loop_unloads_after_ttl_and_stashes_for_reload(monkeypatch):
     assert stash is not None and stash[0] == "unsloth/Idle-GGUF" and stash[1] == "Q4_K_M"
 
 
+def test_idle_loop_deletes_saved_kv_when_unload_fails(monkeypatch, tmp_path):
+    import time
+    from core.inference import llama_keepwarm as kw
+
+    monkeypatch.setattr(settings, "get_auto_unload_idle_seconds", lambda: 0.005)
+    monkeypatch.setattr(settings, "get_auto_unload_keep_kv", lambda: True)
+    kw._inflight = 0
+    kw._pending = 0
+    kw._last_active = time.monotonic() - 3600
+    kw._last_unloaded_model = None
+    kw._kv_resume = None
+
+    saved = tmp_path / "resume-abc-slot0.bin"
+    backend = _FakeBackend("unsloth/Idle-GGUF")
+    manifests = []
+
+    def _save(should_abort = None):
+        if manifests:
+            return None
+        saved.write_bytes(b"kv")
+        manifest = {"dir": str(tmp_path), "slots": [{"id": 0, "filename": saved.name}]}
+        manifests.append(manifest)
+        return manifest
+
+    def _unload():
+        raise RuntimeError("cuda teardown failed")
+
+    backend.save_slots_for_resume = _save
+    backend.unload_model = _unload
+    monkeypatch.setattr(inference_route, "get_llama_cpp_backend", lambda: backend)
+
+    async def _drive():
+        task = asyncio.create_task(kw.idle_unload_loop(poll_seconds = 0.01))
+        for _ in range(200):
+            await asyncio.sleep(0.01)
+            if manifests and not saved.exists():
+                break
+        task.cancel()
+        try:
+            await task
+        except asyncio.CancelledError:
+            pass
+
+    asyncio.run(_drive())
+    assert manifests and not saved.exists()
+    assert kw._kv_resume is None
+
+
+def test_disabling_idle_unload_purges_saved_kv(monkeypatch, tmp_path):
+    # PUT leaves keep-KV on but makes idle unload inactive: saved KV must go too.
+    import routes.settings as settings_route
+    from core.inference import llama_keepwarm as kw
+
+    saved = tmp_path / "resume-abc-slot0.bin"
+    saved.write_bytes(b"kv")
+    kw._kv_resume = {
+        "identity": ("m", None, "m"),
+        "dir": str(tmp_path),
+        "slots": [{"id": 0, "filename": saved.name}],
+    }
+    monkeypatch.setattr(settings_route, "set_openai_auto_switch", lambda *a: (False, 300, True))
+    monkeypatch.setattr(settings_route, "get_auto_unload_idle_seconds", lambda: 0)
+
+    payload = settings_route.OpenAIAutoSwitchPayload(enabled = False)
+    resp = settings_route.update_openai_auto_switch(payload, "tester")
+    assert resp.idle_unload_active is False and resp.auto_unload_keep_kv is True
+    assert kw._kv_resume is None and not saved.exists()
+
+
 def test_audio_generate_is_tracked_as_inference_path():
     # Direct GGUF TTS uses the llama backend and can outlive the idle TTL, so
     # the keep-warm middleware must count it as in-flight inference.
@@ -689,7 +789,7 @@ def test_v1_models_retrieve_is_case_insensitive(monkeypatch):
 
 def test_index_excludes_hidden_models(tmp_path, monkeypatch):
     # The llama.cpp validation probe and RAG embedding weights are hidden from
-    # Studio's pickers; they must never become auto-switch targets.
+    # Unsloth's pickers; they must never become auto-switch targets.
     from types import SimpleNamespace
     import routes.models as models_route
 
@@ -697,6 +797,10 @@ def test_index_excludes_hidden_models(tmp_path, monkeypatch):
     normal.write_bytes(b"x" * 32)
     probe = tmp_path / "stories260K.gguf"  # llama.cpp install-validation probe
     probe.write_bytes(b"x" * 32)
+    embedder = tmp_path / "embedding-Q8_0.gguf"
+    embedder.write_bytes(b"x" * 32)
+    local_default_embedder = tmp_path / "bge-small-en-v1.5-F16.gguf"
+    local_default_embedder.write_bytes(b"x" * 32)
 
     def _info(mid, path):
         return SimpleNamespace(id = mid, path = str(path), model_id = mid, display_name = mid)
@@ -704,7 +808,22 @@ def test_index_excludes_hidden_models(tmp_path, monkeypatch):
     monkeypatch.setattr(
         models_route,
         "_scan_models_dir",
-        lambda *a, **k: [_info("org/Normal-GGUF", normal), _info("ggml-org/models", probe)],
+        lambda *a, **k: [
+            _info("org/Normal-GGUF", normal),
+            _info("ggml-org/models", probe),
+            SimpleNamespace(
+                id = str(embedder),
+                path = str(embedder),
+                model_id = "unsloth/bge-small-en-v1.5-GGUF",
+                display_name = "embedding-Q8_0",
+            ),
+            SimpleNamespace(
+                id = str(local_default_embedder),
+                path = str(local_default_embedder),
+                model_id = None,
+                display_name = local_default_embedder.name,
+            ),
+        ],
     )
     monkeypatch.setattr(models_route, "_scan_hf_cache", lambda *a, **k: [])
     monkeypatch.setattr(models_route, "_resolve_hf_cache_dir", lambda: tmp_path)
@@ -713,6 +832,8 @@ def test_index_excludes_hidden_models(tmp_path, monkeypatch):
     index = resolver._index()
     assert "org/normal-gguf" in index  # keys are normalized to lowercase
     assert "ggml-org/models" not in index
+    assert "unsloth/bge-small-en-v1.5-gguf" not in index
+    assert str(local_default_embedder).lower() not in index
     # And the hidden probe cannot be auto-switched to by name.
     resolver._scan = (0.0, {})
     assert resolver.resolve_local_gguf("ggml-org/models") is None
@@ -975,6 +1096,7 @@ def test_build_index_covers_legacy_default_lmstudio_and_custom_roots(monkeypatch
     from pathlib import Path
     import routes.models as models_route
     from utils import paths as upaths
+    from utils import hf_cache_settings
     import storage.studio_db as studio_db
 
     scanned = []
@@ -995,13 +1117,18 @@ def test_build_index_covers_legacy_default_lmstudio_and_custom_roots(monkeypatch
     )
     monkeypatch.setattr(models_route, "_resolve_hf_cache_dir", lambda: tmp_path / "active")
     monkeypatch.setattr(models_route, "_is_hidden_model", lambda *a, **k: False)
+    monkeypatch.setattr(
+        hf_cache_settings,
+        "known_hf_hub_caches",
+        lambda: [tmp_path / "active", tmp_path / "previous"],
+    )
     monkeypatch.setattr(upaths, "legacy_hf_cache_dir", lambda: tmp_path / "legacy")
     monkeypatch.setattr(upaths, "hf_default_cache_dir", lambda: tmp_path / "default")
     monkeypatch.setattr(upaths, "lmstudio_model_dirs", lambda: [tmp_path / "lmstudio"])
     monkeypatch.setattr(
         studio_db, "list_scan_folders", lambda: [{"path": str(tmp_path / "custom")}]
     )
-    for sub in ("active", "legacy", "default", "lmstudio", "custom"):
+    for sub in ("active", "previous", "legacy", "default", "lmstudio", "custom"):
         (tmp_path / sub).mkdir()
 
     resolver._build_index()
@@ -1010,6 +1137,7 @@ def test_build_index_covers_legacy_default_lmstudio_and_custom_roots(monkeypatch
     lm = {p for k, p in scanned if k == "lm"}
     assert str((tmp_path / "legacy").resolve()) in hf
     assert str((tmp_path / "default").resolve()) in hf
+    assert str((tmp_path / "previous").resolve()) in hf
     assert str((tmp_path / "custom").resolve()) in hf
     assert str((tmp_path / "lmstudio").resolve()) in lm
 
@@ -1089,10 +1217,9 @@ def test_middleware_ignores_non_post(monkeypatch):
 # ── review round 4: swap guard, idle variant identity, load-by-path, stash clear ──
 
 
-def test_auto_switch_refuses_when_another_inference_is_active(monkeypatch):
-    # A cross-model swap must 409 (not kill) while another inference request is in
-    # flight; the requesting call itself is excluded from the count.
-    from fastapi import HTTPException
+def test_auto_switch_waits_for_another_inference_to_finish(monkeypatch):
+    # A cross-model swap queues while another request is generating, then loads
+    # after that request drains. The requesting call itself is excluded.
     from core.inference import llama_keepwarm as kw
 
     backend = _FakeBackend("org/A-GGUF", hf_variant = "Q4_K_M")
@@ -1106,10 +1233,18 @@ def test_auto_switch_refuses_when_another_inference_is_active(monkeypatch):
     )
     monkeypatch.setattr(kw, "_inflight", 2)  # this request + another active one
     monkeypatch.setattr(kw, "_pending", 0)
-    with pytest.raises(HTTPException) as exc:
-        _run_hook("org/B-GGUF:Q8_0")
-    assert exc.value.status_code == 409
-    assert rec.calls == []
+
+    async def _drive():
+        task = asyncio.create_task(
+            inference_route._maybe_auto_switch_model("org/B-GGUF:Q8_0", object(), "tester")
+        )
+        await asyncio.sleep(0.05)
+        assert rec.calls == []
+        kw._note_end()  # the other generation finishes; this request remains counted
+        await asyncio.wait_for(task, timeout = 1)
+
+    asyncio.run(_drive())
+    assert len(rec.calls) == 1
 
 
 def test_auto_switch_swaps_when_only_caller_is_active(monkeypatch):
@@ -1295,13 +1430,12 @@ def test_concurrent_same_target_requests_load_once(monkeypatch):
     monkeypatch.setattr(kw, "_pending", 0)
     inference_route._note_switch_waiter(inference_route._switch_key("org/B-GGUF", "Q8_0"), 1)
     _run_hook("org/B-GGUF:Q8_0")
-    assert len(rec.calls) == 1  # loads once, no 409
+    assert len(rec.calls) == 1
 
 
-def test_swap_still_refused_when_other_request_targets_different_model(monkeypatch):
-    # A concurrent request heading to a different target still blocks the swap: the
-    # same-target exclusion must not swallow a genuinely conflicting request.
-    from fastapi import HTTPException
+def test_queued_different_target_does_not_deadlock_current_swap(monkeypatch):
+    # A concurrent request already queued for another target is not generating,
+    # so it must not prevent the current serialized swap from proceeding.
     from core.inference import llama_keepwarm as kw
 
     backend = _FakeBackend("org/A-GGUF")
@@ -1316,10 +1450,8 @@ def test_swap_still_refused_when_other_request_targets_different_model(monkeypat
     monkeypatch.setattr(kw, "_inflight", 2)
     monkeypatch.setattr(kw, "_pending", 0)
     inference_route._note_switch_waiter(inference_route._switch_key("org/C-GGUF", "Q4_K_M"), 1)
-    with pytest.raises(HTTPException) as exc:
-        _run_hook("org/B-GGUF:Q8_0")
-    assert exc.value.status_code == 409
-    assert rec.calls == []
+    _run_hook("org/B-GGUF:Q8_0")
+    assert len(rec.calls) == 1
 
 
 def test_v1_models_advertises_repo_id_not_load_path(monkeypatch):
@@ -1365,6 +1497,37 @@ def test_load_route_holds_lifecycle_gate(monkeypatch):
     assert "_load_model_impl" in src
 
 
+def test_model_replacements_recheck_sidecar_swap_before_either_backend_is_unloaded():
+    # Both replacement directions drain active inference, then recheck whether a
+    # sidecar install reserved the lifecycle gate during that wait. Exact-model
+    # reuse exits earlier, so an already-loaded model never waits on unrelated inference.
+    import inspect
+
+    src = inspect.getsource(inference_route._load_model_impl)
+    gguf_wait = src.index("await _wait_for_model_switch_idle", src.index("if config.is_gguf:"))
+    gguf_sidecar_check = src.index("_raise_if_sidecar_swap_in_progress()", gguf_wait)
+    unload_unsloth = src.index("unsloth_backend.unload_model", gguf_wait)
+    standard_wait = src.index("await _wait_for_model_switch_idle", gguf_wait + 1)
+    standard_sidecar_check = src.index("_raise_if_sidecar_swap_in_progress()", standard_wait)
+    unload_gguf = src.index("llama_backend.unload_model()", standard_wait)
+    already_loaded = src.index('status = "already_loaded"')
+
+    assert already_loaded < gguf_wait < gguf_sidecar_check < unload_unsloth
+    assert standard_wait < standard_sidecar_check < unload_gguf
+
+
+def test_switch_waiter_deregisters_before_swap_gate_release():
+    # A waiter left registered after the swap gate is released would let a swap on
+    # another event loop count the finished request as still queued, pass the drain
+    # early, and unload the model that request is about to generate against.
+    import inspect
+
+    src = inspect.getsource(inference_route._maybe_auto_switch_model)
+    deregister = src.index("_note_switch_waiter(key, -1)")
+    release = src.index("_auto_switch_process_lock.release()")
+    assert deregister < release
+
+
 def _anthropic_payload(max_tokens = None):
     from models.inference import AnthropicMessagesRequest, AnthropicMessage
     return AnthropicMessagesRequest(
@@ -1403,9 +1566,9 @@ def test_anthropic_400_when_auto_switch_on_and_max_tokens_missing(monkeypatch):
 # ── review round 6: concurrency ordering, external untrack, unload gate, ids ──
 
 
-def test_pending_same_target_request_does_not_force_409(monkeypatch):
+def test_pending_same_target_request_does_not_block_swap(monkeypatch):
     # A second same-target request blocked in the middleware (pending, not yet
-    # generating) must not make the first request 409: pending is excluded.
+    # generating) must not block the first request: pending is excluded.
     from core.inference import llama_keepwarm as kw
 
     backend = _FakeBackend("org/A-GGUF")
@@ -1420,13 +1583,13 @@ def test_pending_same_target_request_does_not_force_409(monkeypatch):
     monkeypatch.setattr(kw, "_inflight", 1)  # just the caller
     monkeypatch.setattr(kw, "_pending", 1)  # second request blocked in middleware
     _run_hook("org/B-GGUF:Q8_0")
-    assert len(rec.calls) == 1  # loads once, no 409
+    assert len(rec.calls) == 1
 
 
-def test_concurrent_same_target_loads_once_while_other_still_resolving(monkeypatch):
+def test_swap_waits_until_concurrent_request_finishes_resolving(monkeypatch):
     # The real middleware counts a concurrent same-model request as in-flight
-    # before it resolves and registers a target waiter. The raw-request waiter,
-    # registered before resolve, must still exclude it so the first request loads.
+    # before it resolves and registers a target waiter. Treat it as active until
+    # its target is known, then recognize it as another queued switch request.
     from core.inference import llama_keepwarm as kw
 
     backend = _FakeBackend("org/A-GGUF")
@@ -1440,10 +1603,20 @@ def test_concurrent_same_target_loads_once_while_other_still_resolving(monkeypat
     )
     monkeypatch.setattr(kw, "_inflight", 2)  # caller + a still-resolving twin
     monkeypatch.setattr(kw, "_pending", 0)
-    # The twin has only registered its raw requested model (not yet a target waiter).
-    inference_route._note_request_waiter(inference_route._request_waiter_key("org/B-GGUF:Q8_0"), 1)
-    _run_hook("org/B-GGUF:Q8_0")
-    assert len(rec.calls) == 1  # loads once, no 409
+    # The twin is still resolving, so it is counted in-flight but has not joined
+    # the concrete target queue yet.
+
+    async def _drive():
+        task = asyncio.create_task(
+            inference_route._maybe_auto_switch_model("org/B-GGUF:Q8_0", object(), "tester")
+        )
+        await asyncio.sleep(0.05)
+        assert rec.calls == []
+        inference_route._note_switch_waiter(inference_route._switch_key("org/B-GGUF", "Q8_0"), 1)
+        await asyncio.wait_for(task, timeout = 1)
+
+    asyncio.run(_drive())
+    assert len(rec.calls) == 1
 
 
 def test_external_untrack_decrements_inflight_and_is_idempotent():
@@ -1479,11 +1652,9 @@ def test_manual_unload_interrupts_even_while_inference_active(monkeypatch):
     assert not backend.is_loaded  # torn down despite the active request
 
 
-def test_auto_switch_refuses_when_unsloth_stream_active(monkeypatch):
+def test_auto_switch_waits_when_unsloth_stream_active(monkeypatch):
     # The GGUF slot is empty but an Unsloth model is streaming (counted in-flight).
-    # _load_model_impl would unload it, so auto-switch must 409, not only when a
-    # GGUF is loaded.
-    from fastapi import HTTPException
+    # The replacement waits for it just as it does for a GGUF generation.
     from core.inference import llama_keepwarm as kw
 
     backend = _FakeBackend(None)  # no GGUF loaded
@@ -1497,10 +1668,18 @@ def test_auto_switch_refuses_when_unsloth_stream_active(monkeypatch):
     )
     monkeypatch.setattr(kw, "_inflight", 2)  # an Unsloth stream + this request
     monkeypatch.setattr(kw, "_pending", 0)
-    with pytest.raises(HTTPException) as exc:
-        _run_hook("org/B-GGUF:Q8_0")
-    assert exc.value.status_code == 409
-    assert rec.calls == []  # the active Unsloth model is not torn down
+
+    async def _drive():
+        task = asyncio.create_task(
+            inference_route._maybe_auto_switch_model("org/B-GGUF:Q8_0", object(), "tester")
+        )
+        await asyncio.sleep(0.05)
+        assert rec.calls == []
+        kw._note_end()
+        await asyncio.wait_for(task, timeout = 1)
+
+    asyncio.run(_drive())
+    assert len(rec.calls) == 1
 
 
 def test_public_model_id_prefers_advertised_over_path():
@@ -1609,11 +1788,11 @@ def test_env_idle_ttl_standalone_when_no_stored_value(monkeypatch):
 def test_stored_idle_value_overrides_env_and_stays_gated(monkeypatch):
     # An explicit stored value wins over the env default and remains gated on the
     # auto-switch toggle.
-    store = {settings.AUTO_UNLOAD_IDLE_SETTING_KEY: 30}
+    store = {settings.AUTO_UNLOAD_IDLE_SETTING_KEY: 90}
     monkeypatch.setattr(settings, "_cached_setting", lambda k, d = None: store.get(k, d))
     monkeypatch.setenv("UNSLOTH_MODEL_IDLE_TTL", "600")
     monkeypatch.setattr(settings, "get_openai_auto_switch_enabled", lambda: True)
-    assert settings.get_auto_unload_idle_seconds() == 30  # stored wins, not env
+    assert settings.get_auto_unload_idle_seconds() == 90  # stored wins, not env
     monkeypatch.setattr(settings, "get_openai_auto_switch_enabled", lambda: False)
     assert settings.get_auto_unload_idle_seconds() == 0  # explicit value still gated off
 
@@ -1729,6 +1908,8 @@ def test_index_advertises_alias_not_filesystem_path(tmp_path, monkeypatch):
     # host path in /v1/models, yet the model stays resolvable by that path too.
     from types import SimpleNamespace
     import routes.models as models_route
+    from storage import studio_db
+    import utils.paths as paths
 
     gguf = tmp_path / "model-Q4_K_M.gguf"
     gguf.write_bytes(b"x" * 32)
@@ -1742,6 +1923,8 @@ def test_index_advertises_alias_not_filesystem_path(tmp_path, monkeypatch):
     monkeypatch.setattr(models_route, "_scan_hf_cache", lambda *a, **k: [])
     monkeypatch.setattr(models_route, "_resolve_hf_cache_dir", lambda: tmp_path)
     monkeypatch.setattr(models_route, "_is_hidden_model", lambda *a, **k: False)
+    monkeypatch.setattr(paths, "lmstudio_model_dirs", lambda: [])
+    monkeypatch.setattr(studio_db, "list_scan_folders", lambda: [])
     resolver._scan = (0.0, {})
 
     # The advertised id is the alias, never the absolute path.
@@ -2887,8 +3070,10 @@ def test_non_gguf_load_clears_reload_stash():
     # A non-GGUF (Transformers/Unsloth) load must clear the stash like the GGUF
     # branch, so it never lingers until the idle poll (or forever, idle-unload off).
     import inspect
+
     src = inspect.getsource(inference_route._load_model_impl)
-    assert src.count("note_model_loaded()") >= 2
+    assert src.count("note_model_loaded()") >= 1  # non-GGUF branch
+    assert "to_thread(note_model_loaded, llama_backend)" in src  # GGUF branch
 
 
 def test_chat_rejects_malformed_tool_choice_before_switch(monkeypatch):
@@ -2975,6 +3160,8 @@ def test_auto_switch_serializes_across_event_loops(monkeypatch):
         request,
         fastapi_request,
         current_subject = None,
+        *,
+        current_request_counted = False,
     ):
         with slock:
             state["cur"] += 1
@@ -2992,7 +3179,6 @@ def test_auto_switch_serializes_across_event_loops(monkeypatch):
     monkeypatch.setattr(inference_route, "get_llama_cpp_backend", lambda: backend)
     monkeypatch.setattr(inference_route, "_load_model_impl", _slow_load)
     monkeypatch.setattr(inference_route, "_auto_switch_waiters", {})
-    monkeypatch.setattr(inference_route, "_auto_switch_request_waiters", {})
 
     barrier = threading.Barrier(2)
 
@@ -3094,3 +3280,542 @@ def test_responses_stream_hint_matches_toggle_regardless_of_active_model(monkeyp
         monkeypatch, enabled = False, active_model_name = "unsloth/Llama-3.2-1B-Instruct"
     )
     assert "Model auto-switch" in non_gguf_loaded
+
+
+# ── idle-unload KV persistence (slot save/restore) ──────────────────
+
+
+def _seed_kv_manifest(
+    tmp_path,
+    identity = ("unsloth/A-GGUF", "Q4_K_M", "unsloth/A-GGUF"),
+    gguf = None,
+):
+    if gguf is None:
+        gguf_file = tmp_path / "model.gguf"
+        gguf_file.write_bytes(b"gguf")
+        gguf = str(gguf_file)
+    st = os.stat(gguf)
+    state_file = tmp_path / "resume-abc-slot0.bin"
+    state_file.write_bytes(b"kv")
+    return state_file, {
+        "identity": identity,
+        "dir": str(tmp_path),
+        "binary": ("/bin/llama-server", 111),
+        "gguf": gguf,
+        "gguf_stat": ((st.st_size, st.st_mtime_ns),),
+        "launch": ((), None, None, 1),
+        "slots": [{"id": 0, "filename": state_file.name, "n_saved": 42}],
+    }
+
+
+def _drive_idle_loop(
+    kw,
+    poll_seconds = 0.02,
+    run_for = 0.2,
+):
+    async def _drive():
+        task = asyncio.create_task(kw.idle_unload_loop(poll_seconds = poll_seconds))
+        await asyncio.sleep(run_for)
+        task.cancel()
+        try:
+            await task
+        except asyncio.CancelledError:
+            pass
+
+    asyncio.run(_drive())
+
+
+def test_idle_unload_saves_slots_before_unload_and_stashes_manifest(monkeypatch, tmp_path):
+    import time
+    from core.inference import llama_keepwarm as kw
+
+    monkeypatch.setattr(settings, "get_auto_unload_idle_seconds", lambda: 0.005)
+    monkeypatch.setattr(settings, "get_auto_unload_keep_kv", lambda: True)
+    kw._inflight = 0
+    kw._pending = 0
+    kw._last_active = time.monotonic() - 3600
+    kw._last_unloaded_model = None
+    kw._kv_resume = None
+
+    events = []
+    backend = _FakeBackend("unsloth/Idle-GGUF", hf_variant = "Q4_K_M")
+    manifest = {
+        "dir": str(tmp_path),
+        "binary": ("bin", 1),
+        "slots": [{"id": 0, "filename": "f.bin", "n_saved": 42}],
+    }
+
+    def _save(should_abort = None):
+        events.append("save")
+        return manifest
+
+    def _unload():
+        events.append("unload")
+        backend.is_loaded = False
+
+    backend.save_slots_for_resume = _save
+    backend.unload_model = _unload
+    monkeypatch.setattr(inference_route, "get_llama_cpp_backend", lambda: backend)
+
+    _drive_idle_loop(kw)
+    # KV must be saved while the server is still alive, then exactly one unload.
+    assert events == ["save", "unload"]
+    assert kw.get_last_unloaded_model()[:2] == ("unsloth/Idle-GGUF", "Q4_K_M")
+    resume = kw.take_kv_resume()
+    assert resume is not None
+    assert resume["identity"][:2] == ("unsloth/Idle-GGUF", "Q4_K_M")
+    assert resume["slots"][0]["filename"] == "f.bin"
+
+
+def test_idle_save_failure_still_unloads_plain(monkeypatch):
+    import time
+    from core.inference import llama_keepwarm as kw
+
+    monkeypatch.setattr(settings, "get_auto_unload_idle_seconds", lambda: 0.005)
+    monkeypatch.setattr(settings, "get_auto_unload_keep_kv", lambda: True)
+    kw._inflight = 0
+    kw._pending = 0
+    kw._last_active = time.monotonic() - 3600
+    kw._last_unloaded_model = None
+    kw._kv_resume = None
+
+    unloads = []
+    backend = _FakeBackend("unsloth/Idle-GGUF", hf_variant = "Q4_K_M")
+
+    def _save(should_abort = None):
+        raise RuntimeError("slot save exploded")
+
+    def _unload():
+        unloads.append(1)
+        backend.is_loaded = False
+
+    backend.save_slots_for_resume = _save
+    backend.unload_model = _unload
+    monkeypatch.setattr(inference_route, "get_llama_cpp_backend", lambda: backend)
+
+    _drive_idle_loop(kw)
+    assert unloads == [1]  # the save failure must not skip the unload
+    assert kw.get_last_unloaded_model() is not None
+    assert kw.take_kv_resume() is None
+
+
+def test_keep_kv_setting_off_skips_save(monkeypatch):
+    import time
+    from core.inference import llama_keepwarm as kw
+
+    monkeypatch.setattr(settings, "get_auto_unload_idle_seconds", lambda: 0.005)
+    monkeypatch.setattr(settings, "get_auto_unload_keep_kv", lambda: False)
+    kw._inflight = 0
+    kw._pending = 0
+    kw._last_active = time.monotonic() - 3600
+    kw._last_unloaded_model = None
+    kw._kv_resume = None
+
+    saves, unloads = [], []
+    backend = _FakeBackend("unsloth/Idle-GGUF")
+
+    def _unload():
+        unloads.append(1)
+        backend.is_loaded = False
+
+    backend.save_slots_for_resume = lambda *a, **k: saves.append(1)
+    backend.unload_model = _unload
+    monkeypatch.setattr(inference_route, "get_llama_cpp_backend", lambda: backend)
+
+    _drive_idle_loop(kw)
+    assert saves == []
+    assert unloads == [1]
+    assert kw.take_kv_resume() is None
+
+
+def test_keep_kv_disabled_mid_save_discards_manifest(monkeypatch, tmp_path):
+    import time
+    from core.inference import llama_keepwarm as kw
+
+    keep = {"on": True}
+    monkeypatch.setattr(settings, "get_auto_unload_idle_seconds", lambda: 0.005)
+    monkeypatch.setattr(settings, "get_auto_unload_keep_kv", lambda: keep["on"])
+    kw._inflight = 0
+    kw._pending = 0
+    kw._last_active = time.monotonic() - 3600
+    kw._last_unloaded_model = None
+    kw._kv_resume = None
+
+    unloads = []
+    backend = _FakeBackend("unsloth/Idle-GGUF", hf_variant = "Q4_K_M")
+    state_file = tmp_path / "resume-mid-slot0.bin"
+    state_file.write_bytes(b"kv")
+    manifest = {
+        "dir": str(tmp_path),
+        "binary": ("bin", 1),
+        "slots": [{"id": 0, "filename": state_file.name, "n_saved": 1}],
+    }
+
+    def _save(should_abort = None):
+        keep["on"] = False  # user flips the toggle while the save runs
+        return manifest
+
+    def _unload():
+        unloads.append(1)
+        backend.is_loaded = False
+
+    backend.save_slots_for_resume = _save
+    backend.unload_model = _unload
+    monkeypatch.setattr(inference_route, "get_llama_cpp_backend", lambda: backend)
+
+    _drive_idle_loop(kw)
+    assert unloads == [1]  # still unloads; only the stash is dropped
+    assert kw.take_kv_resume() is None
+    assert not state_file.exists()
+
+
+def test_idle_ttl_disabled_mid_save_skips_unload(monkeypatch, tmp_path):
+    import time
+    from core.inference import llama_keepwarm as kw
+
+    ttl = {"v": 0.005}
+    monkeypatch.setattr(settings, "get_auto_unload_idle_seconds", lambda: ttl["v"])
+    monkeypatch.setattr(settings, "get_auto_unload_keep_kv", lambda: True)
+    kw._inflight = 0
+    kw._pending = 0
+    kw._last_active = time.monotonic() - 3600
+    kw._last_unloaded_model = None
+    kw._kv_resume = None
+
+    unloads = []
+    backend = _FakeBackend("unsloth/Idle-GGUF", hf_variant = "Q4_K_M")
+    state_file = tmp_path / "resume-mid-slot0.bin"
+    state_file.write_bytes(b"kv")
+    manifest = {
+        "dir": str(tmp_path),
+        "binary": ("bin", 1),
+        "slots": [{"id": 0, "filename": state_file.name, "n_saved": 1}],
+    }
+
+    def _save(should_abort = None):
+        ttl["v"] = 0  # user turns idle unload off while the save runs
+        return manifest
+
+    backend.save_slots_for_resume = _save
+    backend.unload_model = lambda: unloads.append(1)
+    monkeypatch.setattr(inference_route, "get_llama_cpp_backend", lambda: backend)
+
+    _drive_idle_loop(kw)
+    assert unloads == []  # the unload was cancelled by the setting change
+    assert kw.take_kv_resume() is None
+    assert not state_file.exists()
+
+
+def test_alias_reload_restores_slots_and_deletes_files(monkeypatch, tmp_path):
+    from core.inference import llama_keepwarm as kw
+
+    backend = _FakeBackend(None)  # idle-unload emptied the backend
+    backend._slot_save_binary = ("/bin/llama-server", 111)
+    restored = []
+    backend.restore_slots_for_resume = lambda manifest: restored.append(manifest)
+
+    rec = _LoadRecorder(backend)
+    _wire(monkeypatch, enabled = True, resolves_to = None, backend = backend, recorder = rec)
+    monkeypatch.setattr(kw, "_inflight", 0)
+    state_file, manifest = _seed_kv_manifest(tmp_path)
+    monkeypatch.setattr(kw, "_last_unloaded_model", (manifest["gguf"], "Q4_K_M"))
+    monkeypatch.setattr(kw, "_kv_resume", manifest)
+
+    _run_hook("gpt-4o-mini")
+    assert len(rec.calls) == 1
+    assert len(restored) == 1  # same model + binary: restore ran
+    assert not state_file.exists()  # state file deleted after the restore
+    assert kw._kv_resume is None
+
+
+def test_no_restore_when_different_model_loads(monkeypatch, tmp_path):
+    from core.inference import llama_keepwarm as kw
+
+    backend = _FakeBackend(None)
+    backend._slot_save_binary = ("/bin/llama-server", 111)
+    restored = []
+    backend.restore_slots_for_resume = lambda manifest: restored.append(manifest)
+    rec = _LoadRecorder(backend)
+    _wire(
+        monkeypatch,
+        enabled = True,
+        resolves_to = ("unsloth/B-GGUF", None, "unsloth/B-GGUF"),
+        backend = backend,
+        recorder = rec,
+    )
+    monkeypatch.setattr(kw, "_inflight", 0)
+    state_file, manifest = _seed_kv_manifest(tmp_path)  # manifest is for model A
+    monkeypatch.setattr(kw, "_kv_resume", manifest)
+
+    _run_hook("unsloth/B-GGUF")
+    assert len(rec.calls) == 1
+    assert restored == []  # different model: never restored
+    assert not state_file.exists()  # but the stale files are gone
+    assert kw._kv_resume is None
+
+
+def test_restore_skipped_when_binary_changed(monkeypatch, tmp_path):
+    from core.inference import llama_keepwarm as kw
+
+    state_file, manifest = _seed_kv_manifest(tmp_path)
+    backend = _FakeBackend("unsloth/A-GGUF", hf_variant = "Q4_K_M")
+    backend._gguf_path = manifest["gguf"]
+    backend._slot_save_binary = ("/bin/llama-server", 222)  # newer mtime
+    restored = []
+    backend.restore_slots_for_resume = lambda manifest: restored.append(manifest)
+
+    kw.restore_kv_resume(backend, manifest)
+    assert restored == []
+    assert not state_file.exists()
+
+
+def test_restore_skipped_when_launch_config_changed(tmp_path):
+    from core.inference import llama_keepwarm as kw
+
+    state_file, manifest = _seed_kv_manifest(tmp_path)
+    backend = _FakeBackend("unsloth/A-GGUF", hf_variant = "Q4_K_M")
+    backend._gguf_path = manifest["gguf"]
+    backend._slot_save_binary = ("/bin/llama-server", 111)
+    backend._slot_launch_fingerprint = lambda: (("--rope-freq-scale", "0.5"), None, None, 1)
+    restored = []
+    backend.restore_slots_for_resume = lambda manifest: restored.append(manifest)
+
+    kw.restore_kv_resume(backend, manifest)
+    assert restored == []
+    assert not state_file.exists()
+
+
+def test_restore_skipped_when_gguf_rewritten_in_place(tmp_path):
+    from core.inference import llama_keepwarm as kw
+
+    state_file, manifest = _seed_kv_manifest(tmp_path)
+    with open(manifest["gguf"], "wb") as fh:
+        fh.write(b"different weights")  # same path, new content
+    backend = _FakeBackend("unsloth/A-GGUF", hf_variant = "Q4_K_M")
+    backend._gguf_path = manifest["gguf"]
+    backend._slot_save_binary = ("/bin/llama-server", 111)
+    restored = []
+    backend.restore_slots_for_resume = lambda manifest: restored.append(manifest)
+
+    kw.restore_kv_resume(backend, manifest)
+    assert restored == []
+    assert not state_file.exists()
+
+
+def test_note_model_unloaded_purges_manifest_and_files(tmp_path):
+    from core.inference import llama_keepwarm as kw
+
+    state_file, manifest = _seed_kv_manifest(tmp_path)
+    kw._set_last_unloaded(("org/A-GGUF", "Q4_K_M"))
+    kw._set_kv_resume(manifest)
+    kw.note_model_unloaded()
+    assert kw.get_last_unloaded_model() is None
+    assert kw.take_kv_resume() is None
+    assert not state_file.exists()
+
+
+def test_note_model_loaded_purges_manifest_and_files(tmp_path):
+    from core.inference import llama_keepwarm as kw
+
+    state_file, manifest = _seed_kv_manifest(tmp_path)
+    kw._set_last_unloaded(("org/A-GGUF", "Q4_K_M"))
+    kw._set_kv_resume(manifest)
+    kw.note_model_loaded()
+    assert kw.get_last_unloaded_model() is None
+    assert kw.take_kv_resume() is None
+    assert not state_file.exists()
+
+
+def test_new_idle_save_purges_previous_manifest_files(tmp_path):
+    from core.inference import llama_keepwarm as kw
+
+    old_file, old_manifest = _seed_kv_manifest(tmp_path)
+    kw._set_kv_resume(old_manifest)
+    new_file = tmp_path / "resume-def-slot0.bin"
+    new_file.write_bytes(b"kv2")
+    kw._set_kv_resume(
+        {
+            "identity": ("unsloth/B-GGUF", None, "unsloth/B-GGUF"),
+            "dir": str(tmp_path),
+            "binary": ("/bin/llama-server", 111),
+            "slots": [{"id": 0, "filename": new_file.name, "n_saved": 7}],
+        }
+    )
+    assert not old_file.exists()  # replaced manifest's files purged
+    assert new_file.exists()
+    assert kw.take_kv_resume()["slots"][0]["filename"] == new_file.name
+
+
+def test_sweep_slot_save_dir_removes_only_resume_files(monkeypatch, tmp_path):
+    from core.inference import llama_keepwarm as kw
+    from utils.paths import storage_roots
+
+    monkeypatch.setattr(storage_roots, "llama_slot_cache_root", lambda: tmp_path)
+    stale = tmp_path / "resume-old-slot0.bin"
+    stale.write_bytes(b"kv")
+    other = tmp_path / "unrelated.txt"
+    other.write_text("keep")
+    kw.sweep_slot_save_dir()
+    assert not stale.exists()
+    assert other.exists()
+
+
+def test_keep_kv_setting_roundtrip_and_default(monkeypatch):
+    import storage.studio_db as db
+
+    store = {}
+    monkeypatch.setattr(db, "upsert_app_settings", lambda m: store.update(m))
+    monkeypatch.setattr(settings, "_cached_setting", lambda k, d = None: store.get(k, d))
+
+    assert settings.get_auto_unload_keep_kv() is True  # default when never stored
+    assert settings.set_openai_auto_switch(True, 60, False)[2] is False
+    assert store[settings.AUTO_UNLOAD_KEEP_KV_SETTING_KEY] is False
+    assert settings.get_auto_unload_keep_kv() is False
+    # None leaves the stored value untouched (older clients can't reset it).
+    assert settings.set_openai_auto_switch(True, 60, None)[2] is False
+    assert store[settings.AUTO_UNLOAD_KEEP_KV_SETTING_KEY] is False
+    with pytest.raises(ValueError, match = "true or false"):
+        settings.set_openai_auto_switch(True, 60, "garbage")
+
+
+def test_stale_stash_cleanup_waits_for_lifecycle_gate(monkeypatch, tmp_path):
+    # The loop's stale-stash purge must wait on the gate a mid-reload holds.
+    import time
+    from core.inference import llama_keepwarm as kw
+
+    monkeypatch.setattr(settings, "get_auto_unload_idle_seconds", lambda: 3600)
+    kw._inflight = 0
+    kw._pending = 0
+    kw._last_active = time.monotonic()
+    backend = _FakeBackend("unsloth/New-GGUF")
+    monkeypatch.setattr(inference_route, "get_llama_cpp_backend", lambda: backend)
+    state_file, manifest = _seed_kv_manifest(tmp_path)
+    kw._kv_resume = manifest
+    kw._last_unloaded_model = ("unsloth/A-GGUF", "Q4_K_M")
+
+    assert kw._lifecycle_lock.acquire(blocking = False)  # simulate in-flight reload
+    try:
+        _drive_idle_loop(kw)
+        assert kw._kv_resume is manifest  # purge deferred while the gate is held
+        assert state_file.exists()
+    finally:
+        kw._lifecycle_lock.release()
+    _drive_idle_loop(kw)
+    assert kw._kv_resume is None  # gate freed: genuinely stale stash purged
+    assert not state_file.exists()
+
+
+def test_put_route_disabling_keep_kv_purges_saved_state(monkeypatch, tmp_path):
+    import routes.settings as settings_route
+    import storage.studio_db as db
+    from core.inference import llama_keepwarm as kw
+
+    store = {}
+    monkeypatch.setattr(db, "upsert_app_settings", lambda m: store.update(m))
+    monkeypatch.setattr(settings, "_cached_setting", lambda k, d = None: store.get(k, d))
+    state_file, manifest = _seed_kv_manifest(tmp_path)
+    monkeypatch.setattr(kw, "_kv_resume", manifest)
+
+    payload = settings_route.OpenAIAutoSwitchPayload(enabled = True, auto_unload_keep_kv = False)
+    resp = settings_route.update_openai_auto_switch(payload, "tester")
+    assert resp.auto_unload_keep_kv is False
+    assert kw._kv_resume is None
+    assert not state_file.exists()
+
+
+def test_keep_kv_only_update_leaves_env_idle_ttl_active(monkeypatch):
+    # A keep-KV-only update must not materialize the env TTL as a stored value.
+    import routes.settings as settings_route
+    import storage.studio_db as db
+
+    store = {}
+    monkeypatch.setattr(db, "upsert_app_settings", lambda m: store.update(m))
+    monkeypatch.setattr(settings, "_cached_setting", lambda k, d = None: store.get(k, d))
+    monkeypatch.setenv(settings.MODEL_IDLE_TTL_ENV_VAR, "600")
+
+    assert settings_route.OpenAIAutoSwitchPayload(enabled = False).auto_unload_idle_seconds is None
+    enabled, idle, keep_kv = settings.set_openai_auto_switch(False, None, False)
+    assert settings.AUTO_UNLOAD_IDLE_SETTING_KEY not in store  # idle untouched
+    assert settings.get_auto_unload_idle_seconds() == 600  # env TTL still active
+    assert (enabled, idle, keep_kv) == (False, 600, False)
+
+
+def test_load_impl_notes_loaded_with_backend_off_loop():
+    import inspect
+    src = inspect.getsource(inference_route._load_model_impl)
+    assert "to_thread(note_model_loaded, llama_backend)" in src
+
+
+def test_restore_matches_gguf_realpath_across_naming(tmp_path):
+    from core.inference import llama_keepwarm as kw
+
+    blob = tmp_path / "blob.gguf"
+    blob.write_bytes(b"gguf")
+    link = tmp_path / "snapshot.gguf"
+    try:
+        link.symlink_to(blob)
+    except OSError:
+        pytest.skip("symlinks unsupported on this host")
+
+    backend = _FakeBackend("/hf/snapshots/d7f5", hf_variant = None)
+    backend._gguf_path = str(link)  # reload resolved the symlink spelling
+    backend._slot_save_binary = ("/bin/llama-server", 111)
+    restored = []
+    backend.restore_slots_for_resume = lambda manifest: restored.append(manifest)
+    state_file, manifest = _seed_kv_manifest(
+        tmp_path, identity = ("unsloth/A-GGUF", None, "unsloth/A-GGUF"), gguf = str(blob)
+    )
+
+    kw.restore_kv_resume(backend, manifest)
+    assert len(restored) == 1  # names differ, file identical: restore ran
+    assert not state_file.exists()
+
+
+def test_setter_rejects_idle_below_floor(monkeypatch):
+    import storage.studio_db as db
+
+    writes = []
+    monkeypatch.setattr(db, "upsert_app_settings", lambda m: writes.append(dict(m)))
+    settings._cache.clear()
+
+    with pytest.raises(ValueError, match = "at least 60"):
+        settings.set_openai_auto_switch(True, 30)
+    assert writes == []  # rejected before any persist
+    # 0 (off) and >= 60 pass through unchanged.
+    assert settings.set_openai_auto_switch(True, 0)[1] == 0
+    assert settings.set_openai_auto_switch(True, 60)[1] == 60
+    assert settings.set_openai_auto_switch(True, 3600)[1] == 3600
+
+
+def test_put_route_rejects_idle_below_floor():
+    import routes.settings as settings_route
+    from fastapi import HTTPException
+
+    payload = settings_route.OpenAIAutoSwitchPayload(enabled = True, auto_unload_idle_seconds = 30)
+    with pytest.raises(HTTPException) as excinfo:
+        settings_route.update_openai_auto_switch(payload, "tester")
+    assert excinfo.value.status_code == 400
+
+
+def test_stored_legacy_idle_below_floor_is_clamped(monkeypatch):
+    # Values persisted before the floor existed are raised to it on read, for
+    # both the effective TTL and the value the settings UI displays.
+    store = {settings.AUTO_UNLOAD_IDLE_SETTING_KEY: 5}
+    monkeypatch.setattr(settings, "_cached_setting", lambda k, d = None: store.get(k, d))
+    monkeypatch.setattr(settings, "get_openai_auto_switch_enabled", lambda: True)
+    assert settings.get_auto_unload_idle_seconds() == 60
+    assert settings.get_stored_auto_unload_idle_seconds() == 60
+    store[settings.AUTO_UNLOAD_IDLE_SETTING_KEY] = 90
+    assert settings.get_auto_unload_idle_seconds() == 90
+
+
+def test_env_idle_below_floor_is_clamped(monkeypatch):
+    monkeypatch.setattr(settings, "_cached_setting", lambda k, d = None: d)
+    monkeypatch.setenv(settings.MODEL_IDLE_TTL_ENV_VAR, "5")
+    assert settings.get_auto_unload_idle_seconds() == 60
+    monkeypatch.setenv(settings.MODEL_IDLE_TTL_ENV_VAR, "0")
+    assert settings.get_auto_unload_idle_seconds() == 0
+    monkeypatch.setenv(settings.MODEL_IDLE_TTL_ENV_VAR, "600")
+    assert settings.get_auto_unload_idle_seconds() == 600
+    monkeypatch.delenv(settings.MODEL_IDLE_TTL_ENV_VAR)
+    assert settings.get_auto_unload_idle_seconds() == 0
diff --git a/studio/backend/tests/test_openai_compaction.py b/studio/backend/tests/test_openai_compaction.py
index c7de0a9aed..6fad2c5eaf 100644
--- a/studio/backend/tests/test_openai_compaction.py
+++ b/studio/backend/tests/test_openai_compaction.py
@@ -86,7 +86,7 @@ def test_cloud_openai_sets_compaction_block(monkeypatch):
 
 
 def test_cloud_openai_below_default_threshold_passes_through(monkeypatch):
-    # Studio doesn't clamp the OpenAI side -- the API accepts whatever the
+    # Unsloth doesn't clamp the OpenAI side -- the API accepts whatever the
     # caller sends, so a small probe like 60k still goes through.
     captured = _capture(
         monkeypatch,
diff --git a/studio/backend/tests/test_openai_image_generation.py b/studio/backend/tests/test_openai_image_generation.py
index ace57588d3..c2eef0381f 100644
--- a/studio/backend/tests/test_openai_image_generation.py
+++ b/studio/backend/tests/test_openai_image_generation.py
@@ -4,7 +4,7 @@
 """Unit tests for OpenAI Responses API image_generation tool wiring.
 
 The tool is a server-side Responses-API tool (``{type: "image_generation"}``);
-the result comes back as an ``image_generation_call`` output item, which Studio
+the result comes back as an ``image_generation_call`` output item, which Unsloth
 translates into ``_toolEvent`` chunks so the chat adapter renders it inline.
 Tests pin: the tool is added to the body only on a cloud OpenAI base when asked
 for, the done event produces the expected chunks, and non-cloud bases drop it.
diff --git a/studio/backend/tests/test_openai_tool_passthrough.py b/studio/backend/tests/test_openai_tool_passthrough.py
index 5300a48557..161c8743c4 100644
--- a/studio/backend/tests/test_openai_tool_passthrough.py
+++ b/studio/backend/tests/test_openai_tool_passthrough.py
@@ -119,7 +119,7 @@ class TestFriendlyUpstreamError:
         raw = '{"error":{"code":400,"message":"Failed to initialize samplers: failed to parse grammar","type":"invalid_request_error"}}'
         msg = _friendly_upstream_error(raw)
         assert "failed to parse grammar" not in msg  # raw body is not surfaced verbatim
-        assert "tool-calling grammar" in msg and "Update Studio" in msg
+        assert "tool-calling grammar" in msg and "Update Unsloth" in msg
 
     def test_failed_to_initialize_samplers_alone_matches(self):
         assert "tool-calling grammar" in _friendly_upstream_error("Failed to initialize samplers")
@@ -262,7 +262,7 @@ class TestChatMessageToolRoles:
 
     def test_tool_empty_content_accepted(self):
         # Empty tool output (mkdir, git add, ...) is routine in agentic loops;
-        # OpenAI and llama-server both accept it, so Studio must not 400.
+        # OpenAI and llama-server both accept it, so Unsloth must not 400.
         msg = ChatMessage(role = "tool", tool_call_id = "call_1", content = "")
         assert msg.content == ""
 
@@ -400,7 +400,7 @@ class TestChatCompletionRequestToolFields:
         assert req.session_id == "abc"
 
     def test_stream_defaults_false_matching_openai_spec(self):
-        # OpenAI defaults `stream` to false. Studio used to default true,
+        # OpenAI defaults `stream` to false. Unsloth used to default true,
         # breaking naive curl/.NET clients (#5047) that omit it. Pin the fix.
         req = self._make()
         assert req.stream is False
@@ -664,7 +664,7 @@ class TestChatCompletionRequestToolFields:
                 raise AssertionError("client tools must use passthrough")
 
             def generate_chat_completion_with_tools(self, **_kwargs):
-                raise AssertionError("Studio tool loop must stay disabled")
+                raise AssertionError("Unsloth tool loop must stay disabled")
 
         async def fake_passthrough(llama_backend, payload, model_name, **kwargs):
             captured["body"] = inference_route._build_openai_passthrough_body(
@@ -707,11 +707,11 @@ class TestChatCompletionRequestToolFields:
         assert monitor.active_count() == 0
 
     def test_permission_mode_does_not_reject_client_tool_passthrough(self, monkeypatch):
-        # A non-streaming client-tool passthrough (client tools, no Studio tool
+        # A non-streaming client-tool passthrough (client tools, no Unsloth tool
         # loop) that also carries permission_mode "ask"/"auto" must reach the
         # provider passthrough, not the confirm-without-stream guard: the
         # validator leaves confirm_tool_calls unset for passthrough, and a bare
-        # permission_mode only gates Studio's own local tool loop. An explicit
+        # permission_mode only gates Unsloth's own local tool loop. An explicit
         # confirm_tool_calls=True still forces the local-confirm rejection.
         # The pre-switch guard only runs when an automatic load may run, so force
         # that predicate on to exercise it against a resident passthrough backend.
@@ -732,7 +732,7 @@ class TestChatCompletionRequestToolFields:
                 raise AssertionError("client tools must use passthrough")
 
             def generate_chat_completion_with_tools(self, **_kwargs):
-                raise AssertionError("Studio tool loop must stay disabled")
+                raise AssertionError("Unsloth tool loop must stay disabled")
 
         async def fake_passthrough(llama_backend, payload, model_name, **kwargs):
             inference_route.api_monitor.finish(kwargs.get("monitor_id"))
@@ -757,7 +757,7 @@ class TestChatCompletionRequestToolFields:
             return self._v1_client(monkeypatch, _GGUFBackend())
 
         # A process --enable-tools policy must not turn a client-tool passthrough
-        # into a Studio local loop, so a policy of None or True both keep the
+        # into an Unsloth local loop, so a policy of None or True both keep the
         # passthrough (the guard mirrors _explicit_studio_tool_loop_requested).
         for policy in (None, True):
             for mode in ("ask", "auto"):
@@ -810,7 +810,7 @@ class TestChatCompletionRequestToolFields:
         assert "requires stream=true" in resp.json()["error"]["message"]
 
     def test_permission_mode_policy_forced_local_loop_rejected_before_switch(self, monkeypatch):
-        # A process --enable-tools policy forces Studio's own tool loop on even
+        # A process --enable-tools policy forces Unsloth's own tool loop on even
         # when the request omits enable_tools and carries no client tools. A
         # non-streaming ask/auto request is then confirm-gated with no stream to
         # prompt on, so it must 400 at the pre-switch guard -- before
@@ -863,7 +863,7 @@ class TestChatCompletionRequestToolFields:
     def test_enable_tools_on_non_tool_backend_keeps_client_tools_on_passthrough(self, monkeypatch):
         # DiffusionGemma forces supports_tools off while passthrough stays
         # available (#6851): enable_tools=True must not steal client tools
-        # from the passthrough into a Studio tool loop that cannot run.
+        # from the passthrough into an Unsloth tool loop that cannot run.
         import routes.inference as inference_route
 
         captured = {}
@@ -883,7 +883,7 @@ class TestChatCompletionRequestToolFields:
                 raise AssertionError("client tools must use passthrough")
 
             def generate_chat_completion_with_tools(self, **_kwargs):
-                raise AssertionError("Studio tool loop cannot run on a non-tool backend")
+                raise AssertionError("Unsloth tool loop cannot run on a non-tool backend")
 
         async def fake_passthrough(llama_backend, payload, model_name, **kwargs):
             captured["body"] = inference_route._build_openai_passthrough_body(
@@ -1054,7 +1054,7 @@ class TestChatCompletionRequestToolFields:
         monkeypatch.setattr(
             inference_route,
             "_detect_safetensors_features",
-            lambda backend, chat_template: {"supports_tools": True},
+            lambda backend, chat_template, tools = None: {"supports_tools": True},
         )
         monitor = ApiMonitor(max_entries = 3)
         monkeypatch.setattr(inference_route, "api_monitor", monitor)
@@ -2581,7 +2581,7 @@ class TestGgufVisionToolRouting:
             raise AssertionError("plain GGUF path should not be used")
 
         def _tools(**_kwargs):
-            raise AssertionError("Studio tool loop should not steal response_format")
+            raise AssertionError("Unsloth tool loop should not steal response_format")
 
         backend = SimpleNamespace(
             is_loaded = True,
@@ -2654,7 +2654,7 @@ class TestGgufVisionToolRouting:
             raise AssertionError("plain GGUF path should not be used")
 
         def _tools(**_kwargs):
-            raise AssertionError("Studio tool loop should not replace client tools")
+            raise AssertionError("Unsloth tool loop should not replace client tools")
 
         backend = SimpleNamespace(
             is_loaded = True,
@@ -2726,7 +2726,7 @@ class TestGgufVisionToolRouting:
             yield "plain response"
 
         def _tools(**_kwargs):
-            raise AssertionError("tool_choice='none' must not start Studio's tool loop")
+            raise AssertionError("tool_choice='none' must not start Unsloth's tool loop")
 
         backend = SimpleNamespace(
             is_loaded = True,
@@ -2780,7 +2780,7 @@ class TestGgufVisionToolRouting:
             raise AssertionError("plain GGUF path should not be used")
 
         def _tools(**_kwargs):
-            raise AssertionError("enabled_tools alone must not start Studio's tool loop")
+            raise AssertionError("enabled_tools alone must not start Unsloth's tool loop")
 
         backend = SimpleNamespace(
             is_loaded = True,
@@ -2844,7 +2844,7 @@ class TestGgufVisionToolRouting:
             raise AssertionError("plain GGUF path should not be used")
 
         def _tools(**_kwargs):
-            raise AssertionError("enabled_tools alone must not start Studio's tool loop")
+            raise AssertionError("enabled_tools alone must not start Unsloth's tool loop")
 
         backend = SimpleNamespace(
             is_loaded = True,
@@ -6620,6 +6620,29 @@ class TestApiMonitorAudioInput:
             assert entry["reply"] == "hello world"
             assert monitor.active_count() == 0
 
+            def failing_chunks():
+                yield "partial"
+                raise RuntimeError("generation failed")
+
+            self._patch_audio_backend(monkeypatch, failing_chunks())
+            error_monitor = ApiMonitor(max_entries = 3)
+            monkeypatch.setattr(inf_mod, "api_monitor", error_monitor)
+            error_response = await openai_chat_completions(
+                payload,
+                request = request,
+                current_subject = "test",
+            )
+            error_chunks = [
+                chunk.decode() if isinstance(chunk, bytes) else chunk
+                async for chunk in error_response.body_iterator
+            ]
+
+            assert '"type": "server_error"' in error_chunks[-1]
+            assert error_chunks[-1].endswith("data: [DONE]\n\n")
+            [error_entry] = error_monitor.snapshot()
+            assert error_entry["status"] == "error"
+            assert error_monitor.active_count() == 0
+
         asyncio.run(_run())
 
     def test_non_gguf_tts_auto_route_records_monitor(self, monkeypatch):
diff --git a/studio/backend/tests/test_orchestrator_unload_cancel.py b/studio/backend/tests/test_orchestrator_unload_cancel.py
index fb80b6d061..3a36500aee 100644
--- a/studio/backend/tests/test_orchestrator_unload_cancel.py
+++ b/studio/backend/tests/test_orchestrator_unload_cancel.py
@@ -34,6 +34,70 @@ def _bare_orchestrator():
     return o
 
 
+def test_adapter_control_raises_stream_errors(monkeypatch):
+    o = _bare_orchestrator()
+    monkeypatch.setattr(
+        o,
+        "_generate_dispatched",
+        lambda **_kwargs: iter([orch_mod.GenStreamError("Error: adapter failed")]),
+    )
+
+    with pytest.raises(RuntimeError, match = "adapter failed"):
+        list(o.generate_with_adapter_control(use_adapter = False))
+
+    closed = []
+
+    def _stream(**_kwargs):
+        try:
+            yield "token"
+            yield "late token"
+        finally:
+            closed.append(True)
+
+    monkeypatch.setattr(o, "_generate_dispatched", _stream)
+    generator = o.generate_with_adapter_control(use_adapter = False)
+    assert next(generator) == "token"
+    generator.close()
+    assert closed == [True]
+
+
+def test_worker_closes_cancelled_generator_before_gen_done():
+    from core.inference.worker import _handle_generate
+
+    events = []
+
+    class _Backend:
+        last_generation_stats = None
+
+        def generate_with_adapter_control(self, **_kwargs):
+            try:
+                yield "token"
+                yield "late token"
+            finally:
+                events.append("closed")
+
+    class _Responses:
+        def __init__(self):
+            self.items = []
+
+        def put(self, item):
+            if item["type"] == "gen_done":
+                assert events == ["closed"]
+            self.items.append(item)
+
+    responses = _Responses()
+    cancel = threading.Event()
+    cancel.set()
+    _handle_generate(
+        _Backend(),
+        {"request_id": "r1", "messages": [], "use_adapter": False},
+        responses,
+        cancel,
+    )
+
+    assert [item["type"] for item in responses.items] == ["gen_done"]
+
+
 def test_unload_cancels_inflight_generation_then_unloads(monkeypatch):
     o = _bare_orchestrator()
     monkeypatch.setattr(o, "_ensure_subprocess_alive", lambda: True)
diff --git a/studio/backend/tests/test_password_prompt.py b/studio/backend/tests/test_password_prompt.py
index 372d6a2aa4..1af8836065 100644
--- a/studio/backend/tests/test_password_prompt.py
+++ b/studio/backend/tests/test_password_prompt.py
@@ -183,6 +183,22 @@ def test_loop_short_password_reprompts(monkeypatch):
     assert "at least 8 characters" in out
 
 
+def test_loop_whitespace_only_reprompts(monkeypatch):
+    ok, applied, out = _run_loop(monkeypatch, _keys(" " * 8, "long-enough-pw", "long-enough-pw"))
+    assert ok is True
+    assert applied == ["long-enough-pw"]
+    assert "contain spaces" in out
+
+
+def test_loop_password_with_inner_space_reprompts(monkeypatch):
+    ok, applied, out = _run_loop(
+        monkeypatch, _keys("has space pw", "long-enough-pw", "long-enough-pw")
+    )
+    assert ok is True
+    assert applied == ["long-enough-pw"]
+    assert "contain spaces" in out
+
+
 def test_loop_rejects_current_password(monkeypatch):
     ok, applied, out = _run_loop(
         monkeypatch, _keys("bootstrap-pw", "fresh-password", "fresh-password")
diff --git a/studio/backend/tests/test_password_prompt_backstop.py b/studio/backend/tests/test_password_prompt_backstop.py
index 597eac1625..3c2c1956f9 100644
--- a/studio/backend/tests/test_password_prompt_backstop.py
+++ b/studio/backend/tests/test_password_prompt_backstop.py
@@ -3,7 +3,7 @@
 
 """Pre-tunnel terminal password gate: never publish a public Cloudflare URL
 while the seeded default admin password is active. Imports run.py directly,
-so run under the Studio venv."""
+so run under the Unsloth venv."""
 
 from __future__ import annotations
 
diff --git a/studio/backend/tests/test_permission_mode.py b/studio/backend/tests/test_permission_mode.py
index 3b7197fc49..4fc64a6291 100644
--- a/studio/backend/tests/test_permission_mode.py
+++ b/studio/backend/tests/test_permission_mode.py
@@ -1438,7 +1438,7 @@ def test_unknown_permission_mode_normalizes_to_ask_on_request_models():
 
 def test_ask_auto_self_enable_confirm_on_chat_request():
     # "Ask" gates every call, so a direct /chat/completions caller that requests
-    # ask but omits the legacy confirm flag self-enables it when Studio's own tool
+    # ask but omits the legacy confirm flag self-enables it when Unsloth's own tool
     # loop is requested. Only the router's loop-entry signals count (enable_tools /
     # mcp_enabled); enabled_tools alone never starts the loop.
     for loop in ({"enable_tools": True}, {"mcp_enabled": True}):
@@ -1481,7 +1481,7 @@ def test_ask_auto_self_enable_confirm_on_chat_request():
         confirm_tool_calls = False,
     )
     assert req.confirm_tool_calls is False
-    # A plain client-tool passthrough (client-supplied tools that Studio does not
+    # A plain client-tool passthrough (client-supplied tools that Unsloth does not
     # execute) must NOT self-enable confirm, or the route rejects the passthrough.
     req = ChatCompletionRequest(
         messages = [{"role": "user", "content": "hi"}],
diff --git a/studio/backend/tests/test_picker_service.py b/studio/backend/tests/test_picker_service.py
new file mode 100644
index 0000000000..1bdfc135e3
--- /dev/null
+++ b/studio/backend/tests/test_picker_service.py
@@ -0,0 +1,272 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import json
+from types import SimpleNamespace
+
+from picker.service import (
+    MAX_TEMPLATE_METADATA_BYTES,
+    _chat_template_from_dir,
+    _chat_template_from_processor_json,
+    _chat_template_from_tokenizer_config,
+    _chat_template_from_tokenizer_dir,
+    _find_gguf_in_dir,
+    _iter_ggufs,
+    read_default_chat_template,
+    validate_chat_template,
+)
+
+
+def test_iter_ggufs_skips_gguf_companions(tmp_path):
+    mtp_dir = tmp_path / "MTP"
+    mtp_dir.mkdir()
+    main = tmp_path / "model-Q8_0.gguf"
+    main.write_bytes(b"")
+    (tmp_path / "mmproj-F16.gguf").write_bytes(b"")
+    (tmp_path / "mtp-model-Q8_0.gguf").write_bytes(b"")
+    (mtp_dir / "model-Q8_0-MTP.gguf").write_bytes(b"")
+    (tmp_path / "model-Q8_0-be.gguf").write_bytes(b"")
+
+    assert _iter_ggufs(tmp_path) == [main]
+
+
+def test_find_gguf_in_dir_matches_quant_label(tmp_path):
+    mtp_dir = tmp_path / "MTP"
+    mtp_dir.mkdir()
+    main = tmp_path / "model-Q8_0.gguf"
+    main.write_bytes(b"")
+    (mtp_dir / "model-Q8_0-MTP.gguf").write_bytes(b"")
+    (tmp_path / "model-Q4_K_M.gguf").write_bytes(b"")
+
+    assert _find_gguf_in_dir(tmp_path, "Q8_0") == main
+    assert _find_gguf_in_dir(tmp_path, "Q4_K") is None
+
+
+def test_find_gguf_in_dir_without_variant_prefers_largest_model(tmp_path):
+    smaller = tmp_path / "a-model-Q4_K_M.gguf"
+    larger = tmp_path / "z-model-Q8_0.gguf"
+    smaller.write_bytes(b"0")
+    larger.write_bytes(b"00")
+
+    assert _find_gguf_in_dir(tmp_path, None) == larger
+
+
+def test_find_gguf_in_dir_without_variant_prefers_first_split(tmp_path):
+    first = tmp_path / "model-Q4_K_M-00001-of-00003.gguf"
+    second = tmp_path / "model-Q4_K_M-00002-of-00003.gguf"
+    third = tmp_path / "model-Q4_K_M-00003-of-00003.gguf"
+    first.write_bytes(b"0")
+    second.write_bytes(b"000")
+    third.write_bytes(b"00")
+
+    assert _find_gguf_in_dir(tmp_path, None) == first
+
+    first.unlink()
+    assert _find_gguf_in_dir(tmp_path, None) == second
+
+
+def test_find_gguf_in_dir_matches_bpw_variant_base_label(tmp_path):
+    target = tmp_path / "model-IQ4_XS-3.53bpw.gguf"
+    target.write_bytes(b"")
+    (tmp_path / "model-Q4_K_M.gguf").write_bytes(b"")
+
+    assert _find_gguf_in_dir(tmp_path, "IQ4_XS") == target
+    assert _find_gguf_in_dir(tmp_path, "IQ4_XS-3.53bpw") == target
+    assert _find_gguf_in_dir(tmp_path, "Q4_K") is None
+
+
+def test_validate_chat_template_accepts_valid_and_empty():
+    assert validate_chat_template("{{ messages[0].content }}").valid is True
+    assert validate_chat_template("").valid is True
+    assert validate_chat_template("   ").valid is True
+
+
+def test_validate_chat_template_reports_syntax_error_with_line():
+    result = validate_chat_template("{% if %}{% endif %}")
+    assert result.valid is False
+    assert result.error is not None
+    assert result.error.startswith("Line ")
+
+
+def test_chat_template_from_tokenizer_config_reads_string():
+    assert _chat_template_from_tokenizer_config({"chat_template": "HELLO"}) == "HELLO"
+    assert _chat_template_from_tokenizer_config({"chat_template": "   "}) is None
+    assert _chat_template_from_tokenizer_config({}) is None
+
+
+def test_chat_template_from_tokenizer_config_prefers_named_default():
+    config = {
+        "chat_template": [
+            {"name": "tool_use", "template": "TOOL"},
+            {"name": "default", "template": "DEFAULT"},
+        ]
+    }
+    assert _chat_template_from_tokenizer_config(config) == "DEFAULT"
+
+
+def test_chat_template_from_tokenizer_config_falls_back_to_first_entry():
+    config = {
+        "chat_template": [
+            {"name": "tool_use", "template": "TOOL"},
+            {"name": "other", "template": "OTHER"},
+        ]
+    }
+    assert _chat_template_from_tokenizer_config(config) == "TOOL"
+
+
+def test_chat_template_from_tokenizer_dir_prefers_jinja_file(tmp_path):
+    (tmp_path / "chat_template.jinja").write_text("FROM_JINJA", encoding = "utf-8")
+    (tmp_path / "tokenizer_config.json").write_text(
+        json.dumps({"chat_template": "FROM_CONFIG"}), encoding = "utf-8"
+    )
+    assert _chat_template_from_tokenizer_dir(tmp_path) == "FROM_JINJA"
+
+
+def test_chat_template_from_tokenizer_dir_reads_tokenizer_config(tmp_path):
+    (tmp_path / "tokenizer_config.json").write_text(
+        json.dumps({"chat_template": "FROM_CONFIG"}), encoding = "utf-8"
+    )
+    assert _chat_template_from_tokenizer_dir(tmp_path) == "FROM_CONFIG"
+
+
+def test_chat_template_from_dir_without_variant_prefers_tokenizer(tmp_path):
+    (tmp_path / "tokenizer_config.json").write_text(
+        json.dumps({"chat_template": "FROM_CONFIG"}), encoding = "utf-8"
+    )
+    assert _chat_template_from_dir(tmp_path) == "FROM_CONFIG"
+
+
+def test_chat_template_from_dir_with_variant_still_prefers_tokenizer(tmp_path, monkeypatch):
+    (tmp_path / "tokenizer_config.json").write_text(
+        json.dumps({"chat_template": "FROM_CONFIG"}), encoding = "utf-8"
+    )
+    (tmp_path / "model-Q4_K_M.gguf").write_bytes(b"")
+    monkeypatch.setattr("picker.service.read_gguf_chat_template", lambda _path: "FROM_GGUF")
+    # Selecting a variant must not flip precedence to the embedded GGUF template.
+    assert _chat_template_from_dir(tmp_path, "Q4_K_M") == "FROM_CONFIG"
+
+
+def test_chat_template_from_dir_with_variant_falls_back_to_gguf(tmp_path, monkeypatch):
+    (tmp_path / "model-Q4_K_M.gguf").write_bytes(b"")
+    monkeypatch.setattr("picker.service.read_gguf_chat_template", lambda _path: "FROM_GGUF")
+    # With no tokenizer sidecar, the embedded GGUF template is still the fallback.
+    assert _chat_template_from_dir(tmp_path, "Q4_K_M") == "FROM_GGUF"
+
+
+def test_chat_template_from_dir_returns_none_when_absent(tmp_path):
+    assert _chat_template_from_dir(tmp_path) is None
+
+
+def test_read_default_chat_template_direct_gguf_prefers_sidecar(tmp_path, monkeypatch):
+    gguf = tmp_path / "model-Q4_K_M.gguf"
+    gguf.write_bytes(b"")
+    (tmp_path / "tokenizer_config.json").write_text(
+        json.dumps({"chat_template": "FROM_CONFIG"}), encoding = "utf-8"
+    )
+    monkeypatch.setattr("picker.service._build_browse_allowlist", lambda: [tmp_path])
+    monkeypatch.setattr("picker.service.read_gguf_chat_template", lambda _path: "FROM_GGUF")
+    # A directly selected .gguf must prefer a maintained sidecar over its embedded copy.
+    assert read_default_chat_template(str(gguf)) == "FROM_CONFIG"
+
+
+def test_read_default_chat_template_direct_gguf_falls_back_to_embedded(tmp_path, monkeypatch):
+    gguf = tmp_path / "model-Q4_K_M.gguf"
+    gguf.write_bytes(b"")
+    monkeypatch.setattr("picker.service._build_browse_allowlist", lambda: [tmp_path])
+    monkeypatch.setattr("picker.service.read_gguf_chat_template", lambda _path: "FROM_GGUF")
+    # With no sidecar next to the file, the embedded GGUF template is the fallback.
+    assert read_default_chat_template(str(gguf)) == "FROM_GGUF"
+
+
+def test_tokenizer_config_over_size_limit_is_skipped_not_parsed(tmp_path):
+    # An oversized tokenizer_config.json must be skipped before json.loads so a
+    # hostile sidecar cannot exhaust memory.
+    padding = "x" * (MAX_TEMPLATE_METADATA_BYTES + 1024)
+    (tmp_path / "tokenizer_config.json").write_text(
+        json.dumps({"chat_template": "HELLO", "_pad": padding}), encoding = "utf-8"
+    )
+    assert _chat_template_from_tokenizer_dir(tmp_path) is None
+
+
+def test_processor_json_over_size_limit_is_skipped_not_parsed(tmp_path):
+    padding = "x" * (MAX_TEMPLATE_METADATA_BYTES + 1024)
+    (tmp_path / "chat_template.json").write_text(
+        json.dumps({"default": "HELLO", "_pad": padding}), encoding = "utf-8"
+    )
+    assert _chat_template_from_processor_json(tmp_path) is None
+
+
+def test_tokenizer_config_at_size_limit_is_still_read(tmp_path):
+    # A normal-sized config is unaffected by the bound (regression guard).
+    (tmp_path / "tokenizer_config.json").write_text(
+        json.dumps({"chat_template": "FROM_CONFIG"}), encoding = "utf-8"
+    )
+    assert _chat_template_from_tokenizer_dir(tmp_path) == "FROM_CONFIG"
+
+
+def test_remote_template_over_size_limit_is_skipped_before_download(monkeypatch):
+    # An uncached Hub repo whose template exceeds the cap must be skipped via the
+    # remote size pre-check, never downloaded.
+    import huggingface_hub
+
+    monkeypatch.setattr("picker.service.resolve_cached_repo_id_case", lambda name: name)
+    monkeypatch.setattr("picker.service.iter_hf_cache_snapshots", lambda resolved: [])
+
+    def _fail_download(*args, **kwargs):
+        raise AssertionError("oversized remote template must not be downloaded")
+
+    def _fake_get_paths_info(self, repo_id, paths, **kwargs):
+        return [SimpleNamespace(path = p, size = MAX_TEMPLATE_METADATA_BYTES + 1) for p in paths]
+
+    monkeypatch.setattr(huggingface_hub, "hf_hub_download", _fail_download)
+    monkeypatch.setattr(huggingface_hub.HfApi, "get_paths_info", _fake_get_paths_info)
+
+    assert read_default_chat_template("org/oversized-model") is None
+
+
+def test_remote_oversized_jinja_falls_through_to_tokenizer_template(tmp_path, monkeypatch):
+    # A raw chat_template.jinja between the response cap (MAX_CHAT_TEMPLATE_BYTES)
+    # and the download bound (MAX_TEMPLATE_METADATA_BYTES) must not be returned: the
+    # route drops it, so the remote path must skip the oversized Jinja and fall
+    # through to the smaller tokenizer_config.json.
+    import huggingface_hub
+    from picker.schemas import MAX_CHAT_TEMPLATE_BYTES
+
+    big_jinja = tmp_path / "chat_template.jinja"
+    big_jinja.write_text("{{ x }}" * (MAX_CHAT_TEMPLATE_BYTES // 4), encoding = "utf-8")
+    assert MAX_CHAT_TEMPLATE_BYTES < big_jinja.stat().st_size < MAX_TEMPLATE_METADATA_BYTES
+    tokenizer_config = tmp_path / "tokenizer_config.json"
+    tokenizer_config.write_text(json.dumps({"chat_template": "SMALL_TEMPLATE"}), encoding = "utf-8")
+    files = {
+        "chat_template.jinja": big_jinja,
+        "tokenizer_config.json": tokenizer_config,
+    }
+    selected_cache = tmp_path / "selected-cache" / "hub"
+    observed_cache_dirs = []
+
+    monkeypatch.setattr("picker.service.resolve_cached_repo_id_case", lambda name: name)
+    monkeypatch.setattr("picker.service.iter_hf_cache_snapshots", lambda resolved: [])
+    monkeypatch.setattr("picker.service.active_hf_hub_cache", lambda: str(selected_cache))
+
+    def _fake_download(repo_id, rel, **kwargs):
+        observed_cache_dirs.append(kwargs.get("cache_dir"))
+        target = files.get(rel)
+        if target is None:
+            raise FileNotFoundError(rel)
+        return str(target)
+
+    def _fake_get_paths_info(self, repo_id, paths, **kwargs):
+        return [
+            SimpleNamespace(
+                path = p,
+                size = files[p].stat().st_size if p in files else 0,
+            )
+            for p in paths
+        ]
+
+    monkeypatch.setattr(huggingface_hub, "hf_hub_download", _fake_download)
+    monkeypatch.setattr(huggingface_hub.HfApi, "get_paths_info", _fake_get_paths_info)
+
+    assert read_default_chat_template("org/big-jinja-model") == "SMALL_TEMPLATE"
+    assert observed_cache_dirs
+    assert set(observed_cache_dirs) == {str(selected_cache)}
diff --git a/studio/backend/tests/test_providers_api.py b/studio/backend/tests/test_providers_api.py
index 5e24ed752d..7cac3a9e99 100644
--- a/studio/backend/tests/test_providers_api.py
+++ b/studio/backend/tests/test_providers_api.py
@@ -38,11 +38,11 @@ BASE_URL = os.getenv("STUDIO_TEST_URL", "http://localhost:8000")
 USERNAME = os.getenv("STUDIO_TEST_USER", "unsloth")
 PASSWORD = os.getenv("STUDIO_TEST_PASSWORD", "")
 
-# Skip the whole module when no live Studio server / bootstrap password is
+# Skip the whole module when no live Unsloth server / bootstrap password is
 # available (e.g. on CI) so pytest discovery does not error out.
 pytestmark = pytest.mark.skipif(
     not PASSWORD,
-    reason = "Integration test requires a running Studio server; set STUDIO_TEST_PASSWORD to enable.",
+    reason = "Integration test requires a running Unsloth server; set STUDIO_TEST_PASSWORD to enable.",
 )
 
 # provider_type → (env var name, model for inference test)
diff --git a/studio/backend/tests/test_providers_db_models.py b/studio/backend/tests/test_providers_db_models.py
new file mode 100644
index 0000000000..ca9dffbd70
--- /dev/null
+++ b/studio/backend/tests/test_providers_db_models.py
@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Unit tests for provider model persistence (unslothai/unsloth#7281)."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+
+import storage.providers_db as providers_db
+
+
+@pytest.fixture()
+def isolated_providers_db(tmp_path: Path, monkeypatch: pytest.MonkeyPatch):
+    db_path = tmp_path / "studio.db"
+    monkeypatch.setattr(providers_db, "studio_db_path", lambda: db_path)
+    monkeypatch.setattr(providers_db, "ensure_dir", lambda _path: None)
+    providers_db._schema_ready = False
+    yield db_path
+    providers_db._schema_ready = False
+
+
+def test_create_and_list_provider_models(isolated_providers_db: Path):
+    providers_db.create_provider(
+        id = "ollama1",
+        provider_type = "ollama",
+        display_name = "Home Ollama",
+        base_url = "http://127.0.0.1:11434",
+        models = ["llama3.2", "qwen2.5"],
+        available_models = ["llama3.2", "qwen2.5", "mistral"],
+    )
+
+    row = providers_db.get_provider("ollama1")
+    assert row is not None
+    assert row["models"] == ["llama3.2", "qwen2.5"]
+    assert row["available_models"] == ["llama3.2", "qwen2.5", "mistral"]
+
+    listed = providers_db.list_providers()
+    assert len(listed) == 1
+    assert listed[0]["models"] == ["llama3.2", "qwen2.5"]
+
+
+def test_update_provider_models(isolated_providers_db: Path):
+    providers_db.create_provider(
+        id = "vllm1",
+        provider_type = "vllm",
+        display_name = "Remote vLLM",
+        base_url = "http://studio-host:8000/v1",
+        models = ["meta-llama/Llama-3.2-1B-Instruct"],
+        available_models = ["meta-llama/Llama-3.2-1B-Instruct"],
+    )
+
+    assert providers_db.update_provider(
+        id = "vllm1",
+        models = ["meta-llama/Llama-3.2-3B-Instruct"],
+        available_models = [
+            "meta-llama/Llama-3.2-1B-Instruct",
+            "meta-llama/Llama-3.2-3B-Instruct",
+        ],
+    )
+
+    row = providers_db.get_provider("vllm1")
+    assert row is not None
+    assert row["models"] == ["meta-llama/Llama-3.2-3B-Instruct"]
+    assert row["available_models"] == [
+        "meta-llama/Llama-3.2-1B-Instruct",
+        "meta-llama/Llama-3.2-3B-Instruct",
+    ]
diff --git a/studio/backend/tests/test_rag_embed_llama_server.py b/studio/backend/tests/test_rag_embed_llama_server.py
index 0e1f74cefe..3a332ee19b 100644
--- a/studio/backend/tests/test_rag_embed_llama_server.py
+++ b/studio/backend/tests/test_rag_embed_llama_server.py
@@ -149,7 +149,7 @@ def test_build_env_gpu_inherits_devices(monkeypatch):
     monkeypatch.setenv("CUDA_VISIBLE_DEVICES", "0,1")
     b = LlamaServerBackend()
     env = b._build_env("/bin/llama-server", use_gpu = True)
-    assert env.get("CUDA_VISIBLE_DEVICES") == "0,1"  # inherit Studio's selection
+    assert env.get("CUDA_VISIBLE_DEVICES") == "0,1"  # inherit Unsloth's selection
 
 
 def test_use_gpu_explicit_modes(monkeypatch):
diff --git a/studio/backend/tests/test_rag_embeddings.py b/studio/backend/tests/test_rag_embeddings.py
index 28a2f69426..197ae4c495 100644
--- a/studio/backend/tests/test_rag_embeddings.py
+++ b/studio/backend/tests/test_rag_embeddings.py
@@ -5,8 +5,10 @@
 and token counting must be serialized (else threads panic "Already borrowed")."""
 
 import os
+import sys
 import threading
 import time
+from types import SimpleNamespace
 
 import numpy as np
 import pytest
@@ -130,6 +132,35 @@ def test_token_counter_enables_parallelism_only_during_call(monkeypatch):
     assert os.environ.get("TOKENIZERS_PARALLELISM") == "false"  # restored after
 
 
+def test_sentence_transformer_load_uses_live_cache(monkeypatch, tmp_path):
+    observed = {}
+
+    class FakeSentenceTransformer:
+        def __init__(self, name, **kwargs):
+            observed["name"] = name
+            observed.update(kwargs)
+
+    monkeypatch.setitem(
+        sys.modules,
+        "sentence_transformers",
+        SimpleNamespace(SentenceTransformer = FakeSentenceTransformer),
+    )
+    monkeypatch.setattr(embeddings, "_install_torchao_stub_once", lambda: None)
+    monkeypatch.setattr(embeddings, "_guard_model_security", lambda *_a, **_k: None)
+    monkeypatch.setattr(embeddings, "_device", lambda: "cpu")
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.active_hf_hub_cache",
+        lambda: str(tmp_path / "selected-hub"),
+    )
+    embeddings._model = None
+    embeddings._name = None
+
+    embeddings._get("Org/Embedder")
+
+    assert observed["name"] == "Org/Embedder"
+    assert observed["cache_folder"] == str(tmp_path / "selected-hub")
+
+
 class _SentinelLlamaBackend:
     """Stand-in for LlamaServerBackend; never spawns a real server."""
 
diff --git a/studio/backend/tests/test_recommended_folders_permission.py b/studio/backend/tests/test_recommended_folders_permission.py
index 33a457755e..b65695ad93 100644
--- a/studio/backend/tests/test_recommended_folders_permission.py
+++ b/studio/backend/tests/test_recommended_folders_permission.py
@@ -112,7 +112,7 @@ def test_path_under_unreadable_parent_returns_false_not_raises(tmp_path):
 )
 def test_demonstrates_the_underlying_stdlib_regression(tmp_path):
     """Documents *why* _safe_is_dir exists: the old bare pattern raises on
-    the interpreters Studio ships on (3.12+)."""
+    the interpreters Unsloth ships on (3.12+)."""
     parent = tmp_path / "ollama"
     parent.mkdir()
     os.chmod(parent, 0o000)
diff --git a/studio/backend/tests/test_resolve_quant_gguf.py b/studio/backend/tests/test_resolve_quant_gguf.py
index 840c4d8d4c..a137237e80 100644
--- a/studio/backend/tests/test_resolve_quant_gguf.py
+++ b/studio/backend/tests/test_resolve_quant_gguf.py
@@ -68,8 +68,6 @@ def test_skips_mtp_drafter_for_main_weights(tmp_path):
 
 
 def test_prefers_the_complete_snapshot(tmp_path, monkeypatch):
-    from huggingface_hub import constants as hf_constants
-
     cache = tmp_path / "hub"
     snaps = cache / "models--org--repo" / "snapshots"
     # Partial older snapshot: one small shard.
@@ -78,7 +76,10 @@ def test_prefers_the_complete_snapshot(tmp_path, monkeypatch):
     complete_first = _write(snaps / "bbbb" / "model-00001-of-00002-Q4_K_M.gguf", 30)
     _write(snaps / "bbbb" / "model-00002-of-00002-Q4_K_M.gguf", 40)
 
-    monkeypatch.setattr(hf_constants, "HF_HUB_CACHE", str(cache))
+    monkeypatch.setattr(
+        "utils.hf_cache_settings.known_hf_hub_caches",
+        lambda: [cache],
+    )
 
     path, total = models_route._resolve_quant_gguf("org/repo", "Q4_K_M", is_local = False)
 
diff --git a/studio/backend/tests/test_responses_tool_passthrough.py b/studio/backend/tests/test_responses_tool_passthrough.py
index 46dd0d42e4..69715649b7 100644
--- a/studio/backend/tests/test_responses_tool_passthrough.py
+++ b/studio/backend/tests/test_responses_tool_passthrough.py
@@ -120,7 +120,7 @@ class TestResponsesRequestTools:
     def test_builtin_tool_type_passes_validation(self):
         """Non-function built-in tools (web_search, file_search, mcp, ...)
         must not raise at validation so SDKs that default to them don't
-        fail on Studio; they're filtered out during translation."""
+        fail on Unsloth; they're filtered out during translation."""
         req = ResponsesRequest(
             input = "hi",
             tools = [{"type": "web_search_preview"}],
diff --git a/studio/backend/tests/test_rocm_multi_gpu_vram_system_wide.py b/studio/backend/tests/test_rocm_multi_gpu_vram_system_wide.py
new file mode 100644
index 0000000000..bdafdeae9b
--- /dev/null
+++ b/studio/backend/tests/test_rocm_multi_gpu_vram_system_wide.py
@@ -0,0 +1,554 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""The System tab's multi-GPU view must show system-wide VRAM on ROCm (#7072).
+
+When amd-smi is unavailable, get_visible_gpu_utilization fell back to torch,
+whose readings are process-local: a model held by the separate llama-server
+process read as ~0 VRAM used even with the GPU full. These tests cover the
+per-GPU system-wide overlay the multi-device endpoint now applies, matched by
+physical device identity.
+"""
+
+from __future__ import annotations
+
+import importlib
+import sys
+import types
+from pathlib import Path
+
+_BACKEND_DIR = Path(__file__).resolve().parent.parent
+if str(_BACKEND_DIR) not in sys.path:
+    sys.path.insert(0, str(_BACKEND_DIR))
+
+
+def _maybe_stub(name: str, builder):
+    # Stub only if the real module is missing, so we never shadow it for later tests.
+    try:
+        importlib.import_module(name)
+    except ImportError:
+        sys.modules[name] = builder()
+
+
+def _build_loggers_stub():
+    m = types.ModuleType("loggers")
+    m.get_logger = lambda name: __import__("logging").getLogger(name)
+    return m
+
+
+def _build_structlog_stub():
+    m = types.ModuleType("structlog")
+    m.get_logger = lambda *a, **k: __import__("logging").getLogger("stub")
+    return m
+
+
+_maybe_stub("loggers", _build_loggers_stub)
+_maybe_stub("structlog", _build_structlog_stub)
+
+import utils.hardware.hardware as hw  # noqa: E402
+
+
+def _device(
+    index,
+    used,
+    total,
+    *,
+    ordinal = None,
+):
+    return {
+        "index": index,
+        "index_kind": "physical",
+        "visible_ordinal": index if ordinal is None else ordinal,
+        "gpu_utilization_pct": None,
+        "temperature_c": None,
+        "vram_used_gb": used,
+        "vram_total_gb": total,
+        "vram_utilization_pct": round((used / total) * 100, 1) if total > 0 else None,
+        "power_draw_w": None,
+        "power_limit_w": None,
+        "power_utilization_pct": None,
+    }
+
+
+# ── Linux per-card sysfs ──
+
+
+def _fake_drm(tmp_path, monkeypatch, cards):
+    """Fake /sys/class/drm tree; glob returns cards REVERSED so the PCI sort must order them.
+
+    ``cards``: (card_no, pci_bdf, driver, vram) tuples; vram is (used_gb, total_gb)
+    or None for a device with no mem_info_vram_* files.
+    """
+    drivers = tmp_path / "drivers"
+    card_paths = []
+    for card_no, bdf, driver, vram in cards:
+        pci_dir = tmp_path / "pci" / bdf
+        pci_dir.mkdir(parents = True, exist_ok = True)
+        drv_dir = drivers / driver
+        drv_dir.mkdir(parents = True, exist_ok = True)
+        (pci_dir / "driver").symlink_to(drv_dir)
+        if vram is not None:
+            used, total = vram
+            (pci_dir / "mem_info_vram_used").write_text(str(int(used * 1024**3)))
+            (pci_dir / "mem_info_vram_total").write_text(str(int(total * 1024**3)))
+        card_dir = tmp_path / "drm" / f"card{card_no}"
+        card_dir.mkdir(parents = True, exist_ok = True)
+        (card_dir / "device").symlink_to(pci_dir)
+        card_paths.append(str(card_dir))
+    monkeypatch.setattr(hw.glob, "glob", lambda pattern: list(reversed(card_paths)))
+    return card_paths
+
+
+def test_linux_vram_keyed_by_pci_excludes_foreign_adapters(monkeypatch, tmp_path):
+    # Foreign (non-amdgpu) adapters contribute no entry, so they cannot shift ordinals.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    _fake_drm(
+        tmp_path,
+        monkeypatch,
+        [
+            (0, "0000:00:02.0", "i915", (0.5, 2.0)),  # foreign adapter: excluded
+            (1, "0000:03:00.0", "amdgpu", (40, 48)),  # AMD device 0
+            (2, "0000:41:00.0", "amdgpu", (1, 8)),  # AMD device 1
+        ],
+    )
+    assert hw._rocm_linux_sysfs_vram_by_pci_gb() == {
+        "0000:03:00.0": (40.0, 48.0),
+        "0000:41:00.0": (1.0, 8.0),
+    }
+
+
+def test_linux_vram_omits_bad_cards_without_shifting(monkeypatch, tmp_path):
+    # A zero-total card has no entry; identity keying means its absence renumbers nothing.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    _fake_drm(
+        tmp_path,
+        monkeypatch,
+        [
+            (0, "0000:03:00.0", "amdgpu", (0, 0)),  # zero total -> no entry
+            (1, "0000:41:00.0", "amdgpu", (2, 16)),
+        ],
+    )
+    assert hw._rocm_linux_sysfs_vram_by_pci_gb() == {"0000:41:00.0": (2.0, 16.0)}
+
+
+def test_linux_vram_omits_amd_card_without_vram_files(monkeypatch, tmp_path):
+    # An APU with no mem_info_vram_* files has no entry; the discrete card keeps its address.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    _fake_drm(
+        tmp_path,
+        monkeypatch,
+        [
+            (0, "0000:03:00.0", "amdgpu", None),  # APU: no VRAM sysfs files
+            (1, "0000:41:00.0", "amdgpu", (2, 16)),
+        ],
+    )
+    assert hw._rocm_linux_sysfs_vram_by_pci_gb() == {"0000:41:00.0": (2.0, 16.0)}
+
+
+# ── KFD topology: the authoritative ROCm device order ──
+
+
+_AMD = 4098  # 0x1002
+_NVIDIA = 4318  # 0x10DE -- the open kernel module also registers KFD nodes
+
+
+def _fake_kfd(tmp_path, monkeypatch, nodes):
+    """Fake KFD topology nodes tree, returned out of node order so the sort must order it.
+
+    ``nodes``: (node_id, simd_count, location_id, domain, vendor_id); simd_count 0
+    marks a CPU node, location_id None omits the property.
+    """
+    node_paths = []
+    for node_id, simd_count, location_id, domain, vendor_id in nodes:
+        d = tmp_path / "kfd" / str(node_id)
+        d.mkdir(parents = True, exist_ok = True)
+        lines = [f"cpu_cores_count {0 if simd_count else 8}", f"simd_count {simd_count}"]
+        if location_id is not None:
+            lines.append(f"location_id {location_id}")
+        lines.append(f"domain {domain}")
+        if vendor_id is not None:
+            lines.append(f"vendor_id {vendor_id}")
+        (d / "properties").write_text("\n".join(lines) + "\n")
+        node_paths.append(str(d))
+    monkeypatch.setattr(hw.glob, "glob", lambda pattern: list(reversed(node_paths)))
+    return node_paths
+
+
+def test_kfd_lists_gpu_nodes_in_device_order(monkeypatch, tmp_path):
+    # The CPU node (simd_count 0) takes no ordinal; GPU nodes in node-id order are HIP's order.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    _fake_kfd(
+        tmp_path,
+        monkeypatch,
+        [
+            (0, 0, None, 0, None),  # CPU node
+            (1, 304, (0x03 << 8) | (0x00 << 3) | 0, 0, _AMD),  # 0000:03:00.0 -> dev 0
+            (2, 304, (0x41 << 8) | (0x00 << 3) | 0, 0, _AMD),  # 0000:41:00.0 -> dev 1
+        ],
+    )
+    assert hw._rocm_kfd_gpu_pci_ids() == ["0000:03:00.0", "0000:41:00.0"]
+
+
+def test_kfd_decodes_domain_device_and_function(monkeypatch, tmp_path):
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    _fake_kfd(tmp_path, monkeypatch, [(1, 64, (0xC1 << 8) | (0x1F << 3) | 5, 0x1234, _AMD)])
+    assert hw._rocm_kfd_gpu_pci_ids() == ["1234:c1:1f.5"]
+
+
+def test_kfd_skips_non_amd_gpu_nodes(monkeypatch, tmp_path):
+    # An NVIDIA KFD node is not a HIP device: it must take no ordinal, else it
+    # shifts every AMD GPU and ROCm device 1 resolves to AMD GPU 0.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    _fake_kfd(
+        tmp_path,
+        monkeypatch,
+        [
+            (0, 0, None, 0, None),  # CPU
+            (1, 128, (0x01 << 8) | 0, 0, _NVIDIA),  # NVIDIA: no ordinal
+            (2, 304, (0x03 << 8) | 0, 0, _AMD),  # AMD device 0
+            (3, 304, (0x41 << 8) | 0, 0, _AMD),  # AMD device 1
+        ],
+    )
+    assert hw._rocm_kfd_gpu_pci_ids() == ["0000:03:00.0", "0000:41:00.0"]
+
+
+def test_kfd_fails_closed_when_a_gpu_has_no_location(monkeypatch, tmp_path):
+    # Dropping an unplaceable AMD GPU shifts later ordinals; fail closed for the whole map.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    _fake_kfd(
+        tmp_path,
+        monkeypatch,
+        [
+            (1, 304, None, 0, _AMD),  # AMD GPU with no location_id
+            (2, 304, (0x41 << 8) | 0, 0, _AMD),
+        ],
+    )
+    assert hw._rocm_kfd_gpu_pci_ids() == []
+
+
+def test_kfd_fails_closed_when_a_node_is_unreadable(monkeypatch, tmp_path):
+    # An unreadable node could be a GPU; assuming otherwise would shift ordinals.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    paths = _fake_kfd(
+        tmp_path,
+        monkeypatch,
+        [
+            (1, 304, (0x03 << 8) | 0, 0, _AMD),
+            (2, 304, (0x41 << 8) | 0, 0, _AMD),
+        ],
+    )
+    (Path(paths[0]) / "properties").unlink()
+    assert hw._rocm_kfd_gpu_pci_ids() == []
+
+
+def test_kfd_absent_yields_no_device_order(monkeypatch):
+    monkeypatch.setattr(hw.glob, "glob", lambda pattern: [])
+    assert hw._rocm_kfd_gpu_pci_ids() == []
+
+
+# ── overlay ──
+
+
+def _patch_pci_map(monkeypatch, bdfs):
+    """Declare the ROCm device order by PCI address (index N is device N) and clear
+    the visibility masks the overlay requires unset.
+    """
+    for var in (
+        "HIP_VISIBLE_DEVICES",
+        "ROCR_VISIBLE_DEVICES",
+        "CUDA_VISIBLE_DEVICES",
+        "GPU_DEVICE_ORDINAL",
+    ):
+        monkeypatch.delenv(var, raising = False)
+    monkeypatch.setattr(hw, "_rocm_kfd_gpu_pci_ids", lambda: list(bdfs))
+
+
+def _pci(n):
+    """A distinct, well-formed PCI address for card n."""
+    return f"0000:{n:02x}:00.0"
+
+
+def test_overlay_windows_is_noop_keeps_torch(monkeypatch):
+    # Windows is intentionally not overlaid (perf counters can't map to ROCm ordinals): keep torch.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Windows")
+    monkeypatch.setattr(
+        hw,
+        "_rocm_linux_sysfs_vram_by_pci_gb",
+        lambda: (_ for _ in ()).throw(AssertionError("sysfs must not run on Windows")),
+    )
+    devices = [_device(0, used = 0.02, total = 8.0)]
+    _patch_pci_map(monkeypatch, [_pci(0)])
+    hw._overlay_system_wide_vram(devices)
+    assert devices[0]["vram_used_gb"] == 0.02  # untouched
+
+
+def test_overlay_linux_matches_by_device_ordinal(monkeypatch):
+    # Devices arriving as [index 1, index 0] each get their own GPU's figures by ordinal.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    monkeypatch.setattr(
+        hw,
+        "_rocm_linux_sysfs_vram_by_pci_gb",
+        lambda: {_pci(0): (30.0, 45.0), _pci(1): (0.5, 8.0)},  # dev 0 big, dev 1 small
+    )
+    devices = [_device(1, used = 0.01, total = 8.0), _device(0, used = 0.02, total = 45.0)]
+    _patch_pci_map(monkeypatch, [_pci(0), _pci(1)])
+    hw._overlay_system_wide_vram(devices)
+    assert devices[0]["vram_used_gb"] == 0.5  # index 1 -> device 1 (small)
+    assert devices[0]["vram_total_gb"] == 8.0
+    assert devices[1]["vram_used_gb"] == 30.0  # index 0 -> device 0 (big)
+    assert devices[1]["vram_total_gb"] == 45.0
+
+
+def test_overlay_linux_ordinal_hole_does_not_shift(monkeypatch):
+    # Device 0's card dropped: index 0 keeps torch, index 1 still maps to ordinal 1 (no compaction).
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    monkeypatch.setattr(hw, "_rocm_linux_sysfs_vram_by_pci_gb", lambda: {_pci(1): (0.5, 8.0)})
+    devices = [_device(0, used = 0.02, total = 45.0), _device(1, used = 0.01, total = 8.0)]
+    _patch_pci_map(monkeypatch, [_pci(0), _pci(1)])
+    hw._overlay_system_wide_vram(devices)
+    assert devices[0]["vram_used_gb"] == 0.02  # no ordinal 0 -> torch kept
+    assert devices[1]["vram_used_gb"] == 0.5  # ordinal 1 -> device 1, not device 0
+
+
+def test_overlay_linux_skips_unified_memory_card(monkeypatch):
+    # Unified-memory APU: the smaller sysfs total must not shrink torch's GTT-backed pool.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    monkeypatch.setattr(hw, "_rocm_linux_sysfs_vram_by_pci_gb", lambda: {_pci(0): (0.4, 1.0)})
+    devices = [_device(0, used = 12.0, total = 96.0)]  # torch's unified pool
+    _patch_pci_map(monkeypatch, [_pci(0)])
+    hw._overlay_system_wide_vram(devices)
+    assert devices[0]["vram_used_gb"] == 12.0
+    assert devices[0]["vram_total_gb"] == 96.0
+
+
+def test_overlay_linux_skips_partitioned_device(monkeypatch):
+    # Partitioned MI300: the whole-card sysfs total dwarfs the partition, so the overlay must not overwrite it.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    monkeypatch.setattr(hw, "_rocm_linux_sysfs_vram_by_pci_gb", lambda: {_pci(0): (40.0, 192.0)})
+    devices = [_device(0, used = 1.0, total = 24.0)]  # torch partition
+    _patch_pci_map(monkeypatch, [_pci(0)])
+    hw._overlay_system_wide_vram(devices)
+    assert devices[0]["vram_used_gb"] == 1.0  # partition figures kept
+    assert devices[0]["vram_total_gb"] == 24.0
+
+
+def test_overlay_linux_out_of_range_index_untouched(monkeypatch):
+    # A masked host exposing physical index 5 with no card 5: keep torch data.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    monkeypatch.setattr(
+        hw, "_rocm_linux_sysfs_vram_by_pci_gb", lambda: {_pci(0): (30.0, 45.0), _pci(1): (0.5, 8.0)}
+    )
+    devices = [_device(5, used = 0.02, total = 45.0)]
+    _patch_pci_map(monkeypatch, [_pci(0), _pci(1)])
+    hw._overlay_system_wide_vram(devices)
+    assert devices[0]["vram_used_gb"] == 0.02
+
+
+def test_overlay_ignores_adapters_rocm_cannot_enumerate(monkeypatch):
+    # A HIP-unenumerable amdgpu adapter has no KFD node, so device 0 resolves to
+    # the supported GPU's own address, never the display card's.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    monkeypatch.setattr(
+        hw,
+        "_rocm_linux_sysfs_vram_by_pci_gb",
+        # Both in DRM sysfs with similar capacity -- what the total-size guard can't separate.
+        lambda: {_pci(9): (30.0, 45.0), _pci(3): (12.0, 45.0)},
+    )
+    _patch_pci_map(monkeypatch, [_pci(3)])  # KFD lists only the supported GPU
+    devices = [_device(0, used = 0.02, total = 45.0)]  # torch sees that one GPU
+    hw._overlay_system_wide_vram(devices)
+    assert devices[0]["vram_used_gb"] == 12.0  # the supported GPU's own figures
+
+
+def test_overlay_skips_masked_subsets(monkeypatch):
+    # Under a mask the index is not verifiably a host ordinal, so keep torch's figures.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    _patch_pci_map(monkeypatch, [_pci(0), _pci(1), _pci(2), _pci(3)])
+    monkeypatch.setenv("HIP_VISIBLE_DEVICES", "1,3")
+    monkeypatch.setattr(
+        hw,
+        "_rocm_linux_sysfs_vram_by_pci_gb",
+        lambda: {_pci(1): (30.0, 48.0), _pci(3): (12.0, 48.0)},
+    )
+    devices = [_device(1, used = 0.02, total = 48.0), _device(3, used = 0.01, total = 48.0)]
+    hw._overlay_system_wide_vram(devices)
+    assert devices[0]["vram_used_gb"] == 0.02  # torch kept
+    assert devices[1]["vram_used_gb"] == 0.01
+
+
+def test_overlay_skips_device_cgroup_filtered_container(monkeypatch):
+    # A device-cgroup container sets no env var yet compacts torch's indices from
+    # zero while KFD/DRM list every GPU, so the count mismatch must disable the overlay.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    _patch_pci_map(monkeypatch, [_pci(0), _pci(1), _pci(2), _pci(3)])  # host has 4
+    monkeypatch.setattr(
+        hw,
+        "_rocm_linux_sysfs_vram_by_pci_gb",
+        lambda: {_pci(0): (30.0, 48.0), _pci(2): (12.0, 48.0)},
+    )
+    devices = [_device(0, used = 0.02, total = 48.0)]  # container sees 1, as index 0
+    hw._overlay_system_wide_vram(devices)
+    assert devices[0]["vram_used_gb"] == 0.02  # torch kept, not host GPU 0's 30.0
+
+
+def test_overlay_skips_without_kfd_topology(monkeypatch):
+    # No KFD means no identity to join on; fall back to torch rather than guess.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    monkeypatch.setattr(hw, "_rocm_kfd_gpu_pci_ids", lambda: [])
+    monkeypatch.setattr(
+        hw,
+        "_rocm_linux_sysfs_vram_by_pci_gb",
+        lambda: (_ for _ in ()).throw(AssertionError("must not read sysfs without KFD")),
+    )
+    devices = [_device(0, used = 0.02, total = 45.0)]
+    hw._overlay_system_wide_vram(devices)
+    assert devices[0]["vram_used_gb"] == 0.02
+
+
+def test_overlay_empty_devices_is_noop(monkeypatch):
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    hw._overlay_system_wide_vram([])  # must not raise
+
+
+# ── integration: the ROCm torch fallback applies the overlay ──
+
+
+def test_visible_utilization_rocm_fallback_overlays(monkeypatch):
+    for _var in (
+        "HIP_VISIBLE_DEVICES",
+        "ROCR_VISIBLE_DEVICES",
+        "CUDA_VISIBLE_DEVICES",
+        "GPU_DEVICE_ORDINAL",
+    ):
+        monkeypatch.delenv(_var, raising = False)
+    monkeypatch.setattr(hw, "IS_ROCM", True)
+    monkeypatch.setattr(hw, "get_device", lambda: hw.DeviceType.CUDA)
+    monkeypatch.setattr(hw, "_smi_query", lambda *a, **k: None)  # amd-smi unavailable
+    monkeypatch.setattr(
+        hw,
+        "_get_parent_visible_gpu_spec",
+        lambda: {"raw": None, "numeric_ids": [0, 1], "supports_explicit_gpu_ids": True},
+    )
+    monkeypatch.setattr(hw, "get_parent_visible_gpu_ids", lambda: [0, 1])
+    monkeypatch.setattr(
+        hw,
+        "_torch_get_per_device_info",
+        lambda ids: [
+            {"index": 0, "visible_ordinal": 0, "used_gb": 0.02, "total_gb": 45.0},
+            {"index": 1, "visible_ordinal": 1, "used_gb": 0.01, "total_gb": 8.0},
+        ],
+    )
+    overlaid = []
+    monkeypatch.setattr(
+        hw, "_overlay_system_wide_vram", lambda devices: overlaid.append(len(devices))
+    )
+    result = hw.get_visible_gpu_utilization()
+    assert result["available"] is True
+    assert overlaid == [2]
+
+
+def test_visible_utilization_relative_index_skips_overlay(monkeypatch):
+    # UUID/MIG mask gives relative indices; the overlay matches physical index, so it must not run.
+    monkeypatch.setattr(hw, "IS_ROCM", True)
+    monkeypatch.setattr(hw, "get_device", lambda: hw.DeviceType.CUDA)
+    monkeypatch.setattr(hw, "_smi_query", lambda *a, **k: None)
+    monkeypatch.setattr(
+        hw,
+        "_get_parent_visible_gpu_spec",
+        lambda: {"raw": "GPU-uuid-a", "numeric_ids": None, "supports_explicit_gpu_ids": False},
+    )
+    monkeypatch.setattr(hw, "get_parent_visible_gpu_ids", lambda: [])  # UUID mask
+    monkeypatch.setattr(hw, "_torch_get_physical_gpu_count", lambda: 1)
+    monkeypatch.setattr(
+        hw,
+        "_torch_get_per_device_info",
+        lambda ids: [{"index": 0, "visible_ordinal": 0, "used_gb": 0.02, "total_gb": 8.0}],
+    )
+    called = []
+    monkeypatch.setattr(hw, "_overlay_system_wide_vram", lambda devices: called.append(1))
+    result = hw.get_visible_gpu_utilization()
+    assert result["index_kind"] == "relative"
+    assert called == []
+
+
+def test_visible_utilization_nvidia_fallback_skips_overlay(monkeypatch):
+    monkeypatch.setattr(hw, "IS_ROCM", False)
+    monkeypatch.setattr(hw, "get_device", lambda: hw.DeviceType.CUDA)
+    monkeypatch.setattr(hw, "_smi_query", lambda *a, **k: None)
+    monkeypatch.setattr(
+        hw,
+        "_get_parent_visible_gpu_spec",
+        lambda: {"raw": None, "numeric_ids": [0], "supports_explicit_gpu_ids": True},
+    )
+    monkeypatch.setattr(hw, "get_parent_visible_gpu_ids", lambda: [0])
+    monkeypatch.setattr(
+        hw,
+        "_torch_get_per_device_info",
+        lambda ids: [{"index": 0, "visible_ordinal": 0, "used_gb": 1.0, "total_gb": 24.0}],
+    )
+    called = []
+    monkeypatch.setattr(hw, "_overlay_system_wide_vram", lambda devices: called.append(1))
+    result = hw.get_visible_gpu_utilization()
+    assert result["available"] is True
+    assert called == []
+
+
+def test_any_visibility_mask_is_detected(monkeypatch):
+    # Any of these makes the index not a host-physical ordinal, so each must disable the overlay.
+    for var in (
+        "HIP_VISIBLE_DEVICES",
+        "ROCR_VISIBLE_DEVICES",
+        "CUDA_VISIBLE_DEVICES",
+        "GPU_DEVICE_ORDINAL",
+    ):
+        monkeypatch.delenv(var, raising = False)
+    assert hw._rocm_visibility_mask_active() is False
+    for var in (
+        "HIP_VISIBLE_DEVICES",
+        "ROCR_VISIBLE_DEVICES",
+        "CUDA_VISIBLE_DEVICES",
+        "GPU_DEVICE_ORDINAL",
+    ):
+        monkeypatch.setenv(var, "1")
+        assert hw._rocm_visibility_mask_active() is True, var
+        monkeypatch.setenv(var, "  ")  # empty is not an active filter
+        assert hw._rocm_visibility_mask_active() is False, var
+        monkeypatch.delenv(var, raising = False)
+
+
+def test_overlay_skips_under_gpu_device_ordinal(monkeypatch):
+    # GPU_DEVICE_ORDINAL=1 surfaces GPU 1 as torch ordinal 0, so index 0 is not GPU 0; overlay must not run.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    _patch_pci_map(monkeypatch, [_pci(0)])
+    monkeypatch.setenv("GPU_DEVICE_ORDINAL", "1")
+    monkeypatch.setattr(hw, "_rocm_linux_sysfs_vram_by_pci_gb", lambda: {_pci(0): (30.0, 45.0)})
+    devices = [_device(0, used = 0.02, total = 45.0)]
+    hw._overlay_system_wide_vram(devices)
+    assert devices[0]["vram_used_gb"] == 0.02
+
+
+def test_visible_utilization_delegates_gating_to_the_overlay(monkeypatch):
+    # The call site no longer pre-checks masks; the overlay gates itself, so a physical payload always reaches it.
+    monkeypatch.setenv("ROCR_VISIBLE_DEVICES", "2,3")
+    monkeypatch.setenv("HIP_VISIBLE_DEVICES", "1")
+    monkeypatch.setattr(hw, "IS_ROCM", True)
+    monkeypatch.setattr(hw, "get_device", lambda: hw.DeviceType.CUDA)
+    monkeypatch.setattr(hw, "_smi_query", lambda *a, **k: None)
+    monkeypatch.setattr(
+        hw,
+        "_get_parent_visible_gpu_spec",
+        lambda: {"raw": "1", "numeric_ids": [1], "supports_explicit_gpu_ids": True},
+    )
+    monkeypatch.setattr(hw, "get_parent_visible_gpu_ids", lambda: [1])
+    monkeypatch.setattr(
+        hw,
+        "_torch_get_per_device_info",
+        lambda ids: [{"index": 1, "visible_ordinal": 0, "used_gb": 0.02, "total_gb": 8.0}],
+    )
+    # Real overlay + gating: the layered mask must leave torch's figures.
+    monkeypatch.setattr(hw.platform, "system", lambda: "Linux")
+    monkeypatch.setattr(hw, "_rocm_kfd_gpu_pci_ids", lambda: [_pci(0), _pci(1)])
+    monkeypatch.setattr(hw, "_rocm_linux_sysfs_vram_by_pci_gb", lambda: {_pci(1): (30.0, 8.0)})
+    result = hw.get_visible_gpu_utilization()
+    assert result["index_kind"] == "physical"
+    assert result["devices"][0]["vram_used_gb"] == 0.02  # untouched
diff --git a/studio/backend/tests/test_rocm_oom_guard.py b/studio/backend/tests/test_rocm_oom_guard.py
index 6e70c7cde4..ad46f6ee41 100644
--- a/studio/backend/tests/test_rocm_oom_guard.py
+++ b/studio/backend/tests/test_rocm_oom_guard.py
@@ -36,7 +36,7 @@ class TestIsIntegratedSignal:
     """hipDeviceProp_t.integrated wins when truthy; 0/absent never downgrades.
 
     Same universal gate PR #5988's UMA safetensors fast-load uses -- keeps
-    Studio's two unified-memory consumers on one signal."""
+    Unsloth's two unified-memory consumers on one signal."""
 
     def test_integrated_upgrades_unknown_apu(self) -> None:
         # gfx1103 Phoenix iGPU: outside the hardcoded arch set, but the
@@ -163,6 +163,9 @@ class TestDeviceNameFallback:
             "AMD Radeon 8060S",
             "Radeon 8050S Graphics",  # cut-down Strix Halo SKU
             "AMD Radeon 8050S",
+            # gfx1151 Gorgon Halo (Ryzen AI Max 400 refresh)
+            "Radeon 8065S Graphics",  # Ryzen AI Max+ 495
+            "AMD Radeon 8065S",
             # case variants
             "RADEON 8060S GRAPHICS",
             "radeon 8050s",
diff --git a/studio/backend/tests/test_rocm_windows_vram_7072.py b/studio/backend/tests/test_rocm_windows_vram_7072.py
new file mode 100644
index 0000000000..b4079831b7
--- /dev/null
+++ b/studio/backend/tests/test_rocm_windows_vram_7072.py
@@ -0,0 +1,361 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Regression tests for issue #7072 -- "VRAM Usage in System Tab is wrong".
+
+Reporter: dual AMD (Radeon PRO W7900 ~48GB + W7500 8GB), Windows 10, ROCm 7.13,
+torch 2.11.0+rocm7.13. On Windows without a HIP SDK, amd-smi is permanently
+disabled (avoids a UAC/DiskPart prompt) and hipMemGetInfo returns free==total
+(used 0). Two symptoms followed:
+
+  * System tab (/api/system -> get_visible_gpu_utilization) showed ~0 VRAM used
+    on every GPU (torch mem_get_info free==total quirk; ROCm/ROCm#1909).
+  * get_gpu_utilization()'s Windows fallback SUMMED "GPU Adapter Memory\\Dedicated
+    Usage" across all adapters into ONE fake device with only GPU 0's total, so
+    the second GPU never appeared.
+
+The fix reads the per-adapter (LUID-instanced) Dedicated Usage performance
+counter -- Task Manager's source -- for per-GPU used, takes per-GPU total from
+torch device properties, and guards the free==total mem_get_info quirk. CI has no
+AMD GPU/Windows, so torch, the performance counter, and platform are all mocked.
+"""
+
+from __future__ import annotations
+
+import subprocess
+import sys
+import types
+
+import pytest
+
+from utils.hardware import hardware as hw
+
+GB = 1024**3
+MiB = 1024**2
+
+
+# ----------------------------------------------------------------------------- #
+# Fakes
+# ----------------------------------------------------------------------------- #
+def _fake_torch(
+    devices,
+    *,
+    free_equals_total = False,
+    used_per_device = None,
+):
+    """Build a fake `torch` module. devices: list of (name, total_bytes)."""
+    dev = list(devices)
+
+    class _Props:
+        def __init__(self, name, total):
+            self.name = name
+            self.total_memory = total
+
+    def get_device_properties(i):
+        name, total = dev[i]
+        return _Props(name, total)
+
+    def mem_get_info(i):
+        _, total = dev[i]
+        if free_equals_total:
+            return (total, total)
+        used = used_per_device[i] if used_per_device is not None else 0
+        return (total - used, total)
+
+    t = types.ModuleType("torch")
+    t.__version__ = "2.11.0+rocm7.13"
+    t.version = types.SimpleNamespace(hip = "7.13", cuda = None)
+    t.cuda = types.SimpleNamespace(
+        is_available = lambda: len(dev) > 0,
+        device_count = lambda: len(dev),
+        current_device = lambda: 0,
+        get_device_properties = get_device_properties,
+        mem_get_info = mem_get_info,
+        memory_allocated = lambda i: 0,
+        memory_reserved = lambda i: 0,
+    )
+    return t
+
+
+def _adapter_output(adapters):
+    if not adapters:
+        return "__NONE__\n"
+    return "".join(f"{name}|{int(used)}\n" for name, used in adapters)
+
+
+def _subprocess_run(*, adapter_output = "__NONE__\n", util_output = "12.0\n"):
+    def fake_run(cmd, *a, **k):
+        joined = " ".join(cmd) if isinstance(cmd, list) else str(cmd)
+        if "GPU Adapter Memory" in joined and "InstanceName" in joined:
+            out = adapter_output
+        elif "engtype_3D" in joined or "GPU Engine" in joined:
+            out = util_output
+        else:
+            out = "-1\n"
+        return subprocess.CompletedProcess(args = cmd, returncode = 0, stdout = out, stderr = "")
+
+    return fake_run
+
+
+@pytest.fixture
+def win_rocm(monkeypatch):
+    """Configure the hardware module as a Windows ROCm host with 2 visible GPUs."""
+    monkeypatch.setattr(hw, "get_device", lambda: hw.DeviceType.CUDA)
+    monkeypatch.setattr(hw, "IS_ROCM", True)
+    monkeypatch.setattr(hw.platform, "system", lambda: "Windows")
+    monkeypatch.setattr(hw.sys, "platform", "win32")
+    monkeypatch.setattr(hw, "_smi_query", lambda *a, **k: None)  # amd-smi disabled
+    # Visible set via HIP mask so we don't shell out to amd-smi for the count.
+    monkeypatch.setenv("HIP_VISIBLE_DEVICES", "0,1")
+    monkeypatch.delenv("CUDA_VISIBLE_DEVICES", raising = False)
+    monkeypatch.delenv("ROCR_VISIBLE_DEVICES", raising = False)
+    return monkeypatch
+
+
+REPORTER_ADAPTERS = [
+    ("luid_0x00000000_0x0000d1e2_phys_0", 40.0 * GB),  # W7900, model loaded
+    ("luid_0x00000000_0x0000e34a_phys_0", 0.5 * GB),  # W7500, idle
+    ("luid_0x00000000_0x0000f001_phys_0", 3 * MiB),  # Basic Render Driver
+]
+DEVICES = [("AMD Radeon PRO W7900", 48 * GB), ("AMD Radeon PRO W7500", 8 * GB)]
+
+
+# ----------------------------------------------------------------------------- #
+# System tab (get_visible_gpu_utilization) -- the reporter's screenshot
+# ----------------------------------------------------------------------------- #
+def test_system_tab_shows_per_gpu_used(win_rocm, monkeypatch):
+    monkeypatch.setitem(sys.modules, "torch", _fake_torch(DEVICES, free_equals_total = True))
+    monkeypatch.setattr(
+        hw.subprocess, "run", _subprocess_run(adapter_output = _adapter_output(REPORTER_ADAPTERS))
+    )
+
+    devices = hw.get_visible_gpu_utilization()["devices"]
+    by_idx = {d["index"]: d for d in devices}
+    assert len(devices) == 2
+    assert by_idx[0]["vram_total_gb"] == 48.0
+    assert by_idx[0]["vram_used_gb"] == pytest.approx(40.0, abs = 0.01)  # not 0
+    assert by_idx[1]["vram_total_gb"] == 8.0  # own total
+    # The 3 MiB Basic Render Driver counter makes this a hidden-adapter case: only
+    # the 40 GiB is forced onto the 48 GiB card; the idle card reads Unknown.
+    assert by_idx[1]["vram_used_gb"] is None
+    assert by_idx[1]["vram_utilization_pct"] is None
+    assert all(
+        d["vram_used_gb"] <= d["vram_total_gb"] for d in devices if d["vram_used_gb"] is not None
+    )
+
+
+def test_gpu_utilization_does_not_collapse(win_rocm, monkeypatch):
+    monkeypatch.setitem(sys.modules, "torch", _fake_torch(DEVICES, free_equals_total = True))
+    monkeypatch.setattr(
+        hw.subprocess, "run", _subprocess_run(adapter_output = _adapter_output(REPORTER_ADAPTERS))
+    )
+
+    result = hw.get_gpu_utilization()
+    devices = result["devices"]
+    assert sorted(d["index"] for d in devices) == [0, 1]  # both GPUs, no collapse
+    assert {d["vram_total_gb"] for d in devices} == {48.0, 8.0}
+    assert result["vram_total_gb"] == 48.0  # legacy primary mirror preserved
+
+
+def test_localized_counter_reports_unknown_not_zero(win_rocm, monkeypatch):
+    monkeypatch.setitem(sys.modules, "torch", _fake_torch(DEVICES, free_equals_total = True))
+    monkeypatch.setattr(hw.subprocess, "run", _subprocess_run(adapter_output = "__NONE__\n"))
+
+    devices = hw.get_visible_gpu_utilization()["devices"]
+    assert len(devices) == 2  # both still shown with correct totals
+    assert {d["vram_total_gb"] for d in devices} == {48.0, 8.0}
+    assert all(d["vram_used_gb"] is None for d in devices)  # unknown, not fake 0
+    assert all(d["vram_utilization_pct"] is None for d in devices)
+
+
+# ----------------------------------------------------------------------------- #
+# mem_get_info free==total guard scoping
+# ----------------------------------------------------------------------------- #
+def test_mem_get_info_guard_scopes_to_windows_rocm(monkeypatch):
+    torch_mod = _fake_torch(DEVICES, free_equals_total = True)
+    monkeypatch.setattr(hw, "get_device", lambda: hw.DeviceType.CUDA)
+    monkeypatch.setitem(sys.modules, "torch", torch_mod)
+
+    # Windows ROCm -> used unknown (None), total kept.
+    monkeypatch.setattr(hw, "IS_ROCM", True)
+    monkeypatch.setattr(hw.sys, "platform", "win32")
+    win = hw._torch_get_per_device_info([0, 1])
+    assert [d["used_gb"] for d in win] == [None, None]
+    assert [d["total_gb"] for d in win] == [48.0, 8.0]
+
+    # Linux ROCm -> unchanged numeric used.
+    monkeypatch.setattr(hw.sys, "platform", "linux")
+    assert [d["used_gb"] for d in hw._torch_get_per_device_info([0, 1])] == [0.0, 0.0]
+
+    # Windows NVIDIA -> guard must not fire.
+    monkeypatch.setattr(hw, "IS_ROCM", False)
+    monkeypatch.setattr(hw.sys, "platform", "win32")
+    assert [d["used_gb"] for d in hw._torch_get_per_device_info([0, 1])] == [0.0, 0.0]
+
+
+# ----------------------------------------------------------------------------- #
+# Per-adapter attribution helpers (pure unit)
+# ----------------------------------------------------------------------------- #
+def test_match_adapter_pairs_and_clamps():
+    assert hw._match_adapter_used_to_devices([40 * GB, 0.5 * GB], [48 * GB, 8 * GB]) == [
+        40 * GB,
+        0.5 * GB,
+    ]
+    assert hw._match_adapter_used_to_devices([100 * GB], [48 * GB]) == [48 * GB]  # clamp
+    assert hw._match_adapter_used_to_devices([40 * GB], [48 * GB, 8 * GB]) == [40 * GB, None]
+
+
+def test_match_adapter_reports_unknown_when_more_active_than_visible():
+    # More adapters actively using VRAM than are visible (a GPU outside the mask):
+    # attribution would fabricate a value, so report unknown for every device.
+    assert hw._match_adapter_used_to_devices([40 * GB, 0.5 * GB], [8 * GB]) == [None]
+
+
+def test_match_adapter_reports_unknown_when_hidden_high_use_adapter_survives_filter():
+    # Idle 8 GiB card (10 MiB noise) beside a hidden 48 GiB card at 40 GiB: the
+    # 40 GiB can't fit the 8 GiB device, so clamping there would fabricate. Unknown.
+    assert hw._match_adapter_used_to_devices([40 * GB, 10 * MiB], [8 * GB]) == [None]
+    # Order of the counters must not matter.
+    assert hw._match_adapter_used_to_devices([10 * MiB, 40 * GB], [8 * GB]) == [None]
+
+
+def test_match_adapter_reports_unknown_for_placeholder_fallback():
+    # Every counter below the 64 MiB floor plus a placeholder: no LUID-to-ordinal
+    # mapping tells placeholder from idle GPU, so report unknown, not fabricate.
+    # Single visible 8 GiB card idle (10 MiB) beside a 50 MiB placeholder counter.
+    assert hw._match_adapter_used_to_devices([50 * MiB, 10 * MiB], [8 * GB]) == [None]
+    # Order of the counters must not matter.
+    assert hw._match_adapter_used_to_devices([10 * MiB, 50 * MiB], [8 * GB]) == [None]
+    # Two idle visible GPUs plus a placeholder: all three counters below the floor.
+    assert hw._match_adapter_used_to_devices([50 * MiB, 10 * MiB, 5 * MiB], [48 * GB, 8 * GB]) == [
+        None,
+        None,
+    ]
+
+
+def test_match_adapter_reports_unknown_when_usage_not_capacity_ordered():
+    # 8 GiB card at 7 GiB beside a 48 GiB card at 5 GiB: the bigger usage still fits
+    # the smaller card, so both pairings are feasible -> unknown.
+    assert hw._match_adapter_used_to_devices([7 * GB, 5 * GB], [8 * GB, 48 * GB]) == [None, None]
+    # Device order must not matter (same physical situation, ordinals flipped).
+    assert hw._match_adapter_used_to_devices([7 * GB, 5 * GB], [48 * GB, 8 * GB]) == [None, None]
+    # Same-capacity cards with unequal usage are equally unattributable.
+    assert hw._match_adapter_used_to_devices([12 * GB, 8 * GB], [24 * GB, 24 * GB]) == [None, None]
+    # A single usage that fits both cards can sit on either -> unknown.
+    assert hw._match_adapter_used_to_devices([5 * GB], [48 * GB, 8 * GB]) == [None, None]
+    # But a capacity-forced assignment (usage exceeds the smaller card) is kept:
+    # 40 GiB can only be the 48 GiB card, so it is not fabrication.
+    assert hw._match_adapter_used_to_devices([40 * GB], [48 * GB, 8 * GB]) == [40 * GB, None]
+
+
+def test_match_adapter_reports_unknown_when_hidden_usage_fits_visible_card():
+    # A survivor that merely *fits* a visible card must not be pinned onto it. Two
+    # cards (48/8 GiB) at 40 GiB / 10 MiB beside a hidden 6 GiB adapter: the 6 GiB
+    # fits the idle 8 GiB card but isn't forced -> Unknown; only 40 GiB is forced.
+    assert hw._match_adapter_used_to_devices([40 * GB, 10 * MiB, 6 * GB], [48 * GB, 8 * GB]) == [
+        40 * GB,
+        None,
+    ]
+    # Counter order must not matter.
+    assert hw._match_adapter_used_to_devices([6 * GB, 40 * GB, 10 * MiB], [48 * GB, 8 * GB]) == [
+        40 * GB,
+        None,
+    ]
+    # A single visible card with a hidden adapter is never attributable: a fitting
+    # survivor could be the hidden GPU's while the visible card is idle.
+    assert hw._match_adapter_used_to_devices([6 * GB, 10 * MiB], [8 * GB]) == [None]
+
+
+def test_match_adapter_capacity_forced_matrix():
+    """Exhaustive hidden-adapter matrix for the capacity-forced rule.
+
+    A value is emitted only when the supra-threshold counters number exactly the
+    visible devices AND a device's ranked usage strictly exceeds every smaller
+    card's capacity. Otherwise (a visible card idle, a merely-fitting usage, or the
+    smallest card) every device reports unknown.
+    """
+    m = hw._match_adapter_used_to_devices
+    # -- exactly-n supra-threshold counters, capacity-forced survivors are kept - #
+    # Both visible cards have a real reading (the 3 MiB is a placeholder): 40 GiB
+    # forced onto the 48 GiB card, 0.5 GiB not forced -> None.
+    assert m([40 * GB, 0.5 * GB, 3 * MiB], [48 * GB, 8 * GB]) == [40 * GB, None]
+    # Three visible cards all active (supra-threshold) + placeholder: 40 > 24 and
+    # 20 > 8, both forced; the 8 GiB card is not forced -> None.
+    assert m([40 * GB, 20 * GB, 5 * GB, 3 * MiB], [48 * GB, 24 * GB, 8 * GB]) == [
+        40 * GB,
+        20 * GB,
+        None,
+    ]
+    # -- fewer supra-threshold counters than visible cards -> all unknown ------ #
+    # A visible card is idle, so even a "forced" 40 could be the hidden GPU's.
+    assert m([40 * GB, 3 * MiB, 3 * MiB], [48 * GB, 8 * GB]) == [None, None]
+    assert m([40 * GB, 10 * MiB, 10 * MiB], [48 * GB, 8 * GB]) == [None, None]
+    assert m([40 * GB, 20 * GB, 3 * MiB, 3 * MiB], [48 * GB, 24 * GB, 8 * GB]) == [
+        None,
+        None,
+        None,
+    ]
+    # Middle usage (6 GiB) fits both the 24 and 8 GiB cards, and only two cards are
+    # active for three visible -> not a bijection -> all unknown.
+    assert m([40 * GB, 6 * GB, 3 * MiB, 3 * MiB], [48 * GB, 24 * GB, 8 * GB]) == [
+        None,
+        None,
+        None,
+    ]
+    # -- hidden larger than every visible card -> all unknown ----------------- #
+    assert m([40 * GB, 10 * MiB], [8 * GB]) == [None]
+    assert m([48 * GB, 3 * MiB, 3 * MiB], [24 * GB, 8 * GB]) == [None, None]
+    # -- more active adapters than visible cards -> all unknown --------------- #
+    assert m([40 * GB, 7 * GB, 6 * GB, 3 * MiB], [48 * GB, 8 * GB]) == [None, None]
+    assert m([40 * GB, 7 * GB, 6 * GB, 3 * MiB, 3 * MiB], [48 * GB, 8 * GB]) == [None, None]
+    # -- every counter below the noise floor (placeholder fallback) -> unknown - #
+    assert m([50 * MiB, 10 * MiB], [8 * GB]) == [None]
+    assert m([50 * MiB, 10 * MiB, 5 * MiB], [48 * GB, 8 * GB]) == [None, None]
+    # -- equal-capacity cards with a hidden adapter: nothing is forced -------- #
+    assert m([40 * GB, 40 * GB, 3 * MiB], [48 * GB, 48 * GB]) == [None, None]
+    assert m([40 * GB, 30 * GB, 3 * MiB], [48 * GB, 48 * GB]) == [None, None]
+
+
+def test_perf_counter_parser_and_sentinel(monkeypatch):
+    monkeypatch.setattr(hw.platform, "system", lambda: "Windows")
+    monkeypatch.setattr(
+        hw.subprocess, "run", _subprocess_run(adapter_output = _adapter_output(REPORTER_ADAPTERS))
+    )
+    parsed = hw._rocm_windows_perf_counter_vram_by_adapter()
+    assert parsed is not None and len(parsed) == 3
+    assert parsed[0][0].startswith("luid_")
+    monkeypatch.setattr(hw.subprocess, "run", _subprocess_run(adapter_output = "__NONE__\n"))
+    assert hw._rocm_windows_perf_counter_vram_by_adapter() is None
+
+
+# ----------------------------------------------------------------------------- #
+# Unified-memory (Strix Halo APU) total reconciliation (Codex #7238)
+# ----------------------------------------------------------------------------- #
+def test_unified_memory_adopts_torch_total_even_when_used_unknown():
+    """Windows ROCm unified-memory APU: torch's used is None but its total (the full
+    GTT pool) is authoritative. The correction must still adopt the larger total;
+    used stays at amd-smi's figure when torch's is unknown."""
+    metrics = {"vram_total_gb": 8.0, "vram_used_gb": 2.0, "vram_utilization_pct": 25.0}
+    hw._apply_unified_memory_correction(metrics, {"total_gb": 124.0, "used_gb": None, "index": 0})
+    assert metrics["vram_total_gb"] == 124.0  # full unified pool, not the 8 GB carve-out
+    assert metrics["vram_used_gb"] == 2.0  # amd-smi used preserved (torch's was None)
+    assert metrics["vram_utilization_pct"] == pytest.approx(round(2.0 / 124.0 * 100, 1))
+
+
+def test_unified_memory_overwrites_used_when_torch_used_known():
+    """When torch reports both a larger total and a known used, both are adopted
+    and utilization is recomputed against the corrected total (unchanged path)."""
+    metrics = {"vram_total_gb": 8.0, "vram_used_gb": 2.0, "vram_utilization_pct": 25.0}
+    hw._apply_unified_memory_correction(metrics, {"total_gb": 124.0, "used_gb": 40.0, "index": 0})
+    assert metrics["vram_total_gb"] == 124.0
+    assert metrics["vram_used_gb"] == 40.0
+    assert metrics["vram_utilization_pct"] == pytest.approx(round(40.0 / 124.0 * 100, 1))
+
+
+def test_unified_memory_no_op_when_torch_total_not_larger():
+    """A discrete GPU where torch total does not exceed amd-smi's is left untouched."""
+    metrics = {"vram_total_gb": 48.0, "vram_used_gb": 10.0, "vram_utilization_pct": 20.8}
+    hw._apply_unified_memory_correction(metrics, {"total_gb": 48.0, "used_gb": None, "index": 0})
+    assert metrics["vram_total_gb"] == 48.0
+    assert metrics["vram_used_gb"] == 10.0
+    assert metrics["vram_utilization_pct"] == 20.8
diff --git a/studio/backend/tests/test_safetensors_capability_advertise.py b/studio/backend/tests/test_safetensors_capability_advertise.py
index 0ed670ac01..bd3d8d16b9 100644
--- a/studio/backend/tests/test_safetensors_capability_advertise.py
+++ b/studio/backend/tests/test_safetensors_capability_advertise.py
@@ -417,6 +417,59 @@ def test_detect_safetensors_features_gemma_native_tool_call_keeps_tools_on():
     assert flags["supports_tools"] is True
 
 
+def test_detect_safetensors_features_gemma_native_reasoning_is_parseable_not_prefilled():
+    """Native Gemma channels are normalized to <think>, then split by the route."""
+    from routes.inference import _detect_safetensors_features, _sf_reasoning_prefill_mode
+
+    tpl_with_gemma_native = "{% if add_generation_prompt %}<|channel>thought\n<channel|>{% endif %}"
+    backend = SimpleNamespace(
+        active_model_name = "unsloth/gemma-4-E2B-it",
+        models = {
+            "unsloth/gemma-4-E2B-it": {
+                "native_chat_template": tpl_with_gemma_native,
+                "chat_template_info": {"template": "override has no native markers"},
+            }
+        },
+    )
+    flags = _detect_safetensors_features(backend, "override has no native markers")
+    missing_arg_flags = _detect_safetensors_features(backend, None)
+
+    assert flags["supports_reasoning"] is True
+    assert flags["reasoning_always_on"] is True
+    assert missing_arg_flags["supports_reasoning"] is True
+    assert _sf_reasoning_prefill_mode(flags, None, tpl_with_gemma_native) is False
+
+
+def test_detect_safetensors_features_selects_native_reasoning_from_tool_template():
+    """Request tools select a marker-bearing named template without affecting default chat."""
+    from routes.inference import _detect_safetensors_features
+
+    named_template = {
+        "default": "plain default template",
+        "tool_use": "{% if tools %}<|channel>thought\n<channel|>{% endif %}",
+    }
+    backend = SimpleNamespace(
+        active_model_name = "custom/named-native-reasoning",
+        models = {
+            "custom/named-native-reasoning": {
+                "native_chat_template": named_template,
+                "chat_template_info": {"template": "{% if tools %}<tool_call>{% endif %}"},
+            }
+        },
+    )
+
+    default_flags = _detect_safetensors_features(backend, "plain override")
+    tool_flags = _detect_safetensors_features(
+        backend,
+        "plain override",
+        tools = [{"type": "function"}],
+    )
+
+    assert default_flags["supports_reasoning"] is False
+    assert tool_flags["supports_reasoning"] is True
+    assert tool_flags["reasoning_always_on"] is True
+
+
 # Qwen3.5 family pin: the live GGUF + safetensors templates both wrap tool
 # calls as ``<tool_call>\n<function=name>...``. Faithful slice so the
 # classifier never silently regresses for this family.
diff --git a/studio/backend/tests/test_safetensors_reasoning_stream.py b/studio/backend/tests/test_safetensors_reasoning_stream.py
index 4e708139b7..af5a05d266 100644
--- a/studio/backend/tests/test_safetensors_reasoning_stream.py
+++ b/studio/backend/tests/test_safetensors_reasoning_stream.py
@@ -215,3 +215,135 @@ def test_s6_reasoning_effort_none_disables_prefill_for_enable_thinking_effort():
     swallowed = _replay_sf_reasoning_stream(events, prefilled = True)
     assert swallowed["visible"] == ""
     assert swallowed["reasoning"] == "The capital of France is Paris."
+
+
+def test_native_reasoning_streamer_selected_and_errors_raise():
+    import threading
+    import pytest
+
+    torch = pytest.importorskip("torch")
+    inf = pytest.importorskip("core.inference.inference")
+
+    class Batch(dict):
+        def to(self, _device):
+            return self
+
+    class Tok:
+        chat_template = "<|channel>thought\n...<channel|>"
+        all_special_tokens = []
+        eos_token_id = 1
+        pad_token_id = None
+        pieces = {10: "<|channel>thought\n", 11: "r", 12: "<channel|>", 13: "a"}
+
+        def __call__(self, *_args, **_kwargs):
+            return Batch({"input_ids": torch.zeros((1, 1), dtype = torch.long)})
+
+        def decode(self, ids, **_kwargs):
+            return "".join(self.pieces.get(int(token_id), "") for token_id in ids)
+
+    class Model:
+        device = "cpu"
+        generation_config = type("Cfg", (), {"eos_token_id": 1})()
+        config = generation_config
+
+        def __init__(self, fail = False):
+            self.fail = fail
+            self.kwargs = None
+
+        def generate(self, **kwargs):
+            self.kwargs = kwargs
+            streamer = kwargs["streamer"]
+            streamer.put(torch.zeros((1, 1), dtype = torch.long))
+            for token_id in [10, 11, 12, 13]:
+                streamer.put(torch.tensor([token_id]))
+                if self.fail:
+                    raise RuntimeError("boom")
+
+    backend = inf.InferenceBackend.__new__(inf.InferenceBackend)
+    backend.active_model_name = "gemma-test"
+    backend._generation_lock = threading.Lock()
+    backend.models = {"gemma-test": {"model": Model(), "tokenizer": Tok()}}
+
+    assert list(backend.generate_stream("prompt", max_new_tokens = 4))[-1] == "<think>r</think>a"
+
+    backend.models["gemma-test"]["model"] = Model(fail = True)
+
+    with pytest.raises(inf._GenerationThreadError, match = "boom"):
+        list(backend.generate_stream("prompt", max_new_tokens = 4))
+
+
+def test_text_only_vlm_fallback_resolves_native_markers_off():
+    import threading
+    import pytest
+
+    torch = pytest.importorskip("torch")
+    inf = pytest.importorskip("core.inference.inference")
+
+    class Batch(dict):
+        def to(self, _device):
+            return self
+
+    class Tokenizer:
+        all_special_tokens = []
+        eos_token_id = 1
+        pad_token_id = None
+
+        def __call__(self, *_args, **_kwargs):
+            return Batch({"input_ids": torch.zeros((1, 1), dtype = torch.long)})
+
+    class Processor:
+        chat_template = "<|channel>thought\n...<channel|>"
+        tokenizer = Tokenizer()
+
+    class Model:
+        device = "cpu"
+        generation_config = type("Cfg", (), {"eos_token_id": 1})()
+        config = generation_config
+
+        def generate(self, **_kwargs):
+            return None
+
+    class EmptyStreamer:
+        def __next__(self):
+            raise StopIteration
+
+        def end(self):
+            return None
+
+    captured = {}
+    backend = inf.InferenceBackend.__new__(inf.InferenceBackend)
+    backend.active_model_name = "vision-test"
+    backend._generation_lock = threading.Lock()
+    backend.models = {
+        "vision-test": {
+            "model": Model(),
+            "processor": Processor(),
+            "tokenizer": Processor(),
+        }
+    }
+    backend.format_chat_prompt = lambda *_args, **_kwargs: "manual text-only prompt"
+
+    def make_streamer(*_args, **kwargs):
+        captured.update(kwargs)
+        return EmptyStreamer()
+
+    backend._make_text_streamer = make_streamer
+
+    assert (
+        list(
+            backend._generate_vision_response(
+                messages = [{"role": "user", "content": "hello"}],
+                system_prompt = "",
+                image = None,
+                temperature = 0.7,
+                top_p = 0.9,
+                top_k = 40,
+                min_p = 0.0,
+                max_new_tokens = 1,
+                repetition_penalty = 1.0,
+            )
+        )
+        == []
+    )
+    assert captured["reasoning_channel_markers"] is None
+    assert captured["reasoning_channel_markers_resolved"] is True
diff --git a/studio/backend/tests/test_safetensors_tool_loop.py b/studio/backend/tests/test_safetensors_tool_loop.py
index e3633de289..31c728afca 100644
--- a/studio/backend/tests/test_safetensors_tool_loop.py
+++ b/studio/backend/tests/test_safetensors_tool_loop.py
@@ -2230,8 +2230,8 @@ def _reprompt_loop(*, auto_heal_tool_calls):
             tools = [{"type": "function", "function": {"name": "search_knowledge_base"}}],
             execute_tool = exec_fn,
             auto_heal_tool_calls = auto_heal_tool_calls,
-            # Studio always nudges (always-on for the Studio inference paths); the
-            # API opts in per request. Model the Studio caller here.
+            # Unsloth always nudges (always-on for the Unsloth inference paths); the
+            # API opts in per request. Model the Unsloth caller here.
             nudge_tool_calls = True,
             max_tool_iterations = 3,
         )
@@ -3203,7 +3203,197 @@ class TestLoopBehaviour:
 
 
 class TestLoopRePrompt:
-    """Plan-without-action re-prompt parity with GGUF: nudge instead of terminating, up to ``MAX_ACT_REPROMPTS`` extra slots. Studio always nudges, so these drive the loop with ``nudge_tool_calls=True``."""
+    """Plan-without-action re-prompt parity with GGUF: nudge instead of terminating, up to ``MAX_ACT_REPROMPTS`` extra slots. Unsloth always nudges, so these drive the loop with ``nudge_tool_calls=True``."""
+
+    def test_reasoning_intent_does_not_reprompt_a_visible_answer(self):
+        generations = 0
+
+        def _gen(_messages, active_tools = None):
+            nonlocal generations
+            generations += 1
+            yield (
+                "<think>Let me prepare the requested summary carefully.</think>"
+                "This is the final visible answer."
+            )
+
+        exec_fn = FakeExecuteTool([])
+        events = _collect_events(
+            run_safetensors_tool_loop(
+                single_turn = _gen,
+                messages = [{"role": "user", "content": "summarize this"}],
+                tools = [{"type": "function", "function": {"name": "web_search"}}],
+                execute_tool = exec_fn,
+                nudge_tool_calls = True,
+            )
+        )
+
+        assert generations == 1
+        assert exec_fn.calls == []
+        contents = [e["text"] for e in events if e["type"] == "content"]
+        assert contents[-1].endswith("This is the final visible answer.")
+
+    def test_prefilled_reasoning_intent_does_not_reprompt_a_visible_answer(self):
+        generations = 0
+
+        def _gen(_messages, active_tools = None):
+            nonlocal generations
+            generations += 1
+            yield "Let me prepare the requested summary carefully.</think>This is the final visible answer."
+
+        exec_fn = FakeExecuteTool([])
+        events = _collect_events(
+            run_safetensors_tool_loop(
+                single_turn = _gen,
+                messages = [{"role": "user", "content": "summarize this"}],
+                tools = [{"type": "function", "function": {"name": "web_search"}}],
+                execute_tool = exec_fn,
+                nudge_tool_calls = True,
+                reasoning_prefilled = True,
+            )
+        )
+
+        assert generations == 1
+        assert exec_fn.calls == []
+        contents = [e["text"] for e in events if e["type"] == "content"]
+        assert contents[-1].endswith("This is the final visible answer.")
+
+    def test_prefilled_reasoning_with_reemitted_think_does_not_reprompt(self):
+        generations = 0
+
+        def _gen(_messages, active_tools = None):
+            nonlocal generations
+            generations += 1
+            yield (
+                "Let me prepare the requested summary carefully."
+                "<think>more private planning</think>This is the final visible answer."
+            )
+
+        exec_fn = FakeExecuteTool([])
+        events = _collect_events(
+            run_safetensors_tool_loop(
+                single_turn = _gen,
+                messages = [{"role": "user", "content": "summarize this"}],
+                tools = [{"type": "function", "function": {"name": "web_search"}}],
+                execute_tool = exec_fn,
+                nudge_tool_calls = True,
+                reasoning_prefilled = True,
+            )
+        )
+
+        assert generations == 1
+        assert exec_fn.calls == []
+        contents = [e["text"] for e in events if e["type"] == "content"]
+        assert contents[-1].endswith("This is the final visible answer.")
+
+    def test_prefilled_reasoning_with_later_think_does_not_reprompt(self):
+        generations = 0
+
+        def _gen(_messages, active_tools = None):
+            nonlocal generations
+            generations += 1
+            yield (
+                "private prefilled planning</think>"
+                "<think>Let me prepare the requested summary carefully.</think>"
+                "This is the final visible answer."
+            )
+
+        exec_fn = FakeExecuteTool([])
+        events = _collect_events(
+            run_safetensors_tool_loop(
+                single_turn = _gen,
+                messages = [{"role": "user", "content": "summarize this"}],
+                tools = [{"type": "function", "function": {"name": "web_search"}}],
+                execute_tool = exec_fn,
+                nudge_tool_calls = True,
+                reasoning_prefilled = True,
+            )
+        )
+
+        assert generations == 1
+        assert exec_fn.calls == []
+        contents = [e["text"] for e in events if e["type"] == "content"]
+        assert contents[-1].endswith("This is the final visible answer.")
+
+    def test_reasoning_only_intent_still_reprompts_and_uses_a_tool(self):
+        loop, exec_fn = _make_loop(
+            turns = [
+                ["<think>Let me search for that.</think>"],
+                ['<tool_call>{"name":"web_search","arguments":{"query":"cats"}}</tool_call>'],
+                ["Here is the answer."],
+            ],
+            exec_results = ["result"],
+            nudge_tool_calls = True,
+        )
+
+        events = _collect_events(loop)
+
+        assert exec_fn.calls == [("web_search", {"query": "cats"})]
+        contents = [e["text"] for e in events if e["type"] == "content"]
+        assert contents[-1] == "Here is the answer."
+
+    def test_prefilled_no_close_reasoning_intent_still_reprompts(self):
+        loop, exec_fn = _make_loop(
+            turns = [
+                ["I need more context.<think>Let me search for that."],
+                ['<tool_call>{"name":"web_search","arguments":{"query":"cats"}}</tool_call>'],
+                ["Here is the answer."],
+            ],
+            exec_results = ["result"],
+            nudge_tool_calls = True,
+            reasoning_prefilled = True,
+        )
+
+        events = _collect_events(loop)
+
+        assert exec_fn.calls == [("web_search", {"query": "cats"})]
+        contents = [e["text"] for e in events if e["type"] == "content"]
+        assert contents[-1] == "Here is the answer."
+
+    def test_prefilled_reasoning_prefix_is_kept_for_reasoning_only_reprompt(self):
+        loop, exec_fn = _make_loop(
+            turns = [
+                ["Let me search for that.</think><think>checking details</think>"],
+                ['<tool_call>{"name":"web_search","arguments":{"query":"cats"}}</tool_call>'],
+                ["Here is the answer."],
+            ],
+            exec_results = ["result"],
+            nudge_tool_calls = True,
+            reasoning_prefilled = True,
+        )
+
+        events = _collect_events(loop)
+
+        assert exec_fn.calls == [("web_search", {"query": "cats"})]
+        contents = [e["text"] for e in events if e["type"] == "content"]
+        assert contents[-1] == "Here is the answer."
+
+    def test_reprompt_history_uses_visible_intent_text(self):
+        captured: list[list[dict]] = []
+
+        def _gen(messages, active_tools = None):
+            captured.append([dict(message) for message in messages])
+            if len(captured) == 1:
+                yield "<think>private planning details</think>Let me search for that."
+            elif len(captured) == 2:
+                yield '<tool_call>{"name":"web_search","arguments":{"query":"cats"}}</tool_call>'
+            else:
+                yield "Here is the answer."
+
+        exec_fn = FakeExecuteTool(["result"])
+        events = _collect_events(
+            run_safetensors_tool_loop(
+                single_turn = _gen,
+                messages = [{"role": "user", "content": "find cats"}],
+                tools = [{"type": "function", "function": {"name": "web_search"}}],
+                execute_tool = exec_fn,
+                nudge_tool_calls = True,
+            )
+        )
+
+        assert exec_fn.calls == [("web_search", {"query": "cats"})]
+        assert captured[1][1] == {"role": "assistant", "content": "Let me search for that."}
+        contents = [e["text"] for e in events if e["type"] == "content"]
+        assert contents[-1] == "Here is the answer."
 
     def test_intent_signal_triggers_reprompt(self):
         # Turn 1: intent signal, no tool call.
@@ -4068,7 +4258,7 @@ class TestPlanWithoutActionReprompt:
 
     def test_omitted_nudge_flag_is_not_reprompted(self):
         # The retry is new on this loop: API callers who do not send the flag
-        # must keep today's behavior. Studio opts in explicitly.
+        # must keep today's behavior. Unsloth opts in explicitly.
         loop, exec_fn = _make_loop(
             turns = [
                 ["I'll search the web for that."],
diff --git a/studio/backend/tests/test_sampling_resolution.py b/studio/backend/tests/test_sampling_resolution.py
new file mode 100644
index 0000000000..1ebbae2502
--- /dev/null
+++ b/studio/backend/tests/test_sampling_resolution.py
@@ -0,0 +1,270 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Effective sampling resolution: per-model recommendation + operator pins.
+
+Precedence per field: operator UNSLOTH_SAMPLING_* pin -> client explicit value ->
+per-model recommendation (load_inference_config) -> static schema default.
+"""
+
+import pytest
+
+from utils.inference.inference_config import resolve_effective_sampling, SAMPLING_FIELD_NAMES
+from utils.inference import inference_config as ic
+
+_SCHEMA_DEFAULTS = {
+    "temperature": 0.6,
+    "top_p": 0.95,
+    "top_k": 20,
+    "min_p": 0.01,
+    "repetition_penalty": 1.0,
+    "presence_penalty": 0.0,
+}
+
+
+@pytest.fixture(autouse = True)
+def _isolate(monkeypatch):
+    # The recommended lookup is lru-cached; clear it so a patched config takes effect.
+    ic._recommended_sampling.cache_clear()
+    for field in SAMPLING_FIELD_NAMES:
+        monkeypatch.delenv(ic._SAMPLING_FIELDS[field][0], raising = False)
+    yield
+    ic._recommended_sampling.cache_clear()
+
+
+def _all_omitted():
+    return {f: None for f in SAMPLING_FIELD_NAMES}
+
+
+def _set_recommended(monkeypatch, mapping):
+    # _recommended_sampling sources from load_inference_config -- the exact block the Chat UI
+    # seeds from -- so patch that directly. Fields absent from `mapping` fall to schema defaults.
+    monkeypatch.setattr(ic, "load_inference_config", lambda mid: dict(mapping))
+    ic._recommended_sampling.cache_clear()
+
+
+def test_recommended_applies_when_client_omits(monkeypatch):
+    _set_recommended(monkeypatch, {"temperature": 1.0, "top_k": 64, "min_p": 0.0})
+    eff = resolve_effective_sampling("some/model", _all_omitted())
+    assert eff["temperature"] == 1.0
+    assert eff["top_k"] == 64
+    assert eff["min_p"] == 0.0
+    # A field with no recommendation keeps the static schema default.
+    assert eff["top_p"] == 0.95
+
+
+def test_client_explicit_beats_recommended(monkeypatch):
+    _set_recommended(monkeypatch, {"temperature": 1.0})
+    eff = resolve_effective_sampling("some/model", {**_all_omitted(), "temperature": 0.2})
+    assert eff["temperature"] == 0.2
+
+
+def test_operator_pin_beats_client_and_recommended(monkeypatch):
+    _set_recommended(monkeypatch, {"temperature": 1.0})
+    monkeypatch.setenv("UNSLOTH_SAMPLING_TEMPERATURE", "0.9")
+    eff = resolve_effective_sampling("some/model", {**_all_omitted(), "temperature": 0.2})
+    assert eff["temperature"] == 0.9
+
+
+def test_unknown_model_matches_ui_inference_block(monkeypatch):
+    # An unknown model gets the same values the Chat UI would seed (load_inference_config's
+    # default.yaml fallback: temp 0.7 / top_k -1), NOT the request schema defaults.
+    ui_block = {
+        "temperature": 0.7,
+        "top_p": 0.95,
+        "top_k": -1,
+        "min_p": 0.01,
+        "presence_penalty": 0.0,
+        "repetition_penalty": 1.0,
+    }
+    monkeypatch.setattr(ic, "load_inference_config", lambda mid: dict(ui_block))
+    ic._recommended_sampling.cache_clear()
+    eff = resolve_effective_sampling("some/unknown-model", _all_omitted())
+    assert eff["temperature"] == 0.7
+    assert eff["top_k"] == -1
+    assert eff["min_p"] == 0.01
+
+
+def test_empty_recommendation_falls_back_to_schema_defaults(monkeypatch):
+    # If load_inference_config yields nothing usable, the resolver falls back to the request
+    # schema defaults.
+    monkeypatch.setattr(ic, "load_inference_config", lambda mid: {})
+    ic._recommended_sampling.cache_clear()
+    eff = resolve_effective_sampling("some/model", _all_omitted())
+    assert eff == _SCHEMA_DEFAULTS
+
+
+@pytest.mark.parametrize(
+    "model",
+    ["unsloth/gemma-4-E4B", "unsloth/Qwen3-4B", "unsloth/Qwen3.5-9B", "someorg/unknown-xyz"],
+)
+def test_recommendation_matches_ui_source(model):
+    # Parity guard: what the server recommends for omitted fields equals the Chat UI's source
+    # (load_inference_config) for every field the UI adopts (mergeBackendRecommendedInference).
+    ic._recommended_sampling.cache_clear()
+    ui = ic.load_inference_config(model)
+    rec = ic._recommended_sampling(model)
+    for f in ic._UI_RECOMMENDED_FIELDS:
+        cleaned = ic._clean_sampling_value(f, ui.get(f))
+        if cleaned is not None:
+            assert rec.get(f) == cleaned, f"{model}:{f} rec={rec.get(f)} ui={ui.get(f)}"
+
+
+def test_repetition_penalty_not_auto_recommended(monkeypatch):
+    # The Chat UI's mergeBackendRecommendedInference never adopts a backend repetition_penalty
+    # (e.g. lfm2's family value 1.05), so the server must not auto-apply one either. It stays at
+    # the schema default unless the client sends it or an operator pins it.
+    monkeypatch.setattr(
+        ic, "load_inference_config", lambda mid: {"temperature": 0.7, "repetition_penalty": 1.05}
+    )
+    ic._recommended_sampling.cache_clear()
+    eff = resolve_effective_sampling("some/lfm2-model", _all_omitted())
+    assert eff["temperature"] == 0.7  # a UI-adopted field is recommended
+    assert eff["repetition_penalty"] == 1.0  # rep is NOT auto-recommended (matches the UI)
+    # An operator can still pin it explicitly.
+    monkeypatch.setenv("UNSLOTH_SAMPLING_REPETITION_PENALTY", "1.05")
+    eff2 = resolve_effective_sampling("some/lfm2-model", _all_omitted())
+    assert eff2["repetition_penalty"] == 1.05
+
+
+@pytest.mark.parametrize(
+    "raw, expected",
+    [
+        ("0.5", 0.5),
+        ("abc", None),  # unparseable
+        ("9.0", None),  # above temperature max (2.0)
+        ("-1", None),  # below temperature min (0.0)
+        ("   ", None),  # blank
+        ("nan", None),  # NaN would pass a naive range check
+        ("inf", None),  # non-finite
+        ("-inf", None),  # non-finite
+    ],
+)
+def test_operator_override_parsing(monkeypatch, raw, expected):
+    monkeypatch.setenv("UNSLOTH_SAMPLING_TEMPERATURE", raw)
+    assert ic._operator_sampling_override("temperature") == expected
+
+
+def test_out_of_range_recommendation_is_dropped(monkeypatch):
+    # A malformed model recommendation (out of range) is ignored, so the request keeps the
+    # schema default rather than forwarding a bad value to llama-server.
+    _set_recommended(monkeypatch, {"temperature": 5.0, "top_k": 64})
+    eff = resolve_effective_sampling("some/model", _all_omitted())
+    assert eff["temperature"] == 0.6  # 5.0 is outside [0, 2] -> schema default
+    assert eff["top_k"] == 64  # a valid recommendation is still applied
+
+
+def test_operator_override_top_k_int_and_range(monkeypatch):
+    monkeypatch.setenv("UNSLOTH_SAMPLING_TOP_K", "40")
+    assert ic._operator_sampling_override("top_k") == 40
+    monkeypatch.setenv("UNSLOTH_SAMPLING_TOP_K", "200")  # above max 100
+    assert ic._operator_sampling_override("top_k") is None
+    monkeypatch.setenv("UNSLOTH_SAMPLING_TOP_K", "-1")  # min allowed
+    assert ic._operator_sampling_override("top_k") == -1
+
+
+@pytest.mark.parametrize(
+    "field, val",
+    [
+        ("top_k", 10**400),  # oversized int on an int field: int() ok, but math.isfinite raises
+        ("top_k", float("nan")),  # NaN reaching an int field: int(nan) raises ValueError
+        ("top_k", float("inf")),  # inf reaching an int field: int(inf) raises OverflowError
+        (
+            "temperature",
+            10**400,
+        ),  # oversized int on a float field: float(huge_int) raises OverflowError
+    ],
+)
+def test_clean_sampling_value_rejects_unrepresentable(field, val):
+    # None of these may raise; each is unusable and must be dropped to None (regression: an
+    # oversized value used to raise OverflowError before the range check could drop it).
+    assert ic._clean_sampling_value(field, val) is None
+
+
+def test_oversized_operator_override_ignored(monkeypatch):
+    # A huge integer string parses via int() but overflows float(); math.isfinite would raise
+    # OverflowError and 500 the request. It must be ignored like any other bad override and the
+    # field must fall back to the schema default -- no exception.
+    monkeypatch.setenv("UNSLOTH_SAMPLING_TOP_K", "9" * 400)
+    assert ic._operator_sampling_override("top_k") is None
+    _set_recommended(monkeypatch, {})  # no per-model recommendation -> schema default applies
+    eff = resolve_effective_sampling("some/model", _all_omitted())
+    assert eff["top_k"] == 20  # schema default, resolved without raising
+
+
+def test_oversized_recommendation_ignored(monkeypatch):
+    # A malformed per-model recommendation carrying an oversized int must not raise while
+    # resolving either; the field simply falls back to the schema default.
+    _set_recommended(monkeypatch, {"temperature": 10**400, "top_k": 64})
+    eff = resolve_effective_sampling("some/model", _all_omitted())
+    assert eff["temperature"] == 0.6  # oversized -> dropped -> schema default
+    assert eff["top_k"] == 64  # a valid recommendation is still applied
+
+
+def test_fill_recommended_sampling_openai_payload(monkeypatch):
+    from models.inference import ChatCompletionRequest
+    from routes.inference import _fill_recommended_sampling_openai
+
+    _set_recommended(monkeypatch, {"temperature": 1.0, "top_k": 64, "min_p": 0.0})
+
+    # Client sent only temperature; top_k / min_p were omitted.
+    payload = ChatCompletionRequest(
+        model = "m", messages = [{"role": "user", "content": "hi"}], temperature = 0.2
+    )
+    _fill_recommended_sampling_openai(payload, "some/model")
+    assert payload.temperature == 0.2  # explicit client value preserved
+    assert payload.top_k == 64  # recommended fills the omitted field
+    assert payload.min_p == 0.0
+    assert payload.top_p == 0.95  # no recommendation -> schema default unchanged
+
+
+def test_fill_recommended_sampling_openai_operator_pin_overrides_client(monkeypatch):
+    from models.inference import ChatCompletionRequest
+    from routes.inference import _fill_recommended_sampling_openai
+
+    monkeypatch.setattr(ic, "load_model_defaults", lambda mid: {})
+    monkeypatch.setattr(ic, "get_family_inference_params", lambda mid: {})
+    ic._recommended_sampling.cache_clear()
+    monkeypatch.setenv("UNSLOTH_SAMPLING_TEMPERATURE", "0.9")
+
+    payload = ChatCompletionRequest(
+        model = "m", messages = [{"role": "user", "content": "hi"}], temperature = 0.2
+    )
+    _fill_recommended_sampling_openai(payload, "some/model")
+    assert payload.temperature == 0.9  # operator pin wins even over an explicit client value
+
+
+def test_fill_recommended_sampling_completions_body(monkeypatch):
+    # /v1/completions is a raw proxy: recommendations fill omitted fields, but a field with no
+    # recommendation and no pin is left absent so llama-server keeps its own default (unlike the
+    # chat schema, which carries per-field defaults).
+    from routes.inference import _fill_recommended_sampling_completions
+
+    _set_recommended(monkeypatch, {"temperature": 1.0, "top_k": 64, "min_p": 0.0})
+
+    body = {"prompt": "hi", "temperature": 0.2}
+    _fill_recommended_sampling_completions(body, "some/model")
+    assert body["temperature"] == 0.2  # explicit client value preserved
+    assert body["top_k"] == 64  # recommendation fills the omitted field
+    assert body["min_p"] == 0.0
+    # No recommendation and no pin -> NOT injected (llama-server keeps its default).
+    assert "top_p" not in body
+    assert "presence_penalty" not in body
+    assert "repeat_penalty" not in body
+
+
+def test_fill_recommended_sampling_completions_operator_pin(monkeypatch):
+    # An operator pin overrides the client's raw-body value, and the repetition pin is written
+    # under llama-server's "repeat_penalty" key (the schema field is repetition_penalty).
+    from routes.inference import _fill_recommended_sampling_completions
+
+    monkeypatch.setattr(ic, "load_inference_config", lambda mid: {})
+    ic._recommended_sampling.cache_clear()
+    monkeypatch.setenv("UNSLOTH_SAMPLING_TEMPERATURE", "0.9")
+    monkeypatch.setenv("UNSLOTH_SAMPLING_REPETITION_PENALTY", "1.2")
+
+    body = {"prompt": "hi", "temperature": 0.2, "repeat_penalty": 1.05}
+    _fill_recommended_sampling_completions(body, "some/model")
+    assert body["temperature"] == 0.9  # operator pin wins over the client's explicit value
+    assert body["repeat_penalty"] == 1.2  # repetition pin lands on llama-server's key
+    assert "repetition_penalty" not in body  # never leak the schema field name into the body
diff --git a/studio/backend/tests/test_sandbox_tools.py b/studio/backend/tests/test_sandbox_tools.py
index 2970b1a6bb..64201477e3 100644
--- a/studio/backend/tests/test_sandbox_tools.py
+++ b/studio/backend/tests/test_sandbox_tools.py
@@ -297,6 +297,8 @@ class TestSandboxEnvIsolation:
             "PYTHONPATH",
             "VIRTUAL_ENV",
             "SystemRoot",
+            "PATHEXT",  # Windows only; minimal list so cwd scripts cannot hijack
+            "NoDefaultCurrentDirectoryInExePath",  # Windows only; no cwd-first lookup
         }
         extras = set(env.keys()) - allowed
         assert not extras, f"sandbox env added unexpected keys: {extras}"
@@ -305,6 +307,220 @@ class TestSandboxEnvIsolation:
         assert env["PYTHONPATH"].endswith("sandbox_site")
         assert "leak-me" not in env["PYTHONPATH"]
 
+    def test_host_git_dir_appended_after_curated(self, monkeypatch, tmp_path):
+        # #7317: Windows Git lives under Program Files, not System32. Sandbox
+        # PATH resolves bare `git` by appending the dir of the git the HOST
+        # shell resolves (shutil.which), after the curated prefix.
+        import core.inference.tools as tools_mod
+        from core.inference.tools import _build_safe_env
+
+        monkeypatch.setattr(sys, "platform", "win32")
+        prog = tmp_path / "Program Files"
+        monkeypatch.setattr(tools_mod, "_windows_program_roots", lambda: [str(prog)])
+        git_dir = prog / "Git" / "cmd"
+        git_dir.mkdir(parents = True)
+        monkeypatch.setattr(tools_mod.shutil, "which", lambda name: str(git_dir / "git.exe"))
+        env = _build_safe_env(str(tmp_path))
+        parts = env["PATH"].split(os.pathsep)
+        assert str(git_dir) in parts
+        # Curated prefix stays ahead of host Git so Studio python/pip win.
+        assert parts.index(str(git_dir)) > 0
+
+    def test_host_path_dirs_not_inherited(self, monkeypatch, tmp_path):
+        """Host PATH dirs (user-writable, git-lookalike) are never inherited;
+        only the resolved git dir is. No git resolved -> nothing appended."""
+        import core.inference.tools as tools_mod
+        from core.inference.tools import _build_safe_env
+
+        monkeypatch.setattr(sys, "platform", "win32")
+        venv_scripts = tmp_path / "venv" / "Scripts"
+        venv_scripts.mkdir(parents = True)
+        fake_git = tmp_path / "scratch" / "Git" / "cmd"
+        fake_git.mkdir(parents = True)
+        monkeypatch.setenv(
+            "PATH",
+            os.pathsep.join([str(venv_scripts), str(fake_git), os.environ.get("PATH", "")]),
+        )
+        monkeypatch.setattr(tools_mod.shutil, "which", lambda name: None)
+        env = _build_safe_env(str(tmp_path))
+        parts = env["PATH"].split(os.pathsep)
+        assert str(venv_scripts) not in parts
+        # A git-suffixed but unresolved (user-writable) dir is NOT trusted.
+        assert str(fake_git) not in parts
+
+    def test_git_cmd_shim_extension_added_to_pathext(self, monkeypatch, tmp_path):
+        """A host git resolved as a .cmd shim under a trusted root stays
+        resolvable under the restricted PATHEXT (cwd lookup disabled)."""
+        import core.inference.tools as tools_mod
+        from core.inference.tools import _build_safe_env
+
+        monkeypatch.setattr(sys, "platform", "win32")
+        prog = tmp_path / "Program Files"
+        monkeypatch.setattr(tools_mod, "_windows_program_roots", lambda: [str(prog)])
+        git_dir = prog / "Git" / "cmd"
+        git_dir.mkdir(parents = True)
+        monkeypatch.setattr(tools_mod.shutil, "which", lambda name: str(git_dir / "git.cmd"))
+        env = _build_safe_env(str(tmp_path))
+        assert str(git_dir) in env["PATH"].split(os.pathsep)
+        assert env["PATHEXT"] == ".EXE;.COM;.CMD"
+
+    def test_user_writable_git_dir_refused(self, monkeypatch, tmp_path):
+        """Git resolved from a per-user manager (Scoop shims) is NOT trusted:
+        an attacker could drop rg.exe beside it and hit the auto-approve gate."""
+        import core.inference.tools as tools_mod
+        from core.inference.tools import _build_safe_env
+
+        monkeypatch.setattr(sys, "platform", "win32")
+        monkeypatch.setattr(
+            tools_mod, "_windows_program_roots", lambda: [str(tmp_path / "Program Files")]
+        )
+        shim_dir = tmp_path / "users" / "alice" / "scoop" / "shims"
+        shim_dir.mkdir(parents = True)
+        monkeypatch.setattr(tools_mod.shutil, "which", lambda name: str(shim_dir / "git.exe"))
+        env = _build_safe_env(str(tmp_path))
+        assert str(shim_dir) not in env["PATH"].split(os.pathsep)
+        # No trusted git launcher -> PATHEXT stays minimal.
+        assert env["PATHEXT"] == ".EXE;.COM"
+
+    def test_trust_uses_known_folder_not_env_override(self, monkeypatch, tmp_path):
+        """Trust is driven by the resolved Program Files roots, so a git under
+        an attacker-overridden %ProgramFiles% env value is still refused."""
+        import core.inference.tools as tools_mod
+        from core.inference.tools import _build_safe_env
+
+        monkeypatch.setattr(sys, "platform", "win32")
+        real_prog = tmp_path / "RealProgramFiles"
+        (real_prog).mkdir()
+        evil = tmp_path / "attacker"
+        (evil / "Git" / "cmd").mkdir(parents = True)
+        # Resolver returns the genuine root; env is overridden to the evil dir.
+        monkeypatch.setattr(tools_mod, "_windows_program_roots", lambda: [str(real_prog)])
+        monkeypatch.setenv("ProgramFiles", str(evil))
+        monkeypatch.setattr(
+            tools_mod.shutil, "which", lambda name: str(evil / "Git" / "cmd" / "git.exe")
+        )
+        env = _build_safe_env(str(tmp_path))
+        assert str(evil / "Git" / "cmd") not in env["PATH"].split(os.pathsep)
+
+    def test_canonical_git_dir_appended(self, monkeypatch, tmp_path):
+        """The PATH entry is the realpath of the trusted dir, not a junction
+        alias, so it cannot be retargeted after the trust check."""
+        import core.inference.tools as tools_mod
+        from core.inference.tools import _build_safe_env
+
+        monkeypatch.setattr(sys, "platform", "win32")
+        real_prog = tmp_path / "Program Files"
+        real_git = real_prog / "Git" / "cmd"
+        real_git.mkdir(parents = True)
+        link = tmp_path / "link"
+        try:
+            link.symlink_to(real_prog, target_is_directory = True)
+        except (OSError, NotImplementedError):
+            pytest.skip("symlink unsupported in this environment")
+        monkeypatch.setattr(tools_mod, "_windows_program_roots", lambda: [str(real_prog)])
+        monkeypatch.setattr(
+            tools_mod.shutil,
+            "which",
+            lambda name: str(link / "Git" / "cmd" / "git.exe"),
+        )
+        env = _build_safe_env(str(tmp_path))
+        parts = env["PATH"].split(os.pathsep)
+        assert str(real_git) in parts  # canonical, not the `link/...` alias
+
+    def test_windows_temp_git_dir_refused(self, monkeypatch, tmp_path):
+        """A git under a world-writable %SystemRoot% subdir (Windows\\Temp) is
+        NOT trusted, even though it sits under the Windows root."""
+        import core.inference.tools as tools_mod
+        from core.inference.tools import _build_safe_env
+
+        monkeypatch.setattr(sys, "platform", "win32")
+        monkeypatch.setattr(
+            tools_mod, "_windows_program_roots", lambda: [str(tmp_path / "Program Files")]
+        )
+        temp_git = tmp_path / "Windows" / "Temp" / "Git" / "cmd"
+        temp_git.mkdir(parents = True)
+        monkeypatch.setattr(tools_mod.shutil, "which", lambda name: str(temp_git / "git.exe"))
+        env = _build_safe_env(str(tmp_path))
+        assert str(temp_git) not in env["PATH"].split(os.pathsep)
+
+    def test_trusted_program_dir_matches_via_realpath(self, monkeypatch, tmp_path):
+        """The trust check canonicalizes paths, so a symlinked/short alias of
+        Program Files still matches (stand-in for 8.3 PROGRA~1 on Windows)."""
+        import core.inference.tools as tools_mod
+        from core.inference.tools import _build_safe_env
+
+        monkeypatch.setattr(sys, "platform", "win32")
+        real_prog = tmp_path / "Program Files"
+        (real_prog / "Git" / "cmd").mkdir(parents = True)
+        alias = tmp_path / "PROGRA~1"
+        try:
+            alias.symlink_to(real_prog, target_is_directory = True)
+        except (OSError, NotImplementedError):
+            pytest.skip("symlink unsupported in this environment")
+        monkeypatch.setattr(tools_mod, "_windows_program_roots", lambda: [str(real_prog)])
+        git_via_alias = alias / "Git" / "cmd" / "git.exe"
+        monkeypatch.setattr(tools_mod.shutil, "which", lambda name: str(git_via_alias))
+        env = _build_safe_env(str(tmp_path))
+        parts = [os.path.normcase(os.path.realpath(p)) for p in env["PATH"].split(os.pathsep)]
+        assert os.path.normcase(str(real_prog / "Git" / "cmd")) in parts
+
+    def test_scan_past_untrusted_git_shim(self, monkeypatch, tmp_path):
+        """When an untrusted shim sorts first on PATH, the scan still finds a
+        later trusted Program Files git."""
+        import core.inference.tools as tools_mod
+        from core.inference.tools import _build_safe_env
+
+        monkeypatch.setattr(sys, "platform", "win32")
+        prog = tmp_path / "Program Files"
+        trusted_git = prog / "Git" / "cmd"
+        trusted_git.mkdir(parents = True)
+        (trusted_git / "git.EXE").write_text("")  # match PATHEXT case on this FS
+        shim = tmp_path / "scoop" / "shims"
+        shim.mkdir(parents = True)
+        (shim / "git.EXE").write_text("")
+        monkeypatch.setattr(tools_mod, "_windows_program_roots", lambda: [str(prog)])
+        # shutil.which returns the untrusted shim first.
+        monkeypatch.setattr(tools_mod.shutil, "which", lambda name: str(shim / "git.EXE"))
+        monkeypatch.setenv("PATH", os.pathsep.join([str(shim), str(trusted_git)]))
+        monkeypatch.setenv("PATHEXT", ".EXE")
+        env = _build_safe_env(str(tmp_path))
+        parts = env["PATH"].split(os.pathsep)
+        assert str(trusted_git) in parts
+        assert str(shim) not in parts
+
+    def test_program_roots_fails_closed_without_known_folder_api(self, monkeypatch):
+        """When the known-folder API is unavailable, no roots are trusted: env
+        vars (even %SystemDrive%) are caller-overrideable, so we never derive a
+        trusted root from them."""
+        import core.inference.tools as tools_mod
+
+        # ctypes fails on this Linux host, so the API path raises and we fail
+        # closed. Any attacker override of these env vars must be irrelevant.
+        monkeypatch.setenv("ProgramFiles", r"D:\attacker-writable")
+        monkeypatch.setenv("ProgramW6432", r"D:\attacker-writable")
+        monkeypatch.setenv("SystemDrive", "D:")
+        assert tools_mod._windows_program_roots() == []
+
+    def test_augment_native_program_roots_derives_native_sibling(self):
+        """A 32-bit process only sees the x86 root; the native sibling is
+        derived by stripping the ` (x86)` suffix."""
+        import core.inference.tools as tools_mod
+
+        roots = tools_mod._augment_native_program_roots([r"C:\Program Files (x86)"])
+        lowered = [r.lower() for r in roots]
+        assert r"c:\program files (x86)" in lowered
+        assert r"c:\program files" in lowered
+
+    def test_no_default_current_directory_in_exe_path_set_on_windows(self, monkeypatch, tmp_path):
+        """cmd/CreateProcess must not search cwd for bare names in the sandbox."""
+        import core.inference.tools as tools_mod
+        from core.inference.tools import _build_safe_env
+
+        monkeypatch.setattr(sys, "platform", "win32")
+        monkeypatch.setattr(tools_mod.shutil, "which", lambda name: None)
+        env = _build_safe_env(str(tmp_path))
+        assert env["NoDefaultCurrentDirectoryInExePath"] == "1"
+
     def test_home_points_at_sandbox_workdir(self, tmp_path):
         from core.inference.tools import _build_safe_env
 
diff --git a/studio/backend/tests/test_secure_tunnel_gate.py b/studio/backend/tests/test_secure_tunnel_gate.py
index 2c13e13bbb..a8c0c2305f 100644
--- a/studio/backend/tests/test_secure_tunnel_gate.py
+++ b/studio/backend/tests/test_secure_tunnel_gate.py
@@ -2,7 +2,7 @@
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 """Cloudflare tunnel start gate, incl. --secure on loopback. Imports run.py
-directly, so run under the Studio venv."""
+directly, so run under the Unsloth venv."""
 
 from __future__ import annotations
 
diff --git a/studio/backend/tests/test_server_disk_logging.py b/studio/backend/tests/test_server_disk_logging.py
index 05d03d869c..ce733c2aaa 100644
--- a/studio/backend/tests/test_server_disk_logging.py
+++ b/studio/backend/tests/test_server_disk_logging.py
@@ -3,7 +3,7 @@
 
 """Tests for the server session log + native-crash capture in run.py.
 
-Field regression: Studio "terminates without a warning" -- a native crash in
+Field regression: Unsloth "terminates without a warning" -- a native crash in
 the GPU runtime kills the process with no Python traceback, and a desktop-
 shortcut console closes before anything can be read. The server must tee its
 console output to disk and aim faulthandler at the same file so even hard
diff --git a/studio/backend/tests/test_setup_cache_env_hf_home.py b/studio/backend/tests/test_setup_cache_env_hf_home.py
index 4520c93a51..c5d5f820a8 100644
--- a/studio/backend/tests/test_setup_cache_env_hf_home.py
+++ b/studio/backend/tests/test_setup_cache_env_hf_home.py
@@ -28,6 +28,9 @@ def _isolate_studio_home(monkeypatch, tmp_path):
 
 
 def _load_storage_roots():
+    # Each test models a fresh backend process. The cache resolver intentionally
+    # snapshots explicit environment variables once per process.
+    sys.modules.pop("utils.hf_cache_settings", None)
     spec = importlib.util.spec_from_file_location("storage_roots_under_test", _STORAGE_ROOTS_PATH)
     module = importlib.util.module_from_spec(spec)
     spec.loader.exec_module(module)
@@ -40,10 +43,10 @@ def _clear_hf_env(monkeypatch):
 
 
 def test_custom_hf_home_seeds_hub_and_xet(monkeypatch, tmp_path):
-    sr = _load_storage_roots()
     _clear_hf_env(monkeypatch)
     custom = tmp_path / "shared" / "huggingface"
     monkeypatch.setenv("HF_HOME", str(custom))
+    sr = _load_storage_roots()
 
     sr._setup_cache_env()
 
@@ -54,9 +57,9 @@ def test_custom_hf_home_seeds_hub_and_xet(monkeypatch, tmp_path):
 
 
 def test_default_when_hf_home_unset(monkeypatch, tmp_path):
-    sr = _load_storage_roots()
     _clear_hf_env(monkeypatch)
     monkeypatch.setenv("XDG_CACHE_HOME", str(tmp_path / "xdg"))
+    sr = _load_storage_roots()
 
     sr._setup_cache_env()
 
@@ -67,11 +70,11 @@ def test_default_when_hf_home_unset(monkeypatch, tmp_path):
 
 
 def test_explicit_hub_cache_is_not_overridden(monkeypatch, tmp_path):
-    sr = _load_storage_roots()
     _clear_hf_env(monkeypatch)
     monkeypatch.setenv("HF_HOME", str(tmp_path / "home"))
     explicit = tmp_path / "explicit" / "hub"
     monkeypatch.setenv("HF_HUB_CACHE", str(explicit))
+    sr = _load_storage_roots()
 
     sr._setup_cache_env()
 
@@ -81,11 +84,11 @@ def test_explicit_hub_cache_is_not_overridden(monkeypatch, tmp_path):
 
 
 def test_legacy_huggingface_hub_cache_alias_is_honored(monkeypatch, tmp_path):
-    sr = _load_storage_roots()
     _clear_hf_env(monkeypatch)
     monkeypatch.setenv("HF_HOME", str(tmp_path / "home"))
     legacy = tmp_path / "legacy" / "hub"
     monkeypatch.setenv("HUGGINGFACE_HUB_CACHE", str(legacy))
+    sr = _load_storage_roots()
 
     sr._setup_cache_env()
 
@@ -96,15 +99,16 @@ def test_legacy_huggingface_hub_cache_alias_is_honored(monkeypatch, tmp_path):
 
 def test_whitespace_hf_home_falls_back_to_default(monkeypatch, tmp_path):
     # A blank/whitespace HF_HOME must not become " /hub"; fall back to default.
-    sr = _load_storage_roots()
     _clear_hf_env(monkeypatch)
     monkeypatch.setenv("HF_HOME", "   ")
     monkeypatch.setenv("XDG_CACHE_HOME", str(tmp_path / "xdg"))
+    sr = _load_storage_roots()
 
     sr._setup_cache_env()
 
     import os
 
+    assert os.environ["HF_HOME"] == str(tmp_path / "xdg" / "huggingface")
     assert os.environ["HF_HUB_CACHE"] == str(tmp_path / "xdg" / "huggingface" / "hub")
 
 
@@ -114,9 +118,9 @@ def test_unwritable_hf_home_does_not_crash(monkeypatch, tmp_path):
     blocker = tmp_path / "blocker"
     blocker.write_text("not a dir")
     unwritable = blocker / "hf"
-    sr = _load_storage_roots()
     _clear_hf_env(monkeypatch)
     monkeypatch.setenv("HF_HOME", str(unwritable))
+    sr = _load_storage_roots()
 
     sr._setup_cache_env()  # must not raise
 
diff --git a/studio/backend/tests/test_setup_llama_cpp_backend.py b/studio/backend/tests/test_setup_llama_cpp_backend.py
new file mode 100644
index 0000000000..36928c680c
--- /dev/null
+++ b/studio/backend/tests/test_setup_llama_cpp_backend.py
@@ -0,0 +1,154 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""setup.sh and setup.ps1 must map UNSLOTH_LLAMA_CPP_BACKEND=cpu to
+install_llama_prebuilt.py's --force-cpu so users can force the CPU-only prebuilt
+on GPU hosts (#7213). The match is case-insensitive and whitespace-trimmed, an
+unrecognized value warns instead of silently falling back, and macOS warns (no
+CPU-only bundle). Runs the real block extracted from each script so the tests
+track the shipped logic.
+"""
+
+import os
+import re
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+_STUDIO = Path(__file__).resolve().parents[2]
+_SETUP_SH = _STUDIO / "setup.sh"
+_SETUP_PS1 = _STUDIO / "setup.ps1"
+_SKIP_NO_BASH = pytest.mark.skipif(shutil.which("bash") is None, reason = "bash unavailable")
+_SKIP_NO_PWSH = pytest.mark.skipif(shutil.which("pwsh") is None, reason = "pwsh unavailable")
+
+
+def _backend_block() -> str:
+    text = _SETUP_SH.read_text(encoding = "utf-8")
+    m = re.search(r"_llama_backend=.*?esac", text, re.DOTALL)
+    assert m, "UNSLOTH_LLAMA_CPP_BACKEND block not found in setup.sh"
+    return m.group(0)
+
+
+def _run(value: str | None, system: str = "Linux") -> tuple[list[str], str]:
+    # Pass the value through env (not the script text) so whitespace survives, and
+    # stub the setup.sh logging helpers the unknown-value branch calls. system sets
+    # _HOST_SYSTEM so the macOS (Darwin) no-op branch can be exercised.
+    env = {k: v for k, v in os.environ.items() if k != "UNSLOTH_LLAMA_CPP_BACKEND"}
+    if value is not None:
+        env["UNSLOTH_LLAMA_CPP_BACKEND"] = value
+    harness = (
+        f'_PREBUILT_CMD=()\nC_WARN=""\n_HOST_SYSTEM="{system}"\n'
+        'step() { printf "STEP: %s\\n" "$*" >&2; }\n'
+        f"{_backend_block()}\n"
+        'printf "%s\\n" "${_PREBUILT_CMD[@]}"'
+    )
+    out = subprocess.run(
+        ["bash", "-c", harness], capture_output = True, text = True, env = env, check = True
+    )
+    return out.stdout.split(), out.stderr
+
+
+@_SKIP_NO_BASH
+@pytest.mark.parametrize("value", ["cpu", "CPU", "Cpu", " cpu ", "CPU\t"])
+def test_backend_cpu_appends_flag(value):
+    # A deliberate CPU choice persists, so it uses --force-cpu (not the transient
+    # --cpu-fallback the arm64 GPU-build recovery uses).
+    args, stderr = _run(value)
+    assert "--force-cpu" in args
+    assert "--cpu-fallback" not in args
+    assert "Ignoring" not in stderr
+
+
+@_SKIP_NO_BASH
+@pytest.mark.parametrize("value", ["cpu", "CPU", " cpu "])
+def test_backend_cpu_macos_warns_no_flag(value):
+    # macOS has no CPU-only bundle (the universal build already runs on CPU), so the
+    # override warns instead of writing a misleading forced-CPU marker.
+    args, stderr = _run(value, system = "Darwin")
+    assert "--force-cpu" not in args
+    assert "--cpu-fallback" not in args
+    assert "macOS" in stderr
+
+
+@_SKIP_NO_BASH
+@pytest.mark.parametrize("value", [None, "", "auto", "AUTO", "  "])
+def test_backend_auto_no_flag_no_warn(value):
+    args, stderr = _run(value)
+    assert "--force-cpu" not in args
+    assert "Ignoring" not in stderr
+
+
+@_SKIP_NO_BASH
+@pytest.mark.parametrize("value", ["vulkan", "gpu", "cuda"])
+def test_backend_unknown_warns_and_no_flag(value):
+    args, stderr = _run(value)
+    assert "--force-cpu" not in args
+    assert "Ignoring" in stderr
+
+
+@_SKIP_NO_BASH
+def test_arm64_recovery_uses_transient_cpu_fallback():
+    # The arm64 Linux GPU-build recovery must stay transient (--cpu-fallback), never
+    # the persisted --force-cpu, so a later update can still heal to a GPU bundle (#6097).
+    text = _SETUP_SH.read_text(encoding = "utf-8")
+    m = re.search(r"_ARM64_CPU_CMD=\((.*?)\)", text, re.DOTALL)
+    assert m, "arm64 CPU recovery command not found in setup.sh"
+    block = m.group(1)
+    assert "--cpu-fallback" in block
+    assert "--force-cpu" not in block
+
+
+def _ps1_search(pattern: str, flags = 0) -> str:
+    m = re.search(pattern, _SETUP_PS1.read_text(encoding = "utf-8"), flags)
+    assert m, f"setup.ps1 block not found: {pattern}"
+    return m.group(0)
+
+
+def _run_ps1(value: str | None) -> str:
+    # The override is normalized (assign + warn) at the top of the prebuilt block and
+    # applied to $prebuiltArgs lower down; compose both real snippets.
+    normalize = _ps1_search(
+        r'\$llamaBackend = "\$\(\$env:UNSLOTH_LLAMA_CPP_BACKEND\)".*?Write-Host.*?\n\s*\}',
+        re.DOTALL,
+    )
+    apply_flag = _ps1_search(
+        r'if \(\$llamaBackend -eq "cpu"\) \{\s*\$prebuiltArgs \+= "--force-cpu"\s*\}'
+    )
+    env = {k: v for k, v in os.environ.items() if k != "UNSLOTH_LLAMA_CPP_BACKEND"}
+    if value is not None:
+        env["UNSLOTH_LLAMA_CPP_BACKEND"] = value
+    harness = f'$prebuiltArgs = @()\n{normalize}\n{apply_flag}\n"ARGS:" + ($prebuiltArgs -join ",")'
+    out = subprocess.run(
+        ["pwsh", "-NoProfile", "-Command", harness],
+        capture_output = True,
+        text = True,
+        env = env,
+        check = True,
+    )
+    return out.stdout
+
+
+@_SKIP_NO_PWSH
+@pytest.mark.parametrize("value", ["cpu", "CPU", "Cpu", " cpu ", "CPU\t"])
+def test_ps1_backend_cpu_appends_flag(value):
+    out = _run_ps1(value)
+    assert "--force-cpu" in out
+    assert "Ignoring" not in out
+
+
+@_SKIP_NO_PWSH
+@pytest.mark.parametrize("value", [None, "", "auto", "AUTO", "  "])
+def test_ps1_backend_auto_no_flag_no_warn(value):
+    out = _run_ps1(value)
+    assert "--force-cpu" not in out
+    assert "Ignoring" not in out
+
+
+@_SKIP_NO_PWSH
+@pytest.mark.parametrize("value", ["vulkan", "gpu", "cuda"])
+def test_ps1_backend_unknown_warns_and_no_flag(value):
+    out = _run_ps1(value)
+    assert "--force-cpu" not in out
+    assert "Ignoring" in out
diff --git a/studio/backend/tests/test_sf_client_tools_passthrough.py b/studio/backend/tests/test_sf_client_tools_passthrough.py
index 01905b712c..f91eec9817 100644
--- a/studio/backend/tests/test_sf_client_tools_passthrough.py
+++ b/studio/backend/tests/test_sf_client_tools_passthrough.py
@@ -177,6 +177,15 @@ def _sse_objects(chunks):
 # ── Non-streaming ─────────────────────────────────────────────────
 
 
+def test_non_reasoning_backend_keeps_literal_think_tags(monkeypatch):
+    backend = _ScriptedBackend(_fixed("show <think>example</think> tags"))
+    response = _call(_request(stream = False), monkeypatch, backend, supports_tools = False)
+
+    message = _json_body(response)["choices"][0]["message"]
+    assert message["content"] == "show <think>example</think> tags"
+    assert message["reasoning_content"] is None
+
+
 def test_xml_healed_to_tool_calls_non_streaming(monkeypatch):
     backend = _ScriptedBackend(_fixed(_CALL_XML))
     payload = _request(tools = [LOOKUP_TOOL], stream = False)
@@ -485,6 +494,52 @@ def test_streaming_no_tools_verbatim(monkeypatch):
     assert finishes == ["stop"]
 
 
+def test_streaming_gen_stream_error_is_not_model_text(monkeypatch):
+    from core.inference.orchestrator import GenStreamError
+
+    class _ErrorAfterPartial(_ScriptedBackend):
+        def __init__(self):
+            super().__init__(_fixed())
+
+        def generate_chat_response(self, **_kwargs):
+            yield "<think>partial"
+            yield GenStreamError("Error: /tmp/secret traceback")
+
+    backend = _ErrorAfterPartial()
+    payload = _request(stream = True)
+    response = _call(payload, monkeypatch, backend, supports_tools = False)
+    chunks = _collect_sse(response)
+    objs = _sse_objects(chunks)
+
+    deltas = [o.get("choices", [{}])[0].get("delta", {}) for o in objs if o.get("choices")]
+    assert any("partial" in json.dumps(delta) for delta in deltas)
+    assert not any("/tmp/secret" in json.dumps(delta) for delta in deltas)
+    errors = [o["error"]["message"] for o in objs if "error" in o]
+    assert errors == ["An internal error occurred."]
+    assert any(
+        "data: [DONE]" in (chunk.decode() if isinstance(chunk, bytes) else chunk)
+        for chunk in chunks
+    )
+
+
+def test_server_tool_streaming_invalid_event_is_error(monkeypatch):
+    class _InvalidEventBackend(_ScriptedBackend):
+        def __init__(self):
+            super().__init__(_fixed())
+
+        def generate_chat_completion_with_tools(self, **_kwargs):
+            yield {"type": "content", "text": "partial"}
+            yield "not-an-event"
+
+    backend = _InvalidEventBackend()
+    payload = _request(tools = [LOOKUP_TOOL], enable_tools = True, stream = True)
+    response = _call(payload, monkeypatch, backend)
+    objs = _sse_objects(_collect_sse(response))
+
+    errors = [o["error"]["message"] for o in objs if "error" in o]
+    assert errors == ["An internal error occurred."]
+
+
 def test_streaming_repeated_snapshot_no_duplicate_call(monkeypatch):
     # Repeated then shrunk cumulative snapshots must not double-heal.
     backend = _ScriptedBackend(_fixed(_CALL_XML, _CALL_XML, _CALL_XML[:5], _CALL_XML))
diff --git a/studio/backend/tests/test_slot_offload_fit.py b/studio/backend/tests/test_slot_offload_fit.py
index ac606e4627..d354c7e113 100644
--- a/studio/backend/tests/test_slot_offload_fit.py
+++ b/studio/backend/tests/test_slot_offload_fit.py
@@ -3,7 +3,7 @@
 
 """Tests for the offload-avoidance serving-slot reduction (`_slots_that_fit_on_gpu`).
 
-When a pinned context does not fit at the requested `--parallel` slot count, Studio would
+When a pinned context does not fit at the requested `--parallel` slot count, Unsloth would
 flip to `--fit on` and llama-server offloads layers to host RAM, collapsing decode ~3x
 (oobabooga #6718). Instead the loader retries the on-GPU fit at fewer slots and keeps the
 largest count that stays fully on GPU (`-ngl -1`). These tests drive the real helper with
diff --git a/studio/backend/tests/test_stt_download_validation.py b/studio/backend/tests/test_stt_download_validation.py
new file mode 100644
index 0000000000..a612b14531
--- /dev/null
+++ b/studio/backend/tests/test_stt_download_validation.py
@@ -0,0 +1,168 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""The /audio/stt/download route must validate a custom Transformers repo before
+snapshot_download pulls it into the shared HF cache.
+
+Regression for a Codex finding: the Transformers engine accepts arbitrary
+`owner/model` repos, so an authenticated caller could make Studio download a
+large non-STT repository before load-time validation ever ran. Whisper-
+compatibility is now enforced (metadata-only, no weights) before the background
+download starts. The GGUF engine only accepts curated ids, so it is not gated.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import sys
+from pathlib import Path
+
+import pytest
+from fastapi import HTTPException
+
+_BACKEND_ROOT = Path(__file__).resolve().parents[1]
+if str(_BACKEND_ROOT) not in sys.path:
+    sys.path.insert(0, str(_BACKEND_ROOT))
+
+import core.inference.stt_ggml_sidecar as ggml_module  # noqa: E402
+import core.inference.stt_sidecar as stt_module  # noqa: E402
+import routes.inference as ri  # noqa: E402
+from core.inference.stt_sidecar import SttModelCompatibilityError  # noqa: E402
+from models.inference import SttLoadRequest  # noqa: E402
+
+
+def _run(coro):
+    return asyncio.run(coro)
+
+
+def test_custom_non_whisper_repo_is_rejected_before_download(monkeypatch):
+    started: list = []
+    validated: list = []
+
+    def fake_validate(model, hf_token = None):
+        validated.append(model)
+        raise SttModelCompatibilityError(
+            f"STT model '{model}' is not a compatible Transformers Whisper model."
+        )
+
+    def fake_download(model, hf_token = None):
+        started.append(model)
+
+    monkeypatch.setattr(stt_module, "validate_remote_model", fake_validate)
+    monkeypatch.setattr(stt_module, "start_model_download", fake_download)
+
+    with pytest.raises(HTTPException) as excinfo:
+        _run(
+            ri.stt_download(
+                SttLoadRequest(model = "owner/chat-model", engine = "transformers"),
+                current_subject = "tester",
+                hf_token = None,
+            )
+        )
+
+    assert excinfo.value.status_code == 422
+    assert validated == ["owner/chat-model"]
+    # The download never starts for a repo that failed the Whisper check.
+    assert started == []
+
+
+def test_validated_transformers_repo_downloads(monkeypatch):
+    started: list = []
+    revision = "a" * 40
+
+    monkeypatch.setattr(
+        stt_module,
+        "validate_remote_model",
+        lambda model, hf_token = None: {"model": model, "revision": revision},
+    )
+    monkeypatch.setattr(
+        stt_module,
+        "start_model_download",
+        lambda model, hf_token = None, revision = None: started.append((model, revision)),
+    )
+    monkeypatch.setattr(stt_module, "download_status", lambda: {"downloading": True})
+
+    resp = _run(
+        ri.stt_download(
+            SttLoadRequest(model = "owner/real-whisper", engine = "transformers"),
+            current_subject = "tester",
+            hf_token = None,
+        )
+    )
+
+    assert resp.status_code == 200
+    assert started == [("owner/real-whisper", revision)]
+
+
+def test_gguf_engine_skips_the_transformers_repo_check(monkeypatch):
+    started: list = []
+
+    def fail_if_called(model, hf_token = None):
+        raise AssertionError("GGUF downloads must not run the Transformers repo check")
+
+    # whisper-server present, so the GGUF request stays on the GGUF engine.
+    monkeypatch.setattr(ggml_module, "is_available", lambda: True)
+    monkeypatch.setattr(stt_module, "validate_remote_model", fail_if_called)
+    monkeypatch.setattr(
+        ggml_module, "start_model_download", lambda model, hf_token = None: started.append(model)
+    )
+    monkeypatch.setattr(ggml_module, "download_status", lambda: {"downloading": True})
+
+    resp = _run(
+        ri.stt_download(
+            SttLoadRequest(model = "small", engine = "gguf"),
+            current_subject = "tester",
+            hf_token = None,
+        )
+    )
+
+    assert resp.status_code == 200
+    assert started == ["small"]
+
+
+def test_resolve_serving_stt_engine_falls_back_when_whisper_server_absent(monkeypatch):
+    # A curated GGUF request downgrades to Transformers when whisper-server is not
+    # installed (both engines serve curated ids), but stays GGUF when it is.
+    monkeypatch.setattr(ggml_module, "is_available", lambda: False)
+    assert ri._resolve_serving_stt_engine("gguf") == "transformers"
+    monkeypatch.setattr(ggml_module, "is_available", lambda: True)
+    assert ri._resolve_serving_stt_engine("gguf") == "gguf"
+    # Transformers is unaffected by whisper-server availability.
+    monkeypatch.setattr(ggml_module, "is_available", lambda: False)
+    assert ri._resolve_serving_stt_engine("transformers") == "transformers"
+
+
+def test_gguf_download_falls_back_to_transformers_when_server_absent(monkeypatch):
+    """Selecting the default curated model on a host without whisper-server must
+    download through the Transformers engine, not 501/dead-end on GGUF."""
+    gguf_started: list = []
+    tf_started: list = []
+
+    monkeypatch.setattr(ggml_module, "is_available", lambda: False)  # no whisper-server
+    # validate_remote_model no-ops curated ids in production; keep it a no-op here.
+    monkeypatch.setattr(
+        stt_module, "validate_remote_model", lambda model, hf_token = None: {"model": model}
+    )
+    monkeypatch.setattr(
+        stt_module,
+        "start_model_download",
+        lambda model, hf_token = None, revision = None: tf_started.append(model),
+    )
+    monkeypatch.setattr(stt_module, "download_status", lambda: {"downloading": True})
+    monkeypatch.setattr(
+        ggml_module,
+        "start_model_download",
+        lambda model, hf_token = None: gguf_started.append(model),
+    )
+
+    resp = _run(
+        ri.stt_download(
+            SttLoadRequest(model = "small", engine = "gguf"),
+            current_subject = "tester",
+            hf_token = None,
+        )
+    )
+
+    assert resp.status_code == 200
+    assert tf_started == ["small"]  # served by Transformers instead of dead-ending on GGUF
+    assert gguf_started == []
diff --git a/studio/backend/tests/test_stt_ggml_sidecar.py b/studio/backend/tests/test_stt_ggml_sidecar.py
new file mode 100644
index 0000000000..686fd8f546
--- /dev/null
+++ b/studio/backend/tests/test_stt_ggml_sidecar.py
@@ -0,0 +1,780 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import http.server
+import io
+import json
+import os
+import sys
+import threading
+import time
+import wave
+from pathlib import Path
+
+import numpy as np
+import pytest
+
+import core.inference.stt_ggml_sidecar as ggml_module
+from core.inference.stt_ggml_sidecar import (
+    DEFAULT_GGML_STT_MODEL,
+    GGML_STT_MODELS,
+    GGML_STT_REPOS,
+    GgmlSttSidecar,
+    SttEngineUnavailableError,
+    find_whisper_server_binary,
+    resolve_ggml_model_id,
+)
+from core.inference.stt_sidecar import (
+    SttLanguageError,
+    SttLoadCancelledError,
+    SttModelIdError,
+    SttModelNotDownloadedError,
+    SttUnavailableError,
+)
+
+
+@pytest.fixture(autouse = True)
+def isolate_runtime_and_stub_audio_decoder(monkeypatch, tmp_path):
+    """Unit tests exercise orchestration, not PyAV container parsing."""
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path / "studio"))
+    monkeypatch.delenv("WHISPER_SERVER_PATH", raising = False)
+    monkeypatch.delenv("UNSLOTH_WHISPER_CPP_PATH", raising = False)
+    monkeypatch.setenv("PATH", "")
+    monkeypatch.setattr(
+        ggml_module,
+        "_decode_audio_bounded",
+        lambda audio: np.zeros(16000, dtype = np.float32),
+    )
+
+
+# ---------------------------------------------------------------------------
+# Model id resolution
+# ---------------------------------------------------------------------------
+
+
+def test_curated_ids_resolve():
+    for model_id in GGML_STT_MODELS:
+        assert resolve_ggml_model_id(model_id) == model_id
+
+
+def test_default_model_resolves_from_none_and_blank():
+    assert resolve_ggml_model_id(None) == DEFAULT_GGML_STT_MODEL
+    assert resolve_ggml_model_id("  ") == DEFAULT_GGML_STT_MODEL
+
+
+def test_custom_repo_ids_are_rejected():
+    with pytest.raises(SttModelIdError):
+        resolve_ggml_model_id("owner/model")
+    with pytest.raises(SttModelIdError):
+        resolve_ggml_model_id("large-v2")
+
+
+def test_curated_ids_mirror_transformers_sidecar():
+    from core.inference.stt_sidecar import STT_MODELS
+    assert list(GGML_STT_MODELS.keys()) == list(STT_MODELS.keys())
+
+
+def test_curated_filenames_match_repo_naming():
+    # unslothai/whisper-<id>-GGUF hosts whisper-<id>.bin; keep the download
+    # filename in lockstep with the repo so it resolves instead of 404ing.
+    for model_id, repo in GGML_STT_REPOS.items():
+        expected = repo.split("/", 1)[1].removesuffix("-GGUF") + ".bin"
+        assert GGML_STT_MODELS[model_id] == expected
+
+
+# ---------------------------------------------------------------------------
+# Binary discovery
+# ---------------------------------------------------------------------------
+
+
+def test_env_binary_override_wins(monkeypatch, tmp_path):
+    binary = tmp_path / "whisper-server"
+    binary.write_text("#!/bin/sh\n")
+    binary.chmod(0o755)  # find_whisper_server_binary requires an executable
+    monkeypatch.setenv("WHISPER_SERVER_PATH", str(binary))
+    assert find_whisper_server_binary() == str(binary)
+
+
+def test_env_dir_override_scans_layouts(monkeypatch, tmp_path):
+    monkeypatch.delenv("WHISPER_SERVER_PATH", raising = False)
+    build_bin = tmp_path / "build" / "bin"
+    build_bin.mkdir(parents = True)
+    binary = build_bin / "whisper-server"
+    binary.write_text("#!/bin/sh\n")
+    binary.chmod(0o755)  # find_whisper_server_binary requires an executable
+    monkeypatch.setenv("UNSLOTH_WHISPER_CPP_PATH", str(tmp_path))
+    assert find_whisper_server_binary() == str(binary)
+
+
+def test_missing_binary_reports_unavailable(monkeypatch, tmp_path):
+    monkeypatch.delenv("WHISPER_SERVER_PATH", raising = False)
+    monkeypatch.setenv("UNSLOTH_WHISPER_CPP_PATH", str(tmp_path / "nope"))
+    monkeypatch.setattr(ggml_module, "_managed_whisper_cpp_dir", lambda: tmp_path / "gone")
+    monkeypatch.setattr(ggml_module.shutil, "which", lambda name: None)
+    assert find_whisper_server_binary() is None
+    assert not ggml_module.is_available()
+    with pytest.raises(SttEngineUnavailableError):
+        ggml_module.ensure_engine_available()
+
+
+def test_non_executable_binary_is_not_runnable(monkeypatch, tmp_path):
+    if sys.platform == "win32":
+        pytest.skip("X_OK is an existence check on Windows")
+    binary = tmp_path / "whisper-server"
+    binary.write_text("#!/bin/sh\n")  # written but not chmod +x
+    monkeypatch.setenv("WHISPER_SERVER_PATH", str(binary))
+    monkeypatch.setattr(ggml_module.shutil, "which", lambda name: None)
+    assert find_whisper_server_binary() is None
+
+
+# ---------------------------------------------------------------------------
+# Slim-install launch guard
+# ---------------------------------------------------------------------------
+
+
+def _slim_install(
+    tmp_path,
+    *,
+    install_kind = "slim",
+    with_ggml = True,
+    linked_libraries = None,
+    backend = "cpu",
+    linked_runtime_directories = None,
+    runtime_wiring_version = None,
+) -> str:
+    """A managed-looking install tree: marker at the root, server in build/bin."""
+    install_dir = tmp_path / "whisper.cpp"
+    bin_dir = install_dir / "build" / "bin"
+    bin_dir.mkdir(parents = True)
+    binary = bin_dir / "whisper-server"
+    binary.write_text("#!/bin/sh\n")
+    binary.chmod(0o755)
+    marker: dict = {
+        "schema_version": 1,
+        "component": "whisper.cpp",
+        "release_tag": "v1.9.1-unsloth.1",
+        "backend": backend,
+        "paired_llama_tag": "b10069-mix-fb3d4ca",
+    }
+    if install_kind is not None:
+        marker["install_kind"] = install_kind
+    if linked_libraries is not None:
+        marker["linked_libraries"] = linked_libraries
+    if linked_runtime_directories is not None:
+        marker["linked_runtime_directories"] = linked_runtime_directories
+        for name in linked_runtime_directories:
+            catalog = bin_dir / name
+            catalog.mkdir()
+            (catalog / "kernel.dat").write_bytes(b"kernel")
+    if runtime_wiring_version is not None:
+        marker["runtime_wiring_version"] = runtime_wiring_version
+    (install_dir / "UNSLOTH_WHISPER_PREBUILT_INFO.json").write_text(json.dumps(marker))
+    if with_ggml:
+        names = (
+            ("ggml.dll", "ggml-base.dll")
+            if sys.platform == "win32"
+            else ("libggml.so.0", "libggml-base.so.0")
+        )
+        for name in names:
+            (bin_dir / name).write_bytes(b"ggml")
+    return str(binary)
+
+
+def test_slim_guard_flags_missing_ggml_links(monkeypatch, tmp_path):
+    # A slim marker whose linked ggml runtime is gone must read as engine
+    # unavailable (reinstall), never crash into a server launch.
+    binary = _slim_install(tmp_path, with_ggml = False)
+    assert ggml_module.slim_runtime_intact(binary) is False
+    monkeypatch.setattr(ggml_module, "find_whisper_server_binary", lambda: binary)
+    assert not ggml_module.is_available()
+    with pytest.raises(SttEngineUnavailableError, match = "ggml"):
+        ggml_module.ensure_engine_available()
+
+
+def test_slim_guard_passes_with_links_in_place(monkeypatch, tmp_path):
+    names = ["libggml.so.0", "libggml-base.so.0"]
+    binary = _slim_install(tmp_path, with_ggml = True, linked_libraries = names)
+    assert ggml_module.slim_runtime_intact(binary) is True
+    monkeypatch.setattr(ggml_module, "find_whisper_server_binary", lambda: binary)
+    assert ggml_module.ensure_engine_available() == binary
+
+
+def test_slim_guard_verifies_the_marker_linked_libraries(monkeypatch, tmp_path):
+    # New markers record the exact wired filenames; one missing name flips the
+    # install to unavailable even when the legacy core ggml names are present.
+    names = ["libggml.dylib", "libggml-base.dylib", "libggml-metal.dylib"]
+    binary = _slim_install(tmp_path, with_ggml = True, linked_libraries = names)
+    bin_dir = Path(binary).parent
+    for name in names[:-1]:
+        (bin_dir / name).write_bytes(b"ggml")
+    assert ggml_module.slim_runtime_intact(binary) is False  # metal dylib absent
+    (bin_dir / names[-1]).write_bytes(b"ggml")
+    assert ggml_module.slim_runtime_intact(binary) is True
+    monkeypatch.setattr(ggml_module, "find_whisper_server_binary", lambda: binary)
+    assert ggml_module.ensure_engine_available() == binary
+
+
+def test_slim_guard_malformed_authoritative_marker_fails_closed(tmp_path):
+    for bad in ("not-a-list", [], [1, 2]):
+        root = tmp_path / f"case_{type(bad).__name__}_{len(str(bad))}"
+        root.mkdir()
+        binary = _slim_install(root, with_ggml = True, linked_libraries = bad)
+        assert ggml_module.slim_runtime_intact(binary) is False
+
+
+def test_slim_guard_prefers_authoritative_root_marker(tmp_path):
+    names = ["libggml.so.0", "libggml-base.so.0"]
+    binary = _slim_install(tmp_path, with_ggml = True, linked_libraries = names)
+    packaging_marker = Path(binary).parent / "UNSLOTH_WHISPER_PREBUILT_INFO.json"
+    packaging_marker.write_text(json.dumps({"backend": "slim", "release_tag": "packaging"}))
+    assert ggml_module._whisper_install_marker(binary)["install_kind"] == "slim"
+    assert ggml_module.slim_runtime_intact(binary) is True
+
+
+def test_slim_guard_rejects_invalid_root_even_with_inner_marker(tmp_path):
+    binary = _slim_install(tmp_path, with_ggml = True, linked_libraries = ["libggml.so.0"])
+    root_marker = Path(binary).parents[2] / "UNSLOTH_WHISPER_PREBUILT_INFO.json"
+    root_marker.write_text("not json")
+    (Path(binary).parent / root_marker.name).write_text(json.dumps({"backend": "slim"}))
+    assert ggml_module.slim_runtime_intact(binary) is False
+
+
+def test_slim_guard_rejects_missing_rocm_catalog(tmp_path):
+    names = ["libggml.so.0", "libggml-base.so.0", "libggml-hip.so"]
+    binary = _slim_install(
+        tmp_path,
+        linked_libraries = names,
+        backend = "rocm",
+        linked_runtime_directories = ["hipblaslt", "rocblas"],
+        runtime_wiring_version = 2,
+    )
+    bin_dir = Path(binary).parent
+    (bin_dir / "libggml-hip.so").write_bytes(b"ggml")
+    assert ggml_module.slim_runtime_intact(binary) is True
+    (bin_dir / "rocblas" / "kernel.dat").unlink()
+    assert ggml_module.slim_runtime_intact(binary) is False
+
+
+def test_slim_guard_accepts_windows_rocm_dll_overlay(monkeypatch, tmp_path):
+    monkeypatch.setattr(ggml_module.sys, "platform", "win32")
+    names = ["ggml.dll", "ggml-base.dll", "ggml-hip.dll", "amdhip64.dll"]
+    binary = _slim_install(
+        tmp_path,
+        linked_libraries = names,
+        backend = "rocm",
+        linked_runtime_directories = [],
+        runtime_wiring_version = 2,
+    )
+    for name in names:
+        (Path(binary).parent / name).write_bytes(b"dll")
+    assert ggml_module.slim_runtime_intact(binary) is True
+
+
+def test_slim_guard_ignores_fat_and_markerless_installs(tmp_path):
+    # Fat installs carry their own ggml; no marker means source/custom build.
+    fat = _slim_install(tmp_path / "fat", install_kind = None, with_ggml = False)
+    assert ggml_module.slim_runtime_intact(fat) is True
+    bare = tmp_path / "bare" / "whisper-server"
+    bare.parent.mkdir(parents = True)
+    bare.write_text("#!/bin/sh\n")
+    assert ggml_module.slim_runtime_intact(str(bare)) is True
+
+
+# ---------------------------------------------------------------------------
+# whisper-server child-process environment
+# ---------------------------------------------------------------------------
+
+
+def _loader_path_var() -> str:
+    return {"win32": "PATH", "darwin": "DYLD_LIBRARY_PATH"}.get(sys.platform, "LD_LIBRARY_PATH")
+
+
+def test_child_env_scrubs_secrets_and_adds_lib_dir(monkeypatch, tmp_path):
+    monkeypatch.setenv("HF_TOKEN", "secret-token")  # exact name
+    monkeypatch.setenv("MY_API_KEY", "nope")  # marker substring
+    monkeypatch.setenv("HTTPS_PROXY", "http://u:p@px:8080")  # url-name
+    monkeypatch.setenv("SOME_REMOTE", "https://u:pw@host/repo")  # url-userinfo value
+    monkeypatch.setenv("STT_KEEPME", "keep")  # benign
+    binary = tmp_path / "whisper-server"
+    binary.write_text("#!/bin/sh\n")
+    env = ggml_module._whisper_server_child_env(str(binary))
+    for scrubbed in ("HF_TOKEN", "MY_API_KEY", "HTTPS_PROXY", "SOME_REMOTE"):
+        assert scrubbed not in env
+    assert env.get("STT_KEEPME") == "keep"
+    assert str(tmp_path.resolve()) in env[_loader_path_var()].split(os.pathsep)
+
+
+def test_child_env_isolates_home_and_cred_locations(monkeypatch, tmp_path):
+    # The downloaded server must not see the real home (token caches live
+    # there) nor explicit cred-store pointers like HF_HOME / NETRC.
+    monkeypatch.setenv("HOME", "/real/home")
+    monkeypatch.setenv("HF_HOME", "/real/hf")
+    monkeypatch.setenv("NETRC", "/real/.netrc")
+    monkeypatch.setattr(ggml_module, "_managed_whisper_cpp_dir", lambda: tmp_path / "managed")
+    binary = tmp_path / "whisper-server"
+    binary.write_text("#!/bin/sh\n")
+    env = ggml_module._whisper_server_child_env(str(binary))
+    assert env["HOME"] == str(tmp_path / "managed" / ".child_home")
+    assert "HF_HOME" not in env
+    assert "NETRC" not in env
+    assert (tmp_path / "managed" / ".child_home").is_dir()
+
+
+def test_child_env_wsl_rocm_prepends_system_hip(monkeypatch, tmp_path):
+    if sys.platform != "linux":
+        pytest.skip("WSL ROCm library precedence is Linux-only")
+    rocm = tmp_path / "rocm-lib"
+    rocm.mkdir()
+    bindir = tmp_path / "bin"
+    bindir.mkdir()
+    binary = bindir / "whisper-server"
+    binary.write_text("#!/bin/sh\n")
+    monkeypatch.setattr(ggml_module, "_wsl_system_rocm_lib_dirs", lambda: [str(rocm)])
+    env = ggml_module._whisper_server_child_env(str(binary))
+    parts = env["LD_LIBRARY_PATH"].split(os.pathsep)
+    assert parts[0] == str(rocm.resolve())  # system HIP wins
+    assert str(bindir.resolve()) in parts  # bundle libs still present
+    assert env.get("HSA_ENABLE_DXG_DETECTION") == "1"
+
+
+def test_child_env_adds_cuda_runtime_dirs_for_cuda_bundle(monkeypatch, tmp_path):
+    # Versioned CUDA backend modules are valid too. They still need the
+    # CUDA-from-PyTorch wheel dirs for libcudart/libcublas at launch.
+    if sys.platform == "darwin":
+        pytest.skip("no CUDA on macOS")
+    import utils.prebuilt.runtime_libs as rl
+
+    bindir = tmp_path / "bin"
+    bindir.mkdir()
+    (bindir / "whisper-server").write_text("#!/bin/sh\n")
+    module_name = "ggml-cuda.dll" if sys.platform == "win32" else "libggml-cuda.so.0"
+    (bindir / module_name).write_text("")
+    cuda_dir = tmp_path / "nvidia" / "cuda_runtime" / "lib"
+    cuda_dir.mkdir(parents = True)
+    monkeypatch.setattr(rl, "python_runtime_dirs", lambda: [str(cuda_dir)])
+    env = ggml_module._whisper_server_child_env(str(bindir / "whisper-server"))
+    parts = env[_loader_path_var()].split(os.pathsep)
+    assert str(bindir.resolve()) in parts
+    assert str(cuda_dir.resolve()) in parts
+    assert parts.index(str(bindir.resolve())) < parts.index(str(cuda_dir.resolve()))
+
+
+def test_child_env_omits_cuda_runtime_dirs_for_cpu_bundle(monkeypatch, tmp_path):
+    # No libggml-cuda.so beside the binary -> a static CPU/Metal bundle -> the CUDA
+    # wheel discovery must not run and must not touch the loader path.
+    if sys.platform == "darwin":
+        pytest.skip("no CUDA on macOS")
+    import utils.prebuilt.runtime_libs as rl
+
+    bindir = tmp_path / "bin"
+    bindir.mkdir()
+    (bindir / "whisper-server").write_text("#!/bin/sh\n")
+    cuda_dir = tmp_path / "nvidia" / "cuda_runtime" / "lib"
+    cuda_dir.mkdir(parents = True)
+    called = {"n": 0}
+
+    def _fake_dirs():
+        called["n"] += 1
+        return [str(cuda_dir)]
+
+    monkeypatch.setattr(rl, "python_runtime_dirs", _fake_dirs)
+    env = ggml_module._whisper_server_child_env(str(bindir / "whisper-server"))
+    parts = env[_loader_path_var()].split(os.pathsep)
+    assert str(cuda_dir.resolve()) not in parts
+    assert called["n"] == 0
+
+
+def test_engine_unavailable_is_stt_unavailable():
+    # Routes map SttUnavailableError to HTTP 501; the engine error must share it.
+    assert issubclass(SttEngineUnavailableError, SttUnavailableError)
+
+
+# ---------------------------------------------------------------------------
+# WAV packaging
+# ---------------------------------------------------------------------------
+
+
+def test_pcm_to_wav_bytes_shape_and_rate():
+    pcm = np.zeros(3200, dtype = np.float32)
+    data = ggml_module._pcm_to_wav_bytes(pcm)
+    with wave.open(io.BytesIO(data)) as w:
+        assert w.getnchannels() == 1
+        assert w.getsampwidth() == 2
+        assert w.getframerate() == 16000
+        assert w.getnframes() == 3200
+
+
+def test_pcm_to_wav_bytes_clips_out_of_range():
+    pcm = np.array([2.0, -2.0], dtype = np.float32)
+    data = ggml_module._pcm_to_wav_bytes(pcm)
+    with wave.open(io.BytesIO(data)) as w:
+        frames = np.frombuffer(w.readframes(2), dtype = "<i2")
+    assert frames[0] == 32767
+    assert frames[1] == -32767
+
+
+# ---------------------------------------------------------------------------
+# Sidecar orchestration
+# ---------------------------------------------------------------------------
+
+
+def _available(monkeypatch):
+    monkeypatch.setattr(ggml_module, "find_whisper_server_binary", lambda: "/bin/echo")
+
+
+def test_transcribe_requires_engine(monkeypatch):
+    monkeypatch.setattr(ggml_module, "find_whisper_server_binary", lambda: None)
+    sidecar = GgmlSttSidecar()
+    with pytest.raises(SttEngineUnavailableError):
+        sidecar.transcribe(b"RIFF")
+
+
+def test_transcribe_rejects_unknown_language(monkeypatch):
+    _available(monkeypatch)
+    sidecar = GgmlSttSidecar()
+    with pytest.raises(SttLanguageError):
+        sidecar.transcribe(b"RIFF", model = "small", language = "xx-QQ")
+
+
+def test_load_requires_downloaded_model(monkeypatch):
+    _available(monkeypatch)
+    monkeypatch.setattr(ggml_module, "_cached_model_path", lambda model_id: None)
+    sidecar = GgmlSttSidecar()
+    with pytest.raises(SttModelNotDownloadedError):
+        sidecar.load("small")
+
+
+def test_unloaded_sidecar_reports_nothing_resident():
+    sidecar = GgmlSttSidecar()
+    assert sidecar.loaded_model is None
+    assert sidecar.device is None
+    assert sidecar.is_loading() is False
+    sidecar.unload()  # no-op, must not raise
+
+
+def test_update_maintenance_unloads_and_blocks_new_loads(monkeypatch):
+    class FakeProcess:
+        pid = 4242
+
+        def __init__(self):
+            self.running = True
+
+        def poll(self):
+            return None if self.running else 0
+
+        def terminate(self):
+            self.running = False
+
+        def wait(self, timeout = None):
+            return 0
+
+    monkeypatch.setattr(ggml_module, "forget_pid", lambda _pid: None)
+    sidecar = GgmlSttSidecar()
+    sidecar._process = FakeProcess()
+    sidecar._model_id = "small"
+
+    with sidecar.update_maintenance() as model_was_active:
+        assert model_was_active is True
+        assert sidecar.loaded_model is None
+        with pytest.raises(SttEngineUnavailableError, match = "being updated"):
+            sidecar.load("small")
+
+    assert sidecar._update_in_progress is False
+
+
+def test_server_pid_is_tracked_for_parent_lifetime(monkeypatch):
+    # The spawned server must be adopted for the terminate_all backstop and
+    # forgotten once this sidecar has reaped it.
+    _available(monkeypatch)
+    monkeypatch.setattr(ggml_module, "_cached_model_path", lambda model_id: "/tmp/ggml.bin")
+
+    class FakeProcess:
+        pid = 4242
+
+        def __init__(self, *args, **kwargs):
+            self.terminated = False
+
+        def poll(self):
+            return 1 if self.terminated else None
+
+        def terminate(self):
+            self.terminated = True
+
+        def wait(self, timeout = None):
+            return 0
+
+    events = []
+    monkeypatch.setattr(ggml_module.subprocess, "Popen", FakeProcess)
+    monkeypatch.setattr(ggml_module, "adopt_pid", lambda pid: events.append(("adopt", pid)))
+    monkeypatch.setattr(ggml_module, "forget_pid", lambda pid: events.append(("forget", pid)))
+    monkeypatch.setattr(
+        GgmlSttSidecar,
+        "_wait_for_server",
+        staticmethod(lambda process, port, cancel_event = None: None),
+    )
+
+    sidecar = GgmlSttSidecar()
+    sidecar.load("small")
+    assert events == [("adopt", 4242)]
+    sidecar.unload()
+    assert events == [("adopt", 4242), ("forget", 4242)]
+
+
+def test_training_forces_whisper_server_off_gpu(monkeypatch):
+    # Mirror the Transformers sidecar: keep whisper.cpp on CPU during training
+    # so a mid-training dictation cannot reclaim the VRAM training just freed.
+    _available(monkeypatch)
+    monkeypatch.setattr(ggml_module, "_cached_model_path", lambda model_id: "/tmp/ggml.bin")
+    commands: list[list[str]] = []
+
+    class FakeProcess:
+        pid = 4242
+
+        def __init__(self, command, *args, **kwargs):
+            commands.append(command)
+
+        def poll(self):
+            return None
+
+        def terminate(self):
+            pass
+
+        def wait(self, timeout = None):
+            return 0
+
+    monkeypatch.setattr(ggml_module.subprocess, "Popen", FakeProcess)
+    monkeypatch.setattr(ggml_module, "adopt_pid", lambda pid: None)
+    monkeypatch.setattr(ggml_module, "forget_pid", lambda pid: None)
+    monkeypatch.setattr(
+        GgmlSttSidecar,
+        "_wait_for_server",
+        staticmethod(lambda process, port, cancel_event = None: None),
+    )
+
+    monkeypatch.setattr(ggml_module, "_training_active", lambda: False)
+    idle = GgmlSttSidecar()
+    idle.load("small")
+    assert "--no-gpu" not in commands[0]
+    assert idle.is_loading() is False
+    idle.unload()
+
+    monkeypatch.setattr(ggml_module, "_training_active", lambda: True)
+    training = GgmlSttSidecar()
+    training.load("small")
+    assert "--no-gpu" in commands[1]
+    training.unload()
+
+
+def test_cpu_root_marker_forces_no_gpu_despite_inner_packaging_marker(monkeypatch, tmp_path):
+    names = ["libggml.so.0", "libggml-base.so.0"]
+    binary = _slim_install(tmp_path, with_ggml = True, linked_libraries = names)
+    (Path(binary).parent / "UNSLOTH_WHISPER_PREBUILT_INFO.json").write_text(
+        json.dumps({"backend": "slim"})
+    )
+    monkeypatch.setattr(ggml_module, "find_whisper_server_binary", lambda: binary)
+    monkeypatch.setattr(ggml_module, "_cached_model_path", lambda model_id: "/tmp/ggml.bin")
+    commands: list[list[str]] = []
+
+    class FakeProcess:
+        pid = 4244
+
+        def __init__(self, command, *args, **kwargs):
+            commands.append(command)
+
+        def poll(self):
+            return None
+
+        def terminate(self):
+            pass
+
+        def wait(self, timeout = None):
+            return 0
+
+    monkeypatch.setattr(ggml_module.subprocess, "Popen", FakeProcess)
+    monkeypatch.setattr(ggml_module, "adopt_pid", lambda pid: None)
+    monkeypatch.setattr(ggml_module, "forget_pid", lambda pid: None)
+    monkeypatch.setattr(ggml_module, "_training_active", lambda: False)
+    monkeypatch.setattr(
+        GgmlSttSidecar,
+        "_wait_for_server",
+        staticmethod(lambda process, port, cancel_event = None: None),
+    )
+
+    sidecar = GgmlSttSidecar()
+    sidecar.load("small")
+    assert "--no-gpu" in commands[0]
+    sidecar.unload()
+
+
+def test_startup_is_cancellable_before_training(monkeypatch):
+    # A whisper-server still binding its (Metal/CUDA) backend must be preemptible
+    # so training coordination can stop it before admitting the run, instead of
+    # racing an allocating subprocess.
+    _available(monkeypatch)
+    monkeypatch.setattr(ggml_module, "_cached_model_path", lambda model_id: "/tmp/ggml.bin")
+
+    class FakeProcess:
+        pid = 4243
+
+        def __init__(self, *args, **kwargs):
+            self.terminated = False
+            self.killed = False
+
+        def poll(self):
+            return -15 if (self.terminated or self.killed) else None
+
+        def terminate(self):
+            self.terminated = True
+
+        def kill(self):
+            self.killed = True
+
+        def wait(self, timeout = None):
+            return 0
+
+    monkeypatch.setattr(ggml_module.subprocess, "Popen", FakeProcess)
+    monkeypatch.setattr(ggml_module, "adopt_pid", lambda pid: None)
+    monkeypatch.setattr(ggml_module, "forget_pid", lambda pid: None)
+
+    # The server never reports ready, so _wait_for_server loops until cancelled.
+    def never_ready(req, timeout = None):
+        raise OSError("connection refused")
+
+    monkeypatch.setattr(ggml_module.urllib.request, "urlopen", never_ready)
+
+    sidecar = GgmlSttSidecar()
+    result: dict = {}
+
+    def _load():
+        try:
+            sidecar.load("small")
+            result["ok"] = True
+        except Exception as exc:  # noqa: BLE001 - recorded for the assertion below
+            result["error"] = exc
+
+    thread = threading.Thread(target = _load)
+    thread.start()
+    try:
+        deadline = time.monotonic() + 5
+        while time.monotonic() < deadline and not sidecar.is_loading():
+            time.sleep(0.01)
+        assert sidecar.is_loading() is True
+        assert sidecar.cancel_pending_load() is True
+        # Blocks until the cancelled startup has been reaped and the lock freed.
+        sidecar.wait_for_load_to_settle()
+    finally:
+        thread.join(timeout = 5)
+
+    assert thread.is_alive() is False
+    assert isinstance(result.get("error"), SttLoadCancelledError)
+    assert sidecar.is_loading() is False
+    assert sidecar.loaded_model is None
+
+
+class _FakeWhisperHandler(http.server.BaseHTTPRequestHandler):
+    """Stands in for whisper-server's /inference endpoint."""
+
+    response_text = "Hello world.\n Second line."
+
+    def do_POST(self):
+        length = int(self.headers.get("Content-Length", "0"))
+        self.rfile.read(length)
+        body = json.dumps({"text": self.response_text}).encode()
+        self.send_response(200)
+        self.send_header("Content-Type", "application/json")
+        self.send_header("Content-Length", str(len(body)))
+        self.end_headers()
+        self.wfile.write(body)
+
+    def log_message(self, *args):
+        pass
+
+
+@pytest.fixture()
+def fake_whisper_server():
+    server = http.server.ThreadingHTTPServer(("127.0.0.1", 0), _FakeWhisperHandler)
+    thread = threading.Thread(target = server.serve_forever, daemon = True)
+    thread.start()
+    yield server.server_address[1]
+    server.shutdown()
+
+
+def test_transcribe_joins_segments_one_line(monkeypatch, fake_whisper_server):
+    _available(monkeypatch)
+    monkeypatch.setattr(ggml_module, "_cached_model_path", lambda model_id: "/tmp/ggml.bin")
+    sidecar = GgmlSttSidecar()
+
+    def fake_load(model = None):
+        sidecar._port = fake_whisper_server
+        sidecar._model_id = ggml_module.resolve_ggml_model_id(model)
+
+    monkeypatch.setattr(sidecar, "load", fake_load)
+    result = sidecar.transcribe(b"RIFF", model = "small", language = "en", fast = True)
+    assert result["text"] == "Hello world. Second line."
+    assert result["language"] == "en"
+    assert result["model"] == "small"
+    assert result["duration"] == pytest.approx(1.0)
+
+
+def test_transcribe_maps_bad_payload_to_decode_error(monkeypatch, fake_whisper_server):
+    _available(monkeypatch)
+    monkeypatch.setattr(ggml_module, "_cached_model_path", lambda model_id: "/tmp/ggml.bin")
+    monkeypatch.setattr(_FakeWhisperHandler, "response_text", None)
+    sidecar = GgmlSttSidecar()
+
+    def fake_load(model = None):
+        sidecar._port = fake_whisper_server
+        sidecar._model_id = ggml_module.resolve_ggml_model_id(model)
+
+    monkeypatch.setattr(sidecar, "load", fake_load)
+    from core.inference.stt_sidecar import SttAudioDecodeError
+
+    with pytest.raises(SttAudioDecodeError):
+        sidecar.transcribe(b"RIFF", model = "small")
+
+
+def test_beam_size_matches_fast_flag(monkeypatch, fake_whisper_server):
+    _available(monkeypatch)
+    monkeypatch.setattr(ggml_module, "_cached_model_path", lambda model_id: "/tmp/ggml.bin")
+    seen: list[bytes] = []
+
+    orig_post = _FakeWhisperHandler.do_POST
+
+    def capture_post(handler):
+        length = int(handler.headers.get("Content-Length", "0"))
+        body = handler.rfile.read(length)
+        seen.append(body)
+        payload = json.dumps({"text": "ok"}).encode()
+        handler.send_response(200)
+        handler.send_header("Content-Type", "application/json")
+        handler.send_header("Content-Length", str(len(payload)))
+        handler.end_headers()
+        handler.wfile.write(payload)
+
+    monkeypatch.setattr(_FakeWhisperHandler, "do_POST", capture_post)
+    try:
+        sidecar = GgmlSttSidecar()
+
+        def fake_load(model = None):
+            sidecar._port = fake_whisper_server
+            sidecar._model_id = ggml_module.resolve_ggml_model_id(model)
+
+        monkeypatch.setattr(sidecar, "load", fake_load)
+        sidecar.transcribe(b"RIFF", model = "small", fast = True)
+        sidecar.transcribe(b"RIFF", model = "small", fast = False)
+    finally:
+        _FakeWhisperHandler.do_POST = orig_post
+    assert b'name="beam_size"\r\n\r\n1' in seen[0]
+    assert b'name="beam_size"\r\n\r\n5' in seen[1]
+    # Dictation defaults to deterministic decoding.
+    assert b'name="temperature"\r\n\r\n0.0' in seen[0]
+
+
+def test_download_rejects_custom_ids():
+    with pytest.raises(SttModelIdError):
+        ggml_module.start_model_download("owner/model")
+
+
+def test_download_status_idle_shape():
+    status = ggml_module.download_status()
+    assert set(status) >= {"downloading", "model", "error"}
diff --git a/studio/backend/tests/test_stt_review_fixes.py b/studio/backend/tests/test_stt_review_fixes.py
new file mode 100644
index 0000000000..e4495506a3
--- /dev/null
+++ b/studio/backend/tests/test_stt_review_fixes.py
@@ -0,0 +1,219 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Regressions for a fresh review pass on the local STT dictation feature:
+
+1. Curated GGUF dictation repos (unslothai/whisper-*-GGUF) must be hidden from
+   chat pickers, not just their Transformers safetensors companions.
+2. The GGUF sidecar's loaded_model/device status accessors must be lock-free so
+   they never block behind an in-flight transcription (which holds self._lock).
+3. A "gguf" unload on a host without whisper-server must target the Transformers
+   fallback that actually served it, and unload-all must attempt both backends
+   even if one raises.
+4. free_stt_model_for_training must free the GGUF sidecar even when the
+   Transformers unload raises (independent exception boundaries).
+"""
+
+from __future__ import annotations
+
+import asyncio
+import sys
+import threading
+from pathlib import Path
+
+import pytest
+from fastapi import HTTPException
+
+_BACKEND_ROOT = Path(__file__).resolve().parents[1]
+if str(_BACKEND_ROOT) not in sys.path:
+    sys.path.insert(0, str(_BACKEND_ROOT))
+
+
+# 1. Hidden-model GGUF companions ------------------------------------------------
+def test_curated_gguf_dictation_repos_are_hidden():
+    from utils.hidden_models import _HIDDEN_STT_REPO_IDS, is_hidden_model
+    for repo in (
+        "unslothai/whisper-tiny-GGUF",
+        "unslothai/whisper-base-GGUF",
+        "unslothai/whisper-small-GGUF",
+        "unslothai/whisper-large-v3-turbo-GGUF",
+        "unslothai/whisper-large-v3-GGUF",
+    ):
+        assert repo in _HIDDEN_STT_REPO_IDS
+        assert is_hidden_model(repo) is True
+        # Case-insensitive, matching how the cache stores the repo id.
+        assert is_hidden_model(repo.lower()) is True
+
+    # A same-prefix but genuinely different repo is NOT hidden.
+    assert is_hidden_model("unslothai/whisper-large-v3-GGUF-finetune") is False
+
+
+# 2. GGUF status accessors are lock-free ----------------------------------------
+def test_gguf_status_accessors_do_not_block_on_the_inference_lock():
+    from core.inference.stt_ggml_sidecar import GgmlSttSidecar
+
+    sidecar = GgmlSttSidecar()
+
+    class _AliveProc:
+        pid = 4321
+
+        def poll(self):
+            return None  # still running
+
+    sidecar._process = _AliveProc()
+    sidecar._model_id = "small"
+
+    holder_has_lock = threading.Event()
+    release = threading.Event()
+
+    def _hold_inference_lock():
+        # Mimic transcribe() holding self._lock across the whole HTTP call.
+        with sidecar._lock:
+            holder_has_lock.set()
+            release.wait(timeout = 5)
+
+    holder = threading.Thread(target = _hold_inference_lock)
+    holder.start()
+    assert holder_has_lock.wait(timeout = 5)
+
+    result: dict = {}
+
+    def _read_status():
+        result["model"] = sidecar.loaded_model
+        result["device"] = sidecar.device
+
+    reader = threading.Thread(target = _read_status)
+    reader.start()
+    reader.join(timeout = 2)
+    blocked = reader.is_alive()
+
+    release.set()
+    holder.join(timeout = 5)
+    reader.join(timeout = 5)
+
+    assert not blocked, "loaded_model/device blocked on self._lock (should be lock-free)"
+    assert result == {"model": "small", "device": "whisper.cpp"}
+
+
+def test_process_alive_snapshots_process_against_concurrent_unload():
+    # _process_alive() must read self._process exactly once. The lock-free
+    # readers (loaded_model/device) can run while unload() nulls self._process;
+    # the old `self._process is not None and self._process.poll() is None` read it
+    # twice, so a null landing between the two reads called None.poll(). A
+    # property that yields the live process on the first read and None afterwards
+    # reproduces that interleaving deterministically.
+    from core.inference.stt_ggml_sidecar import GgmlSttSidecar
+
+    class _AliveProc:
+        def poll(self):
+            return None  # still running
+
+    live = _AliveProc()
+    reads = {"n": 0}
+
+    class _RacingSidecar(GgmlSttSidecar):
+        @property
+        def _process(self):
+            reads["n"] += 1
+            return live if reads["n"] == 1 else None
+
+        @_process.setter
+        def _process(self, value):
+            pass  # __init__ assigns None; the property drives the read
+
+    sidecar = GgmlSttSidecar()
+    sidecar.__class__ = _RacingSidecar  # data descriptor wins over the instance attr
+
+    # Snapshot fix: exactly one read, no AttributeError from a second None read.
+    assert sidecar._process_alive() is True
+    assert reads["n"] == 1
+
+
+# 3. Unload resolves through the serving engine + attempts every backend ---------
+def test_gguf_unload_targets_transformers_fallback_without_whisper_server(monkeypatch):
+    import core.inference.stt_ggml_sidecar as ggml_module
+    import routes.inference as ri
+
+    monkeypatch.setattr(ggml_module, "is_available", lambda: False)  # no whisper-server
+
+    calls: list = []
+
+    class _Sidecar:
+        def __init__(self, name):
+            self.name = name
+
+        def unload(self):
+            calls.append(self.name)
+
+    monkeypatch.setattr(ri, "_stt_sidecar_for", lambda name: _Sidecar(name))
+
+    resp = asyncio.run(ri.stt_unload(engine = "gguf", current_subject = "tester"))
+    assert resp.status_code == 200
+    # gguf is served by the Transformers fallback here, so that is what unloads.
+    assert calls == ["transformers"]
+
+
+def test_unload_all_attempts_both_backends_even_when_one_fails(monkeypatch):
+    import routes.inference as ri
+
+    attempted: list = []
+
+    class _Sidecar:
+        def __init__(self, name):
+            self.name = name
+
+        def unload(self):
+            attempted.append(self.name)
+            if self.name == "transformers":
+                raise RuntimeError("boom")
+
+    monkeypatch.setattr(ri, "_stt_sidecar_for", lambda name: _Sidecar(name))
+
+    with pytest.raises(HTTPException) as excinfo:
+        asyncio.run(ri.stt_unload(engine = None, current_subject = "tester"))
+
+    assert excinfo.value.status_code == 500
+    # gguf is still attempted after the transformers unload raised.
+    assert attempted == ["transformers", "gguf"]
+
+
+# 4. free_stt_model_for_training isolates the two backends -----------------------
+def test_free_stt_frees_gguf_even_when_transformers_unload_raises(monkeypatch):
+    import routes.training_vram as tv
+
+    class _TransformersSidecar:
+        def is_loading(self):
+            return False
+
+        @property
+        def loaded_model(self):
+            return "whisper-small"
+
+        def unload(self):
+            raise RuntimeError("transformers unload failed")
+
+    class _GgmlSidecar:
+        def __init__(self):
+            self.unloaded = False
+
+        def is_loading(self):
+            return False
+
+        @property
+        def loaded_model(self):
+            return None if self.unloaded else "small"
+
+        def unload(self):
+            self.unloaded = True
+
+    ggml = _GgmlSidecar()
+    monkeypatch.setattr(
+        "core.inference.stt_sidecar.get_stt_sidecar", lambda: _TransformersSidecar()
+    )
+    monkeypatch.setattr("core.inference.stt_ggml_sidecar.get_ggml_stt_sidecar", lambda: ggml)
+
+    freed = tv.free_stt_model_for_training("test")
+
+    # The Transformers failure must not skip GGUF eviction.
+    assert ggml.unloaded is True
+    assert any("small" in entry for entry in freed)
diff --git a/studio/backend/tests/test_stt_review_fixes_2.py b/studio/backend/tests/test_stt_review_fixes_2.py
new file mode 100644
index 0000000000..f0bdab42b5
--- /dev/null
+++ b/studio/backend/tests/test_stt_review_fixes_2.py
@@ -0,0 +1,350 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Regressions for the second review pass on the local STT dictation feature:
+
+1. scripts/build_whisper_cpp.sh must not rm -rf a whisper.cpp/src tree under a
+   custom Studio home unless Studio itself created it (ownership marker), the
+   same policy studio/setup.sh applies before its destructive replacements.
+2. _snapshot_is_complete must reject pickle (pytorch_model.bin) checkpoints
+   outright; only safetensors weights count as a usable snapshot.
+3. _snapshot_is_complete must require tokenizer assets (tokenizer.json or
+   vocab.json + merges.txt); weights + config alone decode to blank text.
+4. Custom-repo downloads must pin the revision validated beforehand and
+   restrict snapshot_download to the model/tokenizer/config/preprocessor file
+   classes (TOCTOU + unbounded-download hardening).
+5. The GGML sidecar's readiness probe must not treat an arbitrary local HTTP
+   responder as whisper-server (mic audio would be posted to it), and the port
+   reservation must stay held until just before spawn.
+"""
+
+from __future__ import annotations
+
+import http.server
+import json
+import os
+import socket
+import stat
+import subprocess
+import sys
+import threading
+from pathlib import Path
+from types import SimpleNamespace
+
+import pytest
+
+_BACKEND_ROOT = Path(__file__).resolve().parents[1]
+if str(_BACKEND_ROOT) not in sys.path:
+    sys.path.insert(0, str(_BACKEND_ROOT))
+
+import core.inference.stt_ggml_sidecar as ggml_module
+import core.inference.stt_sidecar as stt_sidecar_module
+from core.inference.stt_ggml_sidecar import GgmlSttSidecar, SttEngineUnavailableError
+from core.inference.stt_sidecar import validate_remote_model
+
+_BUILD_SCRIPT = _BACKEND_ROOT.parents[1] / "scripts" / "build_whisper_cpp.sh"
+
+
+# 1. build_whisper_cpp.sh ownership gate ----------------------------------------
+
+
+def _stub_tools(tmp_path: Path) -> dict:
+    """PATH with git/cmake stubs so the script never reaches a real build."""
+    bin_dir = tmp_path / "stub-bin"
+    bin_dir.mkdir(exist_ok = True)
+    for tool in ("git", "cmake"):
+        stub = bin_dir / tool
+        stub.write_text("#!/bin/sh\necho stub-%s-invoked >&2\nexit 1\n" % tool)
+        stub.chmod(stub.stat().st_mode | stat.S_IEXEC)
+    env = dict(os.environ)
+    env["PATH"] = f"{bin_dir}:{env['PATH']}"
+    return env
+
+
+def _run_build_script(env: dict) -> subprocess.CompletedProcess:
+    return subprocess.run(
+        ["sh", str(_BUILD_SCRIPT)],
+        env = env,
+        capture_output = True,
+        text = True,
+        timeout = 60,
+    )
+
+
+def test_build_script_refuses_unowned_dir_in_custom_studio_home(tmp_path):
+    home = tmp_path / "studio-home"
+    src = home / "whisper.cpp" / "src"
+    src.mkdir(parents = True)
+    user_file = src / "user-data.txt"
+    user_file.write_text("precious")
+
+    env = _stub_tools(tmp_path)
+    env["UNSLOTH_STUDIO_HOME"] = str(home)
+    result = _run_build_script(env)
+
+    assert result.returncode != 0
+    assert "not marked as an Unsloth-owned" in result.stderr
+    # The unowned tree, and the user's file inside it, survived untouched.
+    assert user_file.read_text() == "precious"
+
+
+def test_build_script_proceeds_when_marker_present(tmp_path):
+    home = tmp_path / "studio-home"
+    install = home / "whisper.cpp"
+    (install / "src").mkdir(parents = True)
+    (install / ".unsloth-studio-owned").write_text("")
+
+    env = _stub_tools(tmp_path)
+    env["UNSLOTH_STUDIO_HOME"] = str(home)
+    result = _run_build_script(env)
+
+    # Past the guard: it fails later at the stubbed git clone, not the gate.
+    assert "not marked as an Unsloth-owned" not in result.stderr
+    assert "stub-git-invoked" in result.stderr
+
+
+def test_build_script_marks_fresh_custom_install_dir(tmp_path):
+    home = tmp_path / "studio-home"
+    home.mkdir()
+
+    env = _stub_tools(tmp_path)
+    env["UNSLOTH_STUDIO_HOME"] = str(home)
+    _run_build_script(env)
+
+    # A directory the script creates is marked so re-runs stay allowed.
+    assert (home / "whisper.cpp" / ".unsloth-studio-owned").is_file()
+
+
+def test_build_script_keeps_legacy_home_behavior(tmp_path):
+    fake_home = tmp_path / "user-home"
+    src = fake_home / ".unsloth" / "whisper.cpp" / "src"
+    src.mkdir(parents = True)
+
+    env = _stub_tools(tmp_path)
+    env.pop("UNSLOTH_STUDIO_HOME", None)
+    env.pop("STUDIO_HOME", None)
+    env["HOME"] = str(fake_home)
+    result = _run_build_script(env)
+
+    # The legacy managed dir is always Studio-owned; no gate, straight to git.
+    assert "not marked as an Unsloth-owned" not in result.stderr
+    assert "stub-git-invoked" in result.stderr
+
+
+# 2 + 3. _snapshot_is_complete --------------------------------------------------
+
+
+def _base_snapshot(tmp_path: Path) -> Path:
+    snap = tmp_path / "snap"
+    snap.mkdir()
+    (snap / "config.json").write_text("{}")
+    (snap / "preprocessor_config.json").write_text("{}")
+    (snap / "tokenizer.json").write_text("{}")
+    return snap
+
+
+def test_pickle_checkpoint_snapshot_is_never_complete(tmp_path):
+    # A cached pytorch_model.bin is a pickle RCE load path; the snapshot must
+    # read as incomplete no matter how many shards are present, so update
+    # re-resolves and _select_snapshot_files fails it closed.
+    snap = _base_snapshot(tmp_path)
+    index = {
+        "weight_map": {
+            "a": "pytorch_model-00001-of-00002.bin",
+            "b": "pytorch_model-00002-of-00002.bin",
+        }
+    }
+    (snap / "pytorch_model.bin.index.json").write_text(json.dumps(index))
+    (snap / "pytorch_model-00001-of-00002.bin").write_bytes(b"w" * 8)
+    (snap / "pytorch_model-00002-of-00002.bin").write_bytes(b"w" * 8)
+    assert stt_sidecar_module._snapshot_is_complete(snap) is False
+
+    # A single-file pickle checkpoint is likewise rejected; the safetensors
+    # equivalent in the same dir makes it complete.
+    (snap / "pytorch_model.bin").write_bytes(b"w" * 8)
+    assert stt_sidecar_module._snapshot_is_complete(snap) is False
+    (snap / "model.safetensors").write_bytes(b"w" * 8)
+    assert stt_sidecar_module._snapshot_is_complete(snap) is True
+
+
+def test_safe_index_naming_pickle_shards_is_not_complete(tmp_path):
+    # A safetensors index that references .bin shards would still pickle-load
+    # via Transformers' per-shard dispatch; the cached snapshot must read as
+    # incomplete so it re-resolves and fails closed at selection.
+    snap = _base_snapshot(tmp_path)
+    (snap / "model.safetensors.index.json").write_text(
+        json.dumps({"weight_map": {"a": "pytorch_model-00001-of-00001.bin"}})
+    )
+    (snap / "pytorch_model-00001-of-00001.bin").write_bytes(b"w" * 8)
+    assert stt_sidecar_module._snapshot_is_complete(snap) is False
+
+
+def test_snapshot_without_tokenizer_assets_is_incomplete(tmp_path):
+    snap = _base_snapshot(tmp_path)
+    (snap / "model.safetensors").write_bytes(b"w" * 8)
+    assert stt_sidecar_module._snapshot_is_complete(snap) is True
+
+    # Weights + config but no tokenizer decodes to blank text; not complete.
+    (snap / "tokenizer.json").unlink()
+    assert stt_sidecar_module._snapshot_is_complete(snap) is False
+
+    # The slow vocab.json + merges.txt pair is an accepted alternative.
+    (snap / "vocab.json").write_text("{}")
+    assert stt_sidecar_module._snapshot_is_complete(snap) is False
+    (snap / "merges.txt").write_text("")
+    assert stt_sidecar_module._snapshot_is_complete(snap) is True
+
+
+# 4. Revision pinning and allow_patterns ----------------------------------------
+
+
+def test_validate_remote_model_returns_the_validated_revision(monkeypatch):
+    revision = "a" * 40
+
+    class _FakeApi:
+        def __init__(self, token = None):
+            pass
+
+        def model_info(
+            self,
+            repo,
+            expand = None,
+            timeout = None,
+        ):
+            return SimpleNamespace(config = {"model_type": "whisper"}, sha = revision)
+
+    import huggingface_hub
+
+    monkeypatch.setattr(huggingface_hub, "HfApi", _FakeApi)
+    result = validate_remote_model("someone/custom-whisper")
+    assert result["revision"] == revision
+
+
+def test_download_pins_revision_and_limits_patterns(monkeypatch):
+    captured = {}
+    validated_revision = "a" * 40
+    head_revision = "b" * 40
+
+    def fake_snapshot_download(**kwargs):
+        captured.update(kwargs)
+        return "/cached"
+
+    class _FakeApi:
+        def __init__(self, token = None):
+            pass
+
+        def model_info(
+            self,
+            repo,
+            revision = None,
+            files_metadata = None,
+            timeout = None,
+        ):
+            names = (
+                "config.json",
+                "preprocessor_config.json",
+                "tokenizer.json",
+                "model.safetensors",
+            )
+            siblings = [
+                SimpleNamespace(rfilename = name, size = 10, blob_id = name, lfs = None) for name in names
+            ]
+            return SimpleNamespace(siblings = siblings, sha = head_revision)
+
+    import huggingface_hub
+
+    monkeypatch.setattr(huggingface_hub, "HfApi", _FakeApi)
+    monkeypatch.setattr(huggingface_hub, "snapshot_download", fake_snapshot_download)
+
+    state = stt_sidecar_module._SnapshotDownloadState()
+    # The revision resolved at validation time wins over the current head.
+    state._run("someone/custom-whisper", None, revision = validated_revision)
+    assert captured["revision"] == validated_revision
+    patterns = captured["allow_patterns"]
+    assert "model.safetensors" in patterns and "tokenizer.json" in patterns
+    # No wildcard that would admit arbitrary repo contents.
+    assert "*" not in patterns
+
+    # Without a validated revision (curated repos), pin to the metadata head.
+    captured.clear()
+    state._run("someone/custom-whisper", None)
+    assert captured["revision"] == head_revision
+    assert captured["allow_patterns"]
+
+
+# 5. GGML readiness must identify whisper-server --------------------------------
+
+
+class _CannedHandler(http.server.BaseHTTPRequestHandler):
+    body = b""
+
+    def do_GET(self):  # noqa: N802
+        payload = type(self).body
+        self.send_response(200)
+        self.send_header("Content-Length", str(len(payload)))
+        self.end_headers()
+        self.wfile.write(payload)
+
+    def log_message(self, *args):
+        pass
+
+
+def _serve(body: bytes):
+    handler = type("Handler", (_CannedHandler,), {"body": body})
+    server = http.server.HTTPServer(("127.0.0.1", 0), handler)
+    thread = threading.Thread(target = server.serve_forever, daemon = True)
+    thread.start()
+    return server, server.server_address[1]
+
+
+def _fake_alive_process():
+    return SimpleNamespace(poll = lambda: None, pid = 999999)
+
+
+def test_wait_for_server_rejects_a_foreign_http_responder(monkeypatch):
+    server, port = _serve(b"<html>hello from some other local app</html>")
+    try:
+        monkeypatch.setattr(ggml_module, "_SERVER_START_TIMEOUT_SECONDS", 1.0)
+        with pytest.raises(SttEngineUnavailableError, match = "did not start in time"):
+            GgmlSttSidecar._wait_for_server(_fake_alive_process(), port)
+    finally:
+        server.shutdown()
+
+
+def test_wait_for_server_accepts_the_whisper_server_page(monkeypatch):
+    server, port = _serve(b"<html><title>Whisper.cpp Server</title></html>")
+    try:
+        monkeypatch.setattr(ggml_module, "_SERVER_START_TIMEOUT_SECONDS", 5.0)
+        GgmlSttSidecar._wait_for_server(_fake_alive_process(), port)
+    finally:
+        server.shutdown()
+
+
+def test_probe_requires_the_managed_child_to_be_alive():
+    server, port = _serve(b"whisper")
+    try:
+        dead = SimpleNamespace(poll = lambda: 0, pid = 999999)
+        assert GgmlSttSidecar._probe_is_whisper_server(dead, port) is False
+        assert GgmlSttSidecar._probe_is_whisper_server(_fake_alive_process(), port) is True
+    finally:
+        server.shutdown()
+
+
+def test_port_reservation_is_held_until_released():
+    reservation, port = GgmlSttSidecar._reserve_free_port()
+    try:
+        probe = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        try:
+            with pytest.raises(OSError):
+                probe.bind(("127.0.0.1", port))
+        finally:
+            probe.close()
+    finally:
+        reservation.close()
+    # Released right before spawn: the port becomes bindable for the child.
+    child = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    child.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    try:
+        child.bind(("127.0.0.1", port))
+    finally:
+        child.close()
diff --git a/studio/backend/tests/test_stt_sidecar.py b/studio/backend/tests/test_stt_sidecar.py
new file mode 100644
index 0000000000..b138f46331
--- /dev/null
+++ b/studio/backend/tests/test_stt_sidecar.py
@@ -0,0 +1,1302 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import gc
+import io
+import json
+import sys
+import threading
+import time
+import wave
+import weakref
+from pathlib import Path
+from types import SimpleNamespace
+
+import numpy as np
+import pytest
+
+import core.inference.stt_sidecar as stt_sidecar_module
+from core.inference.stt_sidecar import (
+    DEFAULT_STT_MODEL,
+    STT_MODELS,
+    SttAudioDecodeError,
+    SttAudioTooLongError,
+    SttLanguageError,
+    SttLoadCancelledError,
+    SttModelCompatibilityError,
+    SttModelIdError,
+    SttModelNotDownloadedError,
+    SttUnavailableError,
+    WhisperSttSidecar,
+    normalize_whisper_language,
+    resolve_model_id,
+    resolve_model_repo,
+    validate_remote_model,
+)
+
+_REAL_DECODE_AUDIO_BOUNDED = stt_sidecar_module._decode_audio_bounded
+_REAL_ENSURE_STT_AVAILABLE = stt_sidecar_module.ensure_stt_available
+_REAL_SNAPSHOT_IS_COMPLETE = stt_sidecar_module._snapshot_is_complete
+_REAL_FIND_COMPLETE_CACHED_SNAPSHOT = stt_sidecar_module._find_complete_cached_snapshot
+
+
+@pytest.fixture(autouse = True)
+def stub_audio_decoder(monkeypatch):
+    """Unit tests below exercise orchestration, not PyAV container parsing."""
+    monkeypatch.setattr(
+        stt_sidecar_module,
+        "_decode_audio_bounded",
+        lambda _audio: np.zeros(8000, dtype = np.float32),
+    )
+    monkeypatch.setattr(
+        "huggingface_hub.snapshot_download",
+        lambda **_kwargs: "/cached/model",
+    )
+    monkeypatch.setattr(
+        stt_sidecar_module,
+        "_find_complete_cached_snapshot",
+        lambda _model: Path("/cached/model"),
+    )
+    # The stubbed snapshot path holds no files; snapshot-integrity tests
+    # restore the real check.
+    monkeypatch.setattr(stt_sidecar_module, "_snapshot_is_complete", lambda _snapshot: True)
+    # transcribe() gates on the runtime up front; treat it as present so these
+    # orchestration tests run without PyTorch/Transformers/PyAV installed.
+    # The runtime-specific tests restore the real check.
+    monkeypatch.setattr(stt_sidecar_module, "ensure_stt_available", lambda: None)
+
+
+class _CaptureInference:
+    """Stand-in for the model inference step; records how it was called."""
+
+    def __init__(
+        self,
+        text = "hello",
+        mutate = None,
+    ) -> None:
+        self.text = text
+        self.mutate = mutate
+        self.generate_kwargs = None
+
+    def __call__(self, model_id, decoded, generate_kwargs):
+        self.generate_kwargs = generate_kwargs
+        if self.mutate is not None:
+            self.mutate()
+        return self.text
+
+
+def test_five_curated_whisper_models_are_offered():
+    assert STT_MODELS == {
+        "tiny": "unsloth/whisper-tiny",
+        "base": "unsloth/whisper-base",
+        "small": "unsloth/whisper-small",
+        "large-v3-turbo": "unsloth/whisper-large-v3-turbo",
+        "large-v3": "unsloth/whisper-large-v3",
+    }
+    assert all(repo.startswith(("unsloth/", "unslothai/")) for repo in STT_MODELS.values())
+    assert DEFAULT_STT_MODEL in STT_MODELS
+
+
+def test_av_is_required_for_stt_availability(monkeypatch):
+    monkeypatch.setattr(stt_sidecar_module, "ensure_stt_available", _REAL_ENSURE_STT_AVAILABLE)
+    monkeypatch.setitem(sys.modules, "torch", SimpleNamespace())
+    monkeypatch.setitem(sys.modules, "transformers", SimpleNamespace())
+    monkeypatch.setitem(sys.modules, "av", None)
+
+    assert stt_sidecar_module.is_available() is False
+
+
+def test_transformers_is_required_for_stt_availability(monkeypatch):
+    monkeypatch.setattr(stt_sidecar_module, "ensure_stt_available", _REAL_ENSURE_STT_AVAILABLE)
+    monkeypatch.setitem(sys.modules, "torch", SimpleNamespace())
+    monkeypatch.setitem(sys.modules, "av", SimpleNamespace())
+    monkeypatch.setitem(sys.modules, "transformers", None)
+
+    assert stt_sidecar_module.is_available() is False
+
+
+@pytest.mark.parametrize("missing", ["transformers", "av"])
+def test_load_rejects_an_incomplete_stt_runtime(monkeypatch, missing):
+    sidecar = WhisperSttSidecar(keep_alive_seconds = 0)
+    monkeypatch.setattr(stt_sidecar_module, "ensure_stt_available", _REAL_ENSURE_STT_AVAILABLE)
+    for module in ("torch", "transformers", "av"):
+        monkeypatch.setitem(sys.modules, module, SimpleNamespace())
+    monkeypatch.setitem(sys.modules, missing, None)
+    monkeypatch.setattr(
+        sidecar,
+        "_ensure_model_downloaded",
+        lambda _model: pytest.fail("runtime must be checked before the model cache"),
+    )
+
+    with pytest.raises(SttUnavailableError, match = "needs PyTorch, Transformers, and PyAV"):
+        sidecar.load("small")
+
+
+def test_model_id_accepts_defaults_and_custom_hub_repositories():
+    assert resolve_model_id("tiny") == "tiny"
+    assert resolve_model_id(None) == DEFAULT_STT_MODEL
+    assert resolve_model_id("large-v3") == "large-v3"
+    assert resolve_model_id("openai/whisper-medium") == "openai/whisper-medium"
+    assert resolve_model_repo("tiny") == "unsloth/whisper-tiny"
+    assert resolve_model_repo("openai/whisper-medium") == "openai/whisper-medium"
+
+
+@pytest.mark.parametrize("model", ["tiny-ish", "owner/model/extra", "../model", "owner/"])
+def test_invalid_custom_model_id_is_rejected(model):
+    with pytest.raises(SttModelIdError, match = "owner/model"):
+        resolve_model_id(model)
+
+
+def test_remote_custom_model_validation_requires_whisper_config(monkeypatch):
+    calls = []
+
+    class FakeApi:
+        def __init__(self, token):
+            calls.append(("token", token))
+
+        def model_info(self, repo, **kwargs):
+            calls.append(("model_info", repo, kwargs))
+            return SimpleNamespace(
+                sha = "a" * 40,
+                config = {
+                    "model_type": "whisper",
+                    "architectures": ["WhisperForConditionalGeneration"],
+                },
+            )
+
+    monkeypatch.setattr("huggingface_hub.HfApi", FakeApi)
+
+    result = validate_remote_model("owner/custom-whisper", "hf_private")
+
+    assert result == {
+        "model": "owner/custom-whisper",
+        "repo": "owner/custom-whisper",
+        "revision": "a" * 40,
+    }
+    assert calls == [
+        ("token", "hf_private"),
+        (
+            "model_info",
+            "owner/custom-whisper",
+            {"expand": ["config", "sha"], "timeout": 10},
+        ),
+    ]
+
+
+def test_remote_custom_model_validation_rejects_non_whisper(monkeypatch):
+    class FakeApi:
+        def __init__(self, token):
+            assert token is False
+
+        def model_info(self, _repo, **_kwargs):
+            return SimpleNamespace(
+                config = {
+                    "model_type": "llama",
+                    "architectures": ["LlamaForCausalLM"],
+                }
+            )
+
+    monkeypatch.setattr("huggingface_hub.HfApi", FakeApi)
+
+    with pytest.raises(SttModelCompatibilityError, match = "not a compatible"):
+        validate_remote_model("owner/chat-model")
+
+
+def test_remote_custom_model_validation_requires_an_immutable_sha(monkeypatch):
+    class FakeApi:
+        def __init__(self, token):
+            pass
+
+        def model_info(self, _repo, **_kwargs):
+            return SimpleNamespace(sha = None, config = {"model_type": "whisper"})
+
+    monkeypatch.setattr("huggingface_hub.HfApi", FakeApi)
+
+    with pytest.raises(SttModelCompatibilityError, match = "immutable revision"):
+        validate_remote_model("owner/custom-whisper")
+
+
+def test_fast_transcription_uses_greedy_decoding(monkeypatch):
+    sidecar = WhisperSttSidecar()
+    infer = _CaptureInference()
+    monkeypatch.setattr(sidecar, "_transcribe_decoded", infer)
+
+    result = sidecar.transcribe(b"encoded audio", language = "en", fast = True)
+
+    assert result["text"] == "hello"
+    assert result["duration"] == 0.5
+    assert result["model"] == DEFAULT_STT_MODEL
+    assert infer.generate_kwargs == {
+        "task": "transcribe",
+        "condition_on_prev_tokens": False,
+        "num_beams": 1,
+        "language": "en",
+    }
+
+
+def test_accurate_transcription_keeps_beam_search_default(monkeypatch):
+    sidecar = WhisperSttSidecar()
+    infer = _CaptureInference()
+    monkeypatch.setattr(sidecar, "_transcribe_decoded", infer)
+
+    sidecar.transcribe(b"encoded audio")
+
+    assert infer.generate_kwargs == {
+        "task": "transcribe",
+        "condition_on_prev_tokens": False,
+        "num_beams": 5,
+    }
+
+
+@pytest.mark.parametrize(
+    ("language", "expected"),
+    [
+        (None, None),
+        ("auto", None),
+        ("en-US", "en"),
+        ("en-GB", "en"),
+        ("zh-CN", "zh"),
+        ("ja-JP", "ja"),
+        ("ko-KR", "ko"),
+        ("es-ES", "es"),
+        ("fr-FR", "fr"),
+        ("de-DE", "de"),
+        ("it-IT", "it"),
+        ("pt_BR", "pt"),
+        ("ru-RU", "ru"),
+        ("hi-IN", "hi"),
+        ("ar-SA", "ar"),
+        ("iw-IL", "he"),
+        ("nb-NO", "no"),
+    ],
+)
+def test_normalize_whisper_language_accepts_bcp47(language, expected):
+    assert normalize_whisper_language(language) == expected
+
+
+def test_transcription_normalizes_region_qualified_language(monkeypatch):
+    sidecar = WhisperSttSidecar()
+    infer = _CaptureInference()
+    monkeypatch.setattr(sidecar, "_transcribe_decoded", infer)
+
+    sidecar.transcribe(b"encoded audio", language = "fr-FR")
+
+    assert infer.generate_kwargs["language"] == "fr"
+
+
+def test_english_only_model_rejects_non_english_before_decode(monkeypatch, tmp_path):
+    (tmp_path / "config.json").write_text('{"model_type": "whisper"}')
+    (tmp_path / "generation_config.json").write_text('{"is_multilingual": false}')
+    sidecar = WhisperSttSidecar()
+
+    def should_not_decode(_audio):
+        pytest.fail("English-only language mismatch must be rejected before decode")
+
+    monkeypatch.setattr(
+        stt_sidecar_module,
+        "_find_complete_cached_snapshot",
+        lambda _model: tmp_path,
+    )
+    monkeypatch.setattr(stt_sidecar_module, "_decode_audio_bounded", should_not_decode)
+
+    with pytest.raises(SttLanguageError, match = "English-only"):
+        sidecar.transcribe(
+            b"encoded audio",
+            model = "owner/whisper-small.en",
+            language = "fr-FR",
+        )
+
+
+def test_english_only_model_omits_forbidden_generation_controls(monkeypatch):
+    calls = []
+
+    class FakeTensor:
+        def to(self, *_args):
+            return self
+
+    class FakeProcessor:
+        def __call__(self, *_args, **_kwargs):
+            return SimpleNamespace(input_features = FakeTensor())
+
+        def batch_decode(self, *_args, **_kwargs):
+            return ["hello"]
+
+    class FakeModel:
+        dtype = None
+        device = "cpu"
+        generation_config = SimpleNamespace(is_multilingual = False)
+
+        def generate(self, _features, **kwargs):
+            calls.append(kwargs)
+            return [[1]]
+
+    class NoGrad:
+        def __enter__(self):
+            return None
+
+        def __exit__(self, *_args):
+            return False
+
+    monkeypatch.setitem(sys.modules, "torch", SimpleNamespace(no_grad = NoGrad))
+    sidecar = WhisperSttSidecar()
+    monkeypatch.setattr(sidecar, "load", lambda _model: (FakeModel(), FakeProcessor()))
+
+    text = sidecar._transcribe_decoded(
+        "owner/whisper-small.en",
+        np.zeros(160, dtype = np.float32),
+        {
+            "task": "transcribe",
+            "language": "en",
+            "condition_on_prev_tokens": False,
+            "num_beams": 1,
+        },
+    )
+
+    assert text == "hello"
+    assert calls == [{"condition_on_prev_tokens": False, "num_beams": 1}]
+
+
+def test_unknown_language_is_rejected_before_decode_or_model_load(monkeypatch):
+    sidecar = WhisperSttSidecar()
+
+    def should_not_run(*_args, **_kwargs):
+        pytest.fail("unknown language must be rejected before expensive work")
+
+    monkeypatch.setattr(stt_sidecar_module, "_known_whisper_languages", lambda: frozenset({"en"}))
+    monkeypatch.setattr(stt_sidecar_module, "_decode_audio_bounded", should_not_run)
+    monkeypatch.setattr(sidecar, "_transcribe_decoded", should_not_run)
+
+    with pytest.raises(SttLanguageError, match = "is not supported"):
+        sidecar.transcribe(b"encoded audio", language = "xx-YY")
+
+
+def test_unknown_language_is_not_reported_as_bad_audio(monkeypatch):
+    sidecar = WhisperSttSidecar()
+    infer = _CaptureInference()
+    monkeypatch.setattr(sidecar, "_transcribe_decoded", infer)
+    monkeypatch.setattr(stt_sidecar_module, "_known_whisper_languages", lambda: frozenset({"en"}))
+
+    with pytest.raises(SttLanguageError, match = "is not supported"):
+        sidecar.transcribe(b"encoded audio", language = "xx-YY")
+
+
+def test_transcription_result_keeps_requested_model_id_during_switch(monkeypatch):
+    sidecar = WhisperSttSidecar()
+
+    # Simulate another request changing the mutable resident-model state after
+    # this request pinned its own model id.
+    infer = _CaptureInference(mutate = lambda: setattr(sidecar, "_model_id", "large-v3"))
+    monkeypatch.setattr(sidecar, "_transcribe_decoded", infer)
+
+    result = sidecar.transcribe(b"encoded audio", model = "small")
+
+    assert result["model"] == "small"
+
+
+def test_inference_failure_propagates(monkeypatch):
+    sidecar = WhisperSttSidecar()
+
+    def boom(*_args, **_kwargs):
+        raise RuntimeError("inference failed")
+
+    monkeypatch.setattr(sidecar, "_transcribe_decoded", boom)
+
+    with pytest.raises(RuntimeError, match = "inference failed"):
+        sidecar.transcribe(b"encoded audio")
+
+
+class _FakeModel:
+    def to(self, *_args, **_kwargs):
+        return self
+
+    def eval(self):
+        return self
+
+
+class _FakeTimer:
+    def __init__(
+        self,
+        interval,
+        function,
+        args = (),
+        kwargs = None,
+    ):
+        self.interval = interval
+        self.function = function
+        self.args = args
+        self.kwargs = kwargs or {}
+        self.cancelled = False
+        self.daemon = False
+        self.started = False
+
+    def start(self):
+        self.started = True
+
+    def cancel(self):
+        self.cancelled = True
+
+    def fire(self):
+        self.function(*self.args, **self.kwargs)
+
+
+def _install_fake_torch(monkeypatch):
+    fake_torch = SimpleNamespace(
+        float16 = "float16",
+        float32 = "float32",
+        device = lambda value: value,
+        cuda = SimpleNamespace(is_available = lambda: False),
+        backends = SimpleNamespace(mps = SimpleNamespace(is_available = lambda: False)),
+    )
+    monkeypatch.setitem(sys.modules, "torch", fake_torch)
+    monkeypatch.setitem(sys.modules, "av", SimpleNamespace())
+    return fake_torch
+
+
+def test_load_uses_model_hub_cache_without_implicit_download(monkeypatch):
+    calls = []
+    _install_fake_torch(monkeypatch)
+
+    class FakeWhisperForConditionalGeneration:
+        @classmethod
+        def from_pretrained(cls, repo, **kwargs):
+            calls.append(("model", repo, kwargs))
+            return _FakeModel()
+
+    class FakeWhisperProcessor:
+        @classmethod
+        def from_pretrained(cls, repo, **kwargs):
+            calls.append(("processor", repo, kwargs))
+            return object()
+
+    monkeypatch.setitem(
+        sys.modules,
+        "transformers",
+        SimpleNamespace(
+            WhisperForConditionalGeneration = FakeWhisperForConditionalGeneration,
+            WhisperProcessor = FakeWhisperProcessor,
+        ),
+    )
+    monkeypatch.setattr(stt_sidecar_module, "_pick_device", lambda: ("cpu", "float32"))
+
+    WhisperSttSidecar(keep_alive_seconds = 0).load("small")
+
+    assert {(kind, repo) for kind, repo, _ in calls} == {
+        ("processor", "/cached/model"),
+        ("model", "/cached/model"),
+    }
+    # Never fetch weights implicitly; the Model Hub owns downloads.
+    assert all(kwargs.get("local_files_only") is True for _, _, kwargs in calls)
+    # The weight load forces safetensors so a pickle checkpoint cannot execute.
+    model_kwargs = next(kwargs for kind, _, kwargs in calls if kind == "model")
+    assert model_kwargs.get("use_safetensors") is True
+
+
+def test_model_cache_preflight_uses_shared_offline_resolver(monkeypatch):
+    seen = []
+    monkeypatch.setattr(
+        stt_sidecar_module,
+        "_find_complete_cached_snapshot",
+        lambda model: seen.append(model) or Path("/cached/model"),
+    )
+
+    WhisperSttSidecar(keep_alive_seconds = 0)._ensure_model_downloaded("small")
+
+    assert seen == ["small"]
+
+
+def test_model_cache_preflight_reports_missing_snapshot(monkeypatch):
+    monkeypatch.setattr(stt_sidecar_module, "_find_complete_cached_snapshot", lambda _model: None)
+
+    with pytest.raises(SttModelNotDownloadedError, match = "not downloaded"):
+        WhisperSttSidecar(keep_alive_seconds = 0)._ensure_model_downloaded("large-v3")
+
+
+def test_load_reports_model_hub_cache_miss(monkeypatch):
+    _install_fake_torch(monkeypatch)
+
+    class LocalEntryNotFoundError(RuntimeError):
+        pass
+
+    class MissingWhisperProcessor:
+        @classmethod
+        def from_pretrained(cls, *_args, **_kwargs):
+            raise LocalEntryNotFoundError("not cached")
+
+    monkeypatch.setitem(
+        sys.modules,
+        "transformers",
+        SimpleNamespace(
+            WhisperForConditionalGeneration = object,
+            WhisperProcessor = MissingWhisperProcessor,
+        ),
+    )
+    monkeypatch.setattr(stt_sidecar_module, "_pick_device", lambda: ("cpu", "float32"))
+
+    with pytest.raises(SttModelNotDownloadedError, match = "not downloaded"):
+        WhisperSttSidecar(keep_alive_seconds = 0).load("large-v3")
+
+
+def test_unavailable_runtime_is_rejected_before_audio_decode(monkeypatch):
+    sidecar = WhisperSttSidecar()
+
+    def unavailable() -> None:
+        raise SttUnavailableError("needs PyTorch, Transformers, and PyAV")
+
+    def should_not_decode(_audio):
+        pytest.fail("runtime must be checked before audio decode")
+
+    monkeypatch.setattr(stt_sidecar_module, "ensure_stt_available", unavailable)
+    monkeypatch.setattr(stt_sidecar_module, "_decode_audio_bounded", should_not_decode)
+
+    with pytest.raises(SttUnavailableError, match = "needs PyTorch"):
+        sidecar.transcribe(b"encoded audio", model = "small")
+
+
+def test_missing_model_is_rejected_before_audio_decode(monkeypatch):
+    sidecar = WhisperSttSidecar(keep_alive_seconds = 0)
+
+    def missing(_model_id):
+        raise SttModelNotDownloadedError("not downloaded")
+
+    def should_not_decode(_audio):
+        pytest.fail("missing models must be rejected before audio decode")
+
+    monkeypatch.setattr(sidecar, "_ensure_model_downloaded", missing, raising = False)
+    monkeypatch.setattr(stt_sidecar_module, "_decode_audio_bounded", should_not_decode)
+
+    with pytest.raises(SttModelNotDownloadedError, match = "not downloaded"):
+        sidecar.transcribe(b"encoded audio", model = "large-v3")
+
+
+def test_missing_model_switch_keeps_resident_model(monkeypatch):
+    sidecar = WhisperSttSidecar(keep_alive_seconds = 0)
+    resident = object()
+    sidecar._engine = resident
+    sidecar._model_id = "small"
+    sidecar._device = "cpu"
+
+    def missing(_model_id):
+        raise SttModelNotDownloadedError("not downloaded")
+
+    monkeypatch.setattr(sidecar, "_ensure_model_downloaded", missing, raising = False)
+    monkeypatch.setattr(stt_sidecar_module, "ensure_stt_available", lambda: None)
+    monkeypatch.setattr(
+        sidecar,
+        "_build_model",
+        lambda *_args: pytest.fail("cache miss must be detected before model replacement"),
+    )
+    _install_fake_torch(monkeypatch)
+
+    with pytest.raises(SttModelNotDownloadedError, match = "not downloaded"):
+        sidecar.load("large-v3")
+
+    assert sidecar._engine is resident
+    assert sidecar.loaded_model == "small"
+
+
+def test_incompatible_custom_model_switch_keeps_resident_model(monkeypatch, tmp_path):
+    (tmp_path / "config.json").write_text(
+        '{"model_type": "llama", "architectures": ["LlamaForCausalLM"]}'
+    )
+    sidecar = WhisperSttSidecar(keep_alive_seconds = 0)
+    resident = (object(), object())
+    sidecar._engine = resident
+    sidecar._model_id = "small"
+    sidecar._device = "cpu"
+    _install_fake_torch(monkeypatch)
+    monkeypatch.setattr(
+        stt_sidecar_module,
+        "_find_complete_cached_snapshot",
+        lambda _model: tmp_path,
+    )
+
+    with pytest.raises(SttModelCompatibilityError, match = "not a compatible"):
+        sidecar.load("owner/chat-model")
+
+    assert sidecar._engine is resident
+    assert sidecar.loaded_model == "small"
+
+
+def test_loaded_model_stays_warm_until_idle_timer_fires(monkeypatch):
+    timers = []
+    _install_fake_torch(monkeypatch)
+
+    def make_timer(*args, **kwargs):
+        timer = _FakeTimer(*args, **kwargs)
+        timers.append(timer)
+        return timer
+
+    sidecar = WhisperSttSidecar(keep_alive_seconds = 300)
+    monkeypatch.setattr(stt_sidecar_module, "ensure_stt_available", lambda: None)
+    monkeypatch.setattr(stt_sidecar_module.threading, "Timer", make_timer)
+    monkeypatch.setattr(sidecar, "_build_model", lambda *_args: (object(), object()))
+    monkeypatch.setattr(stt_sidecar_module, "_pick_device", lambda: ("cpu", "float32"))
+
+    sidecar.load("small")
+
+    assert sidecar.loaded_model == "small"
+    assert timers[-1].interval == 300
+    assert timers[-1].started
+
+    timers[-1].fire()
+
+    assert sidecar.loaded_model is None
+
+
+def test_reusing_loaded_model_refreshes_idle_timer(monkeypatch):
+    timers = []
+    _install_fake_torch(monkeypatch)
+
+    def make_timer(*args, **kwargs):
+        timer = _FakeTimer(*args, **kwargs)
+        timers.append(timer)
+        return timer
+
+    sidecar = WhisperSttSidecar(keep_alive_seconds = 300)
+    monkeypatch.setattr(stt_sidecar_module, "ensure_stt_available", lambda: None)
+    monkeypatch.setattr(stt_sidecar_module.threading, "Timer", make_timer)
+    monkeypatch.setattr(sidecar, "_build_model", lambda *_args: (object(), object()))
+    monkeypatch.setattr(stt_sidecar_module, "_pick_device", lambda: ("cpu", "float32"))
+
+    sidecar.load("small")
+    first = timers[-1]
+    sidecar.load("small")
+
+    assert first.cancelled
+    assert timers[-1] is not first
+
+    first.fire()
+
+    assert sidecar.loaded_model == "small"
+
+
+def test_unload_waits_for_inflight_transcription(monkeypatch):
+    sidecar = WhisperSttSidecar(keep_alive_seconds = 0)
+    started = threading.Event()
+    release = threading.Event()
+
+    def transcribe(*_args):
+        started.set()
+        assert release.wait(timeout = 2)
+        return "hello"
+
+    monkeypatch.setattr(sidecar, "_transcribe_decoded", transcribe)
+    transcribe_thread = threading.Thread(target = lambda: sidecar.transcribe(b"audio"))
+    transcribe_thread.start()
+    assert started.wait(timeout = 2)
+
+    unload_thread = threading.Thread(target = sidecar.unload)
+    unload_thread.start()
+    time.sleep(0.02)
+    assert unload_thread.is_alive()
+
+    release.set()
+    transcribe_thread.join(timeout = 2)
+    unload_thread.join(timeout = 2)
+
+    assert not transcribe_thread.is_alive()
+    assert not unload_thread.is_alive()
+
+
+def test_new_stt_load_uses_cpu_while_training(monkeypatch):
+    fake_torch = SimpleNamespace(
+        float16 = "float16",
+        float32 = "float32",
+        cuda = SimpleNamespace(is_available = lambda: True),
+        backends = SimpleNamespace(mps = SimpleNamespace(is_available = lambda: True)),
+    )
+    monkeypatch.setitem(sys.modules, "torch", fake_torch)
+    monkeypatch.setattr(stt_sidecar_module, "_training_active", lambda: True)
+
+    assert stt_sidecar_module._pick_device() == ("cpu", "float32")
+
+
+def test_new_stt_load_prefers_cuda_when_training_is_idle(monkeypatch):
+    fake_torch = SimpleNamespace(
+        float16 = "float16",
+        float32 = "float32",
+        cuda = SimpleNamespace(is_available = lambda: True),
+        backends = SimpleNamespace(mps = SimpleNamespace(is_available = lambda: False)),
+    )
+    monkeypatch.setitem(sys.modules, "torch", fake_torch)
+    monkeypatch.setattr(stt_sidecar_module, "_training_active", lambda: False)
+
+    assert stt_sidecar_module._pick_device() == ("cuda", "float16")
+
+
+def test_new_stt_load_prefers_mps_when_cuda_is_unavailable(monkeypatch):
+    fake_torch = SimpleNamespace(
+        float16 = "float16",
+        float32 = "float32",
+        cuda = SimpleNamespace(is_available = lambda: False),
+        backends = SimpleNamespace(mps = SimpleNamespace(is_available = lambda: True)),
+    )
+    monkeypatch.setitem(sys.modules, "torch", fake_torch)
+    monkeypatch.setattr(stt_sidecar_module, "_training_active", lambda: False)
+
+    assert stt_sidecar_module._pick_device() == ("mps", "float32")
+
+
+def test_new_stt_load_uses_cpu_without_accelerators(monkeypatch):
+    fake_torch = SimpleNamespace(
+        float16 = "float16",
+        float32 = "float32",
+        cuda = SimpleNamespace(is_available = lambda: False),
+        backends = SimpleNamespace(mps = SimpleNamespace(is_available = lambda: False)),
+    )
+    monkeypatch.setitem(sys.modules, "torch", fake_torch)
+    monkeypatch.setattr(stt_sidecar_module, "_training_active", lambda: False)
+
+    assert stt_sidecar_module._pick_device() == ("cpu", "float32")
+
+
+def test_accelerator_load_failure_retries_on_cpu(monkeypatch):
+    fake_torch = _install_fake_torch(monkeypatch)
+    calls = []
+    sidecar = WhisperSttSidecar(keep_alive_seconds = 0)
+    monkeypatch.setattr(stt_sidecar_module, "ensure_stt_available", lambda: None)
+
+    def build(_repo, device, dtype, _cancel_event):
+        calls.append((device, dtype))
+        if device == "cuda":
+            raise RuntimeError("accelerator allocation failed")
+        return object(), object()
+
+    monkeypatch.setattr(stt_sidecar_module, "_pick_device", lambda: ("cuda", "float16"))
+    monkeypatch.setattr(sidecar, "_build_model", build)
+
+    sidecar.load("small")
+
+    assert calls == [("cuda", "float16"), ("cpu", fake_torch.float32)]
+    assert sidecar.device == "cpu"
+
+
+def test_pending_load_can_be_cancelled_without_waiting_for_model_lock(monkeypatch):
+    _install_fake_torch(monkeypatch)
+    sidecar = WhisperSttSidecar(keep_alive_seconds = 0)
+    build_started = threading.Event()
+    release_build = threading.Event()
+    errors = []
+
+    def build(_repo, _device, _dtype, _cancel_event):
+        build_started.set()
+        assert release_build.wait(timeout = 2)
+        return object(), object()
+
+    def run_load():
+        try:
+            sidecar.load("small")
+        except Exception as exc:
+            errors.append(exc)
+
+    monkeypatch.setattr(stt_sidecar_module, "ensure_stt_available", lambda: None)
+    monkeypatch.setattr(stt_sidecar_module, "_pick_device", lambda: ("cpu", "float32"))
+    monkeypatch.setattr(sidecar, "_build_model", build)
+
+    load_thread = threading.Thread(target = run_load)
+    load_thread.start()
+    assert build_started.wait(timeout = 2)
+
+    result = []
+    cancel_thread = threading.Thread(target = lambda: result.append(sidecar.cancel_pending_load()))
+    cancel_thread.start()
+    cancel_thread.join(timeout = 2)
+
+    assert not cancel_thread.is_alive()
+    assert result == [True]
+    assert load_thread.is_alive()
+
+    release_build.set()
+    load_thread.join(timeout = 2)
+
+    assert not load_thread.is_alive()
+    assert len(errors) == 1
+    assert isinstance(errors[0], SttLoadCancelledError)
+    assert sidecar.loaded_model is None
+    assert sidecar.is_loading() is False
+
+
+def _wav_bytes(sample_count: int, sample_rate: int = 16000) -> bytes:
+    output = io.BytesIO()
+    with wave.open(output, "wb") as wav:
+        wav.setnchannels(1)
+        wav.setsampwidth(2)
+        wav.setframerate(sample_rate)
+        wav.writeframes(np.zeros(sample_count, dtype = np.int16).tobytes())
+    return output.getvalue()
+
+
+def test_bounded_decoder_returns_16khz_float_pcm():
+    pytest.importorskip("av")
+
+    decoded = _REAL_DECODE_AUDIO_BOUNDED(_wav_bytes(1600))
+
+    assert decoded.dtype == np.float32
+    assert decoded.shape == (1600,)
+
+
+def test_bounded_decoder_rejects_audio_as_soon_as_sample_cap_is_crossed(monkeypatch):
+    pytest.importorskip("av")
+    monkeypatch.setattr(stt_sidecar_module, "_MAX_AUDIO_SECONDS", 1)
+
+    with pytest.raises(SttAudioTooLongError, match = "Audio must"):
+        _REAL_DECODE_AUDIO_BOUNDED(_wav_bytes(16001))
+
+
+def test_bounded_decoder_resamples_stereo_48khz_to_mono_16khz():
+    pytest.importorskip("av")
+    output = io.BytesIO()
+    frames = np.zeros((4800, 2), dtype = np.int16)
+    with wave.open(output, "wb") as wav:
+        wav.setnchannels(2)
+        wav.setsampwidth(2)
+        wav.setframerate(48000)
+        wav.writeframes(frames.tobytes())
+
+    decoded = _REAL_DECODE_AUDIO_BOUNDED(output.getvalue())
+
+    assert decoded.dtype == np.float32
+    assert 1590 <= len(decoded) <= 1610
+
+
+@pytest.mark.parametrize("audio", [b"", b"not audio", b"RIFF\x00\x00"])
+def test_bounded_decoder_rejects_malformed_audio(audio):
+    pytest.importorskip("av")
+
+    with pytest.raises(SttAudioDecodeError, match = "Could not decode"):
+        _REAL_DECODE_AUDIO_BOUNDED(audio)
+
+
+def test_bounded_decoder_rejects_container_without_audio_stream(monkeypatch):
+    class FakeFFmpegError(Exception):
+        pass
+
+    class FakeResampler:
+        def __init__(self, **_kwargs):
+            pass
+
+    class FakeFifo:
+        samples = 0
+
+    class FakeContainer:
+        streams = SimpleNamespace(audio = [])
+
+        def __enter__(self):
+            return self
+
+        def __exit__(self, *_args):
+            return False
+
+    fake_av = SimpleNamespace(
+        audio = SimpleNamespace(
+            resampler = SimpleNamespace(AudioResampler = FakeResampler),
+            fifo = SimpleNamespace(AudioFifo = FakeFifo),
+        ),
+        open = lambda *_args, **_kwargs: FakeContainer(),
+    )
+    monkeypatch.setitem(sys.modules, "av", fake_av)
+    monkeypatch.setitem(
+        sys.modules,
+        "av.error",
+        SimpleNamespace(
+            FFmpegError = FakeFFmpegError,
+            InvalidDataError = FakeFFmpegError,
+        ),
+    )
+
+    with pytest.raises(SttAudioDecodeError, match = "Could not decode"):
+        _REAL_DECODE_AUDIO_BOUNDED(b"video-only")
+
+
+def test_unload_releases_model_and_device():
+    sidecar = WhisperSttSidecar()
+    sidecar._engine = object()
+    sidecar._model_id = "small"
+    sidecar._device = "cpu"
+
+    sidecar.unload()
+
+    assert sidecar.loaded_model is None
+    assert sidecar.device is None
+
+
+# ---------------------------------------------------------------------------
+# Snapshot download tracking
+# ---------------------------------------------------------------------------
+
+
+def _write_complete_snapshot(snapshot: Path, *, model_type: str = "whisper") -> None:
+    snapshot.mkdir(parents = True, exist_ok = True)
+    (snapshot / "config.json").write_text(json.dumps({"model_type": model_type}))
+    (snapshot / "preprocessor_config.json").write_text("{}")
+    (snapshot / "tokenizer.json").write_text("{}")
+    (snapshot / "model.safetensors").write_bytes(b"weights")
+
+
+def _sibling(name: str, size: int, key: str):
+    return SimpleNamespace(rfilename = name, size = size, blob_id = key, lfs = None)
+
+
+def test_sha_snapshot_without_main_ref_survives_restart_and_cache_relocation(monkeypatch, tmp_path):
+    repo = "openai/whisper-tiny.en"
+    revision = "c" * 40
+    studio_home = tmp_path / "studio"
+    first_cache = tmp_path / "first-hub"
+    second_cache = tmp_path / "second-hub"
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(studio_home))
+    monkeypatch.setenv("HF_HUB_OFFLINE", "1")
+    monkeypatch.setattr(stt_sidecar_module, "_snapshot_is_complete", _REAL_SNAPSHOT_IS_COMPLETE)
+    monkeypatch.setattr(
+        stt_sidecar_module,
+        "_find_complete_cached_snapshot",
+        _REAL_FIND_COMPLETE_CACHED_SNAPSHOT,
+    )
+
+    first = first_cache / "models--openai--whisper-tiny.en" / "snapshots" / revision
+    _write_complete_snapshot(first)
+    monkeypatch.setenv("HF_HUB_CACHE", str(first_cache))
+    stt_sidecar_module._write_revision_record(repo, revision)
+    assert stt_sidecar_module._find_complete_cached_snapshot(repo) == first.resolve()
+
+    second = second_cache / "models--openai--whisper-tiny.en" / "snapshots" / revision
+    _write_complete_snapshot(second)
+    monkeypatch.setenv("HF_HUB_CACHE", str(second_cache))
+    assert stt_sidecar_module._find_complete_cached_snapshot(repo) == second.resolve()
+
+
+def test_corrupt_or_escaping_revision_record_is_ignored(monkeypatch, tmp_path):
+    repo = "openai/whisper-tiny.en"
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path / "studio"))
+    monkeypatch.setenv("HF_HUB_CACHE", str(tmp_path / "hub"))
+    monkeypatch.setattr(
+        stt_sidecar_module,
+        "_find_complete_cached_snapshot",
+        _REAL_FIND_COMPLETE_CACHED_SNAPSHOT,
+    )
+    record = stt_sidecar_module._revision_record_path(repo)
+    record.parent.mkdir(parents = True)
+    record.write_text(json.dumps({"version": 1, "repo": repo, "revision": "../../outside"}))
+    assert stt_sidecar_module._find_complete_cached_snapshot(repo) is None
+
+    outside = tmp_path / "outside"
+    _write_complete_snapshot(outside)
+    snapshots = tmp_path / "hub" / "models--openai--whisper-tiny.en" / "snapshots"
+    snapshots.mkdir(parents = True)
+    (snapshots / ("d" * 40)).symlink_to(outside, target_is_directory = True)
+    assert stt_sidecar_module._find_complete_cached_snapshot(repo) is None
+
+
+def test_adapter_only_snapshot_is_not_complete(tmp_path):
+    (tmp_path / "config.json").write_text('{"model_type": "whisper"}')
+    (tmp_path / "preprocessor_config.json").write_text("{}")
+    (tmp_path / "tokenizer.json").write_text("{}")
+    (tmp_path / "adapter_model.safetensors").write_bytes(b"adapter")
+
+    assert _REAL_SNAPSHOT_IS_COMPLETE(tmp_path) is False
+
+
+def test_snapshot_selection_prefers_safetensors_and_excludes_unrelated_files():
+    info = SimpleNamespace(
+        siblings = [
+            _sibling("config.json", 10, "config"),
+            _sibling("preprocessor_config.json", 20, "preprocessor"),
+            _sibling("tokenizer.json", 30, "tokenizer"),
+            _sibling("model.safetensors", 100, "safe"),
+            _sibling("pytorch_model.bin", 110, "torch"),
+            _sibling("README.md", 1000, "readme"),
+        ]
+    )
+
+    selected = stt_sidecar_module._select_snapshot_files(
+        info, lambda _name: pytest.fail("unsharded selection must not load an index")
+    )
+
+    assert {item.path for item in selected} == {
+        "config.json",
+        "preprocessor_config.json",
+        "tokenizer.json",
+        "model.safetensors",
+    }
+    assert sum(item.size for item in selected) == 160
+
+
+def test_snapshot_selection_includes_every_indexed_shard():
+    info = SimpleNamespace(
+        siblings = [
+            _sibling("config.json", 10, "config"),
+            _sibling("model.safetensors.index.json", 5, "index"),
+            _sibling("model-00001-of-00002.safetensors", 50, "shard1"),
+            _sibling("model-00002-of-00002.safetensors", 60, "shard2"),
+            _sibling("pytorch_model.bin", 120, "torch"),
+        ]
+    )
+
+    selected = stt_sidecar_module._select_snapshot_files(
+        info,
+        lambda name: {
+            "weight_map": {
+                "a": "model-00001-of-00002.safetensors",
+                "b": "model-00002-of-00002.safetensors",
+            }
+        },
+    )
+
+    assert {item.path for item in selected} == {
+        "config.json",
+        "model.safetensors.index.json",
+        "model-00001-of-00002.safetensors",
+        "model-00002-of-00002.safetensors",
+    }
+
+
+def test_snapshot_selection_rejects_pickle_only_weights():
+    # A custom repo shipping only pytorch_model.bin (pickle) must fail closed:
+    # selecting it would download a checkpoint that runs code at load time.
+    info = SimpleNamespace(
+        siblings = [
+            _sibling("config.json", 10, "config"),
+            _sibling("preprocessor_config.json", 20, "preprocessor"),
+            _sibling("tokenizer.json", 30, "tokenizer"),
+            _sibling("pytorch_model.bin", 110, "torch"),
+        ]
+    )
+
+    with pytest.raises(SttModelCompatibilityError, match = "safetensors"):
+        stt_sidecar_module._select_snapshot_files(
+            info, lambda _name: pytest.fail("pickle weights must not be selected")
+        )
+
+
+def test_snapshot_selection_rejects_safe_index_pointing_at_pickle_shards():
+    # A safetensors index can name .bin shards; Transformers dispatches shard
+    # loading by extension, so those shards would still pickle-load. The index
+    # is attacker-controlled, so a non-safetensors shard must fail closed.
+    info = SimpleNamespace(
+        siblings = [
+            _sibling("config.json", 10, "config"),
+            _sibling("model.safetensors.index.json", 5, "index"),
+            _sibling("pytorch_model-00001-of-00001.bin", 90, "shard"),
+        ]
+    )
+
+    with pytest.raises(SttModelCompatibilityError, match = "non-safetensors shards"):
+        stt_sidecar_module._select_snapshot_files(
+            info,
+            lambda _name: {"weight_map": {"a": "pytorch_model-00001-of-00001.bin"}},
+        )
+
+
+def test_progress_counts_only_selected_blobs_and_caps_incomplete_files(monkeypatch, tmp_path):
+    monkeypatch.setenv("HF_HUB_CACHE", str(tmp_path / "hub"))
+    blobs = tmp_path / "hub" / "models--owner--whisper" / "blobs"
+    blobs.mkdir(parents = True)
+    (blobs / "one").write_bytes(b"x" * 10)
+    (blobs / "two.incomplete").write_bytes(b"x" * 30)
+    (blobs / "unrelated").write_bytes(b"x" * 1000)
+    state = stt_sidecar_module._SnapshotDownloadState()
+    state._repo = "owner/whisper"
+    state._selected_files = (
+        stt_sidecar_module._SelectedHubFile("config.json", 10, "one"),
+        stt_sidecar_module._SelectedHubFile("model.safetensors", 20, "two"),
+    )
+    state._total_bytes = 30
+    state._complete = True
+
+    status = state.status()
+
+    assert status["bytes_total"] == 30
+    assert status["bytes_done"] == 30
+
+
+def test_download_metadata_and_snapshot_use_the_same_revision(monkeypatch, tmp_path):
+    revision = "e" * 40
+    calls = []
+    siblings = [
+        _sibling("config.json", 10, "config"),
+        _sibling("preprocessor_config.json", 20, "preprocessor"),
+        _sibling("tokenizer.json", 30, "tokenizer"),
+        _sibling("model.safetensors", 100, "safe"),
+        _sibling("pytorch_model.bin", 110, "torch"),
+    ]
+
+    class FakeApi:
+        def __init__(self, token):
+            pass
+
+        def model_info(self, repo, **kwargs):
+            calls.append(("info", repo, kwargs))
+            return SimpleNamespace(sha = revision, siblings = siblings)
+
+    def fake_snapshot_download(**kwargs):
+        calls.append(("snapshot", kwargs))
+        return str(tmp_path)
+
+    monkeypatch.setattr("huggingface_hub.HfApi", FakeApi)
+    monkeypatch.setattr("huggingface_hub.snapshot_download", fake_snapshot_download)
+    monkeypatch.setattr(
+        "huggingface_hub.hf_hub_download",
+        lambda **_kwargs: pytest.fail("unsharded selection must not load an index"),
+    )
+    monkeypatch.setattr(stt_sidecar_module, "_snapshot_is_complete", lambda _path: True)
+    monkeypatch.setattr(stt_sidecar_module, "_write_revision_record", lambda *_args: None)
+    state = stt_sidecar_module._SnapshotDownloadState()
+
+    state._run("owner/whisper", None, revision)
+
+    assert calls[0] == (
+        "info",
+        "owner/whisper",
+        {"revision": revision, "files_metadata": True, "timeout": 30},
+    )
+    assert calls[1][0] == "snapshot"
+    assert calls[1][1]["revision"] == revision
+    assert "model.safetensors" in calls[1][1]["allow_patterns"]
+    assert "pytorch_model.bin" not in calls[1][1]["allow_patterns"]
+
+
+def test_download_status_is_idle_before_any_download():
+    state = stt_sidecar_module._SnapshotDownloadState()
+
+    status = state.status()
+
+    assert status == {
+        "downloading": False,
+        "model": None,
+        "error": None,
+        "bytes_total": None,
+        "bytes_done": None,
+    }
+
+
+def test_download_rejects_a_second_model_while_one_is_in_flight(monkeypatch):
+    state = stt_sidecar_module._SnapshotDownloadState()
+    release = threading.Event()
+    monkeypatch.setattr(
+        state,
+        "_run",
+        lambda repo, token, revision: release.wait(timeout = 5),
+    )
+
+    state.start("small")
+    try:
+        # Re-requesting the in-flight model is a no-op, not an error.
+        state.start("small")
+        with pytest.raises(SttModelIdError, match = "still"):
+            state.start("tiny")
+        assert state.status()["downloading"] is True
+        assert state.status()["model"] == "small"
+    finally:
+        release.set()
+
+
+def test_download_failure_is_reported_in_status(monkeypatch):
+    state = stt_sidecar_module._SnapshotDownloadState()
+    # Mask huggingface_hub so the import inside _run fails fast.
+    monkeypatch.setitem(sys.modules, "huggingface_hub", None)
+
+    state.start("small")
+    state._thread.join(timeout = 5)
+
+    status = state.status()
+    assert status["downloading"] is False
+    assert "Download failed" in (status["error"] or "")
+
+
+def test_is_model_downloaded_is_false_for_a_cache_miss(monkeypatch):
+    monkeypatch.setattr(
+        stt_sidecar_module,
+        "_find_complete_cached_snapshot",
+        _REAL_FIND_COMPLETE_CACHED_SNAPSHOT,
+    )
+    monkeypatch.setenv("HF_HUB_CACHE", "/nonexistent/stt-test-cache")
+
+    assert stt_sidecar_module.is_model_downloaded("small") is False
+
+
+def test_sharded_snapshot_with_missing_shard_is_not_downloaded(monkeypatch, tmp_path):
+    import json
+
+    monkeypatch.setenv("HF_HUB_CACHE", str(tmp_path / "hub"))
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path / "studio"))
+    monkeypatch.setattr(
+        stt_sidecar_module,
+        "_find_complete_cached_snapshot",
+        _REAL_FIND_COMPLETE_CACHED_SNAPSHOT,
+    )
+    monkeypatch.setattr(stt_sidecar_module, "_snapshot_is_complete", _REAL_SNAPSHOT_IS_COMPLETE)
+    snap = tmp_path / "hub" / "models--unsloth--whisper-small" / "snapshots" / ("a" * 40)
+    snap.mkdir(parents = True)
+    (snap / "config.json").write_bytes(b"{}")
+    (snap / "preprocessor_config.json").write_bytes(b"{}")
+    (snap / "tokenizer.json").write_bytes(b"{}")
+    index = {
+        "weight_map": {
+            "a": "model-00001-of-00002.safetensors",
+            "b": "model-00002-of-00002.safetensors",
+        }
+    }
+    (snap / "model.safetensors.index.json").write_text(json.dumps(index))
+    (snap / "model-00001-of-00002.safetensors").write_bytes(b"w" * 8)
+
+    assert stt_sidecar_module.is_model_downloaded("small") is False
+
+    # Completing the second shard flips the verdict.
+    (snap / "model-00002-of-00002.safetensors").write_bytes(b"w" * 8)
+    assert stt_sidecar_module.is_model_downloaded("small") is True
+
+
+@pytest.mark.parametrize("model_id", ["small", "openai/whisper-medium"])
+def test_preflight_rejects_partial_snapshot(monkeypatch, tmp_path, model_id):
+    # A resolvable snapshot with metadata but no weights must fail preflight,
+    # not survive until load() after the audio has already been decoded.
+    monkeypatch.setenv("HF_HUB_CACHE", str(tmp_path / "hub"))
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path / "studio"))
+    monkeypatch.setattr(
+        stt_sidecar_module,
+        "_find_complete_cached_snapshot",
+        _REAL_FIND_COMPLETE_CACHED_SNAPSHOT,
+    )
+    monkeypatch.setattr(stt_sidecar_module, "_snapshot_is_complete", _REAL_SNAPSHOT_IS_COMPLETE)
+    repo = STT_MODELS.get(model_id, model_id)
+    snapshot = tmp_path / "hub" / f"models--{repo.replace('/', '--')}" / "snapshots" / ("b" * 40)
+    snapshot.mkdir(parents = True)
+    (snapshot / "config.json").write_text('{"model_type": "whisper"}')
+
+    with pytest.raises(SttModelNotDownloadedError, match = "not downloaded"):
+        WhisperSttSidecar(keep_alive_seconds = 0)._ensure_model_downloaded(model_id)
+
+    # Completing the snapshot clears the preflight.
+    (snapshot / "preprocessor_config.json").write_text("{}")
+    (snapshot / "tokenizer.json").write_text("{}")
+    (snapshot / "model.safetensors").write_bytes(b"w" * 8)
+    WhisperSttSidecar(keep_alive_seconds = 0)._ensure_model_downloaded(model_id)
+
+
+def test_cpu_retry_releases_failed_accelerator_load(monkeypatch):
+    _install_fake_torch(monkeypatch)
+    monkeypatch.setattr(stt_sidecar_module, "_pick_device", lambda: ("mps", "float16"))
+
+    class Marker:
+        pass
+
+    seen = {}
+
+    def fake_build(self, repo, device, dtype, cancel_event):
+        if device != "cpu":
+            # The frame local stands in for a partly loaded accelerator model
+            # kept alive only through the raised traceback.
+            marker = Marker()
+            seen["ref"] = weakref.ref(marker)
+            raise RuntimeError("accelerator load failed")
+        gc.collect()
+        seen["alive_during_retry"] = seen["ref"]() is not None
+        return (_FakeModel(), object())
+
+    monkeypatch.setattr(WhisperSttSidecar, "_build_model", fake_build)
+    sidecar = WhisperSttSidecar(keep_alive_seconds = 0)
+    sidecar.load("small")
+
+    # The failed attempt must be collectable before the CPU model loads, or
+    # its accelerator memory stays stranded for the whole retry.
+    assert seen["alive_during_retry"] is False
+    assert sidecar.device == "cpu"
diff --git a/studio/backend/tests/test_studio_api.py b/studio/backend/tests/test_studio_api.py
index 928b636e3e..087c00b648 100644
--- a/studio/backend/tests/test_studio_api.py
+++ b/studio/backend/tests/test_studio_api.py
@@ -11,7 +11,7 @@ the CLI's ``--help`` output:
     1. curl -- basic chat completions (non-streaming)
     2. curl -- streaming chat completions
     3. Python OpenAI SDK -- streaming completions
-    4. curl -- Studio server-side tools (enable_tools=true)
+    4. curl -- Unsloth server-side tools (enable_tools=true)
     5. curl -- Standard OpenAI function calling (non-streaming)
     6. curl -- Standard OpenAI function calling (streaming)
     7. curl -- Standard OpenAI function calling (multi-turn tool loop)
@@ -31,7 +31,7 @@ Usage:
     python tests/test_studio_api.py
     python tests/test_studio_api.py --model unsloth/... --gguf-variant ...
 
-    # Pytest mode, external server — start a Studio server yourself,
+    # Pytest mode, external server — start an Unsloth server yourself,
     # then point pytest at it. Fastest iteration loop.
     unsloth studio run --model unsloth/Qwen3-1.7B-GGUF --gguf-variant UD-Q4_K_XL &
     export UNSLOTH_E2E_BASE_URL=http://127.0.0.1:8080
@@ -341,7 +341,7 @@ def _final_finish_reason(chunks: list[dict]) -> str | None:
 def test_openai_tools_nonstream(base_url: str, api_key: str):
     """Standard OpenAI function calling, non-streaming, tool_choice='required'.
 
-    Regression: before the fix, Studio stripped `tools` and the model
+    Regression: before the fix, Unsloth stripped `tools` and the model
     returned plain text with finish_reason='stop'. After the fix,
     llama-server's response is forwarded verbatim so the client sees
     finish_reason='tool_calls' with a structured tool_calls array and
diff --git a/studio/backend/tests/test_tensor_parallel.py b/studio/backend/tests/test_tensor_parallel.py
index 0d71b89d87..00c7aeac69 100644
--- a/studio/backend/tests/test_tensor_parallel.py
+++ b/studio/backend/tests/test_tensor_parallel.py
@@ -262,9 +262,12 @@ def test_proportional_tensor_split_is_emitted_in_tensor_mode():
     src = _load_model_source()
     assert '"--tensor-split"' in src
     gate = src.find("if tensor_parallel:")
-    ts = src.find('"--tensor-split"')
+    # Find the TP block's emission (after the gate); manual mode emits its own
+    # --tensor-split earlier in the source from the user's per-GPU shares.
+    ts = src.find('"--tensor-split"', gate)
     nxt_else = src.find("self._tensor_parallel = False")
     assert 0 <= gate < ts < nxt_else, "--tensor-split must be emitted under `if tensor_parallel:`"
+    assert "tp_tensor_split" in src[gate:nxt_else]
 
 
 def test_mtp_decode_probe_wired_under_tensor_parallel():
@@ -420,7 +423,7 @@ def test_runtime_recovery_fires_for_user_env_mtp(monkeypatch):
     # MTP driven by user extra_args / LLAMA_ARG_SPEC_TYPE leaves _speculative_type
     # unset, but the launch flag still gates recovery on (pass-through MTP).
     b = _recovery_backend()
-    b._speculative_type = None  # Studio stepped back; user/env owns the spec
+    b._speculative_type = None  # Unsloth stepped back; user/env owns the spec
     done = threading.Event()
     captured = {}
 
diff --git a/studio/backend/tests/test_think_prefill_reemit.py b/studio/backend/tests/test_think_prefill_reemit.py
index 300ff92776..346399c3b2 100644
--- a/studio/backend/tests/test_think_prefill_reemit.py
+++ b/studio/backend/tests/test_think_prefill_reemit.py
@@ -2,7 +2,7 @@
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 """
-Unit tests for detect_think_prefill.
+Unit tests for local reasoning-stream helpers.
 
 Reasoning templates (Qwen3.6-style) end the generation prompt with an open
 ``<think>\\n`` so the model starts reasoning immediately. skip_prompt
@@ -16,7 +16,13 @@ import sys
 _backend = os.path.join(os.path.dirname(__file__), "..")
 sys.path.insert(0, _backend)
 
-from core.inference.chat_template_helpers import detect_think_prefill
+from core.inference.chat_template_helpers import (
+    ReasoningChannelNormalizer,
+    detect_reasoning_channel_markers,
+    detect_reasoning_channel_markers_from_model_info,
+    detect_think_prefill,
+    render_with_native_template_fallback,
+)
 
 
 QWEN_PROMPT = "<|im_start|>user\nHi!<|im_end|>\n<|im_start|>assistant\n"
@@ -87,3 +93,170 @@ def test_guard_emits_when_think_not_special():
 def test_guard_default_and_empty_keep_emitting():
     assert detect_think_prefill(QWEN_PROMPT + "<think>\n", None) == "<think>\n"
     assert detect_think_prefill(QWEN_PROMPT + "<think>\n", []) == "<think>\n"
+
+
+def test_gemma_channel_detection_uses_active_template_not_token_metadata():
+    class TemplateTokenizer:
+        chat_template = {"default": "...<|channel>thought\\n{{ eoc_token }}"}
+
+    class NamedTemplateTokenizer:
+        chat_template = {
+            "default": "plain assistant template",
+            "tool_use": "...<|channel>thought\\n{{ eoc_token }}",
+        }
+
+    class TokenMetadataOnly:
+        chat_template = None
+        soc_token = "<|channel>"
+        eoc_token = "<channel|>"
+
+    class NamedTemplateProcessor:
+        chat_template = {
+            "default": "plain processor default",
+            "tool_use": "<|channel>thought\nprocessor tool template<channel|>",
+        }
+        tokenizer = TokenMetadataOnly()
+
+        def apply_chat_template(self, *_args, **_kwargs):
+            raise NotImplementedError
+
+    expected = ("<|channel>thought", "<channel|>")
+    assert detect_reasoning_channel_markers(TemplateTokenizer()) == expected
+    assert detect_reasoning_channel_markers(NamedTemplateTokenizer()) is None
+    assert (
+        detect_reasoning_channel_markers(
+            NamedTemplateTokenizer(), tools = [{"function": {"name": "web_search"}}]
+        )
+        == expected
+    )
+    assert detect_reasoning_channel_markers(NamedTemplateTokenizer(), tools = []) is None
+    assert (
+        detect_reasoning_channel_markers(
+            NamedTemplateProcessor(), tools = [{"function": {"name": "web_search"}}]
+        )
+        is None
+    )
+    assert detect_reasoning_channel_markers(TokenMetadataOnly()) is None
+
+
+def test_gemma_channel_detection_tries_no_argument_getter_fallback():
+    class FallbackTokenizer:
+        chat_template = "plain fallback template"
+
+        def get_chat_template(self, **kwargs):
+            if kwargs:
+                raise ValueError("tools are not supported")
+            return "...<|channel>thought\n<channel|>"
+
+    assert detect_reasoning_channel_markers(
+        FallbackTokenizer(), tools = [{"function": {"name": "web_search"}}]
+    ) == ("<|channel>thought", "<channel|>")
+
+
+def test_native_template_fallback_returns_selected_reasoning_metadata():
+    from types import SimpleNamespace
+
+    messages = [{"role": "user", "content": "hi"}]
+    tools = [{"type": "function", "function": {"name": "web_search"}}]
+
+    def render(tokenizer, msgs, *, tools, **_kw):
+        body = "".join(message["content"] for message in msgs)
+        suffix = "|TOOLS" if tools else ""
+        return body + suffix if tokenizer.chat_template == "NATIVE <|channel>thought\n" else body
+
+    result = render_with_native_template_fallback(
+        formatted_prompt = "hi",
+        tokenizer = SimpleNamespace(chat_template = "OVERRIDE"),
+        model_info = {
+            "native_chat_template": "NATIVE <|channel>thought\n",
+            "tokenizer": SimpleNamespace(chat_template = "OVERRIDE"),
+        },
+        active_model_name = "gemma-test",
+        messages = messages,
+        tools = tools,
+        apply_fn = render,
+        return_metadata = True,
+    )
+
+    assert result.prompt == "hi|TOOLS"
+    assert result.reasoning_channel_markers == ("<|channel>thought", "<channel|>")
+
+
+def test_cached_native_template_metadata_recovers_reasoning_markers_without_tools():
+    from types import SimpleNamespace
+
+    model_info = {"chat_template_info": {"template": "native <|channel>thought\n<channel|>"}}
+
+    assert detect_reasoning_channel_markers_from_model_info(
+        SimpleNamespace(chat_template = "override has no native markers"),
+        model_info,
+        tools = None,
+    ) == ("<|channel>thought", "<channel|>")
+    result = render_with_native_template_fallback(
+        formatted_prompt = "prompt from override",
+        tokenizer = SimpleNamespace(chat_template = "override has no native markers"),
+        model_info = model_info,
+        active_model_name = "gemma-test",
+        messages = [{"role": "user", "content": "hi"}],
+        tools = None,
+        return_metadata = True,
+    )
+    assert result.prompt == "prompt from override"
+    assert result.reasoning_channel_markers == ("<|channel>thought", "<channel|>")
+
+
+def test_cached_native_markers_do_not_describe_live_tool_template():
+    from types import SimpleNamespace
+
+    tools = [{"type": "function", "function": {"name": "web_search"}}]
+
+    class LiveTokenizer:
+        chat_template = "live tool template without native markers"
+
+    def render(_tokenizer, _messages, *, tools, **_kwargs):
+        return "prompt with tools" if tools else "prompt without tools"
+
+    result = render_with_native_template_fallback(
+        formatted_prompt = "prompt with tools",
+        tokenizer = LiveTokenizer(),
+        model_info = {
+            "chat_template_info": {"template": "native <|channel>thought\n<channel|>"},
+            "tokenizer": SimpleNamespace(),
+        },
+        active_model_name = "gemma-test",
+        messages = [{"role": "user", "content": "hi"}],
+        tools = tools,
+        apply_fn = render,
+        return_metadata = True,
+    )
+
+    assert result.prompt == "prompt with tools"
+    assert result.reasoning_channel_markers is None
+
+
+def test_gemma_channel_normalization_is_prefix_monotonic_and_preserves_tools():
+    parser = ReasoningChannelNormalizer("<|channel>thought", "<channel|>")
+    output = ""
+    snapshots = []
+    for chunk in (
+        "<|chan",
+        "nel>thought",
+        "\nReason",
+        "<chan",
+        "nel|><|tool_call>web_search<tool_call|>",
+    ):
+        delta = parser.feed(chunk)
+        if delta:
+            output += delta
+            snapshots.append(output)
+
+    assert snapshots == [
+        "<think>",
+        "<think>Reason",
+        "<think>Reason</think><|tool_call>web_search<tool_call|>",
+    ]
+    assert snapshots[1].startswith(snapshots[0])
+    compact = ReasoningChannelNormalizer("<|channel>thought", "<channel|>")
+    assert compact.feed("<|channel>thought<channel|>answer") + compact.finish() == (
+        "<think></think>answer"
+    )
diff --git a/studio/backend/tests/test_tool_confirm_stream.py b/studio/backend/tests/test_tool_confirm_stream.py
index b8e0472e12..0813f6b68d 100644
--- a/studio/backend/tests/test_tool_confirm_stream.py
+++ b/studio/backend/tests/test_tool_confirm_stream.py
@@ -3,12 +3,12 @@
 
 """End-to-end handshake test for the tool-confirmation gate, no model.
 
-The real Studio stream wrappers in ``routes/inference.py`` drive the
+The real Unsloth stream wrappers in ``routes/inference.py`` drive the
 synchronous agentic generator with ``await asyncio.to_thread(next, gen,
 ...)`` so the blocking ``threading.Event`` wait runs off the event loop.
 This test rebuilds that exact pattern around the real
 ``state.tool_approvals`` functions, served by a real uvicorn process on
-loopback (the same server Studio uses), and proves the load-bearing
+loopback (the same server Unsloth uses), and proves the load-bearing
 property:
 
 * ``tool_start`` reaches the client before the gate blocks, and
diff --git a/studio/backend/tests/test_tool_message_empty_content.py b/studio/backend/tests/test_tool_message_empty_content.py
index d63b16ce80..636a35f5a9 100644
--- a/studio/backend/tests/test_tool_message_empty_content.py
+++ b/studio/backend/tests/test_tool_message_empty_content.py
@@ -4,7 +4,7 @@
 """Empty ``role="tool"`` content must be accepted on the OpenAI-compat surface.
 
 Agentic clients send ``content: ""`` when a command produced no output;
-OpenAI and llama-server both accept it. Studio used to 400, which standard
+OpenAI and llama-server both accept it. Unsloth used to 400, which standard
 clients treat as non-retryable and kill the session. The validator must
 normalize empty/missing tool content to ``""`` instead of raising.
 """
diff --git a/studio/backend/tests/test_tp_vision_regression.py b/studio/backend/tests/test_tp_vision_regression.py
index 09af876da6..d1372ca415 100644
--- a/studio/backend/tests/test_tp_vision_regression.py
+++ b/studio/backend/tests/test_tp_vision_regression.py
@@ -126,10 +126,21 @@ _ALLOWED_TP_DROP_GUARDS = {
     # Capability: --split-mode tensor aborted for this (binary, model) (#6415).
     # Self-healing -- tried by default, skipped only after a real abort (vs #6416).
     "tensor_parallel and self._tensor_split_aborts(binary, model_identifier)",
-    # Capacity: tensor needs >= 2 GPUs clearing the compute-buffer reserve.
-    "tensor_parallel and len(tp_gpus) < 2",
+    # Capacity: tensor needs >= 2 GPUs clearing the compute-buffer reserve. Gated
+    # on plan_tp (not raw tensor_parallel) so manual mode skips this planner (#6414).
+    "plan_tp and len(tp_gpus) < 2",
     # Capacity: pooled usable VRAM can't hold weights + MTP reserve -> layer split.
     "_tp_weight_budget_mib <= _tp_required_mib",
+    # Manual mode, Auto layers: --fit owns memory and is incompatible with a
+    # tensor split, so TP is dropped (surfaced via logger.info) before the
+    # cache-drop, so a quantized KV survives into the --fit load (#6414).
+    "tensor_parallel and gpu_memory_mode == 'manual' and (gpu_layers < 0)",
+    # Manual mode, explicit layers: a tensor split still needs >= 2 GPUs in use.
+    "tensor_parallel and gpu_memory_mode == 'manual' and (gpu_layers >= 0) and (self._effective_gpu_count(sorted(gpu_ids) if gpu_ids else None) < 2)",
+    # Manual mode, zero layers: nothing to split on the GPU, and a tensor-mode
+    # launch under the CPU-only GPU mask (no visible devices) aborts the server
+    # instead of the intended CPU-only load (#6414).
+    "gpu_memory_mode == 'manual' and gpu_layers == 0",
 }
 
 
@@ -364,7 +375,7 @@ def test_compute_buffer_downgrade_preserves_multi_gpu_intent():
     full GPU set too, so it is symmetric with the budget/geometry downgrades and
     doesn't collapse a multi-GPU layer load to one card (reviewer.py P1 on #6659)."""
     src = inspect.getsource(LlamaCppBackend.load_model)
-    gate = src.find("tensor_parallel and len(tp_gpus) < 2")
+    gate = src.find("plan_tp and len(tp_gpus) < 2")
     assert gate != -1
     # Bound to exactly this block: from its gate to the next (budget) downgrade.
     nxt = src.find("_tp_weight_budget_mib <= _tp_required_mib", gate)
@@ -625,7 +636,7 @@ def _fallback_loaded_backend(layer_preserves_tensor_intent: bool) -> LlamaCppBac
 
 
 def test_tensor_off_echo_preserves_multi_gpu_fallback():
-    """The Studio UI always sends tensor_parallel and echoes the /load response's
+    """The Unsloth UI always sends tensor_parallel and echoes the /load response's
     resolved value, so after a fallback a ctx/settings reload carries tensor_parallel=
     false even though the user never changed it. That echo must NOT collapse the
     preserved multi-GPU placement -- it dedupes (Codex #6659)."""
diff --git a/studio/backend/tests/test_trained_model_scan.py b/studio/backend/tests/test_trained_model_scan.py
index 7bf572e214..64228cec3c 100644
--- a/studio/backend/tests/test_trained_model_scan.py
+++ b/studio/backend/tests/test_trained_model_scan.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Tests for Studio trained-model discovery used by Chat."""
+"""Tests for Unsloth trained-model discovery used by Chat."""
 
 import json
 from pathlib import Path
@@ -97,6 +97,7 @@ def test_lora_identifier_resolves_remote_adapter_base(tmp_path: Path):
         repo,
         fn,
         token = None,
+        cache_dir = None,
     ):
         assert repo == "someone/my-remote-lora"
         assert fn == "adapter_config.json"
@@ -128,6 +129,7 @@ def test_lora_identifier_retries_transient_then_resolves(tmp_path: Path):
         repo,
         fn,
         token = None,
+        cache_dir = None,
     ):
         calls["n"] += 1
         if calls["n"] == 1:
diff --git a/studio/backend/tests/test_training_config_popover_source.py b/studio/backend/tests/test_training_config_popover_source.py
new file mode 100644
index 0000000000..452a3a1ea8
--- /dev/null
+++ b/studio/backend/tests/test_training_config_popover_source.py
@@ -0,0 +1,110 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Source-level regression guards for the Training Config popover data source
+(#6853).
+
+The live Training Progress popover used to read the editable form store
+(useTrainingConfigStore) while a run was active, so it showed stale/static
+values whenever the user touched the form after starting the run; only the
+History view read the run's saved config snapshot. These guards pin the fixed
+wiring: both views feed ProgressSection a config override mapped from
+GET /api/train/runs/{id}, and ProgressSection prefers that override whenever
+one is present -- not only for historical views.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+_STUDIO_FRONTEND = Path(__file__).resolve().parents[2] / "frontend" / "src" / "features" / "studio"
+
+
+def _read(rel: str) -> str:
+    return (_STUDIO_FRONTEND / rel).read_text(encoding = "utf-8")
+
+
+def test_progress_section_prefers_override_over_form_store():
+    src = _read("sections/progress-section.tsx")
+    # Fields key on the override's presence, not isHistorical: a live view passing
+    # an override wins over the store; without one, live keeps the store while
+    # History shows blanks rather than unrelated live form values.
+    assert "const cfg = configOverride ?? (isHistorical ? undefined : config)" in src
+    assert "const cfgEpochs = cfg?.epochs" in src
+    assert "isHistorical ? configOverride?.epochs" not in src
+
+
+def test_live_view_fetches_the_active_run_config():
+    src = _read("live-training-view.tsx")
+    # Live view resolves the run's saved config snapshot by job id...
+    assert "getTrainingRun(" in src
+    assert "mapRunConfigToOverride(" in src
+    # ...and hands it to the popover.
+    assert "configOverride={runConfigOverride}" in src
+
+
+def test_live_view_fetches_as_soon_as_the_job_id_exists():
+    # start_training() inserts the run row BEFORE the pump consumes any event, so
+    # the saved config is available during configuring/loading/downloading. The
+    # job id is therefore the whole readiness condition: gating on a first step
+    # or a terminal phase would show the wrong config for the entire pre-step
+    # window of a long load, or for a run adopted from another client.
+    src = _read("live-training-view.tsx")
+    assert "if (!runtime.jobId) {" in src
+    assert "[runtime.jobId, fetchedRunConfig, fetchAttempt]" in src
+    # No step/phase readiness gate may creep back in.
+    assert "runRowReady" not in src
+
+
+def test_live_view_retries_the_transient_row_miss():
+    # start_training() creates the row before the pump, but a lookup racing that
+    # commit can still 404. Nothing else in the effect deps changes on failure, so
+    # the retry must be explicit and bounded, else a genuinely absent row would
+    # poll forever instead of falling back to the form store.
+    src = _read("live-training-view.tsx")
+    assert "RUN_CONFIG_FETCH_RETRIES" in src
+    assert "RUN_CONFIG_FETCH_RETRY_MS" in src
+    assert "setFetchAttempt(" in src
+    assert "attempts >= RUN_CONFIG_FETCH_RETRIES" in src
+    # The budget is keyed by job so a new run always starts fresh.
+    assert "fetchAttempt?.jobId === jobId ? fetchAttempt.count : 0" in src
+    # The pending retry must be cancelled with the effect.
+    assert "clearTimeout(retryTimer)" in src
+
+
+def test_live_view_prefers_saved_training_method():
+    # The method label / LoRA-row visibility must come from the run snapshot,
+    # not the editable form (which may have changed since the run started).
+    src = _read("live-training-view.tsx")
+    assert "runConfigOverride?.trainingMethod ?? config.trainingMethod" in src
+
+
+def test_history_view_uses_the_shared_mapper():
+    src = _read("historical-training-view.tsx")
+    # Shared mapper, not a re-inlined field-by-field copy that could drift.
+    assert "mapRunConfigToOverride(detail.config)" in src
+    assert "num_epochs" not in src
+
+
+def test_shared_mapper_matches_backend_config_keys():
+    src = _read("sections/run-config-override.ts")
+    # The mapper reads the run config JSON the backend snapshots at job start;
+    # keep the key set pinned so a silent rename breaks loudly here.
+    for key in (
+        "training_type",
+        "load_in_4bit",
+        "num_epochs",
+        "batch_size",
+        "learning_rate",
+        "max_steps",
+        "max_seq_length",
+        "warmup_steps",
+        "optim",
+        "lora_r",
+        "lora_alpha",
+        "lora_dropout",
+        "use_rslora",
+        "use_loftq",
+        "use_dora",
+    ):
+        assert key in src, f"run-config mapper lost backend key {key}"
diff --git a/studio/backend/tests/test_training_nan_loss_handling.py b/studio/backend/tests/test_training_nan_loss_handling.py
index a2dc78bee2..5a477a084d 100644
--- a/studio/backend/tests/test_training_nan_loss_handling.py
+++ b/studio/backend/tests/test_training_nan_loss_handling.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 
-"""Pin Studio's behavior when a training event reports non-finite (NaN/Inf) loss.
+"""Pin Unsloth's behavior when a training event reports non-finite (NaN/Inf) loss.
 
 The training event handler used to filter NaN/Inf to None silently while
 leaving the previous finite loss in progress.loss — so the API kept reporting
diff --git a/studio/backend/tests/test_training_pump_resilience.py b/studio/backend/tests/test_training_pump_resilience.py
index d75b205f35..e7e47478b5 100644
--- a/studio/backend/tests/test_training_pump_resilience.py
+++ b/studio/backend/tests/test_training_pump_resilience.py
@@ -310,6 +310,80 @@ def test_pump_finalizes_when_read_keeps_raising_on_dead_worker(monkeypatch):
     assert b._pump_running is False
 
 
+def test_interrupted_cancel_clears_in_memory_output_dir(monkeypatch):
+    # Stop-without-save interrupted before its complete event: /status must not
+    # keep serving the cleared run's output_dir.
+    b = TrainingBackend()
+    finalized: dict = {}
+    monkeypatch.setattr(b, "_ensure_db_run_created", lambda: None)
+    monkeypatch.setattr(b, "_finalize_run_in_db", lambda **kw: finalized.update(kw))
+
+    b._proc = _FakeProc(alive = False)
+    b._event_queue = _IdleQueue()
+    b._progress.is_training = True
+    b._should_stop = True
+    b._cancel_requested = True
+    b._output_dir = "/out/x"
+
+    b._pump_loop()
+
+    assert b._output_dir is None
+    assert finalized.get("status") == "stopped"
+    assert finalized.get("output_dir") is None
+    assert finalized.get("clear_output_dir") is True
+
+
+def test_worker_exit_reuses_terminal_stop_save_error(monkeypatch):
+    b = TrainingBackend()
+    finalized: dict = {}
+    monkeypatch.setattr(b, "_ensure_db_run_created", lambda: None)
+    monkeypatch.setattr(b, "_finalize_run_in_db", lambda **kw: finalized.update(kw))
+
+    b._proc = _FakeProc(alive = False)
+    b._event_queue = _IdleQueue()
+    b._progress.is_training = True
+    b._should_stop = True
+    b._cancel_requested = False
+    b._output_dir = "/out/x"
+    b.current_job_id = "job-x"
+    b._terminal_finalize_payload = {
+        "status": "error",
+        "error_message": "checkpoint failed",
+        "output_dir": "/out/x",
+        "clear_output_dir": False,
+        "resume_blocked": True,
+        "expected_job_id": "job-x",
+    }
+
+    b._pump_loop()
+
+    assert b._output_dir == "/out/x"
+    assert finalized.get("status") == "error"
+    assert finalized.get("output_dir") == "/out/x"
+    assert finalized.get("clear_output_dir") is False
+    assert finalized.get("resume_blocked") is True
+
+
+def test_dead_worker_crash_preserves_output_dir(monkeypatch):
+    # A crash (no stop requested) after output_dir was emitted must keep the dir
+    # in the error finalize: checkpoints under it may still exist.
+    b = TrainingBackend()
+    finalized: dict = {}
+    monkeypatch.setattr(b, "_ensure_db_run_created", lambda: None)
+    monkeypatch.setattr(b, "_finalize_run_in_db", lambda **kw: finalized.update(kw))
+
+    b._proc = _FakeProc(alive = False)
+    b._event_queue = _IdleQueue()
+    b._progress.is_training = True
+    b._output_dir = "/out/x"
+
+    b._pump_loop()
+
+    assert finalized.get("status") == "error"
+    assert finalized.get("output_dir") == "/out/x"
+    assert finalized.get("clear_output_dir") is False
+
+
 def test_start_training_clears_stale_pump_running_flag():
     # A prior pump that died abnormally leaves _pump_running True. The next
     # start_training must clear it during reset so the start-time watchdog can't
@@ -492,3 +566,34 @@ def test_db_run_created_before_pump_consumes_events(monkeypatch):
     # The pump observed an already-created run; it would be False if the pump
     # were started before the eager create.
     assert seen["db_created"] is True
+
+
+def test_startup_flag_reports_training_active_before_proc():
+    # Between freeing VRAM and _proc going live, a concurrent STT load must see
+    # training as active so it does not grab the just-freed GPU.
+    b = TrainingBackend()
+    b._spawn_in_progress = True
+    assert b.is_training_active() is True
+
+
+def test_before_spawn_runs_inside_active_window(monkeypatch):
+    # The VRAM-freeing hook must run while training already counts as active, or
+    # an STT load racing it would place Whisper back on the freed GPU.
+    b = TrainingBackend()
+    _stub_spawn(monkeypatch)
+    monkeypatch.setattr(b, "_ensure_db_run_created", lambda: None)
+    monkeypatch.setattr(b, "_pump_loop", lambda: setattr(b, "_pump_running", False))
+
+    active_during_free = {}
+
+    def before_spawn():
+        active_during_free["value"] = b.is_training_active()
+
+    assert b.start_training("job_active_window", model_name = "m", before_spawn = before_spawn) is True
+    if b._pump_thread is not None:
+        b._pump_thread.join(timeout = 2.0)
+
+    assert active_during_free["value"] is True
+    # The transient flag clears, but the live proc keeps training active.
+    assert b._spawn_in_progress is False
+    assert b.is_training_active() is True
diff --git a/studio/backend/tests/test_training_resume.py b/studio/backend/tests/test_training_resume.py
index 91fdac9961..51425b0428 100644
--- a/studio/backend/tests/test_training_resume.py
+++ b/studio/backend/tests/test_training_resume.py
@@ -7,6 +7,9 @@ import importlib.util
 import json
 from pathlib import Path
 
+import pytest
+import torch
+
 
 _BACKEND = Path(__file__).resolve().parents[1]
 
@@ -25,6 +28,30 @@ def _load_resume_module():
 resume = _load_resume_module()
 
 
+def test_resume_request_accepts_sanitized_null_target_modules():
+    from models.training import TrainingStartRequest
+    request = TrainingStartRequest(
+        model_name = "unsloth/Qwen3-0.6B",
+        training_type = "Full Finetuning",
+        format_type = "alpaca",
+        target_modules = None,
+    )
+
+    assert request.target_modules == []
+
+
+def _write_checkpoint(out: Path, step: int) -> Path:
+    checkpoint = out / f"checkpoint-{step}"
+    checkpoint.mkdir(parents = True, exist_ok = True)
+    (checkpoint / "trainer_state.json").write_text(
+        json.dumps({"global_step": step}), encoding = "utf-8"
+    )
+    torch.save({"weight": torch.ones(1)}, checkpoint / "adapter_model.bin")
+    torch.save({"state": {0: torch.ones(1)}}, checkpoint / "optimizer.pt")
+    torch.save({"last_epoch": step}, checkpoint / "scheduler.pt")
+    return checkpoint
+
+
 def _stopped_run(**overrides):
     run = {
         "status": "stopped",
@@ -44,6 +71,36 @@ def test_can_resume_run_allows_checkpointed_non_s3_run(monkeypatch):
     assert resume.can_resume_run(_stopped_run()) is True
 
 
+def test_can_resume_run_allows_errored_run_with_checkpoint(monkeypatch):
+    monkeypatch.setattr(resume, "has_resume_state", lambda _path: True)
+
+    assert resume.can_resume_run(_stopped_run(status = "error")) is True
+
+
+def test_can_resume_run_rejects_errored_run_without_checkpoint(monkeypatch):
+    monkeypatch.setattr(resume, "has_resume_state", lambda _path: False)
+
+    assert resume.can_resume_run(_stopped_run(status = "error")) is False
+
+
+def test_can_resume_run_allows_errored_run_at_final_step(monkeypatch):
+    # A save-time crash records final_step == total_steps; resuming re-runs the
+    # final-save path from the checkpoint.
+    monkeypatch.setattr(resume, "has_resume_state", lambda _path: True)
+
+    run = _stopped_run(status = "error", final_step = 10, total_steps = 10)
+
+    assert resume.can_resume_run(run) is True
+
+
+def test_can_resume_run_rejects_stopped_run_at_final_step(monkeypatch):
+    monkeypatch.setattr(resume, "has_resume_state", lambda _path: True)
+
+    run = _stopped_run(final_step = 10, total_steps = 10)
+
+    assert resume.can_resume_run(run) is False
+
+
 def test_can_resume_run_rejects_s3_dataset_source(monkeypatch):
     monkeypatch.setattr(resume, "has_resume_state", lambda _path: True)
 
@@ -91,3 +148,444 @@ def test_list_runs_includes_config_json_for_resume_policy(monkeypatch, tmp_path)
     result = studio_db.list_runs()
 
     assert result["runs"][0]["config_json"] == config_json
+
+
+def test_crashed_run_with_persisted_output_dir_is_resumable(monkeypatch, tmp_path):
+    from storage import studio_db
+
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    monkeypatch.setattr(studio_db, "_schema_ready", False)
+
+    out = tmp_path / "outputs" / "run_x"
+    _write_checkpoint(out, 10)
+
+    studio_db.create_run(
+        id = "run-crash",
+        model_name = "m",
+        dataset_name = "d",
+        config_json = "{}",
+        started_at = "2026-01-01T00:00:00Z",
+        total_steps = 20,
+    )
+    studio_db.update_run_output_dir("run-crash", str(out))
+    conn = studio_db.get_connection()
+    conn.execute("UPDATE training_runs SET status = 'error' WHERE id = 'run-crash'")
+    conn.commit()
+    conn.close()
+
+    run = studio_db.get_run("run-crash")
+    assert run["output_dir"] == str(out)
+    assert resume.can_resume_run(run) is True
+
+
+def test_checkpoint_discovery_skips_malformed_newest(monkeypatch, tmp_path):
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    out = tmp_path / "outputs" / "run_x"
+    valid = _write_checkpoint(out, 5)
+    (_write_checkpoint(out, 8) / "scheduler.pt").unlink()
+    malformed = out / "checkpoint-10"
+    malformed.mkdir()
+    (malformed / "trainer_state.json").write_text(json.dumps({"global_step": 10}), encoding = "utf-8")
+    (malformed / "adapter_model.bin").write_bytes(b"not a torch archive")
+    (malformed / "optimizer.pt").write_bytes(b"not a torch archive")
+
+    assert resume.get_resume_checkpoint_path(str(out)) == str(valid)
+
+
+def test_completed_run_keeps_output_dir_and_rejects_stale_cancel(monkeypatch, tmp_path):
+    from storage import studio_db
+
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    monkeypatch.setattr(studio_db, "_schema_ready", False)
+
+    studio_db.create_run(
+        id = "r",
+        model_name = "m",
+        dataset_name = "d",
+        config_json = "{}",
+        started_at = "2026-01-01T00:00:00Z",
+        total_steps = 10,
+    )
+    studio_db.update_run_output_dir("r", "/out/x")
+    studio_db.finish_run(
+        id = "r",
+        status = "completed",
+        ended_at = "t",
+        final_step = 2,
+        final_loss = None,
+        duration_seconds = 1,
+        loss_sparkline = "[]",
+        output_dir = "/out/x",
+        error_message = None,
+    )
+
+    assert studio_db.get_run("r")["output_dir"] == "/out/x"
+    assert studio_db.mark_run_cancel_requested("r") is False
+    assert studio_db.get_run("r")["output_dir"] == "/out/x"
+    assert studio_db.get_run("r")["resume_blocked"] == 0
+
+
+def test_finish_run_clears_output_dir_for_stop_without_save(monkeypatch, tmp_path):
+    from storage import studio_db
+
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    monkeypatch.setattr(studio_db, "_schema_ready", False)
+
+    studio_db.create_run(
+        id = "r",
+        model_name = "m",
+        dataset_name = "d",
+        config_json = "{}",
+        started_at = "2026-01-01T00:00:00Z",
+        total_steps = 10,
+    )
+    studio_db.update_run_output_dir("r", "/out/x")
+    studio_db.finish_run(
+        id = "r",
+        status = "stopped",
+        ended_at = "t",
+        final_step = 2,
+        final_loss = None,
+        duration_seconds = 1,
+        loss_sparkline = "[]",
+        output_dir = None,
+        error_message = None,
+        clear_output_dir = True,
+    )
+
+    assert studio_db.get_run("r")["output_dir"] is None
+    conn = studio_db.get_connection()
+    conn.execute(
+        "UPDATE training_runs SET status = 'running', output_dir = '/out/x', resume_blocked = 0 WHERE id = 'r'"
+    )
+    conn.commit()
+    conn.close()
+    studio_db.mark_run_cancel_requested("r")
+    studio_db.cleanup_orphaned_runs()
+    assert studio_db.get_run("r")["status"] == "stopped"
+    assert studio_db.get_run("r")["output_dir"] is None
+
+
+def test_finish_run_clears_output_dir_on_cancel_error_finalize(monkeypatch, tmp_path):
+    from storage import studio_db
+
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    monkeypatch.setattr(studio_db, "_schema_ready", False)
+
+    studio_db.create_run(
+        id = "r",
+        model_name = "m",
+        dataset_name = "d",
+        config_json = "{}",
+        started_at = "2026-01-01T00:00:00Z",
+        total_steps = 10,
+    )
+    studio_db.update_run_output_dir("r", "/out/x")
+    studio_db.finish_run(
+        id = "r",
+        status = "stopped",
+        ended_at = "t",
+        final_step = 2,
+        final_loss = None,
+        duration_seconds = 1,
+        loss_sparkline = "[]",
+        output_dir = "/out/x",
+        error_message = "worker failed during cancel",
+        clear_output_dir = True,
+    )
+
+    assert studio_db.get_run("r")["output_dir"] is None
+
+
+def test_finish_run_preserves_output_dir_for_interrupted_stop_and_save(monkeypatch, tmp_path):
+    from storage import studio_db
+
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    monkeypatch.setattr(studio_db, "_schema_ready", False)
+
+    studio_db.create_run(
+        id = "r",
+        model_name = "m",
+        dataset_name = "d",
+        config_json = "{}",
+        started_at = "2026-01-01T00:00:00Z",
+        total_steps = 10,
+    )
+    studio_db.update_run_output_dir("r", "/out/x")
+    studio_db.finish_run(
+        id = "r",
+        status = "stopped",
+        ended_at = "t",
+        final_step = 2,
+        final_loss = None,
+        duration_seconds = 1,
+        loss_sparkline = "[]",
+        output_dir = None,
+        error_message = None,
+    )
+
+    assert studio_db.get_run("r")["output_dir"] == "/out/x"
+
+
+def test_resumed_errored_run_is_not_offered_again(monkeypatch, tmp_path):
+    from storage import studio_db
+
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    monkeypatch.setattr(studio_db, "_schema_ready", False)
+
+    out = tmp_path / "outputs" / "run_x"
+    _write_checkpoint(out, 10)
+
+    studio_db.create_run(
+        id = "run-old",
+        model_name = "m",
+        dataset_name = "d",
+        config_json = "{}",
+        started_at = "2026-01-01T00:00:00Z",
+        total_steps = 20,
+    )
+    studio_db.update_run_output_dir("run-old", str(out))
+    studio_db.finish_run(
+        id = "run-old",
+        status = "error",
+        ended_at = "2026-01-01T00:05:00Z",
+        final_step = 10,
+        final_loss = None,
+        duration_seconds = 1,
+        loss_sparkline = "[]",
+        output_dir = None,
+        error_message = "killed",
+    )
+    studio_db.create_run(
+        id = "run-new",
+        model_name = "m",
+        dataset_name = "d",
+        config_json = "{}",
+        started_at = "2026-01-02T00:00:00Z",
+        total_steps = 20,
+        output_dir = str(out),
+        resumed_from_run_id = "run-old",
+    )
+    with pytest.raises(RuntimeError, match = "no longer available"):
+        studio_db.create_run(
+            id = "run-duplicate",
+            model_name = "m",
+            dataset_name = "d",
+            config_json = "{}",
+            started_at = "2026-01-02T00:00:01Z",
+            total_steps = 20,
+            output_dir = str(out),
+            resumed_from_run_id = "run-old",
+        )
+    assert studio_db.get_run("run-duplicate") is None
+    studio_db.finish_run(
+        id = "run-new",
+        status = "error",
+        ended_at = "2026-01-02T00:05:00Z",
+        final_step = 15,
+        final_loss = None,
+        duration_seconds = 1,
+        loss_sparkline = "[]",
+        output_dir = None,
+        error_message = "killed again",
+    )
+
+    old_run = studio_db.get_run("run-old")
+    new_run = studio_db.get_run("run-new")
+    assert old_run["resumed_later"] == 1
+    assert resume.can_resume_run(old_run) is False
+    assert new_run["resumed_later"] == 0
+    assert resume.can_resume_run(new_run) is True
+    assert studio_db.get_resumable_run_by_output_dir(str(out))["id"] == "run-new"
+
+
+def test_running_continuation_blocks_older_resume(monkeypatch, tmp_path):
+    from storage import studio_db
+
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    monkeypatch.setattr(studio_db, "_schema_ready", False)
+
+    out = tmp_path / "outputs" / "run_x"
+    _write_checkpoint(out, 10)
+
+    studio_db.create_run(
+        id = "run-old",
+        model_name = "m",
+        dataset_name = "d",
+        config_json = "{}",
+        started_at = "2026-01-01T00:00:00Z",
+        total_steps = 20,
+    )
+    studio_db.update_run_output_dir("run-old", str(out))
+    studio_db.finish_run(
+        id = "run-old",
+        status = "error",
+        ended_at = "2026-01-01T00:05:00Z",
+        final_step = 10,
+        final_loss = None,
+        duration_seconds = 1,
+        loss_sparkline = "[]",
+        output_dir = None,
+        error_message = "killed",
+    )
+    studio_db.create_run(
+        id = "run-new",
+        model_name = "m",
+        dataset_name = "d",
+        config_json = "{}",
+        started_at = "2026-01-02T00:00:00Z",
+        total_steps = 20,
+        output_dir = str(out),
+        resumed_from_run_id = "run-old",
+    )
+
+    old_run = studio_db.get_run("run-old")
+    assert old_run["resumed_later"] == 1
+    assert resume.can_resume_run(old_run) is False
+    assert studio_db.get_resumable_run_by_output_dir(str(out)) is None
+
+
+def test_stop_save_checkpoint_failure_keeps_error_status(monkeypatch, tmp_path):
+    # A stop-and-save whose checkpoint write failed must finalize as an error so
+    # history explains the missing resume state (keep_error_status flag).
+    from core.training.training import TrainingBackend
+    from storage import studio_db
+
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    monkeypatch.setattr(studio_db, "_schema_ready", False)
+
+    studio_db.create_run(
+        id = "run-failed-save",
+        model_name = "m",
+        dataset_name = "d",
+        config_json = "{}",
+        started_at = "2026-01-01T00:00:00Z",
+        total_steps = 10,
+    )
+    backend = TrainingBackend()
+    backend.current_job_id = "run-failed-save"
+    backend._db_run_created = True
+    backend._should_stop = True
+    backend._handle_event(
+        {
+            "type": "error",
+            "error": "Failed to save a resumable checkpoint after stop.",
+            "keep_error_status": True,
+        }
+    )
+
+    run = studio_db.get_run("run-failed-save")
+    assert run["status"] == "error"
+    assert "resumable checkpoint" in run["error_message"]
+
+
+def test_can_resume_run_rejects_resume_blocked_run(monkeypatch):
+    monkeypatch.setattr(resume, "has_resume_state", lambda _path: True)
+
+    assert resume.can_resume_run(_stopped_run(status = "error", resume_blocked = 1)) is False
+
+
+def test_stop_save_checkpoint_failure_with_stale_checkpoint_is_not_resumable(monkeypatch, tmp_path):
+    # A failed stop-and-save must not offer Resume from an older periodic checkpoint;
+    # that would roll back past the recorded final step.
+    from core.training.training import TrainingBackend
+    from storage import studio_db
+
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    monkeypatch.setattr(studio_db, "_schema_ready", False)
+
+    out = tmp_path / "outputs" / "run_x"
+    _write_checkpoint(out, 10)
+
+    studio_db.create_run(
+        id = "run-stale-ckpt",
+        model_name = "m",
+        dataset_name = "d",
+        config_json = "{}",
+        started_at = "2026-01-01T00:00:00Z",
+        total_steps = 20,
+    )
+    studio_db.update_run_output_dir("run-stale-ckpt", str(out))
+    backend = TrainingBackend()
+    backend.current_job_id = "run-stale-ckpt"
+    backend._db_run_created = True
+    backend._should_stop = True
+    backend._output_dir = str(out)
+    backend._handle_event(
+        {
+            "type": "error",
+            "error": "Failed to save a resumable checkpoint after stop.",
+            "keep_error_status": True,
+            "resume_blocked": True,
+        }
+    )
+
+    run = studio_db.get_run("run-stale-ckpt")
+    assert run["status"] == "error"
+    assert run["resume_blocked"] == 1
+    assert run["output_dir"] == str(out)
+    assert resume.can_resume_run(run) is False
+
+
+def test_user_stop_error_without_checkpoint_ack_is_blocked(monkeypatch, tmp_path):
+    from core.training.training import TrainingBackend
+    from storage import studio_db
+
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    monkeypatch.setattr(studio_db, "_schema_ready", False)
+
+    studio_db.create_run(
+        id = "run-user-stop",
+        model_name = "m",
+        dataset_name = "d",
+        config_json = "{}",
+        started_at = "2026-01-01T00:00:00Z",
+        total_steps = 10,
+    )
+    backend = TrainingBackend()
+    backend.current_job_id = "run-user-stop"
+    backend._db_run_created = True
+    backend._should_stop = True
+    backend._handle_event({"type": "error", "error": "interrupted"})
+
+    run = studio_db.get_run("run-user-stop")
+    assert run["status"] == "error" and run["resume_blocked"] == 1
+
+
+def test_terminal_fallback_keeps_resumable_when_current_checkpoint_landed(monkeypatch, tmp_path):
+    # Worker died before its terminal event, but a valid current-step checkpoint
+    # is on disk: the fallback must keep the run resumable, not block it.
+    from core.training.training import TrainingBackend
+
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    out = tmp_path / "outputs" / "run_ok"
+    _write_checkpoint(out, 7)
+
+    backend = TrainingBackend()
+    backend.current_job_id = "run-ok"
+    backend._should_stop = True
+    backend._output_dir = str(out)
+    backend._progress.step = 7
+
+    kwargs = backend._terminal_finalize_kwargs()
+    assert kwargs["status"] == "stopped"
+    assert kwargs["resume_blocked"] is False
+
+
+def test_terminal_fallback_blocks_when_no_current_checkpoint(monkeypatch, tmp_path):
+    # Same path, but only a stale (older-step) checkpoint exists: must block.
+    from core.training.training import TrainingBackend
+
+    monkeypatch.setenv("UNSLOTH_STUDIO_HOME", str(tmp_path))
+    out = tmp_path / "outputs" / "run_stale"
+    _write_checkpoint(out, 5)
+
+    backend = TrainingBackend()
+    backend.current_job_id = "run-stale"
+    backend._should_stop = True
+    backend._output_dir = str(out)
+    backend._progress.step = 7
+
+    kwargs = backend._terminal_finalize_kwargs()
+    assert kwargs["status"] == "error"
+    assert kwargs["resume_blocked"] is True
diff --git a/studio/backend/tests/test_training_stop_watchdog.py b/studio/backend/tests/test_training_stop_watchdog.py
index 457dfc8ea2..cbe2082e82 100644
--- a/studio/backend/tests/test_training_stop_watchdog.py
+++ b/studio/backend/tests/test_training_stop_watchdog.py
@@ -258,15 +258,27 @@ def test_watchdog_no_op_when_worker_superseded(monkeypatch):
 def test_new_run_gets_its_own_watchdog(monkeypatch):
     # A stale watchdog sleeping on an old proc must not stop a new run's stop from
     # creating its own watcher.
-    monkeypatch.setitem(_G, "_STOP_GRACE_S", 100.0)
-    monkeypatch.setitem(_G, "_STOP_TIMEOUT_S", 100.0)
     b = TrainingBackend()
-    _record_force_terminate(monkeypatch, b)
+    started = []
+    release = threading.Event()
+
+    def _blocked_watchdog(
+        target_proc,
+        cancel,
+        watched_job_id = None,
+    ):
+        started.append(target_proc)
+        # No timeout: the finally always releases this, so a superseded watchdog stays
+        # alive through the assertions regardless of load; as a daemon it can't hang exit.
+        release.wait()
+
+    monkeypatch.setattr(b, "_stop_watchdog_loop", _blocked_watchdog)
 
     old_proc = _FakeProc(alive = True)
     b._proc = old_proc
     b._start_stop_watchdog(cancel = False)
     first_wd = b._stop_watchdog
+    assert _wait_until(lambda: started == [old_proc])
 
     # New run: fresh worker replaces the handle; its stop must get a new watcher
     # even though the old (superseded) watchdog is still alive.
@@ -276,12 +288,12 @@ def test_new_run_gets_its_own_watchdog(monkeypatch):
     second_wd = b._stop_watchdog
 
     try:
+        assert _wait_until(lambda: started == [old_proc, new_proc])
         assert first_wd.is_alive()
         assert second_wd is not first_wd, "a new run must get its own watchdog"
         assert b._stop_watchdog_proc is new_proc
     finally:
-        old_proc._alive = False
-        new_proc._alive = False
+        release.set()
         first_wd.join(timeout = 5)
         second_wd.join(timeout = 5)
 
@@ -341,7 +353,7 @@ def test_finalize_after_escalation_clears_state(monkeypatch):
     # stopped so the UI leaves "Stopping..." and a new run can start.
     b = TrainingBackend()
     finstop: list = []
-    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a: finstop.append(a))
+    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a, **k: finstop.append(a))
 
     b._proc = _FakeProc(alive = True)  # wedged: still reports alive
     b._should_stop = True
@@ -353,7 +365,7 @@ def test_finalize_after_escalation_clears_state(monkeypatch):
 
     assert b._proc is None, "the wedged handle must be dropped so is_training_active clears"
     assert b._progress.is_training is False
-    assert b._progress.status_message == "Training stopped."
+    assert "valid current-step checkpoint" in b._progress.status_message
     assert finstop and finstop[0][0] == "job_c", "the captured run must be finalized by id"
     assert b.is_training_active() is False
 
@@ -363,7 +375,7 @@ def test_finalize_after_escalation_preserves_output_dir(monkeypatch):
     # must record it even if the watchdog wins the finalize race against the pump.
     b = TrainingBackend()
     finstop: list = []
-    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a: finstop.append(a))
+    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a, **k: finstop.append(a))
 
     b._proc = _FakeProc(alive = True)
     b._should_stop = True
@@ -378,6 +390,28 @@ def test_finalize_after_escalation_preserves_output_dir(monkeypatch):
     assert finstop[0][1] == "/tmp/outputs/run-123"
 
 
+def test_finalize_after_escalation_clears_output_dir_on_cancel(monkeypatch):
+    # Stop-without-saving promises no resume: a cancel that escalates through the
+    # watchdog clears the persisted output_dir, not a checkpoint path.
+    b = TrainingBackend()
+    finstop: list = []
+    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a, **k: finstop.append((a, k)))
+
+    b._proc = _FakeProc(alive = True)
+    b._should_stop = True
+    b._cancel_requested = True
+    b.current_job_id = "job_c"
+    b._db_run_created = True
+    b._output_dir = "/tmp/outputs/run-123"
+
+    b._finalize_stopped_after_escalation(watched_job_id = "job_c")
+
+    assert finstop and finstop[0][0][0] == "job_c"
+    assert finstop[0][0][1] is None, "a cancelled run must not record a checkpoint path"
+    assert finstop[0][1].get("clear_output_dir") is True
+    assert b._output_dir is None, "/status must stop exposing the cancelled run's dir"
+
+
 def test_stop_training_starts_watchdog_only_when_worker_alive(monkeypatch):
     # No worker -> nothing to escalate; the watchdog must not spawn.
     b = TrainingBackend()
@@ -397,7 +431,7 @@ def test_finalize_after_escalation_no_ops_when_superseded(monkeypatch):
     # The escalation finalize must then leave the NEW run untouched, not drop its handle.
     b = TrainingBackend()
     finstop: list = []
-    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a: finstop.append(a))
+    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a, **k: finstop.append(a))
 
     old_proc = _FakeProc(alive = False)  # force-terminated worker we were watching
     new_proc = _FakeProc(alive = True)  # a new run already took over
@@ -418,7 +452,7 @@ def test_finalize_after_escalation_runs_for_its_own_worker(monkeypatch):
     # finalizes the captured run by id.
     b = TrainingBackend()
     finstop: list = []
-    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a: finstop.append(a))
+    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a, **k: finstop.append(a))
 
     proc = _FakeProc(alive = False)
     b._proc = proc
@@ -439,7 +473,7 @@ def test_finalize_after_escalation_no_ops_on_job_change_during_startup(monkeypat
     # catch this even though the proc-only guard would not.
     b = TrainingBackend()
     finstop: list = []
-    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a: finstop.append(a))
+    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a, **k: finstop.append(a))
 
     old_proc = _FakeProc(alive = False)  # old worker, dead; new _proc not installed yet
     b._proc = old_proc  # still the old handle (== target), so proc guard would pass
@@ -497,6 +531,7 @@ def _install_fake_db(monkeypatch):
         recs["insert_ids"].append(job_id),
     )
     fake_db.update_run_progress = lambda **kw: recs["progress_ids"].append(kw.get("id"))
+    fake_db.mark_run_cancel_requested = lambda _run_id: True
     fake_storage.studio_db = fake_db
     monkeypatch.setitem(sys.modules, "storage", fake_storage)
     monkeypatch.setitem(sys.modules, "storage.studio_db", fake_db)
@@ -506,9 +541,48 @@ def _install_fake_db(monkeypatch):
     return recs
 
 
+def test_stop_without_save_creates_missing_row_before_signal(monkeypatch):
+    recs = _install_fake_db(monkeypatch)
+    b = TrainingBackend()
+    b.current_job_id, b._db_config = "job_missing", {"model_name": "m"}
+    b._stop_queue = queue.Queue()
+    assert b.stop_training(save = False) is True
+    assert [run["id"] for run in recs["created"]] == ["job_missing"]
+    assert b._stop_queue.get_nowait() == {"type": "stop", "save": False}
+
+    b._cancel_requested = b._should_stop = False
+    sys.modules["storage.studio_db"].mark_run_cancel_requested = lambda _run_id: False
+    assert b.stop_training(save = False) is False
+    assert not b._cancel_requested and b._stop_queue.empty()
+
+    new_queue = queue.Queue()
+    b.current_job_id, b._db_run_created = "job_old", True
+    b._cancel_requested = b._should_stop = False
+
+    def _supersede(_run_id):
+        b.current_job_id = "job_new"
+        b._stop_queue = new_queue
+        return True
+
+    sys.modules["storage.studio_db"].mark_run_cancel_requested = _supersede
+    assert b.stop_training(save = False) is False
+    assert not b._cancel_requested and new_queue.empty()
+
+
 def test_finalize_run_in_db_single_winner_under_concurrency(monkeypatch):
     # The watchdog and pump can both finalize; only one call may reach finish_run.
     recs = _install_fake_db(monkeypatch)
+    monkeypatch.setitem(_G, "_DB_FINALIZE_RETRY_S", 0.0)
+    attempts = 0
+
+    def flaky_finish(**kw):
+        nonlocal attempts
+        attempts += 1
+        if attempts < 3:
+            raise RuntimeError("database is locked")
+        recs["finished"].append(kw)
+
+    sys.modules["storage.studio_db"].finish_run = flaky_finish
     b = TrainingBackend()
     b.current_job_id = "job_x"
     b._db_run_created = True
@@ -527,6 +601,7 @@ def test_finalize_run_in_db_single_winner_under_concurrency(monkeypatch):
         t.join(timeout = 5)
 
     assert len(recs["finished"]) == 1, f"finalize must run once, got {len(recs['finished'])}"
+    assert attempts == 3
     assert b._run_finalized is True
 
 
@@ -634,7 +709,13 @@ def test_ensure_db_run_created_publishes_only_after_insert(monkeypatch):
     monkeypatch.setitem(sys.modules, "storage", fake_storage)
     monkeypatch.setitem(sys.modules, "storage.studio_db", fake_db)
 
-    b._ensure_db_run_created()
+    b._run_intent_lock.acquire()
+    creator = threading.Thread(target = b._ensure_db_run_created)
+    creator.start()
+    time.sleep(0.02)
+    assert b._db_create_in_progress is False
+    b._run_intent_lock.release()
+    creator.join(timeout = 5)
 
     assert observed["flag_during_create"] is False, "flag must not be published before insert"
     assert observed["in_progress_during_create"] is True
@@ -706,6 +787,7 @@ def test_escalation_finalizes_watched_run_by_id_end_to_end(monkeypatch):
     b = TrainingBackend()
     b.current_job_id = "job_old"
     b._db_run_created = True
+    b._should_stop = True
     b._proc = _FakeProc(alive = False)
     b._progress.is_training = True
     b._progress.step = 42
@@ -714,7 +796,8 @@ def test_escalation_finalizes_watched_run_by_id_end_to_end(monkeypatch):
     b._finalize_stopped_after_escalation(target_proc = b._proc, watched_job_id = "job_old")
 
     assert [f["id"] for f in recs["finished"]] == ["job_old"], "must finish the captured run by id"
-    assert recs["finished"][0]["status"] == "stopped"
+    assert recs["finished"][0]["status"] == "error"
+    assert recs["finished"][0]["resume_blocked"] is True
     assert recs["insert_ids"] == ["job_old"], "buffered metrics must land on the captured run"
     assert b._metric_buffer == [], "the captured batch must be drained"
 
@@ -725,7 +808,7 @@ def test_escalation_defers_when_row_cannot_be_created_here(monkeypatch):
     # so the pump's create-then-finalize records the run. Parent state still clears.
     b = TrainingBackend()
     called: list = []
-    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a: called.append(a))
+    monkeypatch.setattr(b, "_finish_stopped_run", lambda *a, **k: called.append(a))
 
     b._proc = _FakeProc(alive = False)
     b.current_job_id = "job_q"
@@ -773,7 +856,7 @@ def test_escalation_does_not_drop_a_new_runs_handle(monkeypatch):
     new_proc = _FakeProc(alive = True)
     b._proc = old_proc
 
-    def hijack(*a):
+    def hijack(*a, **k):
         b._proc = new_proc  # a new run takes over during the finalize
 
     monkeypatch.setattr(b, "_finish_stopped_run", hijack)
diff --git a/studio/backend/tests/test_training_vram_coexistence.py b/studio/backend/tests/test_training_vram_coexistence.py
index 2bedc46d1f..217caaa4fb 100644
--- a/studio/backend/tests/test_training_vram_coexistence.py
+++ b/studio/backend/tests/test_training_vram_coexistence.py
@@ -82,6 +82,63 @@ def _patch_backends(inf, llama):
     return patch.dict(sys.modules, {"core.inference": core_inf, "routes.inference": routes_inf})
 
 
+def _fake_stt_sidecar(
+    *,
+    model = None,
+    device = None,
+    loading = False,
+):
+    sidecar = SimpleNamespace(
+        loaded_model = model,
+        device = device,
+        is_loading = lambda: loading,
+    )
+    sidecar.cancel_pending_load = MagicMock(return_value = loading)
+    sidecar.wait_for_load_to_settle = MagicMock()
+    sidecar.unload = MagicMock()
+    return sidecar
+
+
+def _fake_ggml_sidecar(
+    *,
+    model = None,
+    device = None,
+    loading = False,
+):
+    ggml = SimpleNamespace(
+        loaded_model = model,
+        device = device,
+        is_loading = lambda: loading,
+    )
+    ggml.cancel_pending_load = MagicMock(return_value = loading)
+    ggml.wait_for_load_to_settle = MagicMock()
+    ggml.unload = MagicMock()
+    return ggml
+
+
+def _patch_stt(sidecar):
+    stt_module = types.ModuleType("core.inference.stt_sidecar")
+    stt_module.get_stt_sidecar = lambda: sidecar
+    # A fresh import of the GGUF sidecar pulls names from the fake module
+    # above and fails; fake it too so test ordering cannot break that import.
+    ggml_module = types.ModuleType("core.inference.stt_ggml_sidecar")
+    empty_ggml = _fake_ggml_sidecar()
+    ggml_module.get_ggml_stt_sidecar = lambda: empty_ggml
+    return patch.dict(
+        sys.modules,
+        {
+            "core.inference.stt_sidecar": stt_module,
+            "core.inference.stt_ggml_sidecar": ggml_module,
+        },
+    )
+
+
+def _patch_ggml_stt(sidecar):
+    ggml_module = types.ModuleType("core.inference.stt_ggml_sidecar")
+    ggml_module.get_ggml_stt_sidecar = lambda: sidecar
+    return patch.dict(sys.modules, {"core.inference.stt_ggml_sidecar": ggml_module})
+
+
 # ── summarize_resident_chat ──────────────────────────────────────────────────
 
 
@@ -169,6 +226,49 @@ class TestSummarizeResidentChat(_GpuCacheResetMixin, unittest.TestCase):
         self.assertTrue(out["any"])  # GGUF still detected
 
 
+class TestSummarizeResidentStt(_GpuCacheResetMixin, unittest.TestCase):
+    def test_reports_resident_model(self):
+        sidecar = _fake_stt_sidecar(model = "small", device = "cuda")
+        with _patch_stt(sidecar):
+            out = tv.summarize_resident_stt()
+        self.assertEqual(out["model"], "small")
+        self.assertEqual(out["device"], "cuda")
+        self.assertTrue(out["any"])
+        self.assertFalse(out["loading"])
+
+    def test_reports_inflight_load(self):
+        sidecar = _fake_stt_sidecar(loading = True)
+        with _patch_stt(sidecar):
+            out = tv.summarize_resident_stt()
+        self.assertTrue(out["any"])
+        self.assertTrue(out["loading"])
+
+    def test_reports_empty_sidecar(self):
+        with _patch_stt(_fake_stt_sidecar()):
+            out = tv.summarize_resident_stt()
+        self.assertFalse(out["any"])
+
+    def test_reports_resident_gguf_when_transformers_idle(self):
+        ggml = _fake_ggml_sidecar(model = "small", device = "whisper.cpp")
+        with _patch_stt(_fake_stt_sidecar()), _patch_ggml_stt(ggml):
+            out = tv.summarize_resident_stt()
+        self.assertEqual(out["model"], "small")
+        self.assertEqual(out["device"], "whisper.cpp")
+        self.assertTrue(out["any"])
+
+    def test_resident_transformers_does_not_mask_loading_gguf(self):
+        # A Transformers model resident on CPU holds no VRAM, but a GGUF
+        # whisper-server still binding its accelerator backend does; the CPU
+        # model must not hide that in-flight startup from training admission.
+        sidecar = _fake_stt_sidecar(model = "small", device = "cpu")
+        ggml = _fake_ggml_sidecar(loading = True)
+        with _patch_stt(sidecar), _patch_ggml_stt(ggml):
+            out = tv.summarize_resident_stt()
+        self.assertEqual(out["model"], "small")
+        self.assertTrue(out["loading"])
+        self.assertTrue(out["any"])
+
+
 # ── can_keep_during_training (auto mode) ─────────────────────────────────────
 
 
@@ -226,12 +326,21 @@ class TestCanKeepAuto(_GpuCacheResetMixin, unittest.TestCase):
         keep, _, _ = self._run((None, meta))
         self.assertFalse(keep)
 
-    def test_unload_on_non_cuda(self):
+    def test_unload_on_non_accelerator(self):
         keep, info, auto_mock = self._run(([0], {}), device = DeviceType.CPU)
         self.assertFalse(keep)
-        self.assertEqual(info["mode"], "non_cuda")
+        self.assertEqual(info["mode"], "non_accelerator")
         auto_mock.assert_not_called()
 
+    def test_xpu_gets_sized_like_cuda(self):
+        # XPU is a first-class training backend: the keep-guard must size it,
+        # not blanket-unload it as a non-accelerator.
+        meta = {"selection_mode": "auto", "required_gb": 10.0, "usable_gb": 30.0}
+        keep, info, auto_mock = self._run(([0], meta), device = DeviceType.XPU)
+        self.assertTrue(keep)
+        self.assertNotEqual(info.get("mode"), "non_accelerator")
+        auto_mock.assert_called_once()
+
     def test_full_finetuning_forces_16bit_in_estimate(self):
         meta = {"selection_mode": "auto", "required_gb": 10.0, "usable_gb": 30.0}
         _keep, _info, auto_mock = self._run(
@@ -438,5 +547,151 @@ class TestFreeChatModels(_GpuCacheResetMixin, unittest.TestCase):
         self.assertEqual(freed, ["gguf:gemma.gguf"])
 
 
+class TestFreeSttModel(_GpuCacheResetMixin, unittest.TestCase):
+    def test_unloads_resident_model(self):
+        sidecar = _fake_stt_sidecar(model = "small", device = "cuda")
+        with _patch_stt(sidecar):
+            freed = tv.free_stt_model_for_training(reason = "test")
+        sidecar.unload.assert_called_once()
+        self.assertEqual(freed, ["stt:small"])
+
+    def test_cancels_inflight_load_and_waits_to_settle(self):
+        sidecar = _fake_stt_sidecar(loading = True)
+        with _patch_stt(sidecar):
+            freed = tv.free_stt_model_for_training(reason = "test")
+        sidecar.cancel_pending_load.assert_called_once()
+        # The cancelled loader may still hold VRAM; we wait for it to release.
+        sidecar.wait_for_load_to_settle.assert_called_once()
+        # No model surfaced after the wait, so nothing to unload.
+        sidecar.unload.assert_not_called()
+        self.assertEqual(freed, ["stt:loading"])
+
+    def test_cancels_inflight_load_then_unloads_settled_model(self):
+        # A load that finished before observing the cancel leaves a resident
+        # model behind; it must be unloaded so training reclaims the memory.
+        sidecar = _fake_stt_sidecar(model = "small", loading = True)
+        with _patch_stt(sidecar):
+            freed = tv.free_stt_model_for_training(reason = "test")
+        sidecar.cancel_pending_load.assert_called_once()
+        sidecar.wait_for_load_to_settle.assert_called_once()
+        sidecar.unload.assert_called_once()
+        self.assertEqual(freed, ["stt:loading"])
+
+    def test_cancelled_load_still_unloads_gguf_sidecar(self):
+        # Cancelling a Transformers load must not skip the GGUF sidecar; both
+        # engines can hold memory at once (engine switch or direct load calls).
+        sidecar = _fake_stt_sidecar(loading = True)
+        ggml = _fake_ggml_sidecar(model = "small")
+        with _patch_stt(sidecar), _patch_ggml_stt(ggml):
+            freed = tv.free_stt_model_for_training(reason = "test")
+        sidecar.cancel_pending_load.assert_called_once()
+        ggml.unload.assert_called_once()
+        self.assertEqual(freed, ["stt:loading", "stt:small"])
+
+    def test_leaves_empty_sidecar_alone(self):
+        sidecar = _fake_stt_sidecar()
+        with _patch_stt(sidecar):
+            freed = tv.free_stt_model_for_training(reason = "test")
+        sidecar.unload.assert_not_called()
+        self.assertEqual(freed, [])
+
+    def test_cancels_inflight_gguf_load_and_waits_to_settle(self):
+        # A GGUF whisper-server still in startup has no loaded_model yet, so the
+        # coordinator must cancel and wait for it, not skip it, before training
+        # claims the accelerator memory it is binding.
+        sidecar = _fake_stt_sidecar()  # Transformers idle
+        ggml = _fake_ggml_sidecar(loading = True)
+        with _patch_stt(sidecar), _patch_ggml_stt(ggml):
+            freed = tv.free_stt_model_for_training(reason = "test")
+        ggml.cancel_pending_load.assert_called_once()
+        ggml.wait_for_load_to_settle.assert_called_once()
+        ggml.unload.assert_not_called()  # nothing surfaced after the wait
+        self.assertEqual(freed, ["stt:gguf-loading"])
+
+
+class TestCoordinateModels(_GpuCacheResetMixin, unittest.TestCase):
+    def _run(self, chat, stt, keep_results):
+        keep = MagicMock(side_effect = keep_results)
+        with (
+            patch.object(tv, "summarize_resident_chat", return_value = chat),
+            patch.object(tv, "summarize_resident_stt", return_value = stt),
+            patch.object(
+                tv,
+                "free_stt_model_for_training",
+                return_value = ["stt:small"],
+            ) as free_stt,
+            patch.object(
+                tv,
+                "free_chat_models_for_training",
+                return_value = ["hf:chat"],
+            ) as free_chat,
+        ):
+            freed = tv.coordinate_models_for_training(keep)
+        return freed, keep, free_stt, free_chat
+
+    def test_keeps_everything_when_training_fits(self):
+        chat = {"any": True, "loading": False}
+        stt = {"any": True, "loading": False}
+        freed, keep, free_stt, free_chat = self._run(
+            chat,
+            stt,
+            [(True, {"usable_gb": 40, "required_gb": 10})],
+        )
+        self.assertEqual(freed, [])
+        keep.assert_called_once()
+        free_stt.assert_not_called()
+        free_chat.assert_not_called()
+
+    def test_frees_stt_before_chat(self):
+        chat = {"any": True, "loading": False}
+        stt = {"any": True, "loading": False}
+        freed, keep, free_stt, free_chat = self._run(
+            chat,
+            stt,
+            [
+                (False, {"usable_gb": 8, "required_gb": 10}),
+                (True, {"usable_gb": 12, "required_gb": 10}),
+            ],
+        )
+        self.assertEqual(freed, ["stt:small"])
+        self.assertEqual(keep.call_count, 2)
+        free_stt.assert_called_once()
+        free_chat.assert_not_called()
+
+    def test_frees_chat_when_stt_is_not_enough(self):
+        chat = {"any": True, "loading": False}
+        stt = {"any": True, "loading": False}
+        freed, keep, free_stt, free_chat = self._run(
+            chat,
+            stt,
+            [
+                (False, {"usable_gb": 8, "required_gb": 10}),
+                (False, {"usable_gb": 9, "required_gb": 10}),
+            ],
+        )
+        self.assertEqual(freed, ["stt:small", "hf:chat"])
+        self.assertEqual(keep.call_count, 2)
+        free_stt.assert_called_once()
+        free_chat.assert_called_once()
+
+    def test_frees_loading_models_without_probe(self):
+        chat = {"any": True, "loading": True}
+        stt = {"any": True, "loading": True}
+        freed, keep, free_stt, free_chat = self._run(chat, stt, [])
+        self.assertEqual(freed, ["stt:small", "hf:chat"])
+        keep.assert_not_called()
+        free_stt.assert_called_once()
+        free_chat.assert_called_once()
+
+    def test_cancels_loading_stt_without_probe(self):
+        chat = {"any": False, "loading": False}
+        stt = {"any": True, "loading": True}
+        freed, keep, free_stt, free_chat = self._run(chat, stt, [])
+        self.assertEqual(freed, ["stt:small"])
+        keep.assert_not_called()
+        free_stt.assert_called_once()
+        free_chat.assert_not_called()
+
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/studio/backend/tests/test_transformers_latest.py b/studio/backend/tests/test_transformers_latest.py
index 20616dccba..af48d674cc 100644
--- a/studio/backend/tests/test_transformers_latest.py
+++ b/studio/backend/tests/test_transformers_latest.py
@@ -1036,7 +1036,7 @@ def test_upgrade_check_mixed_pypi_main_reports_dev_only(monkeypatch):
 
 
 def test_install_endpoint_not_mounted_on_v1():
-    """The consented pip-install endpoint is a Studio admin action; it must live
+    """The consented pip-install endpoint is an Unsloth admin action; it must live
     on studio_router (kept off the OpenAI-compatible /v1 mount), not router."""
     from routes import inference as ri
 
diff --git a/studio/backend/tests/test_transformers_version.py b/studio/backend/tests/test_transformers_version.py
index a6e6803a5c..acb2ec449b 100644
--- a/studio/backend/tests/test_transformers_version.py
+++ b/studio/backend/tests/test_transformers_version.py
@@ -160,6 +160,25 @@ class TestResolveBaseModel:
 class TestRemoteLoraBase:
     """_remote_lora_base reads a remote adapter's base from its Hub adapter_config.json."""
 
+    @pytest.fixture(autouse = True)
+    def _selected_cache_follows_env(self, monkeypatch):
+        # The cache helpers now read the selected cache (get_hf_cache_paths),
+        # which snapshots env at import; make it follow the HF_HUB_CACHE these
+        # tests set so they keep driving the lookup via env.
+        monkeypatch.setattr(
+            "utils.transformers_version.get_hf_cache_paths",
+            lambda: _types.SimpleNamespace(
+                hub_cache = Path(
+                    os.environ.get("HF_HUB_CACHE")
+                    or os.environ.get("HUGGINGFACE_HUB_CACHE")
+                    or os.path.join(
+                        os.environ.get("HF_HOME") or os.path.expanduser("~/.cache/huggingface"),
+                        "hub",
+                    )
+                )
+            ),
+        )
+
     @staticmethod
     def _resp(cfg: dict):
         class _Resp:
@@ -645,6 +664,24 @@ def _hf_response(cfg: dict):
 class TestConfigJsonHfCacheFallback:
     """HF hub cache is consulted only offline or after a failed fetch (never stale online)."""
 
+    @pytest.fixture(autouse = True)
+    def _selected_cache_follows_env(self, monkeypatch):
+        # As above: route the selected-cache lookup through the HF_HUB_CACHE env
+        # these tests set, since get_hf_cache_paths snapshots env at import.
+        monkeypatch.setattr(
+            "utils.transformers_version.get_hf_cache_paths",
+            lambda: _types.SimpleNamespace(
+                hub_cache = Path(
+                    os.environ.get("HF_HUB_CACHE")
+                    or os.environ.get("HUGGINGFACE_HUB_CACHE")
+                    or os.path.join(
+                        os.environ.get("HF_HOME") or os.path.expanduser("~/.cache/huggingface"),
+                        "hub",
+                    )
+                )
+            ),
+        )
+
     def setup_method(self):
         _config_json_cache.clear()
 
diff --git a/studio/backend/tests/test_utils.py b/studio/backend/tests/test_utils.py
index 64a3c62156..741f19c67a 100644
--- a/studio/backend/tests/test_utils.py
+++ b/studio/backend/tests/test_utils.py
@@ -38,7 +38,7 @@ from utils.hardware import (
     DeviceType,
 )
 import utils.hardware.hardware as _hw_module
-from utils.utils import format_error_message
+from utils.utils import format_error_message, is_hf_authentication_error
 
 
 # ========== Helpers ==========
@@ -439,6 +439,20 @@ class TestFormatErrorMessage:
         msg = format_error_message(err, "any/model")
         assert "invalid" in msg.lower()
 
+    def test_hf_authentication_error_follows_wrapped_401(self):
+        response = type("Response", (), {"status_code": 401})()
+        auth_error = Exception("request failed")
+        auth_error.response = response
+        wrapper = RuntimeError("model validation failed")
+        wrapper.__cause__ = auth_error
+        assert is_hf_authentication_error(wrapper) is True
+
+    def test_hf_authentication_error_does_not_treat_429_as_invalid(self):
+        response = type("Response", (), {"status_code": 429})()
+        rate_error = Exception("too many requests")
+        rate_error.response = response
+        assert is_hf_authentication_error(rate_error) is False
+
     # --- OOM on CUDA ---
 
     @needs_torch
diff --git a/studio/backend/tests/test_whisper_cpp_freshness.py b/studio/backend/tests/test_whisper_cpp_freshness.py
new file mode 100644
index 0000000000..69f0c87cee
--- /dev/null
+++ b/studio/backend/tests/test_whisper_cpp_freshness.py
@@ -0,0 +1,156 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Tests for the whisper.cpp prebuilt freshness check.
+
+Pins the whisper-specific version policy: the release-tag parser, the
+is_behind decision matrix (with its downgrade guard), and one end-to-end
+wiring smoke through the shared freshness flow. The shared marker-walk and
+fail-open mechanics are covered by test_llama_cpp_freshness.py.
+"""
+
+from __future__ import annotations
+
+import json
+import sys
+import types as _types
+from datetime import datetime, timedelta, timezone
+from pathlib import Path
+
+_BACKEND_DIR = str(Path(__file__).resolve().parent.parent)
+if _BACKEND_DIR not in sys.path:
+    sys.path.insert(0, _BACKEND_DIR)
+
+
+class _NoopLogger:
+    """structlog-style logger: every method swallows positional + kwargs."""
+
+    def __getattr__(self, _name):
+        return lambda *a, **k: None
+
+
+_loggers_stub = _types.ModuleType("loggers")
+_loggers_stub.get_logger = lambda *a, **k: _NoopLogger()
+sys.modules.setdefault("loggers", _loggers_stub)
+
+_structlog_stub = _types.ModuleType("structlog")
+_structlog_stub.get_logger = lambda *a, **k: _NoopLogger()
+sys.modules.setdefault("structlog", _structlog_stub)
+
+import pytest
+
+from utils import whisper_cpp_freshness as fr
+
+
+# Helpers.
+
+
+def _write_marker(install_dir: Path, **overrides) -> Path:
+    payload = {
+        "requested_tag": "latest",
+        "release_tag": "v1.9.1-unsloth.1",
+        "upstream_tag": "v1.9.1",
+        "published_repo": "unslothai/whisper.cpp",
+        "asset": "whisper-v1.9.1-unsloth.1-linux-x64-cpu.tar.gz",
+        "asset_sha256": None,
+        "source": "published",
+        "installed_at_utc": (datetime.now(tz = timezone.utc) - timedelta(days = 1))
+        .isoformat()
+        .replace("+00:00", "Z"),
+    }
+    payload.update(overrides)
+    install_dir.mkdir(parents = True, exist_ok = True)
+    marker = install_dir / "UNSLOTH_WHISPER_PREBUILT_INFO.json"
+    marker.write_text(json.dumps(payload))
+    return marker
+
+
+def _fake_binary(install_dir: Path) -> Path:
+    """Stub whisper-server under the canonical cmake install layout."""
+    bin_dir = install_dir / "build" / "bin"
+    bin_dir.mkdir(parents = True, exist_ok = True)
+    bin_path = bin_dir / "whisper-server"
+    bin_path.write_text("stub\n")
+    return bin_path
+
+
+@pytest.fixture(autouse = True)
+def _reset(monkeypatch, tmp_path):
+    # Isolate disk cache per-test; never touch the real cache.
+    monkeypatch.setattr(fr, "_cache_dir", lambda: tmp_path / ".freshness")
+    fr.reset_caches()
+    yield
+    fr.reset_caches()
+
+
+# parse_release_version.
+
+
+def test_parse_release_version():
+    assert fr.parse_release_version("v1.9.1-unsloth.2") == (1, 9, 1, 2)
+    assert fr.parse_release_version("1.10.0") == (1, 10, 0, 0)  # no v, no serial
+    assert fr.parse_release_version(" v2.0.0-unsloth.10 ") == (2, 0, 0, 10)
+    assert fr.parse_release_version("v1.9") == (1, 9, 0, 0)  # padded
+    assert fr.parse_release_version("nightly") is None
+    assert fr.parse_release_version(None) is None
+    assert fr.parse_release_version("") is None
+
+
+# is_behind decision matrix + downgrade guard.
+
+
+def test_is_behind_serial_bump():
+    assert fr.is_behind("v1.9.1-unsloth.1", "v1.9.1-unsloth.2") is True
+
+
+def test_is_behind_downgrade_guard():
+    # A lower serial or version is never "behind".
+    assert fr.is_behind("v1.9.1-unsloth.2", "v1.9.1-unsloth.1") is False
+    assert fr.is_behind("v1.10.0-unsloth.1", "v1.9.1-unsloth.9") is False
+
+
+def test_is_behind_upstream_bump():
+    assert fr.is_behind("v1.9.1-unsloth.1", "v1.10.0-unsloth.1") is True
+
+
+def test_is_behind_identical_is_false():
+    assert fr.is_behind("v1.9.1-unsloth.1", "v1.9.1-unsloth.1") is False
+
+
+def test_is_behind_unparseable_differs_is_behind():
+    assert fr.is_behind("v1.9.1-unsloth.1", "nightly") is True
+
+
+def test_is_behind_missing_side_fails_open():
+    assert fr.is_behind(None, "v1.9.1-unsloth.2") is False
+    assert fr.is_behind("v1.9.1-unsloth.1", None) is False
+
+
+# check_prebuilt_freshness end-to-end.
+
+
+def test_check_prebuilt_freshness_reports_stale_when_old_and_behind(monkeypatch, tmp_path):
+    _write_marker(
+        tmp_path,
+        release_tag = "v1.9.1-unsloth.1",
+        installed_at_utc = (datetime.now(tz = timezone.utc) - timedelta(days = 10))
+        .isoformat()
+        .replace("+00:00", "Z"),
+    )
+    bin_path = _fake_binary(tmp_path)
+    monkeypatch.setattr(fr, "latest_published_release", lambda *a, **k: "v1.9.1-unsloth.3")
+    info = fr.check_prebuilt_freshness(str(bin_path))
+    assert info["has_marker"] is True
+    assert info["behind"] is True
+    assert info["stale"] is True
+    assert info["installed_tag"] == "v1.9.1-unsloth.1"
+    assert info["latest_tag"] == "v1.9.1-unsloth.3"
+
+
+def test_marker_reader_prefers_install_root_over_packaging_marker(tmp_path):
+    root_marker = _write_marker(tmp_path, release_tag = "v1.9.1-unsloth.2")
+    binary = _fake_binary(tmp_path)
+    (binary.parent / root_marker.name).write_text(
+        json.dumps({"backend": "slim", "release_tag": "archive-metadata"})
+    )
+    assert fr.read_install_marker(str(binary))["release_tag"] == "v1.9.1-unsloth.2"
diff --git a/studio/backend/tests/test_windows_external_drive_paths.py b/studio/backend/tests/test_windows_external_drive_paths.py
index 9686d45c9f..5687612916 100644
--- a/studio/backend/tests/test_windows_external_drive_paths.py
+++ b/studio/backend/tests/test_windows_external_drive_paths.py
@@ -57,6 +57,18 @@ def test_windows_drive_roots_empty_off_windows(monkeypatch):
     assert external_media.windows_drive_roots() == []
 
 
+def test_macos_volume_roots_lists_readable_mounts(monkeypatch, tmp_path):
+    volumes = tmp_path / "Volumes"
+    external = volumes / "External SSD"
+    unreadable = volumes / "Unavailable"
+    external.mkdir(parents = True)
+    unreadable.mkdir()
+    monkeypatch.setattr(external_media.platform, "system", lambda: "Darwin")
+    monkeypatch.setattr(external_media.os, "access", lambda path, _mode: Path(path) == external)
+
+    assert external_media.macos_volume_roots(volumes) == [external]
+
+
 def test_windows_drive_roots_lists_readable_drives(monkeypatch):
     _stub_windows(monkeypatch, {"C", "D", "E"})
 
@@ -204,8 +216,10 @@ def test_browse_allowlist_includes_windows_drive_roots(monkeypatch, tmp_path):
     )
     fake_external_media = SimpleNamespace(
         linux_run_media_mount_roots = lambda: [],
+        macos_volume_roots = lambda: [],
         windows_drive_roots = lambda: [drive_root],
     )
+    fake_paths.external_media = fake_external_media
     fake_studio_db = SimpleNamespace(
         list_scan_folders = lambda: [],
         contains_sensitive_path_component = lambda _p: False,
@@ -270,8 +284,10 @@ def test_build_browse_allowlist_reuses_passed_roots(monkeypatch, tmp_path):
     )
     fake_external_media = SimpleNamespace(
         linux_run_media_mount_roots = _media_roots,
+        macos_volume_roots = lambda: [],
         windows_drive_roots = _drive_roots,
     )
+    fake_paths.external_media = fake_external_media
     fake_studio_db = SimpleNamespace(list_scan_folders = lambda: [])
     monkeypatch.setitem(sys.modules, "utils.paths", fake_paths)
     monkeypatch.setitem(sys.modules, "utils.paths.external_media", fake_external_media)
diff --git a/studio/backend/utils/_studio_release_build.py b/studio/backend/utils/_studio_release_build.py
index 267197a202..07ede36912 100644
--- a/studio/backend/utils/_studio_release_build.py
+++ b/studio/backend/utils/_studio_release_build.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Build-stamped Studio release metadata.
+"""Build-stamped Unsloth release metadata.
 
 Release builds may rewrite this module in the build workspace before creating
 Python artifacts. Keep the committed value neutral so source checkouts do not
diff --git a/studio/backend/utils/api_errors.py b/studio/backend/utils/api_errors.py
index cae8daf287..a3686c3a26 100644
--- a/studio/backend/utils/api_errors.py
+++ b/studio/backend/utils/api_errors.py
@@ -20,7 +20,7 @@ client-error responses on the ``/v1/*`` surface:
 CRITICAL: the exception handlers installed by :func:`install_api_error_handlers`
 are global, but they ONLY transform responses for paths that start with ``/v1/``.
 For every other path (``/api/...``, frontend routes) they reproduce FastAPI's
-default behavior byte-for-byte, because the Studio frontend depends on the
+default behavior byte-for-byte, because the Unsloth frontend depends on the
 ``{"detail": ...}`` shape for ``/api/*``.
 
 Public contract (other modules depend on these):
@@ -107,7 +107,7 @@ def anthropic_error_body(
 
     Returns ``{"type": "error", "request_id": None, "error": {"type", "message"}}``.
     ``request_id`` is a required (nullable) field on the spec's ErrorResponse;
-    Studio has no request-id system, so it is null. ``err_type`` defaults to
+    Unsloth has no request-id system, so it is null. ``err_type`` defaults to
     :data:`ANTHROPIC_TYPE_BY_STATUS` for ``status`` (``"api_error"`` fallback).
     """
     return {
@@ -192,7 +192,7 @@ def install_api_error_handlers(app) -> None:
     Both handlers are global but only transform responses for OpenAI/Anthropic-
     compatible surfaces (see :func:`wants_api_error_envelope`: the ``/v1/*`` mount
     and the preview ``/p/.../v1/*`` mount). Every other path reproduces FastAPI's
-    default ``{"detail": ...}`` behavior exactly so the Studio frontend keeps working.
+    default ``{"detail": ...}`` behavior exactly so the Unsloth frontend keeps working.
     """
 
     @app.exception_handler(RequestValidationError)
diff --git a/studio/backend/utils/client_ip.py b/studio/backend/utils/client_ip.py
index 94acbf1809..cc48a096d2 100644
--- a/studio/backend/utils/client_ip.py
+++ b/studio/backend/utils/client_ip.py
@@ -4,12 +4,12 @@
 """Resolve the caller's IP for rate limiting.
 
 Trust model, in order:
-  1. If the operator opts in via ``UNSLOTH_STUDIO_TRUST_FORWARDED`` (Studio behind
+  1. If the operator opts in via ``UNSLOTH_STUDIO_TRUST_FORWARDED`` (Unsloth behind
      their own reverse proxy), honor the *rightmost* ``X-Forwarded-For`` hop -- the
      one the trusted proxy appended. The leftmost entry is client-controlled and
      spoofable, so this assumes a proxy that appends (or overwrites) the header;
      only enable the env var behind such a proxy.
-  2. If the socket peer is loopback, honor ``CF-Connecting-IP``. Studio's managed
+  2. If the socket peer is loopback, honor ``CF-Connecting-IP``. Unsloth's managed
      Cloudflare tunnel terminates at 127.0.0.1, so every tunneled visitor would
      otherwise collapse onto the same socket peer (the local cloudflared process)
      and share one rate-limit bucket. ``CF-Connecting-IP`` is set by Cloudflare's
diff --git a/studio/backend/utils/cpu_threads.py b/studio/backend/utils/cpu_threads.py
index 4ed0021054..91d577408d 100644
--- a/studio/backend/utils/cpu_threads.py
+++ b/studio/backend/utils/cpu_threads.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Early CPU thread-pool configuration for Studio processes."""
+"""Early CPU thread-pool configuration for Unsloth processes."""
 
 import os
 from typing import MutableMapping, Optional
diff --git a/studio/backend/utils/datasets/cache_safe.py b/studio/backend/utils/datasets/cache_safe.py
index e629210f33..d2dc7b737a 100644
--- a/studio/backend/utils/datasets/cache_safe.py
+++ b/studio/backend/utils/datasets/cache_safe.py
@@ -7,7 +7,7 @@ A shared HF datasets cache can contain subtrees owned by another user (for
 example populated by an earlier root-run job). datasets then raises
 "[Errno 13] Permission denied: ..._builder.lock" while locking the cached
 builder, killing the training run even though the dataset itself is fine.
-Retry such loads in a Studio-owned cache so the run proceeds; the worst case
+Retry such loads in an Unsloth-owned cache so the run proceeds; the worst case
 is one rebuild of the dataset in the fallback location.
 """
 
@@ -26,7 +26,7 @@ def studio_datasets_cache() -> str:
 
 
 def load_dataset_cache_safe(*args, **kwargs):
-    """datasets.load_dataset, retried in a Studio-owned cache on EACCES."""
+    """datasets.load_dataset, retried in an Unsloth-owned cache on EACCES."""
     from datasets import load_dataset
     try:
         return load_dataset(*args, **kwargs)
diff --git a/studio/backend/utils/datasets/format_conversion.py b/studio/backend/utils/datasets/format_conversion.py
index 95c9a00534..9035068c01 100644
--- a/studio/backend/utils/datasets/format_conversion.py
+++ b/studio/backend/utils/datasets/format_conversion.py
@@ -406,10 +406,13 @@ def convert_to_vlm_format(
             elif _image_lookup is not None and image_data in _image_lookup:
                 # Bare filename → resolve via HF repo lookup
                 from huggingface_hub import hf_hub_download
+                from utils.hf_cache_settings import active_hf_hub_cache
+
                 local_path = hf_hub_download(
                     dataset_name,
                     _image_lookup[image_data],
                     repo_type = "dataset",
+                    cache_dir = active_hf_hub_cache(),
                 )
                 image_data = Image.open(local_path).convert("RGB")
             else:
@@ -774,10 +777,13 @@ def convert_sharegpt_with_images_to_vlm_format(
                     return Image.open(BytesIO(f.read())).convert("RGB")
             elif _image_lookup is not None and image_data in _image_lookup:
                 from huggingface_hub import hf_hub_download
+                from utils.hf_cache_settings import active_hf_hub_cache
+
                 local_path = hf_hub_download(
                     dataset_name,
                     _image_lookup[image_data],
                     repo_type = "dataset",
+                    cache_dir = active_hf_hub_cache(),
                 )
                 return Image.open(local_path).convert("RGB")
             else:
diff --git a/studio/backend/utils/datasets/llm_assist.py b/studio/backend/utils/datasets/llm_assist.py
index f7b35e2869..c594e883a8 100644
--- a/studio/backend/utils/datasets/llm_assist.py
+++ b/studio/backend/utils/datasets/llm_assist.py
@@ -58,6 +58,7 @@ def precache_helper_gguf():
     try:
         from huggingface_hub import HfApi, hf_hub_download
         from huggingface_hub.utils import disable_progress_bars, enable_progress_bars
+        from utils.hf_cache_settings import active_hf_hub_cache
 
         disable_progress_bars()
         logging.getLogger("huggingface_hub").setLevel(logging.WARNING)
@@ -76,7 +77,11 @@ def precache_helper_gguf():
                 + (f" (+{len(matching) - 1} shards)" if len(matching) > 1 else "")
             )
             for target in matching:
-                hf_hub_download(repo_id = repo, filename = target)
+                hf_hub_download(
+                    repo_id = repo,
+                    filename = target,
+                    cache_dir = active_hf_hub_cache(),
+                )
             logger.info(f"Helper GGUF cached: {len(matching)} file(s)")
         else:
             logger.warning(f"No GGUF matching variant '{variant}' in {repo}")
diff --git a/studio/backend/utils/hardware/VRAM_ESTIMATION.md b/studio/backend/utils/hardware/VRAM_ESTIMATION.md
index a6b4de29d2..68ca1d5ffd 100644
--- a/studio/backend/utils/hardware/VRAM_ESTIMATION.md
+++ b/studio/backend/utils/hardware/VRAM_ESTIMATION.md
@@ -106,7 +106,7 @@ Non_flash_attention = B * num_attention_heads * S^2 * 2 * 12.0 * effective_layer
 Activations = max(Per_layer_with_gc, Non_flash_attention)
 ```
 
-Studio resolves the attention implementation with Unsloth's
+Unsloth resolves the attention implementation with Unsloth's
 `resolve_attention_implementation` helper and uses that result directly. The
 estimator does not duplicate model-family attention policy.
 
diff --git a/studio/backend/utils/hardware/__init__.py b/studio/backend/utils/hardware/__init__.py
index 62b537fbac..138238533f 100644
--- a/studio/backend/utils/hardware/__init__.py
+++ b/studio/backend/utils/hardware/__init__.py
@@ -50,6 +50,11 @@ def export_capability() -> dict:
     return _hardware.export_capability()
 
 
+def get_torch_device_str() -> str:
+    """Return the torch device string ("cuda", "xpu", "cpu") for the detected hardware."""
+    return _hardware.get_torch_device_str()
+
+
 __all__ = [
     "DeviceType",
     "DEVICE",
@@ -75,6 +80,7 @@ __all__ = [
     "estimate_required_model_memory_gb",
     "auto_select_gpu_ids",
     "prepare_gpu_selection",
+    "get_torch_device_str",
     "safe_num_proc",
     "safe_thread_num_proc",
     "dataset_map_num_proc",
diff --git a/studio/backend/utils/hardware/amd.py b/studio/backend/utils/hardware/amd.py
index f5b64c45d0..91a06c9a2a 100644
--- a/studio/backend/utils/hardware/amd.py
+++ b/studio/backend/utils/hardware/amd.py
@@ -125,7 +125,7 @@ def _run_amd_smi(*args: str, timeout: int = _AMD_SMI_DEFAULT_TIMEOUT) -> Optiona
         # amd-smi does not exist on Windows (neither Adrenalin nor the HIP SDK
         # ship a CLI) and can be absent on minimal Linux installs. Disable the
         # poller in one step instead of burning the 3-strike circuit breaker
-        # on guaranteed FileNotFoundError spawns. Studio's VRAM display falls
+        # on guaranteed FileNotFoundError spawns. Unsloth's VRAM display falls
         # back to torch mem_get_info.
         if not _amd_smi_disabled:
             logger.info(
diff --git a/studio/backend/utils/hardware/hardware.py b/studio/backend/utils/hardware/hardware.py
index 117ad7b780..38ebc0b6d4 100644
--- a/studio/backend/utils/hardware/hardware.py
+++ b/studio/backend/utils/hardware/hardware.py
@@ -37,7 +37,7 @@ logger = get_logger(__name__)
 
 # ── GPU index ordering ──────────────────────────────────────────────────────
 # CUDA defaults to CUDA_DEVICE_ORDER=FASTEST_FIRST, numbering GPUs by compute
-# performance. nvidia-smi -- and every free-VRAM probe in Studio -- numbers GPUs
+# performance. nvidia-smi -- and every free-VRAM probe in Unsloth -- numbers GPUs
 # by PCI bus id instead. On a mixed-GPU host (e.g. an RTX 5090 alongside an RTX
 # PRO 6000) the two orderings disagree, so an index picked from nvidia-smi data
 # ("the emptiest card is GPU 1") gets written into CUDA_VISIBLE_DEVICES and then
@@ -49,7 +49,7 @@ logger = get_logger(__name__)
 # and spawn workers copy os.environ. setdefault so an explicit user override wins.
 os.environ.setdefault("CUDA_DEVICE_ORDER", "PCI_BUS_ID")
 
-# Studio workers can import MLX without importing unsloth first, so mirror the
+# Unsloth workers can import MLX without importing unsloth first, so mirror the
 # package bootstrap here. Keep an explicit user value authoritative.
 if platform.system() == "Darwin" and platform.machine() == "arm64":
     os.environ.setdefault("AGX_RELAX_CDM_CTXSTORE_TIMEOUT", "1")
@@ -117,7 +117,7 @@ def _has_mlx() -> bool:
 
 
 def _has_usable_mlx_stack() -> bool:
-    """True only when the FULL Studio MLX training/export stack is usable
+    """True only when the FULL Unsloth MLX training/export stack is usable
     (mlx + mlx-lm + mlx-vlm at the minimum versions unsloth-zoo requires), not
     just a bare ``import mlx.core``. A backtracked/old mlx-vlm still imports but
     breaks VLM Train/Export, so the training gate must match the self-heal's own
@@ -175,18 +175,64 @@ def detect_hardware() -> DeviceType:
     Call once at FastAPI lifespan startup; idempotent.
 
     Detection order:
-      1. CUDA  (NVIDIA GPU, requires torch)
-      2. MLX   (Apple Silicon via MLX framework)
-      3. CPU   (fallback)
+      1. XPU-preferred hint: only on an unambiguous "prefer XPU" signal
+         (CUDA hidden via ``CUDA_VISIBLE_DEVICES="" / "-1"``,
+         ``UNSLOTH_FORCE_XPU=1``, or CUDA unavailable) AND a non-empty
+         ``ZE_AFFINITY_MASK`` AND ``torch.xpu`` reports a device. A stray
+         inherited mask is not enough: CUDA still wins on hybrid hosts.
+      2. CUDA  (NVIDIA GPU, requires torch)
+      3. XPU   (Intel GPU, requires torch with XPU support)
+      4. MLX   (Apple Silicon via MLX framework)
+      5. CPU   (fallback)
     """
     global DEVICE, CHAT_ONLY, CHAT_ONLY_REASON, IS_ROCM
     CHAT_ONLY = True  # reset -- only CUDA/ROCm/XPU/MLX sets it to False
     CHAT_ONLY_REASON = None
     IS_ROCM = False
 
-    # --- CUDA / ROCm: try PyTorch ---
+    # --- CUDA / ROCm / XPU: try PyTorch ---
     if _has_torch():
         import torch
+
+        # --- Explicit-XPU hint ---
+        # Prefer XPU on UNSLOTH_FORCE_XPU=1, or ZE_AFFINITY_MASK set + CUDA
+        # hidden/unavailable. A bare mask alone is NOT enough (can leak from
+        # unrelated Intel tooling); torch.xpu must report a device.
+        ze_mask = os.environ.get("ZE_AFFINITY_MASK")
+        cvd = os.environ.get("CUDA_VISIBLE_DEVICES")
+        cuda_hidden = cvd is not None and cvd.strip() in ("", "-1")
+        force_xpu = os.environ.get("UNSLOTH_FORCE_XPU") == "1"
+        try:
+            cuda_unavailable = not torch.cuda.is_available()
+        except Exception:
+            cuda_unavailable = True
+
+        prefer_xpu = force_xpu or (bool(ze_mask) and (cuda_hidden or cuda_unavailable))
+        if prefer_xpu:
+            try:
+                xpu_ok = hasattr(torch, "xpu") and torch.xpu.is_available()
+            except Exception:
+                xpu_ok = False
+            if xpu_ok:
+                # Forced XPU on a hybrid host: unsloth's device_type picks
+                # CUDA before XPU and ignores this Studio-only env var, so
+                # hide CUDA or spawned workers would silently train on CUDA.
+                if force_xpu and not cuda_hidden and not cuda_unavailable:
+                    os.environ["CUDA_VISIBLE_DEVICES"] = ""
+                DEVICE = DeviceType.XPU
+                CHAT_ONLY = False
+                CHAT_ONLY_REASON = None
+                device_name = torch.xpu.get_device_name(0)
+                if force_xpu and not ze_mask:
+                    reason = "UNSLOTH_FORCE_XPU=1"
+                elif force_xpu:
+                    reason = "UNSLOTH_FORCE_XPU=1 + ZE_AFFINITY_MASK"
+                else:
+                    reason = "ZE_AFFINITY_MASK hint honoured"
+                print(f"Hardware detected: XPU -- {device_name} ({reason})")
+                return DEVICE
+
+        # --- CUDA: NVIDIA GPU ---
         if torch.cuda.is_available():
             DEVICE = DeviceType.CUDA
             CHAT_ONLY = False
@@ -327,9 +373,18 @@ def clear_gpu_cache():
         torch.cuda.empty_cache()
         torch.cuda.ipc_collect()
     elif device == DeviceType.XPU:
-        import torch
-        torch.xpu.synchronize()
-        torch.xpu.empty_cache()
+        # Guard synchronize/empty_cache: older torch-xpu builds may lack
+        # them, and an unguarded AttributeError would propagate to callers.
+        # torch.xpu has no ipc_collect(), so do not call it here.
+        try:
+            import torch
+            if hasattr(torch, "xpu"):
+                if hasattr(torch.xpu, "synchronize"):
+                    torch.xpu.synchronize()
+                if hasattr(torch.xpu, "empty_cache"):
+                    torch.xpu.empty_cache()
+        except Exception as e:
+            logger.debug("Failed to clear XPU cache: %s", e)
     elif device == DeviceType.MLX:
         # MLX manages memory automatically; gc.collect() above is enough.
         pass
@@ -500,14 +555,27 @@ def get_package_versions() -> Dict[str, Optional[str]]:
         except PackageNotFoundError:
             versions[name] = None
 
-    # GPU runtime version bundled with torch
+    # GPU runtime versions bundled with torch (CUDA, ROCm/HIP, Intel XPU)
     try:
         import torch
+
         versions["cuda"] = getattr(torch.version, "cuda", None)
         versions["rocm"] = getattr(torch.version, "hip", None)
+        # Isolated probe: a broken Intel runtime raising in is_available()
+        # must not blank the already-read cuda/rocm versions.
+        try:
+            if hasattr(torch, "xpu") and torch.xpu.is_available():
+                # torch.version.xpu may be None on modern builds; fall back to
+                # "available" so the UI distinguishes present-but-unknown from
+                # "package not found".
+                xpu_ver = getattr(torch.version, "xpu", None)
+                versions["xpu"] = xpu_ver if xpu_ver is not None else "available"
+        except Exception:
+            versions["xpu"] = None
     except Exception:
         versions["cuda"] = None
         versions["rocm"] = None
+        versions["xpu"] = None
 
     return versions
 
@@ -538,21 +606,51 @@ def _torch_get_physical_gpu_count() -> Optional[int]:
 
 
 def _torch_get_per_device_info(device_indices: list[int]) -> list[Dict[str, Any]]:
-    """Query torch for per-GPU name, total VRAM, and used VRAM."""
+    """Query torch for per-GPU name, total VRAM, and used VRAM.
+
+    ``used_gb`` is ``None`` on Windows ROCm when ``hipMemGetInfo`` reports
+    ``free == total`` (ROCm/ROCm#1909): that 0 means unknown, not empty.
+    """
     mod, _ = _torch_get_device_module()
     if mod is None:
         return []
 
+    device = get_device()
+    # free==total is a Windows-ROCm-only quirk.
+    _win_rocm = sys.platform == "win32" and IS_ROCM
     devices = []
     for ordinal, phys_idx in enumerate(device_indices):
         try:
             # torch ordinals are 0-based relative to CUDA_VISIBLE_DEVICES.
             props = mod.get_device_properties(ordinal)
             total_bytes = props.total_memory
+            used_bytes: Optional[int]
             # Prefer mem_get_info (system-wide) so auto-select sees other consumers.
             if hasattr(mod, "mem_get_info"):
-                free_bytes, total_bytes = mod.mem_get_info(ordinal)
-                used_bytes = total_bytes - free_bytes
+                try:
+                    free_bytes, total_bytes = mod.mem_get_info(ordinal)
+                    used_bytes = total_bytes - free_bytes
+                except Exception as e:
+                    if device != DeviceType.XPU:
+                        raise
+                    # Arc B580 and Lunar Lake can report properties while
+                    # rejecting free-memory queries. Preserve the usable
+                    # device and its total memory with unknown utilization.
+                    logger.debug(
+                        "XPU free-memory query failed for ordinal %d: %s",
+                        ordinal,
+                        e,
+                    )
+                    used_bytes = None
+                else:
+                    # free==total is the broken-API sentinel, not an idle GPU.
+                    if _win_rocm and free_bytes == total_bytes:
+                        used_bytes = None
+            elif device == DeviceType.XPU:
+                # XPU without mem_get_info: memory_allocated() is process-local
+                # and misleading for placement, so return None for the
+                # selector's no-telemetry fallback.
+                used_bytes = None
             else:
                 used_bytes = mod.memory_allocated(ordinal)
             devices.append(
@@ -561,7 +659,9 @@ def _torch_get_per_device_info(device_indices: list[int]) -> list[Dict[str, Any]
                     "visible_ordinal": ordinal,
                     "name": props.name,
                     "total_gb": round(total_bytes / (1024**3), 2),
-                    "used_gb": round(used_bytes / (1024**3), 2),
+                    "used_gb": (
+                        round(used_bytes / (1024**3), 2) if used_bytes is not None else None
+                    ),
                 }
             )
         except Exception as e:
@@ -572,6 +672,43 @@ def _torch_get_per_device_info(device_indices: list[int]) -> list[Dict[str, Any]
 # ========== Live GPU Utilization ==========
 
 
+def _xpu_hierarchy_is_composite() -> bool:
+    """Return True iff Level Zero is running in COMPOSITE device hierarchy.
+
+    COMPOSITE: numeric ``ZE_AFFINITY_MASK`` entries address root GPU IDs
+    (tiles use ``N.M``). FLAT (the oneAPI default; also assumed when
+    ``ZE_FLAT_DEVICE_HIERARCHY`` is unset): entries address tile/device
+    handles, so mapping them back to root GPU IDs is unsafe. Only COMPOSITE
+    gives stable root-ID semantics.
+    """
+    hierarchy = (os.environ.get("ZE_FLAT_DEVICE_HIERARCHY") or "FLAT").strip().upper()
+    return hierarchy == "COMPOSITE"
+
+
+def _parse_ze_mask_roots(mask: str) -> list[int]:
+    """Parse a ``ZE_AFFINITY_MASK`` value into an ordered list of root device IDs.
+
+    One root ID per mask token, preserving order and duplicates so logical
+    ordinals map 1-to-1 to physical root IDs (e.g. ``"0.0,0.1"`` -> ``[0, 0]``,
+    ``"2.0,0.1,0.2"`` -> ``[2, 0, 0]``); empty list if no parseable digits.
+    Only meaningful in COMPOSITE hierarchy -- callers needing a stable
+    root-ID mapping must gate on ``_xpu_hierarchy_is_composite()``.
+    """
+    roots: list[int] = []
+    if not mask:
+        return roots
+    for token in mask.split(","):
+        token = token.strip()
+        if not token:
+            continue
+        root = token.split(".", 1)[0]
+        # isdecimal() (not isdigit()) rejects Unicode superscripts like
+        # "²"/"³", which pass isdigit() but crash int() with ValueError.
+        if root.isdecimal():
+            roots.append(int(root))
+    return roots
+
+
 def _smi_query(func_name: str, *args, **kwargs) -> Optional[Dict[str, Any]]:
     """Query the appropriate SMI backend (amd-smi or nvidia-smi).
 
@@ -724,20 +861,165 @@ def _rocm_linux_sysfs_vram_gb() -> tuple[Optional[float], Optional[float]]:
         return None, None
 
 
-def _rocm_windows_perf_counter_vram_gb() -> tuple[Optional[float], Optional[float]]:
-    """Query system-wide dedicated GPU VRAM via Windows Performance Counters.
+# 0x1002. NVIDIA's open kernel module also registers KFD nodes (vendor_id 0x10DE);
+# a non-AMD node is not a HIP device and must never take an ordinal.
+_AMD_PCI_VENDOR_ID = 4098
 
-    Same data source as Task Manager, so cross-process usage is accurate.
-    Works for any GPU vendor without amd-smi or nvidia-smi.
-    Returns (used_gb, total_gb) or (None, None) on failure.
+
+def _rocm_kfd_gpu_pci_ids() -> list[str]:
+    """PCI addresses of the GPUs ROCm enumerates, in HIP device order.
+
+    Reads /sys/class/kfd/kfd/topology/nodes/<N>/properties, the topology ROCm
+    itself enumerates from: AMD GPU nodes (simd_count > 0 excludes CPUs,
+    vendor_id == AMD excludes NVIDIA) in node-id order are HIP's device order, so
+    position N is ROCm physical device N. Unlike DRM sysfs, an amdgpu adapter HIP
+    cannot enumerate has no node here, so it never consumes an ordinal.
+
+    Returns [] (disabling the overlay) when KFD is absent, and FAILS CLOSED the
+    same way on any unreadable node or an AMD node with no location_id: dropping
+    one would shift every later ordinal and let a similar-capacity GPU pass the
+    total-size guard while showing another card's usage.
+
+    location_id is the kernel's (bus << 8) | devfn; domain is separate.
+    """
+    nodes: list[tuple[int, str]] = []
+    try:
+        node_dirs = glob.glob("/sys/class/kfd/kfd/topology/nodes/*")
+    except Exception:
+        return []
+    for node_dir in node_dirs:
+        m = re.fullmatch(r".*/(\d+)", node_dir)
+        if m is None:
+            continue
+        props: dict[str, int] = {}
+        try:
+            with open(os.path.join(node_dir, "properties")) as f:
+                for line in f:
+                    parts = line.split()
+                    if len(parts) == 2:
+                        try:
+                            props[parts[0]] = int(parts[1])
+                        except ValueError:
+                            continue
+        except OSError:
+            return []  # unreadable node could be a GPU: fail closed, don't shift
+        if props.get("simd_count", 0) <= 0:
+            continue  # CPU node, not a GPU
+        if props.get("vendor_id") != _AMD_PCI_VENDOR_ID:
+            continue  # non-AMD GPU node (NVIDIA open driver): not a HIP device
+        location_id = props.get("location_id")
+        if location_id is None:
+            return []  # an AMD GPU we cannot place: fail closed for the whole map
+        domain = props.get("domain", 0)
+        bus = (location_id >> 8) & 0xFF
+        devfn = location_id & 0xFF
+        bdf = f"{domain:04x}:{bus:02x}:{(devfn >> 3) & 0x1F:02x}.{devfn & 0x7}"
+        nodes.append((int(m.group(1)), bdf))
+    nodes.sort(key = lambda n: n[0])
+    return [bdf for _node_id, bdf in nodes]
+
+
+def _rocm_linux_amdgpu_cards() -> list[tuple[str, int, str]]:
+    """The amdgpu-bound DRM cards in PCI order: ``(pci_bdf, card_no, device_dir)``.
+
+    Membership is by the BOUND DRIVER, not the VRAM sysfs files: an AMD device
+    with incomplete sysfs support (some APUs expose no mem_info_vram_*) still
+    consumes a ROCm ordinal, and dropping it would shift every later card down.
+    PCI order is HIP's default enumeration order, so list position is the ROCm
+    ordinal; card_no is a stable tiebreak when the BDF cannot be resolved.
+
+    NOTE this is a superset of the ROCm-visible set (a HIP-unsupported amdgpu
+    adapter appears too), so callers must check the counts agree before assuming
+    a 1:1 mapping onto torch devices.
+    """
+    if platform.system() != "Linux":
+        return []
+    amd_cards: list[tuple[str, int, str]] = []
+    try:
+        for card_path in glob.glob("/sys/class/drm/card*"):
+            # Match card<N> exactly so connector nodes (card0-DP-1) are skipped.
+            m = re.fullmatch(r".*/card(\d+)", card_path)
+            if m is None:
+                continue
+            dev_dir = os.path.join(card_path, "device")
+            try:
+                driver = os.path.basename(os.path.realpath(os.path.join(dev_dir, "driver")))
+            except OSError:
+                continue
+            if driver != "amdgpu":
+                continue  # foreign adapter: not a ROCm device, takes no ordinal
+            try:
+                bdf = os.path.basename(os.path.realpath(dev_dir))
+            except OSError:
+                bdf = ""
+            amd_cards.append((bdf, int(m.group(1)), dev_dir))
+    except Exception:
+        return []
+    amd_cards.sort(key = lambda c: (c[0], c[1]))
+    return amd_cards
+
+
+def _rocm_linux_sysfs_vram_by_pci_gb() -> dict[str, tuple[float, float]]:
+    """System-wide AMD VRAM via Linux DRM sysfs, keyed by the card's PCI address.
+
+    Reads each card's mem_info_vram_{used,total} (kernel-updated across all
+    processes) so every GPU gets its own figure, unlike _rocm_linux_sysfs_vram_gb
+    which sums the host. Keyed by PCI address, not an ordinal, so the caller can
+    join it to _rocm_kfd_gpu_pci_ids() by identity: DRM card numbers include
+    foreign adapters and this set includes cards HIP does not enumerate, so any
+    ordinal from this list alone can be shifted relative to ROCm's. A card with
+    missing/unreadable/zero-total figures simply has no entry. Empty off Linux.
+    """
+    if platform.system() != "Linux":
+        return {}
+
+    try:
+        by_pci: dict[str, tuple[float, float]] = {}
+        for bdf, _card_no, dev_dir in _rocm_linux_amdgpu_cards():
+            if not bdf:
+                continue
+            try:
+                with open(os.path.join(dev_dir, "mem_info_vram_used")) as f:
+                    used_bytes = int(f.read().strip())
+                with open(os.path.join(dev_dir, "mem_info_vram_total")) as f:
+                    total_bytes = int(f.read().strip())
+            except (OSError, ValueError):
+                continue
+            if total_bytes <= 0:
+                continue
+            by_pci[bdf.lower()] = (
+                round(used_bytes / (1024**3), 2),
+                round(total_bytes / (1024**3), 2),
+            )
+        return by_pci
+    except Exception:
+        return {}
+
+
+# ── Windows AMD/ROCm per-adapter VRAM (issue #7072) ──────────────────────────
+# amd-smi is disabled and hipMemGetInfo reports free==total, so read used from the
+# per-LUID "GPU Adapter Memory" perf counters and take each total from torch, so
+# every GPU shows instead of one fake device with GPU 0's total.
+# Placeholder adapters (Basic Render Driver / idle iGPU) drop only when they would
+# outnumber the real torch devices.
+_ROCM_WIN_ADAPTER_MIN_BYTES = 64 * 1024 * 1024  # 64 MiB
+
+
+def _rocm_windows_perf_counter_vram_by_adapter() -> Optional[list[tuple[str, float]]]:
+    """Per-adapter dedicated VRAM usage on Windows via Performance Counters.
+
+    Returns ``[(instance_name, used_bytes)]`` (one per LUID-named adapter), or
+    ``None`` when the counter is unavailable/localized/empty so callers fall back.
     """
     if platform.system() != "Windows":
-        return None, None
+        return None
     try:
+        # Emit "<InstanceName>|<CookedValue>" per sample, or a __NONE__ sentinel.
         ps = (
             "$s=(Get-Counter '\\GPU Adapter Memory(*)\\Dedicated Usage'"
             " -ErrorAction SilentlyContinue).CounterSamples;"
-            "if($s){($s|Measure-Object CookedValue -Sum).Sum}else{-1}"
+            "if($s){$s|ForEach-Object{'{0}|{1}' -f $_.InstanceName,[int64]$_.CookedValue}}"
+            "else{'__NONE__'}"
         )
         r = subprocess.run(
             ["powershell", "-NoProfile", "-NonInteractive", "-Command", ps],
@@ -746,16 +1028,167 @@ def _rocm_windows_perf_counter_vram_gb() -> tuple[Optional[float], Optional[floa
             timeout = 5,
         )
         if r.returncode != 0 or not r.stdout.strip():
-            return None, None
-        used_bytes = float(r.stdout.strip())
-        if used_bytes < 0:
-            return None, None
-        import torch as _torch
-
-        total_bytes = _torch.cuda.get_device_properties(0).total_memory
-        return round(used_bytes / (1024**3), 2), round(total_bytes / (1024**3), 2)
+            return None
+        adapters: list[tuple[str, float]] = []
+        for line in r.stdout.splitlines():
+            line = line.strip()
+            if not line or line == "__NONE__" or "|" not in line:
+                continue
+            instance, _, raw = line.rpartition("|")
+            try:
+                used = float(raw.strip())
+            except (ValueError, TypeError):
+                continue
+            if used < 0:
+                continue
+            adapters.append((instance.strip(), used))
+        return adapters or None
     except Exception:
-        return None, None
+        return None
+
+
+def _match_adapter_used_to_devices(
+    adapter_useds: list[float], device_totals: list[float]
+) -> list[Optional[float]]:
+    """Attribute per-adapter used bytes to torch devices by capacity ranking.
+
+    Windows shares no key between LUID counters and torch ordinals, so usages are
+    ranked against device totals and each is trusted only when capacity *forces* it
+    (it exceeds every smaller device); an ambiguous ranking reports unknown
+    (``None``) rather than fabricate a per-index free.
+
+    Extra counters mean a hidden/display adapter, and the noise filter may have
+    dropped a real reading, so values are emitted only when the supra-threshold
+    counters number EXACTLY the visible devices AND capacity forces the mapping;
+    otherwise every device is unknown. Best-effort but correct for the common
+    loaded-card case (#7072). Returns a list aligned to ``device_totals``.
+    """
+    n = len(device_totals)
+    if n == 0:
+        return []
+    useds = sorted(adapter_useds, reverse = True)
+    ranked_positions = sorted(range(n), key = lambda i: -device_totals[i])
+    ranked_totals = [device_totals[pos] for pos in ranked_positions]
+    assigned: list[Optional[float]]
+    # More counters than devices -> a hidden/display adapter (check before noise filter).
+    if len(useds) > n:
+        non_trivial = [u for u in useds if u >= _ROCM_WIN_ADAPTER_MIN_BYTES]
+        if len(non_trivial) != n:
+            # Not a clean bijection (a masked GPU is busy or a visible card idle):
+            # no counter maps to a specific card, so report unknown.
+            return [None] * n
+        # Exactly n supra-threshold counters: extras were placeholders, so a
+        # capacity-ranked bijection is plausible.
+        useds = non_trivial
+        ranked_useds = [useds[rank] for rank in range(n)]
+        # A usage above its ranked capacity is a hidden larger GPU; clamping onto the
+        # smaller card would fabricate a fully-used reading.
+        for rank in range(n):
+            if ranked_useds[rank] > ranked_totals[rank]:
+                return [None] * n
+        # Capacity forces the mapping only when the usage exceeds the next-smaller
+        # capacity; the smallest card and merely-fitting usages stay unknown.
+        # Keeps 40 GiB over 48/8 GiB -> [40, None].
+        assigned = [None] * n
+        for rank, pos in enumerate(ranked_positions):
+            if rank + 1 < n and ranked_useds[rank] > ranked_totals[rank + 1]:
+                assigned[pos] = min(ranked_useds[rank], device_totals[pos])
+        return assigned
+    # No hidden adapters: every counter is a visible card, so ranking is a permutation.
+    ranked_useds = [useds[rank] if rank < len(useds) else 0.0 for rank in range(n)]
+    # Ambiguous if a strictly larger usage also fits the next smaller card: the two
+    # could be swapped without breaking capacity, so ranking can't tell them apart.
+    for rank in range(n - 1):
+        upper, lower = ranked_useds[rank], ranked_useds[rank + 1]
+        if upper > lower and upper <= ranked_totals[rank + 1]:
+            return [None] * n
+    assigned = [None] * n
+    for rank, pos in enumerate(ranked_positions):
+        if rank < len(useds):
+            assigned[pos] = min(useds[rank], device_totals[pos])
+    return assigned
+
+
+def _rocm_windows_per_device_vram(device_indices: list[int]) -> list[Dict[str, Any]]:
+    """Per-GPU VRAM on Windows AMD/ROCm: total from torch properties (reliable),
+    used from the per-adapter Dedicated Usage counter.
+
+    Returns ``{index, visible_ordinal, name, used_gb, total_gb}`` per visible GPU
+    (``used_gb`` may be ``None`` when the counter is unavailable), or ``[]`` when
+    torch can't enumerate devices so callers fall through to the torch last resort.
+    """
+    if platform.system() != "Windows":
+        return []
+    mod, _ = _torch_get_device_module()
+    if mod is None:
+        return []
+    # Totals/names from torch properties (mem_get_info's free==total quirk zeroes used).
+    dev_meta: list[Dict[str, Any]] = []
+    for ordinal, phys_idx in enumerate(device_indices):
+        try:
+            props = mod.get_device_properties(ordinal)
+            dev_meta.append(
+                {
+                    "index": phys_idx,
+                    "visible_ordinal": ordinal,
+                    "name": props.name,
+                    "total_bytes": int(props.total_memory),
+                }
+            )
+        except Exception as e:
+            logger.debug("torch property probe failed for ordinal %d: %s", ordinal, e)
+    if not dev_meta:
+        return []
+
+    adapters = _rocm_windows_perf_counter_vram_by_adapter()
+    if adapters:
+        assigned = _match_adapter_used_to_devices(
+            [used for _, used in adapters],
+            [d["total_bytes"] for d in dev_meta],
+        )
+    else:
+        # Counter unavailable: show every GPU with a correct total, used unknown.
+        assigned = [None] * len(dev_meta)
+
+    devices: list[Dict[str, Any]] = []
+    for meta, used_bytes in zip(dev_meta, assigned):
+        total_gb = round(meta["total_bytes"] / (1024**3), 2)
+        used_gb = round(used_bytes / (1024**3), 2) if used_bytes is not None else None
+        devices.append(
+            {
+                "index": meta["index"],
+                "visible_ordinal": meta["visible_ordinal"],
+                "name": meta["name"],
+                "used_gb": used_gb,
+                "total_gb": total_gb,
+            }
+        )
+    return devices
+
+
+def _rocm_windows_device_payload_entry(
+    device: DeviceType, dev: Dict[str, Any], gpu_util_pct: Optional[float]
+) -> Dict[str, Any]:
+    """Build a ``get_gpu_utilization`` device entry from a per-device VRAM dict."""
+    total_gb = dev["total_gb"]
+    used_gb = dev["used_gb"]
+    return {
+        "available": True,
+        "backend": _backend_label(device),
+        "index": dev["index"],
+        "visible_ordinal": dev["visible_ordinal"],
+        "name": dev.get("name", "Unknown"),
+        "gpu_utilization_pct": gpu_util_pct,
+        "temperature_c": None,
+        "vram_used_gb": used_gb,
+        "vram_total_gb": total_gb,
+        "vram_utilization_pct": round((used_gb / total_gb) * 100, 1)
+        if total_gb and total_gb > 0 and used_gb is not None
+        else None,
+        "power_draw_w": None,
+        "power_limit_w": None,
+        "power_utilization_pct": None,
+    }
 
 
 def _gpu_utilization_payload(
@@ -821,30 +1254,24 @@ def get_gpu_utilization() -> Dict[str, Any]:
                 index_kind = result.get("index_kind"),
             )
 
-        # Fallback Windows ROCm
+        # Fallback Windows ROCm: per-adapter VRAM attribution (issue #7072), so
+        # every visible GPU is shown instead of a sum collapsed onto one device.
         if IS_ROCM and platform.system() == "Windows":
-            _win_used, _win_total = _rocm_windows_perf_counter_vram_gb()
-            if _win_used is not None and _win_total is not None:
-                _win_util = _rocm_windows_perf_counter_gpu_util_pct()
+            _win_ids = _get_parent_visible_gpu_spec().get("numeric_ids")
+            if not _win_ids:
+                _win_ids = list(range(_torch_get_physical_gpu_count() or 0))
+            _win_devices = _rocm_windows_per_device_vram(_win_ids)
+            if _win_devices:
+                # A single visible GPU can own the aggregate 3D-engine utilization;
+                # across several GPUs the sum isn't per-device, so leave it unset.
+                _win_util = (
+                    _rocm_windows_perf_counter_gpu_util_pct() if len(_win_devices) == 1 else None
+                )
                 return _gpu_utilization_payload(
                     device,
                     [
-                        {
-                            "available": True,
-                            "backend": _backend_label(device),
-                            "index": 0,
-                            "visible_ordinal": 0,
-                            "gpu_utilization_pct": _win_util,
-                            "temperature_c": None,
-                            "vram_used_gb": _win_used,
-                            "vram_total_gb": _win_total,
-                            "vram_utilization_pct": round((_win_used / _win_total) * 100, 1)
-                            if _win_total > 0
-                            else None,
-                            "power_draw_w": None,
-                            "power_limit_w": None,
-                            "power_utilization_pct": None,
-                        }
+                        _rocm_windows_device_payload_entry(device, _wd, _win_util)
+                        for _wd in _win_devices
                     ],
                 )
 
@@ -901,7 +1328,7 @@ def get_gpu_utilization() -> Dict[str, Any]:
                         "vram_used_gb": _used,
                         "vram_total_gb": _total,
                         "vram_utilization_pct": round((_used / _total) * 100, 1)
-                        if _total > 0
+                        if _total > 0 and _used is not None
                         else None,
                         "power_draw_w": None,
                         "power_limit_w": None,
@@ -995,19 +1422,27 @@ def _apply_unified_memory_correction(
     endpoints stay in sync on AMD iGPUs with unified memory.
     """
     torch_total_gb = torch_info["total_gb"]
+    torch_used_gb = torch_info.get("used_gb")
     smi_total_gb = device_metrics.get("vram_total_gb") or 0.0
+    # torch sees the full unified (GTT) pool; amd-smi only the dedicated carve-out.
+    # Adopt torch's larger total regardless of used: on Windows ROCm torch_used is
+    # None (free==total sentinel) but its total stays authoritative. Overwrite used
+    # only when torch's is known, then recompute utilization against whatever remains.
     if torch_total_gb > smi_total_gb:
-        torch_used_gb = torch_info["used_gb"]
         device_metrics["vram_total_gb"] = torch_total_gb
-        device_metrics["vram_used_gb"] = torch_used_gb
+        if torch_used_gb is not None:
+            device_metrics["vram_used_gb"] = torch_used_gb
+        _used_for_pct = device_metrics.get("vram_used_gb")
         device_metrics["vram_utilization_pct"] = (
-            round((torch_used_gb / torch_total_gb) * 100, 1) if torch_total_gb > 0 else None
+            round((_used_for_pct / torch_total_gb) * 100, 1)
+            if torch_total_gb > 0 and _used_for_pct is not None
+            else None
         )
         logger.debug(
-            "ROCm unified memory: replaced amd-smi VRAM (%.2f GB) with "
-            "torch mem_get_info total (%.2f GB) for device %s",
-            smi_total_gb,
+            "ROCm unified memory: adopted torch mem_get_info total (%.2f GB) over "
+            "amd-smi (%.2f GB) for device %s",
             torch_total_gb,
+            smi_total_gb,
             torch_info.get("index"),
         )
 
@@ -1049,6 +1484,75 @@ def _reconcile_primary_rocm_unified_memory(
     _apply_unified_memory_correction(utilization, torch_devices[0])
 
 
+def _rocm_visibility_mask_active() -> bool:
+    """True when any ROCm/CUDA visibility variable filters the device set."""
+    for var in (
+        "HIP_VISIBLE_DEVICES",
+        "ROCR_VISIBLE_DEVICES",
+        "CUDA_VISIBLE_DEVICES",
+        "GPU_DEVICE_ORDINAL",
+    ):
+        value = os.environ.get(var)
+        if value and value.strip():
+            return True
+    return False
+
+
+def _overlay_system_wide_vram(devices: list[Dict[str, Any]]) -> None:
+    """Replace process-local torch VRAM with system-wide Linux ROCm figures.
+
+    The torch fallback is process-local, so a model served by the separate
+    llama-server process reads as ~0 used even with the GPU full (#7072). DRM
+    sysfs gives per-card figures the kernel updates across all processes. Sources
+    are matched by the device's PHYSICAL index (never list position), and only
+    when NO visibility mask is active and the device count equals the host GPU
+    count; under any mask the index is not a verifiable host ordinal, so torch's
+    figures are kept. Best-effort, in place: a device with no matching card, or a
+    unified-memory APU whose sysfs total is below torch's GTT-backed total, keeps
+    torch's (mirrors _apply_unified_memory_correction).
+
+    Windows is intentionally not overlaid: its per-adapter perf counters cannot be
+    mapped to ROCm ordinals and miss WDDM shared memory, so the multi-GPU view
+    keeps torch there rather than risk misattributing another adapter's usage.
+    """
+    if not devices or platform.system() != "Linux":
+        return
+    # Match by PCI identity, never list position: index N in KFD topology is ROCm
+    # physical device N and carries its PCI address, which DRM sysfs keys on too.
+    # The two gates below verify ``index`` really is a host-physical ordinal
+    # (torch exposes no PCI id to check directly):
+    #   * No visibility mask -- any mask makes ``index`` container/ROCR-relative
+    #     rather than a host ordinal.
+    #   * Device count == host GPU count -- rules out a device-cgroup container
+    #     that sets no env var yet compacts torch's indices from zero.
+    pci_by_ordinal = _rocm_kfd_gpu_pci_ids()
+    if not pci_by_ordinal:
+        return
+    if _rocm_visibility_mask_active() or len(devices) != len(pci_by_ordinal):
+        return
+    vram_by_pci = _rocm_linux_sysfs_vram_by_pci_gb()
+    for dev in devices:
+        index = dev.get("index")
+        if not isinstance(index, int) or not (0 <= index < len(pci_by_ordinal)):
+            continue
+        entry = vram_by_pci.get(pci_by_ordinal[index].lower())
+        if entry is None:
+            continue
+        used, total = entry
+        dev_total = dev.get("vram_total_gb") or 0.0
+        # Overlay only a device that maps 1:1 to the whole card: torch total must
+        # match sysfs total within ~10%. A mismatch either way means a different
+        # memory scope -- a unified-memory APU (sysfs sees only the dedicated
+        # slice, torch the GTT pool) or a partitioned MI300 (sysfs reports the
+        # whole card, dwarfing a partition) -- and overlaying would misstate free
+        # VRAM (a partition would look like it has the whole card free).
+        if dev_total <= 0 or abs(total - dev_total) > 0.1 * dev_total:
+            continue
+        dev["vram_used_gb"] = used
+        dev["vram_total_gb"] = total
+        dev["vram_utilization_pct"] = round((used / total) * 100, 1) if total > 0 else None
+
+
 def get_visible_gpu_utilization() -> Dict[str, Any]:
     device = get_device()
 
@@ -1067,6 +1571,49 @@ def get_visible_gpu_utilization() -> Dict[str, Any]:
                 _reconcile_rocm_unified_memory(result, numeric_ids)
             return result
 
+        # Windows AMD/ROCm (issue #7072): the System tab's VRAM source. The torch
+        # fallback below would report used==0 (free==total), so read per-adapter
+        # Dedicated Usage instead; total from torch properties.
+        if IS_ROCM and platform.system() == "Windows":
+            win_numeric_ids = parent_visible_spec.get("numeric_ids")
+            if win_numeric_ids:
+                win_ids = win_numeric_ids
+                win_index_kind = "physical"
+            else:
+                win_ids = list(range(_torch_get_physical_gpu_count() or 0))
+                win_index_kind = "relative"
+            win_devices = _rocm_windows_per_device_vram(win_ids)
+            if win_devices:
+                devices = []
+                for wd in win_devices:
+                    total = wd["total_gb"]
+                    used = wd["used_gb"]
+                    devices.append(
+                        {
+                            "index": wd["index"],
+                            "index_kind": win_index_kind,
+                            "visible_ordinal": wd["visible_ordinal"],
+                            "name": wd.get("name"),
+                            "gpu_utilization_pct": None,
+                            "temperature_c": None,
+                            "vram_used_gb": used,
+                            "vram_total_gb": total,
+                            "vram_utilization_pct": round((used / total) * 100, 1)
+                            if total and total > 0 and used is not None
+                            else None,
+                            "power_draw_w": None,
+                            "power_limit_w": None,
+                            "power_utilization_pct": None,
+                        }
+                    )
+                return {
+                    "available": True,
+                    "backend": _backend_label(device),
+                    "parent_visible_gpu_ids": win_numeric_ids or [],
+                    "devices": devices,
+                    "index_kind": win_index_kind,
+                }
+
     # Torch-based fallback for CUDA (nvidia-smi unavailable, AMD ROCm) and XPU (Intel)
     if device in (DeviceType.CUDA, DeviceType.XPU):
         parent_ids = get_parent_visible_gpu_ids()
@@ -1084,6 +1631,13 @@ def get_visible_gpu_utilization() -> Dict[str, Any]:
             for td in torch_devices:
                 total = td["total_gb"]
                 used = td["used_gb"]
+                # used=None is a deliberate "telemetry unavailable" signal
+                # from _torch_get_per_device_info (e.g. XPU without
+                # mem_get_info); propagate None instead of dividing by it. On
+                # CUDA/ROCm used is always an int, so this stays byte-identical.
+                vram_pct = (
+                    round((used / total) * 100, 1) if used is not None and total > 0 else None
+                )
                 devices.append(
                     {
                         "index": td["index"],
@@ -1093,14 +1647,18 @@ def get_visible_gpu_utilization() -> Dict[str, Any]:
                         "temperature_c": None,
                         "vram_used_gb": used,
                         "vram_total_gb": total,
-                        "vram_utilization_pct": round((used / total) * 100, 1)
-                        if total > 0
-                        else None,
+                        "vram_utilization_pct": vram_pct,
                         "power_draw_w": None,
                         "power_limit_w": None,
                         "power_utilization_pct": None,
                     }
                 )
+            if IS_ROCM and index_kind == "physical":
+                # Swap process-local torch VRAM for system-wide sysfs so a model
+                # held by the separate llama-server process shows up (#7072).
+                # Physical-index only: a relative index (UUID/MIG mask) is not a
+                # host GPU id. The overlay verifies the rest itself.
+                _overlay_system_wide_vram(devices)
             return {
                 "available": True,
                 "backend": _backend_label(device),
@@ -1157,6 +1715,82 @@ _visible_gpu_count: Optional[int] = None
 
 
 def _get_parent_visible_gpu_spec() -> Dict[str, Any]:
+    # On Intel XPU, visibility is controlled by ZE_AFFINITY_MASK (Level Zero),
+    # not CUDA_VISIBLE_DEVICES.
+    if get_device() == DeviceType.XPU:
+        xpu_mask_raw = os.environ.get("ZE_AFFINITY_MASK")
+        composite = _xpu_hierarchy_is_composite()
+
+        if xpu_mask_raw is None:
+            # COMPOSITE: root GPU IDs are stable physical IDs.
+            if composite:
+                return {
+                    "raw": None,
+                    "numeric_ids": list(range(get_physical_gpu_count())),
+                    "supports_explicit_gpu_ids": True,
+                }
+            # FLAT (oneAPI default): ordinals are tile/device handles, not
+            # physical GPU IDs. numeric_ids=None so telemetry uses relative
+            # ordinals; explicit selection needs ZE_FLAT_DEVICE_HIERARCHY=COMPOSITE.
+            return {
+                "raw": None,
+                "numeric_ids": None,
+                "supports_explicit_gpu_ids": False,
+            }
+
+        xpu_mask = xpu_mask_raw.strip()
+        if xpu_mask == "":
+            return {
+                "raw": xpu_mask,
+                "numeric_ids": [],
+                "supports_explicit_gpu_ids": True,
+            }
+
+        # Subdevice syntax ("N.M") expands one root into multiple
+        # logical devices -- not addressable by explicit root-ID selection.
+        has_subdevice = any("." in token.strip() for token in xpu_mask.split(",") if token.strip())
+        if has_subdevice:
+            return {
+                "raw": xpu_mask,
+                "numeric_ids": None,
+                "supports_explicit_gpu_ids": False,
+            }
+
+        # FLAT numeric entries are tile handles, not physical GPU IDs. Keep
+        # numeric_ids unresolved so every telemetry and picker consumer uses
+        # relative torch ordinals and cannot advertise them as pinnable roots.
+        if not composite:
+            tokens = [token.strip() for token in xpu_mask.split(",") if token.strip()]
+            if tokens and all(token.isdecimal() for token in tokens):
+                return {
+                    "raw": xpu_mask,
+                    "numeric_ids": None,
+                    "supports_explicit_gpu_ids": False,
+                }
+            return {
+                "raw": xpu_mask,
+                "numeric_ids": None,
+                "supports_explicit_gpu_ids": False,
+            }
+
+        # COMPOSITE + pure numeric (subdevice handled above). _parse_ze_mask_roots
+        # maps to root GPU IDs, dropping non-decimal tokens so "*"/"GPU-uuid" -> [].
+        roots_with_dupes = _parse_ze_mask_roots(xpu_mask)
+        if not roots_with_dupes:
+            # Unparseable mask (e.g. "*", "GPU-uuid") -- cannot map to
+            # physical root IDs.
+            return {
+                "raw": xpu_mask,
+                "numeric_ids": None,
+                "supports_explicit_gpu_ids": False,
+            }
+
+        return {
+            "raw": xpu_mask,
+            "numeric_ids": roots_with_dupes,
+            "supports_explicit_gpu_ids": True,
+        }
+
     # ROCm uses HIP/ROCR_VISIBLE_DEVICES on top of CUDA_VISIBLE_DEVICES; check
     # them first. Explicit None checks (not `or`) so "" reads as "no visible GPUs".
     cuda_visible = None
@@ -1213,24 +1847,44 @@ def get_parent_visible_gpu_ids() -> list[int]:
     return list(parent_visible_ids) if parent_visible_ids is not None else []
 
 
-def resolve_requested_gpu_ids(gpu_ids: Optional[list[int]]) -> list[int]:
+def resolve_requested_gpu_ids(
+    gpu_ids: Optional[list[int]], *, is_vulkan: bool = False
+) -> list[int]:
     parent_visible_spec = _get_parent_visible_gpu_spec()
     parent_visible_ids = get_parent_visible_gpu_ids()
     physical_gpu_count = get_physical_gpu_count()
 
     if gpu_ids is None:
-        return parent_visible_ids
+        return [] if is_vulkan else parent_visible_ids
 
     requested_ids = list(gpu_ids)
     if len(requested_ids) == 0:
-        return parent_visible_ids
+        return [] if is_vulkan else parent_visible_ids
+
+    if is_vulkan:
+        # A Vulkan build selects by ggml Vulkan ordinal (--device VulkanN), a separate
+        # index space from CUDA/ROCm ids that may be empty under CPU-only torch. The
+        # CUDA parent-visible / physical-count checks below do not apply; only reject
+        # malformed ordinals (issue #7239).
+        if len(set(requested_ids)) != len(requested_ids):
+            raise ValueError(f"Invalid gpu_ids {requested_ids}: duplicate GPU IDs are not allowed.")
+        negative_ids = [gpu_id for gpu_id in requested_ids if gpu_id < 0]
+        if negative_ids:
+            raise ValueError(
+                f"Invalid gpu_ids {requested_ids}: GPU IDs must be non-negative. "
+                f"Rejected IDs: {negative_ids}."
+            )
+        return requested_ids
 
     if not parent_visible_spec["supports_explicit_gpu_ids"]:
+        env_var_name = (
+            "ZE_AFFINITY_MASK" if get_device() == DeviceType.XPU else "CUDA_VISIBLE_DEVICES"
+        )
         raise ValueError(
             f"Invalid gpu_ids {requested_ids}: explicit physical GPU IDs are "
-            f"unsupported when CUDA_VISIBLE_DEVICES uses UUID/MIG entries "
-            f"({parent_visible_spec['raw']!r}). Omit gpu_ids to use the "
-            "parent-visible devices."
+            f"unsupported when {env_var_name} uses non-numeric or subdevice "
+            f"entries ({parent_visible_spec['raw']!r}). Omit gpu_ids to use "
+            "the parent-visible devices."
         )
 
     if len(set(requested_ids)) != len(requested_ids):
@@ -1669,8 +2323,11 @@ def auto_select_gpu_ids(
 ) -> tuple[Optional[list[int]], Dict[str, Any]]:
     metadata: Dict[str, Any] = {"selection_mode": "auto"}
 
-    if get_device() != DeviceType.CUDA:
-        metadata["selection_mode"] = "non_cuda"
+    # Auto-selection needs per-device free-VRAM telemetry, available on CUDA
+    # (nvidia-smi) and XPU (torch.xpu) but not MLX/CPU, which fall
+    # through to inheriting parent visibility.
+    if get_device() not in (DeviceType.CUDA, DeviceType.XPU):
+        metadata["selection_mode"] = "non_accelerator"
         return None, metadata
 
     required_gb, estimate_metadata = estimate_required_model_memory_gb(
@@ -1767,12 +2424,13 @@ def auto_select_gpu_ids(
             metadata["selection_mode"] = "auto"
             metadata["selected_gpu_ids"] = selected
             logger.debug(
-                "Selected GPUs automatically",
-                model_name = model_name,
-                selected_gpu_ids = selected,
-                usable_gb = metadata["usable_gb"],
-                required_gb = metadata.get("required_gb"),
-                multi_gpu_overhead = multi_gpu_overhead,
+                "Selected GPUs automatically: model=%s selected=%s usable_gb=%s "
+                "required_gb=%s multi_gpu_overhead=%s",
+                model_name,
+                selected,
+                metadata["usable_gb"],
+                metadata.get("required_gb"),
+                multi_gpu_overhead,
             )
             return selected, metadata
 
@@ -1788,12 +2446,13 @@ def auto_select_gpu_ids(
     metadata["usable_gb"] = round(fallback_usable, 3)
     metadata["selected_gpu_ids"] = fallback_all
     logger.warning(
-        "Falling back to all visible GPUs -- model may not fit",
-        model_name = model_name,
-        selected_gpu_ids = fallback_all,
-        usable_gb = metadata["usable_gb"],
-        required_gb = metadata.get("required_gb"),
-        multi_gpu_overhead = multi_gpu_overhead,
+        "Falling back to all visible GPUs; model may not fit: model=%s "
+        "selected=%s usable_gb=%s required_gb=%s multi_gpu_overhead=%s",
+        model_name,
+        fallback_all,
+        metadata["usable_gb"],
+        metadata.get("required_gb"),
+        multi_gpu_overhead,
     )
     return fallback_all, metadata
 
@@ -1827,10 +2486,10 @@ def prepare_gpu_selection(
     to a Hugging Face ``device_map`` string) and to ``apply_gpu_ids()`` in the
     worker subprocess (narrows ``CUDA_VISIBLE_DEVICES`` before torch/CUDA init).
     """
-    if gpu_ids and get_device() != DeviceType.CUDA:
+    if gpu_ids and get_device() not in (DeviceType.CUDA, DeviceType.XPU):
         raise ValueError(
-            f"gpu_ids {list(gpu_ids)} is only supported on CUDA devices, "
-            f"but the current backend is '{get_device().value}'."
+            f"gpu_ids {list(gpu_ids)} is only supported on CUDA and Intel XPU "
+            f"devices, but the current backend is '{get_device().value}'."
         )
 
     if gpu_ids:
@@ -1903,11 +2562,14 @@ def get_physical_gpu_count() -> int:
 def _backend_visible_devices_env() -> Optional[str]:
     """Return the raw visibility env string that applies to this backend.
 
-    On ROCm, HIP_VISIBLE_DEVICES / ROCR_VISIBLE_DEVICES take precedence over
-    CUDA_VISIBLE_DEVICES; this mirrors ``_get_parent_visible_gpu_spec`` so
+    On XPU the control is ``ZE_AFFINITY_MASK`` (not ``CUDA_VISIBLE_DEVICES``);
+    on ROCm, HIP_VISIBLE_DEVICES / ROCR_VISIBLE_DEVICES take precedence over
+    CUDA_VISIBLE_DEVICES. Mirrors ``_get_parent_visible_gpu_spec`` so
     ``backend_cuda_visible_devices`` reports the value actually narrowing the
-    visible device set.
+    visible device set on the current backend.
     """
+    if get_device() == DeviceType.XPU:
+        return os.environ.get("ZE_AFFINITY_MASK")
     if IS_ROCM:
         return _get_parent_visible_gpu_spec().get("raw")
     return os.environ.get("CUDA_VISIBLE_DEVICES")
@@ -2022,6 +2684,43 @@ def get_visible_gpu_count() -> int:
     if _visible_gpu_count is not None:
         return _visible_gpu_count
 
+    # Prefer torch.xpu.device_count() on Intel XPU: the Level Zero runtime
+    # correctly interprets ZE_AFFINITY_MASK semantics (e.g. subdevice syntax
+    # "0.0,0.1" collapses onto one root GPU). Supersedes the torch fallback below.
+    if get_device() == DeviceType.XPU:
+        xpu_mask_raw = os.environ.get("ZE_AFFINITY_MASK")
+        xpu_mask_set = xpu_mask_raw is not None
+        xpu_visible = (xpu_mask_raw or "").strip()
+        if xpu_mask_set and xpu_visible == "":
+            _visible_gpu_count = 0
+            return _visible_gpu_count
+
+        try:
+            import torch
+            _visible_gpu_count = torch.xpu.device_count()
+        except Exception as e:
+            logger.debug(
+                "torch.xpu.device_count() failed, falling back to mask parsing: %s",
+                e,
+            )
+            if xpu_visible:
+                # Fallback: count unique root device IDs from the mask.
+                # "device.subdevice" notation means "0.0,0.1" is 1 root, not 2.
+                # Without torch the hierarchy mode is unknown, so root-device
+                # counting is the conservative choice.
+                if xpu_visible == "*":
+                    # Documented wildcard: all physical XPUs visible.
+                    _visible_gpu_count = get_physical_gpu_count()
+                else:
+                    roots = _parse_ze_mask_roots(xpu_visible)
+                    # Non-parseable masks (",,,", "GPU-abc") yield an empty
+                    # roots list, treated as 0 visible devices, not "all
+                    # visible" -- no evidence the whole fleet was intended.
+                    _visible_gpu_count = len(set(roots))
+            else:
+                _visible_gpu_count = get_physical_gpu_count()
+        return _visible_gpu_count
+
     # _get_parent_visible_gpu_spec() already handles HIP_VISIBLE_DEVICES /
     # ROCR_VISIBLE_DEVICES on ROCm.
     visible_spec = _get_parent_visible_gpu_spec()
@@ -2035,20 +2734,18 @@ def get_visible_gpu_count() -> int:
             _visible_gpu_count = len([x for x in raw.split(",") if x.strip()])
         return _visible_gpu_count
 
-    # No visibility env var set -- try torch, else physical count
+    # No visibility env var set -- try torch, else physical count. XPU is
+    # handled by the early return above, so only torch.cuda is needed here.
     try:
         import torch
-        if get_device() == DeviceType.XPU and hasattr(torch, "xpu"):
-            _visible_gpu_count = torch.xpu.device_count()
-        else:
-            _visible_gpu_count = torch.cuda.device_count()
+        _visible_gpu_count = torch.cuda.device_count()
     except Exception:
         _visible_gpu_count = get_physical_gpu_count()
 
     return _visible_gpu_count
 
 
-def apply_gpu_ids(gpu_ids) -> None:
+def apply_gpu_ids(gpu_ids, backend: Optional[str] = None) -> None:
     if gpu_ids is None:
         return
 
@@ -2064,6 +2761,62 @@ def apply_gpu_ids(gpu_ids) -> None:
     else:
         value = str(gpu_ids)
 
+    # Intel XPU honors ZE_AFFINITY_MASK, not CUDA_VISIBLE_DEVICES; route XPU
+    # pinning through it so worker subprocesses are restricted to the intended GPU.
+    # Decide WITHOUT get_device(): workers call this before detect_hardware(),
+    # and a lazy detect would probe torch.cuda against the unmasked parent env,
+    # latching device enumeration before the mask below is written. Pre-detect,
+    # use env + torch BUILD attributes only (no runtime init, like the ROCm
+    # mirror below).
+    _is_xpu = DEVICE == DeviceType.XPU
+    if backend is not None:
+        # The spawning parent's detected backend (config["device_backend"]):
+        # exact and probe-free, so the mask target always matches what
+        # detect_hardware() decided in the parent, including its XPU
+        # availability check and CUDA fallback.
+        _is_xpu = backend == DeviceType.XPU.value
+    elif DEVICE is None:
+        # No parent backend passed (direct caller). version.xpu can be None
+        # on a working XPU build, so also accept torch.xpu._is_compiled()
+        # (a pure symbol-presence check, no runtime init). UNSLOTH_FORCE_XPU
+        # counts only on an XPU-capable build: detect_hardware() falls back
+        # to CUDA when XPU is missing, and the mask target must follow.
+        try:
+            import torch as _torch
+
+            _ver = _torch.version
+            _is_comp = getattr(getattr(_torch, "xpu", None), "_is_compiled", None)
+            _xpu_build = (callable(_is_comp) and bool(_is_comp())) or (
+                getattr(_ver, "xpu", None) is not None
+            )
+            if os.environ.get("UNSLOTH_FORCE_XPU") == "1":
+                _is_xpu = _xpu_build
+            else:
+                # Mirror detect_hardware: hidden CUDA prefers XPU on an
+                # XPU-capable build (with or without a ZE mask -- detection
+                # falls through to XPU either way), where writing these ids
+                # to CUDA_VISIBLE_DEVICES would re-expose the deliberately
+                # hidden CUDA.
+                _cvd = os.environ.get("CUDA_VISIBLE_DEVICES")
+                _cuda_hidden = _cvd is not None and _cvd.strip() in ("", "-1")
+                _is_xpu = _xpu_build and (
+                    _cuda_hidden
+                    or (getattr(_ver, "cuda", None) is None and getattr(_ver, "hip", None) is None)
+                )
+        except Exception as e:
+            logger.debug(
+                "apply_gpu_ids: torch XPU probe skipped (%s: %s)",
+                type(e).__name__,
+                e,
+            )
+    if _is_xpu:
+        os.environ["ZE_AFFINITY_MASK"] = value
+        # Leave inherited CUDA_VISIBLE_DEVICES alone -- clearing it could let
+        # the worker flip back to CUDA on hybrid hosts.
+        _visible_gpu_count = None
+        logger.info("Applied gpu_ids: ZE_AFFINITY_MASK='%s'", value)
+        return
+
     os.environ["CUDA_VISIBLE_DEVICES"] = value
     # Keep ROCm visibility env vars in sync. Workers may call apply_gpu_ids()
     # before detect_hardware() (IS_ROCM still False), so also mirror when the
@@ -2108,26 +2861,41 @@ def get_device_map(gpu_ids: Optional[list[int]] = None) -> str:
 
     Returns ``"balanced"`` (shard evenly across GPUs) when:
       - ``gpu_ids`` explicitly lists >1 GPU, **or**
-      - ``CUDA_VISIBLE_DEVICES`` uses UUID/MIG identifiers (non-numeric) and
-        >1 GPU is visible (fallback: numeric IDs unresolvable, so assume
-        multi-GPU is intended).
+      - ``CUDA_VISIBLE_DEVICES``/``ZE_AFFINITY_MASK`` uses non-numeric
+        identifiers (UUID/MIG/wildcard) and >1 GPU is visible (fallback:
+        numeric IDs unresolvable, so assume multi-GPU is intended).
 
-    Returns ``"sequential"`` (single device) otherwise, including non-CUDA
-    backends (CPU, MLX).
+    Returns ``"sequential"`` (single device) otherwise, including CPU/MLX
+    backends.
 
     Use ``prepare_gpu_selection()`` upstream to determine ``gpu_ids`` -- it
     handles auto-selecting the minimum GPUs needed for a model.
     """
     device = get_device()
-    if device == DeviceType.CUDA:
+    if device in (DeviceType.CUDA, DeviceType.XPU):
         multi_gpu = gpu_ids is not None and len(gpu_ids) > 1
 
         if not multi_gpu:
-            # UUID/MIG masks can't be split into numeric IDs; >1 visible GPU
-            # means multi-GPU sharding is intended.
             parent_visible_spec = _get_parent_visible_gpu_spec()
-            if parent_visible_spec["numeric_ids"] is None and get_visible_gpu_count() > 1:
-                multi_gpu = True
+            if device == DeviceType.CUDA:
+                # UUID/MIG masks can't be split into numeric IDs; >1 visible GPU
+                # means multi-GPU sharding is intended.
+                if parent_visible_spec["numeric_ids"] is None and get_visible_gpu_count() > 1:
+                    multi_gpu = True
+            elif device == DeviceType.XPU and gpu_ids is None:
+                # Shard across visible XPU ordinals via HF (no mask rewrite),
+                # only when no gpu_ids were passed -- an explicit gpu_ids=[0]
+                # means "use exactly device 0" and must stay sequential.
+                supports_physical = parent_visible_spec["supports_explicit_gpu_ids"]
+                has_multiple_numeric = (
+                    parent_visible_spec["numeric_ids"] is not None
+                    and len(parent_visible_spec["numeric_ids"]) > 1
+                )
+                has_multiple_unresolved = (
+                    parent_visible_spec["numeric_ids"] is None and get_visible_gpu_count() > 1
+                )
+                if has_multiple_unresolved or (not supports_physical and has_multiple_numeric):
+                    multi_gpu = True
 
         if multi_gpu:
             return "balanced"
@@ -2162,6 +2930,19 @@ def raise_if_offloaded(
     )
 
 
+def get_torch_device_str() -> str:
+    """
+    Return the torch device string for the detected hardware.
+    E.g. "cuda", "xpu", or "cpu".
+    """
+    device = get_device()
+    if device == DeviceType.CUDA:
+        return "cuda"
+    elif device == DeviceType.XPU:
+        return "xpu"
+    return "cpu"
+
+
 def safe_num_proc(desired: Optional[int] = None) -> int:
     """
     Return a safe ``num_proc`` for ``dataset.map()`` calls.
@@ -2229,7 +3010,32 @@ def dataset_map_num_proc(desired: Optional[int] = None) -> Optional[int]:
     Returns ``None`` on spawn platforms (Windows, macOS) because ``datasets``
     treats ``num_proc=1`` as multiprocessing (creates ``Pool(1)``); only
     ``num_proc=None`` guarantees in-process execution.
+
+    Also returns ``None`` on XPU once its runtime is initialized in this
+    process: ``os.fork()`` corrupts the Level-Zero context, making Triton
+    kernels fail with "Pointer argument doesn't reference XPU device memory".
+    Pre-init XPU hosts can still parallelize CPU-side preprocessing.
     """
     if sys.platform in ("win32", "darwin"):
         return None
+
+    if get_device() == DeviceType.XPU:
+        try:
+            import torch
+        except Exception:
+            # No torch means no active XPU runtime, so CPU-side dataset
+            # parallelism is still safe.
+            return safe_num_proc(desired)
+
+        xpu = getattr(torch, "xpu", None)
+        is_initialized = getattr(xpu, "is_initialized", None)
+        if callable(is_initialized):
+            try:
+                if is_initialized():
+                    return None
+            except Exception as e:
+                # Treat a failing probe as "runtime not touched yet" so
+                # pre-init CPU preprocessing can still parallelize.
+                logger.debug("torch.xpu.is_initialized() probe failed: %s", e)
+
     return safe_num_proc(desired)
diff --git a/studio/backend/utils/helper_precache_settings.py b/studio/backend/utils/helper_precache_settings.py
index db19a2d028..e7d3c0e6dd 100644
--- a/studio/backend/utils/helper_precache_settings.py
+++ b/studio/backend/utils/helper_precache_settings.py
@@ -32,7 +32,7 @@ def helper_model_disabled_by_env() -> bool:
 def get_helper_precache_enabled() -> bool:
     """Read the persisted startup pre-cache preference.
 
-    Missing or unreadable settings default to False so Studio startup never
+    Missing or unreadable settings default to False so Unsloth startup never
     performs optional network work unless the user explicitly opted in.
     """
     try:
@@ -45,7 +45,7 @@ def get_helper_precache_enabled() -> bool:
 
 
 def set_helper_precache_enabled(value: Any) -> bool:
-    """Persist whether Studio should pre-cache the Helper LLM at startup."""
+    """Persist whether Unsloth should pre-cache the Helper LLM at startup."""
     parsed = _coerce_bool(value)
     if parsed is None:
         raise ValueError("Helper LLM startup pre-cache must be true or false.")
diff --git a/studio/backend/utils/hf_cache_settings.py b/studio/backend/utils/hf_cache_settings.py
new file mode 100644
index 0000000000..07d901a3d2
--- /dev/null
+++ b/studio/backend/utils/hf_cache_settings.py
@@ -0,0 +1,362 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Live, persisted Hugging Face cache routing for Unsloth Studio.
+
+Hugging Face reads cache environment variables at import time.  Studio therefore
+owns an explicit cache snapshot for each operation instead of trying to refresh
+``huggingface_hub.constants`` in the long-running API process.
+"""
+
+from __future__ import annotations
+
+import os
+import shutil
+import tempfile
+import threading
+from contextlib import contextmanager
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Iterator, Literal, Mapping, Optional
+
+
+CACHE_HOME_SETTING_KEY = "hugging_face_cache_home"
+CACHE_HISTORY_SETTING_KEY = "hugging_face_cache_history"
+MAX_CACHE_HISTORY = 16
+
+CacheSource = Literal["default", "studio", "environment"]
+
+_CACHE_ENV_KEYS = (
+    "HF_HOME",
+    "HF_HUB_CACHE",
+    "HUGGINGFACE_HUB_CACHE",
+    "HF_XET_CACHE",
+)
+# Imported by storage_roots._setup_cache_env before Studio seeds defaults.
+_EXPLICIT_CACHE_ENV = {
+    key: value.strip()
+    for key in _CACHE_ENV_KEYS
+    if (value := os.environ.get(key)) is not None and value.strip()
+}
+_settings_lock = threading.RLock()
+_spawn_env_lock = threading.RLock()
+
+
+@dataclass(frozen = True)
+class HuggingFaceCachePaths:
+    cache_home: Path
+    hub_cache: Path
+    xet_cache: Path
+    source: CacheSource
+    environment_variable: Optional[str] = None
+
+    @property
+    def editable(self) -> bool:
+        return self.source != "environment"
+
+    @property
+    def is_custom(self) -> bool:
+        return self.source == "studio"
+
+    def child_env(self, base: Optional[Mapping[str, str]] = None) -> dict[str, str]:
+        env = dict(os.environ if base is None else base)
+        # Do not rewrite HF_HOME. It also owns HF's token path, and credentials
+        # must not be moved onto a removable cache volume.
+        env["HF_HUB_CACHE"] = str(self.hub_cache)
+        env["HF_XET_CACHE"] = str(self.xet_cache)
+        env.pop("HUGGINGFACE_HUB_CACHE", None)
+        return env
+
+
+def _default_cache_home() -> Path:
+    xdg = (os.environ.get("XDG_CACHE_HOME") or "").strip()
+    return (Path(xdg).expanduser() if xdg else Path.home() / ".cache") / "huggingface"
+
+
+def _canonical(path: Path | str) -> Path:
+    return Path(path).expanduser().resolve(strict = False)
+
+
+def _environment_paths() -> Optional[HuggingFaceCachePaths]:
+    explicit_home = _EXPLICIT_CACHE_ENV.get("HF_HOME")
+    explicit_hub = _EXPLICIT_CACHE_ENV.get("HF_HUB_CACHE") or _EXPLICIT_CACHE_ENV.get(
+        "HUGGINGFACE_HUB_CACHE"
+    )
+    if not explicit_home and not explicit_hub:
+        return None
+    explicit_xet = _EXPLICIT_CACHE_ENV.get("HF_XET_CACHE")
+    default_home = _default_cache_home()
+    hf_home = _canonical(explicit_home) if explicit_home else default_home
+    hub = _canonical(explicit_hub) if explicit_hub else hf_home / "hub"
+    xet = _canonical(explicit_xet) if explicit_xet else hf_home / "xet"
+    controlling = next(
+        key
+        for key in ("HF_HUB_CACHE", "HUGGINGFACE_HUB_CACHE", "HF_HOME")
+        if key in _EXPLICIT_CACHE_ENV
+    )
+    # Settings describes model downloads, so an explicit hub path is the
+    # displayed/opened location even when HF_HOME points somewhere else for
+    # credentials or XET data.
+    display_home = (
+        (hub.parent if explicit_hub and hub.name.lower() == "hub" else hub)
+        if explicit_hub
+        else hf_home
+    )
+    return HuggingFaceCachePaths(display_home, hub, xet, "environment", controlling)
+
+
+def _stored_cache_home() -> Optional[Path]:
+    try:
+        from storage.studio_db import get_app_setting
+        value = get_app_setting(CACHE_HOME_SETTING_KEY, None)
+    except Exception:
+        return None
+    if not isinstance(value, str) or not value.strip():
+        return None
+    try:
+        return _canonical(value.strip())
+    except (OSError, RuntimeError, ValueError):
+        return None
+
+
+def get_hf_cache_paths() -> HuggingFaceCachePaths:
+    env_paths = _environment_paths()
+    if env_paths is not None:
+        return env_paths
+    stored = _stored_cache_home()
+    if stored is not None:
+        xet = _EXPLICIT_CACHE_ENV.get("HF_XET_CACHE")
+        return HuggingFaceCachePaths(
+            stored,
+            stored / "hub",
+            _canonical(xet) if xet else stored / "xet",
+            "studio",
+        )
+    home = _default_cache_home()
+    xet = _EXPLICIT_CACHE_ENV.get("HF_XET_CACHE")
+    return HuggingFaceCachePaths(
+        home,
+        home / "hub",
+        _canonical(xet) if xet else home / "xet",
+        "default",
+    )
+
+
+def active_hf_hub_cache() -> str:
+    """Return the current hub cache as a string for library call kwargs."""
+
+    return str(get_hf_cache_paths().hub_cache)
+
+
+@contextmanager
+def child_environment_for_spawn(environment: Mapping[str, str]) -> Iterator[None]:
+    """Apply captured env before spawn imports the child entrypoint.
+
+    Applying variables only inside the multiprocessing target can be too late
+    for libraries that snapshot environment variables at import. The lock keeps
+    this short parent-process override atomic through ``Process.start()``.
+    """
+
+    with _spawn_env_lock:
+        missing = object()
+        saved_environment: dict[str, str | object] = {}
+        for key, value in environment.items():
+            saved_environment[key] = os.environ.get(key, missing)
+            os.environ[key] = value
+        try:
+            yield
+        finally:
+            for key, previous in saved_environment.items():
+                if previous is missing:
+                    os.environ.pop(key, None)
+                else:
+                    os.environ[key] = str(previous)
+
+
+def initialize_hf_cache_environment() -> HuggingFaceCachePaths:
+    """Seed import-time HF variables once during backend startup."""
+
+    paths = get_hf_cache_paths()
+    # Preserve an explicit HF_HOME, otherwise keep credentials at the platform
+    # default while routing cache bytes through the selected home.
+    if not os.environ.get("HF_HOME", "").strip():
+        os.environ["HF_HOME"] = str(_default_cache_home())
+    os.environ["HF_HUB_CACHE"] = str(paths.hub_cache)
+    os.environ["HF_XET_CACHE"] = str(paths.xet_cache)
+    if "HUGGINGFACE_HUB_CACHE" not in _EXPLICIT_CACHE_ENV:
+        os.environ.pop("HUGGINGFACE_HUB_CACHE", None)
+    for directory in (paths.hub_cache, paths.xet_cache):
+        try:
+            directory.mkdir(parents = True, exist_ok = True)
+        except OSError:
+            pass
+    return paths
+
+
+def _validate_cache_home(raw_path: str) -> Path:
+    value = raw_path.strip()
+    if not value:
+        raise ValueError("Choose a cache folder.")
+    candidate = Path(value).expanduser()
+    if not candidate.is_absolute():
+        raise ValueError("The Hugging Face cache folder must be an absolute path.")
+    try:
+        resolved = candidate.resolve(strict = False)
+    except (OSError, RuntimeError, ValueError) as exc:
+        raise ValueError("The Hugging Face cache folder is invalid.") from exc
+
+    if resolved.parent == resolved:
+        raise ValueError("Choose a folder inside the filesystem or drive root.")
+    try:
+        from hub.storage.scan_folders import (
+            contains_sensitive_path_component,
+            is_denied_system_path,
+        )
+    except ImportError:
+        contains_sensitive_path_component = is_denied_system_path = None
+    if is_denied_system_path is not None and is_denied_system_path(str(resolved)):
+        raise ValueError("System folders cannot be used for model downloads.")
+    if contains_sensitive_path_component is not None and contains_sensitive_path_component(
+        str(resolved)
+    ):
+        raise ValueError("Credential or config folders cannot be used for model downloads.")
+
+    parent = resolved.parent
+    if not parent.exists() or not parent.is_dir():
+        raise ValueError("The parent folder does not exist.")
+    try:
+        resolved.mkdir(exist_ok = True)
+        if not resolved.is_dir():
+            raise ValueError("The selected cache location is not a folder.")
+        for child in (resolved / "hub", resolved / "xet"):
+            child.mkdir(exist_ok = True)
+            with tempfile.NamedTemporaryFile(prefix = ".unsloth-write-test-", dir = child):
+                pass
+    except PermissionError as exc:
+        raise ValueError("Studio does not have permission to write to this folder.") from exc
+    except OSError as exc:
+        raise ValueError(f"Studio cannot use this cache folder: {exc}") from exc
+    return resolved
+
+
+def _stored_history() -> list[Path]:
+    try:
+        from storage.studio_db import get_app_setting
+        raw = get_app_setting(CACHE_HISTORY_SETTING_KEY, [])
+    except Exception:
+        raw = []
+    if not isinstance(raw, list):
+        return []
+    out: list[Path] = []
+    seen: set[str] = set()
+    for value in raw:
+        if not isinstance(value, str) or not value.strip():
+            continue
+        try:
+            path = _canonical(value)
+        except (OSError, RuntimeError, ValueError):
+            continue
+        key = os.path.normcase(str(path))
+        if key in seen:
+            continue
+        seen.add(key)
+        out.append(path)
+    return out[:MAX_CACHE_HISTORY]
+
+
+def set_hf_cache_home(cache_home: Optional[str]) -> HuggingFaceCachePaths:
+    if _environment_paths() is not None:
+        raise RuntimeError("The Hugging Face cache location is managed by an environment variable.")
+    with _settings_lock:
+        previous = _stored_cache_home()
+        next_home = _validate_cache_home(cache_home) if cache_home is not None else None
+        history = _stored_history()
+        if previous is not None and previous != next_home:
+            history.insert(0, previous)
+        deduped: list[str] = []
+        seen: set[str] = set()
+        for path in history:
+            key = os.path.normcase(str(path))
+            if key in seen or path == next_home:
+                continue
+            seen.add(key)
+            deduped.append(str(path))
+            if len(deduped) >= MAX_CACHE_HISTORY:
+                break
+        from storage.studio_db import upsert_app_settings
+
+        upsert_app_settings(
+            {
+                CACHE_HOME_SETTING_KEY: str(next_home) if next_home is not None else None,
+                CACHE_HISTORY_SETTING_KEY: deduped,
+            }
+        )
+    # Inventory scans are cached independently from settings. Invalidate after
+    # persistence so the next request sees both the new active root and history.
+    from hub.utils.inventory_scan import invalidate_hf_cache_scans
+
+    invalidate_hf_cache_scans()
+    return get_hf_cache_paths()
+
+
+def known_hf_cache_homes() -> list[Path]:
+    paths = get_hf_cache_paths()
+    stored = _stored_cache_home()
+    candidates: list[Path] = []
+    if paths.source != "environment":
+        candidates.append(paths.cache_home)
+    elif explicit_home := _EXPLICIT_CACHE_ENV.get("HF_HOME"):
+        candidates.append(_canonical(explicit_home))
+    if stored is not None:
+        candidates.append(stored)
+    candidates.extend([*_stored_history(), _default_cache_home()])
+    out: list[Path] = []
+    seen: set[str] = set()
+    for candidate in candidates:
+        try:
+            canonical = _canonical(candidate)
+        except (OSError, RuntimeError, ValueError):
+            continue
+        key = os.path.normcase(str(canonical))
+        if key in seen:
+            continue
+        seen.add(key)
+        out.append(canonical)
+    return out
+
+
+def known_hf_hub_caches() -> list[Path]:
+    active = get_hf_cache_paths()
+    out = [active.hub_cache]
+    seen = {os.path.normcase(str(_canonical(active.hub_cache)))}
+    for home in known_hf_cache_homes():
+        hub = _canonical(home / "hub")
+        key = os.path.normcase(str(hub))
+        if key not in seen:
+            seen.add(key)
+            out.append(hub)
+    return out
+
+
+def cache_status(paths: Optional[HuggingFaceCachePaths] = None) -> dict:
+    paths = paths or get_hf_cache_paths()
+    available = paths.cache_home.is_dir()
+    writable = available and os.access(paths.cache_home, os.W_OK | os.X_OK)
+    free_bytes: Optional[int] = None
+    if available:
+        try:
+            free_bytes = int(shutil.disk_usage(paths.cache_home).free)
+        except OSError:
+            pass
+    return {
+        "cache_home": str(paths.cache_home),
+        "hub_cache": str(paths.hub_cache),
+        "xet_cache": str(paths.xet_cache),
+        "source": paths.source,
+        "editable": paths.editable,
+        "is_custom": paths.is_custom,
+        "available": available,
+        "writable": writable,
+        "free_bytes": free_bytes,
+        "environment_variable": paths.environment_variable,
+    }
diff --git a/studio/backend/utils/hf_token_validation.py b/studio/backend/utils/hf_token_validation.py
new file mode 100644
index 0000000000..7247c6e756
--- /dev/null
+++ b/studio/backend/utils/hf_token_validation.py
@@ -0,0 +1,208 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Cached, rate-limited Hugging Face token validation."""
+
+from __future__ import annotations
+
+import hashlib
+import threading
+import time
+from collections import deque
+from dataclasses import dataclass
+from typing import Literal
+
+from huggingface_hub import HfApi
+from huggingface_hub.utils import build_hf_headers, get_session
+
+
+TokenValidationStatus = Literal["valid", "invalid", "rate_limited", "unavailable"]
+
+
+@dataclass(frozen = True)
+class TokenValidationResult:
+    status: TokenValidationStatus
+    retry_after_seconds: int | None = None
+
+
+_WINDOW_SECONDS = 3600.0
+_MAX_ATTEMPTS = 3
+_CACHE_TTL_SECONDS = 3600.0
+_TEMPORARY_CACHE_TTL_SECONDS = 15.0
+_MAX_BUCKETS = 4096
+_MAX_CACHE_ENTRIES = 4096
+_INFLIGHT_WAIT_SECONDS = 30.0
+_REMOTE_TIMEOUT_SECONDS = 10.0
+
+_attempts: dict[str, deque[float]] = {}
+_cache: dict[str, tuple[float, TokenValidationResult]] = {}
+_inflight: dict[str, threading.Event] = {}
+_lock = threading.Lock()
+
+
+def _fingerprint(token: str) -> str:
+    return hashlib.sha256(token.encode("utf-8")).hexdigest()
+
+
+def _prune_attempts(bucket: deque[float], now: float) -> None:
+    while bucket and now - bucket[0] >= _WINDOW_SECONDS:
+        bucket.popleft()
+
+
+def _prune_locked(now: float) -> None:
+    for key in list(_attempts):
+        bucket = _attempts[key]
+        _prune_attempts(bucket, now)
+        if not bucket:
+            del _attempts[key]
+    for key, (expires_at, _result) in list(_cache.items()):
+        if expires_at <= now:
+            del _cache[key]
+
+
+def _cached_locked(fingerprint: str, now: float) -> TokenValidationResult | None:
+    cached = _cache.get(fingerprint)
+    if cached is None:
+        return None
+    expires_at, result = cached
+    if expires_at <= now:
+        del _cache[fingerprint]
+        return None
+    return result
+
+
+def _retry_after(bucket: deque[float], now: float) -> int:
+    return max(1, int(_WINDOW_SECONDS - (now - bucket[0])) + 1)
+
+
+def _reserve_attempt_locked(rate_key: str, now: float) -> TokenValidationResult | None:
+    bucket = _attempts.get(rate_key)
+    if bucket is None:
+        if len(_attempts) >= _MAX_BUCKETS:
+            _prune_locked(now)
+        if len(_attempts) >= _MAX_BUCKETS:
+            return TokenValidationResult(
+                status = "rate_limited",
+                retry_after_seconds = max(1, int(_WINDOW_SECONDS)),
+            )
+        bucket = _attempts[rate_key] = deque()
+    _prune_attempts(bucket, now)
+    if len(bucket) >= _MAX_ATTEMPTS:
+        return TokenValidationResult(
+            status = "rate_limited",
+            retry_after_seconds = _retry_after(bucket, now),
+        )
+    bucket.append(now)
+    return None
+
+
+def _http_status(response: object | None) -> int | None:
+    status = getattr(response, "status_code", None)
+    try:
+        return int(status) if status is not None else None
+    except (TypeError, ValueError):
+        return None
+
+
+def _remote_retry_after(response: object | None) -> int | None:
+    headers = getattr(response, "headers", None)
+    if not headers:
+        return None
+    raw = headers.get("Retry-After")
+    try:
+        return max(1, int(float(raw))) if raw is not None else None
+    except (TypeError, ValueError):
+        return None
+
+
+def _classify_response(response: object | None) -> TokenValidationResult:
+    status = _http_status(response)
+    if status is not None and 200 <= status < 300:
+        return TokenValidationResult(status = "valid")
+    if status == 401:
+        return TokenValidationResult(status = "invalid")
+    if status == 429:
+        return TokenValidationResult(
+            status = "rate_limited",
+            retry_after_seconds = _remote_retry_after(response),
+        )
+    return TokenValidationResult(status = "unavailable")
+
+
+def _check_remote(token: str) -> TokenValidationResult:
+    api = HfApi()
+    try:
+        # HfApi.whoami has no timeout parameter in the pinned Hub client.
+        # Use its session and headers against the same whoami endpoint.
+        response = get_session().get(
+            f"{api.endpoint}/api/whoami-v2",
+            headers = build_hf_headers(token = token),
+            timeout = _REMOTE_TIMEOUT_SECONDS,
+        )
+    except Exception as exc:
+        # huggingface-hub 0.36.x can wrap a 401 as requests.HTTPError.
+        return _classify_response(getattr(exc, "response", None))
+    return _classify_response(response)
+
+
+def validate_hf_token(token: str, *, rate_key: str) -> TokenValidationResult:
+    """Validate ``token`` without retaining it, sharing results across callers.
+
+    Cached checks do not consume the caller's three-per-hour network budget. A
+    single-flight event also prevents simultaneously mounted UI surfaces from
+    sending duplicate ``whoami`` requests for the same token.
+    """
+    normalized = token.strip()
+    if not normalized:
+        return TokenValidationResult(status = "invalid")
+    token_fingerprint = _fingerprint(normalized)
+    owner_event: threading.Event | None = None
+
+    try:
+        while True:
+            now = time.monotonic()
+            with _lock:
+                cached = _cached_locked(token_fingerprint, now)
+                if cached is not None:
+                    return cached
+                waiting = _inflight.get(token_fingerprint)
+                if waiting is None:
+                    limited = _reserve_attempt_locked(rate_key, now)
+                    if limited is not None:
+                        return limited
+                    owner_event = threading.Event()
+                    _inflight[token_fingerprint] = owner_event
+                    break
+            if not waiting.wait(_INFLIGHT_WAIT_SECONDS):
+                return TokenValidationResult(status = "unavailable")
+
+        result = _check_remote(normalized)
+        now = time.monotonic()
+        ttl = (
+            _CACHE_TTL_SECONDS
+            if result.status in ("valid", "invalid")
+            else max(_TEMPORARY_CACHE_TTL_SECONDS, float(result.retry_after_seconds or 0))
+        )
+        with _lock:
+            if len(_cache) >= _MAX_CACHE_ENTRIES:
+                _prune_locked(now)
+            if len(_cache) < _MAX_CACHE_ENTRIES:
+                _cache[token_fingerprint] = (now + ttl, result)
+        return result
+    finally:
+        if owner_event is not None:
+            with _lock:
+                event = _inflight.get(token_fingerprint)
+                if event is owner_event:
+                    _inflight.pop(token_fingerprint, None)
+                    event.set()
+
+
+def reset_hf_token_validation_state() -> None:
+    """Clear process state for test isolation."""
+    with _lock:
+        for event in _inflight.values():
+            event.set()
+        _inflight.clear()
+        _attempts.clear()
+        _cache.clear()
diff --git a/studio/backend/utils/hf_xet_fallback.py b/studio/backend/utils/hf_xet_fallback.py
index 9bc4a60fad..49872f371e 100644
--- a/studio/backend/utils/hf_xet_fallback.py
+++ b/studio/backend/utils/hf_xet_fallback.py
@@ -1,9 +1,9 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Studio shim over the shared ``unsloth_zoo.hf_xet_fallback`` Xet -> HTTP stall fallback.
+"""Unsloth shim over the shared ``unsloth_zoo.hf_xet_fallback`` Xet -> HTTP stall fallback.
 
-Re-exports the shared API and injects Studio's marker-aware cache purge
+Re-exports the shared API and injects Unsloth's marker-aware cache purge
 (``prepare_cache_for_transport``) so the download manager keeps its ``.transport``
 marker semantics on the HTTP retry.
 
@@ -21,6 +21,8 @@ never triggers the heavy load.
 from __future__ import annotations
 
 import threading
+from functools import partial
+from pathlib import Path
 from typing import Any, Callable, Optional
 
 # Defaults mirror unsloth_zoo.hf_xet_fallback; plain literals so they resolve (including as
@@ -68,7 +70,7 @@ def _load_shared() -> bool:
                 _shared_available = True
                 _shared_import_error = None
                 return True
-            except Exception as exc2:  # noqa: BLE001 - degrade so Studio still boots with plain HF
+            except Exception as exc2:  # noqa: BLE001 - degrade so Unsloth still boots with plain HF
                 _shared_import_error = exc2
                 _shared_available = False
                 import logging as _logging
@@ -262,18 +264,28 @@ __all__ = [
 ]
 
 
-def _studio_prepare_for_http(repo_type: str, repo_id: str) -> None:
-    """Studio's marker-aware purge before an HTTP resume, keeping the download manager's ``.transport``
+def _studio_prepare_for_http(
+    repo_type: str,
+    repo_id: str,
+    *,
+    cache_dir: Optional[str] = None,
+) -> None:
+    """Unsloth's marker-aware purge before an HTTP resume, keeping the download manager's ``.transport``
     accounting consistent (vs unsloth_zoo's generic default). Guarded: a purge failure is logged,
     not fatal to the retry."""
     try:
         from hub.utils.download_registry import prepare_cache_for_transport
-        prepare_cache_for_transport(repo_type, repo_id, "http")
+        prepare_cache_for_transport(
+            repo_type,
+            repo_id,
+            "http",
+            root = Path(cache_dir) if cache_dir else None,
+        )
     except Exception as exc:
         try:
             from loggers import get_logger
             get_logger(__name__).debug(
-                "Studio prepare_cache_for_transport failed for %s: %s", repo_id, exc
+                "Unsloth prepare_cache_for_transport failed for %s: %s", repo_id, exc
             )
         except ModuleNotFoundError as logger_exc:
             if logger_exc.name != "loggers":
@@ -293,9 +305,13 @@ def hf_hub_download_with_xet_fallback(
     grace_period: float = DEFAULT_GRACE_PERIOD,
     on_status: Optional[Callable[[str], None]] = None,
     force_download: bool = False,
+    cache_dir: Optional[str] = None,
 ) -> str:
-    """Single-file download via the shared fallback with Studio's marker-aware HTTP-retry prep.
-    ``force_download`` re-fetches a newer blob over a cached one (Studio's model-update path)."""
+    """Single-file download via the shared fallback with Unsloth's marker-aware HTTP-retry prep.
+    ``force_download`` re-fetches a newer blob over a cached one (Unsloth's model-update path)."""
+    if cache_dir is None:
+        from utils.hf_cache_settings import get_hf_cache_paths
+        cache_dir = str(get_hf_cache_paths().hub_cache)
     return _shared_hf_hub_download_with_xet_fallback(
         repo_id,
         filename,
@@ -308,11 +324,18 @@ def hf_hub_download_with_xet_fallback(
         grace_period = grace_period,
         on_status = on_status,
         force_download = force_download,
-        prepare_for_http_fn = _studio_prepare_for_http,
+        cache_dir = cache_dir,
+        prepare_for_http_fn = partial(_studio_prepare_for_http, cache_dir = cache_dir),
     )
 
 
 def snapshot_download_with_xet_fallback(repo_id: str, **kwargs: Any) -> str:
-    """Whole-repo download via the shared fallback with Studio's marker-aware HTTP-retry prep."""
-    kwargs.setdefault("prepare_for_http_fn", _studio_prepare_for_http)
+    """Whole-repo download via the shared fallback with Unsloth's marker-aware HTTP-retry prep."""
+    if kwargs.get("cache_dir") is None:
+        from utils.hf_cache_settings import get_hf_cache_paths
+        kwargs["cache_dir"] = str(get_hf_cache_paths().hub_cache)
+    kwargs.setdefault(
+        "prepare_for_http_fn",
+        partial(_studio_prepare_for_http, cache_dir = kwargs["cache_dir"]),
+    )
     return _shared_snapshot_download_with_xet_fallback(repo_id, **kwargs)
diff --git a/studio/backend/utils/hidden_models.py b/studio/backend/utils/hidden_models.py
new file mode 100644
index 0000000000..e7c3181d71
--- /dev/null
+++ b/studio/backend/utils/hidden_models.py
@@ -0,0 +1,202 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Infra-only model detection shared by the model routes and the hub
+inventory. Lives directly under ``utils`` (not ``utils.models``) so the hub
+cache scanner can import it without pulling in ``utils/models/__init__.py``,
+which eagerly loads the model-config/checkpoint stack, and without importing
+``routes.models`` (import-time side effects, would cycle)."""
+
+from __future__ import annotations
+
+import json
+import re
+from pathlib import Path
+from typing import Optional
+
+# Hub repo id shape ("owner/name", no leading separator); anything else is
+# treated as a local filesystem path.
+_HF_REPO_ID_RE = re.compile(r"^[A-Za-z0-9][\w.\-]*/[\w.\-]+$")
+
+# The llama.cpp install-validation probe repo. Always hidden.
+_PROBE_REPO_ID = "ggml-org/models"
+# The probe's on-disk filename. Carries the ".gguf" so it stays specific and
+# does not hide unrelated repos like ``user/stories260K-finetune-GGUF``.
+_PROBE_FILENAME = "stories260k.gguf"
+# Keep previously cached defaults hidden after settings changes.
+_DEFAULT_EMBEDDING_REPO_IDS = {
+    "unsloth/bge-small-en-v1.5",
+    "unsloth/bge-small-en-v1.5-GGUF",
+}
+# Local copies do not always retain the repo id. Keep a narrow basename
+# fallback for Studio's static default embedder only; configured custom repos
+# remain exact-match-only.
+_DEFAULT_EMBEDDING_PATH_BASENAMES = {"bge-small-en-v1.5"}
+# Curated Whisper dictation checkpoints (STT, never chat), hidden from the chat
+# inventory and pickers: Transformers safetensors repos (unsloth/whisper-*) and
+# their GGUF companions (unslothai/whisper-*-GGUF). Custom checkpoints are caught
+# by config below, but the GGUF companions carry a raw .bin (no config.json), so
+# they must be listed here by id or they leak into chat pickers.
+_HIDDEN_STT_REPO_IDS = frozenset(
+    {
+        "unsloth/whisper-tiny",
+        "unsloth/whisper-base",
+        "unsloth/whisper-small",
+        "unsloth/whisper-large-v3-turbo",
+        "unsloth/whisper-large-v3",
+        "unslothai/whisper-tiny-GGUF",
+        "unslothai/whisper-base-GGUF",
+        "unslothai/whisper-small-GGUF",
+        "unslothai/whisper-large-v3-turbo-GGUF",
+        "unslothai/whisper-large-v3-GGUF",
+    }
+)
+
+
+def _config_is_whisper(path: Path) -> bool:
+    """True if a config.json declares a Whisper model."""
+    try:
+        with open(path, "r", encoding = "utf-8") as file:
+            config = json.load(file)
+    except Exception:
+        return False
+    if not isinstance(config, dict):
+        return False
+    model_type = config.get("model_type")
+    if isinstance(model_type, str) and model_type.strip().lower() == "whisper":
+        return True
+    architectures = config.get("architectures")
+    return isinstance(architectures, list) and any(
+        isinstance(name, str) and name == "WhisperForConditionalGeneration"
+        for name in architectures
+    )
+
+
+def _path_is_whisper_model(value: str) -> bool:
+    """Inspect an existing local model path's config; never hides name-only matches."""
+    if _HF_REPO_ID_RE.fullmatch(value.strip()):
+        return False
+    path = Path(value).expanduser()
+    try:
+        if path.is_file():
+            path = path.parent
+        candidates = [path / "config.json"]
+        snapshots = path / "snapshots"
+        if snapshots.is_dir():
+            candidates.extend(child / "config.json" for child in snapshots.iterdir())
+    except OSError:
+        return False
+    return any(_config_is_whisper(candidate) for candidate in candidates)
+
+
+def _safe_resolve(path: Path) -> Optional[str]:
+    """resolve() to a string, or None when the path is inaccessible."""
+    try:
+        return str(path.resolve())
+    except OSError:
+        return None
+
+
+def _existing_resolved_path(value: str) -> Optional[str]:
+    """Resolve an existing local path."""
+    path = Path(value).expanduser()
+    try:
+        if not path.exists():
+            return None
+    except OSError:
+        return None
+    return _safe_resolve(path)
+
+
+def _path_contains_repo_id(value: str, repo_ids: set[str]) -> bool:
+    """Match exact repo-derived path segments."""
+    parts = [part for part in value.lower().replace("\\", "/").split("/") if part]
+    for repo_id in repo_ids:
+        owner, name = repo_id.split("/", 1)
+        if f"models--{owner}--{name}" in parts:
+            return True
+        if any(
+            parts[index] == owner and parts[index + 1] == name for index in range(len(parts) - 1)
+        ):
+            return True
+    return False
+
+
+def _path_basename_is_default_embedder(value: str) -> bool:
+    """Match a default embedder folder or a suffixed local weight filename."""
+    normalized = value.lower().replace("\\", "/").rstrip("/")
+    basename = normalized.rsplit("/", 1)[-1]
+    return any(
+        basename == needle
+        or any(basename.startswith(f"{needle}{separator}") for separator in ("-", "_", "."))
+        for needle in _DEFAULT_EMBEDDING_PATH_BASENAMES
+    )
+
+
+def is_hidden_model(*values: str | None) -> bool:
+    """True if any id/path is the RAG embedding model (the effective embedder
+    or its GGUF companion repo), the llama.cpp install validation probe
+    (ggml-org/models / stories260K), or a curated/custom Whisper dictation
+    model, so pickers hide them (GGUF and non-GGUF). None are usable chat
+    models; the probe can be cached as a side effect of installing the prebuilt
+    llama-server and otherwise sorts smallest, so it would be auto-selected.
+
+    Hub repo ids are matched EXACTLY (case-insensitive full "owner/name"), so a
+    custom embedder with a generic basename like "org/model" cannot substring
+    hide unrelated cached repos such as "user/model-chat" or "org/model-GGUF".
+    Existing paths take precedence over the identical ``owner/name`` repo
+    shape. Cache and LM Studio paths use exact repo-derived segments. Local
+    copies of the static default embedder also use a boundary-aware basename
+    fallback; configured custom repos never do."""
+    from core.rag import config as rag_config
+
+    hidden_repo_ids = {
+        _PROBE_REPO_ID.lower(),
+        *(repo_id.lower() for repo_id in _DEFAULT_EMBEDDING_REPO_IDS),
+        *(repo_id.lower() for repo_id in _HIDDEN_STT_REPO_IDS),
+    }
+    exact_paths: list[str] = []
+    for model in {
+        rag_config.EMBEDDING_MODEL,
+        rag_config.default_gguf_repo(),
+        rag_config.effective_embedding_model(),
+        rag_config.effective_gguf_repo(),
+    }:
+        existing_path = _existing_resolved_path(model)
+        if existing_path:
+            exact_paths.append(existing_path.lower())
+        elif _HF_REPO_ID_RE.match(model):
+            hidden_repo_ids.add(model.lower())
+        else:
+            resolved = _safe_resolve(Path(model).expanduser())
+            if resolved:
+                exact_paths.append(resolved.lower())
+    for v in values:
+        if not v:
+            continue
+        low = v.lower()
+        if _HF_REPO_ID_RE.match(v):
+            # A repo id ("owner/name"): match the hidden set exactly. It is
+            # never a filesystem path, so skip the path/filename checks.
+            if low in hidden_repo_ids:
+                return True
+            continue
+        # Anything else is treated as a filesystem path (the cached snapshot
+        # path, or a local model id). Match the probe by its exact filename and
+        # any configured local-path embedder by exact resolved path. Split on
+        # both separators so a Windows-style path ("...\\stories260K.gguf") is
+        # matched even when this runs on a POSIX interpreter (and vice versa).
+        if low.replace("\\", "/").rsplit("/", 1)[-1] == _PROBE_FILENAME:
+            return True
+        if _path_basename_is_default_embedder(v):
+            return True
+        if _path_contains_repo_id(v, hidden_repo_ids):
+            return True
+        # Custom Whisper checkpoints keep no curated repo id, so match by config.
+        if _path_is_whisper_model(v):
+            return True
+        if exact_paths:
+            resolved = _safe_resolve(Path(v).expanduser())
+            if resolved and resolved.lower() in exact_paths:
+                return True
+    return False
diff --git a/studio/backend/utils/host_policy.py b/studio/backend/utils/host_policy.py
index f506eadc03..55565bb338 100644
--- a/studio/backend/utils/host_policy.py
+++ b/studio/backend/utils/host_policy.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Bind-host trust policy for the Studio backend.
+"""Bind-host trust policy for the Unsloth backend.
 
 Stdlib only -- safe to import without the rest of the backend.
 
diff --git a/studio/backend/utils/inference/inference_config.py b/studio/backend/utils/inference/inference_config.py
index 05eb08067c..a264e06c85 100644
--- a/studio/backend/utils/inference/inference_config.py
+++ b/studio/backend/utils/inference/inference_config.py
@@ -5,7 +5,10 @@
 
 from pathlib import Path
 from typing import Dict, Any, Optional
+from functools import lru_cache
 import json
+import math
+import os
 import yaml
 import structlog
 from loggers import get_logger
@@ -160,3 +163,137 @@ def load_inference_config(model_identifier: str) -> Dict[str, Any]:
     }
 
     return inference_config
+
+
+# ── Effective sampling resolution for `unsloth run` / `unsloth start` ──────────
+#
+# Per-model recommended sampling is applied to a request only for the fields the
+# client omitted; an operator can pin a field from the CLI via UNSLOTH_SAMPLING_*
+# (a hard override that wins even over an explicit client value). Precedence per
+# field: operator pin -> client explicit -> per-model recommendation -> the static
+# schema default (mirroring ChatCompletionRequest, so behavior is unchanged when
+# nothing is recommended or pinned).
+
+# field -> (env var, static default, min, max, is_int)
+_SAMPLING_FIELDS = {
+    "temperature": ("UNSLOTH_SAMPLING_TEMPERATURE", 0.6, 0.0, 2.0, False),
+    "top_p": ("UNSLOTH_SAMPLING_TOP_P", 0.95, 0.0, 1.0, False),
+    "top_k": ("UNSLOTH_SAMPLING_TOP_K", 20, -1, 100, True),
+    "min_p": ("UNSLOTH_SAMPLING_MIN_P", 0.01, 0.0, 1.0, False),
+    "repetition_penalty": ("UNSLOTH_SAMPLING_REPETITION_PENALTY", 1.0, 1.0, 2.0, False),
+    "presence_penalty": ("UNSLOTH_SAMPLING_PRESENCE_PENALTY", 0.0, 0.0, 2.0, False),
+}
+
+# Public, ordered tuple of the sampling fields callers resolve.
+SAMPLING_FIELD_NAMES = tuple(_SAMPLING_FIELDS)
+
+# Fields the Studio Chat UI adopts as *per-model recommendations* from the backend
+# `.inference` block. Its frontend `mergeBackendRecommendedInference`
+# (presets/preset-policy.ts) seeds exactly these five and never reads repetition_penalty,
+# so the server auto-recommends the same five for request parity. repetition_penalty stays a
+# manual-only knob (client-sent or an UNSLOTH_SAMPLING_REPETITION_PENALTY operator pin),
+# matching the UI where it is never auto-filled per model.
+_UI_RECOMMENDED_FIELDS = ("temperature", "top_p", "top_k", "min_p", "presence_penalty")
+
+
+def _clean_sampling_value(field: str, val: Any):
+    """Coerce ``val`` to the field's numeric type when it is a finite, in-range number, else None.
+
+    Rejects bool, non-numeric, NaN/inf, and out-of-range values so neither a bad operator env
+    var nor a malformed model recommendation can reach llama-server. NaN matters because
+    ``nan < lo`` and ``nan > hi`` are both False, so a plain range check would let it through.
+    Coerce before the finiteness check: ``math.isfinite`` and ``float()`` raise ``OverflowError``
+    on an int too big for a C double (an oversized UNSLOTH_SAMPLING_TOP_K would otherwise 500 the
+    request), while an in-range int is range-checked exactly and ``int()`` rejects a NaN/inf that
+    reached an int field.
+    """
+    if isinstance(val, bool) or not isinstance(val, (int, float)):
+        return None
+    _env, _default, lo, hi, is_int = _SAMPLING_FIELDS[field]
+    try:
+        val = int(val) if is_int else float(val)
+    except (ValueError, OverflowError):
+        # int(nan)/int(inf) and float(oversized_int) raise; treat them as unusable.
+        return None
+    # After coercion an int is always finite; only a float can still be NaN/inf.
+    if isinstance(val, float) and not math.isfinite(val):
+        return None
+    if val < lo or val > hi:
+        return None
+    return val
+
+
+def _operator_sampling_override(field: str):
+    """Operator-pinned value for a sampling field from UNSLOTH_SAMPLING_*, or None.
+
+    An unparseable, non-finite, or out-of-range value is ignored so a bad env var can never
+    reach llama-server; the field then falls back to the client / recommended value.
+    """
+    _env, _default, _lo, _hi, is_int = _SAMPLING_FIELDS[field]
+    raw = os.environ.get(_env)
+    if raw is None or raw.strip() == "":
+        return None
+    try:
+        val = int(raw) if is_int else float(raw)
+    except (TypeError, ValueError):
+        return None
+    return _clean_sampling_value(field, val)
+
+
+@lru_cache(maxsize = 128)
+def _recommended_sampling(model_id: str) -> Dict[str, Any]:
+    """Per-model recommended sampling, resolved through the SAME path the Studio Chat UI uses.
+
+    The Chat UI seeds its sampling from the ``.inference`` block of the load/status responses,
+    which is exactly :func:`load_inference_config` (model-specific YAML -> family defaults
+    (inference_defaults.json) -> default.yaml). Sourcing recommendations here keeps the values
+    the server applies to a request identical to what the UI shows for the same model. Only the
+    fields the UI actually adopts (:data:`_UI_RECOMMENDED_FIELDS`) are recommended; each value
+    is validated (finite + in range) before use. Cached by model id.
+    """
+    if not model_id:
+        return {}
+    try:
+        cfg = load_inference_config(model_id) or {}
+    except Exception as e:
+        logger.debug(f"Could not load recommended sampling for '{model_id}': {e}")
+        return {}
+    recommended: Dict[str, Any] = {}
+    for field in _UI_RECOMMENDED_FIELDS:
+        cleaned = _clean_sampling_value(field, cfg.get(field))
+        if cleaned is not None:
+            recommended[field] = cleaned
+    return recommended
+
+
+def resolve_effective_sampling(
+    model_id: Optional[str],
+    explicit: Dict[str, Any],
+    *,
+    fill_defaults: bool = True,
+) -> Dict[str, Any]:
+    """Resolve the effective sampling params for a request.
+
+    ``explicit`` maps each field in :data:`SAMPLING_FIELD_NAMES` to the client-sent
+    value, or ``None`` when the client omitted it. Precedence (highest first): an
+    operator ``UNSLOTH_SAMPLING_*`` pin, then the client's explicit value, then the
+    per-model recommendation, then the static schema default.
+
+    When ``fill_defaults`` is False a field with no operator pin, client value, or
+    per-model recommendation is omitted from the result instead of set to the static
+    schema default, so a raw proxy body (``/v1/completions``) keeps llama-server's own
+    default for that field rather than being forced onto this schema's value.
+    """
+    recommended = _recommended_sampling(model_id or "")
+    effective: Dict[str, Any] = {}
+    for field, (_env, default, _lo, _hi, _int) in _SAMPLING_FIELDS.items():
+        override = _operator_sampling_override(field)
+        if override is not None:
+            effective[field] = override
+        elif explicit.get(field) is not None:
+            effective[field] = explicit[field]
+        elif field in recommended:
+            effective[field] = recommended[field]
+        elif fill_defaults:
+            effective[field] = default
+    return effective
diff --git a/studio/backend/utils/llama_cpp_freshness.py b/studio/backend/utils/llama_cpp_freshness.py
index 7d077bfa3b..a184fdb3e9 100644
--- a/studio/backend/utils/llama_cpp_freshness.py
+++ b/studio/backend/utils/llama_cpp_freshness.py
@@ -7,28 +7,28 @@ Reads UNSLOTH_PREBUILT_INFO.json (written by install_llama_prebuilt.py)
 and compares the installed release tag against the latest on GitHub.
 Surfaced via main.py:lifespan() and /api/inference/status. Fails open
 on any missing data so we never show a misleading banner.
+
+The mechanics (marker walk-up, GitHub fetch, memo + disk cache, report
+skeleton) live in utils.prebuilt.freshness_flow; this module keeps the
+llama version policy and the per-module caches its tests patch.
 """
 
 from __future__ import annotations
 
-import json
-import os
 import re
-import time
-from datetime import datetime, timezone
+from datetime import datetime
 from pathlib import Path
 from typing import Optional
 
 import structlog
 
+from utils.prebuilt import freshness_flow as _flow
+
 logger = structlog.get_logger(__name__)
 
 # 3 days matches Unsloth's typical llama.cpp release cadence.
 STALENESS_THRESHOLD_DAYS = 3
 
-# 24h TTL keeps the GitHub call off the hot path and within rate limits.
-_RELEASE_CACHE_TTL_SECONDS = 24 * 60 * 60
-
 _INSTALL_MARKER_NAME = "UNSLOTH_PREBUILT_INFO.json"
 
 _marker_cache: dict[str, Optional[dict]] = {}
@@ -49,203 +49,60 @@ def _cache_dir() -> Path:
 def read_install_marker(binary_path: Optional[str]) -> Optional[dict]:
     """Walk up from binary_path to find UNSLOTH_PREBUILT_INFO.json.
     None = no marker (source build / custom path) or invalid JSON."""
-    if not binary_path:
-        return None
-    cached = _marker_cache.get(binary_path)
-    if cached is not None or binary_path in _marker_cache:
-        return cached
-    p = Path(binary_path)
-    marker: Optional[dict] = None
-    # Cover all _find_llama_server_binary layouts (binary is 1-4 dirs deep):
-    for parent in p.parents[:5]:
-        candidate = parent / _INSTALL_MARKER_NAME
-        if candidate.is_file():
-            try:
-                marker = json.loads(candidate.read_text(encoding = "utf-8"))
-            except (OSError, json.JSONDecodeError) as exc:
-                logger.debug(
-                    "failed to parse install marker",
-                    path = str(candidate),
-                    error = str(exc),
-                )
-                marker = None
-            break
-    _marker_cache[binary_path] = marker
-    return marker
-
-
-def _cache_path_for(repo: str) -> Path:
-    safe = repo.replace("/", "__")
-    return _cache_dir() / f"{safe}.json"
+    return _flow.read_install_marker(
+        binary_path,
+        marker_name = _INSTALL_MARKER_NAME,
+        cache = _marker_cache,
+        log_message = "failed to parse install marker",
+    )
 
 
 def _load_disk_cache(repo: str) -> Optional[tuple[float, Optional[str]]]:
-    path = _cache_path_for(repo)
-    try:
-        payload = json.loads(path.read_text(encoding = "utf-8"))
-    except (OSError, json.JSONDecodeError):
-        return None
-    ts = payload.get("fetched_at")
-    tag = payload.get("latest_tag")
-    if not isinstance(ts, (int, float)):
-        return None
-    return float(ts), tag if isinstance(tag, str) else None
+    return _flow.load_disk_cache(repo, _cache_dir())
 
 
 def _save_disk_cache(repo: str, latest_tag: Optional[str]) -> None:
-    path = _cache_path_for(repo)
-    try:
-        path.parent.mkdir(parents = True, exist_ok = True)
-        tmp = path.with_suffix(".tmp")
-        tmp.write_text(
-            json.dumps({"fetched_at": time.time(), "latest_tag": latest_tag}),
-            encoding = "utf-8",
-        )
-        tmp.replace(path)
-    except OSError as exc:
-        logger.debug("freshness cache write failed", repo = repo, error = str(exc))
+    _flow.save_disk_cache(
+        repo, latest_tag, _cache_dir(), log_message = "freshness cache write failed"
+    )
 
 
 def _fetch_latest_release_tag(repo: str, timeout: float = 5.0) -> Optional[str]:
-    """Newest published release tag for `repo`, by publish time.
-
-    Resolves "latest" the way install_llama_prebuilt.py does (newest
-    non-draft/non-prerelease by ``published_at``), NOT via GitHub's
-    ``/releases/latest`` pointer. That pointer sorts by commit date and can lag
-    behind the build the installer actually installs, so detection and apply
-    disagreed -- the cause of the downgrade/sticky banner. None on any failure
-    (offline, rate-limited, etc)."""
-    import urllib.error
-    import urllib.request
-
-    url = f"https://api.github.com/repos/{repo}/releases?per_page=30"
-    headers = {
-        "Accept": "application/vnd.github+json",
-        "User-Agent": "unsloth-studio-freshness-check",
-    }
-    token = os.environ.get("GITHUB_TOKEN") or os.environ.get("GH_TOKEN")
-    if token:
-        headers["Authorization"] = f"Bearer {token}"
-    req = urllib.request.Request(url, headers = headers)
-    try:
-        with urllib.request.urlopen(req, timeout = timeout) as resp:
-            data = json.loads(resp.read().decode("utf-8"))
-    except (
-        urllib.error.URLError,
-        urllib.error.HTTPError,
-        OSError,
-        json.JSONDecodeError,
-    ) as exc:
-        logger.debug("freshness fetch failed", repo = repo, error = str(exc))
-        return None
-    if not isinstance(data, list):
-        return None
-    published = [
-        r
-        for r in data
-        if isinstance(r, dict)
-        and not r.get("draft")
-        and not r.get("prerelease")
-        and isinstance(r.get("tag_name"), str)
-        and r.get("tag_name")
-    ]
-    if not published:
-        return None
-    newest = max(published, key = lambda r: r.get("published_at") or "")
-    return newest["tag_name"]
+    """Newest published release tag for `repo`, by publish time (see
+    freshness_flow for why this is not GitHub's /releases/latest pointer)."""
+    return _flow.fetch_latest_release_tag(repo, timeout, log_message = "freshness fetch failed")
 
 
 def latest_published_release(repo: str, *, force_refresh: bool = False) -> Optional[str]:
     """Latest release tag for `repo`. Memo + disk-cached (24h TTL).
     None when offline and never previously cached."""
-    if not repo:
-        return None
-    now = time.time()
-    if not force_refresh:
-        memo = _release_memo.get(repo)
-        if memo and now - memo[0] < _RELEASE_CACHE_TTL_SECONDS:
-            return memo[1]
-        disk = _load_disk_cache(repo)
-        if disk and now - disk[0] < _RELEASE_CACHE_TTL_SECONDS:
-            _release_memo[repo] = disk
-            return disk[1]
-    latest = _fetch_latest_release_tag(repo)
-    if latest is None:
-        # Keep last-good disk value rather than poisoning with None.
-        disk = _load_disk_cache(repo)
-        if disk:
-            _release_memo[repo] = disk
-            return disk[1]
-        return None
-    _release_memo[repo] = (now, latest)
-    _save_disk_cache(repo, latest)
-    return latest
+    return _flow.latest_published_release(
+        repo,
+        force_refresh = force_refresh,
+        memo = _release_memo,
+        cache_dir = lambda: _cache_dir(),
+        fetch = lambda r: _fetch_latest_release_tag(r),
+        save = lambda r, tag: _save_disk_cache(r, tag),
+    )
 
 
 def _fetch_latest_release_assets(repo: str, timeout: float = 5.0) -> Optional[dict[str, int]]:
     """Asset name -> size (bytes) for the newest published release of `repo`,
     selected exactly like _fetch_latest_release_tag. None on any failure."""
-    import urllib.error
-    import urllib.request
-
-    url = f"https://api.github.com/repos/{repo}/releases?per_page=30"
-    headers = {
-        "Accept": "application/vnd.github+json",
-        "User-Agent": "unsloth-studio-freshness-check",
-    }
-    token = os.environ.get("GITHUB_TOKEN") or os.environ.get("GH_TOKEN")
-    if token:
-        headers["Authorization"] = f"Bearer {token}"
-    req = urllib.request.Request(url, headers = headers)
-    try:
-        with urllib.request.urlopen(req, timeout = timeout) as resp:
-            data = json.loads(resp.read().decode("utf-8"))
-    except (
-        urllib.error.URLError,
-        urllib.error.HTTPError,
-        OSError,
-        json.JSONDecodeError,
-    ) as exc:
-        logger.debug("freshness asset fetch failed", repo = repo, error = str(exc))
-        return None
-    if not isinstance(data, list):
-        return None
-    published = [
-        r
-        for r in data
-        if isinstance(r, dict)
-        and not r.get("draft")
-        and not r.get("prerelease")
-        and isinstance(r.get("tag_name"), str)
-        and r.get("tag_name")
-    ]
-    if not published:
-        return None
-    newest = max(published, key = lambda r: r.get("published_at") or "")
-    assets: dict[str, int] = {}
-    for a in newest.get("assets") or []:
-        name, size = a.get("name"), a.get("size")
-        if isinstance(name, str) and isinstance(size, int):
-            assets[name] = size
-    return assets
+    return _flow.fetch_latest_release_assets(
+        repo, timeout, log_message = "freshness asset fetch failed"
+    )
 
 
 def latest_release_assets(repo: str, *, force_refresh: bool = False) -> Optional[dict[str, int]]:
     """Newest-release asset sizes for `repo`, memoized (24h TTL). None when
     offline and never fetched. In-memory only -- a restart simply re-fetches."""
-    if not repo:
-        return None
-    now = time.time()
-    if not force_refresh:
-        memo = _assets_memo.get(repo)
-        if memo and now - memo[0] < _RELEASE_CACHE_TTL_SECONDS:
-            return memo[1]
-    assets = _fetch_latest_release_assets(repo)
-    if assets is None:
-        memo = _assets_memo.get(repo)
-        return memo[1] if memo else None
-    _assets_memo[repo] = (now, assets)
-    return assets
+    return _flow.latest_release_assets(
+        repo,
+        force_refresh = force_refresh,
+        memo = _assets_memo,
+        fetch = lambda r: _fetch_latest_release_assets(r),
+    )
 
 
 def update_download_size_bytes(
@@ -290,16 +147,7 @@ def update_download_size_bytes(
 
 
 def _parse_installed_at(value: object) -> Optional[datetime]:
-    if not isinstance(value, str) or not value:
-        return None
-    s = value.replace("Z", "+00:00") if value.endswith("Z") else value
-    try:
-        dt = datetime.fromisoformat(s)
-    except ValueError:
-        return None
-    if dt.tzinfo is None:
-        dt = dt.replace(tzinfo = timezone.utc)
-    return dt
+    return _flow.parse_installed_at(value)
 
 
 def parse_base_build(tag: object) -> Optional[int]:
@@ -350,64 +198,27 @@ def check_prebuilt_freshness(
     behind = installed genuinely older than latest (see is_behind).
     stale = behind AND age >= threshold.
     Fails open on missing data (behind/stale stay False)."""
-    out: dict = {
-        "has_marker": False,
-        "stale": False,
-        "behind": False,
-        "installed_tag": None,
-        "latest_tag": None,
-        "installed_at_utc": None,
-        "age_days": None,
-        "published_repo": None,
-        "threshold_days": int(threshold_days),
-    }
-    marker = read_install_marker(binary_path)
-    if not marker:
-        return out
-    out["has_marker"] = True
-    # Display prefers the normalized base ("tag"); comparison below prefers the
-    # full "release_tag" -- deliberately opposite fallbacks.
-    out["installed_tag"] = marker.get("tag") or marker.get("release_tag")
-    out["installed_at_utc"] = marker.get("installed_at_utc")
-    out["published_repo"] = marker.get("published_repo")
-
     # The marker records both a normalized base tag ("tag", e.g. b9596) and the
-    # full release tag ("release_tag", e.g. b9596-mix-<sha>). Compare against the
-    # FULL identity, since GitHub /releases/latest returns the full tag_name --
-    # comparing the normalized base against the full latest is what produced the
-    # permanent "downgrade" banner on every mix release.
-    installed_full = marker.get("release_tag") or marker.get("tag")
-    repo = out["published_repo"]
-    if not repo or not installed_full:
-        return out
-    latest = latest_published_release(repo)
-    out["latest_tag"] = latest
-    out["behind"] = is_behind(installed_full, latest)
-    if not out["behind"]:
-        return out
-
-    installed_at = _parse_installed_at(out["installed_at_utc"])
-    if installed_at is None:
-        return out
-    now = now or datetime.now(tz = timezone.utc)
-    age_seconds = (now - installed_at).total_seconds()
-    out["age_days"] = max(0, int(age_seconds // 86400))
-    if age_seconds >= threshold_days * 86400:
-        out["stale"] = True
-    return out
+    # full release tag ("release_tag", e.g. b9596-mix-<sha>). Display prefers the
+    # normalized base; comparison uses the FULL identity, since GitHub
+    # /releases/latest returns the full tag_name -- comparing the normalized base
+    # against the full latest is what produced the permanent "downgrade" banner
+    # on every mix release. Deliberately opposite fallbacks.
+    return _flow.check_freshness(
+        binary_path,
+        threshold_days = threshold_days,
+        now = now,
+        read_marker = lambda p: read_install_marker(p),
+        latest_release = lambda repo: latest_published_release(repo),
+        behind = lambda installed, latest: is_behind(installed, latest),
+        display_tag = lambda marker: marker.get("tag") or marker.get("release_tag"),
+        compare_tag = lambda marker: marker.get("release_tag") or marker.get("tag"),
+    )
 
 
 def format_stale_warning(info: dict) -> str:
     """Human-readable one-liner for stale prebuilt info."""
-    age = info.get("age_days")
-    installed = info.get("installed_tag") or "unknown"
-    latest = info.get("latest_tag") or "unknown"
-    age_str = f"{age} day{'s' if age != 1 else ''}" if age is not None else "some time"
-    return (
-        f"llama.cpp prebuilt is {age_str} behind: installed "
-        f"{installed}, latest {latest}. Run `unsloth studio update` "
-        f"to refresh."
-    )
+    return _flow.format_stale_warning(info, component = "llama.cpp")
 
 
 def reset_caches(*, drop_disk: bool = False) -> None:
@@ -420,13 +231,8 @@ def reset_caches(*, drop_disk: bool = False) -> None:
     (see its last-good fallback) and the banner could linger. Dropping the disk
     cache makes latest read as None in that offline case, so the banner fails
     open (off) instead of pointing at the just-replaced build."""
-    _marker_cache.clear()
-    _release_memo.clear()
-    _assets_memo.clear()
-    if drop_disk:
-        import shutil
-
-        # _cache_dir() is a dedicated freshness-only subdir; it is re-created on
-        # the next _save_disk_cache. ignore_errors so a missing/locked dir is a
-        # no-op rather than breaking an otherwise successful install.
-        shutil.rmtree(_cache_dir(), ignore_errors = True)
+    _flow.reset_caches(
+        (_marker_cache, _release_memo, _assets_memo),
+        drop_disk = drop_disk,
+        cache_dir = lambda: _cache_dir(),
+    )
diff --git a/studio/backend/utils/llama_cpp_update.py b/studio/backend/utils/llama_cpp_update.py
index f6d3635301..174e6ef4dc 100644
--- a/studio/backend/utils/llama_cpp_update.py
+++ b/studio/backend/utils/llama_cpp_update.py
@@ -17,17 +17,22 @@ Design notes:
   thread; callers poll get_update_status() for the job state.
 - Everything fails open: a missing marker / offline GitHub / source build just
   reports update_available=False and never blocks the app.
+- The mechanics (managed-root resolution, local-link detection, the resolve
+  probe, the streamed installer run) live in utils.prebuilt.update_flow; this
+  module keeps the llama policy and the job dict its callers poll.
+- This is the single main update item: whisper.cpp piggybacks on it. Status
+  folds in a whisper sub-status (update_available becomes the union) and apply
+  chains a whisper phase after the llama phase when whisper is behind (see
+  update_flow.run_chained_update and whisper_cpp_update.chained_phase_plan).
 """
 
 from __future__ import annotations
 
-import json
 import os
 import re
 import subprocess
 import sys
 import threading
-import time
 from pathlib import Path
 from typing import Optional
 
@@ -43,7 +48,7 @@ from utils.llama_cpp_freshness import (
     reset_caches,
     update_download_size_bytes,
 )
-from utils.process_lifetime import child_popen_kwargs
+from utils.prebuilt import update_flow as _flow
 
 logger = structlog.get_logger(__name__)
 
@@ -51,38 +56,23 @@ DEFAULT_PUBLISHED_REPO = "unslothai/llama.cpp"
 _INSTALL_TIMEOUT_SECONDS = 1800  # 30 min ceiling for download + build/validate
 
 # Background job state. Single in-flight update at a time, guarded by _job_lock.
-_JOB_IDLE = "idle"
-_JOB_RUNNING = "running"
-_JOB_SUCCESS = "success"
-_JOB_ERROR = "error"
+_JOB_IDLE = _flow.JOB_IDLE
+_JOB_RUNNING = _flow.JOB_RUNNING
+_JOB_SUCCESS = _flow.JOB_SUCCESS
+_JOB_ERROR = _flow.JOB_ERROR
 
 _job_lock = threading.Lock()
-_job: dict = {
-    "state": _JOB_IDLE,
-    "message": "",
-    "from_tag": None,
-    "to_tag": None,
-    "reload_required": None,
-    "error": None,
-    "progress": None,
-    "started_at": None,
-    "finished_at": None,
-}
+_job: dict = _flow.new_job()
 
-# Matches the installer's download progress lines, e.g.
-# "Downloading x.zip:  35.0% (12.3 MiB/35.1 MiB) at 8.2 MiB/s".
-_PROGRESS_LINE_RE = re.compile(r"(\d+(?:\.\d+)?)%\s*\(")
-# The download dominates the update; extract/validate fill the last slice.
-_DOWNLOAD_PROGRESS_CEILING = 0.95
-
-
-def _utcnow() -> str:
-    return time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime())
+_utcnow = _flow.utcnow
+_is_under = _flow.is_under
+_is_external_link = _flow.is_external_link
+_rocm_install_args = _flow.rocm_install_args
 
 
 def _find_binary() -> Optional[str]:
     """Locate the active llama-server binary via the inference backend's own
-    resolver, so update targets exactly what Studio runs. Lazy import keeps the
+    resolver, so update targets exactly what Unsloth runs. Lazy import keeps the
     heavy inference module off this module's import path."""
     try:
         from core.inference.llama_cpp import LlamaCppBackend
@@ -94,37 +84,19 @@ def _find_binary() -> Optional[str]:
 
 def _install_dir_for(binary_path: Optional[str]) -> Optional[Path]:
     """The directory holding UNSLOTH_PREBUILT_INFO.json -- i.e. the install root
-    install_llama_prebuilt.py wrote and the one we re-install into. Walks up from
-    the binary the same way read_install_marker() does."""
-    if not binary_path:
-        return None
-    p = Path(binary_path)
-    for parent in p.parents[:5]:
-        if (parent / _INSTALL_MARKER_NAME).is_file():
-            return parent
-    return None
+    install_llama_prebuilt.py wrote and the one we re-install into."""
+    return _flow.install_dir_for(binary_path, marker_name = _INSTALL_MARKER_NAME)
 
 
 def _installer_script() -> Optional[Path]:
-    """Locate install_llama_prebuilt.py. Honours UNSLOTH_LLAMA_INSTALLER, then
-    searches up from this file for both ``<root>/install_llama_prebuilt.py`` and
-    ``<root>/studio/install_llama_prebuilt.py`` so it works in the dev tree and
-    in an installed Studio layout."""
-    env = os.environ.get("UNSLOTH_LLAMA_INSTALLER")
-    if env and Path(env).is_file():
-        return Path(env)
-    here = Path(__file__).resolve()
-    for up in here.parents:
-        for cand in (up / "install_llama_prebuilt.py", up / "studio" / "install_llama_prebuilt.py"):
-            if cand.is_file():
-                return cand
-    return None
+    """Locate install_llama_prebuilt.py (UNSLOTH_LLAMA_INSTALLER wins)."""
+    return _flow.find_installer_script(
+        env_var = "UNSLOTH_LLAMA_INSTALLER", script_name = "install_llama_prebuilt.py"
+    )
 
 
 # Markerless (source-build) installs have no UNSLOTH_PREBUILT_INFO.json, so we
-# ask the installer whether an official prebuilt now exists for this host. Memo
-# is 24h; only successful answers are cached so a network blip retries.
-_RESOLVE_TTL_SECONDS = 24 * 60 * 60
+# ask the installer whether an official prebuilt now exists for this host.
 _resolve_memo: dict = {}
 
 
@@ -132,39 +104,12 @@ def _resolve_prebuilt_for_host(*, force_refresh: bool = False) -> Optional[dict]
     """Run install_llama_prebuilt.py --resolve-prebuilt (no download) and return
     {prebuilt_available, repo, release_tag, llama_tag, asset, install_kind} or
     None. Fail-open: any error -> None so a source build never blocks the app."""
-    now = time.time()
-    if not force_refresh and _resolve_memo:
-        if now - _resolve_memo.get("at", 0.0) < _RESOLVE_TTL_SECONDS:
-            return _resolve_memo.get("value")
-    script = _installer_script()
-    if script is None:
-        return None
-    value: Optional[dict] = None
-    try:
-        proc = subprocess.run(
-            [
-                sys.executable,
-                str(script),
-                "--resolve-prebuilt",
-                "latest",
-                "--output-format",
-                "json",
-            ],
-            capture_output = True,
-            text = True,
-            timeout = 60,
-        )
-        out = (proc.stdout or "").strip()
-        if proc.returncode == 0 and out:
-            parsed = json.loads(out.splitlines()[-1])
-            if isinstance(parsed, dict):
-                value = parsed
-    except Exception as exc:  # pragma: no cover - subprocess/json defensive
-        logger.debug("llama update: resolve-prebuilt failed", error = str(exc))
-        value = None
-    if value is not None:  # cache real answers; let failures retry next poll
-        _resolve_memo.update(at = now, value = value)
-    return value
+    return _flow.resolve_prebuilt_for_host(
+        force_refresh = force_refresh,
+        memo = _resolve_memo,
+        installer_script = lambda: _installer_script(),
+        log_message = "llama update: resolve-prebuilt failed",
+    )
 
 
 def _installed_build_number(binary: Optional[str]) -> Optional[int]:
@@ -218,38 +163,16 @@ def get_installed_llama_version() -> Optional[str]:
     return f"b{n}" if n is not None else None
 
 
-def _is_under(path: Path, root: Path) -> bool:
-    try:
-        p, r = path.resolve(), root.resolve()
-    except (OSError, ValueError):
-        p, r = path, root
-    return p == r or r in p.parents
-
-
 def _llama_install_root(binary: Optional[str]) -> Optional[Path]:
-    """The Studio-managed llama.cpp root the active binary lives under, or None
-    when the binary is unmanaged. Installing anywhere the active binary is not
-    would not replace what _find_llama_server_binary runs (which prefers a pinned
-    LLAMA_SERVER_PATH, then UNSLOTH_LLAMA_CPP_PATH, then a llama.cpp tree), so we
-    refuse rather than silently install into an inactive or foreign tree."""
-    marked = _install_dir_for(binary)
-    if marked is not None:
-        return marked
-    if not binary:
-        return None
-    # LLAMA_SERVER_PATH is an explicit user pin that always wins in discovery;
-    # never auto-replace its tree (even a user's own llama.cpp checkout).
-    if os.environ.get("LLAMA_SERVER_PATH"):
-        return None
-    p = Path(binary)
-    env = os.environ.get("UNSLOTH_LLAMA_CPP_PATH")
-    if env and _is_under(p, Path(env)):
-        return Path(env)
-    for parent in p.parents:
-        if parent.name == "llama.cpp":
-            return parent
-    # PATH / system / custom install: not a managed tree, so do not offer.
-    return None
+    """The Unsloth-managed llama.cpp root the active binary lives under, or None
+    when the binary is unmanaged (see update_flow.managed_install_root)."""
+    return _flow.managed_install_root(
+        binary,
+        marker_root = _install_dir_for(binary),
+        server_path_var = "LLAMA_SERVER_PATH",
+        cpp_path_var = "UNSLOTH_LLAMA_CPP_PATH",
+        dir_name = "llama.cpp",
+    )
 
 
 def _source_build_status(binary: str, *, force_refresh: bool) -> Optional[dict]:
@@ -324,69 +247,83 @@ def _source_build_status(binary: str, *, force_refresh: bool) -> Optional[dict]:
     }
 
 
-def _is_external_link(path: Optional[Path]) -> bool:
-    """True when ``path`` is a --with-llama-cpp-dir local link: a POSIX symlink
-    or a Windows directory junction / reparse point. Such a link resolves into
-    the user's own llama.cpp checkout, so Studio must never auto-update it."""
-    if path is None:
-        return False
-    try:
-        if os.path.islink(path):
-            return True
-    except OSError:
-        return False
-    if os.name == "nt":
-        try:
-            import stat
-            attrs = os.lstat(path).st_file_attributes  # type: ignore[attr-defined]
-            return bool(attrs & stat.FILE_ATTRIBUTE_REPARSE_POINT)
-        except (OSError, AttributeError):
-            return False
-    return False
-
-
 def _active_install_is_local_link(binary: Optional[str]) -> bool:
     """True when the active llama-server resolves through a --with-llama-cpp-dir
-    local link at the canonical llama.cpp directory. An update would write
-    through that link into the user's own checkout (or fail), so the install is
-    treated as externally managed: no update is offered or applied. Checks only
-    up to and including the ``llama.cpp`` dir so a symlinked HOME / studio root
-    above it can't trip a false positive."""
-    if not binary:
-        return False
-    for parent in Path(binary).parents:
-        if _is_external_link(parent):
-            return True
-        if parent.name == "llama.cpp":
-            break
-    return False
+    local link at the canonical llama.cpp directory (see
+    update_flow.active_install_is_local_link)."""
+    return _flow.active_install_is_local_link(binary, dir_name = "llama.cpp")
 
 
 def _local_link_status() -> dict:
     """Status payload for a local-link install: unmanaged, no update offered."""
-    with _job_lock:
-        job = dict(_job)
-    return {
-        "supported": False,
-        "update_available": False,
-        "stale": False,
-        "installed_tag": None,
-        "latest_tag": None,
-        "published_repo": None,
-        "installed_at_utc": None,
-        "age_days": None,
-        "source_build": False,
-        "local_link": True,
-        "update_size_bytes": None,
-        "job": job,
+    return _flow.local_link_status(_job, _job_lock)
+
+
+def _whisper_chain_status(
+    *, force_refresh: bool = False, paired_llama_will_update: bool = False
+) -> Optional[dict]:
+    """Whisper's piggyback plan for the combined update item (see
+    whisper_cpp_update.chained_phase_plan). None disables the piggyback --
+    fail-open so whisper can never break the llama status or apply."""
+    try:
+        from utils import whisper_cpp_update
+        return whisper_cpp_update.chained_phase_plan(
+            force_refresh = force_refresh,
+            paired_llama_will_update = paired_llama_will_update,
+        )
+    except Exception as exc:  # pragma: no cover - defensive
+        logger.debug("llama update: whisper piggyback probe failed", error = str(exc))
+        return None
+
+
+def _merge_whisper_status(status: dict, *, force_refresh: bool = False) -> dict:
+    """Fold the whisper sub-status into the llama status payload: the llama
+    update item is the single UI surface, so update_available becomes the union
+    (llama behind OR whisper behind) while llama_update_available keeps the
+    llama-only flag. All pre-existing top-level fields are preserved."""
+    status["llama_update_available"] = bool(status.get("update_available"))
+    plan = _whisper_chain_status(
+        force_refresh = force_refresh,
+        paired_llama_will_update = status["llama_update_available"],
+    )
+    if plan is None:
+        status["whisper"] = None
+        status["update_component"] = "llama" if status["llama_update_available"] else None
+        return status
+    sub = plan.get("status") or {}
+    status["whisper"] = {
+        "update_available": bool(plan.get("update_available")),
+        "installed_tag": sub.get("installed_tag"),
+        "latest_tag": sub.get("latest_tag"),
+        "update_size_bytes": sub.get("update_size_bytes"),
+        "skip_reason": plan.get("skip_reason"),
     }
+    whisper_update_available = bool(plan.get("update_available"))
+    if whisper_update_available:
+        status["update_available"] = True
+    status["update_component"] = (
+        "llama"
+        if status["llama_update_available"]
+        else "whisper"
+        if whisper_update_available
+        else None
+    )
+    return status
 
 
 def get_update_status(*, force_refresh: bool = False) -> dict:
-    """Report whether a newer prebuilt exists plus the current job state.
+    """Report whether an update is available plus the current job state.
 
-    force_refresh bypasses the 24h release cache for an explicit "check now".
+    This is the single main update item: llama.cpp drives it and the whisper
+    piggyback is folded in (see _merge_whisper_status). force_refresh bypasses
+    the 24h release cache for an explicit "check now".
     """
+    status = _llama_only_status(force_refresh = force_refresh)
+    return _merge_whisper_status(status, force_refresh = force_refresh)
+
+
+def _llama_only_status(*, force_refresh: bool = False) -> dict:
+    """The llama.cpp half of get_update_status (no whisper sub-status)."""
     binary = _find_binary()
     # A --with-llama-cpp-dir local link is the user's own tree; never offer to
     # replace it. Bail before any network/freshness work.
@@ -456,32 +393,19 @@ def get_update_status(*, force_refresh: bool = False) -> dict:
     }
 
 
-def _rocm_install_args(asset: Optional[str]) -> list[str]:
-    """Forward --rocm-gfx/--has-rocm from the marker asset, mirroring setup.sh.
-    The installer probe can miss the gfx arch on amd-smi-only hosts; per-gfx
-    ROCm bundles carry the family in the name (rocm-gfx110X), version-tagged
-    bundles only rocm/hip."""
-    if not asset:
-        return []
-    low = asset.lower()
-    if "rocm" not in low and "hip" not in low:
-        return []
-    gfx = re.search(r"-gfx[0-9a-z]+", low)
-    if gfx:
-        # _normalize_forwarded_gfx accepts the family form (gfx110x -> gfx110X).
-        return ["--rocm-gfx", gfx.group(0).lstrip("-")]
-    return ["--has-rocm"]
-
-
-def _run_update(
+def _run_llama_phase(
     install_dir: Path,
     repo: str,
     asset: Optional[str],
     script: Path,
-    pin_release_tag: Optional[str] = None,
-) -> None:
-    """Worker: put the backend into a maintenance state, run the installer for
-    the latest prebuilt, then refresh caches so the next load uses the new build.
+    pin_release_tag: Optional[str],
+    set_progress,
+    force_cpu: bool = False,
+) -> dict:
+    """The llama phase of a chained update: put the backend into a maintenance
+    state, run the installer for the latest prebuilt, then refresh caches so the
+    next load uses the new build. Returns {to_tag, reload_required, message};
+    raises on failure.
 
     pin_release_tag pins the installer to that exact published release instead
     of letting it re-resolve "latest" itself (see start_update for why)."""
@@ -522,8 +446,13 @@ def _run_update(
         if pin_release_tag:
             cmd.extend(["--published-release-tag", pin_release_tag])
         cmd.extend(_rocm_install_args(asset))
+        # Re-assert a deliberate CPU install (--force-cpu) so detect_host on a GPU host
+        # does not re-route to a GPU/Vulkan bundle and revive the crash (#7213). --force-cpu
+        # (not --cpu-fallback) also re-persists force_cpu, keeping the choice across future
+        # updates. A natural fallback (or a legacy marker without the flag) heals to GPU (#6097).
+        if force_cpu:
+            cmd.append("--force-cpu")
         logger.info("llama update: installing", cmd = " ".join(cmd))
-        # Stream progress lines into job["progress"].
         env = dict(os.environ, UNSLOTH_PROGRESS_PERCENT_STEP = "5")
         # Preserve a Vulkan install across updates: detect_host on a CUDA/ROCm
         # box would otherwise re-route and silently replace the Vulkan build.
@@ -531,44 +460,12 @@ def _run_update(
         # _rocm_install_args).
         if asset and "vulkan" in asset.lower():
             env["UNSLOTH_FORCE_VULKAN"] = "1"
-        proc = subprocess.Popen(
+        _flow.stream_installer(
             cmd,
-            stdout = subprocess.PIPE,
-            stderr = subprocess.STDOUT,
-            text = True,
-            env = env,
-            **child_popen_kwargs(),
+            env,
+            set_progress = set_progress,
+            timeout_seconds = _INSTALL_TIMEOUT_SECONDS,
         )
-        timed_out = threading.Event()
-
-        def _kill_on_timeout() -> None:
-            timed_out.set()
-            proc.kill()
-
-        watchdog = threading.Timer(_INSTALL_TIMEOUT_SECONDS, _kill_on_timeout)
-        watchdog.daemon = True
-        watchdog.start()
-        tail_lines: list[str] = []
-        try:
-            assert proc.stdout is not None
-            for line in proc.stdout:
-                tail_lines.append(line)
-                if len(tail_lines) > 80:
-                    del tail_lines[0]
-                m = _PROGRESS_LINE_RE.search(line)
-                if m is None:
-                    continue
-                fraction = min(float(m.group(1)) / 100.0, 1.0) * _DOWNLOAD_PROGRESS_CEILING
-                with _job_lock:
-                    _job["progress"] = max(_job.get("progress") or 0.0, fraction)
-            returncode = proc.wait()
-        finally:
-            watchdog.cancel()
-        if timed_out.is_set():
-            raise RuntimeError(f"installer timed out after {_INSTALL_TIMEOUT_SECONDS}s")
-        if returncode != 0:
-            tail = "".join(tail_lines).strip()[-1500:]
-            raise RuntimeError(f"installer exited {returncode}: {tail or 'no output'}")
 
         # Drop stale caches so the banner re-checks the swapped marker.
         # If GitHub is offline, latest stays unknown and the banner fails open.
@@ -590,29 +487,18 @@ def _run_update(
         ):
             raise RuntimeError(f"pinned release {pin_release_tag} but installer produced {new_tag}")
 
-        with _job_lock:
-            _job.update(
-                state = _JOB_SUCCESS,
-                message = (
-                    f"Updated llama.cpp to {new_tag}."
-                    + (" Reload your model to use it." if model_was_active else "")
-                ),
-                to_tag = new_tag,
-                reload_required = model_was_active,
-                error = None,
-                progress = 1.0,
-                finished_at = _utcnow(),
-            )
         logger.info("llama update: success", to_tag = new_tag)
+        return {
+            "to_tag": new_tag,
+            "reload_required": model_was_active,
+            "message": (
+                f"Updated llama.cpp to {new_tag}."
+                + (" Reload your model to use it." if model_was_active else "")
+            ),
+        }
     except Exception as exc:
         logger.warning("llama update: failed", error = str(exc))
-        with _job_lock:
-            _job.update(
-                state = _JOB_ERROR,
-                message = "llama.cpp update failed.",
-                error = str(exc),
-                finished_at = _utcnow(),
-            )
+        raise
     finally:
         # Always clear maintenance state.
         if backend is not None:
@@ -622,55 +508,64 @@ def _run_update(
                 pass
 
 
-def start_update() -> dict:
-    """Kick off a background update. Idempotent: a second call while one is
-    running returns the in-flight job rather than starting another."""
+# Combined-job progress split when both phases run (download sizes: the llama
+# bundle dwarfs the whisper one); normalized to 0..1 when a phase is skipped.
+_LLAMA_PHASE_WEIGHT = 0.7
+_WHISPER_PHASE_WEIGHT = 0.3
+
+
+def _plan_llama_phase() -> dict:
+    """Decide how the llama phase of a combined update runs. Returns {"spec"}
+    when llama should install, else {"skip_reason", "refusal"}: skip_reason
+    marks the phase skipped inside a chained job, refusal is the started=False
+    response when the whisper phase has nothing to run either."""
     binary = _find_binary()
     # Refuse to update a --with-llama-cpp-dir local link: installing a prebuilt
     # here would write through the link into the user's own checkout (or fail)
     # and silently drop the link the flag created.
     if _active_install_is_local_link(binary):
         return {
-            "started": False,
-            "reason": "local_link",
-            "message": (
-                "llama.cpp is a local directory linked with --with-llama-cpp-dir; "
-                "Studio won't replace it. Update your own llama.cpp checkout instead."
-            ),
-            "job": get_update_status()["job"],
+            "skip_reason": "local_link",
+            "refusal": {
+                "started": False,
+                "reason": "local_link",
+                "message": (
+                    "llama.cpp is a local directory linked with --with-llama-cpp-dir; "
+                    "Unsloth won't replace it. Update your own llama.cpp checkout instead."
+                ),
+            },
         }
     marker = read_install_marker(binary)
     script = _installer_script()
     if script is None:
         return {
-            "started": False,
-            "reason": "installer_missing",
-            "message": "install_llama_prebuilt.py could not be located.",
-            "job": get_update_status()["job"],
+            "skip_reason": "installer_missing",
+            "refusal": {
+                "started": False,
+                "reason": "installer_missing",
+                "message": "install_llama_prebuilt.py could not be located.",
+            },
         }
 
-    # A job already in flight wins over any freshness re-check below (and skips
-    # its network call). The final lock block re-checks to close the TOCTOU.
-    with _job_lock:
-        if _job["state"] == _JOB_RUNNING:
-            return {"started": False, "reason": "already_running", "job": dict(_job)}
-
     if marker:
         # Mirror the detection guard: a direct POST or a stale banner must not
         # start an install when the latest is not actually newer (force a fresh
         # check so a stale 24h cache can't wrongly block a real update either).
-        status = get_update_status(force_refresh = True)
+        status = _llama_only_status(force_refresh = True)
         if not status.get("update_available"):
             return {
-                "started": False,
-                "reason": "up_to_date",
-                "message": "The installed llama.cpp build is already at the latest prebuilt.",
-                "job": status["job"],
+                "skip_reason": "up_to_date",
+                "refusal": {
+                    "started": False,
+                    "reason": "up_to_date",
+                    "message": "The installed llama.cpp build is already at the latest prebuilt.",
+                },
             }
         install_dir = _install_dir_for(binary)
         repo = marker.get("published_repo") or DEFAULT_PUBLISHED_REPO
         from_tag = marker.get("tag") or marker.get("release_tag")
         asset = marker.get("asset")
+        force_cpu = bool(marker.get("force_cpu"))
         # Install exactly the release the banner offered: the installer's own
         # "latest" is commit-date ordered and can lag the published_at pick
         # above, reinstalling the current build in a loop (the #6219 class).
@@ -685,57 +580,151 @@ def start_update() -> dict:
         src = _source_build_status(binary, force_refresh = True) if binary else None
         if src is None:
             return {
-                "started": False,
-                "reason": "no_prebuilt_available",
-                "message": (
-                    "No official llama.cpp prebuilt is available for this host, "
-                    "so the source build cannot be swapped automatically."
-                ),
-                "job": get_update_status()["job"],
+                "skip_reason": "no_prebuilt_available",
+                "refusal": {
+                    "started": False,
+                    "reason": "no_prebuilt_available",
+                    "message": (
+                        "No official llama.cpp prebuilt is available for this host, "
+                        "so the source build cannot be swapped automatically."
+                    ),
+                },
             }
         if not src.get("update_available"):
             return {
-                "started": False,
-                "reason": "up_to_date",
-                "message": "The installed llama.cpp build is already at or newer than the latest prebuilt.",
-                "job": get_update_status()["job"],
+                "skip_reason": "up_to_date",
+                "refusal": {
+                    "started": False,
+                    "reason": "up_to_date",
+                    "message": (
+                        "The installed llama.cpp build is already at or newer than the "
+                        "latest prebuilt."
+                    ),
+                },
             }
         res = _resolve_prebuilt_for_host()
         install_dir = _llama_install_root(binary)
         repo = (res or {}).get("repo") or DEFAULT_PUBLISHED_REPO
         from_tag = None
         asset = (res or {}).get("asset")
+        # Source builds carry no forced-CPU marker, so nothing to preserve here.
+        force_cpu = False
         # No pin: source-build detection resolves via --resolve-prebuilt latest,
         # the same resolver the unpinned apply uses, so the two already agree.
         pin_release_tag = None
 
     if install_dir is None:
         return {
-            "started": False,
-            "reason": "no_install_dir",
-            "message": "Could not determine the llama.cpp install directory.",
-            "job": get_update_status()["job"],
+            "skip_reason": "no_install_dir",
+            "refusal": {
+                "started": False,
+                "reason": "no_install_dir",
+                "message": "Could not determine the llama.cpp install directory.",
+            },
         }
+    return {
+        "spec": {
+            "install_dir": install_dir,
+            "repo": repo,
+            "asset": asset,
+            "script": script,
+            "pin_release_tag": pin_release_tag,
+            "from_tag": from_tag,
+            "force_cpu": force_cpu,
+        }
+    }
+
+
+def start_update() -> dict:
+    """Kick off a background update job. The job chains the llama phase (the
+    existing flow) with a whisper phase that runs only when whisper is actually
+    behind; either phase no-ops cleanly when its component is current or
+    unmanaged. Idempotent: a second call while one is running returns the
+    in-flight job rather than starting another."""
+    # A job already in flight wins over any freshness re-check below (and skips
+    # its network calls). The final lock block re-checks to close the TOCTOU.
+    with _job_lock:
+        if _job["state"] == _JOB_RUNNING:
+            return {"started": False, "reason": "already_running", "job": dict(_job)}
+
+    llama_plan = _plan_llama_phase()
+    llama_spec = llama_plan.get("spec")
+    whisper_plan = _whisper_chain_status(
+        force_refresh = True,
+        paired_llama_will_update = llama_spec is not None,
+    )
+    whisper_spec = (whisper_plan or {}).get("phase")
+    if llama_spec is None and whisper_spec is None:
+        # Nothing to run in either phase: answer with the llama refusal so the
+        # existing reasons (local_link / up_to_date / ...) keep their meaning.
+        refusal = dict(llama_plan["refusal"])
+        with _job_lock:
+            refusal["job"] = dict(_job)
+        return refusal
+
+    whisper_run = None
+    if whisper_spec is not None:
+        from utils import whisper_cpp_update as _whisper
+        whisper_run = lambda set_progress: _whisper.run_chained_phase(whisper_spec, set_progress)
+
+    phases = [
+        {
+            "name": "llama",
+            "weight": _LLAMA_PHASE_WEIGHT,
+            "failure_message": "llama.cpp update failed.",
+            "skip_reason": llama_plan.get("skip_reason"),
+            "run": (
+                (
+                    lambda set_progress: _run_llama_phase(
+                        llama_spec["install_dir"],
+                        llama_spec["repo"],
+                        llama_spec["asset"],
+                        llama_spec["script"],
+                        llama_spec["pin_release_tag"],
+                        set_progress,
+                        force_cpu = llama_spec.get("force_cpu", False),
+                    )
+                )
+                if llama_spec
+                else None
+            ),
+        },
+        {
+            "name": "whisper",
+            "weight": _WHISPER_PHASE_WEIGHT,
+            "failure_message": "whisper.cpp update failed.",
+            # The sidecar reload is whisper-internal; it must not trip the
+            # job-level reload flag the chat frontend resyncs on.
+            "affects_job_reload": False,
+            "skip_reason": (whisper_plan or {}).get("skip_reason") or "unavailable",
+            "run": whisper_run,
+        },
+    ]
+    running = " + ".join(
+        name for name, spec in (("llama.cpp", llama_spec), ("whisper.cpp", whisper_spec)) if spec
+    )
 
     with _job_lock:
         if _job["state"] == _JOB_RUNNING:
             return {"started": False, "reason": "already_running", "job": dict(_job)}
         _job.update(
             state = _JOB_RUNNING,
-            message = "Downloading and installing the latest llama.cpp prebuilt...",
-            from_tag = from_tag,
+            message = f"Downloading and installing the latest {running} prebuilt...",
+            from_tag = (llama_spec or {}).get("from_tag"),
             to_tag = None,
             reload_required = None,
             error = None,
             progress = 0.0,
             started_at = _utcnow(),
             finished_at = None,
+            phases = None,
         )
         job_snapshot = dict(_job)
 
     thread = threading.Thread(
-        target = _run_update,
-        args = (install_dir, repo, asset, script, pin_release_tag),
+        target = _flow.run_chained_update,
+        args = (phases,),
+        kwargs = {"job": _job, "job_lock": _job_lock},
         name = "llama-cpp-update",
         daemon = True,
     )
@@ -745,15 +734,4 @@ def start_update() -> dict:
 
 def _reset_job_for_tests() -> None:
     """Test-only: return the job tracker to idle."""
-    with _job_lock:
-        _job.update(
-            state = _JOB_IDLE,
-            message = "",
-            from_tag = None,
-            to_tag = None,
-            reload_required = None,
-            error = None,
-            progress = None,
-            started_at = None,
-            finished_at = None,
-        )
+    _flow.reset_job(_job, _job_lock)
diff --git a/studio/backend/utils/mlx_repair.py b/studio/backend/utils/mlx_repair.py
index 7e1c9864c9..4ea1ec62f5 100644
--- a/studio/backend/utils/mlx_repair.py
+++ b/studio/backend/utils/mlx_repair.py
@@ -3,7 +3,7 @@
 
 """Best-effort MLX self-heal for Apple Silicon.
 
-On macOS, Studio enables Train/Export only when the MLX training/export stack is
+On macOS, Unsloth enables Train/Export only when the MLX training/export stack is
 usable (see utils.hardware.hardware.detect_hardware -> CHAT_ONLY). MLX is pulled
 only transitively via unsloth-zoo, and a resolver backtrack (mlx-vlm ->
 transformers>=5 vs the single-env transformers pin) can silently drop it, leaving
@@ -13,7 +13,7 @@ a background thread, then re-detects so the gate re-opens without a manual
 
 The install mirrors the main Apple Silicon installer (install_python_stack.py):
 it points UV_OVERRIDE at overrides-darwin-arm64.txt so the resolver keeps the
-Studio transformers pin AND installs a current mlx-vlm, and it requires the same
+Unsloth transformers pin AND installs a current mlx-vlm, and it requires the same
 minimum versions unsloth-zoo declares so a backtracked old mlx-vlm (which still
 imports but breaks VLM Train/Export) is never accepted as healthy.
 
@@ -69,11 +69,11 @@ _MLX_REINSTALL_ARGS = tuple(
 # reject anything. mlx/mlx-metal ship wheels only (no sdist on PyPI) and
 # mlx-lm/mlx-vlm publish py3-none-any wheels, so requiring wheels does not break a
 # healthy self-heal; if a wheel is genuinely unavailable the install fails and
-# Studio stays chat-only (the existing safe fallback) until `unsloth studio update`.
+# Unsloth stays chat-only (the existing safe fallback) until `unsloth studio update`.
 _ONLY_BINARY_ARG = "--only-binary=:all:"
 # Allowlist of environment variables forwarded to the install subprocess. The
 # self-heal runs without confirmation on the default startup path, so it must not
-# hand resolver/build code the full Studio environment. Everything outside this
+# hand resolver/build code the full Unsloth environment. Everything outside this
 # set is dropped, which excludes three dangerous classes by construction:
 #   * secrets (HF_TOKEN, AWS_*, WANDB_API_KEY, ...) that a malicious wheel/sdist
 #     build hook would otherwise read straight out of os.environ;
@@ -207,13 +207,13 @@ def _mlx_install_env() -> dict[str, str]:
 
     The self-heal runs without confirmation on the default startup path, so it
     forwards only the variables uv genuinely needs (see _MLX_ENV_ALLOWLIST) instead
-    of the full Studio environment: secrets and package-source redirects in
+    of the full Unsloth environment: secrets and package-source redirects in
     os.environ are dropped so a malicious resolver-selected artifact cannot read
-    Studio secrets or be steered to a hostile index.
+    Unsloth secrets or be steered to a hostile index.
 
     Mirror the main installer (install_python_stack.py) by pointing UV_OVERRIDE at
     overrides-darwin-arm64.txt, which relaxes mlx-vlm/mlx-lm's transformers>=5
-    requirement to >=4.57.6. Without it, uv keeps the Studio transformers pin only
+    requirement to >=4.57.6. Without it, uv keeps the Unsloth transformers pin only
     by silently backtracking mlx-vlm to an old, unsupported version (uv honours
     UV_OVERRIDE; plain pip ignores it, so the transformers constraint below is the
     pip-path safety net). We set UV_OVERRIDE ourselves, so a poisoned one in the
@@ -234,17 +234,17 @@ def _mlx_install_env() -> dict[str, str]:
 def _transformers_constraint_args() -> tuple[list[str], str | None]:
     """Pin transformers to the running version for the mlx install.
 
-    The install must never upgrade transformers underneath a running Studio
+    The install must never upgrade transformers underneath a running Unsloth
     (the single-env install pins transformers==4.57.6). With UV_OVERRIDE set this
     is belt-and-suspenders; on the plain-pip path (no UV_OVERRIDE support) it is
     the actual guard -- the resolver either finds an mlx build compatible with the
-    pin or fails, leaving us chat-only rather than breaking Studio. Returns
+    pin or fails, leaving us chat-only rather than breaking Unsloth. Returns
     (pip args, temp file path to clean up).
 
     Read the version from installed metadata rather than `import transformers`:
     transformers can have valid metadata yet fail to import (e.g. an incompatible
     huggingface_hub), and in that case we still want to pin it so the mlx install
-    cannot quietly upgrade it out from under Studio."""
+    cannot quietly upgrade it out from under Unsloth."""
     from importlib.metadata import PackageNotFoundError, version as _dist_version
 
     try:
@@ -263,10 +263,10 @@ def attempt_mlx_repair(*, timeout: int = _REPAIR_TIMEOUT_S) -> bool:
     """Install a usable mlx/mlx-lm/mlx-vlm stack by name into the running venv.
     Best-effort; returns True iff the resulting stack meets unsloth-zoo's minimums
     (so a backtracked old mlx-vlm is rejected, not accepted). transformers is held
-    at its pinned version so the install can never upgrade it underneath Studio."""
+    at its pinned version so the install can never upgrade it underneath Unsloth."""
     # Prepare the constraint inside the try: this runs on a daemon thread, so an
     # exception here (e.g. tempfile.mkstemp failing on a full disk or bad TMPDIR)
-    # must leave Studio chat-only, not crash the background self-heal thread.
+    # must leave Unsloth chat-only, not crash the background self-heal thread.
     constraint_path = None
     try:
         constraint_args, constraint_path = _transformers_constraint_args()
@@ -279,7 +279,7 @@ def attempt_mlx_repair(*, timeout: int = _REPAIR_TIMEOUT_S) -> bool:
         )
         if cmd is None:
             logger.warning(
-                "MLX self-heal requires uv so Studio can apply dependency overrides; "
+                "MLX self-heal requires uv so Unsloth can apply dependency overrides; "
                 "staying chat-only. Run `unsloth studio update` to restore uv."
             )
             return False
diff --git a/studio/backend/utils/models/checkpoints.py b/studio/backend/utils/models/checkpoints.py
index b6b080b1c4..f2125ad034 100644
--- a/studio/backend/utils/models/checkpoints.py
+++ b/studio/backend/utils/models/checkpoints.py
@@ -37,7 +37,7 @@ def _checkpoint_sort_key(checkpoint_path: Path) -> tuple[int, int, str]:
 
 
 def _infer_base_model_from_history(checkpoint_dir: Path) -> Optional[str]:
-    """Best-effort base-model lookup using persisted Studio run metadata."""
+    """Best-effort base-model lookup using persisted Unsloth run metadata."""
     checkpoint_name = checkpoint_dir.name
     resolved_checkpoint_dir = str(checkpoint_dir.resolve())
 
diff --git a/studio/backend/utils/models/gguf_metadata.py b/studio/backend/utils/models/gguf_metadata.py
index c24ec28e1d..749f2c9234 100644
--- a/studio/backend/utils/models/gguf_metadata.py
+++ b/studio/backend/utils/models/gguf_metadata.py
@@ -50,9 +50,15 @@ _CACHE_MAX_ENTRIES = 4096
 # keyed by (file cache key, wanted key). None = key absent / file unreadable.
 _BOOL_CACHE: Dict[Tuple[_CacheKey, str], Optional[bool]] = {}
 
-# Native training context length (``{arch}.context_length``). None = absent /
-# unreadable. Lets the UI show the real context ceiling before a model loads.
-_CONTEXT_CACHE: Dict[_CacheKey, Optional[int]] = {}
+_STRING_CACHE: Dict[Tuple[_CacheKey, str], Optional[str]] = {}
+
+# GGUF header dims for the staged/deferred-load UI: context_length, layer_count
+# (block_count), and moe_layer_count (block_count minus leading dense layers; 0
+# if not MoE). One cached pass fills all three so the staged sheet can size every
+# slider before the model loads. None = unreadable / not a GGUF. The native
+# training context length (``{arch}.context_length``) the UI shows before a model
+# loads is read from here via read_gguf_context_length.
+_DIMS_CACHE: Dict[_CacheKey, Optional[Dict[str, Optional[int]]]] = {}
 
 
 def _cache_key(path: str) -> Optional[_CacheKey]:
@@ -142,32 +148,45 @@ def _parse_gguf_header(path: str) -> Optional[Dict[str, str]]:
     return out
 
 
-def read_gguf_context_length(path: str) -> Optional[int]:
-    """Return the GGUF's native training context length (``{arch}.context_length``),
-    or ``None`` if missing/unreadable/not a GGUF. Cached by (path, mtime, size).
-    Lets the UI populate the context slider before the model is loaded."""
+def read_gguf_staged_dims(path: str) -> Optional[Dict[str, Optional[int]]]:
+    """GGUF header dims for the staged-load UI in one cached pass:
+    ``{"context_length", "layer_count", "moe_layer_count"}``. Each may be None
+    when absent (moe_layer_count is 0 for a dense model). Returns ``None`` if not
+    a GGUF / unreadable. Cached by (path, mtime, size). Lets the staged sheet size
+    the context, GPU-layers and MoE sliders before the model loads."""
     key = _cache_key(path)
     if key is None:
         return None
     with _CACHE_LOCK:
-        if key in _CONTEXT_CACHE:
-            return _CONTEXT_CACHE[key]
-    result = _parse_gguf_context_length(path)
+        if key in _DIMS_CACHE:
+            return _DIMS_CACHE[key]
+    result = _parse_gguf_staged_dims(path)
     with _CACHE_LOCK:
-        while len(_CONTEXT_CACHE) >= _CACHE_MAX_ENTRIES:
+        while len(_DIMS_CACHE) >= _CACHE_MAX_ENTRIES:
             try:
-                _CONTEXT_CACHE.pop(next(iter(_CONTEXT_CACHE)))
+                _DIMS_CACHE.pop(next(iter(_DIMS_CACHE)))
             except StopIteration:
                 break
-        _CONTEXT_CACHE[key] = result
+        _DIMS_CACHE[key] = result
     return result
 
 
-def _parse_gguf_context_length(path: str) -> Optional[int]:
-    # The context key is architecture-namespaced (``llama.context_length`` etc.),
-    # so we learn the key only after reading ``general.architecture``. GGUF writes
-    # general.* before arch.* keys, matching the loader's own parser.
-    ctx_key: Optional[str] = None
+def read_gguf_context_length(path: str) -> Optional[int]:
+    """Native training context length (``{arch}.context_length``), or ``None``.
+    Thin accessor over read_gguf_staged_dims."""
+    dims = read_gguf_staged_dims(path)
+    return dims["context_length"] if dims else None
+
+
+def _parse_gguf_arch_uints(path: str, wanted_suffixes: frozenset[str]) -> Optional[Dict[str, int]]:
+    """Walk a GGUF header once and return the requested architecture-namespaced
+    uint (vtype 4/10) keys, e.g. ``{"block_count": 32}``. Keys are
+    ``{arch}.<suffix>``; the arch is learned from ``general.architecture`` (GGUF
+    writes general.* before arch.* keys, matching the loader's own parser).
+    Returns ``None`` if not a GGUF / unreadable, else a dict (possibly empty or
+    partial when some keys are absent)."""
+    arch: Optional[str] = None
+    found: Dict[str, int] = {}
     try:
         with open(path, "rb") as f:
             head = f.read(24)
@@ -204,28 +223,68 @@ def _parse_gguf_context_length(path: str) -> Optional[int]:
                         sbytes = f.read(slen)
                         if len(sbytes) < slen:
                             break
-                        ctx_key = f"{sbytes.decode('utf-8', 'replace')}.context_length"
-                    elif ctx_key is not None and key == ctx_key and vtype in (4, 10):
+                        arch = sbytes.decode("utf-8", "replace")
+                    elif (
+                        arch is not None
+                        and vtype in (4, 10)
+                        and key.startswith(f"{arch}.")
+                        and key[len(arch) + 1 :] in wanted_suffixes
+                    ):
                         width = 4 if vtype == 4 else 8
                         n_bytes = f.read(width)
                         if len(n_bytes) < width:
                             break
-                        value = struct.unpack("<I" if vtype == 4 else "<Q", n_bytes)[0]
-                        # A real context length is positive; treat 0/garbage as
-                        # absent so the UI never builds a slider with max < min.
-                        return value if value > 0 else None
+                        found[key[len(arch) + 1 :]] = struct.unpack(
+                            "<I" if vtype == 4 else "<Q", n_bytes
+                        )[0]
+                        if len(found) == len(wanted_suffixes):
+                            break
                     else:
                         if not _skip_gguf_value(f, vtype):
                             break
                 except (struct.error, UnicodeDecodeError):
                     break
     except OSError as e:
-        logger.debug(f"read_gguf_context_length: cannot open {path}: {e}")
+        logger.debug(f"_parse_gguf_arch_uints: cannot open {path}: {e}")
         return None
     except Exception as e:
-        logger.debug(f"read_gguf_context_length: parse failure on {path}: {e}")
+        logger.debug(f"_parse_gguf_arch_uints: parse failure on {path}: {e}")
         return None
-    return None
+    return found
+
+
+def _parse_gguf_staged_dims(path: str) -> Optional[Dict[str, Optional[int]]]:
+    vals = _parse_gguf_arch_uints(
+        path,
+        frozenset(
+            {
+                "context_length",
+                "block_count",
+                "expert_count",
+                "leading_dense_block_count",
+            }
+        ),
+    )
+    if vals is None:
+        return None
+    ctx = vals.get("context_length")
+    block = vals.get("block_count")
+    # A real context/layer count is positive; treat 0/garbage as absent so the
+    # UI never builds a slider with max < min.
+    context_length = ctx if ctx and ctx > 0 else None
+    layer_count = block if block and block > 0 else None
+    # MoE layer count = block_count - leading dense layers, only when experts
+    # exist; else 0 (dense -> slider hidden). Mirrors n_moe_layers in
+    # core/inference/llama_cpp.py.
+    if not vals.get("expert_count") or not block:
+        moe_layer_count: Optional[int] = 0
+    else:
+        moe_layer_count = max(0, block - (vals.get("leading_dense_block_count") or 0))
+    return {
+        "context_length": context_length,
+        "layer_count": layer_count,
+        "moe_layer_count": moe_layer_count,
+    }
 
 
 # Strings (8) and arrays (9) are handled inline.
@@ -353,6 +412,83 @@ def _read_gguf_bool(path: str, wanted_key: str) -> Optional[bool]:
     return result
 
 
+def _parse_gguf_string(path: str, wanted_key: str) -> Optional[str]:
+    try:
+        with open(path, "rb") as f:
+            head = f.read(24)
+            if len(head) < 24:
+                return None
+            magic, _version, _tcount, kv_count = struct.unpack("<IIQQ", head)
+            if magic != _GGUF_MAGIC:
+                return None
+
+            for _ in range(kv_count):
+                try:
+                    klen_bytes = f.read(8)
+                    if len(klen_bytes) < 8:
+                        break
+                    klen = struct.unpack("<Q", klen_bytes)[0]
+                    if klen > 1 << 20:
+                        break
+                    kbytes = f.read(klen)
+                    if len(kbytes) < klen:
+                        break
+                    key = kbytes.decode("utf-8", "replace")
+                    vt_bytes = f.read(4)
+                    if len(vt_bytes) < 4:
+                        break
+                    vtype = struct.unpack("<I", vt_bytes)[0]
+
+                    if key == wanted_key and vtype == 8:
+                        slen_bytes = f.read(8)
+                        if len(slen_bytes) < 8:
+                            break
+                        slen = struct.unpack("<Q", slen_bytes)[0]
+                        if slen > 1 << 22:
+                            break
+                        sbytes = f.read(slen)
+                        if len(sbytes) < slen:
+                            break
+                        return sbytes.decode("utf-8", "replace")
+                    if not _skip_gguf_value(f, vtype):
+                        break
+                except (struct.error, UnicodeDecodeError):
+                    break
+    except OSError as e:
+        logger.debug(f"_parse_gguf_string: cannot open {path}: {e}")
+        return None
+    except Exception as e:
+        logger.debug(f"_parse_gguf_string: parse failure on {path}: {e}")
+        return None
+    return None
+
+
+def _read_gguf_string(path: str, wanted_key: str) -> Optional[str]:
+    fkey = _cache_key(path)
+    if fkey is None:
+        return None
+    ckey = (fkey, wanted_key)
+    with _CACHE_LOCK:
+        if ckey in _STRING_CACHE:
+            return _STRING_CACHE[ckey]
+    result = _parse_gguf_string(path, wanted_key)
+    with _CACHE_LOCK:
+        while len(_STRING_CACHE) >= _CACHE_MAX_ENTRIES:
+            try:
+                _STRING_CACHE.pop(next(iter(_STRING_CACHE)))
+            except StopIteration:
+                break
+        _STRING_CACHE[ckey] = result
+    return result
+
+
+def read_gguf_chat_template(path: str) -> Optional[str]:
+    template = _read_gguf_string(path, "tokenizer.chat_template")
+    if isinstance(template, str) and template.strip():
+        return template
+    return None
+
+
 def read_mmproj_audio_capability(path: str) -> Optional[bool]:
     """``clip.has_audio_encoder`` from an mmproj GGUF (e.g. Gemma 4's
     gemma4ua): ``True``/``False`` if present, ``None`` if absent/unreadable.
diff --git a/studio/backend/utils/models/model_config.py b/studio/backend/utils/models/model_config.py
index 284bbb5745..4897f05ce4 100644
--- a/studio/backend/utils/models/model_config.py
+++ b/studio/backend/utils/models/model_config.py
@@ -37,6 +37,7 @@ import yaml
 
 
 from utils.native_path_leases import child_env_without_native_path_secret
+from utils.hf_cache_settings import active_hf_hub_cache, get_hf_cache_paths
 from utils.subprocess_compat import (
     windows_hidden_subprocess_kwargs as _windows_hidden_subprocess_kwargs,
 )
@@ -493,6 +494,7 @@ def load_model_config(
             trust_remote_code = trust_remote_code,
             token = token,
             local_files_only = local_files_only,
+            cache_dir = active_hf_hub_cache(),
         )
 
     if not use_auth:
@@ -503,6 +505,7 @@ def load_model_config(
                 trust_remote_code = trust_remote_code,
                 token = None,
                 local_files_only = local_files_only,
+                cache_dir = active_hf_hub_cache(),
             )
 
     # Default auth (cached tokens)
@@ -510,6 +513,7 @@ def load_model_config(
         model_name,
         trust_remote_code = trust_remote_code,
         local_files_only = local_files_only,
+        cache_dir = active_hf_hub_cache(),
     )
 
 
@@ -624,6 +628,7 @@ def _raw_config_has_vision_config(
                     filename = "config.json",
                     token = hf_token,
                     local_files_only = local_files_only,
+                    cache_dir = active_hf_hub_cache(),
                 )
             )
         config = json.loads(config_path.read_text())
@@ -770,7 +775,7 @@ def _is_vision_model_subprocess(model_name: str, hf_token: Optional[str] = None)
             capture_output = True,
             text = True,
             timeout = 60,
-            env = child_env_without_native_path_secret(),
+            env = get_hf_cache_paths().child_env(child_env_without_native_path_secret()),
             **_windows_hidden_subprocess_kwargs(),
         )
 
@@ -1249,6 +1254,77 @@ def _iter_gguf_files(directory: Path, recursive: bool = False):
             yield f
 
 
+_GGUF_SPLIT_FILE_RE = re.compile(
+    r"^(?P<prefix>.+)-(?P<index>\d{5})-of-(?P<total>\d{5})\.gguf$",
+    re.IGNORECASE,
+)
+
+
+def _colocated_first_split_shard(path: Path) -> tuple[Optional[Path], bool]:
+    """Return shard 1 and whether every shard is beside *path*."""
+    match = _GGUF_SPLIT_FILE_RE.match(path.name)
+    if match is None:
+        return None, False
+
+    prefix = match.group("prefix").casefold()
+    total_text = match.group("total")
+    total = int(total_text)
+    if total < 1:
+        return None, False
+
+    first: Optional[Path] = None
+    indices: set[int] = set()
+    try:
+        siblings = path.parent.iterdir()
+        for sibling in siblings:
+            sibling_match = _GGUF_SPLIT_FILE_RE.match(sibling.name)
+            if (
+                sibling_match is None
+                or sibling_match.group("prefix").casefold() != prefix
+                or sibling_match.group("total") != total_text
+            ):
+                continue
+            try:
+                if not sibling.is_file():
+                    continue
+            except OSError:
+                continue
+            index = int(sibling_match.group("index"))
+            if not 1 <= index <= total:
+                continue
+            indices.add(index)
+            if index == 1:
+                first = sibling
+    except OSError:
+        return None, False
+
+    return first, first is not None and len(indices) == total
+
+
+def _local_gguf_load_path(path: Path) -> Path:
+    """Choose a loadable local path while preserving complete symlink sets."""
+    if _GGUF_SPLIT_FILE_RE.match(path.name) is None:
+        return path.absolute()
+
+    first, complete = _colocated_first_split_shard(path)
+    if complete and first is not None:
+        return first.absolute()
+
+    try:
+        is_symlink = path.is_symlink()
+    except OSError:
+        is_symlink = False
+    if is_symlink:
+        try:
+            target = path.resolve()
+        except OSError:
+            return (first or path).absolute()
+        target_first, _ = _colocated_first_split_shard(target)
+        return (target_first or target).absolute()
+
+    return (first or path).absolute()
+
+
 def detect_mmproj_file(path: str, search_root: Optional[str] = None) -> Optional[str]:
     """Find the mmproj GGUF for a model.
 
@@ -1434,7 +1510,7 @@ def detect_gguf_model(path: str) -> Optional[str]:
         except OSError:
             is_dir = False  # stat() unavailable in the lock window
         if not is_dir:
-            return str(p.absolute())  # absolute() keeps symlink names readable
+            return str(_local_gguf_load_path(p))
         # Directory named "*.gguf": fall through to the dir scan below.
 
     # Case 2: directory containing .gguf files (skip mmproj / MTP drafter)
@@ -1452,7 +1528,7 @@ def detect_gguf_model(path: str) -> Optional[str]:
             gguf_files.append(f)
         gguf_files.sort(key = lambda f: f.stat().st_size, reverse = True)
         if gguf_files:
-            return str(gguf_files[0].resolve())
+            return str(_local_gguf_load_path(gguf_files[0]))
 
     return None
 
@@ -1643,19 +1719,20 @@ def _local_gguf_companion_search_root(selected_path: str, gguf_file: str) -> str
     return str(gguf_dir)
 
 
-def _iter_hf_cache_snapshots(repo_id: str):
+def _iter_hf_cache_snapshots(repo_id: str, cache_dir: Optional[str | Path] = None):
     """Yield HF cache snapshot dirs for *repo_id*, newest first.
 
     Empty if HF_HUB_CACHE is missing, the repo isn't cached, or has no
     snapshots. Repo name match is case-insensitive to handle casing drift
     between download time and lookup.
     """
-    try:
-        from huggingface_hub import constants as hf_constants
-    except Exception:
-        return
-
-    cache_dir = Path(hf_constants.HF_HUB_CACHE)
+    if cache_dir is None:
+        try:
+            from utils.hf_cache_settings import get_hf_cache_paths
+            cache_dir = get_hf_cache_paths().hub_cache
+        except Exception:
+            return
+    cache_dir = Path(cache_dir)
     target = f"models--{repo_id.replace('/', '--')}".lower()
     repo_dirs: list[Path] = []
     try:
@@ -1879,7 +1956,7 @@ def _find_local_gguf_by_variant(directory: str, variant: str) -> Optional[str]:
     For sharded GGUFs (multiple files sharing a quant label), returns the
     first shard (sorted by name), which is what ``llama-server -m`` expects.
 
-    Returns the resolved absolute path, or ``None`` if no match.
+    Returns the absolute path, or ``None`` if no match.
     """
     p = _resolve_gguf_dir(Path(directory))
     if p is None:
@@ -1900,7 +1977,7 @@ def _find_local_gguf_by_variant(directory: str, variant: str) -> Optional[str]:
         matches.append(f)
     matches.sort()
     if matches:
-        return str(matches[0].resolve())
+        return str(_local_gguf_load_path(matches[0]))
     return None
 
 
@@ -1997,6 +2074,7 @@ def download_gguf_file(
         repo_id = repo_id,
         filename = filename,
         token = hf_token,
+        cache_dir = active_hf_hub_cache(),
     )
     return local_path
 
@@ -2005,6 +2083,24 @@ def download_gguf_file(
 _embedding_detection_cache: Dict[tuple, bool] = {}
 
 
+# Bound the Hub lookup so a DNS-dead session fails fast to the cache instead of hanging on retries.
+_HUB_MODEL_INFO_TIMEOUT = 15.0
+
+
+def _embedding_marker_in_hf_cache(model_name: str) -> bool:
+    """True when model_name's cached snapshot carries a modules.json (the ST marker).
+    Cache-only, no network; used offline and as a fallback when the Hub lookup times out."""
+    from utils.utils import hf_cache_snapshot_dir
+
+    snapshot = hf_cache_snapshot_dir(model_name)
+    if snapshot is None:
+        return False
+    try:
+        return (snapshot / "modules.json").is_file()
+    except OSError:
+        return False
+
+
 def is_embedding_model(model_name: str, hf_token: Optional[str] = None) -> bool:
     """Detect embedding/sentence-transformer models via HF metadata.
 
@@ -2019,6 +2115,15 @@ def is_embedding_model(model_name: str, hf_token: Optional[str] = None) -> bool:
     Returns:
         True if embedding model, else False (default for local paths or errors).
     """
+    from utils.utils import hf_env_offline
+
+    # Offline (remote repo): reclassify from the local cache on every call, before/without the
+    # memo. An online lookup can memoize True from tags with no weights cached, so trusting it once
+    # the session goes offline would accept a repo _get() cannot load; a cached negative can also be
+    # invalidated by later cache materialization. The cache probe is local-only, so it's cheap.
+    if not is_local_path(model_name) and hf_env_offline():
+        return _embedding_marker_in_hf_cache(model_name)
+
     cache_key = (model_name, hf_token)
     if cache_key in _embedding_detection_cache:
         return _embedding_detection_cache[cache_key]
@@ -2033,7 +2138,7 @@ def is_embedding_model(model_name: str, hf_token: Optional[str] = None) -> bool:
     try:
         from huggingface_hub import model_info as hf_model_info
 
-        info = hf_model_info(model_name, token = hf_token)
+        info = hf_model_info(model_name, token = hf_token, timeout = _HUB_MODEL_INFO_TIMEOUT)
         tags = set(info.tags or [])
         pipeline_tag = info.pipeline_tag or ""
 
@@ -2054,9 +2159,11 @@ def is_embedding_model(model_name: str, hf_token: Optional[str] = None) -> bool:
         return is_emb
 
     except Exception as e:
+        # Timeout or transient network error: fall back to the local cache marker, don't hard-fail.
         logger.warning(f"Could not determine if {model_name} is embedding model: {e}")
-        _embedding_detection_cache[cache_key] = False
-        return False
+        is_emb = _embedding_marker_in_hf_cache(model_name)
+        _embedding_detection_cache[cache_key] = is_emb
+        return is_emb
 
 
 def _has_model_weight_files(model_dir: Path) -> bool:
@@ -2083,7 +2190,7 @@ def _has_model_weight_files(model_dir: Path) -> bool:
 
 
 def _detect_training_output_type(model_dir: Path) -> Optional[str]:
-    """Classify a Studio training output as LoRA or full finetune."""
+    """Classify an Unsloth training output as LoRA or full finetune."""
     adapter_config = model_dir / "adapter_config.json"
     adapter_model = model_dir / "adapter_model.safetensors"
     if adapter_config.exists() or adapter_model.exists():
@@ -2105,7 +2212,7 @@ def _looks_like_lora_adapter(model_dir: Path) -> bool:
 
 
 def scan_trained_models(outputs_dir: str = str(outputs_root())) -> List[Tuple[str, str, str]]:
-    """Scan outputs folder for trained Studio models.
+    """Scan outputs folder for trained Unsloth models.
 
     Returns:
         List of (display_name, model_path, model_type), where model_type is
@@ -2416,7 +2523,10 @@ def get_base_model_from_lora_identifier(
     for _attempt in range(2):  # one retry: a transient blip must not skip the base
         try:
             cfg_path = hf_hub_download(
-                identifier, "adapter_config.json", token = hf_token if hf_token else None
+                identifier,
+                "adapter_config.json",
+                token = hf_token if hf_token else None,
+                cache_dir = active_hf_hub_cache(),
             )
         except (EntryNotFoundError, RepositoryNotFoundError):
             # No adapter_config.json -> not a resolvable LoRA; caller scans the identifier.
@@ -2796,7 +2906,12 @@ class ModelConfig:
                 try:
                     from huggingface_hub import hf_hub_download
 
-                    config_path = hf_hub_download(identifier, "adapter_config.json", token = hf_token)
+                    config_path = hf_hub_download(
+                        identifier,
+                        "adapter_config.json",
+                        token = hf_token,
+                        cache_dir = active_hf_hub_cache(),
+                    )
                     with open(config_path, "r") as f:
                         adapter_config = json.load(f)
                     base_model = adapter_config.get("base_model_name_or_path")
diff --git a/studio/backend/utils/native_path_leases.py b/studio/backend/utils/native_path_leases.py
index 08671cfe39..3ed7faa7c2 100644
--- a/studio/backend/utils/native_path_leases.py
+++ b/studio/backend/utils/native_path_leases.py
@@ -15,6 +15,7 @@ import base64
 import binascii
 import hashlib
 import hmac
+import importlib
 import json
 import os
 import stat as _stat_module
@@ -35,7 +36,7 @@ _USED_NONCES: dict[str, int] = {}
 _REDACTION_LOCK = threading.Lock()
 _NATIVE_PATH_REDACTIONS: list[str] = []
 _NATIVE_PATH_LABELS: dict[str, str] = {}
-_NATIVE_PATH_ENV_LOCK = threading.Lock()
+_NATIVE_PATH_ENV_LOCK = threading.RLock()
 _SECRET_INIT_LOCK = threading.Lock()
 _CACHED_LEASE_SECRET: bytes | None = None
 _SCRUB_REFCOUNT = 0
@@ -80,7 +81,9 @@ def child_env_without_native_path_secret(env: Mapping[str, str] | None = None) -
     return cleaned
 
 
-def run_without_native_path_secret(target: Callable[..., Any], *args: Any, **kwargs: Any) -> Any:
+def run_without_native_path_secret(
+    target: Callable[..., Any] | str, *args: Any, **kwargs: Any
+) -> Any:
     """Run a multiprocessing child target without the native path lease secret."""
 
     # Runs in the spawned child: bind it to the parent's death (Linux), since
@@ -96,6 +99,11 @@ def run_without_native_path_secret(target: Callable[..., Any], *args: Any, **kwa
     os.environ.pop(LEASE_SECRET_ENV, None)
     _CACHED_LEASE_SECRET = None
     _SCRUB_SAVED_SECRET = None
+    if isinstance(target, str):
+        function_name, environment, *args = args
+        for key, value in environment.items():
+            os.environ[key] = value
+        target = getattr(importlib.import_module(target), function_name)
     return target(*args, **kwargs)
 
 
@@ -107,10 +115,9 @@ def native_path_secret_removed_for_child_start() -> Iterator[None]:
             _SCRUB_SAVED_SECRET = os.environ.pop(LEASE_SECRET_ENV, None)
             _CACHED_LEASE_SECRET = None
         _SCRUB_REFCOUNT += 1
-    try:
-        yield
-    finally:
-        with _NATIVE_PATH_ENV_LOCK:
+        try:
+            yield
+        finally:
             _SCRUB_REFCOUNT -= 1
             if _SCRUB_REFCOUNT == 0 and _SCRUB_SAVED_SECRET is not None:
                 os.environ[LEASE_SECRET_ENV] = _SCRUB_SAVED_SECRET
diff --git a/studio/backend/utils/openai_auto_switch_settings.py b/studio/backend/utils/openai_auto_switch_settings.py
index 1689395f40..7007440f4c 100644
--- a/studio/backend/utils/openai_auto_switch_settings.py
+++ b/studio/backend/utils/openai_auto_switch_settings.py
@@ -8,7 +8,9 @@ Two settings, both off by default so existing API behavior is unchanged:
   names a downloaded local GGUF different from the loaded one transparently
   loads it before serving (llama-swap-style). Unknown names pass through.
 - ``openai_api_auto_unload_idle_seconds``: when > 0, the loaded GGUF is
-  unloaded after this many idle seconds to free VRAM.
+  unloaded after this many idle seconds to free VRAM. Enabled values have a
+  60s floor (0 stays "off"): a tiny TTL tears the model down between turns of
+  an active chat, forcing a full weight reload + prompt re-prefill per turn.
 
 The idle TTL can also be set at startup via the ``UNSLOTH_MODEL_IDLE_TTL`` env
 var. Unlike the stored setting (which stays gated on auto-switch), the env value
@@ -28,11 +30,14 @@ from typing import Any, Optional
 
 OPENAI_AUTO_SWITCH_SETTING_KEY = "openai_api_auto_switch_model"
 AUTO_UNLOAD_IDLE_SETTING_KEY = "openai_api_auto_unload_idle_seconds"
+AUTO_UNLOAD_KEEP_KV_SETTING_KEY = "openai_api_auto_unload_keep_kv"
 MODEL_OVERRIDES_SETTING_KEY = "openai_api_auto_switch_overrides"
 MODEL_IDLE_TTL_ENV_VAR = "UNSLOTH_MODEL_IDLE_TTL"
 
 DEFAULT_OPENAI_AUTO_SWITCH_ENABLED = False
 DEFAULT_AUTO_UNLOAD_IDLE_SECONDS = 0
+DEFAULT_AUTO_UNLOAD_KEEP_KV = True
+MIN_AUTO_UNLOAD_IDLE_SECONDS = 60
 
 _CACHE_TTL_S = 2.0
 _cache_lock = threading.Lock()
@@ -58,6 +63,10 @@ def _coerce_int(value: Any) -> int | None:
         return None
 
 
+def _apply_idle_floor(seconds: int) -> int:
+    return 0 if seconds <= 0 else max(MIN_AUTO_UNLOAD_IDLE_SECONDS, seconds)
+
+
 def _cached_setting(key: str, default: Any) -> Any:
     """Read an app setting, memoized for _CACHE_TTL_S to spare the hot path."""
     now = time.monotonic()
@@ -91,12 +100,34 @@ def _stored_idle_seconds() -> Optional[int]:
     return _coerce_int(_cached_setting(AUTO_UNLOAD_IDLE_SETTING_KEY, None))
 
 
+_env_floor_warned = False
+
+
 def _env_idle_seconds() -> Optional[int]:
-    """UNSLOTH_MODEL_IDLE_TTL as a non-negative seconds value, or None if unset/invalid."""
+    """UNSLOTH_MODEL_IDLE_TTL as a non-negative seconds value, or None if unset/invalid.
+
+    Floored to MIN_AUTO_UNLOAD_IDLE_SECONDS here (with a one-time warning) since
+    headless/container deploys have no UI to surface a validation error."""
     raw = os.environ.get(MODEL_IDLE_TTL_ENV_VAR)
     if raw is None or not raw.strip():
         return None
-    return _coerce_int(raw)
+    parsed = _coerce_int(raw)
+    if parsed is None:
+        return None
+    floored = _apply_idle_floor(parsed)
+    if floored != parsed:
+        global _env_floor_warned
+        if not _env_floor_warned:
+            _env_floor_warned = True
+            from loggers import get_logger
+            get_logger(__name__).warning(
+                "%s=%s is below the %ss minimum; using %ss",
+                MODEL_IDLE_TTL_ENV_VAR,
+                parsed,
+                MIN_AUTO_UNLOAD_IDLE_SECONDS,
+                floored,
+            )
+    return floored
 
 
 def get_stored_auto_unload_idle_seconds() -> int:
@@ -108,7 +139,9 @@ def get_stored_auto_unload_idle_seconds() -> int:
     """
     stored = _stored_idle_seconds()
     if stored is not None:
-        return stored
+        # Floor legacy values persisted before the minimum existed, so the UI
+        # displays the effective TTL and round-trips it cleanly.
+        return _apply_idle_floor(stored)
     env = _env_idle_seconds()
     return env if env is not None else DEFAULT_AUTO_UNLOAD_IDLE_SECONDS
 
@@ -118,32 +151,63 @@ def get_auto_unload_idle_seconds() -> int:
     stored = _stored_idle_seconds()
     if stored is not None:
         # An explicit UI/API value stays gated on auto-switch: off reports 0 so the
-        # off state is identical to pre-feature.
-        return stored if get_openai_auto_switch_enabled() else 0
+        # off state is identical to pre-feature. Floored to cover values persisted
+        # before the minimum existed.
+        return _apply_idle_floor(stored) if get_openai_auto_switch_enabled() else 0
     # No stored value: UNSLOTH_MODEL_IDLE_TTL is a standalone startup default that
     # enables idle-unload even with auto-switch off (headless/container deploys).
     env = _env_idle_seconds()
     return env if env is not None else 0
 
 
-def set_openai_auto_switch(enabled: Any, idle_seconds: Any) -> tuple[bool, int]:
-    """Set both auto-switch flags in one transaction so a settings PUT can't leave
-    one key updated and the other stale. Both values are coerced before any write,
-    so an invalid value raises without persisting either."""
+def get_auto_unload_keep_kv() -> bool:
+    """Whether the idle unload persists slot KV to disk for restore on reload."""
+    parsed = _coerce_bool(_cached_setting(AUTO_UNLOAD_KEEP_KV_SETTING_KEY, None))
+    return parsed if parsed is not None else DEFAULT_AUTO_UNLOAD_KEEP_KV
+
+
+def set_openai_auto_switch(
+    enabled: Any,
+    idle_seconds: Any,
+    keep_kv: Any = None,
+) -> tuple[bool, int, bool]:
+    """One-transaction write; ``None`` leaves a stored value untouched."""
     parsed_enabled = _coerce_bool(enabled)
     if parsed_enabled is None:
         raise ValueError("OpenAI auto-switch must be true or false.")
-    parsed_idle = _coerce_int(idle_seconds)
-    if parsed_idle is None:
-        raise ValueError("Auto-unload idle seconds must be a non-negative integer.")
+    parsed_idle = None
+    if idle_seconds is not None:
+        parsed_idle = _coerce_int(idle_seconds)
+        if parsed_idle is None:
+            raise ValueError("Auto-unload idle seconds must be a non-negative integer.")
+        if 0 < parsed_idle < MIN_AUTO_UNLOAD_IDLE_SECONDS:
+            raise ValueError(
+                f"Auto-unload idle seconds must be 0 (off) or at least "
+                f"{MIN_AUTO_UNLOAD_IDLE_SECONDS}."
+            )
+    parsed_keep_kv = None
+    if keep_kv is not None:
+        parsed_keep_kv = _coerce_bool(keep_kv)
+        if parsed_keep_kv is None:
+            raise ValueError("Keep KV on idle unload must be true or false.")
     from storage.studio_db import upsert_app_settings
 
-    upsert_app_settings(
-        {OPENAI_AUTO_SWITCH_SETTING_KEY: parsed_enabled, AUTO_UNLOAD_IDLE_SETTING_KEY: parsed_idle}
-    )
+    updates: dict[str, Any] = {OPENAI_AUTO_SWITCH_SETTING_KEY: parsed_enabled}
+    if parsed_idle is not None:
+        updates[AUTO_UNLOAD_IDLE_SETTING_KEY] = parsed_idle
+    if parsed_keep_kv is not None:
+        updates[AUTO_UNLOAD_KEEP_KV_SETTING_KEY] = parsed_keep_kv
+    upsert_app_settings(updates)
     _invalidate(OPENAI_AUTO_SWITCH_SETTING_KEY)
-    _invalidate(AUTO_UNLOAD_IDLE_SETTING_KEY)
-    return parsed_enabled, parsed_idle
+    if parsed_idle is not None:
+        _invalidate(AUTO_UNLOAD_IDLE_SETTING_KEY)
+    if parsed_keep_kv is not None:
+        _invalidate(AUTO_UNLOAD_KEEP_KV_SETTING_KEY)
+    return (
+        parsed_enabled,
+        parsed_idle if parsed_idle is not None else get_stored_auto_unload_idle_seconds(),
+        parsed_keep_kv if parsed_keep_kv is not None else get_auto_unload_keep_kv(),
+    )
 
 
 def get_model_overrides() -> dict[str, dict]:
diff --git a/studio/backend/utils/paths/external_media.py b/studio/backend/utils/paths/external_media.py
index 0ea0477cc7..1a0d2d2746 100644
--- a/studio/backend/utils/paths/external_media.py
+++ b/studio/backend/utils/paths/external_media.py
@@ -131,6 +131,29 @@ def linux_run_media_mount_roots(
     return roots
 
 
+def macos_volume_roots(base: Path | str = "/Volumes") -> list[Path]:
+    """Readable mounted volumes for the macOS folder browser."""
+
+    if platform.system() != "Darwin":
+        return []
+    base_path = Path(base)
+    try:
+        entries = list(base_path.iterdir())
+    except OSError:
+        return []
+    roots: list[Path] = []
+    for entry in entries:
+        if is_sensitive_path_component(entry.name):
+            continue
+        try:
+            resolved = entry.resolve()
+            if resolved.is_dir() and os.access(resolved, os.R_OK | os.X_OK):
+                roots.append(resolved)
+        except (OSError, RuntimeError, ValueError):
+            continue
+    return roots
+
+
 def _active_windows_drive_bitmask() -> int:
     """Active-logical-drive bitmask from ``GetLogicalDrives`` (bit 0 = ``A:``), or ``0`` when unavailable.
 
diff --git a/studio/backend/utils/paths/path_utils.py b/studio/backend/utils/paths/path_utils.py
index e8dabc8954..65541661f1 100644
--- a/studio/backend/utils/paths/path_utils.py
+++ b/studio/backend/utils/paths/path_utils.py
@@ -122,15 +122,8 @@ def is_model_cached(model_name: str) -> bool:
 
 def _hf_hub_cache_dir() -> Path:
     """Return HF cache root honoring HF_HUB_CACHE when available."""
-    try:
-        from huggingface_hub.constants import HF_HUB_CACHE
-        return Path(HF_HUB_CACHE)
-    except Exception as exc:
-        logger.debug(
-            "Could not read huggingface_hub HF_HUB_CACHE, using default hub path: %s",
-            exc,
-        )
-        return Path.home() / ".cache" / "huggingface" / "hub"
+    from utils.hf_cache_settings import get_hf_cache_paths
+    return get_hf_cache_paths().hub_cache
 
 
 def resolve_cached_repo_id_case(model_name: str, use_memo: bool = True) -> str:
diff --git a/studio/backend/utils/paths/storage_roots.py b/studio/backend/utils/paths/storage_roots.py
index 759681da3f..cea3cc61e3 100644
--- a/studio/backend/utils/paths/storage_roots.py
+++ b/studio/backend/utils/paths/storage_roots.py
@@ -36,7 +36,7 @@ def _infer_studio_home_from_venv() -> Path | None:
 
 
 def studio_root() -> Path:
-    """Studio install root.
+    """Unsloth install root.
 
     Priority: UNSLOTH_STUDIO_HOME, then STUDIO_HOME alias, then sys.prefix
     inference, then legacy ~/.unsloth/studio. UNSLOTH_STUDIO_HOME wins if
@@ -61,8 +61,13 @@ def cache_root() -> Path:
     return studio_root() / "cache"
 
 
+def llama_slot_cache_root() -> Path:
+    """Dir llama-server saves/restores slot KV state in across idle unloads."""
+    return cache_root() / "llama-slots"
+
+
 def studio_bin_root() -> Path:
-    """Dir for Studio-managed executables (the `unsloth` shim, downloaded tools like cloudflared)."""
+    """Dir for Unsloth-managed executables (the `unsloth` shim, downloaded tools like cloudflared)."""
     return studio_root() / "bin"
 
 
@@ -272,27 +277,15 @@ def well_known_model_dirs() -> list[Path]:
 def _setup_cache_env() -> None:
     """Set cache env vars for HuggingFace, uv, and vLLM.
 
-    Respects the standard HF cache chain (explicit HF_HOME / HF_HUB_CACHE,
-    then XDG_CACHE_HOME, then ~/.cache/huggingface) and only sets vars the
-    user hasn't, so explicit overrides are honored. A user-set HF_HOME also
-    seeds HF_HUB_CACHE / HF_XET_CACHE (HF defaults them to $HF_HOME/hub and
-    $HF_HOME/xet); without this, models download to and load from the standard
-    cache even when HF_HOME points elsewhere, and both the Xet and HTTP-fallback
-    download paths inherit the same wrong root.
+    Explicit Hugging Face environment variables take precedence over Studio's
+    stored location. Studio seeds import-time variables once, while each later
+    worker receives its own captured cache location.
     """
     root = cache_root()
-    xdg_cache = Path(os.environ.get("XDG_CACHE_HOME", Path.home() / ".cache")).expanduser()
-    # HUGGINGFACE_HUB_CACHE is HF's legacy alias for HF_HUB_CACHE; honor it.
-    if "HF_HUB_CACHE" not in os.environ and os.environ.get("HUGGINGFACE_HUB_CACHE"):
-        os.environ["HF_HUB_CACHE"] = os.environ["HUGGINGFACE_HUB_CACHE"]
-    # Seed the hub/xet caches from HF_HOME when set, else the platform default.
-    # Strip so a blank/whitespace HF_HOME falls back instead of making " /hub".
-    hf_home = (os.environ.get("HF_HOME") or "").strip()
-    hf_base = Path(hf_home).expanduser() if hf_home else xdg_cache / "huggingface"
+    from utils.hf_cache_settings import initialize_hf_cache_environment
+
+    initialize_hf_cache_environment()
     defaults: dict[str, str] = {
-        "HF_HOME": str(hf_base),
-        "HF_HUB_CACHE": str(hf_base / "hub"),
-        "HF_XET_CACHE": str(hf_base / "xet"),
         "UV_CACHE_DIR": str(root / "uv"),
         "VLLM_CACHE_ROOT": str(root / "vllm"),
     }
@@ -443,7 +436,7 @@ def resolve_export_write_dir(path_value: str | None = None) -> Path:
 
     Unlike :func:`resolve_export_dir`, this function passes absolute
     paths through as-is so users can target a different drive when
-    their Studio install lives on a constrained system volume
+    their Unsloth install lives on a constrained system volume
     (see :gh-issue:`6082`). Used only by the export write path.
     """
     if not path_value or not str(path_value).strip():
diff --git a/studio/backend/utils/prebuilt/__init__.py b/studio/backend/utils/prebuilt/__init__.py
new file mode 100644
index 0000000000..c41cd1150d
--- /dev/null
+++ b/studio/backend/utils/prebuilt/__init__.py
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Backend-importable prebuilt helpers.
+
+The installers reuse install_llama_prebuilt.py directly; this package holds the
+backend-side shapes the studio/ scripts cannot provide (the backend runs with
+studio/backend as its sys.path root): runtime_libs (wheel CUDA dirs), child_env
+(secret scrubbing + WSL ROCm dirs), freshness_flow and update_flow (the shared
+mechanics behind the *_cpp_freshness / *_cpp_update twins).
+"""
diff --git a/studio/backend/utils/prebuilt/child_env.py b/studio/backend/utils/prebuilt/child_env.py
new file mode 100644
index 0000000000..b6b7a40df7
--- /dev/null
+++ b/studio/backend/utils/prebuilt/child_env.py
@@ -0,0 +1,145 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Child-process environment hygiene for the managed ggml servers.
+
+Secret-env scrubbing and the WSL2 ROCm library-dir probe, shared by the STT
+sidecar (and any future launcher of a downloaded binary). Kept in sync with
+install_llama_prebuilt.py's scrub_env / _wsl_system_rocm_lib_dirs; the backend
+cannot import the studio/ installer scripts, so this copy stays importable with
+only the backend root on sys.path.
+"""
+
+from __future__ import annotations
+
+import os
+import re
+from typing import Mapping
+
+SECRET_ENV_EXACT = frozenset(
+    {
+        "HF_TOKEN",
+        "HUGGING_FACE_HUB_TOKEN",
+        "GH_TOKEN",
+        "GITHUB_TOKEN",
+        "WANDB_API_KEY",
+        "OPENAI_API_KEY",
+        "ANTHROPIC_API_KEY",
+        "AWS_ACCESS_KEY_ID",
+        "AWS_SECRET_ACCESS_KEY",
+        "AWS_SESSION_TOKEN",
+        "GOOGLE_APPLICATION_CREDENTIALS",
+        "AZURE_CLIENT_SECRET",
+        "KUBECONFIG",
+        "SSH_AUTH_SOCK",
+    }
+)
+# Case-insensitive substring markers for names we do not enumerate (no bare "KEY").
+SECRET_ENV_MARKERS = (
+    "TOKEN",
+    "SECRET",
+    "PASSWORD",
+    "PASSWD",
+    "PASSPHRASE",
+    "CREDENTIAL",
+    "PRIVATE_KEY",
+    "API_KEY",
+)
+# Proxy / index URLs embed creds in their value; the offline server never needs them.
+SECRET_ENV_URL_NAMES = frozenset(
+    {
+        "HTTP_PROXY",
+        "HTTPS_PROXY",
+        "ALL_PROXY",
+        "FTP_PROXY",
+        "RSYNC_PROXY",
+        "PIP_INDEX_URL",
+        "PIP_EXTRA_INDEX_URL",
+        "UV_INDEX_URL",
+        "UV_DEFAULT_INDEX",
+        "UV_EXTRA_INDEX_URL",
+    }
+)
+# Also drop values with URL userinfo creds (scheme://user:secret@host).
+URL_USERINFO_RE = re.compile(r"://[^/@\s]+@")
+
+
+def is_secret_env_name(name: str) -> bool:
+    upper = name.upper()
+    return (
+        upper in SECRET_ENV_EXACT
+        or upper in SECRET_ENV_URL_NAMES
+        or any(marker in upper for marker in SECRET_ENV_MARKERS)
+    )
+
+
+def scrub_env(env: Mapping[str, str]) -> dict[str, str]:
+    """Copy of ``env`` without secret-bearing names or URL-userinfo values."""
+    return {
+        k: v
+        for k, v in env.items()
+        if not is_secret_env_name(k) and not URL_USERINFO_RE.search(v or "")
+    }
+
+
+# Filesystem pointers a downloaded binary could follow to on-disk credential
+# stores (token caches under $HF_HOME, ~/.netrc, XDG config). Dropped, not
+# repointed; the offline inference server needs none. Mirrors the cred-location
+# list of the tools bypass env (core/inference/tools.py).
+CRED_LOCATION_ENV_NAMES = frozenset(
+    {
+        "HF_HOME",
+        "HF_HUB_CACHE",
+        "HUGGINGFACE_HUB_CACHE",
+        "HF_XET_CACHE",
+        "TRANSFORMERS_CACHE",
+        "HF_DATASETS_CACHE",
+        "XDG_CONFIG_HOME",
+        "XDG_CACHE_HOME",
+        "XDG_DATA_HOME",
+        "NETRC",
+        "BASH_ENV",
+        "GIT_CONFIG_GLOBAL",
+        "GIT_CONFIG_SYSTEM",
+        "GIT_ASKPASS",
+        "SSH_ASKPASS",
+        "HOMEDRIVE",
+        "HOMEPATH",
+    }
+)
+# Home dirs are repointed (not dropped): loaders and SDKs expect them present,
+# but they must not resolve to the user's real profile with its token caches.
+HOME_ENV_NAMES = ("HOME", "USERPROFILE", "APPDATA", "LOCALAPPDATA")
+
+
+def isolate_home(env: dict[str, str], scratch_dir: str) -> dict[str, str]:
+    """Repoint home/profile vars at ``scratch_dir`` and drop credential-store
+    pointers so a compromised downloaded server cannot read token caches or cred
+    files through the environment. Mutates and returns ``env``."""
+    os.makedirs(scratch_dir, exist_ok = True)
+    for name in HOME_ENV_NAMES:
+        if name in env:
+            env[name] = scratch_dir
+    for name in CRED_LOCATION_ENV_NAMES:
+        env.pop(name, None)
+    return env
+
+
+def wsl_system_rocm_lib_dirs() -> list[str]:
+    """System ROCm lib dir(s) to load before a bundle's HIP on WSL2. Strict no-op
+    off WSL (needs /dev/dxg, a "microsoft" /proc/version, and a librocdxg)."""
+    try:
+        if not os.path.exists("/dev/dxg"):
+            return []
+        with open("/proc/version", encoding = "utf-8", errors = "replace") as fh:
+            if "microsoft" not in fh.read().lower():
+                return []
+    except OSError:
+        return []
+    dirs: list[str] = []
+    for d in ("/opt/rocm/lib", "/opt/rocm/lib64"):
+        if os.path.exists(os.path.join(d, "librocdxg.so")) or os.path.exists(
+            os.path.join(d, "librocdxg.so.1")
+        ):
+            dirs.append(d)
+    return dirs
diff --git a/studio/backend/utils/prebuilt/freshness_flow.py b/studio/backend/utils/prebuilt/freshness_flow.py
new file mode 100644
index 0000000000..b90ebf776c
--- /dev/null
+++ b/studio/backend/utils/prebuilt/freshness_flow.py
@@ -0,0 +1,325 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Shared mechanics of the llama.cpp / whisper.cpp prebuilt freshness checks.
+
+The component modules (utils.llama_cpp_freshness / utils.whisper_cpp_freshness)
+keep their public names, per-module caches, and version-comparison policy;
+everything mechanical (marker walk-up, GitHub release fetch, memo + disk cache,
+the freshness report skeleton) lives here, parameterized by call-time callables
+so the modules' monkeypatch seams keep working.
+"""
+
+from __future__ import annotations
+
+import json
+import time
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Any, Callable, Optional
+
+import structlog
+
+logger = structlog.get_logger(__name__)
+
+# 24h TTL keeps the GitHub call off the hot path and within rate limits.
+RELEASE_CACHE_TTL_SECONDS = 24 * 60 * 60
+
+
+def read_install_marker(
+    binary_path: Optional[str],
+    *,
+    marker_name: str,
+    cache: dict[str, Optional[dict]],
+    log_message: str,
+) -> Optional[dict]:
+    """Walk up from binary_path to find the install marker JSON.
+    None = no marker (source build / custom path) or invalid JSON."""
+    if not binary_path:
+        return None
+    cached = cache.get(binary_path)
+    if cached is not None or binary_path in cache:
+        return cached
+    p = Path(binary_path)
+    marker: Optional[dict] = None
+    # Cover all managed binary layouts (binary is 1-4 dirs deep).
+    for parent in p.parents[:5]:
+        candidate = parent / marker_name
+        if candidate.is_file():
+            try:
+                marker = json.loads(candidate.read_text(encoding = "utf-8"))
+            except (OSError, json.JSONDecodeError) as exc:
+                logger.debug(log_message, path = str(candidate), error = str(exc))
+                marker = None
+            break
+    cache[binary_path] = marker
+    return marker
+
+
+def cache_path_for(repo: str, cache_dir: Path) -> Path:
+    safe = repo.replace("/", "__")
+    return cache_dir / f"{safe}.json"
+
+
+def load_disk_cache(repo: str, cache_dir: Path) -> Optional[tuple[float, Optional[str]]]:
+    path = cache_path_for(repo, cache_dir)
+    try:
+        payload = json.loads(path.read_text(encoding = "utf-8"))
+    except (OSError, json.JSONDecodeError):
+        return None
+    ts = payload.get("fetched_at")
+    tag = payload.get("latest_tag")
+    if not isinstance(ts, (int, float)):
+        return None
+    return float(ts), tag if isinstance(tag, str) else None
+
+
+def save_disk_cache(
+    repo: str, latest_tag: Optional[str], cache_dir: Path, *, log_message: str
+) -> None:
+    path = cache_path_for(repo, cache_dir)
+    try:
+        path.parent.mkdir(parents = True, exist_ok = True)
+        tmp = path.with_suffix(".tmp")
+        tmp.write_text(
+            json.dumps({"fetched_at": time.time(), "latest_tag": latest_tag}),
+            encoding = "utf-8",
+        )
+        tmp.replace(path)
+    except OSError as exc:
+        logger.debug(log_message, repo = repo, error = str(exc))
+
+
+def _fetch_newest_published_release(
+    repo: str, timeout: float, *, log_message: str
+) -> Optional[dict]:
+    """Newest published (non-draft/non-prerelease) release object for `repo`, by
+    ``published_at``.
+
+    Resolves "latest" the way the installers do, NOT via GitHub's
+    ``/releases/latest`` pointer, which sorts by commit date and can lag the
+    build the installer installs (detection and apply then disagree -- the
+    downgrade/sticky-banner bug). None on any failure (offline, rate-limited)."""
+    import os
+    import urllib.error
+    import urllib.request
+
+    url = f"https://api.github.com/repos/{repo}/releases?per_page=30"
+    headers = {
+        "Accept": "application/vnd.github+json",
+        "User-Agent": "unsloth-studio-freshness-check",
+    }
+    token = os.environ.get("GITHUB_TOKEN") or os.environ.get("GH_TOKEN")
+    if token:
+        headers["Authorization"] = f"Bearer {token}"
+    req = urllib.request.Request(url, headers = headers)
+    try:
+        with urllib.request.urlopen(req, timeout = timeout) as resp:
+            data = json.loads(resp.read().decode("utf-8"))
+    except (
+        urllib.error.URLError,
+        urllib.error.HTTPError,
+        OSError,
+        json.JSONDecodeError,
+    ) as exc:
+        logger.debug(log_message, repo = repo, error = str(exc))
+        return None
+    if not isinstance(data, list):
+        return None
+    published = [
+        r
+        for r in data
+        if isinstance(r, dict)
+        and not r.get("draft")
+        and not r.get("prerelease")
+        and isinstance(r.get("tag_name"), str)
+        and r.get("tag_name")
+    ]
+    if not published:
+        return None
+    return max(published, key = lambda r: r.get("published_at") or "")
+
+
+def fetch_latest_release_tag(
+    repo: str,
+    timeout: float = 5.0,
+    *,
+    log_message: str,
+) -> Optional[str]:
+    """Newest published release tag for `repo`, by publish time. None on failure."""
+    newest = _fetch_newest_published_release(repo, timeout, log_message = log_message)
+    return newest["tag_name"] if newest else None
+
+
+def fetch_latest_release_assets(
+    repo: str,
+    timeout: float = 5.0,
+    *,
+    log_message: str,
+) -> Optional[dict[str, int]]:
+    """Asset name -> size (bytes) for the newest published release of `repo`,
+    selected exactly like fetch_latest_release_tag. None on any failure."""
+    newest = _fetch_newest_published_release(repo, timeout, log_message = log_message)
+    if newest is None:
+        return None
+    assets: dict[str, int] = {}
+    for a in newest.get("assets") or []:
+        name, size = a.get("name"), a.get("size")
+        if isinstance(name, str) and isinstance(size, int):
+            assets[name] = size
+    return assets
+
+
+def latest_published_release(
+    repo: str,
+    *,
+    force_refresh: bool,
+    memo: dict[str, tuple[float, Optional[str]]],
+    cache_dir: Callable[[], Path],
+    fetch: Callable[[str], Optional[str]],
+    save: Callable[[str, Optional[str]], None],
+) -> Optional[str]:
+    """Latest release tag for `repo`. Memo + disk-cached (24h TTL).
+    None when offline and never previously cached."""
+    if not repo:
+        return None
+    now = time.time()
+    if not force_refresh:
+        cached = memo.get(repo)
+        if cached and now - cached[0] < RELEASE_CACHE_TTL_SECONDS:
+            return cached[1]
+        disk = load_disk_cache(repo, cache_dir())
+        if disk and now - disk[0] < RELEASE_CACHE_TTL_SECONDS:
+            memo[repo] = disk
+            return disk[1]
+    latest = fetch(repo)
+    if latest is None:
+        # Keep the last-good disk value rather than poison it with None.
+        disk = load_disk_cache(repo, cache_dir())
+        if disk:
+            memo[repo] = disk
+            return disk[1]
+        return None
+    memo[repo] = (now, latest)
+    save(repo, latest)
+    return latest
+
+
+def latest_release_assets(
+    repo: str,
+    *,
+    force_refresh: bool,
+    memo: dict[str, tuple[float, dict[str, int]]],
+    fetch: Callable[[str], Optional[dict[str, int]]],
+) -> Optional[dict[str, int]]:
+    """Newest-release asset sizes for `repo`, memoized (24h TTL). None when
+    offline and never fetched. In-memory only -- a restart re-fetches."""
+    if not repo:
+        return None
+    now = time.time()
+    if not force_refresh:
+        cached = memo.get(repo)
+        if cached and now - cached[0] < RELEASE_CACHE_TTL_SECONDS:
+            return cached[1]
+    assets = fetch(repo)
+    if assets is None:
+        cached = memo.get(repo)
+        return cached[1] if cached else None
+    memo[repo] = (now, assets)
+    return assets
+
+
+def parse_installed_at(value: object) -> Optional[datetime]:
+    if not isinstance(value, str) or not value:
+        return None
+    s = value.replace("Z", "+00:00") if value.endswith("Z") else value
+    try:
+        dt = datetime.fromisoformat(s)
+    except ValueError:
+        return None
+    if dt.tzinfo is None:
+        dt = dt.replace(tzinfo = timezone.utc)
+    return dt
+
+
+def check_freshness(
+    binary_path: Optional[str],
+    *,
+    threshold_days: int,
+    now: Optional[datetime],
+    read_marker: Callable[[Optional[str]], Optional[dict]],
+    latest_release: Callable[[str], Optional[str]],
+    behind: Callable[[Optional[str], Optional[str]], bool],
+    display_tag: Callable[[dict], Any],
+    compare_tag: Callable[[dict], Any],
+) -> dict:
+    """Freshness report skeleton shared by both components; the component's
+    marker-tag choice and is_behind policy come in as callables. Fails open on
+    missing data (behind/stale stay False)."""
+    out: dict = {
+        "has_marker": False,
+        "stale": False,
+        "behind": False,
+        "installed_tag": None,
+        "latest_tag": None,
+        "installed_at_utc": None,
+        "age_days": None,
+        "published_repo": None,
+        "threshold_days": int(threshold_days),
+    }
+    marker = read_marker(binary_path)
+    if not marker:
+        return out
+    out["has_marker"] = True
+    out["installed_tag"] = display_tag(marker)
+    out["installed_at_utc"] = marker.get("installed_at_utc")
+    out["published_repo"] = marker.get("published_repo")
+
+    installed_full = compare_tag(marker)
+    repo = out["published_repo"]
+    if not repo or not installed_full:
+        return out
+    latest = latest_release(repo)
+    out["latest_tag"] = latest
+    out["behind"] = behind(installed_full, latest)
+    if not out["behind"]:
+        return out
+
+    installed_at = parse_installed_at(out["installed_at_utc"])
+    if installed_at is None:
+        return out
+    now = now or datetime.now(tz = timezone.utc)
+    age_seconds = (now - installed_at).total_seconds()
+    out["age_days"] = max(0, int(age_seconds // 86400))
+    if age_seconds >= threshold_days * 86400:
+        out["stale"] = True
+    return out
+
+
+def format_stale_warning(info: dict, *, component: str) -> str:
+    """Human-readable one-liner for stale prebuilt info."""
+    age = info.get("age_days")
+    installed = info.get("installed_tag") or "unknown"
+    latest = info.get("latest_tag") or "unknown"
+    age_str = f"{age} day{'s' if age != 1 else ''}" if age is not None else "some time"
+    return (
+        f"{component} prebuilt is {age_str} behind: installed "
+        f"{installed}, latest {latest}. Run `unsloth studio update` "
+        f"to refresh."
+    )
+
+
+def reset_caches(
+    caches: tuple[dict, ...], *, drop_disk: bool, cache_dir: Callable[[], Path]
+) -> None:
+    """Drop the in-memory freshness caches; with drop_disk also the on-disk 24h
+    release cache (see the component modules for why)."""
+    for cache in caches:
+        cache.clear()
+    if drop_disk:
+        import shutil
+
+        # cache_dir() is a dedicated freshness-only subdir, re-created on the next
+        # save_disk_cache. ignore_errors so a missing/locked dir is a no-op rather
+        # than breaking an otherwise successful install.
+        shutil.rmtree(cache_dir(), ignore_errors = True)
diff --git a/studio/backend/utils/prebuilt/runtime_libs.py b/studio/backend/utils/prebuilt/runtime_libs.py
new file mode 100644
index 0000000000..6e51fb8246
--- /dev/null
+++ b/studio/backend/utils/prebuilt/runtime_libs.py
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""CUDA runtime dirs shipped inside Python wheels, for the STT sidecar's child env.
+
+Kept in sync with install_llama_prebuilt.py's python_runtime_dirs; the backend
+cannot import the studio/ installer scripts, so this small copy stays importable
+with only the backend root on sys.path.
+"""
+
+from __future__ import annotations
+
+import site
+import sys
+from pathlib import Path
+from typing import Iterable
+
+
+def dedupe_existing_dirs(paths: Iterable[str | Path]) -> list[str]:
+    unique: list[str] = []
+    seen: set[str] = set()
+    for raw in paths:
+        if not raw:
+            continue
+        try:
+            path = Path(raw).expanduser()
+            if not path.is_dir():
+                continue
+            resolved = str(path.resolve())
+        except (OSError, ValueError):
+            continue
+        if resolved in seen:
+            continue
+        seen.add(resolved)
+        unique.append(resolved)
+    return unique
+
+
+def python_runtime_dirs() -> list[str]:
+    """CUDA runtime dirs shipped inside Python wheels (torch + nvidia-* wheels)."""
+    candidates: list[Path] = []
+    search_roots = [Path(entry) for entry in sys.path if entry]
+    try:
+        search_roots.extend(Path(path) for path in site.getsitepackages())
+    except Exception:
+        pass
+    try:
+        user_site = site.getusersitepackages()
+        if user_site:
+            search_roots.append(Path(user_site))
+    except Exception:
+        pass
+
+    for root in search_roots:
+        if not root.is_dir():
+            continue
+        candidates.extend(root.glob("nvidia/*/lib"))  # Linux convention
+        candidates.extend(root.glob("nvidia/*/bin"))  # legacy modular Windows wheels
+        candidates.extend(root.glob("nvidia/*/bin/x86_64"))  # CUDA 13 Windows wheel layout
+        candidates.extend(root.glob("nvidia/*/bin/x64"))
+        candidates.extend(root.glob("nvidia/*/Library/bin"))  # conda-style repacks
+        candidates.extend(root.glob("nvidia/*/Library/bin/x86_64"))
+        candidates.extend(root.glob("nvidia/*/Library/bin/x64"))
+        candidates.extend(root.glob("torch/lib"))
+    return dedupe_existing_dirs(candidates)
diff --git a/studio/backend/utils/prebuilt/update_flow.py b/studio/backend/utils/prebuilt/update_flow.py
new file mode 100644
index 0000000000..74af0c18f9
--- /dev/null
+++ b/studio/backend/utils/prebuilt/update_flow.py
@@ -0,0 +1,447 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Shared mechanics of the llama.cpp / whisper.cpp in-app prebuilt updates.
+
+The component modules (utils.llama_cpp_update / utils.whisper_cpp_update) keep
+their public names, job dicts, and update policy (version comparison, pinning,
+pre/post install steps); everything mechanical (managed-root resolution,
+local-link detection, the resolve probe, the streamed installer run) lives here,
+parameterized so the modules' monkeypatch seams keep working.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+import re
+import subprocess
+import sys
+import threading
+import time
+from pathlib import Path
+from typing import Callable, Optional
+
+import structlog
+
+from utils.process_lifetime import child_popen_kwargs
+
+logger = structlog.get_logger(__name__)
+
+# Markerless (source-build) resolve answers are memoized for 24h; only
+# successful answers are cached so a network blip retries.
+RESOLVE_TTL_SECONDS = 24 * 60 * 60
+
+# Matches the installer's download progress lines, e.g.
+# "Downloading x.zip:  35.0% (12.3 MiB/35.1 MiB) at 8.2 MiB/s".
+PROGRESS_LINE_RE = re.compile(r"(\d+(?:\.\d+)?)%\s*\(")
+# The download dominates the update; extract/validate fill the last slice.
+DOWNLOAD_PROGRESS_CEILING = 0.95
+
+
+class InstallerExit(RuntimeError):
+    """Installer subprocess exited nonzero; carries the exit code so phase
+    runners can special-case contractual codes (whisper's 2 = unavailable)."""
+
+    def __init__(self, returncode: int, message: str) -> None:
+        super().__init__(message)
+        self.returncode = returncode
+
+
+JOB_IDLE = "idle"
+JOB_RUNNING = "running"
+JOB_SUCCESS = "success"
+JOB_ERROR = "error"
+
+# Per-phase states inside a chained job's "phases" breakdown.
+PHASE_PENDING = "pending"
+PHASE_RUNNING = "running"
+PHASE_SUCCESS = "success"
+PHASE_ERROR = "error"
+PHASE_SKIPPED = "skipped"
+
+_IDLE_JOB_FIELDS = dict(
+    state = JOB_IDLE,
+    message = "",
+    from_tag = None,
+    to_tag = None,
+    reload_required = None,
+    error = None,
+    progress = None,
+    started_at = None,
+    finished_at = None,
+    phases = None,
+)
+
+
+def new_job() -> dict:
+    """A fresh idle job-state dict (one per component module)."""
+    return dict(_IDLE_JOB_FIELDS)
+
+
+def reset_job(job: dict, job_lock: threading.Lock) -> None:
+    """Return a job tracker to idle (test seam)."""
+    with job_lock:
+        job.update(_IDLE_JOB_FIELDS)
+
+
+def utcnow() -> str:
+    return time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime())
+
+
+def is_under(path: Path, root: Path) -> bool:
+    try:
+        p, r = path.resolve(), root.resolve()
+    except (OSError, ValueError):
+        p, r = path, root
+    return p == r or r in p.parents
+
+
+def install_dir_for(binary_path: Optional[str], *, marker_name: str) -> Optional[Path]:
+    """The directory holding the install marker: the install root the installer
+    wrote and the one we re-install into. Walks up from the binary like the
+    freshness marker reader does."""
+    if not binary_path:
+        return None
+    p = Path(binary_path)
+    for parent in p.parents[:5]:
+        if (parent / marker_name).is_file():
+            return parent
+    return None
+
+
+def find_installer_script(*, env_var: str, script_name: str) -> Optional[Path]:
+    """Locate the installer script. Honours the env override, then searches up
+    from this file for both ``<root>/<script>`` and ``<root>/studio/<script>`` so
+    it works in the dev tree and in an installed Unsloth layout."""
+    env = os.environ.get(env_var)
+    if env and Path(env).is_file():
+        return Path(env)
+    here = Path(__file__).resolve()
+    for up in here.parents:
+        for cand in (up / script_name, up / "studio" / script_name):
+            if cand.is_file():
+                return cand
+    return None
+
+
+def resolve_prebuilt_for_host(
+    *,
+    force_refresh: bool,
+    memo: dict,
+    installer_script: Callable[[], Optional[Path]],
+    log_message: str,
+    extra_args: tuple[str, ...] = (),
+) -> Optional[dict]:
+    """Run ``<installer> --resolve-prebuilt latest --output-format json`` (no
+    download); return the parsed payload or None. Fail-open: any error -> None so
+    a source build never blocks the app."""
+    now = time.time()
+    cache_key = tuple(extra_args)
+    if not force_refresh and memo.get("key") == cache_key:
+        if now - memo.get("at", 0.0) < RESOLVE_TTL_SECONDS:
+            return memo.get("value")
+    script = installer_script()
+    if script is None:
+        return None
+    value: Optional[dict] = None
+    try:
+        cmd = [
+            sys.executable,
+            str(script),
+            "--resolve-prebuilt",
+            "latest",
+            "--output-format",
+            "json",
+            *extra_args,
+        ]
+        proc = subprocess.run(
+            cmd,
+            capture_output = True,
+            text = True,
+            timeout = 60,
+        )
+        out = (proc.stdout or "").strip()
+        if proc.returncode == 0 and out:
+            parsed = json.loads(out.splitlines()[-1])
+            if isinstance(parsed, dict):
+                value = parsed
+    except Exception as exc:  # pragma: no cover - subprocess/json defensive
+        logger.debug(log_message, error = str(exc))
+        value = None
+    if value is not None:  # cache real answers; let failures retry next poll
+        memo.update(at = now, key = cache_key, value = value)
+    return value
+
+
+def is_external_link(path: Optional[Path]) -> bool:
+    """True when ``path`` is a locally-linked component dir: a POSIX symlink or a
+    Windows junction / reparse point. Such a link resolves into the user's own
+    checkout, so Unsloth must never auto-update it."""
+    if path is None:
+        return False
+    try:
+        if os.path.islink(path):
+            return True
+    except OSError:
+        return False
+    if os.name == "nt":
+        try:
+            import stat
+            attrs = os.lstat(path).st_file_attributes  # type: ignore[attr-defined]
+            return bool(attrs & stat.FILE_ATTRIBUTE_REPARSE_POINT)
+        except (OSError, AttributeError):
+            return False
+    return False
+
+
+def active_install_is_local_link(binary: Optional[str], *, dir_name: str) -> bool:
+    """True when the active server binary resolves through a locally-linked
+    component directory. An update would write through that link into the user's
+    checkout (or fail), so the install is treated as externally managed: none is
+    offered or applied. Checks only up to and including the component dir so a
+    symlinked HOME / studio root above it can't trip a false positive."""
+    if not binary:
+        return False
+    for parent in Path(binary).parents:
+        if is_external_link(parent):
+            return True
+        if parent.name == dir_name:
+            break
+    return False
+
+
+def managed_install_root(
+    binary: Optional[str],
+    *,
+    marker_root: Optional[Path],
+    server_path_var: str,
+    cpp_path_var: str,
+    dir_name: str,
+) -> Optional[Path]:
+    """The Unsloth-managed component root the active binary lives under, or None
+    when unmanaged. Installing where the active binary is not would not replace
+    what discovery runs (a pinned server path, then the custom dir, then a
+    component tree), so we refuse rather than install into an inactive or foreign
+    tree."""
+    if marker_root is not None:
+        return marker_root
+    if not binary:
+        return None
+    # The server-path pin is an explicit user choice that wins in discovery; never
+    # auto-replace its tree (even the user's own checkout).
+    if os.environ.get(server_path_var):
+        return None
+    p = Path(binary)
+    env = os.environ.get(cpp_path_var)
+    if env and is_under(p, Path(env)):
+        return Path(env)
+    for parent in p.parents:
+        if parent.name == dir_name:
+            return parent
+    # PATH / system / custom install: not a managed tree, so do not offer.
+    return None
+
+
+def local_link_status(job: dict, job_lock: threading.Lock) -> dict:
+    """Status payload for a local-link install: unmanaged, no update offered."""
+    with job_lock:
+        snapshot = dict(job)
+    return {
+        "supported": False,
+        "update_available": False,
+        "stale": False,
+        "installed_tag": None,
+        "latest_tag": None,
+        "published_repo": None,
+        "installed_at_utc": None,
+        "age_days": None,
+        "source_build": False,
+        "local_link": True,
+        "update_size_bytes": None,
+        "job": snapshot,
+    }
+
+
+def rocm_install_args(asset: Optional[str]) -> list[str]:
+    """Forward --rocm-gfx/--has-rocm from the marker asset, mirroring setup.sh.
+    The installer probe can miss the gfx arch on amd-smi-only hosts; per-gfx ROCm
+    bundles carry the family in the name (rocm-gfx110X), version-tagged bundles
+    only rocm/hip."""
+    if not asset:
+        return []
+    low = asset.lower()
+    if "rocm" not in low and "hip" not in low:
+        return []
+    gfx = re.search(r"-gfx[0-9a-z]+", low)
+    if gfx:
+        return ["--rocm-gfx", gfx.group(0).lstrip("-")]
+    return ["--has-rocm"]
+
+
+def stream_installer(
+    cmd: list[str],
+    env: dict[str, str],
+    *,
+    timeout_seconds: int,
+    job: Optional[dict] = None,
+    job_lock: Optional[threading.Lock] = None,
+    set_progress: Optional[Callable[[float], None]] = None,
+) -> None:
+    """Run the installer, streaming its progress lines into job["progress"]
+    (or through set_progress when given, e.g. a chained-phase progress window).
+    Raises RuntimeError on timeout or a nonzero exit (with an output tail)."""
+    if set_progress is None:
+        assert job is not None and job_lock is not None
+
+        def set_progress(fraction: float) -> None:
+            with job_lock:
+                job["progress"] = max(job.get("progress") or 0.0, fraction)
+
+    proc = subprocess.Popen(
+        cmd,
+        stdout = subprocess.PIPE,
+        stderr = subprocess.STDOUT,
+        text = True,
+        env = env,
+        **child_popen_kwargs(),
+    )
+    timed_out = threading.Event()
+
+    def _kill_on_timeout() -> None:
+        timed_out.set()
+        proc.kill()
+
+    watchdog = threading.Timer(timeout_seconds, _kill_on_timeout)
+    watchdog.daemon = True
+    watchdog.start()
+    tail_lines: list[str] = []
+    try:
+        assert proc.stdout is not None
+        for line in proc.stdout:
+            tail_lines.append(line)
+            if len(tail_lines) > 80:
+                del tail_lines[0]
+            m = PROGRESS_LINE_RE.search(line)
+            if m is None:
+                continue
+            set_progress(min(float(m.group(1)) / 100.0, 1.0) * DOWNLOAD_PROGRESS_CEILING)
+        returncode = proc.wait()
+    finally:
+        watchdog.cancel()
+    if timed_out.is_set():
+        raise RuntimeError(f"installer timed out after {timeout_seconds}s")
+    if returncode != 0:
+        tail = "".join(tail_lines).strip()[-1500:]
+        raise InstallerExit(returncode, f"installer exited {returncode}: {tail or 'no output'}")
+
+
+def _new_phase_record(spec: dict) -> dict:
+    """Initial breakdown entry for one phase of a chained job."""
+    runnable = spec.get("run") is not None
+    return {
+        "state": PHASE_PENDING if runnable else PHASE_SKIPPED,
+        "reason": None if runnable else spec.get("skip_reason"),
+        "progress": None,
+        "to_tag": None,
+        "reload_required": None,
+        "message": "",
+        "error": None,
+    }
+
+
+def run_chained_update(phases: list[dict], *, job: dict, job_lock: threading.Lock) -> None:
+    """Run update phases in order into one shared job dict (the worker of a
+    combined llama+whisper apply).
+
+    Each phase spec: ``name`` (breakdown key), ``weight`` (progress slice,
+    normalized over runnable phases), ``run`` (callable(set_progress) -> result
+    dict with to_tag/reload_required/message, raises on failure; None = skipped)
+    and ``skip_reason`` / ``failure_message``. A failing phase aborts the chain:
+    later phases are marked skipped (reason "aborted") and the job goes to error,
+    keeping the reload_required and messages of already-succeeded phases so a
+    partial success stays visible."""
+    runnable = [p for p in phases if p.get("run") is not None]
+    total_weight = sum(float(p.get("weight") or 1.0) for p in runnable) or 1.0
+    with job_lock:
+        job["phases"] = {p["name"]: _new_phase_record(p) for p in phases}
+
+    offset = 0.0
+    done_messages: list[str] = []
+    reload_required = False
+    primary_to_tag: Optional[str] = None
+    for index, phase in enumerate(phases):
+        if phase.get("run") is None:
+            continue
+        name = phase["name"]
+        weight = float(phase.get("weight") or 1.0) / total_weight
+        with job_lock:
+            job["phases"][name].update(state = PHASE_RUNNING, progress = 0.0)
+
+        def set_progress(
+            fraction: float,
+            *,
+            _name: str = name,
+            _base: float = offset,
+            _slice: float = weight,
+        ) -> None:
+            f = max(0.0, min(float(fraction), 1.0))
+            with job_lock:
+                record = job["phases"][_name]
+                record["progress"] = max(record.get("progress") or 0.0, f)
+                job["progress"] = max(job.get("progress") or 0.0, _base + f * _slice)
+
+        try:
+            result = phase["run"](set_progress) or {}
+        except Exception as exc:
+            failure = phase.get("failure_message") or f"{name} update failed."
+            with job_lock:
+                job["phases"][name].update(state = PHASE_ERROR, error = str(exc))
+                for later in phases[index + 1 :]:
+                    if later.get("run") is not None:
+                        job["phases"][later["name"]].update(state = PHASE_SKIPPED, reason = "aborted")
+                # A partial success keeps its messages and reload_required so the
+                # caller sees the earlier phase did land.
+                job.update(
+                    state = JOB_ERROR,
+                    message = " ".join(done_messages + [failure]),
+                    to_tag = primary_to_tag,
+                    error = str(exc),
+                    finished_at = utcnow(),
+                )
+                if done_messages:
+                    job["reload_required"] = reload_required
+            return
+        set_progress(1.0)
+        offset += weight
+        with job_lock:
+            job["phases"][name].update(
+                state = PHASE_SUCCESS,
+                to_tag = result.get("to_tag"),
+                reload_required = result.get("reload_required"),
+                message = result.get("message") or "",
+            )
+        if result.get("message"):
+            done_messages.append(result["message"])
+        # Only phases affecting the primary (llama) server may raise the job-level
+        # reload flag: the frontend resyncs chat model state off it, and a
+        # whisper-only sidecar reload must not clear the chat checkpoint. Per-phase
+        # reload_required stays visible under job["phases"].
+        if phase.get("affects_job_reload", True):
+            reload_required = reload_required or bool(result.get("reload_required"))
+            # The legacy job-level to_tag means "the llama build now installed";
+            # a whisper-only round must leave it unset or the UI reports a llama
+            # update that never ran (per-phase to_tag remains under phases).
+            if primary_to_tag is None:
+                primary_to_tag = result.get("to_tag")
+
+    with job_lock:
+        job.update(
+            state = JOB_SUCCESS,
+            message = " ".join(done_messages) or "Already up to date.",
+            to_tag = primary_to_tag,
+            reload_required = reload_required,
+            error = None,
+            progress = 1.0,
+            finished_at = utcnow(),
+        )
diff --git a/studio/backend/utils/prebuilt/whisper_layout.py b/studio/backend/utils/prebuilt/whisper_layout.py
new file mode 100644
index 0000000000..7444e4e707
--- /dev/null
+++ b/studio/backend/utils/prebuilt/whisper_layout.py
@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Canonical whisper.cpp install-root and marker lookup helpers."""
+
+from __future__ import annotations
+
+import json
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Optional
+
+MARKER_NAME = "UNSLOTH_WHISPER_PREBUILT_INFO.json"
+
+
+@dataclass(frozen = True)
+class MarkerLookup:
+    marker: Optional[dict]
+    root: Optional[Path]
+    authoritative: bool
+    invalid: bool = False
+    slim_collision: bool = False
+
+
+def canonical_install_root(binary_path: Optional[str]) -> Optional[Path]:
+    """Return the managed root for the two supported CMake binary layouts."""
+    if not binary_path:
+        return None
+    parent = Path(binary_path).parent
+    if parent.name == "bin" and parent.parent.name == "build":
+        return parent.parent.parent
+    if (
+        parent.name == "Release"
+        and parent.parent.name == "bin"
+        and parent.parent.parent.name == "build"
+    ):
+        return parent.parent.parent.parent
+    return None
+
+
+def _parse_marker(path: Path) -> tuple[Optional[dict], bool]:
+    try:
+        payload = json.loads(path.read_text(encoding = "utf-8"))
+    except (OSError, json.JSONDecodeError):
+        return None, True
+    return (payload, False) if isinstance(payload, dict) else (None, True)
+
+
+def lookup_marker(binary_path: Optional[str]) -> MarkerLookup:
+    """Prefer the install-root marker over archive metadata beside the binary."""
+    if not binary_path:
+        return MarkerLookup(None, None, False)
+    binary = Path(binary_path)
+    root = canonical_install_root(binary_path)
+    inner_marker = binary.parent / MARKER_NAME
+    inner_payload, _ = _parse_marker(inner_marker) if inner_marker.is_file() else (None, False)
+    slim_collision = bool(
+        inner_payload
+        and (inner_payload.get("install_kind") == "slim" or inner_payload.get("backend") == "slim")
+    )
+    if root is not None:
+        root_marker = root / MARKER_NAME
+        if root_marker.is_file():
+            marker, invalid = _parse_marker(root_marker)
+            return MarkerLookup(marker, root, True, invalid, slim_collision)
+        if slim_collision:
+            return MarkerLookup(None, root, False, True, True)
+
+    for parent in binary.parents[:5]:
+        candidate = parent / MARKER_NAME
+        if candidate.is_file():
+            marker, invalid = _parse_marker(candidate)
+            return MarkerLookup(marker, parent, False, invalid, slim_collision)
+    return MarkerLookup(None, None, False)
diff --git a/studio/backend/utils/preview_rate_limit.py b/studio/backend/utils/preview_rate_limit.py
index dd38cfd5e7..c59a1bf5b3 100644
--- a/studio/backend/utils/preview_rate_limit.py
+++ b/studio/backend/utils/preview_rate_limit.py
@@ -5,7 +5,7 @@
 
 A signed link stops ref guessing, but anyone with a link can still drive GPU
 generation. This bounds sustained abuse from a single source. In-process and
-single-worker only (like the login limiter in ``routes/auth.py``); Studio runs as
+single-worker only (like the login limiter in ``routes/auth.py``); Unsloth runs as
 one uvicorn process, so a shared store isn't needed.
 """
 
diff --git a/studio/backend/utils/process_lifetime.py b/studio/backend/utils/process_lifetime.py
index 3ffd54cc26..c63227ae86 100644
--- a/studio/backend/utils/process_lifetime.py
+++ b/studio/backend/utils/process_lifetime.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Bind Studio child processes to the parent's lifetime so none survive an
+"""Bind Unsloth child processes to the parent's lifetime so none survive an
 abnormal parent exit (terminal-window close, Task Manager "End Task", SIGKILL,
 crash) -- the cooperative shutdown path only runs on graceful exits.
 
@@ -139,7 +139,7 @@ def _install_windows_job() -> None:
             kernel32.CloseHandle(job)
             return
         # AssignProcessToJobObject(parent) makes children inherit the job. May
-        # fail if Studio already runs inside an incompatible host job (pre-Win8);
+        # fail if Unsloth already runs inside an incompatible host job (pre-Win8);
         # degrade to the cooperative path rather than blocking startup.
         if not kernel32.AssignProcessToJobObject(job, kernel32.GetCurrentProcess()):
             kernel32.CloseHandle(job)
diff --git a/studio/backend/utils/security/consent.py b/studio/backend/utils/security/consent.py
index b36131f809..fad52f21bb 100644
--- a/studio/backend/utils/security/consent.py
+++ b/studio/backend/utils/security/consent.py
@@ -147,11 +147,17 @@ def _load_remote_code_configs(model_name: str, hf_token: Optional[str] = None) -
 
         from huggingface_hub import hf_hub_download
         from huggingface_hub.utils import EntryNotFoundError
+        from utils.hf_cache_settings import active_hf_hub_cache
 
         configs = []
         for name in _REMOTE_CODE_CONFIG_FILES:
             try:
-                p = hf_hub_download(repo_id = model_name, filename = name, token = hf_token)
+                p = hf_hub_download(
+                    repo_id = model_name,
+                    filename = name,
+                    token = hf_token,
+                    cache_dir = active_hf_hub_cache(),
+                )
             except EntryNotFoundError:
                 continue  # genuine 404 -> truly absent
             except Exception:
diff --git a/studio/backend/utils/security/file_security.py b/studio/backend/utils/security/file_security.py
index 466f326f18..3e12c15096 100644
--- a/studio/backend/utils/security/file_security.py
+++ b/studio/backend/utils/security/file_security.py
@@ -29,13 +29,24 @@ Policy:
     scanned so a repo cannot dodge the gate by suffixing its name.
 """
 
+import re
 from dataclasses import dataclass, field
+from pathlib import Path
 from typing import Optional
 
 from loggers import get_logger
 
 logger = get_logger(__name__)
 
+# Pickle-format weight files (plain or sharded) that execute code on load; safetensors/gguf
+# are inert. Grouped by weight family so an inert safetensors only suppresses the pickle it
+# actually replaces: the loader won't use an adapter's safetensors for pytorch_model.bin.
+_PICKLE_WEIGHT_RE = re.compile(
+    r"^(model|pytorch_model|adapter_model|consolidated)(-\d+-of-\d+)?"
+    r"\.(bin|pt|pth|ckpt|pkl|pickle)$",
+    re.IGNORECASE,
+)
+
 # Non-blocking levels: clean or not-yet-finished. Anything else (unsafe/suspicious/
 # malicious or a future label) blocks, so Hub schema drift fails CLOSED.
 _NONBLOCKING_LEVELS = frozenset(
@@ -72,6 +83,13 @@ _INERT_SUFFIXES = frozenset(
 _SOURCE_SUFFIXES = frozenset({".py", ".pyc", ".pyx", ".pyi"})
 
 
+# Torch-family weight indexes: from_pretrained feeds each shard they name to load_state_dict, which
+# torch.load()s (pickle) any shard whose name does not end in .safetensors, whatever its stem. A
+# pytorch index is superseded when a base safetensors is present (the loader prefers it); a
+# safetensors index IS the chosen archive, so a non-safetensors target it names still loads. tf/flax
+# indexes load via non-pickle loaders, so they are not a torch.load vector here.
+_TORCH_INDEX_FILES = ("pytorch_model.bin.index.json", "model.safetensors.index.json")
+
 # Root weight-index files. from_pretrained reads these to find sharded weights, so a
 # flagged subdir pickle is a load vector iff a root index references it.
 _TRANSFORMERS_INDEX_FILES = (
@@ -96,6 +114,28 @@ def _file_suffix(path: str) -> str:
     return "." + base.rsplit(".", 1)[1].lower() if "." in base else ""
 
 
+def _hf_cache_snapshot_ref(local_path: str) -> Optional[tuple]:
+    """``(repo_id, revision)`` for an HF-cache snapshot path, else None. An inactive Studio
+    cache loads by its snapshot path but keeps the ``models--org--repo/snapshots/<rev>``
+    layout, so the gate recovers its provenance and scans that exact commit instead of
+    exempting it (an older cached commit can hold a pickle since dropped from the branch)."""
+    try:
+        path = Path(local_path).resolve(strict = False)
+    except (OSError, ValueError):
+        return None
+    for parent in path.parents:
+        if parent.name != "snapshots":
+            continue
+        encoded = parent.parent.name
+        if not encoded.startswith("models--"):
+            return None
+        repo_id = encoded.removeprefix("models--").replace("--", "/")
+        if not repo_id:
+            return None
+        return repo_id, path.relative_to(parent).parts[0]  # <rev> dir under snapshots/
+    return None
+
+
 def _load_relative_path(norm: str, load_subdirs) -> str:
     """``norm`` relative to a ``from_pretrained`` load root. Some loads read from a
     snapshot SUBDIRECTORY (Spark-TTS / BiCodec load ``<snapshot>/LLM``), where a file
@@ -123,19 +163,21 @@ def _indexed_shard_paths(
     model_name: str,
     hf_token: Optional[str],
     load_subdirs = (),
+    revision: Optional[str] = None,
 ):
     """Repo-relative weight paths a load could fetch via weight-index files. Returns a
     set (empty when the repo ships no index files -- a definitive "nothing sharded"), or
     None when the lookup was inconclusive (transient error) so the caller treats a
     flagged subdir pickle conservatively. Reads only small JSON indexes, never weights.
     Indexes are looked up at the root and each ``load_subdirs`` root, with ``weight_map``
-    entries re-prefixed to repo-relative paths.
+    entries re-prefixed to repo-relative paths. ``revision`` scopes to a cached commit.
     """
     import json
 
     try:
         from huggingface_hub import hf_hub_download
         from huggingface_hub.utils import EntryNotFoundError
+        from utils.hf_cache_settings import active_hf_hub_cache
     except Exception:
         return None
 
@@ -144,7 +186,13 @@ def _indexed_shard_paths(
     for prefix in _index_prefixes(load_subdirs):
         for filename in _TRANSFORMERS_INDEX_FILES:
             try:
-                index_path = hf_hub_download(model_name, prefix + filename, token = hf_token or None)
+                index_path = hf_hub_download(
+                    model_name,
+                    prefix + filename,
+                    revision = revision,
+                    token = hf_token or None,
+                    cache_dir = active_hf_hub_cache(),
+                )
             except EntryNotFoundError:
                 continue  # definitively absent, not an error
             except Exception:
@@ -236,9 +284,14 @@ def _load_scan_target(model_name: str, load_subdirs: tuple) -> tuple:
     return model_name, load_subdirs
 
 
-def _fetch_security_status(model_name: str, hf_token: Optional[str]):
+def _fetch_security_status(
+    model_name: str,
+    hf_token: Optional[str],
+    revision: Optional[str] = None,
+):
     """``security_repo_status`` (a dict) or None if unavailable. Hub metadata only;
     retries once on a transient error, then returns None so the caller fails open.
+    ``revision`` scopes the scan to a specific cached commit (else the default branch).
     """
     from huggingface_hub import model_info as hf_model_info
 
@@ -248,6 +301,7 @@ def _fetch_security_status(model_name: str, hf_token: Optional[str]):
         try:
             info = hf_model_info(
                 model_name,
+                revision = revision,
                 token = token_arg,
                 securityStatus = True,
                 timeout = timeout,
@@ -265,11 +319,184 @@ def _fetch_security_status(model_name: str, hf_token: Optional[str]):
     return None
 
 
+def _st_load_roots(snapshot: Path) -> list:
+    """Directories a SentenceTransformer load deserializes weights from: the snapshot root plus
+    each module path in modules.json. Local, no network. Mirrors the online gate (which ignores
+    unreferenced nested pickles ST never loads) so the offline gate doesn't over-block."""
+    roots = [snapshot]
+    try:
+        import json
+        modules = json.loads((snapshot / "modules.json").read_text())
+    except (OSError, ValueError):
+        return roots  # no / invalid modules.json -> snapshot root is the only load root
+    for module in modules or ():
+        path = str((module or {}).get("path", "")).strip().strip("/")
+        # Relative module path only; ignore a crafted "../" escape.
+        if path and ".." not in path.split("/"):
+            candidate = snapshot / path
+            if candidate not in roots:
+                roots.append(candidate)
+    return roots
+
+
+def _indexed_pickle_shards(index_path: Path, root: Path, snapshot: Path) -> list:
+    """Shards a torch weight index points a ``from_pretrained`` load at that load_state_dict would
+    torch.load (pickle): every ``weight_map`` target NOT ending in ``.safetensors``, whatever its
+    stem (an arbitrary name like ``shards/payload`` still deserializes). Resolved relative to the
+    index dir (``root``) like the loader, so a shard in a nested dir is followed (iterdir misses it).
+    Lexical only, never ``Path.resolve()`` (HF snapshot files symlink into ``blobs/``, so resolving
+    escapes the snapshot and false-blocks every shard). Raises OSError -> caller fails CLOSED on an
+    unreadable/invalid index or a target escaping the snapshot."""
+    import json
+    import os
+
+    try:
+        # JSON is UTF-8 by spec; pin it so a non-ASCII index is not misdecoded (and needlessly
+        # blocked) under Windows' cp1252 default.
+        parsed = json.loads(index_path.read_text(encoding = "utf-8"))
+    except (OSError, ValueError) as exc:
+        raise OSError(f"unreadable weight index: {index_path}") from exc
+    weight_map = parsed.get("weight_map") if isinstance(parsed, dict) else None
+    if not isinstance(weight_map, dict):
+        return []  # no dict weight_map -> the loader resolves no shards from this index
+    snapshot_norm = os.path.normpath(str(snapshot))
+    shards = []
+    for shard in weight_map.values():
+        raw = str(shard)
+        if not raw:
+            continue
+        # Join the RAW weight_map value like from_pretrained's os.path.join: on POSIX a backslash is a
+        # literal filename char (not a separator), so normalizing it would probe a different path than
+        # the loader opens. normpath + containment stay platform-aware (os.sep) to block "..".
+        joined = os.path.normpath(os.path.join(str(root), raw))
+        if joined != snapshot_norm and not joined.startswith(snapshot_norm + os.sep):
+            raise OSError(f"weight index escapes the snapshot: {index_path}")
+        shard_path = Path(joined)
+        # Case-SENSITIVE, mirroring load_state_dict's own endswith(".safetensors"): a shard named
+        # payload.SAFETENSORS is not treated as safetensors by the loader and falls to torch.load.
+        if not shard_path.name.endswith(".safetensors") and shard_path.is_file():
+            shards.append(shard_path)
+    return shards
+
+
+def _loader_resolves(root: Path, name: str) -> bool:
+    """True iff from_pretrained would open ``name`` under ``root``. ``is_file()`` honors the platform
+    (case-sensitive on Linux, case-insensitive on Windows/macOS), so it mirrors the loader's own
+    lookup: an oddly-cased decoy counts as an alternative only where the loader would truly open it.
+    A name-fold instead would let an uppercase MODEL.SAFETENSORS suppress the scan on Linux while the
+    loader, asking for the canonical lowercase name, silently falls through to a pickle index."""
+    return (root / name).is_file()
+
+
+def _cached_pickle_weight_files(snapshot: Path) -> list:
+    """Pickle weight files a SentenceTransformer/Transformers load deserializes from snapshot's ST
+    load roots, EXCLUDING those whose weight family also ships an inert safetensors in the same dir
+    (the loader prefers it): a base pickle is suppressed only by a base model.safetensors, an adapter
+    pickle only by adapter_model.safetensors -- an unrelated safetensors is no substitute. Covers
+    both direct-child pickles AND pickle shards referenced by a local weight index (which the loader
+    follows into nested dirs, matching the online gate). Raises OSError -- caller fails CLOSED -- if
+    the snapshot root or a weight index is unreadable, or an index reference escapes the snapshot."""
+    blocked = []
+    seen = set()
+
+    def _add(path: Path):
+        key = str(path)
+        if key not in seen:
+            seen.add(key)
+            blocked.append(path)
+
+    for root in _st_load_roots(snapshot):
+        try:
+            entries = [p for p in root.iterdir() if p.is_file()]
+        except OSError:
+            if root == snapshot:
+                raise  # top-level unreadable -> fail closed
+            continue  # unreadable module subdir: nothing loadable to attest here
+        # Safetensors alternatives the loader would actually resolve (never a bare name-fold, which
+        # fails OPEN: see _loader_resolves). A base pickle is replaced only by a base safetensors, an
+        # adapter pickle only by an adapter one. A single model.safetensors also outranks BOTH indexes.
+        has_direct_base_safetensors = _loader_resolves(root, "model.safetensors")
+        has_base_safetensors = has_direct_base_safetensors or _loader_resolves(
+            root, "model.safetensors.index.json"
+        )
+        has_adapter_safetensors = _loader_resolves(root, "adapter_model.safetensors")
+        for path in entries:
+            if not _PICKLE_WEIGHT_RE.match(path.name):
+                continue
+            is_adapter = path.name.lower().startswith("adapter_model")
+            has_alternative = has_adapter_safetensors if is_adapter else has_base_safetensors
+            if not has_alternative:
+                _add(path)
+        # A torch weight index makes from_pretrained load nested shards iterdir never sees; the loader
+        # torch.loads any not ending in .safetensors. Probe the canonical index name with the loader's
+        # own lookup (_loader_resolves), so an oddly-cased artifact it would never open does not block.
+        # A direct model.safetensors wins over BOTH indexes; failing that a base safetensors still
+        # outranks the pytorch index, while a safetensors index is itself the chosen archive.
+        for index_name in _TORCH_INDEX_FILES:
+            if not _loader_resolves(root, index_name):
+                continue
+            if has_direct_base_safetensors:
+                continue
+            if index_name == "pytorch_model.bin.index.json" and has_base_safetensors:
+                continue
+            for shard_path in _indexed_pickle_shards(root / index_name, root, snapshot):
+                _add(shard_path)
+    return blocked
+
+
+def _evaluate_local_only(model_name: str) -> FileSecurityDecision:
+    """Offline security gate. The Hub scan is unreachable, so inspect the local cache and fail
+    CLOSED on an unscanned pickle weight with no inert safetensors alternative, rather than
+    failing open or hanging. Safetensors/gguf-only cache loads; nothing cached -> allowed."""
+    from utils.utils import hf_cache_snapshot_dir
+
+    try:
+        snapshot = hf_cache_snapshot_dir(model_name)
+    except Exception:
+        logger.warning("Offline gate: could not resolve the cache for '%s'; blocking.", model_name)
+        return FileSecurityDecision(
+            model_name, True, reason = "offline; could not inspect the local cache"
+        )
+
+    if snapshot is None:
+        return FileSecurityDecision(model_name, False, reason = "offline; nothing cached to load")
+
+    try:
+        pickles = _cached_pickle_weight_files(snapshot)
+    except OSError:
+        logger.warning("Offline gate: could not read the cache for '%s'; blocking.", model_name)
+        return FileSecurityDecision(
+            model_name, True, reason = "offline; could not read the local cache"
+        )
+
+    if not pickles:
+        return FileSecurityDecision(
+            model_name, False, reason = "offline; cached weights are inert (safetensors/gguf)"
+        )
+
+    # Snapshot-relative posix paths (match the online gate; disambiguate same-named pickles).
+    rel_paths = sorted(p.relative_to(snapshot).as_posix() for p in pickles)
+    names = ", ".join(rel_paths)
+    logger.warning(
+        "Blocking offline load of '%s': cached pickle weight(s) cannot be malware-scanned "
+        "offline and have no safetensors alternative (%s).",
+        model_name,
+        names,
+    )
+    return FileSecurityDecision(
+        model_name,
+        True,
+        unsafe_files = [{"path": rel, "level": "unscanned"} for rel in rel_paths],
+        reason = f"offline; unscanned pickle weights with no safetensors alternative: {names}",
+    )
+
+
 def evaluate_file_security(
     model_name: str,
     hf_token: Optional[str] = None,
     *,
     load_subdirs = (),
+    local_only_load: bool = False,
 ) -> FileSecurityDecision:
     """Block a load when HF's security scan flags unsafe serialized files.
 
@@ -280,22 +507,34 @@ def evaluate_file_security(
     ``load_subdirs`` names subdirs the load calls ``from_pretrained`` on (e.g. ``("LLM",)``
     for Spark-TTS / BiCodec, loading ``<snapshot>/LLM``): a flagged file directly under one
     is root-level there and blocks, and an index inside it is honored when scoping shards.
+
+    ``local_only_load`` marks an offline load: with the Hub scan unreachable, inspect the local
+    cache and fail CLOSED on an unscanned pickle weight with no safetensors alternative.
     """
     # Scan the repo the load actually fetches, not the literal alias (which 404s and
     # fails open): the Spark-TTS "<parent>/LLM" alias is really unsloth/<parent> from LLM/.
     model_name, load_subdirs = _load_scan_target(model_name, tuple(load_subdirs))
 
-    # Local paths (including a local .gguf) have no Hub scan. A remote ref is scanned
-    # even if named "*.gguf", so a repo cannot dodge the scan via its name.
+    # Local paths have no Hub scan, EXCEPT an HF-cache snapshot whose canonical path
+    # encodes a repo id + commit: scan that exact commit so an inactive-cache load can't
+    # dodge the gate. A remote ref is scanned even if named "*.gguf" (name can't dodge it).
+    snapshot_revision = None
     try:
         from utils.paths import is_local_path
         if is_local_path(model_name):
-            return FileSecurityDecision(model_name, False, reason = "local path; no Hub scan")
+            cache_ref = _hf_cache_snapshot_ref(model_name)
+            if cache_ref is None:
+                return FileSecurityDecision(model_name, False, reason = "local path; no Hub scan")
+            model_name, snapshot_revision = cache_ref
     except Exception:
         # Cannot classify the path -> do not block on that account.
         return FileSecurityDecision(model_name, False, reason = "path check failed; not blocked")
 
-    status = _fetch_security_status(model_name, hf_token)
+    # Offline: inspect the local cache and fail closed rather than hang on model_info or fail open.
+    if local_only_load:
+        return _evaluate_local_only(model_name)
+
+    status = _fetch_security_status(model_name, hf_token, revision = snapshot_revision)
     if not isinstance(status, dict):
         return FileSecurityDecision(
             model_name, False, reason = "scan unavailable; allowed (fail-open)"
@@ -332,7 +571,9 @@ def evaluate_file_security(
             maybe_shard.append({"path": path, "level": level, "norm": norm})
 
     if maybe_shard:
-        indexed = _indexed_shard_paths(model_name, hf_token, load_subdirs)
+        indexed = _indexed_shard_paths(
+            model_name, hf_token, load_subdirs, revision = snapshot_revision
+        )
         for m in maybe_shard:
             # Block if a root index lists this shard, or if the lookup was inconclusive
             # (transient error -> stay conservative). A definitive "no index / not listed"
diff --git a/studio/backend/utils/security/remote_code_scan.py b/studio/backend/utils/security/remote_code_scan.py
index 797e1056f8..583dac94b6 100644
--- a/studio/backend/utils/security/remote_code_scan.py
+++ b/studio/backend/utils/security/remote_code_scan.py
@@ -29,6 +29,7 @@ from dataclasses import dataclass, field
 from typing import Optional
 
 from loggers import get_logger
+from utils.hf_cache_settings import active_hf_hub_cache
 
 logger = get_logger(__name__)
 
@@ -455,7 +456,12 @@ def repo_remote_code_files(model_name: str, hf_token: Optional[str] = None) -> d
         refs = set()
         for cfg_name in REMOTE_CODE_CONFIG_FILES:
             try:
-                cfg_path = hf_hub_download(model_name, cfg_name, token = hf_token)
+                cfg_path = hf_hub_download(
+                    model_name,
+                    cfg_name,
+                    token = hf_token,
+                    cache_dir = active_hf_hub_cache(),
+                )
             except EntryNotFoundError:
                 continue
             except Exception as exc:
@@ -499,7 +505,12 @@ def repo_remote_code_files(model_name: str, hf_token: Optional[str] = None) -> d
         wanted = present_py | (own_refs & repo_file_set)
         for fn in sorted(wanted):
             try:
-                fp = hf_hub_download(model_name, fn, token = hf_token)
+                fp = hf_hub_download(
+                    model_name,
+                    fn,
+                    token = hf_token,
+                    cache_dir = active_hf_hub_cache(),
+                )
             except Exception as exc:
                 # A .py CONFIRMED PRESENT could not be fetched. A partial set would
                 # fingerprint "clean" while transformers later runs this file, so fail
@@ -602,7 +613,12 @@ def external_auto_map_repos(model_name: str, hf_token: Optional[str] = None) ->
 
         for cfg_name in REMOTE_CODE_CONFIG_FILES:
             try:
-                cfg_path = hf_hub_download(model_name, cfg_name, token = hf_token)
+                cfg_path = hf_hub_download(
+                    model_name,
+                    cfg_name,
+                    token = hf_token,
+                    cache_dir = active_hf_hub_cache(),
+                )
             except EntryNotFoundError:
                 continue
             except Exception:
@@ -670,7 +686,12 @@ def _add_external_refs(files: dict, refs, hf_token, model_name: str) -> bool:
             wanted = present_py | set(entry_files)
         for fn in sorted(wanted):
             try:
-                fp = hf_hub_download(repo, fn, token = hf_token)
+                fp = hf_hub_download(
+                    repo,
+                    fn,
+                    token = hf_token,
+                    cache_dir = active_hf_hub_cache(),
+                )
             except Exception as exc:
                 logger.warning(
                     "repo_remote_code_files(%s): external %s:%s unscannable (%s)",
diff --git a/studio/backend/utils/studio_version.py b/studio/backend/utils/studio_version.py
index 9c18070fbb..82ade74bba 100644
--- a/studio/backend/utils/studio_version.py
+++ b/studio/backend/utils/studio_version.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Network-free Studio release version resolution for display-only UI."""
+"""Network-free Unsloth release version resolution for display-only UI."""
 
 from __future__ import annotations
 
@@ -20,7 +20,7 @@ _MAX_VERSION_LENGTH = 64
 
 
 def is_valid_studio_release_version(value: object) -> bool:
-    """Return True for Studio release tags such as ``v0.1.39-beta``."""
+    """Return True for Unsloth release tags such as ``v0.1.39-beta``."""
     if not isinstance(value, str):
         return False
     version = value.strip()
@@ -102,7 +102,7 @@ def _git_branch(repo_root: Path) -> str | None:
 
 
 def get_studio_version(repo_root: Path | None = None) -> str:
-    """Return the installed Studio release tag for display, or ``dev``.
+    """Return the installed Unsloth release tag for display, or ``dev``.
 
     Intentionally separate from the PyPI ``unsloth`` package version used by
     update checks. Never performs network requests.
diff --git a/studio/backend/utils/training_runs.py b/studio/backend/utils/training_runs.py
index dc2535e570..dcdfa1395d 100644
--- a/studio/backend/utils/training_runs.py
+++ b/studio/backend/utils/training_runs.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Helpers for naming and describing Studio training runs."""
+"""Helpers for naming and describing Unsloth training runs."""
 
 from __future__ import annotations
 
diff --git a/studio/backend/utils/transformers_latest.py b/studio/backend/utils/transformers_latest.py
index 40c8f729a5..9f1d11be5b 100644
--- a/studio/backend/utils/transformers_latest.py
+++ b/studio/backend/utils/transformers_latest.py
@@ -5,7 +5,7 @@
 
 When a model's ``model_type`` is absent from every installed transformers overlay
 (base 4.57.x plus the .venv_t5_530/550/510 sidecars and, if provisioned, .venv_t5_latest),
-Studio cannot load it today. This module answers, without authentication, code execution,
+Unsloth cannot load it today. This module answers, without authentication, code execution,
 or trust_remote_code:
 
   1. Does the LATEST transformers release on PyPI ship this ``model_type``?
@@ -387,7 +387,7 @@ def check_upgrade_for_model(model_name: str, hf_token: str | None = None) -> dic
 _SHADOWABLE_DEPS = frozenset({"tokenizers", "safetensors"})
 # Provided by the sidecar recipe; checked against its pin, not the base env.
 _SIDECAR_PROVIDED = {"huggingface-hub": "1.8.0", "hf-xet": "1.4.2"}
-# CLI-only; never imported at runtime in Studio's workers.
+# CLI-only; never imported at runtime in Unsloth's workers.
 _IGNORED_DEPS = frozenset({"typer"})
 
 
@@ -538,7 +538,7 @@ def _install_latest_transformers_locked(version: str, before_swap = None) -> dic
         return {
             "success": False,
             "version": version,
-            "message": "Cannot install: Studio is in offline mode.",
+            "message": "Cannot install: Unsloth is in offline mode.",
         }
     # Re-verify against a LIVE snapshot (a release may land inside the cache TTL);
     # fall back to the cached one on fetch failure.
@@ -573,13 +573,13 @@ def _install_latest_transformers_locked(version: str, before_swap = None) -> dic
             "version": version,
             "message": "Cannot install transformers "
             f"{version}: this environment does not satisfy {', '.join(blockers)}. "
-            "A Studio update is required first.",
+            "An Unsloth update is required first.",
         }
     if not ensure_latest_transformers_venv(version, extra_packages, before_swap = before_swap):
         return {
             "success": False,
             "version": version,
-            "message": f"Installing transformers {version} failed; see the Studio logs.",
+            "message": f"Installing transformers {version} failed; see the Unsloth logs.",
         }
     _invalidate_capability_caches()
     return {
diff --git a/studio/backend/utils/transformers_version.py b/studio/backend/utils/transformers_version.py
index 9f9f8aa3de..475a096248 100644
--- a/studio/backend/utils/transformers_version.py
+++ b/studio/backend/utils/transformers_version.py
@@ -44,6 +44,7 @@ import time
 from pathlib import Path
 
 from utils.native_path_leases import child_env_without_native_path_secret
+from utils.hf_cache_settings import get_hf_cache_paths
 from utils.subprocess_compat import (
     windows_hidden_subprocess_kwargs as _windows_hidden_subprocess_kwargs,
 )
@@ -516,13 +517,10 @@ def _adapter_base_from_hf_cache(model_name: str) -> str | None:
     """
     if not _is_canonical_repo_id(model_name):
         return None
-    hub = (
-        os.environ.get("HF_HUB_CACHE")
-        or os.environ.get("HUGGINGFACE_HUB_CACHE")
-        or os.path.join(
-            os.environ.get("HF_HOME") or os.path.expanduser("~/.cache/huggingface"), "hub"
-        )
-    )
+    # Route through the selected cache: after a no-restart /settings switch the
+    # process HF_HUB_CACHE env is stale, but the model loads from the selected
+    # cache, which get_hf_cache_paths() reflects (the DB switch).
+    hub = str(get_hf_cache_paths().hub_cache)
     repo_dir = Path(hub) / ("models--" + model_name.replace("/", "--"))
     candidates = []
     ref_main = repo_dir / "refs" / "main"
@@ -681,13 +679,10 @@ def _config_json_from_hf_cache(model_name: str) -> dict | None:
     # Only a canonical ``owner/repo`` Hub id maps to a cache dir; reject local paths.
     if not model_name or model_name.count("/") != 1 or model_name[0] in "/.~" or "\\" in model_name:
         return None
-    hub = (
-        os.environ.get("HF_HUB_CACHE")
-        or os.environ.get("HUGGINGFACE_HUB_CACHE")
-        or os.path.join(
-            os.environ.get("HF_HOME") or os.path.expanduser("~/.cache/huggingface"), "hub"
-        )
-    )
+    # Route through the selected cache: after a no-restart /settings switch the
+    # process HF_HUB_CACHE env is stale, but the model loads from the selected
+    # cache, which get_hf_cache_paths() reflects (the DB switch).
+    hub = str(get_hf_cache_paths().hub_cache)
     repo_dir = Path(hub) / ("models--" + model_name.replace("/", "--"))
     candidates = []
     ref_main = repo_dir / "refs" / "main"
@@ -1251,7 +1246,7 @@ def _probe_autoconfig(target_dir: str, model_name: str, hf_token: str | None) ->
     True = parses, False = parse/version failure (escalate), None = transient
     (auth/network/offline/spawn) so the caller fails safe and does not cache.
     """
-    env = child_env_without_native_path_secret()
+    env = get_hf_cache_paths().child_env(child_env_without_native_path_secret())
     if hf_token:
         env["HF_TOKEN"] = hf_token
         # The probe relies on the implicit HF_TOKEN env (no token= arg). Clear any inherited
@@ -1806,7 +1801,7 @@ def _install_to_dir(pkg: str, target_dir: str) -> bool:
             stdout = subprocess.PIPE,
             stderr = subprocess.STDOUT,
             text = True,
-            env = child_env_without_native_path_secret(),
+            env = get_hf_cache_paths().child_env(child_env_without_native_path_secret()),
             **_windows_hidden_subprocess_kwargs(),
         )
         if result.returncode == 0:
@@ -1829,7 +1824,7 @@ def _install_to_dir(pkg: str, target_dir: str) -> bool:
         stdout = subprocess.PIPE,
         stderr = subprocess.STDOUT,
         text = True,
-        env = child_env_without_native_path_secret(),
+        env = get_hf_cache_paths().child_env(child_env_without_native_path_secret()),
         **_windows_hidden_subprocess_kwargs(),
     )
     if result.returncode != 0:
@@ -2151,7 +2146,7 @@ def end_sidecar_swap() -> None:
 
 def sidecar_swap_in_progress() -> bool:
     """True while a .venv_t5_latest install or repair holds the reservation,
-    in this process or any other Studio process (lock file)."""
+    in this process or any other Unsloth process (lock file)."""
     return sidecar_swap_kind() is not None
 
 
@@ -2458,7 +2453,7 @@ def _ensure_venv_llmcompressor_exists() -> bool:
             stdout = subprocess.PIPE,
             stderr = subprocess.STDOUT,
             text = True,
-            env = child_env_without_native_path_secret(),
+            env = get_hf_cache_paths().child_env(child_env_without_native_path_secret()),
             **_windows_hidden_subprocess_kwargs(),
         )
         last_out = result.stdout or ""
diff --git a/studio/backend/utils/upload_limits.py b/studio/backend/utils/upload_limits.py
index c21ea69af7..662af0f1dd 100644
--- a/studio/backend/utils/upload_limits.py
+++ b/studio/backend/utils/upload_limits.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Shared Studio upload/request size limits."""
+"""Shared Unsloth upload/request size limits."""
 
 from __future__ import annotations
 
@@ -14,6 +14,9 @@ MIN_UPLOAD_LIMIT_MB = 1
 MAX_UPLOAD_LIMIT_MB = 8192
 _BYTES_PER_MB = 1024 * 1024
 MULTIPART_OVERHEAD_BYTES = 10 * _BYTES_PER_MB
+STT_AUDIO_RAW_MAX_BYTES = 25 * _BYTES_PER_MB
+STT_AUDIO_B64_MAX_CHARS = ((STT_AUDIO_RAW_MAX_BYTES + 2) // 3) * 4
+STT_AUDIO_JSON_MAX_BYTES = STT_AUDIO_B64_MAX_CHARS + 64 * 1024
 
 LOCAL_SEED_UPLOAD_MAX_BYTES = 100 * _BYTES_PER_MB
 LOCAL_SEED_UPLOAD_MAX_LABEL = "100MB"
diff --git a/studio/backend/utils/utils.py b/studio/backend/utils/utils.py
index 3818253ac9..ce3d6704b7 100644
--- a/studio/backend/utils/utils.py
+++ b/studio/backend/utils/utils.py
@@ -8,6 +8,7 @@ import structlog
 from loggers import get_logger
 from contextlib import contextmanager
 from pathlib import Path
+from typing import Optional
 import shutil
 import tempfile
 
@@ -15,6 +16,132 @@ import tempfile
 logger = get_logger(__name__)
 
 
+# ── Offline / HF-cache helpers ──────────────────────────────────
+# An offline load must never touch the network (a DNS-dead session hangs on hub retries);
+# these read the local HF cache the load itself uses.
+
+_HF_OFFLINE_TRUE_VALUES = frozenset({"1", "true", "yes", "on"})
+
+
+def hf_env_offline() -> bool:
+    """True when HF_HUB_OFFLINE or TRANSFORMERS_OFFLINE requests offline mode.
+
+    Also honors TRANSFORMERS_OFFLINE (hub honors only HF_HUB_OFFLINE) since users set it
+    to keep transformers loads local.
+    """
+    for var in ("HF_HUB_OFFLINE", "TRANSFORMERS_OFFLINE"):
+        if os.environ.get(var, "").strip().lower() in _HF_OFFLINE_TRUE_VALUES:
+            return True
+    return False
+
+
+def st_repo_id_candidates(model_name: str) -> list:
+    """Repo ids a Sentence-Transformers load may resolve model_name to; a slashless name
+    also resolves under the sentence-transformers/ namespace, so both are candidates."""
+    name = (model_name or "").strip().strip("/")
+    if not name:
+        return []
+    candidates = [name]
+    if "/" not in name:
+        candidates.append(f"sentence-transformers/{name}")
+    return candidates
+
+
+def _expand_path(raw: str) -> Path:
+    """Expand ~ and $VARS as huggingface_hub does, so the gate resolves the loader's dir."""
+    return Path(os.path.expandvars(os.path.expanduser(raw)))
+
+
+def _hf_cache_roots() -> list:
+    """Cache roots to search for a model's local snapshot, most-authoritative first.
+
+    The app's selected hub cache (set via /settings) is searched first: after a
+    no-restart cache switch the process env is stale, yet the loader reads the
+    selected cache via ``cache_folder=active_hf_hub_cache()``, so the snapshot
+    and offline security lookups must match where it actually loads. The env
+    precedence (SENTENCE_TRANSFORMERS_HOME, HF_HUB_CACHE, HF_HOME/hub,
+    ~/.cache/huggingface/hub) follows so a copy still in a previous cache resolves."""
+    roots: list = []
+    seen: set = set()
+
+    def _add(path) -> None:
+        if path is None:
+            return
+        expanded = _expand_path(str(path))
+        key = str(expanded)
+        if key not in seen:
+            seen.add(key)
+            roots.append(expanded)
+
+    try:
+        from utils.hf_cache_settings import get_hf_cache_paths
+        _add(get_hf_cache_paths().hub_cache)
+    except Exception:
+        pass
+
+    if st_home := os.environ.get("SENTENCE_TRANSFORMERS_HOME"):
+        _add(st_home)
+    if hub := (os.environ.get("HF_HUB_CACHE") or os.environ.get("HUGGINGFACE_HUB_CACHE")):
+        _add(hub)
+    if hf_home := os.environ.get("HF_HOME"):
+        _add(_expand_path(hf_home) / "hub")
+    if not roots:
+        _add(Path.home() / ".cache" / "huggingface" / "hub")
+    return roots
+
+
+def hf_cache_snapshot_dir(model_name: str) -> Optional[Path]:
+    """Active local snapshot dir for model_name's main revision, or None if not cached.
+    Reads refs/main then snapshots/<commit>; no network. Tries the ST alias for slashless names."""
+    try:
+        from huggingface_hub.file_download import repo_folder_name
+    except Exception:
+        repo_folder_name = None
+    for cache_root in _hf_cache_roots():
+        for repo_id in st_repo_id_candidates(model_name):
+            try:
+                if repo_folder_name is not None:
+                    folder = repo_folder_name(repo_id = repo_id, repo_type = "model")
+                else:
+                    folder = "models--" + repo_id.replace("/", "--")
+                repo_dir = cache_root / folder
+                ref = repo_dir / "refs" / "main"
+                if not ref.is_file():
+                    continue
+                commit = ref.read_text().strip()
+                if not commit:
+                    continue
+                snapshot = repo_dir / "snapshots" / commit
+                if snapshot.is_dir():
+                    return snapshot
+            except OSError:
+                continue
+    return None
+
+
+# A weight file plus a config distinguishes a real cached model from a metadata-only
+# partial cache that resolves refs/main but would fail at load time.
+_LOADABLE_WEIGHT_SUFFIXES = frozenset({".safetensors", ".bin", ".gguf", ".pt", ".pth", ".ckpt"})
+
+
+def hf_cache_snapshot_is_loadable(model_name: str) -> bool:
+    """True when model_name's snapshot is cached and loadable: a config (config.json or
+    modules.json) plus at least one weight file, not a metadata-only partial cache. No network."""
+    snapshot = hf_cache_snapshot_dir(model_name)
+    if snapshot is None:
+        return False
+    try:
+        has_config = (snapshot / "config.json").is_file() or (snapshot / "modules.json").is_file()
+        if not has_config:
+            return False
+        for path in snapshot.rglob("*"):
+            if path.suffix.lower() in _LOADABLE_WEIGHT_SUFFIXES and path.is_file():
+                return True
+    except OSError:
+        return False
+    return False
+
+
 # ── Client-safe error helpers ───────────────────────────────────
 # Never return raw exception text to clients; log server-side, return generic.
 
@@ -123,6 +250,26 @@ def without_hf_auth():
             os.environ.pop("HF_HUB_DISABLE_IMPLICIT_TOKEN", None)
 
 
+def is_hf_authentication_error(error: Exception) -> bool:
+    """Return whether an exception chain contains a definitive HF auth failure."""
+    seen: set[int] = set()
+    current: BaseException | None = error
+    while current is not None and id(current) not in seen:
+        seen.add(id(current))
+        response = getattr(current, "response", None)
+        status = getattr(response, "status_code", None)
+        try:
+            if status is not None and int(status) == 401:
+                return True
+        except (TypeError, ValueError):
+            pass
+        message = str(current).lower()
+        if "invalid user token" in message or "invalid hf token" in message:
+            return True
+        current = current.__cause__ or current.__context__
+    return False
+
+
 def format_error_message(error: Exception, model_name: str) -> str:
     """
     Format a user-friendly error message for common load issues.
@@ -147,17 +294,31 @@ def format_error_message(error: Exception, model_name: str) -> str:
         return "Invalid HF token. Please check your token and try again."
 
     if (
-        "memory" in error_str
-        or "cuda" in error_str
-        or "mlx" in error_str
-        or "out of memory" in error_str
+        "out of memory" in error_str
+        or "out of device memory" in error_str
+        or "out_of_device_memory" in error_str  # ZE_RESULT_ERROR_OUT_OF_DEVICE_MEMORY
+        or "out_of_host_memory" in error_str  # ZE_RESULT_ERROR_OUT_OF_HOST_MEMORY
+        or "not enough memory" in error_str
+        or "cannot allocate memory" in error_str
+        or "memory allocation failed" in error_str
+        or "cublas_status_alloc_failed" in error_str  # cuBLAS workspace OOM
+        or ("cuda error" in error_str and "alloc" in error_str)
+        or ("xpu" in error_str and ("alloc" in error_str or "memory" in error_str))
+        or isinstance(error, MemoryError)
+        or ("mlx" in error_str and ("memory" in error_str or "allocate" in error_str))
     ):
+        # Resolve get_device() at call time (not import time) so tests that
+        # monkey-patch utils.hardware.get_device after this module is loaded
+        # still see the patched backend.
         from utils.hardware import get_device
 
         device = get_device()
-        device_label = {"cuda": "GPU", "mlx": "Apple Silicon GPU", "cpu": "system"}.get(
-            device.value, "GPU"
-        )
+        device_label = {
+            "cuda": "GPU",
+            "xpu": "Intel GPU",
+            "mlx": "Apple Silicon GPU",
+            "cpu": "system",
+        }.get(device.value, "GPU")
         return f"Not enough {device_label} memory to load '{model_short}'. Try a smaller model or free memory."
 
     return str(error)
diff --git a/studio/backend/utils/whisper_cpp_freshness.py b/studio/backend/utils/whisper_cpp_freshness.py
new file mode 100644
index 0000000000..59749455b1
--- /dev/null
+++ b/studio/backend/utils/whisper_cpp_freshness.py
@@ -0,0 +1,254 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""whisper.cpp prebuilt freshness check.
+
+Reads UNSLOTH_WHISPER_PREBUILT_INFO.json (written by install_whisper_prebuilt.py)
+and compares the installed release tag against the latest on GitHub. Surfaced via
+utils.whisper_cpp_update (GET /api/whisper/update-status and the combined
+llama+whisper update status). Fails open on any missing data so we never show a
+misleading banner.
+
+The mechanics (marker walk-up, GitHub fetch, memo + disk cache, report skeleton)
+live in utils.prebuilt.freshness_flow; this module keeps the whisper version
+policy and the per-module caches its tests patch.
+"""
+
+from __future__ import annotations
+
+import re
+from datetime import datetime
+from pathlib import Path
+from typing import Optional
+
+import structlog
+
+from utils.prebuilt import freshness_flow as _flow
+from utils.prebuilt.whisper_layout import lookup_marker
+
+logger = structlog.get_logger(__name__)
+
+# 3 days matches Unsloth's typical whisper.cpp release cadence.
+STALENESS_THRESHOLD_DAYS = 3
+
+_INSTALL_MARKER_NAME = "UNSLOTH_WHISPER_PREBUILT_INFO.json"
+
+_marker_cache: dict[str, Optional[dict]] = {}
+_release_memo: dict[str, tuple[float, Optional[str]]] = {}
+# Newest-release asset sizes (name -> bytes), memoized like the tag (24h TTL).
+_assets_memo: dict[str, tuple[float, dict[str, int]]] = {}
+
+
+def _cache_dir() -> Path:
+    """Lazy import so tests can stub storage_roots."""
+    try:
+        from utils.paths.storage_roots import cache_root
+        return cache_root() / "whisper_cpp_freshness"
+    except Exception:
+        return Path.home() / ".unsloth" / "studio" / "cache" / "whisper_cpp_freshness"
+
+
+def read_install_marker(binary_path: Optional[str]) -> Optional[dict]:
+    """Walk up from binary_path to find UNSLOTH_WHISPER_PREBUILT_INFO.json.
+    None = no marker (source build / custom path) or invalid JSON."""
+    if not binary_path:
+        return None
+    cached = _marker_cache.get(binary_path)
+    if cached is not None or binary_path in _marker_cache:
+        return cached
+    marker = lookup_marker(binary_path).marker
+    _marker_cache[binary_path] = marker
+    return marker
+
+
+def _load_disk_cache(repo: str) -> Optional[tuple[float, Optional[str]]]:
+    return _flow.load_disk_cache(repo, _cache_dir())
+
+
+def _save_disk_cache(repo: str, latest_tag: Optional[str]) -> None:
+    _flow.save_disk_cache(
+        repo, latest_tag, _cache_dir(), log_message = "whisper freshness cache write failed"
+    )
+
+
+def _fetch_latest_release_tag(repo: str, timeout: float = 5.0) -> Optional[str]:
+    """Newest published release tag for `repo`, by publish time (see
+    freshness_flow for why this is not GitHub's /releases/latest pointer)."""
+    return _flow.fetch_latest_release_tag(
+        repo, timeout, log_message = "whisper freshness fetch failed"
+    )
+
+
+def latest_published_release(repo: str, *, force_refresh: bool = False) -> Optional[str]:
+    """Latest release tag for `repo`. Memo + disk-cached (24h TTL).
+    None when offline and never previously cached."""
+    return _flow.latest_published_release(
+        repo,
+        force_refresh = force_refresh,
+        memo = _release_memo,
+        cache_dir = lambda: _cache_dir(),
+        fetch = lambda r: _fetch_latest_release_tag(r),
+        save = lambda r, tag: _save_disk_cache(r, tag),
+    )
+
+
+def _fetch_latest_release_assets(repo: str, timeout: float = 5.0) -> Optional[dict[str, int]]:
+    """Asset name -> size (bytes) for the newest published release of `repo`,
+    selected exactly like _fetch_latest_release_tag. None on any failure."""
+    return _flow.fetch_latest_release_assets(
+        repo, timeout, log_message = "whisper freshness asset fetch failed"
+    )
+
+
+def latest_release_assets(repo: str, *, force_refresh: bool = False) -> Optional[dict[str, int]]:
+    """Newest-release asset sizes for `repo`, memoized (24h TTL). None when
+    offline and never fetched. In-memory only -- a restart simply re-fetches."""
+    return _flow.latest_release_assets(
+        repo,
+        force_refresh = force_refresh,
+        memo = _assets_memo,
+        fetch = lambda r: _fetch_latest_release_assets(r),
+    )
+
+
+def _asset_platform_suffix(asset: str, installed_tag: Optional[str]) -> Optional[str]:
+    """The tag-independent ``<os>-<arch>-<accel>.<ext>`` suffix identifying this
+    host's bundle, from stripping the ``whisper-<tag>-`` prefix off the installed
+    asset name. Falls back to anchoring on the platform token when the marker tag
+    does not line up with the asset's embedded tag."""
+    if isinstance(installed_tag, str) and installed_tag:
+        tag = installed_tag if installed_tag.startswith("v") else f"v{installed_tag}"
+        prefix = f"whisper-{tag}-"
+        if asset.startswith(prefix):
+            return asset[len(prefix) :]
+    m = re.search(r"-((?:linux|macos|windows)-.*)$", asset)
+    return m.group(1) if m else None
+
+
+def update_download_size_bytes(
+    marker: Optional[dict],
+    latest_tag: Optional[str],
+    repo: Optional[str],
+    *,
+    force_refresh: bool = False,
+) -> Optional[int]:
+    """Download size of the latest-release asset matching this host's installed
+    bundle (same platform/arch/accel suffix). None when there is no marker asset,
+    the latest assets can't be read, or no match.
+
+    Assets are named ``whisper-<tag>-<os>-<arch>-<accel>.<ext>`` and the fork
+    builds every slice itself, so only the publish repo is consulted (no
+    upstream/binary_repo passthrough)."""
+    if not marker or not latest_tag or not repo:
+        return None
+    installed_asset = marker.get("asset")
+    if not isinstance(installed_asset, str) or not installed_asset:
+        return None
+    suffix = _asset_platform_suffix(installed_asset, marker.get("release_tag"))
+    if not suffix:
+        return None
+    assets = latest_release_assets(repo, force_refresh = force_refresh)
+    if not assets:
+        return None
+    latest_v = latest_tag if latest_tag.startswith("v") else f"v{latest_tag}"
+    want = f"whisper-{latest_v}-{suffix}"
+    if want in assets:
+        return assets[want]
+    # Tag formatting can vary; fall back to the platform+accel suffix.
+    for name, size in assets.items():
+        if name.endswith(suffix):
+            return size
+    return None
+
+
+def parse_release_version(tag: object) -> Optional[tuple]:
+    """Comparable key ``(upstream_major, upstream_minor, upstream_patch,
+    unsloth_serial)`` for a tag like ``v1.9.1-unsloth.2``.
+
+    Tolerant of a leading ``v`` and a missing ``-unsloth.N`` suffix (serial then
+    0); the upstream version is padded to major/minor/patch. None when the version
+    component is not purely numeric."""
+    if not isinstance(tag, str):
+        return None
+    s = tag.strip()
+    if not s:
+        return None
+    if s[0] in ("v", "V"):
+        s = s[1:]
+    serial = 0
+    m = re.search(r"-unsloth\.(\d+)$", s)
+    if m:
+        serial = int(m.group(1))
+        s = s[: m.start()]
+    parts = s.split(".")
+    nums: list[int] = []
+    for part in parts:
+        if not part.isdigit():
+            return None
+        nums.append(int(part))
+    if not nums:
+        return None
+    while len(nums) < 3:
+        nums.append(0)
+    return (nums[0], nums[1], nums[2], serial)
+
+
+def is_behind(installed: Optional[str], latest: Optional[str]) -> bool:
+    """Whether `installed` is genuinely behind `latest`.
+
+    - identical tags -> not behind (clears the sticky banner post-update)
+    - both parse -> behind only when the latest version key is strictly greater
+      (a lower/equal version is never "behind" -> downgrade guard)
+    - either fails to parse and they differ -> behind (plain inequality)
+    """
+    if not installed or not latest:
+        return False
+    installed, latest = installed.strip(), latest.strip()
+    if installed == latest:
+        return False
+    installed_key, latest_key = parse_release_version(installed), parse_release_version(latest)
+    if installed_key is not None and latest_key is not None:
+        return latest_key > installed_key
+    # One side is unparseable and the tags already differ: treat as behind.
+    return True
+
+
+def check_prebuilt_freshness(
+    binary_path: Optional[str],
+    *,
+    threshold_days: int = STALENESS_THRESHOLD_DAYS,
+    now: Optional[datetime] = None,
+) -> dict:
+    """Returns {has_marker, stale, behind, installed_tag, latest_tag,
+    installed_at_utc, age_days, published_repo, threshold_days}.
+    behind = installed genuinely older than latest (see is_behind).
+    stale = behind AND age >= threshold.
+    Fails open on missing data (behind/stale stay False)."""
+    # The whisper marker records a single ``release_tag`` (e.g. v1.9.1-unsloth.2);
+    # both display and comparison use it directly.
+    return _flow.check_freshness(
+        binary_path,
+        threshold_days = threshold_days,
+        now = now,
+        read_marker = lambda p: read_install_marker(p),
+        latest_release = lambda repo: latest_published_release(repo),
+        behind = lambda installed, latest: is_behind(installed, latest),
+        display_tag = lambda marker: marker.get("release_tag"),
+        compare_tag = lambda marker: marker.get("release_tag"),
+    )
+
+
+def reset_caches(*, drop_disk: bool = False) -> None:
+    """Drop the in-memory freshness caches. The no-arg form is test-only.
+
+    With ``drop_disk = True`` also delete the on-disk 24h release cache. Used by
+    the post-install/update path: clearing memory alone leaves the stale
+    same-version value on disk, so an offline post-install GitHub refresh would
+    replay it (latest_published_release's last-good fallback) and the banner could
+    linger. Dropping the disk cache makes latest read None in that offline case,
+    so the banner fails open (off) rather than point at the just-replaced build."""
+    _flow.reset_caches(
+        (_marker_cache, _release_memo, _assets_memo),
+        drop_disk = drop_disk,
+        cache_dir = lambda: _cache_dir(),
+    )
diff --git a/studio/backend/utils/whisper_cpp_update.py b/studio/backend/utils/whisper_cpp_update.py
new file mode 100644
index 0000000000..cac37c25fc
--- /dev/null
+++ b/studio/backend/utils/whisper_cpp_update.py
@@ -0,0 +1,490 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""In-app whisper.cpp prebuilt update.
+
+Builds on utils.whisper_cpp_freshness (which detects whether a newer prebuilt
+release exists) and adds the *apply* half: run install_whisper_prebuilt.py to
+download the newest bundle for this host and atomically swap it in, so the next
+model load uses it. Applies only run as the whisper phase of the combined
+llama+whisper update (utils.llama_cpp_update.start_update chains
+run_chained_phase); there is no standalone whisper update trigger.
+
+Design notes:
+- Detection is delegated to check_prebuilt_freshness(). We surface an
+  ``update_available`` flag (installed_tag != latest_tag), laxer than freshness'
+  ``stale`` (which also requires the install to be >= 3 days old). The UI shows
+  the single main update item on update_available.
+- Everything fails open: a missing marker / offline GitHub / source build just
+  reports update_available=False and never blocks the app.
+- The mechanics (managed-root resolution, local-link detection, the resolve
+  probe, the streamed installer run) live in utils.prebuilt.update_flow; this
+  module keeps the whisper policy. The ``job`` dict in the status payload stays
+  idle (kept for response-shape stability): chained applies report progress
+  through the llama job.
+"""
+
+from __future__ import annotations
+
+import os
+import re
+import subprocess
+import sys
+import threading
+from pathlib import Path
+from typing import Optional
+
+import structlog
+
+from utils.prebuilt import update_flow as _flow
+from utils.prebuilt.whisper_layout import canonical_install_root
+from utils.whisper_cpp_freshness import (
+    _INSTALL_MARKER_NAME,
+    check_prebuilt_freshness,
+    is_behind,
+    latest_published_release,
+    latest_release_assets,
+    parse_release_version,
+    read_install_marker,
+    reset_caches,
+    update_download_size_bytes,
+)
+
+logger = structlog.get_logger(__name__)
+
+DEFAULT_PUBLISHED_REPO = "unslothai/whisper.cpp"
+_INSTALL_TIMEOUT_SECONDS = 1800  # 30 min ceiling for download + extract/validate
+
+# Always-idle job payload: whisper applies run inside the chained llama job, so
+# nothing flips this to running. Kept so status payload shapes stay stable.
+_job_lock = threading.Lock()
+_job: dict = _flow.new_job()
+
+_rocm_install_args = _flow.rocm_install_args
+
+
+def _find_binary() -> Optional[str]:
+    """Locate the active whisper-server binary via the STT sidecar's own resolver
+    so update targets exactly what Unsloth runs. Lazy import keeps the heavy
+    inference module off this module's import path."""
+    try:
+        from core.inference.stt_ggml_sidecar import find_whisper_server_binary
+        return find_whisper_server_binary()
+    except Exception as exc:  # pragma: no cover - defensive
+        logger.debug("whisper update: binary discovery failed", error = str(exc))
+        return None
+
+
+def _install_dir_for(binary_path: Optional[str]) -> Optional[Path]:
+    """The directory holding UNSLOTH_WHISPER_PREBUILT_INFO.json: the install root
+    install_whisper_prebuilt.py wrote (``<install-dir>`` whose canonical server is
+    ``build/bin/whisper-server``) and the one we re-install into."""
+    root = canonical_install_root(binary_path)
+    if root is not None and (root / _INSTALL_MARKER_NAME).is_file():
+        return root
+    return _flow.install_dir_for(binary_path, marker_name = _INSTALL_MARKER_NAME)
+
+
+def _installer_script() -> Optional[Path]:
+    """Locate install_whisper_prebuilt.py (UNSLOTH_WHISPER_INSTALLER wins)."""
+    return _flow.find_installer_script(
+        env_var = "UNSLOTH_WHISPER_INSTALLER", script_name = "install_whisper_prebuilt.py"
+    )
+
+
+# Markerless (source-build) installs have no UNSLOTH_WHISPER_PREBUILT_INFO.json,
+# so we ask the installer whether an official prebuilt now exists for this host.
+_resolve_memo: dict = {}
+
+
+def _resolve_prebuilt_for_host(
+    *, force_refresh: bool = False, backend: Optional[str] = None
+) -> Optional[dict]:
+    """Run install_whisper_prebuilt.py --resolve-prebuilt (no download); return
+    {prebuilt_available, repo, release_tag, upstream_tag, backend, asset, os,
+    arch, ...} or None. Fail-open: any error -> None so a source build never
+    blocks the app."""
+    extra_args = ("--backend", backend) if backend else ()
+    return _flow.resolve_prebuilt_for_host(
+        force_refresh = force_refresh,
+        memo = _resolve_memo,
+        installer_script = lambda: _installer_script(),
+        log_message = "whisper update: resolve-prebuilt failed",
+        extra_args = extra_args,
+    )
+
+
+def _installed_whisper_version(binary: Optional[str]) -> Optional[str]:
+    """Best-effort ``v<A.B.C>`` from ``whisper-server --version``. None when the
+    binary is missing, reports no version, or cannot run. Used only for the
+    markerless source-build downgrade guard, so it fails open to None."""
+    if not binary:
+        return None
+    try:
+        proc = subprocess.run([binary, "--version"], capture_output = True, text = True, timeout = 20)
+    except Exception:  # pragma: no cover - defensive
+        return None
+    m = re.search(r"v?(\d+\.\d+\.\d+)", (proc.stderr or "") + (proc.stdout or ""))
+    if not m:
+        return None
+    return f"v{m.group(1)}"
+
+
+def _whisper_install_root(binary: Optional[str]) -> Optional[Path]:
+    """The Unsloth-managed whisper.cpp root the active binary lives under, or None
+    when the binary is unmanaged (see update_flow.managed_install_root)."""
+    return _flow.managed_install_root(
+        binary,
+        marker_root = _install_dir_for(binary),
+        server_path_var = "WHISPER_SERVER_PATH",
+        cpp_path_var = "UNSLOTH_WHISPER_CPP_PATH",
+        dir_name = "whisper.cpp",
+    )
+
+
+def _source_build_status(binary: str, *, force_refresh: bool) -> Optional[dict]:
+    """Update status for a markerless (source-build) install: offer the official
+    prebuilt when one exists for this host and is newer than the installed binary.
+    None -> caller falls through to the no-marker default (unsupported)."""
+    res = _resolve_prebuilt_for_host(force_refresh = force_refresh)
+    if not res or not res.get("prebuilt_available"):
+        return None
+    release_tag = res.get("release_tag")
+    if not release_tag:
+        return None
+    # No resolvable install root (e.g. a pinned WHISPER_SERVER_PATH we cannot
+    # manage) means an apply would not take effect, so do not offer it.
+    if _whisper_install_root(binary) is None:
+        return None
+    installed_tag = _installed_whisper_version(binary)
+    installed_key = parse_release_version(installed_tag) if installed_tag else None
+    latest_key = parse_release_version(release_tag)
+    if installed_key is None or latest_key is None:
+        # Unknown installed/latest version (involuntary source-build case): treat
+        # as behind so we still offer the prebuilt.
+        update_available = True
+    else:
+        # Same downgrade guard as is_behind: only a strictly newer key is behind.
+        update_available = latest_key > installed_key
+    latest = release_tag
+    # Size of the resolved prebuilt, so source builds show it like the marker
+    # path. Fails open to None (offline / asset absent from release).
+    update_size_bytes = None
+    if update_available:
+        asset_name = res.get("asset")
+        if isinstance(asset_name, str) and asset_name:
+            try:
+                assets = latest_release_assets(res.get("repo"), force_refresh = force_refresh)
+                if assets:
+                    update_size_bytes = assets.get(asset_name)
+            except Exception as exc:  # pragma: no cover - network defensive
+                logger.debug("whisper update: source-build size lookup failed", error = str(exc))
+    with _job_lock:
+        job = dict(_job)
+    return {
+        "supported": True,
+        "update_available": update_available,
+        "stale": False,
+        "installed_tag": installed_tag,
+        "latest_tag": latest,
+        "published_repo": res.get("repo"),
+        "installed_at_utc": None,
+        "age_days": None,
+        "source_build": True,
+        "update_size_bytes": update_size_bytes,
+        "job": job,
+    }
+
+
+def _active_install_is_local_link(binary: Optional[str]) -> bool:
+    """True when the active whisper-server resolves through a locally-linked
+    whisper.cpp directory (see update_flow.active_install_is_local_link)."""
+    return _flow.active_install_is_local_link(binary, dir_name = "whisper.cpp")
+
+
+def _local_link_status() -> dict:
+    """Status payload for a local-link install: unmanaged, no update offered."""
+    return _flow.local_link_status(_job, _job_lock)
+
+
+def get_update_status(*, force_refresh: bool = False) -> dict:
+    """Report whether a newer prebuilt exists plus the current job state.
+
+    force_refresh bypasses the 24h release cache for an explicit "check now".
+    """
+    binary = _find_binary()
+    # A locally-linked whisper.cpp dir is the user's own tree; never offer to
+    # replace it. Bail before any network/freshness work.
+    if _active_install_is_local_link(binary):
+        return _local_link_status()
+    marker = read_install_marker(binary)
+
+    # No marker = source build / custom path. Offer the official prebuilt if one
+    # exists for this host.
+    if marker is None and binary is not None:
+        src = _source_build_status(binary, force_refresh = force_refresh)
+        if src is not None:
+            return src
+
+    repo = (marker or {}).get("published_repo") or DEFAULT_PUBLISHED_REPO
+
+    if force_refresh and repo:
+        # Prime the cache so the freshness read below sees the newest tag.
+        try:
+            latest_published_release(repo, force_refresh = True)
+        except Exception as exc:  # pragma: no cover - network defensive
+            logger.debug("whisper update: force refresh failed", error = str(exc))
+
+    freshness = check_prebuilt_freshness(binary)
+    installed = freshness.get("installed_tag")
+    latest = freshness.get("latest_tag")
+    compatible_override = False
+    if sys.platform == "darwin" and marker is not None:
+        # The newest published release may require a newer macOS. Ask the same
+        # host-aware resolver the installer uses so the banner compares against
+        # the newest release this host can actually install, avoiding a repeated
+        # offer of an incompatible release after walkback.
+        resolved = _resolve_prebuilt_for_host(
+            force_refresh = force_refresh,
+            backend = marker.get("backend") if isinstance(marker.get("backend"), str) else None,
+        )
+        compatible_latest = (resolved or {}).get("release_tag")
+        if (resolved or {}).get("prebuilt_available") and isinstance(compatible_latest, str):
+            compatible_override = compatible_latest != latest
+            latest = compatible_latest
+    # `behind` compares the release version with a downgrade guard, so a lagging
+    # /releases/latest or lower published tag can't show a false update
+    # (whisper_cpp_freshness.is_behind).
+    update_available = bool(
+        freshness.get("has_marker")
+        and (
+            is_behind(installed, latest)
+            if sys.platform == "darwin" and marker is not None
+            else freshness.get("behind")
+        )
+    )
+
+    # Size of the prebuilt Update would download, for the banner. Only when an
+    # update is offered; fails open to None (offline / no matching asset).
+    update_size_bytes = None
+    if update_available and not compatible_override:
+        try:
+            update_size_bytes = update_download_size_bytes(
+                marker,
+                latest,
+                freshness.get("published_repo") or repo,
+                force_refresh = force_refresh,
+            )
+        except Exception as exc:  # pragma: no cover - network defensive
+            logger.debug("whisper update: size lookup failed", error = str(exc))
+
+    with _job_lock:
+        job = dict(_job)
+
+    return {
+        "supported": bool(freshness.get("has_marker")),
+        "update_available": update_available,
+        "stale": bool(update_available and freshness.get("stale")),
+        "installed_tag": installed,
+        "latest_tag": latest,
+        "published_repo": freshness.get("published_repo") or repo,
+        "installed_at_utc": freshness.get("installed_at_utc"),
+        "age_days": freshness.get("age_days"),
+        "source_build": False,
+        "update_size_bytes": update_size_bytes,
+        "job": job,
+    }
+
+
+def _install_latest(
+    install_dir: Path,
+    repo: str,
+    asset: Optional[str],
+    backend: Optional[str],
+    script: Path,
+    set_progress,
+    pin_release_tag: Optional[str] = None,
+) -> dict:
+    """Replace whisper.cpp while the sidecar blocks every new load."""
+    try:
+        from core.inference.stt_ggml_sidecar import get_ggml_stt_sidecar
+        sidecar = get_ggml_stt_sidecar()
+    except Exception as exc:
+        # Replacing the tree without the singleton's maintenance barrier would
+        # reopen the Windows executable-lock and stale-process races. Fail closed.
+        raise RuntimeError("could not coordinate the whisper.cpp sidecar update") from exc
+
+    # update_maintenance publishes its guard before waiting for an existing
+    # transcription, unloads the warm server, and holds the sidecar lock across
+    # the complete atomic install. No new process can relock or outlive the tree.
+    with sidecar.update_maintenance() as model_was_active:
+        return _install_latest_while_blocked(
+            install_dir,
+            repo,
+            asset,
+            backend,
+            script,
+            set_progress,
+            pin_release_tag = pin_release_tag,
+            model_was_active = model_was_active,
+        )
+
+
+def _install_latest_while_blocked(
+    install_dir: Path,
+    repo: str,
+    asset: Optional[str],
+    backend: Optional[str],
+    script: Path,
+    set_progress,
+    *,
+    pin_release_tag: Optional[str],
+    model_was_active: bool,
+) -> dict:
+    """Run the installer with the sidecar already in update maintenance."""
+
+    cmd = [
+        sys.executable,
+        str(script),
+        "--install-dir",
+        str(install_dir),
+        "--whisper-tag",
+        "latest",
+        "--published-repo",
+        repo,
+    ]
+    # Preserve the installed accelerator across updates. Left unpinned the
+    # installer re-detects the host, fine on unchanged hardware but able to
+    # reroute a deliberate choice (e.g. cpu on a GPU box); forwarding the marker's
+    # backend keeps the same slice.
+    if isinstance(backend, str) and backend:
+        cmd.extend(["--backend", backend])
+    if pin_release_tag:
+        cmd.extend(["--published-release-tag", pin_release_tag])
+    cmd.extend(_rocm_install_args(asset))
+    logger.info("whisper update: installing", cmd = " ".join(cmd))
+    env = dict(os.environ, UNSLOTH_PROGRESS_PERCENT_STEP = "5")
+    # Every nonzero exit is a failed phase. In particular, exit 2 means the
+    # requested release was incompatible and no install happened, so reporting
+    # success would hide the banner and toast an update that never landed.
+    _flow.stream_installer(
+        cmd,
+        env,
+        set_progress = set_progress,
+        timeout_seconds = _INSTALL_TIMEOUT_SECONDS,
+    )
+
+    # Drop stale caches so the banner re-checks the swapped marker. If GitHub is
+    # offline, latest stays unknown and the banner fails open.
+    reset_caches(drop_disk = True)
+    try:
+        latest_published_release(repo, force_refresh = True)
+    except Exception as exc:  # pragma: no cover - network defensive
+        logger.debug("whisper update: post-install freshness refresh failed", error = str(exc))
+    new_marker = read_install_marker(_find_binary())
+    new_tag = (new_marker or {}).get("release_tag")
+    logger.info("whisper update: success", to_tag = new_tag)
+    return {
+        "to_tag": new_tag,
+        "reload_required": model_was_active,
+        "message": (
+            f"Updated whisper.cpp to {new_tag}."
+            + (" Reload your model to use it." if model_was_active else "")
+        ),
+    }
+
+
+def chained_phase_plan(
+    *, force_refresh: bool = False, paired_llama_will_update: bool = False
+) -> dict:
+    """Whisper's side of the combined llama+whisper update item.
+
+    Returns {status, update_available, skip_reason, phase}: `status` is the
+    marker-path status dict (or a minimal one when whisper is skipped),
+    `update_available` says the chained apply would run a whisper phase, and
+    `phase` carries what run_chained_phase needs. Only marker-managed installs are
+    chained: local links, source builds and unmanaged/pinned paths are silently
+    skipped so whisper can never block a llama update. Never raises; failures
+    degrade to a skip."""
+    binary = _find_binary()
+    if _active_install_is_local_link(binary):
+        return {
+            "status": _local_link_status(),
+            "update_available": False,
+            "skip_reason": "local_link",
+            "phase": None,
+        }
+    marker = read_install_marker(binary)
+    if marker is None:
+        # No marker: whisper is absent or a source/custom build. The standalone
+        # utils API can update source builds; the chain does not.
+        return {
+            "status": None,
+            "update_available": False,
+            "skip_reason": "source_build" if binary else "not_installed",
+            "phase": None,
+        }
+    status = get_update_status(force_refresh = force_refresh)
+    plan: dict = {"status": status, "update_available": False, "skip_reason": None, "phase": None}
+    if not status.get("update_available"):
+        # Skew note: when llama just updated but whisper is already latest, a slim
+        # install keeps hardlinks to the OLD llama ggml inodes -- still the exact
+        # build whisper was installed against, so skipping is correct and needs no
+        # re-wiring. A whisper phase that does run re-wires via the installer
+        # (prepare_runtime_payload).
+        plan["skip_reason"] = "up_to_date"
+        return plan
+    if marker.get("install_kind") == "slim" and not paired_llama_will_update:
+        # A slim install can only be refreshed from a completed managed llama
+        # prebuilt. Ask the installer through its read-only resolver so local
+        # links, markerless/current source builds, and incomplete managed trees
+        # never produce an Update button that can only fail. When the llama
+        # phase will run first, it supplies the repaired pairing instead.
+        resolved = _resolve_prebuilt_for_host(
+            force_refresh = force_refresh,
+            backend = marker.get("backend") if isinstance(marker.get("backend"), str) else None,
+        )
+        if not (resolved or {}).get("prebuilt_available"):
+            plan["skip_reason"] = "paired_llama_unavailable"
+            return plan
+    script = _installer_script()
+    if script is None:
+        plan["skip_reason"] = "installer_missing"
+        return plan
+    install_dir = _install_dir_for(binary)
+    if install_dir is None:
+        plan["skip_reason"] = "no_install_dir"
+        return plan
+    plan["update_available"] = True
+    plan["phase"] = {
+        "install_dir": install_dir,
+        "repo": marker.get("published_repo") or DEFAULT_PUBLISHED_REPO,
+        "asset": marker.get("asset"),
+        "backend": marker.get("backend"),
+        "script": script,
+        # Install exactly the release the check offered: the installer's unpinned
+        # "latest" prefers the download-host /releases/latest pointer, which sorts
+        # by commit date and can lag the published_at pick the freshness check
+        # used, reinstalling an older build in a loop (the #6219 class the llama
+        # phase pins against). Not on macOS: the llama phase is unpinned there
+        # (walk-back to an os-compatible release), so pinning whisper to the
+        # newest tag could be an impossible pairing (min_os / requires_llama_tag)
+        # on every retry.
+        "pin_release_tag": None if sys.platform == "darwin" else status.get("latest_tag"),
+    }
+    return plan
+
+
+def run_chained_phase(phase: dict, set_progress) -> dict:
+    """Run the whisper phase of a combined update (spec from chained_phase_plan):
+    same unload/install/cache-refresh path as the standalone job, reporting
+    progress through the chained job's window rather than whisper's own."""
+    return _install_latest(
+        phase["install_dir"],
+        phase["repo"],
+        phase["asset"],
+        phase["backend"],
+        phase["script"],
+        set_progress,
+        pin_release_tag = phase.get("pin_release_tag"),
+    )
diff --git a/studio/frontend/.npmrc b/studio/frontend/.npmrc
index 19783b5ff4..414379da6e 100644
--- a/studio/frontend/.npmrc
+++ b/studio/frontend/.npmrc
@@ -1,4 +1,4 @@
-# Studio frontend npm configuration.
+# Unsloth frontend npm configuration.
 #
 # Mini Shai-Hulud / Axios-style supply chain defense.
 # Requires npm >=11.10.0. Refuses tarballs published less than 7 days ago,
diff --git a/studio/frontend/src/app/auth-guards.ts b/studio/frontend/src/app/auth-guards.ts
index 6849f380b8..a3523ac580 100644
--- a/studio/frontend/src/app/auth-guards.ts
+++ b/studio/frontend/src/app/auth-guards.ts
@@ -23,19 +23,47 @@ interface AuthStatus {
   requires_password_change: boolean;
 }
 
+const AUTH_STATUS_TTL_MS = 30_000;
+let authStatusCheckedAt = 0;
+let authStatusRequest: Promise<AuthStatus> | null = null;
+
+function hasFreshAuthStatus(): boolean {
+  return (
+    authStatusCheckedAt !== 0 &&
+    Date.now() - authStatusCheckedAt < AUTH_STATUS_TTL_MS
+  );
+}
+
 async function fetchAuthStatus(): Promise<AuthStatus> {
-  try {
-    const res = await fetch(apiUrl("/api/auth/status"));
-    if (!res.ok) return { initialized: true, requires_password_change: mustChangePassword() };
-    const status = (await res.json()) as AuthStatus;
-    // Server truth wins; keep localStorage in sync both ways.
-    if (status.requires_password_change !== mustChangePassword()) {
-      setMustChangePassword(status.requires_password_change);
+  if (authStatusRequest) return authStatusRequest;
+
+  const request = (async () => {
+    try {
+      const res = await fetch(apiUrl("/api/auth/status"));
+      if (!res.ok) {
+        return {
+          initialized: true,
+          requires_password_change: mustChangePassword(),
+        };
+      }
+      const status = (await res.json()) as AuthStatus;
+      authStatusCheckedAt = Date.now();
+      // Server truth wins; keep localStorage in sync both ways.
+      if (status.requires_password_change !== mustChangePassword()) {
+        setMustChangePassword(status.requires_password_change);
+      }
+      return status;
+    } catch {
+      return {
+        initialized: true,
+        requires_password_change: mustChangePassword(),
+      };
     }
-    return status;
-  } catch {
-    return { initialized: true, requires_password_change: mustChangePassword() };
-  }
+  })().finally(() => {
+    authStatusRequest = null;
+  });
+  authStatusRequest = request;
+  return request;
 }
 
 function authRedirect(to: "/login" | "/change-password"): never {
@@ -49,12 +77,17 @@ export async function requireAuth(): Promise<void> {
   }
 
   if (await hasActiveSession()) {
-    const { requires_password_change } = await fetchAuthStatus();
-    if (requires_password_change || mustChangePassword()) {
-      authRedirect("/change-password");
+    // Reconcile periodically so local-only routes cannot outlive a server-side
+    // password-change requirement, while nearby route switches stay local.
+    if (mustChangePassword() || !hasFreshAuthStatus()) {
+      const { requires_password_change } = await fetchAuthStatus();
+      if (requires_password_change || mustChangePassword()) {
+        authRedirect("/change-password");
+      }
     }
     return;
   }
+
   const status = await fetchAuthStatus();
   if (status.requires_password_change || mustChangePassword()) {
     authRedirect("/change-password");
diff --git a/studio/frontend/src/app/provider.tsx b/studio/frontend/src/app/provider.tsx
index c35706e50a..e6c89b9cd7 100644
--- a/studio/frontend/src/app/provider.tsx
+++ b/studio/frontend/src/app/provider.tsx
@@ -51,9 +51,12 @@ async function showSetupWindow(isCurrent: WindowLayoutGuard): Promise<void> {
   const { getCurrentWindow, LogicalSize } = await import(
     "@tauri-apps/api/window"
   );
+  const { invoke } = await import("@tauri-apps/api/core");
   if (!isCurrent()) return;
 
   const win = getCurrentWindow();
+  await invoke("reset_app_window_layout_initialized");
+  if (!isCurrent()) return;
   await win.setResizable(false);
   if (!isCurrent()) return;
   await win.setSize(new LogicalSize(SETUP_WINDOW_WIDTH, SETUP_WINDOW_HEIGHT));
@@ -98,18 +101,20 @@ async function applyAppWindowLayout(
   if (!isCurrent()) return;
 
   const win = getCurrentWindow();
-  // Decide first-launch vs restore from the on-disk state file BEFORE touching the
-  // window. Probing the window after restoreStateCurrent is unreliable: on GTK,
-  // set_size on a hidden window is deferred until show(), so innerSize() reads a
-  // stale value and a baseline fallback would overwrite the queued restore. On
-  // macOS the same probe works, hence the inconsistency between prior iterations.
-  const hasSavedState = await invoke<boolean>("has_saved_window_state");
+  // Setup-window activity may create plugin state before the full app is ever
+  // shown, so use a dedicated full-app marker to decide whether restoration is
+  // appropriate. Keep checking plugin state so a missing/corrupt state file
+  // falls back to a monitor-safe centered layout.
+  const [hasInitializedAppLayout, hasSavedState] = await Promise.all([
+    invoke<boolean>("has_initialized_app_window_layout"),
+    invoke<boolean>("has_saved_window_state"),
+  ]);
   if (!isCurrent()) return;
 
   await win.setResizable(true);
   if (!isCurrent()) return;
 
-  if (hasSavedState) {
+  if (hasInitializedAppLayout && hasSavedState) {
     // Subsequent launch: plugin restores size/position/maximized, with built-in
     // off-screen protection for positions saved on a now-disconnected display.
     await restoreStateCurrent(
@@ -144,6 +149,9 @@ async function applyAppWindowLayout(
   });
   if (!isCurrent()) return;
   await enforceMinimumWindowSize(win, LogicalSize, isCurrent);
+
+  if (!isCurrent()) return;
+  await invoke("mark_app_window_layout_initialized");
 }
 
 async function showWindowFallback(): Promise<void> {
@@ -412,7 +420,7 @@ function TauriWrapper({ children }: { children: ReactNode }) {
       {desktopBooting ? (
         <div className="pointer-events-none fixed inset-x-0 bottom-5 z-[9999] flex justify-center px-4">
           <div className="absolute inset-x-4 bottom-16 mx-auto flex max-w-[520px] flex-col items-center gap-2 rounded-2xl border border-border/70 bg-background/95 px-6 py-5 text-center shadow-xl">
-            <div className="font-medium text-sm">Preparing Studio</div>
+            <div className="font-medium text-sm">Preparing Unsloth</div>
             <div className="text-muted-foreground text-xs">
               The local backend is ready. Signing in to your desktop session
               before loading chats.
diff --git a/studio/frontend/src/app/routes/__root.tsx b/studio/frontend/src/app/routes/__root.tsx
index ba56ce7525..7137fd6f96 100644
--- a/studio/frontend/src/app/routes/__root.tsx
+++ b/studio/frontend/src/app/routes/__root.tsx
@@ -16,6 +16,7 @@ import {
   type ChatSearch,
 } from "@/features/chat";
 import { RemoteCodeConsentDialog } from "@/features/security";
+import { HfTokenWarningDialog } from "@/features/hf-auth";
 import { TransformersUpgradeDialog } from "@/features/transformers-upgrade";
 import { useTrainingUnloadGuard } from "@/features/training";
 import { useExportRuntimeLifecycle } from "@/features/export";
@@ -195,9 +196,6 @@ function RootLayout() {
         chatRuntime.setActiveThreadId(null);
         chatRuntime.setActiveProjectId(null);
         chatRuntime.setIncognito(false);
-        // Detach the staging UI but keep any in-flight download running, like Hub.
-        if (chatRuntime.pendingSelection)
-          chatRuntime.abandonStagedModel({ keepDownload: true });
         void navigate({
           to: "/chat",
           search: { new: crypto.randomUUID() },
@@ -220,16 +218,13 @@ function RootLayout() {
     chatRuntime.setActiveProjectId(null);
     chatRuntime.setActiveThreadId(null);
     chatRuntime.setIncognito(false);
-    // Leaving chat must not kill an in-flight download: detach the staging UI
-    // but keep the transfer running in the manager, like a Hub download.
-    if (chatRuntime.pendingSelection)
-      chatRuntime.abandonStagedModel({ keepDownload: true });
   }, [isChatRoute]);
 
   return (
     <AppProvider>
       <PersonalizationSyncMount />
       {!isAuthFlowRoute && <SettingsDialog />}
+      <HfTokenWarningDialog />
       <RemoteCodeConsentDialog />
       <TransformersUpgradeDialog />
       {hideNavbar ? (
@@ -279,7 +274,7 @@ function RootLayout() {
                     initial={{ opacity: 0 }}
                     animate={{ opacity: 1 }}
                     exit={{ opacity: 0 }}
-                    transition={{ duration: 0.15 }}
+                    transition={{ duration: 0.06 }}
                     className="flex min-h-0 min-w-0 flex-1 basis-0 flex-col overflow-visible"
                   >
                     <Suspense fallback={<RouteFallback />}>
diff --git a/studio/frontend/src/app/routes/data-recipes.tsx b/studio/frontend/src/app/routes/data-recipes.tsx
index c35e63da5f..22f87821af 100644
--- a/studio/frontend/src/app/routes/data-recipes.tsx
+++ b/studio/frontend/src/app/routes/data-recipes.tsx
@@ -1,15 +1,13 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { createRoute } from "@tanstack/react-router";
-import { lazy } from "react";
+import { createRoute, lazyRouteComponent } from "@tanstack/react-router";
 import { requireAuth } from "../auth-guards";
 import { Route as rootRoute } from "./__root";
 
-const DataRecipesPage = lazy(() =>
-  import("@/features/data-recipes").then((m) => ({
-    default: m.DataRecipesPage,
-  })),
+const DataRecipesPage = lazyRouteComponent(
+  () => import("@/features/data-recipes"),
+  "DataRecipesPage",
 );
 
 export const Route = createRoute({
diff --git a/studio/frontend/src/app/routes/export.tsx b/studio/frontend/src/app/routes/export.tsx
index 40118c6a92..5a7b586f19 100644
--- a/studio/frontend/src/app/routes/export.tsx
+++ b/studio/frontend/src/app/routes/export.tsx
@@ -1,15 +1,13 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { createRoute } from "@tanstack/react-router";
-import { lazy } from "react";
+import { createRoute, lazyRouteComponent } from "@tanstack/react-router";
 import { requireAuth } from "../auth-guards";
 import { Route as rootRoute } from "./__root";
 
-const ExportPage = lazy(() =>
-  import("@/features/export/export-page").then((m) => ({
-    default: m.ExportPage,
-  })),
+const ExportPage = lazyRouteComponent(
+  () => import("@/features/export/export-page"),
+  "ExportPage",
 );
 
 export type ExportSearch = {
diff --git a/studio/frontend/src/app/routes/hub.tsx b/studio/frontend/src/app/routes/hub.tsx
index c623ef9848..2207490e44 100644
--- a/studio/frontend/src/app/routes/hub.tsx
+++ b/studio/frontend/src/app/routes/hub.tsx
@@ -1,15 +1,13 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { createRoute } from "@tanstack/react-router";
-import { lazy } from "react";
+import { createRoute, lazyRouteComponent } from "@tanstack/react-router";
 import { requireAuth } from "../auth-guards";
 import { Route as rootRoute } from "./__root";
 
-const ModelsPage = lazy(() =>
-  import("@/features/hub/hub-page").then((m) => ({
-    default: m.ModelsPage,
-  })),
+const ModelsPage = lazyRouteComponent(
+  () => import("@/features/hub/hub-page"),
+  "ModelsPage",
 );
 
 export interface ModelsSearch {
@@ -31,7 +29,11 @@ export const Route = createRoute({
     const model = search.model;
     if (typeof model === "string" && model.length > 0) next.model = model;
     const section = search.section;
-    if (section === "trending" || section === "latest" || section === "finetune") {
+    if (
+      section === "trending" ||
+      section === "latest" ||
+      section === "finetune"
+    ) {
       next.section = section;
     }
     const kind = search.kind;
diff --git a/studio/frontend/src/app/routes/projects.tsx b/studio/frontend/src/app/routes/projects.tsx
index c63b1d5838..17f58ef631 100644
--- a/studio/frontend/src/app/routes/projects.tsx
+++ b/studio/frontend/src/app/routes/projects.tsx
@@ -1,15 +1,13 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { createRoute } from "@tanstack/react-router";
-import { lazy } from "react";
+import { createRoute, lazyRouteComponent } from "@tanstack/react-router";
 import { requireAuth } from "../auth-guards";
 import { Route as rootRoute } from "./__root";
 
-const ProjectsPage = lazy(() =>
-  import("@/features/chat/projects-page").then((m) => ({
-    default: m.ProjectsPage,
-  })),
+const ProjectsPage = lazyRouteComponent(
+  () => import("@/features/chat/projects-page"),
+  "ProjectsPage",
 );
 
 export const Route = createRoute({
diff --git a/studio/frontend/src/app/routes/studio.tsx b/studio/frontend/src/app/routes/studio.tsx
index ae7f445e94..798044bf64 100644
--- a/studio/frontend/src/app/routes/studio.tsx
+++ b/studio/frontend/src/app/routes/studio.tsx
@@ -1,15 +1,13 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { createRoute } from "@tanstack/react-router";
-import { lazy } from "react";
+import { createRoute, lazyRouteComponent } from "@tanstack/react-router";
 import { requireAuth } from "../auth-guards";
 import { Route as rootRoute } from "./__root";
 
-const StudioPage = lazy(() =>
-  import("@/features/studio/studio-page").then((m) => ({
-    default: m.StudioPage,
-  })),
+const StudioPage = lazyRouteComponent(
+  () => import("@/features/studio/studio-page"),
+  "StudioPage",
 );
 
 export const Route = createRoute({
diff --git a/studio/frontend/src/components/app-sidebar.tsx b/studio/frontend/src/components/app-sidebar.tsx
index b6e218793a..c95112c748 100644
--- a/studio/frontend/src/components/app-sidebar.tsx
+++ b/studio/frontend/src/components/app-sidebar.tsx
@@ -45,6 +45,7 @@ import { Spinner } from "@/components/ui/spinner";
 import { Switch } from "@/components/ui/switch";
 import { useAnimatedThemeToggle } from "@/components/ui/animated-theme-toggler";
 import {
+  getClientPlatform,
   shouldUseCustomWindowTitlebar,
   shouldUseNativeMacWindowTitlebar,
 } from "@/components/tauri/window-titlebar";
@@ -55,6 +56,7 @@ import {
   Archive03Icon,
   ArrowRight02Icon,
   BadgeInfoIcon,
+  BubbleChatIcon,
   ChefHatIcon,
   CloudIcon,
   CpuIcon,
@@ -93,7 +95,12 @@ import {
 import { Tooltip as TooltipPrimitive } from "radix-ui";
 import { HugeiconsIcon } from "@hugeicons/react";
 import { ChevronDown, Moon } from "lucide-react";
-import { Link, useNavigate, useRouterState } from "@tanstack/react-router";
+import {
+  Link,
+  useNavigate,
+  useRouter,
+  useRouterState,
+} from "@tanstack/react-router";
 import {
   archiveChatItem,
   ChatSearchDialog,
@@ -103,6 +110,7 @@ import {
   deleteChatItem,
   listStoredChatThreads,
   moveChatItemToProject,
+  notifyChatHistoryUpdated,
   renameChatItem,
   renameChatProject,
   useChatRuntimeStore,
@@ -110,6 +118,7 @@ import {
   useChatSearchStore,
   useChatSidebarItems,
   usePinnedChatsStore,
+  usePinnedProjectsStore,
   useChatPreferencesStore,
   type ProjectRecord,
   type SidebarItem,
@@ -135,7 +144,15 @@ import {
 } from "@/features/training";
 import type { TrainingRunSummary } from "@/features/training";
 import { useExportRuntimeStore } from "@/features/export";
-import { useEffect, useMemo, useRef, useState, type ReactNode } from "react";
+import {
+  Fragment,
+  useEffect,
+  useMemo,
+  useRef,
+  useState,
+  type ReactNode,
+} from "react";
+import { isDownloadCancelled } from "@/lib/native-files";
 import { toast } from "@/lib/toast";
 import { ShutdownDialog } from "@/components/shutdown-dialog";
 import { translate, useT, type TranslationKey } from "@/i18n";
@@ -193,6 +210,9 @@ const TestTubeOutlineIcon = TestTube01Icon.slice(
 
 type ConversationExportFormat = "raw-jsonl" | "csv" | "sharegpt-jsonl";
 
+// A pinned project shows this many recent chats before "Show more".
+const PINNED_PROJECT_CHAT_LIMIT = 4;
+
 const CHAT_EXPORT_OPTIONS: Array<{
   label: string;
   format: ConversationExportFormat;
@@ -256,6 +276,10 @@ function createNavigationNonce(): string {
   return `${Date.now()}-${Math.random().toString(36).slice(2, 10)}`;
 }
 
+function preloadSilently(request: Promise<unknown>): void {
+  void request.catch(() => undefined);
+}
+
 function NavItem({
   icon,
   label,
@@ -267,6 +291,7 @@ function NavItem({
   className,
   spinner,
   tooltip,
+  onIntent,
 }: {
   icon: typeof ZapIcon;
   label: string;
@@ -277,6 +302,7 @@ function NavItem({
   dataTour?: string;
   className?: string;
   spinner?: boolean;
+  onIntent?: () => void;
   // Overrides the hover tooltip (defaults to `label`). Used to explain why a
   // disabled item (e.g. Train/Export on a chat-only host) is greyed out.
   tooltip?: string;
@@ -288,12 +314,14 @@ function NavItem({
           tooltip={tooltip ?? label}
           disabled={disabled}
           onClick={onClick}
+          onPointerEnter={disabled ? undefined : onIntent}
+          onFocus={disabled ? undefined : onIntent}
           isActive={active}
           data-tour={dataTour}
           className="sidebar-nav-btn h-[33px] rounded-full gap-[8.5px] pl-3 pr-2.5 font-medium group-data-[collapsible=icon]:px-2.5 group-data-[collapsible=icon]:!w-[32px] group-data-[collapsible=icon]:mx-auto"
         >
           <HugeiconsIcon icon={icon} strokeWidth={1.75} className="size-icon! shrink-0 group-hover/menu-button:animate-icon-pop" />
-          <span className="text-[14.5px] leading-[19px] tracking-nav">{label}</span>
+          <span className="text-ui-14p5 leading-ui-19 tracking-nav">{label}</span>
           {spinner && (
             <Spinner className="ml-auto size-3.5 shrink-0 text-muted-foreground group-data-[collapsible=icon]:hidden" />
           )}
@@ -316,6 +344,8 @@ export function AppSidebar() {
   );
   const [usesCustomTitlebar] = useState(shouldUseCustomWindowTitlebar);
   const [usesNativeMacTitlebar] = useState(shouldUseNativeMacWindowTitlebar);
+  // Mac uses Cmd, others use Ctrl. Not Tauri-gated, so it's right on web too.
+  const [isMacPlatform] = useState(() => getClientPlatform().includes("mac"));
   const { pathname, search } = useRouterState({
     select: (s) => ({
       pathname: s.location.pathname,
@@ -324,6 +354,7 @@ export function AppSidebar() {
   });
   const { togglePinned, isMobile, setOpenMobile } = useSidebar();
   const navigate = useNavigate();
+  const router = useRouter();
 
   // Web update detection: `webUpdate` is non-null only when the installed
   // (PyPI) version is behind the latest release, so the card is hidden by
@@ -430,14 +461,63 @@ export function AppSidebar() {
       ),
     [allChatItems, pinnedIdSet],
   );
-  // Pinned chats, in pin order (most recent first).
+  const [pinnedOpen, setPinnedOpen] = useState(true);
+  // "Projects" section: projects the user pinned, in pin order (most recent
+  // first). The section only appears once at least one project is pinned.
+  const pinnedProjectIds = usePinnedProjectsStore((s) => s.pinnedIds);
+  const unpinProject = usePinnedProjectsStore((s) => s.unpin);
+  const pinnedProjectRecords = useMemo(() => {
+    const byId = new Map(projects.map((p) => [p.id, p]));
+    return pinnedProjectIds
+      .map((id) => byId.get(id))
+      .filter((p): p is ProjectRecord => Boolean(p));
+  }, [projects, pinnedProjectIds]);
+  // Pinned chats, in pin order (most recent first). Includes chats that live
+  // inside a project: pinning promotes a chat into this list, and it is removed
+  // from the project's nested list below so it never shows twice.
   const pinnedChatItems = useMemo(() => {
     const byId = new Map(allChatItems.map((item) => [item.id, item]));
     return pinnedIds
       .map((id) => byId.get(id))
       .filter((item): item is SidebarItem => Boolean(item));
   }, [allChatItems, pinnedIds]);
-  const [pinnedOpen, setPinnedOpen] = useState(true);
+  // A pinned project reveals its recent chats (most recent first) nested below.
+  // Pinned chats are excluded here since they render in the pinned-chats list.
+  const chatsByProjectId = useMemo(() => {
+    const map = new Map<string, SidebarItem[]>();
+    for (const item of allChatItems) {
+      if (!item.projectId) continue;
+      if (pinnedIdSet.has(item.id)) continue;
+      const list = map.get(item.projectId);
+      if (list) list.push(item);
+      else map.set(item.projectId, [item]);
+    }
+    for (const list of map.values())
+      list.sort((a, b) => b.updatedAt - a.updatedAt);
+    return map;
+  }, [allChatItems, pinnedIdSet]);
+  // Default expanded (not collapsed); the row toggles this. Show-more reveals
+  // chats past the first PINNED_PROJECT_CHAT_LIMIT.
+  const [collapsedProjectIds, setCollapsedProjectIds] = useState<Set<string>>(
+    () => new Set(),
+  );
+  const [expandedChatProjectIds, setExpandedChatProjectIds] = useState<
+    Set<string>
+  >(() => new Set());
+  const toggleProjectCollapsed = (id: string) =>
+    setCollapsedProjectIds((prev) => {
+      const next = new Set(prev);
+      if (next.has(id)) next.delete(id);
+      else next.add(id);
+      return next;
+    });
+  const toggleProjectShowAll = (id: string) =>
+    setExpandedChatProjectIds((prev) => {
+      const next = new Set(prev);
+      if (next.has(id)) next.delete(id);
+      else next.add(id);
+      return next;
+    });
   const storeThreadId = useChatRuntimeStore((s) => s.activeThreadId);
   const setActiveThreadId = useChatRuntimeStore((s) => s.setActiveThreadId);
   const anyChatRunning = useChatRuntimeStore((s) =>
@@ -717,6 +797,8 @@ export function AppSidebar() {
     const shouldDeleteProjectFiles =
       target.kind === "project" && deleteProjectFiles;
     setConfirmingDelete(null);
+    // Reset so the next project delete never inherits this checkbox.
+    setDeleteProjectFiles(false);
     if (target.kind === "chat") {
       await deleteChatWithCleanup(target.item);
       return;
@@ -726,7 +808,20 @@ export function AppSidebar() {
         await deleteChatProject(target.project.id, {
           deleteFiles: shouldDeleteProjectFiles,
         });
-        if (activeProjectId === target.project.id) {
+        // Refresh chat history so the project's reparented chats don't linger
+        // as stale top-level rows.
+        notifyChatHistoryUpdated();
+        // activeProjectId is only the ?project= param; on a thread-only URL the
+        // project is resolved from the thread into the runtime store, so check
+        // that too or we strand the user on a now-deleted thread. Only redirect
+        // from a chat route: the runtime store value can be stale elsewhere.
+        const runtimeProjectId =
+          useChatRuntimeStore.getState().activeProjectId;
+        if (
+          isChatRoute &&
+          (activeProjectId === target.project.id ||
+            runtimeProjectId === target.project.id)
+        ) {
           useChatRuntimeStore.getState().setActiveProjectId(null);
           navigate({ to: "/chat", search: { new: createNavigationNonce() } });
         }
@@ -806,21 +901,25 @@ export function AppSidebar() {
         : "group/recent-item relative";
     const actionClass =
       variant === "project"
-        ? "sidebar-row-action group-hover/project-chat-item:opacity-100 group-hover/project-chat-item:pointer-events-auto focus-visible:opacity-100 focus-visible:pointer-events-auto"
-        : "sidebar-row-action group-hover/recent-item:opacity-100 group-hover/recent-item:pointer-events-auto focus-visible:opacity-100 focus-visible:pointer-events-auto";
+        ? "sidebar-row-action sidebar-touch-reveal group-hover/project-chat-item:opacity-100 group-hover/project-chat-item:pointer-events-auto focus-visible:opacity-100 focus-visible:pointer-events-auto"
+        : "sidebar-row-action sidebar-touch-reveal group-hover/recent-item:opacity-100 group-hover/recent-item:pointer-events-auto focus-visible:opacity-100 focus-visible:pointer-events-auto";
     const buttonClass = cn(
-      "sidebar-nav-btn h-[33px] cursor-pointer rounded-full pr-4 text-[14.5px] leading-[19px] tracking-nav font-medium",
+      "sidebar-nav-btn h-[33px] cursor-pointer rounded-full pr-4 text-ui-14p5 leading-ui-19 tracking-nav font-medium",
       // pl-3 (12px) over the content's pl-1.5 (6px) = 18px, aligning the
       // title with the nav items above.
       variant === "project" ? "pl-[39px]" : "pl-3",
+      // Pinned chats carry a chat icon, so add the nav-item icon gap.
+      isPinned && variant !== "project" && "gap-[8.5px]",
       variant === "project"
-        ? "group-hover/project-chat-item:pr-6 group-has-[.sidebar-row-action[data-state=open]]/project-chat-item:pr-6"
+        ? // Room for the hover pin quick-action plus the kebab.
+          "group-hover/project-chat-item:pr-14 group-has-[.sidebar-row-action[data-state=open]]/project-chat-item:pr-8 [@media(pointer:coarse)]:pr-14"
         : isPinned
           ? // Pinned rows show an extra unpin button on hover, so reserve more room
             // (pr-8 when the menu is open keeps the unpin button clear of the title).
-            "group-hover/recent-item:pr-16 group-has-[.sidebar-row-action[data-state=open]]/recent-item:pr-8"
+            "group-hover/recent-item:pr-16 group-has-[.sidebar-row-action[data-state=open]]/recent-item:pr-8 [@media(pointer:coarse)]:pr-16"
           : // Hover room for the kebab only; title keeps one more character.
-            "group-hover/recent-item:pr-6 group-has-[.sidebar-row-action[data-state=open]]/recent-item:pr-6",
+            // Touch rows clear the full always-visible kebab hit area (pr-10).
+            "group-hover/recent-item:pr-6 group-has-[.sidebar-row-action[data-state=open]]/recent-item:pr-6 [@media(pointer:coarse)]:pr-10",
     );
 
     const isRenamingThis =
@@ -841,7 +940,7 @@ export function AppSidebar() {
             aria-label={translate("shell.dialog.renameChat.placeholder")}
             className={cn(
               // No pill or box; edit in place as plain highlighted text.
-              "text-foreground h-[33px] w-full border-0 bg-transparent pr-4 text-[14.5px] leading-[19px] font-medium tracking-nav outline-none",
+              "text-foreground h-[33px] w-full border-0 bg-transparent pr-4 text-ui-14p5 leading-ui-19 font-medium tracking-nav outline-none",
               variant === "project" ? "pl-[39px]" : "pl-3",
             )}
           />
@@ -874,10 +973,43 @@ export function AppSidebar() {
             closeMobileIfOpen();
           }}
         >
+          {isPinned && variant !== "project" && (
+            <HugeiconsIcon icon={BubbleChatIcon} strokeWidth={1.75} className="size-icon! shrink-0" />
+          )}
           <span className="truncate">
             {pendingRename?.id === item.id ? pendingRename.title : item.title}
           </span>
         </SidebarMenuButton>
+        {variant === "project" && (
+          <button
+            type="button"
+            onClick={(e) => {
+              e.stopPropagation();
+              togglePinnedChat(item.id);
+            }}
+            aria-label={isPinned ? "Unpin chat" : "Pin chat"}
+            className="sidebar-row-action sidebar-touch-reveal is-unpin-action group-hover/project-chat-item:opacity-100 group-hover/project-chat-item:pointer-events-auto focus-visible:opacity-100 focus-visible:pointer-events-auto"
+          >
+            <span className="sidebar-row-action-glyph">
+              <HugeiconsIcon icon={isPinned ? PinOffIcon : PinIcon} strokeWidth={1.75} className="size-icon" />
+            </span>
+          </button>
+        )}
+        {variant === "recent" && isPinned && (
+          <button
+            type="button"
+            onClick={(e) => {
+              e.stopPropagation();
+              togglePinnedChat(item.id);
+            }}
+            aria-label="Unpin chat"
+            className="sidebar-row-action sidebar-touch-reveal is-unpin-action group-hover/recent-item:opacity-100 group-hover/recent-item:pointer-events-auto focus-visible:opacity-100 focus-visible:pointer-events-auto"
+          >
+            <span className="sidebar-row-action-glyph">
+              <HugeiconsIcon icon={PinOffIcon} strokeWidth={1.75} className="size-icon" />
+            </span>
+          </button>
+        )}
         <DropdownMenu>
           <DropdownMenuTrigger asChild>
             <button
@@ -957,11 +1089,13 @@ export function AppSidebar() {
                         const ids = item.type === "single"
                           ? [item.id]
                           : (await listStoredChatThreads({ pairId: item.id })).map((t) => t.id);
-                        await Promise.all(
-                          ids.map((id) => exportConversationByFormat(id, format)),
-                        );
-                      } catch {
-                        toast.error("Export failed.");
+                        for (const id of ids) {
+                          await exportConversationByFormat(id, format);
+                        }
+                      } catch (error) {
+                        if (!isDownloadCancelled(error)) {
+                          toast.error("Export failed.");
+                        }
                       }
                     }}
                   >
@@ -969,10 +1103,10 @@ export function AppSidebar() {
                   </DropdownMenuItem>
                 ))}
                 <DropdownMenuSeparator />
-                {/* Bulk export and import live in Settings -> Chat -> Data. */}
+                {/* Bulk export and import live in Settings -> Data. */}
                 <DropdownMenuItem
                   onSelect={() =>
-                    useSettingsDialogStore.getState().openDialog("chat")
+                    useSettingsDialogStore.getState().openDialog("data")
                   }
                 >
                   Export all chats…
@@ -997,28 +1131,6 @@ export function AppSidebar() {
             </DropdownMenuItem>
           </DropdownMenuContent>
         </DropdownMenu>
-        {isPinned ? (
-          <Tooltip>
-            <TooltipPrimitive.Trigger asChild>
-              <button
-                type="button"
-                onClick={(e) => {
-                  e.stopPropagation();
-                  unpinChat(item.id);
-                }}
-                aria-label="Unpin chat"
-                className={cn(actionClass, "is-unpin-action")}
-              >
-                <span className="sidebar-row-action-glyph">
-                  <HugeiconsIcon icon={PinOffIcon} strokeWidth={1.75} className="size-4" />
-                </span>
-              </button>
-            </TooltipPrimitive.Trigger>
-            <TooltipContent side="bottom" sideOffset={6} className="tooltip-compact">
-              Unpin
-            </TooltipContent>
-          </Tooltip>
-        ) : null}
       </SidebarMenuItem>
     );
   }
@@ -1073,40 +1185,70 @@ export function AppSidebar() {
                   aria-disabled={chatDisabled}
                   tabIndex={chatDisabled ? -1 : undefined}
                 >
+                  {/* Logo lockup follows the UI font size at half rate:
+                      base + (root scale - 1) * 8px. Exact base sizes at 16px. */}
                   <img
                     src="/circle-logo-small.png"
                     alt="Unsloth"
-                    className="h-[34px] w-[34px] rounded-full object-cover"
+                    className="h-[calc(26px+0.5rem*var(--ui-font-scale,1))] w-[calc(26px+0.5rem*var(--ui-font-scale,1))] rounded-full object-cover"
                   />
-                  <span className="font-heading text-[21px] font-semibold tracking-[0em] leading-none text-black dark:text-white dark:tracking-[0.02em]">
+                  <span className="font-heading text-[calc(13px+0.5rem*var(--ui-font-scale,1))] font-semibold tracking-[0em] leading-none text-black dark:text-white dark:tracking-[0.02em]">
                     unsloth
                   </span>
-                  <span className="nav-badge ml-0.5 inline-flex items-center justify-center rounded-full border border-nav-beta-border px-[5px] pt-[3px] pb-[2px] text-[8px] font-medium leading-none tracking-[0.04em] text-nav-fg-muted antialiased subpixel-antialiased shadow-[0_1px_2px_rgba(0,0,0,0.06)] dark:shadow-[0_1px_2px_rgba(0,0,0,0.35)]">
+                  <span className="nav-badge ml-0.5 inline-flex items-center justify-center rounded-full border border-nav-beta-border px-[5px] pt-[3px] pb-[2px] text-[calc(0.5rem*var(--ui-font-scale,1))] font-medium leading-none tracking-[0.04em] text-nav-fg-muted antialiased subpixel-antialiased shadow-[0_1px_2px_rgba(0,0,0,0.06)] dark:shadow-[0_1px_2px_rgba(0,0,0,0.35)]">
                     {t("shell.beta")}
                   </span>
                 </Link>
               )}
-              {!isMobile && (
+              <div className="flex items-center gap-0.5">
                 <Tooltip>
                   <TooltipPrimitive.Trigger asChild>
                     <button
                       type="button"
-                      onClick={togglePinned}
+                      onClick={() => {
+                        useChatSearchStore.getState().open();
+                        closeMobileIfOpen();
+                      }}
                       className="inline-flex h-[33px] w-[32px] cursor-pointer items-center justify-center rounded-[10px] text-nav-icon-idle dark:text-nav-fg-muted transition-colors hover:bg-nav-surface-hover hover:text-black dark:hover:text-white focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
-                      aria-label={t("shell.aria.closeSidebar")}
+                      aria-label={t("shell.navigation.search")}
                     >
-                      <HugeiconsIcon icon={LayoutAlignLeftIcon} strokeWidth={1.75} className="size-icon" />
+                      <HugeiconsIcon icon={Search01Icon} strokeWidth={1.75} className="size-icon" />
                     </button>
                   </TooltipPrimitive.Trigger>
                   <TooltipContent
                     side="bottom"
                     sideOffset={6}
-                    className="tooltip-compact"
+                    className="tooltip-compact flex items-center gap-1.5"
+                    hidden={isMobile}
                   >
-                    {t("shell.aria.closeSidebar")}
+                    {t("shell.navigation.search")}
+                    <kbd className="rounded bg-black/10 px-1 py-px text-ui-10 font-medium leading-none dark:bg-white/15">
+                      {isMacPlatform ? "⌘K" : "Ctrl+K"}
+                    </kbd>
                   </TooltipContent>
                 </Tooltip>
-              )}
+                {!isMobile && (
+                  <Tooltip>
+                    <TooltipPrimitive.Trigger asChild>
+                      <button
+                        type="button"
+                        onClick={togglePinned}
+                        className="inline-flex h-[33px] w-[32px] cursor-pointer items-center justify-center rounded-[10px] text-nav-icon-idle dark:text-nav-fg-muted transition-colors hover:bg-nav-surface-hover hover:text-black dark:hover:text-white focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
+                        aria-label={t("shell.aria.closeSidebar")}
+                      >
+                        <HugeiconsIcon icon={LayoutAlignLeftIcon} strokeWidth={1.75} className="size-icon" />
+                      </button>
+                    </TooltipPrimitive.Trigger>
+                    <TooltipContent
+                      side="bottom"
+                      sideOffset={6}
+                      className="tooltip-compact"
+                    >
+                      {t("shell.aria.closeSidebar")}
+                    </TooltipContent>
+                  </Tooltip>
+                )}
+              </div>
             </div>
             {!isMobile && (
               <div className="relative z-10 hidden group-data-[collapsible=icon]:flex h-[33px] items-center justify-center w-full">
@@ -1138,8 +1280,10 @@ export function AppSidebar() {
       {/* Uniform pl-1.5 pr-2 keeps every hover pill the same width, inset from the edge. */}
       <SidebarGroup
         className={cn(
-          "group-data-[collapsible=icon]:px-0 pl-1.5 pr-2 pb-px shrink-0",
+          "group-data-[collapsible=icon]:px-0 pl-1.5 pr-2 shrink-0 transition-[padding]",
           showCompactMacBrand ? "pt-0" : "pt-[9px]",
+          // Scrolled: New Chat is pinned, give a little gap below it.
+          scrolled ? "pb-[5px]" : "pb-px",
         )}
       >
         <SidebarGroupContent>
@@ -1172,10 +1316,18 @@ export function AppSidebar() {
                 openNewChat(null);
               }}
             />
+            {/* Search sits in the header when the brand row is shown (mac/web).
+                Hide this row there, but keep it in the collapsed rail. On custom
+                titlebars (win/linux) there's no header button, so keep the row. */}
             <NavItem
               icon={Search01Icon}
               label={t("shell.navigation.search")}
               active={false}
+              className={
+                showSidebarBrand
+                  ? "hidden group-data-[collapsible=icon]:block"
+                  : undefined
+              }
               onClick={() => {
                 useChatSearchStore.getState().open();
                 closeMobileIfOpen();
@@ -1208,6 +1360,18 @@ export function AppSidebar() {
         <SidebarGroup className="group-data-[collapsible=icon]:px-0 pl-1.5 pr-2 py-0 shrink-0">
           <SidebarGroupContent>
             <SidebarMenu>
+              <NavItem
+                icon={DashboardCircleIcon}
+                label={t("shell.navigation.hub")}
+                active={pathname === "/hub" || pathname.startsWith("/hub/")}
+                onClick={() => {
+                  navigate({ to: "/hub" });
+                  closeMobileIfOpen();
+                }}
+                onIntent={() => {
+                  preloadSilently(router.preloadRoute({ to: "/hub" }));
+                }}
+              />
               <NavItem
                 icon={Folder01Icon}
                 label="Projects"
@@ -1218,6 +1382,9 @@ export function AppSidebar() {
                   navigate({ to: "/projects" });
                   closeMobileIfOpen();
                 }}
+                onIntent={() => {
+                  preloadSilently(router.preloadRoute({ to: "/projects" }));
+                }}
                 className="group/projects-item relative"
               >
                 <button
@@ -1240,15 +1407,6 @@ export function AppSidebar() {
                   </span>
                 </button>
               </NavItem>
-              <NavItem
-                icon={DashboardCircleIcon}
-                label={t("shell.navigation.hub")}
-                active={pathname === "/hub" || pathname.startsWith("/hub/")}
-                onClick={() => {
-                  navigate({ to: "/hub" });
-                  closeMobileIfOpen();
-                }}
-              />
               {/* Train has a labelled section when expanded; plain icon here only when collapsed. */}
               <NavItem
                 icon={TestTubeOutlineIcon}
@@ -1264,6 +1422,9 @@ export function AppSidebar() {
                   navigate({ to: "/studio" });
                   closeMobileIfOpen();
                 }}
+                onIntent={() => {
+                  preloadSilently(router.preloadRoute({ to: "/studio" }));
+                }}
                 className="hidden group-data-[collapsible=icon]:block"
               />
             </SidebarMenu>
@@ -1293,6 +1454,9 @@ export function AppSidebar() {
                       navigate({ to: "/studio" });
                       closeMobileIfOpen();
                     }}
+                    onIntent={() => {
+                      preloadSilently(router.preloadRoute({ to: "/studio" }));
+                    }}
                   />
                   <NavItem
                     icon={ChefHatIcon}
@@ -1302,6 +1466,16 @@ export function AppSidebar() {
                       navigate({ to: "/data-recipes" });
                       closeMobileIfOpen();
                     }}
+                    onIntent={() => {
+                      preloadSilently(
+                        router.preloadRoute({ to: "/data-recipes" }),
+                      );
+                      preloadSilently(
+                        import("@/features/data-recipes").then((module) =>
+                          module.preloadRecipes(),
+                        ),
+                      );
+                    }}
                   />
                   <NavItem
                     icon={DownloadSquare01Icon}
@@ -1312,6 +1486,14 @@ export function AppSidebar() {
                       navigate({ to: "/export" });
                       closeMobileIfOpen();
                     }}
+                    onIntent={() => {
+                      preloadSilently(router.preloadRoute({ to: "/export" }));
+                      preloadSilently(
+                        import(
+                          "@/features/export/export-navigation-cache"
+                        ).then((module) => module.preloadExportData()),
+                      );
+                    }}
                   />
                 </SidebarMenu>
               </SidebarGroupContent>
@@ -1319,28 +1501,156 @@ export function AppSidebar() {
           </SidebarGroup>
         </Collapsible>
 
-        {/* Pinned chats: own section above Recents */}
-        {!isStudioRoute && !showTrainingRecents && pinnedChatItems.length > 0 && (
-          <Collapsible open={pinnedOpen} onOpenChange={setPinnedOpen} asChild>
-            <SidebarGroup className="group-data-[collapsible=icon]:hidden px-0 py-0">
-              <SidebarGroupLabel className={cn("sidebar-sticky-label sidebar-sticky-label-following", scrolled && "is-scrolled")} asChild>
-                <CollapsibleTrigger className="cursor-pointer flex w-full items-center gap-1 group/sb-collap">
-                  Pinned
-                  <ChevronDown className="size-3.5 opacity-0 transition-[transform,opacity] duration-200 group-hover/sb-collap:opacity-100 group-focus-visible/sb-collap:opacity-100 data-[state=open]:rotate-0 [[data-state=closed]_&]:rotate-[-90deg] [[data-state=closed]_&]:opacity-100" />
-                </CollapsibleTrigger>
-              </SidebarGroupLabel>
-              <CollapsibleContent>
-                <SidebarGroupContent className="pl-1.5 pr-2">
-                  <SidebarMenu>
-                    {pinnedChatItems.map((item) =>
-                      renderChatSidebarItem(item, "recent"),
-                    )}
-                  </SidebarMenu>
-                </SidebarGroupContent>
-              </CollapsibleContent>
-            </SidebarGroup>
-          </Collapsible>
-        )}
+        {/* Pinned: pinned projects (with their chats) and pinned chats */}
+        {!isStudioRoute &&
+          !showTrainingRecents &&
+          (pinnedProjectRecords.length > 0 ||
+            pinnedChatItems.length > 0) && (
+            <Collapsible open={pinnedOpen} onOpenChange={setPinnedOpen} asChild>
+              <SidebarGroup className="group-data-[collapsible=icon]:hidden px-0 py-0">
+                <SidebarGroupLabel className={cn("sidebar-sticky-label sidebar-sticky-label-following", scrolled && "is-scrolled")} asChild>
+                  <CollapsibleTrigger className="cursor-pointer flex w-full items-center gap-1 group/sb-collap">
+                    Pinned
+                    <ChevronDown className="size-3.5 opacity-0 transition-[transform,opacity] duration-200 group-hover/sb-collap:opacity-100 group-focus-visible/sb-collap:opacity-100 data-[state=open]:rotate-0 [[data-state=closed]_&]:rotate-[-90deg] [[data-state=closed]_&]:opacity-100" />
+                  </CollapsibleTrigger>
+                </SidebarGroupLabel>
+                <CollapsibleContent>
+                  <SidebarGroupContent className="pl-1.5 pr-2">
+                    <SidebarMenu>
+                      {pinnedProjectRecords.map((project) => {
+                        const projectChats =
+                          chatsByProjectId.get(project.id) ?? [];
+                        const expanded = !collapsedProjectIds.has(project.id);
+                        const showAll = expandedChatProjectIds.has(project.id);
+                        const visibleChats =
+                          expanded && !showAll
+                            ? projectChats.slice(0, PINNED_PROJECT_CHAT_LIMIT)
+                            : projectChats;
+                        return (
+                        <Fragment key={project.id}>
+                        <SidebarMenuItem
+                          className="group/recent-item relative"
+                        >
+                          <SidebarMenuButton
+                            // Highlight the folder only on the project home; when
+                            // a chat inside it is open, only that chat row is active.
+                            isActive={activeProjectId === project.id && !activeThreadId}
+                            onClick={() => toggleProjectCollapsed(project.id)}
+                            className="sidebar-nav-btn h-[33px] rounded-full gap-[8.5px] pl-3 pr-2.5 font-medium group-hover/recent-item:pr-16 group-has-[.sidebar-row-action[data-state=open]]/recent-item:pr-8"
+                          >
+                            <HugeiconsIcon icon={Folder01Icon} strokeWidth={1.75} className="size-icon! shrink-0" />
+                            <span className="truncate text-ui-14p5 leading-ui-19 tracking-nav">{project.name}</span>
+                          </SidebarMenuButton>
+                          {/* New chat in this project */}
+                          <button
+                            type="button"
+                            aria-label="New chat"
+                            onClick={(e) => {
+                              e.stopPropagation();
+                              openNewChat(project.id);
+                            }}
+                            className="sidebar-row-action is-unpin-action group-hover/recent-item:opacity-100 group-hover/recent-item:pointer-events-auto focus-visible:opacity-100 focus-visible:pointer-events-auto"
+                          >
+                            <span className="sidebar-row-action-glyph">
+                              <HugeiconsIcon icon={PencilEdit02Icon} strokeWidth={1.75} className="size-icon" />
+                            </span>
+                          </button>
+                          {/* Project options */}
+                          <DropdownMenu>
+                            <DropdownMenuTrigger asChild>
+                              <button
+                                type="button"
+                                onClick={(e) => e.stopPropagation()}
+                                aria-label="Project options"
+                                className="sidebar-row-action group-hover/recent-item:opacity-100 group-hover/recent-item:pointer-events-auto focus-visible:opacity-100 focus-visible:pointer-events-auto"
+                              >
+                                <span className="sidebar-row-action-glyph">
+                                  <HugeiconsIcon icon={MoreVerticalIcon} strokeWidth={1.75} className="size-icon" />
+                                </span>
+                              </button>
+                            </DropdownMenuTrigger>
+                            <DropdownMenuContent
+                              side="bottom"
+                              align="start"
+                              sideOffset={0}
+                              className="unsloth-plus-menu menu-flat-destructive w-56"
+                            >
+                              <DropdownMenuItem onSelect={() => openProject(project.id)}>
+                                <HugeiconsIcon icon={Folder01Icon} strokeWidth={1.75} className="size-icon" />
+                                <span>Project home</span>
+                              </DropdownMenuItem>
+                              <DropdownMenuItem onSelect={() => openNewChat(project.id)}>
+                                <HugeiconsIcon icon={PencilEdit02Icon} strokeWidth={1.75} className="size-icon" />
+                                <span>New chat</span>
+                              </DropdownMenuItem>
+                              <DropdownMenuItem
+                                onSelect={() => {
+                                  // Seed the shared draft so the dialog opens
+                                  // with the current name, not stale text.
+                                  setRenameDraft(project.name);
+                                  setRenamingTarget({
+                                    kind: "project",
+                                    project,
+                                    current: project.name,
+                                  });
+                                }}
+                              >
+                                <HugeiconsIcon icon={Edit03Icon} strokeWidth={1.75} className="size-icon" />
+                                <span>Rename project</span>
+                              </DropdownMenuItem>
+                              <DropdownMenuItem onSelect={() => unpinProject(project.id)}>
+                                <HugeiconsIcon icon={PinOffIcon} strokeWidth={1.75} className="size-icon" />
+                                <span>Unpin project</span>
+                              </DropdownMenuItem>
+                              <DropdownMenuSeparator />
+                              <DropdownMenuItem
+                                variant="destructive"
+                                onSelect={() => {
+                                  // Start each delete with the file toggle off:
+                                  // Cancel closes programmatically and skips the
+                                  // dialog onOpenChange reset.
+                                  setDeleteProjectFiles(false);
+                                  setConfirmingDelete({ kind: "project", project });
+                                }}
+                              >
+                                <HugeiconsIcon icon={Delete02Icon} strokeWidth={1.75} className="size-icon" />
+                                <span>Delete project</span>
+                              </DropdownMenuItem>
+                            </DropdownMenuContent>
+                          </DropdownMenu>
+                        </SidebarMenuItem>
+                        {expanded &&
+                          visibleChats.map((chat) =>
+                            renderChatSidebarItem(chat, "project"),
+                          )}
+                        {expanded &&
+                          projectChats.length > PINNED_PROJECT_CHAT_LIMIT && (
+                            <SidebarMenuItem>
+                              <SidebarMenuButton
+                                onClick={() => toggleProjectShowAll(project.id)}
+                                // Force the muted token: .sidebar-nav-btn's own
+                                // color rule outweighs a plain text utility, so
+                                // Show more would otherwise match the chat rows.
+                                className="sidebar-nav-btn h-[30px] rounded-full pl-9 pr-4 font-medium text-nav-fg-muted!"
+                              >
+                                <span className="text-ui-13 leading-ui-18 tracking-nav">
+                                  {showAll ? "Show less" : "Show more"}
+                                </span>
+                              </SidebarMenuButton>
+                            </SidebarMenuItem>
+                          )}
+                        </Fragment>
+                        );
+                      })}
+                      {pinnedChatItems.map((item) =>
+                        renderChatSidebarItem(item, "recent"),
+                      )}
+                    </SidebarMenu>
+                  </SidebarGroupContent>
+                </CollapsibleContent>
+              </SidebarGroup>
+            </Collapsible>
+          )}
 
         {!isStudioRoute && !showTrainingRecents && (
           <Collapsible open={chatOpen} onOpenChange={setChatOpen} asChild>
@@ -1402,7 +1712,7 @@ export function AppSidebar() {
                       >
                         <SidebarMenuButton
                           isActive={isActiveRun}
-                          className="sidebar-nav-btn h-auto flex-col items-start gap-0.5 py-[5px] rounded-[14px] pl-3 pr-7 text-[14.5px] tracking-nav font-medium"
+                          className="sidebar-nav-btn h-auto flex-col items-start gap-0.5 py-[5px] rounded-[14px] pl-3 pr-7 text-ui-14p5 tracking-nav font-medium"
                           onClick={() => {
                             setSelectedHistoryRunId(run.id);
                             // From Recipes/Export, jump to Train so the run's
@@ -1422,7 +1732,7 @@ export function AppSidebar() {
                             <span className="truncate">
                               {getTrainingRunDisplayTitle(run)}
                             </span>
-                            <span className="ml-auto mr-0.5 shrink-0 text-[10px] text-muted-foreground">
+                            <span className="ml-auto mr-0.5 shrink-0 text-ui-10 text-muted-foreground">
                               {formatRelativeShort(run.started_at)}
                             </span>
                           </div>
@@ -1523,11 +1833,11 @@ export function AppSidebar() {
                   />
                 </span>
                 <div className="flex min-w-0 flex-col gap-px leading-tight group-data-[collapsible=icon]:hidden">
-                  <span className="truncate font-heading text-[13.5px] font-semibold text-nav-fg">
+                  <span className="truncate font-heading text-ui-13p5 font-semibold text-nav-fg">
                     {t("shell.updateAvailable")}
                   </span>
                   {updateVersion && (
-                    <span className="truncate text-[11.5px] text-muted-foreground">
+                    <span className="truncate text-ui-11p5 text-muted-foreground">
                       v{updateVersion}
                     </span>
                   )}
@@ -1564,8 +1874,8 @@ export function AppSidebar() {
                   {/* min-w-0 so long names truncate instead of overflowing;
                       pr on the button reserves room for the settings cog */}
                   <div className="flex min-w-0 flex-1 flex-col gap-px leading-tight group-data-[collapsible=icon]:hidden">
-                    <span className="truncate font-heading text-[13.5px] tracking-[0.025em] dark:tracking-[0.04em] font-semibold text-nav-fg">{displayTitle}</span>
-                    <span className="truncate text-[11.5px] tracking-nav text-muted-foreground">Unsloth</span>
+                    <span className="truncate font-heading text-ui-13p5 tracking-[0.025em] dark:tracking-[0.04em] font-semibold text-nav-fg">{displayTitle}</span>
+                    <span className="truncate text-ui-11p5 tracking-nav text-muted-foreground">Unsloth</span>
                   </div>
                 </SidebarMenuButton>
               </DropdownMenuTrigger>
diff --git a/studio/frontend/src/components/assistant-ui/attachment.tsx b/studio/frontend/src/components/assistant-ui/attachment.tsx
index 98ebe5ab5f..b26840cc02 100644
--- a/studio/frontend/src/components/assistant-ui/attachment.tsx
+++ b/studio/frontend/src/components/assistant-ui/attachment.tsx
@@ -7,6 +7,7 @@
 import { TooltipIconButton } from "@/components/assistant-ui/tooltip-icon-button";
 import {
   Dialog,
+  DialogClose,
   DialogContent,
   DialogTitle,
   DialogTrigger,
@@ -27,12 +28,7 @@ import {
 import { AudioWave01Icon, File02Icon } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
 import { PlusIcon, XIcon } from "lucide-react";
-import {
-  type FC,
-  type PropsWithChildren,
-  useEffect,
-  useState,
-} from "react";
+import { type FC, type PropsWithChildren, useEffect, useState } from "react";
 import { useShallow } from "zustand/shallow";
 
 const useFileSrc = (file: File | undefined): string | undefined => {
@@ -83,7 +79,7 @@ const AttachmentPreview: FC<AttachmentPreviewProps> = ({ src }) => {
       src={src}
       alt="Preview"
       className={cn(
-        "block h-auto max-h-[80vh] w-auto max-w-full object-contain",
+        "block h-auto max-h-[90dvh] w-auto max-w-[92vw] object-contain",
         isLoaded
           ? "aui-attachment-preview-image-loaded"
           : "aui-attachment-preview-image-loading invisible",
@@ -108,12 +104,23 @@ const AttachmentPreviewDialog: FC<PropsWithChildren> = ({ children }) => {
       >
         {children}
       </DialogTrigger>
-      <DialogContent className="aui-attachment-preview-dialog-content p-2 sm:max-w-3xl [&>button]:rounded-full [&>button]:bg-foreground/60 [&>button]:p-1 [&>button]:opacity-100 [&>button]:ring-0! [&_svg]:text-background [&>button]:hover:[&_svg]:text-destructive">
+      {/* Chrome-free lightbox: the image floats on the dimmed backdrop with
+          no dialog panel, and the close button sits in the screen corner. */}
+      <DialogContent
+        overlayClassName="bg-black/70"
+        className="aui-attachment-preview-dialog-content top-0 left-0 grid h-dvh w-screen max-w-none translate-x-0 translate-y-0 place-items-center rounded-none border-0 bg-transparent p-0 shadow-none ring-0 sm:max-w-none [&>button]:fixed [&>button]:top-4 [&>button]:right-4 [&>button]:z-20 [&>button]:size-9 [&>button]:rounded-full [&>button]:bg-transparent [&>button]:text-white [&>button]:opacity-100 [&>button]:ring-0! [&>button]:hover:bg-white/25 [&>button]:hover:text-white [&_svg]:text-white"
+      >
         <DialogTitle className="aui-sr-only sr-only">
           Image Attachment Preview
         </DialogTitle>
-        <div className="aui-attachment-preview relative mx-auto flex max-h-[80dvh] w-full items-center justify-center overflow-hidden bg-background">
-          <AttachmentPreview src={src} />
+        {/* Clicking the backdrop (anywhere off the image) closes the preview. */}
+        <DialogClose asChild={true}>
+          <div aria-hidden="true" className="absolute inset-0" />
+        </DialogClose>
+        <div className="aui-attachment-preview pointer-events-none relative z-10 flex items-center justify-center">
+          <span className="pointer-events-auto">
+            <AttachmentPreview src={src} />
+          </span>
         </div>
       </DialogContent>
     </Dialog>
diff --git a/studio/frontend/src/components/assistant-ui/audio-player.tsx b/studio/frontend/src/components/assistant-ui/audio-player.tsx
index 8836eddff5..51ea646498 100644
--- a/studio/frontend/src/components/assistant-ui/audio-player.tsx
+++ b/studio/frontend/src/components/assistant-ui/audio-player.tsx
@@ -100,7 +100,7 @@ export const AudioPlayer: FC<AudioPlayerProps> = ({ src }) => {
           onChange={handleSeek}
           className="h-1.5 w-full cursor-pointer accent-primary"
         />
-        <div className="flex justify-between text-[10px] text-muted-foreground">
+        <div className="flex justify-between text-ui-10 text-muted-foreground">
           <span>{formatTime(progress)}</span>
           <span>{formatTime(duration)}</span>
         </div>
diff --git a/studio/frontend/src/components/assistant-ui/chat-dictation-bar.tsx b/studio/frontend/src/components/assistant-ui/chat-dictation-bar.tsx
new file mode 100644
index 0000000000..64b0b46735
--- /dev/null
+++ b/studio/frontend/src/components/assistant-ui/chat-dictation-bar.tsx
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { Spinner } from "@/components/ui/spinner";
+import {
+  cancelActiveStudioDictation,
+  subscribeDictationLevel,
+} from "@/features/chat";
+import { useAui, useAuiState } from "@assistant-ui/react";
+import { CheckIcon, XIcon } from "lucide-react";
+import { type FC, useEffect, useRef, useState } from "react";
+import { TooltipIconButton } from "./tooltip-icon-button";
+
+// Dense row of dots that rise into centered recording bars.
+const BAR_COUNT = 84;
+// Peak height multiple for the loudest audio (dot is 4px). Under the 40px pill
+// so bars don't touch the edges.
+const MAX_SCALE = 8;
+// Time for a sample to slide one bar-width left (drift speed). Bars interpolate
+// between samples each frame, so a slower interval stays smooth.
+const PUSH_INTERVAL_MS = 165;
+// If no real mic level arrives for this long (e.g. Web Audio unavailable), fall
+// back to a gentle idle shimmer so the bar stays alive.
+const IDLE_AFTER_MS = 450;
+const WAVE_BAR_IDS = Array.from(
+  { length: BAR_COUNT },
+  (_, index) => `wave-bar-${index}`,
+);
+
+function formatElapsed(ms: number): string {
+  const total = Math.floor(ms / 1000);
+  const m = Math.floor(total / 60);
+  const s = total % 60;
+  return `${m}:${s.toString().padStart(2, "0")}`;
+}
+
+/**
+ * Recording UI shown in place of the composer input: a live waveform with
+ * discard and confirm on the right. Confirm transcribes; discard keeps the
+ * existing composer text.
+ */
+export const ChatDictationBar: FC = () => {
+  const aui = useAui();
+  const isDictating = useAuiState((s) => s.composer.dictation != null);
+  const [transcribing, setTranscribing] = useState(false);
+  const [elapsed, setElapsed] = useState(0);
+  const transcribingRef = useRef(false);
+  // Extra slot: newest sample lands here; the last visible bar slides toward it.
+  const barsRef = useRef<number[]>(new Array(BAR_COUNT + 1).fill(0));
+  const rowRef = useRef<HTMLDivElement | null>(null);
+
+  useEffect(() => {
+    if (!isDictating) {
+      return;
+    }
+
+    const startedAt = Date.now();
+    let peak = 0; // loudest level seen since the last waveform advance
+    let smoothed = 0;
+    let lastLevelAt = 0;
+    const barEls = rowRef.current
+      ? Array.from(rowRef.current.children).filter(
+          (el): el is HTMLElement => el instanceof HTMLElement,
+        )
+      : [];
+    // Paint the bars imperatively (not via React state) so the waveform does not
+    // thrash renders. The spans carry no style prop, so React never overwrites
+    // these transforms on an elapsed-timer re-render. At rest each is a round dot
+    // (scaleY 1); louder audio scales it into a thin centered bar.
+    for (const el of barEls) {
+      el.style.transform = "scaleY(1)";
+      el.style.opacity = "0.62";
+    }
+
+    // Push one new sample, dropping the oldest.
+    const commitSample = () => {
+      const bars = barsRef.current;
+      let level = peak;
+      peak = 0;
+      if (Date.now() - lastLevelAt > IDLE_AFTER_MS) {
+        level = 0.075 + 0.055 * (1 + Math.sin(Date.now() / 360));
+      }
+      // Quiet speech needs a perceptual lift. Fast attack, slower release:
+      // removes twitching while preserving clear peaks.
+      const visual = Math.min(1, Math.max(0, level) ** 0.62 * 1.45);
+      smoothed =
+        visual >= smoothed
+          ? smoothed * 0.2 + visual * 0.8
+          : smoothed * 0.78 + visual * 0.22;
+      bars.push(smoothed);
+      while (bars.length > BAR_COUNT + 1) {
+        bars.shift();
+      }
+    };
+
+    // Keep the loudest mic level between advances so downsampling to
+    // PUSH_INTERVAL_MS doesn't swallow peaks in quiet gaps.
+    const unsub = subscribeDictationLevel((level) => {
+      if (level > peak) {
+        peak = level;
+      }
+      lastLevelAt = Date.now();
+    });
+
+    // Repaint every frame; bars interpolate between samples so the wave glides.
+    // Timer updates at most once per second.
+    let lastPushAt = performance.now();
+    let shownSecond = -1;
+    let raf = 0;
+
+    const frame = () => {
+      raf = requestAnimationFrame(frame);
+      if (transcribingRef.current) {
+        return;
+      }
+
+      const now = performance.now();
+      const bars = barsRef.current;
+      let steps = 0;
+      while (now - lastPushAt >= PUSH_INTERVAL_MS && steps < BAR_COUNT + 1) {
+        commitSample();
+        lastPushAt += PUSH_INTERVAL_MS;
+        steps++;
+      }
+      // Drop stale backlog if rAF was paused (tab backgrounded).
+      if (now - lastPushAt >= PUSH_INTERVAL_MS) {
+        lastPushAt = now;
+      }
+
+      const phase = Math.min(1, (now - lastPushAt) / PUSH_INTERVAL_MS);
+      for (let i = 0; i < barEls.length; i++) {
+        // Bar i drifts toward its right neighbour as phase goes 0 to 1.
+        const a = bars[i] ?? 0;
+        const b = bars[i + 1] ?? a;
+        const v = a + (b - a) * phase;
+        barEls[i].style.transform = `scaleY(${1 + v * (MAX_SCALE - 1)})`;
+        barEls[i].style.opacity = `${0.62 + v * 0.38}`;
+      }
+
+      const elapsedMs = Date.now() - startedAt;
+      const second = Math.floor(elapsedMs / 1000);
+      if (second !== shownSecond) {
+        shownSecond = second;
+        setElapsed(elapsedMs);
+      }
+    };
+    raf = requestAnimationFrame(frame);
+
+    // Reset in cleanup (dictation end or unmount) so the next session starts
+    // fresh, without a synchronous setState in the effect body.
+    return () => {
+      unsub();
+      cancelAnimationFrame(raf);
+      transcribingRef.current = false;
+      setTranscribing(false);
+      setElapsed(0);
+      barsRef.current = new Array(BAR_COUNT + 1).fill(0);
+    };
+  }, [isDictating]);
+
+  if (!isDictating) {
+    return null;
+  }
+
+  const discard = () => {
+    cancelActiveStudioDictation();
+  };
+
+  const confirm = () => {
+    // Freeze the timer + waveform before the transcription round trip completes
+    // and the session ends.
+    transcribingRef.current = true;
+    setTranscribing(true);
+    aui.composer().stopDictation();
+  };
+
+  return (
+    <fieldset
+      // order-2 places the bar in the input's slot after the left "+" tools.
+      className="unsloth-dictation-bar order-2 m-0 flex min-w-0 flex-1 items-center gap-2 border-0 p-0"
+      aria-label="Voice recording"
+    >
+      <div
+        ref={rowRef}
+        aria-hidden="true"
+        className="unsloth-dictation-wave grid h-10 min-w-0 flex-1 items-center overflow-hidden px-2"
+        style={{
+          gridTemplateColumns: `repeat(${BAR_COUNT}, minmax(1px, 3px))`,
+          justifyContent: "space-between",
+        }}
+      >
+        {WAVE_BAR_IDS.map((barId) => (
+          <span
+            key={barId}
+            className="h-1 w-full origin-center rounded-full bg-foreground opacity-[0.62] will-change-transform"
+          />
+        ))}
+      </div>
+      <span className="shrink-0 tabular-nums text-sm text-muted-foreground">
+        {formatElapsed(elapsed)}
+      </span>
+      <div className="flex shrink-0 items-center gap-1">
+        <TooltipIconButton
+          type="button"
+          tooltip="Discard recording"
+          aria-label="Discard recording"
+          variant="ghost"
+          onClick={discard}
+          className="size-8 rounded-full text-muted-foreground hover:text-foreground"
+        >
+          <XIcon className="size-5" />
+        </TooltipIconButton>
+        <TooltipIconButton
+          type="button"
+          tooltip={transcribing ? "Transcribing…" : "Stop and transcribe"}
+          aria-label="Stop and transcribe"
+          variant="default"
+          onClick={confirm}
+          disabled={transcribing}
+          className="size-8 rounded-full"
+        >
+          {transcribing ? (
+            <Spinner className="size-4" />
+          ) : (
+            <CheckIcon className="size-5" />
+          )}
+        </TooltipIconButton>
+      </div>
+    </fieldset>
+  );
+};
diff --git a/studio/frontend/src/components/assistant-ui/message-response-details-sheet.tsx b/studio/frontend/src/components/assistant-ui/message-response-details-sheet.tsx
index cca61b766a..8b2e9e37ea 100644
--- a/studio/frontend/src/components/assistant-ui/message-response-details-sheet.tsx
+++ b/studio/frontend/src/components/assistant-ui/message-response-details-sheet.tsx
@@ -207,7 +207,7 @@ function DetailRow({
 }) {
   if (value == null || value === "") return null;
   return (
-    <div className="grid grid-cols-[8.5rem_minmax(0,1fr)] items-start gap-3 text-[13px]">
+    <div className="grid grid-cols-[8.5rem_minmax(0,1fr)] items-start gap-3 text-ui-13">
       <span className="text-muted-foreground">{label}</span>
       <span
         className={cn(
diff --git a/studio/frontend/src/components/assistant-ui/message-timing.tsx b/studio/frontend/src/components/assistant-ui/message-timing.tsx
index 8d40f587ad..e0a111820b 100644
--- a/studio/frontend/src/components/assistant-ui/message-timing.tsx
+++ b/studio/frontend/src/components/assistant-ui/message-timing.tsx
@@ -86,7 +86,7 @@ export const MessageTiming: FC<{
           data-slot="message-timing-trigger"
           aria-label="Message timing"
           className={cn(
-            "flex items-center rounded-[10px] p-1 font-mono text-chat-icon-fg text-[13px] tabular-nums transition-colors hover:bg-chat-icon-bg-hover hover:text-chat-icon-fg-hover",
+            "flex items-center rounded-[10px] p-1 font-mono text-chat-icon-fg text-ui-13 tabular-nums transition-colors hover:bg-chat-icon-bg-hover hover:text-chat-icon-fg-hover",
             className,
           )}
         >
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/remembered-load-settings.ts b/studio/frontend/src/components/assistant-ui/model-selector/remembered-load-settings.ts
deleted file mode 100644
index ec75b17f20..0000000000
--- a/studio/frontend/src/components/assistant-ui/model-selector/remembered-load-settings.ts
+++ /dev/null
@@ -1,69 +0,0 @@
-// SPDX-License-Identifier: AGPL-3.0-only
-// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
-
-// Per-model pre-load inference settings, persisted in localStorage so the load
-// dialog can offer "Remember settings for <model>".
-
-const KEY = "unsloth_load_settings";
-
-export interface RememberedLoadSettings {
-  contextLength: number | null;
-  kvCacheDtype: string | null;
-  speculativeType: string | null;
-  specDraftNMax: number | null;
-  tensorParallel: boolean;
-}
-
-// Storage key for a pick's remembered settings. The remembered knobs are
-// VRAM-budget driven (context override, KV-cache dtype, tensor-parallel), so the
-// right values differ per quant. An HF repo collapses all its GGUF variants into
-// one `id`, so fold the variant in to scope settings per quant. Local .gguf
-// paths key by their file path (already file-specific); native drag-drop files
-// key by display label, so same-named files in different folders share an entry.
-export function rememberedLoadSettingsKey(selection: {
-  id: string;
-  ggufVariant?: string | null;
-}): string {
-  return selection.ggufVariant
-    ? `${selection.id}::${selection.ggufVariant}`
-    : selection.id;
-}
-
-function readAll(): Record<string, RememberedLoadSettings> {
-  try {
-    return JSON.parse(localStorage.getItem(KEY) ?? "{}");
-  } catch {
-    return {};
-  }
-}
-
-function writeAll(all: Record<string, RememberedLoadSettings>) {
-  try {
-    localStorage.setItem(KEY, JSON.stringify(all));
-  } catch {
-    // Ignore quota / unavailable storage.
-  }
-}
-
-export function loadRememberedLoadSettings(
-  key: string,
-): RememberedLoadSettings | null {
-  return readAll()[key] ?? null;
-}
-
-export function saveRememberedLoadSettings(
-  key: string,
-  settings: RememberedLoadSettings,
-) {
-  const all = readAll();
-  all[key] = settings;
-  writeAll(all);
-}
-
-export function clearRememberedLoadSettings(key: string) {
-  const all = readAll();
-  if (key in all) {
-    delete all[key];
-    writeAll(all);
-  }
-}
diff --git a/studio/frontend/src/components/assistant-ui/reasoning.tsx b/studio/frontend/src/components/assistant-ui/reasoning.tsx
index 9788c73605..97891e9358 100644
--- a/studio/frontend/src/components/assistant-ui/reasoning.tsx
+++ b/studio/frontend/src/components/assistant-ui/reasoning.tsx
@@ -163,7 +163,7 @@ function ReasoningContent({
     <CollapsibleContent
       data-slot="reasoning-content"
       className={cn(
-        "aui-reasoning-content relative overflow-hidden text-foreground/85 text-[13.5px] outline-none",
+        "aui-reasoning-content relative overflow-hidden text-foreground/85 text-ui-13p5 outline-none",
         "group/collapsible-content ease-out",
         "data-[state=closed]:animate-collapsible-up",
         "data-[state=open]:animate-collapsible-down",
diff --git a/studio/frontend/src/components/assistant-ui/sources.tsx b/studio/frontend/src/components/assistant-ui/sources.tsx
index 18c62fc87f..3a7bf14e45 100644
--- a/studio/frontend/src/components/assistant-ui/sources.tsx
+++ b/studio/frontend/src/components/assistant-ui/sources.tsx
@@ -52,7 +52,7 @@ function SourceIcon({
       <span
         data-slot="source-icon-fallback"
         className={cn(
-          `flex ${sizeClass} shrink-0 items-center justify-center rounded-sm bg-muted font-medium text-[10px]`,
+          `flex ${sizeClass} shrink-0 items-center justify-center rounded-sm bg-muted font-medium text-ui-10`,
           className,
         )}
         {...props}
diff --git a/studio/frontend/src/components/assistant-ui/thread.tsx b/studio/frontend/src/components/assistant-ui/thread.tsx
index 62b8af6e3a..68f96c46c8 100644
--- a/studio/frontend/src/components/assistant-ui/thread.tsx
+++ b/studio/frontend/src/components/assistant-ui/thread.tsx
@@ -34,6 +34,11 @@ import { RenderHtmlToolUI } from "@/components/assistant-ui/tool-ui-render-html"
 import { PythonToolUI } from "@/components/assistant-ui/tool-ui-python";
 import { TerminalToolUI } from "@/components/assistant-ui/tool-ui-terminal";
 import { WebSearchToolUI } from "@/components/assistant-ui/tool-ui-web-search";
+import { ChatDictationBar } from "@/components/assistant-ui/chat-dictation-bar";
+import {
+  isStudioDictationAvailable,
+  notifyStudioDictationUnavailable,
+} from "@/features/chat";
 import { TooltipIconButton } from "@/components/assistant-ui/tooltip-icon-button";
 import {
   IntentAwareScrollProvider,
@@ -102,6 +107,7 @@ import { applyQwenThinkingParams } from "@/features/chat/utils/qwen-params";
 import { isTauri } from "@/lib/api-base";
 import { copyToClipboard } from "@/lib/copy-to-clipboard";
 import { MicIcon } from "@/lib/mic-icon";
+import { downloadFile, isDownloadCancelled } from "@/lib/native-files";
 import { toast } from "@/lib/toast";
 import { Tick02Icon } from "@/lib/tick-icon";
 import { cn } from "@/lib/utils";
@@ -175,6 +181,7 @@ import {
 } from "react";
 import { create } from "zustand";
 import { extractTaggedText, updateThreadMessage } from "@/features/chat/utils/update-thread-message";
+import { useIsMobile } from "@/hooks/use-mobile";
 
 // True while a file is dragged anywhere over the chat page, so the composer
 // can show its "Drop files here" affordance.
@@ -1147,7 +1154,7 @@ const GeneratedImageViewportOverlay: FC<{
               Generated image
             </p>
             {overlay.metadata ? (
-              <p className="truncate text-[11px] font-medium text-muted-foreground">
+              <p className="truncate text-ui-11 font-medium text-muted-foreground">
                 {overlay.metadata}
               </p>
             ) : null}
@@ -1369,7 +1376,13 @@ export const ProjectComposer: FC<{
 }> = ({ disabled, placeholder }) => {
   return (
     <GeneratedImageOverlayProvider>
-      <ComposerAnimated disabled={disabled} placeholder={placeholder} />
+      {/* New chat in a project: queuing follow-ups here misbinds the thread,
+          so the queue only runs once the user is inside a chat session. */}
+      <ComposerAnimated
+        disabled={disabled}
+        placeholder={placeholder}
+        disableQueue
+      />
     </GeneratedImageOverlayProvider>
   );
 };
@@ -1379,11 +1392,17 @@ const ComposerAnimated: FC<{
   placeholder?: string;
   threadId?: string | null;
   menuSide?: "top" | "bottom";
-}> = ({ disabled, threadId, menuSide }) => {
+  disableQueue?: boolean;
+}> = ({ disabled, threadId, menuSide, disableQueue }) => {
   return (
     <div className="relative mx-auto min-w-0 w-full max-w-[46rem]">
       <div className="relative z-10 w-full">
-        <Composer disabled={disabled} threadId={threadId} menuSide={menuSide} />
+        <Composer
+          disabled={disabled}
+          threadId={threadId}
+          menuSide={menuSide}
+          disableQueue={disableQueue}
+        />
       </div>
     </div>
   );
@@ -1418,8 +1437,10 @@ const Composer: FC<{
   placeholder?: string;
   threadId?: string | null;
   menuSide?: "top" | "bottom";
-}> = ({ disabled, threadId, menuSide }) => {
+  disableQueue?: boolean;
+}> = ({ disabled, threadId, menuSide, disableQueue }) => {
   const aui = useAui();
+  const isDictating = useAuiState((s) => s.composer.dictation != null);
   const pageDragging = useContext(PageDragContext);
   const { overlay, closeOverlay } = useGeneratedImageOverlay();
   const setImageToolsEnabled = useChatRuntimeStore(
@@ -1434,18 +1455,17 @@ const Composer: FC<{
   const artifactsEnabled = useChatRuntimeStore((s) => s.artifactsEnabled);
   const mcpEnabledForChat = useChatRuntimeStore((s) => s.mcpEnabledForChat);
   const ragEnabled = useChatRuntimeStore((s) => s.ragEnabled);
-  const permissionMode = useChatRuntimeStore((s) => s.permissionMode);
-  // More than 4 pills: collapse to icons only. Search and Code always show; the
-  // permission pill shows in every mode except "off" (it renders null there);
-  // Images, RAG, Canvas and MCP are conditional.
-  const pillsCompact =
-    2 +
-      (permissionMode !== "off" ? 1 : 0) +
-      (ragEnabled ? 1 : 0) +
-      (supportsBuiltinImageGeneration ? 1 : 0) +
-      (artifactsEnabled ? 1 : 0) +
-      (mcpEnabledForChat ? 1 : 0) >
-    4;
+  // More than 4 pills: collapse to icons only. Search, Code, and permissions
+  // always show; Images, RAG, Canvas and MCP are conditional. Narrow viewports
+  // collapse too: the labelled row is wider than a phone-width composer.
+  const isMobile = useIsMobile();
+  const pillCount =
+    3 +
+    (ragEnabled ? 1 : 0) +
+    (supportsBuiltinImageGeneration ? 1 : 0) +
+    (artifactsEnabled ? 1 : 0) +
+    (mcpEnabledForChat ? 1 : 0);
+  const pillsCompact = isMobile || pillCount > 4;
   const activeThreadId = useChatRuntimeStore((s) => s.activeThreadId);
   const setPendingImageEditReference = useChatRuntimeStore(
     (s) => s.setPendingImageEditReference,
@@ -1536,6 +1556,7 @@ const Composer: FC<{
   const draftThreadId = referenceThreadId;
   const draftKey = draftThreadId ? composerDraftKey(draftThreadId) : null;
   const lastDraftKeyRef = useRef(draftKey);
+  const draftSaveTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
   useEffect(() => {
     const draft = draftKey ? (readComposerDraft(draftKey) ?? "") : "";
     const composer = aui.composer();
@@ -1554,22 +1575,25 @@ const Composer: FC<{
       return;
     }
     const t = setTimeout(() => writeComposerDraft(draftKey, composerText), 300);
+    draftSaveTimerRef.current = t;
     return () => clearTimeout(t);
   }, [composerText, draftKey]);
-  // Two-row layout shows once the input wraps or a tool is on. Tools can
-  // pre-select before a model loads, so an active toggle expands it either way.
-  // Keep the composer expanded whenever the permission pill is visible.
-  const composerExpanded =
-    isMultiline ||
-    hasAttachments ||
-    hasPendingAudio ||
-    toolsEnabled ||
-    codeToolsEnabled ||
-    imageToolsEnabled ||
-    ragEnabled ||
-    artifactsEnabled ||
-    mcpEnabledForChat ||
-    permissionMode !== "off";
+  // Without this the restore effect above puts the sent text back when the
+  // runtime rebinds on the first message.
+  const draftKeyRef = useRef(draftKey);
+  useEffect(() => {
+    draftKeyRef.current = draftKey;
+  }, [draftKey]);
+  const clearStoredDraft = useCallback(() => {
+    if (draftSaveTimerRef.current !== null) {
+      clearTimeout(draftSaveTimerRef.current);
+      draftSaveTimerRef.current = null;
+    }
+    const key = draftKeyRef.current;
+    if (key) {
+      writeComposerDraft(key, "");
+    }
+  }, []);
   // react-textarea-autosize re-measures only on value change or window resize,
   // not on the width swap from expanding, so it keeps the taller height and
   // leaves a stray blank row. Nudge a resize whenever input width changes.
@@ -1720,9 +1744,10 @@ const Composer: FC<{
     setPendingSend(false);
     dismissWaitToast();
     if (text.trim().length > 0 || attachments.length > 0) {
+      clearStoredDraft();
       aui.composer().send();
     }
-  }, [pendingSend, indexingActive, aui, dismissWaitToast]);
+  }, [pendingSend, indexingActive, aui, clearStoredDraft, dismissWaitToast]);
 
   // Drop any queued send + toast on unmount (e.g. thread switch).
   useEffect(
@@ -1742,6 +1767,11 @@ const Composer: FC<{
 
       if (threadIsRunning || promptQueueActive) {
         event.preventDefault();
+        // Project new-chat composer: never queue, just ask the user to wait.
+        if (disableQueue) {
+          toast.error("Wait for the current response to finish");
+          return;
+        }
         if (!canQueueCurrentPrompt) {
           if (overlay || hasAttachments || hasPendingAudio) {
             toast.error(
@@ -1760,6 +1790,7 @@ const Composer: FC<{
         flushResourcesSync(() => {
           aui.composer().setText("");
         });
+        clearStoredDraft();
         startPromptQueue(
           [queuedPrompt],
           createPromptQueueTarget(),
@@ -1793,6 +1824,7 @@ const Composer: FC<{
           closeOverlay();
           return;
         }
+        clearStoredDraft();
         setImageToolsEnabled(true);
         setPendingImageEditReference({
           threadId: overlay.threadId ?? referenceThreadId,
@@ -1810,15 +1842,20 @@ const Composer: FC<{
             );
         });
         closeOverlay();
+        return;
       }
+
+      clearStoredDraft();
     },
     [
       aui,
       canQueueCurrentPrompt,
+      clearStoredDraft,
       closeOverlay,
       composerText,
       createPromptQueueTarget,
       disabled,
+      disableQueue,
       hasAttachments,
       hasPendingAudio,
       interceptSend,
@@ -1838,36 +1875,51 @@ const Composer: FC<{
 
   const startQueue = useCallback(
     (items: string[], waitForCurrentRun = threadIsRunning) => {
+      // Saved-prompt Run-list calls this directly, so honour disableQueue here
+      // too: queuing from the project new-chat composer misbinds the thread.
+      if (disableQueue) return;
       startPromptQueue(items, createPromptQueueTarget(), waitForCurrentRun);
     },
-    [createPromptQueueTarget, threadIsRunning],
+    [createPromptQueueTarget, threadIsRunning, disableQueue],
   );
 
   const queueContextValue: PromptQueueCallbacks = { startQueue, stopQueue };
 
   const composerContent = (
     <>
-      <ComposerAttachments />
-      <PendingAudioChip />
-      <ThreadDocumentsBar
-        threadId={referenceThreadId}
-        onIndexingChange={handleIndexingChange}
-      />
-      <ToolStatusDisplay />
+      {!isDictating ? (
+        <>
+          <ComposerAttachments />
+          <PendingAudioChip />
+        </>
+      ) : null}
+      {/* Keep indexing state subscribed while dictating, but hide its chips so
+          the waveform stays the composer's only status indicator. */}
+      <div className={isDictating ? "hidden" : "contents"}>
+        <ThreadDocumentsBar
+          threadId={referenceThreadId}
+          onIndexingChange={handleIndexingChange}
+        />
+      </div>
+      {!isDictating ? <ToolStatusDisplay /> : null}
       <div
         className="unsloth-composer-line"
-        data-expanded={composerExpanded ? "true" : "false"}
+        // The permission pill is always visible, so keep the two-row layout
+        // expanded whenever not dictating; dictation collapses to the bar.
+        data-expanded={!isDictating ? "true" : "false"}
+        data-dictating={isDictating ? "true" : undefined}
       >
         <div
           className="unsloth-composer-left"
           data-pill-compact={pillsCompact ? "true" : undefined}
         >
           <ComposerToolsMenu side={effectiveMenuSide} />
-          {/* Permission-level pill: always visible, even while the pill row
-              is collapsed; opens the permission level dropdown. */}
-          <PermissionModeComposerPill side={effectiveMenuSide} />
-          {composerExpanded ? (
+          {/* While dictating, show only the "+"; hide the pill and tool toggles
+              so the waveform is the sole status indicator. */}
+          {!isDictating ? (
             <>
+              {/* Permission-level pill: always visible, opens the level dropdown. */}
+              <PermissionModeComposerPill side={effectiveMenuSide} />
               <WebSearchToggle />
               <CodeToolsToggle />
               <ImagesToggle />
@@ -1879,46 +1931,58 @@ const Composer: FC<{
             </>
           ) : null}
         </div>
-        <ComposerPrimitive.Input
-          placeholder={
-            overlay ? "Type your edits for your image" : "Ask anything"
-          }
-          ref={inputRef}
-          className="aui-composer-input unsloth-composer-input"
-          minRows={1}
-          maxRows={12}
-          autoFocus={!disabled}
-          disabled={disabled}
-          aria-label={overlay ? "Image edit instructions" : "Message input"}
-          // dir="auto": browser picks LTR/RTL from the first strong char;
-          // no effect on Latin / CJK / Devanagari.
-          dir="auto"
-          {...inputProps}
-        />
-        <ComposerRightControls
-          disabled={
-            disabled ||
-            !hasSendableContent ||
-            isComposing ||
-            hasPendingAttachments
-          }
-          queueDisabled={!canQueueCurrentPrompt}
-          onQueueClick={() => {
-            const queuedPrompt = composerText.trim();
-            if (queuedPrompt.length === 0) {
-              return;
-            }
-            flushResourcesSync(() => {
-              aui.composer().setText("");
-            });
-            startPromptQueue([queuedPrompt], createPromptQueueTarget(), true);
-          }}
-          onSendClick={interceptSend}
-          onStopClick={stopQueue}
-          pendingSend={pendingSend}
-          menuSide={effectiveMenuSide}
-          queueThreadIds={promptQueueThreadIds}
-        />
+        {isDictating ? (
+          // The recording UI replaces the input and send controls; only the
+          // left plus stays visible alongside it.
+          <ChatDictationBar />
+        ) : (
+          <>
+            <ComposerPrimitive.Input
+              placeholder={
+                overlay ? "Type your edits for your image" : "Ask anything"
+              }
+              ref={inputRef}
+              className="aui-composer-input unsloth-composer-input"
+              minRows={1}
+              maxRows={12}
+              autoFocus={!disabled}
+              disabled={disabled}
+              aria-label={overlay ? "Image edit instructions" : "Message input"}
+              // dir="auto": browser picks LTR/RTL from the first strong char;
+              // no effect on Latin / CJK / Devanagari.
+              dir="auto"
+              {...inputProps}
+            />
+            <ComposerRightControls
+              disabled={
+                disabled ||
+                !hasSendableContent ||
+                isComposing ||
+                hasPendingAttachments
+              }
+              // disableQueue (project new-chat composer) also blocks the queue
+              // button, so a running thread shows Stop instead of Queue.
+              queueDisabled={disableQueue || !canQueueCurrentPrompt}
+              onQueueClick={() => {
+                if (disableQueue) return;
+                const queuedPrompt = composerText.trim();
+                if (queuedPrompt.length === 0) {
+                  return;
+                }
+                flushResourcesSync(() => {
+                  aui.composer().setText("");
+                });
+                clearStoredDraft();
+                startPromptQueue([queuedPrompt], createPromptQueueTarget(), true);
+              }}
+              onSendClick={interceptSend}
+              onStopClick={stopQueue}
+              pendingSend={pendingSend}
+              menuSide={effectiveMenuSide}
+              queueThreadIds={promptQueueThreadIds}
+            />
+          </>
+        )}
       </div>
     </>
   );
@@ -1970,7 +2034,7 @@ function isNativeComposing(event: Event) {
 }
 
 // Fallback timeout for stuck IME composition. With Chrome on Windows against
-// a WSL-hosted Studio (issue #5546), `compositionend` never fires after the
+// a WSL-hosted Unsloth (issue #5546), `compositionend` never fires after the
 // candidate commits, so `composingRef` stays true and Send stays disabled.
 // Every compositionupdate / non-composing input resets the timer; only a true
 // gap-after-commit lets it fire. 2500ms is above a normal candidate-window
@@ -2930,9 +2994,9 @@ const ComposerToolsMenu: FC<{ side?: "top" | "bottom" }> = ({
           <DropdownMenuItem
             onSelect={() => {
               if (!activeThreadId) return;
-              exportConversationRawJsonl(activeThreadId).catch(() =>
-                toast.error("Export failed."),
-              );
+              exportConversationRawJsonl(activeThreadId).catch((error) => {
+                if (!isDownloadCancelled(error)) toast.error("Export failed.");
+              });
             }}
           >
             Raw JSONL
@@ -2940,9 +3004,9 @@ const ComposerToolsMenu: FC<{ side?: "top" | "bottom" }> = ({
           <DropdownMenuItem
             onSelect={() => {
               if (!activeThreadId) return;
-              exportConversationCsv(activeThreadId).catch(() =>
-                toast.error("Export failed."),
-              );
+              exportConversationCsv(activeThreadId).catch((error) => {
+                if (!isDownloadCancelled(error)) toast.error("Export failed.");
+              });
             }}
           >
             CSV
@@ -2950,9 +3014,9 @@ const ComposerToolsMenu: FC<{ side?: "top" | "bottom" }> = ({
           <DropdownMenuItem
             onSelect={() => {
               if (!activeThreadId) return;
-              exportConversationShareGPT(activeThreadId).catch(() =>
-                toast.error("Export failed."),
-              );
+              exportConversationShareGPT(activeThreadId).catch((error) => {
+                if (!isDownloadCancelled(error)) toast.error("Export failed.");
+              });
             }}
           >
             ShareGPT JSONL
@@ -3352,32 +3416,36 @@ const ComposerRightControls: FC<{
     findPromptQueueEntry(s, queueThreadIds),
   );
   const isQueueRunning = Boolean(queueEntry);
+  const aui = useAui();
+  // Keep the mic clickable: if the engine can't run here, explain and point to
+  // the local model instead of disabling the button.
+  const startDictation = () => {
+    if (!isStudioDictationAvailable()) {
+      notifyStudioDictationUnavailable();
+      return;
+    }
+    try {
+      aui.composer().startDictation();
+    } catch {
+      notifyStudioDictationUnavailable();
+    }
+  };
   return (
     <div className="aui-composer-action-wrapper flex shrink-0 items-center gap-1.5">
       <ReasoningToggle side={menuSide} />
+      {/* Starts dictation; the recording bar then covers the input row and owns
+          the stop and discard actions. */}
       <ComposerPrimitive.If dictation={false}>
-        <ComposerPrimitive.Dictate asChild={true}>
-          <TooltipIconButton
-            tooltip="Dictate"
-            aria-label="Dictate"
-            variant="ghost"
-            className="size-8 rounded-full text-foreground"
-          >
-            <MicIcon className="size-5" />
-          </TooltipIconButton>
-        </ComposerPrimitive.Dictate>
-      </ComposerPrimitive.If>
-      <ComposerPrimitive.If dictation={true}>
-        <ComposerPrimitive.StopDictation asChild={true}>
-          <TooltipIconButton
-            tooltip="Stop dictation"
-            aria-label="Stop dictation"
-            variant="ghost"
-            className="size-8 rounded-full text-destructive"
-          >
-            <SquareIcon className="size-3 animate-pulse fill-current" />
-          </TooltipIconButton>
-        </ComposerPrimitive.StopDictation>
+        <TooltipIconButton
+          tooltip="Dictate"
+          aria-label="Dictate"
+          type="button"
+          variant="ghost"
+          className="size-8 rounded-full text-foreground"
+          onClick={startDictation}
+        >
+          <MicIcon className="size-5" />
+        </TooltipIconButton>
       </ComposerPrimitive.If>
       <AuiIf condition={({ thread }) => !thread.isRunning && !isQueueRunning}>
         <ComposerPrimitive.Send asChild={true}>
@@ -3535,14 +3603,14 @@ const DiffusionCanvas: FC = () => {
     canvas.total > 0 ? `step ${canvas.step + 1}/${canvas.total}` : "denoising";
   return (
     <div className="aui-diffusion-canvas my-1.5 overflow-hidden rounded-lg border border-primary/20 bg-primary/[0.03]">
-      <div className="flex items-center gap-2 border-b border-primary/10 px-3 py-1.5 text-[11px] font-medium text-primary/80">
+      <div className="flex items-center gap-2 border-b border-primary/10 px-3 py-1.5 text-ui-11 font-medium text-primary/80">
         <span className="inline-block size-1.5 animate-pulse rounded-full bg-primary" />
         <span>Denoising</span>
         <span className="opacity-60">
           block {canvas.block + 1} - {stepLabel}
         </span>
       </div>
-      <pre className="max-h-[60vh] overflow-auto whitespace-pre-wrap px-3 py-2 font-mono text-[12.5px] leading-relaxed text-foreground/90">
+      <pre className="max-h-[60vh] overflow-auto whitespace-pre-wrap px-3 py-2 font-mono text-ui-12p5 leading-relaxed text-foreground/90">
         {canvas.text}
       </pre>
     </div>
@@ -3616,7 +3684,7 @@ const AssistantMessage: FC = () => {
 
   return (
     <MessagePrimitive.Root
-      className="group/assistant-message aui-assistant-message-root relative mx-auto min-w-0 w-full max-w-(--thread-content-max-width) pt-0.5 pb-4 text-[15.5px] [font-weight:410] tracking-[0.01em] dark:tracking-[0.02em]"
+      className="group/assistant-message aui-assistant-message-root relative mx-auto min-w-0 w-full max-w-(--thread-content-max-width) pt-0.5 pb-4 text-ui-15p5 [font-weight:410] tracking-[0.01em] dark:tracking-[0.02em]"
       data-role="assistant"
     >
       <div className="aui-assistant-message-content wrap-break-word min-w-0 text-[#0d0d0d] dark:text-foreground leading-relaxed">
@@ -3729,7 +3797,7 @@ const ForkCountBadge: FC = () => {
   if (count <= 0) return null;
   return (
     <span
-      className="mx-1 inline-flex items-center gap-1 rounded-sm bg-primary/10 px-1.5 py-0.5 text-[10px] font-medium text-primary"
+      className="mx-1 inline-flex items-center gap-1 rounded-sm bg-primary/10 px-1.5 py-0.5 text-ui-10 font-medium text-primary"
       title={`${count} fork${count === 1 ? "" : "s"} from this message`}
     >
       <GitBranchIcon strokeWidth={1.75} className="size-3" />
@@ -3915,6 +3983,21 @@ const EditAssistantMessageButton: FC = () => {
   );
 };
 
+async function exportMessageMarkdown(content: string): Promise<void> {
+  try {
+    await downloadFile(
+      content,
+      `message-${Date.now()}.md`,
+      "text/markdown",
+    );
+  } catch (error) {
+    if (!isDownloadCancelled(error)) {
+      toast.error("Could not save Markdown export.", {
+        description: error instanceof Error ? error.message : String(error),
+      });
+    }
+  }
+}
 const AssistantActionBar: FC = () => {
   const { forkMessage, forkDisabled } = useForkMessageAction();
   const [detailsOpen, setDetailsOpen] = useState(false);
@@ -3983,7 +4066,10 @@ const AssistantActionBar: FC = () => {
               <GitBranchIcon strokeWidth={1.75} className="size-icon" />
               Fork in new chat
             </ActionBarMorePrimitive.Item>
-            <ActionBarPrimitive.ExportMarkdown asChild={true}>
+            <ActionBarPrimitive.ExportMarkdown
+              asChild={true}
+              onExport={exportMessageMarkdown}
+            >
               <ActionBarMorePrimitive.Item className="aui-action-bar-more-item flex cursor-pointer select-none items-center gap-2 rounded-[12px] px-3 py-2 text-sm outline-none hover:bg-accent hover:text-accent-foreground focus:bg-accent focus:text-accent-foreground">
                 <HugeiconsIcon
                   icon={Download01Icon}
@@ -4036,7 +4122,7 @@ const UserMessageAudio: FC = () => {
 const UserMessage: FC = () => {
   return (
     <MessagePrimitive.Root
-      className="aui-user-message-root fade-in slide-in-from-bottom-1 mx-auto flex w-full max-w-(--thread-content-max-width) animate-in flex-col items-end gap-y-2 pt-6 pb-4 text-[15.5px] [font-weight:410] tracking-[0.01em] dark:tracking-[0.02em] duration-150"
+      className="aui-user-message-root fade-in slide-in-from-bottom-1 mx-auto flex w-full max-w-(--thread-content-max-width) animate-in flex-col items-end gap-y-2 pt-6 pb-4 text-ui-15p5 [font-weight:410] tracking-[0.01em] dark:tracking-[0.02em] duration-150"
       data-role="user"
     >
       <UserMessageAttachments />
@@ -4147,7 +4233,7 @@ const BranchPicker: FC<BranchPickerPrimitive.Root.Props> = ({
     <BranchPickerPrimitive.Root
       hideWhenSingleBranch={true}
       className={cn(
-        "aui-branch-picker-root inline-flex items-center text-chat-icon-fg text-[13px]",
+        "aui-branch-picker-root inline-flex items-center text-chat-icon-fg text-ui-13",
         className,
       )}
       {...rest}
@@ -4161,7 +4247,7 @@ const BranchPicker: FC<BranchPickerPrimitive.Root.Props> = ({
           <ChevronLeftIcon strokeWidth={1.25} className="size-[36px]" />
         </button>
       </BranchPickerPrimitive.Previous>
-      <span className="aui-branch-picker-state font-mono text-[13px] tabular-nums">
+      <span className="aui-branch-picker-state font-mono text-ui-13 tabular-nums">
         <BranchPickerPrimitive.Number />/<BranchPickerPrimitive.Count />
       </span>
       <BranchPickerPrimitive.Next asChild={true}>
diff --git a/studio/frontend/src/components/assistant-ui/tool-ui-python.tsx b/studio/frontend/src/components/assistant-ui/tool-ui-python.tsx
index 1b3dd22000..34e51b9d5a 100644
--- a/studio/frontend/src/components/assistant-ui/tool-ui-python.tsx
+++ b/studio/frontend/src/components/assistant-ui/tool-ui-python.tsx
@@ -8,7 +8,7 @@ import { getAuthToken } from "@/features/auth/session";
 import type { ToolCallMessagePartComponent } from "@assistant-ui/react";
 import { useToolArgsStatus } from "@assistant-ui/react";
 import { code as codePlugin } from "@streamdown/code";
-import { CodeIcon, CopyIcon } from "lucide-react";
+import { CodeIcon, CopyIcon, DownloadIcon } from "lucide-react";
 import { Tick02Icon } from "@/lib/tick-icon";
 import { HugeiconsIcon } from "@hugeicons/react";
 import { Spinner } from "@/components/ui/spinner";
@@ -83,22 +83,98 @@ function CopyBtn({ text }: { text: string }) {
   );
 }
 
-/** Syntax-highlighted code via Streamdown + shiki; inherits parent container. */
-function HighlightedCode({ code: source, language }: { code: string; language: string }) {
-  const markdown = useMemo(
-    () => `\`\`\`${language}\n${truncate(source)}\n\`\`\``,
-    [source, language],
-  );
+/** Save the script as a .py file via a client-side Blob. */
+function DownloadBtn({ code, name = "script.py" }: { code: string; name?: string }) {
+  const download = useCallback(() => {
+    if (typeof document === "undefined") {
+      return;
+    }
+    try {
+      const blob = new Blob([code], { type: "text/x-python" });
+      const url = URL.createObjectURL(blob);
+      const anchor = document.createElement("a");
+      anchor.href = url;
+      anchor.download = name;
+      document.body.appendChild(anchor);
+      anchor.click();
+      anchor.remove();
+      // Revoke next tick, after the click consumes the URL.
+      setTimeout(() => URL.revokeObjectURL(url), 0);
+    } catch {
+      // Best-effort: never break the transcript over a download.
+    }
+  }, [code, name]);
+
   return (
-    <div className="max-h-48 overflow-auto text-xs [&_pre]:!m-0 [&_pre]:!bg-transparent [&_pre]:!p-0 [&_pre]:!text-xs [&_[data-streamdown=code-block]]:!my-0 [&_[data-streamdown=code-block]]:!p-3 [&_[data-streamdown=code-block]]:!border-0">
-      <Streamdown
-        mode="static"
-        plugins={{ code: codePlugin }}
-        controls={{ code: false }}
-        shikiTheme={SHIKI_THEME}
-      >
-        {markdown}
-      </Streamdown>
+    <button
+      type="button"
+      onClick={download}
+      className="inline-flex items-center gap-1 rounded px-1.5 py-0.5 text-xs text-muted-foreground transition-colors hover:bg-muted hover:text-foreground"
+      aria-label="Download script"
+    >
+      <DownloadIcon className="size-3" />
+      Download
+    </button>
+  );
+}
+
+/** Syntax-highlighted code via Streamdown + shiki; inherits parent container.
+ * The script is always in the DOM (a plain monospace placeholder), but shiki
+ * only tokenizes once the block scrolls near the viewport, so a long transcript
+ * with many scripts doesn't highlight every one up front. Falls back to
+ * immediate highlight when IntersectionObserver is unavailable (SSR / tests). */
+function HighlightedCode({ code: source, language }: { code: string; language: string }) {
+  const display = useMemo(() => truncate(source), [source]);
+  const markdown = useMemo(
+    () => `\`\`\`${language}\n${display}\n\`\`\``,
+    [display, language],
+  );
+  const containerRef = useRef<HTMLDivElement>(null);
+  const [highlight, setHighlight] = useState(
+    () => typeof IntersectionObserver === "undefined",
+  );
+  useEffect(() => {
+    if (highlight) return;
+    const el = containerRef.current;
+    if (!el) return;
+    const io = new IntersectionObserver(
+      (entries) => {
+        if (entries.some((entry) => entry.isIntersecting)) {
+          setHighlight(true);
+          io.disconnect();
+        }
+      },
+      // Highlight just before the block enters view so it's colorized by the
+      // time the user reaches it, without tokenizing off-screen scripts.
+      { rootMargin: "200px" },
+    );
+    io.observe(el);
+    return () => io.disconnect();
+  }, [highlight]);
+  return (
+    <div
+      ref={containerRef}
+      className="max-h-48 overflow-auto text-xs [&_pre]:!m-0 [&_pre]:!bg-transparent [&_pre]:!p-0 [&_pre]:!text-xs [&_[data-streamdown=code-block]]:!my-0 [&_[data-streamdown=code-block]]:!p-3 [&_[data-streamdown=code-block]]:!border-0"
+    >
+      {highlight ? (
+        <Streamdown
+          mode="static"
+          plugins={{ code: codePlugin }}
+          controls={{ code: false }}
+          shikiTheme={SHIKI_THEME}
+        >
+          {markdown}
+        </Streamdown>
+      ) : (
+        // A div, not a <pre>: the container's [&_pre]:!p-0 would override a
+        // <pre>'s padding and shift the content by p-3 when shiki swaps in. Keep
+        // the same p-3, and whitespace-pre (not pre-wrap) so long lines scroll in
+        // the container's overflow-auto exactly like the highlighted <pre>, rather
+        // than wrapping taller and then collapsing when shiki swaps in.
+        <div className="whitespace-pre p-3 font-mono text-xs text-muted-foreground">
+          {display}
+        </div>
+      )}
     </div>
   );
 }
@@ -153,23 +229,32 @@ const PythonToolUIImpl: ToolCallMessagePartComponent = ({
   const authToken = getAuthToken();
 
   return (
-    // Open when mounted mid-run so live output shows; collapsed from history.
+    // Status/output collapse from history; the script source renders outside
+    // ToolFallbackContent so it stays visible on reopen (#7165).
     <ToolFallbackRoot defaultOpen={isRunning}>
       <ToolFallbackTrigger
         toolName={firstLine ? `Python: ${firstLine}` : "Python"}
         status={status}
         icon={CodeIcon}
       />
+      {code && (
+        <div className="mt-1 pl-5">
+          <div className="border-l-2 border-muted-foreground/20 pl-2">
+            <div className="flex items-center justify-between">
+              <span className="text-xs font-medium text-muted-foreground">
+                script
+              </span>
+              <div className="flex items-center gap-1">
+                <CopyBtn text={code} />
+                <DownloadBtn code={code} />
+              </div>
+            </div>
+            <HighlightedCode code={code} language="python" />
+          </div>
+        </div>
+      )}
       <ToolFallbackContent>
         <div className="border-l-2 border-muted-foreground/20 pl-2">
-          {/* Code + copy */}
-          {code && (
-            <div className="flex justify-end">
-              <CopyBtn text={code} />
-            </div>
-          )}
-          {code && <HighlightedCode code={code} language="python" />}
-
           {/* Output */}
           {isRunning ? (
             <>
diff --git a/studio/frontend/src/components/assistant-ui/tool-ui-render-html.tsx b/studio/frontend/src/components/assistant-ui/tool-ui-render-html.tsx
index 6ab0afad6f..d9c1fbaf6d 100644
--- a/studio/frontend/src/components/assistant-ui/tool-ui-render-html.tsx
+++ b/studio/frontend/src/components/assistant-ui/tool-ui-render-html.tsx
@@ -123,7 +123,7 @@ const RenderHtmlToolUIImpl: ToolCallMessagePartComponent = ({
                 ? "Canvas interrupted"
                 : "Canvas unavailable"}
           </span>
-          <span className="truncate text-[11px] leading-none text-muted-foreground">
+          <span className="truncate text-ui-11 leading-none text-muted-foreground">
             {errorText ??
               (isStaleGeneratingArtifact
                 ? "Refresh stopped this preview"
diff --git a/studio/frontend/src/components/floating-monitor.tsx b/studio/frontend/src/components/floating-monitor.tsx
index 1272a577e9..80501a518c 100644
--- a/studio/frontend/src/components/floating-monitor.tsx
+++ b/studio/frontend/src/components/floating-monitor.tsx
@@ -70,13 +70,18 @@ export function FloatingMonitor() {
     (sum, device) => sum + (device.memory_total_gb ?? 0),
     0,
   );
-  const vramUsed = devices.reduce(
-    (sum, device) => sum + (device.vram_used_gb ?? 0),
-    0,
-  );
+  // null usage = unknown (e.g. Windows ROCm perf counter): treating it as 0
+  // fabricates a 0-used readout, so the aggregate is unknown if any device is.
+  const vramUsageKnown =
+    devices.length > 0 &&
+    devices.every((device) => Number.isFinite(device.vram_used_gb));
+  const vramUsed = vramUsageKnown
+    ? devices.reduce((sum, device) => sum + (device.vram_used_gb ?? 0), 0)
+    : 0;
   const vramPercent = clampPercent(
-    vramTotal > 0 ? (vramUsed / vramTotal) * 100 : 0,
+    vramUsageKnown && vramTotal > 0 ? (vramUsed / vramTotal) * 100 : 0,
   );
+  const unknownLabel = t("settings.resources.environment.unknown");
 
   const hasGpu = (systemInfo.gpu?.available ?? false) && devices.length > 0;
 
@@ -134,7 +139,7 @@ export function FloatingMonitor() {
               className="space-y-3 overflow-hidden"
             >
               <div className="space-y-1">
-                <div className="flex justify-between text-[11px] font-medium font-mono">
+                <div className="flex justify-between text-ui-11 font-medium font-mono">
                   <span>{t("settings.resources.liveMonitor.ram")}</span>
                   <span
                     className={cn("tabular-nums", usageTextClass(ramPercent))}
@@ -154,7 +159,7 @@ export function FloatingMonitor() {
 
               {hasGpu && (
                 <div className="space-y-1">
-                  <div className="flex justify-between text-[11px] font-medium font-mono">
+                  <div className="flex justify-between text-ui-11 font-medium font-mono">
                     <span className="truncate flex-1 pr-2">
                       {t("settings.resources.liveMonitor.vram")}{" "}
                       {devices.length > 1
@@ -164,17 +169,20 @@ export function FloatingMonitor() {
                     <span
                       className={cn(
                         "shrink-0 tabular-nums",
-                        usageTextClass(vramPercent),
+                        vramUsageKnown
+                          ? usageTextClass(vramPercent)
+                          : "text-muted-foreground",
                       )}
                     >
-                      {Math.round(vramPercent)}%
+                      {vramUsageKnown ? `${Math.round(vramPercent)}%` : "--"}
                     </span>
                   </div>
                   <div className="text-xs text-muted-foreground font-mono tabular-nums">
-                    {formatGiB(vramUsed)} / {formatGiB(vramTotal)}
+                    {vramUsageKnown ? formatGiB(vramUsed) : unknownLabel} /{" "}
+                    {formatGiB(vramTotal)}
                   </div>
                   <Progress
-                    value={vramPercent}
+                    value={vramUsageKnown ? vramPercent : 0}
                     className="mt-1 h-1.5 rounded-full bg-muted"
                     indicatorClassName={usageIndicatorClass(vramPercent)}
                   />
diff --git a/studio/frontend/src/components/llama-update-banner.tsx b/studio/frontend/src/components/llama-update-banner.tsx
index 3db15ffe30..2729558630 100644
--- a/studio/frontend/src/components/llama-update-banner.tsx
+++ b/studio/frontend/src/components/llama-update-banner.tsx
@@ -93,16 +93,17 @@ export function LlamaUpdateBanner({
     });
 
   async function handleUpdate() {
+    const component = status?.component ?? "llama.cpp";
     const result = await apply();
     if (result?.ok) {
       const updatedTag = result.tag ?? status?.latest_tag ?? "the latest build";
       const reloadHint = result.reloadRequired
         ? " Reload your model to use it."
         : "";
-      toast.success(`llama.cpp updated to ${updatedTag}.${reloadHint}`);
+      toast.success(`${component} updated to ${updatedTag}.${reloadHint}`);
     } else if (result) {
       toast.error(
-        `llama.cpp update failed: ${result.error ?? "unknown error"}`,
+        `${component} update failed: ${result.error ?? "unknown error"}`,
       );
     }
   }
@@ -113,6 +114,7 @@ export function LlamaUpdateBanner({
     status != null &&
     (status.update_available || applying);
   const sizeBytes = status?.update_size_bytes ?? null;
+  const component = status?.component ?? "llama.cpp";
   const sizeLabel =
     sizeBytes && sizeBytes > 0
       ? `${Math.round(sizeBytes / (1024 * 1024))} MB`
@@ -142,7 +144,7 @@ export function LlamaUpdateBanner({
             type="button"
             onClick={dismiss}
             className="absolute top-2.5 right-3 flex size-6 items-center justify-center rounded-full text-muted-foreground/60 transition-colors hover:bg-muted hover:text-foreground"
-            aria-label="Dismiss llama.cpp update notification"
+            aria-label={`Dismiss ${component} update notification`}
           >
             <svg
               aria-hidden="true"
@@ -170,7 +172,7 @@ export function LlamaUpdateBanner({
           />
           <div className="min-w-0">
             <p className="font-heading text-base font-medium text-foreground">
-              {applying ? "Updating llama.cpp..." : "New llama.cpp update"}
+              {applying ? `Updating ${component}...` : `New ${component} update`}
             </p>
             <p className="mt-0.5 text-xs text-muted-foreground">
               {status?.installed_tag ?? "unknown"} &rarr;{" "}
@@ -178,7 +180,7 @@ export function LlamaUpdateBanner({
                 {status?.latest_tag ?? ""}
               </span>
             </p>
-            <p className="mt-1 text-[11px] text-muted-foreground/70">
+            <p className="mt-1 text-ui-11 text-muted-foreground/70">
               {sizeLabel ? `${sizeLabel} download · ` : ""}No restart needed
               after update
             </p>
@@ -189,7 +191,7 @@ export function LlamaUpdateBanner({
           <div
             className="mb-1.5 mt-4 h-1 overflow-hidden rounded-full bg-muted"
             role="progressbar"
-            aria-label="Updating llama.cpp"
+            aria-label={`Updating ${component}`}
             aria-valuemin={0}
             aria-valuemax={100}
             aria-valuenow={
@@ -209,7 +211,7 @@ export function LlamaUpdateBanner({
             <Button
               size="sm"
               variant="ghost"
-              className="h-auto rounded-full px-3 py-2 text-[13px] font-medium text-foreground"
+              className="h-auto rounded-full px-3 py-2 text-ui-13 font-medium text-foreground"
               onClick={snooze}
               data-testid="llama-update-snooze-button"
             >
@@ -218,7 +220,7 @@ export function LlamaUpdateBanner({
             <Button
               size="sm"
               // Align pill edge with card padding.
-              className="-mr-1 h-auto rounded-full px-3.5 py-2 text-[13px]"
+              className="-mr-1 h-auto rounded-full px-3.5 py-2 text-ui-13"
               onClick={handleUpdate}
               data-testid="llama-update-button"
             >
diff --git a/studio/frontend/src/components/navbar.tsx b/studio/frontend/src/components/navbar.tsx
index 44387f2480..1165705888 100644
--- a/studio/frontend/src/components/navbar.tsx
+++ b/studio/frontend/src/components/navbar.tsx
@@ -22,7 +22,7 @@ export function Navbar() {
     );
   }
   return (
-    <header className="absolute top-0 inset-x-0 z-40 h-[48px] pointer-events-none">
+    <header className="absolute top-0 inset-x-0 z-[45] h-[48px] pointer-events-none">
       <div className="flex h-full items-start pt-[11px] pl-2">
         <SidebarTrigger className="pointer-events-auto !size-[34px]" />
       </div>
diff --git a/studio/frontend/src/components/section-card.tsx b/studio/frontend/src/components/section-card.tsx
index e894749494..3720cf48bd 100644
--- a/studio/frontend/src/components/section-card.tsx
+++ b/studio/frontend/src/components/section-card.tsx
@@ -77,7 +77,7 @@ export function SectionCard({
           <div className="flex items-center gap-2 pb-1">
             <h3 className="text-sm font-semibold">{title}</h3>
             {badge && (
-              <span className="rounded-full bg-control-accent/15 px-2 py-0.5 text-[10px] font-semibold text-control-accent">
+              <span className="rounded-full bg-control-accent/15 px-2 py-0.5 text-ui-10 font-semibold text-control-accent">
                 {badge}
               </span>
             )}
diff --git a/studio/frontend/src/components/shutdown-dialog.tsx b/studio/frontend/src/components/shutdown-dialog.tsx
index e3e6ca9920..8f746c9414 100644
--- a/studio/frontend/src/components/shutdown-dialog.tsx
+++ b/studio/frontend/src/components/shutdown-dialog.tsx
@@ -52,8 +52,8 @@ export function ShutdownDialog({
     onAfterShutdown?.();
     document.body.innerHTML = `
       <div style="display:flex;flex-direction:column;align-items:center;justify-content:center;height:100vh;font-family:sans-serif;gap:12px">
-        <p style="font-size:1.1rem;font-weight:600;margin:0">Unsloth Studio has stopped.</p>
-        <p style="font-size:0.9rem;color:#888;margin:0">You can now close this tab.</p>
+        <p style="font-size:calc(1.1rem * var(--ui-font-scale, 1));font-weight:600;margin:0">Unsloth Studio has stopped.</p>
+        <p style="font-size:calc(0.9rem * var(--ui-font-scale, 1));color:#888;margin:0">You can now close this tab.</p>
       </div>`;
   };
 
diff --git a/studio/frontend/src/components/tauri/startup-screen.tsx b/studio/frontend/src/components/tauri/startup-screen.tsx
index 678051b36b..74ed2f2cbe 100644
--- a/studio/frontend/src/components/tauri/startup-screen.tsx
+++ b/studio/frontend/src/components/tauri/startup-screen.tsx
@@ -72,7 +72,7 @@ function DiagnosticsCopyActions({
           readOnly
           value={manualReport}
           onFocus={(event) => event.currentTarget.select()}
-          className="h-32 w-full max-w-md resize-none rounded-lg border border-border/50 bg-muted/30 p-2 font-mono text-[10px] text-muted-foreground"
+          className="h-32 w-full max-w-md resize-none rounded-lg border border-border/50 bg-muted/30 p-2 font-mono text-ui-10 text-muted-foreground"
         />
       )}
     </div>
diff --git a/studio/frontend/src/components/tauri/update-banner.tsx b/studio/frontend/src/components/tauri/update-banner.tsx
index 4fe8a54377..6f5e655889 100644
--- a/studio/frontend/src/components/tauri/update-banner.tsx
+++ b/studio/frontend/src/components/tauri/update-banner.tsx
@@ -142,7 +142,7 @@ export function UpdateBanner({
                     </span>
                   </p>
                 )}
-                <p className="mt-1 text-[11px] text-muted-foreground/70">
+                <p className="mt-1 text-ui-11 text-muted-foreground/70">
                   {showFailure
                     ? "Backend recovered. Diagnostics are still available."
                     : isManualLinuxPackage
@@ -166,7 +166,7 @@ export function UpdateBanner({
                   <Button
                     size="sm"
                     variant="ghost"
-                    className="h-auto rounded-full px-3 py-2 text-[13px] font-medium text-foreground"
+                    className="h-auto rounded-full px-3 py-2 text-ui-13 font-medium text-foreground"
                     onClick={() => {
                       handleCopyDiagnostics().catch(console.error);
                     }}
@@ -176,14 +176,14 @@ export function UpdateBanner({
                   <Button
                     size="sm"
                     variant="ghost"
-                    className="h-auto rounded-full px-3 py-2 text-[13px] font-medium text-foreground"
+                    className="h-auto rounded-full px-3 py-2 text-ui-13 font-medium text-foreground"
                     onClick={onDismiss}
                   >
                     Later
                   </Button>
                   <Button
                     size="sm"
-                    className="-mr-1 h-auto rounded-full px-3.5 py-2 text-[13px]"
+                    className="-mr-1 h-auto rounded-full px-3.5 py-2 text-ui-13"
                     onClick={onInstall}
                     disabled={installDisabled}
                   >
@@ -195,14 +195,14 @@ export function UpdateBanner({
                   <Button
                     size="sm"
                     variant="ghost"
-                    className="h-auto rounded-full px-3 py-2 text-[13px] font-medium text-foreground"
+                    className="h-auto rounded-full px-3 py-2 text-ui-13 font-medium text-foreground"
                     onClick={onDismiss}
                   >
                     Remind me later
                   </Button>
                   <Button
                     size="sm"
-                    className="-mr-1 h-auto rounded-full px-3.5 py-2 text-[13px]"
+                    className="-mr-1 h-auto rounded-full px-3.5 py-2 text-ui-13"
                     onClick={onInstall}
                     disabled={installDisabled}
                   >
@@ -219,7 +219,7 @@ export function UpdateBanner({
                 readOnly={true}
                 value={manualReport}
                 onFocus={(event) => event.currentTarget.select()}
-                className="mt-2 h-28 w-full resize-none rounded-lg border border-border/50 bg-muted/30 p-2 font-mono text-[10px] text-muted-foreground"
+                className="mt-2 h-28 w-full resize-none rounded-lg border border-border/50 bg-muted/30 p-2 font-mono text-ui-10 text-muted-foreground"
               />
             )}
           </div>
diff --git a/studio/frontend/src/components/tauri/update-screen.tsx b/studio/frontend/src/components/tauri/update-screen.tsx
index 3199425f69..d37e6873ae 100644
--- a/studio/frontend/src/components/tauri/update-screen.tsx
+++ b/studio/frontend/src/components/tauri/update-screen.tsx
@@ -72,7 +72,7 @@ function LogViewer({ logs }: { logs: string[] }) {
   return (
     <div
       ref={scrollRef}
-      className="mt-4 h-[180px] w-full max-w-xl overflow-y-auto rounded-lg border border-border/40 bg-muted/30 p-3 font-mono text-[11px] leading-relaxed text-muted-foreground"
+      className="mt-4 h-[180px] w-full max-w-xl overflow-y-auto rounded-lg border border-border/40 bg-muted/30 p-3 font-mono text-ui-11 leading-relaxed text-muted-foreground"
     >
       {logs.map((line, i) => (
         <div key={i} className="whitespace-pre-wrap break-all">
@@ -197,7 +197,7 @@ export function UpdateScreen({
             readOnly
             value={manualReport}
             onFocus={(event) => event.currentTarget.select()}
-            className="mt-2 h-32 w-full max-w-xl resize-none rounded-lg border border-border/50 bg-muted/30 p-2 font-mono text-[10px] text-muted-foreground"
+            className="mt-2 h-32 w-full max-w-xl resize-none rounded-lg border border-border/50 bg-muted/30 p-2 font-mono text-ui-10 text-muted-foreground"
           />
         )}
 
diff --git a/studio/frontend/src/components/tauri/window-titlebar.tsx b/studio/frontend/src/components/tauri/window-titlebar.tsx
index d86af54f79..6a0ff8741a 100644
--- a/studio/frontend/src/components/tauri/window-titlebar.tsx
+++ b/studio/frontend/src/components/tauri/window-titlebar.tsx
@@ -40,7 +40,7 @@ type NavigatorWithUserAgentData = Navigator & {
   };
 };
 
-function getClientPlatform(): string {
+export function getClientPlatform(): string {
   if (typeof navigator === "undefined") {
     return "";
   }
@@ -115,7 +115,7 @@ export function WindowTitlebar({
       ? "var(--studio-sidebar-expanded-width,17.5rem)"
       : "var(--studio-sidebar-collapsed-width,3rem)"
     : "0px";
-  const contentBorderLeft = `calc(${sidebarWidth} + 12px)`;
+  const contentBorderLeft = pinned ? `calc(${sidebarWidth} + 12px)` : "0px";
 
   const refreshMaximized = useCallback(async () => {
     if (!enabled) {
@@ -232,10 +232,10 @@ export function WindowTitlebar({
         )}
         aria-label="Window titlebar"
       >
-        {showSidebarSurface && (
+        {showSidebarSurface && pinned && (
           <div
             aria-hidden="true"
-            className="pointer-events-none absolute top-full h-3 w-px -translate-x-px bg-sidebar"
+            className="pointer-events-none absolute top-full size-3 -translate-x-px bg-sidebar"
             style={{ left: sidebarWidth }}
           />
         )}
@@ -246,7 +246,7 @@ export function WindowTitlebar({
             style={{ left: contentBorderLeft, right: 0 }}
           />
         )}
-        {showSidebarSurface && (
+        {showSidebarSurface && pinned && (
           <div
             aria-hidden="true"
             className="pointer-events-none absolute top-full size-3 -translate-x-px rounded-tl-[12px] border-l border-t border-sidebar-border bg-background"
@@ -257,7 +257,7 @@ export function WindowTitlebar({
           <div
             className={cn(
               "pointer-events-auto absolute left-0 top-0 flex h-full min-w-0 items-center",
-              pinned ? "gap-2 px-3" : "justify-center",
+              pinned ? "gap-2 pl-3" : "justify-center",
             )}
             style={{ width: sidebarWidth }}
             onMouseDown={handleDragMouseDown}
@@ -273,7 +273,7 @@ export function WindowTitlebar({
                     draggable={false}
                     className="size-5 shrink-0 rounded-[6px] object-cover"
                   />
-                  <span className="min-w-0 truncate text-[13px] font-semibold leading-none tracking-[0.01em] text-nav-fg">
+                  <span className="min-w-0 truncate text-ui-13 font-semibold leading-none tracking-[0.01em] text-nav-fg">
                     Unsloth Studio
                   </span>
                 </div>
diff --git a/studio/frontend/src/components/ui/calendar.tsx b/studio/frontend/src/components/ui/calendar.tsx
index 6ace64bed6..6ea80b9c88 100644
--- a/studio/frontend/src/components/ui/calendar.tsx
+++ b/studio/frontend/src/components/ui/calendar.tsx
@@ -93,7 +93,7 @@ function Calendar({
         table: "w-full border-collapse",
         weekdays: cn("flex", defaultClassNames.weekdays),
         weekday: cn(
-          "text-muted-foreground rounded-(--cell-radius) flex-1 font-normal text-[0.8rem] select-none",
+          "text-muted-foreground rounded-(--cell-radius) flex-1 font-normal text-[calc(0.8rem*var(--ui-font-scale,1))] select-none",
           defaultClassNames.weekday,
         ),
         week: cn("flex w-full mt-2", defaultClassNames.week),
@@ -102,7 +102,7 @@ function Calendar({
           defaultClassNames.week_number_header,
         ),
         week_number: cn(
-          "text-[0.8rem] select-none text-muted-foreground",
+          "text-[calc(0.8rem*var(--ui-font-scale,1))] select-none text-muted-foreground",
           defaultClassNames.week_number,
         ),
         day: cn(
diff --git a/studio/frontend/src/components/ui/combobox.tsx b/studio/frontend/src/components/ui/combobox.tsx
index 11ba03a3e8..07202d30ae 100644
--- a/studio/frontend/src/components/ui/combobox.tsx
+++ b/studio/frontend/src/components/ui/combobox.tsx
@@ -7,6 +7,7 @@
 
 import { Combobox as ComboboxPrimitive } from "@base-ui/react";
 import * as React from "react";
+import { useWheelScrollRef } from "@/hooks";
 import { createContext, useState } from "react";
 
 import { Button } from "@/components/ui/button";
@@ -100,13 +101,19 @@ function ComboboxInput({
   disabled = false,
   showTrigger = true,
   showClear = false,
+  startAddon,
   ...props
 }: ComboboxPrimitive.Input.Props & {
   showTrigger?: boolean;
   showClear?: boolean;
+  /** Optional leading content (e.g. a search icon) rendered before the input. */
+  startAddon?: React.ReactNode;
 }): React.ReactElement {
   return (
     <InputGroup className={cn("w-auto", className)}>
+      {startAddon && (
+        <InputGroupAddon align="inline-start">{startAddon}</InputGroupAddon>
+      )}
       <ComboboxPrimitive.Input
         render={<InputGroupInput disabled={disabled} />}
         {...props}
@@ -195,8 +202,11 @@ function ComboboxList({
   className,
   ...props
 }: ComboboxPrimitive.List.Props): React.ReactElement {
+  const listRef = useWheelScrollRef<HTMLDivElement>();
+
   return (
     <ComboboxPrimitive.List
+      ref={listRef}
       data-slot="combobox-list"
       className={cn(
         "no-scrollbar max-h-[min(calc(--spacing(72)---spacing(9)),calc(var(--available-height)---spacing(9)))] scroll-py-1 overflow-y-auto p-1 data-empty:p-0 overflow-y-auto overscroll-contain",
diff --git a/studio/frontend/src/components/ui/confetti.tsx b/studio/frontend/src/components/ui/confetti.tsx
index 892bffdb18..35f5913240 100644
--- a/studio/frontend/src/components/ui/confetti.tsx
+++ b/studio/frontend/src/components/ui/confetti.tsx
@@ -34,7 +34,7 @@ export type ConfettiRef = Api | null;
 
 const ConfettiContext = createContext<Api>({} as Api);
 
-// Studio CSP blocks canvas-confetti's default blob: worker, so force
+// Unsloth CSP blocks canvas-confetti's default blob: worker, so force
 // useWorker: false. Module-scoped so the prop default keeps stable
 // identity across renders (`canvasRef` depends on `globalOptions`).
 const DEFAULT_GLOBAL_OPTIONS: ConfettiGlobalOptions = {
diff --git a/studio/frontend/src/components/ui/copyable-error-chip.tsx b/studio/frontend/src/components/ui/copyable-error-chip.tsx
index 595df5cf62..b9759f111c 100644
--- a/studio/frontend/src/components/ui/copyable-error-chip.tsx
+++ b/studio/frontend/src/components/ui/copyable-error-chip.tsx
@@ -72,7 +72,7 @@ export function CopyableErrorChip({
             onClick={handleCopy}
             aria-label={copied ? "Copied" : "Copy error message"}
             className={cn(
-              "inline-flex items-center gap-1 rounded-md border border-border/60 px-2 py-1 text-[11px] text-muted-foreground transition-colors hover:bg-muted/60 focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
+              "inline-flex items-center gap-1 rounded-md border border-border/60 px-2 py-1 text-ui-11 text-muted-foreground transition-colors hover:bg-muted/60 focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
               copied && "border-emerald-500/40 text-emerald-600 dark:text-emerald-500",
             )}
           >
diff --git a/studio/frontend/src/components/ui/data-table.tsx b/studio/frontend/src/components/ui/data-table.tsx
index 31a93b7449..391007b2e6 100644
--- a/studio/frontend/src/components/ui/data-table.tsx
+++ b/studio/frontend/src/components/ui/data-table.tsx
@@ -100,7 +100,7 @@ export function DataTable<TData, TValue>({
                 {row.getVisibleCells().map((cell) => (
                   <TableCell
                     key={cell.id}
-                    className="border-r border-border/20 last:border-r-0 text-[13px] py-3 px-4 align-top whitespace-normal"
+                    className="border-r border-border/20 last:border-r-0 text-ui-13 py-3 px-4 align-top whitespace-normal"
                   >
                     {flexRender(cell.column.columnDef.cell, cell.getContext())}
                   </TableCell>
diff --git a/studio/frontend/src/components/ui/dropdown-menu.tsx b/studio/frontend/src/components/ui/dropdown-menu.tsx
index ea6dbbb6e7..65cf123965 100644
--- a/studio/frontend/src/components/ui/dropdown-menu.tsx
+++ b/studio/frontend/src/components/ui/dropdown-menu.tsx
@@ -39,6 +39,7 @@ function DropdownMenuContent({
   className,
   align = "start",
   sideOffset = 0,
+  children,
   ...props
 }: React.ComponentProps<typeof DropdownMenuPrimitive.Content>) {
   return (
@@ -51,11 +52,21 @@ function DropdownMenuContent({
           // The 3px alignment nudge must be margin, not translate: a transform
           // here makes this scroll container the containing block for nested
           // position:fixed submenu wrappers, clipping every submenu.
-          "data-open:animate-in data-closed:animate-out data-closed:fade-out-0 data-open:fade-in-0 data-closed:zoom-out-95 data-open:zoom-in-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2 bg-popover text-popover-foreground min-w-48 rounded-lg p-1 duration-100 z-50 max-h-(--radix-dropdown-menu-content-available-height) w-[calc(var(--radix-dropdown-menu-trigger-width)_+_6px)] data-[align=start]:-ml-[3px] data-[align=end]:ml-[3px] origin-(--radix-dropdown-menu-content-transform-origin) overflow-x-hidden overflow-y-auto data-[state=closed]:overflow-hidden",
+          "data-open:animate-in data-closed:animate-out data-closed:fade-out-0 data-open:fade-in-0 data-closed:zoom-out-95 data-open:zoom-in-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2 bg-popover text-popover-foreground min-w-48 rounded-lg p-1 duration-100 z-50 max-h-(--radix-dropdown-menu-content-available-height) w-[calc(var(--radix-dropdown-menu-trigger-width)_+_6px)] data-[align=start]:-ml-[3px] data-[align=end]:ml-[3px] origin-(--radix-dropdown-menu-content-transform-origin) flex flex-col overflow-hidden",
           className,
         )}
         {...props}
-      />
+      >
+        {/* Scroll an inner viewport, not the rounded surface: a scrollbar on
+            the surface squares its corners in WebKit. The surface padding
+            insets the scrollbar clear of the curve. */}
+        <div
+          data-slot="dropdown-menu-viewport"
+          className="min-h-0 flex-1 overflow-x-hidden overflow-y-auto"
+        >
+          {children}
+        </div>
+      </DropdownMenuPrimitive.Content>
     </DropdownMenuPrimitive.Portal>
   );
 }
@@ -307,7 +318,7 @@ function DropdownMenuSubContent({
             isMobile && contentWidth === 0 ? "hidden" : style?.visibility,
         }}
         className={cn(
-          "data-open:animate-in data-closed:animate-out data-closed:fade-out-0 data-open:fade-in-0 data-closed:zoom-out-95 data-open:zoom-in-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2 bg-popover text-popover-foreground min-w-36 max-w-[calc(100vw-2rem)] rounded-lg p-1 duration-100 z-50 origin-(--radix-dropdown-menu-content-transform-origin) overflow-hidden",
+          "data-open:animate-in data-closed:animate-out data-closed:fade-out-0 data-open:fade-in-0 data-closed:zoom-out-95 data-open:zoom-in-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2 bg-popover text-popover-foreground min-w-36 max-w-[calc(100vw-32px)] rounded-lg p-1 duration-100 z-50 origin-(--radix-dropdown-menu-content-transform-origin) overflow-hidden",
           className,
         )}
         {...props}
diff --git a/studio/frontend/src/components/ui/input-group.tsx b/studio/frontend/src/components/ui/input-group.tsx
index 55984452f0..7ec7a2e3d4 100644
--- a/studio/frontend/src/components/ui/input-group.tsx
+++ b/studio/frontend/src/components/ui/input-group.tsx
@@ -122,7 +122,7 @@ function InputGroupInput({
     <Input
       data-slot="input-group-control"
       className={cn(
-        "rounded-none border-0 bg-transparent shadow-none ring-0 focus-visible:ring-0 aria-invalid:ring-0 dark:bg-transparent flex-1",
+        "rounded-none border-0 bg-transparent shadow-none ring-0 focus-visible:ring-0 aria-invalid:ring-0 dark:bg-transparent dark:focus-visible:bg-transparent flex-1",
         className,
       )}
       {...props}
diff --git a/studio/frontend/src/components/ui/select.tsx b/studio/frontend/src/components/ui/select.tsx
index 925cc45b36..1bb95848f7 100644
--- a/studio/frontend/src/components/ui/select.tsx
+++ b/studio/frontend/src/components/ui/select.tsx
@@ -126,7 +126,7 @@ function SelectContent({
         data-slot="select-content"
         data-align-trigger={position === "item-aligned"}
         className={cn(
-          "bg-popover text-popover-foreground font-heading data-open:animate-in data-closed:animate-out data-closed:fade-out-0 data-open:fade-in-0 data-closed:zoom-out-95 data-open:zoom-in-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2 min-w-36 rounded-xl p-1 corner-squircle duration-100 relative z-50 max-h-(--radix-select-content-available-height) origin-(--radix-select-content-transform-origin) overflow-x-hidden overflow-y-auto ",
+          "bg-popover text-popover-foreground font-heading data-open:animate-in data-closed:animate-out data-closed:fade-out-0 data-open:fade-in-0 data-closed:zoom-out-95 data-open:zoom-in-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2 min-w-36 rounded-xl p-1 corner-squircle duration-100 relative z-50 max-h-(--radix-select-content-available-height) origin-(--radix-select-content-transform-origin) flex flex-col overflow-hidden",
           // No popper translate offset: the menu sits flush against the trigger.
           className,
         )}
@@ -135,10 +135,18 @@ function SelectContent({
         {...props}
       >
         <SelectScrollUpButton />
+        {/* The Radix viewport is the scroller (not the rounded surface, whose
+            scrollbar would square its corners in WebKit; not a wrapper, which
+            would blind Radix's scroll handling). The surface padding insets
+            the scrollbar clear of the curve. */}
         <SelectPrimitive.Viewport
           data-position={position}
+          // Inline: Radix injects a scrollbar-width:none stylesheet rule that
+          // Firefox lets win over author !important.
+          style={{ scrollbarWidth: "thin" }}
           className={cn(
-            "data-[position=popper]:h-[var(--radix-select-trigger-height)] data-[position=popper]:w-full data-[position=popper]:min-w-[var(--radix-select-trigger-width)]",
+            "min-h-0 flex-1 overflow-x-hidden overflow-y-auto",
+            "data-[position=popper]:w-full data-[position=popper]:min-w-[var(--radix-select-trigger-width)]",
             position === "popper" && "",
           )}
         >
diff --git a/studio/frontend/src/components/ui/sidebar.tsx b/studio/frontend/src/components/ui/sidebar.tsx
index 4eb37d4e89..0fe82eb428 100644
--- a/studio/frontend/src/components/ui/sidebar.tsx
+++ b/studio/frontend/src/components/ui/sidebar.tsx
@@ -471,7 +471,7 @@ function SidebarGroupLabel({
       data-slot="sidebar-group-label"
       data-sidebar="group-label"
       className={cn(
-        "text-[#94a3b8] dark:text-[#666] ring-sidebar-ring h-auto pt-3 pb-2 px-4 rounded-md text-[10px] font-semibold uppercase tracking-[0em] group-data-[collapsible=icon]:-mt-8 group-data-[collapsible=icon]:opacity-0 focus-visible:ring-1 [&>svg]:size-3 flex shrink-0 items-center outline-hidden [&>svg]:shrink-0",
+        "text-[#94a3b8] dark:text-[#666] ring-sidebar-ring h-auto pt-3 pb-2 px-4 rounded-md text-ui-10 font-semibold uppercase tracking-[0em] group-data-[collapsible=icon]:-mt-8 group-data-[collapsible=icon]:opacity-0 focus-visible:ring-1 [&>svg]:size-3 flex shrink-0 items-center outline-hidden [&>svg]:shrink-0",
         className
       )}
       {...props}
diff --git a/studio/frontend/src/components/ui/tooltip.tsx b/studio/frontend/src/components/ui/tooltip.tsx
index cbc1a09a8f..91745af5ec 100644
--- a/studio/frontend/src/components/ui/tooltip.tsx
+++ b/studio/frontend/src/components/ui/tooltip.tsx
@@ -67,9 +67,14 @@ function TooltipTrigger({
 
   const handleClick = useCallback(
     (e: React.MouseEvent<HTMLButtonElement>) => {
+      // Run the composed handler first: when this trigger wraps another Radix
+      // trigger (e.g. DialogTrigger around an attachment tile), that trigger's
+      // action is skipped if the event is already default-prevented.
+      onClick?.(e);
+      // preventDefault keeps Radix Tooltip's internal close-on-click from
+      // undoing the tap-toggle below (its composed handler checks it).
       e.preventDefault();
       toggle?.();
-      onClick?.(e);
     },
     [toggle, onClick],
   );
diff --git a/studio/frontend/src/components/web/update-banner.tsx b/studio/frontend/src/components/web/update-banner.tsx
index 55ef06166b..d8ae92bf5f 100644
--- a/studio/frontend/src/components/web/update-banner.tsx
+++ b/studio/frontend/src/components/web/update-banner.tsx
@@ -132,7 +132,7 @@ export function WebUpdateBanner({
                 href={RELEASE_NOTES_URL}
                 target="_blank"
                 rel="noopener noreferrer"
-                className="-ml-2 whitespace-nowrap rounded-full px-2.5 py-2 text-[13px] font-medium text-foreground transition-colors hover:bg-muted"
+                className="-ml-2 whitespace-nowrap rounded-full px-2.5 py-2 text-ui-13 font-medium text-foreground transition-colors hover:bg-muted"
                 data-testid="web-update-release-notes-link"
               >
                 Release notes
@@ -142,7 +142,7 @@ export function WebUpdateBanner({
                 <Button
                   size="sm"
                   variant="ghost"
-                  className="h-auto rounded-full px-3 py-2 text-[13px] font-medium text-foreground"
+                  className="h-auto rounded-full px-3 py-2 text-ui-13 font-medium text-foreground"
                   onClick={snooze}
                   data-testid="web-update-snooze-button"
                 >
@@ -151,7 +151,7 @@ export function WebUpdateBanner({
                 <Button
                   size="sm"
                   // -mr optically aligns the filled pill's edge with the card padding
-                  className="-mr-1 h-auto rounded-full px-3.5 py-2 text-[13px]"
+                  className="-mr-1 h-auto rounded-full px-3.5 py-2 text-ui-13"
                   onClick={handleCopyCommand}
                   data-testid="web-update-copy-button"
                 >
diff --git a/studio/frontend/src/config/training.ts b/studio/frontend/src/config/training.ts
index 873e9aa203..ca0ad498d6 100644
--- a/studio/frontend/src/config/training.ts
+++ b/studio/frontend/src/config/training.ts
@@ -92,6 +92,17 @@ export const OPTIMIZER_OPTIONS: ReadonlyArray<{ value: string; label: string }>
   { value: "adamw_torch_fused", label: "AdamW (PyTorch Fused)" },
 ];
 
+// MLX trainer optimizers (Apple Silicon); must match SUPPORTED_MLX_OPTIMIZERS in
+// unsloth-zoo's mlx/trainer.py. The CUDA/torch names above are remapped to AdamW on MLX.
+export const MLX_OPTIMIZER_OPTIONS: ReadonlyArray<{ value: string; label: string }> = [
+  { value: "adamw", label: "AdamW" },
+  { value: "adam", label: "Adam" },
+  { value: "lion", label: "Lion" },
+  { value: "muon", label: "Muon" },
+  { value: "sgd", label: "SGD" },
+  { value: "adafactor", label: "Adafactor" },
+];
+
 export const LR_SCHEDULER_OPTIONS: ReadonlyArray<{ value: string; label: string }> = [
   { value: "linear", label: "Linear" },
   { value: "cosine", label: "Cosine" },
diff --git a/studio/frontend/src/features/auth/components/auth-form.tsx b/studio/frontend/src/features/auth/components/auth-form.tsx
index 119471da10..72181b8e4f 100644
--- a/studio/frontend/src/features/auth/components/auth-form.tsx
+++ b/studio/frontend/src/features/auth/components/auth-form.tsx
@@ -196,8 +196,10 @@ export function AuthForm({ mode }: AuthFormProps): ReactElement | null {
     !isLoginMode &&
     (currentPassword.length < 8 ||
       newPassword.length < 8 ||
+      /\s/.test(newPassword) ||
       newPassword !== confirmPassword ||
       currentPassword === newPassword);
+  const showWhitespaceWarning = !isLoginMode && /\s/.test(newPassword);
   const showPasswordMismatchWarning =
     !isLoginMode &&
     newPassword.length > 0 &&
@@ -222,6 +224,10 @@ export function AuthForm({ mode }: AuthFormProps): ReactElement | null {
         setError("New password must be at least 8 characters.");
         return;
       }
+      if (/\s/.test(newPassword)) {
+        setError("New password cannot contain spaces.");
+        return;
+      }
       if (newPassword !== confirmPassword) {
         setError("Passwords do not match.");
         return;
@@ -298,7 +304,7 @@ export function AuthForm({ mode }: AuthFormProps): ReactElement | null {
       // reset-password"), which the installer puts on PATH on every platform.
       // Do NOT rewrite it to a relative Windows path like
       // ".\unsloth_studio\Scripts\unsloth.exe ..." -- that only resolves inside
-      // the Studio home dir and fails with CommandNotFoundException elsewhere.
+      // the Unsloth home dir and fails with CommandNotFoundException elsewhere.
       // Show the backend message as-is.
       const msg = err instanceof Error ? err.message : "Auth failed.";
       setError(msg);
@@ -425,13 +431,17 @@ export function AuthForm({ mode }: AuthFormProps): ReactElement | null {
             </div>
             <p
               className={`min-h-4 text-xs ${
-                showPasswordMismatchWarning ? "text-destructive" : "text-muted-foreground"
+                showWhitespaceWarning || showPasswordMismatchWarning
+                  ? "text-destructive"
+                  : "text-muted-foreground"
               }`}
               aria-live="polite"
             >
-              {showPasswordMismatchWarning
-                ? "Please ensure passwords match."
-                : "Must be at least 8 characters."}
+              {showWhitespaceWarning
+                ? "New password cannot contain spaces."
+                : showPasswordMismatchWarning
+                  ? "Please ensure passwords match."
+                  : "Must be at least 8 characters."}
             </p>
           </>
         )}
@@ -439,7 +449,11 @@ export function AuthForm({ mode }: AuthFormProps): ReactElement | null {
         {helperText && (
           <p className="text-center text-sm text-amber-600">{helperText}</p>
         )}
-        {error && <p className="text-center text-sm text-destructive">{error}</p>}
+        {error && (
+          <p className="text-center text-sm text-destructive [overflow-wrap:anywhere]">
+            {error}
+          </p>
+        )}
 
         <Button
           type="submit"
diff --git a/studio/frontend/src/features/chat/adapters/dictation-level.ts b/studio/frontend/src/features/chat/adapters/dictation-level.ts
new file mode 100644
index 0000000000..e38060ba0e
--- /dev/null
+++ b/studio/frontend/src/features/chat/adapters/dictation-level.ts
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+type LevelListener = (level: number) => void;
+type FrameListener = (rawRms: number, now: number) => void;
+
+const levelListeners = new Set<LevelListener>();
+
+/** Subscribe to the live microphone level (0..1) during dictation. */
+export function subscribeDictationLevel(listener: LevelListener): () => void {
+  levelListeners.add(listener);
+  return () => {
+    levelListeners.delete(listener);
+  };
+}
+
+function publishLevel(level: number): void {
+  for (const listener of levelListeners) {
+    listener(level);
+  }
+}
+
+/**
+ * Start a lightweight Web Audio meter for the shared recording waveform and
+ * optional voice-activity detection. Returns an idempotent cleanup function.
+ */
+export function startDictationLevelMeter(
+  source: MediaStream,
+  onFrame?: FrameListener,
+): () => void {
+  let audioContext: AudioContext | null = null;
+  let levelRaf = 0;
+  let stopped = false;
+
+  const stop = () => {
+    if (stopped) {
+      return;
+    }
+    stopped = true;
+    if (levelRaf) {
+      cancelAnimationFrame(levelRaf);
+    }
+    levelRaf = 0;
+    audioContext?.close().catch(() => {
+      // A closing or already-closed context is harmless.
+    });
+    audioContext = null;
+    publishLevel(0);
+  };
+
+  try {
+    const Ctx =
+      window.AudioContext ||
+      (window as unknown as { webkitAudioContext?: typeof AudioContext })
+        .webkitAudioContext;
+    if (!Ctx) {
+      return stop;
+    }
+    audioContext = new Ctx();
+    audioContext.resume().catch(() => {
+      // Some browsers resume automatically after microphone permission.
+    });
+    const node = audioContext.createMediaStreamSource(source);
+    const analyser = audioContext.createAnalyser();
+    analyser.fftSize = 512;
+    node.connect(analyser);
+    const data = new Uint8Array(analyser.frequencyBinCount);
+    const tick = () => {
+      if (stopped) {
+        return;
+      }
+      analyser.getByteTimeDomainData(data);
+      let sum = 0;
+      for (const sample of data) {
+        const value = (sample - 128) / 128;
+        sum += value * value;
+      }
+      const rms = Math.sqrt(sum / data.length);
+      onFrame?.(rms, performance.now());
+      // Perceptual boost so normal speech remains clearly visible.
+      publishLevel(Math.min(1, rms * 3.2));
+      levelRaf = requestAnimationFrame(tick);
+    };
+    levelRaf = requestAnimationFrame(tick);
+  } catch {
+    // The waveform is cosmetic; recording can continue without Web Audio.
+    stop();
+  }
+
+  return stop;
+}
diff --git a/studio/frontend/src/features/chat/adapters/studio-dictation-adapter.tsx b/studio/frontend/src/features/chat/adapters/studio-dictation-adapter.tsx
new file mode 100644
index 0000000000..d637a32b0d
--- /dev/null
+++ b/studio/frontend/src/features/chat/adapters/studio-dictation-adapter.tsx
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { useSettingsDialogStore } from "@/features/settings/stores/settings-dialog-store";
+import {
+  type DictationEngine,
+  useVoiceSettingsStore,
+} from "@/features/settings/stores/voice-settings-store";
+import { toast } from "@/lib/toast";
+import type { DictationAdapter } from "@assistant-ui/react";
+import { StudioModelDictationAdapter } from "./studio-model-dictation-adapter";
+import {
+  type StudioDictationSession,
+  StudioWebSpeechDictationAdapter,
+} from "./studio-web-speech-dictation-adapter";
+
+// The one live dictation session, so the recording bar's discard (X) can cancel
+// it without going through assistant-ui (which only exposes stop, i.e.
+// transcribe). Cancelling emits no transcript, so composer text is untouched.
+let activeSession: StudioDictationSession | null = null;
+
+/** Discard the current dictation without transcribing. Safe to call when idle. */
+export function cancelActiveStudioDictation(): void {
+  const session = activeSession;
+  activeSession = null;
+  session?.cancel();
+}
+
+/**
+ * Routes dictation to the engine chosen in Voice settings, resolved at listen()
+ * time so switching engines applies without reloading the chat runtime.
+ */
+/** Both local engines (Transformers and GGUF) record via MediaRecorder. */
+function usesModelRecording(dictationEngine: DictationEngine): boolean {
+  return dictationEngine === "model";
+}
+
+export class StudioDictationAdapter implements DictationAdapter {
+  // Chat linked in Recent dictations. undefined follows the active single chat;
+  // null records no chat (composers outside it, e.g. Compare).
+  private readonly chatId: string | null | undefined;
+
+  constructor(options: { chatId?: string | null } = {}) {
+    this.chatId = options.chatId;
+  }
+
+  static isSupported(
+    dictationEngine: DictationEngine = useVoiceSettingsStore.getState()
+      .dictationEngine,
+  ): boolean {
+    return usesModelRecording(dictationEngine)
+      ? StudioModelDictationAdapter.isSupported()
+      : StudioWebSpeechDictationAdapter.isSupported();
+  }
+
+  listen(): StudioDictationSession {
+    const session = this.createSession();
+    // A second entry point (chat, Compare, settings test) replaces the active
+    // session; cancel the old one so it cannot keep the mic open or save a
+    // transcript with no discard button pointing at it.
+    cancelActiveStudioDictation();
+    activeSession = session;
+    // Forget the session once it ends so a later cancel is a no-op.
+    const clear = () => {
+      if (activeSession === session) {
+        activeSession = null;
+      }
+    };
+    session.onSpeechEnd(clear);
+    session.onEnd?.(clear);
+    return session;
+  }
+
+  private createSession(): StudioDictationSession {
+    const { dictationEngine } = useVoiceSettingsStore.getState();
+    if (usesModelRecording(dictationEngine)) {
+      if (StudioModelDictationAdapter.isSupported()) {
+        return new StudioModelDictationAdapter({ chatId: this.chatId }).listen();
+      }
+      throw new Error(
+        "Local model dictation is not supported in this browser.",
+      );
+    }
+    if (StudioWebSpeechDictationAdapter.isSupported()) {
+      return new StudioWebSpeechDictationAdapter({ chatId: this.chatId }).listen();
+    }
+    throw new Error("Browser dictation is not supported in this browser.");
+  }
+}
+
+/** Whether dictation can run now for the chosen engine. */
+export function isStudioDictationAvailable(
+  dictationEngine: DictationEngine = useVoiceSettingsStore.getState()
+    .dictationEngine,
+): boolean {
+  return StudioDictationAdapter.isSupported(dictationEngine);
+}
+
+/** Explain why dictation can't start and point the user to the local model. */
+export function notifyStudioDictationUnavailable(
+  dictationEngine: DictationEngine = useVoiceSettingsStore.getState()
+    .dictationEngine,
+): void {
+  // Both engines need a secure context (localhost or HTTPS).
+  if (typeof window !== "undefined" && !window.isSecureContext) {
+    toast.error("Voice typing needs a secure connection.", {
+      description:
+        "Open Studio at http://127.0.0.1 (localhost) or over HTTPS to dictate.",
+    });
+    return;
+  }
+  if (usesModelRecording(dictationEngine)) {
+    // Defensive: MediaRecorder is effectively always present here.
+    toast.error("Voice recording isn't available in this browser.");
+    return;
+  }
+  // Browser Web Speech is missing (e.g. Firefox). Stack text and button so the
+  // action sits below, not squeezed into a side column.
+  const toastId = toast.error("Voice typing isn't available in this browser.", {
+    description: (
+      <div className="mt-0.5 flex flex-col items-start gap-2 pb-1.5">
+        <span>
+          Choose the local speech-to-text model in Voice settings to dictate
+          here.
+        </span>
+        <button
+          type="button"
+          onClick={() => {
+            useSettingsDialogStore.getState().openDialog("voice");
+            toast.dismiss(toastId);
+          }}
+          className="rounded-full bg-foreground px-2.5 pt-1 pb-1.5 text-xs font-medium text-background transition-colors hover:bg-foreground/90"
+        >
+          Open Voice settings
+        </button>
+      </div>
+    ),
+  });
+}
diff --git a/studio/frontend/src/features/chat/adapters/studio-model-dictation-adapter.ts b/studio/frontend/src/features/chat/adapters/studio-model-dictation-adapter.ts
new file mode 100644
index 0000000000..8546e3eeab
--- /dev/null
+++ b/studio/frontend/src/features/chat/adapters/studio-model-dictation-adapter.ts
@@ -0,0 +1,637 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { authFetch } from "@/features/auth";
+import { hubTokenHeader } from "@/features/hub/lib/hub-token-header";
+import {
+  applyDictationDictionary,
+  isCuratedSttModel,
+  recordRecentDictation,
+  resolveModelDictationLanguage,
+  useVoiceSettingsStore,
+} from "@/features/settings/stores/voice-settings-store";
+import type { DictationAdapter } from "@assistant-ui/react";
+import { toast } from "sonner";
+import { startDictationLevelMeter } from "./dictation-level";
+import {
+  type StudioDictationSession,
+  isMissingDeviceError,
+  resolveDictationChatId,
+} from "./studio-web-speech-dictation-adapter";
+
+// Fine timeslice so the buffer is ready the moment a segment is cut or stopped.
+const SEGMENT_TIMESLICE_MS = 250;
+// Whisper pads input to 30s. Short dictation stays one clip; long dictation cuts
+// at the first pause after 20s or before the 30s boundary.
+const MIN_SEGMENT_MS = 20_000;
+const MAX_SEGMENT_MS = 28_000;
+const SILENCE_CUT_MS = 280;
+// Raw RMS (0..1) above which a frame counts as speech (well above the room floor
+// after noise suppression).
+const VOICE_RMS = 0.015;
+
+// Prefer Opus (small, widely supported); fall back to whatever the browser
+// records. The backend decodes any of these with PyAV.
+const PREFERRED_MIME_TYPES = [
+  "audio/webm;codecs=opus",
+  "audio/webm",
+  "audio/ogg;codecs=opus",
+  "audio/mp4",
+];
+
+function pickMimeType(): string | undefined {
+  if (typeof MediaRecorder === "undefined") return undefined;
+  for (const type of PREFERRED_MIME_TYPES) {
+    if (MediaRecorder.isTypeSupported(type)) return type;
+  }
+  return undefined;
+}
+
+const stopStream = (stream: MediaStream | null) => {
+  for (const track of stream?.getTracks() ?? []) {
+    track.stop();
+  }
+};
+
+/** Backend STT engine, decided by the model: curated ids run GGML through
+ * whisper.cpp; a custom HF repo is safetensors and runs through Transformers. */
+export type SttEngine = "transformers" | "gguf";
+
+export function sttEngineFor(model: string): SttEngine {
+  return isCuratedSttModel(model) ? "gguf" : "transformers";
+}
+
+/** POST audio to the STT sidecar and return the transcript. */
+export async function transcribeAudioBlob(
+  blob: Blob,
+  options: {
+    model?: string;
+    language?: string;
+    engine?: SttEngine;
+    signal?: AbortSignal;
+  } = {},
+): Promise<string> {
+  const settings = useVoiceSettingsStore.getState();
+  const model = options.model ?? settings.sttModel;
+  const language = resolveModelDictationLanguage(
+    model,
+    options.language ?? settings.dictationLanguage,
+  );
+  const engine = options.engine ?? sttEngineFor(model);
+  const params = new URLSearchParams({ model, fast: "true", engine });
+  if (language) params.set("language", language);
+  const response = await authFetch(
+    `/api/inference/audio/transcribe/raw?${params.toString()}`,
+    {
+      method: "POST",
+      headers: { "Content-Type": blob.type || "application/octet-stream" },
+      body: blob,
+      signal: options.signal,
+    },
+  );
+  if (!response.ok) {
+    const body = (await response.json().catch(() => null)) as {
+      detail?: string;
+    } | null;
+    const detail = body?.detail ?? `HTTP ${response.status}`;
+    if (response.status === 501) {
+      throw new Error(
+        "Speech-to-text is not available on this server. Run `unsloth studio update` to install it.",
+      );
+    }
+    throw new Error(detail);
+  }
+  const data = (await response.json()) as { text?: string };
+  return (data.text ?? "").trim();
+}
+
+export interface SttDownloadStatus {
+  downloading: boolean;
+  model: string | null;
+  error: string | null;
+  bytes_total: number | null;
+  bytes_done: number | null;
+}
+
+export interface SttEngineStatus {
+  available: boolean;
+  loaded_model: string | null;
+  loading: boolean;
+  device: string | null;
+  keep_alive_seconds: number;
+  default_model: string;
+  models: string[];
+  downloaded_models: string[];
+  download: SttDownloadStatus;
+}
+
+export interface SttStatus {
+  available: boolean;
+  loaded_model: string | null;
+  loading: boolean;
+  device: string | null;
+  keep_alive_seconds: number;
+  default_model: string;
+  models: string[];
+  /** Per-engine state; absent on servers predating the engine split. */
+  transformers?: SttEngineStatus;
+  gguf?: SttEngineStatus;
+}
+
+// Keep load/unload requests ordered so a new recording cannot race an unload
+// still finishing for the previous one.
+let sttLifecycle: Promise<void> = Promise.resolve();
+
+function queueSttLifecycle(operation: () => Promise<void>): Promise<void> {
+  const result = sttLifecycle.catch(() => {}).then(operation);
+  sttLifecycle = result.catch(() => {});
+  return result;
+}
+
+/** Report whether STT is installed and which model, if any, is resident.
+ * Passing a model extends the downloaded check to custom repos. */
+export async function fetchSttStatus(
+  refreshKey?: number,
+  model?: string,
+): Promise<SttStatus> {
+  const params = new URLSearchParams();
+  if (refreshKey !== undefined) params.set("refresh", String(refreshKey));
+  if (model) params.set("model", model);
+  const query = params.toString();
+  const response = await authFetch(
+    `/api/inference/audio/stt/status${query ? `?${query}` : ""}`,
+  );
+  if (!response.ok) throw new Error(`HTTP ${response.status}`);
+  return (await response.json()) as SttStatus;
+}
+
+/** Verify a custom Hub repository is a Transformers Whisper checkpoint. */
+export async function validateSttModel(
+  model: string,
+  hfToken?: string,
+): Promise<void> {
+  const response = await authFetch("/api/inference/audio/stt/validate", {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/json",
+      ...hubTokenHeader(hfToken),
+    },
+    body: JSON.stringify({ model }),
+  });
+  if (!response.ok) {
+    const body = (await response.json().catch(() => null)) as {
+      detail?: string;
+    } | null;
+    throw new Error(body?.detail ?? `HTTP ${response.status}`);
+  }
+}
+
+/** Load a selected model that is already downloaded. */
+export function loadSttModel(model: string, engine?: SttEngine): Promise<void> {
+  const resolvedEngine = engine ?? sttEngineFor(model);
+  return queueSttLifecycle(async () => {
+    const response = await authFetch("/api/inference/audio/stt/load", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({ model, engine: resolvedEngine }),
+    });
+    if (!response.ok) {
+      const body = (await response.json().catch(() => null)) as {
+        detail?: string;
+      } | null;
+      throw new Error(body?.detail ?? `HTTP ${response.status}`);
+    }
+  });
+}
+
+/** Start a background download of a dictation model. */
+export async function startSttDownload(
+  model: string,
+  hfToken?: string,
+): Promise<void> {
+  const response = await authFetch("/api/inference/audio/stt/download", {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/json",
+      ...hubTokenHeader(hfToken),
+    },
+    body: JSON.stringify({ model, engine: sttEngineFor(model) }),
+  });
+  if (!response.ok) {
+    const body = (await response.json().catch(() => null)) as {
+      detail?: string;
+    } | null;
+    throw new Error(body?.detail ?? `HTTP ${response.status}`);
+  }
+}
+
+/** Release the local STT model and its RAM/VRAM allocations. */
+export function unloadSttModel(): Promise<void> {
+  return queueSttLifecycle(async () => {
+    const response = await authFetch("/api/inference/audio/stt/unload", {
+      method: "POST",
+    });
+    if (!response.ok) {
+      const body = (await response.json().catch(() => null)) as {
+        detail?: string;
+      } | null;
+      throw new Error(body?.detail ?? `HTTP ${response.status}`);
+    }
+  });
+}
+
+/**
+ * Local model dictation. Short recordings use one pass; long ones split near
+ * Whisper's 30s window. Confirm keeps text, discard removes it, and either
+ * releases the microphone immediately.
+ */
+export class StudioModelDictationAdapter implements DictationAdapter {
+  private readonly chatId: string | null | undefined;
+
+  constructor(options: { chatId?: string | null } = {}) {
+    this.chatId = options.chatId;
+  }
+
+  static isSupported(): boolean {
+    return (
+      typeof window !== "undefined" &&
+      window.isSecureContext &&
+      typeof MediaRecorder !== "undefined" &&
+      navigator.mediaDevices?.getUserMedia !== undefined
+    );
+  }
+
+  listen(): DictationAdapter.Session {
+    if (!StudioModelDictationAdapter.isSupported()) {
+      throw new Error("Recording is not supported in this browser.");
+    }
+
+    // Pin the model, language, and linked chat chosen when recording began, so a
+    // mid-session settings change or thread switch cannot affect later segments
+    // or relink the saved transcript.
+    const { sttModel: sessionModel, dictationLanguage } =
+      useVoiceSettingsStore.getState();
+    const sessionLanguage = resolveModelDictationLanguage(
+      sessionModel,
+      dictationLanguage,
+    );
+    const sessionEngine = sttEngineFor(sessionModel);
+    const sessionChatId = resolveDictationChatId(this.chatId);
+
+    const speechStartCallbacks = new Set<() => void>();
+    const speechEndCallbacks = new Set<
+      (result: DictationAdapter.Result) => void
+    >();
+    const speechCallbacks = new Set<
+      (result: DictationAdapter.Result) => void
+    >();
+    const endCallbacks = new Set<() => void>();
+
+    let stream: MediaStream | null = null;
+    let ended = false;
+    let cancelled = false;
+    let finalizing = false;
+    const abortController = new AbortController();
+    const mimeType = pickMimeType();
+    // Shared waveform meter also feeds this adapter's pause detector.
+    let stopLevelMeter = () => {
+      // Replaced after microphone access succeeds.
+    };
+    let onAudioFrame: (rawRms: number, now: number) => void = () => {};
+
+    let resolveEnded: (() => void) | null = null;
+    const endedPromise = new Promise<void>((resolve) => {
+      resolveEnded = resolve;
+    });
+
+    // --- Background transcription pipeline ---------------------------------
+    // Each segment is a self-contained clip transcribed on its own; results are
+    // stored by index so the final text keeps its order.
+    type Segment = {
+      index: number;
+      chunks: Blob[];
+      startedAt: number;
+      voiced: boolean;
+      recorder: MediaRecorder;
+    };
+    const results: string[] = [];
+    const queue: { index: number; blob: Blob }[] = [];
+    let worker = false;
+    let currentSeg: Segment | null = null;
+    let segCounter = 0;
+    let pendingRecorders = 0;
+    let silenceMs = 0;
+    let lastFrameAt = 0;
+    let cutting = false;
+    let finalCutDone = false;
+    let reportedTranscriptionError = false;
+
+    const reportTranscriptionError = (error: unknown) => {
+      if (reportedTranscriptionError || cancelled || ended) return;
+      reportedTranscriptionError = true;
+      const message =
+        error instanceof Error && error.message
+          ? error.message
+          : "A recorded segment could not be transcribed.";
+      console.error("STT transcription error:", error);
+      toast.error(message);
+    };
+
+    const buildTranscript = () =>
+      results
+        .filter((part) => part?.trim())
+        .join(" ")
+        .trim();
+
+    const finishSession = (
+      reason: "stopped" | "cancelled" | "error",
+      transcript?: string,
+    ) => {
+      if (ended) return;
+      ended = true;
+      stopLevelMeter();
+      if (currentSeg && currentSeg.recorder.state !== "inactive") {
+        try {
+          currentSeg.recorder.stop();
+        } catch {
+          // ignore
+        }
+      }
+      session.status = { type: "ended", reason };
+      stopStream(stream);
+      stream = null;
+      const corrected = transcript ? applyDictationDictionary(transcript) : "";
+      if (reason !== "cancelled" && corrected) {
+        for (const callback of speechCallbacks) {
+          callback({ transcript: corrected, isFinal: true });
+        }
+        recordRecentDictation(corrected, sessionChatId);
+      }
+      for (const callback of speechEndCallbacks) {
+        callback({ transcript: corrected });
+      }
+      for (const callback of endCallbacks) callback();
+      resolveEnded?.();
+    };
+
+    // Finish once the final segment has been cut and the queue has drained.
+    const maybeComplete = () => {
+      if (ended || cancelled || !finalizing || !finalCutDone) return;
+      if (pendingRecorders === 0 && queue.length === 0 && !worker) {
+        finishSession("stopped", buildTranscript());
+      }
+    };
+
+    // Transcribe queued segments one at a time so the backend is never flooded.
+    const processQueue = () => {
+      if (worker || cancelled || ended) return;
+      const item = queue.shift();
+      if (!item) {
+        maybeComplete();
+        return;
+      }
+      worker = true;
+      void (async () => {
+        try {
+          const text = await transcribeAudioBlob(item.blob, {
+            model: sessionModel,
+            language: sessionLanguage,
+            engine: sessionEngine,
+            signal: abortController.signal,
+          });
+          if (!cancelled) results[item.index] = text;
+        } catch (error) {
+          if (!cancelled && !abortController.signal.aborted) {
+            // Keep transcribed segments, but never hide that part was lost.
+            reportTranscriptionError(error);
+          }
+        } finally {
+          worker = false;
+          processQueue();
+        }
+      })();
+    };
+
+    // Every non-empty recording is transcribed. The RMS meter only shapes
+    // segment boundaries; a quiet microphone or suspended AudioContext can keep
+    // it below VOICE_RMS for real speech, so it must never discard audio.
+    // Whisper returns an empty transcript for genuine silence.
+    const enqueueSegment = (index: number, blob: Blob) => {
+      if (blob.size > 0) {
+        queue.push({ index, blob });
+        processQueue();
+      } else {
+        results[index] = "";
+        maybeComplete();
+      }
+    };
+
+    // Start recording a fresh segment on the shared mic stream.
+    const startSegment = () => {
+      if (ended || cancelled || !stream) return;
+      const seg: Segment = {
+        index: segCounter++,
+        chunks: [],
+        startedAt: performance.now(),
+        voiced: false,
+        recorder: new MediaRecorder(
+          stream,
+          mimeType ? { mimeType } : undefined,
+        ),
+      };
+      currentSeg = seg;
+      silenceMs = 0;
+      seg.recorder.addEventListener("dataavailable", (event) => {
+        if (event.data.size > 0) seg.chunks.push(event.data);
+      });
+      seg.recorder.addEventListener("stop", () => {
+        pendingRecorders = Math.max(0, pendingRecorders - 1);
+        if (cancelled || ended) {
+          maybeComplete();
+          return;
+        }
+        const blob = new Blob(seg.chunks, {
+          type: seg.recorder.mimeType || "audio/webm",
+        });
+        enqueueSegment(seg.index, blob);
+      });
+      pendingRecorders += 1;
+      try {
+        seg.recorder.start(SEGMENT_TIMESLICE_MS);
+      } catch (error) {
+        pendingRecorders = Math.max(0, pendingRecorders - 1);
+        if (currentSeg === seg) currentSeg = null;
+        throw error;
+      }
+    };
+
+    // Close the current segment at a pause and open the next, so recording stays
+    // continuous while each clip is independently decodable.
+    const cutSegment = () => {
+      const seg = currentSeg;
+      if (cutting || !seg || finalizing) return;
+      cutting = true;
+      const rec = seg.recorder;
+      if (rec.state !== "inactive") {
+        rec.addEventListener(
+          "stop",
+          () => {
+            cutting = false;
+          },
+          { once: true },
+        );
+        try {
+          rec.stop();
+        } catch {
+          cutting = false;
+        }
+      } else {
+        cutting = false;
+      }
+      startSegment();
+    };
+
+    // Pause detector: mark voiced frames. Short dictations stay one segment; long
+    // ones cut at a pause after the target duration, or at the hard limit.
+    onAudioFrame = (rawRms, now) => {
+      const seg = currentSeg;
+      if (!seg || finalizing) {
+        lastFrameAt = now;
+        return;
+      }
+      if (rawRms > VOICE_RMS) {
+        seg.voiced = true;
+        silenceMs = 0;
+      } else if (lastFrameAt) {
+        silenceMs += now - lastFrameAt;
+      }
+      lastFrameAt = now;
+      const duration = now - seg.startedAt;
+      const pauseBreak =
+        seg.voiced && duration > MIN_SEGMENT_MS && silenceMs > SILENCE_CUT_MS;
+      if (!cutting && (pauseBreak || duration > MAX_SEGMENT_MS)) {
+        cutSegment();
+      }
+    };
+
+    const session: StudioDictationSession = {
+      status: { type: "starting" },
+      stop: async () => {
+        if (!ended && !finalizing) {
+          finalizing = true;
+          // Stop publishing zero-valued frames at once so the UI can switch to
+          // its transcription shimmer.
+          stopLevelMeter();
+          const seg = currentSeg;
+          // Cut the final segment (its buffer survives) so only the short tail is
+          // left to transcribe, then release the mic immediately.
+          if (seg && seg.recorder.state !== "inactive") {
+            seg.recorder.addEventListener(
+              "stop",
+              () => {
+                finalCutDone = true;
+                maybeComplete();
+              },
+              { once: true },
+            );
+            try {
+              seg.recorder.stop();
+            } catch {
+              finalCutDone = true;
+              maybeComplete();
+            }
+          } else {
+            finalCutDone = true;
+            maybeComplete();
+          }
+          stopStream(stream);
+          stream = null;
+        }
+        await endedPromise;
+      },
+      cancel: () => {
+        if (ended) return;
+        cancelled = true;
+        finalizing = true;
+        abortController.abort();
+        finishSession("cancelled");
+      },
+      onSpeechStart: (callback) => {
+        speechStartCallbacks.add(callback);
+        return () => {
+          speechStartCallbacks.delete(callback);
+        };
+      },
+      onSpeechEnd: (callback) => {
+        speechEndCallbacks.add(callback);
+        return () => {
+          speechEndCallbacks.delete(callback);
+        };
+      },
+      onSpeech: (callback) => {
+        speechCallbacks.add(callback);
+        return () => {
+          speechCallbacks.delete(callback);
+        };
+      },
+      onEnd: (callback: () => void) => {
+        endCallbacks.add(callback);
+        return () => {
+          endCallbacks.delete(callback);
+        };
+      },
+    };
+
+    void (async () => {
+      try {
+        const { micDeviceId } = useVoiceSettingsStore.getState();
+        const baseAudio: MediaTrackConstraints = {
+          echoCancellation: true,
+          noiseSuppression: true,
+        };
+        try {
+          stream = await navigator.mediaDevices.getUserMedia({
+            audio:
+              micDeviceId && micDeviceId !== "default"
+                ? { ...baseAudio, deviceId: { exact: micDeviceId } }
+                : baseAudio,
+          });
+        } catch (error) {
+          // Saved mic may be unplugged; fall back to the default.
+          if (micDeviceId !== "default" && isMissingDeviceError(error)) {
+            stream = await navigator.mediaDevices.getUserMedia({
+              audio: baseAudio,
+            });
+          } else {
+            throw error;
+          }
+        }
+        if (ended || cancelled) {
+          stopStream(stream);
+          stream = null;
+          return;
+        }
+        // Warm the model only after mic access. The backend loads cache-only
+        // and never downloads here.
+        void loadSttModel(sessionModel, sessionEngine).catch(
+          reportTranscriptionError,
+        );
+        stopLevelMeter = startDictationLevelMeter(stream, (rawRms, now) => {
+          onAudioFrame(rawRms, now);
+        });
+        startSegment();
+        session.status = { type: "running" };
+        for (const callback of speechStartCallbacks) callback();
+      } catch (error) {
+        const message = isMissingDeviceError(error)
+          ? "No microphone was found for dictation."
+          : "Dictation could not access the microphone.";
+        console.error("STT microphone error:", error);
+        toast.error(message);
+        finishSession("error");
+      }
+    })();
+
+    return session;
+  }
+}
diff --git a/studio/frontend/src/features/chat/adapters/studio-speech-synthesis-adapter.ts b/studio/frontend/src/features/chat/adapters/studio-speech-synthesis-adapter.ts
index 5e6a76e949..3a5042f61d 100644
--- a/studio/frontend/src/features/chat/adapters/studio-speech-synthesis-adapter.ts
+++ b/studio/frontend/src/features/chat/adapters/studio-speech-synthesis-adapter.ts
@@ -6,17 +6,19 @@ import { useVoiceSettingsStore } from "@/features/settings/stores/voice-settings
 import { toast } from "@/lib/toast";
 import type { SpeechSynthesisAdapter } from "@assistant-ui/react";
 
-/** Voice for a stored voiceURI; undefined lets the browser pick. */
+/** Voice for a stored voiceURI. "default" resolves to the voice the platform
+ * marks as its default, so the "System default" choice means what it says
+ * instead of falling back to a curated pick. Undefined lets the browser pick. */
 export function findTtsVoice(
   voiceURI: string,
 ): SpeechSynthesisVoice | undefined {
   if (typeof window === "undefined" || !window.speechSynthesis) {
     return undefined;
   }
-  if (!voiceURI || voiceURI === "default") return undefined;
-  return window.speechSynthesis
-    .getVoices()
-    .find((voice) => voice.voiceURI === voiceURI);
+  if (!voiceURI) return undefined;
+  const voices = window.speechSynthesis.getVoices();
+  if (voiceURI === "default") return voices.find((voice) => voice.default);
+  return voices.find((voice) => voice.voiceURI === voiceURI);
 }
 
 // macOS novelty and legacy Eloquence voices that sound robotic and flood the picker.
@@ -59,19 +61,54 @@ function voiceBaseName(voice: SpeechSynthesisVoice): string {
   return name;
 }
 
+// Well-known natural English voices, best first. Breaks ties when the name
+// carries no quality hint, so basic voices are not just alphabetical.
+const PREFERRED_VOICE_NAMES = [
+  "samantha",
+  "alex",
+  "ava",
+  "allison",
+  "susan",
+  "tom",
+  "daniel",
+  "serena",
+  "karen",
+  "moira",
+  "tessa",
+  "fiona",
+];
+
+// Quality tier from vendor hints in the voice name.
 function voiceQualityScore(voice: SpeechSynthesisVoice): number {
   const name = voice.name.toLowerCase();
   let score = 0;
-  if (name.includes("premium")) score += 8;
-  if (name.includes("enhanced")) score += 7;
-  if (name.includes("natural") || name.includes("neural")) score += 6;
-  if (name.includes("siri")) score += 6;
-  if (name.includes("google")) score += 5;
-  if (name.includes("microsoft")) score += 4;
-  if (voice.default) score += 3;
+  if (name.includes("premium")) score += 100;
+  if (name.includes("siri")) score += 90;
+  if (name.includes("enhanced")) score += 80;
+  if (name.includes("natural") || name.includes("neural")) score += 70;
+  if (name.includes("google")) score += 40;
+  if (name.includes("microsoft")) score += 30;
   return score;
 }
 
+// Higher for voices in the user's exact region, then the same language.
+function voiceLocaleScore(voice: SpeechSynthesisVoice): number {
+  const navLang =
+    typeof navigator !== "undefined" && navigator.language
+      ? navigator.language.toLowerCase()
+      : "en-us";
+  const lang = voice.lang.toLowerCase().replace("_", "-");
+  if (lang === navLang) return 2;
+  if (langBase(lang) === langBase(navLang)) return 1;
+  return 0;
+}
+
+// Rank in the preferred list, best first; 0 when the voice is not listed.
+function voicePreferredRank(voice: SpeechSynthesisVoice): number {
+  const index = PREFERRED_VOICE_NAMES.indexOf(voiceBaseName(voice));
+  return index === -1 ? 0 : PREFERRED_VOICE_NAMES.length - index;
+}
+
 function langBase(tag: string): string {
   return tag.toLowerCase().split(/[-_]/)[0] ?? "";
 }
@@ -86,8 +123,8 @@ const MAX_CURATED_VOICES = 20;
 export function curateSystemVoices(
   voices: SpeechSynthesisVoice[],
   selectedVoiceURI?: string,
+  dictationLanguage = useVoiceSettingsStore.getState().dictationLanguage,
 ): SpeechSynthesisVoice[] {
-  const { dictationLanguage } = useVoiceSettingsStore.getState();
   const wantedLangs = new Set<string>(["en"]);
   if (typeof navigator !== "undefined" && navigator.language) {
     wantedLangs.add(langBase(navigator.language));
@@ -107,12 +144,33 @@ export function curateSystemVoices(
   });
 
   kept.sort((a, b) => {
-    const scoreDiff = voiceQualityScore(b) - voiceQualityScore(a);
-    if (scoreDiff !== 0) return scoreDiff;
+    const quality = voiceQualityScore(b) - voiceQualityScore(a);
+    if (quality !== 0) return quality;
+    const locale = voiceLocaleScore(b) - voiceLocaleScore(a);
+    if (locale !== 0) return locale;
+    const preferred = voicePreferredRank(b) - voicePreferredRank(a);
+    if (preferred !== 0) return preferred;
+    const byDefault = Number(b.default) - Number(a.default);
+    if (byDefault !== 0) return byDefault;
     return a.name.localeCompare(b.name);
   });
 
-  const curated = kept.slice(0, MAX_CURATED_VOICES);
+  // macOS reports some voices twice (compact + enhanced) under one name. Keep
+  // one per name and language, preferring the selected voice then the best
+  // ranked, so no duplicates show.
+  const keyOf = (voice: SpeechSynthesisVoice) =>
+    `${voiceBaseName(voice)}|${voice.lang.toLowerCase()}`;
+  const winners = new Map<string, string>();
+  for (const voice of kept) {
+    const key = keyOf(voice);
+    if (!winners.has(key)) winners.set(key, voice.voiceURI);
+    if (voice.voiceURI === selectedVoiceURI) winners.set(key, voice.voiceURI);
+  }
+  const deduped = kept.filter(
+    (voice) => winners.get(keyOf(voice)) === voice.voiceURI,
+  );
+
+  const curated = deduped.slice(0, MAX_CURATED_VOICES);
   if (
     selectedVoiceURI &&
     selectedVoiceURI !== "default" &&
@@ -126,6 +184,22 @@ export function curateSystemVoices(
   return curated;
 }
 
+/**
+ * Best voice when none is chosen. The browser default on macOS is often a
+ * robotic legacy voice, so fall back to the top curated voice instead.
+ */
+function defaultTtsVoice(): SpeechSynthesisVoice | undefined {
+  if (typeof window === "undefined" || !window.speechSynthesis) {
+    return undefined;
+  }
+  const voices = window.speechSynthesis.getVoices();
+  return (
+    curateSystemVoices(voices)[0] ??
+    voices.find((voice) => voice.default) ??
+    voices[0]
+  );
+}
+
 /** Build an utterance from the current Voice settings. */
 export function createConfiguredUtterance(
   text: string,
@@ -133,7 +207,7 @@ export function createConfiguredUtterance(
   const { ttsVoiceURI, ttsRate, ttsPitch, ttsVolume } =
     useVoiceSettingsStore.getState();
   const utterance = new SpeechSynthesisUtterance(text);
-  const voice = findTtsVoice(ttsVoiceURI);
+  const voice = findTtsVoice(ttsVoiceURI) ?? defaultTtsVoice();
   if (voice) {
     utterance.voice = voice;
     utterance.lang = voice.lang;
@@ -272,8 +346,14 @@ export class StudioSpeechSynthesisAdapter implements SpeechSynthesisAdapter {
       if (res.status.type === "ended") return;
       // Surface genuine read-aloud failures; a cancelled/interrupted utterance
       // is a normal stop, not an error, and must not toast.
-      if (reason === "error" && error !== "interrupted" && error !== "canceled") {
-        toast.error(error instanceof Error ? error.message : "Read aloud failed.");
+      if (
+        reason === "error" &&
+        error !== "interrupted" &&
+        error !== "canceled"
+      ) {
+        toast.error(
+          error instanceof Error ? error.message : "Read aloud failed.",
+        );
       }
       res.status = { type: "ended", reason, error };
       for (const handler of subscribers) handler();
diff --git a/studio/frontend/src/features/chat/adapters/studio-web-speech-dictation-adapter.ts b/studio/frontend/src/features/chat/adapters/studio-web-speech-dictation-adapter.ts
index b7a8e904ed..fb0e4fc0ab 100644
--- a/studio/frontend/src/features/chat/adapters/studio-web-speech-dictation-adapter.ts
+++ b/studio/frontend/src/features/chat/adapters/studio-web-speech-dictation-adapter.ts
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
+import { useSettingsDialogStore } from "@/features/settings/stores/settings-dialog-store";
 import {
   applyDictationDictionary,
   recordRecentDictation,
@@ -9,6 +10,39 @@ import {
 } from "@/features/settings/stores/voice-settings-store";
 import type { DictationAdapter } from "@assistant-ui/react";
 import { toast } from "sonner";
+import { useChatRuntimeStore } from "../stores/chat-runtime-store";
+import { startDictationLevelMeter } from "./dictation-level";
+
+/** Chat open while dictating, so the saved dictation can link back to it. */
+export function activeDictationChatId(): string | undefined {
+  return useChatRuntimeStore.getState().activeThreadId ?? undefined;
+}
+
+/**
+ * Resolve the chat a saved dictation links to. undefined falls back to the
+ * active single chat; null (composers without one, e.g. Compare) means none.
+ */
+export function resolveDictationChatId(
+  chatId: string | null | undefined,
+): string | undefined {
+  if (chatId === undefined) return activeDictationChatId();
+  return chatId ?? undefined;
+}
+
+// Reused id so repeated network failures replace, not stack, the same toast.
+const NETWORK_TOAST_ID = "dictation-network-offline";
+
+// Short grace for the browser to finalize its latest interim hypothesis. If it
+// doesn't, promote that text instead of stalling on a finalization spinner.
+const STOP_FINALIZATION_GRACE_MS = 350;
+
+/**
+ * A dictation session with an extra onEnd hook (not part of the assistant-ui
+ * interface) so non-runtime callers can reset when the session ends by itself.
+ */
+export type StudioDictationSession = DictationAdapter.Session & {
+  onEnd?: (callback: () => void) => () => void;
+};
 
 const getSpeechRecognitionAPI = ():
   | SpeechRecognitionConstructor
@@ -18,7 +52,9 @@ const getSpeechRecognitionAPI = ():
 };
 
 const stopStream = (stream: MediaStream | null) => {
-  stream?.getTracks().forEach((track) => track.stop());
+  for (const track of stream?.getTracks() ?? []) {
+    track.stop();
+  }
 };
 
 const mediaErrorName = (error: unknown): unknown =>
@@ -48,7 +84,10 @@ export const describeMediaError = (error: unknown): string => {
     : "Dictation could not access the microphone.";
 };
 
-export const describeSpeechError = (error: string, message?: string): string => {
+export const describeSpeechError = (
+  error: string,
+  message?: string,
+): string => {
   if (error === "not-allowed") {
     return "Speech recognition was blocked by the browser. Check microphone permissions for this Unsloth page.";
   }
@@ -68,18 +107,21 @@ export class StudioWebSpeechDictationAdapter implements DictationAdapter {
   private readonly language: string | undefined;
   private readonly continuous: boolean;
   private readonly interimResults: boolean;
+  private readonly chatId: string | null | undefined;
 
   constructor(
     options: {
       language?: string;
       continuous?: boolean;
       interimResults?: boolean;
+      chatId?: string | null;
     } = {},
   ) {
     // Resolved from Voice settings at listen() time unless overridden.
     this.language = options.language;
     this.continuous = options.continuous ?? true;
     this.interimResults = options.interimResults ?? true;
+    this.chatId = options.chatId;
   }
 
   static isSupported(): boolean {
@@ -101,6 +143,9 @@ export class StudioWebSpeechDictationAdapter implements DictationAdapter {
     recognition.lang = this.language ?? resolveDictationLanguage();
     recognition.continuous = this.continuous;
     recognition.interimResults = this.interimResults;
+    // Pin the linked chat now so a thread switch during finalization cannot
+    // relink the transcript to the newly opened chat.
+    const sessionChatId = resolveDictationChatId(this.chatId);
 
     const speechStartCallbacks = new Set<() => void>();
     const speechEndCallbacks = new Set<
@@ -109,22 +154,38 @@ export class StudioWebSpeechDictationAdapter implements DictationAdapter {
     const speechCallbacks = new Set<
       (result: DictationAdapter.Result) => void
     >();
+    const endCallbacks = new Set<() => void>();
 
     let stream: MediaStream | null = null;
     let finalTranscript = "";
     let ended = false;
     let started = false;
+    let stopping = false;
+    let stopRequestedAt = 0;
+    let stopFallbackTimer = 0;
+    let stopLevelMeter = () => {
+      // Replaced after microphone access succeeds.
+    };
+    const interimParts = new Map<number, string>();
     let resolveEnded: (() => void) | null = null;
     const endedPromise = new Promise<void>((resolve) => {
       resolveEnded = resolve;
     });
 
-    const session: DictationAdapter.Session = {
+    const session: StudioDictationSession = {
       status: { type: "starting" },
 
       stop: async () => {
         if (!ended && started) {
+          stopping = true;
+          stopRequestedAt = performance.now();
           recognition.stop();
+          // Ending the track now gives the browser an audio endpoint to finalize
+          // and releases the mic without waiting on its remote speech service.
+          stopLevelMeter();
+          stopStream(stream);
+          stream = null;
+          scheduleStopFallback();
         } else if (!ended) {
           finish("stopped");
         }
@@ -132,11 +193,9 @@ export class StudioWebSpeechDictationAdapter implements DictationAdapter {
       },
 
       cancel: () => {
-        if (!ended && started) {
-          recognition.abort();
-        } else if (!ended) {
-          finish("cancelled");
-        }
+        if (ended) return;
+        if (started) recognition.abort();
+        finish("cancelled");
       },
 
       onSpeechStart: (callback) => {
@@ -159,23 +218,75 @@ export class StudioWebSpeechDictationAdapter implements DictationAdapter {
           speechCallbacks.delete(callback);
         };
       },
+
+      // Beyond DictationAdapter: lets callers reset UI when the session ends on
+      // its own (silence, error), not just via stop().
+      onEnd: (callback: () => void) => {
+        endCallbacks.add(callback);
+        return () => {
+          endCallbacks.delete(callback);
+        };
+      },
     };
 
+    const currentInterimTranscript = () =>
+      [...interimParts.entries()]
+        .sort(([a], [b]) => a - b)
+        .map(([, transcript]) => transcript.trim())
+        .filter(Boolean)
+        .join(" ");
+
+    const promoteInterim = () => {
+      const interim = currentInterimTranscript();
+      interimParts.clear();
+      if (!interim) return false;
+      const corrected = applyDictationDictionary(interim).trim();
+      if (!corrected) return false;
+      finalTranscript = finalTranscript
+        ? `${finalTranscript} ${corrected}`
+        : corrected;
+      return true;
+    };
+
+    function scheduleStopFallback(): void {
+      if (!stopping || ended || stopFallbackTimer) return;
+      const elapsed = performance.now() - stopRequestedAt;
+      const delay = Math.max(0, STOP_FINALIZATION_GRACE_MS - elapsed);
+      stopFallbackTimer = window.setTimeout(() => {
+        stopFallbackTimer = 0;
+        if (!ended) {
+          promoteInterim();
+          finish("stopped");
+          recognition.abort();
+        }
+      }, delay);
+    }
+
     const finish = (reason: "stopped" | "cancelled" | "error") => {
       if (ended) return;
       ended = true;
+      stopping = false;
+      if (stopFallbackTimer) window.clearTimeout(stopFallbackTimer);
+      stopFallbackTimer = 0;
       session.status = { type: "ended", reason };
+      stopLevelMeter();
       stopStream(stream);
       stream = null;
-      if (finalTranscript) {
-        for (const callback of speechEndCallbacks) {
-          callback({ transcript: finalTranscript });
+      const transcript = reason === "cancelled" ? "" : finalTranscript;
+      if (transcript) {
+        for (const callback of speechCallbacks) {
+          callback({ transcript, isFinal: true });
         }
-        if (reason !== "cancelled") {
-          recordRecentDictation(finalTranscript);
-        }
-        finalTranscript = "";
+        recordRecentDictation(transcript, sessionChatId);
       }
+      // assistant-ui uses this callback to leave dictation mode; required even
+      // for silence and cancelled recordings.
+      for (const callback of speechEndCallbacks) {
+        callback({ transcript });
+      }
+      finalTranscript = "";
+      interimParts.clear();
+      for (const callback of endCallbacks) callback();
       resolveEnded?.();
     };
 
@@ -188,6 +299,7 @@ export class StudioWebSpeechDictationAdapter implements DictationAdapter {
     });
 
     recognition.addEventListener("result", (event) => {
+      if (ended) return;
       const speechEvent = event as SpeechRecognitionEvent;
       for (
         let i = speechEvent.resultIndex;
@@ -198,6 +310,7 @@ export class StudioWebSpeechDictationAdapter implements DictationAdapter {
         if (!result) continue;
         const transcript = result[0]?.transcript ?? "";
         if (result.isFinal) {
+          interimParts.delete(i);
           const corrected = applyDictationDictionary(transcript);
           // Join final chunks with a single space so recorded transcripts do
           // not merge words when a browser omits leading whitespace.
@@ -207,25 +320,34 @@ export class StudioWebSpeechDictationAdapter implements DictationAdapter {
               ? `${finalTranscript} ${trimmed}`
               : trimmed;
           }
-          for (const callback of speechCallbacks) {
-            callback({ transcript: corrected, isFinal: true });
-          }
         } else {
-          for (const callback of speechCallbacks) {
-            callback({ transcript, isFinal: false });
-          }
+          interimParts.set(i, transcript);
         }
       }
+      const interim = currentInterimTranscript();
+      if (interim) {
+        scheduleStopFallback();
+      }
     });
 
     recognition.addEventListener("end", () => {
+      if (ended) {
+        return;
+      }
+      promoteInterim();
       finish("stopped");
     });
 
     recognition.addEventListener("error", (event) => {
+      if (ended) return;
       const errorEvent = event as SpeechRecognitionErrorEvent;
       if (errorEvent.error === "aborted") {
-        finish("cancelled");
+        if (stopping) {
+          promoteInterim();
+          finish("stopped");
+        } else {
+          finish("cancelled");
+        }
         return;
       }
       const description = describeSpeechError(
@@ -233,7 +355,22 @@ export class StudioWebSpeechDictationAdapter implements DictationAdapter {
         errorEvent.message,
       );
       console.error("Dictation error:", errorEvent.error, errorEvent.message);
-      toast.error(description);
+      if (errorEvent.error === "network") {
+        // Online speech service unreachable; point the user to the offline
+        // local engine (the toast opens Voice settings).
+        toast.error("No internet connection", {
+          id: NETWORK_TOAST_ID,
+          description:
+            "Browser dictation needs the online speech service. Switch to Local in Voice settings and pick a local STT model to dictate offline.",
+          action: {
+            label: "Open Voice settings",
+            onClick: () =>
+              useSettingsDialogStore.getState().openDialog("voice"),
+          },
+        });
+      } else {
+        toast.error(description);
+      }
       finish("error");
     });
 
@@ -275,6 +412,7 @@ export class StudioWebSpeechDictationAdapter implements DictationAdapter {
             "NotFoundError",
           );
         }
+        stopLevelMeter = startDictationLevelMeter(stream);
         try {
           recognition.start(audioTrack);
         } catch (error) {
@@ -285,6 +423,7 @@ export class StudioWebSpeechDictationAdapter implements DictationAdapter {
             "Dictation start(audioTrack) failed; retrying start().",
             error,
           );
+          stopLevelMeter();
           stopStream(stream);
           stream = null;
           recognition.start();
diff --git a/studio/frontend/src/features/chat/api/chat-adapter.ts b/studio/frontend/src/features/chat/api/chat-adapter.ts
index 0bf46e7343..d4861e8a3a 100644
--- a/studio/frontend/src/features/chat/api/chat-adapter.ts
+++ b/studio/frontend/src/features/chat/api/chat-adapter.ts
@@ -2,10 +2,7 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { getAuthToken } from "@/features/auth";
-import {
-  loadRememberedLoadSettings,
-  rememberedLoadSettingsKey,
-} from "@/components/assistant-ui/model-selector/remembered-load-settings";
+import { resolveInitialConfig } from "@/features/model-picker";
 import { projectHasSources } from "@/features/rag/api/rag-api";
 import { apiUrl } from "@/lib/api-base";
 import { parseParamCountB } from "@/lib/model-size";
@@ -45,12 +42,18 @@ import {
 import {
   type PendingImageEditReference,
   type RagAutoInject,
+  GPU_LAYERS_AUTO,
+  loadedGpuMemoryFields,
+  reconcilePersistedGpuIds,
   resolveLoadedSpeculativeSettings,
   resolveSpeculativeSettingsForLoad,
+  persistGpuMemoryModeOnLoad,
   resolveToolsEnabledOnLoad,
   saveSpeculativeType,
   useChatRuntimeStore,
 } from "../stores/chat-runtime-store";
+import { resolveFitMaxSeqLength, resolveManualAutoCtxPin } from "../presets/preset-policy";
+import { ensureGpuDeviceCache } from "@/hooks/use-gpu-info";
 import { useExternalProvidersStore } from "../stores/external-providers-store";
 import {
   shouldPreserveFullOutput,
@@ -1401,6 +1404,7 @@ const GGUF_KNOWN_QUANT_RE =
 
 type AutoLoadCandidate = {
   id: string;
+  loadId?: string | null;
   kind: LastLocalModelKind;
   ggufVariant: string | null;
   maxSeqLength: number;
@@ -1489,6 +1493,13 @@ async function autoLoadSmallestModel(): Promise<{
     max_seq_length: number;
     is_lora: boolean;
     gguf_variant?: string | null;
+    // GGUF-only: scopes the training guard to the same placement policy /load
+    // will use. Manual mode must match because it makes placement user-owned.
+    // The layer/MoE/split/KV/spec knobs are deliberately not sent: Auto mode's
+    // guard sizes conservatively, while Manual mode bypasses that estimate.
+    // The safetensors fallback omits both fields and uses HF auto-placement.
+    gpu_ids?: number[];
+    gpu_memory_mode?: "auto" | "manual";
   }): Promise<boolean> {
     const validation = await validateModel({
       ...payload,
@@ -1520,33 +1531,70 @@ async function autoLoadSmallestModel(): Promise<{
       return false;
     }
     const currentStore = useChatRuntimeStore.getState();
-    const remembered = loadRememberedLoadSettings(
-      rememberedLoadSettingsKey({
-        id: candidate.id,
-        ggufVariant: candidate.ggufVariant,
-      }),
-    );
+    const modelPath = candidate.loadId ?? candidate.id;
+    const { config } = resolveInitialConfig(candidate.id, candidate.ggufVariant);
     const effectiveMaxSeqLength = resolveLoadMaxSeqLength({
       modelId: candidate.id,
       ggufVariant: candidate.ggufVariant,
       isGguf: candidate.kind === "gguf",
-      customContextLength: remembered?.contextLength ?? null,
+      customContextLength: config.customContextLength,
       ggufContextLength: null,
       currentCheckpoint: currentStore.params.checkpoint,
       activeGgufVariant: currentStore.activeGgufVariant,
-      maxSeqLength: candidate.maxSeqLength,
+      maxSeqLength: config.maxSeqLength ?? candidate.maxSeqLength,
       presetSource: currentStore.activePresetSource,
     });
+    // The GPU knobs are per-model, so read them from the same per-model config
+    // that fed effectiveMaxSeqLength -- on a background auto-load the live store
+    // holds session defaults, not the saved Manual mode / layer pin / GPU pick.
+    // Absent fields fall back like the interactive restore: the mode to the store
+    // (a persisted standing preference), the per-model knobs to their defaults.
+    // The saved GPU pick is reconciled against the GPUs present now.
+    const effectiveGpuMemoryMode =
+      config.gpuMemoryMode ?? currentStore.gpuMemoryMode;
+    const effectiveGpuLayers = config.gpuLayers ?? GPU_LAYERS_AUTO;
+    const effectiveNCpuMoe = config.nCpuMoe ?? 0;
+    if (config.selectedGpuIds != null) {
+      // Warm the device cache first: on a cold cache the reconcile passes the
+      // saved pick through unvalidated, and a stale cross-host pick then fails
+      // the load with the picker hidden.
+      await ensureGpuDeviceCache();
+    }
+    const effectiveGpuIds =
+      config.selectedGpuIds !== undefined
+        ? reconcilePersistedGpuIds(config.selectedGpuIds)
+        : null;
+    // Under Manual GPU memory + Auto layers, llama.cpp's --fit owns context
+    // sizing, so send 0 (or the pinned length). GGUF-only; a no-op otherwise.
+    // The context pin is per-model too, so it comes from the saved config, not
+    // the live store.
+    const fitMaxSeqLength = resolveFitMaxSeqLength(
+      candidate.kind === "gguf",
+      effectiveGpuMemoryMode,
+      effectiveGpuLayers,
+      config.customContextLength ?? null,
+      effectiveMaxSeqLength,
+    );
     const effectiveSpeculativeType =
-      remembered?.speculativeType ?? specSettings.speculativeType;
+      config.speculativeType ?? specSettings.speculativeType;
     const effectiveSpecDraftNMax =
-      remembered?.specDraftNMax ?? specSettings.specDraftNMax;
+      config.specDraftNMax ?? specSettings.specDraftNMax;
+    const effectiveChatTemplateOverride = config.chatTemplateOverride?.trim()
+      ? config.chatTemplateOverride
+      : null;
     if (
       !(await canAutoLoad({
-        model_path: candidate.id,
-        max_seq_length: effectiveMaxSeqLength,
+        model_path: modelPath,
+        max_seq_length: fitMaxSeqLength,
         is_lora: false,
         gguf_variant: candidate.ggufVariant,
+        // The same remembered-derived GPU pick the load below sends.
+        ...(candidate.kind === "gguf"
+          ? {
+              gpu_ids: effectiveGpuIds ?? undefined,
+              gpu_memory_mode: effectiveGpuMemoryMode,
+            }
+          : {}),
       }))
     ) {
       skippedAutoLoadCandidates.add(
@@ -1556,35 +1604,59 @@ async function autoLoadSmallestModel(): Promise<{
     }
     loadAttempts += 1;
     const loadResp = await loadModel({
-      model_path: candidate.id,
+      model_path: modelPath,
       hf_token: hfToken,
-      max_seq_length: effectiveMaxSeqLength,
+      max_seq_length: fitMaxSeqLength,
       load_in_4bit: true,
       is_lora: false,
       gguf_variant: candidate.ggufVariant,
       trust_remote_code: trustRemoteCode,
-      cache_type_kv: remembered?.kvCacheDtype ?? null,
+      chat_template_override: effectiveChatTemplateOverride,
+      cache_type_kv: config.kvCacheDtype,
       speculative_type: effectiveSpeculativeType,
       spec_draft_n_max: effectiveSpecDraftNMax,
-      tensor_parallel: remembered?.tensorParallel ?? false,
+      tensor_parallel: config.tensorParallel,
+      // GGUF-only: the safetensors fallback loads via HF auto-placement (no
+      // explicit pins). The split ratio is deliberately never remembered
+      // (positionally bound to an exact GPU set), so auto-load leaves llama.cpp's
+      // free-VRAM default in charge rather than sending a stale store value.
+      ...(candidate.kind === "gguf"
+        ? {
+            gpu_memory_mode: effectiveGpuMemoryMode,
+            gpu_layers: effectiveGpuLayers,
+            n_cpu_moe: effectiveNCpuMoe,
+            gpu_ids: effectiveGpuIds ?? undefined,
+          }
+        : {}),
     });
-    saveSpeculativeType(effectiveSpeculativeType);
+    // Only persist the global preference when the value came from the global
+    // settings. A per-model config's choice must stay load-local, or autoloading
+    // a remembered model on startup would rewrite the global default.
+    if (config.speculativeType == null) {
+      saveSpeculativeType(effectiveSpeculativeType);
+    }
+    // Self-gates on is_gguf (skips diffusion), so persists only for a real GGUF load.
+    persistGpuMemoryModeOnLoad(loadResp, effectiveGpuMemoryMode);
+    const loadedModelId = loadResp.model || modelPath;
     useChatRuntimeStore
       .getState()
-      .setCheckpoint(candidate.id, candidate.ggufVariant ?? undefined);
+      .setCheckpoint(loadedModelId, candidate.ggufVariant ?? undefined);
     const store = useChatRuntimeStore.getState();
     store.setModelRequiresTrustRemoteCode(
       loadResp.requires_trust_remote_code ?? false,
     );
     store.setParams({
       ...store.params,
+      ...(candidate.kind === "gguf"
+        ? {}
+        : { maxSeqLength: effectiveMaxSeqLength }),
       maxTokens:
         candidate.kind === "gguf"
           ? loadResp.context_length ?? 131072
           : effectiveMaxSeqLength,
     });
     const autoModel: ChatModelSummary = {
-      id: candidate.id,
+      id: loadedModelId,
       name: loadResp.display_name ?? candidate.id,
       isVision: loadResp.is_vision ?? false,
       isLora: loadResp.is_lora ?? false,
@@ -1593,10 +1665,19 @@ async function autoLoadSmallestModel(): Promise<{
       audioType: loadResp.audio_type ?? null,
       hasAudioInput: loadResp.has_audio_input ?? false,
     };
-    if (!store.models.some((m) => m.id === candidate.id)) {
+    if (!store.models.some((m) => m.id === loadedModelId)) {
       store.setModels([...store.models, autoModel]);
     }
     if (candidate.kind === "gguf") {
+      // Keep an explicit Manual+Auto context pin the load just applied (so a
+      // later Apply doesn't silently revert it to auto-fit sizing), mirroring
+      // the interactive path's keepCustomCtx; other cases baseline on
+      // ggufContextLength.
+      const keepCustomCtx = resolveManualAutoCtxPin(
+        effectiveGpuMemoryMode,
+        effectiveGpuLayers,
+        config.customContextLength ?? null,
+      );
       useChatRuntimeStore.setState({
         ggufContextLength: loadResp.context_length ?? 131072,
         ggufMaxContextLength:
@@ -1613,9 +1694,14 @@ async function autoLoadSmallestModel(): Promise<{
         loadedKvCacheDtype: loadResp.cache_type_kv ?? null,
         tensorParallel: loadResp.tensor_parallel ?? false,
         loadedTensorParallel: loadResp.tensor_parallel ?? false,
+        ...loadedGpuMemoryFields(loadResp),
+        loadedCustomContextLength: keepCustomCtx,
         defaultChatTemplate: loadResp.chat_template ?? null,
-        chatTemplateOverride: null,
-        loadedChatTemplateOverride: null,
+        chatTemplateOverride: effectiveChatTemplateOverride,
+        loadedChatTemplateOverride: effectiveChatTemplateOverride,
+        // Retain the saved requested context so re-saving the config keeps the
+        // override; null stays null (auto/VRAM-fit).
+        customContextLength: config.customContextLength,
         loadedIsMultimodal: isMultimodalResponse(loadResp),
         loadedIsDiffusion: loadResp.is_diffusion ?? false,
         ...resolveLoadedSpeculativeSettings(loadResp),
@@ -1633,9 +1719,13 @@ async function autoLoadSmallestModel(): Promise<{
         loadedKvCacheDtype: loadResp.cache_type_kv ?? null,
         tensorParallel: loadResp.tensor_parallel ?? false,
         loadedTensorParallel: loadResp.tensor_parallel ?? false,
+        // Non-GGUF response: clears any stale GPU baseline a prior manual-GPU
+        // GGUF load left, matching the interactive/status sibling load paths.
+        ...loadedGpuMemoryFields(loadResp),
         defaultChatTemplate: loadResp.chat_template ?? null,
-        chatTemplateOverride: null,
-        loadedChatTemplateOverride: null,
+        chatTemplateOverride: effectiveChatTemplateOverride,
+        loadedChatTemplateOverride: effectiveChatTemplateOverride,
+        customContextLength: null,
         ...resolveLoadedSpeculativeSettings(loadResp),
         loadedIsMultimodal: isMultimodalResponse(loadResp),
         loadedIsDiffusion: loadResp.is_diffusion ?? false,
@@ -1662,7 +1752,10 @@ async function autoLoadSmallestModel(): Promise<{
         const repo = findCachedRepo(ggufRepos, lastLoaded.id);
         if (repo && lastLoaded.ggufVariant) {
           try {
-            const variants = await listGgufVariants(repo.repo_id);
+            const variants = await listGgufVariants(repo.repo_id, undefined, {
+              preferLocalCache: true,
+              localPath: repo.cache_path,
+            });
             const variant = variants.variants.find(
               (entry) =>
                 entry.downloaded &&
@@ -1679,6 +1772,7 @@ async function autoLoadSmallestModel(): Promise<{
               if (
                 await loadAutoLoadCandidate({
                   id: repo.repo_id,
+                  loadId: repo.load_id,
                   kind: "gguf",
                   ggufVariant: variant.quant,
                   maxSeqLength: 0,
@@ -1707,6 +1801,7 @@ async function autoLoadSmallestModel(): Promise<{
             if (
               await loadAutoLoadCandidate({
                 id: repo.repo_id,
+                loadId: repo.load_id,
                 kind: "model",
                 ggufVariant: null,
                 maxSeqLength: store.params.maxSeqLength,
@@ -1736,7 +1831,10 @@ async function autoLoadSmallestModel(): Promise<{
       for (const repo of sorted) {
         if (loadAttempts >= MAX_AUTO_LOAD_ATTEMPTS) break;
         try {
-          const variants = await listGgufVariants(repo.repo_id);
+          const variants = await listGgufVariants(repo.repo_id, undefined, {
+            preferLocalCache: true,
+            localPath: repo.cache_path,
+          });
           const downloaded = variants.variants
             .filter((v) => v.downloaded && isAutoLoadableGgufVariant(v))
             .sort((a, b) => a.size_bytes - b.size_bytes);
@@ -1752,6 +1850,7 @@ async function autoLoadSmallestModel(): Promise<{
             if (
               await loadAutoLoadCandidate({
                 id: repo.repo_id,
+                loadId: repo.load_id,
                 kind: "gguf",
                 ggufVariant: variant.quant,
                 maxSeqLength: 0,
@@ -1786,6 +1885,7 @@ async function autoLoadSmallestModel(): Promise<{
           if (
             await loadAutoLoadCandidate({
               id: repo.repo_id,
+              loadId: repo.load_id,
               kind: "model",
               ggufVariant: null,
               maxSeqLength: 4096,
@@ -1820,12 +1920,17 @@ async function autoLoadSmallestModel(): Promise<{
       duration: 30000,
     });
     try {
+      const rt = useChatRuntimeStore.getState();
       if (
         !(await canAutoLoad({
           model_path: "unsloth/Qwen3.5-4B-MTP-GGUF",
           max_seq_length: 0,
           is_lora: false,
           gguf_variant: "UD-Q4_K_XL",
+          // The same live-store GPU pick the load below sends (a fresh default
+          // model has no remembered settings to prefer).
+          gpu_ids: rt.selectedGpuIds ?? undefined,
+          gpu_memory_mode: rt.gpuMemoryMode,
         }))
       ) {
         toast.dismiss(toastId);
@@ -1835,6 +1940,9 @@ async function autoLoadSmallestModel(): Promise<{
       const loadResp = await loadModel({
         model_path: "unsloth/Qwen3.5-4B-MTP-GGUF",
         hf_token: hfToken,
+        // Model default under both modes: Auto layers + no pin means
+        // resolveFitMaxSeqLength returns 0 for every mode (the canAutoLoad
+        // preflight above sends the same).
         max_seq_length: 0,
         load_in_4bit: true,
         is_lora: false,
@@ -1842,8 +1950,20 @@ async function autoLoadSmallestModel(): Promise<{
         trust_remote_code: trustRemoteCode,
         speculative_type: specSettings.speculativeType,
         spec_draft_n_max: specSettings.specDraftNMax,
+        // GPU Memory mode is a standing preference, so honor it on auto-load.
+        // The layer/MoE/split knobs and the context pin are per-model: the live
+        // store may hold edits drafted for a staged pick, and a fresh default
+        // model has no remembered settings, so those stay at their defaults like
+        // the cached-candidate path. The GPU pick deliberately differs (it's the
+        // picker's current on-screen selection, which the canAutoLoad preflight
+        // above already committed to).
+        gpu_memory_mode: rt.gpuMemoryMode,
+        gpu_layers: GPU_LAYERS_AUTO,
+        n_cpu_moe: 0,
+        gpu_ids: rt.selectedGpuIds ?? undefined,
       });
       saveSpeculativeType(specSettings.speculativeType);
+      persistGpuMemoryModeOnLoad(loadResp, rt.gpuMemoryMode);
       useChatRuntimeStore
         .getState()
         .setCheckpoint("unsloth/Qwen3.5-4B-MTP-GGUF", "UD-Q4_K_XL");
@@ -1880,6 +2000,10 @@ async function autoLoadSmallestModel(): Promise<{
         loadedKvCacheDtype: loadResp.cache_type_kv ?? null,
         tensorParallel: loadResp.tensor_parallel ?? false,
         loadedTensorParallel: loadResp.tensor_parallel ?? false,
+        ...loadedGpuMemoryFields(loadResp),
+        // Drives the GPU Memory controls' diffusion gate; set alongside the
+        // GPU fields on every load path so the gate can't read stale.
+        loadedIsDiffusion: loadResp.is_diffusion ?? false,
         defaultChatTemplate: loadResp.chat_template ?? null,
         chatTemplateOverride: null,
         loadedIsMultimodal: isMultimodalResponse(loadResp),
diff --git a/studio/frontend/src/features/chat/api/chat-api.ts b/studio/frontend/src/features/chat/api/chat-api.ts
index ebf9461172..ffaf099f29 100644
--- a/studio/frontend/src/features/chat/api/chat-api.ts
+++ b/studio/frontend/src/features/chat/api/chat-api.ts
@@ -2,7 +2,12 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { authFetch } from "@/features/auth";
+import { prepareHfTokenForUse } from "@/features/hf-auth";
+// These helpers are deliberately API-layer-only and are not part of their
+// features' React-facing public barrels.
+// eslint-disable-next-line no-restricted-imports
 import { hubTokenHeader } from "@/features/hub/lib/hub-token-header";
+// eslint-disable-next-line no-restricted-imports
 import { consumeNativePathToken } from "@/features/native-intents/api";
 import { formatFastApiDetail } from "@/lib/format-fastapi-error";
 import type {
@@ -28,6 +33,7 @@ import type {
 } from "../types/api";
 
 export const CHAT_HISTORY_UPDATED_EVENT = "unsloth-chat-history-updated";
+export const CHAT_PROJECTS_UPDATED_EVENT = "unsloth-chat-projects-updated";
 
 /**
  * Thrown when the chat SSE stream ends without a terminal signal (`[DONE]` or a
@@ -50,6 +56,13 @@ export function notifyChatHistoryUpdated(): void {
   }
 }
 
+function notifyChatProjectsUpdated(): void {
+  notifyChatHistoryUpdated();
+  if (typeof window !== "undefined") {
+    window.dispatchEvent(new Event(CHAT_PROJECTS_UPDATED_EVENT));
+  }
+}
+
 function parseErrorText(status: number, body: unknown): string {
   if (body && typeof body === "object") {
     const detail = (body as { detail?: unknown }).detail;
@@ -104,11 +117,14 @@ export async function getApiMonitorEntry(id: string): Promise<ApiMonitorEntry> {
 export async function loadModel(
   payload: LoadModelRequest,
 ): Promise<LoadModelResponse> {
+  const preparedToken = await prepareHfTokenForUse(payload.hf_token);
+  if (!preparedToken.proceed) throw new Error("Model load cancelled.");
   const response = await authFetch("/api/inference/load", {
     method: "POST",
     headers: { "Content-Type": "application/json" },
     body: JSON.stringify({
       ...payload,
+      hf_token: preparedToken.token,
       native_path_lease: payload.nativePathLease ?? null,
       nativePathLease: undefined,
     }),
@@ -119,36 +135,48 @@ export async function loadModel(
 export async function validateModel(
   payload: LoadModelRequest,
 ): Promise<ValidateModelResponse> {
+  const preparedToken = await prepareHfTokenForUse(payload.hf_token);
+  if (!preparedToken.proceed) throw new Error("Model load cancelled.");
   const response = await authFetch("/api/inference/validate", {
     method: "POST",
     headers: { "Content-Type": "application/json" },
     body: JSON.stringify({
       model_path: payload.model_path,
       native_path_lease: payload.nativePathLease ?? null,
-      hf_token: payload.hf_token,
+      hf_token: preparedToken.token,
       gguf_variant: payload.gguf_variant ?? null,
-      // Send the intended load settings so validate's VRAM check matches the
-      // follow-up /load and doesn't unload for a load /load would then reject.
+      // Intended load settings so validate's preflight matches the follow-up
+      // /load. Default placement is sized against the selected GPUs.
       max_seq_length: payload.max_seq_length,
       load_in_4bit: payload.load_in_4bit,
+      gpu_ids: payload.gpu_ids,
+      // Manual placement is an explicit override: Auto layers use llama.cpp
+      // --fit, while a pinned layer count is owned by the user. Tell validate
+      // so it applies the same training-guard policy as /load.
+      gpu_memory_mode: payload.gpu_memory_mode,
     }),
   });
   return parseJsonOrThrow<ValidateModelResponse>(response);
 }
 
 /**
- * Read a GGUF's native context length from its local header (no GPU load, no
- * download). Returns null when the file isn't downloaded yet, the model isn't a
- * GGUF, or it's gated. For a native (drag-drop / picked) file, pass
- * `nativePathToken` so the backend reads the granted local path. Used by the
- * deferred-load staging flow to fill the context slider before the single load.
+ * Read a GGUF's header dims (native context length, total layer count, MoE
+ * expert-layer count) from its local file (no GPU load, no download). All are
+ * null when the file isn't downloaded yet, the model isn't a GGUF, or it's
+ * gated. For a native (drag-drop / picked) file, pass `nativePathToken` so the
+ * backend reads the granted local path. Used by the deferred-load staging flow
+ * to size the context, GPU-layers and MoE sliders before the single load.
  */
-export async function fetchGgufContextLength(payload: {
+export async function fetchGgufStagedMetadata(payload: {
   model_path: string;
   gguf_variant?: string | null;
   hf_token?: string | null;
   nativePathToken?: string | null;
-}): Promise<number | null> {
+}): Promise<{
+  contextLength: number | null;
+  layerCount: number | null;
+  moeLayerCount: number | null;
+}> {
   let nativePathLease: string | null = null;
   if (payload.nativePathToken) {
     try {
@@ -156,8 +184,8 @@ export async function fetchGgufContextLength(payload: {
         await consumeNativePathToken(payload.nativePathToken, "validate-model")
       ).nativePathLease;
     } catch {
-      // Lease expired / revoked: degrade to no context (the load can re-mint).
-      return null;
+      // Lease expired / revoked: degrade to no metadata (the load can re-mint).
+      return { contextLength: null, layerCount: null, moeLayerCount: null };
     }
   }
   const response = await authFetch("/api/inference/validate", {
@@ -172,7 +200,11 @@ export async function fetchGgufContextLength(payload: {
     }),
   });
   const res = await parseJsonOrThrow<ValidateModelResponse>(response);
-  return res.context_length ?? null;
+  return {
+    contextLength: res.context_length ?? null,
+    layerCount: res.layer_count ?? null,
+    moeLayerCount: res.moe_layer_count ?? null,
+  };
 }
 
 export async function unloadModel(payload: UnloadModelRequest): Promise<void> {
@@ -211,6 +243,7 @@ export async function resolveToolConfirmation(
 
 export interface CachedGgufRepo {
   repo_id: string;
+  load_id?: string | null;
   size_bytes: number;
   cache_path: string;
   /** Epoch seconds of the newest downloaded quant; sorts Downloaded
@@ -310,43 +343,72 @@ interface LocalModelListResponse {
   models: LocalModelInfo[];
 }
 
-export async function listLocalModels(): Promise<LocalModelListResponse> {
-  const response = await authFetch("/api/models/local");
+export async function listLocalModels(
+  signal?: AbortSignal,
+): Promise<LocalModelListResponse> {
+  const response = await authFetch("/api/models/local", { signal });
   return parseJsonOrThrow<LocalModelListResponse>(response);
 }
 
-export async function listCachedGguf(): Promise<CachedGgufRepo[]> {
-  const response = await authFetch("/api/models/cached-gguf");
+export async function listCachedGguf(
+  signal?: AbortSignal,
+): Promise<CachedGgufRepo[]> {
+  const response = await authFetch("/api/hub/cached-gguf", { signal });
   const data = await parseJsonOrThrow<{ cached: CachedGgufRepo[] }>(response);
   return data.cached;
 }
 
 export interface CachedModelRepo {
   repo_id: string;
+  load_id?: string | null;
   size_bytes: number;
   /** Epoch seconds of the newest downloaded weight file; sorts Downloaded
    * newest-first. Optional for older-backend compatibility. */
   last_modified?: number;
+  /** Owning cache dir; sent so a delete targets this copy, not the active
+   * cache. Optional for older-backend compatibility. */
+  cache_path?: string | null;
 }
 
 export async function listCachedModels(
   hfToken?: string | null,
+  signal?: AbortSignal,
 ): Promise<CachedModelRepo[]> {
-  const response = await authFetch("/api/models/cached-models", {
+  const response = await authFetch("/api/hub/cached-models", {
     headers: hubTokenHeader(hfToken),
+    signal,
   });
   const data = await parseJsonOrThrow<{ cached: CachedModelRepo[] }>(response);
   return data.cached;
 }
 
-export async function deleteCachedModel(
+export interface CachedModelPath {
+  path: string;
+  is_dir: boolean;
+}
+
+/** Absolute on-disk path of a cached repo or one of its GGUF variants. */
+export async function getCachedModelPath(
+  repoId: string,
+  variant?: string,
+): Promise<CachedModelPath> {
+  const params = new URLSearchParams({ repo_id: repoId });
+  if (variant) params.set("variant", variant);
+  const response = await authFetch(
+    `/api/models/cached-model-path?${params.toString()}`,
+  );
+  return parseJsonOrThrow<CachedModelPath>(response);
+}
+
+/** Reveal a cached repo (or one GGUF variant's file) in the OS file manager. */
+export async function revealCachedModel(
   repoId: string,
   variant?: string,
 ): Promise<void> {
   const payload: Record<string, string> = { repo_id: repoId };
   if (variant) payload.variant = variant;
-  const response = await authFetch("/api/models/delete-cached", {
-    method: "DELETE",
+  const response = await authFetch("/api/models/reveal-cached-model", {
+    method: "POST",
     headers: { "Content-Type": "application/json" },
     body: JSON.stringify(payload),
   });
@@ -423,6 +485,73 @@ export async function listChatThreads(
   return Array.isArray(data.threads) ? data.threads : [];
 }
 
+/** One chat message attachment, as listed for the settings uploaded-files view. */
+export interface ChatAttachmentRecord {
+  id: string;
+  messageId: string;
+  threadId: string;
+  pairId?: string | null;
+  threadTitle?: string | null;
+  name: string;
+  type?: string | null;
+  contentType?: string | null;
+  sizeBytes?: number | null;
+  createdAt?: number | null;
+}
+
+export interface ChatAttachmentPage {
+  attachments: ChatAttachmentRecord[];
+  nextOffset: number | null;
+}
+
+export async function listChatAttachments(
+  offset = 0,
+  limit = 50,
+): Promise<ChatAttachmentPage> {
+  const params = new URLSearchParams({
+    limit: String(limit),
+    offset: String(offset),
+  });
+  const response = await authFetch(`/api/chat/attachments?${params}`);
+  const data = await parseJsonOrThrow<{
+    attachments: ChatAttachmentRecord[];
+    nextOffset: number | null;
+  }>(response);
+  return {
+    attachments: Array.isArray(data.attachments) ? data.attachments : [],
+    nextOffset:
+      typeof data.nextOffset === "number" && Number.isFinite(data.nextOffset)
+        ? data.nextOffset
+        : null,
+  };
+}
+
+/** Stored attachment content (image bytes or extracted text) as a Blob. */
+export async function fetchChatAttachmentBlob(
+  messageId: string,
+  attachmentId: string,
+): Promise<Blob> {
+  const response = await authFetch(
+    `/api/chat/attachments/${encodeURIComponent(messageId)}/${encodeURIComponent(attachmentId)}/file`,
+  );
+  if (!response.ok) {
+    const body = await response.json().catch(() => null);
+    throw new Error(parseErrorText(response.status, body));
+  }
+  return response.blob();
+}
+
+export async function deleteChatAttachment(
+  messageId: string,
+  attachmentId: string,
+): Promise<void> {
+  const response = await authFetch(
+    `/api/chat/attachments/${encodeURIComponent(messageId)}/${encodeURIComponent(attachmentId)}`,
+    { method: "DELETE" },
+  );
+  await parseJsonOrThrow<{ ok: boolean }>(response);
+}
+
 export async function getChatThread(
   threadId: string,
 ): Promise<ThreadRecord | null> {
@@ -547,7 +676,7 @@ export async function saveChatProject(
     body: JSON.stringify(project),
   });
   const saved = await parseJsonOrThrow<ProjectRecord>(response);
-  notifyChatHistoryUpdated();
+  notifyChatProjectsUpdated();
   return saved;
 }
 
@@ -564,7 +693,7 @@ export async function updateChatProject(
     },
   );
   const project = await parseJsonOrThrow<ProjectRecord>(response);
-  notifyChatHistoryUpdated();
+  notifyChatProjectsUpdated();
   return project;
 }
 
@@ -580,7 +709,7 @@ export async function deleteChatProject(
     { method: "DELETE" },
   );
   await parseJsonOrThrow<ProjectRecord>(response);
-  notifyChatHistoryUpdated();
+  notifyChatProjectsUpdated();
 }
 
 export async function listChatMessages(
@@ -796,8 +925,19 @@ export async function browseFolders(
 export async function listGgufVariants(
   repoId: string,
   hfToken?: string,
+  options?: {
+    preferLocalCache?: boolean;
+    localPath?: string | null;
+  },
 ): Promise<GgufVariantsResponse> {
   const params = new URLSearchParams({ repo_id: repoId });
+  if (options?.preferLocalCache) {
+    params.set("prefer_local_cache", "true");
+  }
+  const localPath = options?.localPath?.trim();
+  if (localPath) {
+    params.set("local_path", localPath);
+  }
   const response = await authFetch(`/api/models/gguf-variants?${params}`, {
     headers: hubTokenHeader(hfToken),
   });
@@ -946,7 +1086,8 @@ export async function* streamChatCompletions(
           parsed.type === "reasoning_summary"
         ) {
           yield {
-            _reasoningDurationMs: (parsed as { duration_ms?: number }).duration_ms,
+            _reasoningDurationMs: (parsed as { duration_ms?: number })
+              .duration_ms,
           } as unknown as OpenAIChatChunk;
           separatorIndex = buffer.search(/\r?\n\r?\n/);
           continue;
diff --git a/studio/frontend/src/features/chat/api/chat-settings-api.ts b/studio/frontend/src/features/chat/api/chat-settings-api.ts
index 1e00357ea4..ab13130525 100644
--- a/studio/frontend/src/features/chat/api/chat-settings-api.ts
+++ b/studio/frontend/src/features/chat/api/chat-settings-api.ts
@@ -13,6 +13,7 @@ export type PersistedInferenceParams = Partial<
 export interface PersistedChatPreset {
   name: string;
   params: PersistedInferenceParams;
+  loadConfig?: Record<string, unknown>;
 }
 
 export interface PersistedChatSettings {
diff --git a/studio/frontend/src/features/chat/api/providers-api.ts b/studio/frontend/src/features/chat/api/providers-api.ts
index 4ad996d54f..c6c5613272 100644
--- a/studio/frontend/src/features/chat/api/providers-api.ts
+++ b/studio/frontend/src/features/chat/api/providers-api.ts
@@ -23,6 +23,8 @@ export interface ProviderConfig {
   display_name: string;
   base_url: string;
   is_enabled: boolean;
+  models?: string[];
+  available_models?: string[];
   created_at: string;
   updated_at: string;
 }
@@ -123,6 +125,8 @@ export async function createProviderConfig(payload: {
   providerType: string;
   displayName: string;
   baseUrl?: string | null;
+  models?: string[];
+  availableModels?: string[];
 }): Promise<ProviderConfig> {
   const response = await authFetch("/api/providers/", {
     method: "POST",
@@ -131,6 +135,8 @@ export async function createProviderConfig(payload: {
       provider_type: payload.providerType,
       display_name: payload.displayName,
       base_url: payload.baseUrl ?? null,
+      models: payload.models ?? [],
+      available_models: payload.availableModels ?? [],
     }),
   });
   return parseJsonOrThrow<ProviderConfig>(response);
@@ -158,6 +164,8 @@ export async function updateProviderConfig(
     displayName?: string;
     baseUrl?: string | null;
     isEnabled?: boolean;
+    models?: string[];
+    availableModels?: string[];
   },
 ): Promise<ProviderConfig> {
   const response = await authFetch(`/api/providers/${providerId}`, {
@@ -167,6 +175,10 @@ export async function updateProviderConfig(
       ...(payload.displayName === undefined ? {} : { display_name: payload.displayName }),
       ...(payload.baseUrl === undefined ? {} : { base_url: payload.baseUrl }),
       ...(payload.isEnabled === undefined ? {} : { is_enabled: payload.isEnabled }),
+      ...(payload.models === undefined ? {} : { models: payload.models }),
+      ...(payload.availableModels === undefined
+        ? {}
+        : { available_models: payload.availableModels }),
     }),
   });
   return parseJsonOrThrow<ProviderConfig>(response);
diff --git a/studio/frontend/src/features/chat/artifacts/artifact-card.tsx b/studio/frontend/src/features/chat/artifacts/artifact-card.tsx
index ee8c26abf1..531b17522d 100644
--- a/studio/frontend/src/features/chat/artifacts/artifact-card.tsx
+++ b/studio/frontend/src/features/chat/artifacts/artifact-card.tsx
@@ -8,7 +8,7 @@ import { cn } from "@/lib/utils";
 import { useAuiState } from "@assistant-ui/react";
 import { LayoutTwoColumnIcon as Layout2ColumnIcon } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
-import { useLayoutEffect, useMemo } from "react";
+import { useLayoutEffect, useMemo, useRef } from "react";
 import { useChatRuntimeStore } from "../stores/chat-runtime-store";
 import type { ArtifactViewMode } from "./html-frame";
 import {
@@ -83,15 +83,18 @@ export function ArtifactCard({
     ],
   );
   const surface = artifactThreadId ? "panel" : "overlay";
+  // Once per mount, so a view-change cleanup can't re-trigger a stale open.
+  const autoOpenAttemptedRef = useRef(false);
 
   useLayoutEffect(() => {
     if (selectedArtifactId === artifact.id) {
       updateArtifact(artifact);
     }
 
-    if (!autoOpen) {
+    if (!autoOpen || autoOpenAttemptedRef.current) {
       return;
     }
+    autoOpenAttemptedRef.current = true;
     if (hasAutoOpenedArtifact(artifact.id)) {
       return;
     }
@@ -142,12 +145,12 @@ export function ArtifactCard({
             <span className="truncate text-sm font-medium leading-tight text-foreground">
               {isCode ? "HTML Code" : artifact.title}
             </span>
-            <span className="truncate text-[11px] leading-none text-muted-foreground">
+            <span className="truncate text-ui-11 leading-none text-muted-foreground">
               HTML canvas
             </span>
           </span>
           {isStreaming && !isCode ? (
-            <span className="shimmer shrink-0 rounded-full bg-primary/10 px-2 py-0.5 text-[10px] font-medium text-primary motion-reduce:animate-none">
+            <span className="shimmer shrink-0 rounded-full bg-primary/10 px-2 py-0.5 text-ui-10 font-medium text-primary motion-reduce:animate-none">
               Generating
             </span>
           ) : null}
diff --git a/studio/frontend/src/features/chat/artifacts/html-frame.tsx b/studio/frontend/src/features/chat/artifacts/html-frame.tsx
index b26f2f6685..36e3ed8a5b 100644
--- a/studio/frontend/src/features/chat/artifacts/html-frame.tsx
+++ b/studio/frontend/src/features/chat/artifacts/html-frame.tsx
@@ -28,7 +28,7 @@ export function buildArtifactSrcDoc(code: string): string {
 }
 
 // Preview iframes intentionally omit allow-downloads: generated canvases can
-// offer their own UI, but downloads must go through Studio's explicit
+// offer their own UI, but downloads must go through Unsloth's explicit
 // copy/download controls outside the no-same-origin sandbox.
 export function ArtifactHtmlFrame({
   code,
diff --git a/studio/frontend/src/features/chat/bypass-permissions-menu-item.tsx b/studio/frontend/src/features/chat/bypass-permissions-menu-item.tsx
index b35317b2fa..8c9a528e66 100644
--- a/studio/frontend/src/features/chat/bypass-permissions-menu-item.tsx
+++ b/studio/frontend/src/features/chat/bypass-permissions-menu-item.tsx
@@ -20,16 +20,12 @@ import {
   DropdownMenuSubTrigger,
 } from "@/components/ui/dropdown-menu";
 import { useChatRuntimeStore } from "@/features/chat/stores/chat-runtime-store";
-import { PermissionModeMenuItems } from "./permission-mode-select";
+import {
+  FULL_ACCESS_WARNING,
+  PermissionModeMenuItems,
+} from "./permission-mode-select";
 
-// "Bypass permissions" entry for the composer "+" -> More menu. Like the MCP
-// pill, it opens a submenu where the user picks the permission level (Ask for
-// approval / Approve for me / Full access). Picking Full access demands the
-// danger warning; the other levels apply immediately. The menu closes normally
-// on select (no preventDefault) -- the warning dialog lives outside the menu
-// (BypassPermissionsConfirmDialog, mounted once at the chat-page root and
-// driven by the store), so it survives the menu unmounting and the "+"/More
-// popovers don't stay frozen.
+// Tool permissions entry for the composer "+" menu.
 export function BypassPermissionsMenuItem() {
   const permissionMode = useChatRuntimeStore((s) => s.permissionMode);
   const setBypassConfirmOpen = useChatRuntimeStore(
@@ -44,7 +40,7 @@ export function BypassPermissionsMenuItem() {
         }
       >
         <HugeiconsIcon icon={ShieldBanIcon} strokeWidth={2} />
-        Bypass permissions
+        Tool permissions
       </DropdownMenuSubTrigger>
       <DropdownMenuSubContent className="unsloth-plus-menu w-[300px]">
         <PermissionModeMenuItems
@@ -75,9 +71,7 @@ export function BypassPermissionsConfirmDialog() {
         <AlertDialogHeader>
           <AlertDialogTitle>Enable Full access?</AlertDialogTitle>
           <AlertDialogDescription>
-            Full access (Bypass permissions) is dangerous since the AI model
-            might delete, corrupt your machine, and or cause real world damage
-            to you or the world - only accept if you are certain
+            {FULL_ACCESS_WARNING}
           </AlertDialogDescription>
         </AlertDialogHeader>
         <AlertDialogFooter>
diff --git a/studio/frontend/src/features/chat/chat-page.tsx b/studio/frontend/src/features/chat/chat-page.tsx
index 380ce0e0ab..7452cf3447 100644
--- a/studio/frontend/src/features/chat/chat-page.tsx
+++ b/studio/frontend/src/features/chat/chat-page.tsx
@@ -2,24 +2,50 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import {
+  applyModelLoadConfigToRuntime,
+  currentRuntimePerModelConfig,
   type DeletedModelRef,
   type ExternalModelOption,
   type LoraModelOption,
   type ModelOption,
   ModelSelector,
-} from "@/components/assistant-ui/model-selector";
-import {
-  loadRememberedLoadSettings,
-  rememberedLoadSettingsKey,
-} from "@/components/assistant-ui/model-selector/remembered-load-settings";
+  type ModelSelectorChangeMeta,
+  type PerModelConfig,
+  resolveInitialConfig,
+  SidebarModelConfig,
+  useActiveModelConfig,
+} from "@/features/model-picker";
 import { ProjectComposer, Thread } from "@/components/assistant-ui/thread";
 import { CopyableErrorChip } from "@/components/ui/copyable-error-chip";
 import {
   DropdownMenu,
   DropdownMenuContent,
   DropdownMenuItem,
+  DropdownMenuSeparator,
+  DropdownMenuSub,
+  DropdownMenuSubContent,
+  DropdownMenuSubTrigger,
   DropdownMenuTrigger,
 } from "@/components/ui/dropdown-menu";
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+} from "@/components/ui/alert-dialog";
+import { Button } from "@/components/ui/button";
+import {
+  Dialog,
+  DialogContent,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from "@/components/ui/dialog";
+import { Input } from "@/components/ui/input";
 import {
   ResizableHandle,
   ResizablePanel,
@@ -27,10 +53,10 @@ import {
 } from "@/components/ui/resizable";
 import { useSidebar } from "@/components/ui/sidebar";
 import { Tooltip, TooltipContent } from "@/components/ui/tooltip";
-import { useLatestRef } from "@/features/hub/hooks/use-latest-ref";
 import {
   DOWNLOAD_KIND,
   downloadManager,
+  useRepoDownload,
 } from "@/features/hub/download-manager";
 import {
   type NativeIntent,
@@ -43,14 +69,23 @@ import {
 } from "@/features/native-intents";
 import { GuidedTour, useGuidedTourController } from "@/features/tour";
 import { isTauri } from "@/lib/api-base";
+import { isDownloadCancelled } from "@/lib/native-files";
 import { toast } from "@/lib/toast";
 import { cn } from "@/lib/utils";
 import {
+  Archive03Icon,
   BubbleChatTemporaryIcon,
+  Delete02Icon,
+  Download01Icon,
   Edit03Icon,
+  Folder01Icon,
   Folder02Icon,
+  FolderExportIcon,
   LayoutAlignRightIcon,
+  MoreHorizontalIcon,
   MoreVerticalIcon,
+  PinIcon,
+  PinOffIcon,
 } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
 import { useNavigate } from "@tanstack/react-router";
@@ -68,7 +103,7 @@ import {
   useState,
 } from "react";
 import type { PanelImperativeHandle } from "react-resizable-panels";
-import { listLocalModels } from "./api/chat-api";
+import { listLocalModels, notifyChatHistoryUpdated } from "./api/chat-api";
 import { ArtifactSurface } from "./artifacts/artifact-surface";
 import {
   clearAutoOpenedArtifacts,
@@ -87,13 +122,21 @@ import {
 } from "./external-providers";
 import { useChatModelRuntime } from "./hooks/use-chat-model-runtime";
 import type { SelectedModelInput } from "./hooks/use-chat-model-runtime";
-import { useChatProjects } from "./hooks/use-chat-projects";
+import {
+  deleteChatProject,
+  moveChatItemToProject,
+  renameChatProject,
+  useChatProjects,
+} from "./hooks/use-chat-projects";
 import {
   type SidebarItem,
+  archiveChatItem,
+  deleteChatItem,
   renameChatItem,
   useChatSidebarItems,
 } from "./hooks/use-chat-sidebar-items";
-import { useStagedModelPreparation } from "./hooks/use-staged-model-preparation";
+import { usePinnedChatsStore } from "./stores/pinned-chats-store";
+import { usePinnedProjectsStore } from "./stores/pinned-projects-store";
 import {
   clearTrainingCompareHandoff,
   getTrainingCompareHandoff,
@@ -128,12 +171,11 @@ import {
   hasGgufSource,
   isDownloadableHubRepo,
   loadOptionalBool,
-  pendingSelectionMatches,
   useChatRuntimeStore,
 } from "./stores/chat-runtime-store";
-import type { PendingModelSelection } from "./stores/chat-runtime-store";
 import { useChatPreferencesStore } from "./stores/chat-preferences-store";
 import { useExternalProvidersStore } from "./stores/external-providers-store";
+import { syncExternalProvidersFromBackend } from "./sync-external-providers";
 import { buildChatTourSteps } from "./tour";
 import type { ChatView, MessageRecord } from "./types";
 import {
@@ -247,13 +289,13 @@ const SingleContent = memo(function SingleContent({
     useState(false);
   const [isArtifactSurfaceVisible, setIsArtifactSurfaceVisible] =
     useState(false);
+  // Without a URL threadId the artifact must belong to the active thread.
   const showArtifactPanel = Boolean(
     artifact &&
       artifactSurface === "panel" &&
       (threadId
         ? !artifact.threadId || artifact.threadId === threadId
-        : Boolean(newThreadNonce) ||
-          Boolean(artifact.threadId && artifact.threadId === activeThreadId)),
+        : Boolean(artifact.threadId && artifact.threadId === activeThreadId)),
   );
 
   const artifactLayoutActive = showArtifactPanel || isArtifactPanelLayoutActive;
@@ -385,6 +427,7 @@ type CompareModelSelection = {
   id: string;
   isLora: boolean;
   ggufVariant?: string;
+  config?: PerModelConfig;
 };
 
 function modelMatchesDeleted(
@@ -609,7 +652,7 @@ const LoraCompareContent = memo(function LoraCompareContent({
           handleName="base"
           header={
             <div className="shrink-0 px-3 py-1.5">
-              <span className="text-[10px] font-semibold uppercase tracking-wider text-muted-foreground">
+              <span className="text-ui-10 font-semibold uppercase tracking-wider text-muted-foreground">
                 Base Model
               </span>
             </div>
@@ -624,7 +667,7 @@ const LoraCompareContent = memo(function LoraCompareContent({
           borderClassName="border-t border-border/60 md:border-t-0 md:border-l"
           header={
             <div className="shrink-0 px-3 py-1.5 text-start md:text-end md:pr-[calc(4rem+var(--studio-chat-header-right-inset,var(--studio-window-control-inset,0px)))]">
-              <span className="text-[10px] font-semibold uppercase tracking-wider text-primary">
+              <span className="text-ui-10 font-semibold uppercase tracking-wider text-primary">
                 Fine-tuned
               </span>
             </div>
@@ -645,6 +688,8 @@ function GeneralCompareHeader({
   loraModels,
   externalModels,
   value,
+  selectedConfig,
+  selectedGgufVariant,
   onValueChange,
   onFoldersChange,
   onModelsChange,
@@ -655,9 +700,11 @@ function GeneralCompareHeader({
   loraModels: LoraModelOption[];
   externalModels: ExternalModelOption[];
   value: string;
+  selectedConfig?: PerModelConfig | null;
+  selectedGgufVariant?: string | null;
   onValueChange: (
     id: string,
-    meta: { isLora: boolean; ggufVariant?: string },
+    meta: ModelSelectorChangeMeta,
   ) => void;
   onFoldersChange?: () => void;
   onModelsChange?: (deletedModel?: DeletedModelRef) => void;
@@ -684,6 +731,8 @@ function GeneralCompareHeader({
         loraModels={loraModels}
         externalModels={externalModels}
         value={value}
+        selectedConfig={selectedConfig}
+        selectedGgufVariant={selectedGgufVariant}
         onValueChange={onValueChange}
         onFoldersChange={onFoldersChange}
         onModelsChange={onModelsChange}
@@ -811,11 +860,14 @@ const GeneralCompareContent = memo(function GeneralCompareContent({
               loraModels={loraModels}
               externalModels={externalModels}
               value={model1.id}
+              selectedConfig={model1.config}
+              selectedGgufVariant={model1.ggufVariant}
               onValueChange={(id, meta) =>
                 setModel1({
                   id,
                   isLora: meta.isLora,
                   ggufVariant: meta.ggufVariant,
+                  config: meta.config,
                 })
               }
               onFoldersChange={onFoldersChange}
@@ -838,11 +890,14 @@ const GeneralCompareContent = memo(function GeneralCompareContent({
               loraModels={loraModels}
               externalModels={externalModels}
               value={model2.id}
+              selectedConfig={model2.config}
+              selectedGgufVariant={model2.ggufVariant}
               onValueChange={(id, meta) =>
                 setModel2({
                   id,
                   isLora: meta.isLora,
                   ggufVariant: meta.ggufVariant,
+                  config: meta.config,
                 })
               }
               onFoldersChange={onFoldersChange}
@@ -863,6 +918,47 @@ function formatProjectChatDate(timestamp: number): string {
   }).format(new Date(timestamp));
 }
 
+// Unique thread nonce; falls back off crypto.randomUUID for non-secure
+// (HTTP LAN) contexts where it is unavailable.
+function createThreadNonce(): string {
+  if (typeof globalThis.crypto?.randomUUID === "function") {
+    return globalThis.crypto.randomUUID();
+  }
+  return `${Date.now()}-${Math.random().toString(36).slice(2, 10)}`;
+}
+
+// Chat export formats, mirroring the sidebar chat menu.
+type ProjectChatExportFormat = "raw-jsonl" | "csv" | "sharegpt-jsonl";
+const PROJECT_CHAT_EXPORT_OPTIONS: Array<{
+  label: string;
+  format: ProjectChatExportFormat;
+}> = [
+  { label: "Raw JSONL", format: "raw-jsonl" },
+  { label: "CSV", format: "csv" },
+  { label: "ShareGPT JSONL", format: "sharegpt-jsonl" },
+];
+
+async function exportProjectConversation(
+  threadId: string,
+  format: ProjectChatExportFormat,
+): Promise<void> {
+  const exports = await import("./prompt-storage/prompt-storage-dialog");
+  if (format === "raw-jsonl") return exports.exportConversationRawJsonl(threadId);
+  if (format === "csv") return exports.exportConversationCsv(threadId);
+  return exports.exportConversationShareGPT(threadId);
+}
+
+async function exportProjectChatItem(
+  item: SidebarItem,
+  format: ProjectChatExportFormat,
+): Promise<void> {
+  const ids =
+    item.type === "single"
+      ? [item.id]
+      : (await listStoredChatThreads({ pairId: item.id })).map((t) => t.id);
+  for (const id of ids) await exportProjectConversation(id, format);
+}
+
 function extractMessageText(content: MessageRecord["content"]): string {
   if (typeof content === "string") {
     return content;
@@ -897,6 +993,9 @@ function ProjectLanding({
   items: SidebarItem[];
 }): ReactElement {
   const navigate = useNavigate();
+  // Gates body-portaled surfaces so they can't linger or act while the landing
+  // is off-route (e.g. behind another tab).
+  const active = useChatActive();
   const activeThreadId = useChatRuntimeStore((s) => s.activeThreadId);
   const initialActiveThreadRef = useRef<string | null>(null);
   const [projectTab, setProjectTab] = useState<"chats" | "sources">("chats");
@@ -904,7 +1003,7 @@ function ProjectLanding({
     null,
   );
   const [newThreadNonce, setNewThreadNonce] = useState(() =>
-    crypto.randomUUID(),
+    createThreadNonce(),
   );
   const [previews, setPreviews] = useState<
     Record<string, { snippet: string; date: string }>
@@ -923,13 +1022,65 @@ function ProjectLanding({
     title: string;
   } | null>(null);
 
+  // Project-level options (the header kebab menu).
+  const pinnedProjectIds = usePinnedProjectsStore((s) => s.pinnedIds);
+  const togglePinProject = usePinnedProjectsStore((s) => s.togglePin);
+  const projectPinned = pinnedProjectIds.includes(projectId);
+  const [renamingProject, setRenamingProject] = useState(false);
+  const [projectNameDraft, setProjectNameDraft] = useState("");
+  const [deletingProject, setDeletingProject] = useState(false);
+
+  async function handleProjectExport(
+    format: ProjectChatExportFormat,
+  ): Promise<void> {
+    try {
+      const threads = await listStoredChatThreads({
+        projectId,
+        includeArchived: false,
+      });
+      const ids = [...new Set(threads.map((t) => t.id))];
+      for (const id of ids) await exportProjectConversation(id, format);
+    } catch (error) {
+      if (!isDownloadCancelled(error)) toast.error("Export failed.");
+    }
+  }
+
+  async function commitProjectRename(): Promise<void> {
+    const name = projectNameDraft.trim();
+    setRenamingProject(false);
+    if (!name || name === projectName) return;
+    try {
+      await renameChatProject(projectId, name);
+    } catch (err) {
+      toast.error("Failed to rename project", {
+        description: err instanceof Error ? err.message : undefined,
+      });
+    }
+  }
+
+  async function commitProjectDelete(): Promise<void> {
+    setDeletingProject(false);
+    try {
+      await deleteChatProject(projectId);
+      // Refresh chat history so the project's now-deleted chats don't linger
+      // in the sidebar, matching the sidebar delete path.
+      notifyChatHistoryUpdated();
+      useChatRuntimeStore.getState().setActiveProjectId(null);
+      navigate({ to: "/chat", search: { new: createThreadNonce() } });
+    } catch (err) {
+      toast.error("Failed to delete project", {
+        description: err instanceof Error ? err.message : undefined,
+      });
+    }
+  }
+
   useEffect(() => {
     initialActiveThreadRef.current =
       useChatRuntimeStore.getState().activeThreadId;
     useChatRuntimeStore.getState().setActiveThreadId(null);
     useChatRuntimeStore.getState().setContextUsage(null);
     setPendingNewThreadId(null);
-    setNewThreadNonce(crypto.randomUUID());
+    setNewThreadNonce(createThreadNonce());
     setRenamingId(null);
     setPendingRename(null);
   }, [projectId]);
@@ -964,16 +1115,98 @@ function ProjectLanding({
     [renameDraft],
   );
 
+  // Full chat actions, matching the sidebar chat menu.
+  const { projects } = useChatProjects();
+  const pinnedChatIds = usePinnedChatsStore((s) => s.pinnedIds);
+  const togglePinnedChat = usePinnedChatsStore((s) => s.togglePin);
+  const confirmDeleteChats = useChatPreferencesStore(
+    (s) => s.confirmDeleteChats,
+  );
+  const pinnedChatIdSet = useMemo(
+    () => new Set(pinnedChatIds),
+    [pinnedChatIds],
+  );
+  const [confirmingDelete, setConfirmingDelete] = useState<SidebarItem | null>(
+    null,
+  );
+
+  // Landing has no active thread selected, so the onView callback here is a
+  // no-op; the items list refreshes itself once storage emits its update.
+  const noopView = useCallback(() => {}, []);
+
+  const handleArchive = useCallback(
+    async (item: SidebarItem) => {
+      try {
+        await archiveChatItem(item, activeThreadId ?? undefined, noopView);
+      } catch (err) {
+        toast.error("Failed to archive chat", {
+          description: err instanceof Error ? err.message : undefined,
+        });
+      }
+    },
+    [activeThreadId, noopView],
+  );
+
+  const runDelete = useCallback(
+    async (item: SidebarItem) => {
+      try {
+        await deleteChatItem(item, activeThreadId ?? undefined, noopView);
+      } catch (err) {
+        toast.error("Failed to delete chat", {
+          description: err instanceof Error ? err.message : undefined,
+        });
+      }
+    },
+    [activeThreadId, noopView],
+  );
+
+  const handleDelete = useCallback(
+    (item: SidebarItem) => {
+      if (confirmDeleteChats) setConfirmingDelete(item);
+      else void runDelete(item);
+    },
+    [confirmDeleteChats, runDelete],
+  );
+
+  const handleMoveToProject = useCallback(
+    async (item: SidebarItem, targetId: string | null) => {
+      try {
+        await moveChatItemToProject(item, targetId);
+      } catch (err) {
+        toast.error("Failed to move chat", {
+          description: err instanceof Error ? err.message : undefined,
+        });
+      }
+    },
+    [],
+  );
+
+  const handleExport = useCallback(
+    async (item: SidebarItem, format: ProjectChatExportFormat) => {
+      try {
+        await exportProjectChatItem(item, format);
+      } catch (error) {
+        if (!isDownloadCancelled(error)) toast.error("Export failed.");
+      }
+    },
+    [],
+  );
+
   useEffect(() => {
     if (!activeThreadId) {
-      setPendingNewThreadId(null);
+      // Leaving a created chat for a new one: rotate the nonce so the runtime
+      // switches to a fresh thread instead of appending to the old chat.
+      if (pendingNewThreadId) {
+        setNewThreadNonce(createThreadNonce());
+        setPendingNewThreadId(null);
+      }
       return;
     }
     if (activeThreadId === initialActiveThreadRef.current) {
       return;
     }
     setPendingNewThreadId(activeThreadId);
-  }, [activeThreadId]);
+  }, [activeThreadId, pendingNewThreadId]);
 
   useEffect(() => {
     let cancelled = false;
@@ -1037,8 +1270,8 @@ function ProjectLanding({
             } as CSSProperties
           }
         >
-          {/* 46rem matches the composer so every block shares the same edges. */}
-          <div className="mx-auto flex w-full max-w-[46rem] flex-col pt-[120px] pb-14">
+          {/* Slightly narrower than the composer max; every block shares this. */}
+          <div className="mx-auto flex w-full max-w-[44rem] flex-col pt-[120px] pb-14">
             <div className="mb-12 flex items-center gap-4">
               <span className="flex size-13 shrink-0 items-center justify-center rounded-[18px] bg-muted text-foreground/80">
                 <HugeiconsIcon
@@ -1047,9 +1280,64 @@ function ProjectLanding({
                   className="size-6.5"
                 />
               </span>
-              <h1 className="truncate font-sans text-[30px] font-medium leading-tight tracking-normal text-foreground">
+              <h1 className="min-w-0 flex-1 truncate font-sans text-ui-30 font-medium leading-tight tracking-normal text-foreground">
                 {projectName}
               </h1>
+              <DropdownMenu>
+                <DropdownMenuTrigger asChild={true}>
+                  <button
+                    type="button"
+                    aria-label="Project options"
+                    className="inline-flex size-9 shrink-0 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-muted hover:text-foreground focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring data-[state=open]:bg-muted data-[state=open]:text-foreground"
+                  >
+                    <HugeiconsIcon icon={MoreHorizontalIcon} strokeWidth={1.75} className="size-5" />
+                  </button>
+                </DropdownMenuTrigger>
+                <DropdownMenuContent
+                  side="bottom"
+                  align="end"
+                  sideOffset={6}
+                  className="unsloth-plus-menu menu-flat-destructive w-52"
+                >
+                  <DropdownMenuItem
+                    onSelect={() => {
+                      setProjectNameDraft(projectName);
+                      setRenamingProject(true);
+                    }}
+                  >
+                    <HugeiconsIcon icon={Edit03Icon} strokeWidth={1.75} className="size-icon" />
+                    <span>Rename project</span>
+                  </DropdownMenuItem>
+                  <DropdownMenuItem onSelect={() => togglePinProject(projectId)}>
+                    <HugeiconsIcon icon={projectPinned ? PinOffIcon : PinIcon} strokeWidth={1.75} className="size-icon" />
+                    <span>{projectPinned ? "Unpin project" : "Pin project"}</span>
+                  </DropdownMenuItem>
+                  <DropdownMenuSub>
+                    <DropdownMenuSubTrigger>
+                      <HugeiconsIcon icon={Download01Icon} strokeWidth={1.75} className="size-icon" />
+                      <span>Export</span>
+                    </DropdownMenuSubTrigger>
+                    <DropdownMenuSubContent className="unsloth-plus-menu w-48">
+                      {PROJECT_CHAT_EXPORT_OPTIONS.map(({ label, format }) => (
+                        <DropdownMenuItem
+                          key={format}
+                          onSelect={() => void handleProjectExport(format)}
+                        >
+                          {label}
+                        </DropdownMenuItem>
+                      ))}
+                    </DropdownMenuSubContent>
+                  </DropdownMenuSub>
+                  <DropdownMenuSeparator />
+                  <DropdownMenuItem
+                    variant="destructive"
+                    onSelect={() => setDeletingProject(true)}
+                  >
+                    <HugeiconsIcon icon={Delete02Icon} strokeWidth={1.75} className="size-icon" />
+                    <span>Delete project</span>
+                  </DropdownMenuItem>
+                </DropdownMenuContent>
+              </DropdownMenu>
             </div>
 
             <ProjectComposer
@@ -1062,7 +1350,7 @@ function ProjectLanding({
                 type="button"
                 onClick={() => setProjectTab("chats")}
                 data-active={projectTab === "chats"}
-                className="h-10 rounded-full px-5 text-[14px] font-semibold transition-colors data-[active=true]:bg-muted data-[active=true]:text-foreground data-[active=false]:text-muted-foreground data-[active=false]:hover:bg-nav-surface-hover"
+                className="h-10 rounded-full px-5 text-ui-14 font-semibold transition-colors data-[active=true]:bg-muted data-[active=true]:text-foreground data-[active=false]:text-muted-foreground data-[active=false]:hover:bg-nav-surface-hover"
               >
                 Chats
               </button>
@@ -1070,12 +1358,9 @@ function ProjectLanding({
                 type="button"
                 onClick={() => setProjectTab("sources")}
                 data-active={projectTab === "sources"}
-                className="flex h-10 items-center gap-1.5 rounded-full px-5 text-[14px] font-semibold transition-colors data-[active=true]:bg-muted data-[active=true]:text-foreground data-[active=false]:text-muted-foreground data-[active=false]:hover:bg-nav-surface-hover"
+                className="h-10 rounded-full px-5 text-ui-14 font-semibold transition-colors data-[active=true]:bg-muted data-[active=true]:text-foreground data-[active=false]:text-muted-foreground data-[active=false]:hover:bg-nav-surface-hover"
               >
                 Sources
-                <span className="rounded-full bg-emerald-500/10 px-2 py-1 text-[10px] font-semibold leading-none text-emerald-700 dark:text-emerald-300">
-                  New
-                </span>
               </button>
             </div>
 
@@ -1111,9 +1396,17 @@ function ProjectLanding({
                               setRenameDraft(event.target.value)
                             }
                             onKeyDown={(event) => {
+                              // Ignore keydowns fired mid-IME-composition (CJK)
+                              // so a candidate-confirming Enter or candidate-
+                              // cancelling Escape does not commit/cancel the
+                              // rename. Guard before the key branch so Escape is
+                              // covered too (isComposing on WebKit, 229 on Chromium).
+                              if (
+                                event.nativeEvent.isComposing ||
+                                event.keyCode === 229
+                              )
+                                return;
                               if (event.key === "Enter") {
-                                if (event.nativeEvent.isComposing || event.keyCode === 229)
-                                  return;
                                 event.preventDefault();
                                 skipRenameBlurRef.current = true;
                                 void commitRename(item);
@@ -1133,13 +1426,8 @@ function ProjectLanding({
                             onFocus={(event) => event.currentTarget.select()}
                             maxLength={120}
                             aria-label="Rename chat"
-                            className="w-full border-0 bg-transparent text-[15px] font-semibold leading-5 text-foreground outline-none"
+                            className="w-full border-0 bg-transparent text-ui-15 font-semibold leading-5 text-foreground outline-none"
                           />
-                          {preview?.snippet ? (
-                            <div className="mt-0.5 truncate text-[14px] leading-5 text-muted-foreground">
-                              {preview.snippet}
-                            </div>
-                          ) : null}
                         </div>
                       </div>
                     );
@@ -1163,16 +1451,11 @@ function ProjectLanding({
                         className="flex min-h-[58px] min-w-0 flex-1 items-center gap-4 rounded-full px-4 py-2 text-left"
                       >
                         <div className="min-w-0 flex-1">
-                          <div className="truncate text-[15px] font-semibold leading-5 text-foreground">
+                          <div className="truncate text-ui-15 font-semibold leading-5 text-foreground">
                             {displayTitle}
                           </div>
-                          {preview?.snippet ? (
-                            <div className="mt-0.5 truncate text-[14px] leading-5 text-muted-foreground">
-                              {preview.snippet}
-                            </div>
-                          ) : null}
                         </div>
-                        <span className="shrink-0 text-[14px] text-muted-foreground transition-opacity max-md:opacity-0 pointer-coarse:opacity-0 group-hover:opacity-0 group-has-[[data-state=open]]:opacity-0">
+                        <span className="shrink-0 text-ui-14 text-muted-foreground transition-opacity max-md:opacity-0 pointer-coarse:opacity-0 group-hover:opacity-0 group-has-[[data-state=open]]:opacity-0">
                           {preview?.date ??
                             formatProjectChatDate(item.createdAt)}
                         </span>
@@ -1196,7 +1479,7 @@ function ProjectLanding({
                           side="bottom"
                           align="end"
                           sideOffset={4}
-                          className="unsloth-plus-menu w-56"
+                          className="unsloth-plus-menu menu-flat-destructive w-56"
                         >
                           <DropdownMenuItem onSelect={() => openRename(item)}>
                             <HugeiconsIcon
@@ -1206,6 +1489,106 @@ function ProjectLanding({
                             />
                             <span>Rename</span>
                           </DropdownMenuItem>
+                          <DropdownMenuItem
+                            onSelect={() => togglePinnedChat(item.id)}
+                          >
+                            <HugeiconsIcon
+                              icon={
+                                pinnedChatIdSet.has(item.id)
+                                  ? PinOffIcon
+                                  : PinIcon
+                              }
+                              strokeWidth={1.75}
+                              className="size-icon"
+                            />
+                            <span>
+                              {pinnedChatIdSet.has(item.id)
+                                ? "Unpin chat"
+                                : "Pin chat"}
+                            </span>
+                          </DropdownMenuItem>
+                          <DropdownMenuSub>
+                            <DropdownMenuSubTrigger>
+                              <HugeiconsIcon
+                                icon={FolderExportIcon}
+                                strokeWidth={1.75}
+                                className="size-icon"
+                              />
+                              <span>Move to project</span>
+                            </DropdownMenuSubTrigger>
+                            <DropdownMenuSubContent className="unsloth-plus-menu w-52">
+                              <DropdownMenuItem
+                                disabled={item.projectId !== projectId}
+                                onSelect={() =>
+                                  void handleMoveToProject(item, null)
+                                }
+                              >
+                                <span>Recents</span>
+                              </DropdownMenuItem>
+                              {projects.map((p) => (
+                                <DropdownMenuItem
+                                  key={p.id}
+                                  disabled={item.projectId === p.id}
+                                  onSelect={() =>
+                                    void handleMoveToProject(item, p.id)
+                                  }
+                                >
+                                  <HugeiconsIcon
+                                    icon={Folder01Icon}
+                                    strokeWidth={1.75}
+                                    className="size-icon"
+                                  />
+                                  <span className="truncate">{p.name}</span>
+                                </DropdownMenuItem>
+                              ))}
+                            </DropdownMenuSubContent>
+                          </DropdownMenuSub>
+                          <DropdownMenuSub>
+                            <DropdownMenuSubTrigger>
+                              <HugeiconsIcon
+                                icon={Download01Icon}
+                                strokeWidth={1.75}
+                                className="size-icon"
+                              />
+                              <span>Export</span>
+                            </DropdownMenuSubTrigger>
+                            <DropdownMenuSubContent className="unsloth-plus-menu w-52">
+                              {PROJECT_CHAT_EXPORT_OPTIONS.map(
+                                ({ label, format }) => (
+                                  <DropdownMenuItem
+                                    key={format}
+                                    onSelect={() =>
+                                      void handleExport(item, format)
+                                    }
+                                  >
+                                    {label}
+                                  </DropdownMenuItem>
+                                ),
+                              )}
+                            </DropdownMenuSubContent>
+                          </DropdownMenuSub>
+                          <DropdownMenuSeparator />
+                          <DropdownMenuItem
+                            onSelect={() => void handleArchive(item)}
+                          >
+                            <HugeiconsIcon
+                              icon={Archive03Icon}
+                              strokeWidth={1.75}
+                              className="size-icon"
+                            />
+                            <span>Archive</span>
+                          </DropdownMenuItem>
+                          <DropdownMenuItem
+                            variant="destructive"
+                            onSelect={() => handleDelete(item)}
+                          >
+                            <HugeiconsIcon
+                              icon={Delete02Icon}
+                              strokeWidth={1.75}
+                              className="size-icon"
+                            />
+                            <span>Delete</span>
+                          </DropdownMenuItem>
                         </DropdownMenuContent>
                       </DropdownMenu>
                     </div>
@@ -1216,6 +1599,96 @@ function ProjectLanding({
           </div>
         </div>
       )}
+      <AlertDialog
+        open={active && confirmingDelete !== null}
+        onOpenChange={(open) => {
+          if (!open) setConfirmingDelete(null);
+        }}
+      >
+        <AlertDialogContent>
+          <AlertDialogHeader>
+            <AlertDialogTitle>Delete chat</AlertDialogTitle>
+            <AlertDialogDescription>
+              This permanently deletes "{confirmingDelete?.title}". This cannot
+              be undone.
+            </AlertDialogDescription>
+          </AlertDialogHeader>
+          <AlertDialogFooter>
+            <AlertDialogCancel>Cancel</AlertDialogCancel>
+            <AlertDialogAction
+              onClick={() => {
+                const target = confirmingDelete;
+                setConfirmingDelete(null);
+                if (target) void runDelete(target);
+              }}
+            >
+              Delete
+            </AlertDialogAction>
+          </AlertDialogFooter>
+        </AlertDialogContent>
+      </AlertDialog>
+      <Dialog
+        open={active && renamingProject}
+        onOpenChange={(open) => {
+          if (!open) setRenamingProject(false);
+        }}
+      >
+        <DialogContent className="corner-squircle dialog-soft-surface sm:max-w-md">
+          <DialogHeader>
+            <DialogTitle>Rename project</DialogTitle>
+          </DialogHeader>
+          <Input
+            value={projectNameDraft}
+            onChange={(e) => setProjectNameDraft(e.target.value)}
+            onKeyDown={(e) => {
+              if (e.key === "Enter") {
+                e.preventDefault();
+                void commitProjectRename();
+              }
+            }}
+            autoFocus={true}
+            maxLength={120}
+            placeholder="Project name"
+            aria-label="Project name"
+            className="focus-visible:border-input focus-visible:ring-0"
+          />
+          <DialogFooter className="flex-wrap gap-2 sm:justify-end">
+            <Button type="button" variant="ghost" onClick={() => setRenamingProject(false)}>
+              Cancel
+            </Button>
+            <Button
+              type="button"
+              onClick={() => void commitProjectRename()}
+              disabled={
+                !projectNameDraft.trim() || projectNameDraft.trim() === projectName
+              }
+            >
+              Save
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
+      <AlertDialog
+        open={active && deletingProject}
+        onOpenChange={(open) => {
+          if (!open) setDeletingProject(false);
+        }}
+      >
+        <AlertDialogContent>
+          <AlertDialogHeader>
+            <AlertDialogTitle>Delete project</AlertDialogTitle>
+            <AlertDialogDescription>
+              Delete "{projectName}"? Its chats will be permanently deleted.
+            </AlertDialogDescription>
+          </AlertDialogHeader>
+          <AlertDialogFooter>
+            <AlertDialogCancel>Cancel</AlertDialogCancel>
+            <AlertDialogAction onClick={() => void commitProjectDelete()}>
+              Delete
+            </AlertDialogAction>
+          </AlertDialogFooter>
+        </AlertDialogContent>
+      </AlertDialog>
     </ChatRuntimeProvider>
   );
 }
@@ -1236,6 +1709,13 @@ export function validateChatSearch(search: Record<string, unknown>): ChatSearch
   };
 }
 
+type PendingHubAutoLoad = {
+  selection: SelectedModelInput;
+  contextKey: string;
+  originCheckpoint: string;
+  originGgufVariant: string | null;
+};
+
 // `search` comes from RootLayout (not useSearch) so ChatPage stays mounted off-route
 // (keeping an in-flight generation alive), frozen to the last /chat search. `active`
 // is false off-route: close body-portaled surfaces and stop route-specific listeners
@@ -1248,30 +1728,6 @@ export function ChatPage({
 
   const settingsOpen = useChatRuntimeStore((s) => s.settingsPanelOpen);
   const setSettingsOpen = useChatRuntimeStore((s) => s.setSettingsPanelOpen);
-  // Deferred-load staging: downloads a staged GGUF (if needed) and reads its
-  // header context so the sheet can show the context slider before the load.
-  // autoLoad picks instead load the cached file as soon as the download ends;
-  // selectModel is defined below, so the load runs through a ref.
-  const autoLoadStagedRef = useRef<
-    ((pending: PendingModelSelection) => void) | null
-  >(null);
-  const stagedDownload = useStagedModelPreparation({
-    onAutoLoad: (pending) => autoLoadStagedRef.current?.(pending),
-  });
-  // Abandon a staged pick: the store action cancels its in-flight download and
-  // reverts the edited knobs, so nothing lingers after the user walks away.
-  const abandonStaged = useCallback(() => {
-    useChatRuntimeStore.getState().abandonStagedModel();
-  }, []);
-  // Detach a staged pick on navigation without cancelling its download: the
-  // transfer keeps running in the manager and lands in cache, like Hub.
-  const detachStaged = useCallback(() => {
-    useChatRuntimeStore.getState().abandonStagedModel({ keepDownload: true });
-  }, []);
-  // Tracks whether the chat page is still mounted, so a staged-load failure that
-  // resolves after the user left chat doesn't resurrect the abandoned pick.
-  const mountedRef = useRef(true);
-  useEffect(() => () => void (mountedRef.current = false), []);
   const incognito = useChatRuntimeStore((s) => s.incognito);
   const setIncognito = useChatRuntimeStore((s) => s.setIncognito);
   const incognitoLabel = incognito
@@ -1307,8 +1763,18 @@ export function ChatPage({
   const externalProvidersForChat = connectionsEnabled ? externalProviders : [];
 
   useEffect(() => {
-    void hydratePersistedSettings();
-  }, [hydratePersistedSettings]);
+    void (async () => {
+      await hydratePersistedSettings();
+      try {
+        const synced = await syncExternalProvidersFromBackend(
+          useExternalProvidersStore.getState().providers,
+        );
+        setExternalProviders(synced);
+      } catch {
+        // Silent on startup; Connections settings still surfaces load errors.
+      }
+    })();
+  }, [hydratePersistedSettings, setExternalProviders]);
 
   useEffect(() => {
     // Skip while off-route: ChatPage stays mounted, and toast+navigate here would
@@ -1363,6 +1829,9 @@ export function ChatPage({
   const ggufContextLength = useChatRuntimeStore(
     (state) => state.ggufContextLength,
   );
+  const ggufNativeContextLength = useChatRuntimeStore(
+    (state) => state.ggufNativeContextLength,
+  );
   const contextUsage = useChatRuntimeStore((state) => state.contextUsage);
   const modelsFromStore = useChatRuntimeStore((state) => state.models);
   const lorasFromStore = useChatRuntimeStore((state) => state.loras);
@@ -1440,37 +1909,37 @@ export function ChatPage({
     refreshRef.current = refresh;
     selectModelRef.current = selectModel;
   }, [refresh, selectModel]);
-  // Load a cached autoLoad pick once its download finishes. The sheet was never
-  // opened, so on a load failure just drop the orphaned staged knobs. The knobs
-  // were already seeded on stage, so keepSpeculative only when a config was
-  // saved -- otherwise the standing speculative preference should win.
-  autoLoadStagedRef.current = (pending) => {
-    const remembered = loadRememberedLoadSettings(
-      rememberedLoadSettingsKey(pending),
-    );
-    void selectModel({
-      ...pending,
-      isDownloaded: true,
-      forceReload: true,
-      keepSpeculative: remembered != null,
-      throwOnError: true,
-    }).catch(() => {
-      const store = useChatRuntimeStore.getState();
-      // selectModel only clears pendingSelection on success, so a failed
-      // auto-load leaves our staged pick (and its edited load knobs) behind.
-      // Abandon it when it is still the active stage; otherwise just revert the
-      // settings if the stage was already cleared by something else.
-      if (pendingSelectionMatches(store.pendingSelection, pending)) {
-        store.abandonStagedModel();
-      } else if (!store.pendingSelection) {
-        store.resetModelSettingsToLoaded();
-      }
-    });
-  };
+  const rememberedConfigFor = useCallback(
+    (selection: {
+      id: string;
+      ggufVariant?: string | null;
+      source?: string;
+    }) => {
+      if (selection.source === "external") return null;
+      const resolved = resolveInitialConfig(selection.id, selection.ggufVariant);
+      return resolved.remembered ? resolved.config : null;
+    },
+    [],
+  );
   const isExternalModel = useMemo(
     () => isExternalModelId(inferenceParams.checkpoint),
     [inferenceParams.checkpoint],
   );
+  const {
+    checkpoint: runtimeCheckpoint,
+    isGguf: runtimeModelIsGguf,
+    config: activeModelConfig,
+  } = useActiveModelConfig();
+  const activeModelIsGguf =
+    runtimeCheckpoint != null && !isExternalModel && runtimeModelIsGguf;
+  const activeModelIsLora = useMemo(() => {
+    const checkpoint = inferenceParams.checkpoint;
+    if (!checkpoint || isExternalModel) return false;
+    const model = modelsFromStore.find((entry) => entry.id === checkpoint);
+    if (model) return model.isLora;
+    const lora = lorasFromStore.find((entry) => entry.id === checkpoint);
+    return lora?.exportType === "lora";
+  }, [inferenceParams.checkpoint, isExternalModel, modelsFromStore, lorasFromStore]);
   const reasoningEnabled = useChatRuntimeStore((s) => s.reasoningEnabled);
   const reasoningStyle = useChatRuntimeStore((s) => s.reasoningStyle);
   const reasoningEffort = useChatRuntimeStore((s) => s.reasoningEffort);
@@ -1771,10 +2240,8 @@ export function ChatPage({
 
   useEffect(() => {
     if (view.mode !== "single") return;
-    if (view.threadId || view.newThreadNonce || !selectedArtifact) return;
-    // view excludes __LOCALID_ threads (they fall through to mode:"single"
-    // with no threadId/nonce). Don't close a canvas whose thread is the
-    // active local thread.
+    if (view.threadId || !selectedArtifact) return;
+    // Close any canvas that doesn't belong to the active thread.
     if (
       selectedArtifact.threadId &&
       selectedArtifact.threadId === activeThreadId
@@ -1783,75 +2250,21 @@ export function ChatPage({
     closeArtifactSurface();
   }, [activeThreadId, closeArtifactSurface, selectedArtifact, view]);
 
-  // Abandon a staged (not-yet-loaded) pick when the chat context actually
-  // changes — switching threads, leaving single view, or starting a new chat /
-  // project — so a stale Load button can't resurface in a different context.
-  // New Chat keeps activeThreadId null and only bumps the `new` search nonce, so
-  // the key includes the route identity, not just the thread. Mirrors the
-  // incognito reset pattern. (Route exit is handled in __root.tsx, which runs
-  // after this unmounts.) Clear only on a real change, never on mount: staging
-  // from the Hub sets pendingSelection then navigates here, and clearing on
-  // mount would wipe it. Comparing the previous context (rather than a first-run
-  // flag) is also safe under StrictMode's double-invoke and component remounts.
-  const chatContextKey = `${view.mode}|${activeThreadId ?? ""}|${search.new ?? ""}|${search.project ?? ""}`;
-  const chatContextKeyRef = useLatestRef(chatContextKey);
-  const prevChatContextRef = useRef<string | null>(null);
-  useEffect(() => {
-    const prev = prevChatContextRef.current;
-    prevChatContextRef.current = chatContextKey;
-    if (prev === null || prev === chatContextKey) return;
-    detachStaged();
-  }, [chatContextKey, detachStaged]);
-
   const hasActiveModel = Boolean(inferenceParams.checkpoint);
-  // Load immediately, or — when "Load on selection" is off — stage the pick so
-  // its load options can be set first. Shared by the main selector, native
-  // drag-drop/picker, and the dropped-file chip (the Hub stages via the store).
+  const chatContextKey = `${view.mode}|${activeThreadId ?? ""}|${search.new ?? ""}|${search.project ?? ""}`;
+  const [pendingHubAutoLoad, setPendingHubAutoLoad] =
+    useState<PendingHubAutoLoad | null>(null);
   const stageOrLoad = useCallback(
     async (selection: SelectedModelInput) => {
       const store = useChatRuntimeStore.getState();
-      // An un-cached HF repo (GGUF variant or a full non-GGUF snapshot) downloads
-      // through the manager first (global indicator), then auto-loads. Everything
-      // else -- cached picks, local/native files, LoRA, external -- loads now.
       const wantManagerDownload =
         isDownloadableHubRepo(selection) && !selection.isDownloaded;
-      if (
-        (!hasGgufSource(selection) && !wantManagerDownload) ||
-        (store.loadOnSelection && selection.isDownloaded)
-      ) {
-        // Detach any staged pick first so its edited knobs (e.g. a custom
-        // context length) don't leak into this immediate load -- resolveLoad
-        // reads customContextLength before checking the target is GGUF. Detach
-        // (not abandon) keeps its download running.
-        detachStaged();
-        // Load-on-selection skips the sheet, so seed the saved knobs here the
-        // way the sheet's restore effect would; the switch would otherwise reset
-        // the remembered speculative choice (keepSpeculative below prevents it).
-        const remembered = hasGgufSource(selection)
-          ? loadRememberedLoadSettings(rememberedLoadSettingsKey(selection))
-          : null;
-        if (remembered) store.applyRememberedLoadSettings(remembered);
-        await selectModel(
-          remembered ? { ...selection, keepSpeculative: true } : selection,
-        );
-        return;
-      }
-      // Loads can't queue behind each other, but a download is independent: if
-      // the pick needs downloading, start it in the manager so it runs alongside
-      // the load. Nothing to download (already on device) just waits.
       if (store.modelLoading) {
-        // Both an uncached non-GGUF snapshot (wantManagerDownload) and an
-        // uncached remote GGUF quant download through the manager, so either can
-        // run in the background while another model loads. wantManagerDownload
-        // excludes GGUF by design, so the GGUF case is checked separately.
         const wantBackgroundDownload =
           wantManagerDownload ||
           (selection.source === "hub" &&
             hasGgufSource(selection) &&
             !selection.isDownloaded);
-        // The model currently loading already downloads as part of its own load
-        // (the /load flow fetches before setting the checkpoint), so re-picking
-        // it must not kick off a second transfer against the same cache.
         const isLoadingThisPick =
           !!loadingModel &&
           normalizeModelRef(loadingModel.id) ===
@@ -1862,11 +2275,6 @@ export function ChatPage({
             description: "It's downloading as part of the load in progress.",
           });
         } else if (wantBackgroundDownload) {
-          // Only claim the download started once a job is actually created. A
-          // transport conflict records state that is only resolvable from the
-          // Hub download card, so point the user there instead of showing a
-          // success toast for a transfer that never began; "busy" and "error"
-          // already surface their own toasts.
           const outcome = await downloadManager.requestStart({
             kind: DOWNLOAD_KIND.MODEL,
             repoId: selection.id,
@@ -1879,9 +2287,14 @@ export function ChatPage({
                 "It'll be ready to load once the current model finishes.",
             });
           } else if (outcome === "conflict") {
-            toast.info("Resume this download from the Hub", {
+            toast.info("Resume this download from Models", {
               description:
-                "An earlier partial download used a different transport. Open the Hub tab to resume or restart it.",
+                "An earlier partial download used a different transport. Open the Model hub tab to resume or restart it.",
+            });
+          } else if (outcome === "busy") {
+            toast.info("Download already in progress", {
+              description:
+                "Another download for this model is still running. Reselect it once that finishes to load it.",
             });
           }
         } else {
@@ -1891,23 +2304,128 @@ export function ChatPage({
         }
         return;
       }
-      // Detach the prior staged pick (keeping its download) before rebinding, so
-      // a second pick downloads alongside the first instead of cancelling it.
-      detachStaged();
-      store.stageModel({
-        id: selection.id,
-        isLora: selection.isLora,
-        ggufVariant: selection.ggufVariant,
-        isDownloaded: selection.isDownloaded,
-        expectedBytes: selection.expectedBytes,
-        nativePathToken: selection.nativePathToken,
-        isGguf: selection.isGguf,
-        isHubRepo: wantManagerDownload || undefined,
-        autoLoad: store.loadOnSelection,
+      const wantManagerStage =
+        wantManagerDownload ||
+        (selection.source === "hub" &&
+          hasGgufSource(selection) &&
+          !selection.isDownloaded);
+      if (wantManagerStage) {
+        setPendingHubAutoLoad((current) =>
+          current &&
+          current.selection.id === selection.id &&
+          (current.selection.ggufVariant ?? null) ===
+            (selection.ggufVariant ?? null) &&
+          current.contextKey === chatContextKey &&
+          current.originCheckpoint === store.params.checkpoint &&
+          current.originGgufVariant === store.activeGgufVariant
+            ? current
+            : {
+                selection,
+                contextKey: chatContextKey,
+                originCheckpoint: store.params.checkpoint,
+                originGgufVariant: store.activeGgufVariant,
+              },
+        );
+        return;
+      }
+      setPendingHubAutoLoad(null);
+      const previousConfig = currentRuntimePerModelConfig({
+        includeMaxSeqLength: true,
+      });
+      const hasAppliedConfig = applyModelLoadConfigToRuntime(
+        selection.config ?? rememberedConfigFor(selection),
+      );
+      await selectModel({
+        ...selection,
+        ...(hasAppliedConfig ? { keepSpeculative: true } : {}),
+        previousConfig,
       });
     },
-    [detachStaged, selectModel, loadingModel],
+    [selectModel, loadingModel, rememberedConfigFor, chatContextKey],
   );
+  useRepoDownload({
+    kind: DOWNLOAD_KIND.MODEL,
+    repoId: pendingHubAutoLoad?.selection.id ?? "__hub_autoload_idle__",
+    activeVariant: pendingHubAutoLoad?.selection.ggufVariant ?? null,
+    onComplete: (variant) => {
+      const pending = pendingHubAutoLoad;
+      if (
+        !pending ||
+        (pending.selection.ggufVariant ?? null) !== (variant ?? null)
+      ) {
+        return;
+      }
+      setPendingHubAutoLoad(null);
+      const store = useChatRuntimeStore.getState();
+      if (
+        !active ||
+        pending.contextKey !== chatContextKey ||
+        normalizeModelRef(pending.originCheckpoint) !==
+          normalizeModelRef(store.params.checkpoint) ||
+        pending.originGgufVariant !== store.activeGgufVariant
+      ) {
+        return;
+      }
+      void stageOrLoad({ ...pending.selection, isDownloaded: true });
+    },
+    onError: (variant) => {
+      if (
+        pendingHubAutoLoad &&
+        (pendingHubAutoLoad.selection.ggufVariant ?? null) === (variant ?? null)
+      ) {
+        setPendingHubAutoLoad(null);
+      }
+    },
+    onCancelled: (variant) => {
+      if (
+        pendingHubAutoLoad &&
+        (pendingHubAutoLoad.selection.ggufVariant ?? null) === (variant ?? null)
+      ) {
+        setPendingHubAutoLoad(null);
+      }
+    },
+  });
+  useEffect(() => {
+    const pending = pendingHubAutoLoad;
+    if (!pending) return;
+    let active = true;
+    void (async () => {
+      const outcome = await downloadManager.requestStart({
+        kind: DOWNLOAD_KIND.MODEL,
+        repoId: pending.selection.id,
+        variant: pending.selection.ggufVariant ?? null,
+        expectedBytes: pending.selection.expectedBytes ?? 0,
+      });
+      if (!active) return;
+      if (outcome === "started") {
+        toast.info("Downloading model", {
+          description: "It'll load automatically once the download finishes.",
+        });
+        return;
+      }
+      if (outcome === "conflict") {
+        // Keep pendingHubAutoLoad bound so this surface's cleanup does not wipe
+        // the conflict just recorded by requestStart (which the toast points the
+        // user to); resolving it from the Hub completes the download and this
+        // surface's onComplete auto-loads, mirroring the "started" branch.
+        toast.info("Resume this download from Models", {
+          description:
+            "An earlier partial download used a different transport. Open the Model hub tab to resume or restart it.",
+        });
+        return;
+      }
+      if (outcome === "busy") {
+        toast.info("Download already in progress", {
+          description:
+            "Another download for this model is still running. Reselect it once that finishes to load it.",
+        });
+      }
+      setPendingHubAutoLoad((current) => (current === pending ? null : current));
+    })();
+    return () => {
+      active = false;
+    };
+  }, [pendingHubAutoLoad]);
   const loadNativeModelIntent = useCallback(
     async (intent: NativeIntent, loadingDescription: string) => {
       const label =
@@ -1915,6 +2433,7 @@ export function ChatPage({
       await stageOrLoad({
         id: label,
         nativePathToken: intent.path.token,
+        nativePathExpiresAtMs: intent.path.expiresAtMs ?? null,
         isDownloaded: true,
         loadingDescription,
         forceReload: true,
@@ -1965,28 +2484,20 @@ export function ChatPage({
   const handleCheckpointChange = useCallback(
     (
       value: string,
-      meta?: {
-        source?: string;
-        isLora: boolean;
-        ggufVariant?: string;
-        isDownloaded?: boolean;
-        expectedBytes?: number;
-        isGguf?: boolean;
-      },
+      meta?: ModelSelectorChangeMeta,
     ) => {
       const store = useChatRuntimeStore.getState();
       const currentCheckpoint = store.params.checkpoint;
       const currentVariant = store.activeGgufVariant;
-      if (
-        !value ||
-        (value === currentCheckpoint &&
-          (meta?.ggufVariant ?? null) === (currentVariant ?? null))
-      )
+      if (!value) return;
+      setPendingHubAutoLoad(null);
+      const isSameLoadedModel =
+        value === currentCheckpoint &&
+        (meta?.ggufVariant ?? null) === (currentVariant ?? null);
+      if (isSameLoadedModel && !meta?.forceReload) {
         return;
+      }
       if (meta?.source === "external" || isExternalModelId(value)) {
-        // Switching to an external model abandons any staged local pick: cancel
-        // its download too (setCheckpoint below only clears the pending + knobs).
-        abandonStaged();
         const selectedExternal = parseExternalModelId(value);
         const selectedProvider = selectedExternal
           ? externalProvidersForChat.find(
@@ -2087,6 +2598,7 @@ export function ChatPage({
           ggufMaxContextLength: null,
           ggufNativeContextLength: null,
           activeNativePathToken: null,
+          activeNativePathExpiresAtMs: null,
           // Clear previous-model counters, else the relaxed external-provider
           // render gate shows stale stats until the next completion.
           contextUsage: null,
@@ -2158,19 +2670,18 @@ export function ChatPage({
           source: meta?.source,
           isLora: meta?.isLora,
           ggufVariant: meta?.ggufVariant,
-          isDownloaded: meta?.isDownloaded,
+          isDownloaded: meta?.isDownloaded || isSameLoadedModel,
           expectedBytes: meta?.expectedBytes,
           isGguf: meta?.isGguf,
+          config: meta?.config,
+          nativePathToken: meta?.nativePathToken,
+          nativePathExpiresAtMs: meta?.nativePathExpiresAtMs,
+          forceReload: isSameLoadedModel || undefined,
         };
-        // "Load on selection" off: stage the model and open settings so its
-        // load knobs (tensor parallel, context length…) can be set, then it
-        // loads once via the sheet's Load button. The currently loaded model
-        // stays put until the user commits.
         await stageOrLoad(selection);
       })();
     },
     [
-      abandonStaged,
       activeThreadId,
       externalProvidersForChat,
       modelsFromStore,
@@ -2178,6 +2689,45 @@ export function ChatPage({
       view,
     ],
   );
+  const handleReloadActiveModel = useCallback(
+    (config: PerModelConfig) => {
+      const checkpoint = inferenceParams.checkpoint;
+      if (!checkpoint) return;
+      const runtime = useChatRuntimeStore.getState();
+      const nativeToken = runtime.activeNativePathToken;
+      const nativeExpiry = runtime.activeNativePathExpiresAtMs;
+      // A file-picked GGUF is reachable only via its native path token, which
+      // the desktop host prunes after a TTL. Reusing an expired token makes the
+      // reload fail with an opaque error, so prompt the user to re-select the
+      // file instead.
+      if (nativeToken && nativeExpiry != null && Date.now() >= nativeExpiry) {
+        toast.error("This local model file's access has expired.", {
+          description: "Re-select the model file to reload it.",
+        });
+        return;
+      }
+      handleCheckpointChange(checkpoint, {
+        source: "local",
+        isLora: activeModelIsLora,
+        ggufVariant: activeGgufVariant ?? undefined,
+        // Without the native token the reload validates the display label as a
+        // repo and fails.
+        nativePathToken: nativeToken ?? undefined,
+        nativePathExpiresAtMs: nativeExpiry,
+        isGguf: activeModelIsGguf,
+        isDownloaded: true,
+        config,
+        forceReload: true,
+      });
+    },
+    [
+      inferenceParams.checkpoint,
+      activeGgufVariant,
+      activeModelIsLora,
+      activeModelIsGguf,
+      handleCheckpointChange,
+    ],
+  );
   const handleEject = useCallback(() => {
     void (async () => {
       if (await ejectModel()) {
@@ -2446,12 +2996,27 @@ export function ChatPage({
 
         const state = useChatRuntimeStore.getState();
         const targetLora = pickBestLoraForBase(state.loras, handoff.baseModel);
+        const selectWithConfig = async (
+          selection: Pick<SelectedModelInput, "id" | "isLora">,
+        ) => {
+          const previousConfig = currentRuntimePerModelConfig({
+            includeMaxSeqLength: true,
+          });
+          const hasAppliedConfig = applyModelLoadConfigToRuntime(
+            rememberedConfigFor(selection),
+          );
+          await selectModelRef.current({
+            ...selection,
+            ...(hasAppliedConfig ? { keepSpeculative: true } : {}),
+            previousConfig,
+          });
+        };
         if (targetLora) {
           console.info("[chat-handoff] loading lora", {
             id: targetLora.id,
             baseModel: targetLora.baseModel,
           });
-          await selectModelRef.current({ id: targetLora.id, isLora: true });
+          await selectWithConfig({ id: targetLora.id, isLora: true });
           if (canceled) return;
           useChatRuntimeStore.getState().setActiveThreadId(null);
           useChatRuntimeStore.getState().setContextUsage(null);
@@ -2468,10 +3033,7 @@ export function ChatPage({
           console.info("[chat-handoff] no lora match, loading base", {
             id: handoff.baseModel,
           });
-          await selectModelRef.current({
-            id: handoff.baseModel,
-            isLora: false,
-          });
+          await selectWithConfig({ id: handoff.baseModel, isLora: false });
           if (canceled) return;
         } else {
           console.warn("[chat-handoff] no lora/base match found", {
@@ -2491,7 +3053,7 @@ export function ChatPage({
     return () => {
       canceled = true;
     };
-  }, [active, navigate]);
+  }, [active, navigate, rememberedConfigFor]);
 
   const tourSteps = useMemo(
     () =>
@@ -2580,6 +3142,8 @@ export function ChatPage({
                 externalModels={externalModels}
                 value={inferenceParams.checkpoint}
                 activeGgufVariant={activeGgufVariant}
+                activeModelConfig={activeModelConfig}
+                activeGgufContextLength={ggufContextLength}
                 onValueChange={handleCheckpointChange}
                 onEject={handleEject}
                 onFoldersChange={refreshLocalModels}
@@ -2596,7 +3160,7 @@ export function ChatPage({
               />
             )}
             {incognito && view.mode === "single" && (
-              <div className="flex h-[var(--studio-chat-control-height,34px)] shrink-0 items-center gap-1.5 self-center rounded-full bg-primary/10 px-2.5 font-medium text-[13px] text-primary">
+              <div className="flex h-[var(--studio-chat-control-height,34px)] shrink-0 items-center gap-1.5 self-center rounded-full bg-primary/10 px-2.5 font-medium text-ui-13 text-primary">
                 <HugeiconsIcon
                   icon={BubbleChatTemporaryIcon}
                   strokeWidth={2}
@@ -2608,7 +3172,7 @@ export function ChatPage({
             {view.mode !== "compare" && currentProjectId && (
               <nav
                 aria-label="Project location"
-                className="flex h-[var(--studio-chat-control-height,34px)] min-w-0 items-center gap-1.5 self-center text-[13.5px] tracking-nav text-muted-foreground"
+                className="flex h-[var(--studio-chat-control-height,34px)] min-w-0 items-center gap-1.5 self-center text-ui-13p5 tracking-nav text-muted-foreground"
               >
                 <ProjectSwitcher
                   currentProject={currentProject}
@@ -2633,7 +3197,12 @@ export function ChatPage({
               <NativeModelChip
                 intent={pendingNativeModelIntent}
                 nativeReadsDisabled={!nativePathLeasesSupported}
-                onLoad={(selection) => stageOrLoad(selection)}
+                onLoad={() =>
+                  loadNativeModelIntent(
+                    pendingNativeModelIntent,
+                    "Loading selected local GGUF model.",
+                  )
+                }
               />
             ) : null}
             {loadingModel && loadToastDismissed ? (
@@ -2790,13 +3359,22 @@ export function ChatPage({
         open={active && settingsOpen}
         onOpenChange={(open) => {
           setSettingsOpen(open);
-          // Closing the sheet abandons a staged (not-yet-loaded) pick: cancel its
-          // download and revert the staged knobs so nothing lingers as a dirty
-          // edit (or a background download) on the loaded model.
-          if (!open) abandonStaged();
         }}
         params={inferenceParams}
         onParamsChange={setInferenceParams}
+        modelConfig={
+          view.mode !== "compare" && activeModelConfig && !modelLoading ? (
+            <SidebarModelConfig
+              modelId={inferenceParams.checkpoint}
+              ggufVariant={activeGgufVariant ?? null}
+              isGguf={activeModelIsGguf}
+              nativeContextLength={ggufNativeContextLength}
+              loadedContextLength={ggufContextLength}
+              loadedConfig={activeModelConfig}
+              onReload={handleReloadActiveModel}
+            />
+          ) : null
+        }
         isExternalModel={isExternalModel}
         providerCapabilities={activeProviderCapabilities}
         activeExternalProvider={activeExternalProvider}
@@ -2808,62 +3386,6 @@ export function ChatPage({
           );
         }}
         externalProviderType={activeExternalProviderType}
-        loadingModel={loadingModel}
-        onReloadModel={() => {
-          const state = useChatRuntimeStore.getState();
-          if (state.params.checkpoint) {
-            selectModel({
-              id: state.params.checkpoint,
-              ggufVariant: state.activeGgufVariant ?? undefined,
-              forceReload: true,
-              isDownloaded: true,
-              loadingDescription: "Reloading with updated chat template.",
-            });
-          }
-        }}
-        onLoadPendingModel={() => {
-          const pending = useChatRuntimeStore.getState().pendingSelection;
-          if (!pending) return;
-          const keyAtLoad = chatContextKey;
-          // forceReload: the staged model isn't loaded yet, so bypass the
-          // same-checkpoint dedupe. keepSpeculative: honor the speculative mode
-          // set on the sidebar.
-          void selectModel({
-            ...pending,
-            forceReload: true,
-            keepSpeculative: true,
-            throwOnError: true,
-          }).catch(() => {
-            // Recoverable failure (expired token, gated repo, OOM…): the pick is
-            // cleared only on success, so it normally stays staged with edited
-            // knobs intact — nothing to restore.
-            const store = useChatRuntimeStore.getState();
-            // Still staged (this pick, or a newer one queued meanwhile): leave it.
-            if (store.pendingSelection) return;
-            // Cleared mid-load (sheet closed / switched chats). Re-stage only if
-            // the staged-load is still wanted: same chat context, sheet still
-            // open, page still mounted.
-            const stillWanted =
-              mountedRef.current &&
-              store.settingsPanelOpen &&
-              chatContextKeyRef.current === keyAtLoad;
-            if (stillWanted) {
-              store.setPendingSelection(pending);
-            } else {
-              // Abandoned (closed the sheet / switched chats / left chat): drop
-              // the orphaned staged knob edits so they don't linger as dirty
-              // settings over the loaded model.
-              store.resetModelSettingsToLoaded();
-            }
-          });
-        }}
-        stagedDownloadFraction={stagedDownload.progress?.fraction ?? null}
-        onCancelStagedDownload={() =>
-          stagedDownload.cancelDownload(
-            useChatRuntimeStore.getState().pendingSelection?.ggufVariant ??
-              null,
-          )
-        }
       />
     </div>
     </ChatActiveContext.Provider>
diff --git a/studio/frontend/src/features/chat/chat-providers-dialog.tsx b/studio/frontend/src/features/chat/chat-providers-dialog.tsx
index 95e5cfbd79..4ab560e5ad 100644
--- a/studio/frontend/src/features/chat/chat-providers-dialog.tsx
+++ b/studio/frontend/src/features/chat/chat-providers-dialog.tsx
@@ -41,7 +41,6 @@ import {
   type ProviderRegistryEntry,
   createProviderConfig,
   deleteProviderConfig,
-  listProviderConfigs,
   listProviderModels,
   listProviderRegistry,
   testProviderConnection,
@@ -49,7 +48,6 @@ import {
 } from "./api/providers-api";
 import type { ExternalProviderConfig } from "./external-providers";
 import {
-  CUSTOM_BACKEND_PROVIDER_TYPE,
   CUSTOM_PROVIDER_PRESETS,
   allowsManualModelIdsWithCatalog,
   customProviderBaseUrlPlaceholder,
@@ -68,6 +66,10 @@ import {
   toExternalBackendProviderType,
 } from "./external-providers";
 import { useExternalProvidersStore } from "./stores/external-providers-store";
+import {
+  pruneProviderModelIds,
+  syncExternalProvidersFromBackend,
+} from "./sync-external-providers";
 
 /** Matches navbar / thread layout easing (see index.css --ease-out-quart) */
 const PROVIDER_FORM_EASE: [number, number, number, number] = [
@@ -76,58 +78,7 @@ const PROVIDER_FORM_EASE: [number, number, number, number] = [
 const PROVIDER_FORM_DURATION = 0.2;
 const CUSTOM_PROVIDER_MISSING_KEY_MESSAGE =
   "No API key found. Add a valid API key for this connection.";
-const ANTHROPIC_DATED_SNAPSHOT_SUFFIX = /-\d{8}$/;
-const OPENAI_DEPRECATED_MODELS = new Set(["gpt-5.3"]);
 const HIDDEN_PROVIDER_TYPES = new Set(["qwen"]);
-const OPENROUTER_EXCLUDED_MODELS = new Set([
-  "google/chirp-3",
-  "kwaivgi/kling-v3.0-pro",
-  "openai/whisper-1",
-  "openai/gpt-4o-mini-transcribe",
-  "recraft/recraft-v4-pro",
-]);
-
-function normalizeUrl(input: string): string {
-  return input.trim().replace(/\/+$/, "");
-}
-
-function resolveUiProviderTypeFromConfig(
-  configProviderType: string,
-  configDisplayName: string | null | undefined,
-  configBaseUrl: string | null | undefined,
-  registryRows: ProviderRegistryEntry[],
-  existingProviderType: string | undefined,
-): string {
-  if (existingProviderType && isCustomProviderType(existingProviderType)) {
-    return existingProviderType;
-  }
-  if (configProviderType !== CUSTOM_BACKEND_PROVIDER_TYPE) {
-    return configProviderType;
-  }
-  const displayName = (configDisplayName ?? "").trim().toLowerCase();
-  const matchingCustomPreset = CUSTOM_PROVIDER_PRESETS.find(
-    (preset) => preset.displayName.toLowerCase() === displayName,
-  );
-  if (matchingCustomPreset) {
-    return matchingCustomPreset.providerType;
-  }
-  const openAiRegistry = registryRows.find(
-    (entry) => entry.provider_type === CUSTOM_BACKEND_PROVIDER_TYPE,
-  );
-  if (!openAiRegistry) {
-    return configProviderType;
-  }
-  const openAiDisplayName = openAiRegistry.display_name.trim().toLowerCase();
-  if (displayName.length > 0 && displayName !== openAiDisplayName) {
-    return LEGACY_CUSTOM_PROVIDER_TYPE;
-  }
-  const configUrl = normalizeUrl(configBaseUrl ?? "");
-  const defaultUrl = normalizeUrl(openAiRegistry.base_url ?? "");
-  if (configUrl.length > 0 && configUrl !== defaultUrl) {
-    return LEGACY_CUSTOM_PROVIDER_TYPE;
-  }
-  return configProviderType;
-}
 
 function parseManualModelIds(text: string): string[] {
   const seen = new Set<string>();
@@ -182,19 +133,6 @@ function shouldAppendOpenAiVersionPath(providerType: string): boolean {
   );
 }
 
-function pruneProviderModelIds(providerType: string, modelIds: string[]): string[] {
-  if (providerType === "anthropic") {
-    return modelIds.filter((id) => !ANTHROPIC_DATED_SNAPSHOT_SUFFIX.test(id));
-  }
-  if (providerType === "openai") {
-    return modelIds.filter((id) => !OPENAI_DEPRECATED_MODELS.has(id));
-  }
-  if (providerType === "openrouter") {
-    return modelIds.filter((id) => !OPENROUTER_EXCLUDED_MODELS.has(id));
-  }
-  return modelIds;
-}
-
 function formatModelSummary(models: string[]): string {
   if (models.length === 0) {
     return "No models enabled";
@@ -244,8 +182,8 @@ export function ChatProvidersSettings({
     (s) => s.setConnectionsEnabled,
   );
   const isCustomProvider = isCustomProviderType(providerType);
-  // Local presets (Ollama, llama.cpp) never use API keys — hide the field.
-  // vLLM may optionally use a bearer token on secured deployments.
+  // llama.cpp hides the key field. Ollama and vLLM show an optional key:
+  // Ollama cloud and secured vLLM need one; local servers leave it empty.
   const showApiKeyField = !customPresetSkipsApiKeyField(providerType);
   const showReasoningToggle = supportsProviderReasoningToggle(providerType);
 
@@ -360,9 +298,9 @@ export function ChatProvidersSettings({
       }
       let syncSucceeded = false;
       try {
-        const [registryRows, configRows] = await Promise.all([
+        const [registryRows, syncedProviders] = await Promise.all([
           listProviderRegistry(),
-          listProviderConfigs(),
+          syncExternalProvidersFromBackend(providersRef.current),
         ]);
         if (!isMounted) return;
         syncSucceeded = true;
@@ -377,61 +315,6 @@ export function ChatProvidersSettings({
           }
           return registryRows[0]?.provider_type ?? "";
         });
-        const existingById = new Map<string, ExternalProviderConfig>();
-        for (const provider of providersRef.current) {
-          existingById.set(provider.id, provider);
-        }
-        const syncedProviders: ExternalProviderConfig[] = configRows
-          .filter((config) => config.is_enabled)
-          .map((config) => {
-            const existing = existingById.get(config.id);
-            const uiProviderType = resolveUiProviderTypeFromConfig(
-              config.provider_type,
-              config.display_name,
-              config.base_url,
-              registryRows,
-              existing?.providerType,
-            );
-            const createdAt = Number.isFinite(Date.parse(config.created_at))
-              ? Date.parse(config.created_at)
-              : Date.now();
-            const updatedAt = Number.isFinite(Date.parse(config.updated_at))
-              ? Date.parse(config.updated_at)
-              : Date.now();
-            const registryEntry =
-              registryRows.find((entry) => entry.provider_type === uiProviderType) ??
-              registryRows.find((entry) => entry.provider_type === config.provider_type);
-            const defaultModels = pruneProviderModelIds(
-              uiProviderType,
-              registryEntry?.default_models ?? [],
-            );
-            const savedModels = existing?.models ?? [];
-            const savedAvailableModels = existing?.availableModels ?? [];
-            const existingModels = pruneProviderModelIds(
-              uiProviderType,
-              savedModels.length > 0 ? savedModels : defaultModels,
-            );
-            const existingAvailableModels = pruneProviderModelIds(
-              uiProviderType,
-              savedAvailableModels.length > 0 ? savedAvailableModels : defaultModels,
-            );
-            return {
-              id: config.id,
-              providerType: uiProviderType,
-              name: config.display_name,
-              baseUrl: config.base_url ?? "",
-              models: existingModels,
-              availableModels: existingAvailableModels,
-              enablePromptCaching: supportsProviderPromptCaching(uiProviderType)
-                ? (existing?.enablePromptCaching ?? true)
-                : undefined,
-              isReasoningModel: supportsProviderReasoningToggle(uiProviderType)
-                ? existing?.isReasoningModel === true
-                : undefined,
-              createdAt: existing?.createdAt ?? createdAt,
-              updatedAt,
-            };
-          });
         // Trust the backend response. An empty array means every connection was
         // removed (often from another tab); mirror that locally, else stale
         // entries become un-removable here until localStorage is cleared.
@@ -699,6 +582,10 @@ export function ChatProvidersSettings({
         providerType: backendProviderType,
         displayName,
         baseUrl,
+        models: modelsToSave,
+        availableModels: manualOnly
+          ? []
+          : pruneProviderModelIds(providerType, availableModels),
       });
       const createdAt = Number.isFinite(Date.parse(created.created_at))
         ? Date.parse(created.created_at)
@@ -814,6 +701,10 @@ export function ChatProvidersSettings({
             customProviderDisplayName(existing.providerType)
           : existing.name,
         baseUrl,
+        models: modelsToSave,
+        availableModels: manualOnly
+          ? []
+          : pruneProviderModelIds(existing.providerType, availableModels),
       });
       if (apiKey.trim()) {
         setExternalProviderApiKey(editingProviderId, apiKey.trim());
@@ -997,7 +888,7 @@ export function ChatProvidersSettings({
 
   if (page === "form") {
     return (
-      <div className="-mt-3 flex min-h-0 flex-col gap-2">
+      <div className="@container -mt-3 flex min-h-0 flex-col gap-2">
         <header className="flex items-center gap-2 pr-8">
           <Button
             type="button"
@@ -1024,7 +915,7 @@ export function ChatProvidersSettings({
         <div className="flex max-w-[760px] flex-col gap-3">
           <section className="overflow-hidden rounded-[8px] border border-border/70 bg-muted/[0.12]">
             <div className="divide-y divide-border/60">
-              <div className="grid grid-cols-[minmax(150px,0.8fr)_minmax(260px,1.2fr)] items-center gap-4 px-4 py-3 max-sm:grid-cols-1">
+              <div className="grid grid-cols-[minmax(140px,0.8fr)_minmax(0,1.2fr)] items-center gap-4 px-4 py-3 @max-[520px]:grid-cols-1">
                 <div className="flex min-w-0 flex-col gap-0.5">
                   <Label
                     htmlFor="provider-preset"
@@ -1113,7 +1004,7 @@ export function ChatProvidersSettings({
               </div>
 
               {showApiKeyField ? (
-                <div className="grid grid-cols-[minmax(150px,0.8fr)_minmax(260px,1.2fr)] items-center gap-4 px-4 py-3 max-sm:grid-cols-1">
+                <div className="grid grid-cols-[minmax(140px,0.8fr)_minmax(0,1.2fr)] items-center gap-4 px-4 py-3 @max-[520px]:grid-cols-1">
                   <div className="flex min-w-0 flex-col gap-0.5">
                     <Label
                       htmlFor="provider-api-key"
@@ -1152,7 +1043,7 @@ export function ChatProvidersSettings({
               ) : null}
 
               {isCustomProvider ? (
-                <div className="grid grid-cols-[minmax(150px,0.8fr)_minmax(260px,1.2fr)] items-center gap-4 px-4 py-3 max-sm:grid-cols-1">
+                <div className="grid grid-cols-[minmax(140px,0.8fr)_minmax(0,1.2fr)] items-center gap-4 px-4 py-3 @max-[520px]:grid-cols-1">
                   <Label
                     htmlFor="provider-custom-name"
                     className="text-sm font-medium"
@@ -1173,7 +1064,7 @@ export function ChatProvidersSettings({
               ) : null}
 
               {isCustomProvider ? (
-                <div className="grid grid-cols-[minmax(150px,0.8fr)_minmax(260px,1.2fr)] items-center gap-4 px-4 py-3 max-sm:grid-cols-1">
+                <div className="grid grid-cols-[minmax(140px,0.8fr)_minmax(0,1.2fr)] items-center gap-4 px-4 py-3 @max-[520px]:grid-cols-1">
                   <div className="flex min-w-0 flex-col gap-0.5">
                     <Label
                       htmlFor="provider-base-url"
@@ -1197,7 +1088,7 @@ export function ChatProvidersSettings({
               ) : null}
 
               {showReasoningToggle ? (
-                <div className="grid grid-cols-[minmax(150px,0.8fr)_minmax(260px,1.2fr)] items-center gap-4 px-4 py-3 max-sm:grid-cols-1">
+                <div className="grid grid-cols-[minmax(140px,0.8fr)_minmax(0,1.2fr)] items-center gap-4 px-4 py-3 @max-[520px]:grid-cols-1">
                   <Label
                     htmlFor="provider-is-reasoning"
                     className="text-sm font-medium"
@@ -1303,7 +1194,7 @@ export function ChatProvidersSettings({
                     </p>
                     {availableModels.length > 0 ? (
                       <div className="space-y-3 rounded-[8px] border border-border/70 bg-background/50 p-3">
-                        <div className="grid grid-cols-[112px_minmax(220px,330px)_auto] items-center gap-3 max-sm:grid-cols-1">
+                        <div className="grid grid-cols-[minmax(90px,auto)_minmax(0,1fr)_auto] items-center gap-3 @max-[520px]:grid-cols-1">
                           <span className="whitespace-nowrap text-xs font-medium text-muted-foreground">
                             {availableModelsLabel}
                           </span>
@@ -1395,7 +1286,7 @@ export function ChatProvidersSettings({
                   <div className="space-y-3 px-4 py-4">
                     {availableModels.length === 0 ? null : (
                       <>
-                        <div className="grid grid-cols-[112px_minmax(220px,330px)_auto] items-center gap-3 max-sm:grid-cols-1">
+                        <div className="grid grid-cols-[minmax(90px,auto)_minmax(0,1fr)_auto] items-center gap-3 @max-[520px]:grid-cols-1">
                           <span className="whitespace-nowrap text-xs font-medium text-muted-foreground">
                             {availableModelsLabel}
                           </span>
@@ -1556,7 +1447,7 @@ export function ChatProvidersSettings({
         </div>
         <p
           id="chat-connections-description"
-          className="max-w-md text-[11px] leading-snug text-muted-foreground/65 sm:text-right"
+          className="max-w-md text-ui-11 leading-snug text-muted-foreground/65 sm:text-right"
         >
           When off, all connections are disabled.
         </p>
@@ -1616,7 +1507,7 @@ export function ChatProvidersSettings({
                           <span className="truncate text-sm font-medium text-foreground">
                             {provider.name}
                           </span>
-                          <span className="shrink-0 rounded-[6px] border border-control-accent/15 bg-control-accent/8 px-1.5 py-0.5 text-[10px] leading-none text-control-accent">
+                          <span className="shrink-0 rounded-[6px] border border-control-accent/15 bg-control-accent/8 px-1.5 py-0.5 text-ui-10 leading-none text-control-accent">
                             {provider.models.length}{" "}
                             {provider.models.length === 1 ? "model" : "models"}
                           </span>
@@ -1631,7 +1522,7 @@ export function ChatProvidersSettings({
                           ) : null}
                         </div>
                         <div
-                          className="mt-1 truncate text-[11px] leading-4 text-muted-foreground/80"
+                          className="mt-1 truncate text-ui-11 leading-4 text-muted-foreground/80"
                           title={provider.models.join(", ")}
                         >
                           {modelSummary}
diff --git a/studio/frontend/src/features/chat/chat-settings-sheet.tsx b/studio/frontend/src/features/chat/chat-settings-sheet.tsx
index cedd298ecf..c3a59e9860 100644
--- a/studio/frontend/src/features/chat/chat-settings-sheet.tsx
+++ b/studio/frontend/src/features/chat/chat-settings-sheet.tsx
@@ -1,19 +1,7 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import {
-  Alert,
-  AlertDescription,
-  AlertTitle,
-} from "@/components/ui/alert";
 import { Button } from "@/components/ui/button";
-import { Checkbox } from "@/components/ui/checkbox";
-import {
-  clearRememberedLoadSettings,
-  loadRememberedLoadSettings,
-  rememberedLoadSettingsKey,
-  saveRememberedLoadSettings,
-} from "@/components/assistant-ui/model-selector/remembered-load-settings";
 import {
   Dialog,
   DialogContent,
@@ -29,7 +17,7 @@ import {
   DropdownMenuSeparator,
   DropdownMenuTrigger,
 } from "@/components/ui/dropdown-menu";
-import { Input } from "@/components/ui/input";
+import { InfoHint } from "@/components/ui/info-hint";
 import {
   InputGroup,
   InputGroupAddon,
@@ -50,26 +38,22 @@ import {
   SheetTitle,
 } from "@/components/ui/sheet";
 import { Slider } from "@/components/ui/slider";
-import { Spinner } from "@/components/ui/spinner";
 import { Switch } from "@/components/ui/switch";
 import { Textarea } from "@/components/ui/textarea";
-import { InfoHint } from "@/components/ui/info-hint";
 import { Tooltip, TooltipContent } from "@/components/ui/tooltip";
-import { useIsMobile } from "@/hooks/use-mobile";
+import { NumericValueInput, snapToStep } from "@/features/model-picker";
+import { RetrievalSettingsSection } from "@/features/rag";
 import { useLlamaUpdateCheck } from "@/hooks/use-llama-update-check";
-import { cn } from "@/lib/utils";
-import {
-  ArrowTurnBackwardIcon,
-  Edit03Icon,
-  LayoutAlignRightIcon,
-} from "@hugeicons/core-free-icons";
+import { useIsMobile } from "@/hooks/use-mobile";
 import { ChevronDownStandardIcon } from "@/lib/chevron-icons";
+import { toast } from "@/lib/toast";
+import { cn } from "@/lib/utils";
+import { Edit03Icon, LayoutAlignRightIcon } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
 import { Braces, ChevronDown, ExternalLink } from "lucide-react";
 import { Tooltip as TooltipPrimitive } from "radix-ui";
 import { Fragment, type ReactNode } from "react";
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
-import { toast } from "@/lib/toast";
 import { OpenAICodeExecSection } from "./components/openai-code-exec-section";
 import { PermissionModeDropdown } from "./permission-mode-select";
 import { resyncInferenceStatusAfterServerModelChange } from "./hooks/use-chat-model-runtime";
@@ -77,8 +61,8 @@ import {
   type ExternalProviderConfig,
   getExternalProviderApiKey,
   parseExternalModelId,
-  supportsProviderPromptCaching,
   supportsProviderPromptCacheTtl,
+  supportsProviderPromptCaching,
 } from "./external-providers";
 import {
   BUILTIN_PRESETS,
@@ -91,6 +75,12 @@ import {
   isSamePresetConfig,
   toPresetParams,
 } from "./presets/preset-policy";
+import {
+  applyPresetLoadConfig,
+  capturePresetLoadConfig,
+  formatPresetLoadConfigSummary,
+  isSamePresetLoadConfig,
+} from "./presets/preset-load-config";
 import {
   type ProviderCapabilities,
   getExternalMaxOutputTokens,
@@ -98,12 +88,7 @@ import {
   providerSupportsBuiltinCodeExecution,
   providerSupportsFastMode,
 } from "./provider-capabilities";
-import {
-  isPendingGguf,
-  pendingSelectionMatches,
-  useChatRuntimeStore,
-} from "./stores/chat-runtime-store";
-import { RetrievalSettingsSection } from "@/features/rag/components/retrieval-settings-section";
+import { useChatRuntimeStore } from "./stores/chat-runtime-store";
 import type { InferenceParams } from "./types/runtime";
 
 export { defaultInferenceParams, type Preset } from "./presets/preset-policy";
@@ -126,7 +111,7 @@ function getPromptVariablesError(raw: string): string | null {
       return null;
     }
   } catch {
-    return "Use valid JSON, for example { \"env\": \"staging\" }.";
+    return 'Use valid JSON, for example { "env": "staging" }.';
   }
   return "Variables must be a JSON object.";
 }
@@ -135,112 +120,7 @@ function hasPromptVariableSyntax(prompt: string): boolean {
   return PROMPT_VARIABLE_PATTERN.test(prompt);
 }
 
-/**
- * Editable numeric value display, shared by every slider value and the Context
- * Length input. An <input> that looks like text (shows `displayValue ?? value`,
- * so "Off"/"Max" labels render) until focus, when it swaps to the raw number,
- * selects it, and accepts free text. Commits on blur/Enter, reverts on Escape.
- * Clamping happens on commit so typing intermediate values isn't fought.
- */
-function snapToStep(
-  value: number,
-  step: number,
-  min?: number,
-  max?: number,
-): number {
-  const lo = min ?? Number.NEGATIVE_INFINITY;
-  const hi = max ?? Number.POSITIVE_INFINITY;
-  const clamped = Math.min(Math.max(value, lo), hi);
-  const stepStr = String(step);
-  const decimals = stepStr.includes(".") ? stepStr.split(".")[1].length : 0;
-  const base = Number.isFinite(lo) ? lo : 0;
-  const snapped = base + Math.round((clamped - base) / step) * step;
-  const reclamped = Math.min(Math.max(snapped, lo), hi);
-  return Number(reclamped.toFixed(decimals));
-}
-
-function NumericValueInput({
-  value,
-  min,
-  max,
-  step,
-  onChange,
-  displayValue,
-  className,
-  ariaLabel,
-  size: sizeAttr,
-  disabled = false,
-}: {
-  value: number;
-  min?: number;
-  max?: number;
-  step: number;
-  onChange: (v: number) => void;
-  displayValue?: string;
-  className?: string;
-  ariaLabel?: string;
-  size?: number;
-  disabled?: boolean;
-}) {
-  const [focused, setFocused] = useState(false);
-  const [draft, setDraft] = useState("");
-  const cancelBlurCommitRef = useRef(false);
-
-  const commit = (raw: string) => {
-    const parsed = Number.parseFloat(raw);
-    if (!Number.isFinite(parsed)) {
-      return;
-    }
-    const final = snapToStep(parsed, step, min, max);
-    if (final !== value) {
-      onChange(final);
-    }
-  };
-
-  const displayed = focused ? draft : (displayValue ?? String(value));
-
-  return (
-    <input
-      type="text"
-      inputMode="decimal"
-      disabled={disabled}
-      size={sizeAttr}
-      /* Fixed 4ch pill; grows only when a longer value would clip. */
-      style={{ width: `calc(${Math.max(displayed.length, 4)}ch + 18px)` }}
-      value={displayed}
-      aria-label={ariaLabel}
-      onFocus={(e) => {
-        cancelBlurCommitRef.current = false;
-        setDraft(String(value));
-        setFocused(true);
-        // Defer select() so it runs after the value swap above.
-        const target = e.currentTarget;
-        requestAnimationFrame(() => target.select());
-      }}
-      onBlur={() => {
-        if (cancelBlurCommitRef.current) {
-          cancelBlurCommitRef.current = false;
-        } else {
-          commit(draft);
-        }
-        setFocused(false);
-      }}
-      onChange={(e) => setDraft(e.target.value)}
-      onKeyDown={(e) => {
-        if (e.key === "Enter") {
-          e.currentTarget.blur();
-        } else if (e.key === "Escape") {
-          cancelBlurCommitRef.current = true;
-          setDraft(String(value));
-          e.currentTarget.blur();
-        }
-      }}
-      className={cn("panel-number-input", className)}
-    />
-  );
-}
-
-function ParamSlider({
+export function ParamSlider({
   label,
   value,
   min,
@@ -250,6 +130,7 @@ function ParamSlider({
   displayValue,
   info,
   valueSize,
+  disabled,
 }: {
   label: string;
   value: number;
@@ -260,12 +141,13 @@ function ParamSlider({
   displayValue?: string;
   info?: ReactNode;
   valueSize?: number;
+  disabled?: boolean;
 }) {
   return (
     <div className="space-y-3.5">
       <div className="flex items-center justify-between gap-3">
         <div className="flex min-w-0 items-center gap-1.5">
-          <span className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+          <span className="min-w-0 text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
             {label}
           </span>
           {info && <InfoHint>{info}</InfoHint>}
@@ -279,6 +161,8 @@ function ParamSlider({
           displayValue={displayValue}
           ariaLabel={label}
           size={valueSize ?? 4}
+          className="panel-number-input"
+          disabled={disabled}
         />
       </div>
       <Slider
@@ -288,6 +172,7 @@ function ParamSlider({
         value={[value]}
         onValueChange={([v]) => onChange(snapToStep(v, step, min, max))}
         className="panel-slider"
+        disabled={disabled}
       />
     </div>
   );
@@ -370,15 +255,14 @@ function CollapsibleSection({
   };
 
   const headerClasses = cn(
-    "flex w-full items-center justify-between text-[12px] font-medium normal-case tracking-[0.04em] text-nav-fg-muted transition-colors focus-visible:outline-none focus-visible:ring-0",
+    "flex w-full items-center justify-between text-ui-12 font-medium normal-case tracking-[0.04em] text-nav-fg-muted transition-colors focus-visible:outline-none focus-visible:ring-0",
     first ? "pt-4 pb-5" : "py-5",
   );
 
   return (
     <div
       className={cn(
-        !first &&
-          "border-t border-black/[0.13] dark:border-white/[0.09]",
+        !first && "border-t border-black/[0.13] dark:border-white/[0.09]",
       )}
     >
       {labelHref ? (
@@ -450,6 +334,7 @@ interface ChatSettingsPanelProps {
   onOpenChange?: (open: boolean) => void;
   params: InferenceParams;
   onParamsChange: (params: InferenceParams) => void;
+  modelConfig?: ReactNode;
   isExternalModel?: boolean;
   /**
    * Sampling-param capabilities for the active external provider, or `null` for
@@ -464,21 +349,6 @@ interface ChatSettingsPanelProps {
    * Max Tokens floor in the slider.
    */
   externalProviderType?: string | null;
-  onReloadModel?: () => void;
-  /** The in-flight load (id + GGUF variant + native path token), or null when
-   *  idle. Used to show a loading state for the staged pick only — not for an
-   *  unrelated load or a cancel's background unload. */
-  loadingModel?: {
-    id: string;
-    ggufVariant?: string | null;
-    nativePathToken?: string | null;
-  } | null;
-  /** Loads the staged `pendingSelection` (deferred "Load on selection" flow). */
-  onLoadPendingModel?: () => void;
-  /** Download progress (0–1) for a staged GGUF being fetched, or null when idle. */
-  stagedDownloadFraction?: number | null;
-  /** Cancels the in-flight staged download (paired with abandoning the stage). */
-  onCancelStagedDownload?: () => void;
 }
 
 export function ChatSettingsPanel({
@@ -486,16 +356,12 @@ export function ChatSettingsPanel({
   onOpenChange,
   params,
   onParamsChange,
+  modelConfig = null,
   isExternalModel = false,
   providerCapabilities = null,
   activeExternalProvider = null,
   onExternalProviderChange,
   externalProviderType = null,
-  onReloadModel,
-  loadingModel = null,
-  onLoadPendingModel,
-  stagedDownloadFraction,
-  onCancelStagedDownload,
 }: ChatSettingsPanelProps) {
   // Local models show every knob; providerCapabilities is only consulted when
   // isExternalModel. Unknown providers fall back to the OpenAI-compat shape via
@@ -510,55 +376,29 @@ export function ChatSettingsPanel({
   const showPresencePenalty =
     !isExternalModel || Boolean(providerCapabilities?.presencePenalty);
   const isMobile = useIsMobile();
-  const pendingSelection = useChatRuntimeStore((s) => s.pendingSelection);
-  // "Loading" only when the in-flight load IS this staged pick (full id + GGUF
-  // variant + native token match), not an unrelated load or a cancel's
-  // background unload. The variant matters: a different quant of the same repo
-  // staged mid-load must not read as this one loading.
-  const stagedLoading =
-    loadingModel != null &&
-    pendingSelectionMatches(pendingSelection, {
-      id: loadingModel.id,
-      ggufVariant: loadingModel.ggufVariant,
-      nativePathToken: loadingModel.nativePathToken,
-    });
-  // Load settings are snapshotted at click time; lock them while loading.
-  const modelControlsDisabled = stagedLoading;
-  const abandonStagedModel = useChatRuntimeStore((s) => s.abandonStagedModel);
-  const resetModelSettingsToLoaded = useChatRuntimeStore(
-    (s) => s.resetModelSettingsToLoaded,
+  const isLoadedGguf = useChatRuntimeStore((s) => s.activeGgufVariant) != null;
+  const currentCheckpoint = params.checkpoint;
+  const ggufContextLength = useChatRuntimeStore((s) => s.ggufContextLength);
+  // Direct-file / custom-folder GGUFs load without a variant label but still
+  // report a GGUF context, so detect them via the context and the checkpoint
+  // suffix too (mirrors the chat page's activeModelIsGguf). Otherwise Max Tokens
+  // would fall back to params.maxSeqLength instead of the loaded GGUF context.
+  const isGguf =
+    isLoadedGguf ||
+    ggufContextLength != null ||
+    (currentCheckpoint?.toLowerCase().endsWith(".gguf") ?? false);
+  const ggufMaxContextLength = useChatRuntimeStore(
+    (s) => s.ggufMaxContextLength,
   );
-  // A staged GGUF pick (deferred load) shows the GGUF load knobs so they can be
-  // set before the single load.
-  const pendingIsGguf = isPendingGguf(pendingSelection);
-  // Short, human-readable name for the staged pick (HF ids carry an org prefix;
-  // native picks are already a display label). Drives the "staged, not loaded"
-  // callout so it's obvious the selection hasn't loaded yet.
-  const stagedLabel = (() => {
-    const id = pendingSelection?.id ?? "";
-    const slash = id.lastIndexOf("/");
-    const base = slash >= 0 ? id.slice(slash + 1) : id;
-    return base || id;
-  })();
-  const isLoadedGguf =
-    useChatRuntimeStore((s) => s.activeGgufVariant) != null;
-  // While a pick is staged the sheet configures *that* model, so its GGUF-ness
-  // (not the currently loaded model's) decides whether the GGUF-only controls
-  // show. Otherwise a staged non-GGUF Hub repo would inherit the loaded GGUF's
-  // context/KV/speculative controls.
-  const isGguf = pendingSelection != null ? pendingIsGguf : isLoadedGguf;
-  // The Model section (and Load button) shows for any staged pick, even when the
-  // currently active model is external.
-  const hasModelContent =
-    pendingSelection != null ||
-    (!isExternalModel && (isGguf || Boolean(params.checkpoint)));
+  const customContextLength = useChatRuntimeStore((s) => s.customContextLength);
+  const kvCacheDtype = useChatRuntimeStore((s) => s.kvCacheDtype);
+  const gpuMemoryMode = useChatRuntimeStore((s) => s.gpuMemoryMode);
+  const gpuLayers = useChatRuntimeStore((s) => s.gpuLayers);
+  const nCpuMoe = useChatRuntimeStore((s) => s.nCpuMoe);
+  const tensorParallel = useChatRuntimeStore((s) => s.tensorParallel);
+  const specDraftNMax = useChatRuntimeStore((s) => s.specDraftNMax);
   const speculativeType = useChatRuntimeStore((s) => s.speculativeType);
-  const setSpeculativeType = useChatRuntimeStore((s) => s.setSpeculativeType);
-  const loadedSpeculativeType = useChatRuntimeStore(
-    (s) => s.loadedSpeculativeType,
-  );
   const specFallbackReason = useChatRuntimeStore((s) => s.specFallbackReason);
-  // Only binary fallback states are solved by a newer prebuilt.
   const mtpUpdatable =
     specFallbackReason === "binary_no_mtp" ||
     specFallbackReason === "binary_outdated";
@@ -580,43 +420,27 @@ export function ChatSettingsPanel({
         `llama.cpp updated to ${result.tag ?? "the latest build"}.${reloadHint}`,
       );
     } else {
-      toast.error(`llama.cpp update failed: ${result.error ?? "unknown error"}`);
+      toast.error(
+        `llama.cpp update failed: ${result.error ?? "unknown error"}`,
+      );
     }
   }, [applyLlamaUpdate]);
-  const specDraftNMax = useChatRuntimeStore((s) => s.specDraftNMax);
-  const setSpecDraftNMax = useChatRuntimeStore((s) => s.setSpecDraftNMax);
-  const loadedSpecDraftNMax = useChatRuntimeStore(
-    (s) => s.loadedSpecDraftNMax,
-  );
-  const currentCheckpoint = params.checkpoint;
-  const ggufContextLength = useChatRuntimeStore((s) => s.ggufContextLength);
-  const ggufMaxContextLength = useChatRuntimeStore(
-    (s) => s.ggufMaxContextLength,
-  );
-  const ggufNativeContextLength = useChatRuntimeStore(
-    (s) => s.ggufNativeContextLength,
-  );
-  const kvCacheDtype = useChatRuntimeStore((s) => s.kvCacheDtype);
-  const setKvCacheDtype = useChatRuntimeStore((s) => s.setKvCacheDtype);
-  const applyRememberedLoadSettings = useChatRuntimeStore(
-    (s) => s.applyRememberedLoadSettings,
-  );
-  const loadedKvCacheDtype = useChatRuntimeStore((s) => s.loadedKvCacheDtype);
-  const tensorParallel = useChatRuntimeStore((s) => s.tensorParallel);
-  const setTensorParallel = useChatRuntimeStore((s) => s.setTensorParallel);
-  const loadedTensorParallel = useChatRuntimeStore(
-    (s) => s.loadedTensorParallel,
-  );
-  const chatTemplateOverride = useChatRuntimeStore(
-    (s) => s.chatTemplateOverride,
-  );
-  const loadedChatTemplateOverride = useChatRuntimeStore(
-    (s) => s.loadedChatTemplateOverride,
-  );
-  const customContextLength = useChatRuntimeStore((s) => s.customContextLength);
-  const setCustomContextLength = useChatRuntimeStore(
-    (s) => s.setCustomContextLength,
-  );
+  const loadedEffectiveContext = customContextLength ?? ggufContextLength;
+  const showSpecFallback =
+    !isExternalModel &&
+    isGguf &&
+    specFallbackReason != null &&
+    (speculativeType === "auto" ||
+      speculativeType === "mtp" ||
+      speculativeType === "mtp+ngram");
+  const showContextVramWarning =
+    !isExternalModel &&
+    isGguf &&
+    ggufMaxContextLength != null &&
+    loadedEffectiveContext != null &&
+    loadedEffectiveContext > ggufMaxContextLength;
+  const showLoadedDiagnostics = showSpecFallback || showContextVramWarning;
+  const hasModelContent = showLoadedDiagnostics;
   const setActivePresetSource = useChatRuntimeStore(
     (s) => s.setActivePresetSource,
   );
@@ -627,49 +451,7 @@ export function ChatSettingsPanel({
   const setActivePreset = useChatRuntimeStore((s) => s.setActivePreset);
   const settingsHydrated = useChatRuntimeStore((s) => s.settingsHydrated);
 
-  // A staged (not-yet-loaded) GGUF carries its own header context length on
-  // pendingSelection, so the slider can use the staged model's real ceiling
-  // without reading the loaded model's `ggufContextLength`.
-  const stagedContextLength = pendingSelection?.contextLength ?? null;
-  // "Remember settings next time" tick for a staged model. Seeds the store from
-  // the saved per-model settings on stage, so the sheet opens with what was used
-  // last time; the tick reflects whether a saved entry exists.
-  const [remember, setRemember] = useState(false);
-  // Keyed per quant: a different variant of the same repo has its own settings.
-  const pendingKey = pendingSelection
-    ? rememberedLoadSettingsKey(pendingSelection)
-    : null;
-  useEffect(() => {
-    if (!pendingKey) return;
-    const saved = loadRememberedLoadSettings(pendingKey);
-    setRemember(saved != null);
-    if (saved) applyRememberedLoadSettings(saved);
-  }, [pendingKey, applyRememberedLoadSettings]);
-  // While staging, the sheet reflects the STAGED model, so its header context
-  // takes precedence over the loaded model's (which may differ or be larger).
-  const baseContext = pendingIsGguf ? stagedContextLength : ggufContextLength;
-  const baseNativeContext = pendingIsGguf
-    ? stagedContextLength
-    : ggufNativeContextLength;
-  // Context controls render once we actually have a ceiling: for a staged GGUF,
-  // once its header metadata arrives (post-download); otherwise post-load.
-  const showContextControl = pendingIsGguf
-    ? stagedContextLength != null
-    : isLoadedGguf;
-  const stagedDownloading =
-    stagedDownloadFraction != null && stagedDownloadFraction < 1;
-  const ctxDisplayValue = customContextLength ?? baseContext ?? "";
-  const ctxMaxValue = baseNativeContext ?? baseContext ?? null;
-  const kvDirty = kvCacheDtype !== loadedKvCacheDtype;
-  const ctxDirty = customContextLength !== null;
-  const specDirty = speculativeType !== loadedSpeculativeType;
-  const specDraftDirty = specDraftNMax !== loadedSpecDraftNMax;
-  const tpDirty = tensorParallel !== (loadedTensorParallel ?? false);
-  // A saved chat-template override is a reload-time setting too, so surface
-  // Apply for a template-only edit (otherwise it could never be applied).
-  const templateDirty = chatTemplateOverride !== loadedChatTemplateOverride;
-  const modelSettingsDirty =
-    kvDirty || ctxDirty || specDirty || specDraftDirty || tpDirty || templateDirty;
+  const baseContext = ggufContextLength;
   const [presetNameInput, setPresetNameInput] = useState(activePreset);
   const [systemPromptEditorOpen, setSystemPromptEditorOpen] = useState(false);
   const [systemPromptDraft, setSystemPromptDraft] = useState("");
@@ -695,17 +477,53 @@ export function ChatSettingsPanel({
       BUILTIN_PRESETS.find((preset) => preset.name === activePreset) ?? null,
     [activePreset],
   );
-  const hasUnsavedPresetChanges = useMemo(
-    () => {
+  const hasUnsavedPresetChanges = useMemo(() => {
       if (activePresetDefinition == null) {
         return false;
       }
-      if (activePresetDefinition.name === "Default") {
-        return activePresetSource === "modified";
-      }
-      return !isSamePresetConfig(activePresetDefinition.params, params);
-    },
-    [activePresetDefinition, activePresetSource, params],
+      const samplingChanged =
+        activePresetDefinition.name === "Default"
+          ? activePresetSource === "modified"
+          : !isSamePresetConfig(activePresetDefinition.params, params);
+      const currentLoadConfig = capturePresetLoadConfig();
+      const loadChanged = !isSamePresetLoadConfig(
+        activePresetDefinition.loadConfig,
+        currentLoadConfig,
+      );
+      return samplingChanged || loadChanged;
+  }, [
+    activePresetDefinition,
+    activePresetSource,
+    params,
+    customContextLength,
+    ggufContextLength,
+    kvCacheDtype,
+    gpuMemoryMode,
+    gpuLayers,
+    nCpuMoe,
+    tensorParallel,
+    speculativeType,
+    specDraftNMax,
+    params.maxSeqLength,
+  ]);
+  const activePresetLoadSummary = useMemo(
+    () => formatPresetLoadConfigSummary(activePresetDefinition?.loadConfig),
+    [activePresetDefinition],
+  );
+  const currentLoadSummary = useMemo(
+    () => formatPresetLoadConfigSummary(capturePresetLoadConfig()),
+    [
+      customContextLength,
+      ggufContextLength,
+      kvCacheDtype,
+      gpuMemoryMode,
+      gpuLayers,
+      nCpuMoe,
+      tensorParallel,
+      speculativeType,
+      specDraftNMax,
+      params.maxSeqLength,
+    ],
   );
   const presetSaveState = useMemo(
     () =>
@@ -735,6 +553,14 @@ export function ChatSettingsPanel({
   const externalSelection = currentCheckpoint
     ? parseExternalModelId(currentCheckpoint)
     : null;
+  const maxTokensMax = isExternalModel
+      ? getExternalMaxOutputTokens(
+          externalProviderType,
+          externalSelection?.modelId,
+        )
+      : isGguf && baseContext
+        ? baseContext
+        : Math.max(64, params.maxSeqLength);
   const showOpenAICodeExecSection =
     activeExternalProvider != null &&
     providerSupportsBuiltinCodeExecution(
@@ -774,8 +600,14 @@ export function ChatSettingsPanel({
       onParamsChange({
         ...applyPresetParams(params, p.params),
       });
+      if (p.loadConfig) {
+        applyPresetLoadConfig(p.loadConfig);
+      }
       setActivePreset(name);
       setActivePresetSource(getPresetSource(name));
+      if (p.loadConfig && params.checkpoint) {
+        toast.info("Reload the model to apply load settings from this preset.");
+      }
     }
   }
 
@@ -796,9 +628,14 @@ export function ChatSettingsPanel({
       ? getBuiltinVariantName(trimmed, usedNames)
       : trimmed;
     const next = customPresets.filter((p) => p.name !== saveName);
+    const loadConfig = capturePresetLoadConfig();
     const merged = [
       ...next,
-      { name: saveName, params: toPresetParams(params) },
+      {
+        name: saveName,
+        params: toPresetParams(params),
+        ...(loadConfig ? { loadConfig } : {}),
+      },
     ];
     setCustomPresets(merged);
     setActivePreset(saveName);
@@ -817,15 +654,17 @@ export function ChatSettingsPanel({
       return;
     }
     const fallbackPreset =
-      BUILTIN_PRESETS.find((preset) => preset.name === "Default") ??
-      null;
+      BUILTIN_PRESETS.find((preset) => preset.name === "Default") ?? null;
     const next = customPresets.filter((preset) => preset.name !== name);
     setCustomPresets(next);
     if (activePreset === name) {
       if (fallbackPreset) {
         onParamsChange({
-          ...applyPresetParams(params, fallbackPreset.params),
+          ...        applyPresetParams(params, fallbackPreset.params),
         });
+        if (fallbackPreset.loadConfig) {
+          applyPresetLoadConfig(fallbackPreset.loadConfig);
+        }
         setActivePreset(fallbackPreset.name);
         setActivePresetSource("builtin-default");
       }
@@ -921,16 +760,16 @@ export function ChatSettingsPanel({
       {/* Header is outside the scroll area so the scrollbar never shifts the close button. */}
       <div className="flex h-[48px] shrink-0 items-start gap-2 bg-panel-surface pl-[18px] pr-[16px] pt-[11px]">
         {isMobile ? (
-          <span className="flex h-[34px] flex-1 items-center text-[16px] font-semibold tracking-[0em] dark:tracking-[0.015em] text-nav-fg">
+          <span className="flex h-[34px] flex-1 items-center text-ui-16 font-semibold tracking-[0em] dark:tracking-[0.015em] text-nav-fg">
             Run settings
           </span>
         ) : (
           <>
-            <span className="flex h-[34px] flex-1 items-center text-[16px] font-semibold tracking-[0em] dark:tracking-[0.015em] text-nav-fg">
+            <span className="flex h-[34px] flex-1 items-center text-ui-16 font-semibold tracking-[0em] dark:tracking-[0.015em] text-nav-fg">
               Run settings
             </span>
             <Tooltip>
-              <TooltipPrimitive.Trigger asChild>
+                <TooltipPrimitive.Trigger asChild={true}>
                 <button
                   type="button"
                   onClick={() => onOpenChange?.(false)}
@@ -961,377 +800,57 @@ export function ChatSettingsPanel({
         className="run-settings-scroll relative min-h-0 flex-1 overflow-y-auto"
       >
       <div className="px-[18px] pt-3">
-        {hasModelContent && (
-        <CollapsibleSection label="Model" defaultOpen={true} first>
-          <div className="flex flex-col gap-4 pt-1">
-            {pendingSelection && (
-              <Alert className="rounded-[14px] border-primary/30 bg-primary/5 px-3 py-2">
-                <AlertTitle className="text-[12px] font-medium">
-                  {stagedLoading
-                    ? `Loading ${stagedLabel}…`
-                    : `${stagedLabel} is staged, not loaded yet`}
-                </AlertTitle>
-                <AlertDescription className="text-[11.5px] leading-[1.45] text-muted-foreground">
-                  {stagedLoading
-                    ? "Applying your settings."
-                    : "Set the options below, then choose Load model to load it."}
-                </AlertDescription>
-              </Alert>
-            )}
-            {isGguf && (
-              <>
-                {showContextControl && (
-                <div className="space-y-3.5">
-                  <div className="flex items-center justify-between gap-3">
-                    <span className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
-                      Context Length
-                    </span>
-                    <NumericValueInput
-                      value={
-                        typeof ctxDisplayValue === "number"
-                          ? ctxDisplayValue
-                          : (baseContext ?? 0)
-                      }
-                      min={128}
-                      max={ctxMaxValue ?? undefined}
-                      step={1}
-                      onChange={(v) => {
-                        setCustomContextLength(
-                          v === (baseContext ?? 0) ? null : v,
-                        );
-                      }}
-                      ariaLabel="Context Length"
-                      size={8}
-                      disabled={modelControlsDisabled}
-                    />
-                  </div>
-                  <Slider
-                    min={1024}
-                    max={ctxMaxValue ?? 4096}
-                    step={1024}
-                    value={[
-                      Math.min(
-                        typeof ctxDisplayValue === "number"
-                          ? ctxDisplayValue
-                          : (baseContext ?? 4096),
-                        ctxMaxValue ?? 4096,
-                      ),
-                    ]}
-                    onValueChange={([v]) => {
-                      const snapped = Math.round(v);
-                      setCustomContextLength(
-                        snapped === (baseContext ?? 0) ? null : snapped,
-                      );
-                    }}
-                    className="panel-slider"
-                    disabled={modelControlsDisabled}
-                  />
-                  {ggufMaxContextLength != null &&
-                    typeof ctxDisplayValue === "number" &&
-                    ctxDisplayValue > ggufMaxContextLength && (
-                      <p className="text-[11px] text-amber-500">
-                        Exceeds estimated VRAM capacity (
-                        {ggufMaxContextLength.toLocaleString()} tokens). The
-                        model may use system RAM.
-                      </p>
-                    )}
-                </div>
-                )}
-                <div className="flex items-center justify-between gap-3">
-                  <div className="flex min-w-0 items-center gap-1.5">
-                    <span className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
-                      KV Cache Dtype
-                    </span>
-                    <InfoHint>
-                      Lower KV cache precision to save VRAM at the cost of some
-                      quality. f16/bf16 are full precision; q8_0/q5_1/q4_1 are
-                      quantized.
-                    </InfoHint>
-                  </div>
-                  <div className="flex shrink-0 items-center gap-1.5">
-                    <Select
-                      disabled={modelControlsDisabled}
-                      value={kvCacheDtype ?? "f16"}
-                      onValueChange={(v) => {
-                        setKvCacheDtype(v === "f16" ? null : v);
-                      }}
-                    >
-                      <SelectTrigger
-                        animateRadius={false}
-                        icon={ChevronDownStandardIcon}
-                        iconClassName="size-3.5"
-                        className="grid h-7 w-[64px] min-w-0 grid-cols-[minmax(0,1fr)_auto] items-center gap-1 rounded-full border-border bg-background hover:bg-accent/50 dark:border-transparent dark:bg-white/[0.05] dark:hover:bg-white/[0.1] pl-3 pr-2 py-0 text-[13px]! font-medium text-nav-fg focus-visible:ring-0 focus-visible:border-transparent [&_[data-slot=select-value]]:min-w-0 [&_[data-slot=select-value]]:truncate [&>svg]:shrink-0"
-                      >
-                        <SelectValue />
-                      </SelectTrigger>
-                      <SelectContent className="menu-soft-surface ring-0 border-0 rounded-lg">
-                        <SelectItem value="f16">f16</SelectItem>
-                        <SelectItem value="bf16">bf16</SelectItem>
-                        <SelectItem value="q8_0">q8_0</SelectItem>
-                        <SelectItem value="q5_1">q5_1</SelectItem>
-                        <SelectItem value="q4_1">q4_1</SelectItem>
-                      </SelectContent>
-                    </Select>
-                  </div>
-                </div>
-                {isGguf && (
-                  <>
-                <div className="flex items-center justify-between gap-3">
-                  <div className="flex min-w-0 items-center gap-1.5">
-                    <span className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
-                      Speculative Decoding
-                    </span>
-                    <InfoHint>
-                      Faster generation with 0% accuracy hit. Auto picks
-                      MTP / ngram-mod based on the model and platform.
-                      Pick MTP, Ngram, or MTP+Ngram to force a specific
-                      strategy on both GPU and CPU.
-                    </InfoHint>
-                  </div>
-                  <div className="flex shrink-0 items-center gap-1.5">
-                    <Select
-                      disabled={modelControlsDisabled}
-                      value={speculativeType ?? "auto"}
-                      onValueChange={(v) => {
-                        setSpeculativeType(v);
-                        if (v !== "mtp" && v !== "mtp+ngram") {
-                          setSpecDraftNMax(null);
-                        }
-                      }}
-                    >
-                      <SelectTrigger
-                        animateRadius={false}
-                        icon={ChevronDownStandardIcon}
-                        iconClassName="size-3.5"
-                        className="grid h-7 w-[124px] min-w-0 grid-cols-[minmax(0,1fr)_auto] items-center gap-1 rounded-full border-border bg-background hover:bg-accent/50 dark:border-transparent dark:bg-white/[0.05] dark:hover:bg-white/[0.1] pl-3 pr-2 py-0 text-[13px]! font-medium text-nav-fg focus-visible:ring-0 focus-visible:border-transparent [&_[data-slot=select-value]]:min-w-0 [&_[data-slot=select-value]]:truncate [&>svg]:shrink-0"
-                        data-test-id="speculative-type-select"
-                      >
-                        <SelectValue />
-                      </SelectTrigger>
-                      <SelectContent className="menu-soft-surface ring-0 border-0 rounded-lg">
-                        <SelectItem value="auto">Auto</SelectItem>
-                        <SelectItem value="mtp">MTP</SelectItem>
-                        <SelectItem value="ngram">Ngram</SelectItem>
-                        <SelectItem value="mtp+ngram">MTP+Ngram</SelectItem>
-                        <SelectItem value="off">Off</SelectItem>
-                      </SelectContent>
-                    </Select>
-                  </div>
-                </div>
-                {specFallbackReason &&
-                  (speculativeType === "auto" ||
-                    speculativeType === "mtp" ||
-                    speculativeType === "mtp+ngram") && (
-                    <div className="rounded-lg bg-amber-500/[0.08] px-3 py-2 text-[12px] leading-[1.4] text-nav-fg/80">
-                      <p>
-                        {specFallbackReason === "mla_mtp_disabled"
-                          ? "MTP is disabled by default for this model architecture because it currently runs slower than standard decoding. Select MTP above to force it."
-                          : specFallbackReason === "runtime_error"
-                          ? "MTP could not start for this model on the installed llama.cpp build, so it is running without speculative decoding."
-                          : specFallbackReason === "drafter_not_found"
-                            ? "This model supports MTP, but its drafter file could not be downloaded, so MTP is off and it falls back to n-gram speculative decoding where the llama.cpp build supports it. Check your network connection or Hugging Face access, then reload the model to retry the drafter."
-                            : "MTP is not available in the installed llama.cpp build, so this model is running without it." +
-                              (llamaUpdateStatus?.update_available
+        {(hasModelContent || modelConfig) && (
+              <CollapsibleSection label="Model" defaultOpen={true} first={true}>
+            <div className="flex flex-col gap-3 pt-1">
+              {modelConfig}
+              {showSpecFallback && (
+                <div className="rounded-lg bg-amber-500/[0.08] px-3 py-2 text-ui-12 leading-[1.4] text-nav-fg/80">
+                  <p>
+                    {specFallbackReason === "mla_mtp_disabled"
+                      ? "MTP is disabled by default for this model architecture because it currently runs slower than standard decoding. Choose MTP in the model picker to force it."
+                      : specFallbackReason === "runtime_error"
+                        ? "MTP could not start for this model on the installed llama.cpp build, so it is running without speculative decoding."
+                        : specFallbackReason === "drafter_not_found"
+                          ? "This model supports MTP, but its drafter file could not be downloaded, so MTP is off and it falls back to n-gram speculative decoding where the llama.cpp build supports it. Check your network connection or Hugging Face access, then reload the model to retry the drafter."
+                          : `MTP is not available in the installed llama.cpp build, so this model is running without it.${
+                              llamaUpdateStatus?.update_available
                                 ? " Update llama.cpp to enable it."
-                                : "")}
-                      </p>
-                      {mtpUpdatable && llamaUpdateStatus?.update_available && (
-                        <Button
-                          size="sm"
-                          className="corner-squircle mt-2 h-7 text-[12px]"
-                          onClick={handleMtpUpdate}
-                          disabled={llamaUpdating}
-                          data-test-id="mtp-update-button"
-                        >
-                          {llamaUpdating ? "Updating..." : "Update llama.cpp"}
-                        </Button>
-                      )}
-                    </div>
-                  )}
-                {(speculativeType === "mtp" ||
-                  speculativeType === "mtp+ngram") && (
-                  <div className="flex items-center justify-between gap-3">
-                    <div className="flex min-w-0 items-center gap-1.5">
-                      <span className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
-                        Draft Tokens
-                      </span>
-                      <InfoHint>
-                        Max MTP draft tokens per step
-                        (--spec-draft-n-max). Lower = less wasted
-                        draft decode; higher = bigger speedup when
-                        acceptance stays high. Default: 2 on GPU,
-                        3 on CPU/Mac.
-                      </InfoHint>
-                    </div>
-                    <Input
-                      type="number"
-                      disabled={modelControlsDisabled}
-                      min={1}
-                      max={16}
-                      step={1}
-                      value={specDraftNMax ?? ""}
-                      placeholder="auto"
-                      onChange={(e) => {
-                        const raw = e.target.value;
-                        if (raw === "") {
-                          setSpecDraftNMax(null);
-                          return;
-                        }
-                        const parsed = Number.parseInt(raw, 10);
-                        if (Number.isFinite(parsed)) {
-                          const clamped = Math.max(1, Math.min(16, parsed));
-                          setSpecDraftNMax(clamped);
-                        }
-                      }}
-                      data-test-id="spec-draft-n-max-input"
-                      aria-label="Speculative decoding draft tokens"
-                      className="h-7 w-[88px] rounded-full border-border bg-background hover:bg-accent/50 dark:border-transparent dark:bg-white/[0.05] dark:hover:bg-white/[0.1] pl-3 py-0 text-[13px] font-medium text-nav-fg outline-none focus-visible:ring-0"
-                    />
-                  </div>
-                )}
-                  </>
-                )}
-                <div className="flex items-center justify-between gap-3">
-                  <div className="flex min-w-0 items-center gap-1.5">
-                    <span className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
-                      Tensor Parallelism
-                    </span>
-                    <InfoHint>
-                      No effect on a single GPU. On multi-GPU setups, improves
-                      tokens/sec during generation when using dense models. MoE
-                      models don't benefit and can be much slower.
-                    </InfoHint>
-                  </div>
-                  <Switch
-                    className="panel-switch shrink-0"
-                    checked={tensorParallel}
-                    onCheckedChange={setTensorParallel}
-                    disabled={modelControlsDisabled}
-                    data-test-id="tensor-parallel-switch"
-                  />
-                </div>
-              </>
-            )}
-            {/* No persistent "enable custom code" toggle: it is consented per model
-                via the load-time review dialog. */}
-            {/* Apply/Reset belongs to the model-reload settings above (context
-                length, KV cache, speculative decoding). Render it here, before
-                the Chat Template row, so it never reads as attached to Chat
-                Template (which is edited via its own dialog). When a model is
-                staged (deferred load), Load/Cancel takes its place: there's
-                nothing loaded to "apply" against yet. */}
-            {pendingSelection ? (
-              <div className="flex flex-col gap-4">
-                {stagedDownloading && (
-                  <p className="text-[11px] text-muted-foreground">
-                    Downloading…{" "}
-                    {Math.round((stagedDownloadFraction ?? 0) * 100)}%
+                                : ""
+                            }`}
                   </p>
-                )}
-                <label className="flex cursor-pointer items-center gap-2 pb-1.5 text-[12px] text-muted-foreground">
-                  <Checkbox
-                    className="size-3.5 rounded-full [&_[data-slot=checkbox-indicator]_svg]:size-2.5"
-                    checked={remember}
-                    onCheckedChange={(v) => setRemember(v === true)}
-                  />
-                  Remember settings next time
-                </label>
-                {stagedLoading ? (
-                  // Mid-load: nothing to load or abandon until it settles, so disable.
-                  <Button
-                    type="button"
-                    disabled
-                    size="sm"
-                    className="h-9 w-full rounded-full text-[13px] font-medium tracking-nav bg-primary text-primary-foreground hover:bg-primary/90"
-                  >
-                    <Spinner className="size-3.5" />
-                    Loading…
-                  </Button>
-                ) : (
-                  <div className="grid grid-cols-2 gap-3">
+                  {mtpUpdatable && llamaUpdateStatus?.update_available && (
                     <Button
-                      type="button"
-                      onClick={() => {
-                        // Persist (or clear) this model's load knobs before loading.
-                        // Context is stored as the override (null = auto), never the
-                        // resolved native value, so restoring can't force an OOM.
-                        const pid = pendingSelection
-                          ? rememberedLoadSettingsKey(pendingSelection)
-                          : null;
-                        if (pid) {
-                          if (remember) {
-                            saveRememberedLoadSettings(pid, {
-                              contextLength: customContextLength,
-                              kvCacheDtype,
-                              speculativeType,
-                              specDraftNMax,
-                              tensorParallel,
-                            });
-                          } else {
-                            clearRememberedLoadSettings(pid);
-                          }
-                        }
-                        onLoadPendingModel?.();
-                      }}
-                      // Disabled while a different model is mid-load: selectModel
-                      // refuses a concurrent load, so the click could only toast.
-                      disabled={stagedDownloading || loadingModel != null}
                       size="sm"
-                      className="h-9 w-full rounded-full text-[13px] font-medium tracking-nav bg-primary text-primary-foreground hover:bg-primary/90"
+                      className="corner-squircle mt-2 h-7 text-ui-12"
+                      onClick={handleMtpUpdate}
+                      disabled={llamaUpdating}
+                      data-test-id="mtp-update-button"
                     >
-                      {loadingModel != null ? "Another model loading…" : "Load model"}
+                      {llamaUpdating ? "Updating..." : "Update llama.cpp"}
                     </Button>
-                    <Button
-                      type="button"
-                      variant="outline"
-                      size="sm"
-                      onClick={() => {
-                        // Cancel abandons the stage; if a download is mid-flight,
-                        // stop it too rather than leaving it running headless.
-                        if (stagedDownloading) onCancelStagedDownload?.();
-                        abandonStagedModel();
-                      }}
-                      className="h-9 w-full rounded-full text-[13px] font-medium tracking-nav text-muted-foreground"
-                    >
-                      Cancel
-                    </Button>
-                  </div>
-                )}
-              </div>
-            ) : modelSettingsDirty ? (
-              <div className="flex flex-wrap gap-1.5">
-                <Button
-                  type="button"
-                  onClick={() => onReloadModel?.()}
-                  size="sm"
-                  className="h-7 px-3 text-[12px] font-medium tracking-nav bg-primary/92 text-primary-foreground hover:bg-primary"
-                >
-                  Apply
-                </Button>
-                <Button
-                  type="button"
-                  variant="outline"
-                  size="sm"
-                  onClick={() => resetModelSettingsToLoaded()}
-                  className="h-7 px-3 text-[12px] font-medium tracking-nav text-muted-foreground"
-                >
-                  Reset
-                </Button>
-              </div>
-            ) : null}
-            <ChatTemplateFields />
-          </div>
-        </CollapsibleSection>
+                  )}
+                </div>
+              )}
+              {showContextVramWarning && (
+                <p className="text-ui-11 text-amber-500">
+                  Context length exceeds the estimated VRAM capacity (
+                      {ggufMaxContextLength?.toLocaleString()} tokens). The
+                      model may use system RAM.
+                </p>
+              )}
+            </div>
+          </CollapsibleSection>
         )}
 
         <CollapsibleSection
           label="Preset"
           defaultOpen={true}
-          first={!hasModelContent}
+          first={!hasModelContent && !modelConfig}
         >
           <div className="flex flex-col gap-3 pt-1">
             <DropdownMenu>
-              <DropdownMenuTrigger asChild>
+                  <DropdownMenuTrigger asChild={true}>
                 <div
                   className="w-full min-w-0 cursor-pointer outline-none focus-visible:outline-none"
                   aria-label="Open preset list"
@@ -1358,7 +877,7 @@ export function ChatSettingsPanel({
                       maxLength={80}
                       autoComplete="off"
                       className={cn(
-                        "!h-9 min-h-0 min-w-0 self-stretch !pl-3.5 !pr-2 py-0 text-[13px] font-medium leading-9 text-nav-fg md:text-[13px]",
+                        "!h-9 min-h-0 min-w-0 self-stretch !pl-3.5 !pr-2 py-0 text-ui-13 font-medium leading-9 text-nav-fg md:text-ui-13",
                         presetSaveState.isSaveReady &&
                           "placeholder:text-primary/50",
                       )}
@@ -1398,7 +917,7 @@ export function ChatSettingsPanel({
                         }
                         applyPreset(p.name);
                       }}
-                      className="flex min-h-9 items-center px-3 py-0 text-[13px] font-medium leading-[1.4] tracking-nav"
+                      className="flex min-h-9 items-center px-3 py-0 text-ui-13 font-medium leading-[1.4] tracking-nav"
                     >
                       {p.name}
                     </DropdownMenuItem>
@@ -1415,10 +934,12 @@ export function ChatSettingsPanel({
                 type="button"
                 onClick={() => savePresetWithName(presetNameInput)}
                 disabled={!(settingsHydrated && presetSaveState.canSubmit)}
-                variant={presetSaveState.isSaveReady ? "default" : "outline"}
+                    variant={
+                      presetSaveState.isSaveReady ? "default" : "outline"
+                    }
                 size="sm"
                 className={cn(
-                  "h-9 w-full rounded-full text-[13px] font-medium tracking-nav",
+                  "h-9 w-full rounded-full text-ui-13 font-medium tracking-nav",
                   presetSaveState.isSaveReady &&
                     "bg-primary text-primary-foreground hover:bg-primary/90",
                 )}
@@ -1433,7 +954,7 @@ export function ChatSettingsPanel({
                 disabled={!(settingsHydrated && activeCustomPreset)}
                 variant="outline"
                 size="sm"
-                className="h-9 w-full rounded-full text-[13px] font-medium tracking-nav text-muted-foreground"
+                className="h-9 w-full rounded-full text-ui-13 font-medium tracking-nav text-muted-foreground"
                 title={
                   activeCustomPreset
                     ? activeBuiltinPreset
@@ -1445,6 +966,23 @@ export function ChatSettingsPanel({
                 Delete
               </Button>
             </div>
+            <p className="text-[11px] leading-relaxed text-muted-foreground">
+              Saving a preset also stores current load settings (context length,
+              KV cache dtype, speculative decoding, GPU layers).
+              {currentLoadSummary ? (
+                <>
+                  {" "}
+                  Active now: {currentLoadSummary}.
+                </>
+              ) : null}
+              {activePresetLoadSummary &&
+              activePresetLoadSummary !== currentLoadSummary ? (
+                <>
+                  {" "}
+                  Saved in preset: {activePresetLoadSummary}.
+                </>
+              ) : null}
+            </p>
           </div>
         </CollapsibleSection>
 
@@ -1452,11 +990,12 @@ export function ChatSettingsPanel({
           <CollapsibleSection label="Provider" defaultOpen={true}>
             <div className="flex items-center justify-between gap-3 pt-1">
               <div className="flex min-w-0 items-center gap-1.5">
-                <span className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+                <span className="min-w-0 text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
                   Prompt caching
                 </span>
                 <InfoHint>
-                  Reuse compatible prompt prefixes for lower latency and cost.
+                      Reuse compatible prompt prefixes for lower latency and
+                      cost.
                 </InfoHint>
               </div>
               <Switch
@@ -1474,15 +1013,15 @@ export function ChatSettingsPanel({
             {showPromptCacheTtlControl && promptCachingEnabled ? (
               <div className="flex items-center justify-between gap-3 pt-3">
                 <div className="flex min-w-0 items-center gap-1.5">
-                  <span className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+                  <span className="min-w-0 text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
                     Cache TTL
                   </span>
                   <InfoHint>
                     Anthropic exposes a 5 minute and a 1 hour ephemeral
-                    cache pool. The 1 hour pool costs 2x base input on
-                    write vs 1.25x for 5 minute, but reads stay 0.1x for
-                    both, so a single read landing more than 5 minutes
-                    after the write pays off the premium.
+                        cache pool. The 1 hour pool costs 2x base input on write
+                        vs 1.25x for 5 minute, but reads stay 0.1x for both, so
+                        a single read landing more than 5 minutes after the
+                        write pays off the premium.
                   </InfoHint>
                 </div>
                 <Select
@@ -1511,7 +1050,7 @@ export function ChatSettingsPanel({
             {showFastModeControl ? (
               <div className="flex items-center justify-between gap-3 pt-3">
                 <div className="flex min-w-0 items-center gap-1.5">
-                  <span className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+                  <span className="min-w-0 text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
                     Fast mode
                   </span>
                   <InfoHint>
@@ -1550,7 +1089,7 @@ export function ChatSettingsPanel({
           onLabelClick={openSystemPromptEditor}
           headerAction={
             <Tooltip>
-              <TooltipPrimitive.Trigger asChild>
+                  <TooltipPrimitive.Trigger asChild={true}>
                 <button
                   type="button"
                   onClick={openSystemPromptEditor}
@@ -1599,14 +1138,13 @@ export function ChatSettingsPanel({
               placeholder="Example: You are a helpful assistant..."
               aria-label="System prompt"
               className={cn(
-                "block size-full resize-none bg-transparent px-3.5 py-2.5 text-left text-[13px] font-medium leading-relaxed text-nav-fg outline-none placeholder:text-muted-foreground",
+                "block size-full resize-none bg-transparent px-3.5 py-2.5 text-left text-ui-13 font-medium leading-relaxed text-nav-fg outline-none placeholder:text-muted-foreground",
                 systemPromptOverflows && "cursor-pointer",
               )}
             />
           </div>
         </CollapsibleSection>
 
-
         <CollapsibleSection label="Sampling" defaultOpen={true}>
           <div className="flex flex-col gap-5 pt-1">
             {showTemperature ? (
@@ -1677,21 +1215,12 @@ export function ChatSettingsPanel({
                 max={2}
                 step={0.1}
                 onChange={set("presencePenalty")}
-                displayValue={params.presencePenalty === 0 ? "Off" : undefined}
+                    displayValue={
+                      params.presencePenalty === 0 ? "Off" : undefined
+                    }
                 info="Penalizes any token that has already appeared at least once, encouraging the model to introduce new topics. 0 = off."
               />
             ) : null}
-            {!isExternalModel && !isGguf && (
-              <ParamSlider
-                label="Max Seq Length"
-                value={params.maxSeqLength}
-                min={128}
-                max={32768}
-                step={128}
-                onChange={set("maxSeqLength")}
-                info="Maximum context window size in tokens — input prompt plus generated output combined. Capped by the model's trained limit."
-              />
-            )}
             <ParamSlider
               label="Max Tokens"
               value={params.maxTokens}
@@ -1700,31 +1229,24 @@ export function ChatSettingsPanel({
                   ? getExternalMinOutputTokens(externalProviderType)
                   : 64
               }
-              max={
-                // A staged GGUF caps to its own context even over an active
-                // external model (the staged model is what will load).
-                !pendingIsGguf && isExternalModel
-                  ? getExternalMaxOutputTokens(
-                      externalProviderType,
-                      externalSelection?.modelId,
-                    )
-                  : isGguf && baseContext
-                    ? baseContext
-                    : 32768
-              }
+              max={maxTokensMax}
               step={64}
               onChange={set("maxTokens")}
               displayValue={
                 isGguf && baseContext && params.maxTokens >= baseContext
                   ? "Max"
-                  : undefined
+                  : !isExternalModel &&
+                      !isGguf &&
+                      params.maxTokens >= maxTokensMax
+                    ? "Max"
+                    : undefined
               }
               info="Maximum number of tokens to generate per response. Generation stops at this limit or when the model emits an end-of-sequence token."
             />
           </div>
         </CollapsibleSection>
 
-        {!isExternalModel ? (
+            {isExternalModel ? null : (
           <CollapsibleSection label="Tools">
             <div className="flex flex-col gap-5 pt-1">
               <AutoHealToolCallsToggle />
@@ -1735,13 +1257,13 @@ export function ChatSettingsPanel({
               <ToolCallTimeoutSlider />
             </div>
           </CollapsibleSection>
-        ) : null}
+            )}
 
-        {!isExternalModel ? (
+            {isExternalModel ? null : (
           <CollapsibleSection label="Retrieval">
             <RetrievalSettingsSection />
           </CollapsibleSection>
-        ) : null}
+            )}
       </div>
       </div>
       </div>
@@ -1762,13 +1284,13 @@ export function ChatSettingsPanel({
           <div className="space-y-3">
             <div className="space-y-0.5 px-0.5">
               <div className="flex items-center justify-between gap-3">
-                <div className="text-[11px] font-medium">Prompt editor</div>
+                <div className="text-ui-11 font-medium">Prompt editor</div>
                 <Button
                   type="button"
                   variant="ghost"
                   size="sm"
                   onClick={() => setSystemVariablesOpen((open) => !open)}
-                  className="h-7 gap-1.5 rounded-full px-2.5 text-[11px] text-muted-foreground"
+                  className="h-7 gap-1.5 rounded-full px-2.5 text-ui-11 text-muted-foreground"
                   aria-expanded={systemVariablesOpen}
                 >
                   <Braces className="size-3.5" />
@@ -1781,7 +1303,7 @@ export function ChatSettingsPanel({
                   />
                 </Button>
               </div>
-              <p className="text-[11px] text-muted-foreground">
+              <p className="text-ui-11 text-muted-foreground">
                 Use this for longer edits. Save writes back to the active
                 configuration only. Insert variables with {"{{ env }}"}.
               </p>
@@ -1790,16 +1312,16 @@ export function ChatSettingsPanel({
               <div className="space-y-2 px-0.5">
                 <div className="flex flex-wrap items-start justify-between gap-2">
                   <div className="space-y-0.5">
-                    <div className="text-[11px] font-medium">
+                    <div className="text-ui-11 font-medium">
                       Prompt variables
                     </div>
-                    <p className="text-[11px] text-muted-foreground">
+                    <p className="text-ui-11 text-muted-foreground">
                       Define values as JSON below, then use each key in your
                       prompt, like {"{{ env }}"}.
                     </p>
                   </div>
                   <div className="flex flex-col items-end gap-1">
-                    <span className="text-[10px] text-muted-foreground">
+                    <span className="text-ui-10 text-muted-foreground">
                       Built-in, fill in automatically
                     </span>
                     <div className="flex flex-wrap justify-end gap-1">
@@ -1807,7 +1329,7 @@ export function ChatSettingsPanel({
                         <span
                           key={token}
                           title={`${token} is replaced automatically when you send`}
-                          className="rounded-full bg-muted px-2 py-0.5 font-mono text-[10px] text-muted-foreground"
+                          className="rounded-full bg-muted px-2 py-0.5 font-mono text-ui-10 text-muted-foreground"
                         >
                           {token}
                         </span>
@@ -1832,11 +1354,11 @@ export function ChatSettingsPanel({
                   aria-invalid={Boolean(systemVariablesError)}
                 />
                 {systemVariablesError ? (
-                  <p className="px-1 text-[11px] text-destructive">
+                  <p className="px-1 text-ui-11 text-destructive">
                     {systemVariablesError}
                   </p>
                 ) : (
-                  <p className="px-1 text-[11px] text-muted-foreground">
+                  <p className="px-1 text-ui-11 text-muted-foreground">
                     Names you don&apos;t define are left unchanged, so a stray
                     {" {{ typo }} "}stays visible in the prompt.
                   </p>
@@ -1986,7 +1508,7 @@ function AutoHealToolCallsToggle() {
   return (
     <div className="flex items-center justify-between gap-3">
       <div className="flex min-w-0 items-center gap-1.5">
-        <span className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+        <span className="min-w-0 text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
           Auto-Healing Tool Calls
         </span>
         <InfoHint>
@@ -2010,7 +1532,7 @@ function NudgeToolCallsToggle() {
   return (
     <div className="flex items-center justify-between gap-3">
       <div className="flex min-w-0 items-center gap-1.5">
-        <span className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+        <span className="min-w-0 text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
           Nudge Tool Calls
         </span>
         <InfoHint>
@@ -2035,19 +1557,20 @@ function ConfirmToolCallsToggle() {
     <div className="flex items-center justify-between gap-3">
       <div className="flex min-w-0 flex-col gap-0.5">
         <div className="flex min-w-0 items-center gap-1.5">
-          <span className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+          <span className="min-w-0 text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
             Confirm tool calls
           </span>
           <InfoHint>
             When on, every local Unsloth tool call pauses for your approval
             before it runs (the "Ask for approval" level). When off, tool calls
-            run without prompts inside the sandbox (the "Off" level).
+            run without prompts inside the sandbox (the "Run automatically"
+            level).
             Provider-hosted tools are not gated here.
           </InfoHint>
         </div>
         {permissionMode === "full" ? (
-          <span className="text-[11px] text-muted-foreground">
-            Overridden by Full access (Bypass permissions)
+          <span className="text-ui-11 text-muted-foreground">
+            Overridden by Full access
           </span>
         ) : null}
       </div>
@@ -2067,164 +1590,21 @@ function BypassPermissionsToggle() {
   return (
     <div className="flex flex-col gap-2">
       <div className="flex min-w-0 items-center gap-1.5">
-        <span className="whitespace-nowrap text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
-          Bypass permissions
+        <span className="whitespace-nowrap text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
+          Tool permissions
         </span>
         <InfoHint>
-          How Unsloth approves tool calls before they run. Full access is
-          dangerous: it disables confirmations and the code sandbox.
+          Choose how Unsloth approves tool calls before they run. Full access
+          disables confirmations and the code sandbox.
         </InfoHint>
       </div>
       {/* Full width, styled like the panel selects/preset input. */}
-      <PermissionModeDropdown triggerClassName="h-9 w-full justify-between rounded-full border-0 bg-[var(--panel-input-surface)] px-3.5 text-[13px] font-medium text-nav-fg shadow-none hover:bg-[var(--panel-input-surface)]" />
+      <PermissionModeDropdown triggerClassName="h-9 w-full justify-between rounded-full border-0 bg-[var(--panel-input-surface)] px-3.5 text-ui-13 font-medium text-nav-fg shadow-none hover:bg-[var(--panel-input-surface)]" />
       {permissionMode === "full" ? (
-        <span className="text-[11px] text-bypass">
+        <span className="text-ui-11 text-bypass">
           Tool calls run with no confirmation and no sandbox.
         </span>
       ) : null}
     </div>
   );
 }
-
-function ChatTemplateFields() {
-  const defaultTemplate = useChatRuntimeStore((s) => s.defaultChatTemplate);
-  const override = useChatRuntimeStore((s) => s.chatTemplateOverride);
-  const setOverride = useChatRuntimeStore((s) => s.setChatTemplateOverride);
-  const [editorOpen, setEditorOpen] = useState(false);
-  const [draft, setDraft] = useState("");
-
-  if (!defaultTemplate) return null;
-
-  const displayValue = override ?? defaultTemplate;
-  const isModified = override !== null;
-  const draftDirty = draft !== displayValue;
-
-  const openEditor = () => {
-    setDraft(displayValue);
-    setEditorOpen(true);
-  };
-  const saveEditor = () => {
-    const cleared = draft.trim().length === 0 || draft === defaultTemplate;
-    setOverride(cleared ? null : draft);
-    setEditorOpen(false);
-    toast.success(
-      cleared
-        ? "Chat template reset to default. It applies on the next model reload."
-        : "Chat template saved. It applies on the next model reload.",
-    );
-  };
-
-  return (
-    <>
-      <div className="-mb-1.5 flex items-center justify-between gap-2">
-        <button
-          type="button"
-          onClick={openEditor}
-          className="cursor-pointer text-left text-[13px] font-medium tracking-nav text-nav-fg"
-        >
-          Chat Template
-        </button>
-        <div className="flex items-center gap-1">
-          {isModified && (
-            <Tooltip>
-              <TooltipPrimitive.Trigger asChild>
-                <button
-                  type="button"
-                  onClick={() => setOverride(null)}
-                  className="nav-icon-btn text-nav-icon-idle hover:bg-panel-surface-hover hover:text-black dark:hover:text-white"
-                  aria-label="Revert chat template"
-                >
-                  <HugeiconsIcon
-                    icon={ArrowTurnBackwardIcon}
-                    strokeWidth={1.75}
-                    className="size-4"
-                  />
-                </button>
-              </TooltipPrimitive.Trigger>
-              <TooltipContent
-                side="top"
-                sideOffset={6}
-                className="tooltip-compact"
-              >
-                Revert changes
-              </TooltipContent>
-            </Tooltip>
-          )}
-          <Tooltip>
-            <TooltipPrimitive.Trigger asChild>
-              <button
-                type="button"
-                onClick={openEditor}
-                className="nav-icon-btn text-nav-icon-idle hover:bg-panel-surface-hover hover:text-black dark:hover:text-white"
-                aria-label="Edit chat template"
-              >
-                <HugeiconsIcon
-                  icon={Edit03Icon}
-                  strokeWidth={1.75}
-                  className="size-3"
-                />
-              </button>
-            </TooltipPrimitive.Trigger>
-            <TooltipContent
-              side="top"
-              sideOffset={6}
-              className="tooltip-compact"
-            >
-              Edit template
-            </TooltipContent>
-          </Tooltip>
-        </div>
-      </div>
-      <Dialog open={editorOpen} onOpenChange={setEditorOpen}>
-        <DialogContent className="corner-squircle dialog-soft-surface sm:max-w-3xl">
-          <DialogHeader>
-            <DialogTitle>Edit Chat Template</DialogTitle>
-            <DialogDescription>
-              Override the model's chat template. The change applies on the
-              next model reload.
-            </DialogDescription>
-          </DialogHeader>
-          <div className="space-y-2">
-            <div className="space-y-0.5 px-0.5">
-              <div className="text-[11px] font-medium">Template editor</div>
-              <p className="text-[11px] text-muted-foreground">
-                Jinja syntax. Save matching the default clears the override.
-              </p>
-            </div>
-            <Textarea
-              value={draft}
-              onChange={(event) => setDraft(event.target.value)}
-              fieldSizing="fixed"
-              className="min-h-[24rem] max-h-[50vh] overflow-y-auto border-0 font-mono text-xs leading-5 corner-squircle focus-visible:ring-0"
-              rows={14}
-              spellCheck={false}
-            />
-          </div>
-          <DialogFooter className="flex-wrap gap-2 sm:justify-between">
-            <Button
-              type="button"
-              variant="ghost"
-              onClick={() => setDraft(defaultTemplate)}
-              disabled={draft === defaultTemplate}
-              className="text-muted-foreground"
-            >
-              Reset
-            </Button>
-            <div className="flex flex-wrap gap-2">
-              <Button
-                type="button"
-                variant="ghost"
-                onClick={() => setEditorOpen(false)}
-              >
-                Cancel
-              </Button>
-              <Button type="button" onClick={saveEditor} disabled={!draftDirty}>
-                Save
-              </Button>
-            </div>
-          </DialogFooter>
-        </DialogContent>
-      </Dialog>
-    </>
-  );
-}
diff --git a/studio/frontend/src/features/chat/components/chat-search-dialog.tsx b/studio/frontend/src/features/chat/components/chat-search-dialog.tsx
index dc3e1aac29..7bf1b4b2aa 100644
--- a/studio/frontend/src/features/chat/components/chat-search-dialog.tsx
+++ b/studio/frontend/src/features/chat/components/chat-search-dialog.tsx
@@ -143,10 +143,10 @@ export function ChatSearchDialog() {
                   strokeWidth={2}
                   className="size-4 shrink-0 text-muted-foreground"
                 />
-                <span className="min-w-0 flex-1 truncate text-[13px] font-medium">
+                <span className="min-w-0 flex-1 truncate text-ui-13 font-medium">
                   {item.title || "Untitled chat"}
                 </span>
-                <span className="shrink-0 text-[11px] text-muted-foreground">
+                <span className="shrink-0 text-ui-11 text-muted-foreground">
                   {formatRelative(item.createdAt)}
                 </span>
               </CommandPrimitive.Item>
diff --git a/studio/frontend/src/features/chat/components/context-usage-bar.tsx b/studio/frontend/src/features/chat/components/context-usage-bar.tsx
index 80f502e222..9c80ce6b11 100644
--- a/studio/frontend/src/features/chat/components/context-usage-bar.tsx
+++ b/studio/frontend/src/features/chat/components/context-usage-bar.tsx
@@ -71,7 +71,7 @@ export const ContextUsageBar: FC<{
               : `Token usage: ${formatTokenCount(used)} tokens`
           }
           className={cn(
-            "flex items-center gap-2 rounded-[10px] px-2.5 py-1 font-mono text-chat-icon-fg text-[13px] tabular-nums transition-colors hover:bg-chat-icon-bg-hover hover:text-chat-icon-fg-hover",
+            "flex items-center gap-2 rounded-[10px] px-2.5 py-1 font-mono text-chat-icon-fg text-ui-13 tabular-nums transition-colors hover:bg-chat-icon-bg-hover hover:text-chat-icon-fg-hover",
             className,
           )}
         >
@@ -149,7 +149,7 @@ export const ContextUsageBar: FC<{
             </span>
           </div>
           {hasKnownLimit && percent !== null && percent > 85 ? (
-            <div className="mt-1 max-w-64 text-[11px] leading-snug text-muted-foreground/90">
+            <div className="mt-1 max-w-64 text-ui-11 leading-snug text-muted-foreground/90">
               Close to the context limit. Generation will stop at 100%.
               Increase <span className="font-medium">Context Length</span> in
               the chat Settings panel to keep going.
diff --git a/studio/frontend/src/features/chat/components/model-load-status.tsx b/studio/frontend/src/features/chat/components/model-load-status.tsx
index 292c7884fd..6e22c6de4b 100644
--- a/studio/frontend/src/features/chat/components/model-load-status.tsx
+++ b/studio/frontend/src/features/chat/components/model-load-status.tsx
@@ -54,14 +54,14 @@ export function ModelLoadDescription({
         {title ? <p className="text-foreground leading-tight font-semibold">{title}</p> : null}
         {hasProgress ? (
           <div className="w-full pt-1">
-            <div className="flex items-center justify-between gap-2 text-[10px] font-medium tracking-[0.08em] text-muted-foreground/80">
+            <div className="flex items-center justify-between gap-2 text-ui-10 font-medium tracking-[0.08em] text-muted-foreground/80">
               <span className="min-w-0 truncate">{labelPrimary}</span>
               <span className="shrink-0 tabular-nums">
                 {Math.round(clampProgress(progressPercent))}%
               </span>
             </div>
             {labelSecondary ? (
-              <div className="truncate pt-0.5 text-[10px] font-medium tracking-[0.08em] text-muted-foreground/60">
+              <div className="truncate pt-0.5 text-ui-10 font-medium tracking-[0.08em] text-muted-foreground/60">
                 {labelSecondary}
               </div>
             ) : null}
@@ -107,7 +107,7 @@ export function ModelLoadInlineStatus({
             <Progress value={clampProgress(progressPercent)} className="h-1 bg-foreground/[0.08]" />
           </div>
           <div
-            className="flex shrink-0 items-center gap-1 text-[10px] font-medium tracking-[0.08em] text-muted-foreground/80"
+            className="flex shrink-0 items-center gap-1 text-ui-10 font-medium tracking-[0.08em] text-muted-foreground/80"
             title={progressLabel ?? undefined}
           >
             {/* Tight inline layout: show only the primary (bytes) chunk;
@@ -124,7 +124,7 @@ export function ModelLoadInlineStatus({
           type="button"
           size="xs"
           variant="outline"
-          className="shrink-0 text-[11px]"
+          className="shrink-0 text-ui-11"
           onClick={onStop}
         >
           Stop
diff --git a/studio/frontend/src/features/chat/components/openai-code-exec-section.tsx b/studio/frontend/src/features/chat/components/openai-code-exec-section.tsx
index cb0234579b..4da9774192 100644
--- a/studio/frontend/src/features/chat/components/openai-code-exec-section.tsx
+++ b/studio/frontend/src/features/chat/components/openai-code-exec-section.tsx
@@ -435,7 +435,7 @@ export function OpenAICodeExecSection({
         <div className="flex min-w-0 items-center gap-1.5">
           <label
             htmlFor="openai-container-ttl"
-            className="min-w-0 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg"
+            className="min-w-0 text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg"
           >
             Idle timeout
           </label>
@@ -459,7 +459,7 @@ export function OpenAICodeExecSection({
           ACTIVE pill marks which one (no separate picker). */}
       <div className="flex flex-col gap-1.5">
         <div className="flex items-center justify-between gap-2">
-          <span className="text-[11px] uppercase tracking-wider text-muted-foreground">
+          <span className="text-ui-11 uppercase tracking-wider text-muted-foreground">
             Containers
           </span>
           <Button
@@ -531,15 +531,15 @@ export function OpenAICodeExecSection({
                         {c.name ?? "(unnamed)"}
                       </span>
                       {isPending ? (
-                        <span className="shrink-0 rounded-sm bg-muted px-1 py-px text-[9px] font-medium uppercase tracking-wider text-muted-foreground">
+                        <span className="shrink-0 rounded-sm bg-muted px-1 py-px text-ui-9 font-medium uppercase tracking-wider text-muted-foreground">
                           Creating
                         </span>
                       ) : isActive ? (
-                        <span className="shrink-0 rounded-sm bg-primary/15 px-1 py-px text-[9px] font-medium uppercase tracking-wider text-primary">
+                        <span className="shrink-0 rounded-sm bg-primary/15 px-1 py-px text-ui-9 font-medium uppercase tracking-wider text-primary">
                           Active
                         </span>
                       ) : statusLabel ? (
-                        <span className="shrink-0 rounded-sm bg-muted px-1 py-px text-[9px] font-medium uppercase tracking-wider text-muted-foreground">
+                        <span className="shrink-0 rounded-sm bg-muted px-1 py-px text-ui-9 font-medium uppercase tracking-wider text-muted-foreground">
                           {statusLabel}
                         </span>
                       ) : null}
@@ -548,10 +548,10 @@ export function OpenAICodeExecSection({
                       className="flex min-w-0 items-center gap-1.5 text-muted-foreground"
                       title={c.id}
                     >
-                      <span className="min-w-0 truncate font-mono text-[11px]">
+                      <span className="min-w-0 truncate font-mono text-ui-11">
                         {shortContainerId(c.id)}
                       </span>
-                      <span className="shrink-0 text-[10px] uppercase tracking-wider">
+                      <span className="shrink-0 text-ui-10 uppercase tracking-wider">
                         · {ttlMinutes}m
                       </span>
                     </div>
diff --git a/studio/frontend/src/features/chat/components/project-switcher.tsx b/studio/frontend/src/features/chat/components/project-switcher.tsx
index 13360ccf7e..a37df882b4 100644
--- a/studio/frontend/src/features/chat/components/project-switcher.tsx
+++ b/studio/frontend/src/features/chat/components/project-switcher.tsx
@@ -57,7 +57,7 @@ export function ProjectSwitcher({
             className="size-icon shrink-0 text-foreground/70"
           />
           <span className="flex min-w-0 flex-1 items-baseline">
-            <span className="min-w-0 flex max-w-[150px] flex-1 items-baseline truncate font-heading text-[16px] font-medium leading-tight text-black dark:text-white">
+            <span className="min-w-0 flex max-w-[150px] flex-1 items-baseline truncate font-heading text-ui-16 font-medium leading-tight text-black dark:text-white">
               {label}
             </span>
           </span>
@@ -75,8 +75,11 @@ export function ProjectSwitcher({
         side="bottom"
         align="start"
         sideOffset={0}
-        className="unsloth-plus-menu ring-0 min-w-56 max-w-72 max-h-72 font-heading"
+        className="unsloth-plus-menu ring-0 min-w-56 max-w-72 font-heading"
       >
+        {/* Scroll the list here, not the container, so the rounded corners on
+            the scrollbar side are not squared off. */}
+        <div className="max-h-72 overflow-y-auto">
         {showLoadingRow ? (
           <DropdownMenuItem disabled={true} className="text-muted-foreground">
             Loading…
@@ -117,6 +120,7 @@ export function ProjectSwitcher({
         <DropdownMenuItem onSelect={onViewAllProjects}>
           View all projects
         </DropdownMenuItem>
+        </div>
       </DropdownMenuContent>
     </DropdownMenu>
   );
diff --git a/studio/frontend/src/features/chat/external-providers.ts b/studio/frontend/src/features/chat/external-providers.ts
index bc718abbba..eb9e4656b0 100644
--- a/studio/frontend/src/features/chat/external-providers.ts
+++ b/studio/frontend/src/features/chat/external-providers.ts
@@ -184,11 +184,12 @@ export function supportsRemoteModelCatalog(
   );
 }
 
-/** Presets that skip the API-key field (local servers with no auth by default). */
+/** Presets that hide the API-key field. Ollama is not skipped: Ollama cloud
+ * requires a key; local servers leave the optional field empty. */
 export function customPresetSkipsApiKeyField(
   providerType: string | null | undefined,
 ): boolean {
-  return providerType === "ollama" || providerType === "llama_cpp";
+  return providerType === "llama_cpp";
 }
 
 /** Catalog load plus optional manual model IDs. */
diff --git a/studio/frontend/src/features/chat/hooks/use-chat-model-runtime.ts b/studio/frontend/src/features/chat/hooks/use-chat-model-runtime.ts
index 10e0904e4f..76a310ac33 100644
--- a/studio/frontend/src/features/chat/hooks/use-chat-model-runtime.ts
+++ b/studio/frontend/src/features/chat/hooks/use-chat-model-runtime.ts
@@ -29,12 +29,16 @@ import {
 } from "../api/chat-api";
 import { formatEta, formatRate } from "../utils/format-transfer";
 import {
+  GPU_LAYERS_AUTO,
   isLocalModelPath,
-  pendingSelectionMatches,
+  loadedGpuMemoryFields,
+  persistGpuMemoryModeOnLoad,
   readPersistedSpeculativeType,
+  reconcilePersistedGpuIds,
   resolveToolsEnabledOnLoad,
   saveSpeculativeType,
   useChatRuntimeStore,
+  type LoadingModelPick,
   type ReasoningEffort,
 } from "../stores/chat-runtime-store";
 import { clampReasoningEffortToLevels } from "../provider-capabilities";
@@ -46,14 +50,20 @@ import {
 } from "../lib/apply-inference-status-to-store";
 import {
   mergeBackendRecommendedInference,
+  resolveFitMaxSeqLength,
   resolveLoadMaxSeqLength,
+  resolveManualAutoCtxPin,
 } from "../presets/preset-policy";
 import { recordLastLocalModelLoad } from "../utils/last-local-model-load";
+import { ensureGpuDeviceCache } from "@/hooks/use-gpu-info";
 import {
   isMultimodalResponse,
 } from "../types/api";
 import { isExternalModelId } from "../external-providers";
-import { cancelStagedModelDownload } from "@/features/hub";
+import {
+  applyPerModelConfigToRuntime,
+  type PerModelConfig,
+} from "@/features/model-picker";
 import type {
   ChatLoraSummary,
   ChatModelSummary,
@@ -73,14 +83,16 @@ export type SelectedModelInput = {
   expectedBytes?: number;
   forceReload?: boolean;
   nativePathToken?: string;
+  nativePathExpiresAtMs?: number | null;
   /** Direct local .gguf file (no HF variant / native token) — still a GGUF
    *  source, so the staging flow treats it as one. */
   isGguf?: boolean;
   throwOnError?: boolean;
   /** Keep the current speculative-decoding choice across the model switch
-   *  instead of resetting it to the standing preference. Set by the deferred
-   *  ("Load on selection") Load, where the user picked it for this model. */
+   *  instead of resetting it to the standing preference. */
   keepSpeculative?: boolean;
+  config?: PerModelConfig;
+  previousConfig?: PerModelConfig;
 };
 
 // Approved fingerprints by checkpoint, so a rollback after a failed switch can resend
@@ -99,7 +111,7 @@ const MODEL_LOAD_TOAST_CLASSNAMES = {
   title: "leading-5",
   description: "mt-0 w-full",
   cancelButton:
-    "!h-auto !rounded-none !border-0 !bg-transparent !px-1 !text-[11px] !font-normal !text-muted-foreground hover:!bg-transparent hover:!text-destructive focus-visible:!text-destructive",
+    "!h-auto !rounded-none !border-0 !bg-transparent !px-1 !text-ui-11 !font-normal !text-muted-foreground hover:!bg-transparent hover:!text-destructive focus-visible:!text-destructive",
 } as const;
 
 const MODEL_LOADED_TOAST_CLASSNAMES = {
@@ -291,9 +303,12 @@ async function syncInferenceStatusToStore(options?: {
     if (statusRes.active_model && !isExternalSelectionActive) {
       const checkpointId = resolveInferenceCheckpointId(statusRes);
       if (checkpointId) {
+        const previousGgufVariant =
+          useChatRuntimeStore.getState().activeGgufVariant;
         setCheckpoint(checkpointId, statusRes.gguf_variant);
         applyActiveModelStatusToStore(statusRes, {
           previousCheckpoint: selectedCheckpoint,
+          previousGgufVariant,
         });
         // setModels(listRes...) above used catalog data, which omits audio
         // capability. Re-apply live status so attach gates survive a refresh.
@@ -336,6 +351,18 @@ export async function resyncInferenceStatusAfterServerModelChange(): Promise<voi
   await syncInferenceStatusToStore();
 }
 
+function pickOf(info: {
+  id: string;
+  ggufVariant?: string | null;
+  nativePathToken?: string | null;
+}): LoadingModelPick {
+  return {
+    id: info.id,
+    ggufVariant: info.ggufVariant ?? null,
+    nativePathToken: info.nativePathToken ?? null,
+  };
+}
+
 export function useChatModelRuntime() {
   const params = useChatRuntimeStore((state) => state.params);
   const models = useChatRuntimeStore((state) => state.models);
@@ -374,12 +401,16 @@ export function useChatModelRuntime() {
   }, []);
 
   const resetLoadingUi = useCallback(() => {
+    const inFlight = loadingModelRef.current;
     setLoadingModel(null);
     setLoadProgress(null);
     loadingModelRef.current = null;
     loadAbortRef.current = null;
     loadToastIdRef.current = null;
     setLoadToastDismissedState(false);
+    if (inFlight) {
+      useChatRuntimeStore.getState().clearLoadingModelPick(pickOf(inFlight));
+    }
     if (!cancelUnloadPendingRef.current) {
       useChatRuntimeStore.getState().setModelLoading(false);
     }
@@ -413,6 +444,7 @@ export function useChatModelRuntime() {
     loadAbortRef.current?.abort();
     loadAbortRef.current = null;
     loadingModelRef.current = null;
+    useChatRuntimeStore.getState().clearLoadingModelPick(pickOf(model));
     const tid = loadToastIdRef.current;
     loadToastIdRef.current = null;
     setLoadingModel(null);
@@ -449,45 +481,36 @@ export function useChatModelRuntime() {
         typeof selection === "string" ? false : selection.forceReload ?? false;
       const nativePathToken =
         typeof selection === "string" ? undefined : selection.nativePathToken;
+      const nativePathExpiresAtMs =
+        typeof selection === "string"
+          ? null
+          : selection.nativePathExpiresAtMs ?? null;
       const explicitIsGguf =
         typeof selection === "string" ? undefined : selection.isGguf;
       const throwOnError =
         typeof selection === "string" ? false : selection.throwOnError ?? false;
       const keepSpeculative =
         typeof selection === "string" ? false : selection.keepSpeculative ?? false;
-      // Picking/loading any model abandons a staged (deferred) selection.
-      // Before the early-returns below so even a no-op re-select clears the
-      // stage.
-      const staged = useChatRuntimeStore.getState().pendingSelection;
-      if (staged) {
-        // Loading a DIFFERENT model abandons this stage. Loading the staged pick
-        // ITSELF keeps it so the sidebar can show its load settings (context, KV
-        // cache, …) during the load. Cleared on success below; on failure it's
-        // left staged so the user can retry (see onLoadPendingModel's catch).
-        const loadingStagedPick = pendingSelectionMatches(staged, {
-          id: modelId,
-          ggufVariant,
-          nativePathToken,
-        });
-        if (!loadingStagedPick) {
-          cancelStagedModelDownload(staged);
-          useChatRuntimeStore.getState().setPendingSelection(null);
-        }
-      }
       const currentVariant = useChatRuntimeStore.getState().activeGgufVariant;
       if (!forceReload && (!modelId || (params.checkpoint === modelId && (ggufVariant ?? null) === (currentVariant ?? null)))) {
+        if (typeof selection !== "string" && selection.previousConfig) {
+          applyPerModelConfigToRuntime(selection.previousConfig);
+        }
         return;
       }
-      // A load is already in flight. If it's this exact pick (id + GGUF variant +
-      // native path token), ignore the duplicate click. If it's a DIFFERENT model
-      // -- crucially including a different GGUF variant of the same repo, which the
-      // old id+token-only guard wrongly treated as a duplicate and silently
-      // no-op'd -- don't start a second concurrent load (the load path has no clean
-      // supersession) and don't silently swallow the request: surface it so the
-      // user knows to wait for, or cancel, the in-flight load. Centralized here so
-      // every entry point is covered, not just the staged Load button.
-      const inFlightLoad = loadingModelRef.current;
+      // A load is already in flight. If it's this exact pick (id + variant + token),
+      // ignore the duplicate click. If it's a DIFFERENT model (including a different
+      // GGUF variant of the same repo, which the old id+token guard wrongly treated
+      // as a duplicate), don't start a second concurrent load and don't swallow the
+      // request: surface it so the user waits or cancels. Centralized here so every
+      // entry point is covered, not just the staged Load button.
+      const inFlightLoad =
+        loadingModelRef.current ??
+        useChatRuntimeStore.getState().loadingModelPick;
       if (inFlightLoad) {
+        if (typeof selection !== "string" && selection.previousConfig) {
+          applyPerModelConfigToRuntime(selection.previousConfig);
+        }
         const loadingSamePick =
           inFlightLoad.id === modelId &&
           (inFlightLoad.ggufVariant ?? null) === (ggufVariant ?? null) &&
@@ -511,7 +534,15 @@ export function useChatModelRuntime() {
         typeof selection === "string" ? false : selection.isDownloaded ?? false;
       const model = models.find((entry) => entry.id === modelId);
       const lora = loras.find((entry) => entry.id === modelId);
-      const isGguf = explicitIsGguf ?? model?.isGguf ?? false;
+      // A native path-token selection is a local GGUF by construction (the
+      // native model intents only grant .gguf files), but its id is a display
+      // label that need not end in ".gguf" -- without this, Manual + Auto
+      // layers would pin the UI context instead of letting --fit size it.
+      const isGguf =
+        explicitIsGguf ??
+        (ggufVariant != null ||
+          nativePathToken != null ||
+          model?.isGguf === true);
       const loraIsAdapter = lora?.exportType === "lora";
       const isLora =
         explicitIsLora ?? model?.isLora ?? loraIsAdapter ?? false;
@@ -560,6 +591,7 @@ export function useChatModelRuntime() {
       };
       setLoadingModel(loadInfo);
       useChatRuntimeStore.getState().setModelLoading(true);
+      useChatRuntimeStore.getState().setLoadingModelPick(pickOf(loadInfo));
       setLoadProgress(
         isDownloaded || isCachedLora
           ? { percent: null, label: null, phase: "starting" }
@@ -578,31 +610,65 @@ export function useChatModelRuntime() {
           let trustRemoteCode = stateBeforeUnload.params.trustRemoteCode ?? false;
           let approvedRemoteCodeFingerprint: string | null = null;
           const maxSeqLength = stateBeforeUnload.params.maxSeqLength;
+          const previousActiveNativePathToken =
+            stateBeforeUnload.activeNativePathToken;
           const previousIsGguf =
             previousModel?.isGguf === true
             || previousVariant != null
+            || previousActiveNativePathToken != null
             || (previousCheckpoint?.toLowerCase().endsWith(".gguf") ?? false);
-          const rollbackMaxSeqLength = previousIsGguf
-            ? (stateBeforeUnload.ggufContextLength ?? 0)
-            : maxSeqLength;
+          // Roll back to the previous model's own context. previousConfig was
+          // snapshotted before this load pre-applied the next model's config, so
+          // params.maxSeqLength may already be the next model's; use it only when
+          // no snapshot exists.
+          const previousMaxSeqLength =
+            (typeof selection !== "string"
+              ? selection.previousConfig?.maxSeqLength
+              : null) ?? maxSeqLength;
+          // Respect the rolled-back model's auto-layers mode: a Manual+Auto model
+          // with an unpinned context must reload with 0 (so --fit re-auto-sizes),
+          // not the positive context it picked (which the backend treats as a pin).
+          const rollbackMaxSeqLength = resolveFitMaxSeqLength(
+            previousIsGguf,
+            stateBeforeUnload.loadedGpuMemoryMode ?? "auto",
+            stateBeforeUnload.loadedGpuLayers ?? GPU_LAYERS_AUTO,
+            stateBeforeUnload.loadedCustomContextLength,
+            previousIsGguf
+              ? (stateBeforeUnload.ggufContextLength ?? 0)
+              : previousMaxSeqLength,
+          );
           const hfToken = stateBeforeUnload.hfToken || null;
           const previousModelRequiresTrustRemoteCode =
             stateBeforeUnload.modelRequiresTrustRemoteCode;
-          const previousActiveNativePathToken =
-            stateBeforeUnload.activeNativePathToken;
+          const previousActiveNativePathExpiresAtMs =
+            stateBeforeUnload.activeNativePathExpiresAtMs;
           // Snapshot the load settings at click time, before the awaits below
-          // (validation, the trust dialog, unload). For a staged Load these knobs
-          // stay editable and a sheet-close revert (abandonStagedModel) can fire
-          // mid-load; reading them live just before loadModel would let the load
-          // use post-click values. The model-switch speculative reset below
-          // updates this snapshot in lock-step so non-staged loads are unchanged.
+          // (validation, the trust dialog, unload).
           const loadChatTemplateOverride = stateBeforeUnload.chatTemplateOverride;
           const loadKvCacheDtype = stateBeforeUnload.kvCacheDtype;
-          const loadCustomContextLength = stateBeforeUnload.customContextLength;
+          // gpuMemoryMode is a standing preference (kept across a model switch);
+          // the rest are per-model knobs the reset below clears, so they are
+          // re-baselined there in lock-step with the store.
+          let loadCustomContextLength = stateBeforeUnload.customContextLength;
           const loadGgufContextLength = stateBeforeUnload.ggufContextLength;
           const loadTensorParallel = stateBeforeUnload.tensorParallel;
           const loadActivePresetSource = stateBeforeUnload.activePresetSource;
           const loadActiveGgufVariant = stateBeforeUnload.activeGgufVariant;
+          const loadGpuMemoryMode = stateBeforeUnload.gpuMemoryMode;
+          let loadGpuLayers = stateBeforeUnload.gpuLayers;
+          let loadNCpuMoe = stateBeforeUnload.nCpuMoe;
+          let loadSplitRatio = stateBeforeUnload.splitRatio;
+          // Reconcile the persisted pick against the GPUs present now, so a stale
+          // cross-host / now-hidden pick is dropped before /load rather than
+          // rejected there. Warm the device cache first: load-on-selection can
+          // run before any GPU hook mounted, and a cold cache would pass the
+          // pick through unvalidated. validateGpuIds derives from this too.
+          if (stateBeforeUnload.selectedGpuIds != null) {
+            await ensureGpuDeviceCache();
+          }
+          let loadSelectedGpuIds = reconcilePersistedGpuIds(
+            stateBeforeUnload.selectedGpuIds,
+          );
           let loadSpeculativeType = stateBeforeUnload.speculativeType;
           let loadSpecDraftNMax = stateBeforeUnload.specDraftNMax;
           try {
@@ -615,16 +681,44 @@ export function useChatModelRuntime() {
             // context can exceed maxSeqLength, so sizing on raw maxSeqLength could
             // pass, unload, then have /load refuse it. Uses the click-time
             // snapshot (same values loadModel uses below), so the two agree.
-            const validateMaxSeqLength = resolveLoadMaxSeqLength({
-              modelId,
-              ggufVariant,
-              customContextLength: loadCustomContextLength,
-              ggufContextLength: loadGgufContextLength,
-              currentCheckpoint,
-              activeGgufVariant: loadActiveGgufVariant,
-              maxSeqLength,
-              presetSource: loadActivePresetSource,
-            });
+            // Mirror /load on a cross-model switch: the reset below clears the
+            // per-model Auto-layers context pin + GPU pick; gpuMemoryMode is a
+            // standing preference kept across the switch. A same-repo quant switch
+            // (different gguf_variant) is a different model for per-model knobs
+            // (context/gpuLayers/pick/MoE are per variant), so re-baseline them too.
+            const switchingModelOrVariant =
+              currentCheckpoint !== modelId ||
+              (loadActiveGgufVariant ?? null) !== (ggufVariant ?? null);
+            const resetsPerModelSettings = Boolean(
+              currentCheckpoint && switchingModelOrVariant && !keepSpeculative,
+            );
+            const validateCustomContextLength = resetsPerModelSettings
+              ? null
+              : loadCustomContextLength;
+            const validateGpuIds = resetsPerModelSettings
+              ? null
+              : loadSelectedGpuIds;
+            // The reset below re-baselines gpuLayers to Auto; mirror it here.
+            const validateGpuLayers = resetsPerModelSettings
+              ? GPU_LAYERS_AUTO
+              : loadGpuLayers;
+            const validateMaxSeqLength = resolveFitMaxSeqLength(
+              isGguf,
+              loadGpuMemoryMode,
+              validateGpuLayers,
+              validateCustomContextLength,
+              resolveLoadMaxSeqLength({
+                modelId,
+                ggufVariant,
+                isGguf,
+                customContextLength: validateCustomContextLength,
+                ggufContextLength: loadGgufContextLength,
+                currentCheckpoint,
+                activeGgufVariant: loadActiveGgufVariant,
+                maxSeqLength,
+                presetSource: loadActivePresetSource,
+              }),
+            );
             const validation = await validateModel({
               model_path: modelId,
               nativePathLease: validateNativePathLease,
@@ -633,6 +727,8 @@ export function useChatModelRuntime() {
               load_in_4bit: true,
               is_lora: isLora,
               gguf_variant: ggufVariant ?? null,
+              gpu_ids: validateGpuIds ?? undefined,
+              ...(isGguf ? { gpu_memory_mode: loadGpuMemoryMode } : {}),
             });
             // Upgrade consent runs before the security dialogs; Accept installs and the load continues.
             if (validation.requires_transformers_upgrade) {
@@ -697,18 +793,52 @@ export function useChatModelRuntime() {
             // keepSpeculative skips this for a staged Load: the user picked the
             // mode for this model on the sidebar, so honor it (the backend still
             // falls back at runtime if the model has no MTP head).
-            if (currentCheckpoint && currentCheckpoint !== modelId && !keepSpeculative) {
+            if (resetsPerModelSettings) {
               const persistedSpeculativeType = readPersistedSpeculativeType();
               useChatRuntimeStore.setState({
                 speculativeType: persistedSpeculativeType,
                 loadedSpeculativeType: persistedSpeculativeType,
                 specDraftNMax: null,
                 loadedSpecDraftNMax: null,
+                // Per-model GPU knobs must not follow onto a different model
+                // (gpuMemoryMode is a standing preference and is kept).
+                selectedGpuIds: null,
+                gpuLayers: GPU_LAYERS_AUTO,
+                nCpuMoe: 0,
+                splitRatio: null,
+                // A Manual+Auto context pin is per-model; clear it so a different
+                // model loads at Auto/native, not the previous model's pin.
+                customContextLength: null,
               });
               loadSpeculativeType = persistedSpeculativeType;
               loadSpecDraftNMax = null;
+              // Keep the click-time snapshot in lock-step with the store reset so
+              // the load below sizes against the cleared per-model knobs, not the
+              // previous model's (gpuMemoryMode is standing, so left as captured).
+              loadCustomContextLength = null;
+              loadSelectedGpuIds = null;
+              loadGpuLayers = GPU_LAYERS_AUTO;
+              loadNCpuMoe = 0;
+              loadSplitRatio = null;
             }
 
+            // Pinning layers on the SAME model keeps the currently resolved
+            // context: with no explicit pin, a manual+pinned reload would send 0,
+            // which the backend's --fit off branch treats as the NATIVE context --
+            // far larger than the sheet shows when the load was fit-sized (Default
+            // or Manual + Auto layers may auto-reduce context to fit VRAM), a
+            // likely OOM. ggufContextLength is that resolved value; a model already
+            // at native reloads unchanged, so this is safe for any prior mode.
+            if (
+              isGguf &&
+              !switchingModelOrVariant &&
+              loadGpuMemoryMode === "manual" &&
+              loadGpuLayers >= 0 &&
+              loadCustomContextLength == null &&
+              (loadGgufContextLength ?? 0) > 0
+            ) {
+              loadCustomContextLength = loadGgufContextLength;
+            }
             const effectiveMaxSeqLength = resolveLoadMaxSeqLength({
               modelId,
               ggufVariant,
@@ -720,13 +850,20 @@ export function useChatModelRuntime() {
               maxSeqLength,
               presetSource: loadActivePresetSource,
             });
+            const loadMaxSeqLength = resolveFitMaxSeqLength(
+              isGguf,
+              loadGpuMemoryMode,
+              loadGpuLayers,
+              loadCustomContextLength,
+              effectiveMaxSeqLength,
+            );
             const effectiveChatTemplateOverride =
               loadChatTemplateOverride?.trim() ? loadChatTemplateOverride : null;
             const loadResponse = await loadModel({
               model_path: modelId,
               nativePathLease: loadNativePathLease,
               hf_token: hfToken,
-              max_seq_length: effectiveMaxSeqLength,
+              max_seq_length: loadMaxSeqLength,
               load_in_4bit: true,
               is_lora: isLora,
               gguf_variant: ggufVariant ?? null,
@@ -737,6 +874,11 @@ export function useChatModelRuntime() {
               speculative_type: loadSpeculativeType,
               spec_draft_n_max: loadSpecDraftNMax,
               tensor_parallel: loadTensorParallel,
+              gpu_memory_mode: loadGpuMemoryMode,
+              gpu_layers: loadGpuLayers,
+              n_cpu_moe: loadNCpuMoe,
+              tensor_split: loadSplitRatio ?? undefined,
+              gpu_ids: loadSelectedGpuIds ?? undefined,
             });
 
             // If cancelled while loading, don't update UI to show
@@ -746,7 +888,14 @@ export function useChatModelRuntime() {
             // The load applied this spec mode, so persist the user's standing
             // preference now (the requested intent, not the resolved echo;
             // saveSpeculativeType keeps only the universal auto/ngram/off).
-            saveSpeculativeType(loadSpeculativeType);
+            // Skip for a per-model config (keepSpeculative): that choice is
+            // model-specific and must not overwrite the global default.
+            if (!keepSpeculative) {
+              saveSpeculativeType(loadSpeculativeType);
+            }
+            // Persist the GPU Memory mode only on a successful load (not on
+            // dropdown change), so an abandoned selection doesn't stick.
+            persistGpuMemoryModeOnLoad(loadResponse, loadGpuMemoryMode);
 
             const currentParams = useChatRuntimeStore.getState().params;
             setParams(
@@ -782,9 +931,15 @@ export function useChatModelRuntime() {
             const reportedNativeCtx = loadResponse.is_gguf
               ? (loadResponse.native_context_length ?? null)
               : null;
-            // A successful reload has applied settings, so clear pending custom
-            // context state and display the backend-reported effective context.
-            const keepCustomCtx = null;
+            // Keep an explicit Manual+Auto context pin (so a later Apply doesn't
+            // revert it to Auto) and retain the user's requested context so
+            // re-open/re-save keeps the intended override, not the backend's
+            // auto-fit context; null stays null.
+            const keepCustomCtx = resolveManualAutoCtxPin(
+              loadGpuMemoryMode,
+              loadGpuLayers,
+              loadCustomContextLength,
+            );
             const reasoningAlwaysOn = loadResponse.reasoning_always_on ?? false;
             const reasoningStyle = loadResponse.reasoning_style ?? "enable_thinking";
             const supportsReasoning = loadResponse.supports_reasoning ?? false;
@@ -837,17 +992,22 @@ export function useChatModelRuntime() {
               loadedKvCacheDtype: loadedKv,
               tensorParallel: loadedTp,
               loadedTensorParallel: loadedTp,
+              ...loadedGpuMemoryFields(loadResponse),
               speculativeType: loadedSpec,
               loadedSpeculativeType: loadedSpec,
               specDraftNMax: loadResponse.spec_draft_n_max ?? null,
               loadedSpecDraftNMax: loadResponse.spec_draft_n_max ?? null,
               customContextLength: keepCustomCtx,
+              loadedCustomContextLength: keepCustomCtx,
               defaultChatTemplate: loadResponse.chat_template ?? null,
               chatTemplateOverride: effectiveChatTemplateOverride,
               loadedChatTemplateOverride: effectiveChatTemplateOverride,
               loadedIsMultimodal: isMultimodalResponse(loadResponse),
               loadedIsDiffusion: loadResponse.is_diffusion ?? false,
               activeNativePathToken: nativePathToken ?? null,
+              activeNativePathExpiresAtMs: nativePathToken
+                ? nativePathExpiresAtMs
+                : null,
             });
             // Unlock attach menus for capabilities the catalog entry lacked.
             syncModelCapabilities(modelId, loadResponse);
@@ -901,25 +1061,6 @@ export function useChatModelRuntime() {
                 recordLastLocalModelLoad({ id: modelId, kind: "model" });
               }
             }
-            // A successful load owns the shared (pick-unscoped) settings fields,
-            // so any surviving stage is stale: the just-loaded pick itself, or a
-            // pick queued for a different model mid-load whose knobs this load
-            // overwrote. Drop it. Only a DIFFERENT pick's download needs
-            // cancelling; the loaded pick's is already consumed, and cancelling
-            // it inside its post-complete linger window would flicker its card.
-            const staleStage = useChatRuntimeStore.getState().pendingSelection;
-            if (staleStage) {
-              if (
-                !pendingSelectionMatches(staleStage, {
-                  id: modelId,
-                  ggufVariant,
-                  nativePathToken,
-                })
-              ) {
-                cancelStagedModelDownload(staleStage);
-              }
-              useChatRuntimeStore.getState().setPendingSelection(null);
-            }
           } catch (error) {
             // Skip rollback if user cancelled -- model is already being unloaded.
             if (abortCtrl.signal.aborted) throw error;
@@ -938,7 +1079,7 @@ export function useChatModelRuntime() {
                 }
               }
               try {
-                await loadModel({
+                const rollbackResponse = await loadModel({
                   model_path: previousCheckpoint,
                   nativePathLease: rollbackNativePathLease,
                   hf_token: hfToken,
@@ -951,14 +1092,51 @@ export function useChatModelRuntime() {
                   // Resend the previous model's pinned approval so restoring it is not re-blocked.
                   approved_remote_code_fingerprint:
                     approvedRemoteCodeFingerprints.get(previousCheckpoint) ?? null,
+                  chat_template_override:
+                    stateBeforeUnload.loadedChatTemplateOverride,
+                  cache_type_kv: stateBeforeUnload.loadedKvCacheDtype,
+                  speculative_type:
+                    stateBeforeUnload.loadedSpeculativeType,
+                  spec_draft_n_max:
+                    stateBeforeUnload.loadedSpecDraftNMax,
                   // Restore the previous model in the split mode it was running,
                   // not the default layer split.
                   tensor_parallel: stateBeforeUnload.loadedTensorParallel ?? false,
+                  // Restore the previous model's GPU Memory placement, not backend defaults.
+                  gpu_memory_mode: stateBeforeUnload.loadedGpuMemoryMode ?? "auto",
+                  gpu_layers: stateBeforeUnload.loadedGpuLayers ?? GPU_LAYERS_AUTO,
+                  n_cpu_moe: stateBeforeUnload.loadedNCpuMoe ?? 0,
+                  tensor_split: stateBeforeUnload.loadedSplitRatio ?? undefined,
+                  gpu_ids: stateBeforeUnload.loadedGpuIds ?? undefined,
                 });
+                const rollbackSpeculativeType = normalizeSpeculativeType(
+                  rollbackResponse.speculative_type,
+                );
                 useChatRuntimeStore.setState({
                   activeNativePathToken: previousActiveNativePathToken ?? null,
-                  loadedSpeculativeType: null,
-                  loadedSpecDraftNMax: null,
+                  // Restore the previous token's lease together with the token so a
+                  // rollback never pairs restored token A with failed load B's expiry.
+                  activeNativePathExpiresAtMs: previousActiveNativePathToken
+                    ? (previousActiveNativePathExpiresAtMs ?? null)
+                    : null,
+                  // Restore the editable speculative knobs to the rolled-back
+                  // model's; the loaded baselines below come from its reload echo.
+                  speculativeType: stateBeforeUnload.loadedSpeculativeType ?? null,
+                  specDraftNMax: stateBeforeUnload.loadedSpecDraftNMax ?? null,
+                  loadedSpeculativeType: rollbackSpeculativeType,
+                  loadedSpecDraftNMax:
+                    rollbackResponse.spec_draft_n_max ?? null,
+                  loadedKvCacheDtype: rollbackResponse.cache_type_kv ?? null,
+                  loadedChatTemplateOverride:
+                    stateBeforeUnload.loadedChatTemplateOverride,
+                  ...loadedGpuMemoryFields(rollbackResponse),
+                  tensorParallel: rollbackResponse.tensor_parallel ?? false,
+                  loadedTensorParallel:
+                    rollbackResponse.tensor_parallel ?? false,
+                  customContextLength:
+                    stateBeforeUnload.loadedCustomContextLength,
+                  loadedCustomContextLength:
+                    stateBeforeUnload.loadedCustomContextLength,
                 });
                 await refresh();
               } catch {
@@ -1277,6 +1455,9 @@ export function useChatModelRuntime() {
           resetLoadingUi();
         }
       } catch (error) {
+        if (typeof selection !== "string" && selection.previousConfig) {
+          applyPerModelConfigToRuntime(selection.previousConfig);
+        }
         if (abortCtrl.signal.aborted) return; // User cancelled, nothing to report
         resetLoadingUi();
         const message =
@@ -1307,6 +1488,13 @@ export function useChatModelRuntime() {
     if (!params.checkpoint) {
       return false;
     }
+    const runtime = useChatRuntimeStore.getState();
+    if (runtime.modelLoading || runtime.loadingModelPick) {
+      toast.info("A model is loading", {
+        description: "Wait for it to finish or cancel it first.",
+      });
+      return false;
+    }
     setModelsError(null);
     if (isExternalModelId(params.checkpoint)) {
       clearCheckpoint();
diff --git a/studio/frontend/src/features/chat/hooks/use-chat-projects.ts b/studio/frontend/src/features/chat/hooks/use-chat-projects.ts
index 3f0d46982d..86f540654d 100644
--- a/studio/frontend/src/features/chat/hooks/use-chat-projects.ts
+++ b/studio/frontend/src/features/chat/hooks/use-chat-projects.ts
@@ -1,8 +1,8 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { useEffect, useState } from "react";
-import { CHAT_HISTORY_UPDATED_EVENT } from "../api/chat-api";
+import { useEffect, useState, useSyncExternalStore } from "react";
+import { CHAT_PROJECTS_UPDATED_EVENT } from "../api/chat-api";
 import type { ProjectRecord } from "../types";
 import {
   createStoredChatProject,
@@ -15,32 +15,83 @@ import {
 import type { SidebarItem } from "./use-chat-sidebar-items";
 
 let cachedProjects: ProjectRecord[] = [];
+let projectsLoaded = false;
+let projectsRequest: Promise<ProjectRecord[]> | null = null;
+let projectsRefreshPending = false;
+let lastProjectsUpdateEvent: Event | null = null;
+const projectSubscribers = new Set<() => void>();
+
+function subscribeToProjects(onStoreChange: () => void): () => void {
+  projectSubscribers.add(onStoreChange);
+  return () => projectSubscribers.delete(onStoreChange);
+}
+
+function getProjectsSnapshot(): ProjectRecord[] {
+  return cachedProjects;
+}
+
+function publishProjects(projects: ProjectRecord[]): void {
+  cachedProjects = projects;
+  projectsLoaded = true;
+  for (const onStoreChange of projectSubscribers) onStoreChange();
+}
+
+function loadProjects(
+  force = false,
+  followUpIfPending = false,
+): Promise<ProjectRecord[]> {
+  if (projectsRequest) {
+    if (followUpIfPending) projectsRefreshPending = true;
+    return projectsRequest;
+  }
+  if (!force && projectsLoaded) {
+    return Promise.resolve(cachedProjects);
+  }
+
+  async function run(): Promise<ProjectRecord[]> {
+    let nextProjects: ProjectRecord[] | null = null;
+    do {
+      projectsRefreshPending = false;
+      try {
+        const next = await listStoredChatProjects({ includeArchived: false });
+        nextProjects = Array.isArray(next) ? next : [];
+      } catch (error) {
+        if (!isExpectedBackgroundChatStorageError(error)) throw error;
+        nextProjects = null;
+      }
+    } while (projectsRefreshPending);
+    if (nextProjects !== null) publishProjects(nextProjects);
+    return cachedProjects;
+  }
+
+  const request = run().finally(() => {
+    projectsRequest = null;
+  });
+  projectsRequest = request;
+  return request;
+}
 
 export function useChatProjects(): {
   projects: ProjectRecord[];
   isLoading: boolean;
   hasLoaded: boolean;
 } {
-  // Stay null-safe even if the cache was poisoned by a bad response.
-  const cached = Array.isArray(cachedProjects) ? cachedProjects : [];
-  const [projects, setProjects] = useState<ProjectRecord[]>(cached);
-  const [isLoading, setIsLoading] = useState(cached.length === 0);
-  const [hasLoaded, setHasLoaded] = useState(cached.length > 0);
+  const projects = useSyncExternalStore(
+    subscribeToProjects,
+    getProjectsSnapshot,
+    getProjectsSnapshot,
+  );
+  const [isLoading, setIsLoading] = useState(!projectsLoaded);
+  const [hasLoaded, setHasLoaded] = useState(projectsLoaded);
 
   useEffect(() => {
     let cancelled = false;
 
-    async function load() {
-      if (!cancelled) setIsLoading(true);
+    async function refresh(force = false, followUpIfPending = false) {
+      if (!force && projectsLoaded) return;
+      if (!cancelled && !projectsLoaded) setIsLoading(true);
       try {
-        const next = await listStoredChatProjects({ includeArchived: false });
-        cachedProjects = Array.isArray(next) ? next : [];
-        if (!cancelled) setProjects(cachedProjects);
-      } catch (error) {
-        if (isExpectedBackgroundChatStorageError(error)) {
-          return;
-        }
-        if (!cancelled) throw error;
+        await loadProjects(force, followUpIfPending);
       } finally {
         if (!cancelled) {
           setHasLoaded(true);
@@ -49,15 +100,18 @@ export function useChatProjects(): {
       }
     }
 
-    const onHistoryUpdated = () => {
-      void load();
+    const onProjectsUpdated = (event: Event) => {
+      const followUpIfPending = event !== lastProjectsUpdateEvent;
+      lastProjectsUpdateEvent = event;
+      void refresh(true, followUpIfPending);
     };
-
-    void load();
-    window.addEventListener(CHAT_HISTORY_UPDATED_EVENT, onHistoryUpdated);
+    // Cached rows render immediately, then one shared request reconciles
+    // changes made by another browser tab or API client.
+    void refresh(projectsLoaded);
+    window.addEventListener(CHAT_PROJECTS_UPDATED_EVENT, onProjectsUpdated);
     return () => {
       cancelled = true;
-      window.removeEventListener(CHAT_HISTORY_UPDATED_EVENT, onHistoryUpdated);
+      window.removeEventListener(CHAT_PROJECTS_UPDATED_EVENT, onProjectsUpdated);
     };
   }, []);
 
diff --git a/studio/frontend/src/features/chat/hooks/use-chat-sidebar-items.ts b/studio/frontend/src/features/chat/hooks/use-chat-sidebar-items.ts
index 0a0df1139b..a08bd5fa54 100644
--- a/studio/frontend/src/features/chat/hooks/use-chat-sidebar-items.ts
+++ b/studio/frontend/src/features/chat/hooks/use-chat-sidebar-items.ts
@@ -45,7 +45,7 @@ export function groupThreads(
 
   for (const t of threads) {
     // Coerce archived to a boolean before comparing. Legacy threads (from the
-    // older browser-only Studio, or any record predating the archived field)
+    // older browser-only Unsloth, or any record predating the archived field)
     // can have archived === undefined or null; a raw `!== archived` comparison
     // would drop those from BOTH the Recents (archived=false) and Archived
     // (archived=true) lists, hiding existing chats. Treat missing as false.
@@ -217,6 +217,40 @@ export async function archiveChatItem(
   notifyChatHistoryUpdated();
 }
 
+export async function archiveAllChatItems(
+  activeId?: string,
+  onSelect?: (view: { mode: "single"; newThreadNonce: string }) => void,
+): Promise<number> {
+  const threads = await listStoredChatThreads({ includeArchived: true });
+  // Boolean() mirrors groupThreads: legacy records may have archived
+  // undefined/null, which must count as "not archived".
+  const toArchive = threads.filter((t) => !t.archived);
+  if (toArchive.length === 0) return 0;
+
+  for (const t of toArchive) cancelIfRunning(t.id);
+
+  await Promise.all(
+    toArchive.map((t) => updateStoredChatThread(t.id, { archived: true })),
+  );
+
+  // Reset only when this action archived the active single thread or compare
+  // pair. An already-archived chat opened from the archive is not in
+  // toArchive and must stay open.
+  const archivedActive =
+    activeId !== undefined &&
+    toArchive.some(
+      (thread) => thread.id === activeId || thread.pairId === activeId,
+    );
+  if (archivedActive) {
+    useChatRuntimeStore.getState().setActiveThreadId(null);
+    onSelect?.({ mode: "single", newThreadNonce: crypto.randomUUID() });
+  }
+
+  notifyChatHistoryUpdated();
+  // Report sidebar items, not raw threads: a compare pair reads as one chat.
+  return groupThreads(toArchive).length;
+}
+
 export async function unarchiveChatItem(item: SidebarItem): Promise<void> {
   const threadIds: string[] =
     item.type === "single"
diff --git a/studio/frontend/src/features/chat/hooks/use-staged-model-preparation.ts b/studio/frontend/src/features/chat/hooks/use-staged-model-preparation.ts
deleted file mode 100644
index d8076c720b..0000000000
--- a/studio/frontend/src/features/chat/hooks/use-staged-model-preparation.ts
+++ /dev/null
@@ -1,155 +0,0 @@
-// SPDX-License-Identifier: AGPL-3.0-only
-// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
-
-import { useCallback, useEffect } from "react";
-
-import { useRepoDownload } from "@/features/hub/download-manager/use-repo-download";
-import type { DownloadJob } from "@/features/hub/download-manager/use-repo-download";
-import { useLatestRef } from "@/features/hub/hooks/use-latest-ref";
-
-import { fetchGgufContextLength } from "../api/chat-api";
-import {
-  isPendingGguf,
-  pendingSelectionMatches,
-  useChatRuntimeStore,
-} from "../stores/chat-runtime-store";
-import type { PendingModelSelection } from "../stores/chat-runtime-store";
-
-/**
- * Drives the deferred ("Load on selection" off) staging flow for a GGUF:
- * download the file if needed (HF repo) or read it in place (native drag-drop /
- * picked file), then read its header context length so the settings sheet can
- * show the real context slider before the single GPU load. The staged context
- * lands on `pendingSelection.contextLength` (scoped to the staged model, never
- * the loaded model's `ggufContextLength`). Returns the live download job so the
- * sheet can render progress / cancel. Mount once on the chat page.
- */
-export function useStagedModelPreparation(opts?: {
-  /** Load the cached file once an autoLoad pick's download completes. */
-  onAutoLoad?: (pending: PendingModelSelection) => void;
-}): DownloadJob {
-  const pendingId = useChatRuntimeStore((s) => s.pendingSelection?.id ?? null);
-  const pendingVariant = useChatRuntimeStore(
-    (s) => s.pendingSelection?.ggufVariant ?? null,
-  );
-  const pendingNativeToken = useChatRuntimeStore(
-    (s) => s.pendingSelection?.nativePathToken ?? null,
-  );
-  // Only GGUF picks (HF variant or native file) have a header worth reading.
-  const pendingIsGguf = useChatRuntimeStore((s) =>
-    isPendingGguf(s.pendingSelection),
-  );
-  // Non-GGUF HF repos download a full snapshot (variant null) but have no header.
-  const pendingIsHubRepo = useChatRuntimeStore(
-    (s) => s.pendingSelection?.isHubRepo ?? false,
-  );
-  const pendingDownloaded = useChatRuntimeStore(
-    (s) => s.pendingSelection?.isDownloaded ?? false,
-  );
-  const pendingHasContext = useChatRuntimeStore(
-    (s) => s.pendingSelection?.contextLength != null,
-  );
-  const setPendingSelection = useChatRuntimeStore((s) => s.setPendingSelection);
-  const onAutoLoadRef = useLatestRef(opts?.onAutoLoad);
-
-  // A failed or cancelled autoLoad download has no sheet to retry from, so drop
-  // the staged pick rather than leave it waiting on a load that won't come.
-  const handleAutoLoadAbort = useCallback((variant: string | null) => {
-    const latest = useChatRuntimeStore.getState().pendingSelection;
-    if (
-      latest?.autoLoad &&
-      (latest.ggufVariant ?? null) === (variant ?? null)
-    ) {
-      useChatRuntimeStore.getState().abandonStagedModel();
-    }
-  }, []);
-
-  const fetchContextMetadata = useCallback(async () => {
-    const current = useChatRuntimeStore.getState().pendingSelection;
-    if (!current?.id || !isPendingGguf(current)) return;
-    const { id, ggufVariant, nativePathToken } = current;
-    try {
-      const contextLength = await fetchGgufContextLength({
-        model_path: id,
-        gguf_variant: ggufVariant,
-        hf_token: useChatRuntimeStore.getState().hfToken || null,
-        nativePathToken,
-      });
-      // Apply only if the same model is still staged (the user may have switched
-      // picks or loaded/cancelled while the request was in flight).
-      const latest = useChatRuntimeStore.getState().pendingSelection;
-      if (
-        latest &&
-        contextLength != null &&
-        pendingSelectionMatches(latest, { id, ggufVariant, nativePathToken })
-      ) {
-        setPendingSelection({ ...latest, contextLength });
-      }
-    } catch {
-      // Leave contextLength null: the context slider stays hidden and the user
-      // can still load (context fills in from the load response afterwards).
-    }
-  }, [setPendingSelection]);
-
-  const job = useRepoDownload({
-    kind: "model",
-    // useRepoDownload must be called unconditionally; an idle repo id keeps it
-    // inert until something is staged.
-    repoId: pendingId ?? "__staged_idle__",
-    activeVariant: pendingVariant,
-    onComplete: (variant) => {
-      // autoLoad picks load the cached file now; staged picks read the header so
-      // the sheet's context slider can show before a manual load.
-      const latest = useChatRuntimeStore.getState().pendingSelection;
-      if (
-        latest?.autoLoad &&
-        (latest.ggufVariant ?? null) === (variant ?? null)
-      ) {
-        onAutoLoadRef.current?.(latest);
-        return;
-      }
-      void fetchContextMetadata();
-    },
-    onError: handleAutoLoadAbort,
-    onCancelled: handleAutoLoadAbort,
-  });
-
-  // job.requestStartDownload's identity changes per render; hold it in a ref so
-  // the staging effect re-runs only when the staged model itself changes.
-  const startDownloadRef = useLatestRef(job.requestStartDownload);
-  const fetchMetadataRef = useLatestRef(fetchContextMetadata);
-
-  useEffect(() => {
-    // GGUF picks (header worth reading) and uncached non-GGUF hub repos (full
-    // snapshot, no header) both run here; everything else is loaded directly.
-    if (
-      !pendingId ||
-      (!pendingIsGguf && !pendingIsHubRepo) ||
-      pendingHasContext
-    ) {
-      return;
-    }
-    // Native files and already-downloaded HF files are local: read the header
-    // now. Otherwise download first (a GGUF variant, or a null-variant snapshot
-    // for a hub repo); onComplete then reads the header or auto-loads.
-    if (pendingNativeToken || pendingDownloaded) {
-      void fetchMetadataRef.current();
-    } else {
-      const expectedBytes =
-        useChatRuntimeStore.getState().pendingSelection?.expectedBytes ?? 0;
-      void startDownloadRef.current(pendingVariant, expectedBytes);
-    }
-  }, [
-    pendingId,
-    pendingVariant,
-    pendingNativeToken,
-    pendingIsGguf,
-    pendingIsHubRepo,
-    pendingDownloaded,
-    pendingHasContext,
-    startDownloadRef,
-    fetchMetadataRef,
-  ]);
-
-  return job;
-}
diff --git a/studio/frontend/src/features/chat/index.ts b/studio/frontend/src/features/chat/index.ts
index a8b5fc23ad..785212a2c4 100644
--- a/studio/frontend/src/features/chat/index.ts
+++ b/studio/frontend/src/features/chat/index.ts
@@ -3,20 +3,49 @@
 
 export { ChatPage, validateChatSearch, type ChatSearch } from "./chat-page";
 export {
+  addScanFolder,
+  browseFolders,
+  deleteChatAttachment,
+  deleteFineTunedModel,
+  fetchChatAttachmentBlob,
+  fetchGgufStagedMetadata,
+  getCachedModelPath,
   getInferenceStatus,
+  listChatAttachments,
   listGgufVariants,
   listLocalModels,
+  listRecommendedFolders,
+  listScanFolders,
   loadModel,
+  notifyChatHistoryUpdated,
+  removeScanFolder,
+  revealCachedModel,
+  type BrowseFoldersResponse,
+  type CachedGgufRepo,
+  type CachedModelRepo,
+  type ChatAttachmentPage,
+  type ChatAttachmentRecord,
   type LocalModelInfo,
+  type ScanFolderInfo,
 } from "./api/chat-api";
 export type { GgufVariantDetail } from "./types/api";
 export {
   ChatSettingsPanel,
+  ParamSlider,
   defaultInferenceParams,
   type InferenceParams,
   type Preset,
 } from "./chat-settings-sheet";
 export { useChatRuntimeStore } from "./stores/chat-runtime-store";
+export {
+  CHAT_RAG_CAPTION_KEY,
+  CHAT_RAG_OCR_KEY,
+  normalizeSpeculativeType,
+  readPersistedSpeculativeType,
+  readPersistedGpuMemoryMode,
+  reconcilePersistedGpuIds,
+  GPU_LAYERS_AUTO,
+} from "./stores/chat-runtime-store";
 export {
   preferFullToolOutput,
   toolOutputKey,
@@ -25,6 +54,7 @@ export {
 export { PermissionModeDropdown } from "./permission-mode-select";
 export { useChatSearchStore } from "./stores/chat-search-store";
 export { usePinnedChatsStore } from "./stores/pinned-chats-store";
+export { usePinnedProjectsStore } from "./stores/pinned-projects-store";
 export { useChatPreferencesStore } from "./stores/chat-preferences-store";
 export {
   PLUS_MENU_ORDER,
@@ -37,21 +67,27 @@ export {
 } from "./hooks/use-chat-model-runtime";
 export {
   customProviderDisplayName,
+  isCustomProviderType,
   isExternalModelId,
   parseExternalModelId,
 } from "./external-providers";
+export { ApiProviderLogo } from "./api-provider-logo";
 export { useExternalProvidersStore } from "./stores/external-providers-store";
 export { ChatSearchDialog } from "./components/chat-search-dialog";
 export { setTrainingCompareHandoff } from "./lib/training-compare-handoff";
 export type { ProjectRecord } from "./types";
 export { clearAllChats, countAllChats } from "./utils/clear-all-chats";
 export { listStoredChatThreads } from "./utils/chat-history-storage";
+export { emitChatAttachmentDeleted } from "./utils/chat-attachment-events";
 export { ArtifactCard } from "./artifacts/artifact-card";
 export {
   useChatArtifactsStore,
   useSelectedChatArtifact,
 } from "./artifacts/store";
-export { downloadChatExport } from "./utils/export-chat-history";
+export {
+  downloadArchivedChatExport,
+  downloadChatExport,
+} from "./utils/export-chat-history";
 export {
   clearNewChatDraft,
   composerDraftKey,
@@ -60,10 +96,14 @@ export {
 } from "./utils/composer-draft";
 export {
   EXPORT_FORMATS_LIST,
+  buildFineTuneJsonl,
   bulkExportConversationsByScope,
+  exportFineTuneJsonl,
   importConversationsFromFile,
+  type FineTuneFormat,
 } from "./prompt-storage/prompt-storage-dialog";
 export {
+  archiveAllChatItems,
   archiveChatItem,
   deleteChatItem,
   renameChatItem,
@@ -79,3 +119,25 @@ export {
   updateChatProjectInstructions,
   useChatProjects,
 } from "./hooks/use-chat-projects";
+export { subscribeDictationLevel } from "./adapters/dictation-level";
+export {
+  StudioDictationAdapter,
+  cancelActiveStudioDictation,
+  isStudioDictationAvailable,
+  notifyStudioDictationUnavailable,
+} from "./adapters/studio-dictation-adapter";
+export {
+  StudioModelDictationAdapter,
+  fetchSttStatus,
+  loadSttModel,
+  startSttDownload,
+  unloadSttModel,
+  validateSttModel,
+  type SttDownloadStatus,
+} from "./adapters/studio-model-dictation-adapter";
+export {
+  StudioSpeechSynthesisAdapter,
+  createConfiguredUtterance,
+  curateSystemVoices,
+  generateStudioTtsAudio,
+} from "./adapters/studio-speech-synthesis-adapter";
diff --git a/studio/frontend/src/features/chat/lib/apply-inference-status-to-store.ts b/studio/frontend/src/features/chat/lib/apply-inference-status-to-store.ts
index a4b5f848e2..f85ff3246b 100644
--- a/studio/frontend/src/features/chat/lib/apply-inference-status-to-store.ts
+++ b/studio/frontend/src/features/chat/lib/apply-inference-status-to-store.ts
@@ -2,13 +2,17 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { getInferenceStatus } from "../api/chat-api";
-import { mergeBackendRecommendedInference } from "../presets/preset-policy";
+import {
+  mergeBackendRecommendedInference,
+  resolveManualAutoCtxPin,
+} from "../presets/preset-policy";
 import { clampReasoningEffortToLevels } from "../provider-capabilities";
 import {
   CHAT_REASONING_ENABLED_KEY,
   type ReasoningEffort,
   type ReasoningStyle,
   loadOptionalBool,
+  loadedGpuMemoryFields,
   resolveToolsEnabledOnLoad,
   useChatRuntimeStore,
 } from "../stores/chat-runtime-store";
@@ -20,6 +24,10 @@ import type { ChatModelSummary } from "../types/runtime";
 
 type LocalReasoningEffort = Extract<ReasoningEffort, "low" | "medium" | "high">;
 
+function sameArray<T>(a: T[] | null, b: T[] | null): boolean {
+  return JSON.stringify(a) === JSON.stringify(b);
+}
+
 // Canonicalises backend / persisted speculative mode values onto the UI modes.
 export function normalizeSpeculativeType(
   v: string | null | undefined,
@@ -119,6 +127,10 @@ function ensureActiveModelInStoreList(
 
 export type ApplyInferenceStatusOptions = {
   previousCheckpoint?: string;
+  /** activeGgufVariant BEFORE the caller's setCheckpoint synced it to the
+   * status -- without it a variant-only switch underneath the tab reads as
+   * steady state and the hydration reseed keeps the old quant's baselines. */
+  previousGgufVariant?: string | null;
 };
 
 /** Mirror refresh() hydration so adopted CLI models get reasoning/tools flags. */
@@ -144,9 +156,13 @@ export function applyActiveModelStatusToStore(
     );
   }
 
+  const previousGgufVariant =
+    options.previousGgufVariant !== undefined
+      ? options.previousGgufVariant
+      : store.activeGgufVariant;
   const hydratingExistingModel =
     previousCheckpoint !== checkpointId ||
-    store.activeGgufVariant !== (status.gguf_variant ?? null);
+    previousGgufVariant !== (status.gguf_variant ?? null);
   const supportsReasoning = status.supports_reasoning ?? false;
   const reasoningAlwaysOn = status.reasoning_always_on ?? false;
   const reasoningStyle = status.reasoning_style ?? "enable_thinking";
@@ -185,6 +201,68 @@ export function applyActiveModelStatusToStore(
   // While a load is in flight, performLoad owns the load params. Seeding them
   // from a stale poll here would clobber the values the load dialog just set.
   const seedLoadParams = !prevState.modelLoading;
+  // A Manual + Auto-layers load sent its positive context pin as max_seq_length,
+  // and status only exposes the RESOLVED context; re-seed the pin from the
+  // requested value (parity with the load paths' keepCustomCtx). Baselines
+  // unconditionally: anything but an applicable pin is null, so a previous
+  // model's pin can't survive a model change underneath and reload at the old length.
+  const gpuPin = status.is_gguf
+    ? resolveManualAutoCtxPin(
+        status.gpu_memory_mode ?? "auto",
+        status.gpu_layers ?? -1,
+        status.requested_context_length ?? null,
+      )
+    : null;
+  const incomingGpuMode = status.is_gguf
+    ? (status.gpu_memory_mode ?? "auto")
+    : null;
+  const incomingGpuLayers =
+    incomingGpuMode === "manual" ? (status.gpu_layers ?? null) : null;
+  const incomingNCpuMoe =
+    incomingGpuMode === "manual" ? (status.n_cpu_moe ?? null) : null;
+  const incomingSplit =
+    incomingGpuMode === "manual" ? (status.tensor_split ?? null) : null;
+  const incomingGpuIds = status.is_gguf
+    ? (status.requested_gpu_ids ?? status.gpu_ids ?? null)
+    : null;
+  const gpuStatusChanged =
+    prevState.loadedGpuMemoryMode !== incomingGpuMode ||
+    prevState.loadedGpuLayers !== incomingGpuLayers ||
+    prevState.loadedNCpuMoe !== incomingNCpuMoe ||
+    !sameArray(prevState.loadedSplitRatio, incomingSplit) ||
+    !sameArray(prevState.loadedGpuIds, incomingGpuIds) ||
+    prevState.loadedCustomContextLength !== gpuPin;
+  const gpuMemoryEditsPending =
+    (prevState.loadedGpuMemoryMode !== null &&
+      prevState.gpuMemoryMode !== prevState.loadedGpuMemoryMode) ||
+    (prevState.loadedGpuMemoryMode === "manual" &&
+      (prevState.gpuLayers !== prevState.loadedGpuLayers ||
+        prevState.nCpuMoe !== prevState.loadedNCpuMoe ||
+        !sameArray(prevState.splitRatio, prevState.loadedSplitRatio))) ||
+    prevState.customContextLength !== prevState.loadedCustomContextLength;
+  const gpuIdsEditPending = !sameArray(
+    prevState.selectedGpuIds,
+    prevState.loadedGpuIds,
+  );
+  const incomingGpuFields = loadedGpuMemoryFields(status);
+  // A same-model reload from another client advances every loaded baseline.
+  // Preserve each editable group only when this tab has an unapplied change.
+  const preserveSameModelEdits = gpuStatusChanged && !hydratingExistingModel;
+  const gpuStatusFields = {
+    ...incomingGpuFields,
+    customContextLength: gpuPin,
+    loadedCustomContextLength: gpuPin,
+    ...(preserveSameModelEdits &&
+      gpuMemoryEditsPending && {
+        gpuMemoryMode: prevState.gpuMemoryMode,
+        gpuLayers: prevState.gpuLayers,
+        nCpuMoe: prevState.nCpuMoe,
+        splitRatio: prevState.splitRatio,
+        customContextLength: prevState.customContextLength,
+      }),
+    ...(preserveSameModelEdits &&
+      gpuIdsEditPending && { selectedGpuIds: prevState.selectedGpuIds }),
+  };
 
   useChatRuntimeStore.setState({
     supportsReasoning,
@@ -204,41 +282,54 @@ export function applyActiveModelStatusToStore(
     ggufContextLength: currentGgufContextLength,
     ggufMaxContextLength,
     ggufNativeContextLength,
-    // A non-GGUF status must also drop a stale native-path token: without this the
-    // isGguf OR (activeGgufVariant || activeNativePathToken || ggufContextLength)
-    // stays true after switching from a native GGUF to a transformers model, so a
-    // Codex-only detection would auto-select for a model its preflight rejects. A real
-    // GGUF load reports is_gguf: true, so its token is preserved (the load path owns it).
-    ...(status.is_gguf ? {} : { activeNativePathToken: null }),
+    ...(status.is_gguf
+      ? {}
+      : { activeNativePathToken: null, activeNativePathExpiresAtMs: null }),
     modelRequiresTrustRemoteCode: status.requires_trust_remote_code ?? false,
     defaultChatTemplate: nextDefaultChatTemplate,
     loadedIsMultimodal: isMultimodalResponse(status),
     loadedIsDiffusion: status.is_diffusion ?? false,
     specFallbackReason: status.spec_fallback_reason ?? null,
+    // The spec / KV seeds share the GPU-fields reseed mechanism below: a
+    // non-GGUF status leaves their loaded baselines null, so the "unseeded"
+    // guard re-fires every refresh -- hold them too while a staged pick's
+    // settings are being edited, or the refresh resets the staged edit.
+    // hydratingExistingModel reopens every load-param seed: when the active
+    // model changed underneath this tab (auto-switch, another client), the
+    // old model's baselines are stale and must adopt the new status.
     ...(seedLoadParams &&
-      prevState.loadedSpeculativeType === null && {
+      (prevState.loadedSpeculativeType === null || hydratingExistingModel) && {
         speculativeType: currentSpecType,
         loadedSpeculativeType: currentSpecType,
       }),
     ...(seedLoadParams &&
       status.spec_draft_n_max !== undefined &&
-      prevState.loadedSpecDraftNMax === null &&
-      prevState.specDraftNMax === null && {
+      (hydratingExistingModel ||
+        (prevState.loadedSpecDraftNMax === null &&
+          prevState.specDraftNMax === null)) && {
         specDraftNMax: status.spec_draft_n_max ?? null,
         loadedSpecDraftNMax: status.spec_draft_n_max ?? null,
       }),
     ...(seedLoadParams &&
       status.cache_type_kv !== undefined &&
-      prevState.loadedKvCacheDtype === null && {
+      (prevState.loadedKvCacheDtype === null || hydratingExistingModel) && {
         kvCacheDtype: status.cache_type_kv,
         loadedKvCacheDtype: status.cache_type_kv,
       }),
     ...(seedLoadParams &&
       status.tensor_parallel !== undefined &&
-      prevState.loadedTensorParallel === null && {
+      (prevState.loadedTensorParallel === null || hydratingExistingModel) && {
         tensorParallel: status.tensor_parallel,
         loadedTensorParallel: status.tensor_parallel,
       }),
+    // Re-seed on first hydration, model/variant changes, or a same-model backend
+    // placement change. gpuStatusFields preserves dirty local edits in the last
+    // case while advancing their loaded baselines.
+    ...(seedLoadParams &&
+      (prevState.loadedGpuMemoryMode === null ||
+        hydratingExistingModel ||
+        gpuStatusChanged) &&
+      gpuStatusFields),
     ...(status.chat_template_override !== undefined &&
       prevState.loadedChatTemplateOverride === null &&
       prevState.chatTemplateOverride === null && {
@@ -298,7 +389,11 @@ export async function tryAdoptServerActiveModel(): Promise<boolean> {
   if (previousCheckpoint) {
     return true;
   }
+  const previousGgufVariant = useChatRuntimeStore.getState().activeGgufVariant;
   store.setCheckpoint(checkpointId, status.gguf_variant);
-  applyActiveModelStatusToStore(status, { previousCheckpoint });
+  applyActiveModelStatusToStore(status, {
+    previousCheckpoint,
+    previousGgufVariant,
+  });
   return true;
 }
diff --git a/studio/frontend/src/features/chat/lib/friendly-names.ts b/studio/frontend/src/features/chat/lib/friendly-names.ts
index 79744b3181..bc9c77b12d 100644
--- a/studio/frontend/src/features/chat/lib/friendly-names.ts
+++ b/studio/frontend/src/features/chat/lib/friendly-names.ts
@@ -5,7 +5,7 @@
  * Friendly default names for auto-created OpenAI shell containers, used by the
  * chat-adapter's lazy-create path (Code pill on, no thread container, non-default
  * TTL). Goal: a memorable label like "otter" instead of "chat-abc12345"; users
- * can still rename via the Studio alias map.
+ * can still rename via the Unsloth alias map.
  *
  * The list is curated to be unambiguous, non-offensive nouns from natural
  * categories (animals, plants, geography, materials, weather), avoid
diff --git a/studio/frontend/src/features/chat/permission-mode-select.tsx b/studio/frontend/src/features/chat/permission-mode-select.tsx
index 4277c1bfcf..2fafeab7d6 100644
--- a/studio/frontend/src/features/chat/permission-mode-select.tsx
+++ b/studio/frontend/src/features/chat/permission-mode-select.tsx
@@ -1,14 +1,8 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import {
-  ChevronDown,
-  CircleAlert,
-  CircleOff,
-  Hand,
-  ShieldCheck,
-  XIcon,
-} from "lucide-react";
+import { ChevronDown, CircleAlert, Hand, ShieldCheck } from "lucide-react";
+import type { ComponentType } from "react";
 import { useState } from "react";
 
 import {
@@ -30,6 +24,7 @@ import {
   DropdownMenuTrigger,
 } from "@/components/ui/dropdown-menu";
 import { ChevronDownStandardIcon } from "@/lib/chevron-icons";
+import { SparklesGlyph } from "@/lib/sparkles-icon";
 import { Tick02Icon } from "@/lib/tick-icon";
 import { cn } from "@/lib/utils";
 import { HugeiconsIcon } from "@hugeicons/react";
@@ -39,15 +34,14 @@ import {
 } from "./stores/chat-runtime-store";
 
 /**
- * Permission levels for the Bypass permissions dropdowns (General settings,
- * chat settings sheet, composer "+" menu). Off sits last as the toggle that
- * turns the feature off entirely.
+ * Permission levels for tool calls. Full access stays last because it disables
+ * both approval prompts and the code sandbox.
  */
 export const PERMISSION_MODE_OPTIONS: readonly {
   value: PermissionMode;
   label: string;
   description: string;
-  icon: typeof Hand;
+  icon: ComponentType<{ className?: string; strokeWidth?: number }>;
 }[] = [
   {
     value: "ask",
@@ -61,6 +55,12 @@ export const PERMISSION_MODE_OPTIONS: readonly {
     description: "Only ask for actions detected as potentially unsafe",
     icon: ShieldCheck,
   },
+  {
+    value: "off",
+    label: "Run automatically",
+    description: "Run tool calls without approval prompts inside the sandbox",
+    icon: SparklesGlyph,
+  },
   {
     value: "full",
     label: "Full access",
@@ -68,14 +68,11 @@ export const PERMISSION_MODE_OPTIONS: readonly {
       "Unrestricted: no approval prompts and the code sandbox is disabled",
     icon: CircleAlert,
   },
-  {
-    value: "off",
-    label: "Off",
-    description: "Turn off bypass permissions",
-    icon: CircleOff,
-  },
 ] as const;
 
+export const FULL_ACCESS_WARNING =
+  "Full access lets tool calls run without approval prompts or the code sandbox. They can modify or delete files, run commands, and make network requests. Enable it only when you trust the current task.";
+
 export function permissionModeOption(mode: PermissionMode) {
   return (
     PERMISSION_MODE_OPTIONS.find((option) => option.value === mode) ??
@@ -100,10 +97,10 @@ export function PermissionModeMenuItems({
         <DropdownMenuItem
           key={option.value}
           onSelect={() => {
-            // Reselecting the active level toggles the feature off.
             if (option.value === permissionMode) {
-              setPermissionMode("off");
-            } else if (option.value === "full") {
+              return;
+            }
+            if (option.value === "full") {
               onRequestFullAccess();
             } else {
               setPermissionMode(option.value);
@@ -119,7 +116,7 @@ export function PermissionModeMenuItems({
         >
           <option.icon className="mt-0.5 size-4 shrink-0" strokeWidth={2} />
           <span className="flex min-w-0 flex-1 flex-col gap-0.5">
-            <span className="text-[13px] leading-tight">{option.label}</span>
+            <span className="text-ui-13 leading-tight">{option.label}</span>
             <span className="text-xs font-normal leading-snug text-muted-foreground">
               {option.description}
             </span>
@@ -154,9 +151,7 @@ export function FullAccessConfirmDialog({
         <AlertDialogHeader>
           <AlertDialogTitle>Enable Full access?</AlertDialogTitle>
           <AlertDialogDescription>
-            Full access (Bypass permissions) is dangerous since the AI model
-            might delete, corrupt your machine, and or cause real world damage
-            to you or the world - only accept if you are certain
+            {FULL_ACCESS_WARNING}
           </AlertDialogDescription>
         </AlertDialogHeader>
         <AlertDialogFooter>
@@ -260,15 +255,10 @@ export function PermissionModeComposerPill({
   const setBypassConfirmOpen = useChatRuntimeStore(
     (s) => s.setBypassConfirmOpen,
   );
-  const setPermissionMode = useChatRuntimeStore((s) => s.setPermissionMode);
   const active = permissionModeOption(permissionMode);
   const ActiveIcon = active.icon;
   const fullAccess = permissionMode === "full";
 
-  // Off means the feature is off: no pill (re-enable via the "+" menu or
-  // settings, like the pre-levels bypass badge).
-  if (permissionMode === "off") return null;
-
   return (
     <DropdownMenu>
       <DropdownMenuTrigger asChild={true}>
@@ -281,32 +271,8 @@ export function PermissionModeComposerPill({
           aria-label="Permission level for tool calls"
           title={`${active.label}: ${active.description}`}
         >
-          {/* The icon doubles as an off switch (mirrors the MCP pill): hover
-              swaps it to an X; clicking it turns bypass permissions Off (no
-              prompts, sandbox on) without opening the menu. In compact
-              icon-only mode the glyph is the whole button, so clicks fall
-              through and open the menu instead. */}
-          <span
-            role="button"
-            aria-label="Turn off bypass permissions"
-            tabIndex={-1}
-            onPointerDown={(e) => {
-              if (e.currentTarget.closest('[data-pill-compact="true"]')) {
-                return;
-              }
-              e.stopPropagation();
-            }}
-            onClick={(e) => {
-              if (e.currentTarget.closest('[data-pill-compact="true"]')) {
-                return;
-              }
-              e.stopPropagation();
-              setPermissionMode("off");
-            }}
-            className="composer-pill-glyph cursor-pointer"
-          >
+          <span className="composer-pill-glyph">
             <ActiveIcon className="size-[15px]" strokeWidth={2} />
-            <XIcon className="composer-pill-x" />
           </span>
           <span>{active.label}</span>
           <HugeiconsIcon
diff --git a/studio/frontend/src/features/chat/presets/preset-load-config.ts b/studio/frontend/src/features/chat/presets/preset-load-config.ts
new file mode 100644
index 0000000000..1083655cf2
--- /dev/null
+++ b/studio/frontend/src/features/chat/presets/preset-load-config.ts
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import {
+  applyPerModelConfigToRuntime,
+  currentRuntimePerModelConfig,
+  perModelConfigsEqual,
+} from "@/features/model-picker";
+import {
+  CONTEXT_LENGTH_MIN,
+  DEFAULT_PER_MODEL_CONFIG,
+  DEFAULT_MAX_SEQ_LENGTH,
+  KV_CACHE_DTYPES,
+  MTP_SPECULATIVE_TYPES,
+  SPECULATIVE_TYPES,
+  normalizeMaxSeqLength,
+  type PerModelConfig,
+} from "@/features/model-picker/model-config/per-model-config";
+import {
+  GPU_LAYERS_AUTO,
+  useChatRuntimeStore,
+  normalizeSpeculativeType,
+} from "../stores/chat-runtime-store";
+
+/** Load/runtime knobs saved in a chat preset (excludes per-model-only blobs). */
+export type PresetLoadConfig = Pick<
+  PerModelConfig,
+  | "customContextLength"
+  | "maxSeqLength"
+  | "kvCacheDtype"
+  | "speculativeType"
+  | "specDraftNMax"
+  | "tensorParallel"
+  | "gpuMemoryMode"
+  | "gpuLayers"
+  | "nCpuMoe"
+>;
+
+const VALID_KV_CACHE_DTYPES = new Set<string>(KV_CACHE_DTYPES);
+const VALID_SPECULATIVE_TYPES = new Set<string>(SPECULATIVE_TYPES);
+
+export const EMPTY_PRESET_LOAD_CONFIG: PresetLoadConfig = {
+  customContextLength: null,
+  maxSeqLength: null,
+  kvCacheDtype: null,
+  speculativeType: null,
+  specDraftNMax: null,
+  tensorParallel: false,
+};
+
+function toComparablePerModelConfig(
+  config: PresetLoadConfig,
+): PerModelConfig {
+  return {
+    ...DEFAULT_PER_MODEL_CONFIG,
+    ...config,
+    chatTemplateOverride: null,
+    selectedGpuIds: null,
+  };
+}
+
+export function normalizePresetLoadConfig(
+  raw: unknown,
+): PresetLoadConfig | undefined {
+  if (raw == null || typeof raw !== "object" || Array.isArray(raw)) {
+    return undefined;
+  }
+  const partial = raw as Record<string, unknown>;
+  const rawSpecType =
+    typeof partial.speculativeType === "string"
+      ? normalizeSpeculativeType(partial.speculativeType)
+      : null;
+  const speculativeType = rawSpecType ?? null;
+  const specDraftNMax =
+    speculativeType != null &&
+    MTP_SPECULATIVE_TYPES.has(speculativeType) &&
+    typeof partial.specDraftNMax === "number" &&
+    Number.isFinite(partial.specDraftNMax)
+      ? Math.max(1, Math.min(16, Math.round(partial.specDraftNMax)))
+      : null;
+  const gpuMemoryMode =
+    partial.gpuMemoryMode === "manual" ? ("manual" as const) : undefined;
+  let gpuLayers: number | undefined;
+  if (typeof partial.gpuLayers === "number" && Number.isFinite(partial.gpuLayers)) {
+    gpuLayers = partial.gpuLayers < 0 ? GPU_LAYERS_AUTO : Math.floor(partial.gpuLayers);
+  }
+  let nCpuMoe: number | undefined;
+  if (typeof partial.nCpuMoe === "number" && Number.isFinite(partial.nCpuMoe)) {
+    nCpuMoe = Math.max(0, Math.floor(partial.nCpuMoe));
+  }
+
+  const normalized: PresetLoadConfig = {
+    customContextLength:
+      typeof partial.customContextLength === "number" &&
+      Number.isFinite(partial.customContextLength) &&
+      partial.customContextLength > 0
+        ? Math.max(CONTEXT_LENGTH_MIN, Math.floor(partial.customContextLength))
+        : null,
+    maxSeqLength: normalizeMaxSeqLength(partial.maxSeqLength as number | null),
+    kvCacheDtype:
+      typeof partial.kvCacheDtype === "string" &&
+      VALID_KV_CACHE_DTYPES.has(partial.kvCacheDtype)
+        ? partial.kvCacheDtype
+        : null,
+    speculativeType:
+      speculativeType && VALID_SPECULATIVE_TYPES.has(speculativeType)
+        ? speculativeType
+        : null,
+    specDraftNMax,
+    tensorParallel:
+      typeof partial.tensorParallel === "boolean"
+        ? partial.tensorParallel
+        : false,
+    ...(gpuMemoryMode ? { gpuMemoryMode } : {}),
+    ...(gpuLayers !== undefined ? { gpuLayers } : {}),
+    ...(nCpuMoe !== undefined ? { nCpuMoe } : {}),
+  };
+
+  return hasPresetLoadConfig(normalized) ? normalized : undefined;
+}
+
+export function hasPresetLoadConfig(
+  config?: PresetLoadConfig | null,
+): boolean {
+  return !isSamePresetLoadConfig(config, EMPTY_PRESET_LOAD_CONFIG);
+}
+
+export function isSamePresetLoadConfig(
+  a?: PresetLoadConfig | null,
+  b?: PresetLoadConfig | null,
+): boolean {
+  return perModelConfigsEqual(
+    toComparablePerModelConfig({ ...EMPTY_PRESET_LOAD_CONFIG, ...a }),
+    toComparablePerModelConfig({ ...EMPTY_PRESET_LOAD_CONFIG, ...b }),
+  );
+}
+
+export function capturePresetLoadConfig(): PresetLoadConfig | undefined {
+  const snapshot = currentRuntimePerModelConfig({ includeMaxSeqLength: true });
+  const store = useChatRuntimeStore.getState();
+  const isGguf =
+    store.activeGgufVariant != null ||
+    store.ggufContextLength != null ||
+    (store.params.checkpoint?.toLowerCase().endsWith(".gguf") ?? false);
+  const effectiveContextLength =
+    snapshot.customContextLength ??
+    (isGguf ? store.ggufContextLength : null);
+  const captured: PresetLoadConfig = {
+    customContextLength: effectiveContextLength ?? null,
+    maxSeqLength: normalizeMaxSeqLength(snapshot.maxSeqLength),
+    kvCacheDtype: snapshot.kvCacheDtype ?? null,
+    speculativeType: normalizeSpeculativeType(snapshot.speculativeType),
+    specDraftNMax: snapshot.specDraftNMax ?? null,
+    tensorParallel: snapshot.tensorParallel ?? false,
+    ...(snapshot.gpuMemoryMode === "manual"
+      ? { gpuMemoryMode: "manual" as const }
+      : {}),
+    ...(snapshot.gpuLayers != null && snapshot.gpuLayers >= 0
+      ? { gpuLayers: snapshot.gpuLayers }
+      : snapshot.gpuMemoryMode === "manual"
+        ? { gpuLayers: GPU_LAYERS_AUTO }
+        : {}),
+    ...(snapshot.nCpuMoe != null && snapshot.nCpuMoe > 0
+      ? { nCpuMoe: snapshot.nCpuMoe }
+      : {}),
+  };
+  return hasPresetLoadConfig(coalesceDefaultLoadKnobs(captured))
+    ? coalesceDefaultLoadKnobs(captured)
+    : undefined;
+}
+
+function coalesceDefaultLoadKnobs(
+  captured: PresetLoadConfig,
+): PresetLoadConfig {
+  const result: PresetLoadConfig = { ...captured };
+  if (normalizeMaxSeqLength(result.maxSeqLength) === DEFAULT_MAX_SEQ_LENGTH) {
+    result.maxSeqLength = null;
+  }
+  const speculativeType = normalizeSpeculativeType(result.speculativeType);
+  if (speculativeType == null || speculativeType === "auto") {
+    result.speculativeType = null;
+  }
+  if (
+    (result.gpuLayers == null || result.gpuLayers < 0) &&
+    result.gpuMemoryMode !== "manual"
+  ) {
+    delete result.gpuLayers;
+  }
+  if ((result.nCpuMoe ?? 0) === 0) {
+    delete result.nCpuMoe;
+  }
+  return result;
+}
+
+export function applyPresetLoadConfig(
+  config?: PresetLoadConfig | null,
+): void {
+  if (config == null) {
+    return;
+  }
+  const store = useChatRuntimeStore.getState();
+  applyPerModelConfigToRuntime({
+    ...DEFAULT_PER_MODEL_CONFIG,
+    maxSeqLength: normalizeMaxSeqLength(config.maxSeqLength) ?? DEFAULT_MAX_SEQ_LENGTH,
+    customContextLength: config.customContextLength ?? null,
+    kvCacheDtype: config.kvCacheDtype ?? null,
+    speculativeType: config.speculativeType ?? null,
+    specDraftNMax: config.specDraftNMax ?? null,
+    tensorParallel: config.tensorParallel ?? false,
+    chatTemplateOverride: null,
+    gpuMemoryMode: config.gpuMemoryMode,
+    gpuLayers: config.gpuLayers,
+    nCpuMoe: config.nCpuMoe,
+    selectedGpuIds: store.selectedGpuIds,
+  });
+}
+
+export function formatPresetLoadConfigSummary(
+  config?: PresetLoadConfig | null,
+): string | null {
+  if (!config || !hasPresetLoadConfig(config)) {
+    return null;
+  }
+  const parts: string[] = [];
+  if (config.customContextLength != null) {
+    parts.push(`Ctx ${config.customContextLength.toLocaleString()}`);
+  }
+  if (config.kvCacheDtype) {
+    parts.push(`KV ${config.kvCacheDtype}`);
+  }
+  if (config.speculativeType && config.speculativeType !== "auto") {
+    parts.push(`Spec ${config.speculativeType}`);
+  }
+  if (config.gpuMemoryMode === "manual") {
+    parts.push("GPU manual");
+  }
+  if (config.gpuLayers != null && config.gpuLayers >= 0) {
+    parts.push(`${config.gpuLayers} layers`);
+  }
+  if (config.tensorParallel) {
+    parts.push("TP");
+  }
+  return parts.length > 0 ? parts.join(" · ") : null;
+}
diff --git a/studio/frontend/src/features/chat/presets/preset-policy.ts b/studio/frontend/src/features/chat/presets/preset-policy.ts
index f96ee91f1b..61c94707b4 100644
--- a/studio/frontend/src/features/chat/presets/preset-policy.ts
+++ b/studio/frontend/src/features/chat/presets/preset-policy.ts
@@ -5,12 +5,15 @@ import {
   DEFAULT_INFERENCE_PARAMS,
   type InferenceParams,
 } from "../types/runtime";
+import type { PresetLoadConfig } from "./preset-load-config";
 
 export const defaultInferenceParams = DEFAULT_INFERENCE_PARAMS;
 
 export interface Preset {
   name: string;
   params: InferenceParams;
+  /** Optional GGUF/load knobs captured with the preset. */
+  loadConfig?: PresetLoadConfig;
 }
 
 export type PresetOwnedParams = Pick<
@@ -85,6 +88,7 @@ export function normalizeCustomPresets(presets: Preset[]): Preset[] {
       return {
         name,
         params: preset.params,
+        ...(preset.loadConfig ? { loadConfig: preset.loadConfig } : {}),
       };
     })
     .filter((preset): preset is Preset => preset !== null);
@@ -339,3 +343,34 @@ export function resolveLoadMaxSeqLength({
   }
   return maxSeqLength;
 }
+
+/**
+ * Adjust a resolved max-seq-length for the GPU Memory mode. Under Manual + Auto
+ * layers (GGUF, gpuLayers < 0) llama.cpp's --fit owns context sizing, so send 0
+ * (the backend omits -c) unless the user pinned a length; every other case keeps
+ * the resolved fallback. Shared by every GGUF load path so they can't drift.
+ */
+export function resolveFitMaxSeqLength(
+  isGguf: boolean | null | undefined,
+  gpuMemoryMode: "auto" | "manual",
+  gpuLayers: number,
+  customContextLength: number | null,
+  fallback: number,
+): number {
+  if (!isGguf || gpuMemoryMode !== "manual" || gpuLayers >= 0) return fallback;
+  return customContextLength && customContextLength > 0 ? customContextLength : 0;
+}
+
+// A Manual + Auto-layers load sends its positive context pin as max_seq_length;
+// keep it across a status reseed/Apply so the model isn't reverted to auto-fit
+// sizing. Anything else (Auto mode, pinned layers, no pin) baselines to null.
+// The caller keeps its own isGguf/targetIsGguf guard inline.
+export function resolveManualAutoCtxPin(
+  gpuMemoryMode: "auto" | "manual",
+  gpuLayers: number,
+  customContextLength: number | null,
+): number | null {
+  return gpuMemoryMode === "manual" && gpuLayers < 0 && (customContextLength ?? 0) > 0
+    ? customContextLength
+    : null;
+}
diff --git a/studio/frontend/src/features/chat/projects-page.tsx b/studio/frontend/src/features/chat/projects-page.tsx
index 5e0b37895b..e20e517787 100644
--- a/studio/frontend/src/features/chat/projects-page.tsx
+++ b/studio/frontend/src/features/chat/projects-page.tsx
@@ -30,6 +30,8 @@ import {
   SelectTrigger,
   SelectValue,
 } from "@/components/ui/select";
+import { isTauri } from "@/lib/api-base";
+import { isDownloadCancelled, pickNativeChatImport } from "@/lib/native-files";
 import { toast } from "@/lib/toast";
 import {
   createChatProject,
@@ -37,6 +39,7 @@ import {
   renameChatProject,
   useChatProjects,
   useChatRuntimeStore,
+  usePinnedProjectsStore,
   type ProjectRecord,
 } from "@/features/chat";
 import {
@@ -45,13 +48,15 @@ import {
   Edit03Icon,
   Folder02Icon,
   FolderAddIcon,
+  PinIcon,
+  PinOffIcon,
   Search01Icon,
   Upload01Icon,
 } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
 import { MoreHorizontalIcon } from "lucide-react";
 import { useNavigate } from "@tanstack/react-router";
-import { useMemo, useRef, useState } from "react";
+import { useEffect, useMemo, useRef, useState } from "react";
 import {
   exportProjectConversations,
   exportBulkConversationsMerged,
@@ -66,21 +71,38 @@ import {
 
 type SortMode = "activity" | "name";
 
-function formatUpdatedAgo(ts: number): string {
-  const diff = Date.now() - ts;
-  if (!Number.isFinite(diff) || diff < 0) return "just now";
-  const s = Math.floor(diff / 1000);
-  if (s < 60) return "just now";
-  const m = Math.floor(s / 60);
-  if (m < 60) return `${m} minute${m === 1 ? "" : "s"} ago`;
-  const h = Math.floor(m / 60);
-  if (h < 24) return `${h} hour${h === 1 ? "" : "s"} ago`;
-  const d = Math.floor(h / 24);
-  if (d < 30) return `${d} day${d === 1 ? "" : "s"} ago`;
-  const mo = Math.floor(d / 30);
-  if (mo < 12) return `${mo} month${mo === 1 ? "" : "s"} ago`;
-  const y = Math.floor(mo / 12);
-  return `${y} year${y === 1 ? "" : "s"} ago`;
+// Reveal this many more projects each time the user scrolls near the bottom.
+const PROJECTS_PAGE_STEP = 12;
+// Visible count before the fit-to-height measurement runs.
+const PROJECTS_INITIAL_FALLBACK = 8;
+// Approx list row height in px, used to estimate how many rows fit the page.
+const PROJECTS_ROW_HEIGHT = 68;
+
+// Modified column, matching a file-list feel: Today / Yesterday / N days ago,
+// then a short date once it is over a week old.
+function formatModified(ts: number): string {
+  if (!Number.isFinite(ts)) return "";
+  const now = new Date();
+  const then = new Date(ts);
+  const startOfToday = new Date(
+    now.getFullYear(),
+    now.getMonth(),
+    now.getDate(),
+  ).getTime();
+  const startOfThen = new Date(
+    then.getFullYear(),
+    then.getMonth(),
+    then.getDate(),
+  ).getTime();
+  const dayDiff = Math.round((startOfToday - startOfThen) / 86_400_000);
+  if (dayDiff <= 0) return "Today";
+  if (dayDiff === 1) return "Yesterday";
+  if (dayDiff < 7) return `${dayDiff} days ago`;
+  return then.toLocaleDateString(undefined, {
+    month: "short",
+    day: "numeric",
+    year: then.getFullYear() === now.getFullYear() ? undefined : "numeric",
+  });
 }
 
 export function ProjectsPage() {
@@ -89,6 +111,17 @@ export function ProjectsPage() {
 
   const [query, setQuery] = useState("");
   const [sortMode, setSortMode] = useState<SortMode>("activity");
+  // Rows that fit the page height (measured), plus any revealed via Show more.
+  const [baseFit, setBaseFit] = useState(PROJECTS_INITIAL_FALLBACK);
+  const [extraCount, setExtraCount] = useState(0);
+  const listRef = useRef<HTMLDivElement>(null);
+  const sentinelRef = useRef<HTMLDivElement>(null);
+  const pinnedProjectIds = usePinnedProjectsStore((s) => s.pinnedIds);
+  const togglePinProject = usePinnedProjectsStore((s) => s.togglePin);
+  const pinnedProjectIdSet = useMemo(
+    () => new Set(pinnedProjectIds),
+    [pinnedProjectIds],
+  );
 
   const [creating, setCreating] = useState(false);
   const [nameDraft, setNameDraft] = useState("");
@@ -118,6 +151,40 @@ export function ProjectsPage() {
     }
   }
 
+
+  async function selectGlobalImportFile() {
+    if (!isTauri) {
+      globalImportRef.current?.click();
+      return;
+    }
+    try {
+      const selected = await pickNativeChatImport();
+      if (!selected) return;
+      setImportTargetId(projects[0]?.id ?? null);
+      setImportFile(new File([selected.content], selected.name));
+    } catch (error) {
+      toast.error("Import failed.", {
+        description: error instanceof Error ? error.message : String(error),
+      });
+    }
+  }
+
+  async function selectProjectImportFile(projectId: string) {
+    if (!isTauri) {
+      projectImportRefs.current.get(projectId)?.click();
+      return;
+    }
+    try {
+      const selected = await pickNativeChatImport();
+      if (!selected) return;
+      await handleImport(new File([selected.content], selected.name), projectId);
+    } catch (error) {
+      toast.error("Import failed.", {
+        description: error instanceof Error ? error.message : String(error),
+      });
+    }
+  }
+
   async function commitImport() {
     if (!importFile) return;
     const file = importFile;
@@ -126,7 +193,7 @@ export function ProjectsPage() {
     await handleImport(file, target);
   }
 
-  const visibleProjects = useMemo(() => {
+  const sortedProjects = useMemo(() => {
     const trimmed = query.trim().toLowerCase();
     const filtered = trimmed
       ? projects.filter((p) => p.name.toLowerCase().includes(trimmed))
@@ -138,6 +205,51 @@ export function ProjectsPage() {
     );
     return filtered;
   }, [projects, query, sortMode]);
+  // Default view shows as many rows as fit the page, then loads more as the
+  // user scrolls near the bottom. Search always spans every project.
+  const isSearching = query.trim() !== "";
+  const visibleCount = baseFit + extraCount;
+  const visibleProjects = isSearching
+    ? sortedProjects
+    : sortedProjects.slice(0, visibleCount);
+  const hasMore = !isSearching && sortedProjects.length > visibleCount;
+
+  // Estimate how many rows fit below the list's top so the first page fills the
+  // screen without loading everything up front.
+  useEffect(() => {
+    function measure() {
+      const el = listRef.current;
+      if (!el) return;
+      const top = el.getBoundingClientRect().top;
+      const reserve = 24; // bottom breathing room
+      const fits = Math.floor(
+        (window.innerHeight - top - reserve) / PROJECTS_ROW_HEIGHT,
+      );
+      setBaseFit(Math.max(PROJECTS_PAGE_STEP, fits));
+    }
+    measure();
+    window.addEventListener("resize", measure);
+    return () => window.removeEventListener("resize", measure);
+  }, [hasLoaded]);
+
+  // Infinite scroll: reveal another page-step whenever the sentinel near the
+  // list bottom scrolls into view.
+  useEffect(() => {
+    const el = sentinelRef.current;
+    if (!el || !hasMore) return;
+    const io = new IntersectionObserver(
+      (entries) => {
+        if (entries[0]?.isIntersecting) {
+          setExtraCount((n) => n + PROJECTS_PAGE_STEP);
+        }
+      },
+      { rootMargin: "300px" },
+    );
+    io.observe(el);
+    return () => io.disconnect();
+    // Re-observe after each load so it keeps filling while the sentinel stays
+    // in view (IntersectionObserver does not re-fire on a steady intersection).
+  }, [hasMore, visibleCount]);
 
   function openProject(projectId: string) {
     const runtime = useChatRuntimeStore.getState();
@@ -183,8 +295,10 @@ export function ProjectsPage() {
       const threads = await listStoredChatThreads({ projectId: project.id, includeArchived: false });
       const ids = [...new Set(threads.map((t) => t.id))];
       await exportProjectConversations(ids, fmt, project.name);
-    } catch {
-      toast.error("Export failed.");
+    } catch (error) {
+      if (!isDownloadCancelled(error)) {
+        toast.error("Export failed.");
+      }
     }
   }
 
@@ -215,8 +329,10 @@ export function ProjectsPage() {
       } else {
         await exportBulkConversationsSeparate(ids, fmt, basename);
       }
-    } catch {
-      toast.error("Export failed.");
+    } catch (error) {
+      if (!isDownloadCancelled(error)) {
+        toast.error("Export failed.");
+      }
     }
   }
 
@@ -234,7 +350,7 @@ export function ProjectsPage() {
   }
 
   return (
-    <main className="mx-auto w-full max-w-6xl px-6 py-10 font-heading sm:px-10">
+    <main className="mx-auto w-full max-w-5xl px-6 pb-10 pt-16 font-heading sm:px-10">
       {/* Global import file input */}
       <input
         ref={globalImportRef}
@@ -251,7 +367,7 @@ export function ProjectsPage() {
         }}
       />
       <div className="flex flex-wrap items-center justify-between gap-4">
-        <h1 className="text-[30px] font-semibold leading-[1.04] tracking-[-0.028em] text-foreground sm:text-[34px]">
+        <h1 className="text-ui-30 font-semibold leading-[1.04] tracking-[-0.028em] text-foreground sm:text-ui-34">
           Projects
         </h1>
         <div className="flex items-center gap-3">
@@ -294,7 +410,7 @@ export function ProjectsPage() {
               </Button>
             </DropdownMenuTrigger>
             <DropdownMenuContent align="end" className="w-56">
-              <DropdownMenuItem onSelect={() => globalImportRef.current?.click()}>
+              <DropdownMenuItem onSelect={() => void selectGlobalImportFile()}>
                 <HugeiconsIcon icon={Upload01Icon} strokeWidth={1.75} className="size-icon" />
                 Import chats…
               </DropdownMenuItem>
@@ -303,7 +419,7 @@ export function ProjectsPage() {
                 <DropdownMenuSubTrigger>Export All Projects</DropdownMenuSubTrigger>
                 <DropdownMenuSubContent className="w-52">
                   <DropdownMenuGroup>
-                    <DropdownMenuLabel className="pb-1 pt-2 text-[11px] font-medium">
+                    <DropdownMenuLabel className="pb-1 pt-2 text-ui-11 font-medium">
                       Combined
                     </DropdownMenuLabel>
                     {EXPORT_FORMATS_LIST.map(({ fmt, label }) => (
@@ -314,7 +430,7 @@ export function ProjectsPage() {
                   </DropdownMenuGroup>
                   <DropdownMenuSeparator />
                   <DropdownMenuGroup>
-                    <DropdownMenuLabel className="pb-1 pt-2 text-[11px] font-medium">
+                    <DropdownMenuLabel className="pb-1 pt-2 text-ui-11 font-medium">
                       Per chat
                     </DropdownMenuLabel>
                     {EXPORT_FORMATS_LIST.map(({ fmt, label }) => (
@@ -329,7 +445,7 @@ export function ProjectsPage() {
                 <DropdownMenuSubTrigger>Export Projects + Recents</DropdownMenuSubTrigger>
                 <DropdownMenuSubContent className="w-52">
                   <DropdownMenuGroup>
-                    <DropdownMenuLabel className="pb-1 pt-2 text-[11px] font-medium">
+                    <DropdownMenuLabel className="pb-1 pt-2 text-ui-11 font-medium">
                       Combined
                     </DropdownMenuLabel>
                     {EXPORT_FORMATS_LIST.map(({ fmt, label }) => (
@@ -340,7 +456,7 @@ export function ProjectsPage() {
                   </DropdownMenuGroup>
                   <DropdownMenuSeparator />
                   <DropdownMenuGroup>
-                    <DropdownMenuLabel className="pb-1 pt-2 text-[11px] font-medium">
+                    <DropdownMenuLabel className="pb-1 pt-2 text-ui-11 font-medium">
                       Per chat
                     </DropdownMenuLabel>
                     {EXPORT_FORMATS_LIST.map(({ fmt, label }) => (
@@ -365,16 +481,22 @@ export function ProjectsPage() {
       </div>
 
       {!hasLoaded ? (
-        <div className="mt-12 grid grid-cols-1 gap-5 sm:grid-cols-2 lg:grid-cols-3">
+        <div className="mt-16">
+          <div className="mb-1 flex items-center gap-3 px-5 pb-1 text-ui-13 font-medium text-muted-foreground">
+            <span className="flex-1">Name</span>
+            <span className="w-40 shrink-0">Modified</span>
+            <span className="w-8 shrink-0" />
+          </div>
           {Array.from({ length: 6 }).map((_, index) => (
             <div
               key={index}
-              className="min-h-[172px] rounded-[26px] bg-card p-6 shadow-[0_2px_12px_-4px_rgba(0,0,0,0.10)] dark:shadow-none"
+              className="flex items-center gap-3 rounded-xl px-5 py-4"
             >
-              <Skeleton className="size-10 rounded-[14px]" />
-              <Skeleton className="mt-4 h-5 w-2/3 rounded-[8px]" />
-              <Skeleton className="mt-2 h-4 w-4/5 rounded-[8px]" />
-              <Skeleton className="mt-8 h-3 w-24 rounded-[8px]" />
+              <Skeleton className="mr-1 size-9 shrink-0 rounded-[10px]" />
+              <Skeleton className="h-4 w-40 rounded-[8px]" />
+              <span className="flex-1" />
+              <Skeleton className="h-4 w-16 rounded-[8px]" />
+              <span className="w-8 shrink-0" />
             </div>
           ))}
         </div>
@@ -400,9 +522,20 @@ export function ProjectsPage() {
           )}
         </div>
       ) : (
-        <div className="mt-12 grid grid-cols-1 gap-5 sm:grid-cols-2 lg:grid-cols-3">
-          {visibleProjects.map((project) => (
-            <div key={`wrap-${project.id}`} className="contents">
+        <>
+        <div className="mt-16">
+          {/* Column header. Name starts at the folder icon's left edge; the
+              right-anchored columns keep Modified over its values. */}
+          <div className="mb-1 flex items-center gap-3 px-5 pb-1 text-ui-13 font-medium text-muted-foreground">
+            <span className="flex-1">Name</span>
+            <span className="w-40 shrink-0">Modified</span>
+            <span className="w-8 shrink-0" />
+          </div>
+          <div ref={listRef}>
+          {visibleProjects.map((project) => {
+            const pinned = pinnedProjectIdSet.has(project.id);
+            return (
+            <div key={`wrap-${project.id}`}>
             <input
               key={`import-${project.id}`}
               type="file"
@@ -429,23 +562,37 @@ export function ProjectsPage() {
                   openProject(project.id);
                 }
               }}
-              className="group/project-card relative flex min-h-[172px] cursor-pointer flex-col rounded-[26px] bg-card p-6 text-left shadow-[0_2px_12px_-4px_rgba(0,0,0,0.10)] transition-colors duration-150 hover:bg-[#f2f2f2] dark:shadow-none dark:hover:bg-accent/30 focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
+              className="group/project-row relative flex cursor-pointer items-center gap-3 rounded-xl px-5 py-4 text-left transition-colors duration-150 hover:bg-muted/70 dark:hover:bg-white/[0.055] focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
             >
-              <div className="flex items-start justify-between gap-2">
-                <span className="flex size-10 shrink-0 items-center justify-center rounded-[14px] bg-muted text-foreground/70 transition-colors group-hover/project-card:bg-primary/10 group-hover/project-card:text-primary">
-                  <HugeiconsIcon
-                    icon={Folder02Icon}
-                    strokeWidth={1.75}
-                    className="size-5"
-                  />
-                </span>
+              <span className="mr-1 flex size-9 shrink-0 items-center justify-center rounded-[10px] bg-muted text-foreground/70 transition-colors group-hover/project-row:bg-primary/10 group-hover/project-row:text-primary">
+                <HugeiconsIcon
+                  icon={Folder02Icon}
+                  strokeWidth={1.75}
+                  className="size-5"
+                />
+              </span>
+              <span className="min-w-0 flex-1 truncate text-ui-15 font-semibold text-foreground">
+                {project.name}
+              </span>
+              <span className="w-40 shrink-0 text-sm text-muted-foreground">
+                {formatModified(project.updatedAt)}
+              </span>
+              <div className="relative flex w-8 shrink-0 items-center justify-end">
+                {/* Pin fades out and the kebab fades in on hover, focus, or
+                    menu open. Absolute + opacity gating keeps them from
+                    overlapping while leaving the button keyboard-focusable. */}
+                {pinned && (
+                  <span className="text-muted-foreground transition-opacity group-hover/project-row:opacity-0 group-focus-within/project-row:opacity-0 group-has-[[data-state=open]]/project-row:opacity-0">
+                    <HugeiconsIcon icon={PinIcon} strokeWidth={1.75} className="size-4" />
+                  </span>
+                )}
                 <DropdownMenu>
                   <DropdownMenuTrigger asChild>
                     <button
                       type="button"
                       onClick={(e) => e.stopPropagation()}
                       aria-label="Project options"
-                      className="-mr-1 -mt-1 inline-flex size-7 shrink-0 items-center justify-center rounded-full text-muted-foreground opacity-0 transition-opacity hover:bg-black/5 hover:text-foreground dark:hover:bg-white/10 focus-visible:opacity-100 group-hover/project-card:opacity-100 data-[state=open]:bg-black/5 data-[state=open]:opacity-100 dark:data-[state=open]:bg-white/10"
+                      className="absolute right-0 flex size-7 shrink-0 items-center justify-center rounded-full text-muted-foreground opacity-0 transition hover:bg-black/5 hover:text-foreground focus-visible:opacity-100 group-hover/project-row:opacity-100 data-[state=open]:bg-black/5 data-[state=open]:opacity-100 dark:hover:bg-white/10 dark:data-[state=open]:bg-white/10"
                     >
                       <MoreHorizontalIcon strokeWidth={1.75} className="size-icon" />
                     </button>
@@ -458,6 +605,16 @@ export function ProjectsPage() {
                     onKeyDown={(e) => e.stopPropagation()}
                     className="app-user-menu menu-soft-surface menu-flat-destructive ring-0 w-44 py-2 font-heading rounded-[14px] border-0"
                   >
+                    <DropdownMenuItem
+                      onSelect={() => togglePinProject(project.id)}
+                    >
+                      <HugeiconsIcon
+                        icon={pinned ? PinOffIcon : PinIcon}
+                        strokeWidth={1.75}
+                        className="size-icon"
+                      />
+                      <span>{pinned ? "Unpin project" : "Pin project"}</span>
+                    </DropdownMenuItem>
                     <DropdownMenuItem
                       onSelect={() => {
                         setRenameDraft(project.name);
@@ -470,7 +627,7 @@ export function ProjectsPage() {
                     <DropdownMenuItem
                       onSelect={(e) => {
                         e.stopPropagation();
-                        projectImportRefs.current.get(project.id)?.click();
+                        void selectProjectImportFile(project.id);
                       }}
                     >
                       <HugeiconsIcon icon={Upload01Icon} strokeWidth={1.75} className="size-icon" />
@@ -506,21 +663,15 @@ export function ProjectsPage() {
                   </DropdownMenuContent>
                 </DropdownMenu>
               </div>
-              <h2 className="mt-4 truncate text-[16px] font-semibold text-foreground">
-                {project.name}
-              </h2>
-              {project.instructions ? (
-                <p className="mt-1.5 line-clamp-2 text-sm leading-relaxed text-muted-foreground">
-                  {project.instructions}
-                </p>
-              ) : null}
-              <span className="mt-auto pt-4 text-xs text-muted-foreground/80">
-                Updated {formatUpdatedAgo(project.updatedAt)}
-              </span>
             </div>
             </div>
-          ))}
+            );
+          })}
+          {/* Loads the next page-step when scrolled into view. */}
+          {hasMore && <div ref={sentinelRef} className="h-px w-full" />}
+          </div>
         </div>
+        </>
       )}
 
       {/* Create project */}
@@ -644,8 +795,8 @@ export function ProjectsPage() {
             <DialogTitle>Delete project</DialogTitle>
           </DialogHeader>
           <p className="text-sm text-muted-foreground">
-            Are you sure you want to delete <em>{deleting?.name}</em>? Chats in this
-            project will be moved back to Recents.
+            Are you sure you want to delete <em>{deleting?.name}</em>? Its chats will
+            be permanently deleted.
           </p>
           <DialogFooter className="flex-wrap gap-2 sm:justify-end">
             <Button type="button" variant="ghost" onClick={() => setDeleting(null)}>
diff --git a/studio/frontend/src/features/chat/prompt-storage/prompt-storage-dialog.tsx b/studio/frontend/src/features/chat/prompt-storage/prompt-storage-dialog.tsx
index 33fc6286c0..7295605553 100644
--- a/studio/frontend/src/features/chat/prompt-storage/prompt-storage-dialog.tsx
+++ b/studio/frontend/src/features/chat/prompt-storage/prompt-storage-dialog.tsx
@@ -10,6 +10,8 @@ import {
   DialogHeader,
   DialogTitle,
 } from "@/components/ui/dialog";
+import { downloadFile, isDownloadCancelled } from "@/lib/native-files";
+
 import { cn } from "@/lib/utils";
 import { Search01Icon } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
@@ -70,77 +72,73 @@ function sanitizeFilename(name: string): string {
   return name.replace(/[\\/:*?"<>|]/g, "_").slice(0, 80) || "export";
 }
 
-function downloadBlob(content: string | Blob, filename: string, mimeType: string): void {
-  const blob = content instanceof Blob ? content : new Blob([content], { type: mimeType });
-  const url = URL.createObjectURL(blob);
-  const a = document.createElement("a");
-  a.href = url;
-  a.download = filename;
-  document.body.appendChild(a);
-  a.click();
-  document.body.removeChild(a);
-  URL.revokeObjectURL(url);
+async function downloadBlob(
+  content: string | Blob | Uint8Array,
+  filename: string,
+  mimeType: string,
+): Promise<void> {
+  return downloadFile(content, filename, mimeType);
 }
 
 function csvEscape(val: string): string {
   return `"${val.replace(/"/g, '""')}"`;
 }
 
-function exportPromptJsonl(entry: PromptEntry): void {
-  downloadBlob(
+function exportPromptJsonl(entry: PromptEntry): Promise<void> {
+  return downloadBlob(
     JSON.stringify({ name: entry.name, text: entry.text }),
     `${sanitizeFilename(entry.name)}.jsonl`,
     "application/x-ndjson",
   );
 }
 
-function exportPromptCsv(entry: PromptEntry): void {
-  downloadBlob(
+function exportPromptCsv(entry: PromptEntry): Promise<void> {
+  return downloadBlob(
     `name,text\n${csvEscape(entry.name)},${csvEscape(entry.text)}`,
     `${sanitizeFilename(entry.name)}.csv`,
     "text/csv",
   );
 }
 
-function exportAllPromptsJsonl(entries: PromptEntry[]): void {
+function exportAllPromptsJsonl(entries: PromptEntry[]): Promise<void> {
   const lines = entries.map((e) => JSON.stringify({ name: e.name, text: e.text })).join("\n");
-  downloadBlob(lines, "prompts.jsonl", "application/x-ndjson");
+  return downloadBlob(lines, "prompts.jsonl", "application/x-ndjson");
 }
 
-function exportAllPromptsCsv(entries: PromptEntry[]): void {
+function exportAllPromptsCsv(entries: PromptEntry[]): Promise<void> {
   const rows = entries.map((e) => `${csvEscape(e.name)},${csvEscape(e.text)}`).join("\n");
-  downloadBlob(`name,text\n${rows}`, "prompts.csv", "text/csv");
+  return downloadBlob(`name,text\n${rows}`, "prompts.csv", "text/csv");
 }
 
-function exportListJsonl(entry: PromptListEntry): void {
-  downloadBlob(
+function exportListJsonl(entry: PromptListEntry): Promise<void> {
+  return downloadBlob(
     JSON.stringify({ name: entry.name, items: entry.items }),
     `${sanitizeFilename(entry.name)}.jsonl`,
     "application/x-ndjson",
   );
 }
 
-function exportAllListsJsonl(entries: PromptListEntry[]): void {
+function exportAllListsJsonl(entries: PromptListEntry[]): Promise<void> {
   const lines = entries.map((e) => JSON.stringify({ name: e.name, items: e.items })).join("\n");
-  downloadBlob(lines, "prompt-lists.jsonl", "application/x-ndjson");
+  return downloadBlob(lines, "prompt-lists.jsonl", "application/x-ndjson");
 }
 
-function exportListCsv(entry: PromptListEntry): void {
+function exportListCsv(entry: PromptListEntry): Promise<void> {
   const rows = entry.items
     .map((text, i) => `${csvEscape(entry.name)},${i + 1},${csvEscape(text)}`)
     .join("\n");
-  downloadBlob(
+  return downloadBlob(
     `list_name,order,prompt_text\n${rows}`,
     `${sanitizeFilename(entry.name)}.csv`,
     "text/csv",
   );
 }
 
-function exportAllListsCsv(entries: PromptListEntry[]): void {
+function exportAllListsCsv(entries: PromptListEntry[]): Promise<void> {
   const rows = entries
     .flatMap((e) => e.items.map((text, i) => `${csvEscape(e.name)},${i + 1},${csvEscape(text)}`))
     .join("\n");
-  downloadBlob(`list_name,order,prompt_text\n${rows}`, "prompt-lists.csv", "text/csv");
+  return downloadBlob(`list_name,order,prompt_text\n${rows}`, "prompt-lists.csv", "text/csv");
 }
 
 function contentBlocksToText(content: unknown): string {
@@ -186,7 +184,16 @@ function contentBlocksToText(content: unknown): string {
 // predate the user's next message); the parent chain is timestamp-independent.
 type _Msg = { id: string; parentId?: string | null; createdAt?: number };
 
-function orderByParentChain<T extends _Msg>(messages: T[]): T[] {
+function orderByParentChain<T extends _Msg>(
+  messages: T[],
+  options: {
+    /** Append messages off the selected chain (abandoned branches) at the
+     *  end. Full exports keep everything; fine-tune conversion must not,
+     *  since alternate replies would merge into one conversation. */
+    includeSiblings?: boolean;
+  } = {},
+): T[] {
+  const { includeSiblings = true } = options;
   const byId = new Map<string, T>(messages.map((m) => [m.id, m]));
   const childrenOf = new Map<string | null, T[]>();
   for (const m of messages) {
@@ -207,7 +214,9 @@ function orderByParentChain<T extends _Msg>(messages: T[]): T[] {
     byId.delete(next.id);
   }
 
-  for (const [, m] of byId) result.push(m);
+  if (includeSiblings) {
+    for (const [, m] of byId) result.push(m);
+  }
   return result;
 }
 
@@ -352,7 +361,7 @@ export async function exportConversationShareGPT(threadId: string): Promise<void
   }
 
   if (conversations.length === 0) { toast.info("No exportable content."); return; }
-  downloadBlob(
+  await downloadBlob(
     JSON.stringify({ conversations }),
     "conversation-" + exportTs() + ".jsonl",
     "application/x-ndjson",
@@ -367,7 +376,7 @@ export async function exportConversationRawJsonl(threadId: string): Promise<void
 
   const oaiMsgs: OAIMessage[] = messages.flatMap((msg) => messageToOpenAI(msg));
   if (oaiMsgs.length === 0) { toast.info("No exportable content."); return; }
-  downloadBlob(
+  await downloadBlob(
     JSON.stringify({ messages: oaiMsgs }),
     "conversation-" + exportTs() + ".jsonl",
     "application/x-ndjson",
@@ -386,7 +395,11 @@ export async function exportConversationCsv(threadId: string): Promise<void> {
   }
 
   if (rows.length <= 1) { toast.info("No exportable content."); return; }
-  downloadBlob(rows.join("\n"), "conversation-" + exportTs() + ".csv", "text/csv");
+  await downloadBlob(
+    rows.join("\n"),
+    "conversation-" + exportTs() + ".csv",
+    "text/csv",
+  );
 }
 
 export type ConvExportFormat = "jsonl-raw" | "csv" | "sharegpt";
@@ -468,7 +481,11 @@ export async function exportBulkConversationsMerged(
     ? header + "\n" + parts.join("\n")
     : parts.join("\n");
 
-  downloadBlob(body, `${basename}.${exportExt(format)}`, exportMime(format));
+  await downloadBlob(
+    body,
+    `${basename}.${exportExt(format)}`,
+    exportMime(format),
+  );
 }
 
 export async function exportBulkConversationsSeparate(
@@ -493,11 +510,7 @@ export async function exportBulkConversationsSeparate(
   if (Object.keys(files).length === 0) { toast.info("No exportable content."); return; }
 
   const zipped = zipSync(files);
-  downloadBlob(
-    new Blob([zipped], { type: "application/zip" }),
-    `${basename}.zip`,
-    "application/zip",
-  );
+  await downloadBlob(zipped, `${basename}.zip`, "application/zip");
 }
 
 // Scope-level bulk export shared by the sidebar Recents menu and
@@ -525,8 +538,10 @@ export async function bulkExportConversationsByScope(
     } else {
       await exportBulkConversationsSeparate(ids, format, basename);
     }
-  } catch {
-    toast.error("Export failed.");
+  } catch (error) {
+    if (!isDownloadCancelled(error)) {
+      toast.error("Export failed.");
+    }
   }
 }
 
@@ -543,6 +558,214 @@ export async function exportProjectConversations(
   );
 }
 
+// ── Fine-tuning export ─────────────────────────────────────────────────────
+// One JSONL line per conversation: {"messages": [{"role", "content"}]} with
+// string-only content in system/user/assistant turns. Unsloth's training tab
+// detects this as ChatML natively (no column mapping, no standardization) and
+// it works with train-on-completions masking, which only trains on assistant
+// turns. Reasoning, tool calls, and images are dropped: clean SFT targets.
+
+export type FineTuneMessage = {
+  role: "system" | "user" | "assistant";
+  content: string;
+};
+
+const FINE_TUNE_ROLES = new Set(["system", "user", "assistant"]);
+
+/** Plain text of a message: text blocks plus text-type attachment parts. */
+function messageToPlainText(msg: {
+  content: unknown;
+  attachments?: unknown;
+}): string {
+  const parts: string[] = [];
+  const collect = (blocks: unknown) => {
+    // Legacy and imported histories can store content as a plain string.
+    if (typeof blocks === "string") {
+      if (blocks.trim()) parts.push(blocks);
+      return;
+    }
+    if (!Array.isArray(blocks)) return;
+    for (const b of blocks) {
+      if (!b || typeof b !== "object") {
+        continue;
+      }
+      const block = b as Record<string, unknown>;
+      if (block.type === "text" && typeof block.text === "string" && block.text) {
+        parts.push(block.text);
+      }
+    }
+  };
+  collect(msg.content);
+  if (Array.isArray(msg.attachments)) {
+    for (const attachment of msg.attachments as Array<{ content?: unknown }>) {
+      collect(attachment?.content);
+    }
+  }
+  return parts.join("\n\n").trim();
+}
+
+/** Merge consecutive same-role turns so chat templates format cleanly. */
+function mergeSameRoleTurns(turns: FineTuneMessage[]): FineTuneMessage[] {
+  const merged: FineTuneMessage[] = [];
+  for (const turn of turns) {
+    const last = merged[merged.length - 1];
+    if (last && last.role === turn.role) {
+      last.content += `\n\n${turn.content}`;
+    } else {
+      merged.push({ ...turn });
+    }
+  }
+  return merged;
+}
+
+/** Conversation turns for fine-tuning, or null when the thread has no
+ *  usable user + assistant exchange. Consecutive same-role turns merge,
+ *  assistant turns before the first user turn drop (an assistant target
+ *  with no prompt teaches nothing), and trailing non-assistant turns drop
+ *  so chat templates format cleanly. */
+function messagesToFineTuneTurns(
+  messages: Array<{ role: unknown; content: unknown; attachments?: unknown }>,
+): FineTuneMessage[] | null {
+  const raw: FineTuneMessage[] = [];
+  for (const msg of messages) {
+    const role = msg.role as FineTuneMessage["role"];
+    if (!FINE_TUNE_ROLES.has(role)) continue;
+    const content = messageToPlainText(msg);
+    if (!content) continue;
+    raw.push({ role, content });
+  }
+  const firstUser = raw.findIndex((t) => t.role === "user");
+  if (firstUser === -1) return null;
+  const turns = mergeSameRoleTurns(
+    raw.filter((t, i) => i >= firstUser || t.role === "system"),
+  );
+  while (turns.length > 0 && turns[turns.length - 1].role !== "assistant") {
+    turns.pop();
+  }
+  const hasUser = turns.some((t) => t.role === "user");
+  const hasAssistant = turns.some((t) => t.role === "assistant");
+  return hasUser && hasAssistant ? turns : null;
+}
+
+export type FineTuneExportResult = {
+  lines: string[];
+  conversations: number;
+  skipped: number;
+};
+
+/** Dataset shapes the Train tab detects without column mapping. */
+export type FineTuneFormat = "openai" | "sharegpt" | "alpaca";
+
+const SHAREGPT_FROM: Record<FineTuneMessage["role"], string> = {
+  system: "system",
+  user: "human",
+  assistant: "gpt",
+};
+
+/** JSONL lines for one conversation in the chosen format. Alpaca is
+ *  single-turn, so each user to assistant pair becomes its own record with
+ *  the system prompt and earlier exchange carried in the input field. */
+function turnsToFineTuneLines(
+  turns: FineTuneMessage[],
+  format: FineTuneFormat,
+): string[] {
+  if (format === "sharegpt") {
+    return [
+      JSON.stringify({
+        conversations: turns.map((t) => ({
+          from: SHAREGPT_FROM[t.role],
+          value: t.content,
+        })),
+      }),
+    ];
+  }
+  if (format === "alpaca") {
+    const lines: string[] = [];
+    const context: string[] = [];
+    let system = "";
+    let pendingUser: string | null = null;
+    for (const t of turns) {
+      if (t.role === "system") {
+        system = system ? `${system}\n\n${t.content}` : t.content;
+        continue;
+      }
+      if (t.role === "user") {
+        pendingUser = t.content;
+        continue;
+      }
+      if (pendingUser === null) continue;
+      const inputParts = [];
+      if (system) inputParts.push(system);
+      if (context.length > 0) inputParts.push(context.join("\n"));
+      lines.push(
+        JSON.stringify({
+          instruction: pendingUser,
+          input: inputParts.join("\n\n"),
+          output: t.content,
+        }),
+      );
+      context.push(`User: ${pendingUser}`, `Assistant: ${t.content}`);
+      pendingUser = null;
+    }
+    return lines;
+  }
+  return [JSON.stringify({ messages: turns })];
+}
+
+/** Every non-archived chat (Recents and Projects) as training-ready JSONL. */
+export async function buildFineTuneJsonl(
+  format: FineTuneFormat = "openai",
+): Promise<FineTuneExportResult> {
+  const threads = await listStoredChatThreads({ includeArchived: false });
+  const ids = [...new Set(threads.map((t) => t.id))];
+  const lines: string[] = [];
+  let conversations = 0;
+  let skipped = 0;
+  for (const id of ids) {
+    const raw = await listStoredChatMessages(id);
+    const hasParentIds = raw.some(
+      (m) => (m as { parentId?: unknown }).parentId != null,
+    );
+    // Chain only: retries/regenerations leave sibling branches, and mixing
+    // alternate replies into one conversation corrupts the training targets.
+    const ordered = hasParentIds
+      ? (orderByParentChain(raw, { includeSiblings: false }) as typeof raw)
+      : raw;
+    const turns = messagesToFineTuneTurns(ordered);
+    const converted = turns ? turnsToFineTuneLines(turns, format) : [];
+    if (converted.length === 0) {
+      skipped += 1;
+      continue;
+    }
+    conversations += 1;
+    lines.push(...converted);
+  }
+  return { lines, conversations, skipped };
+}
+
+/** Download the fine-tuning JSONL; returns the conversation count. */
+export async function exportFineTuneJsonl(
+  format: FineTuneFormat = "openai",
+): Promise<number> {
+  const { lines, conversations, skipped } = await buildFineTuneJsonl(format);
+  if (conversations === 0) {
+    toast.info("No chats with a user and assistant exchange to export.");
+    return 0;
+  }
+  const suffix = format === "openai" ? "" : `-${format}`;
+  await downloadBlob(
+    lines.join("\n"),
+    `chat-finetune${suffix}-${exportTs()}.jsonl`,
+    "application/x-ndjson",
+  );
+  if (skipped > 0) {
+    toast.success(
+      `Exported ${conversations} conversation${conversations === 1 ? "" : "s"} (${skipped} without a full exchange skipped).`,
+    );
+  }
+  return conversations;
+}
+
 // role:"tool" results are absorbed into the preceding assistant tool-call
 // part's `result` field rather than becoming separate records.
 function oaiMessagesToRecords(
@@ -773,21 +996,21 @@ export async function importConversationsFromFile(
 
 // ShareGPT training exports: prompt → one record (human turn + empty gpt slot);
 // list → one multi-turn record, each item a human turn.
-function exportPromptTrainingJsonl(entry: PromptEntry): void {
+function exportPromptTrainingJsonl(entry: PromptEntry): Promise<void> {
   const record = {
     conversations: [
       { from: "human", value: entry.text },
       { from: "gpt", value: "" },
     ],
   };
-  downloadBlob(
+  return downloadBlob(
     JSON.stringify(record),
     `${sanitizeFilename(entry.name)}-training.jsonl`,
     "application/x-ndjson",
   );
 }
 
-function exportPromptsTrainingJsonl(entries: PromptEntry[]): void {
+function exportPromptsTrainingJsonl(entries: PromptEntry[]): Promise<void> {
   const lines = entries
     .map((e) =>
       JSON.stringify({
@@ -798,22 +1021,22 @@ function exportPromptsTrainingJsonl(entries: PromptEntry[]): void {
       }),
     )
     .join("\n");
-  downloadBlob(lines, "prompts-training.jsonl", "application/x-ndjson");
+  return downloadBlob(lines, "prompts-training.jsonl", "application/x-ndjson");
 }
 
-function exportListTrainingJsonl(entry: PromptListEntry): void {
+function exportListTrainingJsonl(entry: PromptListEntry): Promise<void> {
   const conversations = entry.items.flatMap((text) => [
     { from: "human", value: text },
     { from: "gpt", value: "" },
   ]);
-  downloadBlob(
+  return downloadBlob(
     JSON.stringify({ conversations }),
     `${sanitizeFilename(entry.name)}-training.jsonl`,
     "application/x-ndjson",
   );
 }
 
-function exportListsTrainingJsonl(entries: PromptListEntry[]): void {
+function exportListsTrainingJsonl(entries: PromptListEntry[]): Promise<void> {
   const lines = entries
     .map((e) => {
       const conversations = e.items.flatMap((text) => [
@@ -823,7 +1046,7 @@ function exportListsTrainingJsonl(entries: PromptListEntry[]): void {
       return JSON.stringify({ conversations });
     })
     .join("\n");
-  downloadBlob(lines, "prompt-lists-training.jsonl", "application/x-ndjson");
+  return downloadBlob(lines, "prompt-lists-training.jsonl", "application/x-ndjson");
 }
 
 // RFC 4180 CSV parser: handles quoted fields with embedded newlines/commas.
@@ -1049,38 +1272,44 @@ function ExportModal({
     if (!csvAvailable) setFormat("jsonl");
   }, [csvAvailable]);
 
-  const handleExport = useCallback(() => {
-    if (ctx.kind === "prompt") {
-      if (scope === "training") exportPromptTrainingJsonl(ctx.entry);
-      else if (format === "csv") exportPromptCsv(ctx.entry);
-      else exportPromptJsonl(ctx.entry);
-    } else if (ctx.kind === "list") {
-      if (scope === "training") exportListTrainingJsonl(ctx.entry);
-      else if (format === "csv") exportListCsv(ctx.entry);
-      else exportListJsonl(ctx.entry);
-    } else {
-      const { tab, prompts, lists } = ctx;
-      if (scope === "training") {
-        if (tab === "prompts") {
-          if (prompts.length === 0) { toast.info("No prompts to export"); return; }
-          exportPromptsTrainingJsonl(prompts);
-        } else {
-          if (lists.length === 0) { toast.info("No prompt lists to export"); return; }
-          exportListsTrainingJsonl(lists);
-        }
+  const handleExport = useCallback(async () => {
+    try {
+      if (ctx.kind === "prompt") {
+        if (scope === "training") await exportPromptTrainingJsonl(ctx.entry);
+        else if (format === "csv") await exportPromptCsv(ctx.entry);
+        else await exportPromptJsonl(ctx.entry);
+      } else if (ctx.kind === "list") {
+        if (scope === "training") await exportListTrainingJsonl(ctx.entry);
+        else if (format === "csv") await exportListCsv(ctx.entry);
+        else await exportListJsonl(ctx.entry);
       } else {
-        if (tab === "prompts") {
+        const { tab, prompts, lists } = ctx;
+        if (scope === "training") {
+          if (tab === "prompts") {
+            if (prompts.length === 0) { toast.info("No prompts to export"); return; }
+            await exportPromptsTrainingJsonl(prompts);
+          } else {
+            if (lists.length === 0) { toast.info("No prompt lists to export"); return; }
+            await exportListsTrainingJsonl(lists);
+          }
+        } else if (tab === "prompts") {
           if (prompts.length === 0) { toast.info("No prompts to export"); return; }
-          if (format === "csv") exportAllPromptsCsv(prompts);
-          else exportAllPromptsJsonl(prompts);
+          if (format === "csv") await exportAllPromptsCsv(prompts);
+          else await exportAllPromptsJsonl(prompts);
         } else {
           if (lists.length === 0) { toast.info("No prompt lists to export"); return; }
-          if (format === "csv") exportAllListsCsv(lists);
-          else exportAllListsJsonl(lists);
+          if (format === "csv") await exportAllListsCsv(lists);
+          else await exportAllListsJsonl(lists);
         }
       }
+      onClose();
+    } catch (error) {
+      if (!isDownloadCancelled(error)) {
+        toast.error("Could not save export.", {
+          description: error instanceof Error ? error.message : String(error),
+        });
+      }
     }
-    onClose();
   }, [ctx, scope, format, onClose]);
 
   const singleLabel =
@@ -1112,7 +1341,7 @@ function ExportModal({
 
           {/* */}
           <div className="flex flex-col gap-2">
-            <p className="text-[11px] font-semibold uppercase tracking-wider text-muted-foreground/60">
+            <p className="text-ui-11 font-semibold uppercase tracking-wider text-muted-foreground/60">
               Export as
             </p>
             <div className="flex flex-col gap-2">
@@ -1161,7 +1390,7 @@ function ExportModal({
                   <p className="mt-1 text-xs text-muted-foreground">
                     ShareGPT format for Unsloth fine-tuning
                   </p>
-                  <code className="mt-2 block w-full truncate rounded-md bg-muted px-2 py-1 font-mono text-[10px] text-muted-foreground/60">
+                  <code className="mt-2 block w-full truncate rounded-md bg-muted px-2 py-1 font-mono text-ui-10 text-muted-foreground/60">
                     {`{"conversations":[{"from":"human","value":"..."},{"from":"gpt","value":""}]}`}
                   </code>
                 </div>
@@ -1171,7 +1400,7 @@ function ExportModal({
 
           {/* */}
           <div className="flex flex-col gap-2">
-            <p className="text-[11px] font-semibold uppercase tracking-wider text-muted-foreground/60">
+            <p className="text-ui-11 font-semibold uppercase tracking-wider text-muted-foreground/60">
               Format
             </p>
             <div className="flex items-center gap-1 self-start rounded-lg bg-muted/60 p-1">
@@ -1501,7 +1730,7 @@ function PromptListCard({
     <div className="group rounded-xl border border-border/60 bg-card p-4 flex flex-col gap-2.5 hover:border-border hover:shadow-sm transition-all">
       <div className="flex items-center gap-2">
         <span className="font-semibold text-sm flex-1 truncate tracking-tight">{entry.name}</span>
-        <span className="shrink-0 rounded-full bg-muted px-2 py-0.5 text-[11px] font-medium text-muted-foreground">
+        <span className="shrink-0 rounded-full bg-muted px-2 py-0.5 text-ui-11 font-medium text-muted-foreground">
           {entry.items.length}
         </span>
         <div className="flex items-center gap-0.5 opacity-0 group-hover:opacity-100 transition-opacity">
@@ -1550,7 +1779,7 @@ function PromptListCard({
           </p>
         ))}
         {entry.items.length > 3 && (
-          <p className="text-[11px] text-muted-foreground/50 ml-5">
+          <p className="text-ui-11 text-muted-foreground/50 ml-5">
             +{entry.items.length - 3} more
           </p>
         )}
diff --git a/studio/frontend/src/features/chat/provider-capabilities.ts b/studio/frontend/src/features/chat/provider-capabilities.ts
index 79c9a3205c..ec251cdada 100644
--- a/studio/frontend/src/features/chat/provider-capabilities.ts
+++ b/studio/frontend/src/features/chat/provider-capabilities.ts
@@ -409,7 +409,7 @@ function isGeminiImageModel(modelId: string): boolean {
  * Whether the saved Gemini connection points at a custom OpenAI-compat gateway
  * (any non-Google host). The backend `_is_openai_compatible` routes these
  * through `/chat/completions` instead of the native translator, so native Gemini
- * tool envelopes never reach them. Hide the matching Studio pills here so the
+ * tool envelopes never reach them. Hide the matching Unsloth pills here so the
  * request, builder, and UI agree.
  */
 export function isGeminiCustomOpenAICompatBase(
diff --git a/studio/frontend/src/features/chat/runtime-provider.tsx b/studio/frontend/src/features/chat/runtime-provider.tsx
index 019d0bfd8a..d9e407fd5e 100644
--- a/studio/frontend/src/features/chat/runtime-provider.tsx
+++ b/studio/frontend/src/features/chat/runtime-provider.tsx
@@ -33,8 +33,8 @@ import {
   useRef,
 } from "react";
 import { toast } from "sonner";
+import { StudioDictationAdapter } from "./adapters/studio-dictation-adapter";
 import { StudioSpeechSynthesisAdapter } from "./adapters/studio-speech-synthesis-adapter";
-import { StudioWebSpeechDictationAdapter } from "./adapters/studio-web-speech-dictation-adapter";
 import {
   ThreadAutosaveHandle,
   createOpenAIStreamAdapter,
@@ -56,6 +56,11 @@ import { AudioAttachmentAdapter } from "./audio-attachment-adapter";
 import { useChatRuntimeStore } from "./stores/chat-runtime-store";
 import { ToolPaneScopeContext, toolPaneScope } from "./tool-output-scope";
 import type { MessageRecord, ModelType, ThreadRecord } from "./types";
+import {
+  chatContentPartAttachmentIdFromSignature,
+  chatContentPartAttachmentSignature,
+  onChatAttachmentDeleted,
+} from "./utils/chat-attachment-events";
 import {
   deleteStoredChatThreads,
   ensureStoredChatThread,
@@ -890,6 +895,168 @@ function useStudioRuntimeAdapters(
 ): StudioRuntimeAdapters {
   const aui = useAui();
 
+  // Mirror Data-tab attachment deletions into the loaded thread. The in-memory
+  // repository otherwise keeps the attachment, and a later repo-to-storage sync
+  // (e.g. deleting a message in the thread) would write it back.
+  useEffect(() => {
+    let active = true;
+    let pendingDeletion = Promise.resolve();
+    const unsubscribe = onChatAttachmentDeleted((event) => {
+      pendingDeletion = pendingDeletion.then(async () => {
+        if (!active) return;
+        const { messageId, attachmentId } = event;
+        try {
+          const thread = aui.thread();
+          if (attachmentId.startsWith("content-part-sha256-")) {
+            for (let attempt = 0; attempt < 3 && active; attempt += 1) {
+              const exported = thread.export();
+              const target = exported.messages.find(
+                (item) => item.message.id === messageId,
+              );
+              if (!target || !Array.isArray(target.message.content)) return;
+              const content = target.message.content;
+
+              const signatures = content.map((part) =>
+                chatContentPartAttachmentSignature(part),
+              );
+              const ids = await Promise.all(
+                signatures.map((signature) =>
+                  signature === null
+                    ? null
+                    : chatContentPartAttachmentIdFromSignature(signature),
+                ),
+              );
+              const targetAttachments = (
+                target.message as {
+                  attachments?: readonly { id: string }[];
+                }
+              ).attachments;
+              const hasTargetAttachment =
+                Array.isArray(targetAttachments) &&
+                targetAttachments.some(
+                  (attachment) => attachment.id === attachmentId,
+                );
+              if (
+                (!ids.includes(attachmentId) && !hasTargetAttachment) ||
+                !active
+              ) {
+                return;
+              }
+
+              // Preserve any messages added or streamed while WebCrypto ran.
+              // Retry if the target's managed content itself changed.
+              const latest = thread.export();
+              const latestTarget = latest.messages.find(
+                (item) => item.message.id === messageId,
+              );
+              const latestContent = latestTarget?.message.content;
+              if (!Array.isArray(latestContent)) return;
+              const latestSignatures = latestContent.map((part) =>
+                chatContentPartAttachmentSignature(part),
+              );
+              if (
+                signatures.length !== latestSignatures.length ||
+                signatures.some(
+                  (signature, index) => signature !== latestSignatures[index],
+                )
+              ) {
+                continue;
+              }
+
+              const messages = latest.messages.map((item) => {
+                if (item.message.id !== messageId) return item;
+                const attachments = (
+                  item.message as {
+                    attachments?: readonly { id: string }[];
+                  }
+                ).attachments;
+                return {
+                  ...item,
+                  message: {
+                    ...item.message,
+                    content: latestContent.filter(
+                      (_, index) => ids[index] !== attachmentId,
+                    ),
+                    ...(Array.isArray(attachments)
+                      ? {
+                          attachments: attachments.filter(
+                            (attachment) =>
+                              attachment.id !== attachmentId,
+                          ),
+                        }
+                      : {}),
+                  } as typeof item.message,
+                };
+              });
+              if (active) thread.import({ ...latest, messages });
+              return;
+            }
+            return;
+          }
+
+          const exported = thread.export();
+          let changed = false;
+          const messages = exported.messages.map((item) => {
+            if (item.message.id !== messageId) return item;
+            const message = item.message;
+            const attachments = (
+              message as { attachments?: readonly { id: string }[] }
+            ).attachments;
+            if (
+              Array.isArray(attachments) &&
+              attachments.some(
+                (attachment) => attachment.id === attachmentId,
+              )
+            ) {
+              changed = true;
+              return {
+                ...item,
+                message: {
+                  ...message,
+                  attachments: attachments.filter(
+                    (attachment) => attachment.id !== attachmentId,
+                  ),
+                } as typeof message,
+              };
+            }
+            if (/^content-part-[0-9]+$/.test(attachmentId)) {
+              // Legacy synthetic id for a blob stored as a message content part.
+              const idx = Number(attachmentId.slice("content-part-".length));
+              const content = message.content;
+              if (
+                !Array.isArray(content) ||
+                !Number.isInteger(idx) ||
+                idx < 0 ||
+                idx >= content.length
+              ) {
+                return item;
+              }
+              const part = content[idx] as { type?: string };
+              if (part?.type !== "image" && part?.type !== "audio") return item;
+              changed = true;
+              return {
+                ...item,
+                message: {
+                  ...message,
+                  content: content.filter((_, i) => i !== idx),
+                } as typeof message,
+              };
+            }
+            return item;
+          });
+          if (changed && active) thread.import({ ...exported, messages });
+        } catch {
+          // No active thread mounted: storage already holds the truth.
+        }
+      });
+      return pendingDeletion;
+    });
+    return () => {
+      active = false;
+      unsubscribe();
+    };
+  }, [aui]);
+
   const history = useMemo<ThreadHistoryAdapter>(
     () => ({
       async load() {
@@ -1028,13 +1195,10 @@ function useStudioRuntimeAdapters(
     [aui, modelType, pairId],
   );
 
-  const dictation = useMemo(
-    () =>
-      StudioWebSpeechDictationAdapter.isSupported()
-        ? new StudioWebSpeechDictationAdapter()
-        : undefined,
-    [],
-  );
+  // Always register the adapter so the mic stays clickable for any engine. The
+  // engine is resolved at listen() time and the composer shows guidance when it
+  // cannot run, so engine switches also work on an already-mounted thread.
+  const dictation = useMemo(() => new StudioDictationAdapter(), []);
   const speech = useMemo(
     () =>
       StudioSpeechSynthesisAdapter.isSupported()
diff --git a/studio/frontend/src/features/chat/shared-composer.tsx b/studio/frontend/src/features/chat/shared-composer.tsx
index a0813fe27b..3f89f70ef1 100644
--- a/studio/frontend/src/features/chat/shared-composer.tsx
+++ b/studio/frontend/src/features/chat/shared-composer.tsx
@@ -24,18 +24,15 @@ import {
 } from "@/components/ui/dropdown-menu";
 import { applyQwenThinkingParams } from "@/features/chat/utils/qwen-params";
 import {
-  describeMediaError,
-  describeSpeechError,
-  isMissingDeviceError,
-} from "@/features/chat/adapters/studio-web-speech-dictation-adapter";
-import {
-  applyDictationDictionary,
-  recordRecentDictation,
-  resolveDictationLanguage,
-  useVoiceSettingsStore,
-} from "@/features/settings/stores/voice-settings-store";
+  StudioDictationAdapter,
+  isStudioDictationAvailable,
+  notifyStudioDictationUnavailable,
+} from "@/features/chat/adapters/studio-dictation-adapter";
+import type { StudioDictationSession } from "@/features/chat/adapters/studio-web-speech-dictation-adapter";
+import { useVoiceSettingsStore } from "@/features/settings/stores/voice-settings-store";
 import { AUDIO_ACCEPT, MAX_AUDIO_SIZE, fileToBase64 } from "@/lib/audio-utils";
 import { isTauri } from "@/lib/api-base";
+import { isDownloadCancelled } from "@/lib/native-files";
 import { isMultimodalResponse } from "./types/api";
 import { getImageInputUnavailableReason } from "./utils/image-input-support";
 import { useAui } from "@assistant-ui/react";
@@ -79,24 +76,36 @@ import { KnowledgeBaseComposerButton } from "@/features/rag/components/knowledge
 import { NewProjectDialog } from "./components/new-project-dialog";
 import { useChatProjects } from "./hooks/use-chat-projects";
 import { confirmRemoteCodeIfNeeded } from "@/features/security";
+import {
+  DEFAULT_MAX_SEQ_LENGTH,
+  normalizeMaxSeqLength,
+  resolveInitialConfig,
+  type PerModelConfig,
+} from "@/features/model-picker";
 import {
   confirmTransformersUpgradeIfNeeded,
   useTransformersUpgradeDialogStore,
 } from "@/features/transformers-upgrade";
 import { loadModel, validateModel } from "./api/chat-api";
+import { resolveFitMaxSeqLength, resolveManualAutoCtxPin } from "./presets/preset-policy";
+import { ensureGpuDeviceCache } from "@/hooks/use-gpu-info";
 import {
   parseExternalModelId,
   providerTypeSupportsVision,
 } from "./external-providers";
 import { useExternalProvidersStore } from "./stores/external-providers-store";
+import { useIsMobile } from "@/hooks/use-mobile";
 import {
   PLUS_MENU_ORDER,
   type PlusMenuItemId,
   usePlusMenuPrefsStore,
 } from "./stores/plus-menu-prefs-store";
 import {
+  loadedGpuMemoryFields,
   type ReasoningEffort,
+  reconcilePersistedGpuIds,
   resolveLoadedSpeculativeSettings,
+  persistGpuMemoryModeOnLoad,
   resolveSpeculativeSettingsForLoad,
   saveSpeculativeType,
   useChatRuntimeStore,
@@ -211,173 +220,95 @@ function formatReasoningDisabledLabel(
 function useDictation(
   setText: (value: string | ((prev: string) => string)) => void,
 ) {
+  // Re-render support state when the user switches recognition engines.
+  const dictationEngine = useVoiceSettingsStore((s) => s.dictationEngine);
   const [isDictating, setIsDictating] = useState(false);
-  const recognitionRef = useRef<SpeechRecognition | null>(null);
-
-  const streamRef = useRef<MediaStream | null>(null);
+  // True while a stopped recording's final audio is still transcribing; a
+  // second click then cancels the pending transcription instead of re-stopping.
+  const [isFinalizing, setIsFinalizing] = useState(false);
+  const sessionRef = useRef<StudioDictationSession | null>(null);
   const startingRef = useRef(false);
-  // Guards the getUserMedia await so a mic opened after unmount is released.
-  const disposedRef = useRef(false);
-
-  const releaseStream = useCallback(() => {
-    streamRef.current?.getTracks().forEach((track) => track.stop());
-    streamRef.current = null;
-  }, []);
+  const finalizingRef = useRef(false);
 
   const start = useCallback(async () => {
-    const SpeechRecognitionAPI =
-      typeof window !== "undefined" &&
-      (window.SpeechRecognition ??
-        (
-          window as unknown as {
-            webkitSpeechRecognition?: typeof SpeechRecognition;
-          }
-        ).webkitSpeechRecognition);
-    if (!SpeechRecognitionAPI) {
+    if (startingRef.current || sessionRef.current) return;
+    // Unsupported engine (e.g. Firefox): explain and steer to the local model.
+    if (!isStudioDictationAvailable()) {
+      notifyStudioDictationUnavailable();
       return;
     }
-    if (startingRef.current || recognitionRef.current) return;
     startingRef.current = true;
 
-    // Open the microphone chosen in Voice settings, matching the main chat
-    // adapter, so Compare dictation honors the same device selection.
-    let audioTrack: MediaStreamTrack | undefined;
-    const { micDeviceId } = useVoiceSettingsStore.getState();
-    if (navigator.mediaDevices?.getUserMedia) {
-      try {
-        let stream: MediaStream;
-        try {
-          stream = await navigator.mediaDevices.getUserMedia({
-            audio:
-              micDeviceId && micDeviceId !== "default"
-                ? { deviceId: { exact: micDeviceId } }
-                : true,
-          });
-        } catch (error) {
-          // Saved mic may be unplugged; fall back to the default device.
-          if (micDeviceId !== "default" && isMissingDeviceError(error)) {
-            stream = await navigator.mediaDevices.getUserMedia({
-              audio: true,
-            });
-          } else {
-            throw error;
-          }
-        }
-        streamRef.current = stream;
-        audioTrack = stream.getAudioTracks()[0];
-      } catch (error) {
-        // Permission/security failure: report it and stop instead of silently
-        // recording from a different default device, matching the main adapter.
-        startingRef.current = false;
-        releaseStream();
-        setIsDictating(false);
-        toast.error(describeMediaError(error));
-        return;
-      }
-    }
-
-    if (disposedRef.current) {
-      releaseStream();
-      startingRef.current = false;
-      return;
-    }
-
-    const recognition = new SpeechRecognitionAPI() as SpeechRecognition;
-    recognition.continuous = true;
-    recognition.interimResults = true;
-    recognition.lang = resolveDictationLanguage();
-    let sessionTranscript = "";
-    recognition.onresult = (event: SpeechRecognitionEvent) => {
-      // Iterate every result from resultIndex; a single event can carry more
-      // than one finalized phrase and dropping the rest loses dictated words.
-      for (let i = event.resultIndex; i < event.results.length; i++) {
-        const result = event.results[i];
-        if (!result?.isFinal) continue;
-        const transcript = applyDictationDictionary(
-          result[0]?.transcript?.trim() ?? "",
-        );
-        if (!transcript) continue;
-        sessionTranscript = sessionTranscript
-          ? `${sessionTranscript} ${transcript}`
-          : transcript;
-        setText((prev) => (prev ? `${prev} ${transcript}` : transcript));
-      }
-    };
-    recognition.onerror = (event) => {
-      // Report speech-service failures like the main adapter; aborted is a
-      // normal stop, not an error.
-      const errorEvent = event as SpeechRecognitionErrorEvent;
-      if (errorEvent.error !== "aborted") {
-        toast.error(describeSpeechError(errorEvent.error, errorEvent.message));
-      }
-      setIsDictating(false);
-    };
-    recognition.onend = () => {
-      // A stop()+immediate restart can install a new recognizer before this
-      // old one ends; only tear down shared refs when we are still current.
-      if (recognitionRef.current === recognition) {
-        releaseStream();
-        recognitionRef.current = null;
-        setIsDictating(false);
-      }
-      if (sessionTranscript) {
-        recordRecentDictation(sessionTranscript);
-        sessionTranscript = "";
-      }
-    };
+    let session: StudioDictationSession;
     try {
-      if (audioTrack) {
-        try {
-          recognition.start(audioTrack);
-        } catch {
-          // No start(track) overload: recognition captures from the default
-          // device, so release the selected-device stream.
-          releaseStream();
-          recognition.start();
-        }
-      } else {
-        recognition.start();
-      }
+      // Routes to the engine chosen in Voice settings (browser or STT model),
+      // honoring the selected microphone, language, and dictionary. Compare
+      // feeds two panes, so recent dictations must not link the unrelated
+      // single-chat active thread.
+      session = new StudioDictationAdapter({ chatId: null }).listen();
     } catch {
       startingRef.current = false;
-      releaseStream();
+      notifyStudioDictationUnavailable();
       return;
     }
-    recognitionRef.current = recognition;
-    startingRef.current = false;
+    sessionRef.current = session;
     setIsDictating(true);
-  }, [setText, releaseStream]);
+
+    // Append final transcripts; the adapter has already applied the dictionary
+    // and records the session in Recent dictations.
+    session.onSpeech((result) => {
+      if (!result.isFinal) return;
+      const transcript = result.transcript?.trim() ?? "";
+      if (transcript) {
+        setText((prev) => (prev ? `${prev} ${transcript}` : transcript));
+      }
+    });
+    session.onEnd?.(() => {
+      if (sessionRef.current === session) sessionRef.current = null;
+      finalizingRef.current = false;
+      setIsFinalizing(false);
+      setIsDictating(false);
+    });
+    startingRef.current = false;
+  }, [setText]);
 
   const stop = useCallback(() => {
-    if (recognitionRef.current) {
-      recognitionRef.current.stop();
-      recognitionRef.current = null;
+    const session = sessionRef.current;
+    if (!session) return;
+    // A second click while the final segment is transcribing discards the
+    // pending transcription instead of leaving the pane stuck until timeout.
+    if (finalizingRef.current) {
+      session.cancel();
+      if (sessionRef.current === session) sessionRef.current = null;
+      finalizingRef.current = false;
+      setIsFinalizing(false);
+      setIsDictating(false);
+      return;
     }
-    releaseStream();
-    setIsDictating(false);
-  }, [releaseStream]);
+    finalizingRef.current = true;
+    setIsFinalizing(true);
+    // Keep the session and dictation state alive while its final audio segment
+    // is transcribed. onEnd clears both after the transcript callbacks run.
+    void session.stop().catch((error) => {
+      console.error("Could not stop dictation:", error);
+      session.cancel();
+      if (sessionRef.current === session) sessionRef.current = null;
+      finalizingRef.current = false;
+      setIsFinalizing(false);
+      setIsDictating(false);
+    });
+  }, []);
 
   useEffect(() => {
-    disposedRef.current = false;
     return () => {
-      disposedRef.current = true;
-      if (recognitionRef.current) {
-        recognitionRef.current.abort();
-      }
-      streamRef.current?.getTracks().forEach((track) => track.stop());
-      streamRef.current = null;
+      sessionRef.current?.cancel();
+      sessionRef.current = null;
     };
   }, []);
 
-  const supported =
-    typeof window !== "undefined" &&
-    !!(
-      window.SpeechRecognition ??
-      (window as unknown as { webkitSpeechRecognition?: unknown })
-        .webkitSpeechRecognition
-    );
+  const supported = StudioDictationAdapter.isSupported(dictationEngine);
 
-  return { isDictating, start, stop, supported };
+  return { isDictating, isFinalizing, start, stop, supported };
 }
 
 export type CompareHandles = MutableRefObject<Record<string, CompareHandle>>;
@@ -490,8 +421,24 @@ type CompareModelSelection = {
   id: string;
   isLora: boolean;
   ggufVariant?: string;
+  config?: PerModelConfig;
 };
 
+function cleanCompareChatTemplate(
+  value: string | null | undefined,
+): string | null {
+  return value?.trim() ? value : null;
+}
+
+function resolveCompareSpecDraftNMax(
+  speculativeType: string | null,
+  value: number | null,
+): number | null {
+  return speculativeType === "mtp" || speculativeType === "mtp+ngram"
+    ? value
+    : null;
+}
+
 // Tool icon plus an X overlay CSS reveals on hover when the pill is active.
 function PillGlyph({ children }: { children: ReactNode }) {
   return (
@@ -614,7 +561,6 @@ export function SharedComposer({
   const artifactsEnabled = useChatRuntimeStore((s) => s.artifactsEnabled);
   const setArtifactsEnabled = useChatRuntimeStore((s) => s.setArtifactsEnabled);
   const showCanvasMenuItem = useChatRuntimeStore((s) => s.showCanvasMenuItem);
-  const permissionMode = useChatRuntimeStore((s) => s.permissionMode);
   const mcpEnabledForChat = useChatRuntimeStore((s) => s.mcpEnabledForChat);
   const setMcpEnabledForChat = useChatRuntimeStore(
     (s) => s.setMcpEnabledForChat,
@@ -785,19 +731,18 @@ export function SharedComposer({
   // can still be pre-selected, matching Web search/Code/MCP.
   const ragDisabled = modelLoaded && (isExternalModel || !supportsTools);
   const showRagPill = !isExternalModel;
-  // Above 4 pills, collapse to icons only to cut clutter. Compare, Search and
-  // Code always show; the permission pill shows in every mode except "off"
-  // (it renders null there); the rest are conditional.
-  const permissionPillVisible = permissionMode !== "off";
-  const pillsCompact =
-    3 +
-      (permissionPillVisible ? 1 : 0) +
-      (showImagePill ? 1 : 0) +
-      (showRagPill && ragEnabled && !ragDisabled ? 1 : 0) +
-      (showWebFetchPill ? 1 : 0) +
-      (artifactsEnabled ? 1 : 0) +
-      (mcpEnabledForChat ? 1 : 0) >
-    4;
+  // Above 4 pills, collapse to icons only. Compare, Search, Code, and
+  // permissions always show; the rest are conditional. Narrow viewports
+  // collapse too: the labelled row is wider than a phone-width composer.
+  const isMobile = useIsMobile();
+  const pillCount =
+    4 +
+    (showImagePill ? 1 : 0) +
+    (showRagPill && ragEnabled ? 1 : 0) +
+    (showWebFetchPill ? 1 : 0) +
+    (artifactsEnabled ? 1 : 0) +
+    (mcpEnabledForChat ? 1 : 0);
+  const pillsCompact = isMobile || pillCount > 4;
   // Backwards-compatible alias for call sites still referencing
   // `toolsDisabled` (rare; both pills used it before).
   const toolsDisabled = codeDisabled;
@@ -808,9 +753,9 @@ export function SharedComposer({
 
   const {
     isDictating,
+    isFinalizing: isDictationFinalizing,
     start: startDictation,
     stop: stopDictation,
-    supported: dictationSupported,
   } = useDictation(setText);
 
   useEffect(() => {
@@ -1022,50 +967,144 @@ export function SharedComposer({
     // Generalized compare: load each model before dispatching to its side
     if (isGeneralizedCompare) {
       const store = useChatRuntimeStore.getState();
-      const maxSeqLength = store.params.maxSeqLength;
       const trustRemoteCode = store.params.trustRemoteCode ?? false;
-      const chatTemplateOverride = store.chatTemplateOverride;
-      const effectiveChatTemplateOverride = chatTemplateOverride?.trim()
-        ? chatTemplateOverride
-        : null;
+      const fallbackTensorParallel = store.tensorParallel;
       const specSettings = resolveSpeculativeSettingsForLoad({
         usePersistedPreference: true,
       });
+      let loadedFromConfig = false;
 
       function modelDisplayName(id: string): string {
         const parts = id.split("/");
         return parts[parts.length - 1] || id;
       }
 
+      // Warm the device cache before the snapshot below reconciles the GPU
+      // pick: on a cold cache the reconcile passes a stale pick through.
+      if (store.selectedGpuIds != null) {
+        await ensureGpuDeviceCache();
+      }
+      // The GPU/offload knobs both compare loads must use, snapshotted at Send.
+      // ensureModelLoaded runs sequentially and the first load's response echo
+      // (loadedGpuMemoryFields) rewrites the live store -- a non-GGUF or Auto
+      // first model resets gpuLayers/nCpuMoe/split/pick to defaults -- so
+      // reading the store per load would hand model 2 the first model's echoed
+      // defaults instead of the settings the user pressed Send with.
+      const compareLoadKnobs = {
+        gpuMemoryMode: store.gpuMemoryMode,
+        gpuLayers: store.gpuLayers,
+        nCpuMoe: store.nCpuMoe,
+        splitRatio: store.splitRatio,
+        // Reconcile the pick against the GPUs present now, like the model-switch
+        // path: an early remember-restore can hold a stale cross-host pick that
+        // /load would reject (the device cache is populated by send time).
+        selectedGpuIds: reconcilePersistedGpuIds(store.selectedGpuIds),
+        customContextLength: store.customContextLength,
+      };
       // Set when an accepted transformers install unloaded the active model
       // server-side; a later failure must then clear the stale checkpoint.
       let upgradeUnloadedActive = false;
-
       // Helper: load a model and update store checkpoint
       async function ensureModelLoaded(
         sel: CompareModelSelection,
       ): Promise<string> {
         const currentStore = useChatRuntimeStore.getState();
+        const config = sel.config ?? null;
+        // This pane's effective config: an explicit selection config, else the
+        // remembered store config for this model/quant (never the other pane's).
+        // No saved config resolves to all-null defaults, so settings below fall
+        // through to their session default.
+        const resolved = config
+          ? { config, remembered: true }
+          : resolveInitialConfig(sel.id, sel.ggufVariant ?? null);
+        const ownConfig = resolved.config;
+        const ownRemembered = resolved.remembered;
+        // Mirror single-view resolveLoadMaxSeqLength: a GGUF pane with no explicit
+        // context loads at native (0 -> n_ctx_train), not the session maxSeqLength,
+        // which would silently shrink the shown context.
+        const isGgufLoad =
+          (sel.ggufVariant ?? null) != null ||
+          sel.id.toLowerCase().endsWith(".gguf");
+        // A non-GGUF pane with no saved maxSeqLength falls back to the app default,
+        // not the active model's shared runtime snapshot: else comparing a saved
+        // 128K model against an unconfigured one loads the latter at 128K and OOMs.
+        const effectiveMaxSeqLength =
+          ownConfig.customContextLength ??
+          normalizeMaxSeqLength(ownConfig.maxSeqLength) ??
+          (isGgufLoad ? 0 : DEFAULT_MAX_SEQ_LENGTH);
+        const effectiveChatTemplateOverride = cleanCompareChatTemplate(
+          ownConfig.chatTemplateOverride,
+        );
+        const effectiveSpeculativeType =
+          ownConfig.speculativeType ?? specSettings.speculativeType;
+        const effectiveSpecDraftNMax = ownRemembered
+          ? resolveCompareSpecDraftNMax(
+              effectiveSpeculativeType,
+              ownConfig.specDraftNMax,
+            )
+          : specSettings.specDraftNMax;
+        const effectiveTensorParallel = ownRemembered
+          ? ownConfig.tensorParallel
+          : fallbackTensorParallel;
+        if (ownConfig.selectedGpuIds != null) {
+          await ensureGpuDeviceCache();
+        }
+        const effectiveGpuMemoryMode =
+          ownConfig.gpuMemoryMode ?? compareLoadKnobs.gpuMemoryMode;
+        const effectiveGpuLayers =
+          ownConfig.gpuLayers ?? compareLoadKnobs.gpuLayers;
+        const effectiveNCpuMoe =
+          ownConfig.nCpuMoe ?? compareLoadKnobs.nCpuMoe;
+        const effectiveSelectedGpuIds =
+          ownConfig.selectedGpuIds !== undefined
+            ? reconcilePersistedGpuIds(ownConfig.selectedGpuIds)
+            : compareLoadKnobs.selectedGpuIds;
+        // A pane's context comes from its own config only: a saved pin, or null
+        // (Auto/native). It must not inherit the active model's shared snapshot --
+        // resolveFitMaxSeqLength would treat that as a pin and load this pane at
+        // the other model's context (changing VRAM/results or OOMing).
+        const effectiveCustomContextLength = ownConfig.customContextLength;
         let loadTrustRemoteCode = trustRemoteCode;
         let approvedRemoteCodeFingerprint: string | null = null;
         const isAlreadyActive =
           currentStore.params.checkpoint === sel.id &&
           (currentStore.activeGgufVariant ?? null) ===
             (sel.ggufVariant ?? null);
-        // Already loaded (gate passed at first load): skip a redundant reload that would
-        // re-trigger the gate without the approval fingerprint and fail for HIGH custom code.
-        if (isAlreadyActive) {
+        if (isAlreadyActive && !config && !loadedFromConfig) {
           return "ready";
         }
+        const targetIsGguf =
+          sel.id.toLowerCase().endsWith(".gguf") || sel.ggufVariant != null;
+        // Size validation exactly as the load below, so the training-guard
+        // preflight checks the footprint that actually loads (under Manual + Auto
+        // layers the load sends 0 / the pinned context, not raw maxSeqLength).
+        const compareMaxSeqLength = resolveFitMaxSeqLength(
+          targetIsGguf,
+          effectiveGpuMemoryMode,
+          effectiveGpuLayers,
+          // Prefer this pane's own saved context pin over the shared snapshot,
+          // falling back to its per-pane effective context (GGUF with no saved
+          // context loads at native, not the session maxSeqLength).
+          effectiveCustomContextLength,
+          effectiveMaxSeqLength,
+        );
         const validation = await validateModel({
           model_path: sel.id,
           hf_token: currentStore.hfToken || null,
-          max_seq_length: maxSeqLength,
+          max_seq_length: compareMaxSeqLength,
           load_in_4bit: true,
           is_lora: sel.isLora,
           gguf_variant: sel.ggufVariant ?? null,
           trust_remote_code: loadTrustRemoteCode,
           chat_template_override: effectiveChatTemplateOverride,
+          // Scope the validate to the picked GPUs. GGUF-only, like the load
+          // below: a non-GGUF target must not inherit a hidden GGUF GPU pick.
+          ...(targetIsGguf
+            ? {
+                gpu_ids: effectiveSelectedGpuIds ?? undefined,
+                gpu_memory_mode: effectiveGpuMemoryMode,
+              }
+            : {}),
         });
         // Upgrade dialog first (mirrors the primary load path).
         if (validation.requires_transformers_upgrade) {
@@ -1114,19 +1153,35 @@ export function SharedComposer({
         const resp = await loadModel({
           model_path: sel.id,
           hf_token: useChatRuntimeStore.getState().hfToken || null,
-          max_seq_length: maxSeqLength,
+          max_seq_length: compareMaxSeqLength,
           load_in_4bit: true,
           is_lora: sel.isLora,
           gguf_variant: sel.ggufVariant ?? null,
           trust_remote_code: loadTrustRemoteCode,
           approved_remote_code_fingerprint: approvedRemoteCodeFingerprint,
           chat_template_override: effectiveChatTemplateOverride,
-          speculative_type: specSettings.speculativeType,
-          spec_draft_n_max: specSettings.specDraftNMax,
-          // Honor the Tensor Parallelism toggle on compare loads too.
-          tensor_parallel: currentStore.tensorParallel,
+          cache_type_kv: ownConfig.kvCacheDtype ?? null,
+          speculative_type: effectiveSpeculativeType,
+          spec_draft_n_max: effectiveSpecDraftNMax,
+          tensor_parallel: effectiveTensorParallel,
+          ...(targetIsGguf
+            ? {
+                gpu_memory_mode: effectiveGpuMemoryMode,
+                gpu_layers: effectiveGpuLayers,
+                n_cpu_moe: effectiveNCpuMoe,
+                tensor_split: compareLoadKnobs.splitRatio ?? undefined,
+                gpu_ids: effectiveSelectedGpuIds ?? undefined,
+              }
+            : {}),
         });
-        saveSpeculativeType(specSettings.speculativeType);
+        // Keep a compare pane's per-model speculative choice load-local: persist
+        // the global preference only when it came from global settings.
+        if (ownConfig.speculativeType == null) {
+          saveSpeculativeType(effectiveSpeculativeType);
+        }
+        // Persist the GPU Memory mode on a non-diffusion GGUF compare-load too,
+        // so an applied manual choice survives a restart.
+        persistGpuMemoryModeOnLoad(resp, effectiveGpuMemoryMode);
         upgradeUnloadedActive = false;
         const store = useChatRuntimeStore.getState();
         store.setCheckpoint(
@@ -1136,17 +1191,69 @@ export function SharedComposer({
         store.setModelRequiresTrustRemoteCode(
           resp.requires_trust_remote_code ?? false,
         );
+        // Keep an explicit Manual+Auto context pin the load just applied (so a
+        // later Apply/Reset doesn't silently revert the model to auto-fit
+        // sizing), mirroring the interactive path's keepCustomCtx. Non-GGUF
+        // compare loads don't send the pin, so their baseline clears.
+        const keepCustomCtx = targetIsGguf
+          ? resolveManualAutoCtxPin(
+              effectiveGpuMemoryMode,
+              effectiveGpuLayers,
+              effectiveCustomContextLength,
+            )
+          : null;
         useChatRuntimeStore.setState({
           supportsReasoning: resp.supports_reasoning ?? false,
           reasoningAlwaysOn: resp.reasoning_always_on ?? false,
           ...reasoningCapsFromLoad(resp),
           supportsPreserveThinking: resp.supports_preserve_thinking ?? false,
           supportsTools: resp.supports_tools ?? false,
+          kvCacheDtype: resp.cache_type_kv ?? null,
+          loadedKvCacheDtype: resp.cache_type_kv ?? null,
           tensorParallel: resp.tensor_parallel ?? false,
           loadedTensorParallel: resp.tensor_parallel ?? false,
+          defaultChatTemplate: resp.chat_template ?? null,
+          chatTemplateOverride: effectiveChatTemplateOverride,
+          loadedChatTemplateOverride: effectiveChatTemplateOverride,
+          // The context baseline this pane loaded with (see keepCustomCtx above),
+          // so a later Apply/Reset can't silently revert a Manual+Auto pin.
+          loadedCustomContextLength: keepCustomCtx,
+          // Adopt the load response's GPU-memory fields (mode/layers/MoE/split/pick
+          // plus loaded baselines) so the GPU controls round-trip. (gguf context,
+          // customContextLength and native-path token/expiry clear in the tail below.)
+          ...loadedGpuMemoryFields(resp),
+          // Drives the GPU Memory controls' diffusion gate; set alongside the
+          // GPU fields on every load path so the gate can't read stale.
+          loadedIsDiffusion: resp.is_diffusion ?? false,
           loadedIsMultimodal: isMultimodalResponse(resp),
+          // Record the context this pane loaded with (like the single-model path)
+          // so when it becomes the active model, the UI and later reload/save use
+          // its context, not the previous/default one.
+          customContextLength: isGgufLoad
+            ? (ownConfig.customContextLength ?? keepCustomCtx)
+            : null,
+          ggufContextLength: resp.is_gguf ? (resp.context_length ?? null) : null,
+          ggufNativeContextLength: resp.is_gguf
+            ? (resp.native_context_length ?? null)
+            : null,
+          ggufMaxContextLength: resp.is_gguf
+            ? (resp.max_context_length ?? null)
+            : null,
+          // Compare selections load by repo/variant, never from the file picker,
+          // so they carry no native lease. Clear any prior picked file's
+          // token/expiry so the reload path never sends a stale lease.
+          activeNativePathToken: null,
+          activeNativePathExpiresAtMs: null,
           ...resolveLoadedSpeculativeSettings(resp),
         });
+        if (!isGgufLoad) {
+          // Non-GGUF panes carry their context in params.maxSeqLength.
+          store.setParams({
+            ...useChatRuntimeStore.getState().params,
+            maxSeqLength: effectiveMaxSeqLength,
+          });
+        }
+        loadedFromConfig = config != null;
         // Sync the models[] entry with the load response so attach/send gates
         // read fresh capabilities. /api/models/list can lag a model's actual
         // state (e.g. a GGUF whose mmproj arrived after the snapshot).
@@ -1294,7 +1401,7 @@ export function SharedComposer({
     }
     if (e.key === "Enter" && !e.shiftKey) {
       e.preventDefault();
-      if (!busy) {
+      if (!busy && !isDictating) {
         send();
       }
     }
@@ -1305,7 +1412,8 @@ export function SharedComposer({
       pendingImages.length > 0 ||
       pendingAudio !== null) &&
     !busy &&
-    !isComposing;
+    !isComposing &&
+    !isDictating;
 
   // Adjustable "+" menu items, keyed by id. Pinned ones render at the top
   // level; the rest fall into the "More" overflow submenu. Core items (photos,
@@ -1401,9 +1509,13 @@ export function SharedComposer({
                   toast.error("No conversation to export yet.");
                   return;
                 }
-                Promise.all(exportThreadIds.map((id) => fn(id))).catch(() =>
-                  toast.error("Export failed."),
-                );
+                (async () => {
+                  for (const id of exportThreadIds) {
+                    await fn(id);
+                  }
+                })().catch((error) => {
+                  if (!isDownloadCancelled(error)) toast.error("Export failed.");
+                });
               }}
             >
               {label}
@@ -1591,7 +1703,7 @@ export function SharedComposer({
       />
       <div className="composer-action-wrapper">
         <div
-          className="flex items-center gap-0.5"
+          className="flex min-w-0 flex-wrap items-center gap-0.5"
           data-pill-compact={pillsCompact ? "true" : undefined}
         >
           <input
@@ -2076,7 +2188,7 @@ export function SharedComposer({
               </button>
             )
           ) : null}
-          {dictationSupported && (
+          {
             <>
               {!isDictating ? (
                 <TooltipIconButton
@@ -2092,19 +2204,27 @@ export function SharedComposer({
                 </TooltipIconButton>
               ) : (
                 <TooltipIconButton
-                  tooltip="Stop dictation"
+                  tooltip={
+                    isDictationFinalizing
+                      ? "Cancel transcription"
+                      : "Stop dictation"
+                  }
                   side="bottom"
                   variant="ghost"
                   size="icon"
                   className="size-8 rounded-full text-destructive"
                   onClick={stopDictation}
-                  aria-label="Stop dictation"
+                  aria-label={
+                    isDictationFinalizing
+                      ? "Cancel transcription"
+                      : "Stop dictation"
+                  }
                 >
                   <SquareIcon className="size-3 animate-pulse fill-current" />
                 </TooltipIconButton>
               )}
             </>
-          )}
+          }
           {isQueueRunning ? (
             <button
               type="button"
diff --git a/studio/frontend/src/features/chat/stores/chat-runtime-store.ts b/studio/frontend/src/features/chat/stores/chat-runtime-store.ts
index af99458349..42359b8f7f 100644
--- a/studio/frontend/src/features/chat/stores/chat-runtime-store.ts
+++ b/studio/frontend/src/features/chat/stores/chat-runtime-store.ts
@@ -1,12 +1,8 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import type { RememberedLoadSettings } from "@/components/assistant-ui/model-selector/remembered-load-settings";
-import {
-  cancelStagedModelDownload,
-  mirrorHfTokenInto,
-  useHfTokenStore,
-} from "@/features/hub";
+import { mirrorHfTokenInto, useHfTokenStore } from "@/features/hub";
+import { cachedPinnableGpuIndices } from "@/hooks/use-gpu-info";
 import { toast } from "@/lib/toast";
 import { create } from "zustand";
 import { isExternalModelId, parseExternalModelId } from "../external-providers";
@@ -15,6 +11,7 @@ import {
   type Preset,
   getPresetSource,
 } from "../presets/preset-policy";
+import { normalizePresetLoadConfig } from "../presets/preset-load-config";
 import { getExternalMaxOutputTokens } from "../provider-capabilities";
 import {
   type ChatLoraSummary,
@@ -42,7 +39,6 @@ export const CHAT_ALLOW_ARTIFACT_NETWORK_ACCESS_KEY =
   "unsloth_chat_allow_artifact_network_access";
 export const CHAT_MCP_ENABLED_KEY = "unsloth_chat_mcp_enabled";
 export const CHAT_CONFIRM_TOOL_CALLS_KEY = "unsloth_chat_confirm_tool_calls";
-export const CHAT_LOAD_ON_SELECTION_KEY = "unsloth_chat_load_on_selection";
 export const CHAT_EXPAND_QUANTIZATIONS_KEY =
   "unsloth_chat_expand_quantizations";
 export const CHAT_SHOW_ALL_QUANTIZATIONS_KEY =
@@ -74,6 +70,7 @@ export const CHAT_RAG_AUTOINJECT_MIN_SCORE_KEY =
 export const CHAT_RAG_OCR_KEY = "unsloth_chat_rag_ocr_scanned";
 export const CHAT_RAG_CAPTION_KEY = "unsloth_chat_rag_caption_figures";
 export const CHAT_SPECULATIVE_TYPE_KEY = "unsloth_chat_speculative_type";
+export const CHAT_GPU_MEMORY_MODE_KEY = "unsloth_chat_gpu_memory_mode";
 
 // Persist only the model-agnostic intents (auto/ngram/off). MTP modes
 // (mtp/mtp+ngram) and spec_draft_n_max stay session-only: a persisted MTP
@@ -224,6 +221,11 @@ export type PendingImageEditReference = {
   openaiResponseId?: string;
   openaiReasoningItem?: unknown;
 };
+export type LoadingModelPick = {
+  id: string;
+  ggufVariant: string | null;
+  nativePathToken: string | null;
+};
 export type ReasoningEffort =
   | "none"
   | "minimal"
@@ -497,34 +499,188 @@ export function saveSpeculativeType(value: string | null): void {
   }
 }
 
-/** A local model staged for a deferred load (see `pendingSelection`). Shape is
- *  a subset of the load hook's `SelectedModelInput`, structurally assignable. */
-export type PendingModelSelection = {
-  id: string;
-  isLora?: boolean;
-  ggufVariant?: string;
-  isDownloaded?: boolean;
-  expectedBytes?: number;
-  /** Native (drag-drop / picked-from-disk) GGUF: the path token used to read
-   *  the header and to load. Absent for HF-repo models. */
-  nativePathToken?: string;
-  /** Direct local .gguf file (custom folder / LM Studio): a GGUF source even
-   *  though it carries neither an HF variant nor a native path token. */
-  isGguf?: boolean;
-  /** Native context length read from the GGUF header once the file is local.
-   *  Scoped here (not the shared `ggufContextLength`) so a staged model's
-   *  metadata never pollutes the currently-loaded model's context display. */
-  contextLength?: number | null;
-  /** "Load on selection" on + un-cached GGUF: download via the manager (global
-   *  indicator) without opening the sheet, then load once the download finishes. */
-  autoLoad?: boolean;
-  /** Uncached non-GGUF HF repo: download the full snapshot via the manager
-   *  (variant null) the same way GGUF picks download a variant. */
-  isHubRepo?: boolean;
-};
+// GPU Memory strategy is a standing preference (like speculative type), not a
+// per-model setting: a "manual" choice persists across model switches and reloads.
+export function readPersistedGpuMemoryMode(): "auto" | "manual" {
+  return loadString(CHAT_GPU_MEMORY_MODE_KEY, "auto") === "manual" ? "manual" : "auto";
+}
 
-/** A pick is a GGUF (HF variant, native file, or a direct local .gguf) and so
- *  has pre-load options worth staging. Works on a selection or a staged pick. */
+export function saveGpuMemoryMode(value: "auto" | "manual"): void {
+  saveString(CHAT_GPU_MEMORY_MODE_KEY, value);
+}
+
+/** Persist the GPU Memory mode after a load, but only for a non-diffusion GGUF:
+ *  non-GGUF has no such mode, and diffusion runs mode-agnostic (reports "auto"),
+ *  so neither must clobber the standing manual preference. */
+export function persistGpuMemoryModeOnLoad(
+  resp: { is_gguf?: boolean; is_diffusion?: boolean },
+  mode: "auto" | "manual",
+): void {
+  if (resp.is_gguf && !resp.is_diffusion) saveGpuMemoryMode(mode);
+}
+
+// Manual-mode gpu_layers sentinel: -1 = Auto (hand layer + context sizing to
+// llama.cpp's --fit). The Manual default; "all on GPU" is the slider's max.
+export const GPU_LAYERS_AUTO = -1;
+
+// Round real-valued shares to integers summing exactly to `total`, giving the
+// leftover units to the largest fractional parts (largest-remainder method).
+function largestRemainder(shares: number[], total: number): number[] {
+  const out = shares.map((x) => Math.floor(x));
+  let rem = total - out.reduce((a, b) => a + b, 0);
+  const byFrac = shares
+    .map((x, i) => ({ i, frac: x - Math.floor(x) }))
+    .sort((a, b) => b.frac - a.frac);
+  for (let k = 0; rem > 0 && k < byFrac.length; k++, rem--) out[byFrac[k].i] += 1;
+  return out;
+}
+
+// Spread `total` layers across GPUs in proportion to `weights` (e.g. per-GPU
+// VRAM), as integers summing exactly to `total`; even split for all-zero/empty
+// weights. Default per-GPU layer split before the user edits it (mirrors
+// llama.cpp's free-VRAM default).
+export function distributeByWeight(total: number, weights: number[]): number[] {
+  if (weights.length === 0) return [];
+  const t = Math.max(0, Math.floor(total));
+  const sum = weights.reduce((a, b) => a + b, 0);
+  const w = sum > 0 ? weights : weights.map(() => 1);
+  const wSum = w.reduce((a, b) => a + b, 0);
+  return largestRemainder(
+    w.map((x) => (t * x) / wSum),
+    t,
+  );
+}
+
+// Set GPU `index` to `value` and rebalance the rest so per-GPU counts still sum
+// to `total`; others absorb the remainder in proportion to their counts (evenly
+// if all zero). The --tensor-split editor: counts are sent verbatim, and
+// llama.cpp gives each GPU exactly its count when gpu_layers == sum(counts).
+export function rebalanceSplit(
+  total: number,
+  counts: number[],
+  index: number,
+  value: number,
+): number[] {
+  const v = Math.max(0, Math.min(value, total));
+  const out = counts.slice();
+  const otherIdx = counts.map((_, i) => i).filter((i) => i !== index);
+  // No other GPU to absorb the remainder: this one holds everything.
+  if (otherIdx.length === 0) {
+    out[index] = total;
+    return out;
+  }
+  out[index] = v;
+  const dist = distributeByWeight(
+    total - v,
+    otherIdx.map((i) => counts[i]),
+  );
+  otherIdx.forEach((i, k) => (out[i] = dist[k]));
+  return out;
+}
+
+// Validate a persisted gpu_ids pick against the GPUs present right now, before
+// restoring it from remembered settings. Returns null (= automatic) when the
+// pick is stale (none of the saved ids exist, or the host can't pin a multi-GPU
+// set), so a saved [1] on a now-1-GPU host doesn't get sent and rejected with no
+// way to clear it. A null pick (= automatic) passes through unchanged, and an
+// unpopulated device cache leaves the pick alone (the backend still guards).
+export function reconcilePersistedGpuIds(
+  ids: number[] | null,
+): number[] | null {
+  if (ids == null) return ids;
+  const pinnable = cachedPinnableGpuIndices();
+  if (pinnable === null) return ids; // cache not ready: can't validate, keep it
+  const kept = ids.filter((i) => pinnable.includes(i));
+  return kept.length > 0 ? kept : null;
+}
+
+// Store fields derived from a load/status response's GPU-memory settings.
+// Shared by every load path so the manual-knob round-trip can't drift.
+export function loadedGpuMemoryFields(resp: {
+  is_gguf?: boolean;
+  is_diffusion?: boolean;
+  gpu_memory_mode?: "auto" | "manual";
+  gpu_layers?: number;
+  n_cpu_moe?: number;
+  tensor_split?: number[] | null;
+  n_layers?: number | null;
+  n_moe_layers?: number;
+  gpu_ids?: number[] | null;
+  requested_gpu_ids?: number[] | null;
+}) {
+  // GPU-memory state is meaningful only for a GGUF chat load. A non-GGUF response
+  // still carries gpu_memory_mode (its default "auto" is serialized), so gate on
+  // the authoritative is_gguf flag, not the field's presence -- otherwise loading
+  // a transformers model would reset the standing manual preference.
+  if (!resp.is_gguf) {
+    // Clear the GPU pick / offload baseline a prior GGUF load may have left, so it
+    // reflects the non-GGUF model (no pin) -- else a stale loadedGpuIds reads as
+    // dirty (gpuIdsDirty is ungated) and Reset restores it while the picker is
+    // hidden. gpuMemoryMode (the standing preference) is kept, but its loaded
+    // baseline clears to null so Reset preserves the preference, not a stale mode.
+    return {
+      selectedGpuIds: null,
+      loadedGpuIds: null,
+      loadedGpuMemoryMode: null,
+      gpuLayers: GPU_LAYERS_AUTO,
+      loadedGpuLayers: null,
+      nCpuMoe: 0,
+      loadedNCpuMoe: null,
+      splitRatio: null,
+      loadedSplitRatio: null,
+      ggufLayerCount: null,
+      moeLayerCount: null,
+    };
+  }
+  const mode = resp.gpu_memory_mode ?? "auto";
+  // Keep the user's placement pool editable across status/load hydration.
+  // gpu_ids remains the effective fitted subset for diagnostics.
+  const gpuIds = resp.requested_gpu_ids ?? resp.gpu_ids ?? null;
+  // Layer/MoE/split knobs apply (and are reported) only in manual mode; in auto
+  // the server ignores them, so don't seed the loaded baseline or the editable
+  // knobs with values it never applied. In manual, the server reports gpu_layers
+  // = -1 under Auto, which round-trips the slider back to its Auto position.
+  const manualKnobs =
+    mode === "manual"
+      ? {
+          loadedGpuLayers: resp.gpu_layers ?? null,
+          loadedNCpuMoe: resp.n_cpu_moe ?? null,
+          loadedSplitRatio: resp.tensor_split ?? null,
+          gpuLayers: resp.gpu_layers ?? GPU_LAYERS_AUTO,
+          nCpuMoe: resp.n_cpu_moe ?? 0,
+          splitRatio: resp.tensor_split ?? null,
+        }
+      : {
+          loadedGpuLayers: null,
+          loadedNCpuMoe: null,
+          loadedSplitRatio: null,
+          // Auto ignores these, so reset the editable knobs too (not just the
+          // loaded baseline) -- else a later switch back to Manual would snapshot
+          // and send a previous model's stale gpuLayers/nCpuMoe/split that this
+          // load never applied. Mirrors the non-GGUF branch above.
+          gpuLayers: GPU_LAYERS_AUTO,
+          nCpuMoe: 0,
+          splitRatio: null,
+        };
+  return {
+    // A diffusion GGUF runs mode-agnostic (pins all layers on one GPU, reports
+    // "auto"), so adopt everything a chat GGUF does EXCEPT the live standing
+    // preference -- the next chat load must still honor the user's manual choice.
+    // The loaded baseline is still "auto", but the UI hides mode controls for a
+    // loaded diffusion model so it can't read as dirty against the preference.
+    ...(resp.is_diffusion ? {} : { gpuMemoryMode: mode }),
+    loadedGpuMemoryMode: mode,
+    ggufLayerCount: resp.n_layers ?? null,
+    // MoE expert-layer count: the n_cpu_moe slider max, and 0 hides the slider.
+    moeLayerCount: resp.n_moe_layers ?? null,
+    // The picker reflects the requested placement pool, not a fitted subset.
+    selectedGpuIds: gpuIds,
+    loadedGpuIds: gpuIds,
+    ...manualKnobs,
+  };
+}
+
+/** A pick is a GGUF: HF variant, native file, or a direct local .gguf. */
 export function hasGgufSource(x: {
   ggufVariant?: string;
   nativePathToken?: string;
@@ -562,30 +718,6 @@ export function isDownloadableHubRepo(x: {
   );
 }
 
-export function isPendingGguf(pending: PendingModelSelection | null): boolean {
-  return pending != null && hasGgufSource(pending);
-}
-
-/** Whether `pending` refers to the same model as `pick` (id + GGUF variant +
- *  native path token, optionals null-normalized). Native ids are display labels
- *  that can collide, so the token must match too — id alone can land on the
- *  wrong file. */
-export function pendingSelectionMatches(
-  pending: PendingModelSelection | null,
-  pick: {
-    id: string;
-    ggufVariant?: string | null;
-    nativePathToken?: string | null;
-  },
-): boolean {
-  return (
-    pending != null &&
-    pending.id === pick.id &&
-    (pending.ggufVariant ?? null) === (pick.ggufVariant ?? null) &&
-    (pending.nativePathToken ?? null) === (pick.nativePathToken ?? null)
-  );
-}
-
 type ChatRuntimeStore = {
   settingsHydrated: boolean;
   params: InferenceParams;
@@ -671,7 +803,7 @@ type ChatRuntimeStore = {
   // Describe figures/charts at ingest time (vision model required).
   ragCaptionFigures: boolean;
   /**
-   * When on, local Studio tool calls pause for an explicit allow/deny in the
+   * When on, local Unsloth tool calls pause for an explicit allow/deny in the
    * chat before they run.
    */
   confirmToolCalls: boolean;
@@ -743,10 +875,32 @@ type ChatRuntimeStore = {
   tensorParallel: boolean;
   /** Backend-reported tensor-parallel state; null until first hydrated. */
   loadedTensorParallel: boolean | null;
-  /** Persisted: when false, picking a local model stages it as
-   *  `pendingSelection` (and opens settings) instead of loading immediately,
-   *  so load settings can be set before the single load. */
-  loadOnSelection: boolean;
+  /** GPU memory strategy for GGUF loads. "auto" = Unsloth picks GPUs and context
+   *  to fit; "manual" = you own the offload (gpuLayers < 0 = Auto/--fit, >= 0
+   *  pins layers + nCpuMoe). */
+  gpuMemoryMode: "auto" | "manual";
+  /** Backend-reported gpu memory mode; null until first hydrated. */
+  loadedGpuMemoryMode: "auto" | "manual" | null;
+  /** Manual mode: layers to offload to GPU. -1 = Auto (--fit); >= model layer
+   *  count = all. */
+  gpuLayers: number;
+  loadedGpuLayers: number | null;
+  /** Manual mode: MoE expert layers to keep on CPU (--n-cpu-moe); 0 = none. */
+  nCpuMoe: number;
+  loadedNCpuMoe: number | null;
+  /** Manual mode: per-GPU layer counts (--tensor-split), in GPU-in-use order;
+   *  null = unset (llama.cpp splits by free VRAM). */
+  splitRatio: number[] | null;
+  /** Backend-reported per-GPU split ratio (--tensor-split); null = unset. */
+  loadedSplitRatio: number[] | null;
+  /** Model layer count (GGUF block_count); the manual gpu-layers ceiling is
+   * this + 1 (the output layer is offloadable too). */
+  ggufLayerCount: number | null;
+  /** MoE expert-layer count: the nCpuMoe slider max; 0/null hides the slider. */
+  moeLayerCount: number | null;
+  /** Picked physical GPU indices (null = use all / automatic). */
+  selectedGpuIds: number[] | null;
+  loadedGpuIds: number[] | null;
   /** Persisted: expand every On Device GGUF repo's quantizations by default
    *  instead of waiting for a click. */
   expandQuantizations: boolean;
@@ -755,9 +909,6 @@ type ChatRuntimeStore = {
   /** Persisted, shared by the chat model selector and the Hub page: list only
    *  models whose size fits this device's memory budget. */
   fitOnDeviceOnly: boolean;
-  /** A local model picked while `loadOnSelection` is off: staged, not loaded.
-   *  The settings sheet shows its load knobs and a Load button. */
-  pendingSelection: PendingModelSelection | null;
   loadedIsMultimodal: boolean;
   /** Active model is a block-diffusion model (DiffusionGemma): drives the
    *  denoising-canvas artifact auto-render. */
@@ -766,6 +917,9 @@ type ChatRuntimeStore = {
    *  per step, cleared when the run ends, never persisted into the transcript. */
   activeDiffusionCanvas: DiffusionCanvasFrame | null;
   customContextLength: number | null;
+  /** The pinned context the loaded model used (null = Auto), so dirty-tracking
+   *  and a later fit Apply can tell an explicit pin apart from Auto. */
+  loadedCustomContextLength: number | null;
   defaultChatTemplate: string | null;
   chatTemplateOverride: string | null;
   loadedChatTemplateOverride: string | null;
@@ -793,9 +947,16 @@ type ChatRuntimeStore = {
     cacheWriteTokens?: number;
   } | null;
   modelLoading: boolean;
+  loadingModelPick: LoadingModelPick | null;
   activeNativePathToken: string | null;
+  // Wall-clock expiry (ms) of the active native path token. The desktop host
+  // prunes file leases after a TTL, so a reload checks this to prompt
+  // re-selection instead of reusing a dead token.
+  activeNativePathExpiresAtMs: number | null;
   hydratePersistedSettings: () => Promise<void>;
   setModelLoading: (loading: boolean) => void;
+  setLoadingModelPick: (pick: LoadingModelPick | null) => void;
+  clearLoadingModelPick: (expected: LoadingModelPick) => void;
   setModelRequiresTrustRemoteCode: (required: boolean) => void;
   setParams: (params: InferenceParams) => void;
   setCustomPresets: (presets: Preset[]) => void;
@@ -871,33 +1032,14 @@ type ChatRuntimeStore = {
   setNudgeToolCalls: (enabled: boolean) => void;
   setMaxToolCallsPerMessage: (value: number) => void;
   setToolCallTimeout: (value: number) => void;
-  setKvCacheDtype: (dtype: string | null) => void;
-  setSpeculativeType: (type: string | null) => void;
-  setSpecDraftNMax: (value: number | null) => void;
-  /** Revert the editable load knobs to the loaded model's baseline (or defaults
-   *  when nothing is loaded). Used by the settings-sheet Reset button and to
-   *  start each deferred-staging session clean so one staged pick's settings
-   *  don't leak onto the next. */
-  resetModelSettingsToLoaded: () => void;
-  /** Seed the editable load knobs from a model's remembered settings. Shared by
-   *  the settings sheet's restore effect and the "Load on selection" paths,
-   *  which skip the sheet but must still honor a saved config. */
-  applyRememberedLoadSettings: (settings: RememberedLoadSettings) => void;
-  setTensorParallel: (value: boolean) => void;
-  setLoadOnSelection: (value: boolean) => void;
+  setGpuMemoryMode: (mode: "auto" | "manual") => void;
+  setGpuLayers: (value: number) => void;
+  setNCpuMoe: (value: number) => void;
+  setSplitRatio: (value: number[] | null) => void;
+  setSelectedGpuIds: (ids: number[] | null) => void;
   setExpandQuantizations: (value: boolean) => void;
   setShowAllQuantizations: (value: boolean) => void;
   setFitOnDeviceOnly: (value: boolean) => void;
-  setPendingSelection: (selection: PendingModelSelection | null) => void;
-  /** Stage a pick for a deferred load: revert knobs to the loaded baseline,
-   *  record the selection, and open the settings sheet. */
-  stageModel: (selection: PendingModelSelection) => void;
-  /** Abandon a staged pick without loading: revert knobs to the loaded baseline
-   *  and clear the pending selection. Cancels its in-flight download too, unless
-   *  `keepDownload` is set (navigation keeps the transfer running, like Hub). */
-  abandonStagedModel: (opts?: { keepDownload?: boolean }) => void;
-  setCustomContextLength: (v: number | null) => void;
-  setChatTemplateOverride: (template: string | null) => void;
   setPendingAudio: (base64: string, name: string) => void;
   clearPendingAudio: () => void;
   setPendingImageEditReference: (
@@ -1018,13 +1160,17 @@ function getHydratedCustomPresets(
   state: ChatRuntimeStore,
 ): Preset[] {
   return (
-    settings.customPresets?.map((preset) => ({
-      name: preset.name,
-      params: {
-        ...DEFAULT_INFERENCE_PARAMS,
-        ...preset.params,
-      },
-    })) ?? state.customPresets
+    settings.customPresets?.map((preset) => {
+      const loadConfig = normalizePresetLoadConfig(preset.loadConfig);
+      return {
+        name: preset.name,
+        params: {
+          ...DEFAULT_INFERENCE_PARAMS,
+          ...preset.params,
+        },
+        ...(loadConfig ? { loadConfig } : {}),
+      };
+    }) ?? state.customPresets
   );
 }
 
@@ -1099,23 +1245,6 @@ function setScalarSettingVersion<K extends ScalarSettingKey>(
   saveSettingsPatch({ [key]: value });
 }
 
-/** The "revert to the loaded model" baseline for the editable load knobs.
- *  Shared by resetModelSettingsToLoaded (full revert) and stageModel (which
- *  overrides speculative to start a fresh pick from the standing default). */
-function loadedBaselineSettings(s: ChatRuntimeStore) {
-  const hasLoadedModel = Boolean(s.params.checkpoint);
-  return {
-    customContextLength: null,
-    kvCacheDtype: s.loadedKvCacheDtype,
-    tensorParallel: s.loadedTensorParallel ?? false,
-    speculativeType: hasLoadedModel
-      ? s.loadedSpeculativeType
-      : readPersistedSpeculativeType(),
-    specDraftNMax: hasLoadedModel ? s.loadedSpecDraftNMax : null,
-    chatTemplateOverride: s.loadedChatTemplateOverride,
-  };
-}
-
 export const useChatRuntimeStore = create<ChatRuntimeStore>((set, get) => ({
   settingsHydrated: false,
   // Hydrate the last external checkpoint so the external picker survives a
@@ -1213,14 +1342,25 @@ export const useChatRuntimeStore = create<ChatRuntimeStore>((set, get) => ({
   loadedSpecDraftNMax: null,
   tensorParallel: false,
   loadedTensorParallel: null,
-  loadOnSelection: loadBool(CHAT_LOAD_ON_SELECTION_KEY, true),
+  gpuMemoryMode: readPersistedGpuMemoryMode(),
+  loadedGpuMemoryMode: null,
+  gpuLayers: GPU_LAYERS_AUTO,
+  loadedGpuLayers: null,
+  nCpuMoe: 0,
+  loadedNCpuMoe: null,
+  splitRatio: null,
+  loadedSplitRatio: null,
+  ggufLayerCount: null,
+  moeLayerCount: null,
+  selectedGpuIds: null,
+  loadedGpuIds: null,
   expandQuantizations: loadBool(CHAT_EXPAND_QUANTIZATIONS_KEY, false),
   showAllQuantizations: loadBool(CHAT_SHOW_ALL_QUANTIZATIONS_KEY, true),
   fitOnDeviceOnly: loadBool(MODELS_FIT_ON_DEVICE_ONLY_KEY, false),
-  pendingSelection: null,
   loadedIsMultimodal: false,
   loadedIsDiffusion: false,
   customContextLength: null,
+  loadedCustomContextLength: null,
   defaultChatTemplate: null,
   chatTemplateOverride: null,
   loadedChatTemplateOverride: null,
@@ -1234,7 +1374,9 @@ export const useChatRuntimeStore = create<ChatRuntimeStore>((set, get) => ({
   pendingImageEditReference: null,
   contextUsage: null,
   modelLoading: false,
+  loadingModelPick: null,
   activeNativePathToken: null,
+  activeNativePathExpiresAtMs: null,
   hydratePersistedSettings: async () => {
     if (get().settingsHydrated) {
       return;
@@ -1273,6 +1415,20 @@ export const useChatRuntimeStore = create<ChatRuntimeStore>((set, get) => ({
     return settingsHydrationPromise;
   },
   setModelLoading: (loading) => set({ modelLoading: loading }),
+  setLoadingModelPick: (pick) => set({ loadingModelPick: pick }),
+  clearLoadingModelPick: (expected) =>
+    set((state) => {
+      const current = state.loadingModelPick;
+      if (
+        !current ||
+        current.id !== expected.id ||
+        current.ggufVariant !== expected.ggufVariant ||
+        current.nativePathToken !== expected.nativePathToken
+      ) {
+        return state;
+      }
+      return { loadingModelPick: null };
+    }),
   setModelRequiresTrustRemoteCode: (modelRequiresTrustRemoteCode) =>
     set({ modelRequiresTrustRemoteCode }),
   setParams: (params) =>
@@ -1353,13 +1509,6 @@ export const useChatRuntimeStore = create<ChatRuntimeStore>((set, get) => ({
       // Clear stale per-turn usage on model change; the relaxed external-provider
       // render gate would otherwise show old counters until the next completion.
       const checkpointChanged = state.params.checkpoint !== modelId;
-      const pendingToClear =
-        checkpointChanged && state.params.checkpoint
-          ? state.pendingSelection
-          : null;
-      if (pendingToClear) {
-        cancelStagedModelDownload(pendingToClear);
-      }
       // Clamp maxTokens to the new model's cap when switching into an external
       // model so a value carried over from a local session doesn't exceed the
       // slider's max.
@@ -1387,14 +1536,6 @@ export const useChatRuntimeStore = create<ChatRuntimeStore>((set, get) => ({
         },
         activeGgufVariant: ggufVariant ?? null,
         ...(checkpointChanged ? { contextUsage: null } : {}),
-        // Switching away from a loaded model (e.g. picking an external provider)
-        // abandons any staged pick, so its Load button and edited knobs don't
-        // linger over the newly active model. Same revert as abandonStagedModel.
-        // Guarded on a non-empty current checkpoint: an establishing set from a
-        // background status sync (empty -> active) must not wipe a fresh stage.
-        ...(pendingToClear
-          ? { ...loadedBaselineSettings(state), pendingSelection: null }
-          : {}),
       };
     }),
   setActiveThreadId: (activeThreadId) =>
@@ -1408,7 +1549,6 @@ export const useChatRuntimeStore = create<ChatRuntimeStore>((set, get) => ({
     // clear any stored external selection so the next refresh doesn't snap
     // back to a model the user intentionally cleared.
     saveLastExternalCheckpoint(null);
-    cancelStagedModelDownload(get().pendingSelection);
     return set((state) => ({
       params: {
         ...state.params,
@@ -1416,7 +1556,7 @@ export const useChatRuntimeStore = create<ChatRuntimeStore>((set, get) => ({
       },
       activeGgufVariant: null,
       activeNativePathToken: null,
-      pendingSelection: null,
+      activeNativePathExpiresAtMs: null,
       ggufContextLength: null,
       ggufMaxContextLength: null,
       ggufNativeContextLength: null,
@@ -1455,9 +1595,23 @@ export const useChatRuntimeStore = create<ChatRuntimeStore>((set, get) => ({
       loadedSpecDraftNMax: null,
       tensorParallel: false,
       loadedTensorParallel: null,
+      // Standing preference: survives unload, unlike the per-model knobs above.
+      gpuMemoryMode: readPersistedGpuMemoryMode(),
+      loadedGpuMemoryMode: null,
+      gpuLayers: GPU_LAYERS_AUTO,
+      loadedGpuLayers: null,
+      nCpuMoe: 0,
+      loadedNCpuMoe: null,
+      splitRatio: null,
+      loadedSplitRatio: null,
+      ggufLayerCount: null,
+      moeLayerCount: null,
+      selectedGpuIds: null,
+      loadedGpuIds: null,
       loadedIsMultimodal: false,
       loadedIsDiffusion: false,
       customContextLength: null,
+      loadedCustomContextLength: null,
       defaultChatTemplate: null,
       chatTemplateOverride: null,
       loadedChatTemplateOverride: null,
@@ -1749,25 +1903,14 @@ export const useChatRuntimeStore = create<ChatRuntimeStore>((set, get) => ({
       );
       return { toolCallTimeout };
     }),
-  setKvCacheDtype: (kvCacheDtype) => set({ kvCacheDtype }),
-  setSpeculativeType: (speculativeType) => set({ speculativeType }),
-  setSpecDraftNMax: (specDraftNMax) => set({ specDraftNMax }),
-  setTensorParallel: (tensorParallel) => set({ tensorParallel }),
-  resetModelSettingsToLoaded: () => set((s) => loadedBaselineSettings(s)),
-  applyRememberedLoadSettings: (settings) =>
-    // Coalesce every field: a blob persisted by an older/newer build can omit
-    // keys, and a raw spread would push `undefined` into fields typed non-null.
-    set({
-      customContextLength: settings.contextLength ?? null,
-      kvCacheDtype: settings.kvCacheDtype ?? null,
-      speculativeType: settings.speculativeType ?? "auto",
-      specDraftNMax: settings.specDraftNMax ?? null,
-      tensorParallel: settings.tensorParallel ?? false,
-    }),
-  setLoadOnSelection: (loadOnSelection) => {
-    saveBool(CHAT_LOAD_ON_SELECTION_KEY, loadOnSelection);
-    set({ loadOnSelection });
-  },
+  // Standing preference, but persisted only on a successful load (see
+  // use-chat-model-runtime), not on selection -- so an unapplied pick the user
+  // resets/abandons doesn't stick to the next session.
+  setGpuMemoryMode: (gpuMemoryMode) => set({ gpuMemoryMode }),
+  setGpuLayers: (gpuLayers) => set({ gpuLayers }),
+  setNCpuMoe: (nCpuMoe) => set({ nCpuMoe }),
+  setSplitRatio: (splitRatio) => set({ splitRatio }),
+  setSelectedGpuIds: (selectedGpuIds) => set({ selectedGpuIds }),
   setExpandQuantizations: (expandQuantizations) => {
     saveBool(CHAT_EXPAND_QUANTIZATIONS_KEY, expandQuantizations);
     set({ expandQuantizations });
@@ -1780,39 +1923,6 @@ export const useChatRuntimeStore = create<ChatRuntimeStore>((set, get) => ({
     saveBool(MODELS_FIT_ON_DEVICE_ONLY_KEY, fitOnDeviceOnly);
     set({ fitOnDeviceOnly });
   },
-  setPendingSelection: (pendingSelection) => set({ pendingSelection }),
-  stageModel: (selection) => {
-    // Refuse staging mid-load: post-load cleanup would silently drop the queued
-    // pick. stageOrLoad toasts first for callers that can.
-    if (get().modelLoading) return;
-    // Rebinding to a new pick keeps the prior pick's download running so the
-    // user can queue multiple downloads at once (Hub-style).
-    set((s) => {
-      return {
-        ...loadedBaselineSettings(s),
-        pendingSelection: selection,
-        // autoLoad downloads silently and loads on completion, so keep the sheet shut.
-        settingsPanelOpen: !selection.autoLoad,
-        // Speculative starts from the standing default, not the loaded model's
-        // mode, so a fresh pick doesn't inherit (and then carry, via the staged
-        // Load's keepSpeculative) a forced MTP mode onto a model that may lack it.
-        speculativeType: readPersistedSpeculativeType(),
-        specDraftNMax: null,
-      };
-    });
-  },
-  abandonStagedModel: (opts) => {
-    const { pendingSelection } = get();
-    if (!pendingSelection) return;
-    // Cancel the staged pick's in-flight download (centralized for every abandon
-    // path: sheet close, thread switch, route exit, new chat). `keepDownload`
-    // opts out so navigation leaves the transfer running, like a Hub download.
-    if (!opts?.keepDownload) cancelStagedModelDownload(pendingSelection);
-    set((s) => ({ ...loadedBaselineSettings(s), pendingSelection: null }));
-  },
-  setCustomContextLength: (customContextLength) => set({ customContextLength }),
-  setChatTemplateOverride: (chatTemplateOverride) =>
-    set({ chatTemplateOverride }),
   setPendingAudio: (base64, name) =>
     set({ pendingAudioBase64: base64, pendingAudioName: name }),
   clearPendingAudio: () =>
@@ -1824,7 +1934,7 @@ export const useChatRuntimeStore = create<ChatRuntimeStore>((set, get) => ({
   setContextUsage: (contextUsage) => set({ contextUsage }),
 }));
 
-// Mirror token edits made through the shared store (e.g. Studio's field).
+// Mirror token edits made through the shared store (e.g. Unsloth's field).
 const unsubscribeHfTokenMirror = mirrorHfTokenInto(useChatRuntimeStore);
 if (import.meta.hot) {
   import.meta.hot.dispose(unsubscribeHfTokenMirror);
diff --git a/studio/frontend/src/features/chat/stores/pinned-projects-store.ts b/studio/frontend/src/features/chat/stores/pinned-projects-store.ts
new file mode 100644
index 0000000000..c6dbad5c79
--- /dev/null
+++ b/studio/frontend/src/features/chat/stores/pinned-projects-store.ts
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { create } from "zustand";
+import { persist } from "zustand/middleware";
+
+// Client-side pin state for projects, keyed by project id. Kept in
+// localStorage. Pinned projects drive the sidebar "Projects" section; new pins
+// are prepended so the most recently pinned project sorts first.
+export interface PinnedProjectsState {
+  pinnedIds: string[];
+  togglePin: (id: string) => void;
+  unpin: (id: string) => void;
+}
+
+export const usePinnedProjectsStore = create<PinnedProjectsState>()(
+  persist(
+    (set) => ({
+      pinnedIds: [],
+      togglePin: (id) =>
+        set((state) => ({
+          pinnedIds: state.pinnedIds.includes(id)
+            ? state.pinnedIds.filter((x) => x !== id)
+            : [id, ...state.pinnedIds],
+        })),
+      unpin: (id) =>
+        set((state) => ({
+          pinnedIds: state.pinnedIds.filter((x) => x !== id),
+        })),
+    }),
+    {
+      name: "unsloth_pinned_projects",
+      merge: (persisted, current) => {
+        const saved = persisted as Partial<PinnedProjectsState> | undefined;
+        return {
+          ...current,
+          pinnedIds: Array.isArray(saved?.pinnedIds) ? saved.pinnedIds : [],
+        };
+      },
+    },
+  ),
+);
diff --git a/studio/frontend/src/features/chat/sync-external-providers.ts b/studio/frontend/src/features/chat/sync-external-providers.ts
new file mode 100644
index 0000000000..cd966f7fd4
--- /dev/null
+++ b/studio/frontend/src/features/chat/sync-external-providers.ts
@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import {
+  type ProviderRegistryEntry,
+  listProviderConfigs,
+  listProviderRegistry,
+  updateProviderConfig,
+} from "./api/providers-api";
+import {
+  CUSTOM_BACKEND_PROVIDER_TYPE,
+  CUSTOM_PROVIDER_PRESETS,
+  type ExternalProviderConfig,
+  isCustomProviderType,
+  isPromptCacheTtl,
+  LEGACY_CUSTOM_PROVIDER_TYPE,
+  supportsProviderPromptCaching,
+  supportsProviderPromptCacheTtl,
+  supportsProviderReasoningToggle,
+} from "./external-providers";
+
+const ANTHROPIC_DATED_SNAPSHOT_SUFFIX = /-\d{8}$/;
+const OPENAI_DEPRECATED_MODELS = new Set(["gpt-5.3"]);
+const OPENROUTER_EXCLUDED_MODELS = new Set([
+  "google/chirp-3",
+  "kwaivgi/kling-v3.0-pro",
+  "openai/whisper-1",
+  "openai/gpt-4o-mini-transcribe",
+  "recraft/recraft-v4-pro",
+]);
+
+function normalizeUrl(input: string): string {
+  return input.trim().replace(/\/+$/, "");
+}
+
+export function resolveUiProviderTypeFromConfig(
+  configProviderType: string,
+  configDisplayName: string | null | undefined,
+  configBaseUrl: string | null | undefined,
+  registryRows: ProviderRegistryEntry[],
+  existingProviderType: string | undefined,
+): string {
+  if (existingProviderType && isCustomProviderType(existingProviderType)) {
+    return existingProviderType;
+  }
+  if (configProviderType !== CUSTOM_BACKEND_PROVIDER_TYPE) {
+    return configProviderType;
+  }
+  const displayName = (configDisplayName ?? "").trim().toLowerCase();
+  const matchingCustomPreset = CUSTOM_PROVIDER_PRESETS.find(
+    (preset) => preset.displayName.toLowerCase() === displayName,
+  );
+  if (matchingCustomPreset) {
+    return matchingCustomPreset.providerType;
+  }
+  const openAiRegistry = registryRows.find(
+    (entry) => entry.provider_type === CUSTOM_BACKEND_PROVIDER_TYPE,
+  );
+  if (!openAiRegistry) {
+    return configProviderType;
+  }
+  const openAiDisplayName = openAiRegistry.display_name.trim().toLowerCase();
+  if (displayName.length > 0 && displayName !== openAiDisplayName) {
+    return LEGACY_CUSTOM_PROVIDER_TYPE;
+  }
+  const configUrl = normalizeUrl(configBaseUrl ?? "");
+  const defaultUrl = normalizeUrl(openAiRegistry.base_url ?? "");
+  if (configUrl.length > 0 && configUrl !== defaultUrl) {
+    return LEGACY_CUSTOM_PROVIDER_TYPE;
+  }
+  return configProviderType;
+}
+
+export function pruneProviderModelIds(
+  providerType: string,
+  modelIds: string[],
+): string[] {
+  if (providerType === "anthropic") {
+    return modelIds.filter((id) => !ANTHROPIC_DATED_SNAPSHOT_SUFFIX.test(id));
+  }
+  if (providerType === "openai") {
+    return modelIds.filter((id) => !OPENAI_DEPRECATED_MODELS.has(id));
+  }
+  if (providerType === "openrouter") {
+    return modelIds.filter((id) => !OPENROUTER_EXCLUDED_MODELS.has(id));
+  }
+  return modelIds;
+}
+
+/** Carry browser-local provider knobs through a backend sync rebuild. */
+export function mergeLocalProviderOptions(
+  existing: ExternalProviderConfig | undefined,
+  synced: ExternalProviderConfig,
+): ExternalProviderConfig {
+  if (!existing) {
+    return synced;
+  }
+  const providerType = synced.providerType;
+  return {
+    ...synced,
+    enablePromptCaching: supportsProviderPromptCaching(providerType)
+      ? (existing.enablePromptCaching ?? synced.enablePromptCaching ?? true)
+      : undefined,
+    promptCacheTtl:
+      supportsProviderPromptCacheTtl(providerType) &&
+      isPromptCacheTtl(existing.promptCacheTtl)
+        ? existing.promptCacheTtl
+        : synced.promptCacheTtl,
+    isReasoningModel: supportsProviderReasoningToggle(providerType)
+      ? (existing.isReasoningModel ?? synced.isReasoningModel)
+      : undefined,
+    openaiContainerTtlMinutes:
+      providerType === "openai" &&
+      typeof existing.openaiContainerTtlMinutes === "number" &&
+      existing.openaiContainerTtlMinutes >= 1
+        ? Math.min(existing.openaiContainerTtlMinutes, 20)
+        : synced.openaiContainerTtlMinutes,
+  };
+}
+
+/** Merge enabled backend provider configs with local store state. */
+export async function syncExternalProvidersFromBackend(
+  existingProviders: ExternalProviderConfig[],
+): Promise<ExternalProviderConfig[]> {
+  const [registryRows, configRows] = await Promise.all([
+    listProviderRegistry(),
+    listProviderConfigs(),
+  ]);
+
+  const existingById = new Map<string, ExternalProviderConfig>();
+  for (const provider of existingProviders) {
+    existingById.set(provider.id, provider);
+  }
+
+  const backfillTasks: Promise<unknown>[] = [];
+  const syncedProviders = configRows
+    .filter((config) => config.is_enabled)
+    .map((config) => {
+      const existing = existingById.get(config.id);
+      const uiProviderType = resolveUiProviderTypeFromConfig(
+        config.provider_type,
+        config.display_name,
+        config.base_url,
+        registryRows,
+        existing?.providerType,
+      );
+      const createdAt = Number.isFinite(Date.parse(config.created_at))
+        ? Date.parse(config.created_at)
+        : Date.now();
+      const updatedAt = Number.isFinite(Date.parse(config.updated_at))
+        ? Date.parse(config.updated_at)
+        : Date.now();
+      const registryEntry =
+        registryRows.find((entry) => entry.provider_type === uiProviderType) ??
+        registryRows.find((entry) => entry.provider_type === config.provider_type);
+      const defaultModels = pruneProviderModelIds(
+        uiProviderType,
+        registryEntry?.default_models ?? [],
+      );
+      const serverModels = pruneProviderModelIds(
+        uiProviderType,
+        config.models ?? [],
+      );
+      const serverAvailableModels = pruneProviderModelIds(
+        uiProviderType,
+        config.available_models ?? [],
+      );
+      const savedModels = existing?.models ?? [];
+      const savedAvailableModels = existing?.availableModels ?? [];
+      const resolvedModels = pruneProviderModelIds(
+        uiProviderType,
+        serverModels.length > 0
+          ? serverModels
+          : savedModels.length > 0
+            ? savedModels
+            : defaultModels,
+      );
+      const resolvedAvailableModels = pruneProviderModelIds(
+        uiProviderType,
+        serverAvailableModels.length > 0
+          ? serverAvailableModels
+          : savedAvailableModels.length > 0
+            ? savedAvailableModels
+            : defaultModels,
+      );
+      const needsModelBackfill =
+        serverModels.length === 0 && savedModels.length > 0;
+      const needsAvailableBackfill =
+        serverAvailableModels.length === 0 && savedAvailableModels.length > 0;
+      if (needsModelBackfill || needsAvailableBackfill) {
+        backfillTasks.push(
+          updateProviderConfig(config.id, {
+            models: resolvedModels,
+            availableModels: resolvedAvailableModels,
+          }),
+        );
+      }
+      const synced: ExternalProviderConfig = {
+        id: config.id,
+        providerType: uiProviderType,
+        name: config.display_name,
+        baseUrl: config.base_url ?? "",
+        models: resolvedModels,
+        availableModels: resolvedAvailableModels,
+        enablePromptCaching: supportsProviderPromptCaching(uiProviderType)
+          ? (existing?.enablePromptCaching ?? true)
+          : undefined,
+        isReasoningModel: supportsProviderReasoningToggle(uiProviderType)
+          ? existing?.isReasoningModel === true
+          : undefined,
+        createdAt: existing?.createdAt ?? createdAt,
+        updatedAt,
+      };
+      return mergeLocalProviderOptions(existing, synced);
+    });
+
+  if (backfillTasks.length > 0) {
+    await Promise.allSettled(backfillTasks);
+  }
+  return syncedProviders;
+}
diff --git a/studio/frontend/src/features/chat/thread-sidebar.tsx b/studio/frontend/src/features/chat/thread-sidebar.tsx
index 9e65fc5749..bd1fb9d87c 100644
--- a/studio/frontend/src/features/chat/thread-sidebar.tsx
+++ b/studio/frontend/src/features/chat/thread-sidebar.tsx
@@ -42,6 +42,7 @@ import {
   PencilEdit02Icon,
 } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
+import { isDownloadCancelled } from "@/lib/native-files";
 import { toast } from "sonner";
 import { useChatRuntimeStore } from "./stores/chat-runtime-store";
 import type { ChatView } from "./types";
@@ -133,9 +134,13 @@ export function ThreadSidebar({
   ) {
     try {
       const ids = await getThreadIdsForItem(item);
-      await Promise.all(ids.map((id) => fn(id)));
-    } catch {
-      toast.error("Export failed.");
+      for (const id of ids) {
+        await fn(id);
+      }
+    } catch (error) {
+      if (!isDownloadCancelled(error)) {
+        toast.error("Export failed.");
+      }
     }
   }
 
@@ -162,8 +167,10 @@ export function ThreadSidebar({
       } else {
         await exportBulkConversationsSeparate(ids, fmt, basename);
       }
-    } catch {
-      toast.error("Export failed.");
+    } catch (error) {
+      if (!isDownloadCancelled(error)) {
+        toast.error("Export failed.");
+      }
     }
   }
 
@@ -259,7 +266,7 @@ export function ThreadSidebar({
                   >
                     {item.isFork ? (
                       <span
-                        className="mr-1 rounded-sm bg-primary/10 px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-wide text-primary"
+                        className="mr-1 rounded-sm bg-primary/10 px-1.5 py-0.5 text-ui-10 font-semibold uppercase tracking-wide text-primary"
                         title="Forked from another chat"
                       >
                         fork
diff --git a/studio/frontend/src/features/chat/types/api.ts b/studio/frontend/src/features/chat/types/api.ts
index d72c406fdd..6c3e919efe 100644
--- a/studio/frontend/src/features/chat/types/api.ts
+++ b/studio/frontend/src/features/chat/types/api.ts
@@ -65,6 +65,18 @@ export interface LoadModelRequest {
    * of by layer for GGUF models. Multi-GPU only; no effect on a single GPU.
    */
   tensor_parallel?: boolean | null;
+  /** GPU memory strategy for GGUF models. "auto" (default): Unsloth selects GPUs
+   *  and caps context to fit VRAM. "manual": you own the offload -- gpu_layers
+   *  -1 (Auto) hands sizing to llama.cpp's --fit, >= 0 pins layers/n_cpu_moe. */
+  gpu_memory_mode?: "auto" | "manual";
+  /** Manual mode: layers to offload to GPU (--gpu-layers, --fit off); -1 = Auto (--fit). */
+  gpu_layers?: number;
+  /** Manual mode: MoE expert layers to keep on CPU (--n-cpu-moe); 0 = none. */
+  n_cpu_moe?: number;
+  /** Manual mode: relative model share per GPU (--tensor-split), in GPU order. */
+  tensor_split?: number[] | null;
+  /** Picked physical GPU indices (omit/empty = automatic). */
+  gpu_ids?: number[];
 }
 
 export interface ValidateModelResponse {
@@ -80,6 +92,16 @@ export interface ValidateModelResponse {
   requires_security_review?: boolean;
   /** Native context length from the local GGUF header; null until downloaded. */
   context_length?: number | null;
+  /** Total layer count (GGUF block_count); the manual gpu-layers ceiling is
+   * this + 1 (llama.cpp counts the output layer as offloadable too); null
+   *  until downloaded. */
+  layer_count?: number | null;
+  /** MoE expert-layer count from the GGUF header (manual --n-cpu-moe ceiling);
+   *  0 for dense models, null until downloaded. */
+  moe_layer_count?: number | null;
+  /** Embedded GGUF chat template, returned when include_chat_template is set
+   *  (native lease-backed picks); null for non-GGUF, over-cap, or not read. */
+  chat_template?: string | null;
   /** Architecture only shipped by a newer transformers; UI pauses on the upgrade dialog. */
   requires_transformers_upgrade?: boolean;
   /** Set only when requires_transformers_upgrade. */
@@ -159,6 +181,17 @@ export interface LoadModelResponse {
   spec_draft_n_max?: number | null;
   /** Whether tensor-parallel split (--split-mode tensor) is active. */
   tensor_parallel?: boolean;
+  gpu_memory_mode?: "auto" | "manual";
+  gpu_layers?: number;
+  n_cpu_moe?: number;
+  tensor_split?: number[] | null;
+  n_layers?: number | null;
+  /** Model's MoE expert-layer count (the n_cpu_moe ceiling); 0 if not MoE. */
+  n_moe_layers?: number;
+  /** Effective GPU placement after fit-time narrowing. */
+  gpu_ids?: number[] | null;
+  /** User-requested GPU placement pool before fit-time narrowing. */
+  requested_gpu_ids?: number[] | null;
 }
 
 export interface UnloadModelRequest {
@@ -203,6 +236,20 @@ export interface InferenceStatusResponse {
   spec_draft_n_max?: number | null;
   /** Whether tensor-parallel split (--split-mode tensor) is active. */
   tensor_parallel?: boolean;
+  gpu_memory_mode?: "auto" | "manual";
+  gpu_layers?: number;
+  n_cpu_moe?: number;
+  tensor_split?: number[] | null;
+  /** n_ctx the active GGUF load was invoked with (0 = Auto); re-seeds a
+   * Manual + Auto-layers context pin on hydration. Null for non-GGUF. */
+  requested_context_length?: number | null;
+  /** Effective GPU placement after fit-time narrowing. */
+  gpu_ids?: number[] | null;
+  /** User-requested GPU placement pool before fit-time narrowing. */
+  requested_gpu_ids?: number[] | null;
+  n_layers?: number | null;
+  /** Model's MoE expert-layer count (the n_cpu_moe ceiling); 0 if not MoE. */
+  n_moe_layers?: number;
   /**
    * Why MTP was disabled on the loaded model despite being requested.
    * "binary_no_mtp" / "binary_outdated" -> updating llama.cpp would re-enable
diff --git a/studio/frontend/src/features/chat/utils/archived-chat-export.ts b/studio/frontend/src/features/chat/utils/archived-chat-export.ts
new file mode 100644
index 0000000000..834dfdcf5f
--- /dev/null
+++ b/studio/frontend/src/features/chat/utils/archived-chat-export.ts
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+// Minimal views over the `unknown[]` export fields we filter on.
+type ExportThreadView = {
+  id?: string;
+  archived?: boolean;
+  projectId?: string | null;
+};
+type ExportMessageView = { threadId?: string };
+type ExportProjectView = { id?: string };
+
+// Full chat-export backup shape, kept structural so the pure filter below
+// stays decoupled from the storage layer that produces it.
+export interface ChatExportData {
+  exportedAt?: string;
+  version?: number;
+  threadCount: number;
+  projects?: unknown[];
+  threads: unknown[];
+  messages: unknown[];
+}
+
+// Restrict a full chat export to archived threads, their messages and the
+// projects those threads belong to. Pure: never mutates the input, and keeps
+// the original thread/message objects so the backup re-imports unchanged.
+export function filterArchivedChatExport<T extends ChatExportData>(
+  full: T,
+): { data: T; archivedCount: number } {
+  const archivedThreads = (full.threads as ExportThreadView[]).filter(
+    (thread) => thread.archived === true,
+  );
+  const archivedThreadIds = new Set(
+    archivedThreads
+      .map((thread) => thread.id)
+      .filter((id): id is string => typeof id === "string"),
+  );
+  const messages = (full.messages as ExportMessageView[]).filter(
+    (message) =>
+      typeof message.threadId === "string" &&
+      archivedThreadIds.has(message.threadId),
+  );
+  const referencedProjectIds = new Set(
+    archivedThreads
+      .map((thread) => thread.projectId)
+      .filter((id): id is string => typeof id === "string"),
+  );
+  const projects = (full.projects as ExportProjectView[] | undefined)?.filter(
+    (project) =>
+      typeof project.id === "string" && referencedProjectIds.has(project.id),
+  );
+  return {
+    data: {
+      ...full,
+      threadCount: archivedThreads.length,
+      projects: projects ?? [],
+      threads: archivedThreads as unknown[],
+      messages: messages as unknown[],
+    },
+    archivedCount: archivedThreads.length,
+  };
+}
diff --git a/studio/frontend/src/features/chat/utils/chat-attachment-events.ts b/studio/frontend/src/features/chat/utils/chat-attachment-events.ts
new file mode 100644
index 0000000000..dbde157890
--- /dev/null
+++ b/studio/frontend/src/features/chat/utils/chat-attachment-events.ts
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+/**
+ * Notifies loaded chat runtimes when the Data tab deletes a stored attachment.
+ * Without this, the active thread's in-memory repository still holds the
+ * attachment, and any later repo-to-storage sync (e.g. deleting a message in
+ * that thread) writes it back, undoing the deletion.
+ */
+
+import forge from "node-forge";
+
+export type ChatAttachmentDeletedEvent = {
+  messageId: string;
+  attachmentId: string;
+};
+
+const CONTENT_PART_ID_PREFIX = "content-part-sha256-";
+const URI_SCHEME_RE = /^[A-Za-z][A-Za-z0-9+.-]*:/;
+
+function isLocallyStoredBlob(value: string): boolean {
+  const candidate = value.trimStart();
+  if (!candidate) return false;
+  if (candidate.slice(0, 5).toLowerCase() === "data:") return true;
+  if (candidate.startsWith("//") || candidate.startsWith("\\\\")) {
+    return false;
+  }
+  return !URI_SCHEME_RE.test(candidate);
+}
+
+function stableJson(value: unknown): string {
+  if (Array.isArray(value)) {
+    return `[${value
+      .map((item) => (item === undefined ? "null" : stableJson(item)))
+      .join(",")}]`;
+  }
+  if (value && typeof value === "object") {
+    const record = value as Record<string, unknown>;
+    return `{${Object.keys(record)
+      .filter((key) => record[key] !== undefined)
+      .sort()
+      .map((key) => `${JSON.stringify(key)}:${stableJson(record[key])}`)
+      .join(",")}}`;
+  }
+  return JSON.stringify(value) ?? "null";
+}
+
+/** Canonical payload used to detect whether an async hash still describes the
+ * current message content. */
+export function chatContentPartAttachmentSignature(
+  part: unknown,
+): string | null {
+  if (!part || typeof part !== "object") return null;
+  const record = part as Record<string, unknown>;
+  let payload: ["image" | "audio", unknown] | null = null;
+  if (
+    typeof record.image === "string" &&
+    record.image.slice(0, 5).toLowerCase() === "data:"
+  ) {
+    payload = ["image", record.image];
+  } else if (
+    typeof record.audio === "string" &&
+    isLocallyStoredBlob(record.audio)
+  ) {
+    payload = ["audio", record.audio];
+  } else if (record.audio && typeof record.audio === "object") {
+    const data = (record.audio as Record<string, unknown>).data;
+    if (typeof data === "string" && isLocallyStoredBlob(data)) {
+      payload = ["audio", record.audio];
+    }
+  }
+  if (!payload) return null;
+
+  return stableJson(payload);
+}
+
+/** Mirrors the backend's stable content-part identity without adding private
+ * metadata to the message payload sent to inference. */
+export async function chatContentPartAttachmentIdFromSignature(
+  signature: string,
+): Promise<string> {
+  let hex: string | null = null;
+  const subtle = globalThis.crypto?.subtle;
+  if (subtle) {
+    try {
+      const digest = await subtle.digest(
+        "SHA-256",
+        new TextEncoder().encode(signature),
+      );
+      hex = Array.from(new Uint8Array(digest), (byte) =>
+        byte.toString(16).padStart(2, "0"),
+      ).join("");
+    } catch {
+      // Fall through to the pure-JS implementation below. Some embedded
+      // browsers expose crypto.subtle but reject it outside a secure context.
+    }
+  }
+  if (hex === null) {
+    const digest = forge.md.sha256.create();
+    digest.update(signature, "utf8");
+    hex = digest.digest().toHex();
+  }
+  return `${CONTENT_PART_ID_PREFIX}${hex}`;
+}
+
+type Listener = (event: ChatAttachmentDeletedEvent) => void | Promise<void>;
+
+const listeners = new Set<Listener>();
+
+export function onChatAttachmentDeleted(listener: Listener): () => void {
+  listeners.add(listener);
+  return () => {
+    listeners.delete(listener);
+  };
+}
+
+export function emitChatAttachmentDeleted(
+  event: ChatAttachmentDeletedEvent,
+): void {
+  for (const listener of [...listeners]) {
+    void listener(event);
+  }
+}
diff --git a/studio/frontend/src/features/chat/utils/chat-history-storage.ts b/studio/frontend/src/features/chat/utils/chat-history-storage.ts
index 00df3657b1..2ed17c26a0 100644
--- a/studio/frontend/src/features/chat/utils/chat-history-storage.ts
+++ b/studio/frontend/src/features/chat/utils/chat-history-storage.ts
@@ -324,7 +324,7 @@ async function importLegacyChatsIfNeeded(): Promise<void> {
   if (legacyChatImportPromise) return legacyChatImportPromise;
 
   legacyChatImportPromise = (async () => {
-    // Fast-path: no Dexie DB -- new user, never had browser-only Studio.
+    // Fast-path: no Dexie DB -- new user, never had browser-only Unsloth.
     if (await dexieDbAbsent()) {
       markLegacyChatImportDone();
       return;
diff --git a/studio/frontend/src/features/chat/utils/chat-settings-storage.ts b/studio/frontend/src/features/chat/utils/chat-settings-storage.ts
index 4899cb9c83..48acfdee40 100644
--- a/studio/frontend/src/features/chat/utils/chat-settings-storage.ts
+++ b/studio/frontend/src/features/chat/utils/chat-settings-storage.ts
@@ -8,6 +8,7 @@ import {
   type PersistedChatSettings,
   type PersistedInferenceParams,
 } from "../api/chat-settings-api";
+import { normalizePresetLoadConfig } from "../presets/preset-load-config";
 import {
   BUILTIN_PRESETS,
   defaultInferenceParams,
@@ -152,6 +153,7 @@ function sanitizeInferenceParams(
 }
 
 function toFullPreset(preset: PersistedChatPreset): Preset {
+  const loadConfig = normalizePresetLoadConfig(preset.loadConfig);
   return {
     name: preset.name,
     params: {
@@ -159,6 +161,7 @@ function toFullPreset(preset: PersistedChatPreset): Preset {
       ...preset.params,
       checkpoint: defaultInferenceParams.checkpoint,
     },
+    ...(loadConfig ? { loadConfig } : {}),
   };
 }
 
@@ -174,7 +177,12 @@ function sanitizeCustomPresets(
       const name = item.name.trim();
       if (!name) return null;
       const params = sanitizeInferenceParams(item.params);
-      return { name, params: params ?? {} };
+      const loadConfig = normalizePresetLoadConfig(item.loadConfig);
+      return {
+        name,
+        params: params ?? {},
+        ...(loadConfig ? { loadConfig } : {}),
+      };
     })
     .filter((preset): preset is PersistedChatPreset => preset !== null);
 
@@ -183,6 +191,7 @@ function sanitizeCustomPresets(
     (preset, index) => ({
       name: preset.name,
       params: presets[index]?.params ?? {},
+      ...(preset.loadConfig ? { loadConfig: preset.loadConfig } : {}),
     }),
   );
 }
diff --git a/studio/frontend/src/features/chat/utils/download-json.ts b/studio/frontend/src/features/chat/utils/download-json.ts
new file mode 100644
index 0000000000..0c5ce00ff9
--- /dev/null
+++ b/studio/frontend/src/features/chat/utils/download-json.ts
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+// Save `data` as a pretty-printed JSON file via a temporary object URL. Uses
+// only the standard Blob/anchor download path so it works in every browser.
+export function triggerJsonDownload(data: unknown, filename: string): void {
+  const blob = new Blob([JSON.stringify(data, null, 2)], {
+    type: "application/json",
+  });
+  const url = URL.createObjectURL(blob);
+  const a = document.createElement("a");
+  a.href = url;
+  a.download = filename;
+  document.body.appendChild(a);
+  a.click();
+  a.remove();
+  URL.revokeObjectURL(url);
+}
diff --git a/studio/frontend/src/features/chat/utils/export-chat-history.ts b/studio/frontend/src/features/chat/utils/export-chat-history.ts
index 5faf4dc08a..6f641a9fa9 100644
--- a/studio/frontend/src/features/chat/utils/export-chat-history.ts
+++ b/studio/frontend/src/features/chat/utils/export-chat-history.ts
@@ -1,21 +1,43 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
+import { downloadFile } from "@/lib/native-files";
+
+import { filterArchivedChatExport } from "./archived-chat-export";
 import { buildStoredChatExport } from "./chat-history-storage";
 
 export const buildChatExport = buildStoredChatExport;
 
+function dateStamp(): string {
+  // Date only (no colons) so the filename is valid on every OS.
+  return new Date().toISOString().slice(0, 10);
+}
+
 export async function downloadChatExport(): Promise<void> {
   const data = await buildChatExport();
-  const blob = new Blob([JSON.stringify(data, null, 2)], {
-    type: "application/json",
-  });
-  const url = URL.createObjectURL(blob);
-  const a = document.createElement("a");
-  a.href = url;
-  a.download = `unsloth-chats-${new Date().toISOString().slice(0, 10)}.json`;
-  document.body.appendChild(a);
-  a.click();
-  a.remove();
-  URL.revokeObjectURL(url);
+  await downloadFile(
+    JSON.stringify(data, null, 2),
+    `unsloth-chats-${dateStamp()}.json`,
+    "application/json",
+  );
+}
+
+// Full backup restricted to archived chats. Returns the archived thread count.
+export async function buildArchivedChatExport() {
+  return filterArchivedChatExport(await buildChatExport());
+}
+
+// Download only the archived chats. Returns how many were exported; skips the
+// download entirely when there are none.
+export async function downloadArchivedChatExport(): Promise<number> {
+  const { data, archivedCount } = await buildArchivedChatExport();
+  if (archivedCount === 0) {
+    return 0;
+  }
+  await downloadFile(
+    JSON.stringify(data, null, 2),
+    `unsloth-archived-chats-${dateStamp()}.json`,
+    "application/json",
+  );
+  return archivedCount;
 }
diff --git a/studio/frontend/src/features/data-recipes/data/recipes-db.ts b/studio/frontend/src/features/data-recipes/data/recipes-db.ts
index f89707e159..3ffe09c2d2 100644
--- a/studio/frontend/src/features/data-recipes/data/recipes-db.ts
+++ b/studio/frontend/src/features/data-recipes/data/recipes-db.ts
@@ -16,11 +16,40 @@ db.version(1).stores({
 });
 
 const recentRecipeCache = new Map<string, RecipeRecord>();
+let cachedRecipeList: RecipeRecord[] = [];
+let recipeListReady = false;
+let recipeListRequest: Promise<RecipeRecord[]> | null = null;
 
 export function listRecipes(): Promise<RecipeRecord[]> {
   return db.recipes.orderBy("updatedAt").reverse().toArray();
 }
 
+function cacheRecipeList(recipes: RecipeRecord[]): RecipeRecord[] {
+  for (const recipe of recipes) {
+    writeRecipeCache(recipe);
+  }
+  cachedRecipeList = recipes;
+  recipeListReady = true;
+  return recipes;
+}
+
+export function preloadRecipes(): Promise<RecipeRecord[]> {
+  if (recipeListReady) {
+    return Promise.resolve(cachedRecipeList);
+  }
+  if (recipeListRequest) {
+    return recipeListRequest;
+  }
+
+  const request = listRecipes()
+    .then(cacheRecipeList)
+    .finally(() => {
+      recipeListRequest = null;
+    });
+  recipeListRequest = request;
+  return request;
+}
+
 export function getRecipe(id: string): Promise<RecipeRecord | undefined> {
   return db.recipes.get(id);
 }
@@ -55,12 +84,21 @@ export async function saveRecipe(
   };
   await db.recipes.put(record);
   writeRecipeCache(record);
+  if (recipeListReady) {
+    cachedRecipeList = [
+      record,
+      ...cachedRecipeList.filter((recipe) => recipe.id !== record.id),
+    ].sort((a, b) => b.updatedAt - a.updatedAt);
+  }
   return record;
 }
 
 export async function deleteRecipe(id: string): Promise<void> {
   await db.recipes.delete(id);
   recentRecipeCache.delete(id);
+  if (recipeListReady) {
+    cachedRecipeList = cachedRecipeList.filter((recipe) => recipe.id !== id);
+  }
 }
 
 export function createRecipeDraft(): Promise<RecipeRecord> {
@@ -87,15 +125,13 @@ export function useRecipes(): {
   recipes: RecipeRecord[];
   ready: boolean;
 } {
-  const [recipes, setRecipes] = useState<RecipeRecord[]>([]);
-  const [ready, setReady] = useState(false);
+  const [recipes, setRecipes] = useState<RecipeRecord[]>(cachedRecipeList);
+  const [ready, setReady] = useState(recipeListReady);
 
   useEffect(() => {
     const sub = liveQuery(() => listRecipes()).subscribe({
       next: (value) => {
-        for (const recipe of value) {
-          writeRecipeCache(recipe);
-        }
+        cacheRecipeList(value);
         setRecipes(value);
         setReady(true);
       },
diff --git a/studio/frontend/src/features/data-recipes/index.ts b/studio/frontend/src/features/data-recipes/index.ts
index d085096e0d..a75dd7075a 100644
--- a/studio/frontend/src/features/data-recipes/index.ts
+++ b/studio/frontend/src/features/data-recipes/index.ts
@@ -3,3 +3,4 @@
 
 export { DataRecipesPage } from "./pages/data-recipes-page";
 export { EditRecipePage } from "./pages/edit-recipe-page";
+export { preloadRecipes } from "./data/recipes-db";
diff --git a/studio/frontend/src/features/data-recipes/pages/data-recipes-page.tsx b/studio/frontend/src/features/data-recipes/pages/data-recipes-page.tsx
index 088d016894..7716671151 100644
--- a/studio/frontend/src/features/data-recipes/pages/data-recipes-page.tsx
+++ b/studio/frontend/src/features/data-recipes/pages/data-recipes-page.tsx
@@ -280,7 +280,7 @@ function LearningRecipeCards({
                       <Badge
                         key={`${template.title}-${badge}`}
                         variant="outline"
-                        className="h-5 shrink-0 px-1.5 text-[10px] dark:text-zinc-300"
+                        className="h-5 shrink-0 px-1.5 text-ui-10 dark:text-zinc-300"
                       >
                         {badge}
                       </Badge>
@@ -288,7 +288,7 @@ function LearningRecipeCards({
                     {extraLearningBadgeCount > 0 ? (
                       <Badge
                         variant="outline"
-                        className="h-5 shrink-0 px-1.5 text-[10px] dark:text-zinc-300"
+                        className="h-5 shrink-0 px-1.5 text-ui-10 dark:text-zinc-300"
                       >
                         +{extraLearningBadgeCount}
                       </Badge>
@@ -296,7 +296,7 @@ function LearningRecipeCards({
                     {isReady ? null : (
                       <Badge
                         variant="secondary"
-                        className="h-5 shrink-0 px-1.5 text-[10px] dark:text-zinc-300"
+                        className="h-5 shrink-0 px-1.5 text-ui-10 dark:text-zinc-300"
                       >
                         Soon
                       </Badge>
@@ -403,7 +403,7 @@ export function DataRecipesPage(): ReactElement {
       <main className="mx-auto w-full max-w-7xl px-5 py-8 sm:px-9">
         <div className="flex items-center justify-between gap-4">
           <div>
-            <h1 className="text-[30px] font-semibold leading-[1.04] tracking-[-0.028em] text-foreground sm:text-[34px]">
+            <h1 className="text-ui-30 font-semibold leading-[1.04] tracking-[-0.028em] text-foreground sm:text-ui-34">
               Data Recipes
             </h1>
             <p className="mt-1 text-sm text-muted-foreground">
diff --git a/studio/frontend/src/features/export/components/export-run-panel.tsx b/studio/frontend/src/features/export/components/export-run-panel.tsx
index 29ba5a703b..9d938a5ee3 100644
--- a/studio/frontend/src/features/export/components/export-run-panel.tsx
+++ b/studio/frontend/src/features/export/components/export-run-panel.tsx
@@ -2,7 +2,6 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { Button } from "@/components/ui/button";
-import { FolderBrowser } from "@/components/assistant-ui/model-selector/folder-browser";
 import { Input } from "@/components/ui/input";
 import {
   InputGroup,
@@ -17,6 +16,7 @@ import {
   TooltipContent,
   TooltipTrigger,
 } from "@/components/ui/tooltip";
+import { FolderBrowser } from "@/features/model-picker";
 import {
   AlertCircleIcon,
   ArrowRight01Icon,
@@ -28,17 +28,17 @@ import {
 import { HugeiconsIcon } from "@hugeicons/react";
 import { useEffect, useRef, useState } from "react";
 import { useShallow } from "zustand/react/shallow";
+import type { ExportLogEntry } from "../api/export-api";
 import {
   EXPORT_METHODS,
   type ExportMethod,
   findMergedFormat,
 } from "../constants";
-import type { ExportLogEntry } from "../api/export-api";
 import { getExportLogLineClass } from "../lib/log-style";
 import {
+  type ExportDestination,
   selectExportProgressPercent,
   useExportRuntimeStore,
-  type ExportDestination,
 } from "../stores/export-runtime-store";
 
 function useElapsedSeconds(startedAt: number | null, running: boolean): number {
@@ -165,7 +165,9 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
 
   const isExporting = run.isExporting;
   const isTerminal =
-    run.phase === "success" || run.phase === "error" || run.phase === "canceled";
+    run.phase === "success" ||
+    run.phase === "error" ||
+    run.phase === "canceled";
   const showConfig = run.phase === "idle";
   // Gate the log area on the active run's method (from the store) as well as the
   // local form selection, so it stays visible after navigating away and back
@@ -197,7 +199,9 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
     setFollowTail(nearBottom);
   };
 
-  const methodTitle = EXPORT_METHODS.find((m) => m.value === exportMethod)?.title;
+  const methodTitle = EXPORT_METHODS.find(
+    (m) => m.value === exportMethod,
+  )?.title;
   const summary = run.summary;
   const summaryBaseModel = summary?.baseModelName ?? baseModelName;
   const summaryCheckpoint = summary?.checkpointLabel ?? checkpoint;
@@ -274,7 +278,7 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
               </div>
               <div className="flex items-stretch gap-2">
                 <Input
-                  className="min-w-0 flex-1 font-mono text-[12px]"
+                  className="min-w-0 flex-1 font-mono text-ui-12"
                   value={saveDirectory}
                   onChange={(e) => onSaveDirectoryChange(e.target.value)}
                   spellCheck={false}
@@ -290,19 +294,22 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
                       onClick={() => setFolderBrowserOpen(true)}
                       aria-label="Browse save folder"
                     >
-                      <HugeiconsIcon icon={FolderSearchIcon} className="size-4" />
+                      <HugeiconsIcon
+                        icon={FolderSearchIcon}
+                        className="size-4"
+                      />
                     </Button>
                   </TooltipTrigger>
                   <TooltipContent>Browse</TooltipContent>
                 </Tooltip>
               </div>
-              <p className="text-[11px] text-muted-foreground/70">
+              <p className="text-ui-11 text-muted-foreground/70">
                 {saveDirectory !== defaultSaveDirectory ? (
                   <>Default: {defaultSaveDirectory}</>
                 ) : (
                   <>
-                    Paste an absolute path if the folder browser cannot reach the
-                    drive.
+                    Paste an absolute path if the folder browser cannot reach
+                    the drive.
                   </>
                 )}
               </p>
@@ -343,7 +350,7 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
                         href="https://huggingface.co/settings/tokens"
                         target="_blank"
                         rel="noopener noreferrer"
-                        className="flex items-center gap-1 text-[11px] text-emerald-600 hover:text-emerald-700 transition-colors"
+                        className="flex items-center gap-1 text-ui-11 text-emerald-600 hover:text-emerald-700 transition-colors"
                       >
                         Get token
                         <HugeiconsIcon icon={ArrowRight01Icon} className="size-3" />
@@ -362,7 +369,7 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
                         onChange={(e) => onHfTokenChange(e.target.value)}
                       />
                     </InputGroup>
-                    <p className="text-[11px] text-muted-foreground/70">
+                    <p className="text-ui-11 text-muted-foreground/70">
                       Leave empty if already logged in via CLI.
                     </p>
                   </div>
@@ -410,14 +417,17 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
                     : [];
               const showLabels = items.length > 1;
               return items.map((o, i) => (
-                <div key={`${o.path}-${i}`} className="flex min-w-0 flex-col gap-0.5">
+                <div
+                  key={`${o.path}-${i}`}
+                  className="flex min-w-0 flex-col gap-0.5"
+                >
                   {showLabels && o.label ? (
                     <span className="text-xs text-emerald-700/80 dark:text-emerald-300/80">
                       {o.label}
                     </span>
                   ) : null}
                   <code
-                    className="select-all break-all font-mono text-[12px] text-foreground/90"
+                    className="select-all break-all font-mono text-ui-12 text-foreground/90"
                     title={o.path}
                   >
                     {o.path}
@@ -431,14 +441,22 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
 
       {run.phase === "canceled" && (
         <div className="flex items-start gap-2 rounded-lg bg-amber-500/10 p-3 text-sm text-amber-700 dark:text-amber-300">
-          <HugeiconsIcon icon={CancelCircleIcon} className="mt-0.5 size-4 shrink-0" />
-          <span>Export canceled. Training and inference were not affected.</span>
+          <HugeiconsIcon
+            icon={CancelCircleIcon}
+            className="mt-0.5 size-4 shrink-0"
+          />
+          <span>
+            Export canceled. Training and inference were not affected.
+          </span>
         </div>
       )}
 
       {run.phase === "error" && run.error && (
         <div className="flex items-start gap-2 rounded-lg bg-destructive/10 p-3 text-sm text-destructive">
-          <HugeiconsIcon icon={AlertCircleIcon} className="size-4 mt-0.5 shrink-0" />
+          <HugeiconsIcon
+            icon={AlertCircleIcon}
+            className="size-4 mt-0.5 shrink-0"
+          />
           <span>{run.error}</span>
         </div>
       )}
@@ -447,15 +465,21 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
       <div className="rounded-xl bg-muted/50 p-3 text-xs text-muted-foreground flex flex-col gap-1">
         <div className="flex justify-between">
           <span>Base Model</span>
-          <span className="font-medium text-foreground">{summaryBaseModel}</span>
+          <span className="font-medium text-foreground">
+            {summaryBaseModel}
+          </span>
         </div>
         <div className="flex justify-between">
           <span>{isAdapter ? "Checkpoint" : "Model"}</span>
-          <span className="font-medium text-foreground">{summaryCheckpoint}</span>
+          <span className="font-medium text-foreground">
+            {summaryCheckpoint}
+          </span>
         </div>
         <div className="flex justify-between">
           <span>Export Method</span>
-          <span className="font-medium text-foreground">{summaryMethodLabel}</span>
+          <span className="font-medium text-foreground">
+            {summaryMethodLabel}
+          </span>
         </div>
         {summaryMethod === "merged" && summaryFormats.length > 0 && (
           <div className="flex justify-between gap-3">
@@ -479,18 +503,23 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
       {showProgress && (
         <div className="flex flex-col gap-2">
           <div className="flex flex-wrap items-center gap-2">
-            <span className="rounded-full bg-foreground/10 px-2.5 py-1 text-[10px] font-semibold">
+            <span className="rounded-full bg-foreground/10 px-2.5 py-1 text-ui-10 font-semibold">
               {PHASE_LABELS[run.phase] ?? run.phase}
             </span>
             {summaryMethod === "gguf" && run.quantTotal > 1 && (
-              <span className="text-[10px] tabular-nums text-muted-foreground">
-                Quant {Math.min(run.quantIndex + (isExporting ? 1 : 0), run.quantTotal)} of {run.quantTotal}
+              <span className="text-ui-10 tabular-nums text-muted-foreground">
+                Quant{" "}
+                {Math.min(
+                  run.quantIndex + (isExporting ? 1 : 0),
+                  run.quantTotal,
+                )}{" "}
+                of {run.quantTotal}
               </span>
             )}
-            <span className="rounded-full border border-border/60 px-2.5 py-1 text-[10px] font-medium tabular-nums text-muted-foreground">
+            <span className="rounded-full border border-border/60 px-2.5 py-1 text-ui-10 font-medium tabular-nums text-muted-foreground">
               {progress}%
             </span>
-            <span className="text-[10px] tabular-nums text-muted-foreground/70">
+            <span className="text-ui-10 tabular-nums text-muted-foreground/70">
               {formatElapsed(elapsedSeconds)}
             </span>
           </div>
@@ -506,7 +535,10 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
             }
           />
           {run.stage && (
-            <p className="truncate text-[11px] text-muted-foreground/80" title={run.stage}>
+            <p
+              className="truncate text-ui-11 text-muted-foreground/80"
+              title={run.stage}
+            >
               {run.stage}
             </p>
           )}
@@ -520,7 +552,7 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
                 <label className="text-xs font-medium text-muted-foreground">
                   Export output
                 </label>
-                <div className="flex items-center gap-2 text-[11px] text-muted-foreground/80">
+                <div className="flex items-center gap-2 text-ui-11 text-muted-foreground/80">
                   <span
                     className={
                       run.reconnecting
@@ -544,7 +576,7 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
               <div
                 ref={logScrollRef}
                 onScroll={handleLogScroll}
-                className="h-56 w-full overflow-auto rounded-lg border border-border/40 bg-black/85 p-3 font-mono text-[11px] leading-[1.45] text-emerald-200/90"
+                className="h-56 w-full overflow-auto rounded-lg border border-border/40 bg-black/85 p-3 font-mono text-ui-11 leading-[1.45] text-emerald-200/90"
               >
                 {run.logLines.length === 0 ? (
                   <div className="flex h-full items-center justify-center text-muted-foreground/70">
@@ -556,10 +588,7 @@ export function ExportRunPanel(props: ExportRunPanelProps) {
                 ) : (
                   <div className="whitespace-pre-wrap break-words">
                     {run.logLines.map((entry, idx) => (
-                      <div
-                        key={idx}
-                        className={getExportLogLineClass(entry)}
-                      >
+                  <div key={idx} className={getExportLogLineClass(entry)}>
                         {formatLogLine(entry)}
                       </div>
                     ))}
diff --git a/studio/frontend/src/features/export/components/method-picker.tsx b/studio/frontend/src/features/export/components/method-picker.tsx
index 420a7f6146..0ab72b0b4a 100644
--- a/studio/frontend/src/features/export/components/method-picker.tsx
+++ b/studio/frontend/src/features/export/components/method-picker.tsx
@@ -123,7 +123,7 @@ export function MethodPicker({ value, onChange, disabledMethods = [], disabledRe
                   {m.badge && (
                     <Badge
                       variant="secondary"
-                      className="text-[10px] px-1.5 py-0"
+                      className="text-ui-10 px-1.5 py-0"
                     >
                       {m.badge}
                     </Badge>
diff --git a/studio/frontend/src/features/export/components/quant-picker.tsx b/studio/frontend/src/features/export/components/quant-picker.tsx
index 289f6498ce..b8c8e0fc77 100644
--- a/studio/frontend/src/features/export/components/quant-picker.tsx
+++ b/studio/frontend/src/features/export/components/quant-picker.tsx
@@ -61,7 +61,7 @@ export function QuantPicker({ value, onChange, sizes }: QuantPickerProps) {
             </a>
           </TooltipContent>
         </Tooltip>
-        <span className="text-[11px] text-muted-foreground/70">
+        <span className="text-ui-11 text-muted-foreground/70">
           — select one or more
         </span>
       </div>
@@ -90,10 +90,10 @@ export function QuantPicker({ value, onChange, sizes }: QuantPickerProps) {
               )}
               {q.label}
               {sizeLabel && (
-                <span className="text-[10px] opacity-60">{sizeLabel}</span>
+                <span className="text-ui-10 opacity-60">{sizeLabel}</span>
               )}
               {q.recommended && !active && (
-                <span className="rounded-full bg-emerald-100 px-1.5 py-0 text-[9px] font-semibold text-emerald-700 dark:bg-emerald-900 dark:text-emerald-300">
+                <span className="rounded-full bg-emerald-100 px-1.5 py-0 text-ui-9 font-semibold text-emerald-700 dark:bg-emerald-900 dark:text-emerald-300">
                   rec
                 </span>
               )}
@@ -103,13 +103,13 @@ export function QuantPicker({ value, onChange, sizes }: QuantPickerProps) {
       </div>
       {value.length > 0 && (
         <div className="flex items-center gap-3">
-          <span className="text-[11px] text-muted-foreground">
+          <span className="text-ui-11 text-muted-foreground">
             {value.length} selected
           </span>
           <button
             type="button"
             onClick={() => onChange([])}
-            className="text-[11px] text-muted-foreground/70 hover:text-foreground transition-colors"
+            className="text-ui-11 text-muted-foreground/70 hover:text-foreground transition-colors"
           >
             Clear all
           </button>
diff --git a/studio/frontend/src/features/export/export-navigation-cache.ts b/studio/frontend/src/features/export/export-navigation-cache.ts
new file mode 100644
index 0000000000..f026f64525
--- /dev/null
+++ b/studio/frontend/src/features/export/export-navigation-cache.ts
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { type LocalModelInfo, listLocalModels } from "@/features/training";
+import { type ModelCheckpoints, fetchCheckpoints } from "./api/export-api";
+
+let cachedCheckpoints: ModelCheckpoints[] | null = null;
+let checkpointsRequest: Promise<ModelCheckpoints[]> | null = null;
+let cachedLocalModels: LocalModelInfo[] | null = null;
+let localModelsRequest: Promise<LocalModelInfo[]> | null = null;
+
+export function getCachedCheckpoints(): ModelCheckpoints[] | null {
+  return cachedCheckpoints;
+}
+
+export function getCachedLocalModels(): LocalModelInfo[] | null {
+  return cachedLocalModels;
+}
+
+export function refreshCheckpoints(): Promise<ModelCheckpoints[]> {
+  if (checkpointsRequest) {
+    return checkpointsRequest;
+  }
+  const request = fetchCheckpoints()
+    .then((data) => {
+      cachedCheckpoints = data.models;
+      return data.models;
+    })
+    .finally(() => {
+      checkpointsRequest = null;
+    });
+  checkpointsRequest = request;
+  return request;
+}
+
+export function refreshLocalModels(): Promise<LocalModelInfo[]> {
+  if (localModelsRequest) {
+    return localModelsRequest;
+  }
+  const request = listLocalModels()
+    .then((models) => {
+      cachedLocalModels = models;
+      return models;
+    })
+    .finally(() => {
+      localModelsRequest = null;
+    });
+  localModelsRequest = request;
+  return request;
+}
+
+export async function preloadExportData(): Promise<void> {
+  const requests: Promise<unknown>[] = [];
+  if (cachedCheckpoints === null) {
+    requests.push(refreshCheckpoints());
+  }
+  if (cachedLocalModels === null) {
+    requests.push(refreshLocalModels());
+  }
+  await Promise.allSettled(requests);
+}
diff --git a/studio/frontend/src/features/export/export-page.tsx b/studio/frontend/src/features/export/export-page.tsx
index 4cd7958fb8..fc30555253 100644
--- a/studio/frontend/src/features/export/export-page.tsx
+++ b/studio/frontend/src/features/export/export-page.tsx
@@ -44,10 +44,10 @@ import {
 import { usePlatformStore } from "@/config/env";
 import { useHubModelSearch } from "@/features/hub/hooks/use-hub-model-search";
 import { confirmRemoteCodeIfNeeded } from "@/features/security";
+import { prepareHfTokenForUse } from "@/features/hf-auth";
 import { GuidedTour, useGuidedTourController } from "@/features/tour";
 import {
   type LocalModelInfo,
-  listLocalModels,
   useTrainingConfigStore,
 } from "@/features/training";
 import { useDebouncedValue, useHfTokenValidation } from "@/hooks";
@@ -66,7 +66,6 @@ import { useSearch } from "@tanstack/react-router";
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 import { useShallow } from "zustand/react/shallow";
 import type { ModelCheckpoints } from "./api/export-api";
-import { fetchCheckpoints } from "./api/export-api";
 import { ExportRunPanel } from "./components/export-run-panel";
 import { MethodPicker } from "./components/method-picker";
 import { QuantPicker } from "./components/quant-picker";
@@ -82,6 +81,12 @@ import {
   mergedFormatPayload,
 } from "./constants";
 import { useExportSizeEstimate } from "./hooks/use-export-size-estimate";
+import {
+  getCachedCheckpoints,
+  getCachedLocalModels,
+  refreshCheckpoints,
+  refreshLocalModels,
+} from "./export-navigation-cache";
 import {
   isExportPanelActive,
   useExportRuntimeStore,
@@ -171,8 +176,12 @@ export function ExportPage() {
   );
 
   // ---- API-driven checkpoint state ----
-  const [models, setModels] = useState<ModelCheckpoints[]>([]);
-  const [loadingCheckpoints, setLoadingCheckpoints] = useState(true);
+  const [models, setModels] = useState<ModelCheckpoints[]>(
+    () => getCachedCheckpoints() ?? [],
+  );
+  const [loadingCheckpoints, setLoadingCheckpoints] = useState(
+    getCachedCheckpoints() === null,
+  );
   const [checkpointError, setCheckpointError] = useState<string | null>(null);
 
   const [selectedModelIdx, setSelectedModelIdx] = useState<string | null>(null);
@@ -184,8 +193,12 @@ export function ExportPage() {
     null,
   );
   const [localModelInput, setLocalModelInput] = useState("");
-  const [localModels, setLocalModels] = useState<LocalModelInfo[]>([]);
-  const [isLoadingLocalModels, setIsLoadingLocalModels] = useState(true);
+  const [localModels, setLocalModels] = useState<LocalModelInfo[]>(
+    () => getCachedLocalModels() ?? [],
+  );
+  const [isLoadingLocalModels, setIsLoadingLocalModels] = useState(
+    getCachedLocalModels() === null,
+  );
   const [localModelsError, setLocalModelsError] = useState<string | null>(null);
   const debouncedModelQuery = useDebouncedValue(modelInput);
   const debouncedHfToken = useDebouncedValue(hfToken, 500);
@@ -294,16 +307,15 @@ export function ExportPage() {
   // ---- Fetch checkpoints on mount ----
   useEffect(() => {
     let cancelled = false;
-    setLoadingCheckpoints(true);
-    setCheckpointError(null);
-    fetchCheckpoints()
-      .then((data) => {
+    const hadCache = getCachedCheckpoints() !== null;
+    refreshCheckpoints()
+      .then((models) => {
         if (!cancelled) {
-          setModels(data.models);
+          setModels(models);
         }
       })
       .catch((err) => {
-        if (!cancelled) {
+        if (!cancelled && !hadCache) {
           setCheckpointError(
             err instanceof Error ? err.message : "Failed to load checkpoints",
           );
@@ -342,14 +354,15 @@ export function ExportPage() {
 
   // ---- Fetch local models for direct export ----
   useEffect(() => {
-    const controller = new AbortController();
-    void listLocalModels(controller.signal)
+    let cancelled = false;
+    const hadCache = getCachedLocalModels() !== null;
+    void refreshLocalModels()
       .then((models) => {
-        if (controller.signal.aborted) return;
+        if (cancelled) return;
         setLocalModels(models);
       })
       .catch((error) => {
-        if (controller.signal.aborted) return;
+        if (cancelled || hadCache) return;
         setLocalModelsError(
           error instanceof Error
             ? error.message
@@ -357,10 +370,12 @@ export function ExportPage() {
         );
       })
       .finally(() => {
-        if (controller.signal.aborted) return;
+        if (cancelled) return;
         setIsLoadingLocalModels(false);
       });
-    return () => controller.abort();
+    return () => {
+      cancelled = true;
+    };
   }, []);
 
   // ---- Derived state ----
@@ -724,11 +739,17 @@ export function ExportPage() {
     const checkpointPath = selectedCp?.path ?? null;
 
     const pushToHub = destination === "hub";
+    const preparedToken = await prepareHfTokenForUse(hfToken, {
+      allowAnonymous: !pushToHub,
+    });
+    if (!preparedToken.proceed) return;
+    const actionHfToken = preparedToken.token ?? "";
+
     const repoId =
       pushToHub && hfUsername && modelName
         ? `${hfUsername}/${modelName}`
         : undefined;
-    const token = pushToHub && hfToken ? hfToken : undefined;
+    const token = pushToHub && actionHfToken ? actionHfToken : undefined;
     // The GGUF method with the LoRA target reuses the LoRA-adapter export path.
     const effectiveMethod: ExportMethod = ggufAsLora ? "lora" : exportMethod;
     const emitLoraGguf =
@@ -747,7 +768,7 @@ export function ExportPage() {
     if (sourceMode !== "checkpoint") {
       const remoteCodeOk = await confirmRemoteCodeIfNeeded({
         modelName: source,
-        hfToken: hfToken || null,
+        hfToken: actionHfToken || null,
         // An HF source can need trust_remote_code via its YAML default with no
         // auto_map to review; signal it so a YAML-only model does not export
         // with it false.
@@ -767,7 +788,7 @@ export function ExportPage() {
       modelSource,
       trustRemoteCode,
       approvedRemoteCodeFingerprint,
-      loadToken: hfToken || null,
+      loadToken: actionHfToken || null,
       exportMethod: effectiveMethod,
       isAdapter: adapterExport,
       quantLevels,
@@ -874,7 +895,7 @@ export function ExportPage() {
         <GuidedTour {...tour.tourProps} />
 
         <div className="mb-8 flex flex-col gap-0.5">
-          <h1 className="text-[30px] font-semibold leading-[1.04] tracking-[-0.028em] text-foreground sm:text-[34px]">
+          <h1 className="text-ui-30 font-semibold leading-[1.04] tracking-[-0.028em] text-foreground sm:text-ui-34">
             Export Model
           </h1>
           <p className="text-sm text-muted-foreground">
@@ -943,21 +964,21 @@ export function ExportPage() {
                         <TabsTrigger
                           value="local"
                           indicatorClassName="hub-tab-toggle-pill rounded-full"
-                          className="h-9 rounded-full border-0 px-3 text-[12.5px] text-muted-foreground hover:text-foreground data-active:text-foreground data-[state=active]:text-foreground"
+                          className="h-9 rounded-full border-0 px-3 text-ui-12p5 text-muted-foreground hover:text-foreground data-active:text-foreground data-[state=active]:text-foreground"
                         >
                           Local Model
                         </TabsTrigger>
                         <TabsTrigger
                           value="checkpoint"
                           indicatorClassName="hub-tab-toggle-pill rounded-full"
-                          className="h-9 rounded-full border-0 px-3 text-[12.5px] text-muted-foreground hover:text-foreground data-active:text-foreground data-[state=active]:text-foreground"
+                          className="h-9 rounded-full border-0 px-3 text-ui-12p5 text-muted-foreground hover:text-foreground data-active:text-foreground data-[state=active]:text-foreground"
                         >
                           Fine-tuned
                         </TabsTrigger>
                         <TabsTrigger
                           value="hf"
                           indicatorClassName="hub-tab-toggle-pill rounded-full"
-                          className="h-9 rounded-full border-0 px-3 text-[12.5px] text-muted-foreground hover:text-foreground data-active:text-foreground data-[state=active]:text-foreground"
+                          className="h-9 rounded-full border-0 px-3 text-ui-12p5 text-muted-foreground hover:text-foreground data-active:text-foreground data-[state=active]:text-foreground"
                         >
                           Hugging Face
                         </TabsTrigger>
@@ -1268,7 +1289,7 @@ export function ExportPage() {
                                         <span className="block min-w-0 flex-1 truncate">
                                           {model?.display_name ?? id}
                                         </span>
-                                        <span className="ml-auto shrink-0 text-[10px] text-muted-foreground">
+                                        <span className="ml-auto shrink-0 text-ui-10 text-muted-foreground">
                                           {source}
                                         </span>
                                       </ComboboxItem>
@@ -1279,15 +1300,15 @@ export function ExportPage() {
                             </Combobox>
                           </div>
                           {isLoadingLocalModels ? (
-                            <p className="text-[10px] text-muted-foreground">
+                            <p className="text-ui-10 text-muted-foreground">
                               Scanning local models...
                             </p>
                           ) : localModelsError ? (
-                            <p className="text-[10px] text-red-500">
+                            <p className="text-ui-10 text-red-500">
                               {localModelsError}
                             </p>
                           ) : (
-                            <p className="text-[10px] text-muted-foreground">
+                            <p className="text-ui-10 text-muted-foreground">
                               {exportableLocalModels.length > 0
                                 ? `${exportableLocalModels.length} local/cached models found`
                                 : "No local models found. Enter path manually."}
@@ -1297,7 +1318,7 @@ export function ExportPage() {
                       )}
 
                       <div className="rounded-xl bg-foreground/[0.04] p-3">
-                        <p className="text-[11px] text-muted-foreground">
+                        <p className="text-ui-11 text-muted-foreground">
                           Direct model exports currently support GGUF only.
                         </p>
                       </div>
@@ -1306,7 +1327,7 @@ export function ExportPage() {
 
                   {sourceMode === "checkpoint" && (
                     <div className="rounded-xl bg-foreground/[0.04] p-3 flex flex-col gap-2">
-                      <span className="text-[11px] font-medium text-muted-foreground uppercase tracking-wider">
+                      <span className="text-ui-11 font-medium text-muted-foreground uppercase tracking-wider">
                         Training Info
                       </span>
                       <div className="grid grid-cols-1 gap-x-6 gap-y-1.5 text-xs sm:grid-cols-2">
@@ -1353,7 +1374,7 @@ export function ExportPage() {
                         key={step}
                         className="flex items-start gap-2 text-xs text-muted-foreground"
                       >
-                        <span className="flex size-5 shrink-0 items-center justify-center rounded-full bg-foreground/10 text-[10px] font-semibold">
+                        <span className="flex size-5 shrink-0 items-center justify-center rounded-full bg-foreground/10 text-ui-10 font-semibold">
                           {i + 1}
                         </span>
                         {step}
@@ -1401,7 +1422,7 @@ export function ExportPage() {
                   <div className="space-y-2">
                     <div className="flex items-center justify-between">
                       <div className="text-sm font-medium">Precision</div>
-                      <span className="text-[11px] text-muted-foreground/70">
+                      <span className="text-ui-11 text-muted-foreground/70">
                         — select one or more
                       </span>
                     </div>
@@ -1458,7 +1479,7 @@ export function ExportPage() {
                                       {f.label}
                                       {f.needsCalibration ? " *" : ""}
                                     </span>
-                                    <span className="text-[10px] text-muted-foreground">
+                                    <span className="text-ui-10 text-muted-foreground">
                                       {f.hint}
                                     </span>
                                   </span>
@@ -1471,7 +1492,7 @@ export function ExportPage() {
 
                     {selectedFormats.length > 0 && (
                       <div className="flex flex-wrap items-center gap-x-3 gap-y-1">
-                        <span className="text-[11px] text-muted-foreground">
+                        <span className="text-ui-11 text-muted-foreground">
                           {selectedFormats.length} selected:{" "}
                           {selectedFormats
                             .map(
@@ -1485,7 +1506,7 @@ export function ExportPage() {
                           <button
                             type="button"
                             onClick={() => setSelectedFormats(["16-bit"])}
-                            className="text-[11px] text-muted-foreground/70 hover:text-foreground transition-colors"
+                            className="text-ui-11 text-muted-foreground/70 hover:text-foreground transition-colors"
                           >
                             Reset to 16-bit
                           </button>
@@ -1494,7 +1515,7 @@ export function ExportPage() {
                     )}
 
                     {hubMultiFormat && (
-                      <div className="text-[11px] text-amber-600 dark:text-amber-500">
+                      <div className="text-ui-11 text-amber-600 dark:text-amber-500">
                         Hub export supports one format at a time (each writes to
                         the repository root). Select a single format, or export
                         locally to produce several at once.
@@ -1506,13 +1527,13 @@ export function ExportPage() {
                         MERGED_FORMATS.find((f) => f.value === v)
                           ?.needsCalibration,
                     ) && (
-                      <div className="text-[11px] text-muted-foreground">
+                      <div className="text-ui-11 text-muted-foreground">
                         * calibrates on data (uses a small calibration set).
                       </div>
                     )}
 
                     {!hasNvidia && (
-                      <div className="text-[11px] text-muted-foreground">
+                      <div className="text-ui-11 text-muted-foreground">
                         No NVIDIA GPU detected: compressed-tensors formats are
                         hidden. 16-bit and portable FP8/INT8 (torchao) still
                         work here and load in vLLM.
diff --git a/studio/frontend/src/features/hf-auth/api.ts b/studio/frontend/src/features/hf-auth/api.ts
new file mode 100644
index 0000000000..ab4b049566
--- /dev/null
+++ b/studio/frontend/src/features/hf-auth/api.ts
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { authFetch } from "@/features/auth";
+// This header helper is API-layer-only and is not part of the feature's
+// React-facing public barrel.
+// eslint-disable-next-line no-restricted-imports
+import { hubTokenHeader } from "@/features/hub/lib/hub-token-header";
+
+export type HfTokenValidationStatus =
+  | "missing"
+  | "valid"
+  | "invalid"
+  | "rate_limited"
+  | "unavailable";
+
+export interface HfTokenValidationResult {
+  status: HfTokenValidationStatus;
+  retryAfterSeconds: number | null;
+}
+
+export async function validateHfToken(
+  token: string | null | undefined,
+): Promise<HfTokenValidationResult> {
+  const normalized = token?.trim() ?? "";
+  if (!normalized) {
+    return { status: "missing", retryAfterSeconds: null };
+  }
+  const response = await authFetch("/api/hub/token/validate", {
+    method: "POST",
+    headers: hubTokenHeader(normalized),
+  });
+  if (!response.ok) {
+    return { status: "unavailable", retryAfterSeconds: null };
+  }
+  const body = (await response.json()) as {
+    status?: HfTokenValidationStatus;
+    retry_after_seconds?: number | null;
+  };
+  return {
+    status: body.status ?? "unavailable",
+    retryAfterSeconds: body.retry_after_seconds ?? null,
+  };
+}
diff --git a/studio/frontend/src/features/hf-auth/confirm-token.ts b/studio/frontend/src/features/hf-auth/confirm-token.ts
new file mode 100644
index 0000000000..e1f6e6c705
--- /dev/null
+++ b/studio/frontend/src/features/hf-auth/confirm-token.ts
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+// These stores are used outside React and are not part of their features'
+// React-facing public barrels.
+// eslint-disable-next-line no-restricted-imports
+import { useHfTokenStore } from "@/features/hub/stores/hf-token-store";
+// eslint-disable-next-line no-restricted-imports
+import { useSettingsDialogStore } from "@/features/settings/stores/settings-dialog-store";
+import { validateHfToken } from "./api";
+import { useHfTokenWarningStore } from "./store";
+
+export interface PreparedHfToken {
+  proceed: boolean;
+  token: string | null;
+}
+
+interface PrepareHfTokenOptions {
+  allowAnonymous?: boolean;
+}
+
+// A caller can retain the pre-dialog payload while the shared store is cleared.
+// Remember that one-session choice so a follow-up /load does not prompt again
+// after its preceding /validate already continued anonymously.
+const anonymousForSession = new Set<string>();
+
+export async function prepareHfTokenForUse(
+  token: string | null | undefined,
+  options: PrepareHfTokenOptions = {},
+): Promise<PreparedHfToken> {
+  const normalized = token?.trim() ?? "";
+  if (!normalized) return { proceed: true, token: null };
+  const allowAnonymous = options.allowAnonymous ?? true;
+  if (allowAnonymous && anonymousForSession.has(normalized)) {
+    return { proceed: true, token: null };
+  }
+
+  let validation;
+  try {
+    validation = await validateHfToken(normalized);
+  } catch {
+    // Validation is advisory. Let the real operation retain its own error.
+    return { proceed: true, token: normalized };
+  }
+  if (validation.status !== "invalid") {
+    // A connectivity failure or rate limit cannot prove that a token is bad.
+    // Let the real operation proceed and retain its repository-specific error.
+    return { proceed: true, token: normalized };
+  }
+
+  const decision = await useHfTokenWarningStore
+    .getState()
+    .requestDecision(allowAnonymous);
+  if (decision === "anonymous") {
+    anonymousForSession.add(normalized);
+    useHfTokenStore.getState().clearToken();
+    return { proceed: true, token: null };
+  }
+  if (decision === "replace") {
+    useSettingsDialogStore.getState().openDialog("general");
+  }
+  return { proceed: false, token: normalized };
+}
diff --git a/studio/frontend/src/features/hf-auth/hf-token-warning-dialog.tsx b/studio/frontend/src/features/hf-auth/hf-token-warning-dialog.tsx
new file mode 100644
index 0000000000..4370c39693
--- /dev/null
+++ b/studio/frontend/src/features/hf-auth/hf-token-warning-dialog.tsx
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+} from "@/components/ui/alert-dialog";
+import { Button } from "@/components/ui/button";
+import { AlertTriangle } from "lucide-react";
+import { useHfTokenWarningStore } from "./store";
+
+export function HfTokenWarningDialog() {
+  const open = useHfTokenWarningStore((state) => state.open);
+  const allowAnonymous = useHfTokenWarningStore(
+    (state) => state.allowAnonymous,
+  );
+  const resolve = useHfTokenWarningStore((state) => state.resolve);
+
+  return (
+    <AlertDialog
+      open={open}
+      onOpenChange={(next) => {
+        if (!next) resolve("cancel");
+      }}
+    >
+      <AlertDialogContent className="max-w-md">
+        <AlertDialogHeader>
+          <div className="flex items-start gap-3">
+            <div className="flex size-9 shrink-0 items-center justify-center rounded-full bg-amber-500/10 text-amber-600 dark:text-amber-400">
+              <AlertTriangle className="size-5" />
+            </div>
+            <div className="space-y-1 text-left">
+              <AlertDialogTitle>Hugging Face token is invalid</AlertDialogTitle>
+              <AlertDialogDescription>
+                {allowAnonymous
+                  ? "Hugging Face rejected the saved token. Replace it to access private or gated repositories, or continue without it for public and fully downloaded models."
+                  : "Hugging Face rejected the saved token. Replace it before uploading to the Hub."}
+              </AlertDialogDescription>
+            </div>
+          </div>
+        </AlertDialogHeader>
+        <AlertDialogFooter className="sm:justify-between">
+          <AlertDialogCancel onClick={() => resolve("cancel")}>
+            Cancel
+          </AlertDialogCancel>
+          <div className="flex flex-col-reverse gap-2 sm:flex-row">
+            {allowAnonymous ? (
+              <Button variant="outline" onClick={() => resolve("anonymous")}>
+                Continue without token
+              </Button>
+            ) : null}
+            <AlertDialogAction onClick={() => resolve("replace")}>
+              Replace token
+            </AlertDialogAction>
+          </div>
+        </AlertDialogFooter>
+      </AlertDialogContent>
+    </AlertDialog>
+  );
+}
diff --git a/studio/frontend/src/features/hf-auth/index.ts b/studio/frontend/src/features/hf-auth/index.ts
new file mode 100644
index 0000000000..e8bcb48193
--- /dev/null
+++ b/studio/frontend/src/features/hf-auth/index.ts
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+export { validateHfToken } from "./api";
+export type {
+  HfTokenValidationResult,
+  HfTokenValidationStatus,
+} from "./api";
+export { prepareHfTokenForUse } from "./confirm-token";
+export { HfTokenWarningDialog } from "./hf-token-warning-dialog";
diff --git a/studio/frontend/src/features/hf-auth/store.ts b/studio/frontend/src/features/hf-auth/store.ts
new file mode 100644
index 0000000000..faa2543a8a
--- /dev/null
+++ b/studio/frontend/src/features/hf-auth/store.ts
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { create } from "zustand";
+
+export type HfTokenWarningDecision = "anonymous" | "replace" | "cancel";
+type Resolver = (decision: HfTokenWarningDecision) => void;
+
+let pendingResolver: Resolver | null = null;
+
+interface HfTokenWarningStore {
+  open: boolean;
+  allowAnonymous: boolean;
+  requestDecision: (allowAnonymous: boolean) => Promise<HfTokenWarningDecision>;
+  resolve: (decision: HfTokenWarningDecision) => void;
+}
+
+export const useHfTokenWarningStore = create<HfTokenWarningStore>((set) => ({
+  open: false,
+  allowAnonymous: true,
+  requestDecision: (allowAnonymous) =>
+    new Promise<HfTokenWarningDecision>((resolve) => {
+      pendingResolver?.("cancel");
+      pendingResolver = resolve;
+      set({ open: true, allowAnonymous });
+    }),
+  resolve: (decision) => {
+    const resolver = pendingResolver;
+    pendingResolver = null;
+    set({ open: false, allowAnonymous: true });
+    resolver?.(decision);
+  },
+}));
diff --git a/studio/frontend/src/features/hub/catalog/catalog-states.tsx b/studio/frontend/src/features/hub/catalog/catalog-states.tsx
index 1d9eb63718..513f1c21c8 100644
--- a/studio/frontend/src/features/hub/catalog/catalog-states.tsx
+++ b/studio/frontend/src/features/hub/catalog/catalog-states.tsx
@@ -10,6 +10,7 @@ import {
 } from "@hugeicons/core-free-icons";
 import type { IconSvgElement } from "@hugeicons/react";
 import { HugeiconsIcon } from "@hugeicons/react";
+import type { ReactNode } from "react";
 import { useLayoutEffect, useRef, useState } from "react";
 
 export function NetworkErrorState({
@@ -37,20 +38,20 @@ export function NetworkErrorState({
         <HugeiconsIcon icon={icon} strokeWidth={1.6} className="size-5" />
       </div>
       <div className="space-y-1">
-        <p className="text-[14px] font-semibold tracking-tight text-foreground">
+        <p className="text-ui-14 font-semibold tracking-tight text-foreground">
           {title}
         </p>
-        <p className="max-w-md text-[12.5px] leading-5 text-muted-foreground">
+        <p className="max-w-md text-ui-12p5 leading-5 text-muted-foreground">
           {body}
         </p>
-        <p className="text-[11px] text-muted-foreground/70">{message}</p>
+        <p className="text-ui-11 text-muted-foreground/70">{message}</p>
       </div>
       <div className="flex flex-wrap items-center justify-center gap-2">
         {onSwitchDevice ? (
           <button
             type="button"
             onClick={onSwitchDevice}
-            className="inline-flex h-8 items-center gap-1.5 rounded-full bg-foreground/[0.06] px-3 text-[12px] font-medium text-foreground transition-colors hover:bg-foreground/[0.1] dark:bg-white/[0.06] dark:hover:bg-white/[0.1]"
+            className="inline-flex h-8 items-center gap-1.5 rounded-full bg-foreground/[0.06] px-3 text-ui-12 font-medium text-foreground transition-colors hover:bg-foreground/[0.1] dark:bg-white/[0.06] dark:hover:bg-white/[0.1]"
           >
             On Device
           </button>
@@ -58,7 +59,7 @@ export function NetworkErrorState({
         <button
           type="button"
           onClick={onRetry}
-          className="inline-flex h-8 items-center gap-1.5 rounded-full bg-transparent px-3 text-[12px] font-medium text-foreground transition-colors hover:bg-foreground/[0.04] dark:hover:bg-white/[0.05]"
+          className="inline-flex h-8 items-center gap-1.5 rounded-full bg-transparent px-3 text-ui-12 font-medium text-foreground transition-colors hover:bg-foreground/[0.04] dark:hover:bg-white/[0.05]"
         >
           <HugeiconsIcon
             icon={Refresh01Icon}
@@ -91,10 +92,10 @@ export function DiscoverFetchMoreState({
         <HugeiconsIcon icon={FilterIcon} strokeWidth={1.5} className="size-5" />
       </div>
       <div className="space-y-1">
-        <p className="text-[14px] font-semibold tracking-tight text-foreground">
+        <p className="text-ui-14 font-semibold tracking-tight text-foreground">
           No matches yet
         </p>
-        <p className="max-w-md text-[12.5px] leading-5 text-muted-foreground">
+        <p className="max-w-md text-ui-12p5 leading-5 text-muted-foreground">
           Scanned {scannedCount.toLocaleString()} results. Load another page to
           keep searching Hugging Face.
         </p>
@@ -104,7 +105,7 @@ export function DiscoverFetchMoreState({
           <button
             type="button"
             onClick={onClearFilters}
-            className="inline-flex h-8 items-center gap-1.5 rounded-full bg-foreground/[0.06] px-3 text-[12px] font-medium text-foreground transition-colors hover:bg-foreground/[0.1] dark:bg-white/[0.06] dark:hover:bg-white/[0.1]"
+            className="inline-flex h-8 items-center gap-1.5 rounded-full bg-foreground/[0.06] px-3 text-ui-12 font-medium text-foreground transition-colors hover:bg-foreground/[0.1] dark:bg-white/[0.06] dark:hover:bg-white/[0.1]"
           >
             Clear filters
           </button>
@@ -113,7 +114,7 @@ export function DiscoverFetchMoreState({
           type="button"
           onClick={onFetchMore}
           disabled={isLoadingMore}
-          className="inline-flex h-8 items-center gap-1.5 rounded-full bg-transparent px-3 text-[12px] font-medium text-foreground transition-colors hover:bg-foreground/[0.04] disabled:cursor-not-allowed disabled:opacity-50 dark:hover:bg-white/[0.05]"
+          className="inline-flex h-8 items-center gap-1.5 rounded-full bg-transparent px-3 text-ui-12 font-medium text-foreground transition-colors hover:bg-foreground/[0.04] disabled:cursor-not-allowed disabled:opacity-50 dark:hover:bg-white/[0.05]"
         >
           <HugeiconsIcon
             icon={Refresh01Icon}
@@ -140,7 +141,7 @@ export function DiscoverFetchMoreFooter({
     <div className="relative z-10 flex flex-col items-center gap-2 rounded-[16px] bg-card px-4 py-4 text-center">
       {/* Only warn about hidden results when a filter is actually narrowing them. */}
       {hasActiveFilters && (
-        <p className="text-[11.5px] leading-4 text-muted-foreground">
+        <p className="text-ui-11p5 leading-4 text-muted-foreground">
           Some results may be hidden by your filters.
         </p>
       )}
@@ -148,7 +149,7 @@ export function DiscoverFetchMoreFooter({
         type="button"
         onClick={onFetchMore}
         disabled={isLoadingMore}
-        className="inline-flex h-8 items-center gap-1.5 rounded-full bg-foreground/[0.06] px-3 text-[12px] font-medium text-foreground transition-colors hover:bg-foreground/[0.1] disabled:cursor-not-allowed disabled:opacity-50 dark:bg-white/[0.06] dark:hover:bg-white/[0.1]"
+        className="inline-flex h-8 items-center gap-1.5 rounded-full bg-foreground/[0.06] px-3 text-ui-12 font-medium text-foreground transition-colors hover:bg-foreground/[0.1] disabled:cursor-not-allowed disabled:opacity-50 dark:bg-white/[0.06] dark:hover:bg-white/[0.1]"
       >
         <HugeiconsIcon
           icon={Refresh01Icon}
@@ -174,10 +175,10 @@ export function InventoryErrorState({
         <HugeiconsIcon icon={CloudOffIcon} strokeWidth={1.6} className="size-5" />
       </div>
       <div className="space-y-1">
-        <p className="text-[14px] font-semibold tracking-tight text-foreground">
+        <p className="text-ui-14 font-semibold tracking-tight text-foreground">
           Couldn't load your library
         </p>
-        <p className="max-w-md text-[12.5px] leading-5 text-muted-foreground">
+        <p className="max-w-md text-ui-12p5 leading-5 text-muted-foreground">
           Something went wrong reading your downloaded{" "}
           {isDataset ? "datasets" : "models"}. Check that the backend is running
           and try again.
@@ -186,7 +187,7 @@ export function InventoryErrorState({
       <button
         type="button"
         onClick={onRetry}
-        className="inline-flex h-8 items-center gap-1.5 rounded-full bg-transparent px-3 text-[12px] font-medium text-foreground transition-colors hover:bg-foreground/[0.04] dark:hover:bg-white/[0.05]"
+        className="inline-flex h-8 items-center gap-1.5 rounded-full bg-transparent px-3 text-ui-12 font-medium text-foreground transition-colors hover:bg-foreground/[0.04] dark:hover:bg-white/[0.05]"
       >
         <HugeiconsIcon icon={Refresh01Icon} strokeWidth={1.75} className="size-3.5" />
         Try again
@@ -199,10 +200,12 @@ export function EmptyState({
   title,
   body,
   icon = CubeIcon,
+  action,
 }: {
   title: string;
   body: string;
   icon?: IconSvgElement;
+  action?: ReactNode;
 }) {
   return (
     <div className="flex min-h-[220px] flex-col items-center justify-center gap-3 px-6 text-center">
@@ -210,13 +213,14 @@ export function EmptyState({
         <HugeiconsIcon icon={icon} strokeWidth={1.5} className="size-5" />
       </div>
       <div className="space-y-1">
-        <p className="text-[14px] font-semibold tracking-tight text-foreground">
+        <p className="text-ui-14 font-semibold tracking-tight text-foreground">
           {title}
         </p>
-        <p className="max-w-md text-[12.5px] leading-5 text-muted-foreground">
+        <p className="max-w-md text-ui-12p5 leading-5 text-muted-foreground">
           {body}
         </p>
       </div>
+      {action}
     </div>
   );
 }
diff --git a/studio/frontend/src/features/hub/catalog/dataset-download-section.tsx b/studio/frontend/src/features/hub/catalog/dataset-download-section.tsx
index d407517663..4a3e3f9ff6 100644
--- a/studio/frontend/src/features/hub/catalog/dataset-download-section.tsx
+++ b/studio/frontend/src/features/hub/catalog/dataset-download-section.tsx
@@ -50,7 +50,7 @@ export function DatasetDownloadSection({
   const hfToken = useHfTokenStore((s) => s.token);
   const [deleteOpen, setDeleteOpen] = useState(false);
   const { deleting, runDelete } = useCardDelete({
-    action: () => deleteCachedDataset(repoId),
+    action: () => deleteCachedDataset(repoId, cachePath ?? undefined),
     resourceName: "dataset",
     successMessage: () => `Deleted ${repoId}`,
     onSuccess: () => {
@@ -126,7 +126,7 @@ export function DatasetDownloadSection({
       }
     >
       <div className="relative flex h-9 min-w-0 flex-1 items-center pl-3 pr-2">
-        <span className="flex items-center gap-1.5 text-[12px] text-muted-foreground">
+        <span className="flex items-center gap-1.5 text-ui-12 text-muted-foreground">
           {isDownloaded && <DotTag tone="success" label="On device" />}
           {!isDownloaded && isPartial && !downloading && (
             <Tooltip>
@@ -152,11 +152,7 @@ export function DatasetDownloadSection({
             />
           )}
           {isDownloaded && cachePath && (
-            <PathInfoButton
-              path={cachePath}
-              title="On-device location"
-              description={`Where ${repoId} lives on disk.`}
-            />
+            <PathInfoButton path={cachePath} />
           )}
         </div>
       </div>
diff --git a/studio/frontend/src/features/hub/catalog/dot-tag.tsx b/studio/frontend/src/features/hub/catalog/dot-tag.tsx
index 9452a201d4..5c2a0c8d1a 100644
--- a/studio/frontend/src/features/hub/catalog/dot-tag.tsx
+++ b/studio/frontend/src/features/hub/catalog/dot-tag.tsx
@@ -36,7 +36,7 @@ export function DotTag({
   return (
     <span
       className={cn(
-        "inline-flex h-5 shrink-0 items-center gap-1.5 whitespace-nowrap rounded-full border border-border/60 bg-transparent px-2 text-[11px] font-medium leading-none text-muted-foreground",
+        "inline-flex h-5 shrink-0 items-center gap-1.5 whitespace-nowrap rounded-full border border-border/60 bg-transparent px-2 text-ui-11 font-medium leading-none text-muted-foreground",
         className,
       )}
     >
diff --git a/studio/frontend/src/features/hub/catalog/download-card.tsx b/studio/frontend/src/features/hub/catalog/download-card.tsx
index 9b4bc5fd01..8016a9406d 100644
--- a/studio/frontend/src/features/hub/catalog/download-card.tsx
+++ b/studio/frontend/src/features/hub/catalog/download-card.tsx
@@ -140,7 +140,7 @@ export function CardUpdateButton({
               e.stopPropagation();
               onClick();
             }}
-            className="inline-flex h-7 shrink-0 cursor-pointer items-center gap-1.5 rounded-full bg-amber-500/[0.07] pl-2 pr-2.5 text-[12px] font-medium text-amber-800/90 transition-colors duration-150 hover:bg-amber-500/[0.12] focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-amber-500/25 dark:bg-amber-400/[0.08] dark:text-amber-200/85 dark:hover:bg-amber-400/[0.16]"
+            className="inline-flex h-7 shrink-0 cursor-pointer items-center gap-1.5 rounded-full bg-amber-500/[0.07] pl-2 pr-2.5 text-ui-12 font-medium text-amber-800/90 transition-colors duration-150 hover:bg-amber-500/[0.12] focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-amber-500/25 dark:bg-amber-400/[0.08] dark:text-amber-200/85 dark:hover:bg-amber-400/[0.16]"
           >
             <HugeiconsIcon
               icon={ArrowReloadHorizontalIcon}
diff --git a/studio/frontend/src/features/hub/catalog/download-section.tsx b/studio/frontend/src/features/hub/catalog/download-section.tsx
index fb2921649b..b2dd4592a1 100644
--- a/studio/frontend/src/features/hub/catalog/download-section.tsx
+++ b/studio/frontend/src/features/hub/catalog/download-section.tsx
@@ -1,9 +1,9 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
+import type { ModelInventoryFormat } from "../inventory";
 import { GgufDownloadCard } from "./gguf-download-card";
 import { SafetensorsDownloadCard } from "./safetensors-download-card";
-import type { ModelInventoryFormat } from "../inventory";
 
 export function DownloadSection({
   repoId,
@@ -22,6 +22,7 @@ export function DownloadSection({
   knownBytes,
   onLoad,
   onUseInChat,
+  onEject,
   onTrain,
   onChange,
 }: {
@@ -41,6 +42,7 @@ export function DownloadSection({
   knownBytes?: number | null;
   onLoad: (opts: { ggufVariant?: string; expectedBytes?: number }) => void;
   onUseInChat?: () => void;
+  onEject?: () => void;
   onTrain?: () => void;
   onChange?: () => void;
 }) {
@@ -57,6 +59,7 @@ export function DownloadSection({
         isPartial={isPartial}
         onLoad={onLoad}
         onUseInChat={onUseInChat}
+        onEject={onEject}
         onChange={onChange}
       />
     );
@@ -75,6 +78,7 @@ export function DownloadSection({
       knownBytes={knownBytes}
       onLoad={onLoad}
       onUseInChat={onUseInChat}
+      onEject={onEject}
       onTrain={onTrain}
       onChange={onChange}
     />
diff --git a/studio/frontend/src/features/hub/catalog/external-link-confirm-dialog.tsx b/studio/frontend/src/features/hub/catalog/external-link-confirm-dialog.tsx
index 5a661467fc..b17898a8e0 100644
--- a/studio/frontend/src/features/hub/catalog/external-link-confirm-dialog.tsx
+++ b/studio/frontend/src/features/hub/catalog/external-link-confirm-dialog.tsx
@@ -54,10 +54,10 @@ export function ExternalLinkConfirmDialog() {
         </AlertDialogHeader>
         {pendingUrl && (
           <div className="min-w-0 rounded-[12px] bg-muted/50 px-3 py-2.5 text-left">
-            <p className="truncate text-[13px] font-medium text-foreground">
+            <p className="truncate text-ui-13 font-medium text-foreground">
               {hostOf(pendingUrl)}
             </p>
-            <p className="mt-0.5 break-all text-[11.5px] leading-[16px] text-muted-foreground">
+            <p className="mt-0.5 break-all text-ui-11p5 leading-ui-16 text-muted-foreground">
               {pendingUrl}
             </p>
           </div>
diff --git a/studio/frontend/src/features/hub/catalog/gguf-download-card.tsx b/studio/frontend/src/features/hub/catalog/gguf-download-card.tsx
index f31212e4fd..870adcde11 100644
--- a/studio/frontend/src/features/hub/catalog/gguf-download-card.tsx
+++ b/studio/frontend/src/features/hub/catalog/gguf-download-card.tsx
@@ -1,6 +1,13 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuSeparator,
+  DropdownMenuTrigger,
+} from "@/components/ui/dropdown-menu";
 import {
   Popover,
   PopoverContent,
@@ -12,49 +19,55 @@ import {
   TooltipContent,
   TooltipTrigger,
 } from "@/components/ui/tooltip";
-import {
-  downloadManager,
-  useDownloadManagerStore,
-  useRepoDownload,
-} from "../download-manager";
-import {
-  type GgufVariantDetail,
-  deleteCachedModel,
-} from "../inventory";
-import { formatBytes } from "../lib/format";
-import { type GgufFitClass, classifyGgufFit } from "../lib/gguf-fit";
-import { HUB_GGUF_RUN_ACTIONS_VISIBLE } from "../lib/hub-feature-flags";
-import {
-  ggufVariantsMatch,
-  normalizeGgufVariantIdentity,
-} from "../lib/model-identity";
+import { usePlatformStore } from "@/config/env";
+import { getCachedModelPath, revealCachedModel } from "@/features/chat";
+import { pinKey, usePinnedModelsStore } from "@/features/model-picker";
+import { ChevronDownStandardIcon } from "@/lib/chevron-icons";
+import { copyToClipboard } from "@/lib/copy-to-clipboard";
+import { toast } from "@/lib/toast";
 import { cn } from "@/lib/utils";
-import { useHfTokenStore } from "../stores/hf-token-store";
-import { useOnlineStatus } from "../hooks/use-online-status";
 import {
   ArrowReloadHorizontalIcon,
+  Copy01Icon,
   Delete02Icon,
   Download01Icon,
+  Folder01Icon,
   InformationCircleIcon,
-  PencilEdit02Icon,
+  MoreVerticalIcon,
+  PinIcon,
+  PinOffIcon,
   PlayIcon,
+  RemoveCircleIcon,
 } from "@hugeicons/core-free-icons";
-import { ChevronDownStandardIcon } from "@/lib/chevron-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
 import {
+  type KeyboardEventHandler,
   memo,
   useCallback,
   useEffect,
   useMemo,
   useState,
-  type KeyboardEventHandler,
-  type MouseEventHandler,
 } from "react";
+import {
+  downloadManager,
+  useDownloadManagerStore,
+  useRepoDownload,
+} from "../download-manager";
+import { useOnlineStatus } from "../hooks/use-online-status";
+import { type GgufVariantDetail, deleteCachedModel } from "../inventory";
+import { formatBytes } from "../lib/format";
+import { type GgufFitClass, classifyGgufFit } from "../lib/gguf-fit";
 import {
   ggufVariantDisplayLabel,
   ggufVariantDownloadSizeBytes,
   sortDownloadableGgufVariants,
 } from "../lib/gguf-variant-sort";
+import { HUB_GGUF_RUN_ACTIONS_VISIBLE } from "../lib/hub-feature-flags";
+import {
+  ggufVariantsMatch,
+  normalizeGgufVariantIdentity,
+} from "../lib/model-identity";
+import { useHfTokenStore } from "../stores/hf-token-store";
 import { DotTag } from "./dot-tag";
 import { DownloadCancelIndicator } from "./download-cancel-indicator";
 import {
@@ -72,7 +85,6 @@ import {
   GgufDownloadStatusCard,
   GgufDownloadingFallbackCard,
 } from "./gguf-status-cards";
-import { PathInfoButton } from "./path-info-button";
 import { useDeleteConfirmAction } from "./use-delete-confirm-action";
 import { useDownloadCardState } from "./use-download-card-state";
 import { useGgufVariantFetchState } from "./use-gguf-variant-fetch-state";
@@ -116,7 +128,7 @@ const FIT_BADGE: Record<GgufFitClass, FitBadgeMeta> = {
 
 /** Chip styling matching the on-device list's StatChip, no icon. */
 const CHIP_BASE =
-  "inline-flex h-5 shrink-0 items-center justify-center whitespace-nowrap rounded-full border px-2 text-[11.5px] font-medium tabular-nums leading-3 shadow-[inset_0_1px_0_rgba(255,255,255,0.04)]";
+  "inline-flex h-5 shrink-0 items-center justify-center whitespace-nowrap rounded-full border px-2 text-ui-11p5 font-medium tabular-nums leading-3 shadow-[inset_0_1px_0_rgba(255,255,255,0.04)]";
 const CHIP_DEFAULT =
   "border-foreground/15 bg-muted text-foreground/85 dark:border-border/60 dark:bg-white/[0.04] dark:text-foreground/85";
 const CHIP_ACTIVE =
@@ -172,7 +184,7 @@ function QuantBadge({
       // group's `overflow-hidden` sacrifices the trailing status tags instead.
       <span
         className={cn(
-          "inline-flex shrink-0 cursor-help items-center gap-1.5 whitespace-nowrap text-[12.5px] font-medium tracking-tight tabular-nums",
+          "inline-flex shrink-0 cursor-help items-center gap-1.5 whitespace-nowrap text-ui-12p5 font-medium tracking-tight tabular-nums",
           active ? "text-control-accent" : "text-foreground",
         )}
       >
@@ -204,7 +216,7 @@ function QuantBadge({
       onOpenChange={tooltipMode === "lazy" ? setTooltipOpen : undefined}
     >
       <TooltipTrigger
-        asChild
+        asChild={true}
         onFocusCapture={tooltipMode === "lazy" ? armTooltip : undefined}
         onPointerEnter={tooltipMode === "lazy" ? armTooltip : undefined}
       >
@@ -245,7 +257,181 @@ function createGgufVariantMenuItems(
   }));
 }
 
+// Shared options menu: used on every variant row, the run bar, and the
+// single-model (non-GGUF) run bar. Omit `quant` for a repo-level model. The
+// identifier uses llama.cpp's repo:quant syntax so it pastes into `-hf`.
+export function QuantOptionsMenu({
+  repoId,
+  quant,
+  label,
+  downloaded,
+  canDelete,
+  onDelete,
+  showPin = true,
+  buttonClassName,
+  iconClassName,
+}: {
+  repoId: string;
+  quant?: string;
+  label: string;
+  downloaded: boolean;
+  canDelete: boolean;
+  onDelete: (quant?: string) => void;
+  // Hidden in the run bar; pinning belongs to the On Device list.
+  showPin?: boolean;
+  buttonClassName?: string;
+  iconClassName?: string;
+}) {
+  const pinnedKeys = usePinnedModelsStore((s) => s.pinned);
+  const togglePinned = usePinnedModelsStore((s) => s.togglePinned);
+  const pinned = pinnedKeys.includes(pinKey(repoId, quant));
+  const deviceType = usePlatformStore((s) => s.deviceType);
+  const revealLabel =
+    deviceType === "mac"
+      ? "Reveal in Finder"
+      : deviceType === "windows"
+        ? "Reveal in File Explorer"
+        : "Reveal in File Manager";
+  const handleCopyPath = useCallback(async () => {
+    try {
+      const { path } = await getCachedModelPath(repoId, quant);
+      if (await copyToClipboard(path)) {
+        toast.success("Copied path");
+      } else {
+        toast.error("Failed to copy");
+      }
+    } catch (err) {
+      toast.error(
+        err instanceof Error ? err.message : "Failed to resolve model path",
+      );
+    }
+  }, [repoId, quant]);
+  const handleCopyId = useCallback(async () => {
+    const id = quant ? `${repoId}:${quant}` : repoId;
+    if (await copyToClipboard(id)) {
+      toast.success("Copied identifier");
+    } else {
+      toast.error("Failed to copy");
+    }
+  }, [repoId, quant]);
+
+  return (
+    <DropdownMenu>
+      <DropdownMenuTrigger asChild={true}>
+        <button
+          type="button"
+          onClick={(e) => e.stopPropagation()}
+          aria-label={`More options for ${label}`}
+          className={cn(
+            "inline-flex size-6 shrink-0 cursor-pointer items-center justify-center rounded-full",
+            "text-muted-foreground transition-colors hover:bg-muted hover:text-foreground",
+            "data-[state=open]:bg-muted data-[state=open]:text-foreground",
+            buttonClassName,
+          )}
+        >
+          <HugeiconsIcon
+            icon={MoreVerticalIcon}
+            strokeWidth={1.75}
+            className={cn("size-3.5", iconClassName)}
+          />
+        </button>
+      </DropdownMenuTrigger>
+      <DropdownMenuContent
+        side="bottom"
+        align="end"
+        sideOffset={2}
+        className="unsloth-plus-menu menu-flat-destructive w-48"
+      >
+        {showPin && downloaded && (
+          <DropdownMenuItem
+            onSelect={(e) => {
+              e.stopPropagation();
+              togglePinned(repoId, quant);
+            }}
+          >
+            <HugeiconsIcon
+              icon={pinned ? PinOffIcon : PinIcon}
+              strokeWidth={1.75}
+              className="size-icon"
+            />
+            <span>{pinned ? "Unpin" : "Pin to top"}</span>
+          </DropdownMenuItem>
+        )}
+        {downloaded && (
+          <DropdownMenuItem
+            onSelect={(e) => {
+              e.stopPropagation();
+              revealCachedModel(repoId, quant).catch((err) => {
+                toast.error(
+                  err instanceof Error
+                    ? err.message
+                    : "Failed to open file manager",
+                );
+              });
+            }}
+          >
+            <HugeiconsIcon
+              icon={Folder01Icon}
+              strokeWidth={1.75}
+              className="size-icon"
+            />
+            <span>{revealLabel}</span>
+          </DropdownMenuItem>
+        )}
+        <DropdownMenuItem
+          onSelect={(e) => {
+            e.stopPropagation();
+            void handleCopyId();
+          }}
+        >
+          <HugeiconsIcon
+            icon={Copy01Icon}
+            strokeWidth={1.75}
+            className="size-icon"
+          />
+          <span>Copy identifier</span>
+        </DropdownMenuItem>
+        {downloaded && (
+          <DropdownMenuItem
+            onSelect={(e) => {
+              e.stopPropagation();
+              void handleCopyPath();
+            }}
+          >
+            <HugeiconsIcon
+              icon={Copy01Icon}
+              strokeWidth={1.75}
+              className="size-icon"
+            />
+            <span>Copy path</span>
+          </DropdownMenuItem>
+        )}
+        {canDelete && (
+          <>
+            <DropdownMenuSeparator />
+            <DropdownMenuItem
+              variant="destructive"
+              onSelect={(e) => {
+                e.stopPropagation();
+                onDelete(quant);
+              }}
+            >
+              <HugeiconsIcon
+                icon={Delete02Icon}
+                strokeWidth={1.75}
+                className="size-icon"
+              />
+              <span>Delete</span>
+            </DropdownMenuItem>
+          </>
+        )}
+      </DropdownMenuContent>
+    </DropdownMenu>
+  );
+}
+
 const GgufVariantMenuRow = memo(function GgufVariantMenuRow({
+  repoId,
   item,
   selected,
   loaded,
@@ -254,6 +440,7 @@ const GgufVariantMenuRow = memo(function GgufVariantMenuRow({
   onSelect,
   onDelete,
 }: {
+  repoId: string;
   item: GgufVariantMenuItem;
   selected: boolean;
   loaded: boolean;
@@ -275,13 +462,6 @@ const GgufVariantMenuRow = memo(function GgufVariantMenuRow({
     },
     [selectVariant],
   );
-  const handleDelete = useCallback<MouseEventHandler<HTMLButtonElement>>(
-    (e) => {
-      e.stopPropagation();
-      onDelete(item.quant);
-    },
-    [item.quant, onDelete],
-  );
   const canDelete = (item.downloaded || item.partial) && !loaded && !liveActive;
 
   return (
@@ -317,7 +497,7 @@ const GgufVariantMenuRow = memo(function GgufVariantMenuRow({
         )}
         {!item.downloaded && item.partial && (
           <Tooltip>
-            <TooltipTrigger asChild>
+            <TooltipTrigger asChild={true}>
               <span className="inline-flex">
                 <DotTag
                   tone="warning"
@@ -334,30 +514,23 @@ const GgufVariantMenuRow = memo(function GgufVariantMenuRow({
         )}
       </span>
       <span className="ml-auto flex shrink-0 items-center gap-1.5">
-        <span className="relative">
-          <span className={cn(CHIP_BASE, CHIP_DEFAULT)}>
-            {item.downloadSizeLabel}
-          </span>
-          {canDelete && (
-            <button
-              type="button"
-              onClick={handleDelete}
-              aria-label={`Delete ${item.label}${item.partial && !item.downloaded ? " (partial)" : ""}`}
-              className={cn(
-                "absolute inset-0 inline-flex cursor-pointer items-center justify-center rounded-full",
-                "bg-popover text-foreground/70 ring-1 ring-border transition-colors",
-                "opacity-0 group-hover:opacity-100 focus-visible:opacity-100",
-                "hover:text-destructive hover:ring-destructive/40",
-              )}
-            >
-              <HugeiconsIcon
-                icon={Delete02Icon}
-                strokeWidth={1.75}
-                className="size-3"
-              />
-            </button>
-          )}
+        <span className={cn(CHIP_BASE, CHIP_DEFAULT)}>
+          {item.downloadSizeLabel}
         </span>
+        {/* Options only apply to files on disk; placeholder keeps the size
+            chips column-aligned across rows. */}
+        {item.downloaded || item.partial ? (
+          <QuantOptionsMenu
+            repoId={repoId}
+            quant={item.quant}
+            label={item.label}
+            downloaded={Boolean(item.downloaded)}
+            canDelete={canDelete}
+            onDelete={(q) => q && onDelete(q)}
+          />
+        ) : (
+          <span aria-hidden={true} className="size-6 shrink-0" />
+        )}
       </span>
     </div>
   );
@@ -374,7 +547,7 @@ export function GgufDownloadCard({
   preferLocalCache = false,
   isPartial = false,
   onLoad,
-  onUseInChat,
+  onEject,
   onChange,
 }: {
   repoId: string;
@@ -387,7 +560,9 @@ export function GgufDownloadCard({
   preferLocalCache?: boolean;
   isPartial?: boolean;
   onLoad: (opts: { ggufVariant?: string; expectedBytes?: number }) => void;
+  /** Accepted for API parity; the run bar ejects instead of opening chat. */
   onUseInChat?: () => void;
+  onEject?: () => void;
   onChange?: () => void;
 }) {
   const hfToken = useHfTokenStore((s) => s.token);
@@ -422,7 +597,9 @@ export function GgufDownloadCard({
     () => createLiveGgufVariantStatesSelector(repoId),
     [repoId],
   );
-  const liveVariantStates = useDownloadManagerStore(selectLiveGgufVariantStates);
+  const liveVariantStates = useDownloadManagerStore(
+    selectLiveGgufVariantStates,
+  );
   const sortedVariants = useMemo(() => {
     if (!rawSortedVariants) return null;
     const withLive = applyLiveGgufVariantStates(
@@ -499,12 +676,7 @@ export function GgufDownloadCard({
     if (expectedBytes > progress.expectedBytes) {
       setExpectedBytes(expectedBytes, progress.variant);
     }
-  }, [
-    variants,
-    progress?.variant,
-    progress?.expectedBytes,
-    setExpectedBytes,
-  ]);
+  }, [variants, progress?.variant, progress?.expectedBytes, setExpectedBytes]);
 
   useEffect(() => {
     setCompletedVariantKeys(new Set<string>());
@@ -593,9 +765,15 @@ export function GgufDownloadCard({
   const { deleting, runDelete } = useDeleteConfirmAction({
     action: async () => {
       if (!deleteTarget) return;
-      await deleteCachedModel(repoId, deleteTarget, hfToken || undefined);
+      await deleteCachedModel(
+        repoId,
+        deleteTarget,
+        hfToken || undefined,
+        cachePath ?? undefined,
+      );
     },
-    successMessage: () => `Deleted ${repoId} ${deleteTargetLabel ?? deleteTarget}`,
+    successMessage: () =>
+      `Deleted ${repoId} ${deleteTargetLabel ?? deleteTarget}`,
     errorToast: (err) => ({
       title: err instanceof Error ? err.message : "Failed to delete",
     }),
@@ -654,7 +832,7 @@ export function GgufDownloadCard({
     return (
       <GgufDownloadStatusCard
         job={job}
-        loading
+        loading={true}
         message="Loading available quantizations…"
       />
     );
@@ -666,7 +844,7 @@ export function GgufDownloadCard({
         <GgufDownloadStatusCard
           job={job}
           tone="muted"
-          partial
+          partial={true}
           message="Partial download present. Couldn't load quantizations."
           actionLabel="Reload"
           onAction={() => void refresh()}
@@ -729,7 +907,7 @@ export function GgufDownloadCard({
         }
       >
         <Popover open={open} onOpenChange={setOpen}>
-          <PopoverTrigger asChild>
+          <PopoverTrigger asChild={true}>
             <button
               type="button"
               onClick={(e) => {
@@ -741,7 +919,7 @@ export function GgufDownloadCard({
               {/* Quant label + status tags travel together as one left-aligned
                   group so the fit-info icon never floats orphaned from its tags;
                   only the chevron pins right, the standard select affordance. */}
-              <span className="flex min-w-0 flex-1 items-center gap-2 overflow-hidden text-[12px] text-muted-foreground">
+              <span className="flex min-w-0 flex-1 items-center gap-2 overflow-hidden text-ui-12 text-muted-foreground">
                 {selected ? (
                   <QuantBadge
                     quant={selectedLabel ?? selected.quant}
@@ -750,7 +928,7 @@ export function GgufDownloadCard({
                     active={Boolean(selectedIsActive)}
                   />
                 ) : (
-                  <span className="text-[12.5px] text-muted-foreground">
+                  <span className="text-ui-12p5 text-muted-foreground">
                     Select quantization
                   </span>
                 )}
@@ -762,7 +940,7 @@ export function GgufDownloadCard({
                 )}
                 {selected && !selected.downloaded && selected.partial && (
                   <Tooltip>
-                    <TooltipTrigger asChild>
+                    <TooltipTrigger asChild={true}>
                       <span className="inline-flex">
                         <DotTag
                           tone="warning"
@@ -806,6 +984,7 @@ export function GgufDownloadCard({
                 return (
                   <GgufVariantMenuRow
                     key={item.filename}
+                    repoId={repoId}
                     item={item}
                     selected={item.key === selectedVariantKey}
                     loaded={isActive && item.key === activeVariantKey}
@@ -820,14 +999,29 @@ export function GgufDownloadCard({
           </PopoverContent>
         </Popover>
 
-        {selected?.downloaded && cachePath && (
-          <PathInfoButton
-            path={cachePath}
-            title="On-device location"
-            description={`Where ${repoId} (${selectedLabel}) lives on disk.`}
-            className="ml-0.5"
-          />
-        )}
+        {/* TODO: inference settings gear hidden for now, work on it in a future PR. */}
+        {/* Options only resolve managed HF-cache repos, so skip local paths;
+            they also only apply to quants actually on disk. */}
+        {selected &&
+          Boolean(selected.downloaded || selected.partial) &&
+          !/^([/\\~.]|[A-Za-z]:)/.test(repoId) && (
+            <QuantOptionsMenu
+              repoId={repoId}
+              quant={selected.quant}
+              label={`${repoId} ${selectedLabel}`}
+              downloaded={Boolean(selected.downloaded)}
+              canDelete={
+                Boolean(selected.downloaded || selected.partial) &&
+                !selectedIsActive &&
+                !downloadingThisVariant &&
+                !isLoadingThisModel
+              }
+              onDelete={(q) => q && handleDeleteVariant(q)}
+              showPin={false}
+              buttonClassName="ml-0.5 size-7"
+              iconClassName="size-4"
+            />
+          )}
 
         {!isGgufRunCta && <CardDivider />}
 
@@ -859,7 +1053,7 @@ export function GgufDownloadCard({
               return;
             }
             if (selectedIsActive) {
-              onUseInChat?.();
+              onEject?.();
               return;
             }
             if (!selected) return;
@@ -874,7 +1068,7 @@ export function GgufDownloadCard({
           }}
           aria-label={downloadAction.ariaLabel}
           className={cn(
-            isGgufRunCta ? "hub-run-action-btn w-28" : "hub-action-btn w-28",
+            isGgufRunCta ? "hub-run-action-btn w-24" : "hub-action-btn w-24",
             isGgufRunCta && "ml-2",
             ctaDisabled &&
               !selectedIsActive &&
@@ -917,8 +1111,8 @@ export function GgufDownloadCard({
             </span>
           ) : selectedIsActive ? (
             <>
-              <HugeiconsIcon icon={PencilEdit02Icon} strokeWidth={1.75} />
-              New Chat
+              <HugeiconsIcon icon={RemoveCircleIcon} strokeWidth={1.75} />
+              Eject
             </>
           ) : selected?.downloaded ? (
             <>
@@ -937,7 +1131,7 @@ export function GgufDownloadCard({
         <button
           type="button"
           onClick={() => void refresh()}
-          className="self-start px-1 text-[11px] text-status-warning underline-offset-2 transition-colors hover:underline"
+          className="self-start px-1 text-ui-11 text-status-warning underline-offset-2 transition-colors hover:underline"
         >
           Couldn't refresh quantizations. Retry
         </button>
diff --git a/studio/frontend/src/features/hub/catalog/gguf-status-cards.tsx b/studio/frontend/src/features/hub/catalog/gguf-status-cards.tsx
index 6cc764b876..f4f4fb27d2 100644
--- a/studio/frontend/src/features/hub/catalog/gguf-status-cards.tsx
+++ b/studio/frontend/src/features/hub/catalog/gguf-status-cards.tsx
@@ -34,7 +34,7 @@ export function GgufDownloadStatusCard({
         <div className="relative flex h-9 min-w-0 flex-1 items-center pl-3 pr-2">
           <span
             className={cn(
-              "flex min-w-0 items-center gap-2 text-[12.5px]",
+              "flex min-w-0 items-center gap-2 text-ui-12p5",
               tone === "danger" ? "text-destructive" : "text-muted-foreground",
             )}
           >
@@ -91,7 +91,7 @@ export function GgufDownloadingFallbackCard({
     <div className="flex w-full flex-col gap-2">
       <DownloadCard job={job} progress={progress}>
         <div className="relative flex h-9 min-w-0 flex-1 items-center pl-3 pr-2">
-          <span className="flex min-w-0 items-center gap-2 text-[12.5px] text-muted-foreground">
+          <span className="flex min-w-0 items-center gap-2 text-ui-12p5 text-muted-foreground">
             {progress.variant && <DotTag tone="gguf" label={progress.variant} />}
             <span className="truncate">Downloading…</span>
           </span>
diff --git a/studio/frontend/src/features/hub/catalog/hub-detail-view.tsx b/studio/frontend/src/features/hub/catalog/hub-detail-view.tsx
index d733049ec3..78e1d0a420 100644
--- a/studio/frontend/src/features/hub/catalog/hub-detail-view.tsx
+++ b/studio/frontend/src/features/hub/catalog/hub-detail-view.tsx
@@ -69,7 +69,7 @@ export function HubDetailView({
             <button
               type="button"
               onClick={onBack}
-              className="-ml-1.5 inline-flex h-8 cursor-pointer select-none items-center gap-1.5 rounded-full pl-1.5 pr-2.5 text-[12.5px] font-medium text-muted-foreground transition-colors hover:bg-foreground/[0.05] hover:text-foreground dark:hover:bg-white/[0.06]"
+              className="-ml-1.5 inline-flex h-8 cursor-pointer select-none items-center gap-1.5 rounded-full pl-1.5 pr-2.5 text-ui-12p5 font-medium text-muted-foreground transition-colors hover:bg-foreground/[0.05] hover:text-foreground dark:hover:bg-white/[0.06]"
             >
               <HugeiconsIcon
                 icon={ArrowLeft01Icon}
diff --git a/studio/frontend/src/features/hub/catalog/hub-option-menu.tsx b/studio/frontend/src/features/hub/catalog/hub-option-menu.tsx
index 38464d36e4..5a11c474d4 100644
--- a/studio/frontend/src/features/hub/catalog/hub-option-menu.tsx
+++ b/studio/frontend/src/features/hub/catalog/hub-option-menu.tsx
@@ -6,9 +6,9 @@ import {
   PopoverContent,
   PopoverTrigger,
 } from "@/components/ui/popover";
-import { cn } from "@/lib/utils";
-import { Tick02Icon } from "@/lib/tick-icon";
 import { ChevronDownStandardIcon } from "@/lib/chevron-icons";
+import { Tick02Icon } from "@/lib/tick-icon";
+import { cn } from "@/lib/utils";
 import { HugeiconsIcon } from "@hugeicons/react";
 import {
   type KeyboardEvent,
@@ -71,7 +71,9 @@ export function HubOptionMenu<T extends string>({
       ? -1
       : Math.min(activeIndex, options.length - 1);
   const activeOptionId =
-    resolvedActiveIndex >= 0 ? `${idBase}-option-${resolvedActiveIndex}` : undefined;
+    resolvedActiveIndex >= 0
+      ? `${idBase}-option-${resolvedActiveIndex}`
+      : undefined;
 
   const activateIndex = useCallback((index: number) => {
     setActiveIndex((current) => (current === index ? current : index));
@@ -161,7 +163,7 @@ export function HubOptionMenu<T extends string>({
 
   return (
     <Popover open={open} onOpenChange={handleOpenChange}>
-      <PopoverTrigger asChild>
+      <PopoverTrigger asChild={true}>
         <button
           ref={triggerRef}
           type="button"
@@ -171,7 +173,7 @@ export function HubOptionMenu<T extends string>({
           aria-label={ariaLabel}
           title={title}
           className={cn(
-            "field-trigger hub-menu-trigger field-soft field-filter inline-flex h-9 shrink-0 cursor-pointer items-center justify-between gap-0.5 rounded-full pl-3 pr-2 text-[12.5px] transition-colors",
+            "field-trigger hub-menu-trigger field-soft field-filter inline-flex h-9 shrink-0 cursor-pointer items-center justify-between gap-2.5 rounded-full pl-3 pr-2.5 text-ui-12p5 transition-colors",
             "focus-visible:border-border focus-visible:ring-0 focus-visible:ring-offset-0",
             className,
           )}
@@ -183,7 +185,10 @@ export function HubOptionMenu<T extends string>({
           }}
         >
           <span className="min-w-0 flex-1 truncate text-left">
-            {triggerContent ?? selected?.triggerLabel ?? selected?.label ?? value}
+            {triggerContent ??
+              selected?.triggerLabel ??
+              selected?.label ??
+              value}
           </span>
           {showChevron && (
             <HugeiconsIcon
diff --git a/studio/frontend/src/features/hub/catalog/hub-section-row.tsx b/studio/frontend/src/features/hub/catalog/hub-section-row.tsx
index b51a6cc257..e580c17a73 100644
--- a/studio/frontend/src/features/hub/catalog/hub-section-row.tsx
+++ b/studio/frontend/src/features/hub/catalog/hub-section-row.tsx
@@ -58,7 +58,7 @@ export const HubSectionRow = memo(function HubSectionRow({
           type="button"
           onClick={onOpenList}
           aria-label={`See all ${title}`}
-          className="hub-section-title group/section -mx-1 inline-flex cursor-pointer items-center gap-1.5 rounded-md px-1 text-[18px] font-semibold tracking-[-0.02em] text-foreground outline-none focus-visible:ring-1 focus-visible:ring-ring"
+          className="hub-section-title group/section -mx-1 inline-flex cursor-pointer items-center gap-1.5 rounded-md px-1 text-ui-18 font-semibold tracking-[-0.02em] text-foreground outline-none focus-visible:ring-1 focus-visible:ring-ring"
         >
           {title}
           <HugeiconsIcon
diff --git a/studio/frontend/src/features/hub/catalog/local-dataset-card.tsx b/studio/frontend/src/features/hub/catalog/local-dataset-card.tsx
index ddda124745..a4e6e5c9f5 100644
--- a/studio/frontend/src/features/hub/catalog/local-dataset-card.tsx
+++ b/studio/frontend/src/features/hub/catalog/local-dataset-card.tsx
@@ -25,7 +25,7 @@ export function LocalDatasetCard({
     <div className="hub-download-card">
       <div className="group/dl flex items-center">
         <div className="relative flex h-9 min-w-0 flex-1 items-center pl-3 pr-2">
-          <span className="flex min-w-0 items-center gap-1.5 text-[12px] text-muted-foreground">
+          <span className="flex min-w-0 items-center gap-1.5 text-ui-12 text-muted-foreground">
             <DotTag tone="success" label="On device" />
             {source !== "hf_cache" && (
               <span className="truncate text-muted-foreground/85">
@@ -34,11 +34,7 @@ export function LocalDatasetCard({
             )}
           </span>
           <div className="ml-auto flex items-center gap-0.5">
-            <PathInfoButton
-              path={path}
-              title={sourceLabel}
-              description="Where this dataset lives on disk."
-            />
+            <PathInfoButton path={path} />
           </div>
         </div>
         {HUB_POST_DOWNLOAD_ACTIONS_VISIBLE && (
diff --git a/studio/frontend/src/features/hub/catalog/local-on-device-card.tsx b/studio/frontend/src/features/hub/catalog/local-on-device-card.tsx
index 3c020a7199..9b508a5413 100644
--- a/studio/frontend/src/features/hub/catalog/local-on-device-card.tsx
+++ b/studio/frontend/src/features/hub/catalog/local-on-device-card.tsx
@@ -1,12 +1,6 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { TrainIcon } from "../components/train-icon";
-import {
-  HUB_GGUF_RUN_ACTIONS_VISIBLE,
-  HUB_NON_GGUF_RUN_ACTIONS_VISIBLE,
-  HUB_POST_DOWNLOAD_ACTIONS_VISIBLE,
-} from "../lib/hub-feature-flags";
 import {
   Popover,
   PopoverContent,
@@ -18,37 +12,44 @@ import {
   TooltipContent,
   TooltipTrigger,
 } from "@/components/ui/tooltip";
+import { ChevronDownStandardIcon } from "@/lib/chevron-icons";
+import { cn } from "@/lib/utils";
 import {
-  type BaseModelSource,
-  type LocalModelInfo,
-  type ModelInventoryFormat,
-  deleteCachedModel,
-} from "../inventory";
+  Alert02Icon,
+  CubeIcon,
+  PlayIcon,
+  RemoveCircleIcon,
+  Share05Icon,
+} from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
+import { useCallback, useMemo, useState } from "react";
+import { TrainIcon } from "../components/train-icon";
 import {
   downloadManager,
   jobKeyOf,
   selectActiveJob,
   useDownloadManagerStore,
 } from "../download-manager";
-import { formatBytes } from "../lib/format";
-import { ggufVariantsMatch } from "../lib/model-identity";
-import { cn } from "@/lib/utils";
-import { confirmExternalLink } from "../stores/external-link-confirm";
-import { useHfTokenStore } from "../stores/hf-token-store";
+import { useOnlineStatus } from "../hooks/use-online-status";
 import {
-  Alert02Icon,
-  CubeIcon,
-  PencilEdit02Icon,
-  PlayIcon,
-  Share05Icon,
-} from "@hugeicons/core-free-icons";
-import { ChevronDownStandardIcon } from "@/lib/chevron-icons";
-import { HugeiconsIcon } from "@hugeicons/react";
-import { useCallback, useMemo, useState } from "react";
+  type BaseModelSource,
+  type LocalModelInfo,
+  type ModelInventoryFormat,
+  deleteCachedModel,
+} from "../inventory";
+import { formatBytes } from "../lib/format";
 import {
   ggufVariantDisplayLabel,
   sortLocalGgufVariants,
 } from "../lib/gguf-variant-sort";
+import {
+  HUB_GGUF_RUN_ACTIONS_VISIBLE,
+  HUB_NON_GGUF_RUN_ACTIONS_VISIBLE,
+  HUB_POST_DOWNLOAD_ACTIONS_VISIBLE,
+} from "../lib/hub-feature-flags";
+import { ggufVariantsMatch } from "../lib/model-identity";
+import { confirmExternalLink } from "../stores/external-link-confirm";
+import { useHfTokenStore } from "../stores/hf-token-store";
 import { DotTag } from "./dot-tag";
 import {
   CardDeleteButton,
@@ -60,7 +61,6 @@ import { PathInfoButton } from "./path-info-button";
 import { TransportConflictDialog } from "./transport-conflict-dialog";
 import { useCardDelete } from "./use-card-delete";
 import { useGgufVariantFetchState } from "./use-gguf-variant-fetch-state";
-import { useOnlineStatus } from "../hooks/use-online-status";
 
 type LocalLoadOptions = {
   ggufVariant?: string;
@@ -91,7 +91,9 @@ interface LocalOnDeviceCardProps {
   systemRamGb?: number;
   unsupportedReason?: string | null;
   onLoad: (opts?: LocalLoadOptions) => void;
+  /** Accepted for API parity; the run bar ejects instead of opening chat. */
   onUseInChat: () => void;
+  onEject?: () => void;
   onTrain?: () => void;
   onChange?: () => void;
 }
@@ -136,22 +138,22 @@ function BaseModelReference({
       </div>
       <div className="min-w-0 flex-1">
         <div className="flex min-w-0 items-center gap-1.5">
-          <span className="shrink-0 text-[11px] font-medium text-muted-foreground">
+          <span className="shrink-0 text-ui-11 font-medium text-muted-foreground">
             {baseModelSourceLabel(baseModelSource)}
           </span>
-          <span className="truncate text-[12px] font-medium text-foreground">
+          <span className="truncate text-ui-12 font-medium text-foreground">
             {baseModel}
           </span>
         </div>
         {baseModelSummary && (
-          <p className="mt-0.5 truncate text-[11px] text-muted-foreground">
+          <p className="mt-0.5 truncate text-ui-11 text-muted-foreground">
             {baseModelSummary}
           </p>
         )}
       </div>
       {canOpenHub && (
         <Tooltip>
-          <TooltipTrigger asChild>
+          <TooltipTrigger asChild={true}>
             <a
               href={`https://huggingface.co/${baseModelHubId}`}
               target="_blank"
@@ -160,7 +162,11 @@ function BaseModelReference({
               className="inline-flex size-7 shrink-0 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-background hover:text-foreground"
               onClick={(event) => {
                 event.stopPropagation();
-                if (confirmExternalLink(`https://huggingface.co/${baseModelHubId}`)) {
+                if (
+                  confirmExternalLink(
+                    `https://huggingface.co/${baseModelHubId}`,
+                  )
+                ) {
                   event.preventDefault();
                 }
               }}
@@ -205,7 +211,7 @@ export function LocalOnDeviceCard({
   systemRamGb,
   unsupportedReason,
   onLoad,
-  onUseInChat,
+  onEject,
   onTrain,
   onChange,
 }: LocalOnDeviceCardProps) {
@@ -241,7 +247,10 @@ export function LocalOnDeviceCard({
   const { deleting, runDelete } = useCardDelete({
     action: async () => {
       if (!repoId) return;
-      await deleteCachedModel(repoId, undefined, hfToken || undefined);
+      // Delete is only offered for hf_cache rows (see canDelete), so `path` is
+      // the cache snapshot path: pass it so the delete targets the cache this
+      // card shows instead of falling back to the active cache.
+      await deleteCachedModel(repoId, undefined, hfToken || undefined, path);
     },
     resourceName: "model",
     successMessage: () => `Deleted ${repoId}`,
@@ -371,18 +380,20 @@ export function LocalOnDeviceCard({
   const handleConfirmUpdate = () => {
     if (!repoId || !updateTargetVariant) return;
     setUpdateOpen(false);
-    void downloadManager.requestStart({
-      kind: "model",
-      repoId,
-      variant: updateTargetVariant,
-      expectedBytes: updateExpectedBytes,
-    }).then((outcome) => {
-      if (outcome === "conflict") {
-        setUpdateConflictKey(jobKeyOf("model", repoId, updateTargetVariant));
-      }
-      void currentVariantState.refresh();
-      void remoteVariantState.refresh();
-    });
+    void downloadManager
+      .requestStart({
+        kind: "model",
+        repoId,
+        variant: updateTargetVariant,
+        expectedBytes: updateExpectedBytes,
+      })
+      .then((outcome) => {
+        if (outcome === "conflict") {
+          setUpdateConflictKey(jobKeyOf("model", repoId, updateTargetVariant));
+        }
+        void currentVariantState.refresh();
+        void remoteVariantState.refresh();
+      });
   };
   const selectedVariantIsActive =
     needsVariantSelection && selectedQuant
@@ -416,7 +427,7 @@ export function LocalOnDeviceCard({
   return (
     <div className="flex w-full flex-col gap-2">
       {showOldCacheHint && (
-        <div className="flex items-start gap-2 rounded-[12px] border border-amber-500/20 bg-amber-500/8 px-3 py-2 text-[12px] leading-5 text-amber-700 dark:text-amber-300">
+        <div className="flex items-start gap-2 rounded-[12px] border border-amber-500/20 bg-amber-500/8 px-3 py-2 text-ui-12 leading-5 text-amber-700 dark:text-amber-300">
           <HugeiconsIcon
             icon={Alert02Icon}
             strokeWidth={1.75}
@@ -428,10 +439,11 @@ export function LocalOnDeviceCard({
             can still keep it on disk, or delete it to free space.
           </span>
         </div>
-      )}<div className="hub-download-card">
+      )}
+      <div className="hub-download-card">
         <div className="group/dl flex items-center">
           <div className="relative flex h-9 min-w-0 flex-1 items-center pl-3 pr-2">
-            <span className="flex min-w-0 items-center gap-1.5 text-[12px] text-muted-foreground">
+            <span className="flex min-w-0 items-center gap-1.5 text-ui-12 text-muted-foreground">
               <DotTag
                 tone="success"
                 label={selectedVariantIsActive ? "Loaded" : "On device"}
@@ -443,7 +455,7 @@ export function LocalOnDeviceCard({
                     <button
                       type="button"
                       disabled={currentVariantState.loading}
-                      className="inline-flex h-6 max-w-[170px] shrink-0 cursor-pointer items-center gap-1.5 rounded-[8px] border border-format-gguf/35 px-2 font-mono text-[10.5px] leading-none text-format-gguf transition-colors hover:bg-format-gguf/8 disabled:cursor-not-allowed disabled:opacity-60"
+                      className="inline-flex h-6 max-w-[170px] shrink-0 cursor-pointer items-center gap-1.5 rounded-[8px] border border-format-gguf/35 px-2 font-mono text-ui-10p5 leading-none text-format-gguf transition-colors hover:bg-format-gguf/8 disabled:cursor-not-allowed disabled:opacity-60"
                     >
                       <span className="truncate">
                         {currentVariantState.loading
@@ -455,7 +467,7 @@ export function LocalOnDeviceCard({
                               : "Select"}
                       </span>
                       {selectedVariant && (
-                        <span className="shrink-0 font-sans text-[10px] text-muted-foreground tabular-nums">
+                        <span className="shrink-0 font-sans text-ui-10 text-muted-foreground tabular-nums">
                           {formatBytes(selectedVariant.size_bytes)}
                         </span>
                       )}
@@ -500,14 +512,14 @@ export function LocalOnDeviceCard({
                                 : "hover:bg-foreground/[0.05] dark:hover:bg-foreground/[0.06]",
                             )}
                           >
-                            <span className="min-w-0 flex-1 truncate font-mono text-[12px] text-format-gguf">
+                            <span className="min-w-0 flex-1 truncate font-mono text-ui-12 text-format-gguf">
                               {label}
                             </span>
                             <span className="flex shrink-0 items-center gap-1.5">
                               {isLoaded && (
                                 <DotTag tone="success" label="Loaded" />
                               )}
-                              <span className="text-[10px] text-muted-foreground tabular-nums">
+                              <span className="text-ui-10 text-muted-foreground tabular-nums">
                                 {formatBytes(variant.size_bytes)}
                               </span>
                             </span>
@@ -540,7 +552,7 @@ export function LocalOnDeviceCard({
               {canUpdate && (
                 <CardUpdateButton
                   label={`Update ${repoId}`}
-                  emphasized
+                  emphasized={true}
                   onClick={() => setUpdateOpen(true)}
                 />
               )}
@@ -550,11 +562,7 @@ export function LocalOnDeviceCard({
                   onClick={() => setDeleteOpen(true)}
                 />
               )}
-              <PathInfoButton
-                path={path}
-                title={sourceLabel}
-                description="Where this model lives on disk."
-              />
+              <PathInfoButton path={path} />
             </div>
           </div>
           {onTrain && HUB_POST_DOWNLOAD_ACTIONS_VISIBLE && (
@@ -585,7 +593,7 @@ export function LocalOnDeviceCard({
               onClick={() => {
                 if (!canRun) return;
                 if (selectedVariantIsActive) {
-                  onUseInChat();
+                  onEject?.();
                   return;
                 }
                 if (needsVariantSelection) {
@@ -615,24 +623,24 @@ export function LocalOnDeviceCard({
                 </>
               ) : selectedVariantIsActive ? (
                 <>
-                  <HugeiconsIcon icon={PencilEdit02Icon} strokeWidth={1.75} />
-                  Chat
+                  <HugeiconsIcon icon={RemoveCircleIcon} strokeWidth={1.75} />
+                  Eject
                 </>
               ) : variantActionPending ? (
                 <>
                   <Spinner />
                   Loading…
                 </>
-              ) : !canRun ? (
-                <>
-                  <HugeiconsIcon icon={Alert02Icon} strokeWidth={1.75} />
-                  No run
-                </>
-              ) : (
+              ) : canRun ? (
                 <>
                   <HugeiconsIcon icon={PlayIcon} strokeWidth={1.75} />
                   Run
                 </>
+              ) : (
+                <>
+                  <HugeiconsIcon icon={Alert02Icon} strokeWidth={1.75} />
+                  No run
+                </>
               )}
             </button>
           </div>
diff --git a/studio/frontend/src/features/hub/catalog/model-card.tsx b/studio/frontend/src/features/hub/catalog/model-card.tsx
index 370e5071f4..b042eb1ad0 100644
--- a/studio/frontend/src/features/hub/catalog/model-card.tsx
+++ b/studio/frontend/src/features/hub/catalog/model-card.tsx
@@ -283,14 +283,14 @@ export const ModelCard = memo(function ModelCard({
         <OwnerAvatar
           owner={row.owner}
           repoName={row.repo}
-          className="size-11 shrink-0 rounded-[14px] text-[17px] ring-1 ring-white/10"
+          className="size-11 shrink-0 rounded-[14px] text-ui-17 ring-1 ring-white/10"
           remote={false}
         />
         <div className="min-w-0 flex-1 space-y-0.5">
-          <p className="hub-trending-title line-clamp-2 text-[13.5px] font-semibold leading-[16px] text-foreground">
+          <p className="hub-trending-title line-clamp-2 text-ui-13p5 font-semibold leading-ui-16 text-foreground">
             {row.repo}
           </p>
-          <span className="hub-trending-owner flex min-w-0 items-center gap-1 text-[11.5px] leading-[15px] text-muted-foreground/80">
+          <span className="hub-trending-owner flex min-w-0 items-center gap-1 text-ui-11p5 leading-ui-15 text-muted-foreground/80">
             <span className="truncate">{row.owner}</span>
             {row.owner.toLowerCase() === "unsloth" && (
               <span
diff --git a/studio/frontend/src/features/hub/catalog/model-inspector.tsx b/studio/frontend/src/features/hub/catalog/model-inspector.tsx
index 63cb34678b..c304738ab1 100644
--- a/studio/frontend/src/features/hub/catalog/model-inspector.tsx
+++ b/studio/frontend/src/features/hub/catalog/model-inspector.tsx
@@ -17,9 +17,9 @@ import {
   formatRelativeShort,
   formatShortDate,
 } from "@/features/hub/lib/format";
-import { cn, formatCompact } from "@/lib/utils";
-import { confirmExternalLink } from "../stores/external-link-confirm";
 import { useHfTokenStore } from "@/features/hub/stores/hf-token-store";
+import { Tick02Icon } from "@/lib/tick-icon";
+import { cn, formatCompact } from "@/lib/utils";
 import {
   Calendar03Icon,
   CalendarAdd01Icon,
@@ -37,10 +37,10 @@ import {
   RamMemoryIcon,
   Share05Icon,
 } from "@hugeicons/core-free-icons";
-import { Tick02Icon } from "@/lib/tick-icon";
 import type { IconSvgElement } from "@hugeicons/react";
 import { HugeiconsIcon } from "@hugeicons/react";
 import { memo, useDeferredValue, useMemo } from "react";
+import { selectActiveJob, useDownloadManagerStore } from "../download-manager";
 import { useCopyFeedback } from "../hooks/use-copy-feedback";
 import { useDatasetSize } from "../hooks/use-dataset-size";
 import {
@@ -49,8 +49,8 @@ import {
   formatPipelineTag,
   parseLanguageTags,
 } from "../lib/view-models";
+import { confirmExternalLink } from "../stores/external-link-confirm";
 import type { SelectedModelView } from "../types";
-import { selectActiveJob, useDownloadManagerStore } from "../download-manager";
 import { DatasetDownloadSection } from "./dataset-download-section";
 import { DownloadSection } from "./download-section";
 import { LocalDatasetCard } from "./local-dataset-card";
@@ -59,6 +59,13 @@ import { ModelReadme } from "./model-readme";
 import { OwnerAvatar } from "./owner-avatar";
 import { AccessChip, CapabilityPill } from "./shared";
 
+// HF pipeline_tag values authoritative for embedding-only repos; capability
+// labels (code/vision/audio) can leak onto them via name or tags.
+const EMBEDDING_PIPELINE_TAGS: ReadonlySet<string> = new Set([
+  "feature-extraction",
+  "sentence-similarity",
+]);
+
 function ViewRepositoryButton({
   repoId,
   isDataset,
@@ -159,7 +166,7 @@ function StatRow({
   return (
     <Tooltip>
       <TooltipTrigger asChild={true}>
-        <span className="hub-tag-meta inline-flex cursor-default items-center gap-1.5 px-2.5 py-1 text-[11.5px] text-muted-foreground transition-colors hover:text-foreground/80">
+        <span className="hub-tag-meta inline-flex cursor-default items-center gap-1.5 px-2.5 py-1 text-ui-11p5 text-muted-foreground transition-colors hover:text-foreground/80">
           <HugeiconsIcon
             icon={icon}
             strokeWidth={1.75}
@@ -201,7 +208,7 @@ function StatusChip({
   return (
     <span
       className={cn(
-        "inline-flex h-5 shrink-0 items-center whitespace-nowrap rounded-full border bg-transparent px-2 text-[11px] font-medium leading-none",
+        "inline-flex h-5 shrink-0 items-center whitespace-nowrap rounded-full border bg-transparent px-2 text-ui-11 font-medium leading-none",
         toneClass,
         className,
       )}
@@ -241,12 +248,12 @@ function BaseModelSearchChip({
           <button
             type="button"
             onClick={() => onSearchHub(searchTerm)}
-            className="inline-flex h-6 max-w-full cursor-pointer items-center gap-1.5 rounded-full bg-muted px-2.5 text-[11.5px] transition-colors hover:bg-muted/80 dark:bg-[rgba(255,255,255,0.04)]"
+            className="inline-flex h-6 max-w-full cursor-pointer items-center gap-1.5 rounded-full bg-muted px-2.5 text-ui-11p5 transition-colors hover:bg-muted/80 dark:bg-[rgba(255,255,255,0.04)]"
           >
             {content}
           </button>
         ) : (
-          <span className="inline-flex h-6 max-w-full items-center gap-1.5 rounded-full bg-muted px-2.5 text-[11.5px] dark:bg-[rgba(255,255,255,0.04)]">
+          <span className="inline-flex h-6 max-w-full items-center gap-1.5 rounded-full bg-muted px-2.5 text-ui-11p5 dark:bg-[rgba(255,255,255,0.04)]">
             {content}
           </span>
         )}
@@ -318,11 +325,11 @@ function ModelStatusChips({
           >
             This model may not be supported yet.
             {unslothSupport.reason && (
-              <span className="mt-1 block text-[10.5px] font-normal text-white/75">
+              <span className="mt-1 block text-ui-10p5 font-normal text-white/75">
                 {unslothSupport.reason}
               </span>
             )}
-            <span className="mt-1 block text-[10.5px] font-normal text-white/75">
+            <span className="mt-1 block text-ui-10p5 font-normal text-white/75">
               Still downloadable to your Hugging Face cache.
             </span>
           </TooltipContent>
@@ -342,7 +349,7 @@ function ModelStatusChips({
           >
             This device has no supported GPU or usable MLX, so only GGUF models
             can run here.
-            <span className="mt-1 block text-[10.5px] font-normal text-white/75">
+            <span className="mt-1 block text-ui-10p5 font-normal text-white/75">
               Still downloadable to your Hugging Face cache.
             </span>
           </TooltipContent>
@@ -361,7 +368,7 @@ function ModelStatusChips({
             className="tooltip-compact max-w-xs"
           >
             Estimated 4-bit memory load is around {vramInfo.est} GB.
-            <span className="mt-1 block text-[10.5px] font-normal text-white/75">
+            <span className="mt-1 block text-ui-10p5 font-normal text-white/75">
               {vramDetail}
             </span>
           </TooltipContent>
@@ -392,6 +399,7 @@ export type ModelInspectorActions = {
     expectedBytes?: number;
   }) => void;
   onUseInChat: () => void;
+  onEject?: () => void;
   onTrain?: () => void;
   onInventoryChange?: () => void;
   onSearchHub?: (query: string) => void;
@@ -426,6 +434,7 @@ export const ModelInspector = memo(function ModelInspector({
     onLoad,
     onLoadLocal,
     onUseInChat,
+    onEject,
     onTrain,
     onInventoryChange,
     onSearchHub,
@@ -493,10 +502,10 @@ export const ModelInspector = memo(function ModelInspector({
           <HugeiconsIcon icon={CubeIcon} strokeWidth={1.5} className="size-5" />
         </div>
         <div className="space-y-1">
-          <p className="text-[15px] font-semibold tracking-tight text-foreground">
+          <p className="text-ui-15 font-semibold tracking-tight text-foreground">
             Select a {isDataset ? "dataset" : "model"}
           </p>
-          <p className="max-w-sm text-[12.5px] leading-5 text-muted-foreground">
+          <p className="max-w-sm text-ui-12p5 leading-5 text-muted-foreground">
             {isDataset
               ? "Choose a dataset from the catalog to inspect its download state and details."
               : "Choose an item from the catalog to inspect its runtime fit, download state, and model card."}
@@ -510,14 +519,16 @@ export const ModelInspector = memo(function ModelInspector({
     ? formatRelativeShort(model.updatedAt)
     : formatLocalUpdated(model.localUpdatedAt);
   const updatedLabel = updatedRaw === "Unknown update" ? "N/A" : updatedRaw;
-  const createdLabel = model.createdAt ? formatShortDate(model.createdAt) : null;
+  const createdLabel = model.createdAt
+    ? formatShortDate(model.createdAt)
+    : null;
   const libraryLabel = isDataset ? null : formatLibrary(model.libraryName);
   const gatedAccess = model.gated !== false && model.gated !== undefined;
   const downloadsTooltip =
     model.downloadsAllTime != null ? (
       <>
         Downloads (30 days)
-        <span className="mt-1 block text-[10.5px] font-normal text-white/75">
+        <span className="mt-1 block text-ui-10p5 font-normal text-white/75">
           {formatCompact(model.downloadsAllTime)} all time
         </span>
       </>
@@ -531,11 +542,27 @@ export const ModelInspector = memo(function ModelInspector({
     ? formatCompact(model.totalParams)
     : "N/A";
   const unslothSupported = unslothSupport.status !== "unsupported";
+  // Embedding-only non-GGUF repos have no generative head, so keep them out of
+  // the Run gate. Prefer the pipeline tag, else the capability heuristic.
+  const isEmbeddingOnly =
+    !model.isGguf &&
+    model.capabilities.some((c) => c.key === "embedding") &&
+    (EMBEDDING_PIPELINE_TAGS.has(model.pipelineTag?.toLowerCase() ?? "") ||
+      !model.capabilities.some(
+        (c) =>
+          c.key === "conversational" ||
+          c.key === "tools" ||
+          c.key === "reasoning" ||
+          c.key === "code" ||
+          c.key === "vision" ||
+          c.key === "audio",
+      ));
   // Chat-only hosts (no supported GPU / usable MLX) run inference only through
   // llama.cpp, so only GGUF is loadable.
   const canRunModel =
     !isDataset &&
     (model.runtimeCapabilities?.canChat ?? true) &&
+    !isEmbeddingOnly &&
     (model.isGguf || (!chatOnly && unslothSupported));
   const canTrainModel =
     !isDataset &&
@@ -555,11 +582,11 @@ export const ModelInspector = memo(function ModelInspector({
           <OwnerAvatar
             owner={model.owner}
             repoName={model.title}
-            className="size-[60px] rounded-[18px] text-[19px]"
+            className="size-[60px] rounded-[18px] text-ui-19"
           />
           <div className="min-w-0 flex-1">
             <div className="flex min-w-0 items-center gap-1.5">
-              <h2 className="truncate text-[25px] font-semibold leading-[31px] tracking-normal text-foreground">
+              <h2 className="truncate text-ui-25 font-semibold leading-ui-31 tracking-normal text-foreground">
                 {model.title}
               </h2>
               {model.hubRepoId && (
@@ -572,7 +599,7 @@ export const ModelInspector = memo(function ModelInspector({
                 </div>
               )}
             </div>
-            <div className="mt-0.5 flex min-w-0 items-center gap-1 text-[15px] leading-[24px] text-muted-foreground">
+            <div className="mt-0.5 flex min-w-0 items-center gap-1 text-ui-15 leading-ui-24 text-muted-foreground">
               <span className="truncate">{model.owner}</span>
               {model.owner.toLowerCase() === "unsloth" && (
                 <span
@@ -586,12 +613,12 @@ export const ModelInspector = memo(function ModelInspector({
 
         <div className="mt-4 flex flex-wrap items-center gap-1.5">
           {isDataset && (
-            <span className="inline-flex shrink-0 items-center rounded-full border border-violet-500/40 bg-transparent px-2 py-0.5 text-[11.5px] font-medium text-violet-600 dark:text-violet-400">
+            <span className="inline-flex shrink-0 items-center rounded-full border border-violet-500/40 bg-transparent px-2 py-0.5 text-ui-11p5 font-medium text-violet-600 dark:text-violet-400">
               Dataset
             </span>
           )}
           {!isDataset && (
-            <span className="inline-flex h-6 items-center gap-1.5 rounded-full bg-muted px-2.5 text-[11.5px] font-medium text-foreground dark:bg-[rgba(255,255,255,0.04)]">
+            <span className="inline-flex h-6 items-center gap-1.5 rounded-full bg-muted px-2.5 text-ui-11p5 font-medium text-foreground dark:bg-[rgba(255,255,255,0.04)]">
               <HugeiconsIcon
                 icon={CubeIcon}
                 strokeWidth={1.75}
@@ -673,6 +700,7 @@ export const ModelInspector = memo(function ModelInspector({
               }
               onLoad={onLoadLocal}
               onUseInChat={onUseInChat}
+              onEject={onEject}
               onTrain={
                 model.isDownloaded && canTrainModel ? onTrain : undefined
               }
@@ -696,6 +724,7 @@ export const ModelInspector = memo(function ModelInspector({
               knownBytes={model.cachedBytes}
               onLoad={model.isLocal ? onLoadLocal : onLoad}
               onUseInChat={onUseInChat}
+              onEject={onEject}
               onTrain={
                 model.isDownloaded && canTrainModel ? onTrain : undefined
               }
@@ -707,12 +736,12 @@ export const ModelInspector = memo(function ModelInspector({
 
       <div className="pb-5 pt-5">
         {selectionHiddenByFilters && (
-          <p className="mb-3 rounded-[8px] border border-amber-500/30 bg-amber-500/10 px-3 py-2 text-[11.5px] leading-snug text-muted-foreground">
+          <p className="mb-3 rounded-[8px] border border-amber-500/30 bg-amber-500/10 px-3 py-2 text-ui-11p5 leading-snug text-muted-foreground">
             Current selection is hidden by the active filters or search.
           </p>
         )}
         {metadataUnavailable && (
-          <p className="mb-3 text-[11.5px] leading-snug text-muted-foreground">
+          <p className="mb-3 text-ui-11p5 leading-snug text-muted-foreground">
             Couldn't load full details from Hugging Face. Some fields may be
             incomplete.
           </p>
diff --git a/studio/frontend/src/features/hub/catalog/model-readme.tsx b/studio/frontend/src/features/hub/catalog/model-readme.tsx
index 3d215473e2..889b011399 100644
--- a/studio/frontend/src/features/hub/catalog/model-readme.tsx
+++ b/studio/frontend/src/features/hub/catalog/model-readme.tsx
@@ -126,17 +126,17 @@ function prepareReadmeBody(markdown: string): string {
 }
 
 const PROSE = cn(
-  "max-w-none text-[13.5px] leading-[1.7] text-foreground/85",
-  "[&_h1]:text-[18px] [&_h1]:font-semibold [&_h1]:tracking-tight [&_h1]:mt-2 [&_h1]:mb-3",
-  "[&_h2]:text-[15.5px] [&_h2]:font-semibold [&_h2]:tracking-tight [&_h2]:mt-5 [&_h2]:mb-2",
-  "[&_h3]:text-[14px] [&_h3]:font-semibold [&_h3]:mt-4 [&_h3]:mb-1.5",
+  "max-w-none text-ui-13p5 leading-[1.7] text-foreground/85",
+  "[&_h1]:text-ui-18 [&_h1]:font-semibold [&_h1]:tracking-tight [&_h1]:mt-2 [&_h1]:mb-3",
+  "[&_h2]:text-ui-15p5 [&_h2]:font-semibold [&_h2]:tracking-tight [&_h2]:mt-5 [&_h2]:mb-2",
+  "[&_h3]:text-ui-14 [&_h3]:font-semibold [&_h3]:mt-4 [&_h3]:mb-1.5",
   "[&_p]:my-2.5 [&_ul]:my-2 [&_ol]:my-2 [&_li]:my-0.5",
   "[&_a]:text-primary [&_a:hover]:underline",
-  "[&_code]:rounded-md [&_code]:bg-muted/60 [&_code]:px-1 [&_code]:py-0.5 [&_code]:text-[12px] [&_code]:font-mono",
-  "[&_pre]:rounded-[12px] [&_pre]:border [&_pre]:border-border/60 [&_pre]:bg-muted/40 [&_pre]:p-3 [&_pre]:text-[12px] [&_pre]:overflow-x-auto",
+  "[&_code]:rounded-md [&_code]:bg-muted/60 [&_code]:px-1 [&_code]:py-0.5 [&_code]:text-ui-12 [&_code]:font-mono",
+  "[&_pre]:rounded-[12px] [&_pre]:border [&_pre]:border-border/60 [&_pre]:bg-muted/40 [&_pre]:p-3 [&_pre]:text-ui-12 [&_pre]:overflow-x-auto",
   "[&_pre_code]:bg-transparent [&_pre_code]:p-0",
   "[&_blockquote]:border-l-2 [&_blockquote]:border-border/60 [&_blockquote]:pl-3 [&_blockquote]:text-muted-foreground",
-  "[&_table]:my-3 [&_table]:text-[12.5px]",
+  "[&_table]:my-3 [&_table]:text-ui-12p5",
   "[&_th]:px-2 [&_th]:py-1.5 [&_th]:text-left [&_th]:font-semibold [&_th]:border-b [&_th]:border-border/60",
   "[&_td]:px-2 [&_td]:py-1.5 [&_td]:border-b [&_td]:border-border/40",
   "[&_img]:rounded-[10px] [&_img]:my-2 [&_img]:max-w-full",
@@ -300,7 +300,7 @@ function ReadmePlaceholder({
       aria-busy="true"
       aria-live="polite"
     >
-      <div className="flex items-center gap-2 text-[12.5px] text-muted-foreground">
+      <div className="flex items-center gap-2 text-ui-12p5 text-muted-foreground">
         <Spinner className="size-3.5" />
         {message ?? `Loading ${kind === "dataset" ? "dataset" : "model"} card…`}
       </div>
@@ -540,7 +540,7 @@ export function ModelReadme({
         ? current.error
         : readmeUnavailableMessage(subject);
     return (
-      <p className="min-h-[44px] text-[12.5px] text-muted-foreground">
+      <p className="min-h-[44px] text-ui-12p5 text-muted-foreground">
         {errorMessage}
       </p>
     );
@@ -548,7 +548,7 @@ export function ModelReadme({
 
   if (!current.body) {
     return (
-      <p className="min-h-[44px] text-[12.5px] text-muted-foreground">
+      <p className="min-h-[44px] text-ui-12p5 text-muted-foreground">
         {readmeMissingMessage(subject)}
       </p>
     );
diff --git a/studio/frontend/src/features/hub/catalog/models-catalog-lists.tsx b/studio/frontend/src/features/hub/catalog/models-catalog-lists.tsx
index 355c38a91e..cbae108006 100644
--- a/studio/frontend/src/features/hub/catalog/models-catalog-lists.tsx
+++ b/studio/frontend/src/features/hub/catalog/models-catalog-lists.tsx
@@ -2,13 +2,20 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { Spinner } from "@/components/ui/spinner";
+import {
+  makePinRank,
+  pinKey,
+  usePinnedModelsStore,
+} from "@/features/model-picker";
 import {
   CubeIcon,
   DownloadCircle02Icon,
-  FolderSearchIcon,
+  PinIcon,
+  Search01Icon,
 } from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
 import type { RefObject } from "react";
-import { useMemo } from "react";
+import { useLayoutEffect, useMemo, useState } from "react";
 import {
   inventoryRowMatches,
   scoreInventoryRow,
@@ -61,7 +68,7 @@ export function InventoryWarningRow({
   onRetry: () => void;
 }) {
   return (
-    <div className="mx-5 mt-2 rounded-[8px] border border-amber-500/30 bg-amber-500/10 px-3 py-2 text-[12.5px] text-muted-foreground">
+    <div className="mx-5 mt-2 rounded-[8px] border border-amber-500/30 bg-amber-500/10 px-3 py-2 text-ui-12p5 text-muted-foreground">
       <div className="flex items-center justify-between gap-3">
         <span>
           Some on-device sources couldn't be scanned. Showing available{" "}
@@ -69,7 +76,7 @@ export function InventoryWarningRow({
         </span>
         <button
           type="button"
-          className="shrink-0 text-[12px] font-medium text-foreground transition-colors hover:text-primary"
+          className="shrink-0 text-ui-12 font-medium text-foreground transition-colors hover:text-primary"
           onClick={onRetry}
         >
           Retry
@@ -208,7 +215,7 @@ export function DiscoverList({
           <SkeletonList />
         ) : (
           <EmptyState
-            icon={query.trim() ? FolderSearchIcon : CubeIcon}
+            icon={query.trim() ? Search01Icon : CubeIcon}
             title={
               query.trim()
                 ? `No matching ${isDataset ? "datasets" : "models"}`
@@ -244,6 +251,8 @@ export function DownloadedList({
   downloadedReady,
   inventoryError,
   query,
+  typeFilterActive = false,
+  onClearFilters,
   scrollElement,
   columns = 1,
   activeCheckpoint,
@@ -262,6 +271,8 @@ export function DownloadedList({
   downloadedReady: boolean;
   inventoryError: boolean;
   query: string;
+  typeFilterActive?: boolean;
+  onClearFilters?: () => void;
   scrollElement: HTMLDivElement | null;
   columns?: number;
   activeCheckpoint: string | null;
@@ -274,11 +285,20 @@ export function DownloadedList({
   sort: InventorySort;
   onInventoryChange?: () => void;
 }) {
+  // Pinned repos surface first regardless of the active sort; the chosen sort
+  // still orders rows within the pinned and unpinned groups.
+  const pinnedIds = usePinnedModelsStore((s) => s.pinned);
+  const pinnedSet = useMemo(() => new Set(pinnedIds), [pinnedIds]);
   const inventoryItems = useMemo<InventoryItem[]>(() => {
     const merged: InventoryItem[] = [
       ...cachedRows.map((row) => ({ variant: "cached" as const, row })),
       ...localRows.map((row) => ({ variant: "local" as const, row })),
     ];
+    // Pinned rows order by pin recency (newest pin first), not the active
+    // sort, so "Pin to top" puts the row exactly where the user expects.
+    const rank = makePinRank(pinnedIds);
+    const pinRank = (item: InventoryItem) =>
+      item.row.repoId ? rank(pinKey(item.row.repoId)) : Number.MAX_SAFE_INTEGER;
     if (inventoryTokens.length > 0) {
       return merged
         .map((item, index) => ({
@@ -286,29 +306,89 @@ export function DownloadedList({
           index,
           score: scoreInventoryRow(item.row, inventoryTokens),
         }))
-        .sort((a, b) => b.score - a.score || a.index - b.index)
+        .sort(
+          (a, b) =>
+            pinRank(a.item) - pinRank(b.item) ||
+            b.score - a.score ||
+            a.index - b.index,
+        )
         .map((entry) => entry.item);
     }
     if (sort === "recent") {
-      return merged;
+      return merged
+        .map((item, index) => ({ item, index }))
+        .sort((a, b) => pinRank(a.item) - pinRank(b.item) || a.index - b.index)
+        .map((entry) => entry.item);
     }
     return merged
       .map((item, index) => ({ item, index }))
-      .sort((a, b) =>
-        sort === "name"
-          ? inventoryItemTitle(a.item).localeCompare(
-              inventoryItemTitle(b.item),
-            ) || a.index - b.index
-          : inventoryItemSize(b.item) - inventoryItemSize(a.item) ||
-            a.index - b.index,
+      .sort(
+        (a, b) =>
+          pinRank(a.item) - pinRank(b.item) ||
+          (sort === "name"
+            ? inventoryItemTitle(a.item).localeCompare(
+                inventoryItemTitle(b.item),
+              ) || a.index - b.index
+            : inventoryItemSize(b.item) - inventoryItemSize(a.item) ||
+              a.index - b.index),
       )
       .map((entry) => entry.item);
-  }, [cachedRows, localRows, inventoryTokens, sort]);
+  }, [cachedRows, localRows, inventoryTokens, sort, pinnedIds]);
   const hasInventoryRows = cachedRows.length > 0 || localRows.length > 0;
+  // Pinned repos get their own labelled section so it's clear why they lead
+  // the list; inventoryItems already sorts them first, so this is a prefix.
+  const pinnedCount = useMemo(
+    () =>
+      inventoryItems.filter(
+        (item) => item.row.repoId && pinnedSet.has(pinKey(item.row.repoId)),
+      ).length,
+    [inventoryItems, pinnedSet],
+  );
+  const pinnedItems = inventoryItems.slice(0, pinnedCount);
+  const unpinnedItems = inventoryItems.slice(pinnedCount);
+  const [virtualRowsWrapper, setVirtualRowsWrapper] =
+    useState<HTMLDivElement | null>(null);
+  const [scrollMargin, setScrollMargin] = useState(0);
+  useLayoutEffect(() => {
+    if (!virtualRowsWrapper || !scrollElement) return;
+    const measure = () => {
+      const margin = Math.max(
+        0,
+        Math.round(
+          virtualRowsWrapper.getBoundingClientRect().top -
+            scrollElement.getBoundingClientRect().top +
+            scrollElement.scrollTop,
+        ),
+      );
+      setScrollMargin((current) => (current === margin ? current : margin));
+    };
+    measure();
+    const observer = new ResizeObserver(measure);
+    observer.observe(virtualRowsWrapper.parentElement ?? scrollElement);
+    return () => observer.disconnect();
+  }, [virtualRowsWrapper, scrollElement]);
+  const rowHeightPx = compact
+    ? RESULT_SPLIT_ROW_HEIGHT_PX
+    : RESULT_GRID_ROW_HEIGHT_PX;
+  const cellHeightPx = compact ? RESULT_SPLIT_HEIGHT_PX : RESULT_GRID_HEIGHT_PX;
+  const renderInventoryRow = (item: InventoryItem) => (
+    <InventoryRow
+      row={item.row}
+      selected={selectedId === item.row.id}
+      activeCheckpoint={activeCheckpoint}
+      activeGgufVariant={activeGgufVariant}
+      isDataset={isDataset}
+      dimmed={!inventoryRowMatches(item.row, inventoryTokens)}
+      deviceType={deviceType}
+      compact={compact}
+      onSelect={onSelect}
+      onChange={onInventoryChange}
+    />
+  );
 
   if (!downloadedReady && !hasInventoryRows) {
     return (
-      <div className="flex min-h-[240px] items-center justify-center gap-3 text-[13px] text-muted-foreground">
+      <div className="flex min-h-[240px] items-center justify-center gap-3 text-ui-13 text-muted-foreground">
         <Spinner className="size-4" />
         Loading local inventory...
       </div>
@@ -325,9 +405,29 @@ export function DownloadedList({
   }
 
   if (cachedRows.length === 0 && localRows.length === 0) {
+    if (!query.trim() && typeFilterActive) {
+      return (
+        <EmptyState
+          icon={Search01Icon}
+          title="No matching models on device"
+          body="No downloaded or local model matches the selected type filter."
+          action={
+            onClearFilters && (
+              <button
+                type="button"
+                onClick={onClearFilters}
+                className="inline-flex h-8 items-center gap-1.5 rounded-full bg-transparent px-3 text-ui-12 font-medium text-foreground transition-colors hover:bg-foreground/[0.04] dark:hover:bg-white/[0.05]"
+              >
+                Show all types
+              </button>
+            )
+          }
+        />
+      );
+    }
     return (
       <EmptyState
-        icon={query.trim() ? FolderSearchIcon : DownloadCircle02Icon}
+        icon={query.trim() ? Search01Icon : DownloadCircle02Icon}
         title={query.trim() ? "No matches on device" : "Nothing on device yet"}
         body={
           query.trim()
@@ -341,27 +441,57 @@ export function DownloadedList({
   }
 
   return (
-    <VirtualRows
-      items={inventoryItems}
-      scrollElement={scrollElement}
-      columns={columns}
-      rowHeight={compact ? RESULT_SPLIT_ROW_HEIGHT_PX : RESULT_GRID_ROW_HEIGHT_PX}
-      cellHeight={compact ? RESULT_SPLIT_HEIGHT_PX : RESULT_GRID_HEIGHT_PX}
-      getKey={(item) => `${item.variant}-${item.row.id}`}
-      renderRow={(item) => (
-        <InventoryRow
-          row={item.row}
-          selected={selectedId === item.row.id}
-          activeCheckpoint={activeCheckpoint}
-          activeGgufVariant={activeGgufVariant}
-          isDataset={isDataset}
-          dimmed={!inventoryRowMatches(item.row, inventoryTokens)}
-          deviceType={deviceType}
-          compact={compact}
-          onSelect={onSelect}
-          onChange={onInventoryChange}
-        />
+    <>
+      {pinnedItems.length > 0 && (
+        <>
+          <div className="flex items-center gap-1.5 px-1 pb-2 pt-3 text-ui-11 font-semibold uppercase tracking-wider text-muted-foreground">
+            <HugeiconsIcon
+              icon={PinIcon}
+              strokeWidth={1.75}
+              className="size-3.5"
+            />
+            Pinned
+          </div>
+          {/* Pinned rows are few, so render them as a plain grid matching the
+              virtualized list's lane count and row spacing. */}
+          <div
+            style={{
+              display: "grid",
+              gridTemplateColumns: `repeat(${Math.max(1, columns)}, minmax(0, 1fr))`,
+              columnGap: 12,
+              rowGap: rowHeightPx - cellHeightPx,
+              paddingBottom: rowHeightPx - cellHeightPx,
+            }}
+          >
+            {pinnedItems.map((item) => (
+              <div
+                key={`${item.variant}-${item.row.id}`}
+                className="min-w-0"
+                style={{ height: cellHeightPx }}
+              >
+                {renderInventoryRow(item)}
+              </div>
+            ))}
+          </div>
+          {unpinnedItems.length > 0 && (
+            <div className="px-1 pb-2 pt-2 text-ui-11 font-semibold uppercase tracking-wider text-muted-foreground">
+              All {isDataset ? "datasets" : "models"}
+            </div>
+          )}
+        </>
       )}
-    />
+      <div ref={setVirtualRowsWrapper}>
+        <VirtualRows
+          items={unpinnedItems}
+          scrollElement={scrollElement}
+          scrollMargin={scrollMargin}
+          columns={columns}
+          rowHeight={rowHeightPx}
+          cellHeight={cellHeightPx}
+          getKey={(item) => `${item.variant}-${item.row.id}`}
+          renderRow={renderInventoryRow}
+        />
+      </div>
+    </>
   );
 }
diff --git a/studio/frontend/src/features/hub/catalog/models-catalog-rows.tsx b/studio/frontend/src/features/hub/catalog/models-catalog-rows.tsx
index 111d78f00b..5236c0be74 100644
--- a/studio/frontend/src/features/hub/catalog/models-catalog-rows.tsx
+++ b/studio/frontend/src/features/hub/catalog/models-catalog-rows.tsx
@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { ModelDeleteAction } from "@/components/assistant-ui/model-selector/model-delete-action";
 import {
   Tooltip,
   TooltipContent,
@@ -9,18 +8,26 @@ import {
 } from "@/components/ui/tooltip";
 import {
   type GgufVariantDetail,
-  deleteCachedModel,
   deleteCachedDataset,
+  deleteCachedModel,
   formatLocalUpdated,
   listGgufVariants,
   useGgufVariantsCacheVersion,
-} from "@/features/hub/inventory";
-import { classifyUnslothSupport } from "@/features/hub/hooks/use-hub-model-search";
-import { formatBytes, formatRelativeShort } from "@/features/hub/lib/format";
-import { ggufVariantDisplayLabel } from "@/features/hub/lib/gguf-variant-sort";
-import { modelIdsMatch } from "@/features/hub/lib/model-identity";
+} from "../inventory";
+import {
+  classifyUnslothSupport,
+  formatBytes,
+  formatRelativeShort,
+  ggufVariantDisplayLabel,
+  useHfTokenStore,
+} from "@/features/hub";
+import { modelIdsMatch } from "../lib/model-identity";
+import {
+  ModelRowMenu,
+  pinKey,
+  usePinnedModelsStore,
+} from "@/features/model-picker";
 import { cn, formatCompact } from "@/lib/utils";
-import { useHfTokenStore } from "@/features/hub/stores/hf-token-store";
 import {
   Download01Icon,
   FavouriteIcon,
@@ -39,6 +46,7 @@ import {
   useRef,
   useState,
 } from "react";
+import { paramLabelFromId } from "../lib/view-models";
 import type {
   CachedInventoryRow,
   DiscoverRow,
@@ -46,7 +54,6 @@ import type {
 } from "../types";
 import { OwnerAvatar } from "./owner-avatar";
 import { AccessGlyphs } from "./shared";
-import { paramLabelFromId } from "../lib/view-models";
 
 const COARSE_POINTER =
   typeof window !== "undefined" &&
@@ -142,15 +149,15 @@ function CachedSizeChipLive({
   );
 
   const rows: Array<{ label: string; size_bytes: number }> | null =
-    !needsVariantFetch
-      ? [{ label: repoId, size_bytes: totalBytes }]
-      : currentVariantState.status === "loaded" &&
-          currentVariantState.variants.length > 0
+    needsVariantFetch
+      ? currentVariantState.status === "loaded" &&
+        currentVariantState.variants.length > 0
         ? currentVariantState.variants.map((variant) => ({
             label: ggufVariantDisplayLabel(variant),
             size_bytes: variant.size_bytes,
           }))
-        : null;
+        : null
+      : [{ label: repoId, size_bytes: totalBytes }];
   const variantMessage =
     currentVariantState.status === "loading"
       ? "Loading downloaded variants..."
@@ -181,14 +188,14 @@ function CachedSizeChipLive({
                   <StatChip
                     icon={PackageIcon}
                     value={formatBytes(row.size_bytes)}
-                    className="text-[11px] text-white/70"
+                    className="text-ui-11 text-white/70"
                   />
                 </span>
               </li>
             ))}
           </ul>
         ) : (
-          <span className="block max-w-52 text-[11px] leading-4 text-muted-foreground">
+          <span className="block max-w-52 text-ui-11 leading-4 text-muted-foreground">
             {variantMessage}
           </span>
         )}
@@ -218,7 +225,7 @@ export function StatChip({
   return (
     <span
       className={cn(
-        "inline-flex shrink-0 items-center gap-1 whitespace-nowrap text-[10px] font-medium leading-none tabular-nums text-muted-foreground/75",
+        "inline-flex shrink-0 items-center gap-1 whitespace-nowrap text-ui-10 font-medium leading-none tabular-nums text-muted-foreground/75",
         className,
       )}
     >
@@ -275,7 +282,9 @@ function CatalogRow({
         )}
       />
       <CatalogRowInteractiveContext.Provider value={interactive}>
-        <div className={cn("pointer-events-none relative", card && "z-[1] w-full")}>
+        <div
+          className={cn("pointer-events-none relative", card && "z-[1] w-full")}
+        >
           {children}
         </div>
       </CatalogRowInteractiveContext.Provider>
@@ -473,7 +482,7 @@ export const DiscoverModelRow = memo(function DiscoverModelRow({
         <div className="flex min-w-0 flex-1 flex-col gap-[3px]">
           <div className="flex h-[18px] min-w-0 items-center justify-between gap-2">
             <div className="flex min-w-0 items-center gap-2 pr-2">
-              <p className="truncate text-[12px] font-medium leading-[18px] tracking-[-0.005em] text-foreground">
+              <p className="truncate text-ui-12 font-medium leading-ui-18 tracking-[-0.005em] text-foreground">
                 {row.repo}
               </p>
               <AccessGlyphs
@@ -509,7 +518,7 @@ export const DiscoverModelRow = memo(function DiscoverModelRow({
               />
             </div>
           </div>
-          <div className="flex h-[16px] min-w-0 items-center justify-between gap-2 text-[11.5px] leading-[16px] text-muted-foreground/85">
+          <div className="flex h-[16px] min-w-0 items-center justify-between gap-2 text-ui-11p5 leading-ui-16 text-muted-foreground/85">
             <span className="flex min-w-0 items-center gap-1">
               <span className="truncate">{row.owner}</span>
               {row.owner.toLowerCase() === "unsloth" && (
@@ -519,7 +528,7 @@ export const DiscoverModelRow = memo(function DiscoverModelRow({
                 />
               )}
             </span>
-            <span className="shrink-0 text-[10.5px] tabular-nums">
+            <span className="shrink-0 text-ui-10p5 tabular-nums">
               {formatRelativeShort(row.result.updatedAt)}
             </span>
           </div>
@@ -653,9 +662,11 @@ export const InventoryRow = memo(function InventoryRow({
       <div className="hidden shrink-0 items-center gap-1.5 sm:flex">
         {/* Format already shows as the status dot, so the pill stays neutral. */}
         {formatLabel && <span className="hub-chip">{formatLabel}</span>}
-        {paramLabel && <span className="hub-chip tabular-nums">{paramLabel}</span>}
+        {paramLabel && (
+          <span className="hub-chip tabular-nums">{paramLabel}</span>
+        )}
         {quantLabel && (
-          <span className="hub-chip font-mono text-[10.5px] uppercase">
+          <span className="hub-chip font-mono text-ui-10p5 uppercase">
             {quantLabel}
           </span>
         )}
@@ -697,9 +708,7 @@ export const InventoryRow = memo(function InventoryRow({
   const compactMarkers =
     partialRepoId || unsupported ? (
       <span className="flex shrink-0 items-center gap-1">
-        {partialRepoId && (
-          <StatusDot tone="warning" label="Partial download" />
-        )}
+        {partialRepoId && <StatusDot tone="warning" label="Partial download" />}
         {unsupported && (
           <StatusDot tone="danger" label="May not be supported yet" />
         )}
@@ -707,7 +716,7 @@ export const InventoryRow = memo(function InventoryRow({
     ) : null;
 
   const ownerLine = (
-    <span className="mt-0.5 flex min-w-0 items-center gap-1 text-[11.5px] leading-[15px] text-muted-foreground/80">
+    <span className="mt-0.5 flex min-w-0 items-center gap-1 text-ui-11p5 leading-ui-15 text-muted-foreground/80">
       <span className="truncate">{subLabel}</span>
       {subLabel.toLowerCase() === "unsloth" && (
         <span
@@ -718,37 +727,81 @@ export const InventoryRow = memo(function InventoryRow({
     </span>
   );
 
+  const pinnedKeys = usePinnedModelsStore((s) => s.pinned);
+  const togglePinned = usePinnedModelsStore((s) => s.togglePinned);
+  const rowPinned =
+    cacheDeletableRepoId != null &&
+    pinnedKeys.includes(pinKey(cacheDeletableRepoId));
   const deleteAction =
     canDelete && cacheDeletableRepoId ? (
-      <ModelDeleteAction
-        ariaLabel={`Delete ${cacheDeletableRepoId}`}
-        title={isDataset ? "Delete cached dataset?" : "Delete cached model?"}
-        description={
-          <>
-            This will remove{" "}
-            <span className="font-medium text-foreground">
-              {cacheDeletableRepoId}
-            </span>{" "}
-            {isDataset
-              ? "and its downloaded files"
-              : row.isGguf
-                ? "and all of its downloaded quantizations"
-                : "and all of its downloaded files"}
-            {row.kind === "cache" ? ` (${formatBytes(row.bytes)})` : ""} from
-            disk. You can re-download it later.
-          </>
-        }
-        successMessage={`Deleted ${cacheDeletableRepoId}`}
+      <ModelRowMenu
+        ariaLabel={`More options for ${cacheDeletableRepoId}`}
         buttonClassName="pointer-events-auto hub-modal-pe-guard p-2 opacity-0 transition-opacity group-hover/row:opacity-100 focus-visible:opacity-100 data-[state=open]:opacity-100 [@media(pointer:coarse)]:opacity-100"
         iconClassName="size-4"
-        onConfirm={async () => {
-          if (isDataset) {
-            await deleteCachedDataset(cacheDeletableRepoId);
-          } else {
-            await deleteCachedModel(cacheDeletableRepoId);
-          }
+        pin={
+          isDataset
+            ? undefined
+            : {
+                pinned: rowPinned,
+                pinLabel: "Pin to top",
+                unpinLabel: "Unpin",
+                onToggle: () => togglePinned(cacheDeletableRepoId),
+              }
+        }
+        cachePath={isDataset ? undefined : { repoId: cacheDeletableRepoId }}
+        del={{
+          title: isDataset ? "Delete cached dataset?" : "Delete cached model?",
+          description: (
+            <>
+              This will remove{" "}
+              <span className="font-medium text-foreground">
+                {cacheDeletableRepoId}
+              </span>{" "}
+              {isDataset
+                ? "and its downloaded files"
+                : row.isGguf
+                  ? "and all of its downloaded quantizations"
+                  : "and all of its downloaded files"}
+              {row.kind === "cache" ? ` (${formatBytes(row.bytes)})` : ""} from
+              disk. You can re-download it later.
+            </>
+          ),
+          successMessage: `Deleted ${cacheDeletableRepoId}`,
+          onConfirm: async () => {
+            // Delete only the copy this row shows: cache rows carry the owning
+            // cache path, so pass it through and leave other caches untouched.
+            const rowCachePath =
+              row.kind === "cache" ? (row.cachePath ?? undefined) : undefined;
+            if (isDataset) {
+              await deleteCachedDataset(cacheDeletableRepoId, rowCachePath);
+            } else {
+              await deleteCachedModel(
+                cacheDeletableRepoId,
+                undefined,
+                undefined,
+                rowCachePath,
+              );
+              // Deleted repos can't stay pinned: drop the repo pin and any of
+              // its per-quant pins so stale rows don't linger up top.
+              const { pinned, togglePinned: toggle } =
+                usePinnedModelsStore.getState();
+              for (const key of pinned) {
+                if (
+                  key === pinKey(cacheDeletableRepoId) ||
+                  key.startsWith(`${cacheDeletableRepoId}::`)
+                ) {
+                  toggle(
+                    cacheDeletableRepoId,
+                    key.includes("::")
+                      ? key.slice(key.indexOf("::") + 2)
+                      : undefined,
+                  );
+                }
+              }
+            }
+          },
+          onDeleted: onChange,
         }}
-        onDeleted={onChange}
       />
     ) : null;
 
@@ -773,17 +826,17 @@ export const InventoryRow = memo(function InventoryRow({
           <OwnerAvatar
             owner={row.owner}
             repoName={title}
-            className="size-8 shrink-0 rounded-[9px] text-[12px]"
+            className="size-8 shrink-0 rounded-[9px] text-ui-12"
             remote={false}
           />
           <div className="min-w-0 flex-1">
             <div className="flex min-w-0 items-center gap-1.5">
-              <span className="truncate text-[12.5px] font-semibold leading-[16px] text-foreground">
+              <span className="truncate text-ui-12p5 font-semibold leading-ui-16 text-foreground">
                 {title}
               </span>
               {compactMarkers}
             </div>
-            <span className="mt-0.5 flex min-w-0 items-center gap-1.5 text-[10.5px] leading-[14px] text-muted-foreground/75">
+            <span className="mt-0.5 flex min-w-0 items-center gap-1.5 text-ui-10p5 leading-ui-14 text-muted-foreground/75">
               <span className="flex min-w-0 items-center gap-1">
                 <span className="truncate">{subLabel}</span>
                 {subLabel.toLowerCase() === "unsloth" && (
@@ -807,7 +860,7 @@ export const InventoryRow = memo(function InventoryRow({
               )}
             </span>
           </div>
-          <div className="flex shrink-0 items-center gap-2 text-[10.5px] tabular-nums text-muted-foreground/70">
+          <div className="flex shrink-0 items-center gap-2 text-ui-10p5 tabular-nums text-muted-foreground/70">
             {row.kind === "cache" ? (
               <CachedSizeChip
                 repoId={row.repoId}
@@ -850,7 +903,7 @@ export const InventoryRow = memo(function InventoryRow({
           />
           <div className="min-w-0 flex-1">
             <div className="flex min-w-0 items-center gap-1.5">
-              <span className="truncate text-[13.5px] font-semibold leading-[17px] text-foreground">
+              <span className="truncate text-ui-13p5 font-semibold leading-ui-17 text-foreground">
                 {title}
               </span>
               {statusMarkers}
@@ -871,11 +924,11 @@ export const InventoryRow = memo(function InventoryRow({
               cachePath={row.cachePath}
             />
           ) : trailing ? (
-            <span className="truncate text-[11.5px] tabular-nums text-muted-foreground/70">
+            <span className="truncate text-ui-11p5 tabular-nums text-muted-foreground/70">
               {trailing}
             </span>
           ) : sourceLabel ? (
-            <span className="truncate text-[11.5px] text-muted-foreground/55">
+            <span className="truncate text-ui-11p5 text-muted-foreground/55">
               {sourceLabel}
             </span>
           ) : null}
diff --git a/studio/frontend/src/features/hub/catalog/models-catalog.tsx b/studio/frontend/src/features/hub/catalog/models-catalog.tsx
index 344f5deb49..02b9b62fce 100644
--- a/studio/frontend/src/features/hub/catalog/models-catalog.tsx
+++ b/studio/frontend/src/features/hub/catalog/models-catalog.tsx
@@ -54,6 +54,7 @@ export interface ModelsCatalogState {
   hasMore: boolean;
   manualFetchAvailable: boolean;
   hasActiveFilters: boolean;
+  typeFilterActive: boolean;
 }
 
 export interface ModelsCatalogPagination {
@@ -117,6 +118,7 @@ export const ModelsCatalog = memo(function ModelsCatalog({
     loadingIntentCount,
     hasMore,
     hasActiveFilters,
+    typeFilterActive,
   } = state;
   const { scrollRef, sentinelRef, isLoadingMore } = pagination;
   const {
@@ -469,6 +471,8 @@ export const ModelsCatalog = memo(function ModelsCatalog({
                 downloadedReady={downloadedReady}
                 inventoryError={inventoryError}
                 query={query}
+                typeFilterActive={typeFilterActive}
+                onClearFilters={onClearFilters}
                 scrollElement={downloadedScrollEl}
                 activeCheckpoint={activeCheckpoint}
                 activeGgufVariant={activeGgufVariant}
diff --git a/studio/frontend/src/features/hub/catalog/models-header.tsx b/studio/frontend/src/features/hub/catalog/models-header.tsx
index 10d5a80e5e..f844336d4a 100644
--- a/studio/frontend/src/features/hub/catalog/models-header.tsx
+++ b/studio/frontend/src/features/hub/catalog/models-header.tsx
@@ -64,7 +64,7 @@ export function ModelsHeader({
   return (
     <header className="font-heading flex flex-col gap-3 sm:flex-row sm:flex-wrap sm:items-center sm:justify-between">
       <PageHeading
-        title="Hub"
+        title={isDataset ? "Datasets" : "Model hub"}
         onTitleClick={onTitleClick}
         subtitle={
           isDataset
@@ -91,7 +91,7 @@ export function ModelsHeader({
         <StatPill icon={CpuIcon} label="CPU" value={coreLabel} />
 
         {activeCheckpoint && (
-          <div className="hub-tag-soft ml-1 inline-flex items-center gap-1.5 px-2 py-1 text-[11.5px]">
+          <div className="hub-tag-soft ml-1 inline-flex items-center gap-1.5 px-2 py-1 text-ui-11p5">
             <span
               className="size-1.5 rounded-full bg-emerald-500"
               aria-hidden="true"
@@ -115,7 +115,7 @@ export function ModelsHeader({
             <button
               type="button"
               onClick={onEject}
-              className="-mr-0.5 ml-0.5 inline-flex cursor-pointer items-center gap-1 rounded-md px-1.5 text-[11px] text-muted-foreground transition-colors hover:text-foreground"
+              className="-mr-0.5 ml-0.5 inline-flex cursor-pointer items-center gap-1 rounded-md px-1.5 text-ui-11 text-muted-foreground transition-colors hover:text-foreground"
             >
               <HugeiconsIcon
                 icon={RemoveCircleIcon}
diff --git a/studio/frontend/src/features/hub/catalog/models-table.tsx b/studio/frontend/src/features/hub/catalog/models-table.tsx
index f3887fee28..e3cd77f781 100644
--- a/studio/frontend/src/features/hub/catalog/models-table.tsx
+++ b/studio/frontend/src/features/hub/catalog/models-table.tsx
@@ -17,6 +17,10 @@ import {
   formatRelativeLong,
   formatRelativeShort,
 } from "@/features/hub/lib/format";
+import {
+  MODEL_TYPE_FILTER_OPTIONS,
+  type ModelTypeFilter,
+} from "@/features/hub/lib/model-type-filter";
 import {
   formatModelParamLabel,
   formatPipelineTag,
@@ -25,6 +29,7 @@ import { copyToClipboard } from "@/lib/copy-to-clipboard";
 import { cn, formatCompact } from "@/lib/utils";
 import {
   ArrowLeft01Icon,
+  ArrowUpDownIcon,
   Copy01Icon,
   Download01Icon,
   FavouriteIcon,
@@ -124,6 +129,7 @@ export function InventorySortControl({
   value: InventorySort;
   onChange: (value: InventorySort) => void;
 }) {
+  const selected = INVENTORY_SORTS.find((option) => option.value === value);
   return (
     <HubOptionMenu<InventorySort>
       value={value}
@@ -131,7 +137,46 @@ export function InventorySortControl({
       onValueChange={onChange}
       ariaLabel="Sort downloads"
       align="end"
-      className="h-8 text-[11.5px]"
+      title={selected?.label}
+      // Capped and shrinkable so a long label truncates instead of wrapping
+      // the "On device" heading beside these pills in the narrow split pane.
+      className="h-8 min-w-[72px] max-w-[124px] shrink text-ui-11p5"
+      triggerContent={
+        <span className="flex min-w-0 items-center gap-1">
+          <HugeiconsIcon
+            icon={ArrowUpDownIcon}
+            strokeWidth={1.75}
+            className="size-3.5 shrink-0 text-muted-foreground"
+          />
+          <span className="truncate">{selected?.label ?? value}</span>
+        </span>
+      }
+    />
+  );
+}
+
+// Model-type filter pill (Text / Vision / Embedding / …) beside the sort pill.
+export function InventoryTypeFilterControl({
+  value,
+  onChange,
+}: {
+  value: ModelTypeFilter;
+  onChange: (value: ModelTypeFilter) => void;
+}) {
+  const selected = MODEL_TYPE_FILTER_OPTIONS.find(
+    (option) => option.value === value,
+  );
+  return (
+    <HubOptionMenu<ModelTypeFilter>
+      value={value}
+      options={MODEL_TYPE_FILTER_OPTIONS}
+      onValueChange={onChange}
+      ariaLabel="Filter by model type"
+      align="end"
+      title={selected?.label}
+      // Capped and shrinkable so a long label ("Speech to text") truncates
+      // instead of wrapping the "On device" heading beside these pills.
+      className="h-8 min-w-[72px] max-w-[124px] shrink text-ui-11p5"
     />
   );
 }
@@ -183,11 +228,13 @@ export function HubListHeader({
           </button>
         )}
         <div className="min-w-0 space-y-0.5">
-          <h2 className="text-[18px] font-semibold tracking-[-0.02em] text-foreground">
+          {/* truncate keeps the heading on one line and clips a long search
+              query with an ellipsis instead of overflowing the pills. */}
+          <h2 className="truncate text-ui-18 font-semibold tracking-[-0.02em] text-foreground">
             {title}
           </h2>
           {subtitle && (
-            <p className="text-[12.5px] leading-tight text-muted-foreground">
+            <p className="text-ui-12p5 leading-tight text-muted-foreground">
               {subtitle}
             </p>
           )}
@@ -216,7 +263,9 @@ export function HubListHeader({
         )}
       </div>
       {(actions || onViewChange) && (
-        <div className="flex shrink-0 items-center gap-2">
+        // min-w-0 (not shrink-0) so shrinkable actions (the On-device filter
+        // pills) compress before the title is forced onto two lines.
+        <div className="flex min-w-0 items-center gap-2">
           {actions}
           {onViewChange && (
             <div
@@ -260,7 +309,7 @@ export function HubListHeader({
 
 export function ResultListHeader({ isDataset }: { isDataset: boolean }) {
   return (
-    <div className="flex w-full items-center gap-3 px-4 pb-2 text-[11px] font-medium text-muted-foreground/55">
+    <div className="flex w-full items-center gap-3 px-4 pb-2 text-ui-11 font-medium text-muted-foreground/55">
       <span className={LIST_COLS.model}>{isDataset ? "Dataset" : "Model"}</span>
       <span className={isDataset ? LIST_COLS.caps : LIST_COLS.capsModel}>
         {isDataset ? "Details" : "Capabilities"}
@@ -396,7 +445,7 @@ function CapabilitiesCell({
           ))}
           {extra > 0 && <span className="hub-chip shrink-0">+{extra}</span>}
           {shown.length === 0 && taskLabel && (
-            <span className="truncate text-[12px] text-muted-foreground/75">
+            <span className="truncate text-ui-12 text-muted-foreground/75">
               {taskLabel}
             </span>
           )}
@@ -405,7 +454,7 @@ function CapabilitiesCell({
       <TooltipContent side="top" align="start" className="tooltip-compact">
         <div className="flex flex-col items-start gap-1">
           {taskLabel && (
-            <span className="text-[11px] font-medium text-muted-foreground">
+            <span className="text-ui-11 font-medium text-muted-foreground">
               {taskLabel}
             </span>
           )}
@@ -524,7 +573,9 @@ function useResultRowModel(
     [isDataset, row.id, row.result, deviceType],
   );
   const sizeLabel = formatModelParamLabel(row.repo, row.result.totalParams);
-  const taskLabel = isDataset ? null : formatPipelineTag(row.result.pipelineTag);
+  const taskLabel = isDataset
+    ? null
+    : formatPipelineTag(row.result.pipelineTag);
   const unsupported = support?.status === "unsupported";
   return {
     support,
@@ -591,12 +642,12 @@ export const ResultCard = memo(function ResultCard({
       <OwnerAvatar
         owner={row.owner}
         repoName={row.repo}
-        className="size-[52px] shrink-0 rounded-[16px] text-[16px] ring-1 ring-black/5 dark:ring-white/10"
+        className="size-[52px] shrink-0 rounded-[16px] text-ui-16 ring-1 ring-black/5 dark:ring-white/10"
         remote={false}
       />
       <div className="flex min-w-0 flex-1 flex-col">
         <div className="flex min-w-0 items-center gap-2">
-          <span className="truncate text-[15px] font-semibold leading-[18px] text-foreground">
+          <span className="truncate text-ui-15 font-semibold leading-ui-18 text-foreground">
             {row.repo}
           </span>
           <TitleMarkers
@@ -608,10 +659,10 @@ export const ResultCard = memo(function ResultCard({
             onDevice={onDevice}
           />
         </div>
-        <span className="flex min-w-0 items-center gap-1 text-[12.5px] leading-[16px] text-muted-foreground/80">
+        <span className="flex min-w-0 items-center gap-1 text-ui-12p5 leading-ui-16 text-muted-foreground/80">
           <VerifiedOwner owner={row.owner} />
         </span>
-        <div className="flex min-w-0 items-center gap-2 overflow-hidden text-[11.5px] leading-[16px] tabular-nums text-muted-foreground/65">
+        <div className="flex min-w-0 items-center gap-2 overflow-hidden text-ui-11p5 leading-ui-16 tabular-nums text-muted-foreground/65">
           {textParts.map((part, index) => (
             <Fragment key={part.key}>
               {index > 0 && (
@@ -710,12 +761,12 @@ export const ResultGridRow = memo(function ResultGridRow({
           <OwnerAvatar
             owner={row.owner}
             repoName={row.repo}
-            className="size-9 shrink-0 rounded-[12px] text-[13px] ring-1 ring-black/5 dark:ring-white/10"
+            className="size-9 shrink-0 rounded-[12px] text-ui-13 ring-1 ring-black/5 dark:ring-white/10"
             remote={false}
           />
           <div className="min-w-0 flex-1">
             <div className="flex min-w-0 items-center gap-1.5">
-              <span className="truncate text-[13.5px] font-semibold leading-[17px] text-foreground">
+              <span className="truncate text-ui-13p5 font-semibold leading-ui-17 text-foreground">
                 {row.repo}
               </span>
               <TitleMarkers
@@ -727,7 +778,7 @@ export const ResultGridRow = memo(function ResultGridRow({
                 onDevice={onDevice}
               />
             </div>
-            <span className="mt-0.5 flex min-w-0 items-center gap-1 text-[11.5px] leading-[15px] text-muted-foreground/80">
+            <span className="mt-0.5 flex min-w-0 items-center gap-1 text-ui-11p5 leading-ui-15 text-muted-foreground/80">
               <VerifiedOwner owner={row.owner} />
             </span>
           </div>
@@ -735,7 +786,7 @@ export const ResultGridRow = memo(function ResultGridRow({
         <div className={isDataset ? LIST_COLS.caps : LIST_COLS.capsModel}>
           {isDataset ? (
             row.summary ? (
-              <span className="truncate text-[12px] text-muted-foreground/75">
+              <span className="truncate text-ui-12 text-muted-foreground/75">
                 {row.summary}
               </span>
             ) : null
@@ -750,7 +801,7 @@ export const ResultGridRow = memo(function ResultGridRow({
         <div
           className={cn(
             LIST_COLS.size,
-            "truncate text-[12px] tabular-nums text-muted-foreground",
+            "truncate text-ui-12 tabular-nums text-muted-foreground",
           )}
         >
           {sizeDisplay ?? "—"}
@@ -758,7 +809,7 @@ export const ResultGridRow = memo(function ResultGridRow({
         <div
           className={cn(
             LIST_COLS.updated,
-            "truncate text-[12px] tabular-nums text-muted-foreground",
+            "truncate text-ui-12 tabular-nums text-muted-foreground",
           )}
         >
           {formatRelativeShort(row.result.updatedAt)}
@@ -766,7 +817,7 @@ export const ResultGridRow = memo(function ResultGridRow({
         <div
           className={cn(
             LIST_COLS.downloads,
-            "text-[12px] tabular-nums text-muted-foreground",
+            "text-ui-12 tabular-nums text-muted-foreground",
           )}
         >
           <StatItem
@@ -777,7 +828,7 @@ export const ResultGridRow = memo(function ResultGridRow({
         <div
           className={cn(
             LIST_COLS.likes,
-            "text-[12px] tabular-nums text-muted-foreground",
+            "text-ui-12 tabular-nums text-muted-foreground",
           )}
         >
           <StatItem
@@ -832,12 +883,12 @@ export const ResultSplitRow = memo(function ResultSplitRow({
       <OwnerAvatar
         owner={row.owner}
         repoName={row.repo}
-        className="size-8 shrink-0 rounded-[9px] text-[12px]"
+        className="size-8 shrink-0 rounded-[9px] text-ui-12"
         remote={false}
       />
       <div className="flex min-w-0 flex-1 flex-col">
         <div className="flex min-w-0 items-center gap-1.5">
-          <span className="truncate text-[12.5px] font-semibold leading-[16px] text-foreground">
+          <span className="truncate text-ui-12p5 font-semibold leading-ui-16 text-foreground">
             {row.repo}
           </span>
           <TitleMarkers
@@ -849,11 +900,11 @@ export const ResultSplitRow = memo(function ResultSplitRow({
             onDevice={onDevice}
           />
         </div>
-        <span className="mt-0.5 flex min-w-0 items-center gap-1 text-[10.5px] leading-[14px] text-muted-foreground/80">
+        <span className="mt-0.5 flex min-w-0 items-center gap-1 text-ui-10p5 leading-ui-14 text-muted-foreground/80">
           <VerifiedOwner owner={row.owner} />
         </span>
       </div>
-      <div className="flex shrink-0 flex-col items-end gap-0.5 text-[10.5px] tabular-nums text-muted-foreground/70">
+      <div className="flex shrink-0 flex-col items-end gap-0.5 text-ui-10p5 tabular-nums text-muted-foreground/70">
         <div className="flex items-center gap-2">
           <span className="inline-flex items-center gap-1">
             <HugeiconsIcon
diff --git a/studio/frontend/src/features/hub/catalog/models-toolbar.tsx b/studio/frontend/src/features/hub/catalog/models-toolbar.tsx
index 7c08c9c486..a12b0b5571 100644
--- a/studio/frontend/src/features/hub/catalog/models-toolbar.tsx
+++ b/studio/frontend/src/features/hub/catalog/models-toolbar.tsx
@@ -9,6 +9,7 @@ import {
   TooltipContent,
   TooltipTrigger,
 } from "@/components/ui/tooltip";
+import type { HfSortKey } from "@/features/hub/hooks/use-hub-model-search";
 import { cn } from "@/lib/utils";
 import {
   AiChipIcon,
@@ -19,26 +20,25 @@ import {
   SlidersHorizontalIcon,
 } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
-import type { HfSortKey } from "@/features/hub/hooks/use-hub-model-search";
-import type {
-  CapabilityFilter,
-  ModelFormatFilter,
-  ModelsTab,
-  ResourceTypeFilter,
-} from "../types";
-import {
-  CAPABILITY_FILTER_OPTIONS,
-  FORMAT_FILTER_OPTIONS,
-} from "../lib/view-models";
-import { HubOptionMenu, type HubOption } from "./hub-option-menu";
+import { memo, useMemo, useState } from "react";
 import {
   clearRecentSearches,
   recordRecentSearch,
   removeRecentSearch,
   useRecentSearches,
 } from "../lib/recent-searches";
+import {
+  CAPABILITY_FILTER_OPTIONS,
+  FORMAT_FILTER_OPTIONS,
+} from "../lib/view-models";
+import type {
+  CapabilityFilter,
+  ModelFormatFilter,
+  ModelsTab,
+  ResourceTypeFilter,
+} from "../types";
+import { type HubOption, HubOptionMenu } from "./hub-option-menu";
 import { RecentSearches } from "./recent-searches";
-import { memo, useMemo, useState } from "react";
 
 // Widened so the format dropdown can carry the "Fine-tune ready" pseudo-option,
 // which opens the curated channel instead of becoming the active format filter.
@@ -175,7 +175,7 @@ export const ModelsToolbar = memo(function ModelsToolbar({
     <div className="flex min-w-0 flex-col gap-2 lg:flex-row lg:flex-nowrap lg:items-center">
       <div
         className={cn(
-          "hub-menu-trigger hub-tab-toggle relative inline-flex h-9 w-full shrink-0 items-center rounded-full lg:w-[240px]",
+          "hub-menu-trigger hub-tab-toggle relative inline-flex h-9 w-full shrink-0 items-center rounded-full lg:w-[280px]",
         )}
         role="radiogroup"
         aria-label="View"
@@ -194,7 +194,7 @@ export const ModelsToolbar = memo(function ModelsToolbar({
           aria-checked={tab === "discover"}
           onClick={() => onTabChange("discover")}
           className={cn(
-            "relative z-10 inline-flex h-9 flex-1 items-center justify-center rounded-full px-3 text-[12.5px] transition-colors",
+            "relative z-10 inline-flex h-9 flex-1 items-center justify-center rounded-full px-3 text-ui-12p5 transition-colors",
             tab === "discover"
               ? "text-foreground"
               : "text-muted-foreground hover:text-foreground",
@@ -208,7 +208,7 @@ export const ModelsToolbar = memo(function ModelsToolbar({
           aria-checked={tab === "downloaded"}
           onClick={() => onTabChange("downloaded")}
           className={cn(
-            "relative z-10 inline-flex h-9 flex-1 items-center justify-center rounded-full px-3 text-[12.5px] transition-colors",
+            "relative z-10 inline-flex h-9 flex-1 items-center justify-center rounded-full px-3 text-ui-12p5 transition-colors",
             tab === "downloaded"
               ? "text-foreground"
               : "text-muted-foreground hover:text-foreground",
@@ -219,94 +219,94 @@ export const ModelsToolbar = memo(function ModelsToolbar({
       </div>
 
       <div className="relative min-w-0 flex-1 lg:flex-[1_1_360px]">
-          <HugeiconsIcon
-            icon={Search01Icon}
-            strokeWidth={1.8}
-            className="pointer-events-none absolute left-3.5 top-1/2 size-4 -translate-y-1/2 text-muted-foreground"
-          />
-          <Input
-            // `type="search"` plus these flags stop password managers and noisy
-            // text assistance from acting on this field.
-            type="search"
-            name="hub-search"
-            autoComplete="off"
-            autoCorrect="off"
-            autoCapitalize="off"
-            spellCheck={false}
-            enterKeyHint="search"
-            data-1p-ignore={true}
-            data-lpignore={true}
-            data-form-type="other"
-            value={query}
-            onChange={(event) => onQueryChange(event.target.value)}
-            onFocus={() => setSearchFocused(true)}
-            onBlur={() => {
-              setSearchFocused(false);
-              if (isDiscover) {
-                recordRecentSearch(query);
-              }
-            }}
-            onKeyDown={(event) => {
-              if (event.key === "Enter" && isDiscover) {
-                recordRecentSearch(query);
-              } else if (event.key === "Escape" && showRecentSearches) {
-                event.currentTarget.blur();
-              }
-            }}
-            placeholder={
-              tab === "downloaded"
-                ? `Search on-device ${isDataset ? "datasets" : "models"}`
-                : isDataset
-                  ? "Search datasets"
-                  : "Search all models"
+        <HugeiconsIcon
+          icon={Search01Icon}
+          strokeWidth={1.8}
+          className="pointer-events-none absolute left-3.5 top-1/2 size-4 -translate-y-1/2 text-muted-foreground"
+        />
+        <Input
+          // `type="search"` plus these flags stop password managers and noisy
+          // text assistance from acting on this field.
+          type="search"
+          name="hub-search"
+          autoComplete="off"
+          autoCorrect="off"
+          autoCapitalize="off"
+          spellCheck={false}
+          enterKeyHint="search"
+          data-1p-ignore={true}
+          data-lpignore={true}
+          data-form-type="other"
+          value={query}
+          onChange={(event) => onQueryChange(event.target.value)}
+          onFocus={() => setSearchFocused(true)}
+          onBlur={() => {
+            setSearchFocused(false);
+            if (isDiscover) {
+              recordRecentSearch(query);
             }
-            className={cn(
-              "field-soft h-9 rounded-full !border-0 pl-10 text-[13px] placeholder:text-muted-foreground/80 focus-visible:!ring-0",
-              hasTrailing ? "pr-10" : "pr-4",
-            )}
-          />
-          {query ? (
-            <button
-              type="button"
-              aria-label="Clear search"
-              // Keep focus on the input so clearing reveals recent searches
-              // rather than dismissing the field.
-              onMouseDown={(event) => event.preventDefault()}
-              onClick={() => onQueryChange("")}
-              className="absolute right-2.5 top-1/2 inline-flex size-6 -translate-y-1/2 items-center justify-center rounded-full text-muted-foreground/70 transition-colors hover:text-foreground"
-            >
-              <HugeiconsIcon
-                icon={CancelCircleIcon}
-                strokeWidth={1.75}
-                className="size-[18px]"
-              />
-            </button>
-          ) : isDiscover && isLoading ? (
-            <Spinner className="pointer-events-none absolute right-3.5 top-1/2 size-4 -translate-y-1/2 text-muted-foreground" />
-          ) : null}
-          {showRecentSearches && (
-            <RecentSearches
-              searches={recentSearches}
-              onSelect={(value) => {
-                recordRecentSearch(value);
-                onQueryChange(value);
-              }}
-              onRemove={removeRecentSearch}
-              onClear={clearRecentSearches}
-            />
+          }}
+          onKeyDown={(event) => {
+            if (event.key === "Enter" && isDiscover) {
+              recordRecentSearch(query);
+            } else if (event.key === "Escape" && showRecentSearches) {
+              event.currentTarget.blur();
+            }
+          }}
+          placeholder={
+            tab === "downloaded"
+              ? `Search on-device ${isDataset ? "datasets" : "models"}`
+              : isDataset
+                ? "Search datasets"
+                : "Search all models"
+          }
+          className={cn(
+            "field-soft h-9 rounded-full !border-0 pl-10 text-ui-13 placeholder:text-muted-foreground/80 focus-visible:!ring-0",
+            hasTrailing ? "pr-10" : "pr-4",
           )}
-        </div>
+        />
+        {query ? (
+          <button
+            type="button"
+            aria-label="Clear search"
+            // Keep focus on the input so clearing reveals recent searches
+            // rather than dismissing the field.
+            onMouseDown={(event) => event.preventDefault()}
+            onClick={() => onQueryChange("")}
+            className="absolute right-2.5 top-1/2 inline-flex size-6 -translate-y-1/2 items-center justify-center rounded-full text-muted-foreground/70 transition-colors hover:text-foreground"
+          >
+            <HugeiconsIcon
+              icon={CancelCircleIcon}
+              strokeWidth={1.75}
+              className="size-[18px]"
+            />
+          </button>
+        ) : isDiscover && isLoading ? (
+          <Spinner className="pointer-events-none absolute right-3.5 top-1/2 size-4 -translate-y-1/2 text-muted-foreground" />
+        ) : null}
+        {showRecentSearches && (
+          <RecentSearches
+            searches={recentSearches}
+            onSelect={(value) => {
+              recordRecentSearch(value);
+              onQueryChange(value);
+            }}
+            onRemove={removeRecentSearch}
+            onClear={clearRecentSearches}
+          />
+        )}
+      </div>
 
       <div className="flex min-w-0 flex-wrap items-center gap-2 lg:flex-[0_0_auto] lg:flex-nowrap lg:justify-end">
         {tab === "downloaded" && !isDataset && (
           <Tooltip>
-            <TooltipTrigger asChild>
+            <TooltipTrigger asChild={true}>
               <button
                 type="button"
                 onClick={onManageLocalFolders}
                 className={cn(
                   triggerBase,
-                  "field-filter inline-flex h-9 shrink-0 items-center gap-1.5 rounded-full px-3 text-[12.5px]",
+                  "field-filter inline-flex h-9 shrink-0 items-center gap-1.5 rounded-full px-3 text-ui-12p5",
                 )}
               >
                 <HugeiconsIcon
@@ -359,18 +359,18 @@ export const ModelsToolbar = memo(function ModelsToolbar({
             footer={
               isDataset ? undefined : (
                 <Tooltip>
-                  <TooltipTrigger asChild>
+                  <TooltipTrigger asChild={true}>
                     <button
                       type="button"
                       role="checkbox"
                       aria-checked={fitOnDeviceOnly}
                       onClick={() => onFitOnDeviceOnlyChange(!fitOnDeviceOnly)}
-                      className="flex w-full cursor-pointer select-none items-center gap-2 rounded-[10px] px-3 py-2 text-left text-[12.5px] text-muted-foreground transition-colors hover:text-foreground"
+                      className="flex w-full cursor-pointer select-none items-center gap-2 rounded-[10px] px-3 py-2 text-left text-ui-12p5 text-muted-foreground transition-colors hover:text-foreground"
                     >
                       <Checkbox
                         checked={fitOnDeviceOnly}
                         tabIndex={-1}
-                        aria-hidden
+                        aria-hidden={true}
                         className="pointer-events-none size-3.5 rounded-full [&_svg]:!size-2.5"
                       />
                       Only show models that fit
@@ -402,7 +402,7 @@ export const ModelsToolbar = memo(function ModelsToolbar({
             )}
           />
           <Tooltip>
-            <TooltipTrigger asChild>
+            <TooltipTrigger asChild={true}>
               <button
                 type="button"
                 role="radio"
@@ -428,7 +428,7 @@ export const ModelsToolbar = memo(function ModelsToolbar({
             </TooltipContent>
           </Tooltip>
           <Tooltip>
-            <TooltipTrigger asChild>
+            <TooltipTrigger asChild={true}>
               <button
                 type="button"
                 role="radio"
diff --git a/studio/frontend/src/features/hub/catalog/on-device-folders-dialog.tsx b/studio/frontend/src/features/hub/catalog/on-device-folders-dialog.tsx
index caa89db196..2b0f2c3a8d 100644
--- a/studio/frontend/src/features/hub/catalog/on-device-folders-dialog.tsx
+++ b/studio/frontend/src/features/hub/catalog/on-device-folders-dialog.tsx
@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { FolderBrowser } from "@/components/assistant-ui/model-selector/folder-browser";
 import { Button } from "@/components/ui/button";
 import {
   Dialog,
@@ -22,9 +21,11 @@ import {
   addScanFolder,
   listScanFolders,
   removeScanFolder,
-} from "@/features/hub/inventory";
-import { openModelsDir } from "@/features/native-intents/api";
+} from "@/features/hub";
+import { FolderBrowser } from "@/features/model-picker";
+import { openModelsDir } from "@/features/native-intents";
 import { isTauri } from "@/lib/api-base";
+import { toast } from "@/lib/toast";
 import { cn } from "@/lib/utils";
 import {
   Delete02Icon,
@@ -38,7 +39,6 @@ import {
 } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
-import { toast } from "@/lib/toast";
 
 function pathTail(path: string): string {
   const parts = path.split(/[\\/]/).filter(Boolean);
@@ -123,7 +123,9 @@ export function OnDeviceFoldersDialog({
         setPath("");
         mutationVersionRef.current += 1;
         setFolders((current) => {
-          const withoutDuplicate = current.filter((row) => row.id !== folder.id);
+          const withoutDuplicate = current.filter(
+            (row) => row.id !== folder.id,
+          );
           return [...withoutDuplicate, folder];
         });
         toast.success("Location added", {
@@ -184,15 +186,18 @@ export function OnDeviceFoldersDialog({
           overlayClassName="bg-black/20 backdrop-blur-none"
         >
           <DialogHeader className="border-b border-border/60 px-5 py-4">
-            <DialogTitle className="text-[15px]">On-device locations</DialogTitle>
+            <DialogTitle className="text-ui-15">
+              On-device locations
+            </DialogTitle>
             <DialogDescription className="sr-only">
-              Hugging Face model folders, GGUF files, and adapters are indexed here.
+              Hugging Face model folders, GGUF files, and adapters are indexed
+              here.
             </DialogDescription>
           </DialogHeader>
 
           <div className="space-y-4 px-5 py-4">
             <div className="rounded-[14px] border border-border/70 bg-muted/20 p-3">
-              <div className="mb-2 flex items-center gap-2 text-[12px] font-medium text-foreground">
+              <div className="mb-2 flex items-center gap-2 text-ui-12 font-medium text-foreground">
                 <HugeiconsIcon
                   icon={FolderAddIcon}
                   strokeWidth={1.75}
@@ -217,7 +222,7 @@ export function OnDeviceFoldersDialog({
                       void handleAdd(path);
                     }}
                     placeholder="Paste model folder or file path"
-                    className="field-soft h-9 rounded-full pl-9 pr-3 font-mono text-[12px] placeholder:font-sans"
+                    className="field-soft h-9 rounded-full pl-9 pr-3 font-mono text-ui-12 placeholder:font-sans"
                   />
                 </div>
                 <div className="flex shrink-0 items-center gap-2">
@@ -247,7 +252,7 @@ export function OnDeviceFoldersDialog({
                     size="sm"
                     onClick={() => void handleAdd(path)}
                     disabled={!path.trim() || pending !== null}
-                    className="h-9 rounded-full px-3 text-[12.5px]"
+                    className="h-9 rounded-full px-3 text-ui-12p5"
                   >
                     {pending === "add" ? (
                       <Spinner className="size-3.5" />
@@ -266,14 +271,14 @@ export function OnDeviceFoldersDialog({
             </div>
 
             {error ? (
-              <div className="rounded-[10px] border border-destructive/20 bg-destructive/5 px-3 py-2 text-[12px] text-destructive">
+              <div className="rounded-[10px] border border-destructive/20 bg-destructive/5 px-3 py-2 text-ui-12 text-destructive">
                 {error}
               </div>
             ) : null}
 
             <div className="overflow-hidden rounded-[14px] border border-border/70">
               <div className="flex h-10 items-center justify-between border-b border-border/60 px-3">
-                <span className="text-[12px] font-medium text-foreground">
+                <span className="text-ui-12 font-medium text-foreground">
                   Indexed locations
                 </span>
                 <Tooltip>
@@ -300,12 +305,12 @@ export function OnDeviceFoldersDialog({
 
               <div className="max-h-64 overflow-y-auto">
                 {loading ? (
-                  <div className="flex h-24 items-center justify-center gap-2 text-[12px] text-muted-foreground">
+                  <div className="flex h-24 items-center justify-center gap-2 text-ui-12 text-muted-foreground">
                     <Spinner className="size-3.5" />
                     Loading locations...
                   </div>
                 ) : sortedFolders.length === 0 ? (
-                  <div className="flex h-28 flex-col items-center justify-center gap-2 px-4 text-center text-[12px] text-muted-foreground">
+                  <div className="flex h-28 flex-col items-center justify-center gap-2 px-4 text-center text-ui-12 text-muted-foreground">
                     <HugeiconsIcon
                       icon={FolderOpenIcon}
                       strokeWidth={1.75}
@@ -335,16 +340,14 @@ export function OnDeviceFoldersDialog({
                         </div>
                         <div className="min-w-0 overflow-hidden">
                           <p
-                            className="block w-full truncate text-[12.5px] font-medium text-foreground"
+                            className="block w-full truncate text-ui-12p5 font-medium text-foreground"
                             title={pathTail(folder.path)}
                           >
                             {pathTail(folder.path)}
                           </p>
                           <Tooltip>
                             <TooltipTrigger asChild={true}>
-                              <p
-                                className="block w-full truncate font-mono text-[10.5px] text-muted-foreground"
-                              >
+                              <p className="block w-full truncate font-mono text-ui-10p5 text-muted-foreground">
                                 {folder.path}
                               </p>
                             </TooltipTrigger>
@@ -372,7 +375,10 @@ export function OnDeviceFoldersDialog({
                                 />
                               </button>
                             </TooltipTrigger>
-                            <TooltipContent side="left" className="tooltip-compact">
+                            <TooltipContent
+                              side="left"
+                              className="tooltip-compact"
+                            >
                               Open in file manager
                             </TooltipContent>
                           </Tooltip>
@@ -397,7 +403,10 @@ export function OnDeviceFoldersDialog({
                               )}
                             </button>
                           </TooltipTrigger>
-                          <TooltipContent side="left" className="tooltip-compact">
+                          <TooltipContent
+                            side="left"
+                            className="tooltip-compact"
+                          >
                             Remove from list
                           </TooltipContent>
                         </Tooltip>
diff --git a/studio/frontend/src/features/hub/catalog/owner-avatar.tsx b/studio/frontend/src/features/hub/catalog/owner-avatar.tsx
index 852c09ab5f..ac8bee9ade 100644
--- a/studio/frontend/src/features/hub/catalog/owner-avatar.tsx
+++ b/studio/frontend/src/features/hub/catalog/owner-avatar.tsx
@@ -13,10 +13,10 @@ import {
 type AvatarSize = "xs" | "sm" | "md" | "lg";
 
 const SIZES: Record<AvatarSize, string> = {
-  xs: "size-5 rounded-[8px] text-[9px]",
-  sm: "size-7 rounded-[10px] text-[11px]",
-  md: "size-9 rounded-[12px] text-[13px]",
-  lg: "size-12 rounded-[15px] text-[16px]",
+  xs: "size-5 rounded-[8px] text-ui-9",
+  sm: "size-7 rounded-[10px] text-ui-11",
+  md: "size-9 rounded-[12px] text-ui-13",
+  lg: "size-12 rounded-[15px] text-ui-16",
 };
 
 const AVATAR_IMAGE_RETRY_BASE_MS = 60_000;
diff --git a/studio/frontend/src/features/hub/catalog/owner-scope-toggle.tsx b/studio/frontend/src/features/hub/catalog/owner-scope-toggle.tsx
index 5f36f5d031..d2870a09c4 100644
--- a/studio/frontend/src/features/hub/catalog/owner-scope-toggle.tsx
+++ b/studio/frontend/src/features/hub/catalog/owner-scope-toggle.tsx
@@ -29,7 +29,7 @@ export function OwnerScopeToggle({
       ariaLabel="Publisher scope"
       align="end"
       // Extra gap before the chevron; min-width keeps the pill readable.
-      className="h-8 min-w-[96px] gap-1.5 text-[11.5px]"
+      className="h-8 min-w-[96px] gap-1.5 text-ui-11p5"
     />
   );
 }
diff --git a/studio/frontend/src/features/hub/catalog/path-info-button.tsx b/studio/frontend/src/features/hub/catalog/path-info-button.tsx
index 0d5ca6e00e..403bb0148e 100644
--- a/studio/frontend/src/features/hub/catalog/path-info-button.tsx
+++ b/studio/frontend/src/features/hub/catalog/path-info-button.tsx
@@ -1,38 +1,83 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import {
-  Dialog,
-  DialogContent,
-  DialogDescription,
-  DialogHeader,
-  DialogTitle,
-} from "@/components/ui/dialog";
 import {
   Tooltip,
   TooltipContent,
   TooltipTrigger,
 } from "@/components/ui/tooltip";
+import { usePlatformStore } from "@/config/env";
+import { revealCachedModel } from "@/features/chat";
+import { toast } from "@/lib/toast";
 import { cn } from "@/lib/utils";
-import { Copy01Icon, FolderSearchIcon } from "@hugeicons/core-free-icons";
+import { Copy01Icon, Folder01Icon } from "@hugeicons/core-free-icons";
 import { Tick02Icon } from "@/lib/tick-icon";
 import { HugeiconsIcon } from "@hugeicons/react";
 import type { MouseEvent } from "react";
-import { useState } from "react";
 import { useCopyFeedback } from "../hooks/use-copy-feedback";
 
+/** Reveal a cached repo (or one GGUF variant's file) in the OS file manager.
+ *  Resolved server-side from the HF cache, so only managed repos qualify. */
+export function RevealPathButton({
+  repoId,
+  variant,
+  className,
+}: {
+  repoId: string;
+  variant?: string | null;
+  className?: string;
+}) {
+  const deviceType = usePlatformStore((s) => s.deviceType);
+  const revealLabel =
+    deviceType === "mac"
+      ? "Reveal in Finder"
+      : deviceType === "windows"
+        ? "Reveal in File Explorer"
+        : "Reveal in File Manager";
+
+  return (
+    <Tooltip>
+      <TooltipTrigger asChild={true}>
+        <button
+          type="button"
+          aria-label={revealLabel}
+          onClick={(e) => {
+            e.stopPropagation();
+            revealCachedModel(repoId, variant ?? undefined).catch((err) => {
+              toast.error(
+                err instanceof Error
+                  ? err.message
+                  : "Failed to open file manager",
+              );
+            });
+          }}
+          className={cn(
+            "inline-flex size-7 shrink-0 cursor-pointer items-center justify-center rounded-full text-muted-foreground opacity-0 transition-[opacity,background-color,color] duration-150 hover:bg-muted hover:text-foreground focus-visible:opacity-100 group-hover/dl:opacity-100",
+            className,
+          )}
+        >
+          <HugeiconsIcon
+            icon={Folder01Icon}
+            strokeWidth={1.75}
+            className="size-4"
+          />
+        </button>
+      </TooltipTrigger>
+      <TooltipContent side="bottom" className="tooltip-compact">
+        {revealLabel}
+      </TooltipContent>
+    </Tooltip>
+  );
+}
+
+/** Copies the on-disk path straight to the clipboard, no dialog. */
 export function PathInfoButton({
   path,
-  title = "On-device location",
-  description = "Where this model lives on disk.",
   className,
 }: {
   path: string;
-  title?: string;
-  description?: string;
   className?: string;
 }) {
-  const [open, setOpen] = useState(false);
   const { copied, copy } = useCopyFeedback();
 
   const handleCopy = async (event: MouseEvent<HTMLButtonElement>) => {
@@ -42,67 +87,27 @@ export function PathInfoButton({
   };
 
   return (
-    <>
-      <Tooltip>
-        <TooltipTrigger asChild={true}>
-          <button
-            type="button"
-            aria-label="Show on-device path"
-            onClick={(e) => {
-              e.stopPropagation();
-              setOpen(true);
-            }}
-            className={cn(
-              "inline-flex size-7 shrink-0 cursor-pointer items-center justify-center rounded-full text-muted-foreground opacity-0 transition-[opacity,background-color,color] duration-150 hover:bg-muted hover:text-foreground focus-visible:opacity-100 group-hover/dl:opacity-100",
-              className,
-            )}
-          >
-            <HugeiconsIcon
-              icon={FolderSearchIcon}
-              strokeWidth={1.75}
-              className="size-4"
-            />
-          </button>
-        </TooltipTrigger>
-        <TooltipContent side="bottom" className="tooltip-compact">
-          Show path
-        </TooltipContent>
-      </Tooltip>
-      <Dialog open={open} onOpenChange={setOpen}>
-        <DialogContent
-          className="sm:max-w-[520px]"
-          onClick={(e) => e.stopPropagation()}
+    <Tooltip>
+      <TooltipTrigger asChild={true}>
+        <button
+          type="button"
+          aria-label="Copy on-device path"
+          onClick={handleCopy}
+          className={cn(
+            "inline-flex size-7 shrink-0 cursor-pointer items-center justify-center rounded-full text-muted-foreground opacity-0 transition-[opacity,background-color,color] duration-150 hover:bg-muted hover:text-foreground focus-visible:opacity-100 group-hover/dl:opacity-100",
+            className,
+          )}
         >
-          <DialogHeader>
-            <DialogTitle>{title}</DialogTitle>
-            <DialogDescription>{description}</DialogDescription>
-          </DialogHeader>
-          <div className="flex items-stretch gap-2">
-            <div className="flex-1 select-text rounded-[10px] border border-border bg-muted/30 px-3 py-2.5 text-[12px] leading-5 text-foreground/85 break-all">
-              {path}
-            </div>
-            <Tooltip>
-              <TooltipTrigger asChild={true}>
-                <button
-                  type="button"
-                  aria-label="Copy path"
-                  onClick={handleCopy}
-                  className="inline-flex shrink-0 cursor-pointer items-center justify-center rounded-[10px] border border-border bg-muted/30 px-3 text-muted-foreground transition-colors hover:bg-muted hover:text-foreground"
-                >
-                  <HugeiconsIcon
-                    icon={copied ? Tick02Icon : Copy01Icon}
-                    strokeWidth={1.75}
-                    className="size-4"
-                  />
-                </button>
-              </TooltipTrigger>
-              <TooltipContent side="bottom" className="tooltip-compact">
-                {copied ? "Copied" : "Copy path"}
-              </TooltipContent>
-            </Tooltip>
-          </div>
-        </DialogContent>
-      </Dialog>
-    </>
+          <HugeiconsIcon
+            icon={copied ? Tick02Icon : Copy01Icon}
+            strokeWidth={1.75}
+            className="size-4"
+          />
+        </button>
+      </TooltipTrigger>
+      <TooltipContent side="bottom" className="tooltip-compact">
+        {copied ? "Copied" : "Copy path"}
+      </TooltipContent>
+    </Tooltip>
   );
 }
diff --git a/studio/frontend/src/features/hub/catalog/recent-searches.tsx b/studio/frontend/src/features/hub/catalog/recent-searches.tsx
index 28f4d71510..a7fd10900f 100644
--- a/studio/frontend/src/features/hub/catalog/recent-searches.tsx
+++ b/studio/frontend/src/features/hub/catalog/recent-searches.tsx
@@ -30,13 +30,13 @@ export function RecentSearches({
       onMouseDown={(event) => event.preventDefault()}
     >
       <div className="flex items-center justify-between gap-2 px-2.5 pb-1.5 pt-1">
-        <span className="text-[11px] font-semibold uppercase tracking-[0.04em] text-muted-foreground/70">
+        <span className="text-ui-11 font-semibold uppercase tracking-[0.04em] text-muted-foreground/70">
           Recent searches
         </span>
         <button
           type="button"
           onClick={onClear}
-          className="hub-recent-clear rounded-full px-2 py-0.5 text-[11.5px] font-medium text-muted-foreground transition-colors hover:text-foreground"
+          className="hub-recent-clear rounded-full px-2 py-0.5 text-ui-11p5 font-medium text-muted-foreground transition-colors hover:text-foreground"
         >
           Clear all
         </button>
@@ -55,7 +55,7 @@ export function RecentSearches({
                   strokeWidth={1.75}
                   className="size-4 shrink-0 text-muted-foreground/70"
                 />
-                <span className="truncate text-[13px] text-foreground">
+                <span className="truncate text-ui-13 text-foreground">
                   {query}
                 </span>
               </button>
diff --git a/studio/frontend/src/features/hub/catalog/safetensors-download-card.tsx b/studio/frontend/src/features/hub/catalog/safetensors-download-card.tsx
index 424afa2e05..94c5175e8e 100644
--- a/studio/frontend/src/features/hub/catalog/safetensors-download-card.tsx
+++ b/studio/frontend/src/features/hub/catalog/safetensors-download-card.tsx
@@ -7,37 +7,36 @@ import {
   TooltipContent,
   TooltipTrigger,
 } from "@/components/ui/tooltip";
-import { useRepoDownload } from "../download-manager";
-import { deleteCachedModel } from "../inventory";
 import { cn } from "@/lib/utils";
 import {
   Alert02Icon,
-  PencilEdit02Icon,
   PlayIcon,
+  RemoveCircleIcon,
 } from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
+import { useEffect, useState } from "react";
 import { TrainIcon } from "../components/train-icon";
+import { useRepoDownload } from "../download-manager";
+import { useOnlineStatus } from "../hooks/use-online-status";
+import { deleteCachedModel } from "../inventory";
+import type { ModelInventoryFormat } from "../inventory";
+import { fetchModelSize } from "../lib/dataset-size";
+import { formatBytes } from "../lib/format";
 import {
   HUB_NON_GGUF_RUN_ACTIONS_VISIBLE,
   HUB_POST_DOWNLOAD_ACTIONS_VISIBLE,
 } from "../lib/hub-feature-flags";
-import { HugeiconsIcon } from "@hugeicons/react";
-import { useEffect, useState } from "react";
-import { useHfTokenStore } from "../stores/hf-token-store";
-import { fetchModelSize } from "../lib/dataset-size";
-import { formatBytes } from "../lib/format";
 import { fingerprintToken } from "../lib/token-fingerprint";
-import { useOnlineStatus } from "../hooks/use-online-status";
+import { useHfTokenStore } from "../stores/hf-token-store";
+import { DotTag } from "./dot-tag";
 import {
   CardDivider,
-  CardDeleteButton,
   DeleteConfirmDialog,
   DownloadActionButton,
   DownloadCard,
 } from "./download-card";
-import { DotTag } from "./dot-tag";
-import { PathInfoButton } from "./path-info-button";
+import { QuantOptionsMenu } from "./gguf-download-card";
 import { useCardDelete } from "./use-card-delete";
-import type { ModelInventoryFormat } from "../inventory";
 import { useDownloadCardState } from "./use-download-card-state";
 
 function formatModelLabel(modelFormat?: ModelInventoryFormat | null): string {
@@ -65,7 +64,7 @@ export function SafetensorsDownloadCard({
   cachePath,
   knownBytes,
   onLoad,
-  onUseInChat,
+  onEject,
   onTrain,
   onChange,
 }: {
@@ -77,10 +76,13 @@ export function SafetensorsDownloadCard({
   canRun?: boolean;
   isActive: boolean;
   isLoadingThisModel: boolean;
+  /** Owning cache dir, threaded into delete so it targets this copy. */
   cachePath?: string | null;
   knownBytes?: number | null;
   onLoad: (opts: { ggufVariant?: string; expectedBytes?: number }) => void;
+  /** Accepted for API parity; the run bar ejects instead of opening chat. */
   onUseInChat?: () => void;
+  onEject?: () => void;
   onTrain?: () => void;
   onChange?: () => void;
 }) {
@@ -95,11 +97,12 @@ export function SafetensorsDownloadCard({
     knownBytes && knownBytes > 0
       ? knownBytes
       : modelSize.key === sizeKey
-      ? modelSize.bytes
-      : null;
+        ? modelSize.bytes
+        : null;
   const [deleteRepoOpen, setDeleteRepoOpen] = useState(false);
   const { deleting, runDelete } = useCardDelete({
-    action: () => deleteCachedModel(repoId, undefined, hfToken || undefined),
+    action: () =>
+      deleteCachedModel(repoId, undefined, hfToken || undefined, cachePath ?? undefined),
     resourceName: "model",
     successMessage: () => `Deleted ${repoId}`,
     onSuccess: () => {
@@ -170,7 +173,8 @@ export function SafetensorsDownloadCard({
     !isLoadingThisModel;
 
   return (
-    <div className="flex w-full flex-col gap-2"><DownloadCard
+    <div className="flex w-full flex-col gap-2">
+      <DownloadCard
         job={job}
         progress={downloading ? progress : null}
         dialogs={
@@ -197,7 +201,7 @@ export function SafetensorsDownloadCard({
         }
       >
         <div className="relative flex h-9 min-w-0 flex-1 items-center pl-3 pr-2">
-          <span className="flex items-center gap-1.5 text-[12px] text-muted-foreground">
+          <span className="flex items-center gap-1.5 text-ui-12 text-muted-foreground">
             {(isActive || isDownloaded) && (
               <DotTag
                 tone="success"
@@ -206,7 +210,7 @@ export function SafetensorsDownloadCard({
             )}
             {!isDownloaded && !isActive && isPartial && !downloading && (
               <Tooltip>
-                <TooltipTrigger asChild>
+                <TooltipTrigger asChild={true}>
                   <span className="inline-flex">
                     <DotTag tone="warning" label="Partial" />
                   </span>
@@ -227,17 +231,20 @@ export function SafetensorsDownloadCard({
             )}
           </span>
           <div className="ml-auto flex items-center gap-0.5">
-            {canDelete && (
-              <CardDeleteButton
-                label={`Delete ${repoId}`}
-                onClick={() => setDeleteRepoOpen(true)}
-              />
-            )}
-            {isDownloaded && cachePath && (
-              <PathInfoButton
-                path={cachePath}
-                title="On-device location"
-                description={`Where ${repoId} lives on disk.`}
+            {/* TODO: inference settings gear hidden for now, work on it in a future PR. */}
+            {/* Same 3-dots menu as GGUF, at repo level (no quant); pinning is
+                omitted in the run bar. Managed HF-cache repos only. */}
+            {(isDownloaded || (isPartial && !downloading)) &&
+              !/^([/\\~.]|[A-Za-z]:)/.test(repoId) && (
+              <QuantOptionsMenu
+                repoId={repoId}
+                label={repoId}
+                downloaded={isDownloaded}
+                canDelete={canDelete}
+                onDelete={() => setDeleteRepoOpen(true)}
+                showPin={false}
+                buttonClassName="ml-0.5 size-7"
+                iconClassName="size-4"
               />
             )}
           </div>
@@ -268,7 +275,7 @@ export function SafetensorsDownloadCard({
               onClick={() => {
                 if (!canRun) return;
                 if (isActive) {
-                  onUseInChat?.();
+                  onEject?.();
                   return;
                 }
                 onLoad({});
@@ -287,26 +294,26 @@ export function SafetensorsDownloadCard({
                 </>
               ) : isActive ? (
                 <>
-                  <HugeiconsIcon icon={PencilEdit02Icon} strokeWidth={1.75} />
-                  Chat
+                  <HugeiconsIcon icon={RemoveCircleIcon} strokeWidth={1.75} />
+                  Eject
                 </>
-              ) : !canRun ? (
-                <>
-                  <HugeiconsIcon icon={Alert02Icon} strokeWidth={1.75} />
-                  No run
-                </>
-              ) : (
+              ) : canRun ? (
                 <>
                   <HugeiconsIcon icon={PlayIcon} strokeWidth={1.75} />
                   Run
                 </>
+              ) : (
+                <>
+                  <HugeiconsIcon icon={Alert02Icon} strokeWidth={1.75} />
+                  No run
+                </>
               )}
             </button>
           </div>
         ) : showUnavailableAction ? (
           <button
             type="button"
-            disabled
+            disabled={true}
             className="hub-action-btn w-28 opacity-70"
           >
             <HugeiconsIcon icon={Alert02Icon} strokeWidth={1.75} />
diff --git a/studio/frontend/src/features/hub/catalog/sampling-settings-dialog.tsx b/studio/frontend/src/features/hub/catalog/sampling-settings-dialog.tsx
new file mode 100644
index 0000000000..bc86a6302c
--- /dev/null
+++ b/studio/frontend/src/features/hub/catalog/sampling-settings-dialog.tsx
@@ -0,0 +1,435 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+// Gear button for the GGUF run bar: model config, system prompt, reasoning,
+// sampling, tools and retrieval, using the same controls as the chat page's
+// Run settings. Edits write to the chat runtime store's persisted state.
+
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogHeader,
+  DialogTitle,
+} from "@/components/ui/dialog";
+import { InfoHint } from "@/components/ui/info-hint";
+import { Switch } from "@/components/ui/switch";
+import { Textarea } from "@/components/ui/textarea";
+import {
+  Tooltip,
+  TooltipContent,
+  TooltipTrigger,
+} from "@/components/ui/tooltip";
+import {
+  ParamSlider,
+  useChatModelRuntime,
+  useChatRuntimeStore,
+} from "@/features/chat";
+import {
+  type PerModelConfig,
+  SidebarModelConfig,
+  applyPerModelConfigToRuntime,
+  currentRuntimePerModelConfig,
+  useActiveModelConfig,
+} from "@/features/model-picker";
+import { RetrievalSettingsSection } from "@/features/rag";
+import { toast } from "@/lib/toast";
+import { cn } from "@/lib/utils";
+import { Settings02Icon } from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
+import { type ReactNode, useCallback, useState } from "react";
+import { HubOptionMenu } from "./hub-option-menu";
+
+function SettingsSection({
+  label,
+  labelClassName,
+  children,
+}: {
+  label: string;
+  labelClassName?: string;
+  children: ReactNode;
+}) {
+  return (
+    <div className="border-t border-border/50 pb-5 pt-5 first:border-t-0 first:pt-0">
+      <div
+        className={cn(
+          "pb-4 text-ui-11 font-semibold uppercase tracking-wider text-muted-foreground",
+          labelClassName,
+        )}
+      >
+        {label}
+      </div>
+      <div className="flex flex-col gap-5">{children}</div>
+    </div>
+  );
+}
+
+function ToggleRow({
+  label,
+  info,
+  checked,
+  disabled,
+  onCheckedChange,
+}: {
+  label: string;
+  info?: string;
+  checked: boolean;
+  disabled?: boolean;
+  onCheckedChange: (checked: boolean) => void;
+}) {
+  return (
+    <div className="flex items-center justify-between gap-3">
+      <div className="flex min-w-0 items-center gap-1.5">
+        <span className="text-ui-13 font-medium text-nav-fg">{label}</span>
+        {info && <InfoHint>{info}</InfoHint>}
+      </div>
+      <Switch
+        checked={checked}
+        disabled={disabled}
+        onCheckedChange={(value) => onCheckedChange(value === true)}
+        aria-label={label}
+      />
+    </div>
+  );
+}
+
+export function SamplingSettingsButton({ className }: { className?: string }) {
+  const [open, setOpen] = useState(false);
+  const params = useChatRuntimeStore((s) => s.params);
+  const setParams = useChatRuntimeStore((s) => s.setParams);
+
+  // Loaded model's per-model config (context length etc.), mirroring the chat
+  // page's Run settings Model section.
+  const { selectModel } = useChatModelRuntime();
+  const modelLoading = useChatRuntimeStore((s) => s.modelLoading);
+  const activeGgufVariant = useChatRuntimeStore((s) => s.activeGgufVariant);
+  const ggufContextLength = useChatRuntimeStore((s) => s.ggufContextLength);
+  const ggufNativeContextLength = useChatRuntimeStore(
+    (s) => s.ggufNativeContextLength,
+  );
+  const {
+    checkpoint,
+    isGguf: activeModelIsGguf,
+    config: activeModelConfig,
+  } = useActiveModelConfig();
+  const handleReloadActiveModel = useCallback(
+    (config: PerModelConfig) => {
+      const runtime = useChatRuntimeStore.getState();
+      const activeCheckpoint = runtime.params.checkpoint;
+      if (!activeCheckpoint) return;
+      const nativeToken = runtime.activeNativePathToken;
+      const nativeExpiry = runtime.activeNativePathExpiresAtMs;
+      // Mirrors the chat page: an expired native-path token can't reload.
+      if (nativeToken && nativeExpiry != null && Date.now() >= nativeExpiry) {
+        toast.error("This local model file's access has expired.", {
+          description: "Re-select the model file to reload it.",
+        });
+        return;
+      }
+      // selectModel reads config from the runtime store, not the selection, so
+      // apply it first (snapshotting the current one for rollback).
+      const previousConfig = currentRuntimePerModelConfig({
+        includeMaxSeqLength: true,
+      });
+      applyPerModelConfigToRuntime(config);
+      void selectModel({
+        id: activeCheckpoint,
+        source: "local",
+        ggufVariant: runtime.activeGgufVariant ?? undefined,
+        nativePathToken: nativeToken ?? undefined,
+        nativePathExpiresAtMs: nativeExpiry,
+        isGguf: activeModelIsGguf,
+        isDownloaded: true,
+        keepSpeculative: true,
+        previousConfig,
+        forceReload: true,
+      });
+    },
+    [selectModel, activeModelIsGguf],
+  );
+
+  // Reasoning + tools: same store bindings as the chat page.
+  const reasoningEnabled = useChatRuntimeStore((s) => s.reasoningEnabled);
+  const reasoningAlwaysOn = useChatRuntimeStore((s) => s.reasoningAlwaysOn);
+  const setReasoningEnabled = useChatRuntimeStore((s) => s.setReasoningEnabled);
+  const reasoningEffort = useChatRuntimeStore((s) => s.reasoningEffort);
+  const reasoningEffortLevels = useChatRuntimeStore(
+    (s) => s.reasoningEffortLevels,
+  );
+  const setReasoningEffort = useChatRuntimeStore((s) => s.setReasoningEffort);
+  const supportsPreserveThinking = useChatRuntimeStore(
+    (s) => s.supportsPreserveThinking,
+  );
+  const preserveThinking = useChatRuntimeStore((s) => s.preserveThinking);
+  const setPreserveThinking = useChatRuntimeStore((s) => s.setPreserveThinking);
+  const maxToolCalls = useChatRuntimeStore((s) => s.maxToolCallsPerMessage);
+  const setMaxToolCalls = useChatRuntimeStore(
+    (s) => s.setMaxToolCallsPerMessage,
+  );
+  const toolCallTimeout = useChatRuntimeStore((s) => s.toolCallTimeout);
+  const setToolCallTimeout = useChatRuntimeStore((s) => s.setToolCallTimeout);
+  const autoHealToolCalls = useChatRuntimeStore((s) => s.autoHealToolCalls);
+  const setAutoHealToolCalls = useChatRuntimeStore(
+    (s) => s.setAutoHealToolCalls,
+  );
+  const nudgeToolCalls = useChatRuntimeStore((s) => s.nudgeToolCalls);
+  const setNudgeToolCalls = useChatRuntimeStore((s) => s.setNudgeToolCalls);
+  const permissionMode = useChatRuntimeStore((s) => s.permissionMode);
+  const setConfirmToolCalls = useChatRuntimeStore((s) => s.setConfirmToolCalls);
+
+  const toolsEnabled = useChatRuntimeStore((s) => s.toolsEnabled);
+  const setToolsEnabled = useChatRuntimeStore((s) => s.setToolsEnabled);
+
+  const set = (key: keyof typeof params) => (value: number) =>
+    setParams({ ...params, [key]: value });
+
+  // Slider 0-41; 41 maps to 9999 ("Max"), mirroring the chat page.
+  const toolCallsSliderValue =
+    maxToolCalls >= 9999 ? 41 : Math.min(maxToolCalls, 40);
+  // Slider 1-31; 31 maps to 9999 ("Max").
+  const timeoutSliderValue =
+    toolCallTimeout >= 9999 ? 31 : Math.min(Math.max(toolCallTimeout, 1), 30);
+
+  return (
+    <>
+      <Tooltip>
+        <TooltipTrigger asChild={true}>
+          <button
+            type="button"
+            aria-label="Inference settings"
+            onClick={(e) => {
+              e.stopPropagation();
+              setOpen(true);
+            }}
+            className={cn(
+              "inline-flex size-7 shrink-0 cursor-pointer items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-muted hover:text-foreground",
+              className,
+            )}
+          >
+            <HugeiconsIcon
+              icon={Settings02Icon}
+              strokeWidth={1.75}
+              className="size-4"
+            />
+          </button>
+        </TooltipTrigger>
+        <TooltipContent side="bottom" className="tooltip-compact">
+          Inference settings
+        </TooltipContent>
+      </Tooltip>
+      <Dialog open={open} onOpenChange={setOpen}>
+        <DialogContent
+          className="flex max-h-[85vh] flex-col gap-5 sm:max-w-[580px]"
+          onClick={(e) => e.stopPropagation()}
+        >
+          <DialogHeader>
+            <DialogTitle>Inference settings</DialogTitle>
+            <DialogDescription>
+              Applies to chats with local models.
+            </DialogDescription>
+          </DialogHeader>
+          <div className="-mr-2 flex min-h-0 flex-col overflow-y-auto overflow-x-hidden pr-2 [scrollbar-width:thin]">
+            {checkpoint && activeModelConfig && !modelLoading && (
+              <SettingsSection label="Model">
+                <SidebarModelConfig
+                  modelId={checkpoint}
+                  ggufVariant={activeGgufVariant ?? null}
+                  isGguf={activeModelIsGguf}
+                  nativeContextLength={ggufNativeContextLength}
+                  loadedContextLength={ggufContextLength}
+                  loadedConfig={activeModelConfig}
+                  onReload={handleReloadActiveModel}
+                />
+              </SettingsSection>
+            )}
+
+            <SettingsSection label="System Prompt">
+              <Textarea
+                value={params.systemPrompt}
+                onChange={(e) =>
+                  setParams({ ...params, systemPrompt: e.target.value })
+                }
+                placeholder="Instructions sent before every conversation."
+                aria-label="System prompt"
+                className="min-h-[84px] resize-y text-ui-13"
+              />
+            </SettingsSection>
+
+            <SettingsSection label="Reasoning" labelClassName="pb-5">
+              <ToggleRow
+                label="Enable reasoning"
+                checked={reasoningAlwaysOn || reasoningEnabled}
+                disabled={reasoningAlwaysOn}
+                onCheckedChange={setReasoningEnabled}
+              />
+              {reasoningEffortLevels.length > 0 && (
+                <div className="flex items-center justify-between gap-3">
+                  <span className="text-ui-13 font-medium text-nav-fg">
+                    Reasoning effort
+                  </span>
+                  <HubOptionMenu
+                    value={reasoningEffort}
+                    options={reasoningEffortLevels.map((level) => ({
+                      value: level,
+                      label: level.charAt(0).toUpperCase() + level.slice(1),
+                    }))}
+                    onValueChange={setReasoningEffort}
+                    ariaLabel="Reasoning effort"
+                    align="end"
+                    className="h-8 text-ui-11p5"
+                  />
+                </div>
+              )}
+              {supportsPreserveThinking && (
+                <ToggleRow
+                  label="Preserve thinking"
+                  info="Keep earlier turns' reasoning in context so the model can build on it. Uses more context."
+                  checked={preserveThinking}
+                  onCheckedChange={setPreserveThinking}
+                />
+              )}
+            </SettingsSection>
+
+            <SettingsSection label="Sampling">
+              <ParamSlider
+                label="Temperature"
+                value={params.temperature}
+                min={0}
+                max={2}
+                step={0.01}
+                onChange={set("temperature")}
+                info="Controls randomness. Lower values make output focused and deterministic; higher values increase variety and creativity."
+              />
+              <ParamSlider
+                label="Top P"
+                value={params.topP}
+                min={0}
+                max={1}
+                step={0.05}
+                onChange={set("topP")}
+                displayValue={params.topP === 1 ? "Off" : undefined}
+                info="Nucleus sampling. Restricts choices to the smallest set of tokens whose cumulative probability reaches this threshold. 1.0 = off."
+              />
+              <ParamSlider
+                label="Top K"
+                value={params.topK}
+                min={0}
+                max={100}
+                step={1}
+                onChange={set("topK")}
+                displayValue={params.topK === 0 ? "Off" : undefined}
+                info="Limits sampling to the K most likely tokens at each step. 0 = off."
+              />
+              <ParamSlider
+                label="Min P"
+                value={params.minP}
+                min={0}
+                max={1}
+                step={0.01}
+                onChange={set("minP")}
+                info="Drops tokens whose probability is below this fraction of the top token's probability. Filters unlikely candidates."
+              />
+              <ParamSlider
+                label="Repetition Penalty"
+                value={params.repetitionPenalty}
+                min={1}
+                max={2}
+                step={0.05}
+                onChange={set("repetitionPenalty")}
+                displayValue={
+                  params.repetitionPenalty === 1 ? "Off" : undefined
+                }
+                info="Down-weights tokens that have already appeared, reducing repetition. 1.0 = off; higher values penalize more strongly."
+              />
+              <ParamSlider
+                label="Presence Penalty"
+                value={params.presencePenalty}
+                min={0}
+                max={2}
+                step={0.1}
+                onChange={set("presencePenalty")}
+                displayValue={params.presencePenalty === 0 ? "Off" : undefined}
+                info="Penalizes any token that has already appeared at least once, encouraging the model to introduce new topics. 0 = off."
+              />
+              <ParamSlider
+                label="Max Tokens"
+                value={params.maxTokens}
+                min={64}
+                max={131072}
+                step={64}
+                onChange={set("maxTokens")}
+                valueSize={6}
+                info="Maximum number of tokens to generate per response. Generation stops at this limit or when the model emits an end-of-sequence token."
+              />
+            </SettingsSection>
+
+            <SettingsSection label="Tools">
+              <ToggleRow
+                label="Enable tools"
+                info="Master switch for tool use in chat. When off, the model answers without calling any tools."
+                checked={toolsEnabled}
+                onCheckedChange={setToolsEnabled}
+              />
+              <ToggleRow
+                label="Auto-healing tool calls"
+                info="Unsloth auto-fixes broken tool calls so inference output is never broken."
+                checked={autoHealToolCalls}
+                onCheckedChange={setAutoHealToolCalls}
+              />
+              <ToggleRow
+                label="Nudge tool calls"
+                info="When a tool call cannot be repaired, re-ask the model once so the intended tool still runs."
+                checked={nudgeToolCalls}
+                onCheckedChange={setNudgeToolCalls}
+              />
+              <ToggleRow
+                label="Confirm tool calls"
+                info="Pause every local tool call for your approval before it runs. Overridden by Full access."
+                checked={permissionMode === "ask"}
+                disabled={permissionMode === "full"}
+                onCheckedChange={setConfirmToolCalls}
+              />
+              <ParamSlider
+                label="Max Tool Calls Per Message"
+                value={toolCallsSliderValue}
+                min={0}
+                max={41}
+                step={1}
+                onChange={(v) => setMaxToolCalls(v >= 41 ? 9999 : v)}
+                displayValue={
+                  toolCallsSliderValue >= 41
+                    ? "Max"
+                    : toolCallsSliderValue === 0
+                      ? "Off"
+                      : undefined
+                }
+                info="Cap on tool/function calls the model may invoke within a single response. 0 disables tool use; Max removes the cap."
+              />
+              <ParamSlider
+                label="Max Tool Call Duration"
+                value={timeoutSliderValue}
+                min={1}
+                max={31}
+                step={1}
+                onChange={(v) => setToolCallTimeout(v >= 31 ? 9999 : v)}
+                displayValue={
+                  timeoutSliderValue >= 31
+                    ? "Max"
+                    : timeoutSliderValue === 1
+                      ? "1 minute"
+                      : `${timeoutSliderValue} minutes`
+                }
+                valueSize={10}
+                info="Per-call wall-clock limit. Long-running tool executions are terminated when this elapses; the model continues with what completed."
+              />
+            </SettingsSection>
+
+            <SettingsSection label="Retrieval">
+              <RetrievalSettingsSection />
+            </SettingsSection>
+          </div>
+        </DialogContent>
+      </Dialog>
+    </>
+  );
+}
diff --git a/studio/frontend/src/features/hub/catalog/shared.tsx b/studio/frontend/src/features/hub/catalog/shared.tsx
index c435afcfe6..94040ad3e0 100644
--- a/studio/frontend/src/features/hub/catalog/shared.tsx
+++ b/studio/frontend/src/features/hub/catalog/shared.tsx
@@ -1,12 +1,19 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
+import {
+  Tooltip,
+  TooltipContent,
+  TooltipTrigger,
+} from "@/components/ui/tooltip";
+import { cn } from "@/lib/utils";
 import {
   BrainIcon,
   Chat01Icon,
   CodeIcon,
   GlobeIcon,
   HeadphonesIcon,
+  ImageIcon,
   LockIcon,
   LockKeyIcon,
   SparklesIcon,
@@ -15,12 +22,6 @@ import {
 } from "@hugeicons/core-free-icons";
 import type { IconSvgElement } from "@hugeicons/react";
 import { HugeiconsIcon } from "@hugeicons/react";
-import {
-  Tooltip,
-  TooltipContent,
-  TooltipTrigger,
-} from "@/components/ui/tooltip";
-import { cn } from "@/lib/utils";
 import type { Capability, CapabilityKey } from "../lib/model-capabilities";
 
 const CAPABILITY_ICON: Record<CapabilityKey, IconSvgElement> = {
@@ -30,6 +31,7 @@ const CAPABILITY_ICON: Record<CapabilityKey, IconSvgElement> = {
   reasoning: BrainIcon,
   code: CodeIcon,
   embedding: SparklesIcon,
+  diffusion: ImageIcon,
   multilingual: GlobeIcon,
   conversational: Chat01Icon,
 };
@@ -45,6 +47,8 @@ const CAPABILITY_TONE: Record<CapabilityKey, string> = {
   code: "bg-cyan-500/10 text-cyan-800 dark:bg-cyan-400/20 dark:text-cyan-300",
   embedding:
     "bg-emerald-500/10 text-emerald-700 dark:bg-emerald-400/20 dark:text-emerald-300",
+  diffusion:
+    "bg-pink-500/10 text-pink-700 dark:bg-pink-400/20 dark:text-pink-300",
   multilingual:
     "bg-sky-500/10 text-sky-700 dark:bg-sky-400/20 dark:text-sky-300",
   conversational:
@@ -53,15 +57,13 @@ const CAPABILITY_TONE: Record<CapabilityKey, string> = {
 
 export function AccessChip({ label }: { label: string }) {
   return (
-    <span className="inline-flex h-6 shrink-0 items-center rounded-full border border-amber-500/30 bg-amber-500/8 px-2 text-[11px] font-medium leading-none text-amber-700 dark:text-amber-300">
+    <span className="inline-flex h-6 shrink-0 items-center rounded-full border border-amber-500/30 bg-amber-500/8 px-2 text-ui-11 font-medium leading-none text-amber-700 dark:text-amber-300">
       {label}
     </span>
   );
 }
 
-function isGatedAccess(
-  gated: false | "auto" | "manual" | undefined,
-): boolean {
+function isGatedAccess(gated: false | "auto" | "manual" | undefined): boolean {
   return gated !== false && gated !== undefined;
 }
 
@@ -142,7 +144,7 @@ export function CapabilityPill({
     <span
       aria-label={iconOnly ? capability.label : undefined}
       className={cn(
-        "inline-flex h-6 shrink-0 items-center rounded-full text-[11.5px] font-medium",
+        "inline-flex h-6 shrink-0 items-center rounded-full text-ui-11p5 font-medium",
         iconOnly ? "w-6 justify-center px-0" : "gap-1.5 px-2.5",
         CAPABILITY_TONE[capability.key],
       )}
diff --git a/studio/frontend/src/features/hub/catalog/transport-toggle.tsx b/studio/frontend/src/features/hub/catalog/transport-toggle.tsx
index 9202b88f45..bd6222094a 100644
--- a/studio/frontend/src/features/hub/catalog/transport-toggle.tsx
+++ b/studio/frontend/src/features/hub/catalog/transport-toggle.tsx
@@ -40,7 +40,7 @@ export function TransportToggle() {
   return (
     <fieldset
       aria-label="Download transport"
-      className="hub-tag-soft m-0 inline-flex h-[26px] min-w-0 items-center gap-0.5 rounded-full border-0 p-0.5 text-[11px]"
+      className="hub-tag-soft m-0 inline-flex h-[26px] min-w-0 items-center gap-0.5 rounded-full border-0 p-0.5 text-ui-11"
     >
       {OPTIONS.map((opt) => {
         const active = mode === opt.value;
diff --git a/studio/frontend/src/features/hub/components/hf-token-indicator.tsx b/studio/frontend/src/features/hub/components/hf-token-indicator.tsx
index 1e143a805c..ef45c648f7 100644
--- a/studio/frontend/src/features/hub/components/hf-token-indicator.tsx
+++ b/studio/frontend/src/features/hub/components/hf-token-indicator.tsx
@@ -40,7 +40,7 @@ export function HfTokenIndicator({ showLabel = false }: HfTokenIndicatorProps =
             onClick={() => openDialog("general")}
             aria-label={ariaLabel}
             className={cn(
-              "hub-menu-trigger field-soft inline-flex h-9 w-full items-center justify-between gap-2 rounded-[12px] py-0 pl-1.5 pr-3 text-[12.5px] font-medium text-foreground transition-colors",
+              "hub-menu-trigger field-soft inline-flex h-9 w-full items-center justify-between gap-2 rounded-[12px] py-0 pl-1.5 pr-3 text-ui-12p5 font-medium text-foreground transition-colors",
               "focus-visible:outline-none focus-visible:ring-0 focus-visible:ring-offset-0",
             )}
           >
@@ -64,7 +64,7 @@ export function HfTokenIndicator({ showLabel = false }: HfTokenIndicatorProps =
             </span>
             <span
               className={cn(
-                "shrink-0 text-[11px] font-normal tabular-nums",
+                "shrink-0 text-ui-11 font-normal tabular-nums",
                 hasToken ? "text-verified" : "text-muted-foreground/70",
               )}
             >
@@ -89,7 +89,7 @@ export function HfTokenIndicator({ showLabel = false }: HfTokenIndicatorProps =
           className={cn(
             // Solid circle reads optically larger than the flat HTTP/Xet box, so
             // keep it 22px to sit within the row rather than bulging above it.
-            "inline-flex h-[22px] w-[22px] items-center justify-center rounded-full text-[11.5px] transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
+            "inline-flex h-[22px] w-[22px] items-center justify-center rounded-full text-ui-11p5 transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
             hasToken
               ? "hub-tag-soft text-muted-foreground hover:text-foreground/80"
               : "bg-destructive text-destructive-foreground hover:bg-destructive/90",
diff --git a/studio/frontend/src/features/hub/components/page-heading.tsx b/studio/frontend/src/features/hub/components/page-heading.tsx
index e7c0f003f0..06dfcd922d 100644
--- a/studio/frontend/src/features/hub/components/page-heading.tsx
+++ b/studio/frontend/src/features/hub/components/page-heading.tsx
@@ -13,7 +13,7 @@ type PageHeadingProps = {
 };
 
 const TITLE_CLASS =
-  "text-[30px] font-semibold leading-[1.04] tracking-[-0.028em] text-foreground sm:text-[34px]";
+  "text-ui-30 font-semibold leading-[1.04] tracking-[-0.028em] text-foreground sm:text-ui-34";
 
 export function PageHeading({
   title,
@@ -38,7 +38,7 @@ export function PageHeading({
         <h1 className={TITLE_CLASS}>{title}</h1>
       )}
       {subtitle ? (
-        <p className="mt-2 text-[13px] leading-[19px] text-muted-foreground">
+        <p className="mt-2 text-ui-13 leading-ui-19 text-muted-foreground">
           {subtitle}
         </p>
       ) : null}
diff --git a/studio/frontend/src/features/hub/download-manager/api.ts b/studio/frontend/src/features/hub/download-manager/api.ts
index 3373a47b04..2c55b90edd 100644
--- a/studio/frontend/src/features/hub/download-manager/api.ts
+++ b/studio/frontend/src/features/hub/download-manager/api.ts
@@ -12,7 +12,7 @@ function parseErrorText(status: number, body: unknown): string {
     const detail = (body as { detail?: unknown }).detail;
     const formatted = formatFastApiDetail(detail);
     if (status === 405) {
-      return `${formatted || "Method Not Allowed"} - the Studio backend did not accept this API method. Restart Studio so the frontend and backend are on the same build.`;
+      return `${formatted || "Method Not Allowed"} - the Unsloth backend did not accept this API method. Restart Unsloth so the frontend and backend are on the same build.`;
     }
     if (formatted) return formatted;
     const message = (body as { message?: unknown }).message;
diff --git a/studio/frontend/src/features/hub/download-manager/download-manager-controller.ts b/studio/frontend/src/features/hub/download-manager/download-manager-controller.ts
index da653ddeb7..2cea1d8304 100644
--- a/studio/frontend/src/features/hub/download-manager/download-manager-controller.ts
+++ b/studio/frontend/src/features/hub/download-manager/download-manager-controller.ts
@@ -1,14 +1,10 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { DOWNLOAD_KIND } from "./constants";
 import {
   createDownloadManagerInitialState,
-  jobKeyOf,
   removeJob,
-  selectActiveJob,
   setState,
-  useDownloadManagerStore,
 } from "./download-manager-state";
 import { resetDownloadApiAdapterState } from "./download-api-adapter";
 import {
@@ -69,25 +65,6 @@ export const downloadManager: DownloadManagerController = {
   dismiss: removeJob,
 };
 
-/** Cancel the in-flight download for a staged model pick. No-op when nothing is
- *  downloading (e.g. a native/local file that was never fetched). Lets non-React
- *  callers (the chat store's abandon paths) stop a staged transfer without the
- *  useRepoDownload hook. */
-export function cancelStagedModelDownload(
-  pending: { id: string; ggufVariant?: string | null } | null,
-): void {
-  if (!pending) return;
-  const variant = pending.ggufVariant ?? null;
-  const activeJob = selectActiveJob(
-    useDownloadManagerStore.getState(),
-    DOWNLOAD_KIND.MODEL,
-    pending.id,
-    variant,
-  );
-  void downloadManager.cancel(
-    activeJob?.key ?? jobKeyOf(DOWNLOAD_KIND.MODEL, pending.id, variant),
-  );
-}
 
 if (import.meta.hot) {
   import.meta.hot.dispose(() => {
diff --git a/studio/frontend/src/features/hub/download-manager/download-manager-panel.tsx b/studio/frontend/src/features/hub/download-manager/download-manager-panel.tsx
index d57da2137b..3e5a86a879 100644
--- a/studio/frontend/src/features/hub/download-manager/download-manager-panel.tsx
+++ b/studio/frontend/src/features/hub/download-manager/download-manager-panel.tsx
@@ -108,7 +108,7 @@ function DownloadRow({ jobKey }: { jobKey: string }) {
   return (
     <li className="flex flex-col gap-1.5 py-2.5 pl-4 pr-3">
       <div className="flex items-center gap-2">
-        <span className="min-w-0 flex-1 truncate text-[12.5px] font-medium text-foreground">
+        <span className="min-w-0 flex-1 truncate text-ui-12p5 font-medium text-foreground">
           {job.repoId}
           <span className="text-muted-foreground">{variantSuffix(job)}</span>
         </span>
@@ -165,7 +165,7 @@ function DownloadRow({ jobKey }: { jobKey: string }) {
         />
       ) : null}
       {terminal || job.state === "cancelling" || job.error ? (
-        <div className="px-0 text-[11px] text-muted-foreground tabular-nums">
+        <div className="px-0 text-ui-11 text-muted-foreground tabular-nums">
           <StatusLine job={job} />
         </div>
       ) : null}
@@ -231,7 +231,7 @@ export function DownloadManagerPanel({
       ) : (
         <div className="hub-download-panel pointer-events-auto w-[min(400px,calc(100vw-2rem))] overflow-hidden">
           <div className="flex items-center gap-2 border-b border-foreground/[0.07] py-2 pl-4 pr-3">
-            <span className="min-w-0 flex-1 truncate text-[12.5px] font-semibold text-foreground">
+            <span className="min-w-0 flex-1 truncate text-ui-12p5 font-semibold text-foreground">
               {headerLabel}
             </span>
             <button
diff --git a/studio/frontend/src/features/hub/download-manager/download-progress-bar.tsx b/studio/frontend/src/features/hub/download-manager/download-progress-bar.tsx
index f28fa0c525..9005435aa1 100644
--- a/studio/frontend/src/features/hub/download-manager/download-progress-bar.tsx
+++ b/studio/frontend/src/features/hub/download-manager/download-progress-bar.tsx
@@ -41,7 +41,7 @@ export function DownloadProgressBar({
           style={{ left: `${exactPercent}%` }}
         />
       </div>
-      <div className="flex items-center justify-between gap-2 text-[10.5px] text-muted-foreground tabular-nums">
+      <div className="flex items-center justify-between gap-2 text-ui-10p5 text-muted-foreground tabular-nums">
         <span>
           {formatBytes(progress.downloadedBytes)}
           {totalLabel && ` / ${totalLabel}`}
diff --git a/studio/frontend/src/features/hub/download-manager/index.ts b/studio/frontend/src/features/hub/download-manager/index.ts
index dd88aaf3f0..60ef3851f8 100644
--- a/studio/frontend/src/features/hub/download-manager/index.ts
+++ b/studio/frontend/src/features/hub/download-manager/index.ts
@@ -20,7 +20,6 @@ export {
 } from "./constants";
 export {
   __resetDownloadManagerForTests,
-  cancelStagedModelDownload,
   clearCompletedInventoryHint,
   downloadManager,
   hydrateDownloadManager,
diff --git a/studio/frontend/src/features/hub/hooks/use-hidden-embedding-models.ts b/studio/frontend/src/features/hub/hooks/use-hidden-embedding-models.ts
new file mode 100644
index 0000000000..f78679310f
--- /dev/null
+++ b/studio/frontend/src/features/hub/hooks/use-hidden-embedding-models.ts
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { loadEmbeddingModelSettings } from "@/features/settings";
+import { useEffect, useState } from "react";
+import { useInventoryVersion } from "../stores/inventory-events";
+
+/** Backend-resolved embedding repos that optimistic inventory rows must hide. */
+export function useHiddenEmbeddingModelIds(
+  enabled: boolean,
+): ReadonlySet<string> {
+  const inventoryVersion = useInventoryVersion();
+  const [hiddenIds, setHiddenIds] = useState<ReadonlySet<string>>(
+    () => new Set(),
+  );
+
+  // biome-ignore lint/correctness/useExhaustiveDependencies: inventory invalidation must reload backend-resolved embedder ids
+  useEffect(() => {
+    if (!enabled) {
+      return;
+    }
+    let cancelled = false;
+    loadEmbeddingModelSettings()
+      .then((settings) => {
+        if (cancelled) {
+          return;
+        }
+        setHiddenIds(
+          new Set(
+            [
+              settings.embeddingModel,
+              settings.embeddingGgufRepo,
+              settings.defaultEmbeddingModel,
+              settings.defaultEmbeddingGgufRepo,
+            ].map((value) => value.trim().toLowerCase()),
+          ),
+        );
+      })
+      .catch(() => undefined);
+    return () => {
+      cancelled = true;
+    };
+  }, [enabled, inventoryVersion]);
+
+  return hiddenIds;
+}
diff --git a/studio/frontend/src/features/hub/hooks/use-hub-paginated-search.ts b/studio/frontend/src/features/hub/hooks/use-hub-paginated-search.ts
index 882c530782..d598065d17 100644
--- a/studio/frontend/src/features/hub/hooks/use-hub-paginated-search.ts
+++ b/studio/frontend/src/features/hub/hooks/use-hub-paginated-search.ts
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { useCallback, useEffect, useRef, useState } from "react";
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 
 interface HfPaginatedState<T> {
   results: T[];
@@ -12,6 +12,10 @@ interface HfPaginatedState<T> {
   error: string | null;
 }
 
+interface InternalPaginatedState<T> extends HfPaginatedState<T> {
+  queryKey: object | null;
+}
+
 const INITIAL: HfPaginatedState<never> = {
   results: [],
   scannedCount: 0,
@@ -74,10 +78,15 @@ export function useHubPaginatedSearch<T>(
   options?: { enabled?: boolean },
 ): HfPaginatedState<T> & { fetchMore: () => boolean; retry: () => void } {
   const enabled = options?.enabled ?? true;
-  const [state, setState] = useState<HfPaginatedState<T>>(
-    INITIAL as HfPaginatedState<T>,
-  );
   const [retryNonce, setRetryNonce] = useState(0);
+  const queryKey = useMemo(
+    () => ({ createIter, mapItem, retryNonce }),
+    [createIter, mapItem, retryNonce],
+  );
+  const [state, setState] = useState<InternalPaginatedState<T>>({
+    ...(INITIAL as HfPaginatedState<T>),
+    queryKey: null,
+  });
   const stateRef = useRef(state);
   useEffect(() => {
     stateRef.current = state;
@@ -187,6 +196,7 @@ export function useHubPaginatedSearch<T>(
     setState({
       ...(INITIAL as HfPaginatedState<T>),
       isLoading: true,
+      queryKey,
     });
 
     const iter = createIter(controller.signal);
@@ -203,6 +213,7 @@ export function useHubPaginatedSearch<T>(
           isLoadingMore: false,
           hasMore: !done,
           error: null,
+          queryKey,
         });
       })
       .catch((err) => {
@@ -214,6 +225,7 @@ export function useHubPaginatedSearch<T>(
           isLoadingMore: false,
           hasMore: false,
           error: err instanceof Error ? err.message : "Search failed",
+          queryKey,
         });
       })
       .finally(() => {
@@ -226,7 +238,14 @@ export function useHubPaginatedSearch<T>(
     return () => {
       clearDeferredFetch();
     };
-  }, [createIter, mapItem, enabled, retryNonce, clearDeferredFetch]);
+  }, [
+    createIter,
+    mapItem,
+    enabled,
+    retryNonce,
+    queryKey,
+    clearDeferredFetch,
+  ]);
 
   const retry = useCallback(() => {
     setRetryNonce((n) => n + 1);
@@ -358,5 +377,22 @@ export function useHubPaginatedSearch<T>(
     };
   }, [enabled, fetchMore]);
 
-  return { ...state, fetchMore, retry };
+  const visibleState: InternalPaginatedState<T> =
+    state.queryKey === queryKey
+      ? state
+      : {
+          ...(INITIAL as HfPaginatedState<T>),
+          isLoading: enabled,
+          queryKey,
+        };
+  return {
+    results: visibleState.results,
+    scannedCount: visibleState.scannedCount,
+    isLoading: visibleState.isLoading,
+    isLoadingMore: visibleState.isLoadingMore,
+    hasMore: visibleState.hasMore,
+    error: visibleState.error,
+    fetchMore,
+    retry,
+  };
 }
diff --git a/studio/frontend/src/features/hub/hooks/use-selected-model-view.ts b/studio/frontend/src/features/hub/hooks/use-selected-model-view.ts
index 171dd88d3c..cceac99753 100644
--- a/studio/frontend/src/features/hub/hooks/use-selected-model-view.ts
+++ b/studio/frontend/src/features/hub/hooks/use-selected-model-view.ts
@@ -48,7 +48,12 @@ function localResource(
       ? "cached"
       : "local";
   const id =
-    row.source === "hf_cache" && repoId && !row.partial ? repoId : row.loadId;
+    row.source === "hf_cache" &&
+    row.activeCache !== false &&
+    repoId &&
+    !row.partial
+      ? repoId
+      : row.loadId;
   return {
     repoId,
     localPath: row.path,
diff --git a/studio/frontend/src/features/hub/hub-page.tsx b/studio/frontend/src/features/hub/hub-page.tsx
index 630daa48ad..9fc452b4ed 100644
--- a/studio/frontend/src/features/hub/hub-page.tsx
+++ b/studio/frontend/src/features/hub/hub-page.tsx
@@ -1,34 +1,36 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import {
-  loadRememberedLoadSettings,
-  rememberedLoadSettingsKey,
-} from "@/components/assistant-ui/model-selector/remembered-load-settings";
-import { hfModelFitsDevice } from "@/components/assistant-ui/model-selector/recommended-fit";
-import { useHubInventory } from "@/features/hub/inventory";
-import { useDebouncedValue } from "@/hooks/use-debounced-value";
-import { useGpuInfo } from "@/hooks/use-gpu-info";
-import {
-  type HfModelSearchChannel,
-  type HfSortDirection,
-  type HfSortKey,
-} from "@/features/hub/hooks/use-hub-model-search";
-import { useOnlineStatus } from "@/features/hub/hooks/use-online-status";
-import { useHubInfiniteScroll } from "@/features/hub/hooks/use-hub-infinite-scroll";
-import { ggufVariantsMatch, modelIdsMatch } from "@/features/hub/lib/model-identity";
-import { cn } from "@/lib/utils";
 import { usePlatformStore } from "@/config/env";
 import {
-  hfApiToken,
-  useHfTokenStore,
-} from "@/features/hub/stores/hf-token-store";
+  isChannelEntryFresh,
+  useHubFeedStore,
+} from "./stores/hub-feed-store";
 import {
   getInferenceStatus,
   isExternalModelId,
   useChatModelRuntime,
   useChatRuntimeStore,
 } from "@/features/chat";
+import { useHubInventory } from "./inventory";
+import type {
+  HfModelSearchChannel,
+  HfSortDirection,
+  HfSortKey,
+} from "./hooks/use-hub-model-search";
+import { useOnlineStatus } from "@/features/hub";
+import { useHubInfiniteScroll } from "@/features/hub";
+import { ggufVariantsMatch, modelIdsMatch } from "./lib/model-identity";
+import { hfApiToken, useHfTokenStore } from "./stores/hf-token-store";
+import {
+  applyModelLoadConfigToRuntime,
+  currentRuntimePerModelConfig,
+  hfModelFitsDevice,
+  resolveInitialConfig,
+} from "@/features/model-picker";
+import { useDebouncedValue } from "@/hooks/use-debounced-value";
+import { useGpuInfo } from "@/hooks/use-gpu-info";
+import { cn } from "@/lib/utils";
 import { useNavigate, useSearch } from "@tanstack/react-router";
 import {
   useCallback,
@@ -38,17 +40,10 @@ import {
   useRef,
   useState,
 } from "react";
+import { ExternalLinkConfirmDialog } from "./catalog/external-link-confirm-dialog";
 import { HubDetailView } from "./catalog/hub-detail-view";
-import { HubTopBar } from "./catalog/hub-top-bar";
 import { HubFeed } from "./catalog/hub-feed";
-import { OwnerScopeToggle } from "./catalog/owner-scope-toggle";
-import {
-  type AllModelsView,
-  HubListHeader,
-  type InventorySort,
-  InventorySortControl,
-  ResultListHeader,
-} from "./catalog/models-table";
+import { HubTopBar } from "./catalog/hub-top-bar";
 import {
   ModelsCatalog,
   type ModelsCatalogHandlers,
@@ -56,11 +51,20 @@ import {
   type ModelsCatalogState,
 } from "./catalog/models-catalog";
 import { ModelsHeader } from "./catalog/models-header";
+import {
+  type AllModelsView,
+  HubListHeader,
+  type InventorySort,
+  InventorySortControl,
+  InventoryTypeFilterControl,
+  ResultListHeader,
+} from "./catalog/models-table";
 import { ModelsToolbar } from "./catalog/models-toolbar";
-import { ExternalLinkConfirmDialog } from "./catalog/external-link-confirm-dialog";
 import { OnDeviceFoldersDialog } from "./catalog/on-device-folders-dialog";
+import { OwnerScopeToggle } from "./catalog/owner-scope-toggle";
 import { useDiscoverSearch } from "./hooks/use-discover-search";
 import { useFeedWriteBack } from "./hooks/use-feed-write-back";
+import { useHiddenEmbeddingModelIds } from "./hooks/use-hidden-embedding-models";
 import { useHubFeed } from "./hooks/use-hub-feed";
 import { useHubModelVram } from "./hooks/use-hub-model-vram";
 import { useModelsSelection } from "./hooks/use-models-selection";
@@ -73,9 +77,17 @@ import {
   SECTION_TO_CHANNEL,
   findChannel,
 } from "./lib/channels";
-import { isHiddenModelId } from "./lib/hidden-models";
+import {
+  isConfiguredHiddenModelId,
+  isHiddenModelId,
+} from "./lib/hidden-models";
 import { inventoryRowMatches, tokenizeQuery } from "./lib/inventory-search";
+import {
+  type ModelTypeFilter,
+  matchesModelType,
+} from "./lib/model-type-filter";
 import { resolveOwnerProviderLogo } from "./lib/provider-logos";
+import { fingerprintToken } from "./lib/token-fingerprint";
 import {
   buildDiscoverRows,
   detectResultFormat,
@@ -99,6 +111,10 @@ const ALL_MODELS_VIEW_STORAGE_KEY = "unsloth.hub.allModelsView";
 const INVENTORY_SORT_STORAGE_KEY = "unsloth.hub.inventorySort";
 const OWNER_SCOPE_STORAGE_KEY = "unsloth.hub.ownerScope";
 
+// Iconless models (repo name matches no provider logo, e.g. Ornith, Inkling)
+// still show in the feed once they clear this many Hugging Face likes.
+const MIN_ICONLESS_MODEL_LIKES = 30;
+
 /** Discover browsing scope: the whole Hub (default) or only the unsloth org. */
 export type OwnerScope = "unsloth" | "all";
 
@@ -386,6 +402,7 @@ export function ModelsPage() {
     useState<ModelFormatFilter>("all");
   const isDiscoverTab = tab === "discover";
   const isDatasetMode = resourceType === "datasets";
+  const hiddenEmbeddingModelIds = useHiddenEmbeddingModelIds(!isDatasetMode);
   const urlSection = hubSearch.section ?? null;
   const isModelDiscover = isDiscoverTab && !isDatasetMode;
   const sectionChannelId: ChannelId | null = urlSection
@@ -446,6 +463,8 @@ export function ModelsPage() {
     setInventorySortState(sort);
     writeInventorySortPreference(sort);
   }, []);
+  const [inventoryTypeFilter, setInventoryTypeFilter] =
+    useState<ModelTypeFilter>("all");
   const [foldersDialogOpen, setFoldersDialogOpen] = useState(false);
   const [discoverFetchIntent, setDiscoverFetchIntent] = useState(0);
   const [sortBrowseActive, setSortBrowseActive] = useState(false);
@@ -564,19 +583,23 @@ export function ModelsPage() {
   const hfToken = useHfTokenStore((s) => s.token);
   const debouncedHfToken = useDebouncedValue(hfToken, 500);
   const apiHfToken = hfApiToken(debouncedHfToken);
+  const tokenFingerprint = useMemo(
+    () => fingerprintToken(apiHfToken),
+    [apiHfToken],
+  );
   const deferredFormatFilter = useDeferredValue(formatFilter);
   const deferredCapabilityFilter = useDeferredValue(capabilityFilter);
 
   const hasQuery = deferredDebouncedQuery.trim() !== "";
-  const mode: DiscoverMode = !isModelDiscover
-    ? "search"
-    : hasQuery
+  const mode: DiscoverMode = isModelDiscover
+    ? hasQuery
       ? "search"
       : urlSection != null
         ? "channel-list"
         : sortBrowseActive
           ? "search"
-          : "feed";
+          : "feed"
+    : "search";
   const isFeedMode = mode === "feed";
   const isChannelListMode = mode === "channel-list";
   const isSortBrowseMode =
@@ -628,8 +651,22 @@ export function ModelsPage() {
     online,
   });
 
+  const cachedListEntry = useHubFeedStore((state) =>
+    liveListChannel ? state.channels[liveListChannel.id] : undefined,
+  );
+  const visibleResults =
+    results.length === 0 &&
+    liveListChannel &&
+    isChannelEntryFresh(
+      cachedListEntry,
+      liveListChannel.id,
+      tokenFingerprint,
+    )
+      ? (cachedListEntry?.results ?? results)
+      : results;
+
   useFeedWriteBack({
-    channelId: isChannelListMode ? activeChannelId : null,
+    channelId: liveListChannel?.id ?? null,
     results,
     isLoading,
     accessToken: apiHfToken,
@@ -651,8 +688,13 @@ export function ModelsPage() {
     [effectiveCachedRows, effectiveLocalRows],
   );
   const modelDiscoverRows = useMemo<DiscoverRow[]>(
-    () => buildDiscoverRows(results, effectiveCachedRows, effectiveLocalRows),
-    [results, modelDiscoveryInventorySignature],
+    () =>
+      buildDiscoverRows(
+        visibleResults,
+        effectiveCachedRows,
+        effectiveLocalRows,
+      ),
+    [visibleResults, modelDiscoveryInventorySignature],
   );
 
   const datasetDiscoverRows = useMemo<DiscoverRow[]>(() => {
@@ -700,10 +742,15 @@ export function ModelsPage() {
     return discoverRows.filter(
       (row) =>
         !isHiddenModelId(row.id) &&
-        // The default feed only shows models with a provider logo.
+        !isConfiguredHiddenModelId(hiddenEmbeddingModelIds, row.id) &&
+        // Feed shows logo'd models, plus iconless ones above the likes threshold.
         (!isFeedMode ||
-          resolveOwnerProviderLogo(row.owner, row.repo) !== null) &&
-        matchesFormat(detectResultFormat(row.result), effectiveDiscoverFormat) &&
+          resolveOwnerProviderLogo(row.owner, row.repo) !== null ||
+          (row.result.likes ?? 0) >= MIN_ICONLESS_MODEL_LIKES) &&
+        matchesFormat(
+          detectResultFormat(row.result),
+          effectiveDiscoverFormat,
+        ) &&
         matchesCapability(row.capabilities, deferredCapabilityFilter) &&
         (!activeChannel?.finetunableOnly || isUnslothFinetunable(row.result)) &&
         // Models already on disk stay visible regardless of device fit,
@@ -714,6 +761,7 @@ export function ModelsPage() {
     );
   }, [
     discoverRows,
+    hiddenEmbeddingModelIds,
     isDatasetMode,
     isFeedMode,
     effectiveDiscoverFormat,
@@ -739,7 +787,11 @@ export function ModelsPage() {
         effectiveCachedRows,
         effectiveLocalRows,
       )
-        .filter((row) => !isHiddenModelId(row.id))
+        .filter(
+          (row) =>
+            !isHiddenModelId(row.id) &&
+            !isConfiguredHiddenModelId(hiddenEmbeddingModelIds, row.id),
+        )
         .filter((row) => matchesFormat(row.result.isGguf, "gguf"))
         // Same fit filter as the main Discover list, so the feed carousel
         // honors the toggle too.
@@ -751,6 +803,7 @@ export function ModelsPage() {
         ),
     [
       hubFeed.trending.results,
+      hiddenEmbeddingModelIds,
       modelDiscoveryInventorySignature,
       fitOnDeviceOnly,
       gpu,
@@ -767,33 +820,44 @@ export function ModelsPage() {
     }
     return merged;
   }, [isFeedMode, feedTrendingRows, filteredDiscoverRows]);
-  const feedResults = useMemo(() => feedRows.map((row) => row.result), [feedRows]);
+  const feedResults = useMemo(
+    () => feedRows.map((row) => row.result),
+    [feedRows],
+  );
   const selectionDiscoverRows = isFeedMode ? feedRows : discoverRows;
   const selectionFilteredDiscoverRows = isFeedMode
     ? feedRows
     : filteredDiscoverRows;
-  const selectionResults = isFeedMode ? feedResults : results;
+  const selectionResults = isFeedMode ? feedResults : visibleResults;
 
   const inventoryTokens = useMemo(
     () => (isDiscoverTab ? [] : tokenizeQuery(deferredDebouncedQuery)),
     [isDiscoverTab, deferredDebouncedQuery],
   );
-  // Hide infra models (e.g. the RAG embedder bge-small-en-v1.5) from the On
-  // Device list like Discover, but reveal a row when a query matches it so the
-  // user can confirm it is already downloaded.
+  // Server cache rows already apply variant-aware infra hiding. Optimistic
+  // rows are not server-confirmed, so apply the client filter first.
   const isVisibleInventoryRow = useCallback(
-    (row: CachedInventoryRow | LocalInventoryRow) =>
-      // Local rows can have a null repoId and an id that is a hash rather than
-      // the file path/name, so also check path/title (the backend's
-      // _is_hidden_model checks the on-disk path for the same reason).
-      !isHiddenModelId(
-        row.id,
-        row.repoId,
-        row.kind !== "cache" ? row.path : undefined,
-        row.kind !== "cache" ? row.title : undefined,
-      ) ||
-      (inventoryTokens.length > 0 && inventoryRowMatches(row, inventoryTokens)),
-    [inventoryTokens],
+    (row: CachedInventoryRow | LocalInventoryRow) => {
+      if (row.kind === "cache") {
+        return (
+          !row.optimistic ||
+          (!isHiddenModelId(row.id, row.repoId, row.cachePath) &&
+            !isConfiguredHiddenModelId(
+              hiddenEmbeddingModelIds,
+              row.id,
+              row.repoId,
+              row.cachePath,
+            ))
+        );
+      }
+      // Local rows may lack a repo id, so also check path and title.
+      return (
+        !isHiddenModelId(row.id, row.repoId, row.path, row.title) ||
+        (inventoryTokens.length > 0 &&
+          inventoryRowMatches(row, inventoryTokens))
+      );
+    },
+    [hiddenEmbeddingModelIds, inventoryTokens],
   );
   // Format filter is a deliberate scope narrowing, so hard-filter it out. The
   // text query instead drives dim-not-filter on On Device (see ModelsCatalog) so
@@ -808,6 +872,7 @@ export function ModelsPage() {
             // id/title/path happens to contain an infra needle is not dropped.
             isDatasetMode ||
             (matchesFormat(row.modelFormat, deferredFormatFilter) &&
+              matchesModelType(row, inventoryTypeFilter) &&
               isVisibleInventoryRow(row)),
         ),
         inventoryTokens,
@@ -816,6 +881,7 @@ export function ModelsPage() {
       effectiveCachedRows,
       isDatasetMode,
       deferredFormatFilter,
+      inventoryTypeFilter,
       inventoryTokens,
       isVisibleInventoryRow,
     ],
@@ -831,6 +897,7 @@ export function ModelsPage() {
             // id/title/path happens to contain an infra needle is not dropped.
             isDatasetMode ||
             (matchesFormat(row.modelFormat, deferredFormatFilter) &&
+              matchesModelType(row, inventoryTypeFilter) &&
               isVisibleInventoryRow(row)),
         ),
         inventoryTokens,
@@ -839,6 +906,7 @@ export function ModelsPage() {
       effectiveLocalRows,
       isDatasetMode,
       deferredFormatFilter,
+      inventoryTypeFilter,
       inventoryTokens,
       isVisibleInventoryRow,
     ],
@@ -871,6 +939,7 @@ export function ModelsPage() {
         resourceType,
         deferredFormatFilter,
         deferredCapabilityFilter,
+        inventoryTypeFilter,
         effectiveSort,
         effectiveDirection,
         activeChannelId,
@@ -881,6 +950,7 @@ export function ModelsPage() {
       resourceType,
       deferredFormatFilter,
       deferredCapabilityFilter,
+      inventoryTypeFilter,
       effectiveSort,
       effectiveDirection,
       activeChannelId,
@@ -899,6 +969,7 @@ export function ModelsPage() {
       }
     } else {
       setDownloadedFormat("all");
+      setInventoryTypeFilter("all");
     }
     setCapabilityFilter("all");
   }, [isDiscoverTab, urlSection, navigate]);
@@ -1108,50 +1179,22 @@ export function ModelsPage() {
     (opts: ModelLoadOptions, isDownloaded: boolean) => {
       if (!selectedModel) return;
       const runId = selectedModel.resource.runId;
-      // "Load on selection" off: stage GGUF picks instead of loading, so the
-      // chat page's staging flow can read the header and show the load options.
-      // Non-GGUF models have nothing to configure pre-load, so they load now.
-      if (
-        !useChatRuntimeStore.getState().loadOnSelection &&
-        (opts.ggufVariant != null || selectedModel.isGguf)
-      ) {
-        useChatRuntimeStore.getState().stageModel({
-          id: runId,
-          ggufVariant: opts.ggufVariant,
-          isGguf: selectedModel.isGguf,
-          isDownloaded,
-          expectedBytes: opts.expectedBytes,
-        });
-        openNewChat();
-        return;
-      }
-      // Detach any leftover staged pick first so its edited knobs (e.g. a custom
-      // context length) don't leak into this load -- mirrors the chat page's
-      // detachStaged(); keepDownload keeps any staged download running.
-      useChatRuntimeStore.getState().abandonStagedModel({ keepDownload: true });
-      // Load-on-selection skips the chat sheet, so seed this GGUF pick's saved
-      // load knobs here the way the sheet's restore effect would; otherwise the
-      // remembered config is silently ignored on the Hub run path. keepSpeculative
-      // then honors the restored speculative choice across the switch.
-      const remembered =
-        opts.ggufVariant != null || selectedModel.isGguf
-          ? loadRememberedLoadSettings(
-              rememberedLoadSettingsKey({
-                id: runId,
-                ggufVariant: opts.ggufVariant,
-              }),
-            )
-          : null;
-      if (remembered) {
-        useChatRuntimeStore.getState().applyRememberedLoadSettings(remembered);
-      }
+      const resolvedConfig = resolveInitialConfig(runId, opts.ggufVariant);
+      const rememberedConfig = resolvedConfig.remembered
+        ? resolvedConfig.config
+        : null;
+      const previousConfig = currentRuntimePerModelConfig({
+        includeMaxSeqLength: true,
+      });
+      const hasAppliedConfig = applyModelLoadConfigToRuntime(rememberedConfig);
       void selectModel({
         id: runId,
         ggufVariant: opts.ggufVariant,
         isDownloaded,
         expectedBytes: opts.expectedBytes,
-        keepSpeculative: remembered != null,
+        keepSpeculative: hasAppliedConfig,
         throwOnError: true,
+        previousConfig,
       })
         .then(() => {
           // Read fresh: the load is async, so the checkpoint may have changed.
@@ -1233,6 +1276,7 @@ export function ModelsPage() {
       onLoad: handleLoad,
       onLoadLocal: handleLoadLocal,
       onUseInChat: openNewChat,
+      onEject: () => void ejectModel(),
       onTrain: handleTrain,
       onInventoryChange: refreshInventory,
       onSearchHub: handleSearchHub,
@@ -1241,6 +1285,7 @@ export function ModelsPage() {
       handleLoad,
       handleLoadLocal,
       openNewChat,
+      ejectModel,
       handleTrain,
       handleSearchHub,
       refreshInventory,
@@ -1248,31 +1293,38 @@ export function ModelsPage() {
   );
 
   const catalogState = useMemo<ModelsCatalogState>(
-    () => ({
-      tab,
-      discoverRows: listRows,
-      cachedRows: filteredCachedRows,
-      localRows: filteredLocalRows,
-      selectedId,
-      isLoading,
-      downloadedReady,
-      inventoryError,
-      inventoryWarning,
-      query,
-      activeCheckpoint,
-      activeGgufVariant,
-      searchError,
-      online,
-      isDataset: isDatasetMode,
-      inventoryTokens,
-      scannedCount,
-      loadingIntentCount: discoverFetchIntent,
-      hasMore,
-      manualFetchAvailable: discoverManualFetchAvailable,
-      hasActiveFilters:
-        !isFeedMode &&
-        (deferredFormatFilter !== "all" || deferredCapabilityFilter !== "all"),
-    }),
+    () => {
+      const typeFilterActive =
+        !isDatasetMode && inventoryTypeFilter !== "all";
+      return {
+        tab,
+        discoverRows: listRows,
+        cachedRows: filteredCachedRows,
+        localRows: filteredLocalRows,
+        selectedId,
+        isLoading,
+        downloadedReady,
+        inventoryError,
+        inventoryWarning,
+        query,
+        activeCheckpoint,
+        activeGgufVariant,
+        searchError,
+        online,
+        isDataset: isDatasetMode,
+        inventoryTokens,
+        scannedCount,
+        loadingIntentCount: discoverFetchIntent,
+        hasMore,
+        manualFetchAvailable: discoverManualFetchAvailable,
+        hasActiveFilters:
+          !isFeedMode &&
+          (deferredFormatFilter !== "all" ||
+            deferredCapabilityFilter !== "all" ||
+            (tab === "downloaded" && typeFilterActive)),
+        typeFilterActive,
+      };
+    },
     [
       tab,
       isFeedMode,
@@ -1297,6 +1349,7 @@ export function ModelsPage() {
       discoverManualFetchAvailable,
       deferredFormatFilter,
       deferredCapabilityFilter,
+      inventoryTypeFilter,
     ],
   );
 
@@ -1375,16 +1428,18 @@ export function ModelsPage() {
         </div>
       );
     }
-    const ownerToggle = !isDatasetMode ? (
+    const ownerToggle = isDatasetMode ? undefined : (
       <OwnerScopeToggle value={ownerScope} onChange={setOwnerScope} />
-    ) : undefined;
+    );
     // Compact pill so it stays beside the view-mode tabs even in the narrow
     // split pane instead of dropping to its own row.
     return (
       <div className="flex flex-col gap-3 pt-6">
         {isChannelListMode ? (
           <HubListHeader
-            title={channelSection ? HUB_SECTION_TITLE[channelSection] : "Models"}
+            title={
+              channelSection ? HUB_SECTION_TITLE[channelSection] : "Models"
+            }
             count={listCount}
             view={allModelsView}
             onViewChange={setAllModelsView}
@@ -1427,27 +1482,40 @@ export function ModelsPage() {
   ]);
 
   const downloadedHeader = useMemo(() => {
-    const sortControl = (
-      <InventorySortControl value={inventorySort} onChange={setInventorySort} />
+    // Compact pills so they stay beside the view-mode tabs even in the narrow
+    // split pane instead of dropping to their own row.
+    const controls = (
+      <div className="flex min-w-0 items-center gap-1.5">
+        {!isDatasetMode && (
+          <InventoryTypeFilterControl
+            value={inventoryTypeFilter}
+            onChange={setInventoryTypeFilter}
+          />
+        )}
+        <InventorySortControl
+          value={inventorySort}
+          onChange={setInventorySort}
+        />
+      </div>
     );
-    // Compact pill so it stays beside the view-mode tabs even in the narrow
-    // split pane instead of dropping to its own row.
     return (
       <HubListHeader
         title="On device"
-        count={visibleCachedCount + visibleLocalCount}
+        count={filteredCachedRows.length + filteredLocalRows.length}
         view={allModelsView}
         onViewChange={setAllModelsView}
-        actions={sortControl}
+        actions={controls}
       />
     );
   }, [
-    visibleCachedCount,
-    visibleLocalCount,
+    filteredCachedRows,
+    filteredLocalRows,
     allModelsView,
     setAllModelsView,
     inventorySort,
     setInventorySort,
+    inventoryTypeFilter,
+    isDatasetMode,
   ]);
 
   const detailOpen = urlModel !== null;
@@ -1538,7 +1606,7 @@ export function ModelsPage() {
               />
             </div>
           ) : (
-            <div className="hidden min-h-0 flex-1 items-center justify-center px-6 text-center text-[13px] text-muted-foreground lg:flex">
+            <div className="hidden min-h-0 flex-1 items-center justify-center px-6 text-center text-ui-13 text-muted-foreground lg:flex">
               Select a model to preview its details.
             </div>
           )
diff --git a/studio/frontend/src/features/hub/hub.css b/studio/frontend/src/features/hub/hub.css
index 947dd8cb34..8dc6dac617 100644
--- a/studio/frontend/src/features/hub/hub.css
+++ b/studio/frontend/src/features/hub/hub.css
@@ -469,7 +469,7 @@
   }
 
   .hub-page .hub-focused-heading {
-    font-size: 18px;
+    font-size: calc(1.125rem * var(--ui-font-scale, 1));
     font-weight: 600;
     letter-spacing: 0;
     color: var(--foreground);
@@ -841,7 +841,7 @@
     padding-inline: 0;
     background-color: var(--status-success);
     color: var(--primary-foreground);
-    font-size: 10.5px;
+    font-size: calc(0.65625rem * var(--ui-font-scale, 1));
     font-weight: 600;
     line-height: 1;
     font-variant-numeric: tabular-nums;
@@ -1117,9 +1117,9 @@
     background-color: transparent;
     padding-left: 0.75rem;
     padding-right: 0.75rem;
-    font-size: 13px;
+    font-size: calc(0.8125rem * var(--ui-font-scale, 1));
     font-weight: 500;
-    line-height: 18px;
+    line-height: calc(1.125rem * var(--ui-font-scale, 1));
     letter-spacing: -0.025em;
     color: var(--foreground);
     transition: color 150ms, background-color 150ms;
@@ -1164,9 +1164,9 @@
     background-color: var(--status-success);
     padding-left: 1rem;
     padding-right: 1rem;
-    font-size: 13px;
+    font-size: calc(0.8125rem * var(--ui-font-scale, 1));
     font-weight: 600;
-    line-height: 18px;
+    line-height: calc(1.125rem * var(--ui-font-scale, 1));
     letter-spacing: -0.025em;
     color: var(--primary-foreground);
     transition: background-color 150ms, transform 150ms;
@@ -1273,7 +1273,7 @@
     font-weight: 400;
     padding-top: 0.25rem;
     padding-bottom: 0.25rem;
-    line-height: 1.25rem;
+    line-height: calc(1.25rem * var(--ui-font-scale, 1));
   }
 
   .hub-page .field-trigger.field-filter:hover {
@@ -1290,7 +1290,7 @@
     border-radius: 9999px;
     border: 1px solid color-mix(in srgb, var(--foreground) 8%, transparent);
     background-color: color-mix(in srgb, var(--foreground) 2.5%, transparent);
-    font-size: 12px;
+    font-size: calc(0.75rem * var(--ui-font-scale, 1));
     line-height: 1;
     color: var(--muted-foreground);
     white-space: nowrap;
@@ -1478,7 +1478,7 @@
 
 @layer utilities {
   .hub-chip {
-    @apply inline-flex items-center gap-1 rounded-full px-2 py-[3px] text-[11px] font-medium leading-none;
+    @apply inline-flex items-center gap-1 rounded-full px-2 py-[3px] text-ui-11 font-medium leading-none;
     background-color: color-mix(in srgb, var(--foreground) 5%, transparent);
     color: var(--muted-foreground);
   }
@@ -1488,7 +1488,7 @@
   }
 
   .hub-meta-tag {
-    @apply inline-flex h-[18px] shrink-0 items-center gap-1 rounded-full px-2 text-[11px] font-medium leading-none;
+    @apply inline-flex h-[18px] shrink-0 items-center gap-1 rounded-full px-2 text-ui-11 font-medium leading-none;
     background-color: color-mix(in srgb, var(--foreground) 5%, transparent);
     color: var(--muted-foreground);
   }
diff --git a/studio/frontend/src/features/hub/index.ts b/studio/frontend/src/features/hub/index.ts
index 3515f6ca76..7d9e5b74aa 100644
--- a/studio/frontend/src/features/hub/index.ts
+++ b/studio/frontend/src/features/hub/index.ts
@@ -1,9 +1,58 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-export { cancelStagedModelDownload } from "./download-manager";
+export {
+  DownloadProgressBar,
+  downloadManager,
+  jobKeyOf,
+  subscribeJobListeners,
+  useDownloadManagerStore,
+} from "./download-manager";
+export {
+  useHubInventory,
+  type CachedInventoryRow,
+  type GgufVariantDetail,
+  type LocalInventoryRow,
+  type LocalSource,
+  type ScanFolderInfo,
+  addScanFolder,
+  deleteCachedModel,
+  invalidateGgufVariantsCache,
+  listGgufVariants,
+  listScanFolders,
+  removeScanFolder,
+} from "./inventory";
+export {
+  type HfModelResult,
+  type HfSortKey,
+  useHubModelSearch,
+} from "./hooks/use-hub-model-search";
+export { useOnlineStatus } from "./hooks/use-online-status";
+export { useHubInfiniteScroll } from "./hooks/use-hub-infinite-scroll";
+export { bumpInventoryVersion } from "./stores/inventory-events";
 export {
   getHfToken,
+  hfApiToken,
   mirrorHfTokenInto,
   useHfTokenStore,
 } from "./stores/hf-token-store";
+export { useInventoryVersion } from "./stores/inventory-events";
+export { looksLikeLocalPath } from "./lib/local-path";
+export { hubTokenHeader } from "./lib/hub-token-header";
+export {
+  ggufVariantsMatch,
+  normalizeGgufVariantIdentity,
+  normalizeModelIdentity,
+} from "./lib/model-identity";
+export { formatBytes, formatRelativeShort } from "./lib/format";
+export { ggufVariantDisplayLabel } from "./lib/gguf-variant-sort";
+export {
+  DeleteConfirmDialog,
+  UpdateConfirmDialog,
+} from "./catalog/download-card";
+export { HubOptionMenu, type HubOption } from "./catalog/hub-option-menu";
+export { DotTag } from "./catalog/dot-tag";
+export { TransportConflictDialog } from "./catalog/transport-conflict-dialog";
+export { TrainIcon } from "./components/train-icon";
+export { isHiddenModelId } from "./lib/hidden-models";
+export { classifyUnslothSupport } from "./lib/unsloth-support";
diff --git a/studio/frontend/src/features/hub/inventory/api.ts b/studio/frontend/src/features/hub/inventory/api.ts
index 0e01c5c0cb..d3a1abb540 100644
--- a/studio/frontend/src/features/hub/inventory/api.ts
+++ b/studio/frontend/src/features/hub/inventory/api.ts
@@ -48,6 +48,7 @@ export interface CachedGgufRepo {
   capabilities?: BackendModelCapabilities | null;
   size_bytes: number;
   cache_path?: string;
+  last_modified?: number | null;
   partial?: boolean;
   partial_transport?: string | null;
   pipeline_tag?: string | null;
@@ -65,6 +66,7 @@ export interface CachedModelRepo {
   capabilities?: BackendModelCapabilities | null;
   size_bytes: number;
   cache_path?: string;
+  last_modified?: number | null;
   partial?: boolean;
   partial_transport?: string | null;
   pipeline_tag?: string | null;
@@ -86,6 +88,7 @@ export interface LocalModelInfo {
   capabilities?: BackendModelCapabilities | null;
   source: LocalSource;
   model_id?: string | null;
+  active_cache?: boolean | null;
   base_model?: string | null;
   base_model_source?: BaseModelSource | null;
   adapter_type?: string | null;
@@ -256,11 +259,18 @@ export async function listCachedDatasets(): Promise<CachedDatasetRepo[]> {
   return data.cached;
 }
 
-export async function deleteCachedDataset(repoId: string): Promise<void> {
+export async function deleteCachedDataset(
+  repoId: string,
+  cachePath?: string | null,
+): Promise<void> {
+  const payload: Record<string, string> = { repo_id: repoId };
+  if (cachePath) {
+    payload.cache_path = cachePath;
+  }
   const response = await authFetch("/api/hub/datasets/cached", {
     method: "DELETE",
     headers: { "Content-Type": "application/json" },
-    body: JSON.stringify({ repo_id: repoId }),
+    body: JSON.stringify(payload),
   });
   await throwIfNotOk(response, `Failed to delete dataset (${response.status})`);
   bumpInventoryVersion();
@@ -270,11 +280,17 @@ export async function deleteCachedModel(
   repoId: string,
   variant?: string,
   hfToken?: string | null,
+  cachePath?: string | null,
 ): Promise<void> {
   const payload: Record<string, string> = { repo_id: repoId };
   if (variant) {
     payload.variant = variant;
   }
+  // Scope the delete to the exact cache this row represents so copies in other,
+  // previously selected caches are not removed.
+  if (cachePath) {
+    payload.cache_path = cachePath;
+  }
   const response = await authFetch("/api/hub/delete-cached", {
     method: "DELETE",
     headers: { "Content-Type": "application/json", ...hubTokenHeader(hfToken) },
diff --git a/studio/frontend/src/features/hub/inventory/inventory-hints.ts b/studio/frontend/src/features/hub/inventory/inventory-hints.ts
index af9f254ab3..5e202e3150 100644
--- a/studio/frontend/src/features/hub/inventory/inventory-hints.ts
+++ b/studio/frontend/src/features/hub/inventory/inventory-hints.ts
@@ -12,6 +12,7 @@ export type InventoryHintRow = {
   repo_id: string;
   size_bytes: number;
   partial?: boolean;
+  optimistic?: boolean;
 };
 
 export type InventoryHintReconciliation = {
@@ -41,6 +42,7 @@ function optimisticRow(hint: InventoryHint): InventoryHintRow {
     repo_id: hint.repoId,
     size_bytes: hint.bytes ?? 0,
     partial: false,
+    optimistic: true,
   };
 }
 
@@ -101,9 +103,14 @@ function mergeInventoryHint(
   if (idx === -1) {
     return [...rows, seed];
   }
+  const serverRow = rows[idx];
   const merged = {
-    ...rows[idx],
-    ...seed,
+    ...serverRow,
+    // A completed hint may arrive before a partial server scan catches up. In
+    // that case keep the synthetic row non-runnable. A complete server row is
+    // already authoritative even when its runnable-weight size is smaller than
+    // the hint's full-snapshot byte count, so do not mark that merge optimistic.
+    ...(serverRow.partial ? seed : { optimistic: false }),
     size_bytes: Math.max(rowSizeBytes(rows[idx]), rowSizeBytes(seed)),
   };
   return [...rows.slice(0, idx), merged, ...rows.slice(idx + 1)];
diff --git a/studio/frontend/src/features/hub/inventory/types.ts b/studio/frontend/src/features/hub/inventory/types.ts
index c86ffb1d86..d1f2f993cd 100644
--- a/studio/frontend/src/features/hub/inventory/types.ts
+++ b/studio/frontend/src/features/hub/inventory/types.ts
@@ -47,6 +47,7 @@ export interface CachedInventoryRow {
   capabilities: ModelInventoryCapabilities;
   bytes: number;
   cachePath?: string | null;
+  lastModified?: number | null;
   partial?: boolean;
   partialTransport?: string | null;
   pipelineTag?: string | null;
@@ -54,6 +55,7 @@ export interface CachedInventoryRow {
   libraryName?: string | null;
   quantMethod?: string | null;
   liveDownload?: boolean;
+  optimistic?: boolean;
 }
 
 export interface LocalInventoryRow {
@@ -65,6 +67,8 @@ export interface LocalInventoryRow {
   title: string;
   source: LocalSource;
   sourceLabel: string;
+  modelId?: string | null;
+  displayName?: string;
   path: string;
   isGguf: boolean;
   modelFormat: ModelInventoryFormat;
@@ -79,6 +83,7 @@ export interface LocalInventoryRow {
   updatedAt: number | null;
   partial?: boolean;
   partialTransport?: string | null;
+  activeCache?: boolean | null;
   pipelineTag?: string | null;
   tags?: string[];
   libraryName?: string | null;
diff --git a/studio/frontend/src/features/hub/inventory/use-device-inventory.ts b/studio/frontend/src/features/hub/inventory/use-device-inventory.ts
index 00eaa31a22..5ff57dfff4 100644
--- a/studio/frontend/src/features/hub/inventory/use-device-inventory.ts
+++ b/studio/frontend/src/features/hub/inventory/use-device-inventory.ts
@@ -14,6 +14,7 @@ import {
   listLocalModels,
 } from "./api";
 import { useDebouncedValue } from "@/hooks/use-debounced-value";
+import { ensureHiddenModelMatchers } from "../lib/hidden-models";
 import { fingerprintToken } from "@/features/hub/lib/token-fingerprint";
 import { useInventoryVersion } from "@/features/hub/stores/inventory-events";
 import { useCallback, useEffect, useMemo } from "react";
@@ -146,12 +147,15 @@ async function runSourceFetch<K extends DeviceInventorySource>(
 ): Promise<DeviceInventoryRows[K]> {
   switch (source) {
     case "cachedGguf":
+      await ensureHiddenModelMatchers();
       return (await listCachedGguf(hfToken)) as DeviceInventoryRows[K];
     case "cachedModels":
+      await ensureHiddenModelMatchers();
       return (await listCachedModels(hfToken)) as DeviceInventoryRows[K];
     case "cachedDatasets":
       return (await listCachedDatasets()) as DeviceInventoryRows[K];
     case "localModels":
+      await ensureHiddenModelMatchers();
       return (await listLocalModels()).models as DeviceInventoryRows[K];
     case "localDatasets":
       return (await listLocalDatasets()).datasets as DeviceInventoryRows[K];
diff --git a/studio/frontend/src/features/hub/inventory/use-hub-inventory.ts b/studio/frontend/src/features/hub/inventory/use-hub-inventory.ts
index a7dc7ae3f3..fea7b3d331 100644
--- a/studio/frontend/src/features/hub/inventory/use-hub-inventory.ts
+++ b/studio/frontend/src/features/hub/inventory/use-hub-inventory.ts
@@ -204,6 +204,7 @@ function liveDownloadInventoryRows(
           size_bytes: job.displayBytes,
           partial: true,
           partial_transport: null,
+          optimistic: true,
         },
         modelFormat,
       ),
diff --git a/studio/frontend/src/features/hub/inventory/view-models.ts b/studio/frontend/src/features/hub/inventory/view-models.ts
index 63d70418be..41b4733d19 100644
--- a/studio/frontend/src/features/hub/inventory/view-models.ts
+++ b/studio/frontend/src/features/hub/inventory/view-models.ts
@@ -176,6 +176,8 @@ export function buildCachedInventoryRow(
     runtime?: string | null;
     format_variant?: string | null;
     capabilities?: BackendModelCapabilities | null;
+    last_modified?: number | null;
+    optimistic?: boolean;
   },
   fallbackFormat: ModelInventoryFormat,
 ): CachedInventoryRow {
@@ -185,6 +187,15 @@ export function buildCachedInventoryRow(
   const inferredFromEndpoint =
     rawModelFormat === "unknown" && modelFormat !== "unknown";
   const requiresVariant = modelFormat === "gguf";
+  const capabilities = normalizeCapabilities(
+    inferredFromEndpoint ? null : row.capabilities,
+    modelFormat,
+    row.partial ?? false,
+    requiresVariant,
+  );
+  if (row.optimistic) {
+    capabilities.canChat = false;
+  }
   return {
     kind: "cache",
     id:
@@ -202,20 +213,22 @@ export function buildCachedInventoryRow(
       modelFormat,
     ),
     formatVariant: row.format_variant ?? null,
-    capabilities: normalizeCapabilities(
-      inferredFromEndpoint ? null : row.capabilities,
-      modelFormat,
-      row.partial ?? false,
-      requiresVariant,
-    ),
+    capabilities,
     bytes: row.size_bytes,
     cachePath: row.cache_path ?? null,
+    lastModified:
+      typeof row.last_modified === "number" &&
+      Number.isFinite(row.last_modified) &&
+      row.last_modified > 0
+        ? row.last_modified
+        : null,
     partial: row.partial ?? false,
     partialTransport: row.partial_transport ?? null,
     pipelineTag: row.pipeline_tag ?? null,
     tags: row.tags,
     libraryName: row.library_name ?? null,
     quantMethod: row.quant_method ?? null,
+    optimistic: row.optimistic,
   };
 }
 
@@ -272,6 +285,8 @@ export function buildLocalInventoryRows(
         title,
         source: model.source,
         sourceLabel: localSourceLabel(model.source),
+        modelId: model.model_id ?? null,
+        displayName: model.display_name,
         path: model.path,
         isGguf: modelFormat === "gguf",
         modelFormat,
@@ -286,6 +301,7 @@ export function buildLocalInventoryRows(
         updatedAt: normalizeTimestamp(model.updated_at),
         partial: model.partial ?? false,
         partialTransport: model.partial_transport ?? null,
+        activeCache: model.active_cache ?? null,
         pipelineTag: model.pipeline_tag ?? null,
         tags: model.tags,
         libraryName: model.library_name ?? null,
diff --git a/studio/frontend/src/features/hub/lib/hidden-models.ts b/studio/frontend/src/features/hub/lib/hidden-models.ts
index 2dbe257947..c5c72aea65 100644
--- a/studio/frontend/src/features/hub/lib/hidden-models.ts
+++ b/studio/frontend/src/features/hub/lib/hidden-models.ts
@@ -1,24 +1,125 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-// Infra models hidden from every browse/preview list (Hub discover and the chat
-// model selector). Mirrors the backend `_is_hidden_model`: the RAG embedding
-// model and the llama.cpp validation probe are not usable chat models. Per-repo
-// file/download views are NOT filtered, so a reinstall still shows the model as
-// already downloaded.
+import { authFetch } from "@/features/auth";
+import { getInventoryVersion } from "../stores/inventory-events";
+
+// Infra models hidden from browse/preview lists (Hub Discover, the chat model
+// selector, and local on-device rows). Mirrors the backend
+// `utils.hidden_models`: the RAG embedding model, STT dictation models, and the
+// llama.cpp validation probe are not usable chat models. Server-confirmed cache
+// rows are trusted because the backend applies variant-aware filtering.
+// Optimistic cache rows still use these needles until the server confirms them.
+// The dynamic matchers fetched from `/api/hub/hidden-models` add the user's
+// configured embedder as exact repo ids and exact resolved paths, never
+// substring needles. Per-repo views are not filtered, so reinstall flows still
+// show downloaded files.
 const HIDDEN_NEEDLES = [
   "bge-small-en-v1.5", // RAG embedder: unsloth/bge-small-en-v1.5[-GGUF]
   "ggml-org/models", // llama.cpp validation probe repo
   "stories260k.gguf", // probe filename (carries .gguf so it stays specific)
 ];
+const HIDDEN_STT_REPOS = new Set([
+  // Transformers safetensors repos and their whisper.cpp GGUF companions
+  // (unslothai/whisper-*-GGUF): STT-only, never chat models.
+  "unsloth/whisper-tiny",
+  "unsloth/whisper-base",
+  "unsloth/whisper-small",
+  "unsloth/whisper-large-v3-turbo",
+  "unsloth/whisper-large-v3",
+  "unslothai/whisper-tiny-gguf",
+  "unslothai/whisper-base-gguf",
+  "unslothai/whisper-small-gguf",
+  "unslothai/whisper-large-v3-turbo-gguf",
+  "unslothai/whisper-large-v3-gguf",
+]);
+const HIDDEN_STT_CACHE_NAMES = [...HIDDEN_STT_REPOS].map((repo) =>
+  repo.replace("/", "--"),
+);
+
+let dynamicNeedles: readonly string[] = [];
+let dynamicExactIds: readonly string[] = [];
+let dynamicExactPaths: readonly string[] = [];
+let matchersFetch: Promise<void> | null = null;
+let matchersFetchVersion = -1;
+
+function toLowerStrings(value: unknown): string[] {
+  if (!Array.isArray(value)) {
+    return [];
+  }
+  return value
+    .filter((v): v is string => typeof v === "string" && v.length > 0)
+    .map((v) => v.toLowerCase());
+}
+
+export function ensureHiddenModelMatchers(): Promise<void> {
+  const version = getInventoryVersion();
+  if (matchersFetch && matchersFetchVersion === version) {
+    return matchersFetch;
+  }
+  matchersFetchVersion = version;
+  matchersFetch = (async () => {
+    try {
+      const response = await authFetch("/api/hub/hidden-models");
+      if (!response.ok) {
+        throw new Error(`HTTP ${response.status}`);
+      }
+      const data = (await response.json()) as {
+        needles?: unknown;
+        exact_ids?: unknown;
+        exact_paths?: unknown;
+      };
+      if (
+        getInventoryVersion() !== version ||
+        matchersFetchVersion !== version
+      ) {
+        return;
+      }
+      dynamicNeedles = toLowerStrings(data.needles);
+      dynamicExactIds = toLowerStrings(data.exact_ids);
+      dynamicExactPaths = toLowerStrings(data.exact_paths);
+    } catch {
+      if (
+        getInventoryVersion() === version &&
+        matchersFetchVersion === version
+      ) {
+        matchersFetch = null;
+      }
+    }
+  })();
+  return matchersFetch;
+}
 
 /** True if any id/path is a hidden infra model. */
 export function isHiddenModelId(
   ...values: (string | null | undefined)[]
 ): boolean {
   return values.some((v) => {
-    if (!v) return false;
+    if (!v) {
+      return false;
+    }
     const lower = v.toLowerCase();
-    return HIDDEN_NEEDLES.some((needle) => lower.includes(needle));
+    const normalized = lower.trim().replace(/^\/+|\/+$/g, "");
+    const pathParts = lower.split(/[\\/]/);
+    return (
+      HIDDEN_STT_REPOS.has(normalized) ||
+      HIDDEN_STT_CACHE_NAMES.some((name) =>
+        pathParts.includes(`models--${name}`),
+      ) ||
+      HIDDEN_NEEDLES.some((needle) => lower.includes(needle)) ||
+      dynamicNeedles.some((needle) => lower.includes(needle)) ||
+      dynamicExactIds.includes(lower) ||
+      dynamicExactPaths.includes(lower)
+    );
   });
 }
+
+/** Exact-match configured infra repos without hiding similarly named models. */
+export function isConfiguredHiddenModelId(
+  configuredIds: ReadonlySet<string>,
+  ...values: (string | null | undefined)[]
+): boolean {
+  return values.some(
+    (value) => value != null && configuredIds.has(value.trim().toLowerCase()),
+  );
+}
diff --git a/studio/frontend/src/features/hub/lib/model-capabilities.ts b/studio/frontend/src/features/hub/lib/model-capabilities.ts
index 033a3b6f1f..1baa3fb8e0 100644
--- a/studio/frontend/src/features/hub/lib/model-capabilities.ts
+++ b/studio/frontend/src/features/hub/lib/model-capabilities.ts
@@ -10,6 +10,7 @@ export type CapabilityKey =
   | "reasoning"
   | "code"
   | "embedding"
+  | "diffusion"
   | "multilingual"
   | "conversational";
 
@@ -62,6 +63,20 @@ const REASONING_TAGS = new Set([
   "step-by-step",
 ]);
 
+// Image generation / diffusion (surfaced as "Image generation" in filters).
+const DIFFUSION_TAGS = new Set([
+  "diffusers",
+  "diffusion",
+  "stable-diffusion",
+  "latent-diffusion",
+  "flux",
+  "text-to-image",
+  "image-to-image",
+  "text-to-video",
+  "image-to-video",
+  "unconditional-image-generation",
+]);
+
 const CODE_TAGS = new Set([
   "code",
   "code-generation",
@@ -186,10 +201,7 @@ export function detectCapabilities(
   ) {
     out.push({ key: "code", label: "Code" });
   }
-  if (
-    hasAny(CONVERSATIONAL_TAGS) ||
-    CONVERSATIONAL_ID_RE.test(lowerId)
-  ) {
+  if (hasAny(CONVERSATIONAL_TAGS) || CONVERSATIONAL_ID_RE.test(lowerId)) {
     out.push({ key: "conversational", label: "Conversational" });
   }
   if (
@@ -200,6 +212,14 @@ export function detectCapabilities(
   ) {
     out.push({ key: "embedding", label: "Embeddings" });
   }
+  if (
+    hasAny(DIFFUSION_TAGS) ||
+    /stable[-_]?diffusion|\bsdxl\b|\bflux\b|qwen[-_]?image|hunyuan[-_]?(?:video|image)|wan2|latent[-_]?consistency|[-_]lcm\b|dreamshaper/.test(
+      lowerId,
+    )
+  ) {
+    out.push({ key: "diffusion", label: "Image generation" });
+  }
   const languageCodes = new Set<string>();
   for (const tag of tags ?? []) {
     const lower = tag.toLowerCase();
diff --git a/studio/frontend/src/features/hub/lib/model-type-filter.ts b/studio/frontend/src/features/hub/lib/model-type-filter.ts
new file mode 100644
index 0000000000..2a2e31437e
--- /dev/null
+++ b/studio/frontend/src/features/hub/lib/model-type-filter.ts
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+// Type filter for the On Device list. Mirrors the hub Discover capability
+// options and shares its detection, so both dropdowns behave the same.
+
+import type {
+  CachedInventoryRow,
+  LocalInventoryRow,
+} from "@/features/hub/inventory/types";
+import { type CapabilityKey, detectCapabilities } from "./model-capabilities";
+
+export type ModelTypeFilter =
+  | "all"
+  | "reasoning"
+  | "vision"
+  | "audio"
+  | "embedding"
+  | "diffusion";
+
+export const MODEL_TYPE_FILTER_OPTIONS: ReadonlyArray<{
+  value: ModelTypeFilter;
+  label: string;
+}> = [
+  { value: "all", label: "All types" },
+  { value: "reasoning", label: "Reasoning" },
+  { value: "vision", label: "Vision" },
+  { value: "audio", label: "Audio" },
+  { value: "embedding", label: "Embeddings" },
+  { value: "diffusion", label: "Image generation" },
+];
+
+function rowName(row: CachedInventoryRow | LocalInventoryRow): string {
+  return row.kind === "local"
+    ? `${row.id} ${row.repoId ?? ""} ${row.title} ${row.modelId ?? ""}`
+    : `${row.id} ${row.repoId}`;
+}
+
+export function matchesModelType(
+  row: CachedInventoryRow | LocalInventoryRow,
+  filter: ModelTypeFilter,
+): boolean {
+  if (filter === "all") return true;
+  // Honor the row's own vision flag before falling back to tag detection.
+  if (filter === "vision" && row.capabilities.supportsVision) return true;
+  const caps = detectCapabilities(
+    row.tags ?? undefined,
+    row.pipelineTag ?? undefined,
+    rowName(row),
+  );
+  return caps.some((cap: { key: CapabilityKey }) => cap.key === filter);
+}
diff --git a/studio/frontend/src/features/hub/lib/view-models.ts b/studio/frontend/src/features/hub/lib/view-models.ts
index 9ee6c5de5d..d4efdb6a65 100644
--- a/studio/frontend/src/features/hub/lib/view-models.ts
+++ b/studio/frontend/src/features/hub/lib/view-models.ts
@@ -7,18 +7,18 @@ import type {
   CachedInventoryRow,
   LocalInventoryRow,
 } from "@/features/hub/inventory/types";
+import { ownerOf, repoOf } from "@/features/hub/lib/format";
 import type {
   CapabilityFilter,
   DiscoverRow,
   ModelFormatFilter,
 } from "../types";
+import { estimateSizeFromDtypes, isGgufLike } from "./hf-model-meta";
 import {
+  type CapabilityKey,
   detectBaseModel,
   detectCapabilities,
-  type CapabilityKey,
 } from "./model-capabilities";
-import { ownerOf, repoOf } from "@/features/hub/lib/format";
-import { estimateSizeFromDtypes, isGgufLike } from "./hf-model-meta";
 export {
   detectResultFormat,
   isUnslothFinetunable,
@@ -39,6 +39,7 @@ export const CAPABILITY_FILTER_OPTIONS: ReadonlyArray<{
   { value: "vision", label: "Vision" },
   { value: "audio", label: "Audio" },
   { value: "embedding", label: "Embeddings" },
+  { value: "diffusion", label: "Image generation" },
 ];
 
 export const FORMAT_FILTER_OPTIONS: ReadonlyArray<{
diff --git a/studio/frontend/src/features/model-picker/api/model-metadata.ts b/studio/frontend/src/features/model-picker/api/model-metadata.ts
new file mode 100644
index 0000000000..098ab51271
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/api/model-metadata.ts
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { getModelConfig } from "@/features/training";
+
+export async function fetchModelMaxPositionEmbeddings(
+  modelName: string,
+  hfToken?: string | null,
+  signal?: AbortSignal,
+): Promise<number | null> {
+  const config = await getModelConfig(
+    modelName,
+    signal,
+    hfToken?.trim() || undefined,
+  );
+  const value = config.max_position_embeddings;
+  return typeof value === "number" && Number.isFinite(value) && value > 0
+    ? Math.floor(value)
+    : null;
+}
diff --git a/studio/frontend/src/features/model-picker/api/templates.ts b/studio/frontend/src/features/model-picker/api/templates.ts
new file mode 100644
index 0000000000..29f18cce29
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/api/templates.ts
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { authFetch } from "@/features/auth";
+import { hubTokenHeader } from "@/features/hub";
+import { consumeNativePathToken } from "@/features/native-intents/api";
+import { readFastApiError } from "@/lib/format-fastapi-error";
+
+export interface ValidateChatTemplateResult {
+  valid: boolean;
+  error: string | null;
+}
+
+async function parseJsonOrThrow<T>(response: Response): Promise<T> {
+  if (!response.ok) {
+    throw new Error(await readFastApiError(response));
+  }
+  return response.json();
+}
+
+export async function validateChatTemplate(
+  template: string,
+  signal?: AbortSignal,
+): Promise<ValidateChatTemplateResult> {
+  const response = await authFetch("/api/picker/validate-chat-template", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify({ template }),
+    signal,
+  });
+  return parseJsonOrThrow<ValidateChatTemplateResult>(response);
+}
+
+export async function fetchDefaultChatTemplate(
+  modelName: string,
+  ggufVariant?: string | null,
+  hfToken?: string | null,
+  signal?: AbortSignal,
+  nativePathToken?: string | null,
+): Promise<string | null> {
+  // A native (picked / drag-drop) GGUF lives at a path only its signed lease
+  // knows, and the picker chat-template GET has no lease plumbing, so redeem a
+  // one-shot validate-model lease and read the embedded template through the
+  // lease-aware /api/inference/validate probe instead (mirrors the staged
+  // header-dims fetch). Non-native models keep the plain GET path.
+  if (nativePathToken) {
+    let nativePathLease: string | null = null;
+    try {
+      nativePathLease = (
+        await consumeNativePathToken(nativePathToken, "validate-model")
+      ).nativePathLease;
+    } catch {
+      // Lease expired / revoked: no readable path, so no default template (the
+      // subsequent load re-mints its own lease).
+      return null;
+    }
+    const response = await authFetch("/api/inference/validate", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({
+        model_path: modelName,
+        gguf_variant: ggufVariant ?? null,
+        hf_token: hfToken ?? null,
+        native_path_lease: nativePathLease,
+        include_chat_template: true,
+      }),
+      signal,
+    });
+    const data = await parseJsonOrThrow<{ chat_template?: string | null }>(
+      response,
+    );
+    return data.chat_template ?? null;
+  }
+
+  const query = ggufVariant
+    ? `?gguf_variant=${encodeURIComponent(ggufVariant)}`
+    : "";
+  const response = await authFetch(
+    `/api/picker/chat-template/${encodeURIComponent(modelName)}${query}`,
+    { headers: hubTokenHeader(hfToken), signal },
+  );
+  const data = await parseJsonOrThrow<{
+    model_name: string;
+    chat_template: string | null;
+  }>(response);
+  return data.chat_template ?? null;
+}
diff --git a/studio/frontend/src/features/model-picker/components/chat-template-editor-dialog.tsx b/studio/frontend/src/features/model-picker/components/chat-template-editor-dialog.tsx
new file mode 100644
index 0000000000..5326bebac6
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/components/chat-template-editor-dialog.tsx
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { Button } from "@/components/ui/button";
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from "@/components/ui/dialog";
+import { Spinner } from "@/components/ui/spinner";
+import { Textarea } from "@/components/ui/textarea";
+import { useRef, useState } from "react";
+import { validateChatTemplate } from "../api/templates";
+import {
+  MAX_CHAT_TEMPLATE_BYTES,
+  chatTemplateByteLength,
+  isChatTemplateWithinLimit,
+} from "../model-config/per-model-config";
+
+interface ChatTemplateEditorDialogProps {
+  open: boolean;
+  onOpenChange: (open: boolean) => void;
+  value: string | null;
+  defaultTemplate: string | null;
+  defaultLoading: boolean;
+  onSave: (override: string | null) => void;
+  readOnly?: boolean;
+}
+
+export function ChatTemplateEditorDialog({
+  open,
+  onOpenChange,
+  value,
+  defaultTemplate,
+  defaultLoading,
+  onSave,
+  readOnly = false,
+}: ChatTemplateEditorDialogProps) {
+  const [draft, setDraft] = useState<string | null>(null);
+  const [error, setError] = useState<string | null>(null);
+  const [validating, setValidating] = useState(false);
+  // Bumped whenever the dialog closes so a validation still in flight cannot
+  // apply a template the user has already dismissed.
+  const validationToken = useRef(0);
+  const renderedDraft = draft ?? value ?? defaultTemplate ?? "";
+
+  const byteLength = chatTemplateByteLength(renderedDraft);
+  const overLimit = !isChatTemplateWithinLimit(renderedDraft);
+  const matchesDefault =
+    defaultTemplate != null && renderedDraft === defaultTemplate;
+
+  const handleClose = () => {
+    validationToken.current += 1;
+    setDraft(null);
+    setError(null);
+    setValidating(false);
+    onOpenChange(false);
+  };
+
+  const handleSave = async () => {
+    if (renderedDraft.trim().length === 0 || matchesDefault) {
+      onSave(null);
+      handleClose();
+      return;
+    }
+    if (overLimit) {
+      setError("Template exceeds the size limit.");
+      return;
+    }
+    setValidating(true);
+    const token = validationToken.current;
+    try {
+      const result = await validateChatTemplate(renderedDraft);
+      // Dialog was closed (or reopened) while validating; drop the result so a
+      // discarded template is never applied.
+      if (token !== validationToken.current) {
+        return;
+      }
+      if (!result.valid) {
+        setError(result.error ?? "Invalid Jinja template.");
+        return;
+      }
+      onSave(renderedDraft);
+      handleClose();
+    } catch {
+      if (token === validationToken.current) {
+        setError("Could not validate the template.");
+      }
+    } finally {
+      if (token === validationToken.current) {
+        setValidating(false);
+      }
+    }
+  };
+
+  return (
+    <Dialog
+      open={open}
+      onOpenChange={(nextOpen) => {
+        if (nextOpen) {
+          onOpenChange(true);
+          return;
+        }
+        handleClose();
+      }}
+    >
+      <DialogContent className="corner-squircle dialog-soft-surface sm:max-w-3xl">
+        <DialogHeader>
+          <DialogTitle>
+            {readOnly ? "Chat Template" : "Edit Chat Template"}
+          </DialogTitle>
+          <DialogDescription>
+            {readOnly
+              ? "This is the model's chat template. Custom templates apply to GGUF models for now, so it is view only for safetensors models."
+              : "Override the model's chat template with custom Jinja. The change applies when the model loads. Saving an empty template or one that matches the default clears the override."}
+          </DialogDescription>
+        </DialogHeader>
+        <Textarea
+          value={renderedDraft}
+          onChange={(event) => {
+            if (readOnly) return;
+            setDraft(event.target.value);
+            setError(null);
+          }}
+          readOnly={readOnly}
+          className="min-h-[20rem] max-h-[50vh] overflow-y-auto border-0 font-mono text-xs leading-5 corner-squircle focus-visible:ring-0"
+          rows={14}
+          spellCheck={false}
+          placeholder={defaultLoading ? "Loading model default..." : ""}
+        />
+        {readOnly ? null : (
+          <div className="flex items-center justify-between gap-3 px-0.5 text-ui-11">
+            <span
+              className={overLimit ? "text-amber-500" : "text-muted-foreground"}
+            >
+              {byteLength.toLocaleString()} /{" "}
+              {MAX_CHAT_TEMPLATE_BYTES.toLocaleString()} bytes
+            </span>
+            {error ? (
+              <span className="truncate text-red-500" title={error}>
+                {error}
+              </span>
+            ) : null}
+          </div>
+        )}
+        <DialogFooter className="flex-wrap gap-2 sm:justify-between">
+          {readOnly ? (
+            <div className="flex w-full justify-end">
+              <Button type="button" onClick={handleClose}>
+                Close
+              </Button>
+            </div>
+          ) : (
+            <>
+              <Button
+                type="button"
+                variant="ghost"
+                onClick={() => setDraft(defaultTemplate ?? "")}
+                disabled={
+                  defaultLoading || renderedDraft === (defaultTemplate ?? "")
+                }
+                className="text-muted-foreground"
+              >
+                {defaultLoading ? (
+                  <Spinner className="size-3.5" />
+                ) : (
+                  "Reset to default"
+                )}
+              </Button>
+              <div className="flex gap-2">
+                <Button type="button" variant="ghost" onClick={handleClose}>
+                  Cancel
+                </Button>
+                <Button
+                  type="button"
+                  onClick={handleSave}
+                  disabled={validating || overLimit}
+                >
+                  {validating ? "Validating..." : "Save"}
+                </Button>
+              </div>
+            </>
+          )}
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  );
+}
diff --git a/studio/frontend/src/features/model-picker/components/model-config-page.tsx b/studio/frontend/src/features/model-picker/components/model-config-page.tsx
new file mode 100644
index 0000000000..afbd33af7c
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/components/model-config-page.tsx
@@ -0,0 +1,992 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { Button } from "@/components/ui/button";
+import { Checkbox } from "@/components/ui/checkbox";
+import { InfoHint } from "@/components/ui/info-hint";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
+import { Slider } from "@/components/ui/slider";
+import { Switch } from "@/components/ui/switch";
+import {
+  GPU_LAYERS_AUTO,
+  fetchGgufStagedMetadata,
+  readPersistedSpeculativeType,
+  useChatRuntimeStore,
+} from "@/features/chat";
+import { useGpuDevices } from "@/hooks/use-gpu-info";
+import { ChevronDownStandardIcon } from "@/lib/chevron-icons";
+import { toast } from "@/lib/toast";
+import { ArrowLeft01Icon } from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
+import { type ReactNode, useEffect, useId, useState } from "react";
+import {
+  useDefaultChatTemplate,
+  useModelMaxPositionEmbeddings,
+} from "../hooks/use-model-defaults";
+import { perModelConfigsEqual } from "../model-config/apply-per-model-config";
+import {
+  CONTEXT_LENGTH_MIN,
+  DEFAULT_MAX_SEQ_LENGTH,
+  DEFAULT_PER_MODEL_CONFIG,
+  KV_CACHE_DTYPES,
+  MAX_SEQ_LENGTH_MAX,
+  MAX_SEQ_LENGTH_MIN,
+  MAX_SEQ_LENGTH_STEP,
+  MTP_SPECULATIVE_TYPES,
+  type PerModelConfig,
+  SPECULATIVE_TYPES,
+  deletePerModelConfig,
+  floorMaxSeqLength,
+  isDefaultConfig,
+  normalizeMaxSeqLength,
+  resolveInitialConfig,
+  savePerModelConfig,
+} from "../model-config/per-model-config";
+import { ChatTemplateEditorDialog } from "./chat-template-editor-dialog";
+import type { ModelPickTarget } from "./model-selector/types";
+import { NumericValueInput } from "./numeric-value-input";
+
+const ROW_CLASS = "flex min-h-8 items-center justify-between gap-3";
+const LABEL_CLASS =
+  "min-w-0 truncate text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg";
+const LABEL_CLASS_WRAP =
+  "min-w-0 text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg";
+const CONTROL_SURFACE =
+  "rounded-full border-transparent bg-black/[0.04] dark:bg-white/[0.05] hover:bg-black/[0.06] dark:hover:bg-white/[0.1]";
+const SELECT_TRIGGER_CLASS = `grid h-8 min-w-0 grid-cols-[minmax(0,1fr)_auto] items-center gap-1 ${CONTROL_SURFACE} pl-3 pr-2 py-0 text-ui-13! font-medium text-nav-fg focus-visible:ring-0 focus-visible:border-transparent [&_[data-slot=select-value]]:min-w-0 [&_[data-slot=select-value]]:truncate [&>svg]:shrink-0`;
+const NUMBER_INPUT_CLASS = `h-8 w-[92px] ${CONTROL_SURFACE} pl-3 pr-2 py-0 text-right text-ui-13 font-medium text-nav-fg outline-none focus-visible:ring-0`;
+
+const KV_CACHE_DTYPE_DEFAULT = "f16";
+const SPECULATIVE_TYPE_LABELS: Record<(typeof SPECULATIVE_TYPES)[number], string> =
+  {
+    auto: "Auto",
+    mtp: "MTP",
+    ngram: "Ngram",
+    "mtp+ngram": "MTP+Ngram",
+    off: "Off",
+  };
+
+function hasNonDefaultAdvanced(config: PerModelConfig): boolean {
+  return (
+    config.kvCacheDtype != null ||
+    (config.speculativeType ?? "auto") !== "auto" ||
+    config.specDraftNMax != null ||
+    config.tensorParallel ||
+    config.chatTemplateOverride != null ||
+    (config.gpuMemoryMode ?? "auto") !== "auto" ||
+    (config.gpuLayers != null && config.gpuLayers >= 0) ||
+    (config.nCpuMoe ?? 0) > 0 ||
+    config.selectedGpuIds != null
+  );
+}
+
+function ChatTemplateSetting({
+  config,
+  onEditTemplate,
+  readOnly = false,
+}: {
+  config: PerModelConfig;
+  onEditTemplate: () => void;
+  readOnly?: boolean;
+}) {
+  return (
+    <div className={ROW_CLASS}>
+      <div className="flex min-w-0 items-center gap-1.5">
+        <span className={LABEL_CLASS}>Chat Template</span>
+        <InfoHint>
+          {readOnly
+            ? "Preview the model's chat template. Custom overrides apply to GGUF models for now."
+            : "Override the model's chat template with custom Jinja. Applies when the model loads."}
+        </InfoHint>
+      </div>
+      <div className="flex shrink-0 items-center gap-2">
+        {readOnly ? null : (
+          <span className="text-ui-12 text-muted-foreground">
+            {config.chatTemplateOverride ? "Custom" : "Default"}
+          </span>
+        )}
+        <Button
+          type="button"
+          size="sm"
+          variant="ghost"
+          className={`h-8 px-3 text-ui-13 ${CONTROL_SURFACE}`}
+          onClick={onEditTemplate}
+        >
+          {readOnly ? "View" : "Edit"}
+        </Button>
+      </div>
+    </div>
+  );
+}
+
+function MaxSeqLengthSetting({
+  value,
+  max,
+  inputMax,
+  onChange,
+}: {
+  value: number;
+  max: number;
+  inputMax: number;
+  onChange: (value: number) => void;
+}) {
+  return (
+    <div className="space-y-3">
+      <div className={ROW_CLASS}>
+        <div className="flex min-w-0 items-center gap-1.5">
+          <span className={LABEL_CLASS}>Max Seq Length</span>
+          <InfoHint>
+            Maximum context window size in tokens. Applies when the model loads.
+          </InfoHint>
+        </div>
+        <NumericValueInput
+          value={value}
+          min={MAX_SEQ_LENGTH_MIN}
+          max={inputMax}
+          step={MAX_SEQ_LENGTH_STEP}
+          onChange={onChange}
+          ariaLabel="Max Seq Length"
+          className={NUMBER_INPUT_CLASS}
+          size={8}
+        />
+      </div>
+      <Slider
+        min={MAX_SEQ_LENGTH_MIN}
+        max={max}
+        step={MAX_SEQ_LENGTH_STEP}
+        value={[value]}
+        onValueChange={([next]) => onChange(next)}
+        className="panel-slider"
+        aria-label="Max Seq Length"
+      />
+    </div>
+  );
+}
+
+function clampMaxSeqLength(value: number, max: number): number {
+  const normalized = normalizeMaxSeqLength(value) ?? MAX_SEQ_LENGTH_MIN;
+  return Math.max(MAX_SEQ_LENGTH_MIN, Math.min(max, normalized));
+}
+
+function AdvancedGpuSlider({
+  label,
+  value,
+  min,
+  max,
+  onChange,
+  displayValue,
+  info,
+}: {
+  label: string;
+  value: number;
+  min: number;
+  max: number;
+  onChange: (value: number) => void;
+  displayValue?: string;
+  info?: ReactNode;
+}) {
+  return (
+    <div className="space-y-3">
+      <div className={ROW_CLASS}>
+        <div className="flex min-w-0 items-center gap-1.5">
+          <span className={LABEL_CLASS}>{label}</span>
+          {info && <InfoHint>{info}</InfoHint>}
+        </div>
+        <NumericValueInput
+          value={value}
+          min={min}
+          max={max}
+          step={1}
+          onChange={onChange}
+          displayValue={displayValue}
+          ariaLabel={label}
+          className={NUMBER_INPUT_CLASS}
+          size={8}
+        />
+      </div>
+      <Slider
+        min={min}
+        max={max}
+        step={1}
+        value={[value]}
+        onValueChange={([next]) => onChange(next)}
+        className="panel-slider"
+        aria-label={label}
+      />
+    </div>
+  );
+}
+
+// GPU Memory placement controls (mode / GPU Layers / MoE offload / GPU picker),
+// GGUF only. Slider ceilings come from the GGUF header dims, the picker from the
+// live device list. --tensor-split is not persisted per model, so not exposed here.
+function GpuMemorySettings({
+  config,
+  update,
+  layerCount,
+  moeLayerCount,
+}: {
+  config: PerModelConfig;
+  update: (patch: Partial<PerModelConfig>) => void;
+  layerCount: number | null;
+  moeLayerCount: number | null;
+}) {
+  const gpuDevices = useGpuDevices();
+  const mode = config.gpuMemoryMode ?? "auto";
+  const isManual = mode === "manual";
+  const gpuLayers = config.gpuLayers ?? GPU_LAYERS_AUTO;
+  // Slider at Auto: llama.cpp --fit owns the layout, so MoE-offload doesn't apply.
+  const autoLayers = isManual && gpuLayers < 0;
+  // Ceiling = layer count + 1 (llama.cpp counts the output layer as offloadable),
+  // else a safe fallback.
+  const gpuLayersMax = layerCount != null ? layerCount + 1 : 256;
+  const nCpuMoe = config.nCpuMoe ?? 0;
+  const moeLayersMax = moeLayerCount ?? 0;
+  const showMoeSlider = isManual && !autoLayers && moeLayersMax > 0;
+  const selectedGpuIds = config.selectedGpuIds ?? null;
+  const singleGpuInUse =
+    (selectedGpuIds ?? gpuDevices.map((device) => device.index)).length <= 1;
+  // Multi-GPU only, and only with physical indices (relative ordinals from a
+  // CUDA_VISIBLE_DEVICES mask can't be mapped back to pin a device). null = all (auto).
+  const showGpuPicker =
+    gpuDevices.length > 1 && gpuDevices.every((d) => d.physicalIndex);
+  const isGpuChecked = (index: number) =>
+    selectedGpuIds === null || selectedGpuIds.includes(index);
+  const toggleGpu = (index: number) => {
+    const all = gpuDevices.map((d) => d.index);
+    const current = selectedGpuIds ?? all;
+    const next = current.includes(index)
+      ? current.filter((i) => i !== index)
+      : [...current, index].sort((a, b) => a - b);
+    if (next.length === 0) return; // keep at least one GPU selected
+    update({ selectedGpuIds: next.length === all.length ? null : next });
+  };
+  return (
+    <>
+      <div className={ROW_CLASS}>
+        <div className="flex min-w-0 items-center gap-1.5">
+          <span className={LABEL_CLASS}>GPU Memory</span>
+          <InfoHint>
+            <div className="flex flex-col gap-1.5">
+              <div>
+                <span className="font-medium">Default:</span> Unsloth fits the
+                model and context to your GPUs.
+              </div>
+              <div>
+                <span className="font-medium">Manual:</span> set GPU Layers
+                yourself. Leave it on Auto to let llama.cpp size the context and
+                offload overflow (including MoE experts) to RAM.
+              </div>
+            </div>
+          </InfoHint>
+        </div>
+        <Select
+          value={mode}
+          onValueChange={(v) =>
+            // Returning to Default must clear the Manual-only knobs, else a
+            // remembered config keeps stale gpuLayers/nCpuMoe/GPU pick that a
+            // later load re-applies while the page shows Default.
+            update(
+              v === "manual"
+                ? { gpuMemoryMode: "manual" }
+                : {
+                    gpuMemoryMode: "auto",
+                    gpuLayers: undefined,
+                    nCpuMoe: undefined,
+                    selectedGpuIds: undefined,
+                  },
+            )
+          }
+        >
+          <SelectTrigger
+            animateRadius={false}
+            icon={ChevronDownStandardIcon}
+            iconClassName="size-3.5"
+            className={`w-[124px] shrink-0 ${SELECT_TRIGGER_CLASS}`}
+          >
+            <SelectValue />
+          </SelectTrigger>
+          <SelectContent className="menu-soft-surface ring-0 border-0 rounded-lg">
+            <SelectItem value="auto">Default</SelectItem>
+            <SelectItem value="manual">Manual</SelectItem>
+          </SelectContent>
+        </Select>
+      </div>
+      {isManual && (
+        <>
+          <AdvancedGpuSlider
+            label="GPU Layers"
+            value={Math.max(GPU_LAYERS_AUTO, Math.min(gpuLayers, gpuLayersMax))}
+            min={GPU_LAYERS_AUTO}
+            max={gpuLayersMax}
+            onChange={(v) => update({ gpuLayers: v })}
+            displayValue={autoLayers ? "Auto" : undefined}
+            info={
+              <>
+                Layers to keep on the GPU (--gpu-layers); the rest run on CPU.
+                Auto lets llama.cpp size the split (and the context) to fit VRAM.
+                At the maximum, the whole model is on the GPU.
+              </>
+            }
+          />
+          {showMoeSlider && (
+            <AdvancedGpuSlider
+              label="MoE Layers on CPU"
+              value={Math.min(nCpuMoe, moeLayersMax)}
+              min={0}
+              max={moeLayersMax}
+              onChange={(v) => update({ nCpuMoe: v })}
+              info={
+                <>
+                  Keep the experts of this many MoE layers on the CPU
+                  (--n-cpu-moe) to save VRAM. 0 = all experts on the GPU; at the
+                  maximum, all are on the CPU.
+                </>
+              }
+            />
+          )}
+        </>
+      )}
+      {showGpuPicker && (
+        <div className="space-y-2">
+          <div className="flex min-w-0 items-center gap-1.5">
+            <span className={LABEL_CLASS}>GPUs</span>
+            <InfoHint>
+              Which GPUs this model may use. Unchecked GPUs are hidden from
+              llama.cpp (CUDA_VISIBLE_DEVICES, or HIP_VISIBLE_DEVICES on ROCm).
+              Leave all checked to use every GPU. At least one GPU must stay
+              selected.
+            </InfoHint>
+          </div>
+          <div className="flex flex-col gap-2">
+            {gpuDevices.map((d) => (
+              <div
+                key={d.index}
+                className="flex items-center justify-between gap-3"
+              >
+                <span className="min-w-0 truncate text-ui-12 text-nav-fg/80">
+                  GPU {d.index}: {d.name}
+                  {d.memoryTotalGb
+                    ? ` · ${Math.round(d.memoryTotalGb)} GB`
+                    : ""}
+                </span>
+                <Switch
+                  className="panel-switch shrink-0"
+                  checked={isGpuChecked(d.index)}
+                  onCheckedChange={() => toggleGpu(d.index)}
+                  disabled={isGpuChecked(d.index) && singleGpuInUse}
+                />
+              </div>
+            ))}
+          </div>
+        </div>
+      )}
+    </>
+  );
+}
+
+function GgufAdvancedSettings({
+  config,
+  update,
+  isMtp,
+  speculativeFallback,
+  onEditTemplate,
+  layerCount,
+  moeLayerCount,
+}: {
+  config: PerModelConfig;
+  update: (patch: Partial<PerModelConfig>) => void;
+  isMtp: boolean;
+  speculativeFallback: string;
+  onEditTemplate: () => void;
+  layerCount: number | null;
+  moeLayerCount: number | null;
+}) {
+  return (
+    <>
+      <div className={ROW_CLASS}>
+        <div className="flex min-w-0 items-center gap-1.5">
+          <span className={LABEL_CLASS}>KV Cache Dtype</span>
+          <InfoHint>
+            Lower KV cache precision to save VRAM at the cost of some quality.
+            f16 is the default; bf16 and f32 are full precision; q8_0 through
+            iq4_nl are quantized.
+          </InfoHint>
+        </div>
+        <Select
+          value={config.kvCacheDtype ?? KV_CACHE_DTYPE_DEFAULT}
+          onValueChange={(v) =>
+            update({ kvCacheDtype: v === KV_CACHE_DTYPE_DEFAULT ? null : v })
+          }
+        >
+          <SelectTrigger
+            animateRadius={false}
+            icon={ChevronDownStandardIcon}
+            iconClassName="size-3.5"
+            className={`w-[92px] ${SELECT_TRIGGER_CLASS}`}
+          >
+            <SelectValue />
+          </SelectTrigger>
+          <SelectContent className="menu-soft-surface ring-0 border-0 rounded-lg">
+            <SelectItem value={KV_CACHE_DTYPE_DEFAULT}>
+              {KV_CACHE_DTYPE_DEFAULT}
+            </SelectItem>
+            {KV_CACHE_DTYPES.map((dtype) => (
+              <SelectItem key={dtype} value={dtype}>
+                {dtype}
+              </SelectItem>
+            ))}
+          </SelectContent>
+        </Select>
+      </div>
+
+      <div className={ROW_CLASS}>
+        <div className="flex min-w-0 items-center gap-1.5">
+          <span className={LABEL_CLASS_WRAP}>Speculative Decoding</span>
+          <InfoHint>
+            Faster generation with no accuracy hit. Auto picks MTP / ngram based
+            on the model and platform. Pick a strategy to force it.
+          </InfoHint>
+        </div>
+        <Select
+          value={config.speculativeType ?? speculativeFallback}
+          onValueChange={(v) =>
+            update({
+              speculativeType: v,
+              specDraftNMax:
+                v === "mtp" || v === "mtp+ngram" ? config.specDraftNMax : null,
+            })
+          }
+        >
+          <SelectTrigger
+            animateRadius={false}
+            icon={ChevronDownStandardIcon}
+            iconClassName="size-3.5"
+            className={`w-[124px] shrink-0 ${SELECT_TRIGGER_CLASS}`}
+          >
+            <SelectValue />
+          </SelectTrigger>
+          <SelectContent className="menu-soft-surface ring-0 border-0 rounded-lg">
+            {SPECULATIVE_TYPES.map((type) => (
+              <SelectItem key={type} value={type}>
+                {SPECULATIVE_TYPE_LABELS[type]}
+              </SelectItem>
+            ))}
+          </SelectContent>
+        </Select>
+      </div>
+
+      {isMtp && (
+        <div className={ROW_CLASS}>
+          <div className="flex min-w-0 items-center gap-1.5">
+            <span className={LABEL_CLASS}>Draft Tokens</span>
+            <InfoHint>
+              Max MTP draft tokens per step. Leave blank for the platform
+              default (2 on GPU, 3 on CPU/Mac).
+            </InfoHint>
+          </div>
+          <input
+            type="number"
+            min={1}
+            max={16}
+            step={1}
+            value={config.specDraftNMax ?? ""}
+            placeholder="auto"
+            onChange={(event) => {
+              const raw = event.target.value;
+              if (raw === "") {
+                update({ specDraftNMax: null });
+                return;
+              }
+              const parsed = Number.parseInt(raw, 10);
+              if (Number.isFinite(parsed)) {
+                update({ specDraftNMax: Math.max(1, Math.min(16, parsed)) });
+              }
+            }}
+            aria-label="Speculative decoding draft tokens"
+            className={NUMBER_INPUT_CLASS}
+          />
+        </div>
+      )}
+
+      <div className={ROW_CLASS}>
+        <div className="flex min-w-0 items-center gap-1.5">
+          <span className={LABEL_CLASS}>Tensor Parallelism</span>
+          <InfoHint>
+            No effect on a single GPU. On multi-GPU setups, improves tokens/sec
+            for dense models. MoE models don't benefit.
+          </InfoHint>
+        </div>
+        <Switch
+          className="panel-switch shrink-0"
+          checked={config.tensorParallel}
+          onCheckedChange={(checked) => update({ tensorParallel: checked })}
+        />
+      </div>
+
+      <GpuMemorySettings
+        config={config}
+        update={update}
+        layerCount={layerCount}
+        moeLayerCount={moeLayerCount}
+      />
+
+      <ChatTemplateSetting config={config} onEditTemplate={onEditTemplate} />
+    </>
+  );
+}
+
+interface ModelConfigPageProps {
+  target: ModelPickTarget;
+  onBack?: () => void;
+  onRun: (config: PerModelConfig) => void;
+  loadedConfig?: PerModelConfig | null;
+  loadedContextLength?: number | null;
+  initialConfig?: PerModelConfig | null;
+  variant?: "page" | "sidebar";
+}
+
+export function ModelConfigPage({
+  target,
+  onBack,
+  onRun,
+  loadedConfig = null,
+  loadedContextLength = null,
+  initialConfig = null,
+  variant = "page",
+}: ModelConfigPageProps) {
+  const rememberId = useId();
+  const isActiveModel = loadedConfig != null;
+  const hfToken = useChatRuntimeStore((s) => s.hfToken);
+  const activeNativePathToken = useChatRuntimeStore(
+    (s) => s.activeNativePathToken,
+  );
+  const loadedDefaultChatTemplate = useChatRuntimeStore(
+    (s) => s.defaultChatTemplate,
+  );
+  const loadedMaxContextLength = useChatRuntimeStore(
+    (s) => s.ggufMaxContextLength,
+  );
+  const resolveInitial = () => {
+    const resolved = resolveInitialConfig(target.id, target.ggufVariant);
+    if (loadedConfig) {
+      return { config: loadedConfig, remembered: resolved.remembered };
+    }
+    if (initialConfig) {
+      return {
+        config: initialConfig,
+        remembered:
+          resolved.remembered &&
+          perModelConfigsEqual(initialConfig, resolved.config),
+      };
+    }
+    return resolved;
+  };
+  const [initial] = useState(resolveInitial);
+  const [config, setConfig] = useState<PerModelConfig>(() => initial.config);
+  const [remember, setRemember] = useState(() => initial.remembered);
+  const [savedRemember, setSavedRemember] = useState(() => initial.remembered);
+  const [speculativeFallback] = useState(readPersistedSpeculativeType);
+  const [templateOpen, setTemplateOpen] = useState(false);
+  const [showAdvanced, setShowAdvanced] = useState(() =>
+    hasNonDefaultAdvanced(config),
+  );
+  const nativePathToken =
+    target.meta.nativePathToken ??
+    (isActiveModel ? activeNativePathToken : null);
+  const templateDefaults = useDefaultChatTemplate(
+    target.id,
+    target.ggufVariant,
+    templateOpen,
+    nativePathToken,
+  );
+  const modelMaxPosition = useModelMaxPositionEmbeddings(
+    target.id,
+    !target.isGguf,
+  );
+  const hasLoadedDefaultTemplate =
+    isActiveModel && loadedDefaultChatTemplate != null;
+  const resolvedDefaultTemplate = hasLoadedDefaultTemplate
+    ? loadedDefaultChatTemplate
+    : templateDefaults.template;
+  const resolvedDefaultLoading = hasLoadedDefaultTemplate
+    ? false
+    : templateDefaults.loading;
+
+  const update = (patch: Partial<PerModelConfig>) =>
+    setConfig((current) => ({ ...current, ...patch }));
+
+  // Fetch GGUF header dims (context + layer/MoE counts) to size the GPU Memory
+  // sliders; the context also fills in below when target.meta lacks it.
+  const contextFetchKey = target.isGguf
+    ? `${target.id}\n${target.ggufVariant ?? ""}\n${hfToken || ""}\n${nativePathToken ?? ""}`
+    : null;
+  const [fetchedStagedDims, setFetchedStagedDims] = useState<{
+    key: string;
+    contextLength: number | null;
+    layerCount: number | null;
+    moeLayerCount: number | null;
+  } | null>(null);
+  useEffect(() => {
+    if (contextFetchKey == null) {
+      return;
+    }
+    let cancelled = false;
+    void fetchGgufStagedMetadata({
+      model_path: target.id,
+      gguf_variant: target.ggufVariant ?? null,
+      hf_token: hfToken || null,
+      nativePathToken,
+    })
+      .then((dims) => {
+        if (!cancelled) {
+          setFetchedStagedDims({ key: contextFetchKey, ...dims });
+        }
+      })
+      .catch(() => {
+        if (!cancelled) {
+          setFetchedStagedDims({
+            key: contextFetchKey,
+            contextLength: null,
+            layerCount: null,
+            moeLayerCount: null,
+          });
+        }
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [
+    contextFetchKey,
+    target.id,
+    target.ggufVariant,
+    hfToken,
+    nativePathToken,
+  ]);
+  const stagedDims =
+    fetchedStagedDims?.key === contextFetchKey ? fetchedStagedDims : null;
+
+  const isMtp =
+    config.speculativeType != null &&
+    MTP_SPECULATIVE_TYPES.has(config.speculativeType);
+  const nativeContextLength =
+    target.meta.contextLength ?? stagedDims?.contextLength ?? null;
+  const activeLoadedContext =
+    isActiveModel && target.isGguf ? loadedContextLength : null;
+  const minContext = CONTEXT_LENGTH_MIN;
+  const maxContext = Math.max(
+    minContext,
+    Math.max(
+      nativeContextLength ?? 0,
+      activeLoadedContext ?? 0,
+      config.customContextLength ?? 0,
+    ) || 32768,
+  );
+  const contextValue = Math.min(
+    Math.max(
+      config.customContextLength ??
+        activeLoadedContext ??
+        nativeContextLength ??
+        maxContext,
+      minContext,
+    ),
+    maxContext,
+  );
+  const setContextLength = (v: number) =>
+    update({ customContextLength: v });
+  const baseline = loadedConfig ?? DEFAULT_PER_MODEL_CONFIG;
+  const atBaseline = perModelConfigsEqual(config, baseline);
+  // An explicit customContextLength equal to the native ceiling is still an
+  // override (Reset stays enabled). "At default" means no override at all AND the
+  // shown context matches native (or no native context length is exposed).
+  const contextAtDefault =
+    !target.isGguf ||
+    (config.customContextLength == null &&
+      (nativeContextLength == null || contextValue === nativeContextLength));
+  const atDefault =
+    contextAtDefault &&
+    perModelConfigsEqual(
+      { ...config, customContextLength: null },
+      DEFAULT_PER_MODEL_CONFIG,
+    );
+  const nativeMaxSeqLength =
+    floorMaxSeqLength(modelMaxPosition.maxPositionEmbeddings) ??
+    MAX_SEQ_LENGTH_MAX;
+  // A non-GGUF active model seeds maxSeqLength from its loaded value. Once cleared
+  // (Reset sets null), fall back to the app default, not the loaded runtime value,
+  // else a remembered/active override can never be cleared.
+  const maxSeqLengthValue =
+    normalizeMaxSeqLength(config.maxSeqLength) ??
+    clampMaxSeqLength(DEFAULT_MAX_SEQ_LENGTH, nativeMaxSeqLength);
+  const maxSeqLengthMax = Math.max(nativeMaxSeqLength, maxSeqLengthValue);
+  // An auto-fit-below-native GGUF shows activeLoadedContext while
+  // customContextLength stays null. If the user fixes GPU Layers (Manual) and
+  // remembers, pin that shown context so a later fresh load keeps the fitted
+  // placement instead of sending native/0 for fixed layers and recreating the OOM.
+  const pinFixedLayerContext =
+    target.isGguf &&
+    config.gpuMemoryMode === "manual" &&
+    config.gpuLayers != null &&
+    config.gpuLayers >= 0 &&
+    config.customContextLength == null &&
+    activeLoadedContext != null;
+  // Persisted record: keep config as-is (non-GGUF keeps maxSeqLength null) so
+  // isDefaultConfig recognises it and clears a remembered override instead of
+  // pinning the app default.
+  const runtimeConfig = target.isGguf
+    ? pinFixedLayerContext
+      ? { ...config, customContextLength: activeLoadedContext }
+      : config
+    : config;
+  // Load request needs a concrete max length; substitute the fallback here only,
+  // never in the persisted runtimeConfig.
+  const loadConfig = target.isGguf
+    ? runtimeConfig
+    : { ...runtimeConfig, maxSeqLength: maxSeqLengthValue };
+  const rememberChanged = remember !== savedRemember;
+  const persistenceOnly = isActiveModel && atBaseline && rememberChanged;
+  const primaryActionLabel = persistenceOnly
+    ? remember
+      ? "Save settings"
+      : "Forget settings"
+    : isActiveModel
+      ? "Reload model"
+      : "Load model";
+
+  const handleRun = () => {
+    const defaultConfig = isDefaultConfig(runtimeConfig);
+    let saveFailed = false;
+    if (remember) {
+      saveFailed = !savePerModelConfig(
+        target.id,
+        target.ggufVariant,
+        runtimeConfig,
+      );
+    } else {
+      saveFailed = !deletePerModelConfig(target.id, target.ggufVariant);
+    }
+    if (persistenceOnly) {
+      if (saveFailed) {
+        toast.error("Couldn't save settings for this model.");
+        return;
+      }
+      const nextRemember = remember && !defaultConfig;
+      setSavedRemember(nextRemember);
+      setRemember(nextRemember);
+      toast.success(
+        nextRemember
+          ? "Settings saved."
+          : remember
+            ? "Default settings kept."
+            : "Settings forgotten.",
+      );
+      return;
+    }
+    if (saveFailed) {
+      toast.error("Couldn't save these settings, loading with them anyway.");
+    }
+    onRun(loadConfig);
+  };
+
+  return (
+    <div className="flex flex-col">
+      {variant === "page" && (
+        <div className="flex items-center gap-2.5 pb-4">
+          {onBack && (
+            <button
+              type="button"
+              onClick={onBack}
+              className="nav-icon-btn shrink-0 text-nav-icon-idle hover:bg-panel-surface-hover hover:text-black dark:hover:text-white"
+              aria-label="Back to model list"
+            >
+              <HugeiconsIcon
+                icon={ArrowLeft01Icon}
+                className="size-4"
+                strokeWidth={1.75}
+              />
+            </button>
+          )}
+          <div className="min-w-0 flex-1">
+            <div className="text-ui-10 font-semibold uppercase leading-none tracking-wider text-muted-foreground">
+              Run settings
+            </div>
+            <div className="mt-1.5 truncate text-ui-14 font-semibold leading-tight text-nav-fg">
+              {target.displayName}
+            </div>
+          </div>
+        </div>
+      )}
+
+      <div className="space-y-3.5">
+        {target.isGguf && (
+          <>
+            <div className="space-y-3">
+              <div className={ROW_CLASS}>
+                <div className="flex min-w-0 items-center gap-1.5">
+                  <span className={LABEL_CLASS}>Context Length</span>
+                  <InfoHint>
+                    Tokens of context to allocate. Higher uses more VRAM.
+                    {nativeContextLength != null
+                      ? ` This model's native context is ${nativeContextLength.toLocaleString()} tokens.`
+                      : ""}
+                  </InfoHint>
+                </div>
+                <NumericValueInput
+                  value={contextValue}
+                  min={minContext}
+                  max={maxContext}
+                  step={1}
+                  onChange={setContextLength}
+                  displayValue={
+                    config.customContextLength == null &&
+                    nativeContextLength == null &&
+                    activeLoadedContext == null
+                      ? "Auto"
+                      : undefined
+                  }
+                  ariaLabel="Context Length"
+                  className={NUMBER_INPUT_CLASS}
+                  size={8}
+                />
+              </div>
+              {nativeContextLength != null ? (
+                <Slider
+                  min={minContext}
+                  max={maxContext}
+                  step={128}
+                  value={[contextValue]}
+                  onValueChange={([v]) => setContextLength(v)}
+                  className="panel-slider"
+                  aria-label="Context Length"
+                />
+              ) : null}
+              {isActiveModel &&
+                loadedMaxContextLength != null &&
+                contextValue > loadedMaxContextLength && (
+                  <p className="text-ui-11 text-amber-500">
+                    Exceeds estimated VRAM capacity (
+                    {loadedMaxContextLength.toLocaleString()} tokens). The model
+                    may use system RAM.
+                  </p>
+                )}
+            </div>
+
+            {showAdvanced && (
+              <GgufAdvancedSettings
+                config={config}
+                update={update}
+                isMtp={isMtp}
+                speculativeFallback={speculativeFallback}
+                onEditTemplate={() => setTemplateOpen(true)}
+                layerCount={stagedDims?.layerCount ?? null}
+                moeLayerCount={stagedDims?.moeLayerCount ?? null}
+              />
+            )}
+
+            <div className={ROW_CLASS}>
+              <div className="flex min-w-0 items-center gap-1.5">
+                <span className="min-w-0 text-ui-13 font-medium leading-[1.25] tracking-nav text-muted-foreground">
+                  Advanced settings
+                </span>
+                <InfoHint>
+                  Extra options for how the model loads. Most setups don't need
+                  these.
+                </InfoHint>
+              </div>
+              <Switch
+                className="panel-switch shrink-0"
+                checked={showAdvanced}
+                onCheckedChange={setShowAdvanced}
+                aria-label="Show advanced settings"
+              />
+            </div>
+          </>
+        )}
+        {!target.isGguf && (
+          <>
+            <MaxSeqLengthSetting
+              value={maxSeqLengthValue}
+              max={maxSeqLengthMax}
+              inputMax={MAX_SEQ_LENGTH_MAX}
+              onChange={(value) =>
+                update({
+                  maxSeqLength: clampMaxSeqLength(value, MAX_SEQ_LENGTH_MAX),
+                })
+              }
+            />
+            <ChatTemplateSetting
+              config={config}
+              onEditTemplate={() => setTemplateOpen(true)}
+              readOnly={true}
+            />
+          </>
+        )}
+      </div>
+
+      <div
+        className={
+          variant === "sidebar"
+            ? "mt-4 flex flex-col gap-3 border-t border-border/60 pt-4"
+            : "mt-4 flex items-center justify-between gap-3 border-t border-border/60 pt-4"
+        }
+      >
+        <div className="flex min-w-0 items-center gap-2">
+          <Checkbox
+            id={rememberId}
+            checked={remember}
+            onCheckedChange={(checked) => setRemember(checked === true)}
+          />
+          <label
+            htmlFor={rememberId}
+            className="cursor-pointer select-none truncate text-ui-13 text-nav-fg"
+          >
+            Remember for this model
+          </label>
+        </div>
+        <div
+          className={
+            variant === "sidebar"
+              ? "flex items-center justify-end gap-2"
+              : "flex shrink-0 items-center gap-2"
+          }
+        >
+          <Button
+            type="button"
+            variant="ghost"
+            size="sm"
+            className="h-8"
+            disabled={atDefault}
+            onClick={() => setConfig({ ...DEFAULT_PER_MODEL_CONFIG })}
+          >
+            Reset
+          </Button>
+          <Button
+            type="button"
+            size="sm"
+            className="h-8"
+            disabled={isActiveModel && atBaseline && !rememberChanged}
+            onClick={handleRun}
+          >
+            {primaryActionLabel}
+          </Button>
+        </div>
+      </div>
+
+      <ChatTemplateEditorDialog
+        open={templateOpen}
+        onOpenChange={setTemplateOpen}
+        value={config.chatTemplateOverride}
+        defaultTemplate={resolvedDefaultTemplate}
+        defaultLoading={resolvedDefaultLoading}
+        readOnly={!target.isGguf}
+        onSave={(override) => update({ chatTemplateOverride: override })}
+      />
+    </div>
+  );
+}
diff --git a/studio/frontend/src/components/assistant-ui/model-selector.tsx b/studio/frontend/src/features/model-picker/components/model-selector.tsx
similarity index 82%
rename from studio/frontend/src/components/assistant-ui/model-selector.tsx
rename to studio/frontend/src/features/model-picker/components/model-selector.tsx
index 6bfd1276ac..9ae7e59a1f 100644
--- a/studio/frontend/src/components/assistant-ui/model-selector.tsx
+++ b/studio/frontend/src/features/model-picker/components/model-selector.tsx
@@ -3,6 +3,7 @@
 
 "use client";
 
+import { Input } from "@/components/ui/input";
 import {
   Popover,
   PopoverContent,
@@ -10,7 +11,7 @@ import {
 } from "@/components/ui/popover";
 import { TooltipProvider } from "@/components/ui/tooltip";
 import { usePlatformStore } from "@/config/env";
-import { isCustomProviderType } from "@/features/chat/external-providers";
+import { isCustomProviderType } from "@/features/chat";
 import { ChevronDownStandardIcon } from "@/lib/chevron-icons";
 import { cn } from "@/lib/utils";
 import {
@@ -33,7 +34,11 @@ import {
   useRef,
   useState,
 } from "react";
-import { Input } from "../ui/input";
+import {
+  type PerModelConfig,
+  resolveInitialConfig,
+} from "../model-config/per-model-config";
+import { ModelConfigPage } from "./model-config-page";
 import { HubModelPicker, hasDownloadedModels } from "./model-selector/pickers";
 import { PillTabs } from "./model-selector/pill-tabs";
 import {
@@ -45,6 +50,7 @@ import type {
   ExternalModelOption,
   LoraModelOption,
   ModelOption,
+  ModelPickTarget,
   ModelSelectorChangeMeta,
 } from "./model-selector/types";
 
@@ -122,6 +128,10 @@ interface ModelSelectorProps {
   value?: string;
   defaultValue?: string;
   activeGgufVariant?: string | null;
+  activeModelConfig?: PerModelConfig | null;
+  activeGgufContextLength?: number | null;
+  selectedConfig?: PerModelConfig | null;
+  selectedGgufVariant?: string | null;
   onValueChange?: (value: string, meta: ModelSelectorChangeMeta) => void;
   onEject?: () => void;
   onFoldersChange?: () => void;
@@ -183,15 +193,12 @@ function ModelSelectorTrigger({
       >
         {isLoaded &&
           (onEject ? (
-            // Loaded status doubles as a mouse eject shortcut: green checkmark
-            // at rest, red eject icon on pill hover, click to eject. A plain
-            // span (no role/tabIndex) keeps it out of the trigger button's
-            // content model, which forbids focusable descendants. Keyboard and
-            // screen-reader users eject via the picker's "Eject model" button.
-            // aria-hidden marks it decorative; stopPropagation stops the
-            // popover from toggling. On touch (no hover) the eject icon and
-            // tooltip never reveal, so pointer-events-none disables the
-            // shortcut there and taps open the picker instead of ejecting.
+            // Loaded status doubles as a mouse eject shortcut (checkmark at rest,
+            // eject icon on hover). A plain span keeps it out of the trigger
+            // button's content model (no focusable descendants); keyboard/SR users
+            // eject via the "Eject model" button. aria-hidden marks it decorative;
+            // stopPropagation stops the popover toggling. On touch (no hover)
+            // pointer-events-none disables it so taps open the picker instead.
             <span
               aria-hidden={true}
               title="Eject model"
@@ -225,7 +232,7 @@ function ModelSelectorTrigger({
           </span>
         ) : null}
         <span className="flex min-w-0 flex-1 items-baseline">
-          <span className="min-w-0 flex flex-1 items-baseline truncate font-heading text-[16px] font-medium leading-tight text-black dark:text-white">
+          <span className="min-w-0 flex flex-1 items-baseline truncate font-heading text-ui-16 font-medium leading-tight text-black dark:text-white">
             {currentModel?.name ?? "Select model"}
             {showCloudIndicator ? (
               <HugeiconsIcon
@@ -285,7 +292,8 @@ function saveLastHubSection(section: HubSection): void {
 // when they have downloads, else Recommended.
 function defaultHubSection(): HubSection {
   return (
-    loadLastHubSection() ?? (hasDownloadedModels() ? "downloaded" : "recommended")
+    loadLastHubSection() ??
+    (hasDownloadedModels() ? "downloaded" : "recommended")
   );
 }
 
@@ -293,12 +301,12 @@ const HUB_SECTION_TABS: { value: string; label: string; icon?: ReactNode }[] = [
   {
     value: "recommended",
     label: "Recommended",
-    icon: <HugeiconsIcon icon={StarIcon} className="size-3.5" />,
+    icon: <HugeiconsIcon icon={StarIcon} className="size-3.5 shrink-0" />,
   },
   {
     value: "downloaded",
     label: "On Device",
-    icon: <HugeiconsIcon icon={Download01Icon} className="size-3.5" />,
+    icon: <HugeiconsIcon icon={Download01Icon} className="size-3.5 shrink-0" />,
   },
 ];
 
@@ -308,6 +316,11 @@ function ModelSelectorContent({
   loraModels,
   externalModels,
   value,
+  activeGgufVariant,
+  activeModelConfig,
+  activeGgufContextLength,
+  selectedConfig,
+  selectedGgufVariant,
   onSelect,
   onEject,
   onFoldersChange,
@@ -323,6 +336,11 @@ function ModelSelectorContent({
   loraModels: LoraModelOption[];
   externalModels: ExternalModelOption[];
   value?: string;
+  activeGgufVariant?: string | null;
+  activeModelConfig?: PerModelConfig | null;
+  activeGgufContextLength?: number | null;
+  selectedConfig?: PerModelConfig | null;
+  selectedGgufVariant?: string | null;
   onSelect: (id: string, meta: ModelSelectorChangeMeta) => void;
   onEject?: () => void;
   onFoldersChange?: () => void;
@@ -337,8 +355,7 @@ function ModelSelectorContent({
   const chatOnly = usePlatformStore((s) => s.isChatOnly());
   const hasExternal = externalModels.length > 0;
   // The Fine-tuned tab is for fine-tuned models only. Local models (LM Studio,
-  // Ollama, custom folders) carry source "local" and live in the Hub tab's
-  // Downloaded / Custom sections instead.
+  // Ollama, custom folders) carry source "local" and live in the Hub tab instead.
   const fineTunedModels = useMemo(
     () => loraModels.filter((model) => isFineTunedSource(model.source)),
     [loraModels],
@@ -367,7 +384,9 @@ function ModelSelectorContent({
             {
               value: "connected",
               label: "Connected",
-              icon: <HugeiconsIcon icon={CloudIcon} className="size-3.5" />,
+              icon: (
+                <HugeiconsIcon icon={CloudIcon} className="size-3.5 shrink-0" />
+              ),
             },
           ]
         : HUB_SECTION_TABS,
@@ -391,9 +410,12 @@ function ModelSelectorContent({
   const effectiveHubSection: HubSection =
     hubSection === "connected" && !hasExternal ? "recommended" : hubSection;
 
-  // The picker below remounts on each open, but this tab state does not, so a
-  // persisted selection that lands in lora/external after async load would
-  // reopen on Hub. Re-derive the default tab on the open edge.
+  const [configTarget, setConfigTarget] = useState<ModelPickTarget | null>(
+    null,
+  );
+
+  // The picker remounts on each open but this tab state does not, so re-derive
+  // the default tab on the open edge (else a lora/external selection reopens on Hub).
   const wasOpen = useRef(open);
   useEffect(() => {
     if (open && !wasOpen.current) {
@@ -402,6 +424,9 @@ function ModelSelectorContent({
       // user has downloads, else their last section.
       setHubSection(wantsConnectedDefault ? "connected" : defaultHubSection());
     }
+    if (!open && wasOpen.current) {
+      setConfigTarget(null);
+    }
     wasOpen.current = open;
   }, [
     open,
@@ -452,6 +477,29 @@ function ModelSelectorContent({
     }
   }
 
+  const visibleConfigTarget = open ? configTarget : null;
+  const openConfigPage = (id: string, meta: ModelSelectorChangeMeta) => {
+    const leaf = id.includes("/") ? id.slice(id.lastIndexOf("/") + 1) : id;
+    setConfigTarget({
+      id,
+      displayName: meta.ggufVariant ? `${leaf} · ${meta.ggufVariant}` : leaf,
+      ggufVariant: meta.ggufVariant ?? null,
+      isGguf: meta.isGguf ?? Boolean(meta.ggufVariant),
+      meta,
+    });
+  };
+  const handlePick = (id: string, meta: ModelSelectorChangeMeta) => {
+    if (meta.source === "external") {
+      onSelect(id, meta);
+      return;
+    }
+    const resolved = resolveInitialConfig(id, meta.ggufVariant);
+    onSelect(id, {
+      ...meta,
+      ...(resolved.remembered ? { config: resolved.config } : {}),
+    });
+  };
+
   return (
     <PopoverContent
       align="start"
@@ -459,12 +507,17 @@ function ModelSelectorContent({
       data-tour={dataTour}
       onKeyDown={handlePickerEntryKeyDown}
       className={cn(
-        "unsloth-model-selector-menu menu-soft-surface ring-0 max-w-[calc(100vw-1rem)] min-w-0 gap-0 pt-4 pb-0 pl-4",
-        // Sized so the left-packed row keeps uniform gaps and the last dropdown's
-        // right gap matches the pill's left gap (pl-4 vs pr-4).
-        hasExternal
-          ? "w-[min(614px,calc(100vw-1rem))] pr-4"
-          : "w-[min(506px,calc(100vw-1rem))] pr-2",
+        "unsloth-model-selector-menu menu-soft-surface ring-0 max-w-[calc(100vw-1rem)] min-w-0 gap-0",
+        visibleConfigTarget
+          ? "w-[min(468px,calc(100vw-1rem))] px-4 pt-4 pb-4"
+          : cn(
+              "pt-4 pb-0 pl-4",
+              // Sized so the left-packed row keeps uniform gaps and the last
+              // dropdown's right gap matches the pill's left gap (pl-4 vs pr-4).
+              hasExternal
+                ? "w-[min(614px,calc(100vw-1rem))] pr-4"
+                : "w-[min(506px,calc(100vw-1rem))] pr-2",
+            ),
         className,
       )}
     >
@@ -477,6 +530,42 @@ function ModelSelectorContent({
         skipDelayDuration={0}
         disableHoverableContent={true}
       >
+        {visibleConfigTarget ? (
+          <ModelConfigPage
+            key={`${visibleConfigTarget.id}::${visibleConfigTarget.ggufVariant ?? ""}`}
+            target={visibleConfigTarget}
+            onBack={() => setConfigTarget(null)}
+            onRun={(config) =>
+              onSelect(visibleConfigTarget.id, {
+                ...visibleConfigTarget.meta,
+                config,
+                forceReload: true,
+              })
+            }
+            loadedConfig={
+              value === visibleConfigTarget.id &&
+              (activeGgufVariant ?? null) ===
+                (visibleConfigTarget.ggufVariant ?? null)
+                ? (activeModelConfig ?? null)
+                : null
+            }
+            loadedContextLength={
+              value === visibleConfigTarget.id &&
+              (activeGgufVariant ?? null) ===
+                (visibleConfigTarget.ggufVariant ?? null)
+                ? (activeGgufContextLength ?? null)
+                : null
+            }
+            initialConfig={
+              value === visibleConfigTarget.id &&
+              (selectedGgufVariant ?? null) ===
+                (visibleConfigTarget.ggufVariant ?? null)
+                ? (selectedConfig ?? null)
+                : null
+            }
+          />
+        ) : (
+          <>
         {tabs.length > 1 ? (
           <PillTabs
             ariaLabel="Model source"
@@ -494,13 +583,14 @@ function ModelSelectorContent({
             loraModels={fineTunedModels}
             externalModels={externalModels}
             value={value}
-            onSelect={onSelect}
+            onSelect={handlePick}
             onFoldersChange={onFoldersChange}
             onBrowseHub={onBrowseHub}
             onModelsChange={onModelsChange}
+            onConfigure={openConfigPage}
             deleteDisabled={deleteDisabled}
-            section={effectiveHubSection}
             onEject={hasSelection && onEject ? onEject : undefined}
+            section={effectiveHubSection}
             sectionToggle={
               <PillTabs
                 ariaLabel="Hub section"
@@ -538,10 +628,8 @@ function ModelSelectorContent({
             </button>
           </div>
         ) : null}
-        {/* Hub renders Eject inline as the last list row; other tabs keep the
-          footer button. */}
         {effectiveTab !== "hub" && hasSelection && onEject ? (
-          <div className="mt-1.5 pt-1.5">
+          <div className="mt-1.5 border-t border-border/70 pt-1.5 pb-2">
             <button
               type="button"
               onClick={onEject}
@@ -553,6 +641,8 @@ function ModelSelectorContent({
             </button>
           </div>
         ) : null}
+          </>
+        )}
       </TooltipProvider>
     </PopoverContent>
   );
@@ -565,6 +655,10 @@ export function ModelSelector({
   value,
   defaultValue,
   activeGgufVariant,
+  activeModelConfig,
+  activeGgufContextLength,
+  selectedConfig,
+  selectedGgufVariant,
   onValueChange,
   onEject,
   onFoldersChange,
@@ -693,6 +787,11 @@ export function ModelSelector({
         loraModels={loraModels}
         externalModels={externalModels}
         value={selected}
+        activeGgufVariant={activeGgufVariant}
+        activeModelConfig={activeModelConfig}
+        activeGgufContextLength={activeGgufContextLength}
+        selectedConfig={selectedConfig}
+        selectedGgufVariant={selectedGgufVariant}
         onSelect={handleSelect}
         onEject={onEject ? handleEject : undefined}
         onFoldersChange={onFoldersChange}
@@ -784,7 +883,7 @@ function ExternalModelPicker({
           ) : (
             grouped.map((group) => (
               <div key={group.providerId}>
-                <div className="flex items-center gap-2 px-2.5 py-1.5 text-[10px] font-semibold uppercase tracking-wider text-muted-foreground">
+                <div className="flex items-center gap-2 px-2.5 py-1.5 text-ui-10 font-semibold uppercase tracking-wider text-muted-foreground">
                   <ExternalProviderLogo
                     providerType={group.models[0]?.providerType}
                     className="size-3.5"
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/folder-browser.tsx b/studio/frontend/src/features/model-picker/components/model-selector/folder-browser.tsx
similarity index 79%
rename from studio/frontend/src/components/assistant-ui/model-selector/folder-browser.tsx
rename to studio/frontend/src/features/model-picker/components/model-selector/folder-browser.tsx
index 16cc8a1956..bad6c27bb2 100644
--- a/studio/frontend/src/components/assistant-ui/model-selector/folder-browser.tsx
+++ b/studio/frontend/src/features/model-picker/components/model-selector/folder-browser.tsx
@@ -14,10 +14,7 @@ import {
   DialogTitle,
 } from "@/components/ui/dialog";
 import { Spinner } from "@/components/ui/spinner";
-import {
-  type BrowseFoldersResponse,
-  browseFolders,
-} from "@/features/chat/api/chat-api";
+import { type BrowseFoldersResponse, browseFolders } from "@/features/chat";
 import { ChevronUpStandardIcon } from "@/lib/chevron-icons";
 import { cn } from "@/lib/utils";
 import { Folder02Icon } from "@hugeicons/core-free-icons";
@@ -31,13 +28,16 @@ export interface FolderBrowserProps {
   onSelect: (path: string) => void;
   /** Optional initial directory. Defaults to the user's home on the server. */
   initialPath?: string;
+  title?: string;
+  confirmLabel?: string;
+  showModelHints?: boolean;
 }
 
 function splitBreadcrumb(path: string): { label: string; value: string }[] {
   if (!path) return [];
-  // Detect path style BEFORE normalizing: on POSIX, `\` is a valid filename
-  // char, so blindly rewriting `\` -> `/` mangles names like `my\backup` into
-  // 404ing breadcrumbs. Only Windows-style paths (drive letter, or UNC) convert.
+  // Detect path style BEFORE normalizing: on POSIX `\` is a valid filename char,
+  // so rewriting `\` -> `/` would mangle names like `my\backup`. Only Windows
+  // paths (drive letter or UNC) convert.
   const isWindowsDrive =
     /^[A-Za-z]:[\\/]/.test(path) || /^[A-Za-z]:$/.test(path);
   const isUnc = /^\\\\/.test(path);
@@ -58,9 +58,8 @@ function splitBreadcrumb(path: string): { label: string; value: string }[] {
     return parts;
   }
 
-  // Windows drive path (C:, D:): first segment is the drive. Use `C:/` as the
-  // crumb value so clicking the drive root navigates to the drive root, not the
-  // drive-relative CWD (`C:` alone resolves to CWD-on-C, not `C:\`).
+  // Windows drive path: use `C:/` as the crumb value so clicking the drive root
+  // goes to the drive root, not the drive-relative CWD (`C:` alone is CWD-on-C).
   if (/^[A-Za-z]:$/.test(segments[0])) {
     const driveRoot = `${segments[0]}/`;
     let cur = driveRoot;
@@ -82,6 +81,9 @@ export function FolderBrowser({
   onOpenChange,
   onSelect,
   initialPath,
+  title = "Select folder to detect models",
+  confirmLabel = "Use this folder",
+  showModelHints = true,
 }: FolderBrowserProps) {
   const [data, setData] = useState<BrowseFoldersResponse | null>(null);
   const [path, setPath] = useState<string | undefined>(initialPath);
@@ -90,47 +92,43 @@ export function FolderBrowser({
   const [error, setError] = useState<string | null>(null);
   const abortRef = useRef<AbortController | null>(null);
 
-  const navigate = useCallback(
-    (
-      target: string | undefined,
-      hidden: boolean,
-      opts?: { fallbackOnError?: boolean },
-    ) => {
-      abortRef.current?.abort();
-      const ctrl = new AbortController();
-      abortRef.current = ctrl;
-      setLoading(true);
-      setError(null);
-      // Forward the signal so cancelled navigation aborts the backend
-      // enumeration, not just the response.
-      browseFolders(target, hidden, ctrl.signal)
-        .then((res) => {
-          if (ctrl.signal.aborted) return;
-          setData(res);
-          setPath(res.current);
-        })
-        .catch((err) => {
-          if (ctrl.signal.aborted) return;
-          // Surface the error; if the first request (e.g. a bad initialPath)
-          // fails, fall back to HOME so the modal stays navigable.
-          const message = err instanceof Error ? err.message : String(err);
-          setError(message);
-          if (opts?.fallbackOnError && target !== undefined) {
-            // Re-issue without a target -> backend defaults to HOME.
-            // Don't recurse if HOME itself fails (allowlist always has HOME).
-            queueMicrotask(() => navigate(undefined, hidden));
-          }
-        })
-        .finally(() => {
-          if (!ctrl.signal.aborted) setLoading(false);
-        });
-    },
-    [],
-  );
+  function navigate(
+    target: string | undefined,
+    hidden: boolean,
+    opts?: { fallbackOnError?: boolean },
+  ) {
+    abortRef.current?.abort();
+    const ctrl = new AbortController();
+    abortRef.current = ctrl;
+    setLoading(true);
+    setError(null);
+    // Forward the signal so cancelled navigation aborts the backend
+    // enumeration, not just the response.
+    browseFolders(target, hidden, ctrl.signal)
+      .then((res) => {
+        if (ctrl.signal.aborted) return;
+        setData(res);
+        setPath(res.current);
+      })
+      .catch((err) => {
+        if (ctrl.signal.aborted) return;
+        // Surface the error; if the first request (e.g. a bad initialPath)
+        // fails, fall back to HOME so the modal stays navigable.
+        const message = err instanceof Error ? err.message : String(err);
+        setError(message);
+        if (opts?.fallbackOnError && target !== undefined) {
+          // Re-issue without a target -> backend defaults to HOME.
+          // Don't recurse if HOME itself fails (allowlist always has HOME).
+          queueMicrotask(() => navigate(undefined, hidden));
+        }
+      })
+      .finally(() => {
+        if (!ctrl.signal.aborted) setLoading(false);
+      });
+  }
 
   // Fetch only on closed -> open; later navigation is driven by `navigate()`,
   // so `path` is deliberately kept out of the dependency list.
-  // eslint-disable-next-line react-hooks/exhaustive-deps
   useEffect(() => {
     if (!open) return;
     // fallbackOnError: recover into HOME if initialPath is bad, rather than
@@ -147,7 +145,7 @@ export function FolderBrowser({
 
   const crumbs = useMemo(
     () => (data?.current ? splitBreadcrumb(data.current) : []),
-    [data?.current],
+    [data],
   );
 
   return (
@@ -158,11 +156,11 @@ export function FolderBrowser({
         data-testid="folder-browser-dialog"
       >
         <DialogHeader className="px-6 pt-6 pb-2">
-          <DialogTitle>Select folder to detect models</DialogTitle>
+          <DialogTitle>{title}</DialogTitle>
         </DialogHeader>
 
         {/* Breadcrumb */}
-        <div className="flex flex-wrap items-center gap-0.5 border-t border-border/50 px-6 py-2 font-mono text-[11px] text-muted-foreground">
+        <div className="flex flex-wrap items-center gap-0.5 border-t border-border/50 px-6 py-2 font-mono text-ui-11 text-muted-foreground">
           {crumbs.length === 0 ? (
             <span className="text-muted-foreground/60">(loading…)</span>
           ) : (
@@ -193,7 +191,7 @@ export function FolderBrowser({
                 type="button"
                 onClick={() => navigate(s, showHidden)}
                 disabled={loading}
-                className="rounded-full border border-border/50 px-2 py-0.5 font-mono text-[10px] text-muted-foreground transition-colors hover:bg-muted hover:text-foreground disabled:opacity-40"
+                className="rounded-full border border-border/50 px-2 py-0.5 font-mono text-ui-10 text-muted-foreground transition-colors hover:bg-muted hover:text-foreground disabled:opacity-40"
                 title={s}
               >
                 {s.length > 36 ? `…${s.slice(-33)}` : s}
@@ -238,21 +236,22 @@ export function FolderBrowser({
                 </button>
               )}
               {data.entries.length === 0 &&
-                !(data.model_files_here && data.model_files_here > 0) && (
+                (!showModelHints ||
+                  !(data.model_files_here && data.model_files_here > 0)) && (
                   <div className="px-6 py-3 text-xs text-muted-foreground/60">
                     (empty directory)
                   </div>
                 )}
-              {data.model_files_here !== undefined &&
+              {showModelHints && data.model_files_here !== undefined &&
                 data.model_files_here > 0 && (
-                  <div className="border-t border-border/30 px-6 py-1.5 text-[10px] text-foreground/70">
+                  <div className="border-t border-border/30 px-6 py-1.5 text-ui-10 text-foreground/70">
                     {data.model_files_here} model file
                     {data.model_files_here === 1 ? "" : "s"} in this folder.
                     Click "Use this folder" to scan it.
                   </div>
                 )}
               {data.truncated === true && (
-                <div className="border-t border-border/30 px-6 py-1.5 text-[10px] text-muted-foreground/70">
+                <div className="border-t border-border/30 px-6 py-1.5 text-ui-10 text-muted-foreground/70">
                   Showing first {data.entries.length} entries. Narrow the path
                   to see more.
                 </div>
@@ -280,8 +279,8 @@ export function FolderBrowser({
                     )}
                   />
                   <span className="truncate font-mono">{e.name}</span>
-                  {e.has_models && (
-                    <span className="ml-auto shrink-0 rounded-full border border-border/50 px-1.5 py-0 text-[9px] uppercase tracking-wider text-muted-foreground">
+                  {showModelHints && e.has_models && (
+                    <span className="ml-auto shrink-0 rounded-full border border-border/50 px-1.5 py-0 text-ui-9 uppercase tracking-wider text-muted-foreground">
                       models
                     </span>
                   )}
@@ -320,7 +319,7 @@ export function FolderBrowser({
               onClick={handleConfirm}
               disabled={!path || loading || !!error}
             >
-              Use this folder
+              {confirmLabel}
             </Button>
           </div>
         </DialogFooter>
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/model-capabilities.ts b/studio/frontend/src/features/model-picker/components/model-selector/model-capabilities.ts
similarity index 100%
rename from studio/frontend/src/components/assistant-ui/model-selector/model-capabilities.ts
rename to studio/frontend/src/features/model-picker/components/model-selector/model-capabilities.ts
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/model-delete-action.tsx b/studio/frontend/src/features/model-picker/components/model-selector/model-delete-action.tsx
similarity index 90%
rename from studio/frontend/src/components/assistant-ui/model-selector/model-delete-action.tsx
rename to studio/frontend/src/features/model-picker/components/model-selector/model-delete-action.tsx
index 4de96d3648..09bb43abdc 100644
--- a/studio/frontend/src/components/assistant-ui/model-selector/model-delete-action.tsx
+++ b/studio/frontend/src/features/model-picker/components/model-selector/model-delete-action.tsx
@@ -1,12 +1,12 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { DeleteConfirmDialog } from "@/features/hub/catalog/download-card";
+import { DeleteConfirmDialog } from "@/features/hub";
+import { toast } from "@/lib/toast";
 import { cn } from "@/lib/utils";
 import { Delete02Icon } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
-import { useCallback, useState, type ReactNode } from "react";
-import { toast } from "@/lib/toast";
+import { type ReactNode, useCallback, useState } from "react";
 
 interface ModelDeleteActionProps {
   ariaLabel: string;
@@ -63,7 +63,8 @@ export function ModelDeleteAction({
         disabled={disabled}
         className={cn(
           "shrink-0 rounded-md p-1.5 text-muted-foreground/60 transition-colors hover:bg-destructive/10 hover:text-destructive",
-          disabled && "cursor-not-allowed opacity-40 hover:bg-transparent hover:text-muted-foreground/60",
+          disabled &&
+            "cursor-not-allowed opacity-40 hover:bg-transparent hover:text-muted-foreground/60",
           buttonClassName,
         )}
       >
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/model-load-settings-action.tsx b/studio/frontend/src/features/model-picker/components/model-selector/model-load-settings-action.tsx
similarity index 63%
rename from studio/frontend/src/components/assistant-ui/model-selector/model-load-settings-action.tsx
rename to studio/frontend/src/features/model-picker/components/model-selector/model-load-settings-action.tsx
index 58510762d4..bbef42063f 100644
--- a/studio/frontend/src/components/assistant-ui/model-selector/model-load-settings-action.tsx
+++ b/studio/frontend/src/features/model-picker/components/model-selector/model-load-settings-action.tsx
@@ -6,24 +6,18 @@ import {
   TooltipContent,
   TooltipTrigger,
 } from "@/components/ui/tooltip";
-import { useChatRuntimeStore } from "@/features/chat/stores/chat-runtime-store";
 import { cn } from "@/lib/utils";
 import { Settings02Icon } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
 
-/** Gear button on a downloaded quant row. Stages the model into the Run
- * settings sidebar (always, regardless of the Load-on-selection toggle) so the
- * user can set load options, then click Load model. */
 export function ModelLoadSettingsAction({
   ariaLabel,
-  repoId,
-  quant,
-  maxContext,
+  onConfigure,
+  className,
 }: {
   ariaLabel: string;
-  repoId: string;
-  quant: string;
-  maxContext?: number | null;
+  onConfigure: () => void;
+  className?: string;
 }) {
   return (
     <Tooltip delayDuration={0}>
@@ -32,16 +26,12 @@ export function ModelLoadSettingsAction({
           type="button"
           onClick={(e) => {
             e.stopPropagation();
-            useChatRuntimeStore.getState().stageModel({
-              id: repoId,
-              ggufVariant: quant,
-              isDownloaded: true,
-              contextLength: maxContext ?? null,
-            });
+            onConfigure();
           }}
           aria-label={ariaLabel}
           className={cn(
-            "shrink-0 rounded-md p-1 text-muted-foreground/60 transition-colors hover:bg-muted hover:text-foreground",
+            "shrink-0 rounded-md p-1 text-muted-foreground/60 transition-colors hover:bg-black/5 hover:text-foreground dark:hover:bg-white/10",
+            className,
           )}
         >
           <HugeiconsIcon
diff --git a/studio/frontend/src/features/model-picker/components/model-selector/model-row-menu.tsx b/studio/frontend/src/features/model-picker/components/model-selector/model-row-menu.tsx
new file mode 100644
index 0000000000..ee149d802f
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/components/model-selector/model-row-menu.tsx
@@ -0,0 +1,289 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+// Condensed row actions for model rows: everything except the run-settings
+// gear collapses into one dots menu (pin, update, delete) so rows don't grow
+// an icon strip. Mirrors the sidebar chat rows' MoreVertical menu pattern.
+
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuSeparator,
+  DropdownMenuTrigger,
+} from "@/components/ui/dropdown-menu";
+import { usePlatformStore } from "@/config/env";
+import { revealCachedModel } from "@/features/chat";
+import {
+  DeleteConfirmDialog,
+  UpdateConfirmDialog,
+  ggufVariantsMatch,
+  subscribeJobListeners,
+} from "@/features/hub";
+import { toast } from "@/lib/toast";
+import { cn } from "@/lib/utils";
+import {
+  Delete02Icon,
+  Folder01Icon,
+  MoreVerticalIcon,
+  PinIcon,
+  PinOffIcon,
+} from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
+import { RefreshCw } from "lucide-react";
+import {
+  type ReactNode,
+  useCallback,
+  useEffect,
+  useRef,
+  useState,
+} from "react";
+
+interface ModelRowMenuPin {
+  pinned: boolean;
+  /** Menu item labels, e.g. "Pin quant to the top" / "Unpin quant". */
+  pinLabel: string;
+  unpinLabel: string;
+  onToggle: () => void;
+}
+
+interface ModelRowMenuUpdate {
+  title: string;
+  description: ReactNode;
+  /** Repo + variant the update targets (see ModelUpdateAction). */
+  repoId: string;
+  variant?: string | null;
+  disabled?: boolean;
+  onConfirm: () => Promise<void> | void;
+  onUpdated?: () => void;
+}
+
+interface ModelRowMenuDelete {
+  title: string;
+  description: ReactNode;
+  successMessage: string;
+  disabled?: boolean;
+  onConfirm: () => Promise<void> | void;
+  onDeleted?: () => void;
+}
+
+/** Managed-cache location for "Reveal in Finder" (resolved server-side). */
+interface ModelRowMenuCachePath {
+  repoId: string;
+  variant?: string;
+}
+
+export function ModelRowMenu({
+  ariaLabel,
+  buttonClassName,
+  iconClassName,
+  cachePath,
+  pin,
+  update,
+  del,
+}: {
+  ariaLabel: string;
+  buttonClassName?: string;
+  iconClassName?: string;
+  /** Enables "Reveal in Finder" for cached repos. */
+  cachePath?: ModelRowMenuCachePath;
+  pin?: ModelRowMenuPin;
+  update?: ModelRowMenuUpdate;
+  del?: ModelRowMenuDelete;
+}) {
+  const deviceType = usePlatformStore((s) => s.deviceType);
+  const revealLabel =
+    deviceType === "mac"
+      ? "Reveal in Finder"
+      : deviceType === "windows"
+        ? "Reveal in File Explorer"
+        : "Reveal in File Manager";
+  const [deleteOpen, setDeleteOpen] = useState(false);
+  const [deleting, setDeleting] = useState(false);
+  const [updateOpen, setUpdateOpen] = useState(false);
+
+  // Refresh the caller when this repo+variant's managed update completes
+  // (mirrors ModelUpdateAction).
+  const onUpdatedRef = useRef(update?.onUpdated);
+  useEffect(() => {
+    onUpdatedRef.current = update?.onUpdated;
+  }, [update?.onUpdated]);
+  const updateRepoId = update?.repoId;
+  const updateVariant = update?.variant ?? null;
+  useEffect(() => {
+    if (!updateRepoId) return;
+    return subscribeJobListeners("model", updateRepoId, {
+      onComplete: (completedVariant) => {
+        const matches = updateVariant
+          ? ggufVariantsMatch(completedVariant, updateVariant)
+          : !completedVariant;
+        if (matches) onUpdatedRef.current?.();
+      },
+    });
+  }, [updateRepoId, updateVariant]);
+
+  const onDeleteConfirm = del?.onConfirm;
+  const onDeleted = del?.onDeleted;
+  const deleteSuccessMessage = del?.successMessage;
+  const handleDeleteConfirm = useCallback(async () => {
+    if (!onDeleteConfirm) return;
+    setDeleting(true);
+    try {
+      await onDeleteConfirm();
+      if (deleteSuccessMessage) toast.success(deleteSuccessMessage);
+      onDeleted?.();
+      setDeleteOpen(false);
+    } catch (err) {
+      toast.error(
+        err instanceof Error ? err.message : "Failed to delete model",
+      );
+    } finally {
+      setDeleting(false);
+    }
+  }, [onDeleteConfirm, onDeleted, deleteSuccessMessage]);
+
+  const onUpdateConfirm = update?.onConfirm;
+  const handleUpdateConfirm = useCallback(() => {
+    // Start the re-download and close the dialog; the Downloads panel owns
+    // progress + cancel. Only a failure to START toasts.
+    void Promise.resolve()
+      .then(onUpdateConfirm)
+      .catch((err) => {
+        toast.error(
+          err instanceof Error ? err.message : "Failed to start update",
+        );
+      });
+    setUpdateOpen(false);
+  }, [onUpdateConfirm]);
+
+  const cachePathRepoId = cachePath?.repoId;
+  const cachePathVariant = cachePath?.variant;
+  const handleReveal = useCallback(() => {
+    if (!cachePathRepoId) return;
+    revealCachedModel(cachePathRepoId, cachePathVariant).catch((err) => {
+      toast.error(
+        err instanceof Error ? err.message : "Failed to open file manager",
+      );
+    });
+  }, [cachePathRepoId, cachePathVariant]);
+
+  if (!pin && !update && !del && !cachePath) return null;
+
+  return (
+    <>
+      <DropdownMenu>
+        <DropdownMenuTrigger asChild={true}>
+          <button
+            type="button"
+            onClick={(e) => e.stopPropagation()}
+            aria-label={ariaLabel}
+            className={cn(
+              "shrink-0 rounded-md p-1 text-muted-foreground/60 transition-colors hover:bg-black/5 hover:text-foreground dark:hover:bg-white/10",
+              buttonClassName,
+            )}
+          >
+            <HugeiconsIcon
+              icon={MoreVerticalIcon}
+              strokeWidth={1.75}
+              className={cn("size-3.5", iconClassName)}
+            />
+          </button>
+        </DropdownMenuTrigger>
+        <DropdownMenuContent
+          side="bottom"
+          align="end"
+          sideOffset={2}
+          className="unsloth-plus-menu menu-flat-destructive w-48"
+        >
+          {pin && (
+            <DropdownMenuItem
+              onSelect={(e) => {
+                e.stopPropagation();
+                pin.onToggle();
+              }}
+            >
+              <HugeiconsIcon
+                icon={pin.pinned ? PinOffIcon : PinIcon}
+                strokeWidth={1.75}
+                className="size-icon"
+              />
+              <span>{pin.pinned ? pin.unpinLabel : pin.pinLabel}</span>
+            </DropdownMenuItem>
+          )}
+          {cachePath && (
+            <DropdownMenuItem
+              onSelect={(e) => {
+                e.stopPropagation();
+                handleReveal();
+              }}
+            >
+              <HugeiconsIcon
+                icon={Folder01Icon}
+                strokeWidth={1.75}
+                className="size-icon"
+              />
+              <span>{revealLabel}</span>
+            </DropdownMenuItem>
+          )}
+          {update && (
+            <DropdownMenuItem
+              disabled={update.disabled}
+              onSelect={(e) => {
+                e.stopPropagation();
+                setUpdateOpen(true);
+              }}
+            >
+              <RefreshCw className="size-icon" />
+              <span>Update</span>
+            </DropdownMenuItem>
+          )}
+          {del && (
+            <>
+              {(cachePath || pin || update) && <DropdownMenuSeparator />}
+              <DropdownMenuItem
+                variant="destructive"
+                disabled={del.disabled}
+                onSelect={(e) => {
+                  e.stopPropagation();
+                  setDeleteOpen(true);
+                }}
+              >
+                <HugeiconsIcon
+                  icon={Delete02Icon}
+                  strokeWidth={1.75}
+                  className="size-icon"
+                />
+                <span>Delete</span>
+              </DropdownMenuItem>
+            </>
+          )}
+        </DropdownMenuContent>
+      </DropdownMenu>
+
+      {del && (
+        <DeleteConfirmDialog
+          open={deleteOpen}
+          onOpenChange={(nextOpen) => {
+            if (!nextOpen && deleting) return;
+            setDeleteOpen(nextOpen);
+          }}
+          title={del.title}
+          description={del.description}
+          deleting={deleting}
+          onConfirm={() => void handleDeleteConfirm()}
+        />
+      )}
+
+      {update && (
+        <UpdateConfirmDialog
+          open={updateOpen}
+          onOpenChange={setUpdateOpen}
+          title={update.title}
+          description={update.description}
+          updating={false}
+          onConfirm={handleUpdateConfirm}
+        />
+      )}
+    </>
+  );
+}
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/model-update-action.tsx b/studio/frontend/src/features/model-picker/components/model-selector/model-update-action.tsx
similarity index 82%
rename from studio/frontend/src/components/assistant-ui/model-selector/model-update-action.tsx
rename to studio/frontend/src/features/model-picker/components/model-selector/model-update-action.tsx
index db7628777a..b13ed33d04 100644
--- a/studio/frontend/src/components/assistant-ui/model-selector/model-update-action.tsx
+++ b/studio/frontend/src/features/model-picker/components/model-selector/model-update-action.tsx
@@ -1,12 +1,20 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { subscribeJobListeners } from "@/features/hub/download-manager";
-import { UpdateConfirmDialog } from "@/features/hub/catalog/download-card";
-import { ggufVariantsMatch } from "@/features/hub/lib/model-identity";
+import {
+  UpdateConfirmDialog,
+  ggufVariantsMatch,
+  subscribeJobListeners,
+} from "@/features/hub";
 import { cn } from "@/lib/utils";
 import { RefreshCw } from "lucide-react";
-import { useCallback, useEffect, useRef, useState, type ReactNode } from "react";
+import {
+  type ReactNode,
+  useCallback,
+  useEffect,
+  useRef,
+  useState,
+} from "react";
 import { toast } from "sonner";
 
 interface ModelUpdateActionProps {
@@ -42,10 +50,10 @@ export function ModelUpdateAction({
 }: ModelUpdateActionProps) {
   const [open, setOpen] = useState(false);
 
-  // Refresh the caller when this repo+variant's download finishes so the "update available" cue
-  // clears. A ref keeps the subscription stable across renders.
   const onUpdatedRef = useRef(onUpdated);
-  onUpdatedRef.current = onUpdated;
+  useEffect(() => {
+    onUpdatedRef.current = onUpdated;
+  }, [onUpdated]);
   useEffect(() => {
     return subscribeJobListeners("model", repoId, {
       onComplete: (completedVariant) => {
@@ -83,7 +91,8 @@ export function ModelUpdateAction({
         disabled={disabled}
         className={cn(
           "shrink-0 rounded-md p-1.5 text-muted-foreground/60 transition-colors hover:bg-amber-500/10 hover:text-amber-700 dark:hover:bg-amber-500/15 dark:hover:text-amber-300",
-          disabled && "cursor-not-allowed opacity-40 hover:bg-transparent hover:text-muted-foreground/60",
+          disabled &&
+            "cursor-not-allowed opacity-40 hover:bg-transparent hover:text-muted-foreground/60",
           buttonClassName,
         )}
       >
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/model-usage.ts b/studio/frontend/src/features/model-picker/components/model-selector/model-usage.ts
similarity index 93%
rename from studio/frontend/src/components/assistant-ui/model-selector/model-usage.ts
rename to studio/frontend/src/features/model-picker/components/model-selector/model-usage.ts
index dbcd4b9a1b..c6665e7658 100644
--- a/studio/frontend/src/components/assistant-ui/model-selector/model-usage.ts
+++ b/studio/frontend/src/features/model-picker/components/model-selector/model-usage.ts
@@ -40,7 +40,8 @@ export function loadedAt(times: ModelLoadTimes, id: string): number {
 export function useModelLoadTimes(currentValue?: string): ModelLoadTimes {
   const [times, setTimes] = useState<ModelLoadTimes>(() => readLoadTimes());
   useEffect(() => {
-    if (currentValue) setTimes(recordModelLoaded(currentValue));
+    if (!currentValue) return;
+    queueMicrotask(() => setTimes(recordModelLoaded(currentValue)));
   }, [currentValue]);
   return times;
 }
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/pickers.tsx b/studio/frontend/src/features/model-picker/components/model-selector/pickers.tsx
similarity index 52%
rename from studio/frontend/src/components/assistant-ui/model-selector/pickers.tsx
rename to studio/frontend/src/features/model-picker/components/model-selector/pickers.tsx
index 8e06181585..71b20058f4 100644
--- a/studio/frontend/src/components/assistant-ui/model-selector/pickers.tsx
+++ b/studio/frontend/src/features/model-picker/components/model-selector/pickers.tsx
@@ -10,49 +10,48 @@ import {
   TooltipTrigger,
 } from "@/components/ui/tooltip";
 import { usePlatformStore } from "@/config/env";
-import { ApiProviderLogo } from "@/features/chat/api-provider-logo";
+import { ApiProviderLogo } from "@/features/chat";
 import {
   type ScanFolderInfo,
   addScanFolder,
-  deleteCachedModel,
   deleteFineTunedModel,
-  listCachedGguf,
-  listCachedModels,
   listGgufVariants,
-  listLocalModels,
   listRecommendedFolders,
   listScanFolders,
   removeScanFolder,
-} from "@/features/chat/api/chat-api";
-import { useChatRuntimeStore } from "@/features/chat/stores/chat-runtime-store";
+} from "@/features/chat";
+import { useChatRuntimeStore } from "@/features/chat";
 import type {
   CachedGgufRepo,
   CachedModelRepo,
+  GgufVariantDetail,
   LocalModelInfo,
-} from "@/features/chat/api/chat-api";
-import type { GgufVariantDetail } from "@/features/chat/types/api";
-import { DotTag } from "@/features/hub/catalog/dot-tag";
+} from "@/features/chat";
 import {
+  DotTag,
   type HubOption,
   HubOptionMenu,
-} from "@/features/hub/catalog/hub-option-menu";
-import { TransportConflictDialog } from "@/features/hub/catalog/transport-conflict-dialog";
-import { TrainIcon } from "@/features/hub/components/train-icon";
-import { useHubInfiniteScroll } from "@/features/hub/hooks/use-hub-infinite-scroll";
+  TrainIcon,
+  TransportConflictDialog,
+  deleteCachedModel,
+  listGgufVariants as listGgufVariantsCached,
+  useHubInfiniteScroll,
+} from "@/features/hub";
 import {
   type HfModelResult,
   type HfSortKey,
   useHubModelSearch,
-} from "@/features/hub/hooks/use-hub-model-search";
-import { useOnlineStatus } from "@/features/hub/hooks/use-online-status";
-import { isHiddenModelId } from "@/features/hub/lib/hidden-models";
-import { classifyUnslothSupport } from "@/features/hub/lib/unsloth-support";
-import { useHfTokenStore } from "@/features/hub/stores/hf-token-store";
+} from "@/features/hub";
 import {
+  classifyUnslothSupport,
   downloadManager,
+  hfApiToken,
+  isHiddenModelId,
   jobKeyOf,
   useDownloadManagerStore,
-} from "@/features/hub/download-manager";
+  useHfTokenStore,
+  useOnlineStatus,
+} from "@/features/hub";
 import { useDebouncedValue, useGpuInfo } from "@/hooks";
 import { extractParamLabel } from "@/lib/model-size";
 import { toast } from "@/lib/toast";
@@ -61,12 +60,14 @@ import type { VramFitStatus } from "@/lib/vram";
 import { checkVramFit, estimateLoadingVram } from "@/lib/vram";
 import {
   Add01Icon,
+  ArrowUpDownIcon,
   AudioWave01Icon,
   Cancel01Icon,
   DashboardCircleIcon,
   Download01Icon,
   Flag01Icon,
   Folder02Icon,
+  PinIcon,
   RemoveCircleIcon,
   Search01Icon,
   ViewIcon,
@@ -85,6 +86,7 @@ import {
   useRef,
   useState,
 } from "react";
+import { useChatPickerInventory } from "../../inventory/use-chat-picker-inventory";
 import { FolderBrowser } from "./folder-browser";
 import {
   type ModelCapabilities,
@@ -92,13 +94,19 @@ import {
   hasAnyCapability,
 } from "./model-capabilities";
 import { ModelDeleteAction } from "./model-delete-action";
-import { ModelUpdateAction } from "./model-update-action";
 import { ModelLoadSettingsAction } from "./model-load-settings-action";
+import { ModelRowMenu } from "./model-row-menu";
 import {
   type ModelLoadTimes,
   loadedAt,
   useModelLoadTimes,
 } from "./model-usage";
+import {
+  makePinRank,
+  pinKey,
+  pinnedQuantEntries,
+  usePinnedModelsStore,
+} from "./pinned-models";
 import {
   type FormatFilter,
   estimateQuantBytes,
@@ -313,7 +321,7 @@ function ListLabel({
         divider ? "mt-3 border-t border-border/50 pt-3" : "pt-3",
       )}
     >
-      <span className="flex items-center gap-1.5 text-[10px] font-semibold uppercase tracking-wider text-muted-foreground">
+      <span className="flex items-center gap-1.5 text-ui-10 font-semibold uppercase tracking-wider text-muted-foreground">
         {icon}
         {children}
       </span>
@@ -342,15 +350,12 @@ function ListLabel({
 
 /** Format bytes to a human-readable size string. */
 function formatBytes(bytes: number): string {
-  // Guard non-positive / non-finite sizes (0, missing -> NaN, Infinity) so we
-  // never render "NaN undefined" or a negative unit index.
+  // Guard non-positive / non-finite sizes so we never render "NaN undefined".
   if (!Number.isFinite(bytes) || bytes <= 0) return "0 B";
-  // Decimal (base-1000) units to match what Hugging Face reports for a repo's
-  // file sizes -- e.g. 217 GB, not the 201.8 GiB a base-1024 divide would show.
-  // (GPU-fit math below stays base-1024 since VRAM is binary.)
-  // Divide iteratively rather than via Math.log, which has float error at exact
-  // powers of 1000 (log(1e12)/log(1000) = 3.9999... would mislabel 1 TB as
-  // "1000 GB"); the loop also can't run off the end of units.
+  // Decimal (base-1000) units to match Hugging Face's reported file sizes (GPU-fit
+  // math below stays base-1024 since VRAM is binary). Divide iteratively rather
+  // than via Math.log, which has float error at exact powers of 1000 (mislabeling
+  // 1 TB as "1000 GB") and could run off the end of units.
   const units = ["B", "KB", "MB", "GB", "TB"];
   let i = 0;
   let value = bytes;
@@ -384,10 +389,63 @@ function CapabilityIcons({ caps }: { caps: ModelCapabilities }) {
   );
 }
 
+function normalizeModelIdForPicker(modelId: string): string {
+  const trimmed = modelId.trim();
+  const slashPath = trimmed.replace(/\\/g, "/").replace(/\/+$/, "");
+  const caseInsensitive =
+    !/^(\/|\.{1,2}\/|~\/)/.test(slashPath) ||
+    /^[A-Za-z]:\//.test(slashPath) ||
+    slashPath.startsWith("//") ||
+    /^\/mnt\/[A-Za-z](?:\/|$)/.test(slashPath);
+  return caseInsensitive ? slashPath.toLowerCase() : slashPath;
+}
+
+function modelIdsMatchForPicker(
+  left: string | null | undefined,
+  right: string | null | undefined,
+): boolean {
+  return Boolean(
+    left &&
+      right &&
+      normalizeModelIdForPicker(left) === normalizeModelIdForPicker(right),
+  );
+}
+
+function normalizeGgufVariantForPicker(variant: string | null | undefined) {
+  return variant?.trim().toLowerCase() ?? "";
+}
+
+function ggufVariantsMatchForPicker(
+  left: string | null | undefined,
+  right: string | null | undefined,
+): boolean {
+  return (
+    normalizeGgufVariantForPicker(left) === normalizeGgufVariantForPicker(right)
+  );
+}
+
+function isRuntimeLoadedModel(
+  loadedModelId: string | undefined,
+  activeGgufVariant: string | null | undefined,
+  modelId: string,
+  variantPolicy: "none" | "required" | "ignore",
+): boolean {
+  if (!modelIdsMatchForPicker(loadedModelId, modelId)) return false;
+  if (variantPolicy === "ignore") return true;
+  const hasActiveGgufVariant = !ggufVariantsMatchForPicker(
+    activeGgufVariant,
+    null,
+  );
+  return variantPolicy === "required"
+    ? hasActiveGgufVariant
+    : !hasActiveGgufVariant;
+}
+
 function ModelRow({
   label,
   meta,
   selected,
+  loaded = false,
   onClick,
   vramStatus,
   vramEst,
@@ -405,6 +463,8 @@ function ModelRow({
   label: string;
   meta?: string | null;
   selected?: boolean;
+  /** Override badge state when authoritative runtime state is available. */
+  loaded?: boolean;
   onClick: () => void;
   vramStatus?: VramFitStatus | null;
   vramEst?: number;
@@ -466,7 +526,7 @@ function ModelRow({
     >
       <span className="flex min-w-0 flex-1 items-baseline">
         {owner && !hideOwner ? (
-          <span className="inline-flex min-w-0 max-w-[45%] shrink items-baseline text-[13px] text-muted-foreground/90">
+          <span className="inline-flex min-w-0 max-w-[45%] shrink items-baseline text-ui-13 text-muted-foreground/90">
             <span className="truncate">{owner}</span>
             <span className="shrink-0 text-muted-foreground/45">/</span>
           </span>
@@ -494,7 +554,7 @@ function ModelRow({
             </TooltipContent>
           </Tooltip>
         )}
-        {selected && (
+        {loaded && (
           <DotTag
             tone="success"
             label="Loaded"
@@ -502,7 +562,7 @@ function ModelRow({
             dotClassName="size-[5px]"
           />
         )}
-        {downloaded && !selected && (
+        {downloaded && !loaded && (
           <span
             title="Already downloaded"
             aria-label="Already downloaded"
@@ -516,25 +576,25 @@ function ModelRow({
           </span>
         )}
         {vramStatus === "exceeds" && (
-          <span className="text-[9px] font-medium !text-red-700 !bg-red-50 dark:!text-red-300 dark:!bg-red-500/15 px-1.5 py-0.5 rounded">
+          <span className="text-ui-9 font-medium !text-red-700 !bg-red-50 dark:!text-red-300 dark:!bg-red-500/15 px-1.5 py-0.5 rounded">
             OOM
           </span>
         )}
         {vramStatus === "tight" && (
-          <span className="text-[9px] font-medium !text-amber-400">TIGHT</span>
+          <span className="text-ui-9 font-medium !text-amber-400">TIGHT</span>
         )}
         {paramLabel ? (
-          <span className="rounded-md border border-border/60 px-1.5 py-px text-[10px] font-medium text-muted-foreground tabular-nums">
+          <span className="rounded-md border border-border/60 px-1.5 py-px text-ui-10 font-medium text-muted-foreground tabular-nums">
             {paramLabel}
           </span>
         ) : null}
         {parsed.texts.map((text) => (
-          <span key={text} className="text-[10px] text-muted-foreground">
+          <span key={text} className="text-ui-10 text-muted-foreground">
             {text}
           </span>
         ))}
         {parsed.size !== undefined ? (
-          <span className="text-[10px] text-muted-foreground tabular-nums">
+          <span className="text-ui-10 text-muted-foreground tabular-nums">
             {parsed.size}
           </span>
         ) : null}
@@ -554,7 +614,7 @@ function ModelRow({
   // Optional Hugging Face address line for online/Hub rows, rendered under
   // whichever tooltip shows so the repo id / URL is always visible on hover.
   const hubUrlLine = hubUrl ? (
-    <span className="block mt-1 text-[10px] text-muted-foreground break-all">
+    <span className="block mt-1 text-ui-10 text-muted-foreground break-all">
       {hubUrl}
     </span>
   ) : null;
@@ -562,7 +622,7 @@ function ModelRow({
   const tooltipBody = vramTooltipText ? (
     <>
       {label}
-      <span className="block text-[10px] mt-1">{vramTooltipText}</span>
+      <span className="block text-ui-10 mt-1">{vramTooltipText}</span>
       {hubUrlLine}
     </>
   ) : tooltipText ? (
@@ -611,12 +671,17 @@ function isValidGgufVariant(variant: unknown): variant is GgufVariantDetail {
   );
 }
 
-function normalizeGgufVariantsResponse(res: {
-  variants?: unknown;
-  default_variant?: unknown;
-  has_vision?: unknown;
-  context_length?: unknown;
-} | null | undefined): {
+function normalizeGgufVariantsResponse(
+  res:
+    | {
+        variants?: unknown;
+        default_variant?: unknown;
+        has_vision?: unknown;
+        context_length?: unknown;
+      }
+    | null
+    | undefined,
+): {
   variants: GgufVariantDetail[];
   defaultVariant: string | null;
   hasVision: boolean;
@@ -659,9 +724,11 @@ function GgufVariantExpander({
   parentOptionKey,
   onNavigatePastStart,
   onNavigatePastEnd,
+  onConfigure,
   sourceOverride,
   variantActions,
   onDevice = false,
+  allowPin = false,
   onHasVision,
 }: {
   repoId: string;
@@ -674,6 +741,7 @@ function GgufVariantExpander({
   parentOptionKey?: string;
   onNavigatePastStart?: () => void;
   onNavigatePastEnd?: () => void;
+  onConfigure?: (id: string, meta: ModelSelectorChangeMeta) => void;
   sourceOverride?: ModelSelectorChangeMeta["source"];
   /** Update/delete actions for cached variant rows. Omitted by browse-only
    *  expanders (Recommended, etc.) that don't manage on-disk variants. */
@@ -692,17 +760,27 @@ function GgufVariantExpander({
   /** On Device rows honor the Show all quantizations setting; Recommended and
    *  other browse lists always show every quant. */
   onDevice?: boolean;
+  /** Only managed cached-Hub rows can surface quant pins in the Pinned
+   *  section. Local-path expanders deliberately leave this false. */
+  allowPin?: boolean;
   /** Report GGUF vision support up so the parent row can badge it. */
   onHasVision?: (hasVision: boolean) => void;
 }) {
+  const pinnedKeys = usePinnedModelsStore((s) => s.pinned);
+  const togglePinnedQuant = usePinnedModelsStore((s) => s.togglePinned);
   const onUpdateVariant = variantActions?.onUpdate;
-  const updateVariantTitle = variantActions?.updateTitle ?? "Update cached model?";
-  const renderUpdateVariantDescription = variantActions?.renderUpdateDescription;
+  const updateVariantTitle =
+    variantActions?.updateTitle ?? "Update cached model?";
+  const renderUpdateVariantDescription =
+    variantActions?.renderUpdateDescription;
   const updateDisabled = variantActions?.updateDisabled ?? false;
   const onDeleteVariant = variantActions?.onDelete;
-  const deleteVariantTitle = variantActions?.deleteTitle ?? "Delete cached model?";
-  const renderDeleteVariantDescription = variantActions?.renderDeleteDescription;
-  const getDeleteVariantSuccessMessage = variantActions?.getDeleteSuccessMessage;
+  const deleteVariantTitle =
+    variantActions?.deleteTitle ?? "Delete cached model?";
+  const renderDeleteVariantDescription =
+    variantActions?.renderDeleteDescription;
+  const getDeleteVariantSuccessMessage =
+    variantActions?.getDeleteSuccessMessage;
   const deleteDisabled = variantActions?.deleteDisabled ?? false;
   const [variants, setVariants] = useState<GgufVariantDetail[] | null>(null);
   const [defaultVariant, setDefaultVariant] = useState<string | null>(null);
@@ -715,8 +793,11 @@ function GgufVariantExpander({
 
   useEffect(() => {
     let canceled = false;
-    setLoading(true);
-    setError(null);
+    queueMicrotask(() => {
+      if (canceled) return;
+      setLoading(true);
+      setError(null);
+    });
 
     listGgufVariants(repoId, hfToken)
       .then((res) => {
@@ -744,17 +825,12 @@ function GgufVariantExpander({
   }, [repoId, refreshKey, hfToken]);
 
   // Covers Unix absolute (/), Windows drive (C:\, D:/), UNC (\\server), relative (./, ../), tilde (~/)
-  const isLocalPath = /^(\/|\.{1,2}[\\\/]|~[\\\/]|[A-Za-z]:[\\\/]|\\\\)/.test(
+  const isLocalPath = /^(\/|\.{1,2}[\\/]|~[\\/]|[A-Za-z]:[\\/]|\\\\)/.test(
     repoId,
   );
 
   const handleVariantClick = useCallback(
     (quant: string, downloaded?: boolean, sizeBytes?: number) => {
-      // Only seed the staged context for picks whose weights are already on
-      // disk. The staging effect short-circuits on a known contextLength
-      // (pendingHasContext) before starting the download, so attaching it to an
-      // undownloaded quant from a partially cached repo would skip the download
-      // entirely (and, with Load on selection, never load).
       const isAvailable = isLocalPath || downloaded === true;
       onSelect(repoId, {
         source: sourceOverride ?? (isLocalPath ? "local" : "hub"),
@@ -763,6 +839,7 @@ function GgufVariantExpander({
         isDownloaded: isLocalPath ? true : downloaded,
         expectedBytes: sizeBytes,
         contextLength: isAvailable ? nativeContext : undefined,
+        isGguf: true,
       });
     },
     [repoId, isLocalPath, onSelect, sourceOverride, nativeContext],
@@ -777,13 +854,12 @@ function GgufVariantExpander({
 
   const getGgufFit = useCallback(
     (sizeBytes: number): "fits" | "tight" | "oom" => {
-      // No device budget at all (no GPU and no known system RAM): can't
-      // classify, so don't scare the user with OOM badges.
+      // No device budget at all: can't classify, so don't show OOM badges.
       if (totalBudgetGb <= 0) return "fits";
       const gb = sizeBytes / 1024 ** 3;
       if (gb <= 0 || gb <= gpuBudgetGb) return "fits";
-      // No-GPU / unified-memory hosts (Mac) have only the RAM budget, so the
-      // tier collapses to fit-or-oom against system RAM rather than GPU+offload.
+      // No-GPU / unified-memory hosts (Mac) have only the RAM budget, so the tier
+      // collapses to fit-or-oom against system RAM.
       if (gpuBudgetGb <= 0) return gb <= totalBudgetGb ? "fits" : "oom";
       if (gb <= totalBudgetGb) return "tight";
       return "oom";
@@ -801,17 +877,13 @@ function GgufVariantExpander({
     if (defaultV && getGgufFit(defaultV.size_bytes) !== "oom")
       return defaultVariant;
     // Largest non-OOM variant (best quality that fits)
-    const fitting = variants.filter(
-      (v) => getGgufFit(v.size_bytes) !== "oom",
-    );
+    const fitting = variants.filter((v) => getGgufFit(v.size_bytes) !== "oom");
     if (fitting.length > 0) {
       fitting.sort((a, b) => b.size_bytes - a.size_bytes);
       return fitting[0].quant;
     }
     // All OOM -- recommend smallest (most likely to partially run)
-    const sorted = [...variants].sort(
-      (a, b) => a.size_bytes - b.size_bytes,
-    );
+    const sorted = [...variants].sort((a, b) => a.size_bytes - b.size_bytes);
     return sorted[0]?.quant ?? defaultVariant;
   }, [variants, defaultVariant, totalBudgetGb, getGgufFit]);
 
@@ -904,11 +976,11 @@ function GgufVariantExpander({
           redundant; its Vision badge is relayed to the name instead. */}
       {!onDevice && (
         <div className="px-2 py-1 flex items-center gap-1.5">
-          <span className="text-[10px] font-semibold uppercase tracking-wider text-muted-foreground">
+          <span className="text-ui-10 font-semibold uppercase tracking-wider text-muted-foreground">
             Quantizations
           </span>
           {hasVision && (
-            <span className="flex items-center gap-0.5 text-[9px] font-medium text-indigo-700 dark:text-indigo-300">
+            <span className="flex items-center gap-0.5 text-ui-9 font-medium text-indigo-700 dark:text-indigo-300">
               <HugeiconsIcon
                 icon={ViewIcon}
                 className="size-3"
@@ -927,7 +999,7 @@ function GgufVariantExpander({
         const keyBase = `${repoId}:${v.filename}`;
         const variantOptionKey = makeModelOptionKey("gguf-variant", keyBase);
         return (
-          <div key={v.filename} className="flex items-center gap-0.5">
+          <div key={v.filename} className="flex items-center">
             <button
               type="button"
               {...variantList.getOptionProps(variantOptionKey, false)}
@@ -935,7 +1007,7 @@ function GgufVariantExpander({
                 handleVariantClick(v.quant, v.downloaded, expectedBytes)
               }
               className={cn(
-                "flex min-w-0 flex-1 items-center justify-between gap-2 rounded-full px-2 py-1 text-left text-sm transition-colors hover:bg-[#ececec] focus-visible:bg-[#ececec] focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring dark:hover:bg-[var(--sidebar-accent)] dark:focus-visible:bg-[var(--sidebar-accent)]",
+                "flex min-w-0 flex-1 items-center justify-between gap-2 rounded-full py-1 pl-2 pr-1.5 text-left text-sm transition-colors hover:bg-[#ececec] focus-visible:bg-[#ececec] focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring dark:hover:bg-[var(--sidebar-accent)] dark:focus-visible:bg-[var(--sidebar-accent)]",
               )}
             >
               <span className="min-w-0 flex-1 truncate font-mono text-xs">
@@ -946,93 +1018,135 @@ function GgufVariantExpander({
                 </span>
                 {v.downloaded ? (
                   <>
-                    <span className="ml-1.5 text-[9px] font-sans font-medium text-green-400">
+                    <span className="ml-1.5 text-ui-9 font-sans font-medium text-green-600/90 dark:text-green-400/80">
                       downloaded
                     </span>
                     {v.update_available ? (
-                      <span className="ml-1.5 text-[9px] font-sans font-medium text-amber-700 dark:text-amber-300">
+                      <span className="ml-1.5 text-ui-9 font-sans font-medium text-amber-700 dark:text-amber-300">
                         update available
                       </span>
-                    ): null}
+                    ) : null}
                   </>
                 ) : v.quant === effectiveRecommended ? (
-                  <span className="ml-1.5 text-[9px] font-sans font-medium text-primary/70">
+                  <span className="ml-1.5 text-ui-9 font-sans font-medium text-primary/70">
                     recommended
                   </span>
                 ) : null}
               </span>
               <span className="flex items-center gap-1.5 shrink-0">
                 {oom && (
-                  <span className="text-[9px] font-medium !text-red-700 !bg-red-50 dark:!text-red-300 dark:!bg-red-500/15 px-1.5 py-0.5 rounded">
+                  <span className="text-ui-9 font-medium !text-red-700 !bg-red-50 dark:!text-red-300 dark:!bg-red-500/15 px-1.5 py-0.5 rounded">
                     OOM
                   </span>
                 )}
                 {tight && (
-                  <span className="text-[9px] font-medium !text-amber-400">
+                  <span className="text-ui-9 font-medium !text-amber-400">
                     TIGHT
                   </span>
                 )}
-                <span className="text-[10px] text-muted-foreground">
+                <span className="text-ui-10 text-muted-foreground">
                   {formatBytes(v.size_bytes)}
                 </span>
               </span>
             </button>
-            {v.downloaded && v.update_available && onUpdateVariant && (
-              <ModelUpdateAction
-                ariaLabel={`Update ${repoId} ${v.quant}`}
-                title={updateVariantTitle}
-                description={
-                  renderUpdateVariantDescription?.(v.quant) ?? (
-                    <>
-                      This will update{" "}
-                      <span className="font-medium text-foreground">
-                        {repoId} ({v.quant})
-                      </span>{"."}
-                    </>
-                  )
-                }
-                repoId={repoId}
-                variant={v.quant}
-                buttonClassName="p-1"
-                iconClassName="size-3"
-                disabled={updateDisabled}
-                onConfirm={() => onUpdateVariant(v.quant, expectedBytes)}
-                onUpdated={() => setRefreshKey((key) => key + 1)}
-              />
-            )}
-            {v.downloaded && (
+            {v.downloaded && onConfigure && (
               <ModelLoadSettingsAction
                 ariaLabel={`Inference settings for ${repoId} ${v.quant}`}
-                repoId={repoId}
-                quant={v.quant}
-                maxContext={nativeContext}
-              />
-            )}
-            {v.downloaded && onDeleteVariant && (
-              <ModelDeleteAction
-                ariaLabel={`Delete ${repoId} ${v.quant}`}
-                title={deleteVariantTitle}
-                description={
-                  renderDeleteVariantDescription?.(v.quant) ?? (
-                    <>
-                      This will remove{" "}
-                      <span className="font-medium text-foreground">
-                        {repoId} ({v.quant})
-                      </span>{" "}
-                      from disk. You can re-download it later.
-                    </>
-                  )
-                }
-                successMessage={
-                  getDeleteVariantSuccessMessage?.(v.quant) ??
-                  `Deleted ${repoId} ${v.quant}`
-                }
-                buttonClassName="p-1"
-                iconClassName="size-3"
-                disabled={deleteDisabled}
-                onConfirm={() => onDeleteVariant(v.quant)}
+                className="relative left-0.5"
+                onConfigure={() =>
+                  onConfigure(repoId, {
+                    source: sourceOverride ?? (isLocalPath ? "local" : "hub"),
+                    isLora: false,
+                    ggufVariant: v.quant,
+                    isDownloaded: true,
+                    expectedBytes,
+                    contextLength: nativeContext,
+                    isGguf: true,
+                  })
+                }
               />
             )}
+            {v.downloaded &&
+              (allowPin ||
+                (v.update_available && onUpdateVariant) ||
+                onDeleteVariant ||
+                !isLocalPath) && (
+                <ModelRowMenu
+                  ariaLabel={`More options for ${repoId} ${v.quant}`}
+                  iconClassName="size-3"
+                  cachePath={
+                    isLocalPath ? undefined : { repoId, variant: v.quant }
+                  }
+                  pin={
+                    allowPin
+                      ? {
+                          pinned: pinnedKeys.includes(pinKey(repoId, v.quant)),
+                          pinLabel: "Pin to top",
+                          unpinLabel: "Unpin",
+                          onToggle: () => togglePinnedQuant(repoId, v.quant),
+                        }
+                      : undefined
+                  }
+                  update={
+                    v.update_available && onUpdateVariant
+                      ? {
+                          title: updateVariantTitle,
+                          description: renderUpdateVariantDescription?.(
+                            v.quant,
+                          ) ?? (
+                            <>
+                              This will update{" "}
+                              <span className="font-medium text-foreground">
+                                {repoId} ({v.quant})
+                              </span>
+                              {"."}
+                            </>
+                          ),
+                          repoId,
+                          variant: v.quant,
+                          disabled: updateDisabled,
+                          onConfirm: () =>
+                            onUpdateVariant(v.quant, expectedBytes),
+                          onUpdated: () => setRefreshKey((key) => key + 1),
+                        }
+                      : undefined
+                  }
+                  del={
+                    onDeleteVariant
+                      ? {
+                          title: deleteVariantTitle,
+                          description: renderDeleteVariantDescription?.(
+                            v.quant,
+                          ) ?? (
+                            <>
+                              This will remove{" "}
+                              <span className="font-medium text-foreground">
+                                {repoId} ({v.quant})
+                              </span>{" "}
+                              from disk. You can re-download it later.
+                            </>
+                          ),
+                          successMessage:
+                            getDeleteVariantSuccessMessage?.(v.quant) ??
+                            `Deleted ${repoId} ${v.quant}`,
+                          disabled: deleteDisabled,
+                          onConfirm: async () => {
+                            await onDeleteVariant(v.quant);
+                            // Drop the pin too: a pinned row for a deleted file
+                            // would try to load something that no longer exists.
+                            if (pinnedKeys.includes(pinKey(repoId, v.quant))) {
+                              togglePinnedQuant(repoId, v.quant);
+                            }
+                            // Re-fetch this expander's variants so the deleted
+                            // quant stops showing as downloaded (and clickable to
+                            // reload) while the repo still has other cached quants.
+                            setRefreshKey((key) => key + 1);
+                          },
+                        }
+                      : undefined
+                  }
+                />
+              )}
           </div>
         );
       })}
@@ -1202,13 +1316,26 @@ function localPathTooltip(name: string, path: string): ReactNode {
   return (
     <>
       <span className="block break-words">{name}</span>
-      <span className="block mt-1 text-[10px] text-muted-foreground break-all">
+      <span className="block mt-1 text-ui-10 text-muted-foreground break-all">
         {path}
       </span>
     </>
   );
 }
 
+function localModelMeta(isGguf = false): ModelSelectorChangeMeta {
+  return {
+    source: "local",
+    isLora: false,
+    isDownloaded: true,
+    ...(isGguf ? { isGguf: true } : {}),
+  };
+}
+
+function localDirectGgufMeta(): ModelSelectorChangeMeta {
+  return localModelMeta(true);
+}
+
 /** Hugging Face address for an online/Hub row, or undefined when the repo id is
  * missing so the row shows no (empty) address line on hover. */
 function hubRepoUrl(id: string | null | undefined): string | undefined {
@@ -1219,9 +1346,7 @@ function hubRepoUrl(id: string | null | undefined): string | undefined {
 /** Whether a local model is an MLX build (name hint). MLX runs on Mac only, so
  * callers gate visibility on the host being a Mac. */
 function localModelIsMlx(m: LocalModelInfo): boolean {
-  return (
-    isMlxId(m.id) || isMlxId(m.display_name) || isMlxId(m.model_id ?? "")
-  );
+  return isMlxId(m.id) || isMlxId(m.display_name) || isMlxId(m.model_id ?? "");
 }
 
 /** Whether a local model matches the format toggle (GGUF detected by name/path). */
@@ -1245,6 +1370,7 @@ export function HubModelPicker({
   onFoldersChange,
   onBrowseHub,
   onModelsChange,
+  onConfigure,
   deleteDisabled = false,
   section = "downloaded",
   sectionToggle,
@@ -1261,18 +1387,20 @@ export function HubModelPicker({
   /** Open the full Hub page to browse more models. */
   onBrowseHub?: () => void;
   onModelsChange?: (deletedModel?: DeletedModelRef) => void;
+  onConfigure?: (id: string, meta: ModelSelectorChangeMeta) => void;
   deleteDisabled?: boolean;
   /** Section shown when not searching. Search spans all sections. */
   section?: "downloaded" | "recommended" | "custom" | "connected";
   /** Section toggle rendered under the search bar. */
   sectionToggle?: ReactNode;
-  /** Eject the loaded model. Rendered as the last list row when set. */
   onEject?: () => void;
 }) {
   const gpu = useGpuInfo();
   // Live model id from the runtime store (backend-mirrored active_model), not the dropdown
   // highlight which can be a staged pick. Disables the update action for it.
   const loadedModelId = useChatRuntimeStore((s) => s.params.checkpoint);
+  // Loaded GGUF quant of the active model; marks the matching pinned row.
+  const activeGgufVariant = useChatRuntimeStore((s) => s.activeGgufVariant);
   // Last-loaded timestamps power the "Recent" sort (vs "Downloaded" = file date).
   const loadTimes = useModelLoadTimes(value);
   // Fade the list's top edge once scrolled, and its bottom edge while more
@@ -1285,7 +1413,8 @@ export function HubModelPicker({
   // Shared Hub search stack (the same hooks the Hub page uses) so the picker
   // and Hub run one implementation. Scoped to unsloth like the old listing.
   const online = useOnlineStatus();
-  const accessToken = hfToken || undefined;
+  // Sanitize to anonymous on a malformed token, matching the Hub page.
+  const accessToken = hfApiToken(hfToken);
   // Recommended section: a live unsloth listing sorted by the dropdown. The
   // same sort drives the search results so the dropdown works while searching.
   const [recommendedSort, setRecommendedSort] =
@@ -1307,9 +1436,8 @@ export function HubModelPicker({
     pinUnslothFirst: true,
     keepUnsupportedTags: true,
     accessToken,
-    // Only the Recommended section renders Hub results (On Device / Connected
-    // use local data), so keep the Hub hooks idle on the other tabs to avoid
-    // needless requests/spinner and to preserve offline-local behavior.
+    // Only Recommended renders Hub results, so keep the Hub hooks idle on other
+    // tabs to avoid needless requests and preserve offline-local behavior.
     enabled: online && section === "recommended",
   });
   const recommendedSearch = useHubModelSearch("", {
@@ -1322,10 +1450,9 @@ export function HubModelPicker({
     enabled: online && section === "recommended",
   });
 
-  // Lowercased repo ids confirmed GGUF by the store or HF search.
-  // Absence means "no hint" -> hasGgufSuffix is the fallback (don't
-  // conflate unknown with known-not-GGUF). Lowercased so store and HF
-  // IDs differing only by casing match the same hint.
+  // Lowercased repo ids confirmed GGUF by the store or HF search. Absence means
+  // "no hint" -> hasGgufSuffix is the fallback (don't conflate unknown with
+  // known-not-GGUF). Lowercased so store and HF IDs match regardless of casing.
   const modelGgufIds = useMemo(() => {
     const ids = new Set<string>();
     for (const model of models) {
@@ -1367,12 +1494,14 @@ export function HubModelPicker({
   const setFitOnDeviceOnly = useChatRuntimeStore((s) => s.setFitOnDeviceOnly);
   // Repos the user clicked to collapse while expand-by-default is on. Kept in
   // memory only, so it resets on reload (and when the setting is toggled).
-  const [collapsedGguf, setCollapsedGguf] = useState<Set<string>>(
-    () => new Set(),
-  );
-  useEffect(() => {
-    setCollapsedGguf(new Set());
-  }, [expandQuantizations]);
+  const [collapsedGgufState, setCollapsedGgufState] = useState<{
+    expandQuantizations: boolean;
+    value: Set<string>;
+  }>(() => ({ expandQuantizations, value: new Set() }));
+  const collapsedGguf =
+    collapsedGgufState.expandQuantizations === expandQuantizations
+      ? collapsedGgufState.value
+      : new Set<string>();
   const isGgufExpanded = useCallback(
     (id: string) =>
       expandQuantizations ? !collapsedGguf.has(id) : expandedGguf === id,
@@ -1383,11 +1512,15 @@ export function HubModelPicker({
   const toggleGgufExpanded = useCallback(
     (id: string) => {
       if (expandQuantizations) {
-        setCollapsedGguf((prev) => {
-          const next = new Set(prev);
+        setCollapsedGgufState((prev) => {
+          const current =
+            prev.expandQuantizations === expandQuantizations
+              ? prev.value
+              : new Set<string>();
+          const next = new Set(current);
           if (next.has(id)) next.delete(id);
           else next.add(id);
-          return next;
+          return { expandQuantizations, value: next };
         });
       } else {
         setExpandedGguf((prev) => (prev === id ? null : id));
@@ -1396,6 +1529,7 @@ export function HubModelPicker({
     [expandQuantizations],
   );
 
+  const [pinnedCollapsed, setPinnedCollapsed] = useState(false);
   const [downloadedCollapsed, setDownloadedCollapsed] = useState(false);
   const [otherModelsCollapsed, setOtherModelsCollapsed] = useState(false);
   const [customFoldersCollapsed, setCustomFoldersCollapsed] = useState(false);
@@ -1447,15 +1581,37 @@ export function HubModelPicker({
     });
   }, []);
 
-  // Cached (downloaded) repos -- module-level cache avoids flashing an
-  // empty "Downloaded" section when the popover re-mounts.
-  const [cachedGguf, setCachedGguf] =
-    useState<CachedGgufRepo[]>(_cachedGgufCache);
-  const [cachedModels, setCachedModels] =
-    useState<CachedModelRepo[]>(_cachedModelsCache);
-  const alreadyCached =
-    _cachedGgufCache.length > 0 || _cachedModelsCache.length > 0;
-  const [cachedReady, setCachedReady] = useState(alreadyCached);
+  const pickerInventory = useChatPickerInventory({ enabled: true });
+  const { cachedGguf, cachedModels, cachedReady, refreshInventory } =
+    pickerInventory;
+  const lmStudioModels = useMemo(
+    () =>
+      sortLmStudio(
+        pickerInventory.localModels.filter((m) => m.source === "lmstudio"),
+      ),
+    [pickerInventory.localModels],
+  );
+  const localDirModels = useMemo(
+    () => pickerInventory.localModels.filter((m) => m.source === "models_dir"),
+    [pickerInventory.localModels],
+  );
+  const customFolderModels = useMemo(
+    () => pickerInventory.localModels.filter((m) => m.source === "custom"),
+    [pickerInventory.localModels],
+  );
+  useEffect(() => {
+    _cachedGgufCache = cachedGguf;
+    _cachedModelsCache = cachedModels;
+    _lmStudioCache = lmStudioModels;
+    _localDirCache = localDirModels;
+    _customFolderCache = customFolderModels;
+  }, [
+    cachedGguf,
+    cachedModels,
+    lmStudioModels,
+    localDirModels,
+    customFolderModels,
+  ]);
   const [updateConflictKey, setUpdateConflictKey] = useState<string | null>(
     null,
   );
@@ -1479,16 +1635,6 @@ export function HubModelPicker({
     setUpdateConflictKey(null);
   }, [updateConflictKey]);
 
-  // LM Studio local models -- module-level cache, same pattern as above.
-  const [lmStudioModels, setLmStudioModels] =
-    useState<LocalModelInfo[]>(_lmStudioCache);
-  // Models found under the local models directory (./models), so they stay
-  // selectable on the On Device tab after leaving the Fine-tuned tab.
-  const [localDirModels, setLocalDirModels] =
-    useState<LocalModelInfo[]>(_localDirCache);
-  const [customFolderModels, setCustomFolderModels] =
-    useState<LocalModelInfo[]>(_customFolderCache);
-
   // Custom scan folders management
   const [scanFolders, setScanFolders] =
     useState<ScanFolderInfo[]>(_scanFoldersCache);
@@ -1500,22 +1646,8 @@ export function HubModelPicker({
   const [recommendedFolders, setRecommendedFolders] = useState<string[]>([]);
 
   const refreshLocalModelsList = useCallback(() => {
-    listLocalModels()
-      .then((res) => {
-        const lm = sortLmStudio(
-          res.models.filter((m) => m.source === "lmstudio"),
-        );
-        _lmStudioCache = lm;
-        setLmStudioModels(lm);
-        const ld = res.models.filter((m) => m.source === "models_dir");
-        _localDirCache = ld;
-        setLocalDirModels(ld);
-        const cf = res.models.filter((m) => m.source === "custom");
-        _customFolderCache = cf;
-        setCustomFolderModels(cf);
-      })
-      .catch(() => {});
-  }, []);
+    void pickerInventory.refreshInventory();
+  }, [pickerInventory.refreshInventory]);
 
   const refreshScanFolders = useCallback(() => {
     listScanFolders()
@@ -1535,9 +1667,8 @@ export function HubModelPicker({
       if (!trimmed || folderLoading) return;
       setFolderError(null);
       setFolderLoading(true);
-      // From the folder browser's one-click "Use this folder": the typed-
-      // input panel is closed, so the inline folderError is invisible.
-      // Surface failures (denylisted path, sandbox 403, etc.) via toast.
+      // From the folder browser's "Use this folder": the typed-input panel is
+      // closed, so surface failures (denylisted path, sandbox 403) via toast.
       const fromBrowser = overridePath !== undefined;
       try {
         const created = await addScanFolder(trimmed);
@@ -1594,39 +1725,37 @@ export function HubModelPicker({
   );
 
   const refreshCachedLists = useCallback(() => {
-    listCachedGguf()
-      .then((v) => {
-        _cachedGgufCache = v;
-        setCachedGguf(v);
-      })
-      .catch(() => {});
-    listCachedModels(hfToken || undefined)
-      .then((v) => {
-        _cachedModelsCache = v;
-        setCachedModels(v);
-      })
-      .catch(() => {});
-    refreshLocalModelsList();
-  }, [hfToken, refreshLocalModelsList]);
+    void pickerInventory.refreshInventory();
+  }, [pickerInventory.refreshInventory]);
 
   // Updates run as managed downloads (Downloads panel: progress + Cancel), not a blocking
   // call. The worker pulls only changed blobs, so the cached copy stays usable until done.
-  const startManagedUpdate = useCallback((repoId: string, variant: string, expectedBytes: number) => {
-    return downloadManager
-      .requestStart({
-        kind: "model",
-        repoId,
-        variant,
-        expectedBytes,
-      })
-      .then((outcome) => {
-        if (outcome === "conflict") {
-          setUpdateConflictKey(jobKeyOf("model", repoId, variant));
-        } else if (outcome === "error") {
-          throw new Error("Failed to start update");
-        }
-      });
-  }, []);
+  const startManagedUpdate = useCallback(
+    (repoId: string, variant: string, expectedBytes: number) => {
+      return downloadManager
+        .requestStart({
+          kind: "model",
+          repoId,
+          variant,
+          expectedBytes,
+        })
+        .then((outcome) => {
+          if (outcome === "conflict") {
+            setUpdateConflictKey(jobKeyOf("model", repoId, variant));
+          } else if (outcome === "busy") {
+            // A sibling variant/snapshot for this repo is already downloading,
+            // so this update did not start. Say so instead of closing the
+            // dialog as if it began and leaving the cached copy stale.
+            toast.info("A download for this model is already in progress", {
+              description: "Try updating again once it finishes.",
+            });
+          } else if (outcome === "error") {
+            throw new Error("Failed to start update");
+          }
+        });
+    },
+    [],
+  );
 
   const updateGgufVariant = useCallback(
     (repoId: string, quant: string, expectedBytes: number) =>
@@ -1635,36 +1764,15 @@ export function HubModelPicker({
   );
 
   useEffect(() => {
-    // Always refresh LM Studio + custom folder models (not gated by alreadyCached).
-    refreshLocalModelsList();
     refreshScanFolders();
     listRecommendedFolders()
       .then(setRecommendedFolders)
       .catch(() => {});
+  }, [refreshScanFolders]);
 
-    // Always refetch cached GGUF/model lists. The module-level caches render
-    // instantly with stale data (no spinner flash), but newly downloaded
-    // repos need a fresh backend hit. cachedReady=alreadyCached initially,
-    // so the background refresh is invisible when we already had data.
-    let done = 0;
-    const check = () => {
-      if (++done >= 2) setCachedReady(true);
-    };
-    listCachedGguf()
-      .then((v) => {
-        _cachedGgufCache = v;
-        setCachedGguf(v);
-      })
-      .catch(() => {})
-      .finally(check);
-    listCachedModels(hfToken || undefined)
-      .then((v) => {
-        _cachedModelsCache = v;
-        setCachedModels(v);
-      })
-      .catch(() => {})
-      .finally(check);
-  }, [hfToken, refreshLocalModelsList, refreshScanFolders]);
+  useEffect(() => {
+    void refreshInventory();
+  }, [refreshInventory]);
 
   // Hide downloaded models from the recommended list. Case-insensitive
   // since the HF cache lowercases repo IDs.
@@ -1679,7 +1787,7 @@ export function HubModelPicker({
   const deviceType = usePlatformStore((s) => s.deviceType);
   const isMac = deviceType === "mac";
 
-  // Drop models Studio can't run for chat (diffusion / image / video / etc.)
+  // Drop models Unsloth can't run for chat (diffusion / image / video / etc.)
   // using the Hub's classifier on the tags the listing already carries.
   const isChatSupported = useCallback(
     (r: HfModelResult) =>
@@ -1701,7 +1809,8 @@ export function HubModelPicker({
       // Chat-only keeps runnable formats: GGUF anywhere, plus MLX/safetensors
       // on Mac (matches the empty Recommended view so search stays consistent).
       .filter(
-        (id) => !chatOnly || isRecommendableFormat(id, isKnownGgufRepo(id), isMac),
+        (id) =>
+          !chatOnly || isRecommendableFormat(id, isKnownGgufRepo(id), isMac),
       )
       .filter((id) => !/-FP8[-.]|FP8-Dynamic/i.test(id));
     // Sort: GGUFs first, then hub models
@@ -1730,7 +1839,7 @@ export function HubModelPicker({
     let rows = recommendedSearch.results
       .filter((r) => !isHiddenModelId(r.id))
       .filter((r) => !isMobileVariant(r.id));
-    // Drop models Studio can't run for chat (diffusion / image / video / etc.).
+    // Drop models Unsloth can't run for chat (diffusion / image / video / etc.).
     rows = rows.filter(isChatSupported);
     // With no explicit format, show the device-recommended formats (GGUF, plus
     // MLX on Mac). When the user picks a format, honor it instead so Safetensors
@@ -1868,7 +1977,7 @@ export function HubModelPicker({
     // eslint-disable-next-line react-hooks/exhaustive-deps
     [lmStudioModels, downloadedSort, formatFilter, loadTimes, localQuery],
   );
-  // Local ./models entries. Chat-only Studio runs GGUF (any host) and MLX (Mac
+  // Local ./models entries. Chat-only Unsloth runs GGUF (any host) and MLX (Mac
   // only), so raw checkpoints there are hidden (mirrors the cached non-GGUF
   // rule). An MLX build a Mac user dropped in ./models stays selectable.
   const sortedLocalDir = useMemo(
@@ -1964,6 +2073,125 @@ export function HubModelPicker({
   // logic must use this (not visibleCachedModels) or the picker can go blank.
   const visibleCachedModelRows = chatOnly ? [] : visibleCachedModels;
 
+  // Pinned entries surface in their own section above the Unsloth heading.
+  // GGUF quants pin individually and their repo stays listed below; non-GGUF
+  // repos pin whole and leave the Unsloth / Other models groups.
+  const pinnedIds = usePinnedModelsStore((s) => s.pinned);
+  const togglePinned = usePinnedModelsStore((s) => s.togglePinned);
+  const pinnedSet = useMemo(() => new Set(pinnedIds), [pinnedIds]);
+
+  // Candidate pins whose repo still exists in the cache. Per-quant validation
+  // below is needed because deleting one variant can leave a sibling cached.
+  const pinnedQuantCandidates = useMemo(() => {
+    // The existence check ignores the text query (keeps the format filter) so a
+    // pinned quant stays findable by quant name; querying visibleCachedGguf would
+    // drop the repo before the `${repoId} ${quant}` predicate could surface it.
+    const cached = new Set(
+      sortedCachedGguf
+        .filter((c) => matchesFormatFilter(c.repo_id, true, formatFilter))
+        .map((c) => c.repo_id),
+    );
+    return pinnedQuantEntries(pinnedIds).filter((entry) =>
+      cached.has(entry.repoId),
+    );
+  }, [pinnedIds, sortedCachedGguf, formatFilter]);
+  const [pinnedQuantValidation, setPinnedQuantValidation] = useState<{
+    validated: boolean;
+    downloaded: ReadonlySet<string>;
+  }>({ validated: false, downloaded: new Set() });
+  const prunePinnedQuantValidation = useCallback(
+    (repoId: string, quant: string) => {
+      const key = pinKey(repoId, quant);
+      setPinnedQuantValidation((prev) => {
+        if (!prev.downloaded.has(key)) return prev;
+        const downloaded = new Set(prev.downloaded);
+        downloaded.delete(key);
+        return { ...prev, downloaded };
+      });
+    },
+    [],
+  );
+
+  useEffect(() => {
+    let cancelled = false;
+    const repoIds = Array.from(
+      new Set(pinnedQuantCandidates.map((entry) => entry.repoId)),
+    );
+    if (repoIds.length === 0) return;
+
+    void Promise.all(
+      repoIds.map(async (repoId) => {
+        try {
+          const response = await listGgufVariantsCached(
+            repoId,
+            hfToken || undefined,
+            { preferLocalCache: true },
+          );
+          return normalizeGgufVariantsResponse(response)
+            .variants.filter((variant) => variant.downloaded === true)
+            .map((variant) => pinKey(repoId, variant.quant));
+        } catch {
+          // If the backend cannot verify a quant, hiding the direct-load row
+          // is safer than claiming a missing file is downloaded.
+          return [];
+        }
+      }),
+    ).then((groups) => {
+      if (!cancelled) {
+        setPinnedQuantValidation({
+          validated: true,
+          downloaded: new Set(groups.flat()),
+        });
+      }
+    });
+
+    return () => {
+      cancelled = true;
+    };
+  }, [hfToken, pinnedQuantCandidates]);
+  const downloadedPinnedQuantKeys = useMemo<ReadonlySet<string>>(
+    () =>
+      pinnedQuantValidation.validated
+        ? pinnedQuantValidation.downloaded
+        : new Set(),
+    [pinnedQuantValidation],
+  );
+
+  // Verified downloaded quants, in pin order and filtered by repo id or quant.
+  const pinnedQuants = useMemo(() => {
+    const q = normalizeForSearch(debouncedQuery.trim());
+    return pinnedQuantCandidates.filter(
+      (entry) =>
+        downloadedPinnedQuantKeys.has(pinKey(entry.repoId, entry.quant)) &&
+        (!q ||
+          normalizeForSearch(`${entry.repoId} ${entry.quant}`).includes(q)),
+    );
+  }, [debouncedQuery, downloadedPinnedQuantKeys, pinnedQuantCandidates]);
+
+  const pinnedCachedModelRows = useMemo(
+    () =>
+      visibleCachedModelRows.filter((c) => pinnedSet.has(pinKey(c.repo_id))),
+    [visibleCachedModelRows, pinnedSet],
+  );
+
+  const pinnedRows = useMemo(() => {
+    const rank = makePinRank(pinnedIds);
+    const rows = [
+      ...pinnedQuants.map((entry) => ({
+        key: pinKey(entry.repoId, entry.quant),
+        entry,
+        model: null,
+      })),
+      ...pinnedCachedModelRows.map((model) => ({
+        key: pinKey(model.repo_id),
+        entry: null,
+        model,
+      })),
+    ];
+    rows.sort((a, b) => rank(a.key) - rank(b.key));
+    return rows;
+  }, [pinnedIds, pinnedQuants, pinnedCachedModelRows]);
+
   // Split downloaded models so non-Unsloth repos get their own "Other models"
   // section above Fine-tuned.
   const unslothCachedGguf = useMemo(
@@ -1975,12 +2203,18 @@ export function HubModelPicker({
     [visibleCachedGguf],
   );
   const unslothCachedModelRows = useMemo(
-    () => visibleCachedModelRows.filter((c) => isUnslothRepoId(c.repo_id)),
-    [visibleCachedModelRows],
+    () =>
+      visibleCachedModelRows.filter(
+        (c) => isUnslothRepoId(c.repo_id) && !pinnedSet.has(pinKey(c.repo_id)),
+      ),
+    [visibleCachedModelRows, pinnedSet],
   );
   const otherCachedModelRows = useMemo(
-    () => visibleCachedModelRows.filter((c) => !isUnslothRepoId(c.repo_id)),
-    [visibleCachedModelRows],
+    () =>
+      visibleCachedModelRows.filter(
+        (c) => !isUnslothRepoId(c.repo_id) && !pinnedSet.has(pinKey(c.repo_id)),
+      ),
+    [visibleCachedModelRows, pinnedSet],
   );
 
   // Param counts come straight off the unsloth listings the picker already
@@ -1997,26 +2231,28 @@ export function HubModelPicker({
   const filteredRecommendedIds = useMemo(() => {
     if (!showHfSection) return [];
     const q = normalizeForSearch(debouncedQuery.trim());
-    return recommendedIds
-      .filter((id) => normalizeForSearch(id).includes(q))
-      .filter((id) =>
-        matchesFormatFilter(id, isKnownGgufRepo(id), formatFilter),
-      )
-      // Curated defaults obey the fit toggle like the live HF rows, else large
-      // defaults resurface in search results with the filter on.
-      .filter(
-        (id) =>
-          !fitOnDeviceOnly ||
-          downloadedSet.has(id.toLowerCase()) ||
-          hfModelFitsDevice(
-            {
-              id,
-              totalParams: recommendedParamCountById.get(id),
-              isGguf: isKnownGgufRepo(id),
-            },
-            gpu,
-          ),
-      );
+    return (
+      recommendedIds
+        .filter((id) => normalizeForSearch(id).includes(q))
+        .filter((id) =>
+          matchesFormatFilter(id, isKnownGgufRepo(id), formatFilter),
+        )
+        // Curated defaults obey the fit toggle like the live HF rows, else large
+        // defaults resurface in search results with the filter on.
+        .filter(
+          (id) =>
+            !fitOnDeviceOnly ||
+            downloadedSet.has(id.toLowerCase()) ||
+            hfModelFitsDevice(
+              {
+                id,
+                totalParams: recommendedParamCountById.get(id),
+                isGguf: isKnownGgufRepo(id),
+              },
+              gpu,
+            ),
+        )
+    );
   }, [
     showHfSection,
     debouncedQuery,
@@ -2037,27 +2273,30 @@ export function HubModelPicker({
   const hfIds = useMemo(() => {
     // Only the Unsloth tab searches the HF listing, and only Unsloth models.
     if (!showHfSection || section !== "recommended") return [];
-    return results
-      .filter(isChatSupported)
-      .filter(
-        (r) =>
-          !fitOnDeviceOnly ||
-          downloadedSet.has(r.id.toLowerCase()) ||
-          hfModelFitsDevice(r, gpu),
-      )
-      .map((result) => result.id)
-      .filter((id) => !isHiddenModelId(id))
-      .filter((id) => id.toLowerCase().startsWith("unsloth/"))
-      .filter((id) => !recommendedSet.has(id))
-      // Chat-only keeps runnable formats: GGUF anywhere, plus MLX/safetensors
-      // on Mac (matches the empty Recommended view so search stays consistent).
-      .filter(
-        (id) => !chatOnly || isRecommendableFormat(id, isKnownGgufRepo(id), isMac),
-      )
-      .filter((id) => !/-FP8[-.]|FP8-Dynamic/i.test(id))
-      .filter((id) =>
-        matchesFormatFilter(id, isKnownGgufRepo(id), formatFilter),
-      );
+    return (
+      results
+        .filter(isChatSupported)
+        .filter(
+          (r) =>
+            !fitOnDeviceOnly ||
+            downloadedSet.has(r.id.toLowerCase()) ||
+            hfModelFitsDevice(r, gpu),
+        )
+        .map((result) => result.id)
+        .filter((id) => !isHiddenModelId(id))
+        .filter((id) => id.toLowerCase().startsWith("unsloth/"))
+        .filter((id) => !recommendedSet.has(id))
+        // Chat-only keeps runnable formats: GGUF anywhere, plus MLX/safetensors
+        // on Mac (matches the empty Recommended view so search stays consistent).
+        .filter(
+          (id) =>
+            !chatOnly || isRecommendableFormat(id, isKnownGgufRepo(id), isMac),
+        )
+        .filter((id) => !/-FP8[-.]|FP8-Dynamic/i.test(id))
+        .filter((id) =>
+          matchesFormatFilter(id, isKnownGgufRepo(id), formatFilter),
+        )
+    );
   }, [
     recommendedSet,
     results,
@@ -2076,6 +2315,22 @@ export function HubModelPicker({
   const hubOptionKeys = useMemo(() => {
     const keys: string[] = [];
 
+    // Pinned rows sit above the Unsloth heading on the On Device tab.
+    if (
+      section === "downloaded" &&
+      cachedReady &&
+      !pinnedCollapsed &&
+      pinnedRows.length > 0
+    ) {
+      keys.push(
+        ...pinnedRows.map((row) =>
+          row.entry
+            ? makeModelOptionKey("pinned-quant", row.key)
+            : makeModelOptionKey("downloaded-model", row.model.repo_id),
+        ),
+      );
+    }
+
     // Downloaded (Unsloth) rows (query-filtered) on the On Device tab only.
     if (
       section === "downloaded" &&
@@ -2167,6 +2422,8 @@ export function HubModelPicker({
     chatOnly,
     sortedCustomFolderModels,
     customFoldersCollapsed,
+    pinnedRows,
+    pinnedCollapsed,
     downloadedCollapsed,
     fineTunedRows,
     fineTunedCollapsed,
@@ -2286,9 +2543,8 @@ export function HubModelPicker({
   }, [scrollRef, updateListFades]);
 
   // Sentinel + IntersectionObserver for recommended infinite scroll. Re-running
-  // on each loaded page (results length) re-attaches the observer so a heavily
-  // filtered list keeps paging until the viewport fills or the listing ends;
-  // fetchMore is a no-op while a page is in flight. Callback ref tracks mount.
+  // per loaded page re-attaches the observer so a heavily filtered list keeps
+  // paging until the viewport fills; fetchMore is a no-op while a page is in flight.
   const [recommendedSentinel, setRecommendedSentinel] =
     useState<HTMLDivElement | null>(null);
   const recommendedSentinelRef = useCallback((node: HTMLDivElement | null) => {
@@ -2338,6 +2594,7 @@ export function HubModelPicker({
   const showCustom = section === "downloaded";
   const showRecommendedSection = !showHfSection && section === "recommended";
   const downloadedEmpty =
+    pinnedRows.length === 0 &&
     visibleCachedGguf.length === 0 &&
     visibleCachedModelRows.length === 0 &&
     sortedLmStudio.length === 0 &&
@@ -2346,25 +2603,21 @@ export function HubModelPicker({
     // non-empty Fine-tuned section.
     fineTunedRows.length === 0;
 
-  // Sort dropdown shown inline to the right of the section toggle. Options
-  // depend on the tab and stay visible while searching so results can be
-  // sorted. Fixed width matching the Search Hub button so it and the format
-  // dropdown always line up; text-xs matches that button too. The trigger label
-  // clips (no ellipsis) when long; the open menu expands to show it in full.
+  // Sort dropdown inline right of the section toggle; options depend on the tab
+  // and stay visible while searching. Fixed width matches the Search Hub button
+  // so it and the format dropdown line up. Trigger label clips; the menu shows full.
   const sortTriggerClassName =
     "w-[110px] shrink-0 justify-between pr-2.5 !border-0 text-xs [&>span]:!text-clip";
-  // Tighter menu like the Projects activity Select: less left/top padding and
-  // text-xs to match the trigger. Keep the option's right padding so the
-  // selected-item checkmark never overlaps the label.
+  // Tighter menu (less padding, text-xs) matching the trigger. Keep the option's
+  // right padding so the selected-item checkmark never overlaps the label.
   const sortMenuContentClassName =
     "!p-1 !rounded-[14px] [&_[role=option]]:!pl-2 [&_[role=option]]:!py-1.5 [&_[role=option]]:!text-xs [&_[role=option]]:!rounded-[10px]";
-  // Device-fit toggle lives inside the sort menu (shared with the Hub page).
-  // The whole row is the click target (a button): a Checkbox renders as a
-  // <button>, and label-click forwarding to a button is unreliable, so the row
-  // owns the toggle and the Checkbox is presentational (pointer-events-none).
+  // Device-fit toggle inside the sort menu (shared with the Hub page). The whole
+  // row is the button: a Checkbox renders as a <button> and label-click forwarding
+  // to it is unreliable, so the row owns the toggle and the Checkbox is presentational.
   const fitOnDeviceFooter = (
     <Tooltip>
-      <TooltipTrigger asChild>
+      <TooltipTrigger asChild={true}>
         <button
           type="button"
           role="checkbox"
@@ -2375,7 +2628,7 @@ export function HubModelPicker({
           <Checkbox
             checked={fitOnDeviceOnly}
             tabIndex={-1}
-            aria-hidden
+            aria-hidden={true}
             className="pointer-events-none size-3.5 rounded-full [&_svg]:!size-2.5"
           />
           Only show models that fit
@@ -2387,6 +2640,19 @@ export function HubModelPicker({
       </TooltipContent>
     </Tooltip>
   );
+  // Sort icon + selected label inside the trigger pill.
+  const sortTriggerContent = (label: ReactNode) => (
+    <span className="flex items-center gap-1">
+      <HugeiconsIcon
+        icon={ArrowUpDownIcon}
+        strokeWidth={1.75}
+        className="size-3.5 shrink-0 text-muted-foreground"
+      />
+      <span className="truncate">{label}</span>
+    </span>
+  );
+  // On Device / Custom rows are already on disk, so the device-fit filter
+  // only applies to the Unsloth listing.
   const sectionSortDropdown =
     section === "recommended" ? (
       <HubOptionMenu
@@ -2397,6 +2663,10 @@ export function HubModelPicker({
         align="end"
         className={sortTriggerClassName}
         contentClassName={sortMenuContentClassName}
+        triggerContent={sortTriggerContent(
+          RECOMMENDED_SORT_OPTIONS.find((o) => o.value === recommendedSort)
+            ?.label ?? recommendedSort,
+        )}
         footer={fitOnDeviceFooter}
       />
     ) : section === "downloaded" ? (
@@ -2408,7 +2678,10 @@ export function HubModelPicker({
         align="end"
         className={sortTriggerClassName}
         contentClassName={sortMenuContentClassName}
-        footer={fitOnDeviceFooter}
+        triggerContent={sortTriggerContent(
+          LOCAL_SORT_OPTIONS.find((o) => o.value === downloadedSort)?.label ??
+            downloadedSort,
+        )}
       />
     ) : (
       <HubOptionMenu
@@ -2419,7 +2692,10 @@ export function HubModelPicker({
         align="end"
         className={sortTriggerClassName}
         contentClassName={sortMenuContentClassName}
-        footer={fitOnDeviceFooter}
+        triggerContent={sortTriggerContent(
+          LOCAL_SORT_OPTIONS.find((o) => o.value === customSort)?.label ??
+            customSort,
+        )}
       />
     );
 
@@ -2475,6 +2751,115 @@ export function HubModelPicker({
       selected && "bg-[#ececec] dark:bg-[var(--sidebar-accent)]",
     );
 
+  // A pinned quant: repo name with the quant as a grey chip. One click loads
+  // that quant directly, no expansion needed.
+  const renderPinnedQuantRow = (entry: { repoId: string; quant: string }) => {
+    const optionKey = makeModelOptionKey(
+      "pinned-quant",
+      pinKey(entry.repoId, entry.quant),
+    );
+    const { owner, name } = splitRepoLabel(entry.repoId);
+    const isSelected =
+      value === entry.repoId && activeGgufVariant === entry.quant;
+    const isLoaded =
+      modelIdsMatchForPicker(loadedModelId, entry.repoId) &&
+      !ggufVariantsMatchForPicker(activeGgufVariant, null) &&
+      ggufVariantsMatchForPicker(activeGgufVariant, entry.quant);
+    return (
+      <div key={optionKey} className={downloadedRowShellClassName(isSelected)}>
+        <button
+          type="button"
+          {...hubModelList.getOptionProps(optionKey, isSelected)}
+          onClick={() =>
+            onSelect(entry.repoId, {
+              source: "hub",
+              isLora: false,
+              ggufVariant: entry.quant,
+              isDownloaded: true,
+            })
+          }
+          className={cn(
+            "flex min-w-0 flex-1 items-center gap-2 rounded-full px-2 py-1.5 text-left text-sm transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring/45",
+            downloadedRowButtonClassName,
+          )}
+          title={`${entry.repoId} (${entry.quant})`}
+        >
+          <span className="flex min-w-0 items-baseline">
+            {owner ? (
+              <span className="inline-flex min-w-0 max-w-[45%] shrink items-baseline text-ui-13 text-muted-foreground/90">
+                <span className="truncate">{owner}</span>
+                <span className="shrink-0 text-muted-foreground/45">/</span>
+              </span>
+            ) : null}
+            <span className="min-w-0 truncate">{name}</span>
+          </span>
+          <span className="shrink-0 rounded-md bg-black/[0.06] px-1.5 py-px font-mono text-ui-10 text-muted-foreground dark:bg-white/[0.1]">
+            {entry.quant}
+          </span>
+          {isLoaded && (
+            <DotTag
+              tone="success"
+              label="Loaded"
+              className="ml-auto h-[18px] shrink-0 gap-1 rounded-md px-1.5"
+              dotClassName="size-[5px]"
+            />
+          )}
+        </button>
+        <span className="mr-1 flex shrink-0 items-center opacity-0 transition-opacity focus-within:opacity-100 group-hover:opacity-100 group-focus-within:opacity-100">
+          {onConfigure && (
+            <ModelLoadSettingsAction
+              ariaLabel={`Inference settings for ${entry.repoId} ${entry.quant}`}
+              onConfigure={() =>
+                onConfigure(entry.repoId, {
+                  source: "hub",
+                  isLora: false,
+                  ggufVariant: entry.quant,
+                  isDownloaded: true,
+                  isGguf: true,
+                })
+              }
+            />
+          )}
+          <ModelRowMenu
+            ariaLabel={`More options for ${entry.repoId} ${entry.quant}`}
+            iconClassName="size-3"
+            cachePath={{ repoId: entry.repoId, variant: entry.quant }}
+            pin={{
+              pinned: true,
+              pinLabel: "Pin to top",
+              unpinLabel: "Unpin",
+              onToggle: () => togglePinned(entry.repoId, entry.quant),
+            }}
+            del={{
+              title: "Delete cached model?",
+              description: (
+                <>
+                  This will remove{" "}
+                  <span className="font-medium text-foreground">
+                    {entry.repoId} ({entry.quant})
+                  </span>{" "}
+                  from disk. You can re-download it later.
+                </>
+              ),
+              successMessage: `Deleted ${entry.repoId} ${entry.quant}`,
+              disabled: deleteDisabled,
+              onConfirm: async () => {
+                await deleteCachedModel(
+                  entry.repoId,
+                  entry.quant,
+                  hfToken || undefined,
+                );
+                refreshCachedLists();
+                // The file is gone, so drop its pin too.
+                togglePinned(entry.repoId, entry.quant);
+              },
+            }}
+          />
+        </span>
+      </div>
+    );
+  };
+
   // Shared row renderers so Downloaded (Unsloth) and Other models render alike.
   const renderDownloadedGgufRow = (c: (typeof visibleCachedGguf)[number]) => {
     const optionKey = makeModelOptionKey("downloaded-gguf", c.repo_id);
@@ -2489,6 +2874,12 @@ export function HubModelPicker({
               meta="GGUF"
               showVision={c.has_vision ?? visionByRepo[c.repo_id]}
               selected={isSelected}
+              loaded={isRuntimeLoadedModel(
+                loadedModelId,
+                activeGgufVariant,
+                c.repo_id,
+                "required",
+              )}
               optionProps={hubModelList.getOptionProps(optionKey, isSelected)}
               onClick={() => toggleGgufExpanded(c.repo_id)}
               onArrowDownIntoChildren={
@@ -2506,8 +2897,10 @@ export function HubModelPicker({
           <GgufVariantExpander
             repoId={c.repo_id}
             onDevice={true}
+            allowPin={true}
             onHasVision={(v) => reportVision(c.repo_id, v)}
             onSelect={onSelect}
+            onConfigure={onConfigure}
             hfToken={hfToken || undefined}
             parentOptionKey={optionKey}
             onNavigatePastStart={() => hubModelList.focusOption(optionKey)}
@@ -2517,10 +2910,15 @@ export function HubModelPicker({
             variantActions={{
               onUpdate: (quant, expectedBytes) =>
                 updateGgufVariant(c.repo_id, quant, expectedBytes),
-              // Can't update the model that's live in memory under itself.
               updateDisabled: loadedModelId === c.repo_id,
               onDelete: async (quant) => {
-                await deleteCachedModel(c.repo_id, quant);
+                await deleteCachedModel(
+                  c.repo_id,
+                  quant,
+                  hfToken || undefined,
+                  c.cache_path || undefined,
+                );
+                prunePinnedQuantValidation(c.repo_id, quant);
                 refreshCachedLists();
               },
             }}
@@ -2535,10 +2933,7 @@ export function HubModelPicker({
     const optionKey = makeModelOptionKey("downloaded-model", c.repo_id);
     const isSelected = value === c.repo_id;
     return (
-      <div
-        key={c.repo_id}
-        className={downloadedRowShellClassName(isSelected)}
-      >
+      <div key={c.repo_id} className={downloadedRowShellClassName(isSelected)}>
         <div className="min-w-0 flex-1">
           <ModelRow
             label={c.repo_id}
@@ -2547,10 +2942,13 @@ export function HubModelPicker({
               c.size_bytes,
             )}`}
             selected={isSelected}
-            optionProps={hubModelList.getOptionProps(
-              optionKey,
-              isSelected,
+            loaded={isRuntimeLoadedModel(
+              loadedModelId,
+              activeGgufVariant,
+              c.repo_id,
+              "none",
             )}
+            optionProps={hubModelList.getOptionProps(optionKey, isSelected)}
             onClick={() =>
               onSelect(c.repo_id, {
                 source: "hub",
@@ -2562,20 +2960,53 @@ export function HubModelPicker({
             className={downloadedRowButtonClassName}
           />
         </div>
-        <ModelDeleteAction
-          ariaLabel={`Delete ${c.repo_id}`}
-          title="Delete cached model?"
-          description={
-            <>
-              This will remove{" "}
-              <span className="font-medium text-foreground">{c.repo_id}</span>{" "}
-              from disk. You can re-download it later.
-            </>
-          }
-          successMessage={`Deleted ${c.repo_id}`}
+        {onConfigure && (
+          <ModelLoadSettingsAction
+            ariaLabel={`Inference settings for ${c.repo_id}`}
+            onConfigure={() =>
+              onConfigure(c.repo_id, {
+                source: "hub",
+                isLora: false,
+                isDownloaded: true,
+                isGguf: false,
+              })
+            }
+          />
+        )}
+        <ModelRowMenu
+          ariaLabel={`More options for ${c.repo_id}`}
           buttonClassName="mr-1"
-          onConfirm={() => deleteCachedModel(c.repo_id)}
-          onDeleted={refreshCachedLists}
+          cachePath={{ repoId: c.repo_id }}
+          pin={{
+            pinned: pinnedSet.has(pinKey(c.repo_id)),
+            pinLabel: "Pin to top",
+            unpinLabel: "Unpin",
+            onToggle: () => togglePinned(c.repo_id),
+          }}
+          del={{
+            title: "Delete cached model?",
+            description: (
+              <>
+                This will remove{" "}
+                <span className="font-medium text-foreground">{c.repo_id}</span>{" "}
+                from disk. You can re-download it later.
+              </>
+            ),
+            successMessage: `Deleted ${c.repo_id}`,
+            disabled: deleteDisabled,
+            onConfirm: async () => {
+              await deleteCachedModel(
+                c.repo_id,
+                undefined,
+                hfToken || undefined,
+                c.cache_path || undefined,
+              );
+              if (pinnedSet.has(pinKey(c.repo_id))) {
+                togglePinned(c.repo_id);
+              }
+            },
+            onDeleted: refreshCachedLists,
+          }}
         />
       </div>
     );
@@ -2584,192 +3015,242 @@ export function HubModelPicker({
   return (
     <>
       <div className="relative space-y-2">
-      {/* A small right inset shortens the search bar so Search Hub lands on the
+        {/* A small right inset shortens the search bar so Search Hub lands on the
           last dropdown's right edge (none on the wider Connected box). */}
-      <div
-        className={cn(
-          "flex items-center gap-2 pb-1",
-          hasConnected ? "pr-0" : "pr-2",
-        )}
-      >
-        <div className="relative flex-1">
-          <HugeiconsIcon
-            icon={Search01Icon}
-            className="pointer-events-none absolute left-2.5 top-2.5 size-4 text-muted-foreground"
-          />
-          <Input
-            value={query}
-            onChange={(event) => setQuery(event.target.value)}
-            placeholder={
-              section === "downloaded"
-                ? "Search local models"
-                : "Search Unsloth models"
-            }
-            data-model-picker-search-input={true}
-            className="field-soft h-9 border-0 pl-8 pr-8"
-          />
-          {isLoading && (
-            <Spinner className="pointer-events-none absolute right-2.5 top-2.5 size-4 text-muted-foreground" />
-          )}
-        </div>
-        {onBrowseHub ? (
-          <Tooltip>
-            <TooltipTrigger asChild>
-              <button
-                type="button"
-                onClick={onBrowseHub}
-                aria-label="Search more models on the Hub"
-                className="hub-tab-toggle-pill flex h-9 w-[110px] shrink-0 items-center justify-center gap-[5px] rounded-full border-0 text-xs text-foreground transition-colors"
-              >
-                <HugeiconsIcon icon={DashboardCircleIcon} className="size-4" />
-                Search Hub
-              </button>
-            </TooltipTrigger>
-            <TooltipContent>Search all models</TooltipContent>
-          </Tooltip>
-        ) : null}
-      </div>
-
-      {/* Section tabs then the format and sort dropdowns, packed left with one
-          uniform gap between every control. The box is sized so the last
-          dropdown still lands on Search Hub's edge. Dropdowns hide on Connected. */}
-      <div className="flex items-center gap-2">
-        {sectionToggle}
-        {showConnected ? null : (
-          <div className="flex items-center gap-2">
-            <HubOptionMenu
-              value={formatFilter}
-              options={FORMAT_FILTER_OPTIONS}
-              onValueChange={setFormatFilter}
-              ariaLabel="Filter by format"
-              align="end"
-              className={sortTriggerClassName}
-              contentClassName={sortMenuContentClassName}
-            />
-            {sectionSortDropdown}
-          </div>
-        )}
-      </div>
-
-      <div
-        ref={scrollRef}
-        onScroll={(e) => updateListFades(e.currentTarget)}
-        className={cn(
-          // List sits within the menu padding so left and right gaps match.
-          // Height tracks the content up to the cap, so short lists do not
-          // leave white space. scroll-py + symmetric px keep the focus ring off
-          // the overflow clip edges during keyboard nav.
-          "model-list-scroll max-h-[335px] overflow-y-auto scroll-py-1.5 px-0.5 mr-1",
-          listScrolled && "is-scrolled",
-          listMoreBelow && "is-bottom-faded",
-        )}
-        {...hubModelList.listboxProps}
-      >
-        {/* Clear space for the floating Eject pill when scrolled to the end, so
-            its gap above the last row matches its gap below (applies to every
-            section, including Recommended). */}
         <div
           className={cn(
-            "pr-0",
-            // On Device pulls the heading block tight to the controls; Recommended
-            // keeps a little more top room above its first row.
-            showDownloaded ? "pt-0" : "pt-[4px]",
-            onEject ? "pb-[60px]" : "pb-4",
+            "flex items-center gap-2 pb-1",
+            hasConnected ? "pr-0" : "pr-2",
           )}
         >
-          {showConnected ? (
-            connectedGroups.length === 0 ? (
-              <div className="px-2.5 py-2 text-xs leading-relaxed text-muted-foreground">
-                {externalModels.length === 0
-                  ? "No models from your connections. Set up in Settings then Connections."
-                  : "No models match your search."}
-              </div>
+          <div className="relative flex-1">
+            <HugeiconsIcon
+              icon={Search01Icon}
+              className="pointer-events-none absolute left-2.5 top-2.5 size-4 text-muted-foreground"
+            />
+            <Input
+              value={query}
+              onChange={(event) => setQuery(event.target.value)}
+              placeholder={
+                section === "downloaded"
+                  ? "Search local models"
+                  : "Search Unsloth models"
+              }
+              data-model-picker-search-input={true}
+              className="field-soft h-9 border-0 pl-8 pr-8"
+            />
+            {isLoading && (
+              <Spinner className="pointer-events-none absolute right-2.5 top-2.5 size-4 text-muted-foreground" />
+            )}
+          </div>
+          {onBrowseHub ? (
+            <Tooltip>
+              <TooltipTrigger asChild={true}>
+                <button
+                  type="button"
+                  onClick={onBrowseHub}
+                  aria-label="Search more models on the Hub"
+                  className="hub-tab-toggle-pill flex h-9 w-[110px] shrink-0 items-center justify-center gap-[5px] rounded-full border-0 text-xs text-foreground transition-colors"
+                >
+                  <HugeiconsIcon
+                    icon={DashboardCircleIcon}
+                    className="size-4"
+                  />
+                  Search Hub
+                </button>
+              </TooltipTrigger>
+              <TooltipContent>Search all models</TooltipContent>
+            </Tooltip>
+          ) : null}
+        </div>
+
+        {/* Keep the left-packed controls on one line while they fit, then wrap
+          whole groups before their intrinsic widths cross the picker edge.
+          Dropdowns hide on Connected. */}
+        <div
+          className={cn(
+            "flex flex-wrap items-center gap-2",
+            hasConnected ? "-mr-4" : "-mr-2",
+          )}
+        >
+          {sectionToggle}
+          {showConnected ? null : (
+            <div className="flex max-w-full min-w-0 flex-wrap items-center gap-2">
+              <HubOptionMenu
+                value={formatFilter}
+                options={FORMAT_FILTER_OPTIONS}
+                onValueChange={setFormatFilter}
+                ariaLabel="Filter by format"
+                align="end"
+                className={sortTriggerClassName}
+                contentClassName={sortMenuContentClassName}
+              />
+              {sectionSortDropdown}
+            </div>
+          )}
+        </div>
+
+        <div
+          ref={scrollRef}
+          onScroll={(e) => updateListFades(e.currentTarget)}
+          className={cn(
+            // List sits within the menu padding so gaps match; height tracks content
+            // up to the cap. scroll-py + symmetric px keep the focus ring off the
+            // overflow clip edges during keyboard nav.
+            "model-list-scroll max-h-[335px] overflow-y-auto scroll-py-1.5 px-0.5 mr-1",
+            listScrolled && "is-scrolled",
+            listMoreBelow && "is-bottom-faded",
+          )}
+          {...hubModelList.listboxProps}
+        >
+          <div
+            className={cn(
+              "pr-0",
+              // On Device pulls the heading block tight to the controls; Recommended
+              // keeps a little more top room above its first row.
+              showDownloaded ? "pt-0" : "pt-[4px]",
+              onEject ? "pb-[60px]" : "pb-4",
+            )}
+          >
+            {showConnected ? (
+              connectedGroups.length === 0 ? (
+                <div className="px-2.5 py-2 text-xs leading-relaxed text-muted-foreground">
+                  {externalModels.length === 0
+                    ? "No models from your connections. Set up in Settings then Connections."
+                    : "No models match your search."}
+                </div>
+              ) : (
+                connectedGroups.map((group) => (
+                  <div key={group.providerId}>
+                    <div className="flex items-center gap-2 px-2.5 py-1.5 text-ui-10 font-semibold uppercase tracking-wider text-muted-foreground">
+                      <ApiProviderLogo
+                        providerType={group.providerType}
+                        className="size-3.5"
+                        title={group.providerName}
+                      />
+                      <span className="min-w-0 truncate">
+                        {group.providerName}
+                      </span>
+                    </div>
+                    {group.models.map((model) => (
+                      <button
+                        key={model.id}
+                        type="button"
+                        onClick={() =>
+                          onSelect(model.id, {
+                            source: "external",
+                            isLora: false,
+                          })
+                        }
+                        className={cn(
+                          "flex w-full items-center rounded-md px-2.5 py-1.5 text-left text-sm transition-colors hover:bg-[#ececec] dark:hover:bg-[var(--sidebar-accent)]",
+                          value === model.id &&
+                            "bg-[#ececec] dark:bg-[var(--sidebar-accent)]",
+                        )}
+                      >
+                        <span className="min-w-0 truncate">{model.name}</span>
+                      </button>
+                    ))}
+                  </div>
+                ))
+              )
             ) : (
-              connectedGroups.map((group) => (
-                <div key={group.providerId}>
-                  <div className="flex items-center gap-2 px-2.5 py-1.5 text-[10px] font-semibold uppercase tracking-wider text-muted-foreground">
-                    <ApiProviderLogo
-                      providerType={group.providerType}
-                      className="size-3.5"
-                      title={group.providerName}
-                    />
-                    <span className="min-w-0 truncate">
-                      {group.providerName}
+              <>
+                {/* First-load spinner only when nothing cached is shown yet. */}
+                {showDownloaded &&
+                !cachedReady &&
+                !showHfSection &&
+                downloadedEmpty ? (
+                  <div className="flex items-center gap-2 px-5 py-3">
+                    <Spinner className="size-3 text-muted-foreground" />
+                    <span className="text-xs text-muted-foreground">
+                      Loading models…
                     </span>
                   </div>
-                  {group.models.map((model) => (
-                    <button
-                      key={model.id}
-                      type="button"
-                      onClick={() =>
-                        onSelect(model.id, {
-                          source: "external",
-                          isLora: false,
-                        })
-                      }
-                      className={cn(
-                        "flex w-full items-center rounded-md px-2.5 py-1.5 text-left text-sm transition-colors hover:bg-[#ececec] dark:hover:bg-[var(--sidebar-accent)]",
-                        value === model.id &&
-                          "bg-[#ececec] dark:bg-[var(--sidebar-accent)]",
-                      )}
-                    >
-                      <span className="min-w-0 truncate">{model.name}</span>
-                    </button>
-                  ))}
-                </div>
-              ))
-            )
-          ) : (
-            <>
-              {/* First-load spinner only when nothing cached is shown yet. */}
-              {showDownloaded &&
-              !cachedReady &&
-              !showHfSection &&
-              downloadedEmpty ? (
-                <div className="flex items-center gap-2 px-5 py-3">
-                  <Spinner className="size-3 text-muted-foreground" />
-                  <span className="text-xs text-muted-foreground">
-                    Loading models…
-                  </span>
-                </div>
-              ) : null}
+                ) : null}
 
-              {/* Empty On Device: a search miss vs nothing downloaded yet. Hidden
+                {/* Empty On Device: a search miss vs nothing downloaded yet. Hidden
               when custom folders below still have matches. */}
-              {showDownloaded &&
-              cachedReady &&
-              downloadedEmpty &&
-              sortedCustomFolderModels.length === 0 ? (
-                <div className="px-2.5 py-2 text-xs text-muted-foreground">
-                  {showHfSection
-                    ? "No matching models on device."
-                    : formatFilter === "all"
-                      ? "No downloaded models yet. Search above or pick Recommended."
-                      : `No downloaded ${FORMAT_FILTER_LABELS[formatFilter]} models yet.`}
-                </div>
-              ) : null}
+                {showDownloaded &&
+                cachedReady &&
+                downloadedEmpty &&
+                sortedCustomFolderModels.length === 0 ? (
+                  <div className="px-2.5 py-2 text-xs text-muted-foreground">
+                    {showHfSection
+                      ? "No matching models on device."
+                      : formatFilter === "all"
+                        ? "No downloaded models yet. Search above or pick Recommended."
+                        : `No downloaded ${FORMAT_FILTER_LABELS[formatFilter]} models yet.`}
+                  </div>
+                ) : null}
 
-              {/* Downloaded (Unsloth) stays visible (filtered) while searching. */}
-              {showDownloaded &&
-              (unslothCachedGguf.length > 0 ||
-                unslothCachedModelRows.length > 0) ? (
-                <>
-                  <ListLabel
-                    collapsed={downloadedCollapsed}
-                    onToggle={() => setDownloadedCollapsed((v) => !v)}
-                    action={
-                      <>
-                        {hasOtherModels ? (
+                {/* Pinned quants and models sit above the Unsloth heading so
+              favorites are always first. Filtered by the query like the
+              sections below. */}
+                {showDownloaded && pinnedRows.length > 0 ? (
+                  <>
+                    <ListLabel
+                      icon={
+                        <HugeiconsIcon icon={PinIcon} className="size-3.5" />
+                      }
+                      collapsed={pinnedCollapsed}
+                      onToggle={() => setPinnedCollapsed((v) => !v)}
+                    >
+                      Pinned
+                    </ListLabel>
+                    {!pinnedCollapsed &&
+                      pinnedRows.map((row) =>
+                        row.entry
+                          ? renderPinnedQuantRow(row.entry)
+                          : renderDownloadedModelRow(row.model),
+                      )}
+                  </>
+                ) : null}
+
+                {/* Downloaded (Unsloth) stays visible (filtered) while searching. */}
+                {showDownloaded &&
+                (unslothCachedGguf.length > 0 ||
+                  unslothCachedModelRows.length > 0) ? (
+                  <>
+                    <ListLabel
+                      divider={pinnedRows.length > 0}
+                      collapsed={downloadedCollapsed}
+                      onToggle={() => setDownloadedCollapsed((v) => !v)}
+                      action={
+                        <>
+                          {hasOtherModels ? (
+                            <Tooltip delayDuration={0}>
+                              <TooltipTrigger asChild={true}>
+                                <button
+                                  type="button"
+                                  onClick={scrollToOtherModels}
+                                  aria-label="Go to other models"
+                                  className="shrink-0 rounded p-1 text-muted-foreground/60 transition-colors hover:text-foreground"
+                                >
+                                  <HugeiconsIcon
+                                    icon={Flag01Icon}
+                                    className="size-3"
+                                  />
+                                </button>
+                              </TooltipTrigger>
+                              <TooltipContent
+                                side="bottom"
+                                className="tooltip-compact"
+                              >
+                                Other non-Unsloth models
+                              </TooltipContent>
+                            </Tooltip>
+                          ) : null}
                           <Tooltip delayDuration={0}>
                             <TooltipTrigger asChild={true}>
                               <button
                                 type="button"
-                                onClick={scrollToOtherModels}
-                                aria-label="Go to other models"
+                                onClick={scrollToFineTuned}
+                                aria-label="Go to fine-tuned models"
                                 className="shrink-0 rounded p-1 text-muted-foreground/60 transition-colors hover:text-foreground"
                               >
                                 <HugeiconsIcon
-                                  icon={Flag01Icon}
+                                  icon={TrainIcon}
                                   className="size-3"
                                 />
                               </button>
@@ -2778,796 +3259,809 @@ export function HubModelPicker({
                               side="bottom"
                               className="tooltip-compact"
                             >
-                              Other non-Unsloth models
+                              Go to fine-tuned models
                             </TooltipContent>
                           </Tooltip>
-                        ) : null}
-                        <Tooltip delayDuration={0}>
-                          <TooltipTrigger asChild={true}>
-                            <button
-                              type="button"
-                              onClick={scrollToFineTuned}
-                              aria-label="Go to fine-tuned models"
-                              className="shrink-0 rounded p-1 text-muted-foreground/60 transition-colors hover:text-foreground"
+                          <Tooltip delayDuration={0}>
+                            <TooltipTrigger asChild={true}>
+                              <button
+                                type="button"
+                                onClick={scrollToCustomFolders}
+                                aria-label="Go to custom folders"
+                                className="shrink-0 rounded p-1 text-muted-foreground/60 transition-colors hover:text-foreground"
+                              >
+                                <HugeiconsIcon
+                                  icon={Folder02Icon}
+                                  className="size-3"
+                                />
+                              </button>
+                            </TooltipTrigger>
+                            <TooltipContent
+                              side="bottom"
+                              className="tooltip-compact"
                             >
-                              <HugeiconsIcon
-                                icon={TrainIcon}
-                                className="size-3"
-                              />
-                            </button>
-                          </TooltipTrigger>
-                          <TooltipContent
-                            side="bottom"
-                            className="tooltip-compact"
-                          >
-                            Go to fine-tuned models
-                          </TooltipContent>
-                        </Tooltip>
-                        <Tooltip delayDuration={0}>
-                          <TooltipTrigger asChild={true}>
-                            <button
-                              type="button"
-                              onClick={scrollToCustomFolders}
-                              aria-label="Go to custom folders"
-                              className="shrink-0 rounded p-1 text-muted-foreground/60 transition-colors hover:text-foreground"
-                            >
-                              <HugeiconsIcon
-                                icon={Folder02Icon}
-                                className="size-3"
-                              />
-                            </button>
-                          </TooltipTrigger>
-                          <TooltipContent
-                            side="bottom"
-                            className="tooltip-compact"
-                          >
-                            Go to custom folders
-                          </TooltipContent>
-                        </Tooltip>
-                      </>
-                    }
-                  >
-                    {/* When other providers (LM Studio/Ollama) also show here, name
+                              Go to custom folders
+                            </TooltipContent>
+                          </Tooltip>
+                        </>
+                      }
+                    >
+                      {/* When other providers (LM Studio/Ollama) also show here, name
                     this group "Unsloth" so the two are easy to tell apart. */}
-                    {sortedLmStudio.length > 0 ? "Unsloth" : "Downloaded"}
-                  </ListLabel>
-                  {!downloadedCollapsed &&
-                    unslothCachedGguf.map(renderDownloadedGgufRow)}
-                  {!downloadedCollapsed &&
-                    unslothCachedModelRows.map(renderDownloadedModelRow)}
-                </>
-              ) : null}
+                      {sortedLmStudio.length > 0 ? "Unsloth" : "Downloaded"}
+                    </ListLabel>
+                    {!downloadedCollapsed &&
+                      unslothCachedGguf.map(renderDownloadedGgufRow)}
+                    {!downloadedCollapsed &&
+                      unslothCachedModelRows.map(renderDownloadedModelRow)}
+                  </>
+                ) : null}
 
-              {/* Other models: non-Unsloth downloads, grouped just above
+                {/* Other models: non-Unsloth downloads, grouped just above
               Fine-tuned. Shown only when such models exist. */}
-              {showDownloaded && hasOtherModels ? (
-                <div ref={otherModelsSectionRef}>
-                  <ListLabel
-                    divider={true}
-                    icon={
-                      <HugeiconsIcon icon={Flag01Icon} className="size-3.5" />
-                    }
-                    collapsed={otherModelsCollapsed}
-                    onToggle={() => setOtherModelsCollapsed((v) => !v)}
-                  >
-                    Other models
-                  </ListLabel>
-                  {!otherModelsCollapsed &&
-                    otherCachedGguf.map(renderDownloadedGgufRow)}
-                  {!otherModelsCollapsed &&
-                    otherCachedModelRows.map(renderDownloadedModelRow)}
-                </div>
-              ) : null}
+                {showDownloaded && hasOtherModels ? (
+                  <div ref={otherModelsSectionRef}>
+                    <ListLabel
+                      divider={true}
+                      icon={
+                        <HugeiconsIcon icon={Flag01Icon} className="size-3.5" />
+                      }
+                      collapsed={otherModelsCollapsed}
+                      onToggle={() => setOtherModelsCollapsed((v) => !v)}
+                    >
+                      Other models
+                    </ListLabel>
+                    {!otherModelsCollapsed &&
+                      otherCachedGguf.map(renderDownloadedGgufRow)}
+                    {!otherModelsCollapsed &&
+                      otherCachedModelRows.map(renderDownloadedModelRow)}
+                  </div>
+                ) : null}
 
-              {/* Fine-tuned models: a section above Custom Folders. Always shown on
+                {/* Fine-tuned models: a section above Custom Folders. Always shown on
               On Device so the train shortcut always has a target, with an empty
               state when none exist. */}
-              {section === "downloaded" ? (
-                <>
-                  <div
-                    ref={fineTunedSectionRef}
-                    className="mt-3 flex items-center gap-1 border-t border-border/50 px-2.5 pb-1 pt-3"
-                  >
-                    <span className="flex items-center gap-1.5 text-[10px] font-semibold uppercase tracking-wider text-muted-foreground">
-                      <HugeiconsIcon icon={TrainIcon} className="size-3.5" />
-                      Fine-tuned
-                    </span>
-                    <div className="ml-auto">
-                      <button
-                        type="button"
-                        aria-label={
-                          fineTunedCollapsed
-                            ? "Expand fine-tuned models"
-                            : "Collapse fine-tuned models"
-                        }
-                        title={fineTunedCollapsed ? "Expand" : "Collapse"}
-                        onClick={() => setFineTunedCollapsed((v) => !v)}
-                        className="shrink-0 rounded p-1 text-muted-foreground/60 transition-colors hover:text-foreground"
-                      >
-                        {fineTunedCollapsed ? (
-                          <ChevronRightIcon className="size-3" />
-                        ) : (
-                          <ChevronDownIcon className="size-3" />
-                        )}
-                      </button>
-                    </div>
-                  </div>
-                  {!fineTunedCollapsed && fineTunedRows.length > 0 && (
-                    <FineTunedRows
-                      adapters={fineTunedRows}
-                      value={value}
-                      onSelect={onSelect}
-                      onModelsChange={onModelsChange}
-                      deleteDisabled={deleteDisabled}
-                      loraModelList={hubModelList}
-                      expandedGguf={expandedGguf}
-                      setExpandedGguf={setExpandedGguf}
-                      gpu={gpu}
-                    />
-                  )}
-                </>
-              ) : null}
-
-              {showCustom ? (
-                <>
-                  <div
-                    ref={customFolderSectionRef}
-                    className="mt-3 flex items-center gap-1 border-t border-border/50 px-2.5 pb-1 pt-3"
-                  >
-                    <button
-                      type="button"
-                      onClick={() => setShowFolderBrowser(true)}
-                      title="Browse folders on the server"
-                      className="flex items-center gap-1.5 text-[10px] font-semibold uppercase tracking-wider text-muted-foreground transition-colors hover:text-foreground"
+                {section === "downloaded" ? (
+                  <>
+                    <div
+                      ref={fineTunedSectionRef}
+                      className="mt-3 flex items-center gap-1 border-t border-border/50 px-2.5 pb-1 pt-3"
                     >
-                      <HugeiconsIcon icon={Folder02Icon} className="size-3.5" />
-                      Custom Folders
-                    </button>
-                    <div className="flex items-center gap-0.5">
-                      <button
-                        type="button"
-                        aria-label={
-                          showFolderInput
-                            ? "Cancel adding folder"
-                            : "Add scan folder by path"
-                        }
-                        title={
-                          showFolderInput ? "Cancel" : "Add by typing a path"
-                        }
-                        onClick={() => {
-                          setShowFolderInput((open) => {
-                            if (open) {
-                              setFolderInput("");
-                              setFolderError(null);
-                            }
-                            return !open;
-                          });
-                        }}
-                        className="shrink-0 rounded p-1 text-muted-foreground/60 transition-colors hover:text-foreground"
-                      >
-                        <HugeiconsIcon
-                          icon={showFolderInput ? Cancel01Icon : Add01Icon}
-                          className="size-3"
-                        />
-                      </button>
-                      <button
-                        type="button"
-                        aria-label="Browse for a folder on the server"
-                        title="Browse folders on the server"
-                        onClick={() => setShowFolderBrowser(true)}
-                        className="shrink-0 rounded p-0.5 text-muted-foreground/60 transition-colors hover:text-foreground"
-                      >
-                        <HugeiconsIcon
-                          icon={Search01Icon}
-                          className="size-2.5"
-                        />
-                      </button>
+                      <span className="flex items-center gap-1.5 text-ui-10 font-semibold uppercase tracking-wider text-muted-foreground">
+                        <HugeiconsIcon icon={TrainIcon} className="size-3.5" />
+                        Fine-tuned
+                      </span>
+                      <div className="ml-auto">
+                        <button
+                          type="button"
+                          aria-label={
+                            fineTunedCollapsed
+                              ? "Expand fine-tuned models"
+                              : "Collapse fine-tuned models"
+                          }
+                          title={fineTunedCollapsed ? "Expand" : "Collapse"}
+                          onClick={() => setFineTunedCollapsed((v) => !v)}
+                          className="shrink-0 rounded p-1 text-muted-foreground/60 transition-colors hover:text-foreground"
+                        >
+                          {fineTunedCollapsed ? (
+                            <ChevronRightIcon className="size-3" />
+                          ) : (
+                            <ChevronDownIcon className="size-3" />
+                          )}
+                        </button>
+                      </div>
                     </div>
-                    <div className="ml-auto">
-                      <button
-                        type="button"
-                        aria-label={
-                          customFoldersCollapsed
-                            ? "Expand custom folders"
-                            : "Collapse custom folders"
-                        }
-                        title={customFoldersCollapsed ? "Expand" : "Collapse"}
-                        onClick={() => setCustomFoldersCollapsed((v) => !v)}
-                        className="shrink-0 rounded p-1 text-muted-foreground/60 transition-colors hover:text-foreground"
-                      >
-                        {customFoldersCollapsed ? (
-                          <ChevronRightIcon className="size-3" />
-                        ) : (
-                          <ChevronDownIcon className="size-3" />
-                        )}
-                      </button>
-                    </div>
-                  </div>
+                    {!fineTunedCollapsed && fineTunedRows.length > 0 && (
+                      <FineTunedRows
+                        adapters={fineTunedRows}
+                        value={value}
+                        loadedModelId={loadedModelId}
+                        activeGgufVariant={activeGgufVariant}
+                        onSelect={onSelect}
+                        onConfigure={onConfigure}
+                        onModelsChange={onModelsChange}
+                        deleteDisabled={deleteDisabled}
+                        loraModelList={hubModelList}
+                        expandedGguf={expandedGguf}
+                        setExpandedGguf={setExpandedGguf}
+                        gpu={gpu}
+                      />
+                    )}
+                  </>
+                ) : null}
 
-                  {/* Folder paths */}
-                  {!customFoldersCollapsed &&
-                    scanFolders.map((f) => (
-                      <div
-                        key={f.id}
-                        className="group flex items-center gap-1.5 px-2.5 py-0.5"
+                {showCustom ? (
+                  <>
+                    <div
+                      ref={customFolderSectionRef}
+                      className="mt-3 flex items-center gap-1 border-t border-border/50 px-2.5 pb-1 pt-3"
+                    >
+                      <button
+                        type="button"
+                        onClick={() => setShowFolderBrowser(true)}
+                        title="Browse folders on the server"
+                        className="flex items-center gap-1.5 text-ui-10 font-semibold uppercase tracking-wider text-muted-foreground transition-colors hover:text-foreground"
                       >
                         <HugeiconsIcon
                           icon={Folder02Icon}
-                          className="size-3 shrink-0 text-muted-foreground/40"
+                          className="size-3.5"
                         />
-                        <span
-                          className="min-w-0 flex-1 truncate font-mono text-[10px] text-muted-foreground/70"
-                          title={f.path}
-                        >
-                          {f.path}
-                        </span>
+                        Custom Folders
+                      </button>
+                      <div className="flex items-center gap-0.5">
                         <button
                           type="button"
-                          onClick={() => handleRemoveFolder(f.id)}
-                          aria-label={`Remove folder ${f.path}`}
-                          className="shrink-0 rounded p-1 text-foreground/70 transition-colors hover:bg-destructive/10 hover:text-destructive focus-visible:bg-destructive/10 focus-visible:text-destructive"
+                          aria-label={
+                            showFolderInput
+                              ? "Cancel adding folder"
+                              : "Add scan folder by path"
+                          }
+                          title={
+                            showFolderInput ? "Cancel" : "Add by typing a path"
+                          }
+                          onClick={() => {
+                            setShowFolderInput((open) => {
+                              if (open) {
+                                setFolderInput("");
+                                setFolderError(null);
+                              }
+                              return !open;
+                            });
+                          }}
+                          className="shrink-0 rounded p-1 text-muted-foreground/60 transition-colors hover:text-foreground"
                         >
                           <HugeiconsIcon
-                            icon={Cancel01Icon}
+                            icon={showFolderInput ? Cancel01Icon : Add01Icon}
                             className="size-3"
                           />
                         </button>
-                      </div>
-                    ))}
-
-                  {/* Recommended folders */}
-                  {!customFoldersCollapsed &&
-                    (() => {
-                      const registered = new Set(
-                        scanFolders.map((f) => f.path),
-                      );
-                      const unregistered = recommendedFolders.filter(
-                        (p) => !registered.has(p),
-                      );
-                      if (unregistered.length === 0) return null;
-                      return (
-                        <div className="flex flex-wrap gap-1 px-2.5 pb-0.5">
-                          {unregistered.map((p) => (
-                            <button
-                              key={p}
-                              type="button"
-                              onClick={() => void handleAddFolder(p)}
-                              disabled={folderLoading}
-                              title={`Add ${p}`}
-                              className="rounded-full border border-dashed border-border/50 px-2 py-0.5 font-mono text-[10px] text-muted-foreground/70 transition-colors hover:border-foreground/30 hover:bg-accent hover:text-foreground disabled:opacity-40"
-                            >
-                              <span className="text-[11px] font-semibold">
-                                +
-                              </span>{" "}
-                              {p.length > 30 ? `...${p.slice(-27)}` : p}
-                            </button>
-                          ))}
-                        </div>
-                      );
-                    })()}
-
-                  {/* Add folder input */}
-                  {!customFoldersCollapsed && showFolderInput && (
-                    <div className="px-2.5 pb-1 pt-0.5">
-                      <div className="flex items-center gap-1">
-                        <HugeiconsIcon
-                          icon={Folder02Icon}
-                          className="size-3 shrink-0 text-muted-foreground/40"
-                        />
-                        <input
-                          value={folderInput}
-                          onChange={(e) => {
-                            setFolderInput(e.target.value);
-                            setFolderError(null);
-                          }}
-                          onKeyDown={(e) => {
-                            if (e.key === "Enter") {
-                              e.preventDefault();
-                              handleAddFolder();
-                            }
-                            if (e.key === "Escape") {
-                              e.preventDefault();
-                              e.stopPropagation();
-                              setShowFolderInput(false);
-                              setFolderInput("");
-                              setFolderError(null);
-                            }
-                          }}
-                          placeholder="/path/to/models"
-                          className="h-6 min-w-0 flex-1 rounded border border-border/50 bg-transparent px-1.5 font-mono text-[10px] text-foreground outline-none placeholder:text-muted-foreground/40 focus:border-foreground/20"
-                          disabled={folderLoading}
-                          autoFocus={true}
-                        />
                         <button
                           type="button"
-                          onClick={() => setShowFolderBrowser(true)}
-                          disabled={folderLoading}
-                          aria-label="Browse for folder"
+                          aria-label="Browse for a folder on the server"
                           title="Browse folders on the server"
-                          className="flex h-6 shrink-0 items-center justify-center rounded border border-border/50 px-1.5 text-muted-foreground transition-colors hover:bg-accent hover:text-foreground disabled:opacity-40"
+                          onClick={() => setShowFolderBrowser(true)}
+                          className="shrink-0 rounded p-0.5 text-muted-foreground/60 transition-colors hover:text-foreground"
                         >
                           <HugeiconsIcon
                             icon={Search01Icon}
-                            className="size-3"
+                            className="size-2.5"
                           />
                         </button>
+                      </div>
+                      <div className="ml-auto">
                         <button
                           type="button"
-                          onClick={() => {
-                            void handleAddFolder();
-                          }}
-                          disabled={folderLoading || !folderInput.trim()}
-                          className="h-6 shrink-0 rounded border border-border/50 px-1.5 text-[10px] text-muted-foreground transition-colors hover:bg-accent disabled:opacity-40"
+                          aria-label={
+                            customFoldersCollapsed
+                              ? "Expand custom folders"
+                              : "Collapse custom folders"
+                          }
+                          title={customFoldersCollapsed ? "Expand" : "Collapse"}
+                          onClick={() => setCustomFoldersCollapsed((v) => !v)}
+                          className="shrink-0 rounded p-1 text-muted-foreground/60 transition-colors hover:text-foreground"
                         >
-                          Add
+                          {customFoldersCollapsed ? (
+                            <ChevronRightIcon className="size-3" />
+                          ) : (
+                            <ChevronDownIcon className="size-3" />
+                          )}
                         </button>
                       </div>
-                      {folderError && (
-                        <p className="px-0.5 pt-0.5 text-[10px] text-destructive">
-                          {folderError}
-                        </p>
-                      )}
                     </div>
-                  )}
 
-                  <FolderBrowser
-                    open={showFolderBrowser}
-                    onOpenChange={setShowFolderBrowser}
-                    initialPath={folderInput.trim() || undefined}
-                    onSelect={(picked) => {
-                      setFolderInput(picked);
-                      setFolderError(null);
-                      // Pass the path explicitly: `folderInput` state hasn't
-                      // flushed yet when "Use this folder" submits.
-                      void handleAddFolder(picked);
-                    }}
-                  />
-
-                  {/* Models from custom folders */}
-                  {!customFoldersCollapsed &&
-                    sortedCustomFolderModels.map((m) => {
-                      const isGgufFile = m.path.toLowerCase().endsWith(".gguf");
-                      // Honor the backend model_format hint (suffixless GGUF
-                      // folders) in addition to name/path so the row classifies
-                      // and loads through the same GGUF path as the filter.
-                      const isGguf = localModelIsGguf(m);
-                      // Single .gguf files (e.g. Ollama blobs) load directly;
-                      // GGUF repos/directories expand to pick a variant.
-                      const isDirectGguf = isGgufFile;
-                      const optionKey = makeModelOptionKey(
-                        "custom-folder",
-                        m.id,
-                      );
-                      return (
-                        <div key={m.id}>
-                          <ModelRow
-                            label={m.model_id ?? m.display_name}
-                            meta={isGguf ? "GGUF" : "Local"}
-                            tooltipText={localPathTooltip(
-                              m.model_id ?? m.display_name,
-                              m.path,
-                            )}
-                            selected={value === m.id}
-                            optionProps={hubModelList.getOptionProps(
-                              optionKey,
-                              value === m.id,
-                            )}
-                            onClick={() => {
-                              if (isDirectGguf) {
-                                onSelect(m.id, {
-                                  source: "local",
-                                  isLora: false,
-                                  isDownloaded: true,
-                                  // Mark GGUF so "Load on selection = off" stages
-                                  // through Run settings (matches LM Studio path).
-                                  isGguf: true,
-                                });
-                              } else if (isGguf) {
-                                toggleGgufExpanded(m.id);
-                              } else {
-                                onSelect(m.id, {
-                                  source: "local",
-                                  isLora: false,
-                                  isDownloaded: true,
-                                });
-                              }
-                            }}
-                            onArrowDownIntoChildren={
-                              isGguf && !isDirectGguf && isGgufExpanded(m.id)
-                                ? () => {
-                                    const focused =
-                                      focusFirstChildOption(optionKey);
-                                    return focused;
-                                  }
-                                : undefined
-                            }
-                            vramStatus={null}
+                    {/* Folder paths */}
+                    {!customFoldersCollapsed &&
+                      scanFolders.map((f) => (
+                        <div
+                          key={f.id}
+                          className="group flex items-center gap-1.5 px-2.5 py-0.5"
+                        >
+                          <HugeiconsIcon
+                            icon={Folder02Icon}
+                            className="size-3 shrink-0 text-muted-foreground/40"
                           />
-                          {isGguf && !isDirectGguf && isGgufExpanded(m.id) && (
-                            <GgufVariantExpander
-                              repoId={m.id}
-                              onDevice={true}
-                              onSelect={onSelect}
-                              parentOptionKey={optionKey}
-                              onNavigatePastStart={() =>
-                                hubModelList.focusOption(optionKey)
-                              }
-                              onNavigatePastEnd={() =>
-                                hubModelList.moveFocus(optionKey, "next")
-                              }
-                              gpuGb={
-                                gpu.available ? gpu.memoryTotalGb : undefined
-                              }
-                              systemRamGb={gpu.systemRamAvailableGb || undefined}
+                          <span
+                            className="min-w-0 flex-1 truncate font-mono text-ui-10 text-muted-foreground/70"
+                            title={f.path}
+                          >
+                            {f.path}
+                          </span>
+                          <button
+                            type="button"
+                            onClick={() => handleRemoveFolder(f.id)}
+                            aria-label={`Remove folder ${f.path}`}
+                            className="shrink-0 rounded p-1 text-foreground/70 transition-colors hover:bg-destructive/10 hover:text-destructive focus-visible:bg-destructive/10 focus-visible:text-destructive"
+                          >
+                            <HugeiconsIcon
+                              icon={Cancel01Icon}
+                              className="size-3"
                             />
-                          )}
+                          </button>
                         </div>
-                      );
-                    })}
-                  {!customFoldersCollapsed &&
-                  showHfSection &&
-                  sortedCustomFolderModels.length === 0 ? (
-                    <div className="px-2.5 py-2 text-xs text-muted-foreground">
-                      No matching models in custom folders.
-                    </div>
-                  ) : null}
-                </>
-              ) : null}
+                      ))}
 
-              {section === "downloaded" && sortedLmStudio.length > 0 ? (
-                <>
-                  <ListLabel
-                    divider={true}
-                    collapsed={lmStudioCollapsed}
-                    onToggle={() => setLmStudioCollapsed((v) => !v)}
-                  >
-                    LM Studio
-                  </ListLabel>
-                  {!lmStudioCollapsed &&
-                    sortedLmStudio.map((m) => {
-                      const isGgufFile = m.path.toLowerCase().endsWith(".gguf");
-                      // LM Studio dirs are GGUF but rarely carry a -GGUF suffix;
-                      // use the shared helper (model_format hint) so the row,
-                      // filter, and load path agree.
-                      const isGguf = localModelIsGguf(m);
-                      const optionKey = makeModelOptionKey("lm-studio", m.id);
-                      return (
-                        <div key={m.id}>
-                          <ModelRow
-                            label={m.model_id ?? m.display_name}
-                            meta={isGguf ? "GGUF" : "Local"}
-                            tooltipText={localPathTooltip(
-                              m.model_id ?? m.display_name,
-                              m.path,
-                            )}
-                            selected={value === m.id}
-                            optionProps={hubModelList.getOptionProps(
-                              optionKey,
-                              value === m.id,
-                            )}
-                            onClick={() => {
-                              if (isGgufFile) {
-                                onSelect(m.id, {
-                                  source: "local",
-                                  isLora: false,
-                                  isDownloaded: true,
-                                  isGguf: true,
-                                });
-                              } else if (isGguf) {
-                                toggleGgufExpanded(m.id);
-                              } else {
-                                onSelect(m.id, {
-                                  source: "local",
-                                  isLora: false,
-                                  isDownloaded: true,
-                                });
+                    {/* Recommended folders */}
+                    {!customFoldersCollapsed &&
+                      (() => {
+                        const registered = new Set(
+                          scanFolders.map((f) => f.path),
+                        );
+                        const unregistered = recommendedFolders.filter(
+                          (p) => !registered.has(p),
+                        );
+                        if (unregistered.length === 0) return null;
+                        return (
+                          <div className="flex flex-wrap gap-1 px-2.5 pb-0.5">
+                            {unregistered.map((p) => (
+                              <button
+                                key={p}
+                                type="button"
+                                onClick={() => void handleAddFolder(p)}
+                                disabled={folderLoading}
+                                title={`Add ${p}`}
+                                className="rounded-full border border-dashed border-border/50 px-2 py-0.5 font-mono text-ui-10 text-muted-foreground/70 transition-colors hover:border-foreground/30 hover:bg-accent hover:text-foreground disabled:opacity-40"
+                              >
+                                <span className="text-ui-11 font-semibold">
+                                  +
+                                </span>{" "}
+                                {p.length > 30 ? `...${p.slice(-27)}` : p}
+                              </button>
+                            ))}
+                          </div>
+                        );
+                      })()}
+
+                    {/* Add folder input */}
+                    {!customFoldersCollapsed && showFolderInput && (
+                      <div className="px-2.5 pb-1 pt-0.5">
+                        <div className="flex items-center gap-1">
+                          <HugeiconsIcon
+                            icon={Folder02Icon}
+                            className="size-3 shrink-0 text-muted-foreground/40"
+                          />
+                          <input
+                            value={folderInput}
+                            onChange={(e) => {
+                              setFolderInput(e.target.value);
+                              setFolderError(null);
+                            }}
+                            onKeyDown={(e) => {
+                              if (e.key === "Enter") {
+                                e.preventDefault();
+                                handleAddFolder();
+                              }
+                              if (e.key === "Escape") {
+                                e.preventDefault();
+                                e.stopPropagation();
+                                setShowFolderInput(false);
+                                setFolderInput("");
+                                setFolderError(null);
                               }
                             }}
-                            onArrowDownIntoChildren={
-                              isGguf && !isGgufFile && isGgufExpanded(m.id)
-                                ? () => {
-                                    const focused =
-                                      focusFirstChildOption(optionKey);
-                                    return focused;
-                                  }
-                                : undefined
-                            }
-                            vramStatus={null}
+                            placeholder="/path/to/models"
+                            className="h-6 min-w-0 flex-1 rounded border border-border/50 bg-transparent px-1.5 font-mono text-ui-10 text-foreground outline-none placeholder:text-muted-foreground/40 focus:border-foreground/20"
+                            disabled={folderLoading}
+                            autoFocus={true}
                           />
-                          {isGguf && !isGgufFile && isGgufExpanded(m.id) && (
-                            <GgufVariantExpander
-                              repoId={m.id}
-                              onDevice={true}
-                              onSelect={onSelect}
-                              parentOptionKey={optionKey}
-                              onNavigatePastStart={() =>
-                                hubModelList.focusOption(optionKey)
-                              }
-                              onNavigatePastEnd={() =>
-                                hubModelList.moveFocus(optionKey, "next")
-                              }
-                              gpuGb={
-                                gpu.available ? gpu.memoryTotalGb : undefined
-                              }
-                              systemRamGb={gpu.systemRamAvailableGb || undefined}
+                          <button
+                            type="button"
+                            onClick={() => setShowFolderBrowser(true)}
+                            disabled={folderLoading}
+                            aria-label="Browse for folder"
+                            title="Browse folders on the server"
+                            className="flex h-6 shrink-0 items-center justify-center rounded border border-border/50 px-1.5 text-muted-foreground transition-colors hover:bg-accent hover:text-foreground disabled:opacity-40"
+                          >
+                            <HugeiconsIcon
+                              icon={Search01Icon}
+                              className="size-3"
                             />
-                          )}
-                        </div>
-                      );
-                    })}
-                </>
-              ) : null}
-
-              {section === "downloaded" && sortedLocalDir.length > 0 ? (
-                <>
-                  <ListLabel
-                    divider={true}
-                    collapsed={localDirCollapsed}
-                    onToggle={() => setLocalDirCollapsed((v) => !v)}
-                  >
-                    Local models
-                  </ListLabel>
-                  {!localDirCollapsed &&
-                    sortedLocalDir.map((m) => {
-                      // A loose ./models/*.gguf file loads directly; a GGUF repo
-                      // directory expands to pick a variant. The backend's local
-                      // variant scanner returns nothing for a config-less loose
-                      // file, so expanding it would dead-end at "No GGUF variants".
-                      const isGgufFile = m.path.toLowerCase().endsWith(".gguf");
-                      const isGguf = localModelIsGguf(m);
-                      const optionKey = makeModelOptionKey("local-dir", m.id);
-                      return (
-                        <div key={m.id}>
-                          <ModelRow
-                            label={m.model_id ?? m.display_name}
-                            meta={isGguf ? "GGUF" : "Local"}
-                            tooltipText={localPathTooltip(
-                              m.model_id ?? m.display_name,
-                              m.path,
-                            )}
-                            selected={value === m.id}
-                            optionProps={hubModelList.getOptionProps(
-                              optionKey,
-                              value === m.id,
-                            )}
+                          </button>
+                          <button
+                            type="button"
                             onClick={() => {
-                              if (isGgufFile) {
-                                onSelect(m.id, {
-                                  source: "local",
-                                  isLora: false,
-                                  isDownloaded: true,
-                                  isGguf: true,
-                                });
-                              } else if (isGguf) {
-                                toggleGgufExpanded(m.id);
-                              } else {
-                                onSelect(m.id, {
-                                  source: "local",
-                                  isLora: false,
-                                  isDownloaded: true,
-                                });
-                              }
+                              void handleAddFolder();
                             }}
-                            onArrowDownIntoChildren={
-                              isGguf && !isGgufFile && isGgufExpanded(m.id)
-                                ? () => focusFirstChildOption(optionKey)
-                                : undefined
-                            }
-                            vramStatus={null}
-                          />
-                          {isGguf && !isGgufFile && isGgufExpanded(m.id) && (
-                            <GgufVariantExpander
-                              repoId={m.id}
-                              onDevice={true}
-                              onSelect={onSelect}
-                              parentOptionKey={optionKey}
-                              onNavigatePastStart={() =>
-                                hubModelList.focusOption(optionKey)
-                              }
-                              onNavigatePastEnd={() =>
-                                hubModelList.moveFocus(optionKey, "next")
-                              }
-                              gpuGb={
-                                gpu.available ? gpu.memoryTotalGb : undefined
-                              }
-                              systemRamGb={gpu.systemRamAvailableGb || undefined}
-                            />
-                          )}
+                            disabled={folderLoading || !folderInput.trim()}
+                            className="h-6 shrink-0 rounded border border-border/50 px-1.5 text-ui-10 text-muted-foreground transition-colors hover:bg-accent disabled:opacity-40"
+                          >
+                            Add
+                          </button>
                         </div>
-                      );
-                    })}
-                </>
-              ) : null}
-
-              {showRecommendedSection ? (
-                <>
-                  {recommendedSearch.isLoading &&
-                  recommendedRows.length === 0 ? (
-                    <div className="flex items-center gap-2 px-5 py-3">
-                      <Spinner className="size-3 text-muted-foreground" />
-                      <span className="text-xs text-muted-foreground">
-                        Loading models…
-                      </span>
-                    </div>
-                  ) : recommendedRows.length === 0 ? (
-                    <div className="px-2.5 py-2 text-xs text-muted-foreground">
-                      No models found.
-                    </div>
-                  ) : (
-                    recommendedRows.map((r) => {
-                      const id = r.id;
-                      const info = recommendedMeta.get(id);
-                      const isG = isKnownGgufRepo(id);
-                      const optionKey = makeModelOptionKey("recommended", id);
-                      return (
-                        <div key={id}>
-                          <ModelRow
-                            label={id}
-                            hubUrl={hubRepoUrl(id)}
-                            hideOwner={true}
-                            downloaded={downloadedSet.has(id.toLowerCase())}
-                            capabilities={capsById.get(id)}
-                            meta={
-                              info?.meta ??
-                              (isG ? "GGUF" : extractParamLabel(id))
-                            }
-                            selected={value === id}
-                            optionProps={hubModelList.getOptionProps(
-                              optionKey,
-                              value === id,
-                            )}
-                            onClick={() => {
-                              if (isG) {
-                                setExpandedGguf((prev) =>
-                                  prev === id ? null : id,
-                                );
-                              } else {
-                                handleModelClick(id);
-                              }
-                            }}
-                            vramStatus={info?.status ?? null}
-                            vramEst={info?.est}
-                            gpuGb={
-                              gpu.available ? gpu.memoryTotalGb : undefined
-                            }
-                            onArrowDownIntoChildren={
-                              expandedGguf === id
-                                ? () => focusFirstChildOption(optionKey)
-                                : undefined
-                            }
-                          />
-                          {expandedGguf === id && (
-                            <GgufVariantExpander
-                              repoId={id}
-                              onSelect={onSelect}
-                              hfToken={hfToken || undefined}
-                              parentOptionKey={optionKey}
-                              onNavigatePastStart={() =>
-                                hubModelList.focusOption(optionKey)
-                              }
-                              onNavigatePastEnd={() =>
-                                hubModelList.moveFocus(optionKey, "next")
-                              }
-                              gpuGb={
-                                gpu.available ? gpu.memoryTotalGb : undefined
-                              }
-                              systemRamGb={gpu.systemRamAvailableGb || undefined}
-                              variantActions={{
-                                onDelete: async (quant) => {
-                                  await deleteCachedModel(id, quant);
-                                  refreshCachedLists();
-                                },
-                              }}
-                            />
-                          )}
-                        </div>
-                      );
-                    })
-                  )}
-                  {recommendedSearch.hasMore && (
-                    <>
-                      <div ref={recommendedSentinelRef} className="h-px" />
-                      <div className="flex items-center justify-center py-2">
-                        <Spinner className="size-3.5 text-muted-foreground" />
-                      </div>
-                    </>
-                  )}
-                </>
-              ) : null}
-
-              {showHfSection &&
-              section === "recommended" &&
-              filteredRecommendedIds.length > 0 ? (
-                <>
-                  {filteredRecommendedIds.map((id) => {
-                    const vram = recommendedVramMap.get(id);
-                    const optionKey = makeModelOptionKey(
-                      "search-recommended",
-                      id,
-                    );
-                    return (
-                      <div key={id}>
-                        <ModelRow
-                          label={id}
-                          hubUrl={hubRepoUrl(id)}
-                          capabilities={capsById.get(id)}
-                          meta={
-                            isKnownGgufRepo(id)
-                              ? "GGUF"
-                              : (vram?.detail ?? extractParamLabel(id))
-                          }
-                          selected={value === id}
-                          optionProps={hubModelList.getOptionProps(
-                            optionKey,
-                            value === id,
-                          )}
-                          onClick={() => {
-                            if (isKnownGgufRepo(id)) {
-                              setExpandedGguf((prev) =>
-                                prev === id ? null : id,
-                              );
-                            } else {
-                              handleModelClick(id);
-                            }
-                          }}
-                          vramStatus={
-                            isKnownGgufRepo(id) ? null : (vram?.status ?? null)
-                          }
-                          vramEst={isKnownGgufRepo(id) ? undefined : vram?.est}
-                          gpuGb={gpu.available ? gpu.memoryTotalGb : undefined}
-                          onArrowDownIntoChildren={
-                            expandedGguf === id
-                              ? () => {
-                                  const focused =
-                                    focusFirstChildOption(optionKey);
-                                  return focused;
-                                }
-                              : undefined
-                          }
-                        />
-                        {expandedGguf === id && (
-                          <GgufVariantExpander
-                            repoId={id}
-                            onSelect={onSelect}
-                            hfToken={hfToken || undefined}
-                            parentOptionKey={optionKey}
-                            onNavigatePastStart={() =>
-                              hubModelList.focusOption(optionKey)
-                            }
-                            onNavigatePastEnd={() =>
-                              hubModelList.moveFocus(optionKey, "next")
-                            }
-                            gpuGb={
-                              gpu.available ? gpu.memoryTotalGb : undefined
-                            }
-                            systemRamGb={gpu.systemRamAvailableGb || undefined}
-                            variantActions={{
-                              onDelete: async (quant) => {
-                                await deleteCachedModel(id, quant);
-                                refreshCachedLists();
-                              },
-                            }}
-                          />
+                        {folderError && (
+                          <p className="px-0.5 pt-0.5 text-ui-10 text-destructive">
+                            {folderError}
+                          </p>
                         )}
                       </div>
-                    );
-                  })}
-                </>
-              ) : null}
+                    )}
 
-              {showHfSection && section === "recommended" ? (
-                <>
-                  {hfIds.length === 0 && !isLoading ? (
-                    filteredRecommendedIds.length === 0 ? (
+                    <FolderBrowser
+                      open={showFolderBrowser}
+                      onOpenChange={setShowFolderBrowser}
+                      initialPath={folderInput.trim() || undefined}
+                      onSelect={(picked) => {
+                        setFolderInput(picked);
+                        setFolderError(null);
+                        // Pass the path explicitly: `folderInput` state hasn't
+                        // flushed yet when "Use this folder" submits.
+                        void handleAddFolder(picked);
+                      }}
+                    />
+
+                    {/* Models from custom folders */}
+                    {!customFoldersCollapsed &&
+                      sortedCustomFolderModels.map((m) => {
+                        const isGgufFile = m.path
+                          .toLowerCase()
+                          .endsWith(".gguf");
+                        // Honor the backend model_format hint (suffixless GGUF
+                        // folders) in addition to name/path so the row classifies
+                        // and loads through the same GGUF path as the filter.
+                        const isGguf = localModelIsGguf(m);
+                        // Single .gguf files (e.g. Ollama blobs) load directly;
+                        // GGUF repos/directories expand to pick a variant.
+                        const isDirectGguf = isGgufFile;
+                        const optionKey = makeModelOptionKey(
+                          "custom-folder",
+                          m.id,
+                        );
+                        return (
+                          <div key={m.id}>
+                            <div className="flex items-center gap-0.5">
+                              <div className="min-w-0 flex-1">
+                                <ModelRow
+                                  label={m.model_id ?? m.display_name}
+                                  meta={isGguf ? "GGUF" : "Local"}
+                                  tooltipText={localPathTooltip(
+                                    m.model_id ?? m.display_name,
+                                    m.path,
+                                  )}
+                                  selected={value === m.id}
+                                  loaded={isRuntimeLoadedModel(
+                                    loadedModelId,
+                                    activeGgufVariant,
+                                    m.id,
+                                    isGgufFile
+                                      ? "ignore"
+                                      : isGguf
+                                        ? "required"
+                                        : "none",
+                                  )}
+                                  optionProps={hubModelList.getOptionProps(
+                                    optionKey,
+                                    value === m.id,
+                                  )}
+                                  onClick={() => {
+                                    if (isDirectGguf) {
+                                      onSelect(m.id, localDirectGgufMeta());
+                                    } else if (isGguf) {
+                                      toggleGgufExpanded(m.id);
+                                    } else {
+                                      onSelect(m.id, localModelMeta());
+                                    }
+                                  }}
+                                  onArrowDownIntoChildren={
+                                    isGguf &&
+                                    !isDirectGguf &&
+                                    isGgufExpanded(m.id)
+                                      ? () => {
+                                          const focused =
+                                            focusFirstChildOption(optionKey);
+                                          return focused;
+                                        }
+                                      : undefined
+                                  }
+                                  vramStatus={null}
+                                />
+                              </div>
+                              {isDirectGguf && onConfigure && (
+                                <ModelLoadSettingsAction
+                                  ariaLabel={`Inference settings for ${
+                                    m.model_id ?? m.display_name
+                                  }`}
+                                  onConfigure={() =>
+                                    onConfigure(m.id, localDirectGgufMeta())
+                                  }
+                                />
+                              )}
+                              {!isGguf && onConfigure && (
+                                <ModelLoadSettingsAction
+                                  ariaLabel={`Inference settings for ${
+                                    m.model_id ?? m.display_name
+                                  }`}
+                                  onConfigure={() =>
+                                    onConfigure(m.id, localModelMeta())
+                                  }
+                                />
+                              )}
+                            </div>
+                            {isGguf &&
+                              !isDirectGguf &&
+                              isGgufExpanded(m.id) && (
+                                <GgufVariantExpander
+                                  repoId={m.id}
+                                  onDevice={true}
+                                  onSelect={onSelect}
+                                  onConfigure={onConfigure}
+                                  parentOptionKey={optionKey}
+                                  onNavigatePastStart={() =>
+                                    hubModelList.focusOption(optionKey)
+                                  }
+                                  onNavigatePastEnd={() =>
+                                    hubModelList.moveFocus(optionKey, "next")
+                                  }
+                                  gpuGb={
+                                    gpu.available
+                                      ? gpu.memoryTotalGb
+                                      : undefined
+                                  }
+                                  systemRamGb={
+                                    gpu.systemRamAvailableGb || undefined
+                                  }
+                                />
+                              )}
+                          </div>
+                        );
+                      })}
+                    {!customFoldersCollapsed &&
+                    showHfSection &&
+                    sortedCustomFolderModels.length === 0 ? (
                       <div className="px-2.5 py-2 text-xs text-muted-foreground">
-                        No matching Unsloth models.
+                        No matching models in custom folders.
                       </div>
-                    ) : null
-                  ) : (
-                    hfIds.map((id) => {
-                      const vram = vramMap.get(id);
-                      const isSearchGguf = isKnownGgufRepo(id);
-                      const optionKey = makeModelOptionKey("search-hf", id);
+                    ) : null}
+                  </>
+                ) : null}
+
+                {section === "downloaded" && sortedLmStudio.length > 0 ? (
+                  <>
+                    <ListLabel
+                      divider={true}
+                      collapsed={lmStudioCollapsed}
+                      onToggle={() => setLmStudioCollapsed((v) => !v)}
+                    >
+                      LM Studio
+                    </ListLabel>
+                    {!lmStudioCollapsed &&
+                      sortedLmStudio.map((m) => {
+                        const isGgufFile = m.path
+                          .toLowerCase()
+                          .endsWith(".gguf");
+                        // LM Studio dirs are GGUF but rarely carry a -GGUF suffix;
+                        // use the shared helper (model_format hint) so the row,
+                        // filter, and load path agree.
+                        const isGguf = localModelIsGguf(m);
+                        const optionKey = makeModelOptionKey("lm-studio", m.id);
+                        return (
+                          <div key={m.id}>
+                            <div className="flex items-center gap-0.5">
+                              <div className="min-w-0 flex-1">
+                                <ModelRow
+                                  label={m.model_id ?? m.display_name}
+                                  meta={isGguf ? "GGUF" : "Local"}
+                                  tooltipText={localPathTooltip(
+                                    m.model_id ?? m.display_name,
+                                    m.path,
+                                  )}
+                                  selected={value === m.id}
+                                  loaded={isRuntimeLoadedModel(
+                                    loadedModelId,
+                                    activeGgufVariant,
+                                    m.id,
+                                    isGgufFile
+                                      ? "ignore"
+                                      : isGguf
+                                        ? "required"
+                                        : "none",
+                                  )}
+                                  optionProps={hubModelList.getOptionProps(
+                                    optionKey,
+                                    value === m.id,
+                                  )}
+                                  onClick={() => {
+                                    if (isGgufFile) {
+                                      onSelect(m.id, localDirectGgufMeta());
+                                    } else if (isGguf) {
+                                      toggleGgufExpanded(m.id);
+                                    } else {
+                                      onSelect(m.id, localModelMeta());
+                                    }
+                                  }}
+                                  onArrowDownIntoChildren={
+                                    isGguf &&
+                                    !isGgufFile &&
+                                    isGgufExpanded(m.id)
+                                      ? () => {
+                                          const focused =
+                                            focusFirstChildOption(optionKey);
+                                          return focused;
+                                        }
+                                      : undefined
+                                  }
+                                  vramStatus={null}
+                                />
+                              </div>
+                              {isGgufFile && onConfigure && (
+                                <ModelLoadSettingsAction
+                                  ariaLabel={`Inference settings for ${
+                                    m.model_id ?? m.display_name
+                                  }`}
+                                  onConfigure={() =>
+                                    onConfigure(m.id, localDirectGgufMeta())
+                                  }
+                                />
+                              )}
+                              {!isGguf && onConfigure && (
+                                <ModelLoadSettingsAction
+                                  ariaLabel={`Inference settings for ${
+                                    m.model_id ?? m.display_name
+                                  }`}
+                                  onConfigure={() =>
+                                    onConfigure(m.id, localModelMeta())
+                                  }
+                                />
+                              )}
+                            </div>
+                            {isGguf && !isGgufFile && isGgufExpanded(m.id) && (
+                              <GgufVariantExpander
+                                repoId={m.id}
+                                onDevice={true}
+                                onSelect={onSelect}
+                                onConfigure={onConfigure}
+                                parentOptionKey={optionKey}
+                                onNavigatePastStart={() =>
+                                  hubModelList.focusOption(optionKey)
+                                }
+                                onNavigatePastEnd={() =>
+                                  hubModelList.moveFocus(optionKey, "next")
+                                }
+                                gpuGb={
+                                  gpu.available ? gpu.memoryTotalGb : undefined
+                                }
+                                systemRamGb={
+                                  gpu.systemRamAvailableGb || undefined
+                                }
+                              />
+                            )}
+                          </div>
+                        );
+                      })}
+                  </>
+                ) : null}
+
+                {section === "downloaded" && sortedLocalDir.length > 0 ? (
+                  <>
+                    <ListLabel
+                      divider={true}
+                      collapsed={localDirCollapsed}
+                      onToggle={() => setLocalDirCollapsed((v) => !v)}
+                    >
+                      Local models
+                    </ListLabel>
+                    {!localDirCollapsed &&
+                      sortedLocalDir.map((m) => {
+                        // A loose ./models/*.gguf loads directly; a GGUF repo dir
+                        // expands to pick a variant. The variant scanner returns
+                        // nothing for a config-less loose file, so expanding it would
+                        // dead-end at "No GGUF variants".
+                        const isGgufFile = m.path
+                          .toLowerCase()
+                          .endsWith(".gguf");
+                        const isGguf = localModelIsGguf(m);
+                        const optionKey = makeModelOptionKey("local-dir", m.id);
+                        return (
+                          <div key={m.id}>
+                            <div className="flex items-center gap-0.5">
+                              <div className="min-w-0 flex-1">
+                                <ModelRow
+                                  label={m.model_id ?? m.display_name}
+                                  meta={isGguf ? "GGUF" : "Local"}
+                                  tooltipText={localPathTooltip(
+                                    m.model_id ?? m.display_name,
+                                    m.path,
+                                  )}
+                                  selected={value === m.id}
+                                  loaded={isRuntimeLoadedModel(
+                                    loadedModelId,
+                                    activeGgufVariant,
+                                    m.id,
+                                    isGgufFile
+                                      ? "ignore"
+                                      : isGguf
+                                        ? "required"
+                                        : "none",
+                                  )}
+                                  optionProps={hubModelList.getOptionProps(
+                                    optionKey,
+                                    value === m.id,
+                                  )}
+                                  onClick={() => {
+                                    if (isGgufFile) {
+                                      onSelect(m.id, localDirectGgufMeta());
+                                    } else if (isGguf) {
+                                      toggleGgufExpanded(m.id);
+                                    } else {
+                                      onSelect(m.id, localModelMeta());
+                                    }
+                                  }}
+                                  onArrowDownIntoChildren={
+                                    isGguf &&
+                                    !isGgufFile &&
+                                    isGgufExpanded(m.id)
+                                      ? () => focusFirstChildOption(optionKey)
+                                      : undefined
+                                  }
+                                  vramStatus={null}
+                                />
+                              </div>
+                              {isGgufFile && onConfigure && (
+                                <ModelLoadSettingsAction
+                                  ariaLabel={`Inference settings for ${
+                                    m.model_id ?? m.display_name
+                                  }`}
+                                  onConfigure={() =>
+                                    onConfigure(m.id, localDirectGgufMeta())
+                                  }
+                                />
+                              )}
+                              {!isGguf && onConfigure && (
+                                <ModelLoadSettingsAction
+                                  ariaLabel={`Inference settings for ${
+                                    m.model_id ?? m.display_name
+                                  }`}
+                                  onConfigure={() =>
+                                    onConfigure(m.id, localModelMeta())
+                                  }
+                                />
+                              )}
+                            </div>
+                            {isGguf && !isGgufFile && isGgufExpanded(m.id) && (
+                              <GgufVariantExpander
+                                repoId={m.id}
+                                onDevice={true}
+                                onSelect={onSelect}
+                                onConfigure={onConfigure}
+                                parentOptionKey={optionKey}
+                                onNavigatePastStart={() =>
+                                  hubModelList.focusOption(optionKey)
+                                }
+                                onNavigatePastEnd={() =>
+                                  hubModelList.moveFocus(optionKey, "next")
+                                }
+                                gpuGb={
+                                  gpu.available ? gpu.memoryTotalGb : undefined
+                                }
+                                systemRamGb={
+                                  gpu.systemRamAvailableGb || undefined
+                                }
+                              />
+                            )}
+                          </div>
+                        );
+                      })}
+                  </>
+                ) : null}
+
+                {showRecommendedSection ? (
+                  <>
+                    {recommendedSearch.isLoading &&
+                    recommendedRows.length === 0 ? (
+                      <div className="flex items-center gap-2 px-5 py-3">
+                        <Spinner className="size-3 text-muted-foreground" />
+                        <span className="text-xs text-muted-foreground">
+                          Loading models…
+                        </span>
+                      </div>
+                    ) : recommendedRows.length === 0 ? (
+                      <div className="px-2.5 py-2 text-xs text-muted-foreground">
+                        No models found.
+                      </div>
+                    ) : (
+                      recommendedRows.map((r) => {
+                        const id = r.id;
+                        const info = recommendedMeta.get(id);
+                        const isG = isKnownGgufRepo(id);
+                        const optionKey = makeModelOptionKey("recommended", id);
+                        return (
+                          <div key={id}>
+                            <ModelRow
+                              label={id}
+                              hubUrl={hubRepoUrl(id)}
+                              hideOwner={true}
+                              downloaded={downloadedSet.has(id.toLowerCase())}
+                              capabilities={capsById.get(id)}
+                              meta={
+                                info?.meta ??
+                                (isG ? "GGUF" : extractParamLabel(id))
+                              }
+                              selected={value === id}
+                              loaded={isRuntimeLoadedModel(
+                                loadedModelId,
+                                activeGgufVariant,
+                                id,
+                                isG ? "required" : "none",
+                              )}
+                              optionProps={hubModelList.getOptionProps(
+                                optionKey,
+                                value === id,
+                              )}
+                              onClick={() => {
+                                if (isG) {
+                                  setExpandedGguf((prev) =>
+                                    prev === id ? null : id,
+                                  );
+                                } else {
+                                  handleModelClick(id);
+                                }
+                              }}
+                              vramStatus={info?.status ?? null}
+                              vramEst={info?.est}
+                              gpuGb={
+                                gpu.available ? gpu.memoryTotalGb : undefined
+                              }
+                              onArrowDownIntoChildren={
+                                expandedGguf === id
+                                  ? () => focusFirstChildOption(optionKey)
+                                  : undefined
+                              }
+                            />
+                            {expandedGguf === id && (
+                              <GgufVariantExpander
+                                repoId={id}
+                                onSelect={onSelect}
+                                onConfigure={onConfigure}
+                                hfToken={hfToken || undefined}
+                                parentOptionKey={optionKey}
+                                onNavigatePastStart={() =>
+                                  hubModelList.focusOption(optionKey)
+                                }
+                                onNavigatePastEnd={() =>
+                                  hubModelList.moveFocus(optionKey, "next")
+                                }
+                                gpuGb={
+                                  gpu.available ? gpu.memoryTotalGb : undefined
+                                }
+                                systemRamGb={
+                                  gpu.systemRamAvailableGb || undefined
+                                }
+                                variantActions={{
+                                  onDelete: async (quant) => {
+                                    await deleteCachedModel(
+                                      id,
+                                      quant,
+                                      hfToken || undefined,
+                                    );
+                                    prunePinnedQuantValidation(id, quant);
+                                    refreshCachedLists();
+                                  },
+                                }}
+                              />
+                            )}
+                          </div>
+                        );
+                      })
+                    )}
+                    {recommendedSearch.hasMore && (
+                      <>
+                        <div ref={recommendedSentinelRef} className="h-px" />
+                        <div className="flex items-center justify-center py-2">
+                          <Spinner className="size-3.5 text-muted-foreground" />
+                        </div>
+                      </>
+                    )}
+                  </>
+                ) : null}
+
+                {showHfSection &&
+                section === "recommended" &&
+                filteredRecommendedIds.length > 0 ? (
+                  <>
+                    {filteredRecommendedIds.map((id) => {
+                      const vram = recommendedVramMap.get(id);
+                      const optionKey = makeModelOptionKey(
+                        "search-recommended",
+                        id,
+                      );
                       return (
                         <div key={id}>
                           <ModelRow
@@ -3575,23 +4069,23 @@ export function HubModelPicker({
                             hubUrl={hubRepoUrl(id)}
                             capabilities={capsById.get(id)}
                             meta={
-                              isSearchGguf
+                              isKnownGgufRepo(id)
                                 ? "GGUF"
-                                : [
-                                    metricsById.get(id) ??
-                                      extractParamLabel(id),
-                                    isMlxId(id) ? "MLX" : "Safetensors",
-                                  ]
-                                    .filter(Boolean)
-                                    .join(" · ")
+                                : (vram?.detail ?? extractParamLabel(id))
                             }
                             selected={value === id}
+                            loaded={isRuntimeLoadedModel(
+                              loadedModelId,
+                              activeGgufVariant,
+                              id,
+                              isKnownGgufRepo(id) ? "required" : "none",
+                            )}
                             optionProps={hubModelList.getOptionProps(
                               optionKey,
                               value === id,
                             )}
                             onClick={() => {
-                              if (isSearchGguf) {
+                              if (isKnownGgufRepo(id)) {
                                 setExpandedGguf((prev) =>
                                   prev === id ? null : id,
                                 );
@@ -3600,9 +4094,13 @@ export function HubModelPicker({
                               }
                             }}
                             vramStatus={
-                              isSearchGguf ? null : (vram?.status ?? null)
+                              isKnownGgufRepo(id)
+                                ? null
+                                : (vram?.status ?? null)
+                            }
+                            vramEst={
+                              isKnownGgufRepo(id) ? undefined : vram?.est
                             }
-                            vramEst={isSearchGguf ? undefined : vram?.est}
                             gpuGb={
                               gpu.available ? gpu.memoryTotalGb : undefined
                             }
@@ -3620,6 +4118,7 @@ export function HubModelPicker({
                             <GgufVariantExpander
                               repoId={id}
                               onSelect={onSelect}
+                              onConfigure={onConfigure}
                               hfToken={hfToken || undefined}
                               parentOptionKey={optionKey}
                               onNavigatePastStart={() =>
@@ -3631,10 +4130,17 @@ export function HubModelPicker({
                               gpuGb={
                                 gpu.available ? gpu.memoryTotalGb : undefined
                               }
-                              systemRamGb={gpu.systemRamAvailableGb || undefined}
+                              systemRamGb={
+                                gpu.systemRamAvailableGb || undefined
+                              }
                               variantActions={{
                                 onDelete: async (quant) => {
-                                  await deleteCachedModel(id, quant);
+                                  await deleteCachedModel(
+                                    id,
+                                    quant,
+                                    hfToken || undefined,
+                                  );
+                                  prunePinnedQuantValidation(id, quant);
                                   refreshCachedLists();
                                 },
                               }}
@@ -3642,35 +4148,138 @@ export function HubModelPicker({
                           )}
                         </div>
                       );
-                    })
-                  )}
-                  <div ref={sentinelRef} className="h-px" />
-                  {isLoadingMore ? (
-                    <div className="flex items-center justify-center py-2">
-                      <Spinner className="size-3.5 text-muted-foreground" />
-                    </div>
-                  ) : null}
-                </>
-              ) : null}
-            </>
-          )}
+                    })}
+                  </>
+                ) : null}
+
+                {showHfSection && section === "recommended" ? (
+                  <>
+                    {hfIds.length === 0 && !isLoading ? (
+                      filteredRecommendedIds.length === 0 ? (
+                        <div className="px-2.5 py-2 text-xs text-muted-foreground">
+                          No matching Unsloth models.
+                        </div>
+                      ) : null
+                    ) : (
+                      hfIds.map((id) => {
+                        const vram = vramMap.get(id);
+                        const isSearchGguf = isKnownGgufRepo(id);
+                        const optionKey = makeModelOptionKey("search-hf", id);
+                        return (
+                          <div key={id}>
+                            <ModelRow
+                              label={id}
+                              hubUrl={hubRepoUrl(id)}
+                              capabilities={capsById.get(id)}
+                              meta={
+                                isSearchGguf
+                                  ? "GGUF"
+                                  : [
+                                      metricsById.get(id) ??
+                                        extractParamLabel(id),
+                                      isMlxId(id) ? "MLX" : "Safetensors",
+                                    ]
+                                      .filter(Boolean)
+                                      .join(" · ")
+                              }
+                              selected={value === id}
+                              loaded={isRuntimeLoadedModel(
+                                loadedModelId,
+                                activeGgufVariant,
+                                id,
+                                isSearchGguf ? "required" : "none",
+                              )}
+                              optionProps={hubModelList.getOptionProps(
+                                optionKey,
+                                value === id,
+                              )}
+                              onClick={() => {
+                                if (isSearchGguf) {
+                                  setExpandedGguf((prev) =>
+                                    prev === id ? null : id,
+                                  );
+                                } else {
+                                  handleModelClick(id);
+                                }
+                              }}
+                              vramStatus={
+                                isSearchGguf ? null : (vram?.status ?? null)
+                              }
+                              vramEst={isSearchGguf ? undefined : vram?.est}
+                              gpuGb={
+                                gpu.available ? gpu.memoryTotalGb : undefined
+                              }
+                              onArrowDownIntoChildren={
+                                expandedGguf === id
+                                  ? () => {
+                                      const focused =
+                                        focusFirstChildOption(optionKey);
+                                      return focused;
+                                    }
+                                  : undefined
+                              }
+                            />
+                            {expandedGguf === id && (
+                              <GgufVariantExpander
+                                repoId={id}
+                                onSelect={onSelect}
+                                onConfigure={onConfigure}
+                                hfToken={hfToken || undefined}
+                                parentOptionKey={optionKey}
+                                onNavigatePastStart={() =>
+                                  hubModelList.focusOption(optionKey)
+                                }
+                                onNavigatePastEnd={() =>
+                                  hubModelList.moveFocus(optionKey, "next")
+                                }
+                                gpuGb={
+                                  gpu.available ? gpu.memoryTotalGb : undefined
+                                }
+                                systemRamGb={
+                                  gpu.systemRamAvailableGb || undefined
+                                }
+                                variantActions={{
+                                  onDelete: async (quant) => {
+                                    await deleteCachedModel(
+                                      id,
+                                      quant,
+                                      hfToken || undefined,
+                                    );
+                                    prunePinnedQuantValidation(id, quant);
+                                    refreshCachedLists();
+                                  },
+                                }}
+                              />
+                            )}
+                          </div>
+                        );
+                      })
+                    )}
+                    <div ref={sentinelRef} className="h-px" />
+                    {isLoadingMore ? (
+                      <div className="flex items-center justify-center py-2">
+                        <Spinner className="size-3.5 text-muted-foreground" />
+                      </div>
+                    ) : null}
+                  </>
+                ) : null}
+              </>
+            )}
+          </div>
         </div>
-      </div>
-      {/* Floating eject pill: overlaid on the list bottom, outside the scroll
-          so the edge fade never touches it. Only the pill catches clicks. */}
-      {onEject ? (
-        <div className="pointer-events-none absolute inset-x-0 bottom-0 flex justify-end pr-3.5 pb-[19px]">
-          <button
-            type="button"
-            onClick={onEject}
-            className="pointer-events-auto inline-flex items-center justify-center gap-2 rounded-md bg-popover px-3 py-2 text-[13px] font-medium text-destructive shadow-[0_2px_8px_-2px_rgba(0,0,0,0.16)] transition-colors hover:bg-[color-mix(in_srgb,var(--destructive)_12%,var(--popover))] dark:bg-[color-mix(in_srgb,var(--foreground)_10%,var(--sidebar))] dark:shadow-none dark:hover:bg-[color-mix(in_srgb,var(--destructive)_22%,var(--sidebar))]"
-            title="Eject model"
-          >
-            <HugeiconsIcon icon={RemoveCircleIcon} className="size-3.5" />
-            Eject model
-          </button>
-        </div>
-      ) : null}
+        {onEject ? (
+          <div className="pointer-events-none absolute inset-x-0 bottom-0 flex justify-end pr-3.5 pb-[19px]">
+            <button
+              type="button"
+              onClick={onEject}
+              className="pointer-events-auto inline-flex items-center justify-center gap-2 rounded-md bg-popover px-3 py-2 text-ui-13 font-medium text-destructive shadow-[0_2px_8px_-2px_rgba(0,0,0,0.16)] transition-colors hover:bg-[color-mix(in_srgb,var(--destructive)_12%,var(--popover))] dark:bg-[color-mix(in_srgb,var(--foreground)_10%,var(--sidebar))] dark:shadow-none dark:hover:bg-[color-mix(in_srgb,var(--destructive)_22%,var(--sidebar))]"
+              title="Eject model"
+            >
+              <HugeiconsIcon icon={RemoveCircleIcon} className="size-3.5" />
+              Eject model
+            </button>
+          </div>
+        ) : null}
       </div>
       <TransportConflictDialog
         conflict={updateTransportConflict}
@@ -3687,7 +4296,10 @@ export function HubModelPicker({
 function FineTunedRows({
   adapters,
   value,
+  loadedModelId,
+  activeGgufVariant,
   onSelect,
+  onConfigure,
   onModelsChange,
   deleteDisabled = false,
   loraModelList,
@@ -3697,7 +4309,10 @@ function FineTunedRows({
 }: {
   adapters: LoraModelOption[];
   value?: string;
+  loadedModelId?: string;
+  activeGgufVariant?: string | null;
   onSelect: (id: string, meta: ModelSelectorChangeMeta) => void;
+  onConfigure?: (id: string, meta: ModelSelectorChangeMeta) => void;
   onModelsChange?: (deletedModel?: DeletedModelRef) => void;
   deleteDisabled?: boolean;
   loraModelList: ReturnType<typeof useRovingModelList>;
@@ -3722,6 +4337,13 @@ function FineTunedRows({
         const isTrainingFull = isTraining && isMerged;
         const isLocalGgufDir =
           isLocal && (isGgufRepo(adapter.id) || isGgufRepo(adapter.name));
+        const selectionMeta: ModelSelectorChangeMeta = {
+          source: isLocal ? "local" : isExported ? "exported" : "lora",
+          isLora: !isLocal && !isMerged && !isGguf,
+          isDownloaded: true,
+          isGguf: false,
+        };
+        const canConfigure = !(isLocalGgufDir || isExportedGguf);
         const optionKey = makeModelOptionKey("lora", adapter.id);
         const tag = isLocal
           ? isLocalGgufDir
@@ -3753,6 +4375,12 @@ function FineTunedRows({
                   label={adapter.name}
                   meta={meta}
                   selected={value === adapter.id}
+                  loaded={isRuntimeLoadedModel(
+                    loadedModelId,
+                    activeGgufVariant,
+                    adapter.id,
+                    isLocalGgufDir || isExportedGguf ? "required" : "none",
+                  )}
                   optionProps={loraModelList.getOptionProps(
                     optionKey,
                     value === adapter.id,
@@ -3763,21 +4391,13 @@ function FineTunedRows({
                         prev === adapter.id ? null : adapter.id,
                       );
                     } else {
-                      onSelect(adapter.id, {
-                        source: isLocal
-                          ? "local"
-                          : isExported
-                            ? "exported"
-                            : "lora",
-                        isLora: !isLocal && !isMerged && !isGguf,
-                        isDownloaded: true,
-                      });
+                      onSelect(adapter.id, selectionMeta);
                     }
                   }}
                   tooltipText={
                     <>
                       <span className="block break-words">{adapter.name}</span>
-                      <span className="block mt-1 text-[10px] text-muted-foreground break-all">
+                      <span className="block mt-1 text-ui-10 text-muted-foreground break-all">
                         {adapter.id}
                       </span>
                     </>
@@ -3792,6 +4412,12 @@ function FineTunedRows({
                   }
                 />
               </div>
+              {canConfigure && onConfigure && (
+                <ModelLoadSettingsAction
+                  ariaLabel={`Inference settings for ${adapter.name}`}
+                  onConfigure={() => onConfigure(adapter.id, selectionMeta)}
+                />
+              )}
               {canDelete && (
                 <ModelDeleteAction
                   ariaLabel={`Delete ${adapter.name}`}
@@ -3822,6 +4448,7 @@ function FineTunedRows({
               <GgufVariantExpander
                 repoId={adapter.id}
                 onSelect={onSelect}
+                onConfigure={onConfigure}
                 parentOptionKey={optionKey}
                 onNavigatePastStart={() => loraModelList.focusOption(optionKey)}
                 onNavigatePastEnd={() =>
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/pill-tabs.tsx b/studio/frontend/src/features/model-picker/components/model-selector/pill-tabs.tsx
similarity index 89%
rename from studio/frontend/src/components/assistant-ui/model-selector/pill-tabs.tsx
rename to studio/frontend/src/features/model-picker/components/model-selector/pill-tabs.tsx
index e6da8a7b74..ed2d10ead3 100644
--- a/studio/frontend/src/components/assistant-ui/model-selector/pill-tabs.tsx
+++ b/studio/frontend/src/features/model-picker/components/model-selector/pill-tabs.tsx
@@ -29,7 +29,8 @@ export function PillTabs({
   className?: string;
   compact?: boolean;
   /** Size each tab to its label instead of equal widths. The active tab carries
-   * the pill background directly (the toggle never animates). */
+   * the pill background directly (the toggle never animates). Tabs only shrink
+   * when their combined intrinsic width exceeds the available space. */
   fit?: boolean;
 }) {
   const activeIndex = Math.max(
@@ -78,13 +79,14 @@ export function PillTabs({
             onValueChange(tabs[next].value);
             e.currentTarget.parentElement
               ?.querySelectorAll<HTMLElement>('button[role="tab"]')
-              [next]?.focus();
+              .item(next)
+              ?.focus();
           }}
           onClick={() => onValueChange(tab.value)}
           className={cn(
             "relative z-10 inline-flex items-center justify-center gap-1.5 rounded-full transition-colors",
-            fit ? "shrink-0" : "min-w-0 flex-1",
-            compact ? "h-7 px-2.5 text-[11px]" : "h-9 px-3 text-[12.5px]",
+            fit ? "min-w-0 shrink" : "min-w-0 flex-1",
+            compact ? "h-7 px-2.5 text-ui-11" : "h-9 px-3 text-ui-12p5",
             value === tab.value
               ? "text-foreground"
               : "text-muted-foreground hover:text-foreground",
@@ -96,7 +98,7 @@ export function PillTabs({
           )}
         >
           {tab.icon}
-          {tab.label}
+          <span className="min-w-0 truncate">{tab.label}</span>
         </button>
       ))}
     </div>
diff --git a/studio/frontend/src/features/model-picker/components/model-selector/pinned-models.ts b/studio/frontend/src/features/model-picker/components/model-selector/pinned-models.ts
new file mode 100644
index 0000000000..0444b9f3cc
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/components/model-selector/pinned-models.ts
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+// Pinned models for the model selector's On Device list, persisted in
+// localStorage so pins survive reloads. GGUF quants pin individually
+// (repoId + quant); non-GGUF repos pin as a whole. Pinned entries surface
+// in a "Pinned" section above the Unsloth/Downloaded group.
+
+import { create } from "zustand";
+
+const KEY = "unsloth_pinned_models";
+
+// Entries are stored as strings: "repoId" pins a whole (non-GGUF) repo,
+// "repoId::quant" pins one GGUF quant. Neither part contains "::".
+export function pinKey(repoId: string, quant?: string): string {
+  return quant ? `${repoId}::${quant}` : repoId;
+}
+
+export interface PinnedQuantEntry {
+  repoId: string;
+  quant: string;
+}
+
+export function makePinRank(
+  pinned: readonly string[],
+): (key: string) => number {
+  const pinIndex = new Map(pinned.map((key, index) => [key, index]));
+  return (key) => pinIndex.get(key) ?? Number.MAX_SAFE_INTEGER;
+}
+
+/** The pinned GGUF quants, in pin order. Plain repo pins are excluded. */
+export function pinnedQuantEntries(pinned: string[]): PinnedQuantEntry[] {
+  const out: PinnedQuantEntry[] = [];
+  for (const key of pinned) {
+    const sep = key.indexOf("::");
+    if (sep <= 0) continue;
+    const repoId = key.slice(0, sep);
+    const quant = key.slice(sep + 2);
+    if (repoId && quant) out.push({ repoId, quant });
+  }
+  return out;
+}
+
+function readPinned(): string[] {
+  try {
+    const raw = JSON.parse(localStorage.getItem(KEY) ?? "[]");
+    return Array.isArray(raw)
+      ? raw.filter((v): v is string => typeof v === "string")
+      : [];
+  } catch {
+    return [];
+  }
+}
+
+function writePinned(pinned: string[]): void {
+  try {
+    localStorage.setItem(KEY, JSON.stringify(pinned));
+  } catch {
+    // Ignore unavailable storage; pins stay session-only.
+  }
+}
+
+interface PinnedModelsState {
+  pinned: string[];
+  togglePinned: (repoId: string, quant?: string) => void;
+}
+
+export const usePinnedModelsStore = create<PinnedModelsState>((set) => ({
+  pinned: readPinned(),
+  togglePinned: (repoId, quant) =>
+    set((state) => {
+      const key = pinKey(repoId, quant);
+      // Newest pin first, so "Pin to top" literally lands on top of the
+      // pinned group rather than under earlier pins.
+      const next = state.pinned.includes(key)
+        ? state.pinned.filter((id) => id !== key)
+        : [key, ...state.pinned];
+      writePinned(next);
+      return { pinned: next };
+    }),
+}));
+
+if (typeof window !== "undefined") {
+  window.addEventListener("storage", (event) => {
+    if (event.key === KEY || event.key === null) {
+      usePinnedModelsStore.setState({ pinned: readPinned() });
+    }
+  });
+}
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/recommended-fit.ts b/studio/frontend/src/features/model-picker/components/model-selector/recommended-fit.ts
similarity index 91%
rename from studio/frontend/src/components/assistant-ui/model-selector/recommended-fit.ts
rename to studio/frontend/src/features/model-picker/components/model-selector/recommended-fit.ts
index 7c2ed266c0..b8fe47c706 100644
--- a/studio/frontend/src/components/assistant-ui/model-selector/recommended-fit.ts
+++ b/studio/frontend/src/features/model-picker/components/model-selector/recommended-fit.ts
@@ -64,9 +64,8 @@ export function matchesFormatFilter(
   }
 }
 
-// First "<n>B" token in a repo id, e.g. "Qwen3-4B-GGUF" -> 4, "gpt-oss-20b" ->
-// 20, "Qwen3-30B-A3B" -> 30 (MoE total), "gemma-4-E4B" -> 4 (effective-param
-// "E" series). The digits must be bounded by a separator so we never read "16"
+// First "<n>B" token in a repo id, e.g. "Qwen3-30B-A3B" -> 30 (MoE total),
+// "gemma-4-E4B" -> 4. Digits must be separator-bounded so we never read "16"
 // from "bf16" or the "2" in "Kimi-K2".
 const PARAM_RE = /(?:^|[-_/. ])[eE]?(\d+(?:\.\d+)?)\s*[bB](?=$|[-_./ ])/;
 
@@ -79,9 +78,8 @@ export function paramsFromId(id: string): number | undefined {
   return Number.isFinite(billions) && billions > 0 ? billions * 1e9 : undefined;
 }
 
-// Smallest practical GGUF/MLX quant (~Q2_K, low-bit). The fit check asks whether
-// a model can run at all, so it uses this rather than a default 4-bit size; a
-// user with a smaller device can still pick a low-bit variant.
+// Smallest practical GGUF/MLX quant (~Q2_K). The fit check asks whether a model
+// can run at all, so it uses this rather than a default 4-bit size.
 const MIN_QUANT_BYTES_PER_PARAM = 0.4;
 
 /** Rough on-disk bytes for the smallest practical quant of `params` weights. */
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/row-meta.ts b/studio/frontend/src/features/model-picker/components/model-selector/row-meta.ts
similarity index 100%
rename from studio/frontend/src/components/assistant-ui/model-selector/row-meta.ts
rename to studio/frontend/src/features/model-picker/components/model-selector/row-meta.ts
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/source-tabs.ts b/studio/frontend/src/features/model-picker/components/model-selector/source-tabs.ts
similarity index 100%
rename from studio/frontend/src/components/assistant-ui/model-selector/source-tabs.ts
rename to studio/frontend/src/features/model-picker/components/model-selector/source-tabs.ts
diff --git a/studio/frontend/src/components/assistant-ui/model-selector/types.ts b/studio/frontend/src/features/model-picker/components/model-selector/types.ts
similarity index 74%
rename from studio/frontend/src/components/assistant-ui/model-selector/types.ts
rename to studio/frontend/src/features/model-picker/components/model-selector/types.ts
index 6a86515267..9adf2d899e 100644
--- a/studio/frontend/src/components/assistant-ui/model-selector/types.ts
+++ b/studio/frontend/src/features/model-picker/components/model-selector/types.ts
@@ -2,6 +2,7 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import type { ReactNode } from "react";
+import type { PerModelConfig } from "../../model-config/per-model-config";
 
 export interface ModelOption {
   id: string;
@@ -36,6 +37,19 @@ export interface ModelSelectorChangeMeta {
   /** Direct local .gguf file picked without a variant (custom folder / LM
    *  Studio). Marks it as a GGUF source for the deferred-load staging flow. */
   isGguf?: boolean;
+  config?: PerModelConfig;
+  forceReload?: boolean;
+  /** Native path token so an active-model reload can reopen a file-picked GGUF. */
+  nativePathToken?: string;
+  nativePathExpiresAtMs?: number | null;
+}
+
+export interface ModelPickTarget {
+  id: string;
+  displayName: string;
+  ggufVariant?: string | null;
+  isGguf: boolean;
+  meta: ModelSelectorChangeMeta;
 }
 
 export interface DeletedModelRef {
diff --git a/studio/frontend/src/features/model-picker/components/numeric-value-input.tsx b/studio/frontend/src/features/model-picker/components/numeric-value-input.tsx
new file mode 100644
index 0000000000..2489927fc2
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/components/numeric-value-input.tsx
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { cn } from "@/lib/utils";
+import { useRef, useState } from "react";
+
+export function snapToStep(
+  value: number,
+  step: number,
+  min?: number,
+  max?: number,
+): number {
+  const lo = min ?? Number.NEGATIVE_INFINITY;
+  const hi = max ?? Number.POSITIVE_INFINITY;
+  const clamped = Math.min(Math.max(value, lo), hi);
+  const stepStr = String(step);
+  const decimals = stepStr.includes(".") ? stepStr.split(".")[1].length : 0;
+  const base = Number.isFinite(lo) ? lo : 0;
+  const snapped = base + Math.round((clamped - base) / step) * step;
+  const reclamped = Math.min(Math.max(snapped, lo), hi);
+  return Number(reclamped.toFixed(decimals));
+}
+
+function sanitizeNumeric(raw: string, allowNegative: boolean): string {
+  const sign = allowNegative && raw.startsWith("-") ? "-" : "";
+  const [head, ...rest] = raw.replace(/[^\d.]/g, "").split(".");
+  const tail = rest.length > 0 ? `.${rest.join("")}` : "";
+  return `${sign}${head}${tail}`;
+}
+
+export function NumericValueInput({
+  value,
+  min,
+  max,
+  step,
+  onChange,
+  displayValue,
+  className,
+  ariaLabel,
+  size: sizeAttr,
+  disabled = false,
+}: {
+  value: number;
+  min?: number;
+  max?: number;
+  step: number;
+  onChange: (v: number) => void;
+  displayValue?: string;
+  className?: string;
+  ariaLabel?: string;
+  size?: number;
+  disabled?: boolean;
+}) {
+  const [focused, setFocused] = useState(false);
+  const [draft, setDraft] = useState("");
+  const cancelBlurCommitRef = useRef(false);
+
+  const commit = (raw: string) => {
+    const parsed = Number.parseFloat(raw);
+    if (!Number.isFinite(parsed)) {
+      return;
+    }
+    const final = snapToStep(parsed, step, min, max);
+    if (final !== value) {
+      onChange(final);
+    }
+  };
+
+  const displayed = focused ? draft : (displayValue ?? String(value));
+
+  return (
+    <input
+      type="text"
+      inputMode="decimal"
+      disabled={disabled}
+      size={sizeAttr}
+      style={{
+        boxSizing: "content-box",
+        width: `calc(${Math.max(displayed.length, 4)}ch + 2px)`,
+      }}
+      value={displayed}
+      aria-label={ariaLabel}
+      onFocus={(e) => {
+        cancelBlurCommitRef.current = false;
+        setDraft(String(value));
+        setFocused(true);
+        const target = e.currentTarget;
+        requestAnimationFrame(() => target.select());
+      }}
+      onBlur={() => {
+        if (cancelBlurCommitRef.current) {
+          cancelBlurCommitRef.current = false;
+        } else {
+          commit(draft);
+        }
+        setFocused(false);
+      }}
+      onChange={(e) =>
+        setDraft(sanitizeNumeric(e.target.value, (min ?? 0) < 0))
+      }
+      onKeyDown={(e) => {
+        if (e.key === "Enter") {
+          e.currentTarget.blur();
+        } else if (e.key === "Escape") {
+          cancelBlurCommitRef.current = true;
+          setDraft(String(value));
+          e.currentTarget.blur();
+        }
+      }}
+      className={cn(className)}
+    />
+  );
+}
diff --git a/studio/frontend/src/features/model-picker/components/sidebar-model-config.tsx b/studio/frontend/src/features/model-picker/components/sidebar-model-config.tsx
new file mode 100644
index 0000000000..2d12c503a4
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/components/sidebar-model-config.tsx
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { useMemo } from "react";
+import { gpuFieldsSignature } from "../model-config/apply-per-model-config";
+import type { PerModelConfig } from "../model-config/per-model-config";
+import { ModelConfigPage } from "./model-config-page";
+import type { ModelPickTarget } from "./model-selector/types";
+
+interface SidebarModelConfigProps {
+  modelId: string;
+  ggufVariant: string | null;
+  isGguf: boolean;
+  nativeContextLength: number | null;
+  loadedContextLength: number | null;
+  loadedConfig: PerModelConfig;
+  onReload: (config: PerModelConfig) => void;
+}
+
+const TRAILING_SEPARATORS = /[\\/]+$/;
+
+function leafName(id: string): string {
+  const trimmed = id.replace(TRAILING_SEPARATORS, "");
+  const separator = Math.max(
+    trimmed.lastIndexOf("/"),
+    trimmed.lastIndexOf("\\"),
+  );
+  return separator >= 0 ? trimmed.slice(separator + 1) : trimmed;
+}
+
+function hashString(value: string): number {
+  let hash = 5381;
+  for (let i = 0; i < value.length; i += 1) {
+    hash = (Math.imul(hash, 33) ^ value.charCodeAt(i)) >>> 0;
+  }
+  return hash;
+}
+
+function configSignature(config: PerModelConfig): string {
+  return [
+    config.customContextLength ?? "",
+    config.maxSeqLength ?? "",
+    config.kvCacheDtype ?? "",
+    config.speculativeType ?? "",
+    config.specDraftNMax ?? "",
+    config.tensorParallel ? "1" : "0",
+    config.chatTemplateOverride == null
+      ? ""
+      : `${config.chatTemplateOverride.length}:${hashString(config.chatTemplateOverride)}`,
+    gpuFieldsSignature(config),
+  ].join("|");
+}
+
+export function SidebarModelConfig({
+  modelId,
+  ggufVariant,
+  isGguf,
+  nativeContextLength,
+  loadedContextLength,
+  loadedConfig,
+  onReload,
+}: SidebarModelConfigProps) {
+  const target = useMemo<ModelPickTarget>(() => {
+    const leaf = leafName(modelId);
+    return {
+      id: modelId,
+      displayName: ggufVariant ? `${leaf} · ${ggufVariant}` : leaf,
+      ggufVariant,
+      isGguf,
+      meta: {
+        source: "local",
+        isLora: false,
+        ggufVariant: ggufVariant ?? undefined,
+        isGguf,
+        isDownloaded: true,
+        contextLength: nativeContextLength,
+      },
+    };
+  }, [modelId, ggufVariant, isGguf, nativeContextLength]);
+
+  return (
+    <ModelConfigPage
+      key={`${modelId}::${ggufVariant ?? ""}::${configSignature(loadedConfig)}`}
+      target={target}
+      onRun={onReload}
+      loadedConfig={loadedConfig}
+      loadedContextLength={loadedContextLength}
+      variant="sidebar"
+    />
+  );
+}
diff --git a/studio/frontend/src/features/model-picker/hooks/use-active-model-config.ts b/studio/frontend/src/features/model-picker/hooks/use-active-model-config.ts
new file mode 100644
index 0000000000..9d09ee6897
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/hooks/use-active-model-config.ts
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { isExternalModelId, useChatRuntimeStore } from "@/features/chat";
+import { useMemo } from "react";
+import type { PerModelConfig } from "../model-config/per-model-config";
+
+export interface ActiveModelConfigState {
+  checkpoint: string | null;
+  isGguf: boolean;
+  config: PerModelConfig | null;
+}
+
+export function useActiveModelConfig(): ActiveModelConfigState {
+  const checkpoint = useChatRuntimeStore((s) => s.params.checkpoint) || null;
+  const maxSeqLength = useChatRuntimeStore((s) => s.params.maxSeqLength);
+  const activeGgufVariant = useChatRuntimeStore((s) => s.activeGgufVariant);
+  const ggufContextLength = useChatRuntimeStore((s) => s.ggufContextLength);
+  const customContextLength = useChatRuntimeStore((s) => s.customContextLength);
+  const kvCacheDtype = useChatRuntimeStore((s) => s.kvCacheDtype);
+  const speculativeType = useChatRuntimeStore((s) => s.speculativeType);
+  const specDraftNMax = useChatRuntimeStore((s) => s.specDraftNMax);
+  const tensorParallel = useChatRuntimeStore((s) => s.tensorParallel);
+  const chatTemplateOverride = useChatRuntimeStore(
+    (s) => s.chatTemplateOverride,
+  );
+  const gpuMemoryMode = useChatRuntimeStore((s) => s.gpuMemoryMode);
+  const gpuLayers = useChatRuntimeStore((s) => s.gpuLayers);
+  const nCpuMoe = useChatRuntimeStore((s) => s.nCpuMoe);
+  const selectedGpuIds = useChatRuntimeStore((s) => s.selectedGpuIds);
+
+  const isGguf =
+    activeGgufVariant != null ||
+    ggufContextLength != null ||
+    (checkpoint?.toLowerCase().endsWith(".gguf") ?? false);
+
+  const config = useMemo<PerModelConfig | null>(() => {
+    if (!checkpoint || isExternalModelId(checkpoint)) {
+      return null;
+    }
+    const base: PerModelConfig = {
+      customContextLength: customContextLength ?? null,
+      maxSeqLength: isGguf ? null : maxSeqLength,
+      kvCacheDtype: kvCacheDtype ?? null,
+      speculativeType: speculativeType ?? "auto",
+      specDraftNMax: specDraftNMax ?? null,
+      tensorParallel: tensorParallel ?? false,
+      chatTemplateOverride: chatTemplateOverride ?? null,
+    };
+    if (!isGguf) {
+      return base;
+    }
+    return {
+      ...base,
+      gpuMemoryMode,
+      gpuLayers,
+      nCpuMoe,
+      selectedGpuIds,
+    };
+  }, [
+    checkpoint,
+    isGguf,
+    maxSeqLength,
+    customContextLength,
+    kvCacheDtype,
+    speculativeType,
+    specDraftNMax,
+    tensorParallel,
+    chatTemplateOverride,
+    gpuMemoryMode,
+    gpuLayers,
+    nCpuMoe,
+    selectedGpuIds,
+  ]);
+
+  return { checkpoint, isGguf, config };
+}
diff --git a/studio/frontend/src/features/model-picker/hooks/use-model-defaults.ts b/studio/frontend/src/features/model-picker/hooks/use-model-defaults.ts
new file mode 100644
index 0000000000..530e6e06d8
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/hooks/use-model-defaults.ts
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { useHfTokenStore, useInventoryVersion } from "@/features/hub";
+import { useEffect, useState } from "react";
+import { fetchModelMaxPositionEmbeddings } from "../api/model-metadata";
+import { fetchDefaultChatTemplate } from "../api/templates";
+
+export interface DefaultChatTemplateState {
+  template: string | null;
+  loading: boolean;
+  error: string | null;
+}
+
+export interface ModelMaxPositionState {
+  maxPositionEmbeddings: number | null;
+  loading: boolean;
+  error: string | null;
+}
+
+const TEMPLATE_CACHE_MAX_ENTRIES = 50;
+const templateCache = new Map<string, string | null>();
+const maxPositionCache = new Map<string, number | null>();
+
+function cacheTemplate(key: string, template: string | null): void {
+  templateCache.delete(key);
+  templateCache.set(key, template);
+  while (templateCache.size > TEMPLATE_CACHE_MAX_ENTRIES) {
+    const oldest = templateCache.keys().next().value;
+    if (oldest === undefined) {
+      break;
+    }
+    templateCache.delete(oldest);
+  }
+}
+
+function cacheMaxPosition(key: string, value: number | null): void {
+  maxPositionCache.delete(key);
+  maxPositionCache.set(key, value);
+  while (maxPositionCache.size > TEMPLATE_CACHE_MAX_ENTRIES) {
+    const oldest = maxPositionCache.keys().next().value;
+    if (oldest === undefined) {
+      break;
+    }
+    maxPositionCache.delete(oldest);
+  }
+}
+
+export function useDefaultChatTemplate(
+  modelId: string | null,
+  ggufVariant: string | null | undefined,
+  enabled: boolean,
+  nativePathToken?: string | null,
+): DefaultChatTemplateState {
+  const token = useHfTokenStore((s) => s.token);
+  const inventoryVersion = useInventoryVersion();
+  // The native token is part of the identity: a picked GGUF resolves its
+  // template through the lease, not the model id, so two picks of the same
+  // basename must not share a cache entry.
+  const cacheKey =
+    enabled && modelId
+      ? `${modelId}::${ggufVariant ?? ""}::${token}::${inventoryVersion}::${nativePathToken ?? ""}`
+      : null;
+  const [fetched, setFetched] = useState<{
+    key: string;
+    state: DefaultChatTemplateState;
+  } | null>(null);
+
+  useEffect(() => {
+    if (cacheKey == null || !modelId || templateCache.has(cacheKey)) {
+      return;
+    }
+    const controller = new AbortController();
+    fetchDefaultChatTemplate(
+      modelId,
+      ggufVariant,
+      token,
+      controller.signal,
+      nativePathToken,
+    )
+      .then((template) => {
+        if (controller.signal.aborted) {
+          return;
+        }
+        // Cache the terminal result, including a null "no default template",
+        // so reopening the viewer for such a model reuses it instead of
+        // re-running the backend/Hugging Face lookup every time.
+        cacheTemplate(cacheKey, template);
+        setFetched({
+          key: cacheKey,
+          state: { template, loading: false, error: null },
+        });
+      })
+      .catch((err: unknown) => {
+        if (controller.signal.aborted) {
+          return;
+        }
+        setFetched({
+          key: cacheKey,
+          state: {
+            template: null,
+            loading: false,
+            error:
+              err instanceof Error ? err.message : "Failed to load template",
+          },
+        });
+      });
+
+    return () => controller.abort();
+  }, [cacheKey, modelId, ggufVariant, token, nativePathToken]);
+
+  if (cacheKey == null) {
+    return { template: null, loading: false, error: null };
+  }
+  if (templateCache.has(cacheKey)) {
+    return {
+      template: templateCache.get(cacheKey) ?? null,
+      loading: false,
+      error: null,
+    };
+  }
+  if (fetched?.key === cacheKey) {
+    return fetched.state;
+  }
+  return { template: null, loading: true, error: null };
+}
+
+export function useModelMaxPositionEmbeddings(
+  modelId: string | null,
+  enabled: boolean,
+): ModelMaxPositionState {
+  const token = useHfTokenStore((s) => s.token);
+  const inventoryVersion = useInventoryVersion();
+  const cacheKey =
+    enabled && modelId ? `${modelId}::${token}::${inventoryVersion}` : null;
+  const [fetched, setFetched] = useState<{
+    key: string;
+    state: ModelMaxPositionState;
+  } | null>(null);
+
+  useEffect(() => {
+    if (cacheKey == null || !modelId || maxPositionCache.has(cacheKey)) {
+      return;
+    }
+    const controller = new AbortController();
+    fetchModelMaxPositionEmbeddings(modelId, token, controller.signal)
+      .then((maxPositionEmbeddings) => {
+        if (controller.signal.aborted) {
+          return;
+        }
+        cacheMaxPosition(cacheKey, maxPositionEmbeddings);
+        setFetched({
+          key: cacheKey,
+          state: { maxPositionEmbeddings, loading: false, error: null },
+        });
+      })
+      .catch((err: unknown) => {
+        if (controller.signal.aborted) {
+          return;
+        }
+        setFetched({
+          key: cacheKey,
+          state: {
+            maxPositionEmbeddings: null,
+            loading: false,
+            error:
+              err instanceof Error
+                ? err.message
+                : "Failed to load model metadata",
+          },
+        });
+      });
+
+    return () => controller.abort();
+  }, [cacheKey, modelId, token]);
+
+  if (cacheKey == null) {
+    return { maxPositionEmbeddings: null, loading: false, error: null };
+  }
+  if (maxPositionCache.has(cacheKey)) {
+    return {
+      maxPositionEmbeddings: maxPositionCache.get(cacheKey) ?? null,
+      loading: false,
+      error: null,
+    };
+  }
+  if (fetched?.key === cacheKey) {
+    return fetched.state;
+  }
+  return { maxPositionEmbeddings: null, loading: true, error: null };
+}
diff --git a/studio/frontend/src/features/model-picker/index.ts b/studio/frontend/src/features/model-picker/index.ts
new file mode 100644
index 0000000000..d2b4785ec3
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/index.ts
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+export { ModelSelector } from "./components/model-selector";
+export { FolderBrowser } from "./components/model-selector/folder-browser";
+export { ModelRowMenu } from "./components/model-selector/model-row-menu";
+export {
+  makePinRank,
+  pinKey,
+  usePinnedModelsStore,
+} from "./components/model-selector/pinned-models";
+export { hfModelFitsDevice } from "./components/model-selector/recommended-fit";
+export {
+  NumericValueInput,
+  snapToStep,
+} from "./components/numeric-value-input";
+export { SidebarModelConfig } from "./components/sidebar-model-config";
+export {
+  useActiveModelConfig,
+} from "./hooks/use-active-model-config";
+export type {
+  DeletedModelRef,
+  ExternalModelOption,
+  LoraModelOption,
+  ModelOption,
+  ModelSelectorChangeMeta,
+} from "./components/model-selector";
+export {
+  applyModelLoadConfigToRuntime,
+  applyPerModelConfigToRuntime,
+  currentRuntimePerModelConfig,
+  perModelConfigsEqual,
+} from "./model-config/apply-per-model-config";
+export {
+  DEFAULT_MAX_SEQ_LENGTH,
+  normalizeMaxSeqLength,
+  type PerModelConfig,
+  resolveInitialConfig,
+} from "./model-config/per-model-config";
diff --git a/studio/frontend/src/features/model-picker/inventory/use-chat-picker-inventory.ts b/studio/frontend/src/features/model-picker/inventory/use-chat-picker-inventory.ts
new file mode 100644
index 0000000000..b46e83819c
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/inventory/use-chat-picker-inventory.ts
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import type {
+  CachedGgufRepo,
+  CachedModelRepo,
+  LocalModelInfo,
+} from "@/features/chat";
+import {
+  type CachedInventoryRow,
+  type LocalInventoryRow,
+  type LocalSource,
+  isHiddenModelId,
+  useHubInventory,
+} from "@/features/hub";
+import { useMemo } from "react";
+
+const PICKER_LOCAL_SOURCES: ReadonlySet<LocalSource> = new Set([
+  "lmstudio",
+  "models_dir",
+  "custom",
+]);
+
+function isCompleteCachedRow(row: CachedInventoryRow): boolean {
+  return !row.partial && !row.liveDownload;
+}
+
+function toCachedGgufRepo(row: CachedInventoryRow): CachedGgufRepo {
+  return {
+    repo_id: row.repoId,
+    size_bytes: row.bytes,
+    cache_path: row.cachePath ?? "",
+    last_modified: row.lastModified ?? undefined,
+    has_vision: row.capabilities.supportsVision,
+  };
+}
+
+function toCachedModelRepo(row: CachedInventoryRow): CachedModelRepo {
+  return {
+    repo_id: row.repoId,
+    size_bytes: row.bytes,
+    last_modified: row.lastModified ?? undefined,
+  };
+}
+
+function toLocalModelInfo(row: LocalInventoryRow): LocalModelInfo {
+  return {
+    id: row.loadId,
+    display_name: row.displayName ?? row.title,
+    path: row.path,
+    source: row.source as LocalModelInfo["source"],
+    model_id: row.modelId ?? row.repoId,
+    model_format: row.modelFormat,
+    updated_at: row.updatedAt,
+  };
+}
+
+export interface ChatPickerInventory {
+  cachedGguf: CachedGgufRepo[];
+  cachedModels: CachedModelRepo[];
+  cachedReady: boolean;
+  localModels: LocalModelInfo[];
+  refreshInventory: () => Promise<void>;
+}
+
+export function useChatPickerInventory(
+  options: { enabled?: boolean } = {},
+): ChatPickerInventory {
+  const inventory = useHubInventory({
+    kind: "models",
+    enabled: options.enabled,
+    includeLocal: true,
+  });
+
+  const cachedGguf = useMemo(
+    () =>
+      inventory.cachedRows
+        .filter(
+          (row) =>
+            row.modelFormat === "gguf" &&
+            isCompleteCachedRow(row) &&
+            !isHiddenModelId(row.repoId),
+        )
+        .map(toCachedGgufRepo),
+    [inventory.cachedRows],
+  );
+  const cachedModels = useMemo(
+    () =>
+      inventory.cachedRows
+        .filter(
+          (row) =>
+            row.modelFormat !== "gguf" &&
+            isCompleteCachedRow(row) &&
+            !isHiddenModelId(row.repoId),
+        )
+        .map(toCachedModelRepo),
+    [inventory.cachedRows],
+  );
+  const localModels = useMemo(
+    () =>
+      inventory.localRows
+        .filter(
+          (row) =>
+            PICKER_LOCAL_SOURCES.has(row.source) &&
+            // Skip non-chat rows (e.g. a folder with only config.json is
+            // classified "unknown" -> canChat false); selecting one would try to
+            // load a weightless path. toLocalModelInfo drops capabilities, so
+            // this is the only place the guard can live.
+            row.capabilities.canChat &&
+            !isHiddenModelId(row.modelId, row.repoId, row.path),
+        )
+        .map(toLocalModelInfo),
+    [inventory.localRows],
+  );
+
+  return {
+    cachedGguf,
+    cachedModels,
+    cachedReady: inventory.downloadedReady,
+    localModels,
+    refreshInventory: inventory.refreshInventory,
+  };
+}
diff --git a/studio/frontend/src/features/model-picker/model-config/apply-per-model-config.ts b/studio/frontend/src/features/model-picker/model-config/apply-per-model-config.ts
new file mode 100644
index 0000000000..c21d3e164a
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/model-config/apply-per-model-config.ts
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import {
+  GPU_LAYERS_AUTO,
+  defaultInferenceParams,
+  normalizeSpeculativeType,
+  readPersistedGpuMemoryMode,
+  readPersistedSpeculativeType,
+  reconcilePersistedGpuIds,
+  useChatRuntimeStore,
+} from "@/features/chat";
+import {
+  DEFAULT_PER_MODEL_CONFIG,
+  type PerModelConfig,
+  normalizeMaxSeqLength,
+} from "./per-model-config";
+
+function cleanTemplate(value: string | null | undefined): string | null {
+  return value?.trim() ? value : null;
+}
+
+export function applyPerModelConfigToRuntime(config: PerModelConfig): void {
+  // Fall back to the standing default when the model has no saved
+  // maxSeqLength. maxSeqLength is the only per-model field carried on
+  // params (the rest are reset below), so without this a model with no
+  // remembered config would inherit the previously loaded model's value.
+  const maxSeqLength =
+    normalizeMaxSeqLength(config.maxSeqLength) ??
+    defaultInferenceParams.maxSeqLength;
+  const store = useChatRuntimeStore.getState();
+  if (maxSeqLength !== store.params.maxSeqLength) {
+    store.setParams({ ...store.params, maxSeqLength });
+  }
+  useChatRuntimeStore.setState({
+    customContextLength: config.customContextLength ?? null,
+    kvCacheDtype: config.kvCacheDtype ?? null,
+    speculativeType:
+      normalizeSpeculativeType(config.speculativeType) ??
+      readPersistedSpeculativeType(),
+    specDraftNMax: config.specDraftNMax ?? null,
+    tensorParallel: config.tensorParallel ?? false,
+    chatTemplateOverride: cleanTemplate(config.chatTemplateOverride),
+    // GPU Memory knobs are per-model (GGUF-only). Absent = defaults; the mode is
+    // a standing preference so an absent mode falls back to the persisted one.
+    // The per-GPU split ratio is never remembered, so it always resets. The GPU
+    // pick is reconciled against the GPUs present now (a saved [1] on a 1-GPU
+    // host would otherwise be sent and rejected).
+    gpuMemoryMode: config.gpuMemoryMode ?? readPersistedGpuMemoryMode(),
+    gpuLayers: config.gpuLayers ?? GPU_LAYERS_AUTO,
+    nCpuMoe: config.nCpuMoe ?? 0,
+    splitRatio: null,
+    selectedGpuIds:
+      config.selectedGpuIds !== undefined
+        ? reconcilePersistedGpuIds(config.selectedGpuIds)
+        : null,
+  });
+}
+
+export function applyModelLoadConfigToRuntime(
+  config: PerModelConfig | null | undefined,
+): boolean {
+  const hasConfig = config != null;
+  applyPerModelConfigToRuntime(config ?? DEFAULT_PER_MODEL_CONFIG);
+  return hasConfig;
+}
+
+export function currentRuntimePerModelConfig(
+  options: { includeMaxSeqLength?: boolean } = {},
+): PerModelConfig {
+  const s = useChatRuntimeStore.getState();
+  return {
+    customContextLength: s.customContextLength ?? null,
+    maxSeqLength: options.includeMaxSeqLength
+      ? normalizeMaxSeqLength(s.params.maxSeqLength)
+      : null,
+    kvCacheDtype: s.kvCacheDtype ?? null,
+    speculativeType: normalizeSpeculativeType(s.speculativeType),
+    specDraftNMax: s.specDraftNMax ?? null,
+    tensorParallel: s.tensorParallel ?? false,
+    chatTemplateOverride: cleanTemplate(s.chatTemplateOverride),
+    // Snapshot the live GPU knobs too so a failed switch rolls the previous
+    // model's GPU Memory settings back (see applyPerModelConfigToRuntime). The
+    // split ratio is intentionally never remembered.
+    gpuMemoryMode: s.gpuMemoryMode,
+    gpuLayers: s.gpuLayers,
+    nCpuMoe: s.nCpuMoe,
+    selectedGpuIds: s.selectedGpuIds,
+  };
+}
+
+export function perModelConfigsEqual(
+  a: PerModelConfig,
+  b: PerModelConfig,
+): boolean {
+  return (
+    (a.customContextLength ?? null) === (b.customContextLength ?? null) &&
+    normalizeMaxSeqLength(a.maxSeqLength) ===
+      normalizeMaxSeqLength(b.maxSeqLength) &&
+    (a.kvCacheDtype ?? null) === (b.kvCacheDtype ?? null) &&
+    normalizeSpeculativeType(a.speculativeType) ===
+      normalizeSpeculativeType(b.speculativeType) &&
+    (a.specDraftNMax ?? null) === (b.specDraftNMax ?? null) &&
+    Boolean(a.tensorParallel) === Boolean(b.tensorParallel) &&
+    cleanTemplate(a.chatTemplateOverride) ===
+      cleanTemplate(b.chatTemplateOverride) &&
+    gpuFieldsEqual(a, b)
+  );
+}
+
+// Serialize the per-model GPU knobs with the same "absent == default"
+// coalescing the store applies: mode auto/absent, gpuLayers Auto (< 0) /
+// absent, nCpuMoe 0 / absent, and the GPU pick (null / absent = all GPUs).
+export function gpuFieldsSignature(config: PerModelConfig): string {
+  return [
+    config.gpuMemoryMode ?? "auto",
+    config.gpuLayers == null || config.gpuLayers < 0 ? -1 : config.gpuLayers,
+    config.nCpuMoe ?? 0,
+    config.selectedGpuIds == null
+      ? "all"
+      : [...config.selectedGpuIds].sort((a, b) => a - b).join(","),
+  ].join("|");
+}
+
+function gpuFieldsEqual(a: PerModelConfig, b: PerModelConfig): boolean {
+  return gpuFieldsSignature(a) === gpuFieldsSignature(b);
+}
diff --git a/studio/frontend/src/features/model-picker/model-config/model-identity.ts b/studio/frontend/src/features/model-picker/model-config/model-identity.ts
new file mode 100644
index 0000000000..0caa7c1312
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/model-config/model-identity.ts
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import {
+  normalizeGgufVariantIdentity,
+  normalizeModelIdentity,
+} from "@/features/hub";
+
+export {
+  normalizeGgufVariantIdentity,
+  normalizeModelIdentity,
+} from "@/features/hub";
+
+const MODEL_STORAGE_KEY_PREFIX = "v2:";
+
+type ParsedModelStorageKey = {
+  modelId: string;
+  ggufVariant: string;
+};
+
+function parseVersionedModelStorageKey(
+  key: string,
+): ParsedModelStorageKey | null {
+  if (!key.startsWith(MODEL_STORAGE_KEY_PREFIX)) {
+    return null;
+  }
+  try {
+    const parsed = JSON.parse(key.slice(MODEL_STORAGE_KEY_PREFIX.length));
+    if (
+      !Array.isArray(parsed) ||
+      parsed.length !== 2 ||
+      typeof parsed[0] !== "string" ||
+      typeof parsed[1] !== "string"
+    ) {
+      return null;
+    }
+    return { modelId: parsed[0], ggufVariant: parsed[1] };
+  } catch {
+    return null;
+  }
+}
+
+export function modelStorageKey(
+  modelId: string,
+  ggufVariant?: string | null,
+): string {
+  return `${MODEL_STORAGE_KEY_PREFIX}${JSON.stringify([
+    normalizeModelIdentity(modelId),
+    normalizeGgufVariantIdentity(ggufVariant),
+  ])}`;
+}
+
+export function modelIdFromStorageKey(key: string): string | null {
+  const parsed = parseVersionedModelStorageKey(key);
+  if (parsed) {
+    return parsed.modelId;
+  }
+  const separator = key.lastIndexOf("::");
+  return separator >= 0 ? key.slice(0, separator) : null;
+}
+
+export function ggufVariantFromStorageKey(key: string): string | null {
+  const parsed = parseVersionedModelStorageKey(key);
+  if (parsed) {
+    return parsed.ggufVariant;
+  }
+  const separator = key.lastIndexOf("::");
+  return separator >= 0 ? key.slice(separator + 2) : null;
+}
diff --git a/studio/frontend/src/features/model-picker/model-config/per-model-config.ts b/studio/frontend/src/features/model-picker/model-config/per-model-config.ts
new file mode 100644
index 0000000000..ba6d4cec99
--- /dev/null
+++ b/studio/frontend/src/features/model-picker/model-config/per-model-config.ts
@@ -0,0 +1,675 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import {
+  ggufVariantFromStorageKey,
+  modelIdFromStorageKey,
+  modelStorageKey,
+  normalizeGgufVariantIdentity,
+  normalizeModelIdentity,
+} from "./model-identity";
+
+export interface PerModelConfig {
+  customContextLength: number | null;
+  maxSeqLength: number | null;
+  kvCacheDtype: string | null;
+  speculativeType: string | null;
+  specDraftNMax: number | null;
+  tensorParallel: boolean;
+  chatTemplateOverride: string | null;
+  // GPU Memory controls (per-model, GGUF-only), optional so older blobs still
+  // parse. null selectedGpuIds (all GPUs) is distinct from absent. The --tensor-split
+  // ratio is deliberately not remembered: it is positionally bound to the exact
+  // GPU set/order and unvalidated.
+  gpuMemoryMode?: "auto" | "manual";
+  gpuLayers?: number;
+  nCpuMoe?: number;
+  selectedGpuIds?: number[] | null;
+}
+
+export const DEFAULT_PER_MODEL_CONFIG: PerModelConfig = {
+  customContextLength: null,
+  maxSeqLength: null,
+  kvCacheDtype: null,
+  speculativeType: null,
+  specDraftNMax: null,
+  tensorParallel: false,
+  chatTemplateOverride: null,
+};
+
+export const MAX_SEQ_LENGTH_MIN = 128;
+export const MAX_SEQ_LENGTH_MAX = 1048576;
+export const MAX_SEQ_LENGTH_STEP = 128;
+// App-default max sequence length when a non-GGUF model has no override. Both
+// paths fall back to this rather than an active model's runtime value, so an
+// unconfigured pane never inherits another model's larger context and OOMs.
+export const DEFAULT_MAX_SEQ_LENGTH = 4096;
+export const CONTEXT_LENGTH_MIN = 128;
+
+// Matches studio/backend/core/inference/llama_cpp.py _valid_cache_types (f16 is the UI default).
+export const KV_CACHE_DTYPES = [
+  "bf16",
+  "q8_0",
+  "q4_0",
+  "q4_1",
+  "q5_0",
+  "q5_1",
+  "iq4_nl",
+  "f32",
+] as const;
+const VALID_KV_CACHE_DTYPES = new Set<string>(KV_CACHE_DTYPES);
+
+export const SPECULATIVE_TYPES = [
+  "auto",
+  "mtp",
+  "ngram",
+  "mtp+ngram",
+  "off",
+] as const;
+export const MTP_SPECULATIVE_TYPES: ReadonlySet<string> = new Set([
+  "mtp",
+  "mtp+ngram",
+]);
+
+const STORAGE_KEY = "unsloth_model_configs";
+const LEGACY_STORAGE_KEY = "unsloth_load_settings";
+const LEGACY_MIGRATION_FLAG = "unsloth_model_configs_migrated";
+const STORAGE_SCHEMA_VERSION = 1;
+const MAX_ENTRIES = 500;
+const MAX_PER_MODEL_CONFIG_STORAGE_BYTES = 1024 * 1024;
+export const MAX_CHAT_TEMPLATE_BYTES = 65_536;
+
+type StoredPerModelConfig = PerModelConfig & {
+  version: typeof STORAGE_SCHEMA_VERSION;
+};
+type StoredMap = Record<string, PerModelConfig | StoredPerModelConfig>;
+type RawConfig = Partial<PerModelConfig> & { version?: unknown };
+
+const STORED_CONFIG_FIELDS = new Set([
+  "version",
+  "customContextLength",
+  "maxSeqLength",
+  "kvCacheDtype",
+  "speculativeType",
+  "specDraftNMax",
+  "tensorParallel",
+  "chatTemplateOverride",
+  "gpuMemoryMode",
+  "gpuLayers",
+  "nCpuMoe",
+  "selectedGpuIds",
+]);
+
+function normalizeGpuFields(partial: RawConfig): {
+  gpuMemoryMode?: "auto" | "manual";
+  gpuLayers?: number;
+  nCpuMoe?: number;
+  selectedGpuIds?: number[] | null;
+} {
+  const out: {
+    gpuMemoryMode?: "auto" | "manual";
+    gpuLayers?: number;
+    nCpuMoe?: number;
+    selectedGpuIds?: number[] | null;
+  } = {};
+  // Only "manual" is a real override; persisting "auto" would pin the model and
+  // stop it following later changes to the global GPU Memory preference.
+  if (partial.gpuMemoryMode === "manual") {
+    out.gpuMemoryMode = "manual";
+  }
+  if (
+    typeof partial.gpuLayers === "number" &&
+    Number.isFinite(partial.gpuLayers)
+  ) {
+    out.gpuLayers = Math.trunc(partial.gpuLayers);
+  }
+  if (
+    typeof partial.nCpuMoe === "number" &&
+    Number.isFinite(partial.nCpuMoe) &&
+    partial.nCpuMoe >= 0
+  ) {
+    out.nCpuMoe = Math.trunc(partial.nCpuMoe);
+  }
+  if (partial.selectedGpuIds === null) {
+    out.selectedGpuIds = null;
+  } else if (
+    Array.isArray(partial.selectedGpuIds) &&
+    partial.selectedGpuIds.every(
+      (n) => typeof n === "number" && Number.isFinite(n),
+    )
+  ) {
+    out.selectedGpuIds = partial.selectedGpuIds.map((n) => Math.trunc(n));
+  }
+  return out;
+}
+
+function canonicalizeSpeculativeType(value: string): string | null {
+  const s = value.trim().toLowerCase();
+  if (!s) {
+    return null;
+  }
+  // "auto"/"default" is the follow-global sentinel; store as null so it is never
+  // persisted as an override and global speculative-decoding changes keep applying.
+  if (s === "auto" || s === "default") {
+    return null;
+  }
+  if (s === "off") {
+    return "off";
+  }
+  if (s === "mtp" || s === "draft-mtp") {
+    return "mtp";
+  }
+  if (s === "ngram" || s === "ngram-mod" || s === "ngram-simple") {
+    return "ngram";
+  }
+  if (s === "mtp+ngram") {
+    return "mtp+ngram";
+  }
+  return null;
+}
+
+export function normalizeMaxSeqLength(value: unknown): number | null {
+  if (typeof value !== "number" || !Number.isFinite(value) || value <= 0) {
+    return null;
+  }
+  const snapped = Math.round(value / MAX_SEQ_LENGTH_STEP) * MAX_SEQ_LENGTH_STEP;
+  return Math.max(MAX_SEQ_LENGTH_MIN, Math.min(MAX_SEQ_LENGTH_MAX, snapped));
+}
+
+export function floorMaxSeqLength(value: unknown): number | null {
+  if (typeof value !== "number" || !Number.isFinite(value) || value <= 0) {
+    return null;
+  }
+  const snapped = Math.floor(value / MAX_SEQ_LENGTH_STEP) * MAX_SEQ_LENGTH_STEP;
+  return Math.max(MAX_SEQ_LENGTH_MIN, Math.min(MAX_SEQ_LENGTH_MAX, snapped));
+}
+
+function canUseStorage(): boolean {
+  return typeof window !== "undefined";
+}
+
+function serializedByteLength(value: string): number {
+  return typeof TextEncoder !== "undefined"
+    ? new TextEncoder().encode(value).byteLength
+    : value.length;
+}
+
+export function chatTemplateByteLength(value: string): number {
+  return serializedByteLength(value);
+}
+
+export function isChatTemplateWithinLimit(value: string): boolean {
+  return chatTemplateByteLength(value) <= MAX_CHAT_TEMPLATE_BYTES;
+}
+
+function serializedMapSize(map: StoredMap): number {
+  return serializedByteLength(JSON.stringify(map));
+}
+
+function serializedMapEntrySize(key: string, value: StoredMap[string]): number {
+  return (
+    serializedByteLength(JSON.stringify(key)) +
+    1 +
+    serializedByteLength(JSON.stringify(value))
+  );
+}
+
+function deleteOldestEvictableEntry(
+  map: StoredMap,
+  protectedKeys?: ReadonlySet<string>,
+): { key: string; value: StoredMap[string] } | null {
+  for (const key of Object.keys(map)) {
+    // Never evict a future-schema entry an older client cannot interpret.
+    if (
+      protectedKeys?.has(key) ||
+      storedConfigVersion(map[key]) > STORAGE_SCHEMA_VERSION
+    ) {
+      continue;
+    }
+    const value = map[key];
+    delete map[key];
+    return { key, value };
+  }
+  return null;
+}
+
+function enforceStorageBudget(
+  map: StoredMap,
+  protectedKeys?: ReadonlySet<string>,
+): boolean {
+  let entryCount = Object.keys(map).length;
+  while (entryCount > MAX_ENTRIES) {
+    if (!deleteOldestEvictableEntry(map, protectedKeys)) {
+      return false;
+    }
+    entryCount -= 1;
+  }
+  let bytes = serializedMapSize(map);
+  while (bytes > MAX_PER_MODEL_CONFIG_STORAGE_BYTES) {
+    const removed = deleteOldestEvictableEntry(map, protectedKeys);
+    if (!removed) {
+      return false;
+    }
+    bytes -=
+      serializedMapEntrySize(removed.key, removed.value) +
+      (entryCount > 1 ? 1 : 0);
+    entryCount -= 1;
+  }
+  return true;
+}
+
+function storedConfigVersion(raw: unknown): number {
+  if (!raw || typeof raw !== "object" || Array.isArray(raw)) {
+    return 0;
+  }
+  const version = (raw as RawConfig).version;
+  return typeof version === "number" && Number.isFinite(version) ? version : 0;
+}
+
+let legacyMigrationChecked = false;
+
+function parseLegacyModelKey(
+  key: string,
+): { modelId: string; ggufVariant: string | null } | null {
+  const separator = key.lastIndexOf("::");
+  if (separator >= 0) {
+    const modelId = key.slice(0, separator);
+    return modelId
+      ? { modelId, ggufVariant: key.slice(separator + 2) || null }
+      : null;
+  }
+  return key ? { modelId: key, ggufVariant: null } : null;
+}
+
+function legacyEntryToConfig(raw: Record<string, unknown>): PerModelConfig {
+  return normalizeV1({
+    customContextLength:
+      typeof raw.contextLength === "number" ? raw.contextLength : null,
+    maxSeqLength: null,
+    kvCacheDtype:
+      typeof raw.kvCacheDtype === "string" ? raw.kvCacheDtype : null,
+    speculativeType:
+      typeof raw.speculativeType === "string" ? raw.speculativeType : null,
+    specDraftNMax:
+      typeof raw.specDraftNMax === "number" ? raw.specDraftNMax : null,
+    tensorParallel:
+      typeof raw.tensorParallel === "boolean" ? raw.tensorParallel : false,
+    chatTemplateOverride: null,
+    // Carry legacy GPU Memory knobs; normalizeGpuFields drops anything malformed.
+    gpuMemoryMode:
+      raw.gpuMemoryMode === "auto" || raw.gpuMemoryMode === "manual"
+        ? raw.gpuMemoryMode
+        : undefined,
+    gpuLayers: typeof raw.gpuLayers === "number" ? raw.gpuLayers : undefined,
+    nCpuMoe: typeof raw.nCpuMoe === "number" ? raw.nCpuMoe : undefined,
+    selectedGpuIds:
+      raw.selectedGpuIds === null
+        ? null
+        : Array.isArray(raw.selectedGpuIds)
+          ? (raw.selectedGpuIds as number[])
+          : undefined,
+  });
+}
+
+function mergeLegacyEntries(
+  map: StoredMap,
+  legacy: Record<string, unknown>,
+): string[] {
+  const addedKeys: string[] = [];
+  for (const [legacyKey, value] of Object.entries(legacy)) {
+    if (!value || typeof value !== "object") {
+      continue;
+    }
+    const parsedKey = parseLegacyModelKey(legacyKey);
+    if (!parsedKey) {
+      continue;
+    }
+    const migrated = legacyEntryToConfig(value as Record<string, unknown>);
+    const key = modelStorageKey(parsedKey.modelId, parsedKey.ggufVariant);
+    if (isDefaultConfig(migrated) || Object.hasOwn(map, key)) {
+      continue;
+    }
+    map[key] = toStoredConfig(migrated);
+    addedKeys.push(key);
+  }
+  return addedKeys;
+}
+
+function migrateLegacyLoadSettingsOnce(): void {
+  if (legacyMigrationChecked || !canUseStorage()) {
+    return;
+  }
+  legacyMigrationChecked = true;
+  try {
+    if (localStorage.getItem(LEGACY_MIGRATION_FLAG)) {
+      return;
+    }
+    let legacy: unknown = null;
+    try {
+      legacy = JSON.parse(localStorage.getItem(LEGACY_STORAGE_KEY) ?? "null");
+    } catch {
+      legacy = null;
+    }
+    if (!legacy || typeof legacy !== "object" || Array.isArray(legacy)) {
+      localStorage.setItem(LEGACY_MIGRATION_FLAG, "1");
+      return;
+    }
+    const map = readMapRaw();
+    // Snapshot existing entries so eviction can protect them: importing old load
+    // settings must never discard a newer per-model config the user already has.
+    const existingKeys = new Set(Object.keys(map));
+    const migratedKeys = mergeLegacyEntries(
+      map,
+      legacy as Record<string, unknown>,
+    );
+    if (migratedKeys.length === 0) {
+      localStorage.setItem(LEGACY_MIGRATION_FLAG, "1");
+      return;
+    }
+    // Protect pre-existing entries so only just-migrated legacy entries are
+    // dropped when over budget.
+    if (!enforceStorageBudget(map, existingKeys)) {
+      return;
+    }
+    if (writeMap(map)) {
+      localStorage.setItem(LEGACY_MIGRATION_FLAG, "1");
+    }
+  } catch (err) {
+    console.warn("Failed to migrate legacy load settings:", err);
+  }
+}
+
+function readMapRaw(): StoredMap {
+  if (!canUseStorage()) {
+    return {};
+  }
+  try {
+    const raw = localStorage.getItem(STORAGE_KEY);
+    if (!raw) {
+      return {};
+    }
+    const parsed = JSON.parse(raw);
+    if (!parsed || typeof parsed !== "object" || Array.isArray(parsed)) {
+      return {};
+    }
+    return parsed as StoredMap;
+  } catch {
+    return {};
+  }
+}
+
+function readMap(): StoredMap {
+  migrateLegacyLoadSettingsOnce();
+  return readMapRaw();
+}
+
+function writeMap(map: StoredMap): boolean {
+  if (!canUseStorage()) {
+    return false;
+  }
+  try {
+    localStorage.setItem(STORAGE_KEY, JSON.stringify(map));
+    return true;
+  } catch (err) {
+    console.warn("Failed to persist per-model config:", err);
+    return false;
+  }
+}
+
+function warnDroppedFields(raw: Record<string, unknown>, version: number): void {
+  if (!import.meta.env?.DEV) {
+    return;
+  }
+  const dropped = Object.keys(raw).filter(
+    (key) => !STORED_CONFIG_FIELDS.has(key),
+  );
+  if (dropped.length > 0) {
+    console.warn("Dropped unknown per-model config fields:", dropped);
+  }
+  if (version > STORAGE_SCHEMA_VERSION) {
+    console.warn("Per-model config schema is newer than this app:", version);
+  }
+}
+
+function normalizeV1(partial: RawConfig): PerModelConfig {
+  const rawSpecType =
+    typeof partial.speculativeType === "string"
+      ? canonicalizeSpeculativeType(partial.speculativeType)
+      : null;
+  const speculativeType = rawSpecType ?? DEFAULT_PER_MODEL_CONFIG.speculativeType;
+  const specDraftNMax =
+    speculativeType != null &&
+    MTP_SPECULATIVE_TYPES.has(speculativeType) &&
+    typeof partial.specDraftNMax === "number" &&
+    Number.isFinite(partial.specDraftNMax)
+      ? Math.max(1, Math.min(16, Math.round(partial.specDraftNMax)))
+      : null;
+  return {
+    customContextLength:
+      typeof partial.customContextLength === "number" &&
+      Number.isFinite(partial.customContextLength) &&
+      partial.customContextLength > 0
+        ? Math.max(CONTEXT_LENGTH_MIN, Math.floor(partial.customContextLength))
+        : null,
+    maxSeqLength: normalizeMaxSeqLength(partial.maxSeqLength),
+    kvCacheDtype:
+      typeof partial.kvCacheDtype === "string" &&
+      VALID_KV_CACHE_DTYPES.has(partial.kvCacheDtype)
+        ? partial.kvCacheDtype
+        : null,
+    speculativeType,
+    specDraftNMax,
+    tensorParallel:
+      typeof partial.tensorParallel === "boolean"
+        ? partial.tensorParallel
+        : DEFAULT_PER_MODEL_CONFIG.tensorParallel,
+    chatTemplateOverride:
+      typeof partial.chatTemplateOverride === "string" &&
+      isChatTemplateWithinLimit(partial.chatTemplateOverride)
+        ? partial.chatTemplateOverride
+        : null,
+    ...normalizeGpuFields(partial),
+  };
+}
+
+function normalize(raw: unknown): PerModelConfig {
+  if (!raw || typeof raw !== "object" || Array.isArray(raw)) {
+    return normalizeV1({});
+  }
+  const partial = raw as RawConfig;
+  const version =
+    typeof partial.version === "number" && Number.isFinite(partial.version)
+      ? partial.version
+      : 0;
+  warnDroppedFields(raw as Record<string, unknown>, version);
+  return normalizeV1(partial);
+}
+
+function toStoredConfig(config: PerModelConfig): StoredPerModelConfig {
+  return {
+    version: STORAGE_SCHEMA_VERSION,
+    ...normalize(config),
+  };
+}
+
+function legacyModelStorageKey(
+  modelId: string,
+  ggufVariant?: string | null,
+): string {
+  return `${modelId}::${ggufVariant ?? ""}`;
+}
+
+function storageKeysForModelVariant(
+  modelId: string,
+  ggufVariant?: string | null,
+): string[] {
+  const key = modelStorageKey(modelId, ggufVariant);
+  const legacyKey = legacyModelStorageKey(modelId, ggufVariant);
+  return key === legacyKey ? [key] : [key, legacyKey];
+}
+
+function configKeyMatchesModelVariant(
+  key: string,
+  modelId: string,
+  ggufVariant?: string | null,
+): boolean {
+  const storedModelId = modelIdFromStorageKey(key);
+  if (!storedModelId) {
+    return false;
+  }
+  return (
+    normalizeModelIdentity(storedModelId) === normalizeModelIdentity(modelId) &&
+    normalizeGgufVariantIdentity(ggufVariantFromStorageKey(key)) ===
+      normalizeGgufVariantIdentity(ggufVariant)
+  );
+}
+
+function findConfigKeyForModelVariant(
+  map: StoredMap,
+  modelId: string,
+  ggufVariant?: string | null,
+): string | null {
+  for (const key of storageKeysForModelVariant(modelId, ggufVariant)) {
+    if (Object.hasOwn(map, key)) {
+      return key;
+    }
+  }
+  for (const key of Object.keys(map)) {
+    if (configKeyMatchesModelVariant(key, modelId, ggufVariant)) {
+      return key;
+    }
+  }
+  return null;
+}
+
+function hasFutureConfigForModelVariant(
+  map: StoredMap,
+  modelId: string,
+  ggufVariant?: string | null,
+): boolean {
+  for (const key of Object.keys(map)) {
+    if (
+      configKeyMatchesModelVariant(key, modelId, ggufVariant) &&
+      storedConfigVersion(map[key]) > STORAGE_SCHEMA_VERSION
+    ) {
+      return true;
+    }
+  }
+  return false;
+}
+
+function deleteConfigEntriesForModelVariant(
+  map: StoredMap,
+  modelId: string,
+  ggufVariant?: string | null,
+): boolean {
+  let changed = false;
+  for (const key of Object.keys(map)) {
+    if (!configKeyMatchesModelVariant(key, modelId, ggufVariant)) {
+      continue;
+    }
+    delete map[key];
+    changed = true;
+  }
+  return changed;
+}
+
+function loadPerModelConfig(
+  modelId: string,
+  ggufVariant?: string | null,
+): PerModelConfig | null {
+  const map = readMap();
+  const key = findConfigKeyForModelVariant(map, modelId, ggufVariant);
+  if (!key) {
+    return null;
+  }
+  // Never apply a future-schema record an older client cannot interpret.
+  if (storedConfigVersion(map[key]) > STORAGE_SCHEMA_VERSION) {
+    return null;
+  }
+  return normalize(map[key]);
+}
+
+export function isDefaultConfig(config: PerModelConfig): boolean {
+  return (
+    config.customContextLength == null &&
+    config.maxSeqLength == null &&
+    (config.kvCacheDtype ?? null) === DEFAULT_PER_MODEL_CONFIG.kvCacheDtype &&
+    config.speculativeType === DEFAULT_PER_MODEL_CONFIG.speculativeType &&
+    config.specDraftNMax == null &&
+    Boolean(config.tensorParallel) ===
+      Boolean(DEFAULT_PER_MODEL_CONFIG.tensorParallel) &&
+    (config.chatTemplateOverride ?? null) === null &&
+    gpuFieldsAtDefault(config)
+  );
+}
+
+// GPU knobs are "default" when mode is Auto with no explicit choice: mode
+// auto/absent, gpuLayers < 0/absent, nCpuMoe 0/absent, selectedGpuIds null/absent.
+function gpuFieldsAtDefault(config: PerModelConfig): boolean {
+  return (
+    (config.gpuMemoryMode ?? "auto") === "auto" &&
+    (config.gpuLayers == null || config.gpuLayers < 0) &&
+    (config.nCpuMoe == null || config.nCpuMoe === 0) &&
+    config.selectedGpuIds == null
+  );
+}
+
+export function savePerModelConfig(
+  modelId: string,
+  ggufVariant: string | null | undefined,
+  config: PerModelConfig,
+): boolean {
+  if (
+    typeof config.chatTemplateOverride === "string" &&
+    !isChatTemplateWithinLimit(config.chatTemplateOverride)
+  ) {
+    return false;
+  }
+  const normalized = normalize(config);
+  const map = readMap();
+  if (hasFutureConfigForModelVariant(map, modelId, ggufVariant)) {
+    return false;
+  }
+  if (isDefaultConfig(normalized)) {
+    const changed = deleteConfigEntriesForModelVariant(
+      map,
+      modelId,
+      ggufVariant,
+    );
+    return changed ? writeMap(map) : true;
+  }
+  const [key] = storageKeysForModelVariant(modelId, ggufVariant);
+  deleteConfigEntriesForModelVariant(map, modelId, ggufVariant);
+  map[key] = toStoredConfig(normalized);
+  if (!enforceStorageBudget(map, new Set([key]))) {
+    return false;
+  }
+  return writeMap(map);
+}
+
+export function deletePerModelConfig(
+  modelId: string,
+  ggufVariant?: string | null,
+): boolean {
+  const map = readMap();
+  // Mirror savePerModelConfig: never let an older client destroy a future-schema entry.
+  if (hasFutureConfigForModelVariant(map, modelId, ggufVariant)) {
+    return false;
+  }
+  if (!deleteConfigEntriesForModelVariant(map, modelId, ggufVariant)) {
+    return true;
+  }
+  return writeMap(map);
+}
+
+export function resolveInitialConfig(
+  modelId: string,
+  ggufVariant?: string | null,
+): { config: PerModelConfig; remembered: boolean } {
+  const saved = loadPerModelConfig(modelId, ggufVariant);
+  if (saved) {
+    return { config: saved, remembered: true };
+  }
+  return { config: { ...DEFAULT_PER_MODEL_CONFIG }, remembered: false };
+}
diff --git a/studio/frontend/src/features/native-intents/api.ts b/studio/frontend/src/features/native-intents/api.ts
index b5c7e33b3a..98caa709b9 100644
--- a/studio/frontend/src/features/native-intents/api.ts
+++ b/studio/frontend/src/features/native-intents/api.ts
@@ -23,6 +23,11 @@ export async function pickNativeModel(): Promise<NativeIntent | null> {
   return invokeNative<NativeIntent | null>("pick_native_model");
 }
 
+export async function pickHuggingFaceCacheDir(): Promise<string | null> {
+  if (!isTauri) return null;
+  return invokeNative<string | null>("pick_hugging_face_cache_dir");
+}
+
 export async function registerNativeModelPath(path: string): Promise<NativeIntent> {
   return invokeNative<NativeIntent>("register_native_model_path", { path });
 }
diff --git a/studio/frontend/src/features/native-intents/components/native-model-drop-overlay.tsx b/studio/frontend/src/features/native-intents/components/native-model-drop-overlay.tsx
index 725fb14259..33b8934756 100644
--- a/studio/frontend/src/features/native-intents/components/native-model-drop-overlay.tsx
+++ b/studio/frontend/src/features/native-intents/components/native-model-drop-overlay.tsx
@@ -60,7 +60,7 @@ export function NativeModelDropOverlay({ state }: { state: NativeModelDropState
           <div className="truncate text-xs font-medium text-foreground">
             {title}
           </div>
-          <div className="mt-0.5 truncate text-[11px] leading-4 text-muted-foreground">
+          <div className="mt-0.5 truncate text-ui-11 leading-4 text-muted-foreground">
             {description}
           </div>
         </div>
diff --git a/studio/frontend/src/features/native-intents/index.ts b/studio/frontend/src/features/native-intents/index.ts
index a82c39a9ec..98b89f08f3 100644
--- a/studio/frontend/src/features/native-intents/index.ts
+++ b/studio/frontend/src/features/native-intents/index.ts
@@ -3,7 +3,7 @@
 
 export { NativeModelChip } from "./components/native-model-chip";
 export { NativeModelDropOverlay } from "./components/native-model-drop-overlay";
-export { openModelsDir } from "./api";
+export { openModelsDir, pickHuggingFaceCacheDir } from "./api";
 export { useNativeIntentStore } from "./store";
 export type { NativeIntent } from "./types";
 export { useChooseNativeModel } from "./use-native-dialogs";
diff --git a/studio/frontend/src/features/onboarding/components/steps/model-selection-step.tsx b/studio/frontend/src/features/onboarding/components/steps/model-selection-step.tsx
index a5ce25dd32..b22e91eaf0 100644
--- a/studio/frontend/src/features/onboarding/components/steps/model-selection-step.tsx
+++ b/studio/frontend/src/features/onboarding/components/steps/model-selection-step.tsx
@@ -113,7 +113,7 @@ export function ModelSelectionStep() {
     return applyPriorityOrdering(ids);
   }, [hfResults]);
 
-  // Match Studio: only show exception signals (OOM/TIGHT) in training flows.
+  // Match Unsloth: only show exception signals (OOM/TIGHT) in training flows.
   const vramMap = useMemo(() => {
     const fitMap = buildModelVramMap(
       hfResults,
@@ -286,12 +286,12 @@ export function ModelSelectionStep() {
                         </Tooltip>
                         <span className="flex items-center gap-1.5 shrink-0">
                           {fitStatus === "exceeds" && (
-                            <span className="text-[9px] font-medium !text-red-700 !bg-red-50 dark:!text-red-400 dark:!bg-red-950 px-1.5 py-0.5 rounded">
+                            <span className="text-ui-9 font-medium !text-red-700 !bg-red-50 dark:!text-red-400 dark:!bg-red-950 px-1.5 py-0.5 rounded">
                               OOM
                             </span>
                           )}
                           {fitStatus === "tight" && (
-                            <span className="text-[9px] font-medium !text-amber-400">
+                            <span className="text-ui-9 font-medium !text-amber-400">
                               TIGHT
                             </span>
                           )}
diff --git a/studio/frontend/src/features/onboarding/components/steps/model-type-step.tsx b/studio/frontend/src/features/onboarding/components/steps/model-type-step.tsx
index 4f9f1ffea9..038b19cdc9 100644
--- a/studio/frontend/src/features/onboarding/components/steps/model-type-step.tsx
+++ b/studio/frontend/src/features/onboarding/components/steps/model-type-step.tsx
@@ -106,7 +106,7 @@ export function ModelTypeStep(): ReactElement {
                 {isDisabled && (
                   <Badge
                     variant="secondary"
-                    className="absolute top-2 right-2 text-[10px]"
+                    className="absolute top-2 right-2 text-ui-10"
                   >
                     Coming Soon
                   </Badge>
diff --git a/studio/frontend/src/features/onboarding/components/wizard-sidebar.tsx b/studio/frontend/src/features/onboarding/components/wizard-sidebar.tsx
index 4637336c6c..d5e11110ab 100644
--- a/studio/frontend/src/features/onboarding/components/wizard-sidebar.tsx
+++ b/studio/frontend/src/features/onboarding/components/wizard-sidebar.tsx
@@ -17,14 +17,16 @@ export function WizardSidebar({ returnTo }: { returnTo: string }) {
   return (
     <aside className="w-full shrink-0 bg-muted/70 p-4 md:w-64 md:p-6">
       <div className="flex items-center gap-3 py-1 md:py-2">
+        {/* Logo lockup follows the UI font size at half rate:
+            base + (root scale - 1) * 8px. Exact base sizes at 16px. */}
         <img
           src={`${import.meta.env.BASE_URL}sticker.png`}
           alt="Unsloth"
-          className="size-12"
+          className="size-[calc(40px+0.5rem*var(--ui-font-scale,1))]"
         />
         <div className="flex flex-col">
-          <span className="font-semibold text-lg leading-tight">Unsloth</span>
-          <span className="text-xs text-muted-foreground">Studio</span>
+          <span className="font-semibold text-[calc(10px+0.5rem*var(--ui-font-scale,1))] leading-tight">Unsloth</span>
+          <span className="text-[calc(4px+0.5rem*var(--ui-font-scale,1))] text-muted-foreground">Studio</span>
         </div>
       </div>
       <div className="mt-3 md:mt-0">
diff --git a/studio/frontend/src/features/profile/components/profile-personalization-panel.tsx b/studio/frontend/src/features/profile/components/profile-personalization-panel.tsx
index 5fc6d090db..d403f7fe66 100644
--- a/studio/frontend/src/features/profile/components/profile-personalization-panel.tsx
+++ b/studio/frontend/src/features/profile/components/profile-personalization-panel.tsx
@@ -191,7 +191,7 @@ export function ProfilePersonalizationPanel() {
           name={previewName}
           imageUrl={shownAvatar}
           size="lg"
-          className="size-[124px] text-[3.15rem]"
+          className="size-[124px] text-[calc(3.15rem*var(--ui-font-scale,1))]"
         />
         <input
           ref={fileInputRef}
@@ -288,7 +288,7 @@ export function ProfilePersonalizationPanel() {
               onClick={() => setAvatarShape(shape)}
               aria-pressed={avatarShape === shape}
               className={cn(
-                "inline-flex h-8 items-center rounded-full px-4 text-[13px] font-medium transition-colors",
+                "inline-flex h-8 items-center rounded-full px-4 text-ui-13 font-medium transition-colors",
                 avatarShape === shape
                   ? "hub-tab-toggle-pill text-foreground"
                   : "text-muted-foreground hover:text-foreground",
@@ -366,7 +366,7 @@ export function ProfilePersonalizationPanel() {
               shownAvatar === null && "ring-ring-strong hover:ring-ring-strong",
             )}
           >
-            <span className="text-[11px] font-medium">
+            <span className="text-ui-11 font-medium">
               {t("settings.profile.noneLabel")}
             </span>
           </button>
diff --git a/studio/frontend/src/features/profile/components/user-avatar.tsx b/studio/frontend/src/features/profile/components/user-avatar.tsx
index 2db103c1d4..e883fc5fad 100644
--- a/studio/frontend/src/features/profile/components/user-avatar.tsx
+++ b/studio/frontend/src/features/profile/components/user-avatar.tsx
@@ -21,7 +21,7 @@ const SIZE: Record<"sm" | "md" | "lg", string> = {
   sm: "size-9 text-xs",
   md: "size-11 text-sm",
   /** ~10% larger than `size-24` / `text-2xl` for the edit-profile dialog. */
-  lg: "size-[106px] text-[1.65rem]",
+  lg: "size-[106px] text-[calc(1.65rem*var(--ui-font-scale,1))]",
 };
 
 // Percentage radius keeps the rounded-rectangle proportional across sizes.
diff --git a/studio/frontend/src/features/rag/api/rag-api.ts b/studio/frontend/src/features/rag/api/rag-api.ts
index 20800230b5..c0bad1a9d5 100644
--- a/studio/frontend/src/features/rag/api/rag-api.ts
+++ b/studio/frontend/src/features/rag/api/rag-api.ts
@@ -10,6 +10,7 @@ import type {
   KnowledgeBase,
   PreviewTarget,
   RagDocument,
+  UploadedDocument,
 } from "../types/rag";
 
 const RAG_BASE = "/api/rag";
@@ -194,10 +195,25 @@ export function invalidateProjectSources(projectId: string): void {
   projectSourcesCache.delete(projectId);
 }
 
-export function deleteDocument(documentId: string): Promise<{ ok: boolean }> {
-  return ragRequest(`/documents/${encodeURIComponent(documentId)}`, {
-    method: "DELETE",
-  });
+export async function listAllDocuments(): Promise<UploadedDocument[]> {
+  const data = await ragRequest<{ documents: UploadedDocument[] }>(
+    "/documents",
+  );
+  return data.documents ?? [];
+}
+
+export async function deleteDocument(
+  documentId: string,
+  projectId?: string | null,
+): Promise<{ ok: boolean }> {
+  const result = await ragRequest<{ ok: boolean }>(
+    `/documents/${encodeURIComponent(documentId)}`,
+    {
+      method: "DELETE",
+    },
+  );
+  if (projectId) invalidateProjectSources(projectId);
+  return result;
 }
 
 export function getJob(jobId: string): Promise<IndexJob> {
@@ -237,7 +253,8 @@ export async function* streamJobEvents(
 
         const dataLines: string[] = [];
         for (const line of rawEvent.split(/\r?\n/)) {
-          if (line.startsWith("data:")) dataLines.push(line.slice(5).trimStart());
+          if (line.startsWith("data:"))
+            dataLines.push(line.slice(5).trimStart());
         }
         if (dataLines.length > 0) {
           const dataText = dataLines.join("\n");
diff --git a/studio/frontend/src/features/rag/components/project-sources-panel.tsx b/studio/frontend/src/features/rag/components/project-sources-panel.tsx
index 941e385563..1bbbc58c0c 100644
--- a/studio/frontend/src/features/rag/components/project-sources-panel.tsx
+++ b/studio/frontend/src/features/rag/components/project-sources-panel.tsx
@@ -77,7 +77,7 @@ export function ProjectSourcesPanel({ projectId }: { projectId: string }) {
             />
           </span>
           <div className="space-y-1">
-            <p className="text-[15px] font-semibold text-foreground">
+            <p className="text-ui-15 font-semibold text-foreground">
               Give this project context
             </p>
             <p className="max-w-sm text-sm text-muted-foreground">
@@ -94,7 +94,7 @@ export function ProjectSourcesPanel({ projectId }: { projectId: string }) {
           >
             Add sources
           </Button>
-          <p className="text-[11px] text-muted-foreground">Or drop files here</p>
+          <p className="text-ui-11 text-muted-foreground">Or drop files here</p>
         </div>
       ) : (
         <div className="flex flex-col gap-4 rounded-[26px] bg-muted/30 px-6 py-5">
diff --git a/studio/frontend/src/features/rag/components/retrieval-settings-section.tsx b/studio/frontend/src/features/rag/components/retrieval-settings-section.tsx
index be791b8e6d..9c91360d44 100644
--- a/studio/frontend/src/features/rag/components/retrieval-settings-section.tsx
+++ b/studio/frontend/src/features/rag/components/retrieval-settings-section.tsx
@@ -75,10 +75,10 @@ function SliderRow({
       )}
     >
       <div className="flex items-center justify-between">
-        <span className="text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+        <span className="text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
           {label}
         </span>
-        <span className="text-[13px] tabular-nums text-muted-foreground">
+        <span className="text-ui-13 tabular-nums text-muted-foreground">
           {format(value)}
         </span>
       </div>
@@ -120,7 +120,7 @@ export function RetrievalSettingsSection() {
   return (
     <div className="flex flex-col gap-5 pt-1">
       <div className="flex flex-col gap-2">
-        <span className="text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+        <span className="text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
           Search mode
         </span>
         <Select
@@ -143,10 +143,10 @@ export function RetrievalSettingsSection() {
 
       <div className="flex flex-col gap-2">
         <div className="flex items-center justify-between">
-          <span className="text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+          <span className="text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
             Passages (top K)
           </span>
-          <span className="text-[13px] tabular-nums text-muted-foreground">
+          <span className="text-ui-13 tabular-nums text-muted-foreground">
             {ragTopK}
           </span>
         </div>
@@ -163,7 +163,7 @@ export function RetrievalSettingsSection() {
 
       <div className="flex flex-col gap-3">
         <div className="flex flex-col">
-          <span className="flex items-center gap-1.5 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+          <span className="flex items-center gap-1.5 text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
             Auto-retrieve documents
             <InfoHint>
               Auto turns retrieval on for smaller models (9B and below), which
@@ -171,7 +171,7 @@ export function RetrievalSettingsSection() {
               larger ones. On and Off force it either way.
             </InfoHint>
           </span>
-          <span className="text-[12px] leading-[1.3] text-muted-foreground">
+          <span className="text-ui-12 leading-[1.3] text-muted-foreground">
             Search attached documents before answering.
           </span>
         </div>
@@ -212,7 +212,7 @@ export function RetrievalSettingsSection() {
 
       <div className="flex items-start justify-between gap-3">
         <div className="flex flex-col">
-          <span className="flex items-center gap-1.5 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+          <span className="flex items-center gap-1.5 text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
             OCR scanned pages
             <InfoHint>
               Read text off scanned or image-only PDF pages with the loaded
@@ -221,7 +221,7 @@ export function RetrievalSettingsSection() {
               unaffected.
             </InfoHint>
           </span>
-          <span className="text-[12px] leading-[1.3] text-muted-foreground">
+          <span className="text-ui-12 leading-[1.3] text-muted-foreground">
             Transcribe image-only PDF pages when attaching.
           </span>
         </div>
@@ -235,7 +235,7 @@ export function RetrievalSettingsSection() {
 
       <div className="flex items-start justify-between gap-3">
         <div className="flex flex-col">
-          <span className="flex items-center gap-1.5 text-[13px] font-medium leading-[1.25] tracking-nav text-nav-fg">
+          <span className="flex items-center gap-1.5 text-ui-13 font-medium leading-[1.25] tracking-nav text-nav-fg">
             Describe figures &amp; charts
             <InfoHint>
               Caption PDF figures, charts, tables and diagrams at upload with the
@@ -243,7 +243,7 @@ export function RetrievalSettingsSection() {
               vision model; adds vision calls for detected figures.
             </InfoHint>
           </span>
-          <span className="text-[12px] leading-[1.3] text-muted-foreground">
+          <span className="text-ui-12 leading-[1.3] text-muted-foreground">
             Read charts and diagrams when attaching.
           </span>
         </div>
diff --git a/studio/frontend/src/features/rag/components/use-rag-documents.ts b/studio/frontend/src/features/rag/components/use-rag-documents.ts
index 8e756b2782..8d6433d8c3 100644
--- a/studio/frontend/src/features/rag/components/use-rag-documents.ts
+++ b/studio/frontend/src/features/rag/components/use-rag-documents.ts
@@ -2,12 +2,11 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { useCallback, useEffect, useRef, useState } from "react";
-import { useChatRuntimeStore } from "@/features/chat";
-
 import {
   CHAT_RAG_CAPTION_KEY,
   CHAT_RAG_OCR_KEY,
-} from "@/features/chat/stores/chat-runtime-store";
+  useChatRuntimeStore,
+} from "@/features/chat";
 import { toast } from "@/lib/toast";
 import {
   deleteDocument,
@@ -60,9 +59,7 @@ export function useRagDocuments(
     if (ids.size === 0) return false;
     const docs = documentsRef.current.filter((d) => ids.has(d.id));
     if (docs.length === 0) return false; // sig tracked but doc gone -> allow re-upload
-    return docs.some(
-      (d) => d.status !== "completed" || (d.numChunks ?? 0) > 0,
-    );
+    return docs.some((d) => d.status !== "completed" || (d.numChunks ?? 0) > 0);
   }, []);
   // True while upload() runs, so the scope-change effect can tell a real switch
   // from lazy thread materialization mid-upload (which must not reset).
@@ -80,9 +77,7 @@ export function useRagDocuments(
   const patchDoc = useCallback(
     (documentId: string, patch: Partial<TrackedDocument>) => {
       setDocuments((rows) =>
-        rows.map((row) =>
-          row.id === documentId ? { ...row, ...patch } : row,
-        ),
+        rows.map((row) => (row.id === documentId ? { ...row, ...patch } : row)),
       );
     },
     [],
@@ -176,49 +171,61 @@ export function useRagDocuments(
     [patchDoc],
   );
 
-  const refresh = useCallback(async (opts?: { quiet?: boolean }) => {
-    if (!scope) return;
-    if (!opts?.quiet) setLoading(true);
-    try {
-      // Merge server truth with local progress so a refresh mid-index keeps a
-      // live "running %" chip. Failed docs hidden (toast warned at upload).
-      const rows = (await lister()).filter((row) => row.status !== "failed");
-      setDocuments((prev) => {
-        const merged = rows.map((row) => {
-          const tracked = prev.find((p) => p.id === row.id);
-          return tracked && tracked.progress != null && row.status !== "completed"
-            ? { ...row, progress: tracked.progress }
-            : row;
+  const refresh = useCallback(
+    async (opts?: { quiet?: boolean }) => {
+      if (!scope) return;
+      if (!opts?.quiet) setLoading(true);
+      try {
+        // Merge server truth with local progress so a refresh mid-index keeps a
+        // live "running %" chip. Failed docs hidden (toast warned at upload).
+        const rows = (await lister()).filter((row) => row.status !== "failed");
+        setDocuments((prev) => {
+          const merged = rows.map((row) => {
+            const tracked = prev.find((p) => p.id === row.id);
+            return tracked &&
+              tracked.progress != null &&
+              row.status !== "completed"
+              ? { ...row, progress: tracked.progress }
+              : row;
+          });
+          // Keep optimistic chips (not yet listed) so a refresh racing an upload
+          // can't make them vanish.
+          const serverIds = new Set(rows.map((row) => row.id));
+          const pendingLocal = prev.filter(
+            (row) => row.id.startsWith("pending_") && !serverIds.has(row.id),
+          );
+          return [...merged, ...pendingLocal];
         });
-        // Keep optimistic chips (not yet listed) so a refresh racing an upload
-        // can't make them vanish.
-        const serverIds = new Set(rows.map((row) => row.id));
-        const pendingLocal = prev.filter(
-          (row) => row.id.startsWith("pending_") && !serverIds.has(row.id),
-        );
-        return [...merged, ...pendingLocal];
-      });
-    } catch (err) {
-      toast.error("Failed to load documents", {
-        description: err instanceof Error ? err.message : String(err),
-      });
-    } finally {
-      if (!opts?.quiet) setLoading(false);
-    }
-  }, [scope, lister]);
+      } catch (err) {
+        toast.error("Failed to load documents", {
+          description: err instanceof Error ? err.message : String(err),
+        });
+      } finally {
+        if (!opts?.quiet) setLoading(false);
+      }
+    },
+    [scope, lister],
+  );
 
   // A real switch (thread/KB swap) resets + reloads; first acquiring a scope just
   // loads. Skip both during materialization mid-upload (scope null -> new thread
   // while upload() runs) so we don't abort tracking or wipe optimistic chips.
   useEffect(() => {
+    const jobs = trackedJobs.current;
     const prev = prevScopeKeyRef.current;
     prevScopeKeyRef.current = scopeKey;
     if (prev !== null && prev !== scopeKey) {
-      for (const controller of trackedJobs.current.values()) controller.abort();
-      trackedJobs.current.clear();
+      for (const controller of jobs.values()) controller.abort();
+      jobs.clear();
       sigByDocId.current.clear();
+      // Scope changes intentionally clear the old scope before fetching the new
+      // one. Keep this synchronous so React StrictMode's setup/cleanup replay
+      // cannot cancel the only refresh after prevScopeKeyRef has advanced.
       setDocuments([]);
-      if (scope) void refresh();
+      if (scope) {
+        // eslint-disable-next-line react-hooks/set-state-in-effect
+        void refresh();
+      }
     } else if (prev === null && scope && !uploadInFlightRef.current) {
       void refresh();
     }
@@ -226,8 +233,8 @@ export function useRagDocuments(
       // Preserve in-flight tracking when cleanup is the materialization flip,
       // not a real switch/unmount.
       if (uploadInFlightRef.current) return;
-      for (const controller of trackedJobs.current.values()) controller.abort();
-      trackedJobs.current.clear();
+      for (const controller of jobs.values()) controller.abort();
+      jobs.clear();
     };
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [scopeKey]);
@@ -260,21 +267,41 @@ export function useRagDocuments(
         // otherwise backend env defaults own the ingest policy.
         const state = useChatRuntimeStore.getState();
         const hasLocal = (key: string) =>
-          typeof window !== "undefined" && window.localStorage.getItem(key) !== null;
-        const ocr = hasLocal(CHAT_RAG_OCR_KEY) ? state.ragOcrScanned : undefined;
+          typeof window !== "undefined" &&
+          window.localStorage.getItem(key) !== null;
+        const ocr = hasLocal(CHAT_RAG_OCR_KEY)
+          ? state.ragOcrScanned
+          : undefined;
         const caption = hasLocal(CHAT_RAG_CAPTION_KEY)
           ? state.ragCaptionFigures
           : undefined;
         const result =
           activeScope.type === "kb"
-            ? await uploadKnowledgeBaseDocument(activeScope.kbId, file, ocr, caption)
+            ? await uploadKnowledgeBaseDocument(
+                activeScope.kbId,
+                file,
+                ocr,
+                caption,
+              )
             : activeScope.type === "project"
-              ? await uploadProjectDocument(activeScope.projectId, file, ocr, caption)
-              : await uploadThreadDocument(activeScope.threadId, file, ocr, caption);
+              ? await uploadProjectDocument(
+                  activeScope.projectId,
+                  file,
+                  ocr,
+                  caption,
+                )
+              : await uploadThreadDocument(
+                  activeScope.threadId,
+                  file,
+                  ocr,
+                  caption,
+                );
         sigByDocId.current.set(result.documentId, fileSignature(file));
         if (seenIds.has(result.documentId)) {
           setDocuments((rows) => rows.filter((row) => row.id !== tempId));
-          toast.info(`${result.filename || file.name} is already indexed - skipping`);
+          toast.info(
+            `${result.filename || file.name} is already indexed - skipping`,
+          );
           return;
         }
         seenIds.add(result.documentId);
@@ -341,7 +368,9 @@ export function useRagDocuments(
         ]);
 
         const resolved =
-          overrideScope instanceof Promise ? await overrideScope : overrideScope;
+          overrideScope instanceof Promise
+            ? await overrideScope
+            : overrideScope;
         const activeScope = resolved ?? scope;
         if (!activeScope) {
           // Materialization failed: drop the chips so they don't hang "pending".
@@ -377,7 +406,10 @@ export function useRagDocuments(
       const prevSig = sigByDocId.current.get(documentId);
       sigByDocId.current.delete(documentId);
       try {
-        await deleteDocument(documentId);
+        await deleteDocument(
+          documentId,
+          scope?.type === "project" ? scope.projectId : undefined,
+        );
       } catch (err) {
         setDocuments(prev);
         if (prevSig !== undefined) sigByDocId.current.set(documentId, prevSig);
@@ -386,7 +418,7 @@ export function useRagDocuments(
         });
       }
     },
-    [documents],
+    [documents, scope],
   );
 
   return { documents, loading, uploading, refresh, upload, remove };
diff --git a/studio/frontend/src/features/rag/index.ts b/studio/frontend/src/features/rag/index.ts
index 9e35e345ee..b06c7e09cc 100644
--- a/studio/frontend/src/features/rag/index.ts
+++ b/studio/frontend/src/features/rag/index.ts
@@ -5,4 +5,9 @@ export { KnowledgeBaseComposerButton } from "./components/knowledge-base-compose
 export { KnowledgeBaseDialog } from "./components/knowledge-base-dialog";
 export { RetrievalSettingsSection } from "./components/retrieval-settings-section";
 export { ThreadDocumentsBar } from "./components/thread-documents-bar";
-export type { KnowledgeBase, RagDocument } from "./types/rag";
+export {
+  deleteDocument,
+  getDocumentFileUrl,
+  listAllDocuments,
+} from "./api/rag-api";
+export type { KnowledgeBase, RagDocument, UploadedDocument } from "./types/rag";
diff --git a/studio/frontend/src/features/rag/types/rag.ts b/studio/frontend/src/features/rag/types/rag.ts
index 1277500ae6..9922c740af 100644
--- a/studio/frontend/src/features/rag/types/rag.ts
+++ b/studio/frontend/src/features/rag/types/rag.ts
@@ -24,6 +24,13 @@ export interface RagDocument {
   createdAt?: string | null;
 }
 
+/** RagDocument enriched for the global uploaded-files list (settings Data tab). */
+export interface UploadedDocument extends RagDocument {
+  sizeBytes?: number | null;
+  kbName?: string | null;
+  projectName?: string | null;
+}
+
 export interface DocumentUploadResult {
   documentId: string;
   jobId: string;
diff --git a/studio/frontend/src/features/recipe-studio/components/block-sheet.tsx b/studio/frontend/src/features/recipe-studio/components/block-sheet.tsx
index 1b38f91d64..6aebac66df 100644
--- a/studio/frontend/src/features/recipe-studio/components/block-sheet.tsx
+++ b/studio/frontend/src/features/recipe-studio/components/block-sheet.tsx
@@ -205,12 +205,12 @@ function BlockSheetButton({
             {title}
           </p>
           {badge ? (
-            <Badge variant="outline" className="rounded-full text-[10px]">
+            <Badge variant="outline" className="rounded-full text-ui-10">
               {badge}
             </Badge>
           ) : null}
         </div>
-        <p className="break-words text-[11px] text-muted-foreground">
+        <p className="break-words text-ui-11 text-muted-foreground">
           {description}
         </p>
       </div>
diff --git a/studio/frontend/src/features/recipe-studio/components/executions/execution-sidebar.tsx b/studio/frontend/src/features/recipe-studio/components/executions/execution-sidebar.tsx
index a8ae8ff188..f613c775b3 100644
--- a/studio/frontend/src/features/recipe-studio/components/executions/execution-sidebar.tsx
+++ b/studio/frontend/src/features/recipe-studio/components/executions/execution-sidebar.tsx
@@ -66,7 +66,7 @@ export function ExecutionSidebar({
                   </p>
                   <Badge
                     variant="outline"
-                    className={cn("capitalize text-[11px]", statusTone(execution.status))}
+                    className={cn("capitalize text-ui-11", statusTone(execution.status))}
                   >
                     {formatStatus(execution.status)}
                   </Badge>
diff --git a/studio/frontend/src/features/recipe-studio/components/inline/inline-category-badges.tsx b/studio/frontend/src/features/recipe-studio/components/inline/inline-category-badges.tsx
index a2e352a8f7..8db276eca3 100644
--- a/studio/frontend/src/features/recipe-studio/components/inline/inline-category-badges.tsx
+++ b/studio/frontend/src/features/recipe-studio/components/inline/inline-category-badges.tsx
@@ -64,7 +64,7 @@ export function InlineCategoryBadges({
           <Badge
             key={`m-${v}-${i}`}
             variant="secondary"
-            className="corner-squircle h-4 shrink-0 px-1.5 text-[10px]"
+            className="corner-squircle h-4 shrink-0 px-1.5 text-ui-10"
           >
             {v}
           </Badge>
@@ -76,13 +76,13 @@ export function InlineCategoryBadges({
           <Badge
             key={`${v}-${i}`}
             variant="secondary"
-            className="corner-squircle h-4 px-1.5 text-[10px]"
+            className="corner-squircle h-4 px-1.5 text-ui-10"
           >
             {v}
           </Badge>
         ))}
         {overflow > 0 && (
-          <Badge variant="outline" className="corner-squircle h-4 px-1.5 text-[10px]">
+          <Badge variant="outline" className="corner-squircle h-4 px-1.5 text-ui-10">
             +{overflow}
           </Badge>
         )}
diff --git a/studio/frontend/src/features/recipe-studio/components/inline/inline-field.tsx b/studio/frontend/src/features/recipe-studio/components/inline/inline-field.tsx
index e52ee00425..76eddd2c9e 100644
--- a/studio/frontend/src/features/recipe-studio/components/inline/inline-field.tsx
+++ b/studio/frontend/src/features/recipe-studio/components/inline/inline-field.tsx
@@ -17,7 +17,7 @@ export function InlineField({
 }: InlineFieldProps): ReactElement {
   return (
     <div className={cn("grid gap-1.5", className)}>
-      <p className="text-[11px] font-semibold uppercase tracking-wide text-muted-foreground">
+      <p className="text-ui-11 font-semibold uppercase tracking-wide text-muted-foreground">
         {label}
       </p>
       {children}
diff --git a/studio/frontend/src/features/recipe-studio/components/inline/inline-llm.tsx b/studio/frontend/src/features/recipe-studio/components/inline/inline-llm.tsx
index 45fb1b52a0..36479d2b58 100644
--- a/studio/frontend/src/features/recipe-studio/components/inline/inline-llm.tsx
+++ b/studio/frontend/src/features/recipe-studio/components/inline/inline-llm.tsx
@@ -184,7 +184,7 @@ export function InlineLlm({ config, onUpdate }: InlineLlmProps): ReactElement {
           </Select>
         </InlineField>
       )}
-      <p className="text-[11px] text-muted-foreground">
+      <p className="text-ui-11 text-muted-foreground">
         Prompt/system edited on aux nodes.
       </p>
     </div>
diff --git a/studio/frontend/src/features/recipe-studio/components/inline/inline-seed.tsx b/studio/frontend/src/features/recipe-studio/components/inline/inline-seed.tsx
index 82ec2f1de8..c4ca2d1834 100644
--- a/studio/frontend/src/features/recipe-studio/components/inline/inline-seed.tsx
+++ b/studio/frontend/src/features/recipe-studio/components/inline/inline-seed.tsx
@@ -74,7 +74,7 @@ export function InlineSeed({
         </div>
         <div className="min-w-0">
           <p className="truncate text-xs font-medium">{summary}</p>
-          <p className="truncate text-[11px] text-muted-foreground">
+          <p className="truncate text-ui-11 text-muted-foreground">
             {warning ??
               `${itemsLabel} · limit ${limit} · ${commentsLabel} · ${tokenLabel}`}
           </p>
@@ -106,7 +106,7 @@ export function InlineSeed({
             placeholder="org/repo"
           />
         </InlineField>
-        <p className="text-[11px] text-muted-foreground">
+        <p className="text-ui-11 text-muted-foreground">
           Load columns in dialog.
         </p>
       </div>
@@ -132,7 +132,7 @@ export function InlineSeed({
         <p className="truncate text-xs font-medium">
           {fileName || "No file selected"}
         </p>
-        <p className="text-[11px] text-muted-foreground">
+        <p className="text-ui-11 text-muted-foreground">
           {isLocal ? "Structured file" : "Unstructured document"} · configure in
           dialog
         </p>
diff --git a/studio/frontend/src/features/recipe-studio/components/recipe-graph-node.tsx b/studio/frontend/src/features/recipe-studio/components/recipe-graph-node.tsx
index a13c651149..9ad483d738 100644
--- a/studio/frontend/src/features/recipe-studio/components/recipe-graph-node.tsx
+++ b/studio/frontend/src/features/recipe-studio/components/recipe-graph-node.tsx
@@ -338,7 +338,7 @@ function renderNodeBody(
               <Badge
                 key={providerName}
                 variant="secondary"
-                className="corner-squircle font-mono text-[11px]"
+                className="corner-squircle font-mono text-ui-11"
               >
                 {providerName}
               </Badge>
@@ -505,7 +505,7 @@ function RecipeGraphNodeBase({
             <BaseNodeHeaderTitle className="truncate text-sm">
               {data.name}
             </BaseNodeHeaderTitle>
-            <p className="truncate text-[11px] text-muted-foreground">
+            <p className="truncate text-ui-11 text-muted-foreground">
               {data.subtype} · {data.title}
             </p>
           </div>
diff --git a/studio/frontend/src/features/recipe-studio/components/recipe-studio-header.tsx b/studio/frontend/src/features/recipe-studio/components/recipe-studio-header.tsx
index 385bef2b77..af22778ce5 100644
--- a/studio/frontend/src/features/recipe-studio/components/recipe-studio-header.tsx
+++ b/studio/frontend/src/features/recipe-studio/components/recipe-studio-header.tsx
@@ -118,7 +118,7 @@ export function RecipeStudioHeader({
               {workflowName}
             </button>
           )}
-          <Badge variant="secondary" className="h-6 shrink-0 text-[10px]">
+          <Badge variant="secondary" className="h-6 shrink-0 text-ui-10">
             {STATUS_MESSAGE_CLASS[saveTone]}
           </Badge>
           <span
@@ -148,7 +148,7 @@ export function RecipeStudioHeader({
             <PopoverTrigger asChild={true}>
               <button
                 type="button"
-                className={`inline-flex h-6 shrink-0 items-center gap-1 rounded-md border px-2 text-[10px] font-medium ${RECIPE_STUDIO_WARNING_BADGE_TONE}`}
+                className={`inline-flex h-6 shrink-0 items-center gap-1 rounded-md border px-2 text-ui-10 font-medium ${RECIPE_STUDIO_WARNING_BADGE_TONE}`}
               >
                 <HugeiconsIcon icon={Alert02Icon} className="size-3" />
                 {warnings.length}
diff --git a/studio/frontend/src/features/recipe-studio/components/runtime/execution-progress-island.tsx b/studio/frontend/src/features/recipe-studio/components/runtime/execution-progress-island.tsx
index 587fd6c262..f67019498e 100644
--- a/studio/frontend/src/features/recipe-studio/components/runtime/execution-progress-island.tsx
+++ b/studio/frontend/src/features/recipe-studio/components/runtime/execution-progress-island.tsx
@@ -156,7 +156,7 @@ export function ExecutionProgressIsland({
           {showLoadingSpinner && (
             <Spinner className="size-3.5 text-muted-foreground" />
           )}
-          <span className="shrink-0 text-[11px] text-muted-foreground">
+          <span className="shrink-0 text-ui-11 text-muted-foreground">
             {formatPercent(progressPercent)}
           </span>
           <button
@@ -180,7 +180,7 @@ export function ExecutionProgressIsland({
 
       {!minimized && (
         <>
-          <div className="grid grid-cols-2 gap-2 px-3 pt-2 text-[11px] text-muted-foreground sm:grid-cols-4">
+          <div className="grid grid-cols-2 gap-2 px-3 pt-2 text-ui-11 text-muted-foreground sm:grid-cols-4">
             <p
               className="truncate"
               title={`Done: ${formatMetricValue(execution.progress?.done)}`}
@@ -207,7 +207,7 @@ export function ExecutionProgressIsland({
             </p>
           </div>
           {showSourceProgress ? (
-            <div className="mt-1 flex items-center gap-1.5 px-3 text-[11px] text-muted-foreground">
+            <div className="mt-1 flex items-center gap-1.5 px-3 text-ui-11 text-muted-foreground">
               <HugeiconsIcon
                 icon={Flag02Icon}
                 className="size-3.5 shrink-0 text-amber-700 dark:text-amber-300"
@@ -217,7 +217,7 @@ export function ExecutionProgressIsland({
               </p>
             </div>
           ) : (
-            <div className="mt-1 flex items-center gap-1.5 px-3 text-[11px] text-muted-foreground">
+            <div className="mt-1 flex items-center gap-1.5 px-3 text-ui-11 text-muted-foreground">
               <HugeiconsIcon
                 icon={currentColumnIcon}
                 className="size-3.5 shrink-0"
@@ -229,7 +229,7 @@ export function ExecutionProgressIsland({
           )}
           {showBatch && (
             <div
-              className="mt-1 truncate px-3 text-[11px] text-muted-foreground"
+              className="mt-1 truncate px-3 text-ui-11 text-muted-foreground"
               title={`Batch: ${execution.batch?.idx ?? "--"}/${execution.batch?.total ?? "--"}`}
             >
               Batch: {execution.batch?.idx ?? "--"}/
@@ -241,7 +241,7 @@ export function ExecutionProgressIsland({
               type="button"
               variant="outline"
               size="sm"
-              className="h-7 w-full text-[11px]"
+              className="h-7 w-full text-ui-11"
               onClick={onViewExecutions}
             >
               View run details
diff --git a/studio/frontend/src/features/recipe-studio/components/shared/available-references-inline.tsx b/studio/frontend/src/features/recipe-studio/components/shared/available-references-inline.tsx
index fad7985ae1..ec75f59c05 100644
--- a/studio/frontend/src/features/recipe-studio/components/shared/available-references-inline.tsx
+++ b/studio/frontend/src/features/recipe-studio/components/shared/available-references-inline.tsx
@@ -66,7 +66,7 @@ export function AvailableReferencesInline({
 
   return (
     <div className="space-y-1">
-      <p className="text-[10px] font-medium text-muted-foreground">
+      <p className="text-ui-10 font-medium text-muted-foreground">
         Available references
       </p>
       <div ref={wrapperRef} className="relative">
@@ -83,8 +83,8 @@ export function AvailableReferencesInline({
                   variant="secondary"
                   className={
                     entry.source === "seed"
-                      ? "corner-squircle h-4 border-blue-500/25 bg-blue-500/10 px-1.5 font-mono text-[10px] text-blue-700 dark:text-blue-300"
-                      : "corner-squircle h-4 px-1.5 font-mono text-[10px]"
+                      ? "corner-squircle h-4 border-blue-500/25 bg-blue-500/10 px-1.5 font-mono text-ui-10 text-blue-700 dark:text-blue-300"
+                      : "corner-squircle h-4 px-1.5 font-mono text-ui-10"
                   }
                 >
                   {entry.name}
@@ -100,8 +100,8 @@ export function AvailableReferencesInline({
               variant="secondary"
               className={
                 entry.source === "seed"
-                  ? "corner-squircle h-4 border-blue-500/25 bg-blue-500/10 px-1.5 font-mono text-[10px] text-blue-700 dark:text-blue-300"
-                  : "corner-squircle h-4 px-1.5 font-mono text-[10px]"
+                  ? "corner-squircle h-4 border-blue-500/25 bg-blue-500/10 px-1.5 font-mono text-ui-10 text-blue-700 dark:text-blue-300"
+                  : "corner-squircle h-4 px-1.5 font-mono text-ui-10"
               }
             >
               {entry.name}
@@ -110,7 +110,7 @@ export function AvailableReferencesInline({
           {!expanded && hiddenCount > 0 && (
             <button
               type="button"
-              className="corner-squircle h-4 px-1.5 text-[10px] text-muted-foreground hover:text-foreground"
+              className="corner-squircle h-4 px-1.5 text-ui-10 text-muted-foreground hover:text-foreground"
               onClick={() => setExpanded(true)}
             >
               +{hiddenCount} more
@@ -119,7 +119,7 @@ export function AvailableReferencesInline({
           {expanded && collapsedCount < entries.length && (
             <button
               type="button"
-              className="corner-squircle h-4 px-1.5 text-[10px] text-muted-foreground hover:text-foreground"
+              className="corner-squircle h-4 px-1.5 text-ui-10 text-muted-foreground hover:text-foreground"
               onClick={() => setExpanded(false)}
             >
               Show less
diff --git a/studio/frontend/src/features/recipe-studio/dialogs/models/local-recipe-model-selector.tsx b/studio/frontend/src/features/recipe-studio/dialogs/models/local-recipe-model-selector.tsx
index c857b88a91..48229ecdcc 100644
--- a/studio/frontend/src/features/recipe-studio/dialogs/models/local-recipe-model-selector.tsx
+++ b/studio/frontend/src/features/recipe-studio/dialogs/models/local-recipe-model-selector.tsx
@@ -190,7 +190,7 @@ function LocalGgufVariantList({
 
   return (
     <div className="ml-6 mt-1 rounded-lg bg-muted/25 p-1.5">
-      <div className="mb-1 px-2 text-[10px] font-medium uppercase tracking-wide text-muted-foreground">
+      <div className="mb-1 px-2 text-ui-10 font-medium uppercase tracking-wide text-muted-foreground">
         Quantization
       </div>
       <div className="space-y-0.5">
@@ -210,12 +210,12 @@ function LocalGgufVariantList({
                 {variant.quant}
               </span>
               {variant.quant === defaultVariant ? (
-                <Badge variant="secondary" className="h-4 px-1.5 text-[10px]">
+                <Badge variant="secondary" className="h-4 px-1.5 text-ui-10">
                   recommended
                 </Badge>
               ) : null}
               {variant.downloaded ? (
-                <Badge variant="outline" className="h-4 px-1.5 text-[10px]">
+                <Badge variant="outline" className="h-4 px-1.5 text-ui-10">
                   ready
                 </Badge>
               ) : null}
@@ -276,7 +276,7 @@ const SelectorTrigger = forwardRef<HTMLButtonElement, SelectorTriggerProps>(
             {selected.label || "Choose a local model"}
           </span>
           {compact ? null : (
-            <span className="mt-0.5 flex min-w-0 items-center gap-1.5 text-[11px] text-muted-foreground">
+            <span className="mt-0.5 flex min-w-0 items-center gap-1.5 text-ui-11 text-muted-foreground">
               <span className="truncate">
                 {selected.label
                   ? selected.source
@@ -292,7 +292,7 @@ const SelectorTrigger = forwardRef<HTMLButtonElement, SelectorTriggerProps>(
         {compact && ggufVariant ? (
           <Badge
             variant="secondary"
-            className="h-4 px-1.5 font-mono text-[10px]"
+            className="h-4 px-1.5 font-mono text-ui-10"
           >
             {ggufVariant}
           </Badge>
@@ -347,7 +347,7 @@ function LocalModelRow({
           <span className="block truncate font-medium">
             {getModelLabel(model)}
           </span>
-          <span className="mt-0.5 block truncate text-[11px] text-muted-foreground">
+          <span className="mt-0.5 block truncate text-ui-11 text-muted-foreground">
             {model.id}
           </span>
         </span>
@@ -356,11 +356,11 @@ function LocalModelRow({
             <Spinner className="size-3 text-muted-foreground" />
           ) : null}
           {expandable || directGguf ? (
-            <Badge variant="secondary" className="h-4 px-1.5 text-[10px]">
+            <Badge variant="secondary" className="h-4 px-1.5 text-ui-10">
               GGUF
             </Badge>
           ) : null}
-          <Badge variant="outline" className="h-4 px-1.5 text-[10px]">
+          <Badge variant="outline" className="h-4 px-1.5 text-ui-10">
             {sourceLabel(model)}
           </Badge>
         </span>
diff --git a/studio/frontend/src/features/recipe-studio/dialogs/preview-dialog.tsx b/studio/frontend/src/features/recipe-studio/dialogs/preview-dialog.tsx
index 3181d9fe67..f2ef34df8c 100644
--- a/studio/frontend/src/features/recipe-studio/dialogs/preview-dialog.tsx
+++ b/studio/frontend/src/features/recipe-studio/dialogs/preview-dialog.tsx
@@ -653,7 +653,7 @@ function RunDialogBody({
             />
             <Badge
               variant="outline"
-              className="rounded-full text-[10px] text-destructive"
+              className="rounded-full text-ui-10 text-destructive"
             >
               Before you run
             </Badge>
diff --git a/studio/frontend/src/features/recipe-studio/dialogs/seed/seed-dialog.tsx b/studio/frontend/src/features/recipe-studio/dialogs/seed/seed-dialog.tsx
index 53f8566090..fedd603a9d 100644
--- a/studio/frontend/src/features/recipe-studio/dialogs/seed/seed-dialog.tsx
+++ b/studio/frontend/src/features/recipe-studio/dialogs/seed/seed-dialog.tsx
@@ -319,7 +319,7 @@ export function GithubRepoSeedForm({
             hint="Prefer the server GH_TOKEN / GITHUB_TOKEN env var. Use public_repo for public repos or repo for private repos."
           />
           {usingEnvToken && (
-            <span className="shrink-0 rounded-md border border-emerald-500/40 bg-emerald-500/10 px-1.5 py-0.5 text-[10px] font-medium text-emerald-700 dark:text-emerald-300">
+            <span className="shrink-0 rounded-md border border-emerald-500/40 bg-emerald-500/10 px-1.5 py-0.5 text-ui-10 font-medium text-emerald-700 dark:text-emerald-300">
               Using server env var
             </span>
           )}
diff --git a/studio/frontend/src/features/recipe-studio/dialogs/tool-profile/tool-profile-dialog.tsx b/studio/frontend/src/features/recipe-studio/dialogs/tool-profile/tool-profile-dialog.tsx
index bf5a61ac00..802729fcd8 100644
--- a/studio/frontend/src/features/recipe-studio/dialogs/tool-profile/tool-profile-dialog.tsx
+++ b/studio/frontend/src/features/recipe-studio/dialogs/tool-profile/tool-profile-dialog.tsx
@@ -135,11 +135,11 @@ function McpServerCard({
                   <p className="truncate text-sm font-semibold text-foreground">
                     {summaryTitle}
                   </p>
-                  <Badge variant="outline" className="rounded-full text-[10px] uppercase">
+                  <Badge variant="outline" className="rounded-full text-ui-10 uppercase">
                     {transportLabel}
                   </Badge>
                   {toolsLabel ? (
-                    <Badge variant="secondary" className="rounded-full text-[10px]">
+                    <Badge variant="secondary" className="rounded-full text-ui-10">
                       {toolsLabel}
                     </Badge>
                   ) : null}
@@ -680,7 +680,7 @@ export function ToolProfileDialog({
                     <p className="text-xs font-semibold uppercase text-muted-foreground">
                       {providerName}
                     </p>
-                    <Badge variant="outline" className="rounded-full text-[10px]">
+                    <Badge variant="outline" className="rounded-full text-ui-10">
                       {toolNames.length}
                     </Badge>
                   </div>
diff --git a/studio/frontend/src/features/recipe-studio/recipe-studio-page.tsx b/studio/frontend/src/features/recipe-studio/recipe-studio-page.tsx
index ec9358ee0f..30302b86a7 100644
--- a/studio/frontend/src/features/recipe-studio/recipe-studio-page.tsx
+++ b/studio/frontend/src/features/recipe-studio/recipe-studio-page.tsx
@@ -670,7 +670,7 @@ export function RecipeStudioPage({
                 />
               </div>
               <div className="mt-4 space-y-2">
-                <p className="text-[11px] font-semibold uppercase tracking-wide text-primary">
+                <p className="text-ui-11 font-semibold uppercase tracking-wide text-primary">
                   Best place to start
                 </p>
                 <p className="text-sm font-semibold text-foreground">
diff --git a/studio/frontend/src/features/recipe-studio/utils/ui-tones.ts b/studio/frontend/src/features/recipe-studio/utils/ui-tones.ts
index 3d9ecff15a..1dc3666687 100644
--- a/studio/frontend/src/features/recipe-studio/utils/ui-tones.ts
+++ b/studio/frontend/src/features/recipe-studio/utils/ui-tones.ts
@@ -27,10 +27,10 @@ export const RECIPE_STUDIO_USER_NODE_TONE =
 
 export const RECIPE_STUDIO_REFERENCE_BADGE_TONES = {
   user:
-    "corner-squircle border-amber-500/25 bg-amber-500/10 font-mono text-[11px] text-amber-700 dark:text-amber-300",
+    "corner-squircle border-amber-500/25 bg-amber-500/10 font-mono text-ui-11 text-amber-700 dark:text-amber-300",
   seed:
-    "corner-squircle border-blue-500/25 bg-blue-500/10 font-mono text-[11px] text-blue-700 dark:text-blue-300",
-  default: "corner-squircle font-mono text-[11px]",
+    "corner-squircle border-blue-500/25 bg-blue-500/10 font-mono text-ui-11 text-blue-700 dark:text-blue-300",
+  default: "corner-squircle font-mono text-ui-11",
 } as const;
 
 export const RECIPE_STUDIO_WARNING_BADGE_TONE =
diff --git a/studio/frontend/src/features/security/components/remote-code-consent-dialog.tsx b/studio/frontend/src/features/security/components/remote-code-consent-dialog.tsx
index 6426225e7f..69bab2156e 100644
--- a/studio/frontend/src/features/security/components/remote-code-consent-dialog.tsx
+++ b/studio/frontend/src/features/security/components/remote-code-consent-dialog.tsx
@@ -111,7 +111,7 @@ function UnsafeFileCard({ file }: { file: UnsafeFile }) {
       <Badge
         variant="outline"
         className={cn(
-          "shrink-0 text-[10px] font-semibold uppercase tracking-wide",
+          "shrink-0 text-ui-10 font-semibold uppercase tracking-wide",
           severityTone("CRITICAL"),
         )}
       >
@@ -134,7 +134,7 @@ function FindingCard({ finding }: { finding: RemoteCodeFinding }) {
         <Badge
           variant="outline"
           className={cn(
-            "shrink-0 text-[10px] font-semibold tracking-wide",
+            "shrink-0 text-ui-10 font-semibold tracking-wide",
             severityTone(finding.severity),
           )}
         >
diff --git a/studio/frontend/src/features/settings/api/embedding-model.ts b/studio/frontend/src/features/settings/api/embedding-model.ts
index 9a61142f73..cc21559f38 100644
--- a/studio/frontend/src/features/settings/api/embedding-model.ts
+++ b/studio/frontend/src/features/settings/api/embedding-model.ts
@@ -2,11 +2,14 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { authFetch } from "@/features/auth";
+import { bumpInventoryVersion } from "@/features/hub";
 import { readFastApiError } from "@/lib/format-fastapi-error";
 
 export type EmbeddingModelSettings = {
   embeddingModel: string;
+  embeddingGgufRepo: string;
   defaultEmbeddingModel: string;
+  defaultEmbeddingGgufRepo: string;
   isCustom: boolean;
 };
 
@@ -14,8 +17,12 @@ type ApiEmbeddingModelSettings = {
   // biome-ignore lint/style/useNamingConvention: API schema
   embedding_model: string;
   // biome-ignore lint/style/useNamingConvention: API schema
+  embedding_gguf_repo: string;
+  // biome-ignore lint/style/useNamingConvention: API schema
   default_embedding_model: string;
   // biome-ignore lint/style/useNamingConvention: API schema
+  default_embedding_gguf_repo: string;
+  // biome-ignore lint/style/useNamingConvention: API schema
   is_custom: boolean;
 };
 
@@ -30,7 +37,9 @@ export class EmbeddingModelBlockedError extends Error {}
 function fromApi(settings: ApiEmbeddingModelSettings): EmbeddingModelSettings {
   return {
     embeddingModel: settings.embedding_model,
+    embeddingGgufRepo: settings.embedding_gguf_repo,
     defaultEmbeddingModel: settings.default_embedding_model,
+    defaultEmbeddingGgufRepo: settings.default_embedding_gguf_repo,
     isCustom: settings.is_custom,
   };
 }
@@ -75,7 +84,9 @@ export async function updateEmbeddingModelSettings(
       await readFastApiError(res, "Failed to save embedding model"),
     );
   }
-  return fromApi(await res.json());
+  const settings = fromApi(await res.json());
+  bumpInventoryVersion();
+  return settings;
 }
 
 export async function resetEmbeddingModelSettings(): Promise<EmbeddingModelSettings> {
@@ -87,5 +98,7 @@ export async function resetEmbeddingModelSettings(): Promise<EmbeddingModelSetti
       await readFastApiError(res, "Failed to reset embedding model"),
     );
   }
-  return fromApi(await res.json());
+  const settings = fromApi(await res.json());
+  bumpInventoryVersion();
+  return settings;
 }
diff --git a/studio/frontend/src/features/settings/api/hugging-face-cache.ts b/studio/frontend/src/features/settings/api/hugging-face-cache.ts
new file mode 100644
index 0000000000..3ca0f31053
--- /dev/null
+++ b/studio/frontend/src/features/settings/api/hugging-face-cache.ts
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { authFetch } from "@/features/auth";
+import {
+  bumpInventoryVersion,
+  invalidateGgufVariantsCache,
+} from "@/features/hub";
+import { readFastApiError } from "@/lib/format-fastapi-error";
+
+export type HuggingFaceCacheSettings = {
+  cacheHome: string;
+  hubCache: string;
+  xetCache: string;
+  source: "default" | "studio" | "environment";
+  editable: boolean;
+  isCustom: boolean;
+  available: boolean;
+  writable: boolean;
+  freeBytes: number | null;
+  environmentVariable: string | null;
+};
+
+type ApiHuggingFaceCacheSettings = {
+  // biome-ignore lint/style/useNamingConvention: API schema
+  cache_home: string;
+  // biome-ignore lint/style/useNamingConvention: API schema
+  hub_cache: string;
+  // biome-ignore lint/style/useNamingConvention: API schema
+  xet_cache: string;
+  source: HuggingFaceCacheSettings["source"];
+  editable: boolean;
+  // biome-ignore lint/style/useNamingConvention: API schema
+  is_custom: boolean;
+  available: boolean;
+  writable: boolean;
+  // biome-ignore lint/style/useNamingConvention: API schema
+  free_bytes: number | null;
+  // biome-ignore lint/style/useNamingConvention: API schema
+  environment_variable: string | null;
+};
+
+function fromApi(value: ApiHuggingFaceCacheSettings): HuggingFaceCacheSettings {
+  return {
+    cacheHome: value.cache_home,
+    hubCache: value.hub_cache,
+    xetCache: value.xet_cache,
+    source: value.source,
+    editable: value.editable,
+    isCustom: value.is_custom,
+    available: value.available,
+    writable: value.writable,
+    freeBytes: value.free_bytes,
+    environmentVariable: value.environment_variable,
+  };
+}
+
+export async function loadHuggingFaceCacheSettings() {
+  const response = await authFetch("/api/settings/hugging-face-cache");
+  if (!response.ok) {
+    throw new Error(
+      await readFastApiError(
+        response,
+        "Failed to load the model cache location",
+      ),
+    );
+  }
+  return fromApi(await response.json());
+}
+
+export async function updateHuggingFaceCacheSettings(cacheHome: string | null) {
+  const response = await authFetch("/api/settings/hugging-face-cache", {
+    method: "PUT",
+    headers: { "Content-Type": "application/json" },
+    // biome-ignore lint/style/useNamingConvention: API schema
+    body: JSON.stringify({ cache_home: cacheHome }),
+  });
+  if (!response.ok) {
+    throw new Error(
+      await readFastApiError(
+        response,
+        "Failed to update the model cache location",
+      ),
+    );
+  }
+  const settings = fromApi(await response.json());
+  bumpInventoryVersion();
+  invalidateGgufVariantsCache();
+  return settings;
+}
diff --git a/studio/frontend/src/features/settings/api/models-folder.ts b/studio/frontend/src/features/settings/api/models-folder.ts
deleted file mode 100644
index 13e8c065c3..0000000000
--- a/studio/frontend/src/features/settings/api/models-folder.ts
+++ /dev/null
@@ -1,40 +0,0 @@
-// SPDX-License-Identifier: AGPL-3.0-only
-// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
-
-import { authFetch } from "@/features/auth";
-import { readFastApiError } from "@/lib/format-fastapi-error";
-
-export type ModelsFolder = {
-  path: string;
-};
-
-// The path is resolved once at backend startup and never changes, so cache it
-// and dedupe concurrent loads (same shape as the sibling settings loaders).
-let cachedModelsFolder: ModelsFolder | null = null;
-let inFlightModelsFolder: Promise<ModelsFolder> | null = null;
-
-async function fetchModelsFolder(): Promise<ModelsFolder> {
-  const res = await authFetch("/api/hub/models-folder");
-  if (!res.ok) {
-    throw new Error(
-      await readFastApiError(res, "Failed to load models folder"),
-    );
-  }
-  const data = (await res.json()) as { path: string };
-  return { path: data.path };
-}
-
-export async function loadModelsFolder(): Promise<ModelsFolder> {
-  if (cachedModelsFolder) {
-    return cachedModelsFolder;
-  }
-  inFlightModelsFolder ??= fetchModelsFolder()
-    .then((folder) => {
-      cachedModelsFolder = folder;
-      return folder;
-    })
-    .finally(() => {
-      inFlightModelsFolder = null;
-    });
-  return inFlightModelsFolder;
-}
diff --git a/studio/frontend/src/features/settings/api/openai-auto-switch.ts b/studio/frontend/src/features/settings/api/openai-auto-switch.ts
index 80ffc084d0..47bad56eab 100644
--- a/studio/frontend/src/features/settings/api/openai-auto-switch.ts
+++ b/studio/frontend/src/features/settings/api/openai-auto-switch.ts
@@ -11,6 +11,8 @@ export type OpenAIAutoSwitchSettings = {
   // True when the idle-unload loop will actually unload (e.g. enabled via the
   // UNSLOTH_MODEL_IDLE_TTL env var even while the toggle is off).
   idleUnloadActive: boolean;
+  // Persist the KV cache to disk on idle unload and restore it on reload.
+  autoUnloadKeepKv: boolean;
 };
 
 type ApiOpenAIAutoSwitchSettings = {
@@ -21,6 +23,8 @@ type ApiOpenAIAutoSwitchSettings = {
   default_enabled: boolean;
   // biome-ignore lint/style/useNamingConvention: API schema
   idle_unload_active?: boolean;
+  // biome-ignore lint/style/useNamingConvention: API schema
+  auto_unload_keep_kv?: boolean;
 };
 
 let cachedSettings: OpenAIAutoSwitchSettings | null = null;
@@ -34,6 +38,7 @@ function fromApi(
     autoUnloadIdleSeconds: settings.auto_unload_idle_seconds,
     defaultEnabled: settings.default_enabled,
     idleUnloadActive: settings.idle_unload_active ?? false,
+    autoUnloadKeepKv: settings.auto_unload_keep_kv ?? true,
   };
 }
 
@@ -66,15 +71,23 @@ export async function loadOpenAIAutoSwitchSettings() {
 
 export async function updateOpenAIAutoSwitchSettings(
   enabled: boolean,
-  autoUnloadIdleSeconds: number,
+  autoUnloadIdleSeconds?: number,
+  autoUnloadKeepKv?: boolean,
 ): Promise<OpenAIAutoSwitchSettings> {
   const res = await authFetch("/api/settings/openai-auto-switch", {
     method: "PUT",
     headers: { "Content-Type": "application/json" },
     body: JSON.stringify({
       enabled,
-      // biome-ignore lint/style/useNamingConvention: API schema
-      auto_unload_idle_seconds: autoUnloadIdleSeconds,
+      // Omitted fields keep their stored value.
+      ...(autoUnloadIdleSeconds === undefined
+        ? {}
+        : // biome-ignore lint/style/useNamingConvention: API schema
+          { auto_unload_idle_seconds: autoUnloadIdleSeconds }),
+      ...(autoUnloadKeepKv === undefined
+        ? {}
+        : // biome-ignore lint/style/useNamingConvention: API schema
+          { auto_unload_keep_kv: autoUnloadKeepKv }),
     }),
   });
   if (!res.ok) {
diff --git a/studio/frontend/src/features/settings/components/api-key-row.tsx b/studio/frontend/src/features/settings/components/api-key-row.tsx
index 9a6e1ee207..7100634942 100644
--- a/studio/frontend/src/features/settings/components/api-key-row.tsx
+++ b/studio/frontend/src/features/settings/components/api-key-row.tsx
@@ -69,11 +69,11 @@ export function ApiKeyRow({
           <span className="truncate text-sm font-medium text-foreground" title={apiKey.name}>
             {apiKey.name}
           </span>
-          <code className="shrink-0 font-mono text-[11px] text-muted-foreground">
+          <code className="shrink-0 font-mono text-ui-11 text-muted-foreground">
             {prefix}
           </code>
         </div>
-        <div className="flex flex-wrap gap-x-1.5 text-[11px] text-muted-foreground">
+        <div className="flex flex-wrap gap-x-1.5 text-ui-11 text-muted-foreground">
           <span>
             {t("settings.apiKeys.created", {
               value: relative(apiKey.created_at, t),
diff --git a/studio/frontend/src/features/settings/components/api-monitor-console.tsx b/studio/frontend/src/features/settings/components/api-monitor-console.tsx
index ef4daa1349..0f931ff4da 100644
--- a/studio/frontend/src/features/settings/components/api-monitor-console.tsx
+++ b/studio/frontend/src/features/settings/components/api-monitor-console.tsx
@@ -127,7 +127,7 @@ function MonitorEntry({
               {compactEndpoint(entry.endpoint)}
             </span>
           </div>
-          <div className="mt-1 truncate text-[11px] text-muted-foreground">
+          <div className="mt-1 truncate text-ui-11 text-muted-foreground">
             {entry.model}
           </div>
           <div className="mt-2 line-clamp-2 whitespace-pre-wrap break-words text-xs text-muted-foreground">
@@ -137,7 +137,7 @@ function MonitorEntry({
               (entry.status === "running" ? "Waiting..." : "No preview")}
           </div>
         </div>
-        <div className="flex shrink-0 items-start gap-2 text-right text-[11px] text-muted-foreground">
+        <div className="flex shrink-0 items-start gap-2 text-right text-ui-11 text-muted-foreground">
           <div>
             <div>{formatTime(entry.started_at)}</div>
             <div>{formatDuration(entry.duration_ms)}</div>
@@ -155,7 +155,7 @@ function MonitorEntry({
         <div className="border-t border-border/60 p-3 pt-2">
           <div className="grid gap-2">
             <div>
-              <div className="mb-1 flex items-center justify-between gap-2 text-[10px] font-semibold uppercase text-muted-foreground">
+              <div className="mb-1 flex items-center justify-between gap-2 text-ui-10 font-semibold uppercase text-muted-foreground">
                 <span>Prompt</span>
                 {entry.prompt_truncated && !detail ? <span>Preview</span> : null}
               </div>
@@ -164,7 +164,7 @@ function MonitorEntry({
               </pre>
             </div>
             <div>
-              <div className="mb-1 flex items-center justify-between gap-2 text-[10px] font-semibold uppercase text-muted-foreground">
+              <div className="mb-1 flex items-center justify-between gap-2 text-ui-10 font-semibold uppercase text-muted-foreground">
                 <span>Reply</span>
                 {entry.reply_truncated && !detail ? <span>Preview</span> : null}
               </div>
@@ -174,7 +174,7 @@ function MonitorEntry({
             </div>
           </div>
 
-          <div className="mt-3 text-[11px] text-muted-foreground">
+          <div className="mt-3 text-ui-11 text-muted-foreground">
             {formatTokens(entry)}
             {entry.context_length ? (
               <> / {entry.context_length.toLocaleString()} context</>
diff --git a/studio/frontend/src/features/settings/components/archived-chats-dialog.tsx b/studio/frontend/src/features/settings/components/archived-chats-dialog.tsx
index 836b4d25d4..43b2900fbe 100644
--- a/studio/frontend/src/features/settings/components/archived-chats-dialog.tsx
+++ b/studio/frontend/src/features/settings/components/archived-chats-dialog.tsx
@@ -12,26 +12,24 @@ import {
   AlertDialogTitle,
 } from "@/components/ui/alert-dialog";
 import {
-  Dialog,
-  DialogContent,
-  DialogHeader,
-  DialogTitle,
-} from "@/components/ui/dialog";
-import {
+  type SidebarItem,
   deleteChatItem,
   unarchiveChatItem,
   useChatPreferencesStore,
   useChatRuntimeStore,
   useChatSidebarItems,
-  type SidebarItem,
 } from "@/features/chat";
 import { toast } from "@/lib/toast";
 import { ArchiveRestoreIcon, Delete02Icon } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
+import { Button } from "@/components/ui/button";
 import { useNavigate, useRouterState } from "@tanstack/react-router";
 import { useState } from "react";
 import { useSettingsDialogStore } from "../stores/settings-dialog-store";
 
+/** Archived chats shown per page; "Show more" reveals the next page. */
+const ARCHIVED_PAGE_SIZE = 20;
+
 function formatCreatedAt(ms: number): string {
   return new Date(ms).toLocaleDateString(undefined, {
     year: "numeric",
@@ -40,13 +38,7 @@ function formatCreatedAt(ms: number): string {
   });
 }
 
-export function ArchivedChatsDialog({
-  open,
-  onOpenChange,
-}: {
-  open: boolean;
-  onOpenChange: (open: boolean) => void;
-}) {
+export function ArchivedChatsView() {
   const { archivedItems } = useChatSidebarItems({ requireMessages: false });
   const navigate = useNavigate();
   const closeSettings = useSettingsDialogStore((s) => s.closeDialog);
@@ -66,6 +58,9 @@ export function ArchivedChatsDialog({
   const [confirmingDelete, setConfirmingDelete] = useState<SidebarItem | null>(
     null,
   );
+  // Pagination: the view remounts with its settings tab, so plain state
+  // restarts from the first page on each visit.
+  const [visibleCount, setVisibleCount] = useState(ARCHIVED_PAGE_SIZE);
 
   // Open an archived chat: leave it archived, just navigate to it.
   function openChat(item: SidebarItem) {
@@ -74,7 +69,6 @@ export function ArchivedChatsDialog({
       search:
         item.type === "single" ? { thread: item.id } : { compare: item.id },
     });
-    onOpenChange(false);
     closeSettings();
   }
 
@@ -114,72 +108,79 @@ export function ArchivedChatsDialog({
   }
 
   return (
-    <Dialog open={open} onOpenChange={onOpenChange}>
-      <DialogContent className="max-w-2xl">
-        <DialogHeader>
-          <DialogTitle>Archived chats</DialogTitle>
-        </DialogHeader>
-
-        {archivedItems.length === 0 ? (
-          <p className="py-8 text-center text-sm text-muted-foreground">
-            No archived chats.
-          </p>
-        ) : (
-          <div className="max-h-[60vh] overflow-y-auto">
-            <div className="flex items-center gap-4 border-b border-border/60 px-1 pb-2 text-xs font-semibold text-foreground">
-              <span className="flex-1">Name</span>
-              <span className="w-32 shrink-0">Date created</span>
-              <span className="w-16 shrink-0" />
-            </div>
-            {archivedItems.map((item) => (
-              <div
-                key={item.id}
-                className="group flex items-center gap-4 border-b border-border/40 px-1 py-2.5 text-sm last:border-0"
+    <div className="flex flex-col gap-4">
+      {archivedItems.length === 0 ? (
+        <p className="py-8 text-center text-sm text-muted-foreground">
+          No archived chats.
+        </p>
+      ) : (
+        <div>
+          <div className="flex items-center gap-4 border-b border-border/60 px-1 pb-2 text-xs font-semibold text-foreground">
+            <span className="flex-1">Name</span>
+            <span className="w-32 shrink-0">Date created</span>
+            <span className="w-16 shrink-0" />
+          </div>
+          {archivedItems.slice(0, visibleCount).map((item) => (
+            <div
+              key={item.id}
+              className="group flex items-center gap-4 border-b border-border/40 px-1 py-2.5 text-sm last:border-0"
+            >
+              <button
+                type="button"
+                onClick={() => openChat(item)}
+                className="min-w-0 flex-1 truncate text-left text-primary hover:underline"
+                title={item.title}
               >
+                {item.title}
+              </button>
+              <span className="w-32 shrink-0 text-muted-foreground tabular-nums">
+                {formatCreatedAt(item.createdAt)}
+              </span>
+              <span className="flex w-16 shrink-0 items-center justify-end gap-1">
                 <button
                   type="button"
-                  onClick={() => openChat(item)}
-                  className="min-w-0 flex-1 truncate text-left text-primary hover:underline"
-                  title={item.title}
+                  onClick={() => void handleUnarchive(item)}
+                  aria-label="Unarchive chat"
+                  title="Unarchive"
+                  className="inline-flex size-7 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-muted hover:text-foreground"
                 >
-                  {item.title}
+                  <HugeiconsIcon
+                    icon={ArchiveRestoreIcon}
+                    strokeWidth={1.75}
+                    className="size-4"
+                  />
                 </button>
-                <span className="w-32 shrink-0 text-muted-foreground tabular-nums">
-                  {formatCreatedAt(item.createdAt)}
-                </span>
-                <span className="flex w-16 shrink-0 items-center justify-end gap-1">
-                  <button
-                    type="button"
-                    onClick={() => void handleUnarchive(item)}
-                    aria-label="Unarchive chat"
-                    title="Unarchive"
-                    className="inline-flex size-7 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-muted hover:text-foreground"
-                  >
-                    <HugeiconsIcon
-                      icon={ArchiveRestoreIcon}
-                      strokeWidth={1.75}
-                      className="size-4"
-                    />
-                  </button>
-                  <button
-                    type="button"
-                    onClick={() => requestDelete(item)}
-                    aria-label="Delete chat"
-                    title="Delete"
-                    className="inline-flex size-7 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-destructive/10 hover:text-destructive"
-                  >
-                    <HugeiconsIcon
-                      icon={Delete02Icon}
-                      strokeWidth={1.75}
-                      className="size-4"
-                    />
-                  </button>
-                </span>
-              </div>
-            ))}
-          </div>
-        )}
-      </DialogContent>
+                <button
+                  type="button"
+                  onClick={() => requestDelete(item)}
+                  aria-label="Delete chat"
+                  title="Delete"
+                  className="inline-flex size-7 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-destructive/10 hover:text-destructive"
+                >
+                  <HugeiconsIcon
+                    icon={Delete02Icon}
+                    strokeWidth={1.75}
+                    className="size-4"
+                  />
+                </button>
+              </span>
+            </div>
+          ))}
+          {archivedItems.length > visibleCount ? (
+            <div className="flex justify-center pt-3">
+              <Button
+                variant="outline"
+                size="sm"
+                onClick={() =>
+                  setVisibleCount(visibleCount + ARCHIVED_PAGE_SIZE)
+                }
+              >
+                Show more ({archivedItems.length - visibleCount})
+              </Button>
+            </div>
+          ) : null}
+        </div>
+      )}
 
       <AlertDialog
         open={confirmingDelete !== null}
@@ -213,6 +214,6 @@ export function ArchivedChatsDialog({
           </AlertDialogFooter>
         </AlertDialogContent>
       </AlertDialog>
-    </Dialog>
+    </div>
   );
 }
diff --git a/studio/frontend/src/features/settings/components/change-password-dialog.tsx b/studio/frontend/src/features/settings/components/change-password-dialog.tsx
index cd30d37d5d..c88fc48cac 100644
--- a/studio/frontend/src/features/settings/components/change-password-dialog.tsx
+++ b/studio/frontend/src/features/settings/components/change-password-dialog.tsx
@@ -78,6 +78,9 @@ function passwordValidationMessage(
       minLength: MIN_PASSWORD_LENGTH,
     });
   }
+  if (/\s/.test(nextPassword)) {
+    return t("settings.general.passwordDialog.newHasSpaces");
+  }
   if (nextPassword !== confirmPassword) {
     return t("settings.general.passwordDialog.mismatch");
   }
@@ -160,6 +163,7 @@ export function ChangePasswordDialog() {
 
   const currentTooShort = hasStartedTooShortPassword(current);
   const nextTooShort = hasStartedTooShortPassword(next);
+  const nextHasSpaces = /\s/.test(next);
   const mismatch = confirm.length > 0 && next !== confirm;
   const samePassword = hasReusablePassword(current, next);
   const validationMessage = passwordValidationMessage(
@@ -279,13 +283,15 @@ export function ChangePasswordDialog() {
                 minLength={MIN_PASSWORD_LENGTH}
                 disabled={submitting}
               />
-              {nextTooShort || samePassword ? (
+              {nextTooShort || nextHasSpaces || samePassword ? (
                 <p className="text-xs text-destructive" aria-live="polite">
                   {nextTooShort
                     ? t("settings.general.passwordDialog.newTooShort", {
                         minLength: MIN_PASSWORD_LENGTH,
                       })
-                    : t("settings.general.passwordDialog.samePassword")}
+                    : nextHasSpaces
+                      ? t("settings.general.passwordDialog.newHasSpaces")
+                      : t("settings.general.passwordDialog.samePassword")}
                 </p>
               ) : null}
             </div>
diff --git a/studio/frontend/src/features/settings/components/color-picker.tsx b/studio/frontend/src/features/settings/components/color-picker.tsx
index d42e439349..77ff8b1b7f 100644
--- a/studio/frontend/src/features/settings/components/color-picker.tsx
+++ b/studio/frontend/src/features/settings/components/color-picker.tsx
@@ -156,7 +156,7 @@ export function ColorPickerSwatch({
           type="button"
           aria-label={label}
           className={cn(
-            "flex h-8 w-24 cursor-pointer items-center gap-1.5 rounded-full border px-2.5 font-mono text-xs uppercase transition-colors",
+            "flex h-8 min-w-24 cursor-pointer items-center gap-1.5 rounded-full border px-2.5 font-mono text-xs uppercase transition-colors",
             light
               ? "border-black/10 text-black/80"
               : "border-white/15 text-white",
diff --git a/studio/frontend/src/features/settings/components/create-key-form.tsx b/studio/frontend/src/features/settings/components/create-key-form.tsx
index 642d9ad320..a16f67f1c1 100644
--- a/studio/frontend/src/features/settings/components/create-key-form.tsx
+++ b/studio/frontend/src/features/settings/components/create-key-form.tsx
@@ -64,7 +64,7 @@ export function CreateKeyForm({
                 onClick={() => setExpiry(p.value)}
                 aria-pressed={active}
                 className={cn(
-                  "inline-flex h-8 items-center rounded-full px-3.5 text-[12px] font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
+                  "inline-flex h-8 items-center rounded-full px-3.5 text-ui-12 font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
                   active
                     ? "hub-tab-toggle-pill text-foreground"
                     : "text-muted-foreground hover:text-foreground",
diff --git a/studio/frontend/src/features/settings/components/dictation-dictionary-view.tsx b/studio/frontend/src/features/settings/components/dictation-dictionary-view.tsx
new file mode 100644
index 0000000000..41b8b21156
--- /dev/null
+++ b/studio/frontend/src/features/settings/components/dictation-dictionary-view.tsx
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { useT } from "@/i18n";
+import {
+  ArrowLeft01Icon,
+  Delete02Icon,
+  PlusSignIcon,
+} from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
+import { useState } from "react";
+import { useVoiceSettingsStore } from "../stores/voice-settings-store";
+
+// Full-page editor for the dictation dictionary. Kept on its own subpage so a
+// long list of entries does not crowd the main Voice settings.
+export function DictationDictionaryView({ onBack }: { onBack: () => void }) {
+  const t = useT();
+  const dictionary = useVoiceSettingsStore((s) => s.dictionary);
+  const addDictionaryEntry = useVoiceSettingsStore((s) => s.addDictionaryEntry);
+  const updateDictionaryEntry = useVoiceSettingsStore(
+    (s) => s.updateDictionaryEntry,
+  );
+  const commitDictionaryEntry = useVoiceSettingsStore(
+    (s) => s.commitDictionaryEntry,
+  );
+  const removeDictionaryEntry = useVoiceSettingsStore(
+    (s) => s.removeDictionaryEntry,
+  );
+  const [newEntry, setNewEntry] = useState("");
+
+  const handleAddEntry = () => {
+    const trimmed = newEntry.trim();
+    if (!trimmed) return;
+    addDictionaryEntry(trimmed);
+    setNewEntry("");
+  };
+
+  return (
+    <div className="flex flex-col gap-6">
+      <header className="flex items-center gap-2">
+        <button
+          type="button"
+          onClick={onBack}
+          aria-label={t("settings.voice.dictionary.backToVoice")}
+          className="inline-flex size-7 shrink-0 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-muted hover:text-foreground focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
+        >
+          <HugeiconsIcon icon={ArrowLeft01Icon} className="size-4" />
+        </button>
+        <h1 className="font-heading text-xl font-semibold">
+          {t("settings.voice.title")}
+        </h1>
+      </header>
+
+      <div className="flex flex-col gap-1">
+        <h2 className="text-sm font-semibold">
+          {t("settings.voice.dictionary.sectionTitle")}
+        </h2>
+        <p className="text-xs text-muted-foreground">
+          {t("settings.voice.dictionary.sectionDescription")}
+        </p>
+      </div>
+
+      <div className="flex flex-col">
+        {dictionary.map((entry, index) => (
+          <div
+            // biome-ignore lint/suspicious/noArrayIndexKey: entries are editable in place
+            key={index}
+            className="flex items-center gap-2 py-1.5"
+          >
+            <Input
+              value={entry}
+              onChange={(e) => updateDictionaryEntry(index, e.target.value)}
+              // Tabbing to this row's remove button must not commit-splice the
+              // row first, which shifts indices and deletes the wrong entry.
+              onBlur={(e) => {
+                if (
+                  e.relatedTarget instanceof HTMLElement &&
+                  e.relatedTarget.dataset.removeIndex === String(index)
+                ) {
+                  return;
+                }
+                commitDictionaryEntry(index);
+              }}
+              className="h-8 flex-1 text-sm"
+              aria-label={`Dictionary entry ${index + 1}`}
+            />
+            <Button
+              variant="ghost"
+              size="icon"
+              className="size-8 shrink-0 text-muted-foreground hover:text-destructive"
+              data-remove-index={index}
+              // Keep the click from blurring an empty input first, which would
+              // commit-splice this row and make onClick delete the next one.
+              onMouseDown={(e) => e.preventDefault()}
+              onClick={() => removeDictionaryEntry(index)}
+              aria-label={`Remove dictionary entry ${index + 1}`}
+            >
+              <HugeiconsIcon icon={Delete02Icon} className="size-3.5" />
+            </Button>
+          </div>
+        ))}
+        <div className="flex items-center gap-2 py-1.5">
+          <Input
+            value={newEntry}
+            onChange={(e) => setNewEntry(e.target.value)}
+            onKeyDown={(e) => {
+              if (e.key === "Enter") {
+                e.preventDefault();
+                handleAddEntry();
+              }
+            }}
+            placeholder="Jane Doe"
+            className="h-8 flex-1 text-sm"
+            aria-label="New dictionary entry"
+          />
+          <Button
+            variant="outline"
+            size="sm"
+            className="shrink-0"
+            onClick={handleAddEntry}
+            disabled={!newEntry.trim()}
+          >
+            <HugeiconsIcon icon={PlusSignIcon} className="mr-1.5 size-3.5" />
+            {t("settings.voice.dictionary.addEntry")}
+          </Button>
+        </div>
+      </div>
+    </div>
+  );
+}
diff --git a/studio/frontend/src/features/settings/components/embedding-model-combobox.tsx b/studio/frontend/src/features/settings/components/embedding-model-combobox.tsx
index b0e9a41b7d..28df663ec7 100644
--- a/studio/frontend/src/features/settings/components/embedding-model-combobox.tsx
+++ b/studio/frontend/src/features/settings/components/embedding-model-combobox.tsx
@@ -100,7 +100,7 @@ export function EmbeddingModelCombobox({
         autoHighlight={true}
       >
         <ComboboxInput
-          className="h-8 w-full font-mono [&_input]:text-[11px]"
+          className="h-8 w-full font-mono [&_input]:text-ui-11"
           placeholder={placeholder}
           aria-label={ariaLabel}
           disabled={disabled}
@@ -123,7 +123,7 @@ export function EmbeddingModelCombobox({
                   selectingRef.current = true;
                 }}
               >
-                <span className="truncate font-mono text-[11px]">{id}</span>
+                <span className="truncate font-mono text-ui-11">{id}</span>
               </ComboboxItem>
             )}
           </ComboboxList>
diff --git a/studio/frontend/src/features/settings/components/finetune-recipe.ts b/studio/frontend/src/features/settings/components/finetune-recipe.ts
new file mode 100644
index 0000000000..c98f422a35
--- /dev/null
+++ b/studio/frontend/src/features/settings/components/finetune-recipe.ts
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+// Settings Data tab glue: turn chat history into a fine-tuning JSONL, stage
+// it as a Data Recipe seed upload, and open a new recipe on that file.
+
+import { type FineTuneFormat, buildFineTuneJsonl } from "@/features/chat";
+import { saveRecipe } from "@/features/data-recipes/data/recipes-db";
+import { createEmptyRecipePayload } from "@/features/recipe-studio";
+import { inspectSeedUpload } from "@/features/recipe-studio/api";
+import { uploadTrainingDataset } from "@/features/training/api/datasets-api";
+import { useTrainingConfigStore } from "@/features/training/stores/training-config-store";
+import { toast } from "@/lib/toast";
+
+/** btoa cannot handle code points above latin-1, so encode UTF-8 bytes. */
+function base64FromString(value: string): string {
+  const bytes = new TextEncoder().encode(value);
+  let binary = "";
+  const CHUNK = 0x8000;
+  for (let i = 0; i < bytes.length; i += CHUNK) {
+    binary += String.fromCharCode(...bytes.subarray(i, i + CHUNK));
+  }
+  return btoa(binary);
+}
+
+/** Builds the JSONL, uploads it as a local recipe seed, and saves a new
+ *  recipe whose seed block points at the file. Returns the recipe id, or
+ *  null when there is nothing to export. */
+export async function createFineTuneRecipeFromChats(
+  format: FineTuneFormat = "openai",
+): Promise<string | null> {
+  const { lines, conversations } = await buildFineTuneJsonl(format);
+  if (conversations === 0) {
+    toast.info("No chats with a user and assistant exchange to export.");
+    return null;
+  }
+
+  const dateLabel = new Date().toISOString().slice(0, 10);
+  const suffix = format === "openai" ? "" : `-${format}`;
+  const filename = `chat-finetune${suffix}-${dateLabel}.jsonl`;
+  const inspected = await inspectSeedUpload({
+    filename,
+    // biome-ignore lint/style/useNamingConvention: api schema
+    content_base64: base64FromString(lines.join("\n")),
+    // biome-ignore lint/style/useNamingConvention: api schema
+    preview_size: 10,
+  });
+
+  const payload = createEmptyRecipePayload();
+  payload.recipe.seed_config = {
+    source: {
+      // biome-ignore lint/style/useNamingConvention: api schema
+      seed_type: "local",
+      path: inspected.resolved_path,
+    },
+    // biome-ignore lint/style/useNamingConvention: api schema
+    sampling_strategy: "ordered",
+    // biome-ignore lint/style/useNamingConvention: api schema
+    selection_strategy: null,
+  };
+  payload.ui.nodes = [{ id: "seed", x: 0, y: 0, width: 400 }];
+  payload.ui.seed_source_type = "local";
+  payload.ui.seed_columns = inspected.columns;
+  payload.ui.seed_preview_rows = inspected.preview_rows ?? [];
+  payload.ui.local_file_name = filename;
+
+  const record = await saveRecipe({
+    name: `Chat fine-tuning ${dateLabel}`,
+    payload,
+  });
+  return record.id;
+}
+
+/** Builds the JSONL, uploads it as a training dataset, and selects it in the
+ *  Train tab's config store so the Train page opens with it loaded. Returns
+ *  false when there is nothing to export. */
+export async function loadFineTuneDatasetInTrainTab(
+  format: FineTuneFormat = "openai",
+): Promise<boolean> {
+  const { lines, conversations } = await buildFineTuneJsonl(format);
+  if (conversations === 0) {
+    toast.info("No chats with a user and assistant exchange to export.");
+    return false;
+  }
+
+  const dateLabel = new Date().toISOString().slice(0, 10);
+  const suffix = format === "openai" ? "" : `-${format}`;
+  const file = new File(
+    [lines.join("\n")],
+    `chat-finetune${suffix}-${dateLabel}.jsonl`,
+    { type: "application/x-ndjson" },
+  );
+  const uploaded = await uploadTrainingDataset(file);
+  // Selecting also kicks off the dataset format check, so the Train tab
+  // shows the detected format as soon as it mounts.
+  useTrainingConfigStore.getState().selectLocalDataset(uploaded.stored_path);
+  return true;
+}
diff --git a/studio/frontend/src/features/settings/components/key-reveal-card.tsx b/studio/frontend/src/features/settings/components/key-reveal-card.tsx
index 34517cf3bd..80c93d7770 100644
--- a/studio/frontend/src/features/settings/components/key-reveal-card.tsx
+++ b/studio/frontend/src/features/settings/components/key-reveal-card.tsx
@@ -61,7 +61,7 @@ export function KeyRevealCard({
         />
       </button>
       <div className="flex items-center justify-between gap-3 pt-0.5">
-        <p className="text-[11px] text-muted-foreground">
+        <p className="text-ui-11 text-muted-foreground">
           {t("settings.apiKeys.copyNow")}
         </p>
         <Button
diff --git a/studio/frontend/src/features/settings/components/model-auto-switch-section.tsx b/studio/frontend/src/features/settings/components/model-auto-switch-section.tsx
index 5bebefa84c..aa6857cff5 100644
--- a/studio/frontend/src/features/settings/components/model-auto-switch-section.tsx
+++ b/studio/frontend/src/features/settings/components/model-auto-switch-section.tsx
@@ -14,6 +14,9 @@ import {
 import { SettingsRow } from "./settings-row";
 import { SettingsSection } from "./settings-section";
 
+// Mirrors MIN_AUTO_UNLOAD_IDLE_SECONDS in the backend settings store.
+const MIN_IDLE_SECONDS = 60;
+
 export function ModelAutoSwitchSection() {
   const t = useT();
   const [settings, setSettings] = useState<OpenAIAutoSwitchSettings | null>(
@@ -45,24 +48,32 @@ export function ModelAutoSwitchSection() {
     };
   }, [t]);
 
-  // Parse the idle-seconds draft to a non-negative integer; empty/invalid -> null.
+  // Parse the idle-seconds draft: 0 (off) or >= MIN_IDLE_SECONDS; else null.
   const parseIdleSeconds = (): number | null => {
     if (!draftIdleSeconds.trim()) {
       return null;
     }
     const parsed = Number(draftIdleSeconds);
-    return Number.isInteger(parsed) && parsed >= 0 ? parsed : null;
+    if (!Number.isInteger(parsed)) {
+      return null;
+    }
+    return parsed === 0 || parsed >= MIN_IDLE_SECONDS ? parsed : null;
   };
 
   const persist = async (
     enabled: boolean,
-    idleSeconds: number,
+    idleSeconds: number | undefined,
     syncDraft = true,
+    keepKv?: boolean,
   ) => {
     setIsSaving(true);
     setError(null);
     try {
-      const saved = await updateOpenAIAutoSwitchSettings(enabled, idleSeconds);
+      const saved = await updateOpenAIAutoSwitchSettings(
+        enabled,
+        idleSeconds,
+        keepKv,
+      );
       setSettings(saved);
       if (syncDraft) {
         setDraftIdleSeconds(String(saved.autoUnloadIdleSeconds));
@@ -101,6 +112,11 @@ export function ModelAutoSwitchSection() {
     void persist(true, idleSeconds);
   };
 
+  const handleKeepKvToggle = (keepKv: boolean) => {
+    if (!settings) return;
+    void persist(settings.enabled, undefined, false, keepKv);
+  };
+
   return (
     <SettingsSection title={t("settings.general.modelAutoSwitch.sectionTitle")}>
       <SettingsRow
@@ -160,6 +176,18 @@ export function ModelAutoSwitchSection() {
           ) : null}
         </div>
       </SettingsRow>
+      {settings?.idleUnloadActive ? (
+        <SettingsRow
+          label={t("settings.general.modelAutoSwitch.keepKv")}
+          description={t("settings.general.modelAutoSwitch.keepKvDescription")}
+        >
+          <Switch
+            checked={settings.autoUnloadKeepKv}
+            disabled={isSaving}
+            onCheckedChange={handleKeepKvToggle}
+          />
+        </SettingsRow>
+      ) : null}
     </SettingsSection>
   );
 }
diff --git a/studio/frontend/src/features/settings/components/recent-dictations-view.tsx b/studio/frontend/src/features/settings/components/recent-dictations-view.tsx
new file mode 100644
index 0000000000..f4c58818bd
--- /dev/null
+++ b/studio/frontend/src/features/settings/components/recent-dictations-view.tsx
@@ -0,0 +1,515 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+} from "@/components/ui/alert-dialog";
+import { Button } from "@/components/ui/button";
+import {
+  InputGroup,
+  InputGroupAddon,
+  InputGroupInput,
+} from "@/components/ui/input-group";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
+import {
+  deleteChatItem,
+  useChatRuntimeStore,
+  type SidebarItem,
+} from "@/features/chat";
+import { useT } from "@/i18n";
+import { copyToClipboard } from "@/lib/copy-to-clipboard";
+import { toast } from "@/lib/toast";
+import {
+  ArrowLeft01Icon,
+  Copy01Icon,
+  Delete02Icon,
+  Message01Icon,
+  Search01Icon,
+  ViewIcon,
+} from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
+import { useNavigate } from "@tanstack/react-router";
+import { useMemo, useState } from "react";
+import {
+  type RecentDictation,
+  useVoiceSettingsStore,
+} from "../stores/voice-settings-store";
+import { useSettingsDialogStore } from "../stores/settings-dialog-store";
+
+/** Dictations shown per page; "Show more" reveals the next page. */
+const PAGE_SIZE = 20;
+
+type PendingDelete =
+  | { kind: "one"; dictation: RecentDictation }
+  | { kind: "all" }
+  | null;
+
+type SortOrder = "newest" | "oldest" | "az";
+
+function formatDictationDate(ms: number): string {
+  return new Date(ms).toLocaleString(undefined, {
+    year: "numeric",
+    month: "short",
+    day: "numeric",
+    hour: "numeric",
+    minute: "2-digit",
+  });
+}
+
+export function RecentDictationsView({
+  selectedId,
+  onSelect,
+  onBack,
+}: {
+  selectedId: string | null;
+  onSelect: (id: string | null) => void;
+  onBack: () => void;
+}) {
+  const t = useT();
+  const recentDictations = useVoiceSettingsStore((s) => s.recentDictations);
+  const removeRecentDictation = useVoiceSettingsStore(
+    (s) => s.removeRecentDictation,
+  );
+  const clearRecentDictations = useVoiceSettingsStore(
+    (s) => s.clearRecentDictations,
+  );
+  const [pendingDelete, setPendingDelete] = useState<PendingDelete>(null);
+  const [search, setSearch] = useState("");
+  const [sortOrder, setSortOrder] = useState<SortOrder>("newest");
+  // Pagination is keyed to the search/sort inputs so changing either restarts
+  // from the first page without an effect.
+  const pageKey = `${sortOrder}::${search}`;
+  const [page, setPage] = useState({ key: pageKey, count: PAGE_SIZE });
+  const visibleCount = page.key === pageKey ? page.count : PAGE_SIZE;
+  const navigate = useNavigate();
+  const closeSettings = useSettingsDialogStore((s) => s.closeDialog);
+  const selected =
+    recentDictations.find((dictation) => dictation.id === selectedId) ?? null;
+
+  function openChat(chatId: string) {
+    closeSettings();
+    void navigate({ to: "/chat", search: { thread: chatId } });
+  }
+
+  const visible = useMemo(() => {
+    const query = search.trim().toLowerCase();
+    const filtered = query
+      ? recentDictations.filter((d) => d.text.toLowerCase().includes(query))
+      : recentDictations;
+    const sorted = [...filtered];
+    if (sortOrder === "oldest") {
+      sorted.sort((a, b) => a.at - b.at);
+    } else if (sortOrder === "az") {
+      sorted.sort((a, b) => a.text.localeCompare(b.text));
+    } else {
+      sorted.sort((a, b) => b.at - a.at);
+    }
+    return sorted;
+  }, [recentDictations, search, sortOrder]);
+
+  async function handleCopy(text: string) {
+    if (await copyToClipboard(text)) {
+      toast.success(t("settings.voice.recents.copied"));
+    } else {
+      toast.error(t("settings.voice.recents.copyFailed"));
+    }
+  }
+
+  function confirmDelete() {
+    try {
+      if (pendingDelete?.kind === "one") {
+        removeRecentDictation(pendingDelete.dictation.id);
+        if (pendingDelete.dictation.id === selectedId) {
+          onSelect(null);
+        }
+      } else if (pendingDelete?.kind === "all") {
+        clearRecentDictations();
+        onSelect(null);
+      }
+    } finally {
+      setPendingDelete(null);
+    }
+  }
+
+  // Delete a linked dictation together with the chat it was used in.
+  async function confirmDeleteWithChat() {
+    if (pendingDelete?.kind !== "one") {
+      return;
+    }
+    const dictation = pendingDelete.dictation;
+    setPendingDelete(null);
+    if (dictation.chatId) {
+      const item: SidebarItem = {
+        type: "single",
+        id: dictation.chatId,
+        title: "",
+        createdAt: 0,
+        updatedAt: 0,
+      };
+      try {
+        await deleteChatItem(
+          item,
+          useChatRuntimeStore.getState().activeThreadId ?? undefined,
+          () => {
+            // The deleted chat was open; leave the user on a fresh chat.
+            void navigate({
+              to: "/chat",
+              search: { new: crypto.randomUUID() },
+            });
+          },
+        );
+      } catch (error) {
+        toast.error(t("settings.voice.recents.deleteWithChatFailed"), {
+          description: error instanceof Error ? error.message : undefined,
+        });
+        return;
+      }
+    }
+    removeRecentDictation(dictation.id);
+    if (dictation.id === selectedId) {
+      onSelect(null);
+    }
+  }
+
+  return (
+    <div className="flex flex-col gap-6">
+      <header className="flex items-center gap-2">
+        <button
+          type="button"
+          onClick={() => (selected ? onSelect(null) : onBack())}
+          aria-label={
+            selected
+              ? t("settings.voice.recents.backToRecents")
+              : t("settings.voice.recents.backToVoice")
+          }
+          className="inline-flex size-7 shrink-0 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-muted hover:text-foreground focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
+        >
+          <HugeiconsIcon icon={ArrowLeft01Icon} className="size-4" />
+        </button>
+        <h1 className="font-heading text-xl font-semibold">
+          {t("settings.voice.title")}
+        </h1>
+      </header>
+
+      <div className="flex flex-col gap-1">
+        <h2 className="text-sm font-semibold">
+          {selected
+            ? t("settings.voice.recents.detailTitle")
+            : t("settings.voice.recents.sectionTitle")}
+        </h2>
+        <p className="text-xs text-muted-foreground">
+          {selected
+            ? formatDictationDate(selected.at)
+            : t("settings.voice.recents.pageDescription")}
+        </p>
+      </div>
+
+      {selected ? (
+        <div className="flex min-h-0 flex-col gap-4">
+          <article className="rounded-lg border border-border/60 bg-muted/20 p-4">
+            <p className="whitespace-pre-wrap break-words text-sm leading-relaxed text-foreground select-text">
+              {selected.text}
+            </p>
+          </article>
+          <div className="flex justify-end gap-2">
+            {selected.chatId ? (
+              <Button
+                variant="outline"
+                size="sm"
+                onClick={() => openChat(selected.chatId as string)}
+              >
+                <HugeiconsIcon
+                  icon={Message01Icon}
+                  className="mr-1.5 size-3.5"
+                />
+                {t("settings.voice.recents.openChat")}
+              </Button>
+            ) : null}
+            <Button
+              variant="outline"
+              size="sm"
+              onClick={async () => {
+                await handleCopy(selected.text);
+              }}
+            >
+              <HugeiconsIcon icon={Copy01Icon} className="mr-1.5 size-3.5" />
+              {t("settings.voice.recents.copy")}
+            </Button>
+            <Button
+              variant="outline"
+              size="sm"
+              onClick={() =>
+                setPendingDelete({ kind: "one", dictation: selected })
+              }
+              className="text-destructive hover:border-destructive/60 hover:text-destructive"
+            >
+              <HugeiconsIcon icon={Delete02Icon} className="mr-1.5 size-3.5" />
+              {t("settings.voice.recents.delete")}
+            </Button>
+          </div>
+        </div>
+      ) : recentDictations.length === 0 ? (
+        <p className="py-8 text-center text-sm text-muted-foreground">
+          {t("settings.voice.recents.empty")}
+        </p>
+      ) : (
+        <div className="flex flex-col gap-3">
+          <div className="flex items-center gap-2">
+            <InputGroup className="h-8 flex-1">
+              <InputGroupAddon align="inline-start">
+                <HugeiconsIcon
+                  icon={Search01Icon}
+                  strokeWidth={2}
+                  className="size-3.5 text-muted-foreground"
+                />
+              </InputGroupAddon>
+              <InputGroupInput
+                value={search}
+                onChange={(e) => setSearch(e.target.value)}
+                placeholder={t("settings.voice.recents.searchPlaceholder")}
+                aria-label={t("settings.voice.recents.searchPlaceholder")}
+                className="text-sm"
+              />
+            </InputGroup>
+            <Select
+              value={sortOrder}
+              onValueChange={(value) => setSortOrder(value as SortOrder)}
+            >
+              <SelectTrigger
+                size="sm"
+                className="w-36 shrink-0"
+                aria-label={t("settings.voice.recents.sortLabel")}
+              >
+                <SelectValue />
+              </SelectTrigger>
+              <SelectContent>
+                <SelectItem value="newest">
+                  {t("settings.voice.recents.sortNewest")}
+                </SelectItem>
+                <SelectItem value="oldest">
+                  {t("settings.voice.recents.sortOldest")}
+                </SelectItem>
+                <SelectItem value="az">
+                  {t("settings.voice.recents.sortAlpha")}
+                </SelectItem>
+              </SelectContent>
+            </Select>
+            <Button
+              variant="outline"
+              size="sm"
+              onClick={() => setPendingDelete({ kind: "all" })}
+              className="shrink-0 text-destructive hover:border-destructive/60 hover:text-destructive"
+            >
+              <HugeiconsIcon icon={Delete02Icon} className="mr-1.5 size-3.5" />
+              {t("settings.voice.recents.clear")}
+            </Button>
+          </div>
+
+          {visible.length === 0 ? (
+            <p className="py-8 text-center text-sm text-muted-foreground">
+              {t("settings.voice.recents.noMatches")}
+            </p>
+          ) : (
+            <div className="flex flex-col">
+              <div className="flex items-center gap-4 border-b border-border/60 px-1 pb-2 text-xs font-semibold text-foreground">
+                <span className="min-w-0 flex-1">
+                  {t("settings.voice.recents.dictationColumn")}
+                </span>
+                <span className="hidden w-40 shrink-0 items-center gap-1.5 sm:flex">
+                  {/* Spacer matching the row's chat-link icon slot so the
+                      header starts exactly where the dates start. */}
+                  <span className="size-3.5 shrink-0" />
+                  {t("settings.voice.recents.dateColumn")}
+                </span>
+                <span className="w-24 shrink-0" />
+              </div>
+              {visible.slice(0, visibleCount).map((dictation) => (
+                <div
+                  key={dictation.id}
+                  className="group flex items-stretch gap-2 border-b border-border/40 last:border-0"
+                >
+                  <button
+                    type="button"
+                    onClick={() =>
+                      dictation.chatId
+                        ? openChat(dictation.chatId)
+                        : onSelect(dictation.id)
+                    }
+                    aria-label={
+                      dictation.chatId
+                        ? t("settings.voice.recents.openChat")
+                        : t("settings.voice.recents.view")
+                    }
+                    className="flex min-w-0 flex-1 items-start gap-4 rounded-md px-1 py-3 text-left transition-colors hover:bg-muted/50 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
+                  >
+                    <span className="min-w-0 flex-1">
+                      <span className="line-clamp-3 whitespace-pre-wrap break-words text-sm text-foreground">
+                        {dictation.text}
+                      </span>
+                      <span className="mt-1 flex items-center gap-1.5 text-xs text-muted-foreground sm:hidden">
+                        {dictation.chatId ? (
+                          <HugeiconsIcon
+                            icon={Message01Icon}
+                            className="size-3"
+                          />
+                        ) : null}
+                        {formatDictationDate(dictation.at)}
+                      </span>
+                    </span>
+                    <span className="hidden w-40 shrink-0 items-center gap-1.5 text-left text-xs text-muted-foreground tabular-nums sm:flex">
+                      {/* Fixed icon slot keeps every date starting at the
+                          same column whether or not a chat is linked. */}
+                      <span className="flex size-3.5 shrink-0 items-center justify-center">
+                        {dictation.chatId ? (
+                          <HugeiconsIcon
+                            icon={Message01Icon}
+                            className="size-3.5"
+                            aria-label={t("settings.voice.recents.openChat")}
+                          />
+                        ) : null}
+                      </span>
+                      <span className="whitespace-nowrap">
+                        {formatDictationDate(dictation.at)}
+                      </span>
+                    </span>
+                  </button>
+                  <span className="flex w-24 shrink-0 items-center justify-end gap-1">
+                    {dictation.chatId ? (
+                      <button
+                        type="button"
+                        onClick={() => onSelect(dictation.id)}
+                        aria-label={t("settings.voice.recents.view")}
+                        title={t("settings.voice.recents.view")}
+                        className="inline-flex size-7 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-muted hover:text-foreground focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
+                      >
+                        <HugeiconsIcon
+                          icon={ViewIcon}
+                          strokeWidth={1.75}
+                          className="size-4"
+                        />
+                      </button>
+                    ) : null}
+                    <button
+                      type="button"
+                      onClick={async () => {
+                        await handleCopy(dictation.text);
+                      }}
+                      aria-label={t("settings.voice.recents.copy")}
+                      title={t("settings.voice.recents.copy")}
+                      className="inline-flex size-7 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-muted hover:text-foreground focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
+                    >
+                      <HugeiconsIcon
+                        icon={Copy01Icon}
+                        strokeWidth={1.75}
+                        className="size-4"
+                      />
+                    </button>
+                    <button
+                      type="button"
+                      onClick={() =>
+                        setPendingDelete({ kind: "one", dictation })
+                      }
+                      aria-label={t("settings.voice.recents.delete")}
+                      title={t("settings.voice.recents.delete")}
+                      className="inline-flex size-7 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-destructive/10 hover:text-destructive focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
+                    >
+                      <HugeiconsIcon
+                        icon={Delete02Icon}
+                        strokeWidth={1.75}
+                        className="size-4"
+                      />
+                    </button>
+                  </span>
+                </div>
+              ))}
+            </div>
+          )}
+
+          {visible.length > visibleCount ? (
+            <div className="flex justify-center pt-1">
+              <Button
+                variant="outline"
+                size="sm"
+                onClick={() =>
+                  setPage({ key: pageKey, count: visibleCount + PAGE_SIZE })
+                }
+              >
+                {t("settings.voice.recents.showMore", {
+                  count: visible.length - visibleCount,
+                })}
+              </Button>
+            </div>
+          ) : null}
+        </div>
+      )}
+
+      <AlertDialog
+        open={pendingDelete !== null}
+        onOpenChange={(open) => {
+          if (!open) {
+            setPendingDelete(null);
+          }
+        }}
+      >
+        <AlertDialogContent>
+          <AlertDialogHeader>
+            <AlertDialogTitle>
+              {pendingDelete?.kind === "all"
+                ? t("settings.voice.recents.clearTitle")
+                : t("settings.voice.recents.deleteTitle")}
+            </AlertDialogTitle>
+            <AlertDialogDescription>
+              {pendingDelete?.kind === "all"
+                ? t("settings.voice.recents.clearDescription")
+                : pendingDelete?.kind === "one" &&
+                    pendingDelete.dictation.chatId
+                  ? t("settings.voice.recents.deleteLinkedDescription")
+                  : t("settings.voice.recents.deleteDescription")}
+            </AlertDialogDescription>
+          </AlertDialogHeader>
+          <AlertDialogFooter>
+            <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
+            {pendingDelete?.kind === "one" && pendingDelete.dictation.chatId ? (
+              <AlertDialogAction
+                variant="outline"
+                className="text-destructive hover:border-destructive/60 hover:text-destructive"
+                onClick={(event) => {
+                  // Close only through state so the dismissal can't race a
+                  // click on whatever ends up under the pointer.
+                  event.preventDefault();
+                  void confirmDeleteWithChat();
+                }}
+              >
+                {t("settings.voice.recents.deleteWithChat")}
+              </AlertDialogAction>
+            ) : null}
+            <AlertDialogAction
+              variant="destructive"
+              onClick={(event) => {
+                event.preventDefault();
+                confirmDelete();
+              }}
+            >
+              {pendingDelete?.kind === "all"
+                ? t("settings.voice.recents.clearConfirm")
+                : t("common.delete")}
+            </AlertDialogAction>
+          </AlertDialogFooter>
+        </AlertDialogContent>
+      </AlertDialog>
+    </div>
+  );
+}
diff --git a/studio/frontend/src/features/settings/components/sidebar-menu-customizer.tsx b/studio/frontend/src/features/settings/components/sidebar-menu-customizer.tsx
index e7e6576eef..bd8ca69b66 100644
--- a/studio/frontend/src/features/settings/components/sidebar-menu-customizer.tsx
+++ b/studio/frontend/src/features/settings/components/sidebar-menu-customizer.tsx
@@ -45,7 +45,7 @@ function FixedRow({ icon, label }: { icon: IconSvgElement; label: string }) {
       {/* Spacer where the drag handle sits on movable rows. */}
       <span className="size-4" aria-hidden="true" />
       <HugeiconsIcon icon={icon} strokeWidth={1.75} className="size-4" />
-      <span className="text-[13px]">{label}</span>
+      <span className="text-ui-13">{label}</span>
     </div>
   );
 }
@@ -93,7 +93,7 @@ function MovableRow({ item }: { item: SidebarMenuItemPref }) {
         strokeWidth={1.75}
         className="size-4 text-foreground/80"
       />
-      <span className="text-[13px] text-foreground">{t(meta.labelKey)}</span>
+      <span className="text-ui-13 text-foreground">{t(meta.labelKey)}</span>
       <Switch
         className="ml-auto"
         checked={item.visible}
diff --git a/studio/frontend/src/features/settings/components/update-studio-instructions.tsx b/studio/frontend/src/features/settings/components/update-studio-instructions.tsx
index e7ec970cc0..9854fa54e4 100644
--- a/studio/frontend/src/features/settings/components/update-studio-instructions.tsx
+++ b/studio/frontend/src/features/settings/components/update-studio-instructions.tsx
@@ -91,7 +91,7 @@ function CopyableCommand({
         type="text"
         readOnly={true}
         value={command}
-        className="min-w-0 flex-1 bg-transparent px-2 py-1.5 font-mono text-[11px] text-foreground outline-none"
+        className="min-w-0 flex-1 bg-transparent px-2 py-1.5 font-mono text-ui-11 text-foreground outline-none"
         title={command}
         aria-label={t("settings.about.update.commandText", {
           label: copyLabel,
@@ -187,7 +187,7 @@ function ShellToggleButton({
       onClick={onClick}
       aria-pressed={active}
       className={cn(
-        "inline-flex h-8 items-center justify-center rounded-full px-3.5 text-[12px] font-medium transition-colors",
+        "inline-flex h-8 items-center justify-center rounded-full px-3.5 text-ui-12 font-medium transition-colors",
         active
           ? "hub-tab-toggle-pill text-foreground"
           : "cursor-pointer text-muted-foreground hover:text-foreground",
diff --git a/studio/frontend/src/features/settings/components/uploaded-files-dialog.tsx b/studio/frontend/src/features/settings/components/uploaded-files-dialog.tsx
new file mode 100644
index 0000000000..cb5ed0ad34
--- /dev/null
+++ b/studio/frontend/src/features/settings/components/uploaded-files-dialog.tsx
@@ -0,0 +1,644 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+} from "@/components/ui/alert-dialog";
+import { Spinner } from "@/components/ui/spinner";
+import {
+  type ChatAttachmentRecord,
+  deleteChatAttachment,
+  emitChatAttachmentDeleted,
+  fetchChatAttachmentBlob,
+  listChatAttachments,
+} from "@/features/chat";
+import {
+  deleteDocument,
+  getDocumentFileUrl,
+  listAllDocuments,
+  type UploadedDocument,
+} from "@/features/rag";
+import { toast } from "@/lib/toast";
+import {
+  ArrowUpRight01Icon,
+  Delete02Icon,
+  File02Icon,
+} from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
+import { useNavigate } from "@tanstack/react-router";
+import { type ReactNode, useEffect, useRef, useState } from "react";
+import { useSettingsDialogStore } from "../stores/settings-dialog-store";
+
+function formatUploadedAt(value: string | number | null | undefined): string {
+  if (value === null || value === undefined || value === "") return "-";
+  // Chat attachments carry ms epoch numbers; RAG documents carry SQLite
+  // ISO-ish strings (no timezone). Unparseable strings fall through raw.
+  const parsed = new Date(value);
+  if (Number.isNaN(parsed.getTime())) return String(value);
+  return parsed.toLocaleDateString(undefined, {
+    year: "numeric",
+    month: "long",
+    day: "numeric",
+  });
+}
+
+function formatSize(bytes: number | null | undefined): string {
+  if (bytes === null || bytes === undefined) return "-";
+  if (bytes < 1024) return `${bytes} B`;
+  const units = ["KB", "MB", "GB"];
+  let value = bytes;
+  let unit = "B";
+  for (const next of units) {
+    if (value < 1024) break;
+    value /= 1024;
+    unit = next;
+  }
+  return `${value >= 10 ? Math.round(value) : value.toFixed(1)} ${unit}`;
+}
+
+function ragLocationLabel(doc: UploadedDocument): string {
+  if (doc.kbId) return doc.kbName ? `KB · ${doc.kbName}` : "Knowledge base";
+  if (doc.projectId) {
+    return doc.projectName ? `Project · ${doc.projectName}` : "Project";
+  }
+  if (doc.threadId) return "Chat files (RAG)";
+  return "-";
+}
+
+/** Short uppercase file-type label from the filename extension, falling back
+ *  to the content-type subtype (e.g. "image/webp" gives WEBP). */
+function fileTypeLabel(
+  name: string,
+  contentType?: string | null,
+): string | null {
+  const dot = name.lastIndexOf(".");
+  const ext = dot > 0 ? name.slice(dot + 1).trim() : "";
+  if (ext && ext.length <= 5) return ext.toUpperCase();
+  const subtype = contentType?.split("/")[1]?.split("+")[0]?.trim();
+  return subtype && subtype.length <= 10 ? subtype.toUpperCase() : null;
+}
+
+/** Lazy image thumbnail for a chat attachment; a file icon until it loads.
+ *  The stored blob only downloads once the row scrolls into view, so a long
+ *  history of screenshots does not fetch every image on open. */
+function ChatImageThumb({
+  messageId,
+  attachmentId,
+}: {
+  messageId: string;
+  attachmentId: string;
+}) {
+  const [src, setSrc] = useState<string | null>(null);
+  const [visible, setVisible] = useState(false);
+  const holderRef = useRef<HTMLSpanElement>(null);
+
+  useEffect(() => {
+    const el = holderRef.current;
+    if (!el) return;
+    if (typeof IntersectionObserver === "undefined") {
+      return;
+    }
+    const observer = new IntersectionObserver((entries) => {
+      if (entries.some((entry) => entry.isIntersecting)) {
+        setVisible(true);
+        observer.disconnect();
+      }
+    });
+    observer.observe(el);
+    return () => observer.disconnect();
+  }, []);
+
+  useEffect(() => {
+    if (!visible) return;
+    let cancelled = false;
+    let url: string | null = null;
+    fetchChatAttachmentBlob(messageId, attachmentId)
+      .then((blob) => {
+        if (cancelled) return;
+        url = URL.createObjectURL(blob);
+        setSrc(url);
+      })
+      .catch(() => {
+        // Keep the file icon on failure.
+      });
+    return () => {
+      cancelled = true;
+      if (url) URL.revokeObjectURL(url);
+    };
+  }, [visible, messageId, attachmentId]);
+
+  if (!src) {
+    return (
+      <span
+        ref={holderRef}
+        className="flex h-full w-full items-center justify-center"
+      >
+        <FileIconThumb />
+      </span>
+    );
+  }
+  return <img src={src} alt="" className="h-full w-full object-cover" />;
+}
+
+function FileIconThumb() {
+  return (
+    <HugeiconsIcon
+      icon={File02Icon}
+      strokeWidth={1.75}
+      className="size-4 text-muted-foreground"
+    />
+  );
+}
+
+/** One display row: a RAG document or a chat message attachment. */
+interface UploadedFileRow {
+  key: string;
+  source: "rag" | "chat";
+  name: string;
+  location: string;
+  sizeBytes?: number | null;
+  createdAt?: string | number | null;
+  failed?: boolean;
+  /** Epoch ms for sorting; rows with unknown dates sort last. */
+  sortTime: number;
+  typeLabel: string | null;
+  /** Image rows render a thumbnail; others show a file icon. */
+  thumb: ReactNode;
+  /** Chat rows link back to their thread. */
+  threadId?: string | null;
+  /** Compare-chat rows navigate by pair id instead of opening one pane alone. */
+  pairId?: string | null;
+  open: () => Promise<void>;
+  remove: () => Promise<void>;
+  deleteDescription: string;
+}
+
+function toSortTime(value: string | number | null | undefined): number {
+  if (value === null || value === undefined || value === "") return 0;
+  const parsed = new Date(value).getTime();
+  return Number.isNaN(parsed) ? 0 : parsed;
+}
+
+// Safari and Firefox block window.open after an await (the user gesture is
+// gone), so open a blank tab synchronously and point it at the URL once
+// resolved. A blocked synchronous open is surfaced instead of silently losing
+// the file after the asynchronous URL lookup.
+async function openResolvedUrl(resolve: () => Promise<string>): Promise<void> {
+  const win = window.open("", "_blank");
+  if (!win) {
+    throw new Error(
+      "Your browser blocked the new tab. Allow popups and retry.",
+    );
+  }
+  win.opener = null;
+  let url: string;
+  try {
+    url = await resolve();
+  } catch (err) {
+    win.close();
+    throw err;
+  }
+  win.location.replace(url);
+}
+
+function ragRow(doc: UploadedDocument): UploadedFileRow {
+  return {
+    key: `rag-${doc.id}`,
+    source: "rag",
+    name: doc.filename,
+    location: ragLocationLabel(doc),
+    sizeBytes: doc.sizeBytes,
+    createdAt: doc.createdAt,
+    failed: doc.status === "failed",
+    sortTime: toSortTime(doc.createdAt),
+    typeLabel: fileTypeLabel(doc.filename),
+    // RAG uploads are documents (pdf, txt, md, docx, html), not images.
+    thumb: <FileIconThumb />,
+    open: () => openResolvedUrl(() => getDocumentFileUrl(doc.id)),
+    remove: async () => {
+      await deleteDocument(doc.id, doc.projectId);
+    },
+    deleteDescription:
+      "The file and its indexed content are removed. This cannot be undone.",
+  };
+}
+
+function chatAttachmentRow(att: ChatAttachmentRecord): UploadedFileRow {
+  const isImage =
+    att.type === "image" || Boolean(att.contentType?.startsWith("image/"));
+  return {
+    key: `chat-${att.messageId}-${att.id}`,
+    source: "chat",
+    name: att.name,
+    location: att.threadTitle ? `Chat · ${att.threadTitle}` : "Chat",
+    sizeBytes: att.sizeBytes,
+    createdAt: att.createdAt,
+    sortTime: toSortTime(att.createdAt),
+    typeLabel: fileTypeLabel(att.name, att.contentType),
+    threadId: att.threadId,
+    pairId: att.pairId,
+    thumb: isImage ? (
+      <ChatImageThumb messageId={att.messageId} attachmentId={att.id} />
+    ) : (
+      <FileIconThumb />
+    ),
+    open: () =>
+      openResolvedUrl(async () => {
+        const blob = await fetchChatAttachmentBlob(att.messageId, att.id);
+        const url = URL.createObjectURL(blob);
+        // Give the new tab time to load the blob before revoking.
+        setTimeout(() => URL.revokeObjectURL(url), 60_000);
+        return url;
+      }),
+    remove: async () => {
+      await deleteChatAttachment(att.messageId, att.id);
+      // Patch any loaded runtime copy so a later repo sync cannot write the
+      // deleted attachment back to storage.
+      emitChatAttachmentDeleted({
+        messageId: att.messageId,
+        attachmentId: att.id,
+      });
+    },
+    deleteDescription:
+      "The attachment is removed from its chat message; the message text is kept. This cannot be undone.",
+  };
+}
+
+type SourceLoad<T> = {
+  status: "loading" | "ready" | "error";
+  data: T;
+  error: string | null;
+};
+
+function errorMessage(error: unknown, fallback: string): string {
+  return error instanceof Error ? error.message : fallback;
+}
+
+/** Inline settings page listing uploaded files from each available source. */
+export function UploadedFilesView() {
+  const [ragFiles, setRagFiles] = useState<SourceLoad<UploadedDocument[]>>({
+    status: "loading",
+    data: [],
+    error: null,
+  });
+  const [chatFiles, setChatFiles] = useState<
+    SourceLoad<ChatAttachmentRecord[]>
+  >({ status: "loading", data: [], error: null });
+  const [chatNextOffset, setChatNextOffset] = useState<number | null>(null);
+  const [loadingMore, setLoadingMore] = useState(false);
+  const [confirmingDelete, setConfirmingDelete] =
+    useState<UploadedFileRow | null>(null);
+  const navigate = useNavigate();
+
+  const rows = [
+    ...ragFiles.data.map(ragRow),
+    ...chatFiles.data.map(chatAttachmentRow),
+  ].sort((a, b) => b.sortTime - a.sortTime);
+
+  // Jump to the chat thread the attachment lives in, closing the settings
+  // dialog so the thread is actually visible.
+  function goToChat(row: UploadedFileRow) {
+    if (!row.threadId) return;
+    useSettingsDialogStore.getState().closeDialog();
+    if (row.pairId) {
+      void navigate({ to: "/chat", search: { compare: row.pairId } });
+    } else {
+      void navigate({ to: "/chat", search: { thread: row.threadId } });
+    }
+  }
+
+  useEffect(() => {
+    let cancelled = false;
+    void listAllDocuments().then(
+      (data) => {
+        if (!cancelled) setRagFiles({ status: "ready", data, error: null });
+      },
+      (error: unknown) => {
+        if (!cancelled) {
+          setRagFiles({
+            status: "error",
+            data: [],
+            error: errorMessage(error, "Failed to load RAG documents"),
+          });
+        }
+      },
+    );
+    void listChatAttachments().then(
+      (page) => {
+        if (!cancelled) {
+          setChatFiles({
+            status: "ready",
+            data: page.attachments,
+            error: null,
+          });
+          setChatNextOffset(page.nextOffset);
+        }
+      },
+      (error: unknown) => {
+        if (!cancelled) {
+          setChatFiles({
+            status: "error",
+            data: [],
+            error: errorMessage(error, "Failed to load chat attachments"),
+          });
+        }
+      },
+    );
+    return () => {
+      cancelled = true;
+    };
+  }, []);
+
+  function retryRagFiles() {
+    setRagFiles((current) => ({ ...current, status: "loading", error: null }));
+    void listAllDocuments().then(
+      (data) => setRagFiles({ status: "ready", data, error: null }),
+      (error: unknown) =>
+        setRagFiles((current) => ({
+          ...current,
+          status: "error",
+          error: errorMessage(error, "Failed to load RAG documents"),
+        })),
+    );
+  }
+
+  async function loadChatPage(offset: number, append: boolean) {
+    setLoadingMore(true);
+    setChatFiles((current) => ({ ...current, status: "loading", error: null }));
+    try {
+      const page = await listChatAttachments(offset);
+      setChatFiles((current) => ({
+        status: "ready",
+        data: append
+          ? [
+              ...current.data,
+              ...page.attachments.filter(
+                (incoming) =>
+                  !current.data.some(
+                    (existing) =>
+                      existing.id === incoming.id &&
+                      existing.messageId === incoming.messageId,
+                  ),
+              ),
+            ]
+          : page.attachments,
+        error: null,
+      }));
+      setChatNextOffset(page.nextOffset);
+    } catch (error) {
+      setChatFiles((current) => ({
+        ...current,
+        status: "error",
+        error: errorMessage(error, "Failed to load chat attachments"),
+      }));
+    } finally {
+      setLoadingMore(false);
+    }
+  }
+
+  function retryChatFiles() {
+    const append = chatFiles.data.length > 0 && chatNextOffset !== null;
+    void loadChatPage(append ? chatNextOffset : 0, append);
+  }
+
+  async function handleOpen(row: UploadedFileRow) {
+    try {
+      await row.open();
+    } catch (err) {
+      toast.error("Failed to open file", {
+        description: err instanceof Error ? err.message : undefined,
+      });
+    }
+  }
+
+  async function handleDelete(row: UploadedFileRow) {
+    // Offset pages and destructive mutations must not race: a deletion shifts
+    // the boundary used by an in-flight page request.
+    if (loadingMore) return;
+    try {
+      await row.remove();
+      if (row.source === "rag") {
+        setRagFiles((current) => ({
+          ...current,
+          data: current.data.filter((doc) => `rag-${doc.id}` !== row.key),
+        }));
+      } else {
+        setChatFiles((current) => ({
+          ...current,
+          data: current.data.filter(
+            (attachment) =>
+              `chat-${attachment.messageId}-${attachment.id}` !== row.key,
+          ),
+        }));
+        // Offset pagination is relative to the current server inventory. A
+        // deletion before the next page shifts every later row back by one.
+        setChatNextOffset((current) =>
+          current === null ? null : Math.max(0, current - 1),
+        );
+      }
+      toast.success("File deleted");
+    } catch (err) {
+      toast.error("Failed to delete file", {
+        description: err instanceof Error ? err.message : undefined,
+      });
+    }
+  }
+
+  return (
+    <div className="flex flex-col gap-4">
+      {ragFiles.status === "error" ? (
+        <div className="flex flex-wrap items-center justify-between gap-2 rounded-md border border-destructive/30 bg-destructive/5 px-3 py-2 text-sm">
+          <span>RAG documents unavailable: {ragFiles.error}</span>
+          <button
+            type="button"
+            onClick={retryRagFiles}
+            className="font-medium underline underline-offset-2"
+          >
+            Retry
+          </button>
+        </div>
+      ) : null}
+      {chatFiles.status === "error" ? (
+        <div className="flex flex-wrap items-center justify-between gap-2 rounded-md border border-destructive/30 bg-destructive/5 px-3 py-2 text-sm">
+          <span>Chat attachments unavailable: {chatFiles.error}</span>
+          <button
+            type="button"
+            onClick={retryChatFiles}
+            className="font-medium underline underline-offset-2"
+          >
+            Retry
+          </button>
+        </div>
+      ) : null}
+
+      {rows.length === 0 &&
+      (ragFiles.status === "loading" || chatFiles.status === "loading") ? (
+        <div className="flex justify-center py-8">
+          <Spinner className="size-5 text-muted-foreground" />
+        </div>
+      ) : rows.length === 0 &&
+        ragFiles.status !== "error" &&
+        chatFiles.status !== "error" ? (
+        <p className="py-8 text-center text-sm text-muted-foreground">
+          No uploaded files.
+        </p>
+      ) : rows.length > 0 ? (
+        <div>
+          <div className="hidden items-center gap-3 border-b border-border/60 px-1 pb-2 text-xs font-semibold text-foreground sm:flex">
+            <span className="flex-1">Name</span>
+            <span className="w-36 shrink-0">Location</span>
+            <span className="w-24 shrink-0">Uploaded</span>
+            <span className="w-16 shrink-0" />
+          </div>
+          {rows.map((row) => (
+            <div
+              key={row.key}
+              className="group flex flex-wrap items-center gap-x-3 gap-y-1 border-b border-border/40 px-1 py-2.5 text-sm last:border-0 sm:flex-nowrap"
+            >
+              {/* Clicking the file jumps to its chat; files without one
+                open directly. The theme scales rounded-md up to a near
+                circle at this size, so the thumb pins a small radius. */}
+              <button
+                type="button"
+                onClick={() =>
+                  row.threadId ? goToChat(row) : void handleOpen(row)
+                }
+                title={
+                  row.threadId ? `Go to ${row.location}` : `Open ${row.name}`
+                }
+                className="group/name flex min-w-0 flex-1 basis-[calc(100%-5rem)] items-center gap-2.5 overflow-hidden text-left sm:basis-auto"
+              >
+                <span className="flex size-8 shrink-0 items-center justify-center overflow-hidden rounded-[7px] border border-border/50 bg-muted/40">
+                  {row.thumb}
+                </span>
+                <span className="flex min-w-0 flex-1 flex-col">
+                  <span className="flex min-w-0 items-center gap-2">
+                    {/* Floor keeps the name visible when the chip and fixed
+                      columns squeeze the cell at narrow widths. */}
+                    <span className="min-w-[3.5rem] truncate underline-offset-2 group-hover/name:underline">
+                      {row.name}
+                    </span>
+                    {row.typeLabel ? (
+                      <span className="shrink-0 rounded-md bg-black/[0.06] px-1.5 py-px text-ui-9 font-medium uppercase tracking-wide text-muted-foreground dark:bg-white/[0.1]">
+                        {row.typeLabel}
+                      </span>
+                    ) : null}
+                    {row.failed ? (
+                      <span className="shrink-0 text-xs text-destructive">
+                        failed
+                      </span>
+                    ) : null}
+                  </span>
+                  <span className="text-xs text-muted-foreground tabular-nums">
+                    {formatSize(row.sizeBytes)}
+                  </span>
+                </span>
+              </button>
+              {row.threadId ? (
+                <button
+                  type="button"
+                  onClick={() => goToChat(row)}
+                  title={`Go to ${row.location}`}
+                  className="order-3 w-full truncate pl-10 text-left text-muted-foreground underline-offset-2 transition-colors hover:text-foreground hover:underline sm:order-none sm:w-36 sm:pl-0"
+                >
+                  {row.location}
+                </button>
+              ) : (
+                <span
+                  className="order-3 w-full truncate pl-10 text-muted-foreground sm:order-none sm:w-36 sm:pl-0"
+                  title={row.location}
+                >
+                  {row.location}
+                </span>
+              )}
+              <span className="order-4 w-full pl-10 text-muted-foreground tabular-nums sm:order-none sm:w-24 sm:pl-0">
+                {formatUploadedAt(row.createdAt)}
+              </span>
+              <span className="flex w-16 shrink-0 items-center justify-end gap-1">
+                <button
+                  type="button"
+                  onClick={() => void handleOpen(row)}
+                  aria-label={`Open ${row.name}`}
+                  title="Open"
+                  className="inline-flex size-7 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-muted hover:text-foreground"
+                >
+                  <HugeiconsIcon
+                    icon={ArrowUpRight01Icon}
+                    strokeWidth={1.75}
+                    className="size-4"
+                  />
+                </button>
+                <button
+                  type="button"
+                  disabled={loadingMore}
+                  onClick={() => setConfirmingDelete(row)}
+                  aria-label={`Delete ${row.name}`}
+                  title="Delete"
+                  className="inline-flex size-7 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-destructive/10 hover:text-destructive disabled:cursor-wait disabled:opacity-50"
+                >
+                  <HugeiconsIcon
+                    icon={Delete02Icon}
+                    strokeWidth={1.75}
+                    className="size-4"
+                  />
+                </button>
+              </span>
+            </div>
+          ))}
+          {chatNextOffset !== null ? (
+            <div className="flex justify-center pt-3">
+              <button
+                type="button"
+                disabled={loadingMore}
+                onClick={() => void loadChatPage(chatNextOffset, true)}
+                className="rounded-md border border-border px-3 py-1.5 text-sm font-medium hover:bg-muted disabled:cursor-wait disabled:opacity-60"
+              >
+                {loadingMore ? "Loading..." : "Load more chat attachments"}
+              </button>
+            </div>
+          ) : null}
+        </div>
+      ) : null}
+
+      <AlertDialog
+        open={confirmingDelete !== null}
+        onOpenChange={(o) => {
+          if (!o) setConfirmingDelete(null);
+        }}
+      >
+        <AlertDialogContent>
+          <AlertDialogHeader>
+            <AlertDialogTitle>Delete file</AlertDialogTitle>
+            <AlertDialogDescription>
+              Delete{" "}
+              <span className="font-medium text-foreground">
+                &quot;{confirmingDelete?.name}&quot;
+              </span>
+              ? {confirmingDelete?.deleteDescription}
+            </AlertDialogDescription>
+          </AlertDialogHeader>
+          <AlertDialogFooter>
+            <AlertDialogCancel>Cancel</AlertDialogCancel>
+            <AlertDialogAction
+              variant="destructive"
+              onClick={() => {
+                const row = confirmingDelete;
+                setConfirmingDelete(null);
+                if (row) void handleDelete(row);
+              }}
+            >
+              Delete
+            </AlertDialogAction>
+          </AlertDialogFooter>
+        </AlertDialogContent>
+      </AlertDialog>
+    </div>
+  );
+}
diff --git a/studio/frontend/src/features/settings/components/usage-examples.tsx b/studio/frontend/src/features/settings/components/usage-examples.tsx
index 86125585cc..ade181f632 100644
--- a/studio/frontend/src/features/settings/components/usage-examples.tsx
+++ b/studio/frontend/src/features/settings/components/usage-examples.tsx
@@ -229,12 +229,12 @@ curl.exe ${base}/v1/chat/completions \`
 }
 
 // A second OpenAI call naming a different downloaded GGUF: with auto-switch on,
-// Studio loads it before serving, so the model field selects the served model.
+// Unsloth loads it before serving, so the model field selects the served model.
 function pythonSwitchDemo(): string {
   return `
 
 # "Switch model by request" is on: replace the model below with another GGUF you
-# have downloaded and Studio loads it before serving. Unknown names keep serving
+# have downloaded and Unsloth loads it before serving. Unknown names keep serving
 # the current model.
 response = client.chat.completions.create(
     model=${j(SWITCH_MODEL)},
@@ -349,7 +349,7 @@ function javascriptSwitchDemo(): string {
   return `
 
 // "Switch model by request" is on: replace the model below with another GGUF you
-// have downloaded and Studio loads it before serving. Unknown names keep serving
+// have downloaded and Unsloth loads it before serving. Unknown names keep serving
 // the current model.
 const switchResponse = await client.chat.completions.create({
   model: ${j(SWITCH_MODEL)},
@@ -454,7 +454,7 @@ function HighlightedCode({
     [code, language],
   );
   return (
-    <div className="max-w-full overflow-x-auto p-3 pr-16 text-[11px] leading-relaxed [&_pre]:!m-0 [&_pre]:!whitespace-pre-wrap [&_pre]:!break-words [&_pre]:!border-0 [&_pre]:!bg-transparent [&_pre]:!p-0 [&_pre]:!text-[11px] [&_pre]:!leading-relaxed [&_code]:!text-[11px] [&_[data-streamdown=code-block]]:!my-0 [&_[data-streamdown=code-block]]:!border-0 [&_[data-streamdown=code-block]]:!bg-transparent [&_[data-streamdown=code-block]]:!p-0 [&_[data-streamdown=code-block]]:!text-[11px]">
+    <div className="max-w-full overflow-x-auto p-3 pr-16 text-ui-11 leading-relaxed [&_pre]:!m-0 [&_pre]:!whitespace-pre-wrap [&_pre]:!break-words [&_pre]:!border-0 [&_pre]:!bg-transparent [&_pre]:!p-0 [&_pre]:!text-ui-11 [&_pre]:!leading-relaxed [&_code]:!text-ui-11 [&_[data-streamdown=code-block]]:!my-0 [&_[data-streamdown=code-block]]:!border-0 [&_[data-streamdown=code-block]]:!bg-transparent [&_[data-streamdown=code-block]]:!p-0 [&_[data-streamdown=code-block]]:!text-ui-11">
       <Streamdown
         mode="static"
         plugins={{ code: codePlugin }}
@@ -512,7 +512,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
     if (!localAgentDetection) {
       setDetectedAgents([]);
       // A previously auto-picked agent was only ever verified against the
-      // Studio backend's PATH, which is meaningless now that this panel no
+      // Unsloth backend's PATH, which is meaningless now that this panel no
       // longer targets a loopback base -- don't leave it selected, but
       // never touch a choice the user made by hand.
       if (!agentPickedByUserRef.current) {
@@ -668,7 +668,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
               onCheckedChange={handleToggleAutoSwitch}
               aria-label={t("settings.general.modelAutoSwitch.enable")}
             />
-            <span className="text-[11px] font-medium text-foreground">
+            <span className="text-ui-11 font-medium text-foreground">
               {t("settings.general.modelAutoSwitch.enable")}
             </span>
             <Tooltip>
@@ -686,7 +686,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
                   />
                 </button>
               </TooltipTrigger>
-              <TooltipContent className="max-w-[260px] text-[11px] leading-snug">
+              <TooltipContent className="max-w-[260px] text-ui-11 leading-snug">
                 {t("settings.general.modelAutoSwitch.enableDescription")}
               </TooltipContent>
             </Tooltip>
@@ -701,7 +701,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
                 onCheckedChange={handleToggleTunnel}
                 aria-label={t("settings.apiKeys.secureHttps")}
               />
-              <span className="text-[11px] font-medium text-foreground">
+              <span className="text-ui-11 font-medium text-foreground">
                 {t("settings.apiKeys.secureHttps")}
               </span>
               {/* Only when not launched with --secure: the raw 0.0.0.0 port is
@@ -720,7 +720,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
                       />
                     </button>
                   </TooltipTrigger>
-                  <TooltipContent className="max-w-[260px] text-[11px] leading-snug">
+                  <TooltipContent className="max-w-[260px] text-ui-11 leading-snug">
                     {t("settings.apiKeys.secureHttpsHint")}
                   </TooltipContent>
                 </Tooltip>
@@ -730,7 +730,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
               type="button"
               onClick={handleCopyUrl}
               className={cn(
-                "flex min-w-0 items-center gap-1 rounded px-1.5 py-1 text-[11px] text-muted-foreground transition-colors hover:text-foreground focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
+                "flex min-w-0 items-center gap-1 rounded px-1.5 py-1 text-ui-11 text-muted-foreground transition-colors hover:text-foreground focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
                 !useTunnel && "opacity-50",
               )}
               title={cloudflareUrl}
@@ -759,7 +759,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
                   onClick={() => setLang(tab.id)}
                   aria-pressed={active}
                   className={cn(
-                    "rounded-full px-2.5 py-1 text-[11px] font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
+                    "rounded-full px-2.5 py-1 text-ui-11 font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
                     active
                       ? "hub-tab-toggle-pill text-foreground"
                       : "text-muted-foreground hover:text-foreground",
@@ -778,7 +778,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
               onClick={() => setOs("unix")}
               aria-pressed={os === "unix"}
               className={cn(
-                "rounded-full px-2.5 py-1 text-[11px] font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
+                "rounded-full px-2.5 py-1 text-ui-11 font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
                 os === "unix"
                   ? "hub-tab-toggle-pill text-foreground"
                   : "text-muted-foreground hover:text-foreground",
@@ -791,7 +791,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
               onClick={() => setOs("windows")}
               aria-pressed={os === "windows"}
               className={cn(
-                "rounded-full px-2.5 py-1 text-[11px] font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
+                "rounded-full px-2.5 py-1 text-ui-11 font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
                 os === "windows"
                   ? "hub-tab-toggle-pill text-foreground"
                   : "text-muted-foreground hover:text-foreground",
@@ -805,7 +805,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
           <button
             type="button"
             onClick={handleCopy}
-            className="absolute right-2 top-2 z-10 flex items-center gap-1 rounded border border-border bg-background/80 px-1.5 py-1 text-[11px] text-muted-foreground backdrop-blur transition-colors hover:text-foreground focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
+            className="absolute right-2 top-2 z-10 flex items-center gap-1 rounded border border-border bg-background/80 px-1.5 py-1 text-ui-11 text-muted-foreground backdrop-blur transition-colors hover:text-foreground focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
             aria-label={t("settings.apiKeys.copySnippet")}
           >
             <HugeiconsIcon
@@ -821,10 +821,10 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
           />
         </div>
         <div className="flex min-w-0 flex-col gap-1.5 border-t border-border px-3 py-2.5">
-          <span className="text-[11px] font-semibold text-foreground">
+          <span className="text-ui-11 font-semibold text-foreground">
             {t("settings.apiKeys.codingAgents")}
           </span>
-          <span className="text-[11px] leading-snug text-muted-foreground">
+          <span className="text-ui-11 leading-snug text-muted-foreground">
             {t("settings.apiKeys.codingAgentsHint")}
           </span>
           <div className="flex min-w-0 flex-wrap items-center gap-1">
@@ -846,7 +846,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
                       : undefined
                   }
                   className={cn(
-                    "flex items-center gap-1 rounded-full px-2.5 py-1 text-[11px] font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
+                    "flex items-center gap-1 rounded-full px-2.5 py-1 text-ui-11 font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring",
                     active
                       ? "hub-tab-toggle-pill text-foreground"
                       : "text-muted-foreground hover:text-foreground",
@@ -864,13 +864,13 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
             })}
           </div>
           <div className="relative mt-0.5 min-w-0">
-            <code className="block min-w-0 overflow-x-auto rounded border border-border bg-muted/30 px-2 py-1.5 pr-14 font-mono text-[11px] text-foreground">
+            <code className="block min-w-0 overflow-x-auto rounded border border-border bg-muted/30 px-2 py-1.5 pr-14 font-mono text-ui-11 text-foreground">
               {agentCommand}
             </code>
             <button
               type="button"
               onClick={handleCopyAgent}
-              className="absolute right-1.5 top-1/2 flex -translate-y-1/2 items-center gap-1 rounded border border-border bg-background/80 px-1.5 py-0.5 text-[11px] text-muted-foreground backdrop-blur transition-colors hover:text-foreground focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
+              className="absolute right-1.5 top-1/2 flex -translate-y-1/2 items-center gap-1 rounded border border-border bg-background/80 px-1.5 py-0.5 text-ui-11 text-muted-foreground backdrop-blur transition-colors hover:text-foreground focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
               aria-label={t("settings.apiKeys.copySnippet")}
             >
               <HugeiconsIcon
@@ -879,7 +879,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
               />
             </button>
           </div>
-          <span className="text-[11px] leading-snug text-muted-foreground">
+          <span className="text-ui-11 leading-snug text-muted-foreground">
             {detectedAgents.length > 0
               ? t("settings.apiKeys.codingAgentsDetectedHint", {
                   agents: detectedAgents
@@ -889,7 +889,7 @@ export function UsageExamples({ apiKey }: { apiKey?: string | null }) {
               : t("settings.apiKeys.codingAgentsSwap")}
           </span>
         </div>
-        <div className="flex flex-wrap items-center gap-x-2 gap-y-1 border-t border-border px-3 py-2 text-[11px] text-muted-foreground">
+        <div className="flex flex-wrap items-center gap-x-2 gap-y-1 border-t border-border px-3 py-2 text-ui-11 text-muted-foreground">
           <span>{t("settings.apiKeys.setupDocs")}</span>
           {DOC_LINKS.map((link) => (
             <a
diff --git a/studio/frontend/src/features/settings/index.ts b/studio/frontend/src/features/settings/index.ts
index 1e4d9d8844..f27100a322 100644
--- a/studio/frontend/src/features/settings/index.ts
+++ b/studio/frontend/src/features/settings/index.ts
@@ -2,6 +2,7 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 export { SettingsDialog } from "./settings-dialog";
+export { loadEmbeddingModelSettings } from "./api/embedding-model";
 export {
   loadPersonalization,
   savePersonalization,
diff --git a/studio/frontend/src/features/settings/settings-dialog.tsx b/studio/frontend/src/features/settings/settings-dialog.tsx
index 08588be8fe..7a3a3c58f7 100644
--- a/studio/frontend/src/features/settings/settings-dialog.tsx
+++ b/studio/frontend/src/features/settings/settings-dialog.tsx
@@ -15,6 +15,7 @@ import {
   Cancel01Icon,
   CloudIcon,
   CpuIcon,
+  DatabaseSettingIcon,
   Globe02Icon,
   HelpCircleIcon,
   Message01Icon,
@@ -43,6 +44,7 @@ import { ApiKeysTab } from "./tabs/api-keys-tab";
 import { AppearanceTab } from "./tabs/appearance-tab";
 import { ChatTab } from "./tabs/chat-tab";
 import { ConnectionsTab } from "./tabs/connections-tab";
+import { DataTab } from "./tabs/data-tab";
 import { GeneralTab } from "./tabs/general-tab";
 import { ProfileTab } from "./tabs/profile-tab";
 import { ResourcesTab } from "./tabs/resources-tab";
@@ -93,6 +95,12 @@ const TABS: TabDef[] = [
     iconComponent: MicIcon,
     badgeKey: "common.new",
   },
+  {
+    id: "data",
+    labelKey: "settings.tabs.data",
+    icon: DatabaseSettingIcon,
+    badgeKey: "common.new",
+  },
   { id: "about", labelKey: "settings.tabs.about", icon: HelpCircleIcon },
 ];
 
@@ -112,6 +120,8 @@ function renderTab(tab: SettingsTab) {
       return <VoiceTab />;
     case "connections":
       return <ConnectionsTab />;
+    case "data":
+      return <DataTab />;
     case "api-keys":
       return <ApiKeysTab />;
     case "about":
@@ -210,6 +220,7 @@ export function SettingsDialog() {
     chat: null,
     voice: null,
     connections: null,
+    data: null,
     "api-keys": null,
     about: null,
   });
@@ -298,7 +309,7 @@ export function SettingsDialog() {
                         <button
                           type="button"
                           onClick={() => openResult(tab.id)}
-                          className="flex h-[30px] items-center gap-2.5 rounded-full pl-3 pr-2.5 text-[13.5px] font-medium text-muted-foreground transition-colors hover:bg-accent hover:text-accent-foreground"
+                          className="flex h-[30px] items-center gap-2.5 rounded-full pl-3 pr-2.5 text-ui-13p5 font-medium text-muted-foreground transition-colors hover:bg-accent hover:text-accent-foreground"
                         >
                           {tab.iconComponent ? (
                             <tab.iconComponent className="size-icon shrink-0" />
@@ -316,7 +327,7 @@ export function SettingsDialog() {
                             key={entry}
                             type="button"
                             onClick={() => openResult(tab.id, entry)}
-                            className="flex h-[30px] items-center rounded-full pl-10 pr-2.5 text-left text-[14px] text-foreground transition-colors hover:bg-accent hover:text-accent-foreground"
+                            className="flex h-[30px] items-center rounded-full pl-10 pr-2.5 text-left text-ui-14 text-foreground transition-colors hover:bg-accent hover:text-accent-foreground"
                           >
                             <span className="min-w-0 truncate">{entry}</span>
                           </button>
@@ -328,7 +339,7 @@ export function SettingsDialog() {
               ) : null}
               <p
                 className={cn(
-                  "pl-4 pt-3 pb-2.5 text-[13px] font-medium text-muted-foreground max-sm:hidden",
+                  "pl-4 pt-3 pb-2.5 text-ui-13 font-medium text-muted-foreground max-sm:hidden",
                   results !== null && "hidden",
                 )}
               >
@@ -351,7 +362,7 @@ export function SettingsDialog() {
                       type="button"
                       onClick={() => setActiveTab(tab.id)}
                       className={cn(
-                        "relative flex h-[32px] items-center gap-2.5 rounded-full pl-3 pr-2.5 text-[14.5px] leading-[19px] tracking-nav font-medium transition-colors",
+                        "relative flex h-[32px] items-center gap-2.5 rounded-full pl-3 pr-2.5 text-ui-14p5 leading-ui-19 tracking-nav font-medium transition-colors",
                         "max-sm:shrink-0",
                         "focus-visible:outline-none",
                         // The active pill already marks the current tab, so
@@ -390,7 +401,7 @@ export function SettingsDialog() {
                         {t(tab.labelKey)}
                       </span>
                       {tab.badgeKey ? (
-                        <span className="relative z-10 ml-auto rounded-full bg-control-accent/10 px-2 py-1 text-[10px] leading-none font-semibold text-control-accent">
+                        <span className="relative z-10 ml-auto rounded-full bg-control-accent/10 px-2 py-1 text-ui-10 leading-none font-semibold text-control-accent">
                           {t(tab.badgeKey)}
                         </span>
                       ) : null}
diff --git a/studio/frontend/src/features/settings/settings-search.ts b/studio/frontend/src/features/settings/settings-search.ts
index 786ee11d0a..63b492878f 100644
--- a/studio/frontend/src/features/settings/settings-search.ts
+++ b/studio/frontend/src/features/settings/settings-search.ts
@@ -16,8 +16,6 @@ export const SETTINGS_SEARCH_INDEX: Record<SettingsTab, TranslationKey[]> = {
     "settings.general.huggingFaceToken",
     "settings.general.gettingStarted",
     "settings.general.startOnboarding",
-    "settings.general.storage.sectionTitle",
-    "settings.general.storage.modelsFolder",
     "settings.appearance.language.title",
     "settings.appearance.language.label",
     "settings.general.notifications.sectionTitle",
@@ -71,6 +69,7 @@ export const SETTINGS_SEARCH_INDEX: Record<SettingsTab, TranslationKey[]> = {
     "settings.resources.gpu.title",
     "settings.resources.storage.title",
     "settings.resources.storage.modelsFolder",
+    "settings.resources.storage.futureDownloads",
     "settings.resources.storage.systemDisk",
     "settings.resources.environment.title",
     "settings.resources.environment.backend",
@@ -85,12 +84,19 @@ export const SETTINGS_SEARCH_INDEX: Record<SettingsTab, TranslationKey[]> = {
     "settings.chat.artifacts.title",
     "settings.chat.artifacts.collapseHtmlBlocks",
     "settings.chat.artifacts.allowNetworkAccess",
-    "settings.chat.data",
+    "settings.chat.modelDisclaimer",
+  ],
+  // Chat data management moved to the Data tab; keep these rows findable there.
+  data: [
+    "settings.data.fineTuneExport",
+    "settings.data.archivedChats",
+    "settings.data.archiveAllChats",
+    "settings.data.confirmBeforeDeleting",
+    "settings.data.uploadedFiles",
+    "settings.chat.exportHistory",
     "settings.chat.exportConversations",
     "settings.chat.importChats",
     "settings.chat.clearAllChats",
-    "settings.chat.exportHistory",
-    "settings.chat.modelDisclaimer",
   ],
   "api-keys": [
     "settings.apiKeys.title",
@@ -102,7 +108,6 @@ export const SETTINGS_SEARCH_INDEX: Record<SettingsTab, TranslationKey[]> = {
     "settings.voice.dictation.sectionTitle",
     "settings.voice.dictation.microphoneLabel",
     "settings.voice.dictation.languageLabel",
-    "settings.voice.dictation.testLabel",
     "settings.voice.dictionary.sectionTitle",
     "settings.voice.recents.sectionTitle",
     "settings.voice.readAloud.sectionTitle",
diff --git a/studio/frontend/src/features/settings/stores/appearance-custom-store.ts b/studio/frontend/src/features/settings/stores/appearance-custom-store.ts
index b8c8d96f5a..0e449092e5 100644
--- a/studio/frontend/src/features/settings/stores/appearance-custom-store.ts
+++ b/studio/frontend/src/features/settings/stores/appearance-custom-store.ts
@@ -479,6 +479,8 @@ export function applyCustomizationToDocument(
     "--font-sans",
     c.uiFont ? `"${c.uiFont}", ${DEFAULT_SANS_STACK}` : null,
   );
+  // Custom interface fonts cascade into chat and opt out of its Inter tuning.
+  el.toggleAttribute("data-ui-font", Boolean(c.uiFont));
   setVar(
     "--font-heading",
     c.headingFont ? `"${c.headingFont}", ${DEFAULT_HEADING_STACK}` : null,
@@ -508,11 +510,20 @@ export function applyCustomizationToDocument(
     setVar("--custom-chat-font", null);
   }
 
+  // The UI font size drives a typography scale factor, never the root font
+  // size: rem-based layout geometry must not move with the preference. The
+  // scale reaches text through the --text-* / --text-ui-* / --leading-*
+  // tokens in index.css.
   if (c.uiFontSize !== null && c.uiFontSize !== UI_FONT_SIZE_RANGE.default) {
-    style.fontSize = `${c.uiFontSize}px`;
+    setVar("--ui-font-scale", String(c.uiFontSize / UI_FONT_SIZE_RANGE.default));
+    el.setAttribute("data-ui-font-size", String(c.uiFontSize));
   } else {
-    style.removeProperty("font-size");
+    setVar("--ui-font-scale", null);
+    el.removeAttribute("data-ui-font-size");
   }
+  // Older builds scaled the root font size directly; clear any stale inline
+  // value so layout never scales with the preference again.
+  style.removeProperty("font-size");
 
   if (c.codeFontSize !== null) {
     el.setAttribute("data-code-font-size", "");
diff --git a/studio/frontend/src/features/settings/stores/settings-dialog-store.ts b/studio/frontend/src/features/settings/stores/settings-dialog-store.ts
index b9e9c75b14..51908a5ad0 100644
--- a/studio/frontend/src/features/settings/stores/settings-dialog-store.ts
+++ b/studio/frontend/src/features/settings/stores/settings-dialog-store.ts
@@ -11,6 +11,7 @@ export type SettingsTab =
   | "chat"
   | "voice"
   | "connections"
+  | "data"
   | "api-keys"
   | "about";
 
@@ -30,7 +31,7 @@ interface SettingsDialogState {
   // explicitly via onCloseAutoFocus.
   opener: HTMLElement | null;
   // Set when something asks to jump straight to the archived chats list (the
-  // archive toast). ChatTab consumes it to open the dialog, then clears it.
+  // archive toast). DataTab uses it as its initial subpage, then clears it.
   archivedChatsRequested: boolean;
   openDialog: (tab?: SettingsTab, options?: OpenDialogOptions) => void;
   openArchivedChats: () => void;
@@ -66,6 +67,7 @@ function loadInitialTab(): SettingsTab {
     "chat",
     "voice",
     "connections",
+    "data",
     "api-keys",
     "about",
   ];
@@ -90,7 +92,7 @@ export const useSettingsDialogStore = create<SettingsDialogState>((set) => ({
   openArchivedChats: () =>
     set({
       open: true,
-      activeTab: "chat",
+      activeTab: "data",
       scrollTarget: null,
       archivedChatsRequested: true,
       opener: captureOpener(),
diff --git a/studio/frontend/src/features/settings/stores/voice-settings-store.ts b/studio/frontend/src/features/settings/stores/voice-settings-store.ts
index 9e38f4c6ce..5f71085981 100644
--- a/studio/frontend/src/features/settings/stores/voice-settings-store.ts
+++ b/studio/frontend/src/features/settings/stores/voice-settings-store.ts
@@ -2,28 +2,118 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { create } from "zustand";
-import { persist } from "zustand/middleware";
+import { createJSONStorage, persist } from "zustand/middleware";
 
 // Voice preferences in localStorage. Adapters read them at call time so
 // changes apply without reloading the chat runtime.
 
 export interface RecentDictation {
+  id: string;
   text: string;
   at: number;
+  /** Chat the dictation was spoken into, when one was open at the time. */
+  chatId?: string;
 }
 
-const MAX_RECENT_DICTATIONS = 20;
+// Dictation history is kept in full; the list view paginates. QUOTA_TRIM_KEEP is
+// the emergency floor if localStorage runs out of room (see persist wrapper).
+const QUOTA_TRIM_KEEP = 200;
 // Cap stored transcript length so a few long dictations cannot bloat the
 // persisted blob and trip a synchronous localStorage quota error on save.
 const MAX_RECENT_DICTATION_LENGTH = 2000;
 const MAX_DICTIONARY_ENTRIES = 100;
 const MAX_DICTIONARY_ENTRY_LENGTH = 120;
 
+/** Five curated Whisper choices, mirrored by the backend (stt_sidecar.py). */
+export const STT_MODELS = [
+  "tiny",
+  "base",
+  "small",
+  "large-v3-turbo",
+  "large-v3",
+] as const;
+export type DefaultSttModel = (typeof STT_MODELS)[number];
+/** A curated id or a user-selected Hugging Face `owner/model` repository. */
+export type SttModel = string;
+/** Whisper repos downloaded through Studio's existing Model Hub manager. */
+export const STT_MODEL_REPOS: Record<DefaultSttModel, string> = {
+  tiny: "unsloth/whisper-tiny",
+  base: "unsloth/whisper-base",
+  small: "unsloth/whisper-small",
+  "large-v3-turbo": "unsloth/whisper-large-v3-turbo",
+  "large-v3": "unsloth/whisper-large-v3",
+};
+export const DEFAULT_STT_MODEL: DefaultSttModel = "small";
+const HF_REPO_ID =
+  /^[A-Za-z0-9][A-Za-z0-9._-]{0,95}\/[A-Za-z0-9][A-Za-z0-9._-]{0,95}$/;
+
+export function isSttModelId(value: string): boolean {
+  const normalized = value.trim();
+  return (
+    (STT_MODELS as readonly string[]).includes(normalized) ||
+    HF_REPO_ID.test(normalized)
+  );
+}
+
+export function normalizeSttModel(value: unknown): SttModel {
+  if (typeof value !== "string") {
+    return DEFAULT_STT_MODEL;
+  }
+  const normalized = value.trim();
+  return isSttModelId(normalized) ? normalized : DEFAULT_STT_MODEL;
+}
+
+export function getSttModelRepo(model: SttModel): string {
+  return STT_MODEL_REPOS[model as DefaultSttModel] ?? normalizeSttModel(model);
+}
+
+// All curated models are multilingual. Custom `.en` checkpoints are treated as
+// English-only so a later language change falls back safely.
+export const ENGLISH_ONLY_STT_MODELS: ReadonlySet<SttModel> = new Set([]);
+
+/** Whether a model can honor the selected dictation language. */
+export function isSttModelLanguageCompatible(
+  model: SttModel,
+  language: string,
+): boolean {
+  const isEnglishOnly =
+    ENGLISH_ONLY_STT_MODELS.has(model) ||
+    getSttModelRepo(model).toLowerCase().endsWith(".en");
+  if (!isEnglishOnly) {
+    return true;
+  }
+  const normalized = language.trim().replaceAll("_", "-").toLowerCase();
+  // Auto sends no forced language, which English-only checkpoints accept.
+  return normalized === "auto" || normalized.split("-", 1)[0] === "en";
+}
+
+export type DictationEngine = "browser" | "model";
+
+/**
+ * Whether a model id is one of the five curated Whisper choices. Curated models
+ * run GGML through whisper.cpp; custom repos are safetensors and run through
+ * Transformers.
+ */
+export function isCuratedSttModel(model: SttModel): boolean {
+  return (STT_MODELS as readonly string[]).includes(model.trim());
+}
+
 export interface VoiceSettingsState {
   /** Input device for dictation. "default" = system default microphone. */
   micDeviceId: string;
   setMicDeviceId: (value: string) => void;
 
+  /**
+   * "browser": Web Speech API. "model": local transcription; the model decides
+   * the backend (whisper.cpp for curated GGML, Transformers for custom repos).
+   */
+  dictationEngine: DictationEngine;
+  setDictationEngine: (value: DictationEngine) => void;
+
+  /** STT model to use when dictationEngine is "model". */
+  sttModel: SttModel;
+  setSttModel: (value: SttModel) => void;
+
   /** BCP 47 tag for speech recognition, or "auto" for the browser locale. */
   dictationLanguage: string;
   setDictationLanguage: (value: string) => void;
@@ -38,7 +128,8 @@ export interface VoiceSettingsState {
 
   /** Final transcripts, newest first, so text can be recovered. */
   recentDictations: RecentDictation[];
-  addRecentDictation: (text: string) => void;
+  addRecentDictation: (text: string, chatId?: string) => void;
+  removeRecentDictation: (id: string) => void;
   clearRecentDictations: () => void;
 
   /** Show the read-aloud button on assistant responses. */
@@ -61,14 +152,81 @@ export interface VoiceSettingsState {
   setTtsVolume: (value: number) => void;
 }
 
+/**
+ * localStorage wrapper that keeps the full dictation history until the browser's
+ * quota is hit, then drops the oldest entries instead of losing the whole save.
+ */
+const quotaSafeLocalStorage = {
+  getItem: (key: string) => localStorage.getItem(key),
+  removeItem: (key: string) => localStorage.removeItem(key),
+  setItem: (key: string, value: string) => {
+    try {
+      localStorage.setItem(key, value);
+      return;
+    } catch {
+      // Quota exceeded: trim dictation history, oldest first, and retry.
+    }
+    let parsed: { state?: { recentDictations?: RecentDictation[] } };
+    try {
+      parsed = JSON.parse(value) as typeof parsed;
+    } catch {
+      return;
+    }
+    const state = parsed.state;
+    const recents = state?.recentDictations;
+    if (!state || !Array.isArray(recents)) return;
+    // Halve the history until the save fits, down to an empty history, so even
+    // a small history shrinks when another store already consumed the quota.
+    let keep = Math.min(QUOTA_TRIM_KEEP, recents.length);
+    for (;;) {
+      keep = keep >= recents.length ? Math.floor(recents.length / 2) : keep;
+      try {
+        state.recentDictations = recents.slice(0, keep);
+        localStorage.setItem(key, JSON.stringify(parsed));
+        return;
+      } catch {
+        // Still over quota: trim harder.
+      }
+      if (keep === 0) return;
+      keep = Math.floor(keep / 2);
+    }
+  },
+};
+
 export const useVoiceSettingsStore = create<VoiceSettingsState>()(
   persist(
     (set) => ({
       micDeviceId: "default",
       setMicDeviceId: (micDeviceId) => set({ micDeviceId }),
 
+      dictationEngine: "browser",
+      setDictationEngine: (dictationEngine) => set({ dictationEngine }),
+
+      sttModel: DEFAULT_STT_MODEL,
+      setSttModel: (value) =>
+        set((state) => {
+          const sttModel = normalizeSttModel(value);
+          return {
+            sttModel: isSttModelLanguageCompatible(
+              sttModel,
+              state.dictationLanguage,
+            )
+              ? sttModel
+              : DEFAULT_STT_MODEL,
+          };
+        }),
+
       dictationLanguage: "auto",
-      setDictationLanguage: (dictationLanguage) => set({ dictationLanguage }),
+      setDictationLanguage: (dictationLanguage) =>
+        set((state) => ({
+          dictationLanguage,
+          sttModel: isSttModelLanguageCompatible(
+            state.sttModel,
+            dictationLanguage,
+          )
+            ? state.sttModel
+            : DEFAULT_STT_MODEL,
+        })),
 
       dictionary: [],
       addDictionaryEntry: (value) =>
@@ -111,17 +269,31 @@ export const useVoiceSettingsStore = create<VoiceSettingsState>()(
         })),
 
       recentDictations: [],
-      addRecentDictation: (text) =>
+      addRecentDictation: (text, chatId) =>
         set((state) => {
           const trimmed = text.trim().slice(0, MAX_RECENT_DICTATION_LENGTH);
-          if (!trimmed) return state;
+          if (!trimmed) {
+            return state;
+          }
+          const at = Date.now();
           return {
             recentDictations: [
-              { text: trimmed, at: Date.now() },
+              {
+                id: `${at}-${Math.random().toString(36).slice(2, 10)}`,
+                text: trimmed,
+                at,
+                ...(chatId ? { chatId } : {}),
+              },
               ...state.recentDictations,
-            ].slice(0, MAX_RECENT_DICTATIONS),
+            ],
           };
         }),
+      removeRecentDictation: (id) =>
+        set((state) => ({
+          recentDictations: state.recentDictations.filter(
+            (dictation) => dictation.id !== id,
+          ),
+        })),
       clearRecentDictations: () => set({ recentDictations: [] }),
 
       ttsEnabled: true,
@@ -142,30 +314,37 @@ export const useVoiceSettingsStore = create<VoiceSettingsState>()(
     }),
     {
       name: "unsloth_voice_settings",
+      storage: createJSONStorage(() => quotaSafeLocalStorage),
       merge: (persisted, current) => {
         const saved = persisted as Partial<VoiceSettingsState> | undefined;
+        const dictationLanguage = asString(saved?.dictationLanguage, "auto");
+        // "gguf" was a short-lived separate engine choice; both local
+        // backends now live under "model".
+        const savedEngine = saved?.dictationEngine as string | undefined;
+        const dictationEngine: DictationEngine =
+          savedEngine === "model" || savedEngine === "gguf"
+            ? "model"
+            : "browser";
+        const savedSttModel = normalizeSttModel(saved?.sttModel);
+        const sttModel = isSttModelLanguageCompatible(
+          savedSttModel,
+          dictationLanguage,
+        )
+          ? savedSttModel
+          : DEFAULT_STT_MODEL;
         return {
           ...current,
           micDeviceId: asString(saved?.micDeviceId, "default"),
-          dictationLanguage: asString(saved?.dictationLanguage, "auto"),
+          dictationEngine,
+          sttModel,
+          dictationLanguage,
           dictionary: Array.isArray(saved?.dictionary)
             ? saved.dictionary
                 .filter((v): v is string => typeof v === "string" && !!v.trim())
                 .map((v) => v.trim().slice(0, MAX_DICTIONARY_ENTRY_LENGTH))
                 .slice(0, MAX_DICTIONARY_ENTRIES)
             : [],
-          recentDictations: Array.isArray(saved?.recentDictations)
-            ? saved.recentDictations
-                .filter(
-                  (v): v is RecentDictation =>
-                    typeof v?.text === "string" && typeof v?.at === "number",
-                )
-                .slice(0, MAX_RECENT_DICTATIONS)
-                .map((v) => ({
-                  text: v.text.slice(0, MAX_RECENT_DICTATION_LENGTH),
-                  at: v.at,
-                }))
-            : [],
+          recentDictations: normalizeRecentDictations(saved?.recentDictations),
           ttsEnabled:
             typeof saved?.ttsEnabled === "boolean" ? saved.ttsEnabled : true,
           ttsEngine: saved?.ttsEngine === "studio" ? "studio" : "system",
@@ -183,6 +362,40 @@ function asString(value: unknown, fallback: string): string {
   return typeof value === "string" && value ? value : fallback;
 }
 
+function normalizeRecentDictations(value: unknown): RecentDictation[] {
+  if (!Array.isArray(value)) {
+    return [];
+  }
+
+  const normalized: RecentDictation[] = [];
+  for (const [index, entry] of value.entries()) {
+    if (!entry || typeof entry !== "object") {
+      continue;
+    }
+    const candidate = entry as Partial<RecentDictation>;
+    if (
+      typeof candidate.text !== "string" ||
+      !candidate.text.trim() ||
+      typeof candidate.at !== "number" ||
+      !Number.isFinite(candidate.at)
+    ) {
+      continue;
+    }
+    normalized.push({
+      id:
+        typeof candidate.id === "string" && candidate.id
+          ? candidate.id
+          : `legacy-${candidate.at}-${index}`,
+      text: candidate.text.trim().slice(0, MAX_RECENT_DICTATION_LENGTH),
+      at: candidate.at,
+      ...(typeof candidate.chatId === "string" && candidate.chatId
+        ? { chatId: candidate.chatId }
+        : {}),
+    });
+  }
+  return normalized;
+}
+
 function clampNumber(
   value: unknown,
   min: number,
@@ -202,6 +415,47 @@ export function resolveDictationLanguage(setting?: string): string {
     : "en-US";
 }
 
+// Whisper's language codes: transformers `LANGUAGES` keys plus the backend's
+// BCP-47 aliases (stt_sidecar.py `_WHISPER_LANGUAGE_ALIASES`). Keep in sync with
+// `_known_whisper_languages()`; Auto only resolves to a code in this set, so a
+// UI locale Whisper cannot honor stays on auto-detect.
+const WHISPER_DICTATION_LANGUAGES = new Set([
+  "af", "am", "ar", "as", "az", "ba", "be", "bg", "bn", "bo", "br", "bs",
+  "ca", "cmn", "cs", "cy", "da", "de", "el", "en", "es", "et", "eu", "fa",
+  "fi", "fil", "fo", "fr", "gl", "gu", "ha", "haw", "he", "hi", "hr", "ht",
+  "hu", "hy", "id", "in", "is", "it", "iw", "ja", "ji", "jw", "ka", "kk",
+  "km", "kn", "ko", "la", "lb", "ln", "lo", "lt", "lv", "mg", "mi", "mk",
+  "ml", "mn", "mr", "ms", "mt", "my", "nb", "ne", "nl", "nn", "no", "oc",
+  "pa", "pl", "ps", "pt", "ro", "ru", "sa", "sd", "si", "sk", "sl", "sn",
+  "so", "sq", "sr", "su", "sv", "sw", "ta", "te", "tg", "th", "tk", "tl",
+  "tr", "tt", "uk", "ur", "uz", "vi", "yi", "yo", "yue", "zh",
+]);
+
+/**
+ * Resolve Auto for the model STT engine (the browser engine resolves it via
+ * `resolveDictationLanguage`). Only the literal "auto" resolves to a concrete
+ * locale; an explicit or malformed setting passes through unchanged. Gated so
+ * Auto only becomes a language the model AND Whisper can honor, else it stays
+ * auto-detect rather than forcing a locale Whisper cannot handle (e.g. Irish)
+ * or 422ing every dictation.
+ */
+export function resolveModelDictationLanguage(
+  model: SttModel,
+  requested: string,
+): string {
+  if (requested !== "auto") return requested;
+  const resolved = resolveDictationLanguage(requested);
+  const primary = resolved
+    .trim()
+    .replaceAll("_", "-")
+    .toLowerCase()
+    .split("-", 1)[0];
+  return isSttModelLanguageCompatible(model, resolved) &&
+    WHISPER_DICTATION_LANGUAGES.has(primary)
+    ? resolved
+    : requested;
+}
+
 function escapeRegExp(value: string): string {
   return value.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
 }
@@ -240,6 +494,6 @@ export function applyDictationDictionary(
 }
 
 /** Record a finished dictation so it can be recovered from settings. */
-export function recordRecentDictation(text: string): void {
-  useVoiceSettingsStore.getState().addRecentDictation(text);
+export function recordRecentDictation(text: string, chatId?: string): void {
+  useVoiceSettingsStore.getState().addRecentDictation(text, chatId);
 }
diff --git a/studio/frontend/src/features/settings/tabs/chat-tab.tsx b/studio/frontend/src/features/settings/tabs/chat-tab.tsx
index d5c9f10a4f..a6fcf87c57 100644
--- a/studio/frontend/src/features/settings/tabs/chat-tab.tsx
+++ b/studio/frontend/src/features/settings/tabs/chat-tab.tsx
@@ -1,63 +1,32 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { Button } from "@/components/ui/button";
-import {
-  Dialog,
-  DialogContent,
-  DialogDescription,
-  DialogFooter,
-  DialogHeader,
-  DialogTitle,
-} from "@/components/ui/dialog";
-import {
-  DropdownMenu,
-  DropdownMenuContent,
-  DropdownMenuItem,
-  DropdownMenuSeparator,
-  DropdownMenuSub,
-  DropdownMenuSubContent,
-  DropdownMenuSubTrigger,
-  DropdownMenuTrigger,
-} from "@/components/ui/dropdown-menu";
 import { Switch } from "@/components/ui/switch";
 import {
-  EXPORT_FORMATS_LIST,
   type PlusMenuItemId,
-  bulkExportConversationsByScope,
-  clearAllChats,
-  countAllChats,
-  downloadChatExport,
-  importConversationsFromFile,
   useChatPreferencesStore,
   useChatRuntimeStore,
   usePlusMenuPrefsStore,
 } from "@/features/chat";
 import { useT } from "@/i18n";
-import { toast } from "@/lib/toast";
 import {
   Bookmark02Icon,
-  Delete02Icon,
   Download01Icon,
   FileDatabaseIcon,
   Folder01Icon,
   McpServerIcon,
   PencilRulerIcon,
-  Settings02Icon,
   ShieldBanIcon,
-  Upload01Icon,
 } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
 import { Columns2Icon, PlusIcon } from "lucide-react";
-import { useEffect, useRef, useState } from "react";
+import { useEffect } from "react";
 import type { ReactNode } from "react";
-import { ArchivedChatsDialog } from "../components/archived-chats-dialog";
 import { SettingsRow } from "../components/settings-row";
 import {
   SettingsGroupDivider,
   SettingsSection,
 } from "../components/settings-section";
-import { useSettingsDialogStore } from "../stores/settings-dialog-store";
 
 // Adjustable "+" menu items shown in settings, in display order. Icons mirror
 // the ones used in the composer + menu itself.
@@ -140,7 +109,7 @@ const PLUS_MENU_SETTINGS: {
   },
   {
     id: "bypassPermissions",
-    label: "Bypass permissions",
+    label: "Tool permissions",
     icon: (
       <HugeiconsIcon
         icon={ShieldBanIcon}
@@ -155,24 +124,6 @@ export function ChatTab() {
   const t = useT();
   const plusPins = usePlusMenuPrefsStore((state) => state.pins);
   const togglePlusPin = usePlusMenuPrefsStore((state) => state.togglePin);
-  const [confirmOpen, setConfirmOpen] = useState(false);
-  const [archivedOpen, setArchivedOpen] = useState(false);
-  const [count, setCount] = useState<number | null>(null);
-  const archivedChatsRequested = useSettingsDialogStore(
-    (s) => s.archivedChatsRequested,
-  );
-  const consumeArchivedChatsRequest = useSettingsDialogStore(
-    (s) => s.consumeArchivedChatsRequest,
-  );
-
-  // Open the archived list when the archive toast asked to jump here.
-  useEffect(() => {
-    if (!archivedChatsRequested) return;
-    setArchivedOpen(true);
-    consumeArchivedChatsRequest();
-  }, [archivedChatsRequested, consumeArchivedChatsRequest]);
-  const [exporting, setExporting] = useState(false);
-  const [clearing, setClearing] = useState(false);
   const autoTitle = useChatRuntimeStore((state) => state.autoTitle);
   const setAutoTitle = useChatRuntimeStore((state) => state.setAutoTitle);
   const showCanvasMenuItem = useChatRuntimeStore(
@@ -196,10 +147,6 @@ export function ChatTab() {
   const hydratePersistedSettings = useChatRuntimeStore(
     (state) => state.hydratePersistedSettings,
   );
-  const loadOnSelection = useChatRuntimeStore((state) => state.loadOnSelection);
-  const setLoadOnSelection = useChatRuntimeStore(
-    (state) => state.setLoadOnSelection,
-  );
   const expandQuantizations = useChatRuntimeStore(
     (state) => state.expandQuantizations,
   );
@@ -212,12 +159,6 @@ export function ChatTab() {
   const setShowAllQuantizations = useChatRuntimeStore(
     (state) => state.setShowAllQuantizations,
   );
-  const confirmDeleteChats = useChatPreferencesStore(
-    (state) => state.confirmDeleteChats,
-  );
-  const setConfirmDeleteChats = useChatPreferencesStore(
-    (state) => state.setConfirmDeleteChats,
-  );
   const showModelDisclaimer = useChatPreferencesStore(
     (state) => state.showModelDisclaimer,
   );
@@ -232,95 +173,9 @@ export function ChatTab() {
   );
 
   useEffect(() => {
-    void countAllChats().then(setCount);
     void hydratePersistedSettings();
   }, [hydratePersistedSettings]);
 
-  const handleExport = async () => {
-    setExporting(true);
-    try {
-      await downloadChatExport();
-    } finally {
-      setExporting(false);
-    }
-  };
-
-  const importInputRef = useRef<HTMLInputElement>(null);
-  const handleImport = async (file: File) => {
-    try {
-      const imported = await importConversationsFromFile(file, null);
-      if (imported === 0) {
-        toast.info(t("settings.chat.importNoConversations"));
-      } else {
-        toast.success(
-          imported === 1
-            ? t("settings.chat.importedOneChat")
-            : t("settings.chat.importedChatCount", { count: imported }),
-        );
-        setCount(await countAllChats().catch(() => count));
-      }
-    } catch {
-      toast.error(t("settings.chat.importFailed"));
-    }
-  };
-
-  const handleClear = async () => {
-    setClearing(true);
-    try {
-      const result = await clearAllChats();
-      const clearedCount = result.deletedThreadIds.length;
-      const hasFailedStore =
-        result.backend === "failed" || result.legacy === "failed";
-      if (!hasFailedStore && result.failedThreadIds.length === 0) {
-        setCount(0);
-        setConfirmOpen(false);
-        toast.success(
-          clearedCount === 0
-            ? t("settings.chat.clearedAllChats")
-            : clearedCount === 1
-              ? t("settings.chat.clearedOneChat")
-              : t("settings.chat.clearedChatCount", { count: clearedCount }),
-        );
-        return;
-      }
-
-      const fallbackRemaining =
-        result.failedThreadIds.length > 0
-          ? result.failedThreadIds.length
-          : (count ?? 0);
-      const remaining = await countAllChats().catch(() => fallbackRemaining);
-      setCount(remaining);
-      setConfirmOpen(false);
-      toast.warning(t("settings.chat.someChatsCouldNotBeCleared"), {
-        description:
-          result.failedThreadIds.length > 0
-            ? clearedCount === 1 && result.failedThreadIds.length === 1
-              ? t("settings.chat.oneChatClearedRemainOne")
-              : clearedCount === 1
-                ? t("settings.chat.oneChatClearedRemain", {
-                    remainingCount: result.failedThreadIds.length,
-                  })
-                : result.failedThreadIds.length === 1
-                  ? t("settings.chat.chatsClearedRemainOne", { clearedCount })
-                  : t("settings.chat.chatsClearedRemain", {
-                      clearedCount,
-                      remainingCount: result.failedThreadIds.length,
-                    })
-            : remaining === 1
-              ? t("settings.chat.storageClearFailedOne")
-              : t("settings.chat.storageClearFailed", { count: remaining }),
-      });
-    } catch (error) {
-      const remaining = await countAllChats().catch(() => count);
-      setCount(remaining);
-      toast.error(t("settings.chat.failedToClearChats"), {
-        description: error instanceof Error ? error.message : undefined,
-      });
-    } finally {
-      setClearing(false);
-    }
-  };
-
   return (
     <div className="flex flex-col gap-6">
       <header className="flex flex-col gap-1">
@@ -333,40 +188,6 @@ export function ChatTab() {
       </header>
 
       <SettingsSection title="Select model settings">
-        <SettingsRow
-          label="Load on selection"
-          alignTop={true}
-          description={
-            <span>
-              On: Unsloth auto-picks the best settings and loads it.
-              <br />
-              Off: opens Run settings to customize, then load.
-              <br />
-              The gear always opens Run settings:{" "}
-              <span className="ml-2 inline-flex items-center gap-3 align-middle">
-                <span className="font-mono text-xs text-foreground">
-                  Q4_K_M
-                </span>
-                <span className="text-[9px] font-medium text-green-400">
-                  downloaded
-                </span>
-                <span className="text-[10px] text-muted-foreground">16 GB</span>
-                <span className="inline-flex size-4 items-center justify-center rounded bg-black/[0.06] dark:bg-white/[0.08]">
-                  <HugeiconsIcon
-                    icon={Settings02Icon}
-                    strokeWidth={1.75}
-                    className="size-2.5 text-muted-foreground/80"
-                  />
-                </span>
-              </span>
-            </span>
-          }
-        >
-          <Switch
-            checked={loadOnSelection}
-            onCheckedChange={setLoadOnSelection}
-          />
-        </SettingsRow>
         <SettingsRow
           label="Expand quantizations"
           description={
@@ -481,191 +302,6 @@ export function ChatTab() {
           />
         </SettingsRow>
       </SettingsSection>
-
-      <SettingsSection title={t("settings.chat.data")}>
-        <SettingsRow
-          label="Archived chats"
-          description="View and manage chats you have archived."
-        >
-          <Button
-            variant="outline"
-            size="sm"
-            onClick={() => setArchivedOpen(true)}
-          >
-            Manage
-          </Button>
-        </SettingsRow>
-
-        <SettingsRow
-          label="Confirm before deleting"
-          description="Ask for confirmation before a chat is deleted. Turn off to delete instantly."
-        >
-          <Switch
-            checked={confirmDeleteChats}
-            onCheckedChange={setConfirmDeleteChats}
-          />
-        </SettingsRow>
-
-        <SettingsRow
-          label={t("settings.chat.exportHistory")}
-          description={t("settings.chat.exportHistoryDescription")}
-        >
-          <Button
-            variant="outline"
-            size="sm"
-            onClick={handleExport}
-            disabled={exporting || count === 0}
-          >
-            <HugeiconsIcon icon={Download01Icon} className="size-3.5 mr-1.5" />
-            {exporting
-              ? t("settings.chat.exportingAction")
-              : t("settings.chat.exportAction")}
-          </Button>
-        </SettingsRow>
-
-        <SettingsRow
-          label={t("settings.chat.exportConversations")}
-          description={t("settings.chat.exportConversationsDescription")}
-        >
-          <DropdownMenu>
-            <DropdownMenuTrigger asChild={true}>
-              <Button variant="outline" size="sm" disabled={count === 0}>
-                <HugeiconsIcon
-                  icon={Download01Icon}
-                  className="size-3.5 mr-1.5"
-                />
-                {t("settings.chat.exportConversationsAction")}
-              </Button>
-            </DropdownMenuTrigger>
-            <DropdownMenuContent align="end" className="w-56">
-              {(
-                [
-                  { scope: "recents", label: "exportScopeRecents" },
-                  { scope: "all", label: "exportScopeAll" },
-                ] as const
-              ).map(({ scope, label }) => (
-                <DropdownMenuSub key={scope}>
-                  <DropdownMenuSubTrigger>
-                    <HugeiconsIcon
-                      icon={Download01Icon}
-                      className="size-3.5 mr-1"
-                    />
-                    {t(`settings.chat.${label}`)}
-                  </DropdownMenuSubTrigger>
-                  <DropdownMenuSubContent className="w-56">
-                    {EXPORT_FORMATS_LIST.map(({ fmt, label: fmtLabel }) => (
-                      <DropdownMenuItem
-                        key={`${scope}-m-${fmt}`}
-                        onSelect={() =>
-                          void bulkExportConversationsByScope(scope, fmt, true)
-                        }
-                      >
-                        {fmtLabel} {t("settings.chat.exportCombinedSuffix")}
-                      </DropdownMenuItem>
-                    ))}
-                    <DropdownMenuSeparator />
-                    {EXPORT_FORMATS_LIST.map(({ fmt, label: fmtLabel }) => (
-                      <DropdownMenuItem
-                        key={`${scope}-s-${fmt}`}
-                        onSelect={() =>
-                          void bulkExportConversationsByScope(scope, fmt, false)
-                        }
-                      >
-                        {fmtLabel} {t("settings.chat.exportPerChatSuffix")}
-                      </DropdownMenuItem>
-                    ))}
-                  </DropdownMenuSubContent>
-                </DropdownMenuSub>
-              ))}
-            </DropdownMenuContent>
-          </DropdownMenu>
-        </SettingsRow>
-
-        <SettingsRow
-          label={t("settings.chat.importChats")}
-          description={t("settings.chat.importChatsDescription")}
-        >
-          <Button
-            variant="outline"
-            size="sm"
-            onClick={() => importInputRef.current?.click()}
-          >
-            <HugeiconsIcon icon={Upload01Icon} className="size-3.5 mr-1.5" />
-            {t("settings.chat.importChatsAction")}
-          </Button>
-          <input
-            ref={importInputRef}
-            type="file"
-            accept=".jsonl,.ndjson,.csv"
-            className="hidden"
-            onChange={(e) => {
-              const file = e.target.files?.[0];
-              e.target.value = "";
-              if (file) void handleImport(file);
-            }}
-          />
-        </SettingsRow>
-
-        <SettingsRow
-          destructive={true}
-          label={t("settings.chat.clearAllChats")}
-          description={
-            count === null
-              ? t("settings.chat.clearAllChatsDescription")
-              : count === 0
-                ? t("settings.chat.noChatsToClear")
-                : count === 1
-                  ? t("settings.chat.clearOneChatDescription")
-                  : t("settings.chat.clearChatCountDescription", { count })
-          }
-        >
-          <Button
-            variant="outline"
-            size="sm"
-            onClick={() => setConfirmOpen(true)}
-            disabled={count === 0}
-            className="text-destructive hover:text-destructive hover:border-destructive/60"
-          >
-            <HugeiconsIcon icon={Delete02Icon} className="size-3.5 mr-1.5" />
-            {t("settings.chat.clearChatsAction")}
-          </Button>
-        </SettingsRow>
-      </SettingsSection>
-
-      <ArchivedChatsDialog open={archivedOpen} onOpenChange={setArchivedOpen} />
-
-      <Dialog open={confirmOpen} onOpenChange={setConfirmOpen}>
-        <DialogContent className="max-w-md">
-          <DialogHeader>
-            <DialogTitle>
-              {count === 1
-                ? t("settings.chat.clearOneChatTitle")
-                : t("settings.chat.clearChatsTitle", { count: count ?? 0 })}
-            </DialogTitle>
-            <DialogDescription>
-              {t("settings.chat.clearChatsConfirmDescription")}
-            </DialogDescription>
-          </DialogHeader>
-          <DialogFooter>
-            <Button variant="outline" onClick={() => setConfirmOpen(false)}>
-              {t("common.cancel")}
-            </Button>
-            <Button
-              onClick={handleClear}
-              disabled={clearing}
-              className="bg-destructive hover:bg-destructive/90 text-destructive-foreground"
-            >
-              {clearing
-                ? t("settings.chat.clearingAction")
-                : count === 1
-                  ? t("settings.chat.clearOneChatAction")
-                  : t("settings.chat.clearChatCountAction", {
-                      count: count ?? 0,
-                    })}
-            </Button>
-          </DialogFooter>
-        </DialogContent>
-      </Dialog>
     </div>
   );
 }
diff --git a/studio/frontend/src/features/settings/tabs/data-tab.tsx b/studio/frontend/src/features/settings/tabs/data-tab.tsx
new file mode 100644
index 0000000000..e2b524f46e
--- /dev/null
+++ b/studio/frontend/src/features/settings/tabs/data-tab.tsx
@@ -0,0 +1,758 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { Button } from "@/components/ui/button";
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from "@/components/ui/dialog";
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuSeparator,
+  DropdownMenuSub,
+  DropdownMenuSubContent,
+  DropdownMenuSubTrigger,
+  DropdownMenuTrigger,
+} from "@/components/ui/dropdown-menu";
+import { Spinner } from "@/components/ui/spinner";
+import { Switch } from "@/components/ui/switch";
+import { usePlatformStore } from "@/config/env";
+import {
+  EXPORT_FORMATS_LIST,
+  type FineTuneFormat,
+  archiveAllChatItems,
+  bulkExportConversationsByScope,
+  clearAllChats,
+  countAllChats,
+  downloadArchivedChatExport,
+  downloadChatExport,
+  exportFineTuneJsonl,
+  importConversationsFromFile,
+  useChatPreferencesStore,
+  useChatRuntimeStore,
+  useChatSidebarItems,
+} from "@/features/chat";
+import { useT } from "@/i18n";
+
+import { isTauri } from "@/lib/api-base";
+import { isDownloadCancelled, pickNativeChatImport } from "@/lib/native-files";
+import {
+  ChevronDownStandardIcon,
+  ChevronRightStandardIcon,
+} from "@/lib/chevron-icons";
+import { toast } from "@/lib/toast";
+import {
+  Archive02Icon,
+  ArrowLeft01Icon,
+  Delete02Icon,
+  Download01Icon,
+  Tick02Icon,
+  Upload01Icon,
+} from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
+import { useNavigate, useRouterState } from "@tanstack/react-router";
+import { useEffect, useRef, useState } from "react";
+import { ArchivedChatsView } from "../components/archived-chats-dialog";
+import {
+  createFineTuneRecipeFromChats,
+  loadFineTuneDatasetInTrainTab,
+} from "../components/finetune-recipe";
+import { SettingsRow } from "../components/settings-row";
+import { SettingsSection } from "../components/settings-section";
+import { UploadedFilesView } from "../components/uploaded-files-dialog";
+import { useSettingsDialogStore } from "../stores/settings-dialog-store";
+
+export function DataTab() {
+  const t = useT();
+  const navigate = useNavigate();
+  const archivedChatsRequested = useSettingsDialogStore(
+    (s) => s.archivedChatsRequested,
+  );
+  const consumeArchivedChatsRequest = useSettingsDialogStore(
+    (s) => s.consumeArchivedChatsRequest,
+  );
+  const [confirmOpen, setConfirmOpen] = useState(false);
+  const [archiveConfirmOpen, setArchiveConfirmOpen] = useState(false);
+  // Subpages swap the Data tab body instead of opening nested dialogs.
+  const [subpage, setSubpage] = useState<"main" | "archived" | "files">(
+    archivedChatsRequested ? "archived" : "main",
+  );
+  const [count, setCount] = useState<number | null>(null);
+  const [exporting, setExporting] = useState(false);
+  const [archivedExporting, setArchivedExporting] = useState(false);
+  // Gates the archived subpage Export button.
+  const { archivedItems } = useChatSidebarItems({ requireMessages: false });
+  const [clearing, setClearing] = useState(false);
+  const [archiving, setArchiving] = useState(false);
+  const [fineTuneExporting, setFineTuneExporting] = useState(false);
+  const [openingRecipe, setOpeningRecipe] = useState(false);
+  const [loadingTraining, setLoadingTraining] = useState(false);
+  // Chat-only hosts redirect /studio back to /chat, so loading a dataset in
+  // the Train tab would upload it and then strand the user; gate the action
+  // the same way the sidebar gates Train.
+  const chatOnly = usePlatformStore((s) => s.isChatOnly());
+  const [fineTuneAction, setFineTuneAction] = useState<
+    "train" | "recipes" | "export"
+  >(chatOnly ? "export" : "train");
+  // Chat Completions (OpenAI messages) is the only export format we ship.
+  const fineTuneFormat: FineTuneFormat = "openai";
+
+  // The MLX self-heal can flip chat-only while the dialog is open.
+  useEffect(() => {
+    if (chatOnly) {
+      setFineTuneAction((a) => (a === "train" ? "export" : a));
+    }
+  }, [chatOnly]);
+  // Requests can arrive after Data is already mounted (for example from the
+  // archive-all toast), so always switch before consuming the flag.
+  useEffect(() => {
+    if (!archivedChatsRequested) return;
+    let cancelled = false;
+    queueMicrotask(() => {
+      if (cancelled) return;
+      setSubpage("archived");
+      consumeArchivedChatsRequest();
+    });
+    return () => {
+      cancelled = true;
+    };
+  }, [archivedChatsRequested, consumeArchivedChatsRequest]);
+
+  const confirmDeleteChats = useChatPreferencesStore(
+    (state) => state.confirmDeleteChats,
+  );
+  const setConfirmDeleteChats = useChatPreferencesStore(
+    (state) => state.setConfirmDeleteChats,
+  );
+
+  const storeThreadId = useChatRuntimeStore((s) => s.activeThreadId);
+  // Open chat id from the route (single thread or compare pair), mirroring
+  // ArchivedChatsView: compare panes only live in the search params.
+  const openChatId = useRouterState({
+    select: (s) => {
+      if (!s.location.pathname.startsWith("/chat")) return undefined;
+      const search = s.location.search as Record<string, string | undefined>;
+      return search.thread ?? search.compare ?? storeThreadId ?? undefined;
+    },
+  });
+
+  useEffect(() => {
+    void countAllChats().then(setCount);
+  }, []);
+
+  const handleExport = async () => {
+    setExporting(true);
+    try {
+      await downloadChatExport();
+    } catch (error) {
+      if (!isDownloadCancelled(error)) {
+        toast.error("Could not export chats", {
+          description: error instanceof Error ? error.message : String(error),
+        });
+      }
+    } finally {
+      setExporting(false);
+    }
+  };
+
+  const handleExportArchived = async () => {
+    setArchivedExporting(true);
+    try {
+      const exported = await downloadArchivedChatExport();
+      toast.success(
+        exported === 0
+          ? t("settings.data.noArchivedChatsToExport")
+          : exported === 1
+            ? t("settings.data.exportedOneArchivedChat")
+            : t("settings.data.exportedArchivedChatCount", { count: exported }),
+      );
+    } catch (error) {
+      if (!isDownloadCancelled(error)) {
+        toast.error(t("settings.data.failedToExportArchivedChats"), {
+          description: error instanceof Error ? error.message : undefined,
+        });
+      }
+    } finally {
+      setArchivedExporting(false);
+    }
+  };
+
+  const importInputRef = useRef<HTMLInputElement>(null);
+  const handleImport = async (file: File) => {
+    try {
+      const imported = await importConversationsFromFile(file, null);
+      if (imported === 0) {
+        toast.info(t("settings.chat.importNoConversations"));
+      } else {
+        toast.success(
+          imported === 1
+            ? t("settings.chat.importedOneChat")
+            : t("settings.chat.importedChatCount", { count: imported }),
+        );
+        setCount(await countAllChats().catch(() => count));
+      }
+    } catch {
+      toast.error(t("settings.chat.importFailed"));
+    }
+  };
+
+  const handleImportClick = async () => {
+    if (!isTauri) {
+      importInputRef.current?.click();
+      return;
+    }
+    try {
+      const selected = await pickNativeChatImport();
+      if (!selected) {
+        return;
+      }
+      await handleImport(new File([selected.content], selected.name));
+    } catch (error) {
+      toast.error(t("settings.chat.importFailed"), {
+        description: error instanceof Error ? error.message : String(error),
+      });
+    }
+  };
+
+  const handleArchiveAll = async () => {
+    setArchiving(true);
+    try {
+      const archived = await archiveAllChatItems(openChatId, (view) => {
+        navigate({ to: "/chat", search: { new: view.newThreadNonce } });
+      });
+      setArchiveConfirmOpen(false);
+      toast.success(
+        archived === 0
+          ? t("settings.data.noChatsToArchive")
+          : archived === 1
+            ? t("settings.data.archivedOneChat")
+            : t("settings.data.archivedChatCount", { count: archived }),
+      );
+    } catch (error) {
+      toast.error(t("settings.data.failedToArchiveChats"), {
+        description: error instanceof Error ? error.message : undefined,
+      });
+    } finally {
+      setArchiving(false);
+    }
+  };
+
+  const handleFineTuneExport = async () => {
+    setFineTuneExporting(true);
+    try {
+      await exportFineTuneJsonl(fineTuneFormat);
+    } catch (error) {
+      if (!isDownloadCancelled(error)) {
+        toast.error(t("settings.data.fineTuneExportFailed"), {
+          description: error instanceof Error ? error.message : undefined,
+        });
+      }
+    } finally {
+      setFineTuneExporting(false);
+    }
+  };
+
+  const handleOpenInRecipes = async () => {
+    setOpeningRecipe(true);
+    try {
+      const recipeId = await createFineTuneRecipeFromChats(fineTuneFormat);
+      if (!recipeId) return;
+      useSettingsDialogStore.getState().closeDialog();
+      void navigate({ to: "/data-recipes/$recipeId", params: { recipeId } });
+    } catch (error) {
+      toast.error(t("settings.data.fineTuneRecipeFailed"), {
+        description: error instanceof Error ? error.message : undefined,
+      });
+    } finally {
+      setOpeningRecipe(false);
+    }
+  };
+
+  const handleUseInTraining = async () => {
+    setLoadingTraining(true);
+    try {
+      const loaded = await loadFineTuneDatasetInTrainTab(fineTuneFormat);
+      if (!loaded) return;
+      useSettingsDialogStore.getState().closeDialog();
+      void navigate({ to: "/studio" });
+    } catch (error) {
+      toast.error(t("settings.data.fineTuneTrainFailed"), {
+        description: error instanceof Error ? error.message : undefined,
+      });
+    } finally {
+      setLoadingTraining(false);
+    }
+  };
+
+  const fineTuneActionLabels = {
+    train: t("settings.data.fineTuneTrainAction"),
+    recipes: t("settings.data.fineTuneOpenRecipesAction"),
+    export: t("settings.data.fineTuneExportAction"),
+  } as const;
+  const fineTuneBusy = loadingTraining || openingRecipe || fineTuneExporting;
+  const runFineTuneAction = () => {
+    if (fineTuneAction === "train") {
+      if (chatOnly) return;
+      void handleUseInTraining();
+    } else if (fineTuneAction === "recipes") void handleOpenInRecipes();
+    else void handleFineTuneExport();
+  };
+
+  const handleClear = async () => {
+    setClearing(true);
+    try {
+      const result = await clearAllChats();
+      const clearedCount = result.deletedThreadIds.length;
+      const hasFailedStore =
+        result.backend === "failed" || result.legacy === "failed";
+      if (!hasFailedStore && result.failedThreadIds.length === 0) {
+        setCount(0);
+        setConfirmOpen(false);
+        toast.success(
+          clearedCount === 0
+            ? t("settings.chat.clearedAllChats")
+            : clearedCount === 1
+              ? t("settings.chat.clearedOneChat")
+              : t("settings.chat.clearedChatCount", { count: clearedCount }),
+        );
+        return;
+      }
+
+      const fallbackRemaining =
+        result.failedThreadIds.length > 0
+          ? result.failedThreadIds.length
+          : (count ?? 0);
+      const remaining = await countAllChats().catch(() => fallbackRemaining);
+      setCount(remaining);
+      setConfirmOpen(false);
+      toast.warning(t("settings.chat.someChatsCouldNotBeCleared"), {
+        description:
+          result.failedThreadIds.length > 0
+            ? clearedCount === 1 && result.failedThreadIds.length === 1
+              ? t("settings.chat.oneChatClearedRemainOne")
+              : clearedCount === 1
+                ? t("settings.chat.oneChatClearedRemain", {
+                    remainingCount: result.failedThreadIds.length,
+                  })
+                : result.failedThreadIds.length === 1
+                  ? t("settings.chat.chatsClearedRemainOne", { clearedCount })
+                  : t("settings.chat.chatsClearedRemain", {
+                      clearedCount,
+                      remainingCount: result.failedThreadIds.length,
+                    })
+            : remaining === 1
+              ? t("settings.chat.storageClearFailedOne")
+              : t("settings.chat.storageClearFailed", { count: remaining }),
+      });
+    } catch (error) {
+      const remaining = await countAllChats().catch(() => count);
+      setCount(remaining);
+      toast.error(t("settings.chat.failedToClearChats"), {
+        description: error instanceof Error ? error.message : undefined,
+      });
+    } finally {
+      setClearing(false);
+    }
+  };
+
+  if (subpage === "archived") {
+    return (
+      <div className="flex flex-col gap-6">
+        <header className="flex items-center gap-2">
+          <button
+            type="button"
+            onClick={() => setSubpage("main")}
+            aria-label={`Back to ${t("settings.data.title")}`}
+            className="inline-flex size-7 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-muted hover:text-foreground"
+          >
+            <HugeiconsIcon icon={ArrowLeft01Icon} className="size-4" />
+          </button>
+          <h1 className="text-xl font-semibold font-heading">
+            {t("settings.data.title")}
+          </h1>
+        </header>
+        <div className="flex items-start justify-between gap-4">
+          <div className="flex flex-col gap-1">
+            <h2 className="text-sm font-semibold">
+              {t("settings.data.archivedChats")}
+            </h2>
+            <p className="text-xs text-muted-foreground">
+              {t("settings.data.archivedChatsDescription")}
+            </p>
+          </div>
+          {archivedItems.length > 0 && (
+            <Button
+              variant="outline"
+              size="sm"
+              className="shrink-0"
+              onClick={handleExportArchived}
+              disabled={archivedExporting}
+            >
+              {archivedExporting ? (
+                <Spinner className="size-4" />
+              ) : (
+                <HugeiconsIcon
+                  icon={Download01Icon}
+                  strokeWidth={1.75}
+                  className="size-4"
+                />
+              )}
+              {archivedExporting
+                ? t("settings.data.exportingArchivedChats")
+                : t("settings.data.exportArchivedChats")}
+            </Button>
+          )}
+        </div>
+        <ArchivedChatsView />
+      </div>
+    );
+  }
+
+  if (subpage === "files") {
+    return (
+      <div className="flex flex-col gap-6">
+        <header className="flex items-center gap-2">
+          <button
+            type="button"
+            onClick={() => setSubpage("main")}
+            aria-label={`Back to ${t("settings.data.title")}`}
+            className="inline-flex size-7 items-center justify-center rounded-full text-muted-foreground transition-colors hover:bg-muted hover:text-foreground"
+          >
+            <HugeiconsIcon icon={ArrowLeft01Icon} className="size-4" />
+          </button>
+          <h1 className="text-xl font-semibold font-heading">
+            {t("settings.data.title")}
+          </h1>
+        </header>
+        <div className="flex flex-col gap-1">
+          <h2 className="text-sm font-semibold">
+            {t("settings.data.uploadedFiles")}
+          </h2>
+          <p className="text-xs text-muted-foreground">
+            {t("settings.data.uploadedFilesDescription")}
+          </p>
+        </div>
+        <UploadedFilesView />
+      </div>
+    );
+  }
+
+  return (
+    <div className="flex flex-col gap-6">
+      <header className="flex flex-col gap-1">
+        <h1 className="text-xl font-semibold font-heading">
+          {t("settings.data.title")}
+        </h1>
+        <p className="text-xs text-muted-foreground">
+          {t("settings.data.description")}
+        </p>
+      </header>
+
+      <div className="flex flex-col divide-y divide-border/60">
+        <SettingsRow
+          alignTop={true}
+          label={t("settings.data.fineTuneExport")}
+          description={t("settings.data.fineTuneExportDescription")}
+        >
+          <div className="flex items-center gap-2">
+            <DropdownMenu>
+              <DropdownMenuTrigger asChild={true}>
+                {/* Fixed width so switching actions never resizes the row. */}
+                <Button
+                  variant="outline"
+                  size="sm"
+                  disabled={count === 0}
+                  className="w-44 justify-between"
+                >
+                  <span className="truncate">
+                    {fineTuneActionLabels[fineTuneAction]}
+                  </span>
+                  <HugeiconsIcon
+                    icon={ChevronDownStandardIcon}
+                    className="size-3.5 shrink-0"
+                  />
+                </Button>
+              </DropdownMenuTrigger>
+              <DropdownMenuContent align="end" className="w-56">
+                {(["export", "train", "recipes"] as const).map((action) => (
+                  <DropdownMenuItem
+                    key={action}
+                    disabled={action === "train" && chatOnly}
+                    onSelect={() => setFineTuneAction(action)}
+                  >
+                    <span className="flex-1">
+                      {fineTuneActionLabels[action]}
+                    </span>
+                    {fineTuneAction === action ? (
+                      <HugeiconsIcon icon={Tick02Icon} className="size-4" />
+                    ) : null}
+                  </DropdownMenuItem>
+                ))}
+              </DropdownMenuContent>
+            </DropdownMenu>
+            <Button
+              size="icon-sm"
+              onClick={runFineTuneAction}
+              disabled={fineTuneBusy || count === 0}
+              aria-label={t("settings.data.fineTuneRunAction")}
+              title={`${t("settings.data.fineTuneRunAction")}: ${fineTuneActionLabels[fineTuneAction]}`}
+              className="shrink-0 rounded-full"
+            >
+              {fineTuneBusy ? (
+                <Spinner className="size-4" />
+              ) : (
+                <HugeiconsIcon
+                  icon={ChevronRightStandardIcon}
+                  strokeWidth={2.5}
+                  className="size-4"
+                />
+              )}
+            </Button>
+          </div>
+        </SettingsRow>
+
+        <SettingsRow
+          label={t("settings.data.archivedChats")}
+          description={t("settings.data.archivedChatsDescription")}
+        >
+          <Button
+            variant="outline"
+            size="sm"
+            onClick={() => setSubpage("archived")}
+          >
+            {t("settings.data.manageAction")}
+          </Button>
+        </SettingsRow>
+
+        <SettingsRow
+          label={t("settings.data.archiveAllChats")}
+          description={t("settings.data.archiveAllChatsDescription")}
+        >
+          <Button
+            variant="outline"
+            size="sm"
+            onClick={() => setArchiveConfirmOpen(true)}
+          >
+            <HugeiconsIcon icon={Archive02Icon} className="size-3.5 mr-1.5" />
+            {t("settings.data.archiveAllAction")}
+          </Button>
+        </SettingsRow>
+
+        <SettingsRow
+          label={t("settings.data.confirmBeforeDeleting")}
+          description={t("settings.data.confirmBeforeDeletingDescription")}
+        >
+          <Switch
+            checked={confirmDeleteChats}
+            onCheckedChange={setConfirmDeleteChats}
+          />
+        </SettingsRow>
+
+        <SettingsRow
+          label={t("settings.chat.exportHistory")}
+          description={t("settings.chat.exportHistoryDescription")}
+        >
+          <Button
+            variant="outline"
+            size="sm"
+            onClick={handleExport}
+            disabled={exporting || count === 0}
+          >
+            <HugeiconsIcon icon={Download01Icon} className="size-3.5 mr-1.5" />
+            {exporting
+              ? t("settings.chat.exportingAction")
+              : t("settings.chat.exportAction")}
+          </Button>
+        </SettingsRow>
+
+        <SettingsRow
+          label={t("settings.chat.exportConversations")}
+          description={t("settings.chat.exportConversationsDescription")}
+        >
+          <DropdownMenu>
+            <DropdownMenuTrigger asChild={true}>
+              <Button variant="outline" size="sm" disabled={count === 0}>
+                <HugeiconsIcon
+                  icon={Download01Icon}
+                  className="size-3.5 mr-1.5"
+                />
+                {t("settings.chat.exportConversationsAction")}
+              </Button>
+            </DropdownMenuTrigger>
+            <DropdownMenuContent align="end" className="w-56">
+              {(
+                [
+                  { scope: "recents", label: "exportScopeRecents" },
+                  { scope: "all", label: "exportScopeAll" },
+                ] as const
+              ).map(({ scope, label }) => (
+                <DropdownMenuSub key={scope}>
+                  <DropdownMenuSubTrigger>
+                    <HugeiconsIcon
+                      icon={Download01Icon}
+                      className="size-3.5 mr-1"
+                    />
+                    {t(`settings.chat.${label}`)}
+                  </DropdownMenuSubTrigger>
+                  <DropdownMenuSubContent className="w-56">
+                    {EXPORT_FORMATS_LIST.map(({ fmt, label: fmtLabel }) => (
+                      <DropdownMenuItem
+                        key={`${scope}-m-${fmt}`}
+                        onSelect={() =>
+                          void bulkExportConversationsByScope(scope, fmt, true)
+                        }
+                      >
+                        {fmtLabel} {t("settings.chat.exportCombinedSuffix")}
+                      </DropdownMenuItem>
+                    ))}
+                    <DropdownMenuSeparator />
+                    {EXPORT_FORMATS_LIST.map(({ fmt, label: fmtLabel }) => (
+                      <DropdownMenuItem
+                        key={`${scope}-s-${fmt}`}
+                        onSelect={() =>
+                          void bulkExportConversationsByScope(scope, fmt, false)
+                        }
+                      >
+                        {fmtLabel} {t("settings.chat.exportPerChatSuffix")}
+                      </DropdownMenuItem>
+                    ))}
+                  </DropdownMenuSubContent>
+                </DropdownMenuSub>
+              ))}
+            </DropdownMenuContent>
+          </DropdownMenu>
+        </SettingsRow>
+
+        <SettingsRow
+          destructive={true}
+          // divide-y already draws the row separator; drop the extra border.
+          className="border-t-0 mt-0 pt-3"
+          label={t("settings.chat.clearAllChats")}
+          description={
+            count === null
+              ? t("settings.chat.clearAllChatsDescription")
+              : count === 0
+                ? t("settings.chat.noChatsToClear")
+                : count === 1
+                  ? t("settings.chat.clearOneChatDescription")
+                  : t("settings.chat.clearChatCountDescription", { count })
+          }
+        >
+          <Button
+            variant="outline"
+            size="sm"
+            onClick={() => setConfirmOpen(true)}
+            disabled={count === 0}
+            className="text-destructive hover:text-destructive hover:border-destructive/60"
+          >
+            <HugeiconsIcon icon={Delete02Icon} className="size-3.5 mr-1.5" />
+            {t("settings.chat.clearChatsAction")}
+          </Button>
+        </SettingsRow>
+
+        <SettingsRow
+          label={t("settings.chat.importChats")}
+          description={t("settings.chat.importChatsDescription")}
+        >
+          <Button
+            variant="outline"
+            size="sm"
+            onClick={() => void handleImportClick()}
+          >
+            <HugeiconsIcon icon={Upload01Icon} className="size-3.5 mr-1.5" />
+            {t("settings.chat.importChatsAction")}
+          </Button>
+          <input
+            ref={importInputRef}
+            type="file"
+            accept=".jsonl,.ndjson,.csv"
+            className="hidden"
+            onChange={(e) => {
+              const file = e.target.files?.[0];
+              e.target.value = "";
+              if (file) void handleImport(file);
+            }}
+          />
+        </SettingsRow>
+      </div>
+
+      <SettingsSection title={t("settings.data.filesSection")}>
+        <SettingsRow
+          label={t("settings.data.uploadedFiles")}
+          description={t("settings.data.uploadedFilesDescription")}
+        >
+          <Button
+            variant="outline"
+            size="sm"
+            onClick={() => setSubpage("files")}
+          >
+            {t("settings.data.manageAction")}
+          </Button>
+        </SettingsRow>
+      </SettingsSection>
+
+      <Dialog open={archiveConfirmOpen} onOpenChange={setArchiveConfirmOpen}>
+        <DialogContent className="max-w-md">
+          <DialogHeader>
+            <DialogTitle>{t("settings.data.archiveAllChatsTitle")}</DialogTitle>
+            <DialogDescription>
+              {t("settings.data.archiveAllChatsConfirmDescription")}
+            </DialogDescription>
+          </DialogHeader>
+          <DialogFooter>
+            <Button
+              variant="outline"
+              onClick={() => setArchiveConfirmOpen(false)}
+            >
+              {t("common.cancel")}
+            </Button>
+            <Button onClick={handleArchiveAll} disabled={archiving}>
+              {archiving
+                ? t("settings.data.archivingAction")
+                : t("settings.data.archiveAllAction")}
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
+
+      <Dialog open={confirmOpen} onOpenChange={setConfirmOpen}>
+        <DialogContent className="max-w-md">
+          <DialogHeader>
+            <DialogTitle>
+              {count === 1
+                ? t("settings.chat.clearOneChatTitle")
+                : t("settings.chat.clearChatsTitle", { count: count ?? 0 })}
+            </DialogTitle>
+            <DialogDescription>
+              {t("settings.chat.clearChatsConfirmDescription")}
+            </DialogDescription>
+          </DialogHeader>
+          <DialogFooter>
+            <Button variant="outline" onClick={() => setConfirmOpen(false)}>
+              {t("common.cancel")}
+            </Button>
+            <Button
+              onClick={handleClear}
+              disabled={clearing}
+              className="bg-destructive hover:bg-destructive/90 text-destructive-foreground"
+            >
+              {clearing
+                ? t("settings.chat.clearingAction")
+                : count === 1
+                  ? t("settings.chat.clearOneChatAction")
+                  : t("settings.chat.clearChatCountAction", {
+                      count: count ?? 0,
+                    })}
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
+    </div>
+  );
+}
diff --git a/studio/frontend/src/features/settings/tabs/general-tab.tsx b/studio/frontend/src/features/settings/tabs/general-tab.tsx
index 73a33fd155..1d5c533a25 100644
--- a/studio/frontend/src/features/settings/tabs/general-tab.tsx
+++ b/studio/frontend/src/features/settings/tabs/general-tab.tsx
@@ -15,15 +15,14 @@ import { Switch } from "@/components/ui/switch";
 import { usePlatformStore } from "@/config/env";
 import { resetOnboardingDone } from "@/features/auth";
 import { PermissionModeDropdown, useChatRuntimeStore } from "@/features/chat";
-import { openModelsDir } from "@/features/native-intents";
 import { emitTrainingRunsChanged } from "@/features/training";
 import {
   setShowLlamaUpdateBanner,
   useShowLlamaUpdateBanner,
 } from "@/hooks/use-llama-update-pref";
+import { useHfTokenValidation } from "@/hooks";
 import { LOCALE_STORAGE_KEY, useT } from "@/i18n";
 import { isTauri } from "@/lib/api-base";
-import { copyToClipboard } from "@/lib/copy-to-clipboard";
 import { toast } from "@/lib/toast";
 import { cn } from "@/lib/utils";
 import { useNavigate, useRouterState } from "@tanstack/react-router";
@@ -42,7 +41,6 @@ import {
   loadHelperPrecacheSettings,
   updateHelperPrecacheSettings,
 } from "../api/helper-precache";
-import { type ModelsFolder, loadModelsFolder } from "../api/models-folder";
 import {
   type PreviewSharingSettings,
   loadPreviewSharing,
@@ -92,9 +90,11 @@ const PREFS_KEYS: string[] = [
   "unsloth_chat_inference_params",
   "unsloth_chat_collapsible_state",
   "unsloth_chat_preferences",
+  "unsloth_model_configs",
+  "unsloth_model_configs_migrated",
   "unsloth_load_settings",
-  // Model selector settings ("Select model settings" group)
   "unsloth_chat_load_on_selection",
+  // Model selector settings ("Select model settings" group)
   "unsloth_chat_expand_quantizations",
   "unsloth_chat_show_all_quantizations",
   "unsloth_models_fit_on_device_only",
@@ -180,7 +180,6 @@ export function GeneralTab() {
   const [isSavingPreviewSharing, setIsSavingPreviewSharing] = useState(false);
   const [revokePreviewOpen, setRevokePreviewOpen] = useState(false);
   const [isRevokingPreview, setIsRevokingPreview] = useState(false);
-  const [modelsFolder, setModelsFolder] = useState<ModelsFolder | null>(null);
   const [embeddingModel, setEmbeddingModel] =
     useState<EmbeddingModelSettings | null>(null);
   const [draftEmbeddingModel, setDraftEmbeddingModel] = useState("");
@@ -216,11 +215,19 @@ export function GeneralTab() {
     if (trimmed !== hfToken) setHfToken(trimmed);
   };
 
-  // Show an "accepted" tick once a non-empty token has been committed to the
-  // store and the field still matches it (i.e. not mid-edit). Gives the user
-  // feedback that a pasted token was saved.
-  const tokenSaved =
+  const clearHfToken = () => {
+    draftRef.current = "";
+    setDraftToken("");
+    setHfToken("");
+  };
+
+  // Only show the success tick for the currently displayed token after the
+  // authenticated validation endpoint has confirmed it. A saved token alone
+  // may still be malformed, expired, or revoked.
+  const tokenIsCurrent =
     draftToken.trim().length > 0 && draftToken.trim() === (hfToken ?? "");
+  const tokenValidation = useHfTokenValidation(hfToken ?? "");
+  const tokenValidated = tokenIsCurrent && tokenValidation.isValid === true;
 
   useEffect(() => {
     let cancelled = false;
@@ -306,43 +313,6 @@ export function GeneralTab() {
     };
   }, [t]);
 
-  useEffect(() => {
-    let cancelled = false;
-    void loadModelsFolder()
-      .then((folder) => {
-        if (cancelled) return;
-        setModelsFolder(folder);
-      })
-      .catch(() => {
-        // Non-critical: leave the row hidden if the path can't be resolved.
-      });
-    return () => {
-      cancelled = true;
-    };
-  }, []);
-
-  // Desktop opens the folder in the OS file manager; the browser can't, so it
-  // falls back to copying the path (which is the info users actually want).
-  const handleModelsFolder = async () => {
-    const folder = modelsFolder;
-    if (!folder) return;
-    if (isTauri) {
-      try {
-        await openModelsDir(folder.path);
-      } catch (error) {
-        toast.error(t("settings.general.storage.openError"), {
-          description: error instanceof Error ? error.message : undefined,
-        });
-      }
-      return;
-    }
-    if (await copyToClipboard(folder.path)) {
-      toast.success(t("settings.general.storage.copied"));
-    } else {
-      toast.error(t("settings.general.storage.copyError"));
-    }
-  };
-
   const saveHelperPrecache = async (enabled: boolean) => {
     setIsSavingHelperPrecache(true);
     setHelperPrecacheError(null);
@@ -498,46 +468,70 @@ export function GeneralTab() {
           label={t("settings.general.huggingFaceToken")}
           description={t("settings.general.huggingFaceTokenDescription")}
         >
-          <div className="relative w-[260px]">
-            <Input
-              type={showToken ? "text" : "password"}
-              placeholder="hf_…"
-              value={draftToken}
-              onChange={(e) => setDraftToken(e.target.value)}
-              onBlur={commitToken}
-              className={cn(
-                "h-8 w-full font-mono text-xs",
-                tokenSaved ? "pr-14" : "pr-8",
-              )}
-            />
-            {tokenSaved ? (
-              // Decorative: pointer-events-none lets clicks reach the input
-              // underneath so the field still focuses anywhere.
-              <span
-                className="pointer-events-none absolute right-7 top-1/2 flex size-5 -translate-y-1/2 items-center justify-center text-emerald-600 duration-150 animate-in fade-in zoom-in dark:text-emerald-500"
-                role="img"
-                aria-label={t("settings.general.tokenSaved")}
+          <div className="flex flex-col items-end gap-1.5">
+            <div className="flex items-center gap-2">
+              <div className="relative w-[260px]">
+                <Input
+                  type={showToken ? "text" : "password"}
+                  name="hf-token"
+                  autoComplete="new-password"
+                  spellCheck={false}
+                  placeholder="hf_…"
+                  value={draftToken}
+                  onChange={(e) => setDraftToken(e.target.value)}
+                  onBlur={commitToken}
+                  className={cn(
+                    "h-8 w-full font-mono text-xs",
+                    tokenValidated ? "pr-14" : "pr-8",
+                  )}
+                />
+                {tokenValidated ? (
+                  // Decorative: pointer-events-none lets clicks reach the input
+                  // underneath so the field still focuses anywhere.
+                  <span
+                    className="pointer-events-none absolute right-7 top-1/2 flex size-5 -translate-y-1/2 items-center justify-center text-emerald-600 duration-150 animate-in fade-in zoom-in dark:text-emerald-500"
+                    role="img"
+                    aria-label={t("settings.general.tokenValidated")}
+                  >
+                    <Check className="size-4" strokeWidth={2.5} />
+                  </span>
+                ) : null}
+                <button
+                  type="button"
+                  onClick={() => setShowToken((s) => !s)}
+                  className="absolute right-1.5 top-1/2 flex size-5 -translate-y-1/2 items-center justify-center rounded text-muted-foreground transition-colors hover:text-foreground"
+                  aria-label={
+                    showToken
+                      ? t("settings.general.hideToken")
+                      : t("settings.general.showToken")
+                  }
+                  tabIndex={-1}
+                >
+                  {showToken ? (
+                    <EyeOff className="size-3.5" />
+                  ) : (
+                    <Eye className="size-3.5" />
+                  )}
+                </button>
+              </div>
+              <Button
+                type="button"
+                variant="outline"
+                size="sm"
+                className="h-8"
+                disabled={!draftToken && !hfToken}
+                onClick={clearHfToken}
               >
-                <Check className="size-4" strokeWidth={2.5} />
-              </span>
+                Clear
+              </Button>
+            </div>
+            {tokenValidation.isChecking ? (
+              <p className="text-xs text-muted-foreground">Checking token…</p>
+            ) : tokenValidation.error ? (
+              <p className="max-w-[330px] text-right text-xs text-destructive">
+                {tokenValidation.error}
+              </p>
             ) : null}
-            <button
-              type="button"
-              onClick={() => setShowToken((s) => !s)}
-              className="absolute right-1.5 top-1/2 flex size-5 -translate-y-1/2 items-center justify-center rounded text-muted-foreground transition-colors hover:text-foreground"
-              aria-label={
-                showToken
-                  ? t("settings.general.hideToken")
-                  : t("settings.general.showToken")
-              }
-              tabIndex={-1}
-            >
-              {showToken ? (
-                <EyeOff className="size-3.5" />
-              ) : (
-                <Eye className="size-3.5" />
-              )}
-            </button>
           </div>
         </SettingsRow>
         {/* The desktop app authenticates via desktop auto-auth with a generated
@@ -553,33 +547,6 @@ export function GeneralTab() {
         )}
       </SettingsSection>
 
-      {modelsFolder ? (
-        <SettingsSection title={t("settings.general.storage.sectionTitle")}>
-          <SettingsRow
-            label={t("settings.general.storage.modelsFolder")}
-            description={t("settings.general.storage.modelsFolderDescription")}
-          >
-            <div className="flex items-center gap-2">
-              <span
-                title={modelsFolder.path}
-                className="max-w-[280px] truncate font-mono text-xs text-muted-foreground"
-              >
-                {modelsFolder.path}
-              </span>
-              <Button
-                variant="outline"
-                size="sm"
-                onClick={() => void handleModelsFolder()}
-              >
-                {isTauri
-                  ? t("settings.general.storage.openAction")
-                  : t("settings.general.storage.copyAction")}
-              </Button>
-            </div>
-          </SettingsRow>
-        </SettingsSection>
-      ) : null}
-
       <SettingsSection title={t("settings.appearance.language.title")}>
         <SettingsRow
           label={t("settings.appearance.language.label")}
diff --git a/studio/frontend/src/features/settings/tabs/resources-tab.tsx b/studio/frontend/src/features/settings/tabs/resources-tab.tsx
index 9a359f0f38..b22a54cb0b 100644
--- a/studio/frontend/src/features/settings/tabs/resources-tab.tsx
+++ b/studio/frontend/src/features/settings/tabs/resources-tab.tsx
@@ -2,9 +2,14 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
 import { Progress } from "@/components/ui/progress";
 import { Switch } from "@/components/ui/switch";
-import { openModelsDir } from "@/features/native-intents";
+import { FolderBrowser } from "@/features/model-picker";
+import {
+  openModelsDir,
+  pickHuggingFaceCacheDir,
+} from "@/features/native-intents";
 import { useSystemInfo, type GpuDevice } from "@/hooks/use-system";
 import { isTauri } from "@/lib/api-base";
 import { copyToClipboard } from "@/lib/copy-to-clipboard";
@@ -12,11 +17,15 @@ import { toast } from "@/lib/toast";
 import { cn } from "@/lib/utils";
 import { useT } from "@/i18n";
 import { useEffect, useMemo, useState } from "react";
-import { loadModelsFolder, type ModelsFolder } from "../api/models-folder";
+import {
+  type HuggingFaceCacheSettings,
+  loadHuggingFaceCacheSettings,
+  updateHuggingFaceCacheSettings,
+} from "../api/hugging-face-cache";
 import { SettingsRow } from "../components/settings-row";
 import { SettingsSection } from "../components/settings-section";
 import { useMonitorOverlayStore } from "../stores/monitor-overlay-store";
-import { LayersIcon } from "lucide-react";
+import { CopyIcon, FolderOpenIcon, LayersIcon } from "lucide-react";
 
 const POLL_MS = 3000;
 
@@ -47,6 +56,12 @@ function formatGb(value: number | null | undefined): string {
   return `${safe.toFixed(digits)} GB`;
 }
 
+function formatBytes(value: number | null): string | null {
+  if (value === null || !Number.isFinite(value)) return null;
+  const gib = value / 1024 ** 3;
+  return `${gib >= 10 ? gib.toFixed(1) : gib.toFixed(2)} GiB`;
+}
+
 // RAM/VRAM come from the backend in binary units (bytes / 1024**3), matching
 // nvidia-smi and PyTorch, so label those readouts GiB. Disk stays on formatGb
 // because the backend reports disk in decimal GB (bytes / 1e9).
@@ -90,22 +105,25 @@ function MetricTile({
   label: string;
   value: string;
   detail: string;
-  percent: number;
+  // null = usage unknown (e.g. Windows ROCm perf counter): show a dash and
+  // empty bar rather than a fabricated 0%.
+  percent: number | null;
 }) {
+  const percentKnown = isFiniteNumber(percent);
   const safePercent = clampPercent(percent);
   return (
     <div className="flex min-w-0 flex-col gap-2 rounded-md border border-border/60 bg-muted/20 p-3">
       <div className="flex items-center justify-between gap-3">
-        <span className="truncate text-[11px] font-semibold uppercase tracking-[0.08em] text-muted-foreground">
+        <span className="truncate text-ui-11 font-semibold uppercase tracking-[0.08em] text-muted-foreground">
           {label}
         </span>
         <span
           className={cn(
             "shrink-0 font-mono text-xs tabular-nums",
-            usageTextClass(safePercent),
+            percentKnown ? usageTextClass(safePercent) : "text-muted-foreground",
           )}
         >
-          {formatPercent(safePercent)}
+          {percentKnown ? formatPercent(safePercent) : "--"}
         </span>
       </div>
       <div className="min-w-0">
@@ -117,7 +135,7 @@ function MetricTile({
         </div>
       </div>
       <Progress
-        value={safePercent}
+        value={percentKnown ? safePercent : 0}
         aria-label={label}
         className="h-1.5 rounded-full bg-muted"
         indicatorClassName={usageIndicatorClass(safePercent)}
@@ -162,20 +180,22 @@ export function ResourcesTab() {
     enabled: liveUpdates,
     pollMs: liveUpdates ? POLL_MS : undefined,
   });
-  const [modelsFolder, setModelsFolder] = useState<ModelsFolder | null>(null);
-  const [modelsFolderLoaded, setModelsFolderLoaded] = useState(false);
+  const [hfCache, setHfCache] = useState<HuggingFaceCacheSettings | null>(null);
+  const [hfCacheLoaded, setHfCacheLoaded] = useState(false);
+  const [cacheBrowserOpen, setCacheBrowserOpen] = useState(false);
+  const [cacheSaving, setCacheSaving] = useState(false);
 
   useEffect(() => {
     let cancelled = false;
-    void loadModelsFolder()
-      .then((folder) => {
+    void loadHuggingFaceCacheSettings()
+      .then((settings) => {
         if (cancelled) return;
-        setModelsFolder(folder);
-        setModelsFolderLoaded(true);
+        setHfCache(settings);
+        setHfCacheLoaded(true);
       })
       .catch(() => {
         if (cancelled) return;
-        setModelsFolderLoaded(true);
+        setHfCacheLoaded(true);
       });
     return () => {
       cancelled = true;
@@ -194,18 +214,30 @@ export function ResourcesTab() {
       (sum, device) => sum + (device.memory_total_gb ?? 0),
       0,
     );
-    const vramUsed = devices.reduce(
-      (sum, device) => sum + (device.vram_used_gb ?? 0),
-      0,
-    );
-    const vramFree = devices.reduce(
-      (sum, device) =>
-        sum +
-        (device.vram_free_gb ??
-          Math.max(0, (device.memory_total_gb ?? 0) - (device.vram_used_gb ?? 0))),
-      0,
-    );
-    const vramPercent = vramTotal > 0 ? (vramUsed / vramTotal) * 100 : 0;
+    // null usage = unknown (e.g. Windows ROCm perf counter): treating it as 0
+    // fabricates a 0-used total, so the aggregate is unknown if any device is.
+    const vramUsageKnown =
+      devices.length > 0 &&
+      devices.every((device) => isFiniteNumber(device.vram_used_gb));
+    const vramUsed = vramUsageKnown
+      ? devices.reduce((sum, device) => sum + (device.vram_used_gb ?? 0), 0)
+      : null;
+    const vramFree = vramUsageKnown
+      ? devices.reduce(
+          (sum, device) =>
+            sum +
+            (device.vram_free_gb ??
+              Math.max(
+                0,
+                (device.memory_total_gb ?? 0) - (device.vram_used_gb ?? 0),
+              )),
+          0,
+        )
+      : null;
+    const vramPercent =
+      vramUsageKnown && isFiniteNumber(vramUsed) && vramTotal > 0
+        ? (vramUsed / vramTotal) * 100
+        : 0;
 
     return {
       devices,
@@ -218,15 +250,15 @@ export function ResourcesTab() {
       vramUsed,
       vramFree,
       vramPercent,
+      vramUsageKnown,
     };
   }, [systemInfo]);
 
-  const handleModelsFolder = async () => {
-    const folder = modelsFolder;
-    if (!folder) return;
+  const handleCacheFolder = async () => {
+    if (!hfCache) return;
     if (isTauri) {
       try {
-        await openModelsDir(folder.path);
+        await openModelsDir(hfCache.cacheHome);
       } catch (error) {
         toast.error(t("settings.resources.storage.openError"), {
           description: error instanceof Error ? error.message : undefined,
@@ -234,13 +266,43 @@ export function ResourcesTab() {
       }
       return;
     }
-    if (await copyToClipboard(folder.path)) {
+    if (await copyToClipboard(hfCache.cacheHome)) {
       toast.success(t("settings.resources.storage.copied"));
     } else {
       toast.error(t("settings.resources.storage.copyError"));
     }
   };
 
+  const saveCacheFolder = async (path: string | null) => {
+    setCacheSaving(true);
+    try {
+      const settings = await updateHuggingFaceCacheSettings(path);
+      setHfCache(settings);
+      toast.success(t("settings.resources.storage.cacheSaved"));
+    } catch (error) {
+      toast.error(t("settings.resources.storage.cacheSaveError"), {
+        description: error instanceof Error ? error.message : undefined,
+      });
+    } finally {
+      setCacheSaving(false);
+    }
+  };
+
+  const changeCacheFolder = async () => {
+    if (!isTauri) {
+      setCacheBrowserOpen(true);
+      return;
+    }
+    try {
+      const path = await pickHuggingFaceCacheDir();
+      if (path) await saveCacheFolder(path);
+    } catch (error) {
+      toast.error(t("settings.resources.storage.cachePickerError"), {
+        description: error instanceof Error ? error.message : undefined,
+      });
+    }
+  };
+
   const cpuCoresLabel =
     systemInfo.cpu?.logical_count && systemInfo.cpu?.physical_count
       ? t("settings.resources.liveMonitor.cpuCores", {
@@ -254,11 +316,28 @@ export function ResourcesTab() {
   const backendLabel = (
     systemInfo.gpu?.backend ?? systemInfo.device_backend ?? "cpu"
   ).toUpperCase();
-  const modelsFolderPath = modelsFolder
-    ? modelsFolder.path
-    : modelsFolderLoaded
+  const modelsFolderPath = hfCache
+    ? hfCache.cacheHome
+    : hfCacheLoaded
       ? t("settings.resources.environment.unknown")
       : t("common.loading");
+  const cacheLocationDetail = hfCache
+    ? hfCache.source === "environment"
+      ? t("settings.resources.storage.environmentManaged", {
+          variable: hfCache.environmentVariable ?? "HF_HOME",
+        })
+      : [
+          t("settings.resources.storage.futureDownloads"),
+          hfCache.freeBytes !== null
+            ? t("settings.resources.storage.locationFree", {
+                free: formatBytes(hfCache.freeBytes) ?? "",
+              })
+            : null,
+        ]
+          .filter(Boolean)
+          .join(" · ")
+    : null;
+  const unknownLabel = t("settings.resources.environment.unknown");
 
   return (
     <div className="flex flex-col gap-6">
@@ -327,17 +406,21 @@ export function ResourcesTab() {
             label={t("settings.resources.liveMonitor.vram")}
             value={
               hasGpu
-                ? `${formatGiB(metrics.vramUsed)} / ${formatGiB(metrics.vramTotal)}`
+                ? metrics.vramUsageKnown
+                  ? `${formatGiB(metrics.vramUsed)} / ${formatGiB(metrics.vramTotal)}`
+                  : `${unknownLabel} / ${formatGiB(metrics.vramTotal)}`
                 : t("settings.resources.liveMonitor.noGpu")
             }
             detail={
               hasGpu
-                ? t("settings.resources.liveMonitor.free", {
-                    value: formatGiB(metrics.vramFree),
-                  })
+                ? metrics.vramUsageKnown
+                  ? t("settings.resources.liveMonitor.free", {
+                      value: formatGiB(metrics.vramFree),
+                    })
+                  : unknownLabel
                 : backendLabel
             }
-            percent={metrics.vramPercent}
+            percent={metrics.vramUsageKnown ? metrics.vramPercent : null}
           />
         </div>
       </SettingsSection>
@@ -346,13 +429,33 @@ export function ResourcesTab() {
         {hasGpu ? (
           metrics.devices.map((device, index) => {
             const ordinal = deviceOrdinal(device);
-            const total = device.memory_total_gb ?? 0;
-            const used = device.vram_used_gb ?? 0;
-            const free = device.vram_free_gb ?? Math.max(0, total - used);
+            // Preserve null (unknown, e.g. Windows ROCm perf counter); coercing
+            // to 0 would render a fabricated 0 used / full free.
+            const total = device.memory_total_gb ?? null;
+            const used = device.vram_used_gb ?? null;
+            const free =
+              device.vram_free_gb ??
+              (isFiniteNumber(total) && isFiniteNumber(used)
+                ? Math.max(0, total - used)
+                : null);
             const percent =
               device.vram_utilization_pct ??
-              (total > 0 ? (used / total) * 100 : null);
+              (isFiniteNumber(total) && total > 0 && isFiniteNumber(used)
+                ? (used / total) * 100
+                : null);
             const safePercent = clampPercent(percent);
+            const usedText = isFiniteNumber(used)
+              ? formatGiB(used)
+              : unknownLabel;
+            const freeText = isFiniteNumber(free)
+              ? formatGiB(free)
+              : unknownLabel;
+            const totalText = isFiniteNumber(total)
+              ? formatGiB(total)
+              : unknownLabel;
+            const percentText = isFiniteNumber(percent)
+              ? formatPercent(safePercent)
+              : unknownLabel;
             return (
               <div
                 key={`${device.index ?? index}-${device.name ?? "gpu"}`}
@@ -374,7 +477,7 @@ export function ResourcesTab() {
                   </div>
                   <div className="shrink-0 font-mono text-xs tabular-nums text-muted-foreground">
                     <span>
-                      {formatPercent(safePercent)}{" "}
+                      {percentText}{" "}
                       {t("settings.resources.gpu.vramUtilization")}
                     </span>
                   </div>
@@ -382,17 +485,17 @@ export function ResourcesTab() {
                 <div className="grid gap-1 text-xs text-muted-foreground sm:grid-cols-3 sm:gap-2">
                   <span className="min-w-0 truncate font-mono tabular-nums">
                     {t("settings.resources.gpu.used", {
-                      value: formatGiB(used),
+                      value: usedText,
                     })}
                   </span>
                   <span className="min-w-0 truncate font-mono tabular-nums sm:text-center">
                     {t("settings.resources.gpu.free", {
-                      value: formatGiB(free),
+                      value: freeText,
                     })}
                   </span>
                   <span className="min-w-0 truncate font-mono tabular-nums sm:text-right">
                     {t("settings.resources.gpu.total", {
-                      value: formatGiB(total),
+                      value: totalText,
                     })}
                   </span>
                 </div>
@@ -426,29 +529,86 @@ export function ResourcesTab() {
         <SettingsRow
           label={t("settings.resources.storage.modelsFolder")}
           description={t("settings.resources.storage.modelsFolderDescription")}
-          className="max-sm:flex-col max-sm:items-start max-sm:gap-2"
+          className="max-[840px]:flex-col max-[840px]:items-stretch max-[840px]:gap-2"
         >
-          <div className="flex min-w-0 items-center gap-2 max-sm:max-w-[calc(100vw-5rem)]">
-            <span
-              title={modelsFolder?.path}
-              className="min-w-0 max-w-[280px] truncate font-mono text-xs text-muted-foreground max-sm:max-w-[180px]"
-            >
-              {modelsFolderPath}
-            </span>
+          <div className="grid w-[392px] min-w-0 grid-cols-[minmax(0,1fr)_auto] gap-x-2 gap-y-1.5 max-[840px]:w-full">
+            <div className="relative min-w-0">
+              <Input
+                readOnly
+                aria-label={t("settings.resources.storage.modelsFolder")}
+                value={modelsFolderPath}
+                title={hfCache?.cacheHome}
+                className="h-8 w-full pr-7 font-mono text-xs"
+              />
+              <button
+                type="button"
+                disabled={!hfCache}
+                onClick={() => void handleCacheFolder()}
+                aria-label={
+                  isTauri
+                    ? t("settings.resources.storage.openAction")
+                    : t("settings.resources.storage.copyAction")
+                }
+                title={
+                  isTauri
+                    ? t("settings.resources.storage.openAction")
+                    : t("settings.resources.storage.copyAction")
+                }
+                className="absolute right-1.5 top-1/2 flex size-5 -translate-y-1/2 items-center justify-center rounded text-muted-foreground transition-colors hover:text-foreground focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring disabled:pointer-events-none disabled:opacity-50"
+              >
+                {isTauri ? (
+                  <FolderOpenIcon className="size-3.5" />
+                ) : (
+                  <CopyIcon className="size-3.5" />
+                )}
+              </button>
+            </div>
             <Button
               variant="outline"
               size="sm"
-              disabled={!modelsFolder}
-              onClick={() => void handleModelsFolder()}
+              className="h-8"
+              disabled={!hfCache?.editable || cacheSaving}
+              onClick={() => void changeCacheFolder()}
             >
-              {isTauri
-                ? t("settings.resources.storage.openAction")
-                : t("settings.resources.storage.copyAction")}
+              {t("settings.resources.storage.changeAction")}
             </Button>
+            {cacheLocationDetail || hfCache?.isCustom ? (
+              <div className="col-span-2 flex min-w-0 items-center justify-between gap-2 pl-3.5 pr-1 text-xs text-muted-foreground">
+                {cacheLocationDetail ? (
+                  <span
+                    title={cacheLocationDetail}
+                    className="min-w-0 truncate"
+                  >
+                    {cacheLocationDetail}
+                  </span>
+                ) : null}
+                {hfCache?.isCustom ? (
+                  <Button
+                    variant="link"
+                    size="xs"
+                    className="h-auto px-0 text-xs"
+                    disabled={cacheSaving}
+                    onClick={() => void saveCacheFolder(null)}
+                  >
+                    {t("settings.resources.storage.resetAction")}
+                  </Button>
+                ) : null}
+              </div>
+            ) : null}
           </div>
         </SettingsRow>
       </SettingsSection>
 
+      <FolderBrowser
+        open={!isTauri && cacheBrowserOpen}
+        onOpenChange={setCacheBrowserOpen}
+        onSelect={(path) => void saveCacheFolder(path)}
+        initialPath={hfCache?.cacheHome}
+        title={t("settings.resources.storage.chooseTitle")}
+        confirmLabel={t("settings.resources.storage.chooseAction")}
+        showModelHints={false}
+      />
+
       <SettingsSection title={t("settings.resources.environment.title")}>
         <InfoRow
           label={t("settings.resources.environment.backend")}
diff --git a/studio/frontend/src/features/settings/tabs/voice-tab.tsx b/studio/frontend/src/features/settings/tabs/voice-tab.tsx
index 4b86105926..2dc3d01de8 100644
--- a/studio/frontend/src/features/settings/tabs/voice-tab.tsx
+++ b/studio/frontend/src/features/settings/tabs/voice-tab.tsx
@@ -3,6 +3,11 @@
 
 import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
+import {
+  Popover,
+  PopoverContent,
+  PopoverTrigger,
+} from "@/components/ui/popover";
 import {
   Select,
   SelectContent,
@@ -11,41 +16,52 @@ import {
   SelectValue,
 } from "@/components/ui/select";
 import { Slider } from "@/components/ui/slider";
+import { Spinner } from "@/components/ui/spinner";
 import { Switch } from "@/components/ui/switch";
 import {
+  StudioModelDictationAdapter,
+  type SttDownloadStatus,
+  fetchSttStatus,
+  loadSttModel,
+  startSttDownload,
+  unloadSttModel,
+  validateSttModel,
   StudioSpeechSynthesisAdapter,
   createConfiguredUtterance,
   curateSystemVoices,
   generateStudioTtsAudio,
-} from "@/features/chat/adapters/studio-speech-synthesis-adapter";
+} from "@/features/chat";
 import {
-  StudioWebSpeechDictationAdapter,
-  describeSpeechError,
-  isMissingDeviceError,
-} from "@/features/chat/adapters/studio-web-speech-dictation-adapter";
+  DownloadProgressBar,
+  hfApiToken,
+  useHfTokenStore,
+  useHubModelSearch,
+} from "@/features/hub";
+import { useDebouncedValue, useWheelScrollRef } from "@/hooks";
 import { useT } from "@/i18n";
-import { toast } from "@/lib/toast";
+import { ChevronDownStandardIcon } from "@/lib/chevron-icons";
 import { MicIcon } from "@/lib/mic-icon";
-import { copyToClipboard } from "@/lib/copy-to-clipboard";
-import {
-  Copy01Icon,
-  Delete02Icon,
-  PlusSignIcon,
-  VolumeHighIcon,
-} from "@hugeicons/core-free-icons";
+import { toast } from "@/lib/toast";
+import { Search01Icon, VolumeHighIcon } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
 import { SquareIcon } from "lucide-react";
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
+import { DictationDictionaryView } from "../components/dictation-dictionary-view";
+import { RecentDictationsView } from "../components/recent-dictations-view";
 import { SettingsRow } from "../components/settings-row";
 import { SettingsSection } from "../components/settings-section";
 import {
-  applyDictationDictionary,
-  recordRecentDictation,
-  resolveDictationLanguage,
+  type DefaultSttModel,
+  STT_MODELS,
+  type SttModel,
+  getSttModelRepo,
+  isCuratedSttModel,
+  isSttModelId,
+  isSttModelLanguageCompatible,
   useVoiceSettingsStore,
 } from "../stores/voice-settings-store";
 
-// Languages offered for browser speech recognition.
+// Languages shared by browser speech recognition and local STT.
 const DICTATION_LANGUAGES: { value: string; label: string }[] = [
   { value: "auto", label: "" }, // label rendered via i18n
   { value: "en-US", label: "English (US)" },
@@ -63,6 +79,225 @@ const DICTATION_LANGUAGES: { value: string; label: string }[] = [
   { value: "ar-SA", label: "العربية" },
 ];
 
+// Speech-recognition models, not voices. Name and size are separate so the list
+// can right-align the size; the speed/accuracy note lives in the row description.
+const STT_MODEL_NAMES: Record<DefaultSttModel, string> = {
+  tiny: "Whisper Tiny",
+  base: "Whisper Base",
+  small: "Whisper Small",
+  "large-v3-turbo": "Whisper Large v3 Turbo",
+  "large-v3": "Whisper Large v3",
+};
+// Curated models run as f16 GGML files through whisper.cpp.
+const STT_MODEL_SIZES: Record<DefaultSttModel, string> = {
+  tiny: "78 MB",
+  base: "148 MB",
+  small: "488 MB",
+  "large-v3-turbo": "1.6 GB",
+  "large-v3": "3.1 GB",
+};
+
+function sttModelName(model: SttModel): string {
+  return STT_MODEL_NAMES[model as DefaultSttModel] ?? model;
+}
+
+function sttModelSize(model: SttModel): string {
+  return STT_MODEL_SIZES[model as DefaultSttModel] ?? "";
+}
+
+/** Source repository shown under a model row. Curated models download from
+ * the Unsloth GGUF repos, mirrored by the backend (stt_ggml_sidecar.py). */
+function sttModelSource(model: SttModel): string {
+  return isCuratedSttModel(model)
+    ? `unslothai/whisper-${model}-GGUF`
+    : getSttModelRepo(model);
+}
+
+/**
+ * Model picker for local transcription. Lists the curated whisper.cpp
+ * checkpoints and searches Hugging Face for other Whisper repos (safetensors via
+ * Transformers). The trigger is a plain button so the selection never renders
+ * inside a text input.
+ */
+function SttModelPicker({
+  value,
+  language,
+  onChange,
+}: {
+  value: SttModel;
+  language: string;
+  onChange: (model: SttModel) => void;
+}) {
+  const t = useT();
+  const hfToken = useHfTokenStore((state) => state.token);
+  const [open, setOpen] = useState(false);
+  const [query, setQuery] = useState("");
+  const [validating, setValidating] = useState(false);
+  const resultsRef = useWheelScrollRef<HTMLDivElement>();
+  const debouncedQuery = useDebouncedValue(query.trim());
+
+  const { results, isLoading } = useHubModelSearch(debouncedQuery, {
+    task: "automatic-speech-recognition",
+    accessToken: hfApiToken(hfToken),
+    excludeGguf: true,
+    enabled: debouncedQuery.length >= 2,
+    keepUnsupportedTags: true,
+    ownerScope: "all",
+  });
+
+  const items = useMemo(() => {
+    if (!debouncedQuery) {
+      const defaults: string[] = STT_MODELS.filter((model) =>
+        isSttModelLanguageCompatible(model, language),
+      );
+      if (!defaults.includes(value)) {
+        defaults.push(value);
+      }
+      return defaults;
+    }
+    const ids: string[] = [];
+    for (const result of results) {
+      const tags = result.tags?.map((tag) => tag.toLowerCase()) ?? [];
+      const isWhisper =
+        result.id.toLowerCase().includes("whisper") || tags.includes("whisper");
+      const isExactMatch =
+        result.id.toLowerCase() === debouncedQuery.toLowerCase();
+      if (
+        (isExactMatch ||
+          (isWhisper &&
+            result.pipelineTag === "automatic-speech-recognition")) &&
+        isSttModelLanguageCompatible(result.id, language) &&
+        !ids.includes(result.id)
+      ) {
+        ids.push(result.id);
+      }
+    }
+    return ids;
+  }, [debouncedQuery, language, results, value]);
+
+  const selectModel = async (model: string) => {
+    if (!isSttModelId(model) || validating) {
+      return;
+    }
+    if (!isCuratedSttModel(model)) {
+      setValidating(true);
+      try {
+        await validateSttModel(model, hfApiToken(hfToken));
+      } catch (error) {
+        toast.error(t("settings.voice.dictation.sttModelInvalid"), {
+          description: error instanceof Error ? error.message : undefined,
+        });
+        return;
+      } finally {
+        setValidating(false);
+      }
+    }
+    onChange(model);
+    setOpen(false);
+    setQuery("");
+  };
+
+  return (
+    <Popover
+      open={open}
+      onOpenChange={(next) => {
+        setOpen(next);
+        if (!next) setQuery("");
+      }}
+    >
+      <PopoverTrigger asChild={true}>
+        <button
+          type="button"
+          aria-label="Speech recognition model"
+          className="border-border bg-background hover:bg-accent/50 dark:border-transparent dark:bg-white/[0.06] dark:hover:bg-white/10 focus-visible:border-ring flex h-8 w-full cursor-pointer items-center justify-between gap-1.5 rounded-full border px-3.5 text-sm outline-none transition-colors"
+        >
+          <span className="truncate">{sttModelName(value)}</span>
+          <HugeiconsIcon
+            icon={ChevronDownStandardIcon}
+            strokeWidth={2}
+            className="text-muted-foreground pointer-events-none size-4 shrink-0"
+          />
+        </button>
+      </PopoverTrigger>
+      <PopoverContent align="start" sideOffset={4} className="w-72 gap-0 p-0">
+        <div className="relative p-1.5 pb-0.5">
+          <HugeiconsIcon
+            icon={Search01Icon}
+            strokeWidth={2}
+            className="text-muted-foreground pointer-events-none absolute top-[calc(50%+2px)] left-4 size-3.5 -translate-y-1/2"
+          />
+          <Input
+            value={query}
+            onChange={(event) => setQuery(event.target.value)}
+            placeholder={t(
+              "settings.voice.dictation.sttModelSearchPlaceholder",
+            )}
+            className="h-8 pl-8 text-sm"
+            autoFocus={true}
+            onKeyDown={(event) => {
+              if (event.key === "Enter" && items.length > 0) {
+                event.preventDefault();
+                void selectModel(items[0]);
+              }
+            }}
+          />
+        </div>
+        <div
+          ref={resultsRef}
+          data-testid="stt-model-results"
+          className="max-h-64 overflow-y-auto p-1"
+        >
+          {(isLoading && debouncedQuery) || validating ? (
+            <div className="flex items-center gap-2 px-3 py-3 text-xs text-muted-foreground">
+              <Spinner className="size-3.5" />
+              {validating
+                ? t("settings.voice.dictation.sttModelValidating")
+                : t("settings.voice.dictation.sttModelSearching")}
+            </div>
+          ) : items.length === 0 ? (
+            <div className="px-3 py-3 text-xs text-muted-foreground">
+              {t("settings.voice.dictation.sttModelNoResults")}
+            </div>
+          ) : (
+            items.map((model) => {
+              // A custom repo's name is its id: one-line rows keep a pill shape,
+              // two-line rows use a subtler radius.
+              const twoLines = sttModelSource(model) !== sttModelName(model);
+              return (
+                <button
+                  key={model}
+                  type="button"
+                  onClick={() => void selectModel(model)}
+                  aria-selected={model === value}
+                  className={`flex w-full items-center justify-between gap-3 px-2.5 py-1.5 text-left transition-colors hover:bg-muted ${
+                    twoLines ? "rounded-sm" : "rounded-full"
+                  } ${model === value ? "bg-accent font-medium" : ""}`}
+                >
+                  <span className="min-w-0 flex-1 truncate">
+                    <span className="block truncate text-xs">
+                      {sttModelName(model)}
+                    </span>
+                    {twoLines ? (
+                      <span className="mt-0.5 block truncate font-mono text-ui-9 leading-tight text-muted-foreground">
+                        {sttModelSource(model)}
+                      </span>
+                    ) : null}
+                  </span>
+                  {sttModelSize(model) ? (
+                    <span className="shrink-0 text-ui-10 tabular-nums text-muted-foreground">
+                      {sttModelSize(model)}
+                    </span>
+                  ) : null}
+                </button>
+              );
+            })
+          )}
+        </div>
+      </PopoverContent>
+    </Popover>
+  );
+}
+
 const TTS_PREVIEW_TEXT =
   "Hello from Unsloth Studio! This is a preview of the selected voice.";
 
@@ -84,11 +319,29 @@ function useAudioInputDevices() {
   }, []);
 
   useEffect(() => {
-    void refresh();
     const media = navigator.mediaDevices;
-    if (!media?.addEventListener) return;
+    if (!media?.addEventListener) {
+      return;
+    }
+    let cancelled = false;
+    media
+      .enumerateDevices()
+      .then((all) => {
+        if (cancelled) {
+          return;
+        }
+        const inputs = all.filter((device) => device.kind === "audioinput");
+        setDevices(inputs);
+        setHasLabels(inputs.some((device) => device.label));
+      })
+      .catch(() => {
+        // Enumeration can fail in insecure contexts; leave the list empty.
+      });
     media.addEventListener("devicechange", refresh);
-    return () => media.removeEventListener("devicechange", refresh);
+    return () => {
+      cancelled = true;
+      media.removeEventListener("devicechange", refresh);
+    };
   }, [refresh]);
 
   // Labels are hidden until mic permission; open a short stream to get them.
@@ -102,7 +355,9 @@ function useAudioInputDevices() {
       const stream = await navigator.mediaDevices.getUserMedia({
         audio: true,
       });
-      stream.getTracks().forEach((track) => track.stop());
+      for (const track of stream.getTracks()) {
+        track.stop();
+      }
       await refresh();
     } catch {
       toast.error(t("settings.voice.dictation.micAccessBlocked"));
@@ -127,234 +382,18 @@ function useSystemVoices() {
   return voices;
 }
 
-/** Inline mic test: runs speech recognition and shows the live transcript. */
-function DictationTest() {
-  const t = useT();
-  const [testing, setTesting] = useState(false);
-  const [transcript, setTranscript] = useState("");
-  const [interim, setInterim] = useState("");
-  const recognitionRef = useRef<SpeechRecognition | null>(null);
-  const streamRef = useRef<MediaStream | null>(null);
-  // Guards the getUserMedia await so a mic opened after unmount is released.
-  const disposedRef = useRef(false);
-  // Mirrors the transcript state so onend can record it without stale closures.
-  const transcriptRef = useRef("");
-
-  // Single cleanup path: the browser can end recognition on its own (silence
-  // timeout, service disconnect), so onend must release the mic and save the
-  // transcript, not just the Stop button.
-  const finalize = useCallback(() => {
-    streamRef.current?.getTracks().forEach((track) => track.stop());
-    streamRef.current = null;
-    recognitionRef.current = null;
-    if (transcriptRef.current) {
-      recordRecentDictation(transcriptRef.current);
-      transcriptRef.current = "";
-    }
-    setTesting(false);
-    setInterim("");
-  }, []);
-
-  const stop = useCallback(() => {
-    const recognition = recognitionRef.current;
-    if (recognition) {
-      // onend fires next and runs finalize()
-      recognition.stop();
-    } else {
-      finalize();
-    }
-  }, [finalize]);
-
-  useEffect(() => {
-    disposedRef.current = false;
-    return () => {
-      disposedRef.current = true;
-      recognitionRef.current?.abort();
-      streamRef.current?.getTracks().forEach((track) => track.stop());
-      streamRef.current = null;
-    };
-  }, []);
-
-  // Set before the getUserMedia await so a double click or a slow
-  // permission prompt cannot start a second recognizer over the first.
-  const startingRef = useRef(false);
-
-  const start = useCallback(async () => {
-    const SpeechRecognitionAPI =
-      window.SpeechRecognition ?? window.webkitSpeechRecognition;
-    if (!SpeechRecognitionAPI) return;
-    if (startingRef.current || recognitionRef.current) return;
-    startingRef.current = true;
-    setTranscript("");
-    setInterim("");
-    transcriptRef.current = "";
-
-    const { micDeviceId } = useVoiceSettingsStore.getState();
-    let audioTrack: MediaStreamTrack | undefined;
-    try {
-      let stream: MediaStream;
-      try {
-        stream = await navigator.mediaDevices.getUserMedia({
-          audio:
-            micDeviceId && micDeviceId !== "default"
-              ? { deviceId: { exact: micDeviceId } }
-              : true,
-        });
-      } catch (error) {
-        // Saved mic may be unplugged; fall back to the default device.
-        if (micDeviceId !== "default" && isMissingDeviceError(error)) {
-          stream = await navigator.mediaDevices.getUserMedia({ audio: true });
-        } else {
-          throw error;
-        }
-      }
-      if (disposedRef.current) {
-        stream.getTracks().forEach((track) => track.stop());
-        startingRef.current = false;
-        return;
-      }
-      streamRef.current = stream;
-      audioTrack = stream.getAudioTracks()[0];
-    } catch {
-      startingRef.current = false;
-      toast.error(t("settings.voice.dictation.micOpenFailed"));
-      return;
-    }
-
-    const recognition = new SpeechRecognitionAPI();
-    recognition.lang = resolveDictationLanguage();
-    recognition.continuous = true;
-    recognition.interimResults = true;
-    recognition.onresult = (event: SpeechRecognitionEvent) => {
-      let interimText = "";
-      for (let i = event.resultIndex; i < event.results.length; i++) {
-        const result = event.results[i];
-        const text = result?.[0]?.transcript ?? "";
-        if (result?.isFinal) {
-          const corrected = applyDictationDictionary(text.trim());
-          setTranscript((prev) => {
-            const next = prev ? `${prev} ${corrected}` : corrected;
-            transcriptRef.current = next;
-            return next;
-          });
-        } else {
-          interimText += text;
-        }
-      }
-      setInterim(interimText);
-    };
-    recognition.onerror = (event) => {
-      // onend follows and runs finalize(); surface non-abort failures here.
-      const errorEvent = event as SpeechRecognitionErrorEvent;
-      if (errorEvent.error !== "aborted") {
-        toast.error(describeSpeechError(errorEvent.error, errorEvent.message));
-      }
-    };
-    recognition.onend = () => finalize();
-    try {
-      if (audioTrack) {
-        try {
-          recognition.start(audioTrack);
-        } catch {
-          // Engine has no start(track) overload: it will capture from the
-          // default device, so release the selected-device stream.
-          streamRef.current?.getTracks().forEach((track) => track.stop());
-          streamRef.current = null;
-          recognition.start();
-        }
-      } else {
-        recognition.start();
-      }
-    } catch {
-      startingRef.current = false;
-      finalize();
-      return;
-    }
-    recognitionRef.current = recognition;
-    startingRef.current = false;
-    setTesting(true);
-  }, [finalize, t]);
-
-  const finishedTest = !testing && transcript;
-
-  return (
-    <div className="flex flex-col gap-2">
-      <SettingsRow
-        label={t("settings.voice.dictation.testLabel")}
-        description={t("settings.voice.dictation.testDescription")}
-      >
-        <Button
-          variant="outline"
-          size="sm"
-          onClick={() => {
-            if (testing) {
-              stop();
-            } else {
-              void start();
-            }
-          }}
-        >
-          {testing ? (
-            <>
-              <SquareIcon className="mr-1.5 size-3 animate-pulse fill-current text-destructive" />
-              {t("settings.voice.dictation.stopTest")}
-            </>
-          ) : (
-            <>
-              <MicIcon className="mr-1.5 size-3.5" />
-              {t("settings.voice.dictation.startTest")}
-            </>
-          )}
-        </Button>
-      </SettingsRow>
-      {(testing || transcript) && (
-        <div className="rounded-lg border border-border/60 bg-muted/30 px-3 py-2 text-sm">
-          {transcript || interim ? (
-            <>
-              <span className="text-foreground">{transcript}</span>
-              {interim ? (
-                <span className="text-muted-foreground"> {interim}</span>
-              ) : null}
-            </>
-          ) : (
-            <span className="text-muted-foreground">
-              {testing ? t("settings.voice.dictation.listening") : ""}
-            </span>
-          )}
-          {finishedTest ? (
-            <div className="mt-1 text-xs text-muted-foreground">
-              {t("settings.voice.dictation.testSaved")}
-            </div>
-          ) : null}
-        </div>
-      )}
-    </div>
-  );
-}
-
 export function VoiceTab() {
   const t = useT();
   const micDeviceId = useVoiceSettingsStore((s) => s.micDeviceId);
   const setMicDeviceId = useVoiceSettingsStore((s) => s.setMicDeviceId);
+  const dictationEngine = useVoiceSettingsStore((s) => s.dictationEngine);
+  const setDictationEngine = useVoiceSettingsStore((s) => s.setDictationEngine);
+  const sttModel = useVoiceSettingsStore((s) => s.sttModel);
+  const setSttModel = useVoiceSettingsStore((s) => s.setSttModel);
   const dictationLanguage = useVoiceSettingsStore((s) => s.dictationLanguage);
   const setDictationLanguage = useVoiceSettingsStore(
     (s) => s.setDictationLanguage,
   );
-  const dictionary = useVoiceSettingsStore((s) => s.dictionary);
-  const addDictionaryEntry = useVoiceSettingsStore((s) => s.addDictionaryEntry);
-  const updateDictionaryEntry = useVoiceSettingsStore(
-    (s) => s.updateDictionaryEntry,
-  );
-  const commitDictionaryEntry = useVoiceSettingsStore(
-    (s) => s.commitDictionaryEntry,
-  );
-  const removeDictionaryEntry = useVoiceSettingsStore(
-    (s) => s.removeDictionaryEntry,
-  );
-  const recentDictations = useVoiceSettingsStore((s) => s.recentDictations);
-  const clearRecentDictations = useVoiceSettingsStore(
-    (s) => s.clearRecentDictations,
-  );
   const ttsEnabled = useVoiceSettingsStore((s) => s.ttsEnabled);
   const setTtsEnabled = useVoiceSettingsStore((s) => s.setTtsEnabled);
   const ttsEngine = useVoiceSettingsStore((s) => s.ttsEngine);
@@ -371,29 +410,288 @@ export function VoiceTab() {
   const { devices, hasLabels, requestAccess } = useAudioInputDevices();
   const rawVoices = useSystemVoices();
   const voices = useMemo(
-    () => curateSystemVoices(rawVoices, ttsVoiceURI),
-    // dictationLanguage feeds the curation language filter.
+    () => curateSystemVoices(rawVoices, ttsVoiceURI, dictationLanguage),
     [rawVoices, ttsVoiceURI, dictationLanguage],
   );
-  const [newEntry, setNewEntry] = useState("");
   const [previewing, setPreviewing] = useState(false);
+  const [subpage, setSubpage] = useState<"main" | "recents" | "dictionary">(
+    "main",
+  );
+  const [selectedDictationId, setSelectedDictationId] = useState<string | null>(
+    null,
+  );
 
-  const dictationSupported = StudioWebSpeechDictationAdapter.isSupported();
+  const modelSttSupported = StudioModelDictationAdapter.isSupported();
   const ttsSupported = StudioSpeechSynthesisAdapter.isSupported();
   const systemTtsSupported =
     StudioSpeechSynthesisAdapter.systemVoicesSupported();
   const effectiveTtsEngine = systemTtsSupported ? ttsEngine : "studio";
 
+  // Local STT stays on-demand. Track its phase without fetching model weights.
+  type SttPhase =
+    | "idle"
+    | "checking"
+    | "on-demand"
+    | "unavailable"
+    | "loading"
+    | "ready"
+    | "error";
+  type SttDownloadAvailability =
+    | "checking"
+    | "missing"
+    | "downloaded"
+    | "error";
+  const [sttPhase, setSttPhase] = useState<SttPhase>("idle");
+  const [sttDevice, setSttDevice] = useState<string | null>(null);
+  const [statusNonce, setStatusNonce] = useState(0);
+  const [sttDownloadStarting, setSttDownloadStarting] = useState(false);
+  const [sttUnloading, setSttUnloading] = useState(false);
+  const isLocalEngine = dictationEngine === "model";
+  // The model decides the backend: curated ids run GGML through whisper.cpp,
+  // custom repos run through Transformers.
+  const isGgufModel = isCuratedSttModel(sttModel);
+  // Progress of the selected engine's model download, from /stt/status.
+  const [sttDownload, setSttDownload] = useState<SttDownloadStatus | null>(
+    null,
+  );
+  const [downloadBytesPerSec, setDownloadBytesPerSec] = useState(0);
+  // Last observed (bytes, time) so successive polls yield a transfer rate.
+  const downloadRateSampleRef = useRef<{ bytes: number; at: number } | null>(
+    null,
+  );
+  // Model whose download this tab watched; completion auto-loads it.
+  const watchedDownloadRef = useRef<string | null>(null);
+
+  // Selecting a model (or finishing its download) loads it without a Load
+  // click. A model that is not downloaded fails quietly and stays on demand.
+  const autoLoadSttModel = useCallback(async (model: string) => {
+    setSttPhase("loading");
+    try {
+      await loadSttModel(model);
+    } catch {
+      // Not downloaded (or the engine is busy): the status poll resets the phase
+      // and the user still sees the Download button.
+    } finally {
+      setStatusNonce((nonce) => nonce + 1);
+    }
+  }, []);
+  const sttRepoId = getSttModelRepo(sttModel);
+  const hfToken = useHfTokenStore((state) => state.token);
+  const [sttDownloadAvailability, setSttDownloadAvailability] = useState<{
+    repoId: string;
+    state: SttDownloadAvailability;
+  }>({ repoId: "", state: "checking" });
+  const effectiveSttDownloadAvailability =
+    sttDownloadAvailability.repoId === sttRepoId
+      ? sttDownloadAvailability.state
+      : "checking";
+  useEffect(() => {
+    if (!isLocalEngine || !modelSttSupported) {
+      return;
+    }
+    let cancelled = false;
+    void (async () => {
+      // Only surface "checking" on the first poll; background refreshes keep
+      // the last phase so the status line doesn't flicker while polling.
+      setSttPhase((phase) => (phase === "idle" ? "checking" : phase));
+      try {
+        const status = await fetchSttStatus(statusNonce, sttModel);
+        if (cancelled) return;
+        // A curated model prefers the GGUF (whisper.cpp) engine, but without
+        // whisper-server the backend serves it through Transformers instead of
+        // failing. Fall back to the Transformers status here too, or the model
+        // shows as unavailable and download is blocked even though it works.
+        const engineStatus =
+          isGgufModel && status.gguf?.available
+            ? status.gguf
+            : status.transformers;
+        if (!engineStatus?.available) {
+          setSttPhase("unavailable");
+          return;
+        }
+        const download = engineStatus.download;
+        setSttDownload(download);
+        setSttDownloadAvailability({
+          repoId: sttRepoId,
+          state: engineStatus.downloaded_models.includes(sttModel)
+            ? "downloaded"
+            : download.error
+              ? "error"
+              : "missing",
+        });
+        if (download.downloading) {
+          watchedDownloadRef.current = download.model;
+          const bytes = download.bytes_done ?? 0;
+          const sample = downloadRateSampleRef.current;
+          const now = Date.now();
+          if (sample && bytes > sample.bytes && now > sample.at) {
+            setDownloadBytesPerSec(
+              ((bytes - sample.bytes) * 1000) / (now - sample.at),
+            );
+          }
+          downloadRateSampleRef.current = { bytes, at: now };
+          // Keep the download progress fresh.
+          window.setTimeout(() => {
+            if (!cancelled) setStatusNonce((n) => n + 1);
+          }, 800);
+        } else {
+          const finished = watchedDownloadRef.current;
+          watchedDownloadRef.current = null;
+          downloadRateSampleRef.current = null;
+          setDownloadBytesPerSec(0);
+          if (
+            finished === sttModel &&
+            engineStatus.downloaded_models.includes(sttModel) &&
+            engineStatus.loaded_model !== sttModel
+          ) {
+            // The download this tab watched just finished; load the model.
+            void autoLoadSttModel(sttModel);
+            return;
+          }
+        }
+        if (engineStatus.loading) {
+          setSttPhase("loading");
+          window.setTimeout(() => {
+            if (!cancelled) setStatusNonce((n) => n + 1);
+          }, 600);
+          return;
+        }
+        if (engineStatus.loaded_model === sttModel && !engineStatus.loading) {
+          setSttDevice(engineStatus.device);
+          setSttPhase("ready");
+          window.setTimeout(
+            () => {
+              if (!cancelled) setStatusNonce((n) => n + 1);
+            },
+            Math.max(
+              1000,
+              Math.min(engineStatus.keep_alive_seconds * 1000, 15_000),
+            ),
+          );
+          return;
+        }
+        // Merely opening settings or selecting local STT never downloads or
+        // loads a model. Loading begins from Load or when recording starts.
+        setSttDevice(null);
+        setSttPhase("on-demand");
+      } catch {
+        if (!cancelled) setSttPhase("error");
+      }
+    })();
+    return () => {
+      cancelled = true;
+    };
+  }, [
+    isLocalEngine,
+    isGgufModel,
+    sttModel,
+    sttRepoId,
+    modelSttSupported,
+    statusNonce,
+    autoLoadSttModel,
+  ]);
+
+  const sttStatusText = (() => {
+    switch (sttPhase) {
+      case "checking":
+        return t("settings.voice.dictation.sttChecking");
+      case "loading":
+        return t("settings.voice.dictation.sttLoadingModel");
+      case "on-demand":
+        return t("settings.voice.dictation.sttOnDemand");
+      case "ready":
+        // The GGML backend reports its runtime name, not a device; show a plain
+        // "Loaded" rather than surfacing it.
+        return sttDevice && sttDevice !== "whisper.cpp"
+          ? t("settings.voice.dictation.sttReady", {
+              device: sttDevice.toUpperCase(),
+            })
+          : t("settings.voice.dictation.sttLoaded");
+      case "unavailable":
+        return t("settings.voice.dictation.sttUnavailable");
+      case "error":
+        return t("settings.voice.dictation.sttModelFailed");
+      default:
+        return "";
+    }
+  })();
+
+  const downloadingThisModel =
+    isLocalEngine &&
+    sttDownload?.downloading === true &&
+    sttDownload.model === sttModel;
+
+  const sttModelStatusText = (() => {
+    if (downloadingThisModel) {
+      const total = sttDownload?.bytes_total ?? 0;
+      const done = sttDownload?.bytes_done ?? 0;
+      return t("settings.voice.dictation.sttDownloading", {
+        progress:
+          total > 0 ? Math.min(99, Math.round((done / total) * 100)) : 0,
+      });
+    }
+    if (sttPhase === "unavailable") {
+      return sttStatusText;
+    }
+    switch (effectiveSttDownloadAvailability) {
+      case "checking":
+        return t("settings.voice.dictation.sttDownloadChecking");
+      case "missing":
+        return t("settings.voice.dictation.sttNotDownloaded");
+      case "error":
+        return t("settings.voice.dictation.sttDownloadStatusFailed");
+      case "downloaded":
+        return sttStatusText;
+      default:
+        return "";
+    }
+  })();
+
+  const beginSttDownload = async () => {
+    setSttDownloadStarting(true);
+    try {
+      // Engine-managed download; progress arrives via /stt/status.
+      await startSttDownload(sttModel, hfApiToken(hfToken));
+      setStatusNonce((nonce) => nonce + 1);
+    } catch (error) {
+      toast.error(t("settings.voice.dictation.sttDownloadFailed"), {
+        description: error instanceof Error ? error.message : undefined,
+      });
+    } finally {
+      setSttDownloadStarting(false);
+    }
+  };
+
+  const warmSttModel = async () => {
+    setSttPhase("loading");
+    try {
+      await loadSttModel(sttModel);
+      setStatusNonce((nonce) => nonce + 1);
+    } catch (error) {
+      setSttPhase("error");
+      toast.error(t("settings.voice.dictation.sttModelFailed"), {
+        description: error instanceof Error ? error.message : undefined,
+      });
+    }
+  };
+
+  const releaseSttModel = async () => {
+    setSttUnloading(true);
+    try {
+      await unloadSttModel();
+      setStatusNonce((nonce) => nonce + 1);
+    } catch (error) {
+      toast.error(t("settings.voice.dictation.sttModelFailed"), {
+        description: error instanceof Error ? error.message : undefined,
+      });
+    } finally {
+      setSttUnloading(false);
+    }
+  };
+
   // Keep an item for an unplugged saved mic so the value stays visible.
   const knownMic = devices.some((d) => d.deviceId === micDeviceId);
 
-  const handleAddEntry = () => {
-    const trimmed = newEntry.trim();
-    if (!trimmed) return;
-    addDictionaryEntry(trimmed);
-    setNewEntry("");
-  };
-
   const previewAudioRef = useRef<HTMLAudioElement | null>(null);
   const previewAbortRef = useRef<AbortController | null>(null);
   // Mirrors `previewing` so unmount cleanup can tell whether this tab owns
@@ -450,8 +748,7 @@ export function VoiceTab() {
         const audio = new Audio(url);
         audio.playbackRate = ttsRate;
         audio.volume = ttsVolume;
-        // Some browsers reset playbackRate to 1 once the source loads; reapply
-        // it on loadedmetadata so the speed setting reliably takes effect.
+        // Some browsers reset playbackRate once metadata loads.
         audio.addEventListener("loadedmetadata", () => {
           audio.playbackRate = ttsRate;
         });
@@ -462,8 +759,6 @@ export function VoiceTab() {
         audio.addEventListener("error", () => {
           releasePreviewAudio();
           markPreviewing(false);
-          // Surface playback failures like the catch below, instead of just
-          // resetting the button with no explanation.
           toast.error("TTS preview failed");
         });
         previewAudioRef.current = audio;
@@ -501,6 +796,23 @@ export function VoiceTab() {
   // Stop any preview playback when the tab unmounts.
   useEffect(() => stopPreview, [stopPreview]);
 
+  if (subpage === "recents") {
+    return (
+      <RecentDictationsView
+        selectedId={selectedDictationId}
+        onSelect={setSelectedDictationId}
+        onBack={() => {
+          setSelectedDictationId(null);
+          setSubpage("main");
+        }}
+      />
+    );
+  }
+
+  if (subpage === "dictionary") {
+    return <DictationDictionaryView onBack={() => setSubpage("main")} />;
+  }
+
   return (
     <div className="flex flex-col gap-6">
       <header className="flex flex-col gap-1">
@@ -513,6 +825,191 @@ export function VoiceTab() {
       </header>
 
       <SettingsSection title={t("settings.voice.dictation.sectionTitle")}>
+        <SettingsRow
+          label={t("settings.voice.dictation.engineLabel")}
+          description={
+            dictationEngine === "model"
+              ? t("settings.voice.dictation.engineModelDescription")
+              : t("settings.voice.dictation.engineBrowserDescription")
+          }
+        >
+          <Select
+            value={dictationEngine}
+            onValueChange={(value) => {
+              const next = value === "model" ? "model" : "browser";
+              if (next !== dictationEngine) {
+                // Unload whichever backend was resident for the old engine.
+                void unloadSttModel().catch(() => {});
+                if (next === "model") {
+                  setSttPhase("checking");
+                  setSttDevice(null);
+                  setSttDownload(null);
+                }
+              }
+              setDictationEngine(next);
+            }}
+          >
+            <SelectTrigger
+              aria-label="Dictation engine"
+              className="w-56"
+              size="sm"
+            >
+              <SelectValue />
+            </SelectTrigger>
+            <SelectContent>
+              <SelectItem value="browser">
+                {t("settings.voice.dictation.engineBrowser")}
+              </SelectItem>
+              <SelectItem value="model">
+                {t("settings.voice.dictation.engineModel")}
+              </SelectItem>
+            </SelectContent>
+          </Select>
+        </SettingsRow>
+
+        {isLocalEngine ? (
+          modelSttSupported ? (
+            <SettingsRow
+              label={t("settings.voice.dictation.sttModelLabel")}
+              description={t("settings.voice.dictation.sttModelDescription")}
+            >
+              <div className="flex w-56 flex-col items-stretch gap-2">
+                <SttModelPicker
+                  value={sttModel}
+                  language={dictationLanguage}
+                  onChange={(next) => {
+                    if (next !== sttModel) {
+                      void unloadSttModel().catch(() => {});
+                      void autoLoadSttModel(next);
+                    }
+                    setSttModel(next);
+                  }}
+                />
+                {downloadingThisModel ? (
+                  <div className="rounded-md border border-border/60 bg-muted/20 px-2.5 pt-2">
+                    <div className="mb-1.5 flex items-center justify-between gap-3">
+                      <span className="text-xs text-muted-foreground">
+                        {sttModelStatusText}
+                      </span>
+                    </div>
+                    <DownloadProgressBar
+                      progress={{
+                        expectedBytes: sttDownload?.bytes_total ?? 0,
+                        downloadedBytes: sttDownload?.bytes_done ?? 0,
+                        fraction:
+                          sttDownload?.bytes_total &&
+                          sttDownload.bytes_total > 0
+                            ? (sttDownload.bytes_done ?? 0) /
+                              sttDownload.bytes_total
+                            : 0,
+                      }}
+                      bytesPerSec={downloadBytesPerSec}
+                    />
+                  </div>
+                ) : (
+                  <div className="flex min-h-7 items-center justify-between gap-3">
+                    <span className="flex min-w-0 items-center gap-2 text-xs text-muted-foreground">
+                      {effectiveSttDownloadAvailability === "checking" ||
+                      sttPhase === "loading" ||
+                      sttPhase === "checking" ? (
+                        <span className="size-1.5 shrink-0 animate-pulse rounded-full bg-current" />
+                      ) : sttPhase === "ready" ||
+                        (effectiveSttDownloadAvailability === "downloaded" &&
+                          sttPhase === "on-demand") ? (
+                        <span className="size-1.5 shrink-0 rounded-full bg-emerald-500" />
+                      ) : effectiveSttDownloadAvailability === "error" ||
+                        sttPhase === "error" ? (
+                        <span className="size-1.5 shrink-0 rounded-full bg-destructive" />
+                      ) : null}
+                      <span>{sttModelStatusText}</span>
+                    </span>
+                    {sttPhase === "unavailable" ? (
+                      <Button
+                        variant="ghost"
+                        size="sm"
+                        className="h-7 px-2 text-xs"
+                        onClick={() => setStatusNonce((nonce) => nonce + 1)}
+                      >
+                        {t("settings.voice.dictation.sttRetry")}
+                      </Button>
+                    ) : effectiveSttDownloadAvailability === "error" ? (
+                      <Button
+                        variant="ghost"
+                        size="sm"
+                        className="h-7 px-2 text-xs"
+                        disabled={sttDownloadStarting || downloadingThisModel}
+                        // Restart the download; the sidecar error is sticky until
+                        // a new start(), so re-polling alone never clears it.
+                        onClick={beginSttDownload}
+                      >
+                        {t("settings.voice.dictation.sttRetry")}
+                      </Button>
+                    ) : effectiveSttDownloadAvailability === "missing" ? (
+                      <Button
+                        variant="outline"
+                        size="sm"
+                        className="h-7 px-2.5 text-xs"
+                        disabled={sttDownloadStarting || downloadingThisModel}
+                        onClick={beginSttDownload}
+                      >
+                        {sttDownloadStarting || downloadingThisModel ? (
+                          <Spinner className="mr-1.5" />
+                        ) : null}
+                        {t("settings.voice.dictation.sttDownload")}
+                      </Button>
+                    ) : effectiveSttDownloadAvailability === "downloaded" ? (
+                      sttPhase === "ready" ? (
+                        <Button
+                          variant="outline"
+                          size="sm"
+                          className="h-7 px-2.5 text-xs"
+                          disabled={sttUnloading}
+                          onClick={releaseSttModel}
+                        >
+                          {sttUnloading ? <Spinner className="mr-1.5" /> : null}
+                          {sttUnloading
+                            ? t("settings.voice.dictation.sttUnloading")
+                            : t("settings.voice.dictation.sttUnload")}
+                        </Button>
+                      ) : sttPhase === "loading" || sttPhase === "checking" ? (
+                        // The status line already says "Loading model…"; the
+                        // button only needs the spinner.
+                        <Button
+                          variant="outline"
+                          size="sm"
+                          className="h-7 px-2.5 text-xs"
+                          disabled={true}
+                          aria-label={t(
+                            "settings.voice.dictation.sttLoadingModel",
+                          )}
+                        >
+                          <Spinner />
+                        </Button>
+                      ) : (
+                        <Button
+                          variant="outline"
+                          size="sm"
+                          className="h-7 px-2.5 text-xs"
+                          onClick={warmSttModel}
+                        >
+                          {sttPhase === "error"
+                            ? t("settings.voice.dictation.sttRetry")
+                            : t("settings.voice.dictation.sttLoad")}
+                        </Button>
+                      )
+                    ) : null}
+                  </div>
+                )}
+              </div>
+            </SettingsRow>
+          ) : (
+            <SettingsRow
+              label={t("settings.voice.dictation.sttModelLabel")}
+              description={t("settings.voice.dictation.sttModelUnsupported")}
+            />
+          )
+        ) : null}
+
         <SettingsRow
           label={t("settings.voice.dictation.microphoneLabel")}
           description={
@@ -525,7 +1022,7 @@ export function VoiceTab() {
         >
           {hasLabels ? (
             <Select value={micDeviceId} onValueChange={setMicDeviceId}>
-              <SelectTrigger aria-label="Microphone" className="w-56" size="sm">
+              <SelectTrigger aria-label="Microphone" className="min-w-56 max-w-72" size="sm">
                 <SelectValue />
               </SelectTrigger>
               <SelectContent>
@@ -564,7 +1061,7 @@ export function VoiceTab() {
           >
             <SelectTrigger
               aria-label="Dictation language"
-              className="w-56"
+              className="min-w-56 max-w-72"
               size="sm"
             >
               <SelectValue />
@@ -581,144 +1078,34 @@ export function VoiceTab() {
           </Select>
         </SettingsRow>
 
-        {dictationSupported ? (
-          <DictationTest />
-        ) : (
-          <SettingsRow
-            label={t("settings.voice.dictation.testLabel")}
-            description={t("settings.voice.dictation.notSupported")}
-          />
-        )}
-      </SettingsSection>
-
-      <SettingsSection
-        title={t("settings.voice.dictionary.sectionTitle")}
-        description={t("settings.voice.dictionary.sectionDescription")}
-      >
-        {dictionary.map((entry, index) => (
-          <div
-            // biome-ignore lint/suspicious/noArrayIndexKey: entries are editable in place
-            key={index}
-            className="flex items-center gap-2 py-1.5"
-          >
-            <Input
-              value={entry}
-              onChange={(e) => updateDictionaryEntry(index, e.target.value)}
-              // Skip the empty-row commit-splice when focus moves to this row's
-              // Remove button (keyboard Tab), so its index stays valid and its
-              // activation deletes this row instead of the next one.
-              onBlur={(e) => {
-                if (
-                  (e.relatedTarget as HTMLElement | null)?.dataset.dictRemove ===
-                  String(index)
-                ) {
-                  return;
-                }
-                commitDictionaryEntry(index);
-              }}
-              className="h-8 flex-1 text-sm"
-              aria-label={`Dictionary entry ${index + 1}`}
-            />
-            <Button
-              variant="ghost"
-              size="icon"
-              className="size-8 shrink-0 text-muted-foreground hover:text-destructive"
-              data-dict-remove={index}
-              // Mouse: keep the click from blurring an empty input first, which
-              // would commit-splice this row and make onClick delete the next.
-              onMouseDown={(e) => e.preventDefault()}
-              onClick={() => removeDictionaryEntry(index)}
-              aria-label={`Remove dictionary entry ${index + 1}`}
-            >
-              <HugeiconsIcon icon={Delete02Icon} className="size-3.5" />
-            </Button>
-          </div>
-        ))}
-        <div className="flex items-center gap-2 py-1.5">
-          <Input
-            value={newEntry}
-            onChange={(e) => setNewEntry(e.target.value)}
-            onKeyDown={(e) => {
-              if (e.key === "Enter") {
-                e.preventDefault();
-                handleAddEntry();
-              }
-            }}
-            placeholder="Jane Doe"
-            className="h-8 flex-1 text-sm"
-            aria-label="New dictionary entry"
-          />
+        <SettingsRow
+          label={t("settings.voice.dictionary.manageLabel")}
+          description={t("settings.voice.dictionary.sectionDescription")}
+        >
           <Button
             variant="outline"
             size="sm"
-            className="shrink-0"
-            onClick={handleAddEntry}
-            disabled={!newEntry.trim()}
+            onClick={() => setSubpage("dictionary")}
           >
-            <HugeiconsIcon icon={PlusSignIcon} className="mr-1.5 size-3.5" />
-            {t("settings.voice.dictionary.addEntry")}
+            {t("settings.voice.dictionary.manage")}
           </Button>
-        </div>
-      </SettingsSection>
+        </SettingsRow>
 
-      <SettingsSection
-        title={t("settings.voice.recents.sectionTitle")}
-        description={t("settings.voice.recents.sectionDescription")}
-      >
-        {recentDictations.length === 0 ? (
-          <p className="py-3 text-sm text-muted-foreground">
-            {t("settings.voice.recents.empty")}
-          </p>
-        ) : (
-          <>
-            {recentDictations.map((item) => (
-              <div
-                key={`${item.at}-${item.text.slice(0, 24)}`}
-                className="flex items-start justify-between gap-3 py-2.5"
-              >
-                <div className="min-w-0 flex-1">
-                  <p className="whitespace-pre-wrap break-words text-sm text-foreground">
-                    {item.text}
-                  </p>
-                  <p className="mt-0.5 text-xs text-muted-foreground">
-                    {new Date(item.at).toLocaleString()}
-                  </p>
-                </div>
-                <Button
-                  variant="ghost"
-                  size="icon"
-                  className="size-8 shrink-0 text-muted-foreground"
-                  aria-label="Copy dictation"
-                  onClick={async () => {
-                    // Helper falls back to execCommand where navigator.clipboard
-                    // is unavailable (Safari, insecure http LAN contexts).
-                    if (await copyToClipboard(item.text)) {
-                      toast.success(t("settings.voice.recents.copied"));
-                    } else {
-                      toast.error(t("settings.voice.recents.copyFailed"));
-                    }
-                  }}
-                >
-                  <HugeiconsIcon icon={Copy01Icon} className="size-3.5" />
-                </Button>
-              </div>
-            ))}
-            <div className="flex justify-end py-2">
-              <Button
-                variant="outline"
-                size="sm"
-                onClick={clearRecentDictations}
-                className="text-destructive hover:text-destructive hover:border-destructive/60"
-              >
-                <HugeiconsIcon
-                  icon={Delete02Icon}
-                  className="mr-1.5 size-3.5"
-                />
-                {t("settings.voice.recents.clear")}
-              </Button>
-            </div>
-          </>
-        )}
+        <SettingsRow
+          label={t("settings.voice.recents.manageLabel")}
+          description={t("settings.voice.recents.sectionDescription")}
+        >
+          <Button
+            variant="outline"
+            size="sm"
+            onClick={() => {
+              setSelectedDictationId(null);
+              setSubpage("recents");
+            }}
+          >
+            {t("settings.voice.recents.manage")}
+          </Button>
+        </SettingsRow>
       </SettingsSection>
 
       <SettingsSection title={t("settings.voice.readAloud.sectionTitle")}>
@@ -747,7 +1134,7 @@ export function VoiceTab() {
               >
                 <SelectTrigger
                   aria-label="TTS engine"
-                  className="w-56"
+                  className="min-w-56 max-w-72"
                   size="sm"
                 >
                   <SelectValue />
@@ -778,7 +1165,7 @@ export function VoiceTab() {
                 <Select value={ttsVoiceURI} onValueChange={setTtsVoiceURI}>
                   <SelectTrigger
                     aria-label="Text to speech voice"
-                    className="w-56"
+                    className="min-w-56 max-w-72"
                     size="sm"
                   >
                     <SelectValue />
diff --git a/studio/frontend/src/features/studio/historical-training-view.tsx b/studio/frontend/src/features/studio/historical-training-view.tsx
index 2f80fc29ca..4a123875a8 100644
--- a/studio/frontend/src/features/studio/historical-training-view.tsx
+++ b/studio/frontend/src/features/studio/historical-training-view.tsx
@@ -2,18 +2,29 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import type { TrainingViewData } from "@/features/training";
-import { getTrainingRun, onTrainingRunUpdated } from "@/features/training";
+import {
+  getTrainingRun,
+  onTrainingRunUpdated,
+  useTrainingActions,
+  useTrainingRuntimeStore,
+} from "@/features/training";
 import type { TrainingRunDetailResponse } from "@/features/training";
 import { parseBackendTrainingMethod } from "@/features/training/lib/training-methods";
 import { type ReactElement, useEffect, useState } from "react";
 import { ChartsSection } from "./sections/charts-section";
 import { ProgressSection } from "./sections/progress-section";
+import { mapRunConfigToOverride } from "./sections/run-config-override";
+import { Button } from "@/components/ui/button";
+import { Spinner } from "@/components/ui/spinner";
+import { PlayIcon } from "@hugeicons/core-free-icons";
+import { HugeiconsIcon } from "@hugeicons/react";
 import { translate, useT } from "@/i18n";
 
 type StudioT = ReturnType<typeof useT>;
 
 interface HistoricalTrainingViewProps {
   runId: string;
+  onResumeStarted?: () => void;
 }
 
 function mapToViewData(
@@ -92,10 +103,27 @@ function mapToViewData(
 
 export function HistoricalTrainingView({
   runId,
+  onResumeStarted,
 }: HistoricalTrainingViewProps): ReactElement {
   const t = useT();
   const [detail, setDetail] = useState<TrainingRunDetailResponse | null>(null);
   const [error, setError] = useState<string | null>(null);
+  const [resuming, setResuming] = useState(false);
+  const { resumeTrainingRunFromHistory } = useTrainingActions();
+  const isStarting = useTrainingRuntimeStore((state) => state.isStarting);
+  const isTrainingRunning = useTrainingRuntimeStore(
+    (state) => state.isTrainingRunning,
+  );
+
+  const handleResume = async () => {
+    setResuming(true);
+    try {
+      const ok = await resumeTrainingRunFromHistory(runId);
+      if (ok) onResumeStarted?.();
+    } finally {
+      setResuming(false);
+    }
+  };
 
   // Derive loading from detail/error; no separate state.
   const loading = detail === null && error === null;
@@ -147,28 +175,31 @@ export function HistoricalTrainingView({
   }
 
   const viewData = mapToViewData(detail, t);
-  const configOverride = detail.config
-    ? {
-        epochs: detail.config.num_epochs as number | undefined,
-        batchSize: detail.config.batch_size as number | undefined,
-        learningRate: detail.config.learning_rate as string | undefined,
-        maxSteps: detail.config.max_steps as number | undefined,
-        contextLength: detail.config.max_seq_length as number | undefined,
-        warmupSteps: detail.config.warmup_steps as number | undefined,
-        optimizerType: detail.config.optim as string | undefined,
-        loraRank: detail.config.lora_r as number | undefined,
-        loraAlpha: detail.config.lora_alpha as number | undefined,
-        loraDropout: detail.config.lora_dropout as number | undefined,
-        loraVariant: detail.config.use_rslora
-          ? "rslora"
-          : detail.config.use_loftq
-            ? "loftq"
-            : "lora",
-      }
-    : undefined;
+  const configOverride = mapRunConfigToOverride(detail.config);
 
   return (
     <div className="flex flex-col gap-6">
+      {detail.run.can_resume && (
+        <div className="flex justify-end">
+          <Button
+            type="button"
+            size="sm"
+            variant="outline"
+            className="gap-1.5"
+            disabled={isStarting || resuming || isTrainingRunning}
+            onClick={() => void handleResume()}
+          >
+            {resuming ? (
+              <Spinner className="size-3.5" />
+            ) : (
+              <HugeiconsIcon icon={PlayIcon} className="size-3.5" />
+            )}
+            {resuming
+              ? t("studio.history.resuming")
+              : t("studio.history.resumeTraining")}
+          </Button>
+        </div>
+      )}
       <ProgressSection
         data={viewData}
         isHistorical
diff --git a/studio/frontend/src/features/studio/history-card-grid.tsx b/studio/frontend/src/features/studio/history-card-grid.tsx
index bd76171ce2..21dc786e34 100644
--- a/studio/frontend/src/features/studio/history-card-grid.tsx
+++ b/studio/frontend/src/features/studio/history-card-grid.tsx
@@ -78,13 +78,17 @@ function wasContinuedInVisibleRuns(
   run: TrainingRunSummary,
   runs: TrainingRunSummary[],
 ): boolean {
-  if (run.status !== "stopped" || !run.output_dir) return false;
+  if ((run.status !== "stopped" && run.status !== "error") || !run.output_dir)
+    return false;
   const startedAt = new Date(run.started_at).getTime();
   return runs.some(
     (other) =>
       other.id !== run.id &&
       other.output_dir === run.output_dir &&
-      (other.status === "stopped" || other.status === "completed") &&
+      (other.status === "stopped" ||
+        other.status === "completed" ||
+        other.status === "error" ||
+        other.status === "running") &&
       new Date(other.started_at).getTime() > startedAt,
   );
 }
@@ -421,14 +425,14 @@ export function HistoryCardGrid({
               <div className="flex items-center justify-between pr-6">
                 <span
                   className={cn(
-                    "inline-flex items-center gap-1.5 rounded-full px-2 py-0.5 text-[10px] font-semibold",
+                    "inline-flex items-center gap-1.5 rounded-full px-2 py-0.5 text-ui-10 font-semibold",
                     badge.className,
                   )}
                 >
                   {isRunning && <Spinner className="size-2.5" />}
                   {formatStatusLabel(wasContinued ? "resumed_later" : run.status, t)}
                 </span>
-                <span className="text-[10px] text-muted-foreground">
+                <span className="text-ui-10 text-muted-foreground">
                   {formatRelativeTime(run.started_at, t)}
                 </span>
               </div>
@@ -437,7 +441,7 @@ export function HistoryCardGrid({
                   type="button"
                   size="xs"
                   variant="outline"
-                  className="absolute bottom-3 left-4 h-6 rounded-full px-2.5 text-[11px] leading-none shadow-sm"
+                  className="absolute bottom-3 left-4 h-6 rounded-full px-2.5 text-ui-11 leading-none shadow-sm"
                   disabled={isStarting || isResuming}
                   onClick={(e) => {
                     e.stopPropagation();
@@ -452,7 +456,7 @@ export function HistoryCardGrid({
                   type="button"
                   size="xs"
                   variant="outline"
-                  className="absolute bottom-3 right-4 h-6 rounded-full px-2.5 text-[11px] leading-none shadow-sm"
+                  className="absolute bottom-3 right-4 h-6 rounded-full px-2.5 text-ui-11 leading-none shadow-sm"
                   onClick={async (e) => {
                     e.stopPropagation();
                     // Encode each segment but keep "/" so the /p route matches.
@@ -520,7 +524,7 @@ export function HistoryCardGrid({
                   />
                 </div>
               )}
-              <div className="flex flex-wrap gap-x-4 gap-y-1 text-[11px] text-muted-foreground">
+              <div className="flex flex-wrap gap-x-4 gap-y-1 text-ui-11 text-muted-foreground">
                 <span>
                   {t("studio.history.loss")}:{" "}
                   {run.final_loss != null ? run.final_loss.toFixed(4) : "--"}
diff --git a/studio/frontend/src/features/studio/live-training-view.tsx b/studio/frontend/src/features/studio/live-training-view.tsx
index cce39adbf4..0aecc7030e 100644
--- a/studio/frontend/src/features/studio/live-training-view.tsx
+++ b/studio/frontend/src/features/studio/live-training-view.tsx
@@ -1,18 +1,42 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { cn } from "@/lib/utils";
 import {
+  getTrainingRun,
   useTrainingConfigStore,
   useTrainingRuntimeStore,
 } from "@/features/training";
 import type { TrainingViewData } from "@/features/training";
+import { cn } from "@/lib/utils";
 import type { ReactElement } from "react";
+import { useEffect, useState } from "react";
 import { useShallow } from "zustand/react/shallow";
 import { ChartsSection } from "./sections/charts-section";
 import { ProgressSection } from "./sections/progress-section";
+import {
+  type RunConfigOverride,
+  mapRunConfigToOverride,
+} from "./sections/run-config-override";
 import { TrainingStartOverlay } from "./training-start-overlay";
 
+/** Retry budget for the run-config lookup. The row is inserted at
+ * start_training(), but a lookup issued in the same instant can still miss it;
+ * a few short retries cover that without polling a genuinely absent row. */
+const RUN_CONFIG_FETCH_RETRIES = 5;
+const RUN_CONFIG_FETCH_RETRY_MS = 1000;
+
+/** The fetched run config only applies while it belongs to the active job;
+ * a stale record from a previous run falls back to the form store. */
+function activeRunOverride(
+  fetched: { jobId: string; override: RunConfigOverride | undefined } | null,
+  jobId: string | null,
+): RunConfigOverride | undefined {
+  if (fetched === null || fetched.jobId !== jobId) {
+    return undefined;
+  }
+  return fetched.override;
+}
+
 export function LiveTrainingView(): ReactElement {
   const runtime = useTrainingRuntimeStore(
     useShallow((state) => ({
@@ -52,6 +76,59 @@ export function LiveTrainingView(): ReactElement {
     })),
   );
 
+  // Show the ACTIVE run's saved config, not the editable form store the user may
+  // have changed since starting (#6853). start_training() commits the run row
+  // before the pump, so the job id alone gates the fetch; the bounded retry below
+  // covers the narrow uncommitted window, and until it loads ProgressSection falls
+  // back to the form store. The result is keyed by job id and filtered at render.
+  const [fetchedRunConfig, setFetchedRunConfig] = useState<{
+    jobId: string;
+    override: RunConfigOverride | undefined;
+  } | null>(null);
+  // Retry budget for the transient 404 below, keyed by job so a new run always
+  // starts with a fresh budget.
+  const [fetchAttempt, setFetchAttempt] = useState<{
+    jobId: string;
+    count: number;
+  } | null>(null);
+  useEffect(() => {
+    if (!runtime.jobId) {
+      return;
+    }
+    const jobId = runtime.jobId;
+    if (fetchedRunConfig !== null && fetchedRunConfig.jobId === jobId) {
+      return; // already resolved for this job
+    }
+    const attempts = fetchAttempt?.jobId === jobId ? fetchAttempt.count : 0;
+    const controller = new AbortController();
+    let retryTimer: ReturnType<typeof setTimeout> | undefined;
+    getTrainingRun(jobId, controller.signal)
+      .then((detail) => {
+        setFetchedRunConfig({
+          jobId,
+          override: mapRunConfigToOverride(detail.config),
+        });
+      })
+      .catch(() => {
+        // A lookup racing the row commit can miss transiently; nothing else in
+        // the deps changes on failure, so retry explicitly. Bounded so a genuinely
+        // absent row falls back to the form store instead of polling forever.
+        if (controller.signal.aborted || attempts >= RUN_CONFIG_FETCH_RETRIES) {
+          return;
+        }
+        retryTimer = setTimeout(() => {
+          setFetchAttempt({ jobId, count: attempts + 1 });
+        }, RUN_CONFIG_FETCH_RETRY_MS);
+      });
+    return () => {
+      controller.abort();
+      if (retryTimer !== undefined) {
+        clearTimeout(retryTimer);
+      }
+    };
+  }, [runtime.jobId, fetchedRunConfig, fetchAttempt]);
+  const runConfigOverride = activeRunOverride(fetchedRunConfig, runtime.jobId);
+
   const activeProjectName =
     runtime.startProjectName !== null
       ? runtime.startProjectName.trim() || null
@@ -76,7 +153,11 @@ export function LiveTrainingView(): ReactElement {
     isTrainingRunning: runtime.isTrainingRunning,
     modelName: runtime.startModelName ?? config.selectedModel ?? "",
     projectName: activeProjectName,
-    trainingMethod: config.trainingMethod ?? "",
+    // Prefer the saved run's method: the form may have been edited (e.g. LoRA
+    // -> Full) after the run started, which would relabel the run and hide its
+    // saved LoRA rows in the popover.
+    trainingMethod:
+      runConfigOverride?.trainingMethod ?? config.trainingMethod ?? "",
     lossHistory: runtime.lossHistory,
     lrHistory: runtime.lrHistory,
     gradNormHistory: runtime.gradNormHistory,
@@ -105,7 +186,11 @@ export function LiveTrainingView(): ReactElement {
         )}
       >
         <div data-tour="studio-training-progress">
-          <ProgressSection key={runtime.jobId ?? "no-job"} data={viewData} />
+          <ProgressSection
+            key={runtime.jobId ?? "no-job"}
+            data={viewData}
+            configOverride={runConfigOverride}
+          />
         </div>
         <ChartsSection
           currentStep={viewData.currentStep}
diff --git a/studio/frontend/src/features/studio/recent-trainings-section.tsx b/studio/frontend/src/features/studio/recent-trainings-section.tsx
index 43808a7ca9..092732b486 100644
--- a/studio/frontend/src/features/studio/recent-trainings-section.tsx
+++ b/studio/frontend/src/features/studio/recent-trainings-section.tsx
@@ -8,7 +8,7 @@ import { HistoryCardGrid } from "./history-card-grid";
 
 /**
  * Recent training runs surfaced on Data Recipes and Export. Selecting a run
- * stores its id and navigates to Studio, which auto-opens its History tab.
+ * stores its id and navigates to Unsloth, which auto-opens its History tab.
  * Renders nothing once we know there are no runs.
  */
 export function RecentTrainingsSection() {
@@ -22,7 +22,7 @@ export function RecentTrainingsSection() {
 
   return (
     <section className="mt-10">
-      <h2 className="mb-4 text-[18px] font-semibold tracking-[-0.02em] text-foreground">
+      <h2 className="mb-4 text-ui-18 font-semibold tracking-[-0.02em] text-foreground">
         Recent trainings
       </h2>
       <HistoryCardGrid
diff --git a/studio/frontend/src/features/studio/sections/charts/chart-settings-sheet.tsx b/studio/frontend/src/features/studio/sections/charts/chart-settings-sheet.tsx
index baa66e8b83..f0f030dace 100644
--- a/studio/frontend/src/features/studio/sections/charts/chart-settings-sheet.tsx
+++ b/studio/frontend/src/features/studio/sections/charts/chart-settings-sheet.tsx
@@ -251,7 +251,7 @@ export function ChartSettingsSheet(): ReactElement {
                   max={0.9}
                   step={0.01}
                 />
-                <p className="text-[11px] text-muted-foreground">
+                <p className="text-ui-11 text-muted-foreground">
                   {t("studio.charts.smoothingDescription")}
                 </p>
               </div>
diff --git a/studio/frontend/src/features/studio/sections/charts/training-loss-chart-card.tsx b/studio/frontend/src/features/studio/sections/charts/training-loss-chart-card.tsx
index 16113f3219..738305eaca 100644
--- a/studio/frontend/src/features/studio/sections/charts/training-loss-chart-card.tsx
+++ b/studio/frontend/src/features/studio/sections/charts/training-loss-chart-card.tsx
@@ -152,7 +152,7 @@ export function TrainingLossChartCard({
                     value: formatMetric(avgRaw),
                   }),
                   position: "insideTopRight",
-                  fontSize: 10,
+                  fontSize: "calc(0.625rem * var(--ui-font-scale, 1))",
                   fill: "#3b82f6",
                 }}
               />
diff --git a/studio/frontend/src/features/studio/sections/dataset-preview-dialog-mapping.tsx b/studio/frontend/src/features/studio/sections/dataset-preview-dialog-mapping.tsx
index 5be1c32f69..d20cc0b63d 100644
--- a/studio/frontend/src/features/studio/sections/dataset-preview-dialog-mapping.tsx
+++ b/studio/frontend/src/features/studio/sections/dataset-preview-dialog-mapping.tsx
@@ -74,15 +74,15 @@ export function HeaderRolePicker({
       value={currentRole ?? "_none"}
       onValueChange={(v) => onRoleChange(v === "_none" ? undefined : v)}
     >
-      <SelectTrigger className="h-6 w-[90px] text-[10px] px-2 py-0 border-dashed cursor-pointer">
+      <SelectTrigger className="h-6 w-[90px] text-ui-10 px-2 py-0 border-dashed cursor-pointer">
         <SelectValue placeholder="Role..." />
       </SelectTrigger>
       <SelectContent>
-        <SelectItem value="_none" className="text-[11px]">
+        <SelectItem value="_none" className="text-ui-11">
           None
         </SelectItem>
         {availableRoles.map((role) => (
-          <SelectItem key={role} value={role} className="text-[11px]">
+          <SelectItem key={role} value={role} className="text-ui-11">
             {ROLE_LABELS[role] ?? role}
           </SelectItem>
         ))}
@@ -179,7 +179,7 @@ export function DatasetMappingCard({
                 <Badge
                   key={col}
                   variant="outline"
-                  className="h-6 text-[11px] bg-white/60 dark:bg-transparent"
+                  className="h-6 text-ui-11 bg-white/60 dark:bg-transparent"
                 >
                   <span className="font-mono">{col}</span>
                   <span className="mx-1 text-muted-foreground/60">&rarr;</span>
@@ -211,7 +211,7 @@ export function DatasetMappingCard({
                   <>
                     <Sparkles className="mr-1.5 h-3.5 w-3.5" />
                     AI Assist
-                    <Badge variant="outline" className="ml-1.5 text-[9px] px-1 py-0 h-4 font-medium">Beta</Badge>
+                    <Badge variant="outline" className="ml-1.5 text-ui-9 px-1 py-0 h-4 font-medium">Beta</Badge>
                   </>
                 )}
               </Button>
@@ -227,7 +227,7 @@ export function DatasetMappingCard({
                 <span>{advisorNotification}</span>
               </div>
               {advisorSystemPrompt && (
-                <div className="pl-5.5 text-[11px] font-mono text-indigo-600/80 dark:text-indigo-400/80">
+                <div className="pl-5.5 text-ui-11 font-mono text-indigo-600/80 dark:text-indigo-400/80">
                   <span className="font-sans font-medium text-indigo-500 dark:text-indigo-400">System:</span>{" "}
                   <span className="break-words">{advisorSystemPrompt}</span>
                 </div>
@@ -256,7 +256,7 @@ export function DatasetMappingFooter({
   return (
     <div className="mt-3 flex flex-col gap-2">
       <div className="flex items-center justify-between gap-3">
-        <p className="text-[11px] text-muted-foreground/70 leading-relaxed">
+        <p className="text-ui-11 text-muted-foreground/70 leading-relaxed">
           Tip: use the role dropdowns in the column headers to assign roles.
         </p>
         <div className="flex items-center gap-2">
diff --git a/studio/frontend/src/features/studio/sections/dataset-preview-dialog.tsx b/studio/frontend/src/features/studio/sections/dataset-preview-dialog.tsx
index c467880b6b..71939aaee2 100644
--- a/studio/frontend/src/features/studio/sections/dataset-preview-dialog.tsx
+++ b/studio/frontend/src/features/studio/sections/dataset-preview-dialog.tsx
@@ -261,7 +261,7 @@ export function DatasetPreviewDialog({
       accessorKey: colName,
       header: () => (
         <div className="flex flex-col gap-2">
-          <span className="font-heading text-[13px] font-semibold tracking-tight text-foreground">
+          <span className="font-heading text-ui-13 font-semibold tracking-tight text-foreground">
             {colName}
           </span>
           {mappingEnabled && (
@@ -308,7 +308,7 @@ export function DatasetPreviewDialog({
         const text = formatCell(value);
         if (!text) {
           return (
-            <span className="text-muted-foreground/40 italic text-[13px]">
+            <span className="text-muted-foreground/40 italic text-ui-13">
               --
             </span>
           );
@@ -316,7 +316,7 @@ export function DatasetPreviewDialog({
         const full = typeof value === "string" ? value : JSON.stringify(value);
         return (
           <p
-            className="text-[13px] leading-relaxed line-clamp-6"
+            className="text-ui-13 leading-relaxed line-clamp-6"
             title={full}
           >
             {text}
@@ -331,11 +331,11 @@ export function DatasetPreviewDialog({
         id: "__system_generated",
         header: () => (
           <div className="flex flex-col gap-2">
-            <span className="font-heading text-[13px] font-semibold tracking-tight text-foreground">
+            <span className="font-heading text-ui-13 font-semibold tracking-tight text-foreground">
               System <span className="text-muted-foreground font-normal">(generated)</span>
             </span>
             {mappingEnabled && (
-              <Badge variant="outline" className="h-6 w-fit text-[10px] px-2 py-0 border-dashed text-muted-foreground">
+              <Badge variant="outline" className="h-6 w-fit text-ui-10 px-2 py-0 border-dashed text-muted-foreground">
                 System
               </Badge>
             )}
@@ -343,7 +343,7 @@ export function DatasetPreviewDialog({
         ),
         cell: () => (
           <p
-            className="text-[13px] leading-relaxed line-clamp-6 text-muted-foreground italic"
+            className="text-ui-13 leading-relaxed line-clamp-6 text-muted-foreground italic"
             title={datasetSystemPrompt}
           >
             {datasetSystemPrompt}
@@ -443,7 +443,7 @@ export function DatasetPreviewDialog({
                         <Badge
                           key={col}
                           variant="outline"
-                          className="text-[11px] font-mono h-5"
+                          className="text-ui-11 font-mono h-5"
                         >
                           {col}
                         </Badge>
@@ -493,7 +493,7 @@ export function DatasetPreviewDialog({
 
               {/* Footer */}
               <div className="mt-3">
-                <p className="text-[11px] text-muted-foreground/60 text-center tabular-nums">
+                <p className="text-ui-11 text-muted-foreground/60 text-center tabular-nums">
                   Showing {rows.length}
                   {data.total_rows != null &&
                     ` of ${data.total_rows.toLocaleString()}`}{" "}
@@ -501,7 +501,7 @@ export function DatasetPreviewDialog({
                 </p>
 
                 {mode === "preview" && mappingEnabled && (
-                  <p className="mt-2 text-[11px] text-muted-foreground/70 text-center">
+                  <p className="mt-2 text-ui-11 text-muted-foreground/70 text-center">
                     Mapping is saved automatically. You can start training anytime.
                   </p>
                 )}
@@ -540,7 +540,7 @@ function MetaRow({
       <span className="text-muted-foreground font-medium text-xs w-24 shrink-0">
         {label}:
       </span>
-      <span className="text-foreground text-[13px] min-w-0">{value}</span>
+      <span className="text-foreground text-ui-13 min-w-0">{value}</span>
     </div>
   );
 }
diff --git a/studio/frontend/src/features/studio/sections/dataset-section.tsx b/studio/frontend/src/features/studio/sections/dataset-section.tsx
index e7bab1f47f..6a3cc8129a 100644
--- a/studio/frontend/src/features/studio/sections/dataset-section.tsx
+++ b/studio/frontend/src/features/studio/sections/dataset-section.tsx
@@ -70,11 +70,13 @@ import {
 } from "@hugeicons/core-free-icons";
 import { HugeiconsIcon } from "@hugeicons/react";
 import { useNavigate } from "@tanstack/react-router";
+import { motion, useReducedMotion } from "motion/react";
 import {
   type ChangeEvent,
   type DragEvent,
   useCallback,
   useEffect,
+  useId,
   useMemo,
   useRef,
   useState,
@@ -153,6 +155,9 @@ function normalizeSliceInput(value: string): string | null {
 export function DatasetSection() {
   const t = useT();
   const navigate = useNavigate();
+  const reducedMotion = useReducedMotion();
+  // Scopes the pill layoutId so multiple instances never share one.
+  const sourcePillLayoutId = useId();
   const {
     dataset,
     datasetSource,
@@ -686,6 +691,9 @@ export function DatasetSection() {
           {(() => {
             // Hub-style sliding-pill segmented control, matching the Hub tabs
             // via the shared .hub-tab-toggle / .hub-tab-toggle-pill classes.
+            // flex-auto buttons share leftover space equally so padding stays
+            // equal for all labels; the pill sits inside the active button so
+            // it always matches its bounds.
             const sourceTabs: {
               value: "huggingface" | "upload" | "s3";
               label: string;
@@ -696,24 +704,12 @@ export function DatasetSection() {
                 ? []
                 : [{ value: "s3" as const, label: "Amazon S3" }]),
             ];
-            const activeIndex = Math.max(
-              0,
-              sourceTabs.findIndex((item) => item.value === datasetSource),
-            );
             return (
               <div
                 role="radiogroup"
                 aria-label="Dataset source"
-                className="hub-tab-toggle relative inline-flex h-9 w-full items-center rounded-full"
+                className="hub-tab-toggle relative flex h-9 w-full items-center rounded-full"
               >
-                <span
-                  aria-hidden="true"
-                  className="hub-tab-toggle-pill pointer-events-none absolute inset-y-0 left-0 rounded-full transition-transform duration-200 ease-out"
-                  style={{
-                    width: `${100 / sourceTabs.length}%`,
-                    transform: `translateX(${activeIndex * 100}%)`,
-                  }}
-                />
                 {sourceTabs.map((item) => (
                   <button
                     key={item.value}
@@ -732,13 +728,30 @@ export function DatasetSection() {
                       }
                     }}
                     className={cn(
-                      "relative z-10 inline-flex h-9 flex-1 cursor-pointer items-center justify-center rounded-full px-3 text-[12.5px] font-medium transition-colors",
+                      "relative inline-flex h-9 flex-auto cursor-pointer items-center justify-center rounded-full px-3 text-ui-12p5 font-medium transition-colors",
                       datasetSource === item.value
                         ? "text-foreground"
                         : "text-muted-foreground hover:text-foreground",
                     )}
                   >
-                    {item.label}
+                    {datasetSource === item.value && (
+                      <motion.span
+                        aria-hidden="true"
+                        layoutId={sourcePillLayoutId}
+                        className="hub-tab-toggle-pill absolute inset-0 rounded-full"
+                        transition={
+                          reducedMotion
+                            ? { duration: 0 }
+                            : {
+                                type: "spring",
+                                stiffness: 500,
+                                damping: 35,
+                                mass: 0.5,
+                              }
+                        }
+                      />
+                    )}
+                    <span className="relative z-10">{item.label}</span>
                   </button>
                 ))}
               </div>
@@ -751,7 +764,7 @@ export function DatasetSection() {
             <div className="flex min-w-0 flex-col gap-2">
               <span className="flex items-center gap-1.5 text-xs font-medium text-muted-foreground">
                 {t("studio.dataset.chooseDataset")}
-                <span className="rounded-full border border-border/70 bg-muted/40 px-2 py-0.5 text-[10px] font-medium text-foreground/80">
+                <span className="rounded-full border border-border/70 bg-muted/40 px-2 py-0.5 text-ui-10 font-medium text-foreground/80">
                   {datasetSource === "upload"
                     ? t("studio.dataset.localTab")
                     : "Hugging Face"}
@@ -1017,7 +1030,7 @@ export function DatasetSection() {
                 </p>
               )}
               {pickerTab !== activeSourceTab && (
-                <p className="text-[11px] text-muted-foreground">
+                <p className="text-ui-11 text-muted-foreground">
                   {t("studio.dataset.browsingSource", {
                     browsing:
                       pickerTab === "local"
@@ -1055,7 +1068,7 @@ export function DatasetSection() {
                       <p className="text-xs font-medium text-muted-foreground">
                         {t("studio.dataset.localDatasetMetadata")}
                       </p>
-                      <p className="text-[10px] text-muted-foreground/80">
+                      <p className="text-ui-10 text-muted-foreground/80">
                         {t("studio.dataset.dataRecipeOutput")}
                       </p>
                     </div>
@@ -1159,7 +1172,7 @@ export function DatasetSection() {
                       ? t("studio.dataset.uploading")
                       : t("studio.dataset.uploadEvalFile")}
                   </Button>
-                  <p className="text-[10px] text-muted-foreground/80">
+                  <p className="text-ui-10 text-muted-foreground/80">
                     {t("studio.dataset.evalDatasetDescription")}
                   </p>
                 </div>
@@ -1366,7 +1379,7 @@ export function DatasetSection() {
                           deriveLocalDatasetName(selectedDatasetName))
                         : selectedDatasetName}
                     </p>
-                    <p className="text-[10px] text-muted-foreground">
+                    <p className="text-ui-10 text-muted-foreground">
                       {datasetSource === "upload" ? (
                         uploadedFile ? (
                           <>
@@ -1420,7 +1433,7 @@ export function DatasetSection() {
                     <span className="block text-xs font-medium text-foreground">
                       {t("studio.dataset.dropFileOrClick")}
                     </span>
-                    <span className="mt-0.5 block truncate text-[10px] text-muted-foreground">
+                    <span className="mt-0.5 block truncate text-ui-10 text-muted-foreground">
                       {TRAINING_DATASET_UPLOAD_LABEL} · up to {uploadLimitLabel}
                       ; {DOCUMENT_REDIRECT_LABEL}
                     </span>
diff --git a/studio/frontend/src/features/studio/sections/model-section.tsx b/studio/frontend/src/features/studio/sections/model-section.tsx
index c8f36b397c..0589fde350 100644
--- a/studio/frontend/src/features/studio/sections/model-section.tsx
+++ b/studio/frontend/src/features/studio/sections/model-section.tsx
@@ -374,7 +374,7 @@ export function ModelSection() {
                               {model?.path ?? id}
                             </TooltipContent>
                           </Tooltip>
-                          <span className="ml-auto shrink-0 text-[10px] text-muted-foreground">
+                          <span className="ml-auto shrink-0 text-ui-10 text-muted-foreground">
                             {source}
                           </span>
                         </ComboboxItem>
@@ -385,13 +385,13 @@ export function ModelSection() {
               </Combobox>
             </div>
             {isLoadingLocalModels ? (
-              <p className="text-[10px] text-muted-foreground">
+              <p className="text-ui-10 text-muted-foreground">
                 {t("studio.model.scanningLocalModels")}
               </p>
             ) : localModelsError ? (
-              <p className="text-[10px] text-red-500">{localModelsError}</p>
+              <p className="text-ui-10 text-red-500">{localModelsError}</p>
             ) : (
-              <p className="text-[10px] text-muted-foreground">
+              <p className="text-ui-10 text-muted-foreground">
                 {trainableLocalModels.length > 0
                   ? t("studio.model.localModelsFound", {
                       count: trainableLocalModels.length,
@@ -507,7 +507,7 @@ export function ModelSection() {
                                 {vramEst != null &&
                                   vramEst > 0 &&
                                   gpu.available && (
-                                    <span className="block text-[10px] mt-1">
+                                    <span className="block text-ui-10 mt-1">
                                       {exceeds
                                         ? t("studio.model.needsVram", {
                                             vram: vramEst,
@@ -527,17 +527,17 @@ export function ModelSection() {
                             </Tooltip>
                             <span className="ml-auto flex items-center gap-1.5 shrink-0">
                               {fitStatus === "exceeds" && (
-                                <span className="text-[9px] font-medium !text-red-700 !bg-red-50 dark:!text-red-400 dark:!bg-red-950 px-1.5 py-0.5 rounded">
+                                <span className="text-ui-9 font-medium !text-red-700 !bg-red-50 dark:!text-red-400 dark:!bg-red-950 px-1.5 py-0.5 rounded">
                                   OOM
                                 </span>
                               )}
                               {fitStatus === "tight" && (
-                                <span className="text-[9px] font-medium !text-amber-400">
+                                <span className="text-ui-9 font-medium !text-amber-400">
                                   TIGHT
                                 </span>
                               )}
                               {detail && (
-                                <span className="text-[10px] text-muted-foreground">
+                                <span className="text-ui-10 text-muted-foreground">
                                   {detail}
                                 </span>
                               )}
diff --git a/studio/frontend/src/features/studio/sections/params-section.tsx b/studio/frontend/src/features/studio/sections/params-section.tsx
index ad438f63f1..66e3a26567 100644
--- a/studio/frontend/src/features/studio/sections/params-section.tsx
+++ b/studio/frontend/src/features/studio/sections/params-section.tsx
@@ -36,6 +36,7 @@ import {
   CONTEXT_LENGTHS,
   CPT_TARGET_MODULES,
   LR_SCHEDULER_OPTIONS,
+  MLX_OPTIMIZER_OPTIONS,
   OPTIMIZER_OPTIONS,
   TARGET_MODULES,
 } from "@/config/training";
@@ -204,6 +205,40 @@ export function ParamsSection(): ReactElement {
     setCtxInput(String(store.contextLength));
   }, [store.contextLength]);
 
+  // Apple Silicon (MLX) supports a different optimizer set than the CUDA list.
+  const isMac = platformDeviceType === "mac";
+  const optimizerOptions = isMac ? MLX_OPTIMIZER_OPTIONS : OPTIMIZER_OPTIONS;
+
+  // On Mac the MLX backend remaps CUDA optimizers to AdamW, so label those as
+  // AdamW; other values (MLX or imported) show as-is. Non-Mac unchanged.
+  const isCudaAliasOptimizer = OPTIMIZER_OPTIONS.some(
+    (o) => o.value === store.optimizerType,
+  );
+  const selectedOptimizer =
+    isMac && isCudaAliasOptimizer ? "adamw" : store.optimizerType;
+
+  // LoftQ and DoRA are not supported on MLX (the backend rejects both), so
+  // clear a stale selection to lora on Apple Silicon -- whether persisted,
+  // applied from a model default, or imported -- so the backend never
+  // receives it.
+  const setLoraVariant = store.setLoraVariant;
+  useEffect(() => {
+    if (
+      isMac &&
+      (store.loraVariant === "loftq" || store.loraVariant === "dora")
+    ) {
+      setLoraVariant("lora");
+    }
+  }, [isMac, store.loraVariant, setLoraVariant]);
+
+  // Packing is unsupported on MLX; clear it on Apple Silicon (checkbox disabled).
+  const setPacking = store.setPacking;
+  useEffect(() => {
+    if (isMac && store.packing) {
+      setPacking(false);
+    }
+  }, [isMac, store.packing, setPacking]);
+
   const trySetContextLength = (input: string): number | null => {
     const n = Number(input);
     if (Number.isInteger(n) && n > 0) {
@@ -238,7 +273,7 @@ export function ParamsSection(): ReactElement {
           <div className="flex flex-col gap-2">
             <span className="flex items-center gap-1.5 text-xs font-medium text-muted-foreground">
               {t("studio.params.projectName")}
-              <span className="text-[10px] font-normal text-muted-foreground/70">
+              <span className="text-ui-10 font-normal text-muted-foreground/70">
                 {t("studio.params.optional")}
               </span>
             </span>
@@ -248,7 +283,7 @@ export function ParamsSection(): ReactElement {
               placeholder="customer-support-lora"
               maxLength={80}
             />
-            <p className="text-[10px] text-muted-foreground">
+            <p className="text-ui-10 text-muted-foreground">
               {t("studio.params.projectNameDescription")}
             </p>
           </div>
@@ -337,7 +372,7 @@ export function ParamsSection(): ReactElement {
                 max={useEpochs ? epochsSliderMax : maxStepsSliderMax}
                 step={1}
               />
-              <p className="text-[10px] text-muted-foreground">
+              <p className="text-ui-10 text-muted-foreground">
                 {useEpochs
                   ? t("studio.params.epochsDescription")
                   : t("studio.params.maxStepsDescription")}
@@ -425,7 +460,7 @@ export function ParamsSection(): ReactElement {
                 </ComboboxContent>
               </Combobox>
             </div>
-            <p className="text-[10px] text-muted-foreground">
+            <p className="text-ui-10 text-muted-foreground">
               {t("studio.params.contextLengthDescription")}
             </p>
           </div>
@@ -466,7 +501,7 @@ export function ParamsSection(): ReactElement {
               onChange={(e) => store.setLearningRate(Number(e.target.value))}
               className="w-full font-mono"
             />
-            <p className="text-[10px] text-muted-foreground">
+            <p className="text-ui-10 text-muted-foreground">
               {t("studio.params.learningRateDescription")}
             </p>
           </div>
@@ -511,7 +546,7 @@ export function ParamsSection(): ReactElement {
                 }}
                 className="w-full font-mono"
               />
-              <p className="text-[10px] text-muted-foreground">
+              <p className="text-ui-10 text-muted-foreground">
                 {t("studio.params.embeddingLearningRateDescription")}
               </p>
             </div>
@@ -667,7 +702,7 @@ export function ParamsSection(): ReactElement {
                                       : [...store.targetModules, mod],
                                   );
                                 }}
-                                className={`cursor-pointer rounded-full border px-2.5 py-0.5 text-[11px] font-mono transition-colors ${
+                                className={`cursor-pointer rounded-full border px-2.5 py-0.5 text-ui-11 font-mono transition-colors ${
                                   active
                                     ? "border-orange-300 bg-orange-50 text-orange-700 dark:border-orange-700 dark:bg-orange-950 dark:text-orange-300"
                                     : "text-muted-foreground hover:bg-muted/50"
@@ -683,7 +718,7 @@ export function ParamsSection(): ReactElement {
                   )}
 
                   {/* LoRA variant */}
-                  <div className="flex gap-2">
+                  <div className="grid grid-cols-2 gap-2">
                     {(
                       [
                         {
@@ -701,21 +736,32 @@ export function ParamsSection(): ReactElement {
                           label: "LoftQ",
                           desc: t("studio.params.memoryEfficient"),
                         },
+                        {
+                          value: "dora",
+                          label: "DoRA",
+                          desc: t("studio.params.weightDecomposed"),
+                        },
                       ] as const
                     ).map((opt) => (
                       <button
                         key={opt.value}
                         type="button"
+                        disabled={
+                          isMac &&
+                          (opt.value === "loftq" || opt.value === "dora")
+                        }
                         onClick={() => store.setLoraVariant(opt.value)}
-                        className={`flex-1 corner-squircle rounded-xl border px-3 py-2 text-left transition-colors cursor-pointer ${
+                        className={`flex-1 corner-squircle rounded-xl border px-3 py-2 text-left transition-colors cursor-pointer disabled:cursor-not-allowed disabled:opacity-60 ${
                           store.loraVariant === opt.value
                             ? "border-ring-strong bg-primary/5"
                             : "border-border hover:border-foreground/20"
                         }`}
                       >
                         <p className="text-xs font-medium">{opt.label}</p>
-                        <p className="text-[10px] text-muted-foreground">
-                          {opt.desc}
+                        <p className="text-ui-10 text-muted-foreground">
+                          {isMac && (opt.value === "loftq" || opt.value === "dora")
+                            ? "Not supported on Apple Silicon"
+                            : opt.desc}
                         </p>
                       </button>
                     ))}
@@ -765,7 +811,11 @@ export function ParamsSection(): ReactElement {
                     label={t("studio.params.optimizer")}
                     tooltip={
                       <>
-                        {t("studio.params.optimizerTooltip")}{" "}
+                        {t(
+                          isMac
+                            ? "studio.params.optimizerTooltipMlx"
+                            : "studio.params.optimizerTooltip",
+                        )}{" "}
                         <a
                           href="https://unsloth.ai/docs/get-started/fine-tuning-llms-guide/lora-hyperparameters-guide"
                           target="_blank"
@@ -778,14 +828,14 @@ export function ParamsSection(): ReactElement {
                     }
                   >
                     <Select
-                      value={store.optimizerType}
+                      value={selectedOptimizer}
                       onValueChange={(v) => store.setOptimizerType(v)}
                     >
                       <SelectTrigger className="w-48">
                         <SelectValue />
                       </SelectTrigger>
                       <SelectContent>
-                        {OPTIMIZER_OPTIONS.map((opt) => (
+                        {optimizerOptions.map((opt) => (
                           <SelectItem key={opt.value} value={opt.value}>
                             {formatOptimizerLabel(opt.value, opt.label, t)}
                           </SelectItem>
@@ -1105,14 +1155,37 @@ export function ParamsSection(): ReactElement {
                       <Checkbox
                         id="packing"
                         checked={store.packing}
+                        disabled={isMac}
                         onCheckedChange={(v) => store.setPacking(!!v)}
                       />
                       <label
                         htmlFor="packing"
-                        className="text-xs cursor-pointer text-muted-foreground"
+                        className={`text-xs text-muted-foreground ${
+                          isMac
+                            ? "cursor-not-allowed opacity-60"
+                            : "cursor-pointer"
+                        }`}
                       >
                         {t("studio.params.enablePacking")}
                       </label>
+                      {isMac && (
+                        <Tooltip>
+                          <TooltipTrigger asChild={true}>
+                            <button
+                              type="button"
+                              className="text-foreground/70 hover:text-foreground"
+                            >
+                              <HugeiconsIcon
+                                icon={InformationCircleIcon}
+                                className="size-3"
+                              />
+                            </button>
+                          </TooltipTrigger>
+                          <TooltipContent>
+                            Packing is not supported on Apple Silicon (MLX).
+                          </TooltipContent>
+                        </Tooltip>
+                      )}
                     </div>
                   )}
                   {!store.isEmbeddingModel && !isCpt && !isRawText && (
diff --git a/studio/frontend/src/features/studio/sections/progress-section.tsx b/studio/frontend/src/features/studio/sections/progress-section.tsx
index 1aaa3b6889..a2cf711296 100644
--- a/studio/frontend/src/features/studio/sections/progress-section.tsx
+++ b/studio/frontend/src/features/studio/sections/progress-section.tsx
@@ -19,7 +19,8 @@ import {
   PopoverTrigger,
 } from "@/components/ui/popover";
 import { Progress } from "@/components/ui/progress";
-import { OPTIMIZER_OPTIONS } from "@/config/training";
+import { usePlatformStore } from "@/config/env";
+import { MLX_OPTIMIZER_OPTIONS, OPTIMIZER_OPTIONS } from "@/config/training";
 import { setTrainingCompareHandoff } from "@/features/chat";
 import {
   useTrainingActions,
@@ -28,6 +29,7 @@ import {
 } from "@/features/training";
 import { getTrainingMethodLabel } from "@/features/training/lib/training-methods";
 import type { TrainingViewData } from "@/features/training";
+import type { RunConfigOverride } from "./run-config-override";
 import { useGpuUtilization } from "@/hooks";
 import type { GpuUtilization } from "@/hooks/use-gpu-utilization";
 import { cn } from "@/lib/utils";
@@ -81,19 +83,7 @@ function configRow(
 interface ProgressSectionProps {
   data: TrainingViewData;
   isHistorical?: boolean;
-  configOverride?: {
-    epochs?: number;
-    batchSize?: number;
-    learningRate?: string;
-    maxSteps?: number;
-    contextLength?: number;
-    warmupSteps?: number;
-    optimizerType?: string;
-    loraRank?: number;
-    loraAlpha?: number;
-    loraDropout?: number;
-    loraVariant?: string;
-  };
+  configOverride?: RunConfigOverride;
 }
 
 export function ProgressSection({
@@ -103,6 +93,7 @@ export function ProgressSection({
 }: ProgressSectionProps): ReactElement {
   const t = useT();
   const navigate = useNavigate();
+  const platformDeviceType = usePlatformStore((s) => s.deviceType);
   const trainingMethodLabel = getTrainingMethodLabel(data.trainingMethod);
 
   const config = useTrainingConfigStore(
@@ -183,21 +174,32 @@ export function ProgressSection({
     ? data.currentGradNorm
     : (lastValue(data.gradNormHistory) ?? data.currentGradNorm);
 
-  const cfgEpochs = isHistorical ? configOverride?.epochs : config.epochs;
-  const cfgBatchSize = isHistorical ? configOverride?.batchSize : config.batchSize;
-  const cfgLearningRate = isHistorical ? configOverride?.learningRate : config.learningRate;
-  const cfgMaxSteps = isHistorical ? configOverride?.maxSteps : config.maxSteps;
-  const cfgContextLength = isHistorical ? configOverride?.contextLength : config.contextLength;
-  const cfgWarmupSteps = isHistorical ? configOverride?.warmupSteps : config.warmupSteps;
-  const cfgOptimizerType = isHistorical ? configOverride?.optimizerType : config.optimizerType;
-  const cfgLoraRank = isHistorical ? configOverride?.loraRank : config.loraRank;
-  const cfgLoraAlpha = isHistorical ? configOverride?.loraAlpha : config.loraAlpha;
-  const cfgLoraDropout = isHistorical ? configOverride?.loraDropout : config.loraDropout;
-  const cfgLoraVariant = isHistorical ? configOverride?.loraVariant : config.loraVariant;
+  // Prefer the run's saved snapshot when present (#6853). Live falls back to the
+  // editable form store until it loads; History shows blanks, never live form values.
+  const cfg = configOverride ?? (isHistorical ? undefined : config);
+  const cfgEpochs = cfg?.epochs;
+  const cfgBatchSize = cfg?.batchSize;
+  const cfgLearningRate = cfg?.learningRate;
+  const cfgMaxSteps = cfg?.maxSteps;
+  const cfgContextLength = cfg?.contextLength;
+  const cfgWarmupSteps = cfg?.warmupSteps;
+  const cfgOptimizerType = cfg?.optimizerType;
+  const cfgLoraRank = cfg?.loraRank;
+  const cfgLoraAlpha = cfg?.loraAlpha;
+  const cfgLoraDropout = cfg?.loraDropout;
+  const cfgLoraVariant = cfg?.loraVariant;
 
+  // Mirror the training form: on Mac the MLX backend runs CUDA optimizers as
+  // AdamW, so label them AdamW here too.
+  const effectiveOptimizer =
+    platformDeviceType === "mac" &&
+    OPTIMIZER_OPTIONS.some((o) => o.value === cfgOptimizerType)
+      ? "adamw"
+      : cfgOptimizerType;
   const optimizerLabel =
-    OPTIMIZER_OPTIONS.find((o) => o.value === cfgOptimizerType)?.label ??
-    cfgOptimizerType;
+    [...OPTIMIZER_OPTIONS, ...MLX_OPTIMIZER_OPTIONS].find(
+      (o) => o.value === effectiveOptimizer,
+    )?.label ?? effectiveOptimizer;
 
   const configItems: ConfigGroup[] = [
     {
@@ -266,21 +268,21 @@ export function ProgressSection({
         <div className="flex flex-col gap-4">
           <div className="flex flex-wrap items-center gap-2">
             <span
-              className={`rounded-full px-2.5 py-1 text-[10px] font-semibold ${phaseColors[data.phase]}`}
+              className={`rounded-full px-2.5 py-1 text-ui-10 font-semibold ${phaseColors[data.phase]}`}
             >
               {t(phaseLabelKeys[data.phase])}
             </span>
             {data.projectName && (
-              <span className="rounded-full border border-border/60 px-2.5 py-1 text-[10px] font-medium text-foreground/80">
+              <span className="rounded-full border border-border/60 px-2.5 py-1 text-ui-10 font-medium text-foreground/80">
                 {data.projectName}
               </span>
             )}
-            <span className="text-[10px] tabular-nums text-muted-foreground">
+            <span className="text-ui-10 tabular-nums text-muted-foreground">
               {t("studio.progress.epoch", {
                 value: formatNumber(data.currentEpoch, 2),
               })}
             </span>
-            <span className="rounded-full border border-border/60 px-2.5 py-1 text-[10px] font-medium tabular-nums text-muted-foreground">
+            <span className="rounded-full border border-border/60 px-2.5 py-1 text-ui-10 font-medium tabular-nums text-muted-foreground">
               {t("studio.progress.percentComplete", { percent: pct })}
             </span>
           </div>
@@ -402,7 +404,7 @@ function LiveGpuPanel({
             <select
               value={selectedGpu}
               onChange={(e) => setSelectedGpu(Number(e.target.value))}
-              className="h-6 cursor-pointer rounded-md border border-border bg-popover px-1.5 py-0.5 text-[11px] text-popover-foreground outline-none hover:bg-muted focus:border-ring transition-colors font-medium appearance-none"
+              className="h-6 cursor-pointer rounded-md border border-border bg-popover px-1.5 py-0.5 text-ui-11 text-popover-foreground outline-none hover:bg-muted focus:border-ring transition-colors font-medium appearance-none"
               title="Select GPU"
             >
               {gpus.map((device, index) => (
@@ -417,7 +419,7 @@ function LiveGpuPanel({
             </select>
           )}
         </div>
-        <span className="text-[11px] text-muted-foreground">
+        <span className="text-ui-11 text-muted-foreground">
           {t("studio.progress.live")}
         </span>
       </div>
@@ -535,7 +537,7 @@ function ConfigPopoverButton({
           <p className="text-xs font-semibold">{t("studio.progress.configLabel")}</p>
           {configItems.map((group) => (
             <div key={group.section} className="flex flex-col gap-1">
-              <p className="text-[10px] font-semibold uppercase tracking-wider text-muted-foreground">
+              <p className="text-ui-10 font-semibold uppercase tracking-wider text-muted-foreground">
                 {group.section}
               </p>
               {group.rows.map(([label, value]) => (
@@ -636,7 +638,7 @@ function MilestoneCallout({
       <div className="flex items-start justify-between gap-3">
         <div className="min-w-0">
           {!showCompletedHint && (
-            <p className="text-[10px] font-medium uppercase tracking-[0.12em] text-muted-foreground">
+            <p className="text-ui-10 font-medium uppercase tracking-[0.12em] text-muted-foreground">
               {t("studio.training.milestone")}
             </p>
           )}
@@ -652,7 +654,7 @@ function MilestoneCallout({
           </p>
         </div>
         {!showCompletedHint && (
-          <span className="rounded-full border border-border/60 bg-background/80 px-2 py-0.5 text-[10px] font-medium text-muted-foreground">
+          <span className="rounded-full border border-border/60 bg-background/80 px-2 py-0.5 text-ui-10 font-medium text-muted-foreground">
             50%+
           </span>
         )}
@@ -682,7 +684,7 @@ function MetricStat({
 }): ReactElement {
   return (
     <div className="min-w-0">
-      <p className="text-[11px] text-muted-foreground">{label}</p>
+      <p className="text-ui-11 text-muted-foreground">{label}</p>
       <p
         className={`mt-1 text-base font-semibold tabular-nums ${valueClassName ?? ""}`}
       >
diff --git a/studio/frontend/src/features/studio/sections/run-config-override.ts b/studio/frontend/src/features/studio/sections/run-config-override.ts
new file mode 100644
index 0000000000..8ef3d9d1b6
--- /dev/null
+++ b/studio/frontend/src/features/studio/sections/run-config-override.ts
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { parseBackendTrainingMethod } from "@/features/training";
+
+/** Shape of the Training Config popover's data when it is driven by a saved
+ * run snapshot instead of the editable form store. */
+export interface RunConfigOverride {
+  trainingMethod?: string;
+  epochs?: number;
+  batchSize?: number;
+  learningRate?: string;
+  maxSteps?: number;
+  contextLength?: number;
+  warmupSteps?: number;
+  optimizerType?: string;
+  loraRank?: number;
+  loraAlpha?: number;
+  loraDropout?: number;
+  loraVariant?: string;
+}
+
+/** Map a saved run's config (GET /api/train/runs/{id} `detail.config`) into the
+ * Training Config popover's override shape. Shared by the History view and the
+ * live Current Run view so both read the same authoritative run snapshot
+ * instead of the editable form store (#6853). */
+export function mapRunConfigToOverride(
+  config: Record<string, unknown> | null | undefined,
+): RunConfigOverride | undefined {
+  if (!config) {
+    return undefined;
+  }
+  return {
+    trainingMethod: parseBackendTrainingMethod(
+      config.training_type,
+      config.load_in_4bit,
+    ),
+    epochs: config.num_epochs as number | undefined,
+    batchSize: config.batch_size as number | undefined,
+    learningRate: config.learning_rate as string | undefined,
+    maxSteps: config.max_steps as number | undefined,
+    contextLength: config.max_seq_length as number | undefined,
+    warmupSteps: config.warmup_steps as number | undefined,
+    optimizerType: config.optim as string | undefined,
+    loraRank: config.lora_r as number | undefined,
+    loraAlpha: config.lora_alpha as number | undefined,
+    loraDropout: config.lora_dropout as number | undefined,
+    loraVariant: config.use_rslora
+      ? "rslora"
+      : config.use_loftq
+        ? "loftq"
+        : config.use_dora
+          ? "dora"
+          : "lora",
+  };
+}
diff --git a/studio/frontend/src/features/studio/sections/s3-config-form.tsx b/studio/frontend/src/features/studio/sections/s3-config-form.tsx
index 8126027cf9..e7daffb750 100644
--- a/studio/frontend/src/features/studio/sections/s3-config-form.tsx
+++ b/studio/frontend/src/features/studio/sections/s3-config-form.tsx
@@ -51,7 +51,7 @@ export function S3ConfigForm() {
         <p className="text-xs font-medium text-foreground">
           {t("studio.dataset.s3.title")}
         </p>
-        <p className="text-[10px] text-muted-foreground/80">
+        <p className="text-ui-10 text-muted-foreground/80">
           {t("studio.dataset.s3.description")}
         </p>
       </div>
diff --git a/studio/frontend/src/features/studio/studio-page.tsx b/studio/frontend/src/features/studio/studio-page.tsx
index 4d3a32fab3..f50dcf5155 100644
--- a/studio/frontend/src/features/studio/studio-page.tsx
+++ b/studio/frontend/src/features/studio/studio-page.tsx
@@ -165,7 +165,7 @@ export function StudioPage(): ReactElement {
         />
 
         <div className="mb-6 flex flex-col gap-0.5 sm:mb-8">
-          <h1 className="text-[30px] font-semibold leading-[1.04] tracking-[-0.028em] text-foreground sm:text-[34px]">
+          <h1 className="text-ui-30 font-semibold leading-[1.04] tracking-[-0.028em] text-foreground sm:text-ui-34">
             {t("studio.title")}
           </h1>
           <p className="text-sm text-muted-foreground">{subtitle}</p>
@@ -217,7 +217,13 @@ export function StudioPage(): ReactElement {
 
             <TabsContent value="history">
               {selectedHistoryRunId ? (
-                <HistoricalTrainingView runId={selectedHistoryRunId} />
+                <HistoricalTrainingView
+                  runId={selectedHistoryRunId}
+                  onResumeStarted={() => {
+                    setSelectedHistoryRunId(null);
+                    handleTabChange("current-run");
+                  }}
+                />
               ) : (
                 <HistoryCardGrid onSelectRun={(runId) => {
                   if (runId === currentJobId && isTrainingRunning) {
diff --git a/studio/frontend/src/features/studio/training-start-overlay.tsx b/studio/frontend/src/features/studio/training-start-overlay.tsx
index db2ca91313..c836b61ce4 100644
--- a/studio/frontend/src/features/studio/training-start-overlay.tsx
+++ b/studio/frontend/src/features/studio/training-start-overlay.tsx
@@ -210,7 +210,7 @@ function DownloadRow({ label, state }: DownloadRowProps): ReactElement | null {
           <span className="text-xs text-foreground/90">{label}</span>
           {statusLabel ? (
             <span
-              className={`rounded-full px-1.5 py-0.5 text-[10px] font-medium ${isComplete ? "bg-emerald-100 text-emerald-700 ring-1 ring-emerald-200/80 dark:bg-emerald-500/15 dark:text-emerald-300 dark:ring-emerald-500/30" : "bg-muted text-muted-foreground"}`}
+              className={`rounded-full px-1.5 py-0.5 text-ui-10 font-medium ${isComplete ? "bg-emerald-100 text-emerald-700 ring-1 ring-emerald-200/80 dark:bg-emerald-500/15 dark:text-emerald-300 dark:ring-emerald-500/30" : "bg-muted text-muted-foreground"}`}
             >
               {statusLabel}
             </span>
@@ -221,7 +221,7 @@ function DownloadRow({ label, state }: DownloadRowProps): ReactElement | null {
         </span>
       </div>
       {sizeLabel ? (
-        <div className="text-[11px] tabular-nums text-muted-foreground">
+        <div className="text-ui-11 tabular-nums text-muted-foreground">
           {sizeLabel}
         </div>
       ) : null}
@@ -233,7 +233,7 @@ function DownloadRow({ label, state }: DownloadRowProps): ReactElement | null {
       ) : null}
       {state.cachePath ? (
         <div
-          className="truncate rounded bg-muted/50 px-2 py-1 text-[10px] text-muted-foreground/70"
+          className="truncate rounded bg-muted/50 px-2 py-1 text-ui-10 text-muted-foreground/70"
           title={state.cachePath}
         >
           {formatCachePath(state.cachePath)}
diff --git a/studio/frontend/src/features/tour/components/guided-tour.tsx b/studio/frontend/src/features/tour/components/guided-tour.tsx
index a0ed6be98c..c0730d0389 100644
--- a/studio/frontend/src/features/tour/components/guided-tour.tsx
+++ b/studio/frontend/src/features/tour/components/guided-tour.tsx
@@ -313,13 +313,13 @@ export function GuidedTour({
                   <div className="relative p-5">
                     <div className="flex items-start justify-between gap-3">
                       <div className="min-w-0">
-                        <div className="inline-flex items-center gap-2 rounded-full bg-black/[0.04] px-2.5 py-1 text-[10px] font-mono text-foreground/60 ring-1 ring-black/10 dark:bg-white/[0.04] dark:text-zinc-200/75 dark:ring-white/14">
+                        <div className="inline-flex items-center gap-2 rounded-full bg-black/[0.04] px-2.5 py-1 text-ui-10 font-mono text-foreground/60 ring-1 ring-black/10 dark:bg-white/[0.04] dark:text-zinc-200/75 dark:ring-white/14">
                           {idx + 1}/{total}
                           <span className="size-1 rounded-full bg-control-accent/70" />
                           guided tour
                         </div>
                         <DialogPrimitive.Title
-                          className="mt-2 text-[18px] leading-tight"
+                          className="mt-2 text-ui-18 leading-tight"
                           style={{ fontFamily: "var(--font-serif)" }}
                         >
                           {step?.title ?? "Quick tour"}
@@ -383,7 +383,7 @@ export function GuidedTour({
                   </div>
 
                   <div className="h-px bg-gradient-to-r from-transparent via-black/10 to-transparent dark:via-white/14" />
-                  <div className="px-5 py-3 text-[11px] text-foreground/55 dark:text-zinc-300/65">
+                  <div className="px-5 py-3 text-ui-11 text-foreground/55 dark:text-zinc-300/65">
                     Tip: `Esc` skips. Tour blocks clicks so you can read.
                   </div>
                 </motion.div>
diff --git a/studio/frontend/src/features/training/api/mappers.ts b/studio/frontend/src/features/training/api/mappers.ts
index c2e23dbf3c..1b90e67f7f 100644
--- a/studio/frontend/src/features/training/api/mappers.ts
+++ b/studio/frontend/src/features/training/api/mappers.ts
@@ -125,8 +125,9 @@ export function buildTrainingStartPayload(
     lora_dropout: config.loraDropout,
     target_modules: adapterMethod ? config.targetModules : [],
     gradient_checkpointing: config.gradientCheckpointing,
-    use_rslora: config.loraVariant === "rslora",
-    use_loftq: config.loraVariant === "loftq",
+    use_rslora: adapterMethod && config.loraVariant === "rslora",
+    use_loftq: adapterMethod && config.loraVariant === "loftq",
+    use_dora: adapterMethod && config.loraVariant === "dora",
     // CPT always trains on full sequences (no chat format masking)
     train_on_completions: (isEmbedding || isCpt || isRawText) ? false : config.trainOnCompletions,
     finetune_vision_layers: config.finetuneVisionLayers,
diff --git a/studio/frontend/src/features/training/api/models-api.ts b/studio/frontend/src/features/training/api/models-api.ts
index e5fd8b043d..8fb7f4acf6 100644
--- a/studio/frontend/src/features/training/api/models-api.ts
+++ b/studio/frontend/src/features/training/api/models-api.ts
@@ -2,6 +2,7 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { authFetch } from "@/features/auth";
+import { hubTokenHeader } from "@/features/hub";
 
 interface VisionCheckResponse {
   model_name: string;
@@ -41,6 +42,7 @@ interface BackendLoraDefaults {
   target_modules?: string[];
   use_rslora?: boolean;
   use_loftq?: boolean;
+  use_dora?: boolean;
   finetune_vision_layers?: boolean;
   finetune_language_layers?: boolean;
   finetune_attention_modules?: boolean;
@@ -98,8 +100,9 @@ export async function checkVisionModel(
   hfToken?: string | null,
 ): Promise<boolean> {
   const encoded = encodeURIComponent(modelName);
-  const query = hfToken?.trim() ? `?hf_token=${encodeURIComponent(hfToken.trim())}` : "";
-  const response = await authFetch(`/api/models/check-vision/${encoded}${query}`);
+  const response = await authFetch(`/api/models/check-vision/${encoded}`, {
+    headers: hubTokenHeader(hfToken?.trim() || null),
+  });
   if (!response.ok) {
     // If the check fails (e.g. network error), default to non-vision
     return false;
@@ -114,8 +117,9 @@ export async function checkEmbeddingModel(
   hfToken?: string | null,
 ): Promise<boolean> {
   const encoded = encodeURIComponent(modelName);
-  const query = hfToken?.trim() ? `?hf_token=${encodeURIComponent(hfToken.trim())}` : "";
-  const response = await authFetch(`/api/models/check-embedding/${encoded}${query}`);
+  const response = await authFetch(`/api/models/check-embedding/${encoded}`, {
+    headers: hubTokenHeader(hfToken?.trim() || null),
+  });
   if (!response.ok) {
     // If the check fails (e.g. network error), default to non-embedding
     return false;
@@ -130,8 +134,10 @@ export async function getModelConfig(
   hfToken?: string,
 ): Promise<ModelConfigResponse> {
   const encoded = encodeURIComponent(modelName);
-  const params = hfToken ? `?hf_token=${encodeURIComponent(hfToken)}` : "";
-  const response = await authFetch(`/api/models/config/${encoded}${params}`, { signal });
+  const response = await authFetch(`/api/models/config/${encoded}`, {
+    headers: hubTokenHeader(hfToken?.trim() || null),
+    signal,
+  });
   if (!response.ok) {
     throw new Error(`Failed to fetch model config (${response.status})`);
   }
diff --git a/studio/frontend/src/features/training/api/train-api.ts b/studio/frontend/src/features/training/api/train-api.ts
index 609e4f8591..c5f09c8bd0 100644
--- a/studio/frontend/src/features/training/api/train-api.ts
+++ b/studio/frontend/src/features/training/api/train-api.ts
@@ -2,6 +2,7 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { authFetch } from "@/features/auth";
+import { prepareHfTokenForUse } from "@/features/hf-auth";
 import { readFastApiError } from "@/lib/format-fastapi-error";
 import type {
   TrainingStartRequest,
@@ -30,10 +31,12 @@ async function parseJson<T>(response: Response): Promise<T> {
 export async function startTraining(
   payload: TrainingStartRequest,
 ): Promise<TrainingStartResponse> {
+  const preparedToken = await prepareHfTokenForUse(payload.hf_token);
+  if (!preparedToken.proceed) throw new Error("Training start cancelled.");
   const response = await authFetch("/api/train/start", {
     method: "POST",
     headers: { "Content-Type": "application/json" },
-    body: JSON.stringify(payload),
+    body: JSON.stringify({ ...payload, hf_token: preparedToken.token }),
   });
   return parseJson<TrainingStartResponse>(response);
 }
diff --git a/studio/frontend/src/features/training/hooks/use-training-actions.ts b/studio/frontend/src/features/training/hooks/use-training-actions.ts
index 2f04656c23..9bb8206f28 100644
--- a/studio/frontend/src/features/training/hooks/use-training-actions.ts
+++ b/studio/frontend/src/features/training/hooks/use-training-actions.ts
@@ -2,6 +2,7 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { primeNativeNotificationPermission } from "@/lib/native-notifications";
+import { prepareHfTokenForUse } from "@/features/hf-auth";
 import { confirmRemoteCodeIfNeeded } from "@/features/security";
 import { useCallback } from "react";
 import { toast } from "@/lib/toast";
@@ -43,7 +44,7 @@ export function useTrainingActions() {
   const startError = useTrainingRuntimeStore((state) => state.startError);
 
   const startTrainingRun = useCallback(async (): Promise<boolean> => {
-    const config = useTrainingConfigStore.getState();
+    let config = useTrainingConfigStore.getState();
     const runtimeStore = useTrainingRuntimeStore.getState();
     const dialogStore = useDatasetPreviewDialogStore.getState();
 
@@ -54,6 +55,13 @@ export function useTrainingActions() {
       return false;
     }
 
+    const preparedToken = await prepareHfTokenForUse(config.hfToken);
+    if (!preparedToken.proceed) return false;
+    if ((preparedToken.token ?? "") !== config.hfToken) {
+      config.setHfToken(preparedToken.token ?? "");
+      config = useTrainingConfigStore.getState();
+    }
+
     primeNativeNotificationPermission().catch(() => undefined);
 
     runtimeStore.setStartResources(
@@ -209,7 +217,7 @@ export function useTrainingActions() {
       const detail = await getTrainingRun(runId);
       const outputDir = detail.run.output_dir;
       if (!detail.run.can_resume || !outputDir) {
-        throw new Error("Only stopped runs with a saved checkpoint can be resumed.");
+        throw new Error("Only stopped or errored runs with a saved checkpoint can be resumed.");
       }
 
       primeNativeNotificationPermission().catch(() => undefined);
@@ -226,6 +234,13 @@ export function useTrainingActions() {
         resume_from_checkpoint: outputDir,
       } as TrainingStartRequest;
 
+      const preparedToken = await prepareHfTokenForUse(payload.hf_token);
+      if (!preparedToken.proceed) {
+        runtimeStore.setStarting(false);
+        return false;
+      }
+      payload.hf_token = preparedToken.token;
+
       runtimeStore.setStartResources(
         payload.model_name,
         payload.hf_dataset,
diff --git a/studio/frontend/src/features/training/index.ts b/studio/frontend/src/features/training/index.ts
index 553dcc2af5..81514b4415 100644
--- a/studio/frontend/src/features/training/index.ts
+++ b/studio/frontend/src/features/training/index.ts
@@ -12,6 +12,7 @@ export {
   getTrainingRunDisplayTitle,
   getTrainingRunModelSubtitle,
 } from "./lib/run-display";
+export { parseBackendTrainingMethod } from "./lib/training-methods";
 export { useTrainingHistorySidebarItems } from "./hooks/use-training-history-sidebar";
 export { useTrainingRuntimeLifecycle } from "./hooks/use-training-runtime-lifecycle";
 export { useTrainingCompletionWatch } from "./hooks/use-training-completion-watch";
@@ -24,8 +25,8 @@ export { HfDatasetSubsetSplitSelectors } from "./components/hf-dataset-subset-sp
 export { useDatasetPreviewDialogStore } from "./stores/dataset-preview-dialog-store";
 export { listLocalDatasets, uploadTrainingDataset } from "./api/datasets-api";
 export type { LocalDatasetInfo } from "./types/datasets";
-export { listLocalModels } from "./api/models-api";
-export type { LocalModelInfo } from "./api/models-api";
+export { getModelConfig, listLocalModels } from "./api/models-api";
+export type { LocalModelInfo, ModelConfigResponse } from "./api/models-api";
 export type {
   TrainingPhase,
   TrainingViewData,
diff --git a/studio/frontend/src/features/training/lib/model-defaults.ts b/studio/frontend/src/features/training/lib/model-defaults.ts
index 3a0a14b150..82ce9ccc4a 100644
--- a/studio/frontend/src/features/training/lib/model-defaults.ts
+++ b/studio/frontend/src/features/training/lib/model-defaults.ts
@@ -181,6 +181,7 @@ export function mapBackendModelConfigToTrainingPatch(
 
   if (lora?.use_loftq === true) patch.loraVariant = "loftq";
   else if (lora?.use_rslora === true) patch.loraVariant = "rslora";
+  else if (lora?.use_dora === true) patch.loraVariant = "dora";
   else if (lora) patch.loraVariant = "lora";
 
   const finetuneVisionLayers = toBoolean(lora?.finetune_vision_layers);
diff --git a/studio/frontend/src/features/training/lib/yaml-config.ts b/studio/frontend/src/features/training/lib/yaml-config.ts
index d25f5a56f8..d2eef17efe 100644
--- a/studio/frontend/src/features/training/lib/yaml-config.ts
+++ b/studio/frontend/src/features/training/lib/yaml-config.ts
@@ -69,6 +69,7 @@ export function serializeConfigToYaml(
     target_modules: state.targetModules,
     use_rslora: state.loraVariant === "rslora",
     use_loftq: state.loraVariant === "loftq",
+    use_dora: state.loraVariant === "dora",
   };
 
   if (includeVisionFields) {
diff --git a/studio/frontend/src/features/training/stores/training-config-store.ts b/studio/frontend/src/features/training/stores/training-config-store.ts
index a927f83fd8..d204e24f47 100644
--- a/studio/frontend/src/features/training/stores/training-config-store.ts
+++ b/studio/frontend/src/features/training/stores/training-config-store.ts
@@ -1004,7 +1004,7 @@ export const useTrainingConfigStore = create<TrainingConfigStore>()(
         }
         if (version < 12) {
           // hfToken moved to the shared hf-token-store; seed it once so an
-          // existing Studio-only token isn't lost.
+          // existing Unsloth-only token isn't lost.
           const legacyToken = typeof s.hfToken === "string" ? s.hfToken.trim() : "";
           if (legacyToken && !getHfToken()) {
             useHfTokenStore.getState().setToken(legacyToken);
diff --git a/studio/frontend/src/features/training/stores/training-runtime-store.ts b/studio/frontend/src/features/training/stores/training-runtime-store.ts
index acc80a3be2..131ea30d30 100644
--- a/studio/frontend/src/features/training/stores/training-runtime-store.ts
+++ b/studio/frontend/src/features/training/stores/training-runtime-store.ts
@@ -223,7 +223,10 @@ export const useTrainingRuntimeStore = create<TrainingRuntimeStore>()((set) => (
           typeof detailLr === "number" ? detailLr : state.currentLearningRate,
         currentEpoch:
           typeof detailEpoch === "number" ? detailEpoch : state.currentEpoch,
-        outputDir: payload.details?.output_dir ?? state.outputDir,
+        outputDir:
+          payload.details?.output_dir !== undefined
+            ? payload.details.output_dir
+            : state.outputDir,
         lossHistory: metricHistory.lossHistory ?? state.lossHistory,
         lrHistory: metricHistory.lrHistory ?? state.lrHistory,
         gradNormHistory: metricHistory.gradNormHistory ?? state.gradNormHistory,
diff --git a/studio/frontend/src/features/training/types/api.ts b/studio/frontend/src/features/training/types/api.ts
index ecd29a2ff0..31aef4697c 100644
--- a/studio/frontend/src/features/training/types/api.ts
+++ b/studio/frontend/src/features/training/types/api.ts
@@ -54,6 +54,7 @@ export interface TrainingStartRequest {
   gradient_checkpointing: string;
   use_rslora: boolean;
   use_loftq: boolean;
+  use_dora: boolean;
   train_on_completions: boolean;
   finetune_vision_layers: boolean;
   finetune_language_layers: boolean;
diff --git a/studio/frontend/src/features/training/types/config.ts b/studio/frontend/src/features/training/types/config.ts
index 5658dfc7a1..617992ce4f 100644
--- a/studio/frontend/src/features/training/types/config.ts
+++ b/studio/frontend/src/features/training/types/config.ts
@@ -12,7 +12,7 @@ import type {
 } from "@/types/training";
 import type { BackendModelConfig } from "../api/models-api";
 
-export type LoraVariant = "lora" | "rslora" | "loftq";
+export type LoraVariant = "lora" | "rslora" | "loftq" | "dora";
 
 /** Column-to-role mapping, e.g. { "problem": "user", "solution": "assistant", "context": "system" } */
 export type DatasetManualMapping = Record<string, string>;
diff --git a/studio/frontend/src/features/training/types/runtime.ts b/studio/frontend/src/features/training/types/runtime.ts
index 8ed0ce0037..373e876653 100644
--- a/studio/frontend/src/features/training/types/runtime.ts
+++ b/studio/frontend/src/features/training/types/runtime.ts
@@ -26,7 +26,8 @@ export interface TrainingStatusResponse {
     total_steps?: number;
     loss?: number;
     learning_rate?: number;
-    output_dir?: string;
+    // null = explicit clear (run stopped without saving); absent = unchanged.
+    output_dir?: string | null;
   } | null;
   metric_history?: {
     steps?: number[];
diff --git a/studio/frontend/src/features/transformers-upgrade/components/transformers-upgrade-dialog.tsx b/studio/frontend/src/features/transformers-upgrade/components/transformers-upgrade-dialog.tsx
index 98c590e5e4..3e39a8ff1c 100644
--- a/studio/frontend/src/features/transformers-upgrade/components/transformers-upgrade-dialog.tsx
+++ b/studio/frontend/src/features/transformers-upgrade/components/transformers-upgrade-dialog.tsx
@@ -82,7 +82,7 @@ export function TransformersUpgradeDialog() {
                     <>
                       Even the latest transformers release on PyPI does not
                       support it yet: the architecture is only available on the
-                      transformers development branch (main), and Studio does
+                      transformers development branch (main), and Unsloth does
                       not install development builds. Support arrives with the
                       next transformers release on PyPI.
                     </>
diff --git a/studio/frontend/src/hooks/index.ts b/studio/frontend/src/hooks/index.ts
index 5b2fa43ae7..33289ffe9e 100644
--- a/studio/frontend/src/hooks/index.ts
+++ b/studio/frontend/src/hooks/index.ts
@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-
 export { useDebouncedValue } from "./use-debounced-value";
 export { useGpuInfo } from "./use-gpu-info";
 export { useGpuUtilization } from "./use-gpu-utilization";
@@ -11,3 +10,4 @@ export { useHfTokenValidation } from "./use-hf-token-validation";
 export { useTauriBackend } from "./use-tauri-backend";
 export { useCollapseScrollLock } from "./use-collapse-scroll-lock";
 export { useSystemInfo } from "./use-system";
+export { useWheelScrollRef } from "./use-wheel-scroll-ref";
diff --git a/studio/frontend/src/hooks/use-gpu-info.ts b/studio/frontend/src/hooks/use-gpu-info.ts
index 1e313acdf3..db2cc021be 100644
--- a/studio/frontend/src/hooks/use-gpu-info.ts
+++ b/studio/frontend/src/hooks/use-gpu-info.ts
@@ -15,6 +15,19 @@ export interface GpuInfo {
   systemRamTotalGb: number
 }
 
+export interface SystemGpuDevice {
+  index: number;
+  name: string;
+  memoryTotalGb: number;
+  /** Free VRAM at fetch time. Degrades to the total when the utilization
+   * probe had no usage data; 0 only when the total is unknown too. */
+  memoryFreeGb: number;
+  /** "physical" = `index` is a stable physical/PCI id safe to pin via gpu_ids;
+   *  "relative" = an ordinal into a parent CUDA_VISIBLE_DEVICES mask, which the
+   *  backend can't map back, so the picker must not offer it. */
+  physicalIndex: boolean;
+}
+
 const DEFAULT_GPU: GpuInfo = {
   available: false,
   name: "Unknown",
@@ -25,70 +38,135 @@ const DEFAULT_GPU: GpuInfo = {
   systemRamTotalGb: 0
 };
 
-// Module-level cache so multiple components share one fetch.
-let cachedGpu: GpuInfo | null = null;
-let fetchPromise: Promise<GpuInfo> | null = null;
+// One module-level cache so every GPU hook shares a single /api/system fetch.
+let cachedSystem: SystemInfoResponse | null = null;
+let systemPromise: Promise<SystemInfoResponse | null> | null = null;
 
-async function fetchGpuOnce(): Promise<GpuInfo> {
-  if (cachedGpu) return cachedGpu;
-  if (fetchPromise) return fetchPromise;
-
-  fetchPromise = (async () => {
+async function fetchSystemOnce(): Promise<SystemInfoResponse | null> {
+  if (cachedSystem) return cachedSystem;
+  if (systemPromise) return systemPromise;
+  systemPromise = (async () => {
     try {
       const res = await authFetch("/api/system");
       if (!res.ok) throw new Error(`HTTP ${res.status}`);
-
-      const data = await res.json() as SystemInfoResponse;
-      const gpuData = data?.gpu;
-
-      // CPU/RAM exist even on hosts without a GPU, so populate them on every path.
-      // No discrete GPU (e.g. Mac): still surface system RAM so memory math
-      // (unified memory) has a budget to work with.
-      const base = {
-        cpuCore: data?.cpu?.physical_count ?? 0,
-        cpuThread: data?.cpu?.logical_count ?? 0,
-        systemRamAvailableGb: data?.memory?.available_gb ?? 0,
-        systemRamTotalGb: data?.memory?.total_gb ?? 0,
-      };
-
-      const devices = gpuData?.devices ?? [];
-      const info: GpuInfo =
-        gpuData?.available && devices.length
-          ? {
-              ...base,
-              available: true,
-              name: devices[0]?.name ?? "Unknown",
-              memoryTotalGb: devices.reduce((sum, d) => sum + (d.memory_total_gb ?? 0), 0),
-            }
-          : { ...DEFAULT_GPU, ...base };
-      cachedGpu = info;
-      return info;
+      cachedSystem = (await res.json()) as SystemInfoResponse;
+      return cachedSystem;
     } catch {
-      // Reset promise so subsequent calls retry (e.g. backend wasn't ready)
-      fetchPromise = null;
-      return DEFAULT_GPU;
+      systemPromise = null; // reset so a later call retries (backend not ready)
+      return null;
     }
   })();
+  return systemPromise;
+}
 
-  return fetchPromise;
+function toGpuInfo(data: SystemInfoResponse | null): GpuInfo {
+  // CPU/RAM exist even on GPU-less hosts (e.g. Mac), so populate them on every
+  // path: unified-memory math still needs a RAM budget to work with.
+  const base = {
+    cpuCore: data?.cpu?.physical_count ?? 0,
+    cpuThread: data?.cpu?.logical_count ?? 0,
+    systemRamAvailableGb: data?.memory?.available_gb ?? 0,
+    systemRamTotalGb: data?.memory?.total_gb ?? 0,
+  };
+  const gpuData = data?.gpu;
+  const devices = gpuData?.devices ?? [];
+  if (!gpuData?.available || !devices.length) {
+    return { ...DEFAULT_GPU, ...base };
+  }
+  return {
+    ...base,
+    available: true,
+    name: devices[0]?.name ?? "Unknown",
+    memoryTotalGb: devices.reduce((sum, d) => sum + (d.memory_total_gb ?? 0), 0),
+  };
+}
+
+function toGpuDevices(data: SystemInfoResponse | null): SystemGpuDevice[] {
+  // Unpinnable configurations must hide every pick surface: XPU indices are
+  // torch-xpu ordinals no applicator speaks, and Vulkan-only builds pin ggml's
+  // own ordinals -- /load and /validate 400 picks on both, so the backend
+  // reports gpu.gguf_gpu_ids_supported and every gate keyed on physicalIndex
+  // (picker, persisted-pick reconcile) follows it. The device flavor lives on
+  // the TOP-LEVEL device_backend field; absent support info defaults to
+  // pinnable (older backend).
+  const pinnableBackend =
+    data?.device_backend !== "xpu" &&
+    data?.gpu?.gguf_gpu_ids_supported !== false;
+  return (data?.gpu?.devices ?? [])
+    .filter((d) => typeof d.index === "number")
+    .map((d) => ({
+      index: d.index as number,
+      name: d.name ?? `GPU ${d.index}`,
+      memoryTotalGb: d.memory_total_gb ?? 0,
+      memoryFreeGb: d.vram_free_gb ?? 0,
+      physicalIndex: pinnableBackend && d.index_kind === "physical",
+    }));
+}
+
+/** Aggregate GPU info from /api/system; shares one module-level fetch across all GPU hooks. */
+export function useGpuInfo(): GpuInfo {
+  const [gpu, setGpu] = useState<GpuInfo>(
+    cachedSystem ? toGpuInfo(cachedSystem) : DEFAULT_GPU,
+  );
+  useEffect(() => {
+    // No early return on cachedSystem: a consumer mounting as the cache fills
+    // (between render and effect) would otherwise stay stuck at the default.
+    let cancelled = false;
+    fetchSystemOnce().then((d) => {
+      if (!cancelled) setGpu(toGpuInfo(d));
+    });
+    return () => {
+      cancelled = true;
+    };
+  }, []);
+  return gpu;
+}
+
+/** All backend-visible GPUs (index, name, total VRAM); shares the same fetch. */
+export function useGpuDevices(): SystemGpuDevice[] {
+  const [devices, setDevices] = useState<SystemGpuDevice[]>(
+    cachedSystem ? toGpuDevices(cachedSystem) : [],
+  );
+  useEffect(() => {
+    // No early return on cachedSystem: a consumer mounting as the cache fills
+    // (between render and effect) would otherwise stay stuck at the default.
+    let cancelled = false;
+    fetchSystemOnce().then((d) => {
+      if (!cancelled) setDevices(toGpuDevices(d));
+    });
+    return () => {
+      cancelled = true;
+    };
+  }, []);
+  return devices;
 }
 
 /**
- * Fetch GPU info from /api/system. Cached at module level, so only one request
- * is made no matter how many components call this hook.
+ * Await the shared /api/system fetch so cachedPinnableGpuIndices (and the
+ * store's reconcilePersistedGpuIds) can validate a persisted pick before a
+ * load path sends it -- on a cold cache the reconcile passes ids through
+ * unvalidated, and a stale cross-host pick then fails /load with the picker
+ * hidden. Resolves immediately once the module cache is warm; a failed fetch
+ * keeps the cache cold, preserving the "can't validate, backend guards"
+ * degradation.
  */
-export function useGpuInfo(): GpuInfo {
-  const [gpu, setGpu] = useState<GpuInfo>(cachedGpu ?? DEFAULT_GPU);
+export async function ensureGpuDeviceCache(): Promise<void> {
+  await fetchSystemOnce();
+}
 
-  useEffect(() => {
-    if (cachedGpu) return;
-
-    let cancelled = false;
-    fetchGpuOnce().then((info) => {
-      if (!cancelled) setGpu(info);
-    });
-    return () => { cancelled = true; };
-  }, []);
-
-  return gpu;
-}
\ No newline at end of file
+/**
+ * Pinnable physical GPU indices from the already-fetched /api/system cache, for
+ * non-React code (the store) that needs to validate a persisted `gpu_ids` pick
+ * without triggering a fetch. Returns:
+ *  - `null` when the cache isn't populated yet (caller can't validate, so keep
+ *    the pick and let the backend guard reject a truly bad one);
+ *  - `[]` when the host has no pinnable multi-GPU set (single GPU, or relative/
+ *    UUID-masked indices) -- the picker is hidden, so any saved pick is stale;
+ *  - the physical indices otherwise.
+ */
+export function cachedPinnableGpuIndices(): number[] | null {
+  if (!cachedSystem) return null;
+  const physical = toGpuDevices(cachedSystem).filter((d) => d.physicalIndex);
+  // Mirrors the sheet's showGpuPicker gate: only a 2+ physical-GPU host can pin.
+  return physical.length > 1 ? physical.map((d) => d.index) : [];
+}
diff --git a/studio/frontend/src/hooks/use-hf-token-validation.ts b/studio/frontend/src/hooks/use-hf-token-validation.ts
index 11f56a2151..64e8a869b4 100644
--- a/studio/frontend/src/hooks/use-hf-token-validation.ts
+++ b/studio/frontend/src/hooks/use-hf-token-validation.ts
@@ -1,8 +1,8 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-import { whoAmI } from "@huggingface/hub";
-import { useCallback, useEffect, useRef, useState } from "react";
+import { validateHfToken } from "@/features/hf-auth";
+import { useEffect, useRef, useState } from "react";
 import { useDebouncedValue } from "./use-debounced-value";
 
 export interface HfTokenValidationState {
@@ -17,48 +17,96 @@ const INITIAL: HfTokenValidationState = {
   isChecking: false,
 };
 
+interface CompletedValidation extends HfTokenValidationState {
+  token: string;
+}
+
+const NO_COMPLETED_VALIDATION: CompletedValidation = {
+  ...INITIAL,
+  token: "",
+};
+
+// Current user access tokens contain 34 characters after the hf_ prefix.
+// Action-time validation still accepts legacy shapes without spending quota
+// on every intermediate value typed into a live form field.
+const COMPLETE_HF_TOKEN = /^hf_[A-Za-z0-9]{34}$/;
+
 /**
  * Validates the HF token via the whoami-v2 API, debounced to avoid excessive
  * requests while typing. isValid is null until checked.
  */
 export function useHfTokenValidation(token: string): HfTokenValidationState {
-  const debouncedToken = useDebouncedValue(
-    token.trim().replace(/^["']+|["']+$/g, ""),
-    500,
+  const normalizedToken = token.trim().replace(/^["']+|["']+$/g, "");
+  const debouncedToken = useDebouncedValue(normalizedToken, 500);
+  const [completed, setCompleted] = useState<CompletedValidation>(
+    NO_COMPLETED_VALIDATION,
   );
-  const [state, setState] = useState<HfTokenValidationState>(INITIAL);
   const versionRef = useRef(0);
-
-  const runCheck = useCallback(async (t: string) => {
-    if (!t) {
-      setState({ isValid: null, error: null, isChecking: false });
-      return;
-    }
-
-    const v = ++versionRef.current;
-    setState((prev) => ({ ...prev, isChecking: true, error: null }));
-
-    try {
-      await whoAmI({ accessToken: t });
-      if (versionRef.current !== v) return;
-      setState({ isValid: true, error: null, isChecking: false });
-    } catch {
-      if (versionRef.current !== v) return;
-      setState({
-        isValid: false,
-        error: "invalid or expired token",
-        isChecking: false,
-      });
-    }
-  }, []);
+  const shouldValidate = COMPLETE_HF_TOKEN.test(debouncedToken);
 
   useEffect(() => {
-    if (!debouncedToken) {
-      setState(INITIAL);
+    if (!shouldValidate) {
+      versionRef.current += 1;
       return;
     }
-    runCheck(debouncedToken);
-  }, [debouncedToken, runCheck]);
+    const version = ++versionRef.current;
+    void validateHfToken(debouncedToken).then(
+      (result) => {
+        if (versionRef.current !== version) return;
+        if (result.status === "valid") {
+          setCompleted({
+            token: debouncedToken,
+            isValid: true,
+            error: null,
+            isChecking: false,
+          });
+        } else if (result.status === "invalid") {
+          setCompleted({
+            token: debouncedToken,
+            isValid: false,
+            error: "invalid or expired token",
+            isChecking: false,
+          });
+        } else if (result.status === "rate_limited") {
+          const wait = result.retryAfterSeconds
+            ? ` Try again in about ${Math.ceil(result.retryAfterSeconds / 60)} minute(s).`
+            : " Try again later.";
+          setCompleted({
+            token: debouncedToken,
+            isValid: null,
+            error: `Token verification is rate limited.${wait}`,
+            isChecking: false,
+          });
+        } else {
+          setCompleted({
+            token: debouncedToken,
+            isValid: null,
+            error:
+              "Could not verify the token. Check your connection and try again.",
+            isChecking: false,
+          });
+        }
+      },
+      () => {
+        if (versionRef.current !== version) return;
+        setCompleted({
+          token: debouncedToken,
+          isValid: null,
+          error:
+            "Could not verify the token. Check your connection and try again.",
+          isChecking: false,
+        });
+      },
+    );
+  }, [debouncedToken, shouldValidate]);
 
-  return state;
+  if (!COMPLETE_HF_TOKEN.test(normalizedToken)) return INITIAL;
+  if (completed.token !== normalizedToken) {
+    return { isValid: null, error: null, isChecking: true };
+  }
+  return {
+    isValid: completed.isValid,
+    error: completed.error,
+    isChecking: false,
+  };
 }
diff --git a/studio/frontend/src/hooks/use-llama-update-check.ts b/studio/frontend/src/hooks/use-llama-update-check.ts
index e3a735ffde..999700ae1f 100644
--- a/studio/frontend/src/hooks/use-llama-update-check.ts
+++ b/studio/frontend/src/hooks/use-llama-update-check.ts
@@ -30,6 +30,7 @@ export interface LlamaUpdateJob {
 export interface LlamaUpdateStatus {
   supported: boolean;
   update_available: boolean;
+  component: "llama.cpp" | "whisper.cpp";
   installed_tag: string | null;
   latest_tag: string | null;
   // Prebuilt download size in bytes, if known.
@@ -55,13 +56,30 @@ function parseJob(value: unknown): LlamaUpdateJob {
 function parseStatus(value: unknown): LlamaUpdateStatus | null {
   if (!value || typeof value !== "object") return null;
   const s = value as Record<string, unknown>;
+  const component =
+    s.update_component === "whisper" ? "whisper.cpp" : "llama.cpp";
+  const whisper =
+    s.whisper && typeof s.whisper === "object"
+      ? (s.whisper as Record<string, unknown>)
+      : null;
+  // Legacy top-level version fields intentionally retain their llama meaning.
+  // A whisper-only update must display the nested whisper release instead of
+  // presenting equal llama tags as a new llama update.
+  const details = component === "whisper.cpp" && whisper ? whisper : s;
   return {
     supported: s.supported === true,
     update_available: s.update_available === true,
-    installed_tag: typeof s.installed_tag === "string" ? s.installed_tag : null,
-    latest_tag: typeof s.latest_tag === "string" ? s.latest_tag : null,
+    component,
+    installed_tag:
+      typeof details.installed_tag === "string"
+        ? details.installed_tag
+        : null,
+    latest_tag:
+      typeof details.latest_tag === "string" ? details.latest_tag : null,
     update_size_bytes:
-      typeof s.update_size_bytes === "number" ? s.update_size_bytes : null,
+      typeof details.update_size_bytes === "number"
+        ? details.update_size_bytes
+        : null,
     job: parseJob(s.job),
   };
 }
@@ -163,8 +181,12 @@ export function useLlamaUpdateCheck({
   // can drop or double-fire the notification.
   const notifyReloadIfNeeded = useCallback(
     (job: Pick<LlamaUpdateJob, "state" | "reload_required" | "finished_at">) => {
+      // "error" is included for partial chained updates: the llama phase can
+      // land (and unload the server) before a later phase fails, and the
+      // backend keeps reload_required set in exactly that case. Without the
+      // resync the chat UI would keep pointing at the unloaded model.
       if (
-        job.state === "success" &&
+        (job.state === "success" || job.state === "error") &&
         job.reload_required &&
         job.finished_at !== reloadNotifiedForRef.current
       ) {
@@ -202,7 +224,9 @@ export function useLlamaUpdateCheck({
             reloadRequired: s.job.reload_required,
           });
         } else if (s.job.state === "error") {
-          // Keep the banner visible so retry is available.
+          // Keep the banner visible so retry is available. A partial chained
+          // update can still have unloaded the llama server before failing.
+          notifyReloadIfNeeded(s.job);
           onDone?.({ ok: false, error: s.job.error });
         } else {
           onDone?.({ ok: false, error: "update did not complete" });
diff --git a/studio/frontend/src/hooks/use-system.ts b/studio/frontend/src/hooks/use-system.ts
index a135cce86e..8cfe2bace4 100644
--- a/studio/frontend/src/hooks/use-system.ts
+++ b/studio/frontend/src/hooks/use-system.ts
@@ -40,6 +40,9 @@ export interface SystemInfoResponse {
   gpu: {
     available: boolean;
     backend?: string;
+    /** Whether GGUF loads accept an explicit gpu_ids pick (false on XPU hosts
+     * and Vulkan-only builds, where /load and /validate 400 picks). */
+    gguf_gpu_ids_supported?: boolean;
     backend_cuda_visible_devices?: string | null;
     parent_visible_gpu_ids?: number[];
     index_kind?: string;
diff --git a/studio/frontend/src/hooks/use-tauri-backend.ts b/studio/frontend/src/hooks/use-tauri-backend.ts
index db996768a6..53122864e7 100644
--- a/studio/frontend/src/hooks/use-tauri-backend.ts
+++ b/studio/frontend/src/hooks/use-tauri-backend.ts
@@ -71,8 +71,8 @@ function externalConflictMessage(preflight: DesktopPreflightResult) {
   }
 
   return preflight.port
-    ? `A Unsloth server for this install is already running from a terminal on port ${preflight.port}. Stop that server, or run \`unsloth studio update\` from that terminal before using the desktop app.`
-    : "A Unsloth server for this install is already running from a terminal. Stop that server, or run `unsloth studio update` from that terminal before using the desktop app.";
+    ? `An Unsloth server for this install is already running from a terminal on port ${preflight.port}. Stop that server, or run \`unsloth studio update\` from that terminal before using the desktop app.`
+    : "An Unsloth server for this install is already running from a terminal. Stop that server, or run `unsloth studio update` from that terminal before using the desktop app.";
 }
 
 async function waitForManagedServerPort(
diff --git a/studio/frontend/src/hooks/use-wheel-scroll-ref.ts b/studio/frontend/src/hooks/use-wheel-scroll-ref.ts
new file mode 100644
index 0000000000..09d0ea5a97
--- /dev/null
+++ b/studio/frontend/src/hooks/use-wheel-scroll-ref.ts
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { useCallback, useRef } from "react";
+
+/**
+ * Callback ref for scroll containers inside modal scroll locks. The lock may
+ * cancel native wheel scrolling, so apply the delta before it reaches the
+ * portaled dialog boundary.
+ */
+export function useWheelScrollRef<T extends HTMLElement>() {
+  const detachRef = useRef<(() => void) | null>(null);
+
+  return useCallback((node: T | null) => {
+    detachRef.current?.();
+    detachRef.current = null;
+    if (!node) {
+      return;
+    }
+
+    const onWheel = (event: WheelEvent) => {
+      if (event.ctrlKey || node.scrollHeight <= node.clientHeight) {
+        return;
+      }
+      const multiplier =
+        event.deltaMode === WheelEvent.DOM_DELTA_LINE
+          ? 16
+          : event.deltaMode === WheelEvent.DOM_DELTA_PAGE
+            ? node.clientHeight
+            : 1;
+      const delta = event.deltaY * multiplier;
+      if (delta === 0) {
+        return;
+      }
+      node.scrollTop += delta;
+      event.preventDefault();
+      event.stopPropagation();
+    };
+
+    node.addEventListener("wheel", onWheel, { passive: false });
+    detachRef.current = () => node.removeEventListener("wheel", onWheel);
+  }, []);
+}
diff --git a/studio/frontend/src/i18n/README.md b/studio/frontend/src/i18n/README.md
index ba8cce5d8d..7594e4723f 100644
--- a/studio/frontend/src/i18n/README.md
+++ b/studio/frontend/src/i18n/README.md
@@ -8,5 +8,5 @@
 - Preserve interpolation variables exactly, for example `{count}`, `{model}`, and `{provider}`.
 - Keep product and technical names unchanged unless there is an established localized name, for example `Unsloth Studio`, `LoRA`, `GGUF`, and `Hugging Face`.
 - Keep translation changes small and reviewable. Prefer separate commits for runtime changes, UI migration, and locale text.
-- When adding user-facing Studio UI text, add the English message key first and add non-English overrides only when the translation is clear.
+- When adding user-facing Unsloth UI text, add the English message key first and add non-English overrides only when the translation is clear.
 - Run `npx tsx src/i18n/check-parity.ts` before committing to ensure there are no shape mismatches or placeholder discrepancies in the non-English overlays.
diff --git a/studio/frontend/src/i18n/locales/ar.ts b/studio/frontend/src/i18n/locales/ar.ts
index 28f404a384..4b2a9e5ec0 100644
--- a/studio/frontend/src/i18n/locales/ar.ts
+++ b/studio/frontend/src/i18n/locales/ar.ts
@@ -39,7 +39,7 @@ export const ar = {
       returnToChat: "العودة إلى المحادثة",
       compare: "مقارنة",
       search: "بحث",
-      hub: "Hub",
+      hub: "مركز النماذج",
       train: "تدريب",
       recipes: "الوصفات",
       export: "تصدير",
@@ -111,9 +111,9 @@ export const ar = {
         "يُستخدم لتحميل النماذج المقيّدة ورفع المخرجات.",
       hideToken: "إخفاء التوكن",
       showToken: "إظهار التوكن",
-      tokenSaved: "تم حفظ التوكن",
+      tokenValidated: "تم التحقق من الرمز",
       password: "كلمة المرور",
-      passwordDescription: "تغيير كلمة المرور لحساب Studio هذا.",
+      passwordDescription: "تغيير كلمة المرور لحساب Unsloth هذا.",
       passwordDialog: {
         trigger: "تغيير كلمة المرور",
         title: "تغيير كلمة المرور",
@@ -155,14 +155,14 @@ export const ar = {
           "عندما يسمّي طلب متوافق مع OpenAI ملف GGUF مُنزّلاً مختلفًا، يتم تحميله قبل الخدمة. مُعطّل افتراضيًا؛ الأسماء غير المعروفة تُبقي على النموذج المُحمَّل.",
         idleUnload: "الإلغاء التلقائي عند الخمول",
         idleUnloadDescription:
-          "إلغاء تحميل النموذج بعد هذا العدد من ثواني الخمول لتحرير الـ VRAM؛ الطلب التالي يعيد تحميله. القيمة 0 تُبقيه محمَّلاً.",
+          "إلغاء تحميل النموذج بعد هذا العدد من ثواني الخمول لتحرير الـ VRAM؛ الطلب التالي يعيد تحميله. القيمة 0 تُبقيه محمَّلاً. الحد الأدنى 60 ثانية.",
         idleNeedsEnable:
           "فعّل تبديل النموذج حسب الطلب حتى يعاد تحميل النموذج غير المحمَّل عند الاستخدام التالي.",
         idleActiveViaEnv:
           "الإلغاء التلقائي عند الخمول مُفعَّل عبر متغير البيئة UNSLOTH_MODEL_IDLE_TTL.",
         loadError: "فشل تحميل إعدادات التبديل التلقائي للنموذج.",
         saveError: "فشل حفظ إعدادات التبديل التلقائي للنموذج.",
-        idleError: "أدخل عددًا صحيحًا من الثواني (0 أو أكثر).",
+        idleError: "أدخل 0 لإبقاء النموذج محمَّلاً، أو 60 ثانية على الأقل.",
       },
       previewSharing: {
         sectionTitle: "مشاركة المعاينة",
@@ -284,7 +284,7 @@ export const ar = {
     },
     resources: {
       title: "النظام",
-      description: "مراقبة أجهزة خادم Studio هذا وتخزينه.",
+      description: "مراقبة أجهزة خادم Unsloth هذا وتخزينه.",
       liveUpdates: "التحديثات المباشرة",
       floatingWindow: "نافذة عائمة",
       disableOverlay: "تعطيل التراكب",
@@ -752,6 +752,7 @@ export const ar = {
       trainWithLora: "التدريب باستخدام LoRA",
       stableRank: "Rank مستقر",
       memoryEfficient: "موفّر للذاكرة",
+      weightDecomposed: "أوزان مُفكَّكة",
       optimization: "التحسين",
       schedule: "الجدولة",
       memory: "الذاكرة",
diff --git a/studio/frontend/src/i18n/locales/de.ts b/studio/frontend/src/i18n/locales/de.ts
index e38cdbfa0e..a508fbb9fc 100644
--- a/studio/frontend/src/i18n/locales/de.ts
+++ b/studio/frontend/src/i18n/locales/de.ts
@@ -39,7 +39,7 @@ export const de = {
       returnToChat: "Zurück zum Chat",
       compare: "Vergleichen",
       search: "Suchen",
-      hub: "Hub",
+      hub: "Modell-Hub",
       train: "Trainieren",
       recipes: "Rezepte",
       export: "Exportieren",
@@ -112,10 +112,10 @@ export const de = {
         "Wird verwendet, um gated Modelle zu laden und Artefakte zu pushen.",
       hideToken: "Token verbergen",
       showToken: "Token anzeigen",
-      tokenSaved: "Token gespeichert",
+      tokenValidated: "Token validiert",
       password: "Passwort",
       passwordDescription:
-        "Ändern Sie das Passwort für dieses Studio-Konto.",
+        "Ändern Sie das Passwort für dieses Unsloth-Konto.",
       passwordDialog: {
         trigger: "Passwort ändern",
         title: "Passwort ändern",
@@ -158,7 +158,7 @@ export const de = {
           "Wenn eine OpenAI-kompatible Anfrage ein anderes heruntergeladenes GGUF nennt, wird dieses vor der Auslieferung geladen. Standardmäßig aus; unbekannte Namen liefern weiterhin das geladene Modell aus.",
         idleUnload: "Automatisches Entladen bei Inaktivität",
         idleUnloadDescription:
-          "Entlädt das Modell nach dieser Anzahl inaktiver Sekunden, um VRAM freizugeben; die nächste Anfrage lädt es erneut. 0 hält es geladen.",
+          "Entlädt das Modell nach dieser Anzahl inaktiver Sekunden, um VRAM freizugeben; die nächste Anfrage lädt es erneut. 0 hält es geladen. Minimum 60 Sekunden.",
         idleNeedsEnable:
           "Aktivieren Sie \"Modell je Anfrage wechseln\", damit ein entladenes Modell bei der nächsten Nutzung erneut geladen wird.",
         idleActiveViaEnv:
@@ -167,7 +167,7 @@ export const de = {
           "Einstellungen für automatischen Modellwechsel konnten nicht geladen werden.",
         saveError:
           "Einstellungen für automatischen Modellwechsel konnten nicht gespeichert werden.",
-        idleError: "Geben Sie eine ganze Anzahl an Sekunden ein (0 oder mehr).",
+        idleError: "Geben Sie 0 ein, um das Modell geladen zu halten, oder mindestens 60 Sekunden.",
       },
       previewSharing: {
         sectionTitle: "Vorschau-Freigabe",
@@ -295,7 +295,7 @@ export const de = {
     resources: {
       title: "System",
       description:
-        "Überwachen Sie Hardware und Speicher dieses Studio-Servers.",
+        "Überwachen Sie Hardware und Speicher dieses Unsloth-Servers.",
       liveUpdates: "Live-Updates",
       floatingWindow: "Schwebendes Fenster",
       disableOverlay: "Overlay deaktivieren",
@@ -781,6 +781,7 @@ export const de = {
       trainWithLora: "Mit LoRA trainieren",
       stableRank: "Stable Rank",
       memoryEfficient: "Speichereffizient",
+      weightDecomposed: "Gewichtszerlegt",
       optimization: "Optimierung",
       schedule: "Zeitplan",
       memory: "Speicher",
diff --git a/studio/frontend/src/i18n/locales/en.ts b/studio/frontend/src/i18n/locales/en.ts
index fe3a6f8542..2e6571c300 100644
--- a/studio/frontend/src/i18n/locales/en.ts
+++ b/studio/frontend/src/i18n/locales/en.ts
@@ -32,11 +32,11 @@ export const en = {
       runOptions: "Run options",
     },
     navigation: {
-      newChat: "New Chat",
+      newChat: "New chat",
       returnToChat: "Return to Chat",
       compare: "Compare",
       search: "Search",
-      hub: "Hub",
+      hub: "Model hub",
       train: "Train",
       recipes: "Recipes",
       export: "Export",
@@ -99,14 +99,51 @@ export const en = {
       chat: "Chat",
       voice: "Voice",
       connections: "Connections",
+      data: "Data",
       apiKeys: "API",
       about: "About",
     },
     voice: {
       title: "Voice",
-      description: "Microphone, dictation, and read-aloud",
+      description: "Microphone, dictation, speech-to-text and read-aloud",
       dictation: {
         sectionTitle: "Dictation",
+        engineLabel: "Dictation engine",
+        engineBrowser: "Browser",
+        engineBrowserDescription:
+          "Transcribes audio using your browser speech service. Select 'Local transcription' to use a STT model.",
+        engineModel: "Local transcription",
+        engineModelDescription:
+          "Runs a speech-to-text (STT) model locally and works offline. Download, load, then unloads after inactivity.",
+        sttModelLabel: "Speech recognition model",
+        sttModelDescription: "Choose or search a STT model to run locally.",
+        sttModelSearchPlaceholder: "Search model",
+        sttModelSearching: "Searching Hugging Face…",
+        sttModelValidating: "Checking Whisper compatibility…",
+        sttModelNoResults: "No Whisper models found",
+        sttModelInvalid: "This repository cannot be used for dictation",
+        sttModelFailed: "Could not load the STT model",
+        sttModelUnsupported: "Recording is not supported in this browser",
+        sttChecking: "Checking…",
+        sttOnDemand: "Downloaded",
+        sttLoadingModel: "Loading model…",
+        sttReady: "Loaded on {device}",
+        sttLoaded: "Loaded",
+        sttUnavailable:
+          "Not installed on this server. Run `unsloth studio update` to enable local dictation.",
+        sttRetry: "Retry",
+        sttDownloadChecking: "Checking download status…",
+        sttNotDownloaded: "Not downloaded",
+        sttDownloadStatusFailed: "Could not check download status",
+        sttDownload: "Download",
+        sttDownloading: "Downloading… {progress}%",
+        sttCancelDownload: "Cancel",
+        sttCancellingDownload: "Cancelling…",
+        sttDownloadComplete: "Speech recognition model downloaded",
+        sttDownloadFailed: "Could not download the speech recognition model",
+        sttLoad: "Load",
+        sttUnload: "Unload",
+        sttUnloading: "Unloading…",
         microphoneLabel: "Microphone",
         microphoneDescription: "Used for dictation",
         microphoneFallbackHint:
@@ -117,35 +154,58 @@ export const en = {
           "Microphone access was blocked. Allow microphone access for this Unsloth page, then try again.",
         micAccessUnsupported:
           "Microphone access is not supported in this browser or context.",
-        micOpenFailed:
-          "Could not open the selected microphone. Check permissions or pick another device.",
         systemDefault: "System default",
         savedMicDisconnected: "Saved microphone (not connected)",
         languageLabel: "Dictation language",
         languageDescription: "Language to recognize",
         languageAuto: "Auto (browser language)",
-        testLabel: "Test dictation",
-        testDescription: "Speak to check your mic and settings",
-        startTest: "Start test",
-        stopTest: "Stop test",
-        listening: "Listening…",
-        testSaved: "Saved to recent dictations",
-        notSupported: "Not supported in this browser",
       },
       dictionary: {
         sectionTitle: "Dictation dictionary",
-        sectionDescription:
-          "Apply the spelling entered here when dictation recognizes the same words or phrase",
+        sectionDescription: "Set how dictation spells specific words or phrases",
+        manageLabel: "Custom spellings",
+        manage: "Manage",
+        backToVoice: "Back to Voice",
         addEntry: "Add entry",
       },
       recents: {
-        sectionTitle: "Recent dictations",
+        sectionTitle: "Dictation history",
         sectionDescription:
-          "Your recent dictations will appear here so you can recover text",
+          "Every dictation is saved here so you can recover text",
+        manageLabel: "Dictation history",
+        manage: "Manage",
+        pageDescription:
+          "Every dictation is saved. View, copy, or delete them, or open the chat a dictation was used in.",
+        searchPlaceholder: "Search dictations",
+        sortLabel: "Sort dictations",
+        sortNewest: "Newest",
+        sortOldest: "Oldest",
+        sortAlpha: "A to Z",
+        noMatches: "No dictations match your search",
+        detailTitle: "Saved dictation",
+        backToVoice: "Back to Voice",
+        backToRecents: "Back to recent dictations",
+        view: "View full dictation",
         empty: "No dictations yet",
+        dictationColumn: "Dictation",
+        dateColumn: "Date created",
+        copy: "Copy dictation",
         copied: "Copied to clipboard",
         copyFailed: "Could not copy to clipboard",
-        clear: "Clear recent dictations",
+        delete: "Delete dictation",
+        deleteTitle: "Delete dictation",
+        deleteDescription:
+          "Delete this saved dictation? This cannot be undone.",
+        deleteLinkedDescription:
+          "Delete this saved dictation? You can also delete the chat it was used in. This cannot be undone.",
+        deleteWithChat: "Delete chat and dictation",
+        deleteWithChatFailed: "Could not delete the chat",
+        clear: "Clear history",
+        clearTitle: "Clear dictation history",
+        clearDescription: "Delete all saved dictations? This cannot be undone.",
+        clearConfirm: "Clear all",
+        showMore: "Show more ({count})",
+        openChat: "Open chat",
       },
       readAloud: {
         sectionTitle: "Read aloud",
@@ -181,7 +241,7 @@ export const en = {
         "Used to load gated models and push artifacts.",
       hideToken: "Hide token",
       showToken: "Show token",
-      tokenSaved: "Token saved",
+      tokenValidated: "Token validated",
       password: "Password",
       passwordDescription: "Change the password for this Unsloth account.",
       passwordDialog: {
@@ -195,6 +255,7 @@ export const en = {
         currentTooShort:
           "Current password must be at least {minLength} characters.",
         newTooShort: "New password must be at least {minLength} characters.",
+        newHasSpaces: "New password cannot contain spaces.",
         mismatch: "Passwords do not match.",
         samePassword:
           "New password must be different from your current password.",
@@ -224,14 +285,17 @@ export const en = {
           "When an OpenAI-compatible request names a different downloaded GGUF, load it before serving. Off by default; unknown names keep serving the loaded model.",
         idleUnload: "Idle auto-unload",
         idleUnloadDescription:
-          "Unload the model after this many idle seconds to free VRAM; the next request reloads it. 0 keeps it loaded.",
+          "Unload the model after this many idle seconds to free VRAM; the next request reloads it. 0 keeps it loaded. Minimum 60 seconds.",
         idleNeedsEnable:
           "Turn on Switch model by request so an unloaded model reloads on next use.",
         idleActiveViaEnv:
           "Idle auto-unload is active via the UNSLOTH_MODEL_IDLE_TTL environment variable.",
         loadError: "Failed to load model auto-switch settings.",
         saveError: "Failed to save model auto-switch settings.",
-        idleError: "Enter a whole number of seconds (0 or more).",
+        idleError: "Enter 0 to keep the model loaded, or at least 60 seconds.",
+        keepKv: "Keep chat context across idle unload",
+        keepKvDescription:
+          "Save the model's KV cache to disk before an idle unload and restore it on reload, so resumed chats skip re-reading their history. Chat context is written to disk (up to 10 GB) until it is restored or cleaned up.",
       },
       previewSharing: {
         sectionTitle: "Preview sharing",
@@ -254,7 +318,7 @@ export const en = {
       },
       permissions: {
         sectionTitle: "Permissions",
-        bypassLabel: "Bypass permissions",
+        bypassLabel: "Tool permissions",
         bypassDescription:
           "How Unsloth approves chat tool calls (terminal, python, web, MCP) before they run. Full access disables approvals and the code sandbox.",
       },
@@ -486,10 +550,20 @@ export const en = {
         systemDisk: "System disk",
         diskUsage: "{used} used / {total}",
         diskFree: "{free} free",
-        modelsFolder: "Models folder",
-        modelsFolderDescription: "Where downloaded models are stored.",
+        modelsFolder: "Model downloads",
+        modelsFolderDescription: "Hugging Face cache used for model downloads.",
+        futureDownloads: "New downloads only",
+        environmentManaged: "Managed by the {variable} environment variable.",
+        locationFree: "{free} free",
         openAction: "Open",
         copyAction: "Copy path",
+        changeAction: "Change",
+        resetAction: "Use default",
+        chooseTitle: "Choose model download location",
+        chooseAction: "Use for future downloads",
+        cacheSaved: "Model download location updated",
+        cacheSaveError: "Couldn't update the model download location",
+        cachePickerError: "Couldn't open the folder picker",
         copied: "Path copied",
         openError: "Couldn't open the folder",
         copyError: "Couldn't copy the path",
@@ -508,7 +582,7 @@ export const en = {
     },
     chat: {
       title: "Chat",
-      description: "Manage chat history stored on this device.",
+      description: "Customize how chat behaves on this device.",
       modelDisclaimer: "Show model disclaimer",
       modelDisclaimerDescription:
         'Show "LLMs can make mistakes" under the chat box.',
@@ -577,6 +651,53 @@ export const en = {
         "A storage clear failed; {count} chats may remain. Please retry.",
       failedToClearChats: "Failed to clear chats",
     },
+    data: {
+      title: "Data",
+      description:
+        "Manage chat history and uploaded files stored on this device.",
+      archivedChats: "Archived chats",
+      archivedChatsDescription: "View and manage chats you have archived.",
+      manageAction: "Manage",
+      exportArchivedChats: "Export",
+      exportingArchivedChats: "Exporting...",
+      exportedOneArchivedChat: "Exported 1 archived chat",
+      exportedArchivedChatCount: "Exported {count} archived chats",
+      noArchivedChatsToExport: "No archived chats to export.",
+      failedToExportArchivedChats: "Failed to export archived chats",
+      archiveAllChats: "Archive all chats",
+      archiveAllChatsDescription:
+        "Move every chat in Recents and Projects to the archive.",
+      noChatsToArchive: "No chats to archive.",
+      archiveAllAction: "Archive all",
+      archivingAction: "Archiving...",
+      archiveAllChatsTitle: "Archive all chats?",
+      archiveAllChatsConfirmDescription:
+        "Moves every chat on this device to the archive. Archived chats stay available and can be unarchived at any time.",
+      archivedAllChats: "Archived all chats",
+      archivedOneChat: "Archived 1 chat",
+      archivedChatCount: "Archived {count} chats",
+      failedToArchiveChats: "Failed to archive chats",
+      confirmBeforeDeleting: "Confirm before deleting",
+      confirmBeforeDeletingDescription:
+        "Ask for confirmation before a chat is deleted. Turn off to delete instantly.",
+      filesSection: "Files",
+      uploadedFiles: "Uploaded files",
+      uploadedFilesDescription:
+        "View and manage files uploaded to chats, projects, and knowledge bases.",
+      fineTuneExport: "Use chats as training data",
+      fineTuneExportDescription:
+        "Create a fine-tuning JSONL dataset from your chats. Load it in Train, refine in Recipes, or export it.",
+      fineTuneExportAction: "Export JSONL",
+      fineTuneRunAction: "Run",
+      fineTuneExportingAction: "Exporting...",
+      fineTuneOpenRecipesAction: "Open in Recipes",
+      fineTuneOpeningRecipesAction: "Opening...",
+      fineTuneTrainAction: "Load in Train tab",
+      fineTuneTrainingAction: "Loading...",
+      fineTuneExportFailed: "Failed to export training data",
+      fineTuneRecipeFailed: "Failed to open chats in Recipes",
+      fineTuneTrainFailed: "Failed to load dataset in the Train tab",
+    },
     connections: {
       title: "Connections",
       description: "Manage providers and external connections.",
@@ -924,12 +1045,15 @@ export const en = {
       trainWithLora: "Train with LoRA",
       stableRank: "Stable Rank",
       memoryEfficient: "Memory Efficient",
+      weightDecomposed: "Weight-Decomposed",
       optimization: "Optimization",
       schedule: "Schedule",
       memory: "Memory",
       optimizer: "Optimizer",
       optimizerTooltip:
         "Optimization algorithm. 8-bit variants reduce memory usage. Fused is recommended for vision models.",
+      optimizerTooltipMlx:
+        "Optimization algorithm. AdamW is the default. Lion uses less memory but usually needs a lower learning rate.",
       lrScheduler: "LR scheduler",
       lrSchedulerTooltip:
         "How the learning rate changes over training. Linear decays steadily; cosine decays in a curve.",
@@ -1002,7 +1126,8 @@ export const en = {
       continueAction: "Continue Training",
       cancelAction: "Cancel Training",
       stopTitle: "Stop Training",
-      stopDescription: "Choose how you want to stop the current training run.",
+      stopDescription:
+        "Choose how you want to stop the current training run. Stop and Save writes a checkpoint you can resume from later; Stop cannot be resumed.",
       stopAction: "Stop",
       stopping: "Stopping...",
       stopAndSave: "Stop and Save",
diff --git a/studio/frontend/src/i18n/locales/es.ts b/studio/frontend/src/i18n/locales/es.ts
index e5f9650bef..26e5e062dd 100644
--- a/studio/frontend/src/i18n/locales/es.ts
+++ b/studio/frontend/src/i18n/locales/es.ts
@@ -39,7 +39,7 @@ export const es = {
       returnToChat: "Volver al chat",
       compare: "Comparar",
       search: "Buscar",
-      hub: "Hub",
+      hub: "Centro de modelos",
       train: "Entrenar",
       recipes: "Recetas",
       export: "Exportar",
@@ -112,10 +112,10 @@ export const es = {
         "Se usa para cargar modelos restringidos y subir artefactos.",
       hideToken: "Ocultar token",
       showToken: "Mostrar token",
-      tokenSaved: "Token guardado",
+      tokenValidated: "Token validado",
       password: "Contraseña",
       passwordDescription:
-        "Cambia la contraseña de esta cuenta de Studio.",
+        "Cambia la contraseña de esta cuenta de Unsloth.",
       passwordDialog: {
         trigger: "Cambiar contraseña",
         title: "Cambiar contraseña",
@@ -157,7 +157,7 @@ export const es = {
           "Cuando una solicitud compatible con OpenAI nombra un GGUF descargado distinto, se carga antes de responder. Desactivado por defecto; los nombres desconocidos siguen usando el modelo cargado.",
         idleUnload: "Descarga automática por inactividad",
         idleUnloadDescription:
-          "Descarga el modelo tras este número de segundos inactivo para liberar VRAM; la siguiente solicitud lo recarga. 0 lo mantiene cargado.",
+          "Descarga el modelo tras este número de segundos inactivo para liberar VRAM; la siguiente solicitud lo recarga. 0 lo mantiene cargado. Mínimo 60 segundos.",
         idleNeedsEnable:
           "Activa Cambiar de modelo según la solicitud para que un modelo descargado se recargue en el próximo uso.",
         idleActiveViaEnv:
@@ -166,7 +166,7 @@ export const es = {
           "No se pudo cargar la configuración de cambio automático de modelo.",
         saveError:
           "No se pudo guardar la configuración de cambio automático de modelo.",
-        idleError: "Introduce un número entero de segundos (0 o más).",
+        idleError: "Introduce 0 para mantener el modelo cargado, o al menos 60 segundos.",
       },
       previewSharing: {
         sectionTitle: "Compartir vista previa",
@@ -294,7 +294,7 @@ export const es = {
     resources: {
       title: "Sistema",
       description:
-        "Monitorea el hardware y el almacenamiento de este servidor de Studio.",
+        "Monitorea el hardware y el almacenamiento de este servidor de Unsloth.",
       liveUpdates: "Actualizaciones en vivo",
       floatingWindow: "Ventana flotante",
       disableOverlay: "Desactivar superposición",
@@ -780,6 +780,7 @@ export const es = {
       trainWithLora: "Entrenar con LoRA",
       stableRank: "Rango estable",
       memoryEfficient: "Eficiente en memoria",
+      weightDecomposed: "Pesos descompuestos",
       optimization: "Optimización",
       schedule: "Programación",
       memory: "Memoria",
diff --git a/studio/frontend/src/i18n/locales/fr.ts b/studio/frontend/src/i18n/locales/fr.ts
index 190284175d..704eac3fe2 100644
--- a/studio/frontend/src/i18n/locales/fr.ts
+++ b/studio/frontend/src/i18n/locales/fr.ts
@@ -39,7 +39,7 @@ export const fr = {
       returnToChat: "Retour à la discussion",
       compare: "Comparer",
       search: "Rechercher",
-      hub: "Hub",
+      hub: "Hub de modèles",
       train: "Entraîner",
       recipes: "Recettes",
       export: "Exporter",
@@ -112,10 +112,10 @@ export const fr = {
         "Utilisé pour charger des modèles restreints et publier des artefacts.",
       hideToken: "Masquer le token",
       showToken: "Afficher le token",
-      tokenSaved: "Token enregistré",
+      tokenValidated: "Jeton validé",
       password: "Mot de passe",
       passwordDescription:
-        "Changez le mot de passe de ce compte Studio.",
+        "Changez le mot de passe de ce compte Unsloth.",
       passwordDialog: {
         trigger: "Changer le mot de passe",
         title: "Changer le mot de passe",
@@ -157,7 +157,7 @@ export const fr = {
           "Lorsqu'une requête compatible OpenAI nomme un autre GGUF téléchargé, le charger avant de répondre. Désactivé par défaut ; les noms inconnus continuent de servir le modèle chargé.",
         idleUnload: "Déchargement automatique en cas d'inactivité",
         idleUnloadDescription:
-          "Décharger le modèle après ce nombre de secondes d'inactivité pour libérer la VRAM ; la requête suivante le recharge. 0 le maintient chargé.",
+          "Décharger le modèle après ce nombre de secondes d'inactivité pour libérer la VRAM ; la requête suivante le recharge. 0 le maintient chargé. Minimum 60 secondes.",
         idleNeedsEnable:
           "Activez Changer de modèle par requête pour qu'un modèle déchargé se recharge à la prochaine utilisation.",
         idleActiveViaEnv:
@@ -166,7 +166,7 @@ export const fr = {
           "Échec du chargement des paramètres de changement automatique de modèle.",
         saveError:
           "Échec de l'enregistrement des paramètres de changement automatique de modèle.",
-        idleError: "Saisissez un nombre entier de secondes (0 ou plus).",
+        idleError: "Saisissez 0 pour garder le modèle chargé, ou au moins 60 secondes.",
       },
       previewSharing: {
         sectionTitle: "Partage de l'aperçu",
@@ -291,7 +291,7 @@ export const fr = {
     resources: {
       title: "Système",
       description:
-        "Surveillez le matériel et le stockage de ce serveur Studio.",
+        "Surveillez le matériel et le stockage de ce serveur Unsloth.",
       liveUpdates: "Mises à jour en direct",
       floatingWindow: "Fenêtre flottante",
       disableOverlay: "Désactiver la superposition",
@@ -777,6 +777,7 @@ export const fr = {
       trainWithLora: "Entraîner avec LoRA",
       stableRank: "Rang stable",
       memoryEfficient: "Économe en mémoire",
+      weightDecomposed: "Poids décomposés",
       optimization: "Optimisation",
       schedule: "Planification",
       memory: "Mémoire",
diff --git a/studio/frontend/src/i18n/locales/hi.ts b/studio/frontend/src/i18n/locales/hi.ts
index 97f55251c5..c18a86809f 100644
--- a/studio/frontend/src/i18n/locales/hi.ts
+++ b/studio/frontend/src/i18n/locales/hi.ts
@@ -39,7 +39,7 @@ export const hi = {
       returnToChat: "चैट पर लौटें",
       compare: "तुलना करें",
       search: "खोजें",
-      hub: "Hub",
+      hub: "मॉडल हब",
       train: "ट्रेनिंग",
       recipes: "रेसिपी",
       export: "एक्सपोर्ट",
@@ -111,9 +111,9 @@ export const hi = {
         "गेटेड मॉडल लोड करने और आर्टिफैक्ट पुश करने के लिए उपयोग किया जाता है।",
       hideToken: "token छिपाएं",
       showToken: "token दिखाएं",
-      tokenSaved: "Token सहेजा गया",
+      tokenValidated: "Token सत्यापित",
       password: "पासवर्ड",
-      passwordDescription: "इस Studio खाते के लिए पासवर्ड बदलें।",
+      passwordDescription: "इस Unsloth खाते के लिए पासवर्ड बदलें।",
       passwordDialog: {
         trigger: "पासवर्ड बदलें",
         title: "पासवर्ड बदलें",
@@ -154,14 +154,14 @@ export const hi = {
           "जब कोई OpenAI-संगत अनुरोध किसी अन्य डाउनलोड किए गए GGUF का नाम लेता है, तो सर्व करने से पहले उसे लोड करें। डिफ़ॉल्ट रूप से बंद; अज्ञात नाम लोड किए गए मॉडल को सर्व करते रहते हैं।",
         idleUnload: "निष्क्रिय ऑटो-अनलोड",
         idleUnloadDescription:
-          "VRAM मुक्त करने के लिए इतने निष्क्रिय सेकंड के बाद मॉडल को अनलोड करें; अगला अनुरोध इसे फिर से लोड करता है। 0 इसे लोड रखता है।",
+          "VRAM मुक्त करने के लिए इतने निष्क्रिय सेकंड के बाद मॉडल को अनलोड करें; अगला अनुरोध इसे फिर से लोड करता है। 0 इसे लोड रखता है। न्यूनतम 60 सेकंड।",
         idleNeedsEnable:
           "अनुरोध के अनुसार मॉडल बदलें चालू करें ताकि अनलोड किया गया मॉडल अगले उपयोग पर फिर से लोड हो।",
         idleActiveViaEnv:
           "निष्क्रिय ऑटो-अनलोड UNSLOTH_MODEL_IDLE_TTL एनवायरनमेंट वेरिएबल के माध्यम से सक्रिय है।",
         loadError: "मॉडल ऑटो-स्विच सेटिंग्स लोड करने में विफल।",
         saveError: "मॉडल ऑटो-स्विच सेटिंग्स सहेजने में विफल।",
-        idleError: "सेकंड की पूरी संख्या दर्ज करें (0 या अधिक)।",
+        idleError: "मॉडल को लोड रखने के लिए 0 दर्ज करें, या कम से कम 60 सेकंड।",
       },
       previewSharing: {
         sectionTitle: "पूर्वावलोकन साझाकरण",
@@ -283,7 +283,7 @@ export const hi = {
     },
     resources: {
       title: "सिस्टम",
-      description: "इस Studio सर्वर के हार्डवेयर और स्टोरेज की निगरानी करें।",
+      description: "इस Unsloth सर्वर के हार्डवेयर और स्टोरेज की निगरानी करें।",
       liveUpdates: "लाइव अपडेट",
       floatingWindow: "फ्लोटिंग विंडो",
       disableOverlay: "ओवरले अक्षम करें",
@@ -750,6 +750,7 @@ export const hi = {
       trainWithLora: "LoRA के साथ ट्रेन करें",
       stableRank: "स्थिर Rank",
       memoryEfficient: "मेमोरी कुशल",
+      weightDecomposed: "भार-विघटित",
       optimization: "ऑप्टिमाइज़ेशन",
       schedule: "शेड्यूल",
       memory: "मेमोरी",
diff --git a/studio/frontend/src/i18n/locales/ja.ts b/studio/frontend/src/i18n/locales/ja.ts
index 23752b6c26..9cde9c98ed 100644
--- a/studio/frontend/src/i18n/locales/ja.ts
+++ b/studio/frontend/src/i18n/locales/ja.ts
@@ -40,7 +40,7 @@ export const ja = {
       returnToChat: "チャットに戻る",
       compare: "比較",
       search: "検索",
-      hub: "ハブ",
+      hub: "モデルハブ",
       train: "トレーニング",
       recipes: "レシピ",
       export: "エクスポート",
@@ -114,7 +114,7 @@ export const ja = {
       huggingFaceTokenDescription: "ゲート付きモデルの読み込みや、アーティファクトのプッシュに使用されます。",
       hideToken: "トークンを非表示",
       showToken: "トークンを表示",
-      tokenSaved: "トークンを保存しました",
+      tokenValidated: "トークンは検証済みです",
       password: "パスワード",
       passwordDescription: "この Unsloth アカウントのパスワードを変更します。",
       passwordDialog: {
@@ -149,12 +149,12 @@ export const ja = {
         enable: "リクエストごとにモデルを切り替え",
         enableDescription: "OpenAI互換のリクエストが別のダウンロード済み GGUF を指定した場合、応答する前にそのモデルを読み込みます。デフォルトはオフです。不明な名前の場合は、読み込み済みのモデルで応答を続けます。",
         idleUnload: "アイドル時の自動アンロード",
-        idleUnloadDescription: "指定した秒数だけアイドル状態が続くとモデルをアンロードして VRAM を解放します。次のリクエストで再読み込みされます。0 にすると読み込んだままにします。",
+        idleUnloadDescription: "指定した秒数だけアイドル状態が続くとモデルをアンロードして VRAM を解放します。次のリクエストで再読み込みされます。0 にすると読み込んだままにします。最小 60 秒。",
         idleNeedsEnable: "アンロードされたモデルが次回使用時に再読み込みされるように、「リクエストごとにモデルを切り替え」をオンにしてください。",
         idleActiveViaEnv: "アイドル時の自動アンロードは UNSLOTH_MODEL_IDLE_TTL 環境変数によって有効になっています。",
         loadError: "モデル自動切り替え設定の読み込みに失敗しました。",
         saveError: "モデル自動切り替え設定の保存に失敗しました。",
-        idleError: "秒数を整数（0 以上）で入力してください。",
+        idleError: "モデルを読み込んだままにするには 0 を、それ以外は 60 秒以上を入力してください。",
       },
       previewSharing: {
         sectionTitle: "プレビュー共有",
@@ -360,7 +360,7 @@ export const ja = {
     },
     resources: {
       title: "システム",
-      description: "この Studio サーバーのハードウェアとストレージを監視します。",
+      description: "この Unsloth サーバーのハードウェアとストレージを監視します。",
       liveUpdates: "リアルタイム更新",
       floatingWindow: "フローティングウィンドウ",
       disableOverlay: "オーバーレイを無効化",
@@ -783,6 +783,7 @@ export const ja = {
       trainWithLora: "LoRA でトレーニング",
       stableRank: "Stable Rank",
       memoryEfficient: "メモリ効率化",
+      weightDecomposed: "重み分解",
       optimization: "最適化",
       schedule: "スケジュール",
       memory: "メモリ",
diff --git a/studio/frontend/src/i18n/locales/ko.ts b/studio/frontend/src/i18n/locales/ko.ts
index a11a94faf2..a5b7c14940 100644
--- a/studio/frontend/src/i18n/locales/ko.ts
+++ b/studio/frontend/src/i18n/locales/ko.ts
@@ -39,7 +39,7 @@ export const ko = {
       returnToChat: "채팅으로 돌아가기",
       compare: "비교",
       search: "검색",
-      hub: "Hub",
+      hub: "모델 허브",
       train: "학습",
       recipes: "레시피",
       export: "내보내기",
@@ -111,9 +111,9 @@ export const ko = {
         "게이트된 모델을 불러오고 아티팩트를 푸시하는 데 사용됩니다.",
       hideToken: "토큰 숨기기",
       showToken: "토큰 표시",
-      tokenSaved: "토큰이 저장되었습니다",
+      tokenValidated: "토큰이 확인되었습니다",
       password: "비밀번호",
-      passwordDescription: "이 Studio 계정의 비밀번호를 변경합니다.",
+      passwordDescription: "이 Unsloth 계정의 비밀번호를 변경합니다.",
       passwordDialog: {
         trigger: "비밀번호 변경",
         title: "비밀번호 변경",
@@ -153,14 +153,14 @@ export const ko = {
           "OpenAI 호환 요청이 다운로드된 다른 GGUF를 지정하면, 응답하기 전에 해당 모델을 불러옵니다. 기본값은 꺼짐이며, 알 수 없는 이름은 불러온 모델을 계속 제공합니다.",
         idleUnload: "유휴 시 자동 해제",
         idleUnloadDescription:
-          "지정한 유휴 시간(초)이 지나면 모델을 해제하여 VRAM을 확보합니다. 다음 요청 시 다시 불러옵니다. 0으로 설정하면 계속 로드된 상태로 유지됩니다.",
+          "지정한 유휴 시간(초)이 지나면 모델을 해제하여 VRAM을 확보합니다. 다음 요청 시 다시 불러옵니다. 0으로 설정하면 계속 로드된 상태로 유지됩니다. 최소 60초입니다.",
         idleNeedsEnable:
           "해제된 모델이 다음 사용 시 다시 로드되도록 하려면 요청에 따라 모델 전환을 켜세요.",
         idleActiveViaEnv:
           "유휴 시 자동 해제가 UNSLOTH_MODEL_IDLE_TTL 환경 변수를 통해 활성화되어 있습니다.",
         loadError: "모델 자동 전환 설정을 불러오지 못했습니다.",
         saveError: "모델 자동 전환 설정을 저장하지 못했습니다.",
-        idleError: "정수(초)를 입력하세요(0 이상).",
+        idleError: "모델을 로드 상태로 유지하려면 0을, 그렇지 않으면 60초 이상을 입력하세요.",
       },
       previewSharing: {
         sectionTitle: "미리보기 공유",
@@ -282,7 +282,7 @@ export const ko = {
     },
     resources: {
       title: "시스템",
-      description: "이 Studio 서버의 하드웨어와 저장소를 모니터링합니다.",
+      description: "이 Unsloth 서버의 하드웨어와 저장소를 모니터링합니다.",
       liveUpdates: "실시간 업데이트",
       floatingWindow: "플로팅 창",
       disableOverlay: "오버레이 비활성화",
@@ -752,6 +752,7 @@ export const ko = {
       trainWithLora: "LoRA로 학습",
       stableRank: "안정 랭크",
       memoryEfficient: "메모리 효율적",
+      weightDecomposed: "가중치 분해",
       optimization: "최적화",
       schedule: "스케줄",
       memory: "메모리",
diff --git a/studio/frontend/src/i18n/locales/pt-br.ts b/studio/frontend/src/i18n/locales/pt-br.ts
index 07832ef1d0..5922e69890 100644
--- a/studio/frontend/src/i18n/locales/pt-br.ts
+++ b/studio/frontend/src/i18n/locales/pt-br.ts
@@ -39,7 +39,7 @@ export const ptBR = {
       returnToChat: "Retornar ao Chat",
       compare: "Comparar",
       search: "Buscar",
-      hub: "Hub",
+      hub: "Hub de modelos",
       train: "Treinar",
       recipes: "Receitas",
       export: "Exportar",
@@ -112,7 +112,7 @@ export const ptBR = {
       huggingFaceToken: "Token do Hugging Face",
       huggingFaceTokenDescription:
         "Usado para carregar modelos restritos e enviar artefatos.",
-      tokenSaved: "Token salvo",
+      tokenValidated: "Token validado",
       hideToken: "Ocultar token",
       showToken: "Mostrar token",
       password: "Senha",
@@ -157,14 +157,14 @@ export const ptBR = {
           "Quando uma requisição compatível com OpenAI nomear um GGUF baixado diferente, carrega-o antes de responder. Desativado por padrão; nomes desconhecidos continuam usando o modelo carregado.",
         idleUnload: "Descarregamento automático por inatividade",
         idleUnloadDescription:
-          "Descarrega o modelo após esta quantidade de segundos de inatividade para liberar VRAM; a próxima requisição o recarrega. 0 mantém o modelo carregado.",
+          "Descarrega o modelo após esta quantidade de segundos de inatividade para liberar VRAM; a próxima requisição o recarrega. 0 mantém o modelo carregado. Mínimo de 60 segundos.",
         idleNeedsEnable:
           "Ative Trocar de modelo por requisição para que um modelo descarregado seja recarregado no próximo uso.",
         idleActiveViaEnv:
           "O descarregamento automático por inatividade está ativo por meio da variável de ambiente UNSLOTH_MODEL_IDLE_TTL.",
         loadError: "Falha ao carregar as configurações de troca automática de modelo.",
         saveError: "Falha ao salvar as configurações de troca automática de modelo.",
-        idleError: "Insira um número inteiro de segundos (0 ou mais).",
+        idleError: "Insira 0 para manter o modelo carregado, ou pelo menos 60 segundos.",
       },
       previewSharing: {
         sectionTitle: "Compartilhamento de pré-visualização",
@@ -851,6 +851,7 @@ export const ptBR = {
       trainWithLora: "Treinar com LoRA",
       stableRank: "Stable Rank",
       memoryEfficient: "Eficiente em Memória",
+      weightDecomposed: "Pesos Decompostos",
       optimization: "Otimização",
       schedule: "Cronograma",
       memory: "Memória",
diff --git a/studio/frontend/src/i18n/locales/ru.ts b/studio/frontend/src/i18n/locales/ru.ts
index 81d20cc2ea..c680ff1ba9 100644
--- a/studio/frontend/src/i18n/locales/ru.ts
+++ b/studio/frontend/src/i18n/locales/ru.ts
@@ -39,7 +39,7 @@ export const ru = {
       returnToChat: "Вернуться к чату",
       compare: "Сравнить",
       search: "Поиск",
-      hub: "Hub",
+      hub: "Хаб моделей",
       train: "Обучение",
       recipes: "Рецепты",
       export: "Экспорт",
@@ -111,9 +111,9 @@ export const ru = {
         "Используется для загрузки закрытых моделей и публикации артефактов.",
       hideToken: "Скрыть токен",
       showToken: "Показать токен",
-      tokenSaved: "Токен сохранён",
+      tokenValidated: "Токен проверен",
       password: "Пароль",
-      passwordDescription: "Изменить пароль для этого аккаунта Studio.",
+      passwordDescription: "Изменить пароль для этого аккаунта Unsloth.",
       passwordDialog: {
         trigger: "Изменить пароль",
         title: "Изменить пароль",
@@ -154,14 +154,14 @@ export const ru = {
           "Когда OpenAI-совместимый запрос указывает другую загруженную GGUF, загружать её перед обслуживанием. По умолчанию выключено; неизвестные имена продолжают обслуживать загруженную модель.",
         idleUnload: "Автовыгрузка при простое",
         idleUnloadDescription:
-          "Выгружать модель после указанного числа секунд простоя, чтобы освободить VRAM; следующий запрос загрузит её снова. 0 оставляет модель загруженной.",
+          "Выгружать модель после указанного числа секунд простоя, чтобы освободить VRAM; следующий запрос загрузит её снова. 0 оставляет модель загруженной. Минимум 60 секунд.",
         idleNeedsEnable:
           "Включите «Переключать модель по запросу», чтобы выгруженная модель загружалась при следующем использовании.",
         idleActiveViaEnv:
           "Автовыгрузка при простое активна через переменную окружения UNSLOTH_MODEL_IDLE_TTL.",
         loadError: "Не удалось загрузить настройки автопереключения модели.",
         saveError: "Не удалось сохранить настройки автопереключения модели.",
-        idleError: "Введите целое число секунд (0 или больше).",
+        idleError: "Введите 0, чтобы модель оставалась загруженной, или не менее 60 секунд.",
       },
       previewSharing: {
         sectionTitle: "Публикация предпросмотра",
@@ -283,7 +283,7 @@ export const ru = {
     },
     resources: {
       title: "Система",
-      description: "Мониторинг оборудования и хранилища этого сервера Studio.",
+      description: "Мониторинг оборудования и хранилища этого сервера Unsloth.",
       liveUpdates: "Обновления в реальном времени",
       floatingWindow: "Плавающее окно",
       disableOverlay: "Отключить оверлей",
@@ -750,6 +750,7 @@ export const ru = {
       trainWithLora: "Обучать с LoRA",
       stableRank: "Стабильный ранг",
       memoryEfficient: "Экономия памяти",
+      weightDecomposed: "Декомпозиция весов",
       optimization: "Оптимизация",
       schedule: "Расписание",
       memory: "Память",
diff --git a/studio/frontend/src/i18n/locales/zh-CN.ts b/studio/frontend/src/i18n/locales/zh-CN.ts
index 4c51755244..22f1e06d80 100644
--- a/studio/frontend/src/i18n/locales/zh-CN.ts
+++ b/studio/frontend/src/i18n/locales/zh-CN.ts
@@ -39,7 +39,7 @@ export const zhCN = {
       returnToChat: "返回聊天",
       compare: "对比",
       search: "搜索",
-      hub: "Hub",
+      hub: "模型中心",
       train: "训练",
       recipes: "配方",
       export: "导出",
@@ -113,7 +113,7 @@ export const zhCN = {
       huggingFaceTokenDescription: "用于加载受限模型和推送产物。",
       hideToken: "隐藏 token",
       showToken: "显示 token",
-      tokenSaved: "Token 已保存",
+      tokenValidated: "Token 已验证",
       password: "密码",
       passwordDescription: "更改此 Unsloth 账号的密码。",
       passwordDialog: {
@@ -152,14 +152,14 @@ export const zhCN = {
           "当兼容 OpenAI 的请求指定了另一个已下载的 GGUF 时，先加载它再提供服务。默认关闭；未知名称将继续使用已加载的模型。",
         idleUnload: "空闲自动卸载",
         idleUnloadDescription:
-          "空闲达到该秒数后卸载模型以释放 VRAM；下次请求会重新加载。设为 0 则保持加载。",
+          "空闲达到该秒数后卸载模型以释放 VRAM；下次请求会重新加载。设为 0 则保持加载。最小 60 秒。",
         idleNeedsEnable:
           "开启“按请求切换模型”，以便已卸载的模型在下次使用时重新加载。",
         idleActiveViaEnv:
           "空闲自动卸载已通过 UNSLOTH_MODEL_IDLE_TTL 环境变量启用。",
         loadError: "加载模型自动切换设置失败。",
         saveError: "保存模型自动切换设置失败。",
-        idleError: "请输入整数秒数（0 或以上）。",
+        idleError: "输入 0 保持模型加载，或输入至少 60 秒。",
       },
       previewSharing: {
         sectionTitle: "预览分享",
@@ -375,7 +375,7 @@ export const zhCN = {
     },
     resources: {
       title: "系统",
-      description: "监控此 Studio 服务器的硬件和存储。",
+      description: "监控此 Unsloth 服务器的硬件和存储。",
       liveUpdates: "实时更新",
       floatingWindow: "悬浮窗口",
       disableOverlay: "禁用悬浮层",
@@ -826,6 +826,7 @@ export const zhCN = {
       trainWithLora: "使用 LoRA 训练",
       stableRank: "稳定 Rank",
       memoryEfficient: "节省内存",
+      weightDecomposed: "权重分解",
       optimization: "优化",
       schedule: "计划",
       memory: "内存",
@@ -901,7 +902,8 @@ export const zhCN = {
       continueAction: "继续训练",
       cancelAction: "取消训练",
       stopTitle: "停止训练",
-      stopDescription: "选择如何停止当前训练运行。",
+      stopDescription:
+        "选择如何停止当前训练运行。“停止并保存”会写入检查点，之后可从该处恢复；“停止”则无法恢复。",
       stopAction: "停止",
       stopping: "停止中...",
       stopAndSave: "停止并保存",
diff --git a/studio/frontend/src/index.css b/studio/frontend/src/index.css
index 333ed70f6a..ba112d5f53 100644
--- a/studio/frontend/src/index.css
+++ b/studio/frontend/src/index.css
@@ -633,6 +633,22 @@ html.no-font-smoothing body {
 	-moz-osx-font-smoothing: auto;
 }
 
+/* Match Inter's lighter macOS rendering. Dark surfaces need a stronger
+   correction than light surfaces. Keep 410 when smoothing is off or a custom
+   font reaches chat. */
+html.render-linux:not(.no-font-smoothing):not([data-chat-font]):not([data-ui-font])
+	:is(.aui-assistant-message-root, .aui-user-message-root) {
+	font-weight: 390;
+}
+
+html.dark.render-linux:not(.no-font-smoothing):not([data-chat-font]):not([data-ui-font])
+	:is(.aui-assistant-message-root, .aui-user-message-root) {
+	font-weight: 350;
+	/* The lighter variable-font instance has narrower advances. Reduce
+	   dark-mode line-wrap drift without changing custom-font paths. */
+	letter-spacing: 0.023em;
+}
+
 /* Chat font: only applies while a custom chat font is set. Elements with
    explicit font utilities (headings, code) keep their own families. */
 html[data-chat-font] .aui-root {
@@ -669,6 +685,59 @@ html[data-chat-font] .aui-root {
 }
 
 @theme inline {
+	/* UI typography scale (Settings > Appearance). Every token multiplies
+	   its default size by --ui-font-scale, so text follows the preference
+	   while rem-based layout stays put. Identity at the 16px default. */
+	--text-xs: calc(0.75rem * var(--ui-font-scale, 1));
+	--text-sm: calc(0.875rem * var(--ui-font-scale, 1));
+	--text-base: calc(1rem * var(--ui-font-scale, 1));
+	--text-lg: calc(1.125rem * var(--ui-font-scale, 1));
+	--text-xl: calc(1.25rem * var(--ui-font-scale, 1));
+	--text-2xl: calc(1.5rem * var(--ui-font-scale, 1));
+	--text-3xl: calc(1.875rem * var(--ui-font-scale, 1));
+	--text-4xl: calc(2.25rem * var(--ui-font-scale, 1));
+	/* Arbitrary px sizes from the design, one token per size. */
+	--text-ui-8: calc(0.5rem * var(--ui-font-scale, 1));
+	--text-ui-9: calc(0.5625rem * var(--ui-font-scale, 1));
+	--text-ui-10: calc(0.625rem * var(--ui-font-scale, 1));
+	--text-ui-10p5: calc(0.65625rem * var(--ui-font-scale, 1));
+	--text-ui-11: calc(0.6875rem * var(--ui-font-scale, 1));
+	--text-ui-11p5: calc(0.71875rem * var(--ui-font-scale, 1));
+	--text-ui-12: calc(0.75rem * var(--ui-font-scale, 1));
+	--text-ui-12p5: calc(0.78125rem * var(--ui-font-scale, 1));
+	--text-ui-13: calc(0.8125rem * var(--ui-font-scale, 1));
+	--text-ui-13p5: calc(0.84375rem * var(--ui-font-scale, 1));
+	--text-ui-14: calc(0.875rem * var(--ui-font-scale, 1));
+	--text-ui-14p5: calc(0.90625rem * var(--ui-font-scale, 1));
+	--text-ui-15: calc(0.9375rem * var(--ui-font-scale, 1));
+	--text-ui-15p5: calc(0.96875rem * var(--ui-font-scale, 1));
+	--text-ui-16: calc(1rem * var(--ui-font-scale, 1));
+	--text-ui-17: calc(1.0625rem * var(--ui-font-scale, 1));
+	--text-ui-18: calc(1.125rem * var(--ui-font-scale, 1));
+	--text-ui-19: calc(1.1875rem * var(--ui-font-scale, 1));
+	--text-ui-21: calc(1.3125rem * var(--ui-font-scale, 1));
+	--text-ui-25: calc(1.5625rem * var(--ui-font-scale, 1));
+	--text-ui-30: calc(1.875rem * var(--ui-font-scale, 1));
+	--text-ui-34: calc(2.125rem * var(--ui-font-scale, 1));
+	/* Exact line-heights paired with the sizes above. */
+	--leading-ui-14: calc(0.875rem * var(--ui-font-scale, 1));
+	--leading-ui-15: calc(0.9375rem * var(--ui-font-scale, 1));
+	--leading-ui-16: calc(1rem * var(--ui-font-scale, 1));
+	--leading-ui-17: calc(1.0625rem * var(--ui-font-scale, 1));
+	--leading-ui-18: calc(1.125rem * var(--ui-font-scale, 1));
+	--leading-ui-19: calc(1.1875rem * var(--ui-font-scale, 1));
+	--leading-ui-24: calc(1.5rem * var(--ui-font-scale, 1));
+	--leading-ui-31: calc(1.9375rem * var(--ui-font-scale, 1));
+	/* Numeric leading is typographic: scale it too (it would
+	   otherwise pin through --spacing). Same values at 16px. */
+	--leading-3: calc(0.75rem * var(--ui-font-scale, 1));
+	--leading-4: calc(1rem * var(--ui-font-scale, 1));
+	--leading-5: calc(1.25rem * var(--ui-font-scale, 1));
+	--leading-6: calc(1.5rem * var(--ui-font-scale, 1));
+	--leading-7: calc(1.75rem * var(--ui-font-scale, 1));
+	--leading-8: calc(2rem * var(--ui-font-scale, 1));
+	--leading-9: calc(2.25rem * var(--ui-font-scale, 1));
+	--leading-10: calc(2.5rem * var(--ui-font-scale, 1));
 	/* Reference the :root tokens instead of literal stacks so the runtime
 	   font overrides (Settings > Appearance) reach every font-* utility. */
 	--font-sans: var(--font-sans);
@@ -949,6 +1018,12 @@ html[data-chat-font] .aui-root {
 	.sidebar-row-action {
 		@apply absolute top-0 bottom-0 right-0 inline-flex cursor-pointer items-center justify-end pl-2 pr-1.5 opacity-0 pointer-events-none outline-none;
 	}
+	@media (pointer: coarse) {
+		/* Only chat rows reserve touch padding (#7276); other rows stay hover-revealed to avoid clipped labels. */
+		.sidebar-row-action.sidebar-touch-reveal {
+			@apply opacity-100 pointer-events-auto;
+		}
+	}
 	.sidebar-row-action[data-state="open"] {
 		@apply opacity-100 pointer-events-auto;
 	}
@@ -980,7 +1055,7 @@ html[data-chat-font] .aui-root {
 	}
 
 	.sidebar-sticky-label {
-		@apply rounded-none bg-sidebar pt-0 pb-[8px] pl-[16px] pr-4 text-[14px]! leading-[17px] font-medium normal-case focus-visible:ring-0! focus-visible:outline-none transition-shadow duration-150;
+		@apply rounded-none bg-sidebar pt-0 pb-[8px] pl-[16px] pr-4 text-ui-14! leading-ui-17 font-medium normal-case focus-visible:ring-0! focus-visible:outline-none transition-shadow duration-150;
 		/* Muted section-header gray, matching Gemini's "Notebooks"/"Recents".
 		   Lightened from #5f6368 so the label reads as a header, clearly
 		   lighter than the near-black nav items. */
@@ -1119,7 +1194,7 @@ html[data-chat-font] .aui-root {
 	   fade-in, just enough to read as interactive without competing
 	   with the slider row's quiet aesthetic. */
 	.panel-number-input {
-		@apply h-7 min-w-8 shrink-0 rounded-full border-0 bg-transparent px-2 text-right text-[13px]! font-medium tabular-nums text-nav-fg shadow-none transition-colors hover:bg-black/[0.04] focus:bg-black/[0.05] focus-visible:ring-0! focus-visible:outline-none md:text-[13px]!;
+		@apply h-7 min-w-8 shrink-0 rounded-full border-0 bg-transparent px-2 text-right text-ui-13! font-medium tabular-nums text-nav-fg shadow-none transition-colors hover:bg-black/[0.04] focus:bg-black/[0.05] focus-visible:ring-0! focus-visible:outline-none md:text-ui-13!;
 	}
 	.dark .panel-number-input {
 		@apply hover:bg-white/[0.04] focus:bg-white/[0.06];
@@ -1142,7 +1217,7 @@ html[data-chat-font] .aui-root {
 	}
 
 	.tooltip-compact {
-		@apply rounded-[11px] border-transparent bg-black px-2.5 py-1.5 text-[11px] font-medium leading-snug text-white shadow-md;
+		@apply rounded-[11px] border-transparent bg-black px-2.5 py-1.5 text-ui-11 font-medium leading-snug text-white shadow-md;
 	}
 
 	/* Dialog popups: borderless; chatbox shadow in light, flat card
@@ -1179,8 +1254,8 @@ html[data-chat-font] .aui-root {
 		gap: 9.5px !important;
 		border-radius: 12px;
 		font-weight: 500;
-		font-size: 15px;
-		line-height: 20px;
+		font-size: calc(0.9375rem * var(--ui-font-scale, 1));
+		line-height: calc(1.25rem * var(--ui-font-scale, 1));
 		letter-spacing: 0;
 		color: var(--nav-fg);
 	}
@@ -1424,7 +1499,7 @@ html[data-chat-font] .aui-root {
 	}
 
 	.composer-pill-btn {
-		@apply flex cursor-pointer items-center gap-1.5 rounded-full py-1.5 pl-2 pr-2.5 text-[14px] font-medium text-muted-foreground/70 transition-colors hover:bg-primary/10 dark:hover:bg-white/[0.1] disabled:cursor-not-allowed disabled:opacity-40;
+		@apply flex cursor-pointer items-center gap-1.5 rounded-full py-1.5 pl-2 pr-2.5 text-ui-14 font-medium text-muted-foreground/70 transition-colors hover:bg-primary/10 dark:hover:bg-white/[0.1] disabled:cursor-not-allowed disabled:opacity-40;
 	}
 
 	/* Caret pills (RAG, MCP): the chevron carries its own whitespace, so the
@@ -1467,7 +1542,9 @@ html[data-chat-font] .aui-root {
 	}
 
 	/* With more than 4 tools on, drop pill labels to icons only to cut clutter.
-	   Compare keeps its label via data-keep-label. */
+	   Compare and the bypass-permissions pill keep their labels via
+	   data-keep-label; the permission pill sits before the collapsed icons, so
+	   they line up to its right. */
 	[data-pill-compact="true"]
 		.composer-pill-btn:not([data-keep-label])
 		> span:not(.composer-pill-glyph) {
@@ -1510,7 +1587,7 @@ html[data-chat-font] .aui-root {
 		.composer-pill-btn:not([data-keep-label])[data-pill-label]:hover::after {
 		content: attr(data-pill-label);
 		/* Always one nowrap line, so always a full pill. */
-		@apply pointer-events-none absolute bottom-[calc(100%+6px)] left-1/2 z-50 -translate-x-1/2 rounded-full bg-black px-2.5 py-1.5 text-[11px] font-medium leading-snug whitespace-nowrap text-white shadow-md;
+		@apply pointer-events-none absolute bottom-[calc(100%+6px)] left-1/2 z-50 -translate-x-1/2 rounded-full bg-black px-2.5 py-1.5 text-ui-11 font-medium leading-snug whitespace-nowrap text-white shadow-md;
 	}
 
 	/* Compact caret pills (RAG, MCP) open their menu on click instead of
@@ -1530,12 +1607,12 @@ html[data-chat-font] .aui-root {
 	}
 
 	/* Hovering an active pill swaps the icon for an X (click to turn off). */
-	.composer-pill-btn[data-active="true"]:hover .composer-pill-glyph > :not(.composer-pill-x),
+	.composer-pill-btn[data-active="true"]:has(.composer-pill-x):hover .composer-pill-glyph > :not(.composer-pill-x),
 	.unsloth-thinking-pill[data-active="true"]:hover .composer-pill-glyph > :not(.composer-pill-x) {
 		@apply opacity-0;
 	}
 
-	.composer-pill-btn[data-active="true"]:hover .composer-pill-x,
+	.composer-pill-btn[data-active="true"]:has(.composer-pill-x):hover .composer-pill-x,
 	.unsloth-thinking-pill[data-active="true"]:hover .composer-pill-x {
 		@apply opacity-100;
 	}
@@ -1563,7 +1640,7 @@ html[data-chat-font] .aui-root {
 	}
 
 	.composer-footer-note {
-		@apply mt-1.5 text-center text-[11px] tracking-[0em] text-muted-foreground;
+		@apply mt-1.5 text-center text-ui-11 tracking-[0em] text-muted-foreground;
 		font-family: var(--font-sans);
 	}
 
@@ -1603,8 +1680,14 @@ html[data-chat-font] .aui-root {
 		@apply flex w-full flex-wrap items-center gap-0.5 px-1;
 	}
 
+	/* Recording is a dedicated one-line mode. Active tool pills must not force
+	   the composer back into the normal two-row layout. */
+	.unsloth-composer-line[data-dictating="true"] {
+		@apply flex-nowrap;
+	}
+
 	.unsloth-composer-left {
-		@apply flex shrink-0 items-center gap-0.5;
+		@apply flex min-w-0 flex-wrap items-center gap-0.5;
 		order: 1;
 		/* Pull the plus button closer to the composer edge. */
 		margin-left: -0.25rem;
@@ -1650,7 +1733,7 @@ html[data-chat-font] .aui-root {
 	}
 
 	.unsloth-composer-input {
-		@apply min-h-[40px] min-w-0 flex-1 resize-none overflow-y-auto bg-transparent pl-0.5 pr-2 py-2 text-[15px] font-[450] leading-6 outline-none placeholder:text-muted-foreground focus-visible:ring-0;
+		@apply min-h-[40px] min-w-0 flex-1 resize-none overflow-y-auto bg-transparent pl-0.5 pr-2 py-2 text-ui-15 font-[450] leading-6 outline-none placeholder:text-muted-foreground focus-visible:ring-0;
 	}
 
 	.unsloth-composer-plus {
@@ -1729,7 +1812,7 @@ html[data-chat-font] .aui-root {
 	/* Right-side Thinking pill (toggle or dropdown). pl-2 matches the left
 	   pills so the hover X is not pushed in too far. */
 	.unsloth-thinking-pill {
-		@apply inline-flex shrink-0 cursor-pointer items-center gap-1 rounded-full py-1.5 pl-2 pr-2.5 text-[14px] font-medium text-muted-foreground transition-colors hover:bg-primary/10 dark:hover:bg-white/[0.1] disabled:cursor-not-allowed disabled:opacity-40;
+		@apply inline-flex shrink-0 cursor-pointer items-center gap-1 rounded-full py-1.5 pl-2 pr-2.5 text-ui-14 font-medium text-muted-foreground transition-colors hover:bg-primary/10 dark:hover:bg-white/[0.1] disabled:cursor-not-allowed disabled:opacity-40;
 		/* Reserve a text line so the icon-only (inactive) pill matches the
 		   text pills' height instead of collapsing to the icon. */
 		min-height: calc(1lh + 0.75rem);
@@ -1764,7 +1847,7 @@ html[data-chat-font] .aui-root {
 
 		.unsloth-thinking-pill[data-pill-label]:not([data-state="open"]):hover::after {
 			content: attr(data-pill-label);
-			@apply pointer-events-none absolute bottom-[calc(100%+6px)] left-1/2 z-50 -translate-x-1/2 rounded-full bg-black px-2.5 py-1.5 text-[11px] font-medium leading-snug whitespace-nowrap text-white shadow-md;
+			@apply pointer-events-none absolute bottom-[calc(100%+6px)] left-1/2 z-50 -translate-x-1/2 rounded-full bg-black px-2.5 py-1.5 text-ui-11 font-medium leading-snug whitespace-nowrap text-white shadow-md;
 		}
 	}
 
@@ -1809,7 +1892,7 @@ html[data-chat-font] .aui-root {
 			[data-slot="dropdown-menu-item"],
 			[data-slot="dropdown-menu-sub-trigger"]
 		) {
-		@apply gap-3 pl-3 pr-3 py-2 text-[14px];
+		@apply gap-3 pl-3 pr-3 py-2 text-ui-14;
 		cursor: pointer;
 		/* Pin hover-box radius so dark matches light (container radius minus the
 		   side gutter keeps the curves concentric). */
@@ -1817,7 +1900,7 @@ html[data-chat-font] .aui-root {
 	}
 
 	.unsloth-plus-menu [data-slot="dropdown-menu-label"] {
-		@apply pl-3 pr-3 py-1.5 text-[12px];
+		@apply pl-3 pr-3 py-1.5 text-ui-12;
 	}
 
 	/* Active (green) items keep their primary text and icon color on hover. */
@@ -2107,21 +2190,21 @@ html[data-chat-font] .aui-root {
 
 	/* Chat thread: code slightly smaller by default; step up when the thread column is wide. */
 	.aui-thread-root [data-streamdown="code-block"] {
-		font-size: 0.8125rem;
+		font-size: calc(0.8125rem * var(--ui-font-scale, 1));
 		line-height: 1.55;
 	}
 
 	.aui-thread-root [data-streamdown="code-block-header"] {
-		font-size: 0.6875rem;
+		font-size: calc(0.6875rem * var(--ui-font-scale, 1));
 	}
 
 	@container (min-width: 36rem) {
 		.aui-thread-root [data-streamdown="code-block"] {
-			font-size: 0.875rem;
+			font-size: calc(0.875rem * var(--ui-font-scale, 1));
 		}
 
 		.aui-thread-root [data-streamdown="code-block-header"] {
-			font-size: 0.75rem;
+			font-size: calc(0.75rem * var(--ui-font-scale, 1));
 		}
 	}
 
@@ -2597,7 +2680,7 @@ html[data-chat-font] .aui-root {
  * the documented WCAG outcome (motion is "minimised, not removed").
  *
  * .animate-spin and generated image loading dots are the exceptions: loading
- * indicators across Studio (tool execution loaders, sonner toasts, Tauri
+ * indicators across Unsloth (tool execution loaders, sonner toasts, Tauri
  * startup / update screens, the <Spinner /> primitive, and image generation
  * cards). Freezing them removes the only visual signal that work is in flight,
  * so they keep animating.
@@ -2653,3 +2736,37 @@ html[data-chat-font] .aui-root {
 .aui-tool-group-root .aui-tool-fallback-trigger:focus-visible .aui-tool-fallback-trigger-chevron {
   opacity: 1;
 }
+
+/* Third-party UI text follows the typography scale. Values equal the
+   library defaults at the 16px setting. KaTeX's internal font-size:1px
+   sizing trick is layout, not text, and stays untouched. */
+.before\:text-\[13px\]::before {
+	/* streamdown citation chip utility (class scanned from node_modules). */
+	font-size: calc(0.8125rem * var(--ui-font-scale, 1));
+}
+.recharts-text {
+	/* Chart axis/label text; beats the fontSize presentation attribute. */
+	font-size: calc(0.625rem * var(--ui-font-scale, 1));
+}
+.react-flow__edge-text.react-flow__edge-text {
+	/* Doubled class: react-flow's stylesheet loads after this file, so win
+	   on specificity, not order. */
+	font-size: calc(0.625rem * var(--ui-font-scale, 1));
+}
+.react-flow__attribution.react-flow__attribution {
+	font-size: calc(0.625rem * var(--ui-font-scale, 1));
+}
+.react-flow__node-input.react-flow__node-input,
+.react-flow__node-default.react-flow__node-default,
+.react-flow__node-output.react-flow__node-output,
+.react-flow__node-group.react-flow__node-group {
+	font-size: calc(0.75rem * var(--ui-font-scale, 1));
+}
+
+/* Radix hides the select viewport scrollbar (the viewport is the scroller
+   so menu corners stay rounded); restore the app's thin one. The inline
+   scrollbar-width on the viewport handles Firefox. */
+[data-slot="select-content"] [data-radix-select-viewport]::-webkit-scrollbar {
+	display: block !important;
+	width: 8px;
+}
diff --git a/studio/frontend/src/lib/native-files.ts b/studio/frontend/src/lib/native-files.ts
new file mode 100644
index 0000000000..48a6bd4ab7
--- /dev/null
+++ b/studio/frontend/src/lib/native-files.ts
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { isTauri } from "@/lib/api-base";
+
+const NATIVE_FILE_NAME_HEADER = "x-unsloth-default-name";
+export class DownloadCancelledError extends Error {
+  constructor() {
+    super("Save cancelled.");
+    this.name = "DownloadCancelledError";
+  }
+}
+
+export function isDownloadCancelled(error: unknown): boolean {
+  return error instanceof DownloadCancelledError;
+}
+
+function encodeNativeFilename(filename: string): string {
+  const bytes = new TextEncoder().encode(filename);
+  let binary = "";
+  for (const byte of bytes) {
+    binary += String.fromCharCode(byte);
+  }
+  return btoa(binary);
+}
+
+export interface NativeChatImport {
+  name: string;
+  content: string;
+}
+
+function browserDownload(blob: Blob, filename: string): void {
+  const url = URL.createObjectURL(blob);
+  const anchor = document.createElement("a");
+  anchor.href = url;
+  anchor.download = filename;
+  document.body.appendChild(anchor);
+  anchor.click();
+  anchor.remove();
+  URL.revokeObjectURL(url);
+}
+
+/** Save through a native chooser in Tauri and retain normal downloads on web. */
+export async function downloadFile(
+  content: string | Blob | Uint8Array,
+  filename: string,
+  mimeType = "application/octet-stream",
+): Promise<void> {
+  if (isTauri) {
+    const { invoke } = await import("@tauri-apps/api/core");
+    const bytes =
+      typeof content === "string"
+        ? new TextEncoder().encode(content)
+        : content instanceof Blob
+          ? new Uint8Array(await content.arrayBuffer())
+          : content;
+    const savedPath = await invoke<string | null>("save_native_file", bytes, {
+      headers: {
+        [NATIVE_FILE_NAME_HEADER]: encodeNativeFilename(filename),
+      },
+    });
+    if (savedPath === null) {
+      throw new DownloadCancelledError();
+    }
+    return;
+  }
+
+  const browserContent =
+    content instanceof Uint8Array ? Uint8Array.from(content).buffer : content;
+  const blob =
+    browserContent instanceof Blob
+      ? browserContent
+      : new Blob([browserContent], { type: mimeType });
+
+  browserDownload(blob, filename);
+  return;
+}
+
+/** Open the bounded native chat-import picker. Cancellation returns null. */
+export async function pickNativeChatImport(): Promise<NativeChatImport | null> {
+  if (!isTauri) {
+    return null;
+  }
+  const { invoke } = await import("@tauri-apps/api/core");
+  return invoke<NativeChatImport | null>("pick_native_chat_import");
+}
diff --git a/studio/frontend/src/lib/sparkles-icon.tsx b/studio/frontend/src/lib/sparkles-icon.tsx
new file mode 100644
index 0000000000..de4c911158
--- /dev/null
+++ b/studio/frontend/src/lib/sparkles-icon.tsx
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import { HugeiconsIcon, type IconSvgElement } from "@hugeicons/react";
+
+// Hugeicons "AI Security 03" (stroke-rounded). A four-point sparkle inside a
+// shield. https://hugeicons.com/icon/ai-security-03
+export const SparklesIcon: IconSvgElement = [
+  [
+    "path",
+    {
+      d: "M11.6769 8.67348C11.8274 8.43697 12.1726 8.43697 12.3231 8.67348L12.7586 9.35767C13.2401 10.1143 13.8818 10.756 14.6384 11.2375L15.3226 11.6729C15.5591 11.8235 15.5591 12.1687 15.3226 12.3192L14.6384 12.7547C13.8818 13.2362 13.2401 13.8779 12.7586 14.6345L12.3231 15.3187C12.1726 15.5552 11.8274 15.5552 11.6769 15.3187L11.2414 14.6345C10.7599 13.8779 10.1182 13.2362 9.36157 12.7547L8.67738 12.3192C8.44087 12.1687 8.44087 11.8235 8.67738 11.6729L9.36157 11.2375C10.1182 10.756 10.7599 10.1143 11.2414 9.35767L11.6769 8.67348Z",
+      stroke: "currentColor",
+      strokeLinejoin: "round",
+      strokeWidth: "1.5",
+      key: "0",
+    },
+  ],
+  [
+    "path",
+    {
+      d: "M3.9068 5.28387C6.87149 5.4984 8.78311 2.49713 12.0262 2.49713C15.2208 2.43341 16.784 5.32395 20.059 5.32395C21.8147 14.2606 18.1622 19.8743 12.053 21.4961C6.38992 20.15 2.13481 14.4788 3.9068 5.28387Z",
+      stroke: "currentColor",
+      strokeLinejoin: "round",
+      strokeWidth: "1.5",
+      key: "1",
+    },
+  ],
+];
+
+/**
+ * AI Security shield glyph wrapped as a lucide-compatible component so it can drop
+ * into the permission-mode option list alongside lucide icons (same className /
+ * strokeWidth props). strokeWidth is a number here (lucide style); Hugeicons
+ * accepts it directly.
+ */
+export function SparklesGlyph({
+  className,
+  strokeWidth,
+}: {
+  className?: string;
+  strokeWidth?: number;
+}) {
+  return (
+    <HugeiconsIcon
+      icon={SparklesIcon}
+      className={className}
+      strokeWidth={strokeWidth}
+    />
+  );
+}
diff --git a/studio/frontend/src/lib/tauri-diagnostics.ts b/studio/frontend/src/lib/tauri-diagnostics.ts
index 5c07931a86..2b687478fe 100644
--- a/studio/frontend/src/lib/tauri-diagnostics.ts
+++ b/studio/frontend/src/lib/tauri-diagnostics.ts
@@ -62,7 +62,7 @@ export function redactDiagnosticsText(text: string): string {
     "$1$2<redacted>",
   );
 
-  // Redact Studio paths before broader home-directory paths.
+  // Redact Unsloth paths before broader home-directory paths.
   redacted = redacted.replace(
     /(?:\/Users|\/home)\/[^\s/]+\/\.unsloth\/studio/gi,
     "<studio_home>",
diff --git a/studio/frontend/src/lib/utils.ts b/studio/frontend/src/lib/utils.ts
index fcea359efd..7408fc4fe9 100644
--- a/studio/frontend/src/lib/utils.ts
+++ b/studio/frontend/src/lib/utils.ts
@@ -2,7 +2,21 @@
 // Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import { type ClassValue, clsx } from "clsx";
-import { twMerge } from "tailwind-merge";
+import { extendTailwindMerge } from "tailwind-merge";
+
+// text-ui-* / leading-ui-* are the scaled typography tokens from index.css.
+// Register them as font-size / line-height so twMerge does not treat
+// text-ui-* as a text color and drop it when a color class follows.
+const isUiToken = (value: string) => /^ui-\d+(p5)?$/.test(value);
+
+const twMerge = extendTailwindMerge({
+  extend: {
+    classGroups: {
+      "font-size": [{ text: [isUiToken] }],
+      leading: [{ leading: [isUiToken] }],
+    },
+  },
+});
 
 export function cn(...inputs: ClassValue[]): string {
   return twMerge(clsx(inputs));
diff --git a/studio/frontend/src/main.tsx b/studio/frontend/src/main.tsx
index d0ddf2fc6e..e3b2bceccf 100644
--- a/studio/frontend/src/main.tsx
+++ b/studio/frontend/src/main.tsx
@@ -36,6 +36,13 @@ if (!rootElement) {
 
 initializeLocale();
 
+// Rasterization follows the browser OS, not the potentially remote server.
+// This adjustment is calibrated for desktop Linux, so exclude Android.
+const uaLower = navigator.userAgent.toLowerCase();
+if (uaLower.includes("linux") && !uaLower.includes("android")) {
+  document.documentElement.classList.add("render-linux");
+}
+
 createRoot(rootElement).render(
   <StrictMode>
     <App />
diff --git a/studio/frontend/src/types/training.ts b/studio/frontend/src/types/training.ts
index a09c92878c..f621e78ee9 100644
--- a/studio/frontend/src/types/training.ts
+++ b/studio/frontend/src/types/training.ts
@@ -40,7 +40,7 @@ export interface WizardState {
   loraRank: number;
   loraAlpha: number;
   loraDropout: number;
-  loraVariant: "lora" | "rslora" | "loftq";
+  loraVariant: "lora" | "rslora" | "loftq" | "dora";
   batchSize: number;
   gradientAccumulation: number;
   weightDecay: number;
@@ -84,7 +84,7 @@ export interface WizardActions {
   setLoraRank: (rank: number) => void;
   setLoraAlpha: (alpha: number) => void;
   setLoraDropout: (dropout: number) => void;
-  setLoraVariant: (v: "lora" | "rslora" | "loftq") => void;
+  setLoraVariant: (v: "lora" | "rslora" | "loftq" | "dora") => void;
   setBatchSize: (v: number) => void;
   setGradientAccumulation: (v: number) => void;
   setWeightDecay: (v: number) => void;
diff --git a/studio/install_llama_prebuilt.py b/studio/install_llama_prebuilt.py
index cca8886777..6ea850139e 100644
--- a/studio/install_llama_prebuilt.py
+++ b/studio/install_llama_prebuilt.py
@@ -43,6 +43,21 @@ except ImportError:
 from pathlib import Path
 from typing import Any, Iterable, Iterator
 
+# Shared component-agnostic machinery lives in prebuilt_core (same directory);
+# put studio/ on sys.path so it resolves whether this file is run as a script
+# (from any cwd) or loaded via an importlib spec by the tests.
+_STUDIO_DIR = os.path.dirname(os.path.abspath(__file__))
+if _STUDIO_DIR not in sys.path:
+    sys.path.insert(0, _STUDIO_DIR)
+
+import prebuilt_core as _core  # noqa: E402
+
+# Late-binding seam: core functions resolve collaborators (download_file,
+# fetch_json, ...) through this module's globals at call time, so tests that
+# monkeypatch names on this module keep working.
+_OPS = _core.ModuleOps(globals())
+USER_AGENT = "unsloth-studio-llama-prebuilt"
+
 
 EXIT_SUCCESS = 0
 EXIT_FALLBACK = 2
@@ -121,26 +136,7 @@ def _amd_smi_allowed() -> bool:
     return False
 
 
-def windows_hidden_subprocess_kwargs() -> dict[str, object]:
-    """Return Windows-only subprocess kwargs that suppress console windows."""
-    if sys.platform != "win32":
-        return {}
-
-    kwargs: dict[str, object] = {}
-    create_no_window = getattr(subprocess, "CREATE_NO_WINDOW", 0)
-    if create_no_window:
-        kwargs["creationflags"] = create_no_window
-
-    startupinfo_factory = getattr(subprocess, "STARTUPINFO", None)
-    startf_use_showwindow = getattr(subprocess, "STARTF_USESHOWWINDOW", 0)
-    sw_hide = getattr(subprocess, "SW_HIDE", 0)
-    if startupinfo_factory is not None and startf_use_showwindow:
-        startupinfo = startupinfo_factory()
-        startupinfo.dwFlags |= startf_use_showwindow
-        startupinfo.wShowWindow = sw_hide
-        kwargs["startupinfo"] = startupinfo
-
-    return kwargs
+windows_hidden_subprocess_kwargs = _core.windows_hidden_subprocess_kwargs
 
 
 def env_int(
@@ -190,8 +186,24 @@ VALIDATION_MODEL_CACHE_FILENAME = "stories260K.gguf"
 # in validate_prebuilt_choice. Disabled for now: the llama-server GPU forward pass
 # JIT-compiles CUDA kernels on first load and stalls every install and update by
 # minutes on Blackwell (sm_100). The check and the source-build fallback it triggers
-# are kept intact -- set this to True to re-enable them.
+# are kept intact -- set this to True, or set UNSLOTH_LLAMA_STAGED_VALIDATION=1, to
+# re-enable them (#5854 gap 2).
 _RUN_STAGED_PREBUILT_VALIDATION = False
+
+
+def staged_validation_enabled() -> bool:
+    """True when the expensive llama-server GPU smoke test should run.
+
+    Default off (Blackwell CUDA JIT stalls installs). Opt in via the module
+    constant or ``UNSLOTH_LLAMA_STAGED_VALIDATION`` (1/true/yes/on). Used by both
+    the prebuilt path and setup.sh's source-build post-check (#5854).
+    """
+    if _RUN_STAGED_PREBUILT_VALIDATION:
+        return True
+    raw = os.environ.get("UNSLOTH_LLAMA_STAGED_VALIDATION", "").strip().lower()
+    return raw in ("1", "true", "yes", "on")
+
+
 INSTALL_LOCK_TIMEOUT_SECONDS = 300
 INSTALL_STAGING_ROOT_NAME = ".staging"
 GITHUB_AUTH_HOSTS = {"api.github.com", "github.com"}
@@ -347,10 +359,7 @@ class LinuxCudaSelection:
         return self.attempts[0]
 
 
-@dataclass
-class CudaRuntimePreference:
-    runtime_line: str | None
-    selection_log: list[str]
+CudaRuntimePreference = _core.CudaRuntimePreference
 
 
 @dataclass(frozen = True)
@@ -404,12 +413,8 @@ class InstallReleasePlan:
     approved_checksums: ApprovedReleaseChecksums
 
 
-class PrebuiltFallback(RuntimeError):
-    pass
-
-
-class BusyInstallConflict(RuntimeError):
-    pass
+PrebuiltFallback = _core.PrebuiltFallback
+BusyInstallConflict = _core.BusyInstallConflict
 
 
 class ExistingInstallSatisfied(RuntimeError):
@@ -419,51 +424,8 @@ class ExistingInstallSatisfied(RuntimeError):
         self.used_fallback = used_fallback
 
 
-def _os_error_messages(exc: BaseException) -> list[str]:
-    messages: list[str] = []
-    if isinstance(exc, OSError):
-        for value in (
-            getattr(exc, "strerror", None),
-            getattr(exc, "filename", None),
-            getattr(exc, "filename2", None),
-        ):
-            if isinstance(value, str) and value:
-                messages.append(value)
-    text = str(exc)
-    if text:
-        messages.append(text)
-    return [message.lower() for message in messages if message]
-
-
-def is_busy_lock_error(exc: BaseException) -> bool:
-    if isinstance(exc, BusyInstallConflict):
-        return True
-    if isinstance(exc, OSError):
-        if exc.errno in {
-            errno.EACCES,
-            errno.EBUSY,
-            errno.EPERM,
-            errno.ETXTBSY,
-        }:
-            return True
-        if getattr(exc, "winerror", None) in {5, 32, 145}:
-            return True
-    for message in _os_error_messages(exc):
-        if any(
-            needle in message
-            for needle in (
-                "access is denied",
-                "being used by another process",
-                "device or resource busy",
-                "permission denied",
-                "text file busy",
-                "file is in use",
-                "process cannot access the file",
-                "cannot create a file when that file already exists",
-            )
-        ):
-            return True
-    return False
+_os_error_messages = _core._os_error_messages
+is_busy_lock_error = _core.is_busy_lock_error
 
 
 # Status logs default to stderr so resolver modes keep stdout machine-readable
@@ -481,153 +443,30 @@ def log_lines(lines: Iterable[str]) -> None:
         log(line)
 
 
-def parsed_hostname(url: str | None) -> str | None:
-    if not url:
-        return None
-    try:
-        hostname = urllib.parse.urlparse(url).hostname
-    except Exception:
-        return None
-    if not hostname:
-        return None
-    return hostname.lower()
-
-
-def should_send_github_auth(url: str | None) -> bool:
-    return parsed_hostname(url) in GITHUB_AUTH_HOSTS
-
-
-def should_send_hf_auth(url: str | None) -> bool:
-    return parsed_hostname(url) in HF_AUTH_HOSTS
+parsed_hostname = _core.parsed_hostname
+should_send_github_auth = _core.should_send_github_auth
+should_send_hf_auth = _core.should_send_hf_auth
 
 
 def auth_headers(url: str | None = None) -> dict[str, str]:
-    headers = {
-        "User-Agent": "unsloth-studio-llama-prebuilt",
-    }
-    token = os.environ.get("GH_TOKEN") or os.environ.get("GITHUB_TOKEN")
-    if token and should_send_github_auth(url):
-        headers["Authorization"] = f"Bearer {token}"
-        return headers
-    # Anonymous huggingface.co fetches share a per-IP rate limit that CI
-    # fleets exhaust (HTTP 429), sinking the prebuilt path into a source
-    # build. Authenticate when a token is available.
-    hf_token = os.environ.get("HF_TOKEN") or os.environ.get("HUGGING_FACE_HUB_TOKEN")
-    if hf_token and should_send_hf_auth(url):
-        headers["Authorization"] = f"Bearer {hf_token}"
-    return headers
+    return _core.auth_headers(_OPS, url)
 
 
-class _CrossHostAuthStrippingRedirectHandler(urllib.request.HTTPRedirectHandler):
-    """Drop Authorization when a redirect leaves the original host.
-
-    huggingface.co redirects file downloads to CDN hosts whose signed URLs
-    can reject foreign Authorization headers; urllib forwards headers to
-    redirect targets by default (requests/huggingface_hub strip them).
-    """
-
-    def redirect_request(self, req, fp, code, msg, headers, newurl):
-        new_request = super().redirect_request(req, fp, code, msg, headers, newurl)
-        if new_request is not None and parsed_hostname(newurl) != parsed_hostname(req.full_url):
-            new_request.headers.pop("Authorization", None)
-            new_request.unredirected_hdrs.pop("Authorization", None)
-        return new_request
-
-
-_URL_OPENER = urllib.request.build_opener(_CrossHostAuthStrippingRedirectHandler())
+_CrossHostAuthStrippingRedirectHandler = _core._CrossHostAuthStrippingRedirectHandler
+_URL_OPENER = _core._URL_OPENER
 
 
 def github_api_headers(url: str | None = None) -> dict[str, str]:
-    return {
-        "Accept": "application/vnd.github+json",
-        **auth_headers(url),
-    }
-
-
-def is_github_api_url(url: str | None) -> bool:
-    return parsed_hostname(url) == "api.github.com"
-
-
-def is_retryable_url_error(exc: Exception) -> bool:
-    if isinstance(exc, urllib.error.HTTPError):
-        # GitHub returns 403 (not the standard 429) when the API rate
-        # limit is hit. Anonymous calls share a 60-req/hour bucket per
-        # runner IP, which CI fleets can exhaust trivially. Treat 403
-        # against api.github.com as retryable so we get one or two
-        # backoff cycles before the source-build fallback fires; honour
-        # Retry-After / X-RateLimit-Reset in sleep_backoff for accurate
-        # waits. Real 403s on other hosts (private artefact downloads,
-        # auth failures) stay non-retryable.
-        if exc.code == 403:
-            return is_github_api_url(getattr(exc, "url", None))
-        return exc.code in RETRYABLE_HTTP_STATUS
-    if isinstance(exc, urllib.error.URLError):
-        return True
-    if isinstance(exc, TimeoutError):
-        return True
-    if isinstance(exc, socket.timeout):
-        return True
-    return False
+    return _core.github_api_headers(_OPS, url)
 
 
+is_github_api_url = _core.is_github_api_url
+is_retryable_url_error = _core.is_retryable_url_error
 _RATE_LIMIT_WAIT_CAP_SECONDS = 60.0
-
-
-def _http_error_retry_delay(exc: Exception) -> float | None:
-    """Extract a recommended wait from rate-limit headers on a 403/429.
-
-    Returns None when no header is present or the indicated wait is
-    longer than _RATE_LIMIT_WAIT_CAP_SECONDS (in which case the caller
-    should not block on it -- the source-build fallback is faster).
-    """
-    if not isinstance(exc, urllib.error.HTTPError):
-        return None
-    headers = getattr(exc, "headers", None)
-    if headers is None:
-        return None
-    retry_after = headers.get("Retry-After")
-    if retry_after and retry_after.strip().isdigit():
-        wait = float(retry_after.strip())
-        return wait if wait <= _RATE_LIMIT_WAIT_CAP_SECONDS else None
-    rate_reset = headers.get("X-RateLimit-Reset")
-    if rate_reset and rate_reset.strip().isdigit():
-        wait = float(rate_reset.strip()) - time.time()
-        if 0.0 < wait <= _RATE_LIMIT_WAIT_CAP_SECONDS:
-            return wait + 1.0  # +1s of slack so the bucket is fresh
-    return None
-
-
-def sleep_backoff(
-    attempt: int,
-    *,
-    base_delay: float = HTTP_FETCH_BASE_DELAY_SECONDS,
-    exc: Exception | None = None,
-) -> None:
-    delay = base_delay * (2 ** max(attempt - 1, 0))
-    header_delay = _http_error_retry_delay(exc) if exc is not None else None
-    if header_delay is not None:
-        delay = max(delay, header_delay)
-    delay += random.uniform(0.0, 0.2)
-    time.sleep(delay)
-
-
-def atomic_write_bytes(destination: Path, data: bytes) -> None:
-    destination.parent.mkdir(parents = True, exist_ok = True)
-    with tempfile.NamedTemporaryFile(
-        prefix = destination.name + ".tmp-",
-        dir = destination.parent,
-        delete = False,
-    ) as handle:
-        tmp_path = Path(handle.name)
-        handle.write(data)
-        handle.flush()
-        os.fsync(handle.fileno())
-    os.replace(tmp_path, destination)
-
-
-def atomic_replace_from_tempfile(tmp_path: Path, destination: Path) -> None:
-    destination.parent.mkdir(parents = True, exist_ok = True)
-    os.replace(tmp_path, destination)
+_http_error_retry_delay = _core._http_error_retry_delay
+sleep_backoff = _core.sleep_backoff
+atomic_write_bytes = _core.atomic_write_bytes
+atomic_replace_from_tempfile = _core.atomic_replace_from_tempfile
 
 
 def source_archive_logical_name(upstream_tag: str) -> str:
@@ -638,27 +477,9 @@ def exact_source_archive_logical_name(source_commit: str) -> str:
     return f"llama.cpp-source-commit-{source_commit}.tar.gz"
 
 
-def sha256_file(path: Path) -> str:
-    digest = hashlib.sha256()
-    with path.open("rb") as handle:
-        for chunk in iter(lambda: handle.read(1024 * 1024), b""):
-            digest.update(chunk)
-    return digest.hexdigest()
-
-
-def sha256_bytes(data: bytes) -> str:
-    return hashlib.sha256(data).hexdigest()
-
-
-def normalize_sha256_digest(value: str | None) -> str | None:
-    if not isinstance(value, str) or not value:
-        return None
-    lowered = value.lower()
-    if lowered.startswith("sha256:"):
-        lowered = lowered.split(":", 1)[1]
-    if len(lowered) != 64 or any(ch not in "0123456789abcdef" for ch in lowered):
-        return None
-    return lowered
+sha256_file = _core.sha256_file
+sha256_bytes = _core.sha256_bytes
+normalize_sha256_digest = _core.normalize_sha256_digest
 
 
 def normalize_source_ref_kind(value: str | None) -> str | None:
@@ -682,15 +503,7 @@ def normalize_source_commit(value: str | None) -> str | None:
 
 
 def validate_schema_version(payload: dict[str, Any], *, label: str) -> None:
-    schema_version = payload.get("schema_version")
-    if schema_version is None:
-        return
-    try:
-        normalized = int(schema_version)
-    except (TypeError, ValueError) as exc:
-        raise RuntimeError(f"{label} schema_version was not an integer") from exc
-    if normalized != 1:
-        raise RuntimeError(f"{label} schema_version={normalized} is unsupported")
+    _core.validate_schema_version(payload, label = label)
 
 
 def repo_slug_from_source(value: str | None) -> str | None:
@@ -856,127 +669,10 @@ def _published_windows_cuda_runtime(
     return f"{major}.{best}" if best is not None else None
 
 
-def format_byte_count(num_bytes: float) -> str:
-    units = ["B", "KiB", "MiB", "GiB", "TiB"]
-    value = float(num_bytes)
-    for unit in units:
-        if abs(value) < 1024.0 or unit == units[-1]:
-            if unit == "B":
-                return f"{int(value)} {unit}"
-            return f"{value:.1f} {unit}"
-        value /= 1024.0
-    return f"{num_bytes:.1f} B"
-
-
-def _progress_percent_step() -> int:
-    """Non-tty milestone granularity. The in-app updater sets
-    UNSLOTH_PROGRESS_PERCENT_STEP=5 to stream finer progress lines."""
-    try:
-        step = int(os.environ.get("UNSLOTH_PROGRESS_PERCENT_STEP", "25"))
-    except ValueError:
-        return 25
-    return min(max(step, 1), 50)
-
-
-class DownloadProgress:
-    def __init__(self, label: str, total_bytes: int | None) -> None:
-        self.label = label
-        self.total_bytes = total_bytes if total_bytes and total_bytes > 0 else None
-        self.start_time = time.monotonic()
-        self.last_emit = 0.0
-        term_ok = os.environ.get("TERM", "").lower() != "dumb"
-        self.stream = (
-            sys.stderr if sys.stderr.isatty() else sys.stdout if sys.stdout.isatty() else sys.stderr
-        )
-        self.is_tty = term_ok and self.stream.isatty()
-        self.completed = False
-        self.milestone_step = _progress_percent_step()
-        self.last_milestone_percent = -1
-        self.last_milestone_bytes = 0
-        self.has_rendered_tty_progress = False
-
-    def _render(
-        self,
-        downloaded_bytes: int,
-        *,
-        final: bool = False,
-    ) -> str:
-        elapsed = max(time.monotonic() - self.start_time, 1e-6)
-        speed = downloaded_bytes / elapsed
-        speed_text = f"{format_byte_count(speed)}/s"
-        if self.total_bytes is not None:
-            percent = min(100.0, (downloaded_bytes / self.total_bytes) * 100.0)
-            return (
-                f"{self.label}: {percent:5.1f}% "
-                f"({format_byte_count(downloaded_bytes)}/{format_byte_count(self.total_bytes)}) "
-                f"at {speed_text}"
-            )
-        if final:
-            return f"{self.label}: {format_byte_count(downloaded_bytes)} downloaded at {speed_text}"
-        return f"{self.label}: {format_byte_count(downloaded_bytes)} downloaded at {speed_text}"
-
-    def update(self, downloaded_bytes: int) -> None:
-        now = time.monotonic()
-        if self.is_tty:
-            elapsed = now - self.start_time
-            if not self.has_rendered_tty_progress:
-                if self.total_bytes is not None and downloaded_bytes >= self.total_bytes:
-                    return
-                if elapsed < TTY_PROGRESS_START_DELAY_SECONDS:
-                    return
-            min_interval = 0.2
-            if (
-                self.has_rendered_tty_progress
-                and not self.completed
-                and (now - self.last_emit) < min_interval
-            ):
-                return
-            self.last_emit = now
-            line = self._render(downloaded_bytes)
-            self.stream.write("\r\033[K" + line)
-            self.stream.flush()
-            self.has_rendered_tty_progress = True
-            return
-
-        should_emit = False
-        if self.total_bytes is not None:
-            percent = int((downloaded_bytes * 100) / max(self.total_bytes, 1))
-            step = self.milestone_step
-            milestone_percent = min((percent // step) * step, 100)
-            if milestone_percent > self.last_milestone_percent and milestone_percent < 100:
-                self.last_milestone_percent = milestone_percent
-                should_emit = True
-        else:
-            byte_step = 25 * 1024 * 1024
-            if (
-                downloaded_bytes - self.last_milestone_bytes >= byte_step
-                and (now - self.last_emit) >= 5.0
-            ):
-                self.last_milestone_bytes = downloaded_bytes
-                should_emit = True
-
-        if not should_emit:
-            return
-
-        self.last_emit = now
-        self.stream.write(self._render(downloaded_bytes) + "\n")
-        self.stream.flush()
-
-    def finish(self, downloaded_bytes: int) -> None:
-        self.completed = True
-        line = self._render(downloaded_bytes, final = True)
-        if self.is_tty:
-            if not self.has_rendered_tty_progress:
-                return
-            self.stream.write("\r\033[K")
-        else:
-            self.stream.write(line + "\n")
-        self.stream.flush()
-
-
-def download_label_from_url(url: str) -> str:
-    name = Path(urllib.parse.urlparse(url).path).name
-    return name or url
+format_byte_count = _core.format_byte_count
+_progress_percent_step = _core._progress_percent_step
+DownloadProgress = _core.DownloadProgress
+download_label_from_url = _core.download_label_from_url
 
 
 def download_bytes(
@@ -987,151 +683,30 @@ def download_bytes(
     headers: dict[str, str] | None = None,
     progress_label: str | None = None,
 ) -> bytes:
-    last_exc: Exception | None = None
-    for attempt in range(1, attempts + 1):
-        try:
-            request = urllib.request.Request(url, headers = headers or auth_headers(url))
-            with _URL_OPENER.open(request, timeout = timeout) as response:
-                total_bytes: int | None = None
-                content_length = response.headers.get("Content-Length")
-                if content_length and content_length.isdigit():
-                    total_bytes = int(content_length)
-                progress = DownloadProgress(progress_label, total_bytes) if progress_label else None
-                data = bytearray()
-                while True:
-                    chunk = response.read(1024 * 1024)
-                    if not chunk:
-                        break
-                    data.extend(chunk)
-                    if progress is not None:
-                        progress.update(len(data))
-                if progress is not None:
-                    progress.finish(len(data))
-                return bytes(data)
-        except Exception as exc:
-            last_exc = exc
-            if attempt >= attempts or not is_retryable_url_error(exc):
-                raise
-            log(f"fetch failed ({attempt}/{attempts}) for {url}: {exc}; retrying")
-            sleep_backoff(attempt, exc = exc)
-    assert last_exc is not None
-    raise last_exc
+    return _core.download_bytes(
+        _OPS,
+        url,
+        timeout = timeout,
+        attempts = attempts,
+        headers = headers,
+        progress_label = progress_label,
+    )
 
 
 def fetch_json(url: str) -> Any:
-    attempts = JSON_FETCH_ATTEMPTS if is_github_api_url(url) else 1
-    last_decode_exc: Exception | None = None
-    for attempt in range(1, attempts + 1):
-        try:
-            data = download_bytes(
-                url,
-                timeout = 30,
-                headers = github_api_headers(url) if is_github_api_url(url) else auth_headers(url),
-            )
-        except urllib.error.HTTPError as exc:
-            if exc.code == 403 and is_github_api_url(url):
-                hint = ""
-                if not (os.environ.get("GH_TOKEN") or os.environ.get("GITHUB_TOKEN")):
-                    hint = "; set GH_TOKEN or GITHUB_TOKEN to avoid GitHub API rate limits"
-                raise RuntimeError(f"GitHub API returned 403 for {url}{hint}") from exc
-            raise
-        if not data:
-            last_decode_exc = RuntimeError(f"downloaded empty JSON payload from {url}")
-        else:
-            try:
-                payload = json.loads(data.decode("utf-8"))
-            except (UnicodeDecodeError, json.JSONDecodeError) as exc:
-                last_decode_exc = RuntimeError(f"downloaded invalid JSON from {url}: {exc}")
-            else:
-                if not isinstance(payload, dict) and not isinstance(payload, list):
-                    raise RuntimeError(
-                        f"downloaded unexpected JSON type from {url}: {type(payload).__name__}"
-                    )
-                return payload
-        if attempt >= attempts:
-            assert last_decode_exc is not None
-            raise last_decode_exc
-        log(f"json fetch failed ({attempt}/{attempts}) for {url}; retrying")
-        sleep_backoff(attempt)
-    assert last_decode_exc is not None
-    raise last_decode_exc
+    return _core.fetch_json(_OPS, url)
 
 
 def download_file(url: str, destination: Path) -> None:
-    destination.parent.mkdir(parents = True, exist_ok = True)
-    last_exc: Exception | None = None
-    for attempt in range(1, HTTP_FETCH_ATTEMPTS + 1):
-        tmp_path: Path | None = None
-        try:
-            request = urllib.request.Request(url, headers = auth_headers(url))
-            with tempfile.NamedTemporaryFile(
-                prefix = destination.name + ".tmp-",
-                dir = destination.parent,
-                delete = False,
-            ) as handle:
-                tmp_path = Path(handle.name)
-                with _URL_OPENER.open(request, timeout = 120) as response:
-                    total_bytes: int | None = None
-                    content_length = response.headers.get("Content-Length")
-                    if content_length and content_length.isdigit():
-                        total_bytes = int(content_length)
-                    progress = DownloadProgress(f"Downloading {destination.name}", total_bytes)
-                    downloaded_bytes = 0
-                    while True:
-                        chunk = response.read(1024 * 1024)
-                        if not chunk:
-                            break
-                        handle.write(chunk)
-                        downloaded_bytes += len(chunk)
-                        progress.update(downloaded_bytes)
-                    progress.finish(downloaded_bytes)
-                handle.flush()
-                os.fsync(handle.fileno())
-            if not tmp_path.exists() or tmp_path.stat().st_size == 0:
-                raise RuntimeError(f"downloaded empty file from {url}")
-            atomic_replace_from_tempfile(tmp_path, destination)
-            return
-        except Exception as exc:
-            last_exc = exc
-            if tmp_path is not None:
-                try:
-                    tmp_path.unlink(missing_ok = True)
-                except Exception:
-                    pass
-            if attempt >= HTTP_FETCH_ATTEMPTS or not is_retryable_url_error(exc):
-                raise
-            log(f"download failed ({attempt}/{HTTP_FETCH_ATTEMPTS}) for {url}: {exc}; retrying")
-            sleep_backoff(attempt, exc = exc)
-    assert last_exc is not None
-    raise last_exc
+    _core.download_file(_OPS, url, destination)
 
 
 def download_file_verified(
     url: str, destination: Path, *, expected_sha256: str | None, label: str
 ) -> None:
-    normalized_expected = normalize_sha256_digest(expected_sha256)
-    if not normalized_expected:
-        download_file(url, destination)
-        log(f"downloaded {label} without a published sha256; relying on install validation")
-        return
-
-    for attempt in range(1, 3):
-        download_file(url, destination)
-        actual_sha256 = sha256_file(destination)
-        if actual_sha256 == normalized_expected:
-            log(f"verified {label} sha256={actual_sha256}")
-            return
-
-        log(
-            f"{label} checksum mismatch on attempt {attempt}/2: "
-            f"expected={normalized_expected} actual={actual_sha256}"
-        )
-        destination.unlink(missing_ok = True)
-        if attempt == 2:
-            raise PrebuiltFallback(
-                f"{label} checksum mismatch after retry: expected={normalized_expected} actual={actual_sha256}"
-            )
-        log(f"retrying {label} download after checksum mismatch")
+    _core.download_file_verified(
+        _OPS, url, destination, expected_sha256 = expected_sha256, label = label
+    )
 
 
 def upstream_source_archive_urls(tag: str) -> list[str]:
@@ -1165,21 +740,11 @@ def release_asset_download_url(
 
 
 def github_release_assets(repo: str, tag: str) -> dict[str, str]:
-    payload = fetch_json(
-        f"https://api.github.com/repos/{repo}/releases/tags/{urllib.parse.quote(tag, safe = '')}"
-    )
-    if not isinstance(payload, dict):
-        raise RuntimeError(f"unexpected release payload for {repo}@{tag}")
-    return release_asset_map(payload)
+    return _core.github_release_assets(_OPS, repo, tag)
 
 
 def github_release(repo: str, tag: str) -> dict[str, Any]:
-    payload = fetch_json(
-        f"https://api.github.com/repos/{repo}/releases/tags/{urllib.parse.quote(tag, safe = '')}"
-    )
-    if not isinstance(payload, dict):
-        raise RuntimeError(f"unexpected release payload for {repo}@{tag}")
-    return payload
+    return _core.github_release(_OPS, repo, tag)
 
 
 def github_releases(
@@ -1542,10 +1107,7 @@ def resolve_simple_install_release_plans(
                 if not allow_older_release_fallback:
                     raise
                 release_tag = release.get("tag_name") or "unknown"
-                log(
-                    "published release skipped for install planning: "
-                    f"{repo}@{release_tag} ({exc})"
-                )
+                log(f"published release skipped for install planning: {repo}@{release_tag} ({exc})")
                 continue
 
             plans.append(plan)
@@ -1571,198 +1133,23 @@ def normalized_requested_llama_tag(requested_tag: str | None) -> str:
     return "latest"
 
 
-def normalize_compute_cap(value: Any) -> str | None:
-    raw = str(value).strip()
-    if not raw:
-        return None
-    if "." in raw:
-        parts = raw.split(".", 1)
-        if len(parts) != 2:
-            return None
-        major, minor = parts
-        if not major.isdigit() or not minor.isdigit():
-            return None
-        return f"{int(major)}{int(minor)}"
-    if raw.isdigit():
-        return str(int(raw))
-    return None
-
-
-def normalize_compute_caps(compute_caps: Iterable[str]) -> list[str]:
-    normalized: list[str] = []
-    seen: set[str] = set()
-    for raw in compute_caps:
-        normalized_value = normalize_compute_cap(raw)
-        if normalized_value is None:
-            continue
-        if normalized_value in seen:
-            continue
-        seen.add(normalized_value)
-        normalized.append(normalized_value)
-    normalized.sort(key = int)
-    return normalized
-
-
-def parse_cuda_visible_devices(value: str | None) -> list[str] | None:
-    if value is None:
-        return None
-    raw = value.strip()
-    if not raw or raw == "-1":
-        return []
-    return [token.strip() for token in raw.split(",") if token.strip()]
-
-
-def supports_explicit_visible_device_matching(visible_devices: list[str] | None) -> bool:
-    if not visible_devices:
-        return False
-    for token in visible_devices:
-        lowered = token.lower()
-        if token.isdigit() or lowered.startswith("gpu-"):
-            continue
-        return False
-    return True
-
-
-def select_visible_gpu_rows(
-    gpu_rows: Iterable[tuple[str, str, str]], visible_devices: list[str] | None
-) -> list[tuple[str, str, str]]:
-    rows = list(gpu_rows)
-    if visible_devices is None:
-        return rows
-    if not visible_devices:
-        return []
-
-    by_index = {index: (index, uuid, cap) for index, uuid, cap in rows}
-    by_uuid = {uuid.lower(): (index, uuid, cap) for index, uuid, cap in rows}
-    selected: list[tuple[str, str, str]] = []
-    seen_indices: set[str] = set()
-    for token in visible_devices:
-        row = by_index.get(token)
-        if row is None:
-            normalized_token = token.lower()
-            row = by_uuid.get(normalized_token)
-            if row is None and normalized_token.startswith("gpu-"):
-                row = by_uuid.get(normalized_token)
-            if row is None and not normalized_token.startswith("gpu-"):
-                row = by_uuid.get("gpu-" + normalized_token)
-        if row is None:
-            continue
-        index = row[0]
-        if index in seen_indices:
-            continue
-        seen_indices.add(index)
-        selected.append(row)
-    return selected
-
-
-def dir_provides_exact_library(directory: str | Path, library: str) -> bool:
-    if not library:
-        return False
-    candidate = Path(directory) / library
-    return candidate.exists() and (candidate.is_file() or candidate.is_symlink())
+normalize_compute_cap = _core.normalize_compute_cap
+normalize_compute_caps = _core.normalize_compute_caps
+parse_cuda_visible_devices = _core.parse_cuda_visible_devices
+supports_explicit_visible_device_matching = _core.supports_explicit_visible_device_matching
+select_visible_gpu_rows = _core.select_visible_gpu_rows
+dir_provides_exact_library = _core.dir_provides_exact_library
 
 
 def linux_runtime_dirs_for_required_libraries(required_libraries: Iterable[str]) -> list[str]:
-    required = [library for library in required_libraries if library]
-    candidates: list[str | Path] = []
-
-    env_dirs = os.environ.get("CUDA_RUNTIME_LIB_DIR", "")
-    if env_dirs:
-        candidates.extend(part for part in env_dirs.split(os.pathsep) if part)
-    ld_library_path = os.environ.get("LD_LIBRARY_PATH", "")
-    if ld_library_path:
-        candidates.extend(part for part in ld_library_path.split(os.pathsep) if part)
-
-    cuda_roots: list[Path] = []
-    for name in ("CUDA_HOME", "CUDA_PATH", "CUDA_ROOT"):
-        value = os.environ.get(name)
-        if value:
-            cuda_roots.append(Path(value))
-    cuda_roots.extend(Path(path) for path in glob_paths("/usr/local/cuda", "/usr/local/cuda-*"))
-
-    for root in cuda_roots:
-        candidates.extend(
-            [
-                root / "lib",
-                root / "lib64",
-                root / "targets" / "x86_64-linux" / "lib",
-            ]
-        )
-
-    candidates.extend(
-        Path(path)
-        for path in glob_paths(
-            "/lib",
-            "/lib64",
-            "/usr/lib",
-            "/usr/lib64",
-            "/usr/local/lib",
-            "/usr/local/lib64",
-            "/lib/x86_64-linux-gnu",
-            "/usr/lib/x86_64-linux-gnu",
-        )
-    )
-    candidates.extend(
-        Path(path) for path in glob_paths("/usr/local/lib/ollama/cuda_v*", "/usr/lib/wsl/lib")
-    )
-    candidates.extend(Path(path) for path in python_runtime_dirs())
-    candidates.extend(Path(path) for path in ldconfig_runtime_dirs(required))
-
-    resolved = dedupe_existing_dirs(candidates)
-    if not required:
-        return resolved
-
-    matched: list[tuple[int, str]] = []
-    for directory in resolved:
-        base = Path(directory)
-        provided = sum(1 for library in required if dir_provides_exact_library(directory, library))
-        if provided:
-            matched.append((provided, directory))
-
-    matched.sort(key = lambda item: item[0], reverse = True)
-    return [directory for _, directory in matched]
+    return _core.linux_runtime_dirs_for_required_libraries(_OPS, required_libraries)
 
 
 def detected_linux_runtime_lines() -> tuple[list[str], dict[str, list[str]]]:
-    line_requirements = {
-        f"cuda{m}": [f"libcudart.so.{m}", f"libcublas.so.{m}"]
-        for m in range(_MAX_PROBE_CUDA_MAJOR, _MIN_CUDA_MAJOR - 1, -1)
-    }
-    detected: list[str] = []
-    runtime_dirs: dict[str, list[str]] = {}
-    for line, required in line_requirements.items():
-        dirs = linux_runtime_dirs_for_required_libraries(required)
-        library_matches: dict[str, list[str]] = {}
-        matching_dirs: list[str] = []
-        for library in required:
-            matched_dirs = [
-                directory for directory in dirs if any(Path(directory).glob(f"{library}*"))
-            ]
-            if not matched_dirs:
-                library_matches = {}
-                matching_dirs = []
-                break
-            library_matches[library] = matched_dirs
-            for directory in matched_dirs:
-                if directory not in matching_dirs:
-                    matching_dirs.append(directory)
-        if library_matches:
-            detected.append(line)
-            runtime_dirs[line] = matching_dirs
-    return detected, runtime_dirs
+    return _core.detected_linux_runtime_lines(_OPS)
 
 
-def release_asset_map(release: dict[str, Any]) -> dict[str, str]:
-    assets = release.get("assets")
-    if not isinstance(assets, list):
-        return {}
-    return {
-        asset["name"]: asset.get("browser_download_url", "")
-        for asset in assets
-        if isinstance(asset, dict)
-        and isinstance(asset.get("name"), str)
-        and isinstance(asset.get("browser_download_url"), str)
-    }
+release_asset_map = _core.release_asset_map
 
 
 def parse_published_artifact(raw: Any) -> PublishedLlamaArtifact | None:
@@ -2067,47 +1454,9 @@ def iter_published_release_bundles(
         yield bundle
 
 
-def _artifact_covers_sms(artifact: PublishedLlamaArtifact, host_sms: Iterable[str]) -> bool:
-    """True when every host SM is listed in the artifact's supported_sms and
-    falls within its [min_sm, max_sm] range."""
-    if not artifact.supported_sms or artifact.min_sm is None or artifact.max_sm is None:
-        return False
-    supported = {str(value) for value in artifact.supported_sms}
-    return all(sm in supported and artifact.min_sm <= int(sm) <= artifact.max_sm for sm in host_sms)
-
-
-def _sm_range(artifact: PublishedLlamaArtifact) -> int:
-    """SM-coverage span used as a sort key, where a tighter (smaller) range wins.
-    A bundle with no SM metadata (legacy/upstream-named) gets a max range so it
-    sorts last and can't outrank a real targeted bundle whose tight range would
-    otherwise sort first."""
-    if artifact.min_sm is not None and artifact.max_sm is not None:
-        return artifact.max_sm - artifact.min_sm
-    return 9999
-
-
-def _blackwell_capable_linux_runtime_lines(
-    host_sms: list[str], artifacts: list[PublishedLlamaArtifact]
-) -> list[str]:
-    """CUDA runtime lines (highest major first) shipping a bundle that covers every
-    visible host SM. Lets a Blackwell host prefer a native sm_120 line over torch's
-    reported line, mirroring the Windows Blackwell preference."""
-    lines: set[str] = set()
-    for artifact in artifacts:
-        line = artifact.runtime_line
-        # Only rank "cuda<major>" lines; ignore malformed/future-format values
-        # (e.g. "cuda13.1") so they are skipped, as pre-existing code does, rather
-        # than crashing the major sort.
-        if not (line and line.startswith("cuda") and line[len("cuda") :].isdigit()):
-            continue
-        if not artifact.supported_sms or artifact.min_sm is None or artifact.max_sm is None:
-            continue
-        supported = {str(value) for value in artifact.supported_sms}
-        if all(
-            sm in supported and artifact.min_sm <= int(sm) <= artifact.max_sm for sm in host_sms
-        ):
-            lines.add(line)
-    return sorted(lines, key = lambda line: int(line[len("cuda") :]), reverse = True)
+_artifact_covers_sms = _core.artifact_covers_sms
+_sm_range = _core.sm_range
+_blackwell_capable_linux_runtime_lines = _core.blackwell_capable_linux_runtime_lines
 
 
 def linux_cuda_choice_from_release(
@@ -2398,50 +1747,15 @@ def _download_host_resolve_enabled() -> bool:
 
 
 def _release_asset_download_url(repo: str, tag: str, asset_name: str) -> str:
-    """Tag-pinned asset URL on the release-assets CDN (not api.github.com, so no
-    rate limit)."""
-    return (
-        f"https://github.com/{urllib.parse.quote(repo, safe = '/')}/releases/download/"
-        f"{urllib.parse.quote(tag, safe = '')}/"
-        f"{urllib.parse.quote(asset_name, safe = '')}"
-    )
+    return _core.release_asset_download_url(repo, tag, asset_name)
 
 
 def _download_host_latest_release_tag(repo: str) -> str | None:
-    """Authoritative latest tag from GitHub's /releases/latest redirect target
-    (github.com, no api.github.com rate limit); the fast path pins URLs to it rather
-    than the checksum asset's self-reported release_tag. /releases/latest resolves by
-    created_at/make_latest, which can lag the published_at newest the freshness
-    detection uses. None on 404 so the caller falls back to the API."""
-    url = f"https://github.com/{urllib.parse.quote(repo, safe = '/')}/releases/latest"
-    request = urllib.request.Request(
-        url,
-        method = "HEAD",
-        headers = {"User-Agent": "unsloth-studio-llama-prebuilt"},
-    )
-    try:
-        with _URL_OPENER.open(request, timeout = 30) as response:
-            final_url = response.geturl()
-    except urllib.error.HTTPError as exc:
-        if exc.code == 404:
-            return None
-        raise
-    marker = "/releases/tag/"
-    index = final_url.find(marker)
-    if index == -1:
-        return None
-    tag = urllib.parse.unquote(final_url[index + len(marker) :]).strip("/")
-    return tag or None
+    return _core.download_host_latest_release_tag(_OPS, repo)
 
 
 def _fetch_download_host_json(url: str) -> Any:
-    # Public CDN asset: plain unauthenticated GET, not the rate-limited API.
-    data = download_bytes(
-        url,
-        timeout = 30,
-        headers = {"User-Agent": "unsloth-studio-llama-prebuilt"},
-    )
-    return json.loads(data.decode("utf-8"))
+    return _core.fetch_download_host_json(_OPS, url)
 
 
 def _download_host_resolved_release(repo: str) -> ResolvedPublishedRelease | None:
@@ -2897,7 +2211,7 @@ def _pick_rocm_gfx_target(out: str) -> str | None:
             break
     if _vis_raw is not None:
         _vis = _vis_raw.strip()
-        # Empty or "-1" means "no AMD GPU visible" (matches the rest of Studio).
+        # Empty or "-1" means "no AMD GPU visible" (matches the rest of Unsloth).
         if _vis == "" or _vis == "-1":
             return None
         _first = _vis.split(",")[0].strip()
@@ -3292,38 +2606,14 @@ def pick_windows_cuda_runtime(host: HostInfo) -> str | None:
     return None
 
 
-def compatible_linux_runtime_lines(host: HostInfo) -> list[str]:
-    if not host.driver_cuda_version:
-        return []
-    major, _minor = host.driver_cuda_version
-    if major < _MIN_CUDA_MAJOR:
-        return []
-    return _cuda_runtime_lines_for_major(major)
+compatible_linux_runtime_lines = _core.compatible_linux_runtime_lines
 
 
-def windows_runtime_line_info() -> dict[str, tuple[str, ...]]:
-    # Generated per CUDA major (newest first) so a new toolkit is detected
-    # without a code change while the cudart64_<major>.dll naming holds.
-    return {
-        f"cuda{m}": (
-            f"cudart64_{m}*.dll",
-            f"cublas64_{m}*.dll",
-            f"cublasLt64_{m}*.dll",
-        )
-        for m in range(_MAX_PROBE_CUDA_MAJOR, _MIN_CUDA_MAJOR - 1, -1)
-    }
+windows_runtime_line_info = _core.windows_runtime_line_info
 
 
 def detected_windows_runtime_lines() -> tuple[list[str], dict[str, list[str]]]:
-    dirs = windows_runtime_dirs()
-    detected: list[str] = []
-    runtime_dirs: dict[str, list[str]] = {}
-    for runtime_line, required_patterns in windows_runtime_line_info().items():
-        matching_dirs = windows_runtime_dirs_for_patterns(required_patterns, dirs)
-        if matching_dirs:
-            detected.append(runtime_line)
-            runtime_dirs[runtime_line] = matching_dirs
-    return detected, runtime_dirs
+    return _core.detected_windows_runtime_lines(_OPS)
 
 
 def compatible_windows_runtime_lines(host: HostInfo) -> list[str]:
@@ -3337,68 +2627,8 @@ def compatible_windows_runtime_lines(host: HostInfo) -> list[str]:
     return _cuda_runtime_lines_for_major(major)
 
 
-def runtime_line_from_cuda_version(cuda_version: str | None) -> str | None:
-    if not cuda_version:
-        return None
-    raw = str(cuda_version).strip()
-    if not raw:
-        return None
-    major, _, _ = raw.partition(".")
-    if major == "12":
-        return "cuda12"
-    if major == "13":
-        return "cuda13"
-    return None
-
-
-def detect_torch_cuda_runtime_preference(host: HostInfo) -> CudaRuntimePreference:
-    selection_log: list[str] = []
-    if host.is_macos:
-        selection_log.append("torch_cuda_preference: skipped on macOS")
-        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
-    if not (host.has_usable_nvidia and (host.is_linux or host.is_windows)):
-        selection_log.append(
-            "torch_cuda_preference: skipped because CUDA host prerequisites were not met"
-        )
-        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
-
-    try:
-        import torch
-    except Exception as exc:
-        selection_log.append(f"torch_cuda_preference: import failed: {exc}")
-        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
-
-    cuda_version = getattr(getattr(torch, "version", None), "cuda", None)
-    if not isinstance(cuda_version, str) or not cuda_version.strip():
-        selection_log.append(
-            "torch_cuda_preference: torch.version.cuda missing; skipping Torch shortcut"
-        )
-        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
-
-    try:
-        cuda_available = bool(torch.cuda.is_available())
-    except Exception as exc:
-        selection_log.append(f"torch_cuda_preference: torch.cuda.is_available() failed: {exc}")
-        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
-
-    if not cuda_available:
-        selection_log.append(
-            "torch_cuda_preference: torch.cuda.is_available() returned False; falling back to normal selection"
-        )
-        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
-
-    runtime_line = runtime_line_from_cuda_version(cuda_version)
-    if runtime_line is None:
-        selection_log.append(
-            f"torch_cuda_preference: unsupported torch.version.cuda={cuda_version}; falling back to normal selection"
-        )
-        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
-
-    selection_log.append(
-        "torch_cuda_preference: selected runtime_line="
-        f"{runtime_line} from torch.version.cuda={cuda_version}"
-    )
-    return CudaRuntimePreference(runtime_line = runtime_line, selection_log = selection_log)
+runtime_line_from_cuda_version = _core.runtime_line_from_cuda_version
+detect_torch_cuda_runtime_preference = _core.detect_torch_cuda_runtime_preference
 
 
 def windows_cuda_attempts(
@@ -3569,18 +2799,8 @@ def _windows_cuda_attempt_covers_blackwell(
     return attempt.max_sm is not None and attempt.max_sm >= _BLACKWELL_MIN_SM
 
 
-def _host_is_blackwell(host: HostInfo) -> bool:
-    caps = normalize_compute_caps(host.compute_caps)
-    return bool(caps) and int(caps[-1]) >= _BLACKWELL_MIN_SM
-
-
-def _blackwell_min_toolkit_for_host(host: HostInfo) -> tuple[int, int]:
-    """Minimum CUDA toolkit this Blackwell host needs: 12.8 for the family,
-    12.9 if any of its SMs is sm_103/sm_121 (no native target before 12.9)."""
-    req = _BLACKWELL_MIN_TOOLKIT
-    for sm in normalize_compute_caps(host.compute_caps):
-        req = max(req, _BLACKWELL_SM_MIN_TOOLKIT.get(int(sm), _BLACKWELL_MIN_TOOLKIT))
-    return req
+_host_is_blackwell = _core.host_is_blackwell
+_blackwell_min_toolkit_for_host = _core.blackwell_min_toolkit_for_host
 
 
 def _drop_blackwell_incapable_windows_cuda(
@@ -4204,169 +3424,7 @@ def resolve_release_asset_choice(
     )
 
 
-def extract_archive(archive_path: Path, destination: Path) -> None:
-    def safe_extract_path(base: Path, member_name: str) -> Path:
-        normalized = member_name.replace("\\", "/")
-        member_path = Path(normalized)
-        if member_path.is_absolute():
-            raise PrebuiltFallback(f"archive member used an absolute path: {member_name}")
-
-        target = (base / member_path).resolve()
-        base_resolved = base.resolve()
-        try:
-            target.relative_to(base_resolved)
-        except ValueError as exc:
-            raise PrebuiltFallback(f"archive member escaped destination: {member_name}") from exc
-        return target
-
-    def _try_repair_missing_slash(
-        member_name: str, link_name: str, archive_names: set[str]
-    ) -> str | None:
-        """Some upstream llama.cpp Mac releases (e.g. b9165, b9169) ship
-        symlinks whose linkname is missing the directory separator AND
-        the leading character of the file basename between the
-        top-level dir and the rest of the path:
-
-            llama-b9165/libggml-rpc.0.dylib -> llama-b9165ibggml-rpc.0.11.1.dylib
-
-        That cannot be resolved as written. Detect the pattern
-        (linkname starts with the top-level dir name but no following
-        slash) and search archive entries under that dir for a real
-        file whose basename ends with the mangled suffix. Only accept
-        when the suffix uniquely identifies a real archive entry.
-        Returns the corrected linkname expressed relative to the
-        member's parent directory -- callers join it with
-        `target.parent`, so a full `top/file` path would double the
-        prefix into `top/top/file`."""
-        if "/" not in member_name or "/" in link_name:
-            return None
-        top, _, _ = member_name.partition("/")
-        if not link_name.startswith(top) or len(link_name) <= len(top):
-            return None
-        bad_suffix = link_name[len(top) :]
-        if not bad_suffix or bad_suffix.startswith("/"):
-            return None
-        prefix = f"{top}/"
-        candidates = [
-            name
-            for name in archive_names
-            if name.startswith(prefix)
-            and "/" not in name[len(prefix) :]
-            and name[len(prefix) :].endswith(bad_suffix)
-        ]
-        if len(candidates) != 1:
-            return None
-        # Strip the top-level dir so the caller's `target.parent / Path(...)`
-        # composition resolves inside the staging dir, not into a duplicate
-        # `top/top/...` path.
-        return candidates[0][len(prefix) :]
-
-    def safe_link_target(
-        base: Path, member_name: str, link_name: str, target: Path, archive_names: set[str]
-    ) -> tuple[str, Path]:
-        normalized = link_name.replace("\\", "/")
-        repaired = _try_repair_missing_slash(member_name, normalized, archive_names)
-        if repaired is not None:
-            normalized = repaired
-        link_path = Path(normalized)
-        if link_path.is_absolute():
-            raise PrebuiltFallback(
-                f"archive link used an absolute target: {member_name} -> {link_name}"
-            )
-        if not normalized:
-            raise PrebuiltFallback(f"archive link used an empty target: {member_name}")
-
-        resolved = (target.parent / link_path).resolve()
-        base_resolved = base.resolve()
-        try:
-            resolved.relative_to(base_resolved)
-        except ValueError as exc:
-            raise PrebuiltFallback(
-                f"archive link escaped destination: {member_name} -> {link_name}"
-            ) from exc
-        return normalized, resolved
-
-    def extract_zip_safely(source: Path, base: Path) -> None:
-        with zipfile.ZipFile(source) as archive:
-            for member in archive.infolist():
-                target = safe_extract_path(base, member.filename)
-                mode = (member.external_attr >> 16) & 0o170000
-                if mode == 0o120000:
-                    raise PrebuiltFallback(
-                        f"zip archive contained a symlink entry: {member.filename}"
-                    )
-                if member.is_dir():
-                    target.mkdir(parents = True, exist_ok = True)
-                    continue
-                target.parent.mkdir(parents = True, exist_ok = True)
-                with archive.open(member, "r") as src, target.open("wb") as dst:
-                    shutil.copyfileobj(src, dst)
-
-    def extract_tar_safely(source: Path, base: Path) -> None:
-        pending_links: list[tuple[tarfile.TarInfo, Path]] = []
-        archive_names: set[str] = set()
-        with tarfile.open(source, "r:gz") as archive:
-            for member in archive.getmembers():
-                archive_names.add(member.name)
-                target = safe_extract_path(base, member.name)
-                if member.isdir():
-                    target.mkdir(parents = True, exist_ok = True)
-                    continue
-                if member.islnk() or member.issym():
-                    pending_links.append((member, target))
-                    continue
-                if not member.isfile():
-                    raise PrebuiltFallback(
-                        f"tar archive contained an unsupported entry: {member.name}"
-                    )
-                target.parent.mkdir(parents = True, exist_ok = True)
-                extracted = archive.extractfile(member)
-                if extracted is None:
-                    raise PrebuiltFallback(f"tar archive entry could not be read: {member.name}")
-                with extracted, target.open("wb") as dst:
-                    shutil.copyfileobj(extracted, dst)
-
-        unresolved = list(pending_links)
-        while unresolved:
-            next_round: list[tuple[tarfile.TarInfo, Path]] = []
-            progressed = False
-            for member, target in unresolved:
-                normalized_link, resolved_target = safe_link_target(
-                    base, member.name, member.linkname, target, archive_names
-                )
-                if not resolved_target.exists() and not resolved_target.is_symlink():
-                    next_round.append((member, target))
-                    continue
-                if resolved_target.is_dir():
-                    raise PrebuiltFallback(
-                        f"archive link targeted a directory: {member.name} -> {member.linkname}"
-                    )
-
-                target.parent.mkdir(parents = True, exist_ok = True)
-                if target.exists() or target.is_symlink():
-                    target.unlink()
-
-                if member.issym():
-                    target.symlink_to(normalized_link)
-                else:
-                    shutil.copy2(resolved_target, target)
-                progressed = True
-
-            if not progressed:
-                details = ", ".join(
-                    f"{member.name} -> {member.linkname}" for member, _ in next_round
-                )
-                raise PrebuiltFallback(f"tar archive contained unresolved link entries: {details}")
-            unresolved = next_round
-
-    destination.mkdir(parents = True, exist_ok = True)
-    if archive_path.name.endswith(".zip"):
-        extract_zip_safely(archive_path, destination)
-        return
-    if archive_path.name.endswith(".tar.gz"):
-        extract_tar_safely(archive_path, destination)
-        return
-    raise PrebuiltFallback(f"unsupported archive format: {archive_path.name}")
+extract_archive = _core.extract_archive
 
 
 def copy_globs(
@@ -4437,7 +3495,7 @@ def ensure_diffusion_visual_server(
     approved_checksums: ApprovedReleaseChecksums,
 ) -> None:
     """Best-effort placement of the DiffusionGemma visual-server binary next to
-    llama-server in the install tree, so Studio can serve DiffusionGemma GGUFs
+    llama-server in the install tree, so Unsloth can serve DiffusionGemma GGUFs
     without any DG_* env. This is an Unsloth artifact (not a ggml-org one), so it
     is optional: if it is already present we just make it executable, otherwise we
     try the published release and quietly skip on absence. A source build
@@ -4719,7 +3777,7 @@ def runtime_patterns_for_choice(choice: AssetChoice) -> list[str]:
     # repackage the SO/DLL set (e.g. ggml-org/llama.cpp#23462 split the
     # per-binary entry code into paired ``lib<binary>-impl.so`` shared
     # libraries between b9279 and b9283) without us re-enumerating
-    # every new file. Studio invokes llama-server, llama-quantize, and the
+    # every new file. Unsloth invokes llama-server, llama-quantize, and the
     # DiffusionGemma visual-server (when the bundle ships it, for native
     # DiffusionGemma serving); other CLIs upstream ships (llama-cli,
     # llama-bench, ...) are skipped.
@@ -4778,83 +3836,8 @@ def metadata_patterns_for_choice(choice: AssetChoice) -> list[str]:
     return patterns
 
 
-@contextmanager
-def install_lock(lock_path: Path) -> Iterator[None]:
-    lock_path.parent.mkdir(parents = True, exist_ok = True)
-
-    if FileLock is None:
-        # Fallback: exclusive file creation as a simple lock.
-        # Write our PID so stale locks from crashed processes can be detected.
-        fd: int | None = None
-        deadline = time.monotonic() + INSTALL_LOCK_TIMEOUT_SECONDS
-        while True:
-            try:
-                fd = os.open(str(lock_path), os.O_CREAT | os.O_EXCL | os.O_RDWR)
-                try:
-                    os.write(fd, f"{os.getpid()}\n".encode())
-                    os.fsync(fd)
-                except Exception:
-                    os.close(fd)
-                    fd = None
-                    lock_path.unlink(missing_ok = True)
-                    raise
-                break
-            except FileExistsError:
-                # Check if the holder process is still alive
-                stale = False
-                try:
-                    raw = lock_path.read_text().strip()
-                except FileNotFoundError:
-                    # Lock vanished between our open attempt and read -- retry
-                    continue
-                if not raw:
-                    # File exists but PID not yet written -- another process
-                    # just created it. Wait briefly for the write to land.
-                    if time.monotonic() >= deadline:
-                        raise BusyInstallConflict(
-                            f"timed out after {INSTALL_LOCK_TIMEOUT_SECONDS}s waiting for concurrent install lock: {lock_path}"
-                        )
-                    time.sleep(0.1)
-                    continue
-                try:
-                    holder_pid = int(raw)
-                    os.kill(holder_pid, 0)  # signal 0 = existence check
-                except ValueError:
-                    # PID unreadable (corrupted file)
-                    stale = True
-                except ProcessLookupError:
-                    # Process is dead
-                    stale = True
-                except PermissionError:
-                    # Process is alive but owned by another user -- not stale
-                    pass
-                if stale:
-                    lock_path.unlink(missing_ok = True)
-                    continue
-                if time.monotonic() >= deadline:
-                    raise BusyInstallConflict(
-                        f"timed out after {INSTALL_LOCK_TIMEOUT_SECONDS}s waiting for concurrent install lock: {lock_path}"
-                    )
-                time.sleep(0.5)
-        try:
-            yield
-        finally:
-            if fd is not None:
-                os.close(fd)
-            lock_path.unlink(missing_ok = True)
-        return
-
-    try:
-        with FileLock(lock_path, timeout = INSTALL_LOCK_TIMEOUT_SECONDS):
-            yield
-    except FileLockTimeout as exc:
-        raise BusyInstallConflict(
-            f"timed out after {INSTALL_LOCK_TIMEOUT_SECONDS}s waiting for concurrent install lock: {lock_path}"
-        ) from exc
-
-
-def install_lock_path(install_dir: Path) -> Path:
-    return install_dir.parent / f".{install_dir.name}.install.lock"
+install_lock = _core.install_lock
+install_lock_path = _core.install_lock_path
 
 
 def install_staging_root(install_dir: Path) -> Path:
@@ -5441,18 +4424,7 @@ _CPU_TYPE_X86_64 = 0x01000007
 _CPU_TYPE_ARM64 = 0x0100000C
 
 
-def parse_macos_version(value: str | None) -> tuple[int, int] | None:
-    """Parse a macOS product version string into (major, minor).
-
-    Handles "14.7.1", "15.5", "26.0" and bare "26". Returns None when the
-    value is empty or cannot be parsed (callers then defer to runtime
-    validation rather than rejecting every prebuilt)."""
-    if not value:
-        return None
-    match = re.match(r"\s*(\d+)(?:\.(\d+))?", str(value))
-    if not match:
-        return None
-    return int(match.group(1)), int(match.group(2) or 0)
+parse_macos_version = _core.parse_macos_version
 
 
 def host_supports_macos_minos(host: HostInfo, minos: tuple[int, int] | None) -> bool:
@@ -5717,6 +4689,50 @@ def _wsl_system_rocm_lib_dirs() -> list[str]:
     return out
 
 
+def _bundled_hip_present(binary_dir: str) -> bool:
+    if not binary_dir:
+        return False
+    try:
+        # Glob the version suffix (libggml-hip.so, .so.0, .so.0.11.1) the same
+        # way the installer's runtime health check matches libggml-hip.so*.
+        return any(Path(str(binary_dir)).glob("libggml-hip.so*"))
+    except OSError:
+        return False
+
+
+def _native_linux_system_rocm_lib_dirs(binary_dir: str = "") -> list[str]:
+    # UNSLOTH_LLAMA_NO_SYSTEM_ROCM=1 keeps the bundled runtime (opt-out).
+    if os.environ.get("UNSLOTH_LLAMA_NO_SYSTEM_ROCM") == "1":
+        return []
+    if sys.platform != "linux" or os.path.exists("/dev/dxg"):
+        return []
+    if not os.path.exists("/dev/kfd"):
+        return []
+    if not _bundled_hip_present(binary_dir):
+        return []
+    # Env-configured ROCm root first; /opt/rocm only as a fallback so a stale
+    # /opt/rocm doesn't shadow the driver-matching install these vars point at.
+    candidates = []
+    for var in ("HIP_PATH", "HIP_PATH_57", "ROCM_PATH"):
+        val = os.environ.get(var)
+        if val:
+            candidates.append(val)
+    candidates.append("/opt/rocm")
+    out: list[str] = []
+    seen: set[str] = set()
+    for base in candidates:
+        for lib_sub in ("lib", "lib64"):
+            d = os.path.join(base, lib_sub)
+            if d in seen:
+                continue
+            seen.add(d)
+            if os.path.exists(os.path.join(d, "libhsa-runtime64.so")) or os.path.exists(
+                os.path.join(d, "libhsa-runtime64.so.1")
+            ):
+                out.append(d)
+    return out
+
+
 # Secrets a downloaded llama.cpp binary never needs; keep them out of binary_env().
 # The installer's own API calls read os.environ directly, so auth is unaffected.
 _SECRET_ENV_EXACT_NAMES = frozenset(
@@ -5877,6 +4893,11 @@ def binary_env(
         if _wsl_rocm:
             ld_dirs = [*_wsl_rocm, *ld_dirs]
             env.setdefault("HSA_ENABLE_DXG_DETECTION", "1")
+        # Native Linux AMD: system ROCm libs before the bundle's bundled HIP
+        # runtime, which can be incompatible with the host amdkfd driver.
+        _native_rocm = _native_linux_system_rocm_lib_dirs(str(binary_path.parent))
+        if _native_rocm:
+            ld_dirs = [*_native_rocm, *ld_dirs]
         existing = [part for part in env.get("LD_LIBRARY_PATH", "").split(os.pathsep) if part]
         env["LD_LIBRARY_PATH"] = os.pathsep.join(dedupe_existing_dirs([*ld_dirs, *existing]))
     elif host.is_macos:
@@ -6320,7 +5341,7 @@ def _linux_published_attempts(host: HostInfo, bundle: PublishedReleaseBundle) ->
     from asset names."""
     attempts: list[AssetChoice] = []
     if host.has_usable_nvidia:
-        # Prefer the cudart major Studio loads at runtime (torch's bundled
+        # Prefer the cudart major Unsloth loads at runtime (torch's bundled
         # libcudart), not the newest detected on disk. Without this a stray
         # cuda13 runtime outranks the torch cuda12 the binary links against.
         torch_preference = detect_torch_cuda_runtime_preference(host)
@@ -6450,6 +5471,7 @@ def write_prebuilt_metadata(
     choice: AssetChoice,
     approved_checksums: ApprovedReleaseChecksums,
     prebuilt_fallback_used: bool,
+    force_cpu: bool = False,
 ) -> None:
     source_asset_name, source_sha256 = selected_source_archive_metadata(
         approved_checksums,
@@ -6474,6 +5496,10 @@ def write_prebuilt_metadata(
         "release_tag": release_tag,
         "published_repo": approved_checksums.repo,
         "asset": choice.name,
+        # True only for a deliberate CPU choice (--force-cpu). The updater re-asserts it
+        # so a forced CPU install is not re-routed to a GPU bundle (#7213). An automatic
+        # --cpu-fallback (e.g. arm64 GPU-build recovery) stays False so it can heal to GPU.
+        "force_cpu": force_cpu,
         "asset_sha256": choice.expected_sha256,
         "source": choice.source_label,
         # Binary-side repo/tag for non-fork sources (e.g. the ggml-org upstream
@@ -6501,6 +5527,24 @@ def write_prebuilt_metadata(
     (install_dir / "UNSLOTH_PREBUILT_INFO.json").write_text(json.dumps(metadata, indent = 2) + "\n")
 
 
+def sync_marker_force_cpu(install_dir: Path, persist_force_cpu: bool) -> None:
+    """Sync only the force_cpu flag of an existing marker when the resolved bundle is
+    unchanged, so the install is skipped without a full metadata rewrite. A deliberate
+    --force-cpu on top of a naturally installed CPU bundle (same asset) must still be
+    recorded, else the updater will not re-assert it and can re-route the install to a
+    GPU/Vulkan bundle that revives the crash (#7213)."""
+    marker_path = install_dir / "UNSLOTH_PREBUILT_INFO.json"
+    try:
+        marker = json.loads(marker_path.read_text())
+    except (OSError, ValueError):
+        return
+    if not isinstance(marker, dict) or bool(marker.get("force_cpu")) == persist_force_cpu:
+        return
+    marker["force_cpu"] = persist_force_cpu
+    marker_path.write_text(json.dumps(marker, indent = 2) + "\n")
+    log(f"existing install reused; recorded force_cpu={persist_force_cpu} from this run")
+
+
 def expected_install_fingerprint(
     *,
     llama_tag: str,
@@ -6551,6 +5595,52 @@ def load_prebuilt_metadata(install_dir: Path) -> dict[str, Any] | None:
     return payload
 
 
+def default_managed_llama_dir() -> Path:
+    """The managed llama.cpp install root, mirroring setup.sh and the updater:
+    the UNSLOTH_LLAMA_CPP_PATH override, else <custom studio home>/llama.cpp,
+    else the legacy ~/.unsloth/llama.cpp."""
+    override = (os.environ.get("UNSLOTH_LLAMA_CPP_PATH") or "").strip()
+    if override:
+        return Path(override).expanduser()
+    home = (os.environ.get("UNSLOTH_STUDIO_HOME") or os.environ.get("STUDIO_HOME") or "").strip()
+    if home:
+        root = Path(home).expanduser()
+        legacy_studio = Path.home() / ".unsloth" / "studio"
+        try:
+            is_legacy = root.resolve() == legacy_studio.resolve()
+        except (OSError, ValueError):
+            is_legacy = root == legacy_studio
+        if not is_legacy:
+            return root / "llama.cpp"
+    return Path.home() / ".unsloth" / "llama.cpp"
+
+
+def installed_llama_runtime(install_dir: Path | None = None) -> tuple[Path, str, str] | None:
+    """The completed managed llama.cpp prebuilt install, or None.
+
+    Returns (runtime bin dir holding the ggml libraries, installed release tag,
+    bundle profile). install_whisper_prebuilt.py reads this to pair slim whisper
+    bundles with the ggml runtime the llama install already provides; tests pass
+    an explicit ``install_dir``.
+    """
+    root = install_dir if install_dir is not None else default_managed_llama_dir()
+    metadata = load_prebuilt_metadata(root)
+    if metadata is None:
+        return None
+    release_tag = metadata.get("release_tag")
+    if not isinstance(release_tag, str) or not release_tag:
+        return None
+    # Same layout install_runtime_dir() derives; a marker on disk always
+    # belongs to this host, so the running OS picks the variant.
+    bin_dir = root / "build" / "bin"
+    if os.name == "nt":
+        bin_dir = bin_dir / "Release"
+    if not bin_dir.is_dir():
+        return None
+    profile = metadata.get("bundle_profile")
+    return bin_dir, release_tag, profile if isinstance(profile, str) else ""
+
+
 def runtime_payload_health_groups(choice: AssetChoice) -> list[list[str]]:
     if choice.install_kind in {"linux-cpu", "linux-arm64"}:
         return [
@@ -6746,6 +5836,7 @@ def validate_prebuilt_choice(
     approved_checksums: ApprovedReleaseChecksums,
     prebuilt_fallback_used: bool,
     quantized_path: Path,
+    force_cpu: bool = False,
 ) -> tuple[Path, Path]:
     source_repo, source_ref, source_archive, exact_source = preferred_source_archive(
         approved_checksums, llama_tag
@@ -6786,15 +5877,17 @@ def validate_prebuilt_choice(
         choice = choice,
         approved_checksums = approved_checksums,
         prebuilt_fallback_used = prebuilt_fallback_used,
+        force_cpu = force_cpu,
     )
     # Hashless external prebuilts are not in the approved-sha256
     # manifest and rely on the functional smoke test as their only integrity gate,
     # so they are always validated. For an approved bundle the sha256 manifest
     # already proves integrity, so its runtime smoke test -- a cold CUDA-JIT pass
     # costing minutes on Blackwell sm_100 -- is gated behind
-    # _RUN_STAGED_PREBUILT_VALIDATION, disabled for now. The check and the
-    # source-build fallback it triggers are kept intact; flip the flag to restore it.
-    if choice.expected_sha256 is None or _RUN_STAGED_PREBUILT_VALIDATION:
+    # staged_validation_enabled() (constant or UNSLOTH_LLAMA_STAGED_VALIDATION),
+    # disabled for now. The check and the source-build fallback it triggers are
+    # kept intact; flip the flag / env to restore it (#5854).
+    if choice.expected_sha256 is None or staged_validation_enabled():
         validate_quantize(
             quantize_path,
             probe_path,
@@ -6815,6 +5908,49 @@ def validate_prebuilt_choice(
     return server_path, quantize_path
 
 
+def validate_existing_install(
+    install_dir: Path,
+    *,
+    install_kind: str | None = None,
+    host: HostInfo | None = None,
+) -> None:
+    """Run the staged smoke test against an already-built llama.cpp tree (#5854).
+
+    Used by setup.sh after a GPU source build when ``UNSLOTH_LLAMA_STAGED_VALIDATION``
+    is set. Raises ``PrebuiltFallback`` on failure so the caller can retry CPU.
+    """
+    host = host or detect_host()
+    bin_dir = install_dir / "build" / "bin"
+    server_name = "llama-server.exe" if host.is_windows else "llama-server"
+    quantize_name = "llama-quantize.exe" if host.is_windows else "llama-quantize"
+    server_path = bin_dir / server_name
+    quantize_path = bin_dir / quantize_name
+    if not server_path.is_file():
+        raise PrebuiltFallback(f"llama-server not found at {server_path}")
+
+    with tempfile.TemporaryDirectory(prefix = "unsloth-llama-source-validate-") as tmp:
+        work_dir = Path(tmp)
+        probe_path = work_dir / "stories260K.gguf"
+        quantized_path = work_dir / "stories260K-q4.gguf"
+        download_validation_model(probe_path, validation_model_cache_path(install_dir))
+        if quantize_path.is_file():
+            validate_quantize(
+                quantize_path,
+                probe_path,
+                quantized_path,
+                install_dir,
+                host,
+            )
+        validate_server(
+            server_path,
+            probe_path,
+            host,
+            install_dir,
+            install_kind = install_kind,
+        )
+    log(f"staged source-build validation succeeded for {install_dir}")
+
+
 def validate_prebuilt_attempts(
     attempts: Iterable[AssetChoice],
     host: HostInfo,
@@ -6828,6 +5964,7 @@ def validate_prebuilt_attempts(
     approved_checksums: ApprovedReleaseChecksums,
     initial_fallback_used: bool = False,
     existing_install_dir: Path | None = None,
+    force_cpu: bool = False,
 ) -> tuple[AssetChoice, Path, bool]:
     attempt_list = list(attempts)
     if not attempt_list:
@@ -6880,6 +6017,7 @@ def validate_prebuilt_attempts(
                 approved_checksums = approved_checksums,
                 prebuilt_fallback_used = tried_fallback,
                 quantized_path = quantized_path,
+                force_cpu = force_cpu,
             )
         except Exception as exc:
             remove_tree(staging_dir)
@@ -6939,8 +6077,8 @@ def _route_to_vulkan_prebuilt(
     """Point a Vulkan-capable host at the upstream ggml-org Vulkan prebuilt.
 
     The unsloth published repo ships only CUDA/ROCm/CPU assets, so Vulkan comes
-    from UPSTREAM_REPO. Two triggers route here, both suppressed under
-    --cpu-fallback (the explicit "give me CPU" last resort wins):
+    from UPSTREAM_REPO. Two triggers route here, both suppressed when a CPU flag
+    (--cpu-fallback or --force-cpu, folded into force_cpu) wins:
       * UNSLOTH_FORCE_VULKAN forces Vulkan over the detected CUDA/ROCm backend;
       * an auto-detected Intel GPU with NO physical NVIDIA/ROCm -- the purpose
         of the has_intel_gpu probe, since the fork manifest ships no Vulkan asset.
@@ -7020,8 +6158,11 @@ def install_prebuilt(
     override_has_rocm: bool = False,
     override_rocm_gfx: str | None = None,
     force_cpu: bool = False,
+    persist_force_cpu: bool = False,
     instruction_cleanup_root: Path | None = None,
 ) -> None:
+    # force_cpu drops GPU detection (mechanism, both --cpu-fallback and --force-cpu);
+    # persist_force_cpu records the deliberate choice so the updater re-asserts it.
     host = detect_host()
     host = _apply_host_overrides(
         host,
@@ -7072,6 +6213,9 @@ def install_prebuilt(
                         "existing llama.cpp install already matches selected release "
                         f"{current.release_tag} upstream_tag={current.llama_tag}; skipping download and install"
                     )
+                    # Reused bundle is unchanged, but a fresh --force-cpu still must be
+                    # recorded so the updater re-asserts it (#7213).
+                    sync_marker_force_cpu(install_dir, persist_force_cpu)
                     return
             with tempfile.TemporaryDirectory(prefix = "unsloth-llama-prebuilt-") as tmp:
                 work_dir = Path(tmp)
@@ -7092,6 +6236,7 @@ def install_prebuilt(
                                 "existing llama.cpp install already matches fallback release "
                                 f"{plan.release_tag} upstream_tag={plan.llama_tag}; skipping reinstall"
                             )
+                            sync_marker_force_cpu(install_dir, persist_force_cpu)
                             return
                     log(
                         "selected "
@@ -7112,6 +6257,8 @@ def install_prebuilt(
                             initial_fallback_used = release_index > 0,
                             # Skip is gated per-attempt inside, so pass the dir always.
                             existing_install_dir = install_dir,
+                            # Persist only the deliberate choice, not a transient fallback.
+                            force_cpu = persist_force_cpu,
                         )
                     except ExistingInstallSatisfied:
                         return
@@ -7209,8 +6356,21 @@ def parse_args() -> argparse.Namespace:
         default = False,
         help = (
             "Select the CPU prebuilt for this OS/arch even when a GPU is present. "
-            "setup.sh uses this as a last resort for arm64 Linux GPU hosts whose "
-            "source build failed (no arm64 CUDA prebuilt exists anywhere)."
+            "Automatic/transient: setup.sh uses this as a last resort for arm64 Linux "
+            "GPU hosts whose source build failed. Does NOT persist, so a later update "
+            "heals back to a GPU bundle once one is available (#6097). Use --force-cpu "
+            "for a deliberate CPU-only choice that survives updates."
+        ),
+    )
+    parser.add_argument(
+        "--force-cpu",
+        action = "store_true",
+        default = False,
+        help = (
+            "Deliberate CPU-only install (UNSLOTH_LLAMA_CPP_BACKEND=cpu). Drops GPU "
+            "detection like --cpu-fallback but also records force_cpu in the marker, so "
+            "the in-app updater re-asserts CPU and never re-routes to a GPU/Vulkan "
+            "bundle that would revive the Intel iGPU crash (#7213)."
         ),
     )
     resolve_group = parser.add_mutually_exclusive_group()
@@ -7245,6 +6405,24 @@ def parse_args() -> argparse.Namespace:
             "fork). Use --output-format json."
         ),
     )
+    resolve_group.add_argument(
+        "--validate-install",
+        metavar = "DIR",
+        help = (
+            "Run the staged llama-server smoke test against an existing build "
+            "tree (setup.sh source-build post-check, #5854). Exit 2 on failure. "
+            "Normally gated by UNSLOTH_LLAMA_STAGED_VALIDATION; this flag always "
+            "runs the check."
+        ),
+    )
+    parser.add_argument(
+        "--install-kind",
+        default = None,
+        help = (
+            "Install kind for --validate-install GPU offload (e.g. linux-cuda, "
+            "linux-rocm, macos-arm64). When omitted, host detection decides."
+        ),
+    )
     parser.add_argument(
         "--output-format",
         choices = ("plain", "json"),
@@ -7281,6 +6459,17 @@ def emit_resolver_output(payload: dict[str, Any], *, output_format: str) -> None
 
 def main() -> int:
     args = parse_args()
+    if args.validate_install is not None:
+        try:
+            validate_existing_install(
+                Path(args.validate_install),
+                install_kind = args.install_kind,
+            )
+        except PrebuiltFallback as exc:
+            print(str(exc), file = sys.stderr)
+            raise SystemExit(EXIT_FALLBACK) from exc
+        return EXIT_SUCCESS
+
     if args.resolve_llama_tag is not None:
         resolved = resolve_requested_llama_tag(
             args.resolve_llama_tag,
@@ -7333,16 +6522,19 @@ def main() -> int:
         # Host-aware "is a prebuilt available" probe, no download. Every host now
         # plans against the fork (args.published_repo defaults to it); an explicit
         # --published-repo overrides. PrebuiltFallback == source build.
+        # Both flags drop GPU detection; --force-cpu additionally persists (install
+        # path only). The probe only needs the mechanism, so OR them.
+        _cpu_mechanism = args.cpu_fallback or args.force_cpu
         host = _apply_host_overrides(
             detect_host(),
             override_has_rocm = args.has_rocm,
             override_rocm_gfx = args.rocm_gfx,
-            force_cpu = args.cpu_fallback,
+            force_cpu = _cpu_mechanism,
         )
         # Same Vulkan routing the install path applies, so the probe's answer
         # matches what would install (an Intel/forced-Vulkan host -> upstream).
         host, repo, release_tag = _route_to_vulkan_prebuilt(
-            host, args.published_repo, args.published_release_tag or "", force_cpu = args.cpu_fallback
+            host, args.published_repo, args.published_release_tag or "", force_cpu = _cpu_mechanism
         )
         try:
             _requested, plans = resolve_simple_install_release_plans(
@@ -7380,7 +6572,10 @@ def main() -> int:
         published_release_tag = args.published_release_tag or "",
         override_has_rocm = args.has_rocm,
         override_rocm_gfx = args.rocm_gfx,
-        force_cpu = args.cpu_fallback,
+        # Both drop GPU detection; only --force-cpu (deliberate) is recorded so the
+        # updater re-asserts it. --cpu-fallback stays transient and heals to GPU.
+        force_cpu = args.cpu_fallback or args.force_cpu,
+        persist_force_cpu = args.force_cpu,
         instruction_cleanup_root = install_arg.absolute(),
     )
     return EXIT_SUCCESS
diff --git a/studio/install_node_prebuilt.py b/studio/install_node_prebuilt.py
index 4038216eef..fb40634e95 100644
--- a/studio/install_node_prebuilt.py
+++ b/studio/install_node_prebuilt.py
@@ -6,7 +6,7 @@
 
 Downloads an official Node.js archive from nodejs.org into an isolated
 ``<UNSLOTH_HOME>/node`` and never touches the system Node/npm. Pinning Node 24+
-LTS clears the Studio frontend build floor (Vite 8: Node ^20.19 || >=22.12,
+LTS clears the Unsloth frontend build floor (Vite 8: Node ^20.19 || >=22.12,
 npm >= 11) with the npm it bundles.
 
 Archives are verified against sha256 digests pinned in ``node_prebuilt_pins.json``
diff --git a/studio/install_python_stack.py b/studio/install_python_stack.py
index 19c492deaa..a29ba0d7e5 100644
--- a/studio/install_python_stack.py
+++ b/studio/install_python_stack.py
@@ -44,11 +44,10 @@ IS_MAC_INTEL = IS_MACOS and platform.machine() == "x86_64"
 IS_MAC_ARM = IS_MACOS and platform.machine() == "arm64"
 IS_LINUX = sys.platform.startswith("linux")
 
-# DiskPart-prompt suppression: amd-smi auto-elevates on Windows, popping a
-# UAC/DiskPart prompt mid-install. This installer only spawns probes and pip/uv
-# (none need elevation), so set __COMPAT_LAYER=RunAsInvoker process-wide -- every
-# amd-smi subprocess then runs un-elevated, no per-call guard needed. setup.ps1
-# keeps per-call guards since it ALSO spawns winget installers that need elevation.
+# amd-smi auto-elevates on Windows (UAC/DiskPart prompt mid-install). This installer
+# only spawns probes and pip/uv (no elevation), so set __COMPAT_LAYER=RunAsInvoker
+# process-wide; amd-smi then runs un-elevated. setup.ps1 keeps per-call guards (it
+# also spawns winget installers that need elevation).
 if IS_WINDOWS:
     os.environ.setdefault("__COMPAT_LAYER", "RunAsInvoker")
 # torchcodec ships wheels only for manylinux_2_28_x86_64, macosx_12_0_arm64,
@@ -74,6 +73,35 @@ _ROCM_TORCH_INDEX: dict[tuple[int, int], str] = {
     (6, 0): "rocm6.0",
 }
 
+
+def _generic_pytorch_rocm_tag(ver: tuple[int, int]) -> str | None:
+    """Newest download.pytorch.org rocmX.Y tag for a host ROCm version."""
+    return next(
+        (t for (maj, mn), t in sorted(_ROCM_TORCH_INDEX.items(), reverse = True) if ver >= (maj, mn)),
+        None,
+    )
+
+
+_ROCM_ARCH_INDEX_FLOOR = (7, 13)  # AMD per-arch index ships torch 2.11+rocm7.13
+
+
+def _strix_needs_amd_arch_index(ver: tuple[int, int]) -> bool:
+    """True when Strix's generic pytorch.org index sits below the AMD arch floor
+    (7.13), so gfx1150/1151 must use repo.amd.com's per-arch wheels. Mirrors
+    install.sh _rocm_leaf_below: reroute any generic rocm index (6.x/7.0/7.2 and a
+    future 7.3+), never one at/above the floor."""
+    key = next((k for k in sorted(_ROCM_TORCH_INDEX, reverse = True) if ver >= k), None)
+    return key is not None and key < _ROCM_ARCH_INDEX_FLOOR
+
+
+# AMD per-arch leaves needing the torch 2.11 floor (the _grouped_mm <2.11 bug).
+# Mirrors *FloorMap in install.ps1 / setup.ps1; other arches ship <2.11 and stay bare.
+_ROCM_GFX_TORCH211_LEAVES: frozenset[str] = frozenset({"gfx120x-all", "gfx1151", "gfx1150"})
+
+# pytorch.org rocmX.Y indexes KNOWN to ship torch 2.11 (rocm7.2 only today); don't
+# floor an unknown newer rocm speculatively. Match install.sh / setup.ps1 / install.ps1.
+_ROCM_KNOWN_TORCH211_VERSIONS: frozenset[tuple[int, int]] = frozenset({(7, 2)})
+
 # Per-tag pip specs; rocm7.2 ships torch 2.11.0 (older tags cap at 2.10.x).
 _ROCM_TORCH_PKG_SPECS: dict[str, tuple[str, str, str]] = {
     "rocm7.2": (
@@ -81,18 +109,16 @@ _ROCM_TORCH_PKG_SPECS: dict[str, tuple[str, str, str]] = {
         "torchvision>=0.26.0,<0.27.0",
         "torchaudio>=2.11.0,<2.12.0",
     ),
-    # Default for rocm7.1 and earlier: torch 2.x below 2.11
+    # rocm7.1 and earlier: torch 2.x below 2.11
     "_default": (
         "torch>=2.4,<2.11.0",
         "torchvision>=0.19,<0.26.0",
         "torchaudio>=2.4,<2.11.0",
     ),
 }
-# Windows AMD per-arch companion pins for the repo.amd.com index, mirroring the
-# install.ps1 / setup.ps1 floor maps (gfx120X and Strix Halo/Point use the rocm7.2
-# torch 2.11 trio). Pinning the companions keeps AMD's per-arch index -- which
-# publishes each independently -- from resolving an ABI-mismatched one. Unlisted
-# arches have no published floor, so stay bare. Bump with the PS maps at 2.12.x.
+# Windows AMD per-arch companion pins for the repo.amd.com index (mirrors the install.ps1 /
+# setup.ps1 floor maps): pinning stops the per-arch index (each published independently) from
+# resolving an ABI-mismatched companion. Unlisted arches have no floor, so stay bare.
 _WINDOWS_ROCM_TORCH_PKG_SPECS: dict[str, tuple[str, str, str]] = {
     "gfx1201": _ROCM_TORCH_PKG_SPECS["rocm7.2"],
     "gfx1200": _ROCM_TORCH_PKG_SPECS["rocm7.2"],
@@ -103,19 +129,79 @@ _PYTORCH_WHL_BASE = (
     os.environ.get("UNSLOTH_PYTORCH_MIRROR") or "https://download.pytorch.org/whl"
 ).rstrip("/")
 
-# CUDA torch repair specs (see _ensure_cuda_torch). torch 2.11 is allowed: its
-# torchao 0.17 cpp kernels load cleanly (0.16 crashes on cu130), and the flash-attn
-# / causal-conv1d / mamba torch2.10 wheels load and pass their upstream suites on
-# 2.11 (see wheel_utils._PREBUILT_WHEEL_TORCH_MM). torchvision/torchaudio are pinned
-# (not bare) because the install uses an exclusive --index-url (no PyPI fallback), so
-# a bare name could resolve one built against a different torch major (e.g. 0.27 for
-# torch 2.12) and fail at runtime with an ABI mismatch.
+
+def _strip_index_url_credentials(url: str) -> str:
+    """Strip userinfo (user:password@) AND query/fragment from a wheel index URL.
+
+    An authenticated pin must not leak credentials in printed output; query/fragment
+    may hold tokens and aren't part of the PEP 503 index identity. Host/path stay
+    exact. MUST match install.sh / setup.ps1 / install.ps1.
+    """
+    scheme, sep, rest = url.partition("://")
+    if not sep:
+        return url
+    rest = rest.split("?", 1)[0].split("#", 1)[0]  # drop query / fragment
+    authority, slash, tail = rest.partition("/")
+    host = authority.rpartition("@")[2]  # drop user:pass@ userinfo
+    return f"{scheme}://{host}{slash}{tail}"
+
+
+_URL_USERINFO_RE = re.compile(r"(https?://)[^/@\s`]+@")
+_URL_QUERY_VALUE_RE = re.compile(r"([?&][^=\s&`]+)=[^&#\s`]+")
+# URL-anchored so a bare "#..." (a shell comment in tool output) is never touched.
+_URL_FRAGMENT_RE = re.compile(r"(https?://[^\s`#]+)#[^\s`]+")
+
+
+def _redact_install_output(output: "bytes | str") -> str:
+    """Redact index-URL credentials (userinfo + query values + fragments) from captured
+    installer output before printing. uv/pip failure text embeds the failing --index-url
+    verbatim, which can carry a user:token@, ?token= or #token= secret. MUST match
+    install.sh / setup.ps1 / install.ps1's output sanitizers."""
+    text = output.decode(errors = "replace") if isinstance(output, bytes) else output
+    text = _URL_USERINFO_RE.sub(r"\1<redacted>@", text)
+    text = _URL_QUERY_VALUE_RE.sub(r"\1=<redacted>", text)
+    return _URL_FRAGMENT_RE.sub(r"\1#<redacted>", text)
+
+
+def _trim_index_path_slashes(url: str) -> str:
+    """Trim trailing slashes from the URL PATH only, preserving ?query / #fragment. A
+    whole-URL rstrip("/") corrupts a token that ends in "/" (e.g. base64 ...abc/) and a
+    single-slash strip leaves .../cu128// classifying as an empty leaf. MUST match
+    install.sh / setup.ps1 / install.ps1."""
+    value = url.strip()
+    match = re.fullmatch(r"([^?#]*)([?#].*)?", value)
+    if match is None:
+        return value.rstrip("/")
+    return match.group(1).rstrip("/") + (match.group(2) or "")
+
+
+def _torch_index_leaf(url: str) -> str:
+    """Final URL path segment, lowercased, query/fragment removed first.
+
+    So a token-authenticated pin (.../cu128?token=x) classifies as cu128 (a raw leaf
+    keeps the query, never equals the +cu128 tag, and force-reinstalls every update).
+    CLASSIFICATION only; the install keeps the full URL. MUST match install.sh /
+    setup.ps1 / install.ps1.
+    """
+    path = url.split("?", 1)[0].split("#", 1)[0]
+    return path.rstrip("/").rsplit("/", 1)[-1].lower()
+
+
+# CUDA torch repair specs (see _ensure_cuda_torch). torch 2.11 is allowed (torchao
+# 0.17 cpp loads cleanly, and the flash-attn/causal-conv1d/mamba wheels pass on 2.11).
+# torchvision/torchaudio are pinned (not bare) so the exclusive --index-url can't
+# resolve one built against a different torch major -> ABI mismatch.
 _CUDA_TORCH_PKG_SPEC: tuple[str, str, str] = (
     "torch>=2.4,<2.12.0",
     "torchvision>=0.19,<0.27.0",
     "torchaudio>=2.4,<2.12.0",
 )
 
+# CPU torch repair specs (see _ensure_cpu_torch). Same bounds/reasoning as CUDA: the
+# /cpu index also serves newer torch, so a bare trio could resolve out of range or ABI-
+# mismatched.
+_CPU_TORCH_PKG_SPEC: tuple[str, str, str] = _CUDA_TORCH_PKG_SPEC
+
 # torchao's cpp extensions are pinned to ONE torch release AND CUDA major. A torch
 # mismatch just skips the cpp kernels (slow Python fallback); a CUDA mismatch fails
 # to import ("libcudart.so.12: cannot open shared object file"). The torch pin is a
@@ -287,6 +373,13 @@ _GFX_TO_AMD_INDEX_ARCH: dict[str, str] = {
     "gfx1102": "gfx110X-all",  # RDNA 3
     "gfx1101": "gfx110X-all",
     "gfx1100": "gfx110X-all",
+    "gfx1036": "gfx103X-all",
+    "gfx1035": "gfx103X-all",  # RDNA 2 (RX 6000)
+    "gfx1034": "gfx103X-all",
+    "gfx1033": "gfx103X-all",
+    "gfx1032": "gfx103X-all",
+    "gfx1031": "gfx103X-all",
+    "gfx1030": "gfx103X-all",
     "gfx90a": "gfx90a",
     "gfx908": "gfx908",  # MI200/MI100
 }
@@ -408,9 +501,8 @@ def _detect_rocm_version() -> tuple[int, int] | None:
         try:
             with open(path) as fh:
                 parts = fh.read().strip().split("-")[0].split(".")
-            # Explicit length guard so we don't rely on the broad except
-            # below to swallow IndexError when the version file has a
-            # single component (e.g. "6\n" on a partial install).
+            # Explicit length guard: don't rely on the broad except below to
+            # swallow IndexError on a single-component version (e.g. "6\n").
             if len(parts) >= 2:
                 return int(parts[0]), int(parts[1])
         except Exception:
@@ -455,11 +547,10 @@ def _detect_rocm_version() -> tuple[int, int] | None:
         except Exception:
             pass
 
-    # Distro package-manager fallbacks. Package-managed ROCm installs can
-    # expose GPUs via rocminfo/amd-smi but lack /opt/rocm/.info/version and
-    # hipconfig, so probe dpkg (Debian/Ubuntu) and rpm (RHEL/Fedora/SUSE)
-    # for the rocm-core version. Matches install.sh::get_torch_index_url so
-    # `unsloth studio update` behaves like a fresh `curl | sh` install.
+    # Distro package-manager fallbacks: package-managed ROCm can expose GPUs via
+    # rocminfo/amd-smi but lack /opt/rocm/.info/version and hipconfig, so probe
+    # dpkg (Debian/Ubuntu) and rpm (RHEL/Fedora/SUSE) for the rocm-core version.
+    # Matches install.sh::get_torch_index_url so `studio update` == fresh install.
     for cmd in (
         ["dpkg-query", "-W", "-f=${Version}\n", "rocm-core"],
         ["rpm", "-q", "--qf", "%{VERSION}\n", "rocm-core"],
@@ -561,11 +652,10 @@ def _detect_windows_gfx_arch() -> str | None:
                 stderr = subprocess.DEVNULL,
                 timeout = 10,
             )
-            # Accept partial output even when hipinfo crashes (e.g. exit code
-            # 0xC0000005 / STATUS_ACCESS_VIOLATION on some RDNA 4 hosts): if
-            # gcnArchName is present in stdout the device was enumerated before
-            # the crash, so the arch is trustworthy.  Ignoring it causes a
-            # silent CPU PyTorch fallback (issue #6043).
+            # Accept partial output even when hipinfo crashes (e.g. 0xC0000005 /
+            # STATUS_ACCESS_VIOLATION on some RDNA 4 hosts): a gcnArchName in stdout
+            # means the device was enumerated pre-crash, so the arch is trustworthy.
+            # Ignoring it causes a silent CPU PyTorch fallback (issue #6043).
             text = result.stdout.decode(errors = "replace")
             # findall gets every gcnArchName line so multi-GPU hosts are
             # enumerable and HIP_VISIBLE_DEVICES selects correctly.
@@ -650,8 +740,8 @@ def _detect_windows_gfx_arch() -> str | None:
 _WIN_GPU_NAME_ARCH_TABLE: "list[tuple[str, str]]" = [
     (r"9070 XT|9080", "gfx1201"),  # RDNA 4 (Radeon RX 9070 XT / 9080)
     (r"9070|9060", "gfx1200"),  # RDNA 4 (Radeon RX 9070 / 9060)
-    # RDNA 3.5 (Strix Halo: Radeon 8060S/8050S/8040S iGPU, Ryzen AI Max+)
-    (r"8060S|8050S|8040S|Strix Halo|Ryzen AI Max|AI Max", "gfx1151"),
+    # RDNA 3.5 (Strix Halo + Gorgon Halo: Radeon 8065S/8060S/8050S/8040S iGPU, Ryzen AI Max / Max+)
+    (r"8065S|8060S|8050S|8040S|Strix Halo|Ryzen AI Max|AI Max", "gfx1151"),
     # RDNA 3.5 (Strix/Krackan Point: Radeon 890M/880M iGPU, Ryzen AI 9 HX 370/375)
     (
         r"890M|880M|860M|840M|Strix Point|Krackan|HX 37[05]|AI 9 HX|AI 9 36[05]"
@@ -679,6 +769,142 @@ def _gfx_arch_from_gpu_name(name: str) -> "str | None":
     return None
 
 
+def _linux_amd_gfx_from_cpuinfo() -> "str | None":
+    """Infer gfx arch from /proc/cpuinfo on integrated AMD APUs (Strix Halo/Point)."""
+    try:
+        text = Path("/proc/cpuinfo").read_text(encoding = "utf-8", errors = "replace")
+    except OSError:
+        return None
+    if re.search(r"Ryzen AI Max|Radeon 80[0-9][05]S|Strix Halo", text, re.IGNORECASE):
+        return "gfx1151"
+    if re.search(
+        r"890M|880M|860M|840M|Strix Point|Krackan|HX 37[05]|AI 9 HX|AI 9 36[05]"
+        r"|AI 7 35[05]|AI 5 34[05]|AI 7 PRO 35|AI 5 33",
+        text,
+        re.IGNORECASE,
+    ):
+        return "gfx1150"
+    return None
+
+
+def _linux_amd_gfx_from_lspci() -> "str | None":
+    """First AMD display-class lspci line mapping to a known gfx arch. A non-AMD
+    controller can enumerate first (Intel/ASPEED before an AMD dGPU), so scan
+    them all. The vendor guard is case-SENSITIVE: a -i "ATI" would match
+    "CorporATIon" on every Intel/NVIDIA line. Whole-line matching also survives
+    the 0000: PCI domain prefix."""
+    lspci = shutil.which("lspci")
+    if not lspci:
+        return None
+    try:
+        result = subprocess.run(
+            [lspci, "-nn"],
+            stdout = subprocess.PIPE,
+            stderr = subprocess.DEVNULL,
+            text = True,
+            timeout = 10,
+        )
+    except Exception:
+        return None
+    if result.returncode != 0:
+        return None
+    for line in result.stdout.splitlines():
+        if not re.search(r"VGA compatible controller|3D controller|Display controller", line, re.I):
+            continue
+        if not re.search(r"AMD|ATI", line):
+            continue
+        arch = _gfx_arch_from_gpu_name(line)
+        if arch:
+            return arch
+    return None
+
+
+def _is_wsl() -> bool:
+    """True on WSL, where the AMD GPU is reached via /dev/dxg (not /dev/kfd)."""
+    if os.path.exists("/dev/dxg"):
+        return True
+    try:
+        with open("/proc/version", encoding = "utf-8", errors = "replace") as fh:
+            return "microsoft" in fh.read().lower()
+    except OSError:
+        return False
+
+
+def _wsl_rocm_runtime_present() -> bool:
+    """librocdxg (the WSL ROCDXG bridge that lets HIP reach the GPU over /dev/dxg)
+    under a ROCm lib dir. Its absence marks a WSL box whose ROCm was never set up."""
+    dirs = ["/opt/rocm/lib", "/opt/rocm/lib64"]
+    dirs += glob.glob("/opt/rocm-*/lib") + glob.glob("/opt/rocm-*/lib64")
+    return any(
+        os.path.exists(os.path.join(d, so))
+        for d in dirs
+        for so in ("librocdxg.so", "librocdxg.so.1")
+    )
+
+
+def _linux_amd_display_device_present() -> bool:
+    """Any AMD (vendor 0x1002) PCI display-class (0x03*) device in sysfs.
+    /proc/cpuinfo leaks the HOST CPU model into VMs/containers that received no
+    AMD GPU, so the CPU-model text alone is not GPU evidence; this is the
+    device-level check (mirrors install.sh _amd_gpu_present_via_pci)."""
+    try:
+        for dev in Path("/sys/bus/pci/devices").iterdir():
+            try:
+                if (dev / "vendor").read_text().strip() != "0x1002":
+                    continue
+                if (dev / "class").read_text().strip().startswith("0x03"):
+                    return True
+            except OSError:
+                continue
+    except OSError:
+        pass
+    return False
+
+
+def _infer_linux_amd_gfx_arch() -> "str | None":
+    """Infer gfx when ROCm runtime is absent but the host is a known AMD arch (unslothai#7301)."""
+    override = (os.environ.get("UNSLOTH_ROCM_GFX_ARCH") or "").strip().lower()
+    if override:
+        return override
+    if _is_wsl():
+        # cpuinfo/lspci see the host APU even on a WSL box whose ROCDXG runtime
+        # was never bootstrapped; inferring there would install per-arch ROCm
+        # wheels into an env that still can't expose the GPU. Skip unless that
+        # runtime is present -- WSL enumerates no PCI display device, so
+        # /dev/dxg + librocdxg IS the GPU evidence there.
+        if not _wsl_rocm_runtime_present():
+            return None
+    elif not _linux_amd_display_device_present():
+        # Native Linux: a VM/container on a Strix host still shows the host CPU
+        # model in /proc/cpuinfo while receiving no AMD GPU, so require an AMD
+        # display device before trusting the CPU-model inference. The lspci
+        # fallback reads the same PCI space and would find nothing here either.
+        return None
+    cpu_gfx = _linux_amd_gfx_from_cpuinfo()
+    if cpu_gfx:
+        return cpu_gfx
+    return _linux_amd_gfx_from_lspci()
+
+
+def _amd_arch_index_url(gfx_arch: str | None) -> str | None:
+    """Return the AMD per-arch pip index URL for a gfx arch (Linux + Windows).
+
+    Windows honors UNSLOTH_ROCM_WINDOWS_MIRROR (via _windows_rocm_index_url);
+    Linux honors UNSLOTH_AMD_ROCM_MIRROR -- the same var install.sh uses -- so a
+    mirrored/air-gapped Linux repair reaches the index install.sh chose rather
+    than falling back to repo.amd.com. Both default to repo.amd.com when unset.
+    """
+    if IS_WINDOWS:
+        return _windows_rocm_index_url(gfx_arch)
+    arch_family = _GFX_TO_AMD_INDEX_ARCH.get(gfx_arch or "")
+    if arch_family is None:
+        return None
+    base = (os.environ.get("UNSLOTH_AMD_ROCM_MIRROR") or "https://repo.amd.com/rocm/whl").rstrip(
+        "/"
+    )
+    return f"{base}/{arch_family}/"
+
+
 def _windows_rocm_index_url(gfx_arch: str | None) -> str | None:
     """Return the AMD pip index URL for the given GPU arch, or None if unsupported."""
     arch_family = _GFX_TO_AMD_INDEX_ARCH.get(gfx_arch or "")
@@ -706,9 +932,8 @@ def _detect_bnb_rocm_dll_ver() -> str | None:
             m = re.search(r"libbitsandbytes_rocm(\d+)\.dll", os.path.basename(dll))
             if m:
                 all_vers.append(m.group(1))
-    # Pick the highest numeric suffix so e.g. "713" wins over "72" when both
-    # variants are present. Glob order is not guaranteed, so always sort
-    # rather than stopping at the first match.
+    # Highest numeric suffix wins (e.g. "713" over "72"); glob order is not
+    # guaranteed, so sort rather than take the first match.
     return max(all_vers, key = lambda v: int(v)) if all_vers else None
 
 
@@ -825,17 +1050,14 @@ def _has_rocm_gpu() -> bool:
         if result.returncode == 0 and result.stdout.strip():
             if check_fn(result.stdout):
                 return True
-    # sysfs KFD topology fallback (Linux only) -- matches install.sh's
-    # runtime-only detection. On minimal package-managed installs (no
-    # rocminfo / no amd-smi tools), the kernel exposes AMD GPUs via
-    # /sys/class/kfd so `studio update` can still detect and repair.
+    # sysfs KFD topology fallback (Linux only) -- matches install.sh's runtime-only
+    # detection. On minimal package-managed installs (no rocminfo / amd-smi), the
+    # kernel exposes AMD GPUs via /sys/class/kfd so `studio update` can still repair.
     #
-    # Guard: reject any KFD node whose properties file reports a non-AMD
-    # vendor. With the NVIDIA open kernel module (driver 560+), NVIDIA GPUs
-    # can register KFD topology nodes with a non-zero gpu_id; those nodes
-    # have vendor_id 4318 (0x10DE) rather than the AMD value 4098 (0x1002).
-    # Without this check the fallback returns True on NVIDIA-only systems,
-    # causing _ensure_rocm_torch to install ROCm wheels on NVIDIA hardware.
+    # Guard: reject any KFD node whose properties file reports a non-AMD vendor. The
+    # NVIDIA open kernel module (driver 560+) registers KFD nodes with a non-zero
+    # gpu_id and vendor_id 4318 (0x10DE), not the AMD 4098 (0x1002); without this
+    # check the fallback returns True on NVIDIA-only hosts, installing ROCm wheels.
     if sys.platform != "win32":
         try:
             kfd_nodes = "/sys/class/kfd/kfd/topology/nodes"
@@ -849,12 +1071,10 @@ def _has_rocm_gpu() -> bool:
                         continue
                     if not gpu_id or gpu_id == "0":  # gpu_id 0 = CPU node
                         continue
-                    # Require AMD vendor_id 4098 (0x1002) in the properties file.
-                    # KFD properties files exist on every kernel that exposes
-                    # /sys/class/kfd, so absence of the file means we cannot
-                    # confirm AMD ownership -- skip the node rather than risk a
-                    # false positive (e.g. NVIDIA open driver KFD nodes that
-                    # lack a properties file on some kernel versions).
+                    # Require AMD vendor_id 4098 (0x1002). KFD properties files exist
+                    # on every kernel exposing /sys/class/kfd, so a missing file means
+                    # AMD ownership is unconfirmed -- skip the node rather than risk a
+                    # false positive (e.g. NVIDIA open-driver KFD nodes lacking it).
                     props_path = os.path.join(kfd_nodes, entry, "properties")
                     try:
                         with open(props_path) as fh:
@@ -981,13 +1201,10 @@ def _install_bnb_windows_rocm() -> bool:
     )
     if not _ok:
         return False
-    # After install: detect the actual ROCm DLL suffix shipped in the wheel and
-    # set BNB_ROCM_VERSION so bitsandbytes loads the correct DLL regardless of
-    # what torch.version.hip reports.  The wheel may ship an older suffix (e.g.
-    # "72") while torch reports a newer HIP version (e.g. 7.13); the env var
-    # override ensures bitsandbytes does not fail looking for a non-existent DLL.
-    # The worker subprocess inherits this env var automatically.
-    # Fall back to "72" if detection fails (e.g. install was a no-op / dry-run).
+    # Detect the actual ROCm DLL suffix in the wheel and set BNB_ROCM_VERSION so bnb
+    # loads the right DLL regardless of torch.version.hip (the wheel may ship "72"
+    # while torch reports 7.13). The worker subprocess inherits it; fall back to "72"
+    # if detection fails (e.g. a no-op / dry-run install).
     _env_ver = os.environ.get("BNB_ROCM_VERSION")
     _env_is_persisted_default = (
         os.environ.get(_BNB_ROCM_VERSION_SOURCE_ENV) == _BNB_ROCM_VERSION_SOURCE_SITECUSTOMIZE
@@ -1002,13 +1219,11 @@ def _install_bnb_windows_rocm() -> bool:
         _persist_detected_version = True
     if _persist_detected_version:
         _persist_bnb_rocm_version(_ver)
-    # Make hipInfo.exe (shipped into the venv Scripts dir by the AMD torch
-    # wheel) resolvable via PATH for this process and every child python the
-    # installer spawns (import checks, precompile): bitsandbytes runs
-    # `hipinfo.exe` at import time to detect the GPU arch and logs a scary
-    # (harmless) ERROR + WARNING on every import when it is missing. The venv
-    # Scripts dir is on PATH only when the venv is activated, which neither
-    # Studio nor the installer's child processes ever do.
+    # Make hipInfo.exe (shipped into venv Scripts by the AMD torch wheel) resolvable
+    # via PATH for this process and every child python (import checks, precompile):
+    # bitsandbytes runs hipinfo.exe at import to detect the GPU arch and logs a scary
+    # (harmless) ERROR + WARNING when it is missing. Scripts is on PATH only for an
+    # activated venv, which neither Unsloth nor the installer's children ever do.
     _scripts_dir = os.path.dirname(sys.executable)
     if os.path.isfile(os.path.join(_scripts_dir, "hipInfo.exe")) and not shutil.which(
         "hipinfo.exe"
@@ -1020,13 +1235,18 @@ def _install_bnb_windows_rocm() -> bool:
 def _detect_cuda_torch_index_url() -> str:
     """Return the pytorch.org CUDA wheel index URL for the host's NVIDIA driver.
 
-    Mirrors install.sh::get_torch_index_url's CUDA ladder so `studio update`
-    repairs to the same wheel family a fresh `curl | sh` install would pick.
-    Probes nvidia-smi (PATH, then /usr/bin/nvidia-smi) and parses both the
-    legacy "CUDA Version:" and the newer "CUDA UMD Version:" spellings.
-    Defaults to cu126 when nvidia-smi is missing or the version is unreadable
-    (e.g. NVIDIA detected only via the /proc/driver/nvidia/gpus fallback).
+    Mirrors install.sh::get_torch_index_url's CUDA ladder so `studio update` repairs
+    to the same wheel family a fresh install would pick. Honours the explicit
+    overrides first (UNSLOTH_TORCH_INDEX_URL / _FAMILY) so a headless / CI install
+    never lets the host GPU decide. Otherwise probes nvidia-smi (parsing both "CUDA
+    Version:" and "CUDA UMD Version:"), defaulting to cu126 when unreadable.
     """
+    _override_url = os.environ.get("UNSLOTH_TORCH_INDEX_URL", "").strip()
+    if _override_url:
+        return _trim_index_path_slashes(_override_url)
+    _override_family = os.environ.get("UNSLOTH_TORCH_INDEX_FAMILY", "").strip()
+    if _override_family:
+        return f"{_PYTORCH_WHL_BASE}/{_override_family.strip('/')}"
     exe = shutil.which("nvidia-smi")
     if not exe and os.path.isfile("/usr/bin/nvidia-smi"):
         exe = "/usr/bin/nvidia-smi"
@@ -1061,6 +1281,157 @@ def _detect_cuda_torch_index_url() -> str:
     return f"{_PYTORCH_WHL_BASE}/{tag}"
 
 
+def _explicit_torch_index_url() -> "str | None":
+    """The wheel index URL pinned via UNSLOTH_TORCH_INDEX_URL / _FAMILY, else None.
+
+    Lets the CUDA/ROCm repair helpers honour the exact pinned family/URL instead
+    of re-probing the GPU. Mirrors install.sh::get_torch_index_url's override.
+    """
+    url = os.environ.get("UNSLOTH_TORCH_INDEX_URL", "").strip()
+    if url:
+        return _trim_index_path_slashes(url)
+    family = os.environ.get("UNSLOTH_TORCH_INDEX_FAMILY", "").strip()
+    if family:
+        return f"{_PYTORCH_WHL_BASE}/{family.strip('/')}"
+    return None
+
+
+def _is_pip_rocm_family_leaf(leaf: str) -> bool:
+    """True when a lowercased leaf names a pip --index-url ROCm family: an EXACT
+    rocm<digits>[.<digits>] leaf or a gfx leaf. A suffixed leaf (rocm-rel-7.2.1,
+    rocm7.2-private) starts with "rocm" but is a custom pin the verbatim path owns, so
+    match EXACTLY. Mirrors install.sh / setup.ps1.
+    """
+    # gfx must be followed by a digit (gfx90a, gfx1151, gfx120X-all): a gfx-prefixed
+    # custom leaf (gfx-private) is a verbatim pin, like rocm7.2-private.
+    return bool(re.fullmatch(r"rocm\d+(?:\.\d+)?", leaf)) or bool(re.match(r"gfx\d", leaf))
+
+
+def _explicit_rocm_torch_index_url() -> "str | None":
+    """The pinned wheel index URL when it names a pip ROCm family (rocm<d>/gfx*), else None."""
+    url = _explicit_torch_index_url()
+    if url is None:
+        return None
+    return url if _is_pip_rocm_family_leaf(_torch_index_leaf(url)) else None
+
+
+def _rocm_pin_family_mismatch(pin_url: str, installed_ver: str) -> bool:
+    """True when an explicit ROCm pin names a different ROCm family than the installed
+    ROCm torch, so the pin needs a reinstall. Mirrors setup.ps1's stale-venv comparison;
+    same three pin-leaf cases as _ensure_rocm_torch. A same-family pin is NOT a mismatch.
+    """
+    leaf = _torch_index_leaf(pin_url)
+    # Pinned ROCm version. The family classifier accepts a major-only rocm<d> leaf too,
+    # so parse the minor as optional; a major-only pin compares on the major alone.
+    _pin_rocm = re.match(r"^rocm(\d+)(?:\.(\d+))?", leaf)
+    _pin_major = int(_pin_rocm.group(1)) if _pin_rocm else None
+    _pin_ver = (
+        (int(_pin_rocm.group(1)), int(_pin_rocm.group(2)))
+        if _pin_rocm and _pin_rocm.group(2) is not None
+        else None
+    )
+    # Installed +rocmX.Y version; a THREE-part +rocmA.B.C tag is the AMD per-arch
+    # (repo.amd.com/gfx*) signature vs a two-part pytorch.org wheel.
+    _inst_rocm = re.search(r"\+rocm(\d+)\.(\d+)", installed_ver)
+    _inst_ver = (int(_inst_rocm.group(1)), int(_inst_rocm.group(2))) if _inst_rocm else None
+    _inst_is_perarch = re.search(r"\+rocm\d+\.\d+\.\d+", installed_ver) is not None
+    # A ROCm build MUST carry a +rocm tag; an untagged wheel never satisfies a ROCm pin.
+    _inst_has_rocm = re.search(r"\+rocm", installed_ver) is not None
+    # Installed torch RELEASE (before "+") is 2.11+.
+    _inst_rel = re.match(r"^(\d+)\.(\d+)", installed_ver)
+    _inst_is_211 = (
+        (int(_inst_rel.group(1)), int(_inst_rel.group(2))) >= (2, 11) if _inst_rel else False
+    )
+
+    if leaf.startswith("gfx"):
+        # 2.11-allowlist arches expect the AMD per-arch wheel (three-part +rocmA.B.C,
+        # torch 2.11+); a generic or pre-2.11 build is a mismatch.
+        if leaf in _ROCM_GFX_TORCH211_LEAVES:
+            return not (_inst_is_211 and _inst_is_perarch)
+        # Non-2.11 gfx leaf (<2.11 specs): mismatch on an untagged wheel or torch 2.11+.
+        return (not _inst_has_rocm) or _inst_is_211
+
+    # Major-only rocm pin (rocm7): compare majors only -- a +rocm6.4 wheel under a rocm7
+    # pin is a mismatch, any +rocm7.x wheel satisfies it (there is no pinned minor to
+    # compare, and the 2.11-line fallback below would invert both verdicts).
+    if _pin_major is not None and _pin_ver is None:
+        if _inst_ver is not None:
+            return _inst_ver[0] != _pin_major
+        # Untagged wheel never satisfies a ROCm pin; a +rocm tag with an unreadable
+        # version is accepted (matches the lenient unreadable fallback below).
+        return not _inst_has_rocm
+
+    # rocmX.Y pin. Only KNOWN-2.11 rocm is the 2.11 line (no speculative floor).
+    _pin_is_211 = _pin_ver in _ROCM_KNOWN_TORCH211_VERSIONS if _pin_ver is not None else False
+    if _pin_ver is not None and _inst_ver is not None:
+        # Both readable: exact (major, minor) compare (rocm7.2 pin over +rocm7.13.x ->
+        # mismatch, reinstall the pinned wheel).
+        if _pin_ver != _inst_ver:
+            return True
+        # Same family: a KNOWN-2.11 pin whose release drifted off 2.11 (2.12+rocm7.2)
+        # violates the spec -> reinstall to floor (exact compare, not >=2.11).
+        if _pin_is_211 and _inst_rel is not None:
+            if (int(_inst_rel.group(1)), int(_inst_rel.group(2))) != (2, 11):
+                return True
+        return False
+    # rocm pin, unreadable installed version: compare on the 2.11 line, but an untagged
+    # wheel never satisfies a rocmX.Y pin -> mismatch.
+    if not _inst_has_rocm:
+        return True
+    return _pin_is_211 != _inst_is_211
+
+
+def _explicit_cpu_torch_index_url() -> "str | None":
+    """The pinned wheel index URL when it names the CPU family (leaf == cpu), else None.
+
+    An explicit CPU pin (UNSLOTH_TORCH_INDEX_FAMILY=cpu or a URL ending in /cpu)
+    is authoritative -- see _ensure_cpu_torch.
+    """
+    url = _explicit_torch_index_url()
+    if url is None:
+        return None
+    return url if _torch_index_leaf(url) == "cpu" else None
+
+
+def _is_cuda_family_leaf(leaf: str) -> bool:
+    """True only for a real CUDA wheel-family leaf: "cu" + digits (cu118, cu128, ...).
+
+    A bare startswith("cu") would match "custom"/"current". The match is EXACT so
+    "cu128-private" is NOT a family leaf and routes to the verbatim path instead.
+    """
+    return re.fullmatch(r"cu[0-9]+", leaf) is not None
+
+
+def _explicit_cuda_torch_index_url() -> "str | None":
+    """The pinned wheel index URL when it names a CUDA family (leaf cuXXX), else None.
+
+    Mirrors _explicit_rocm/cpu_torch_index_url so _ensure_cuda_torch only treats a
+    *CUDA* pin as authority to override the NVIDIA-presence gate (an arbitrary mirror
+    or a ROCm/CPU pin must not force a CUDA reinstall on a non-NVIDIA host).
+    """
+    url = _explicit_torch_index_url()
+    if url is None:
+        return None
+    return url if _is_cuda_family_leaf(_torch_index_leaf(url)) else None
+
+
+def _explicit_unknown_family_torch_index_url() -> "str | None":
+    """The pinned index URL when its leaf names NO known torch family, else None.
+
+    Known = rocm* / gfx* / cpu / cuXXX. Anything else (a private mirror /simple,
+    /current) is UNKNOWN: version-tag heuristics can't judge it, so the family
+    repair helpers must leave it alone (the install applied it verbatim).
+    Matches install.sh / setup.ps1 / install.ps1.
+    """
+    url = _explicit_torch_index_url()
+    if url is None:
+        return None
+    leaf = _torch_index_leaf(url)
+    if _is_pip_rocm_family_leaf(leaf) or leaf == "cpu" or _is_cuda_family_leaf(leaf):
+        return None
+    return url
+
+
 def _ensure_cuda_torch() -> None:
     """Repair a venv whose torch is a ROCm build on an NVIDIA host.
 
@@ -1073,44 +1444,47 @@ def _ensure_cuda_torch() -> None:
     Only repairs when torch actually links against HIP/ROCm. Healthy CUDA
     torch and deliberate CPU-only torch are left untouched.
     """
-    # Respect an explicit backend choice from install.sh: only "" (standalone
-    # `studio update`) or "cuda" should ever force CUDA wheels. "rocm"/"cpu"
-    # (or any unrecognised value) are deliberate and must not be overridden.
+    # Respect install.sh's backend: only "" (standalone update) or "cuda" force CUDA
+    # wheels; "rocm"/"cpu"/unrecognised are deliberate.
     if _TORCH_BACKEND not in ("", "cuda"):
         return
-    # No CUDA torch on macOS; Windows venv/torch lifecycle is owned by
-    # install.ps1 (and the KFD poisoning bug is Linux-only), so skip both.
+    # An explicit unknown-family pin was applied VERBATIM at install time; leave it alone.
+    if _explicit_unknown_family_torch_index_url() is not None:
+        return
+    # No CUDA torch on macOS; Windows torch is owned by install.ps1 (KFD bug is Linux-only).
     if IS_MACOS or IS_WINDOWS or NO_TORCH:
         return
     # Never undo a deliberate ROCm install (setup.ps1 sets this marker).
     if os.environ.get("UNSLOTH_ROCM_TORCH_INSTALLED") == "1":
         return
-    # CUDA_VISIBLE_DEVICES="" / "-1" deliberately hides the NVIDIA GPU (for
-    # example a mixed AMD+NVIDIA host that runs ROCm torch on the AMD card);
-    # never force CUDA wheels over that choice.
+    # An explicit CUDA pin (headless / CI cross-install) commits to CUDA wheels and skips ALL
+    # GPU probing, so it clears both the CUDA_VISIBLE_DEVICES hide gate and the NVIDIA gate below.
+    _cuda_pinned = _explicit_cuda_torch_index_url() is not None
+    # CUDA_VISIBLE_DEVICES="" / "-1" deliberately hides the NVIDIA GPU; never force CUDA
+    # wheels over that unless a CUDA index is pinned.
     _cvd = os.environ.get("CUDA_VISIBLE_DEVICES")
-    if _cvd is not None and _cvd.strip() in ("", "-1"):
+    if not _cuda_pinned and _cvd is not None and _cvd.strip() in ("", "-1"):
         return
-    # Only NVIDIA hosts should carry CUDA torch. _has_usable_nvidia_gpu()
-    # covers the /proc/driver/nvidia/gpus fallback when nvidia-smi is absent.
-    if not _has_usable_nvidia_gpu():
+    # Only NVIDIA hosts carry CUDA torch (the CUDA pin overrides this gate too).
+    if not _cuda_pinned and not _has_usable_nvidia_gpu():
         return
 
-    # Classify the installed torch: "hip" (ROCm build -- the poisoning
-    # signature), "cuda" (healthy), or "cpu" (deliberate CPU wheel). A
-    # non-zero exit means torch is missing or un-importable; the base install
-    # step handles that, so leave it alone.
+    # Classify the installed torch: "hip" (ROCm poisoning signature), "cuda" (healthy),
+    # or "cpu". A non-zero exit means torch is missing/un-importable: without a pin the
+    # base install owns it, but a pinned CUDA index reinstalls it below.
     try:
         probe = subprocess.run(
             [
                 sys.executable,
                 "-c",
                 (
-                    "import torch; "
+                    "import torch, re; "
                     "hip = getattr(torch.version, 'hip', '') or ''; "
                     "cuda = getattr(torch.version, 'cuda', '') or ''; "
                     "ver = getattr(torch, '__version__', '').lower(); "
-                    "print('hip' if (hip or 'rocm' in ver) else ('cuda' if cuda else 'cpu'))"
+                    "m = re.search(r'\\+(cu\\d+)', ver); "
+                    "marker = 'hip' if (hip or 'rocm' in ver) else ('cuda' if cuda else 'cpu'); "
+                    "print(marker + '|' + (m.group(1) if m else ''))"
                 ),
             ],
             stdout = subprocess.PIPE,
@@ -1120,22 +1494,60 @@ def _ensure_cuda_torch() -> None:
     except (OSError, subprocess.TimeoutExpired):
         return
     if probe.returncode != 0:
+        # torch present but can't import. Without a pin the base install owns it; but an
+        # explicit CUDA pin forces this pass (failed probe) and the base update won't
+        # reinstall an already-installed torch, so reinstall from the pin (self-resolving).
+        if not _cuda_pinned:
+            return
+        index_url = _detect_cuda_torch_index_url()
+        _torch_pkg, _vision_pkg, _audio_pkg = _CUDA_TORCH_PKG_SPEC
+        print(
+            f"   torch cannot import but an explicit CUDA index is pinned -- reinstalling "
+            f"CUDA torch from {_strip_index_url_credentials(index_url)}"
+        )
+        pip_install(
+            "CUDA torch repair",
+            "--force-reinstall",
+            "--no-cache-dir",
+            _torch_pkg,
+            _vision_pkg,
+            _audio_pkg,
+            "--index-url",
+            index_url,
+            constrain = False,
+        )
         return
-    # Take the last non-empty stdout line: stray output from sitecustomize or
-    # an import hook must not mask the marker (fail-closed either way).
+    # Last non-empty line: stray sitecustomize/import-hook output must not mask the marker.
     _marker_lines = [
         line.strip() for line in probe.stdout.decode(errors = "replace").splitlines() if line.strip()
     ]
-    if not _marker_lines or _marker_lines[-1] != "hip":
-        return  # healthy CUDA torch, or a deliberate CPU wheel -- leave as-is
+    if not _marker_lines:
+        return
+    _marker, _, _installed_cu = _marker_lines[-1].partition("|")
+    # Reinstall CUDA torch on a ROCm build on an NVIDIA host (poisoning signature), or when a
+    # CUDA index is pinned but the venv has the wrong family (CPU or a different cuXXX). A
+    # healthy match, or a CPU wheel with no CUDA pin, is left alone.
+    _pin = _explicit_torch_index_url()
+    _pin_leaf = _torch_index_leaf(_pin) if _pin else ""
+    _pinned_cuda = _is_cuda_family_leaf(_pin_leaf)
+    if _marker == "hip":
+        _why = "torch is a ROCm build on an NVIDIA host"
+    elif _marker == "cpu" and _pinned_cuda:
+        _why = "torch is a CPU build but an explicit CUDA index is pinned"
+    elif _marker == "cuda" and _pinned_cuda and _installed_cu != _pin_leaf:
+        # Installed cuXXX differs from the pin. An untagged build (empty) counts too:
+        # the family can't be confirmed, so reinstall to enforce it (idempotent).
+        _installed_desc = _installed_cu if _installed_cu else "an untagged CUDA build"
+        _why = f"torch is {_installed_desc} but the pinned CUDA index is {_pin_leaf}"
+    else:
+        return  # healthy CUDA torch matching the pin, or a deliberate CPU wheel
 
     index_url = _detect_cuda_torch_index_url()
     _torch_pkg, _vision_pkg, _audio_pkg = _CUDA_TORCH_PKG_SPEC
     print(
-        f"   torch is a ROCm build on an NVIDIA host -- reinstalling "
-        f"CUDA torch from {index_url}\n"
-        f"   (set UNSLOTH_TORCH_BACKEND=rocm to keep a deliberate ROCm torch "
-        f"on a mixed AMD+NVIDIA host)"
+        f"   {_why} -- reinstalling CUDA torch from {_strip_index_url_credentials(index_url)}\n"
+        f"   (set UNSLOTH_TORCH_BACKEND=rocm or cpu to keep a deliberate "
+        f"non-CUDA torch)"
     )
     pip_install(
         "CUDA torch repair",
@@ -1150,6 +1562,90 @@ def _ensure_cuda_torch() -> None:
     )
 
 
+def _ensure_cpu_torch() -> None:
+    """Reinstall CPU torch when an explicit CPU pin is set but the venv has a GPU build.
+
+    Counterpart to _ensure_cuda/rocm_torch for the explicit-CPU case (those treat a CPU
+    backend as a skip, so a standalone `studio update` would ignore the authoritative CPU
+    pin). Only fires for an EXPLICIT pin.
+    """
+    if NO_TORCH:
+        return
+    pin = _explicit_cpu_torch_index_url()
+    if pin is None:
+        return
+
+    # Classify the installed torch family. A non-zero exit means torch is missing or
+    # un-importable: the explicit CPU pin reinstalls it below.
+    try:
+        probe = subprocess.run(
+            [
+                sys.executable,
+                "-c",
+                (
+                    "import torch, re; "
+                    "hip = getattr(torch.version, 'hip', '') or ''; "
+                    "cuda = getattr(torch.version, 'cuda', '') or ''; "
+                    "ver = getattr(torch, '__version__', '').lower(); "
+                    "gpu = bool(hip) or 'rocm' in ver or bool(cuda) or bool(re.search(r'\\+cu\\d+', ver)); "
+                    "print('gpu' if gpu else 'cpu')"
+                ),
+            ],
+            stdout = subprocess.PIPE,
+            stderr = subprocess.DEVNULL,
+            timeout = 90,
+        )
+    except (OSError, subprocess.TimeoutExpired):
+        return
+    if probe.returncode != 0:
+        # torch present but can't import. The explicit CPU pin forces this pass (failed
+        # probe) and the base update won't reinstall an already-installed torch, so
+        # reinstall from the pin (self-resolving, no loop).
+        _torch_pkg, _vision_pkg, _audio_pkg = _CPU_TORCH_PKG_SPEC
+        print(
+            f"   torch cannot import but an explicit CPU index is pinned -- reinstalling "
+            f"CPU torch from {_strip_index_url_credentials(pin)}"
+        )
+        pip_install(
+            "CPU torch repair",
+            "--force-reinstall",
+            "--no-cache-dir",
+            _torch_pkg,
+            _vision_pkg,
+            _audio_pkg,
+            "--index-url",
+            pin,
+            constrain = False,
+        )
+        return
+    _lines = [
+        line.strip() for line in probe.stdout.decode(errors = "replace").splitlines() if line.strip()
+    ]
+    if not _lines:
+        return  # unreadable -- the base install step handles a missing torch
+    if _lines[-1] != "gpu":
+        return  # already a CPU build
+
+    print(
+        "   torch is a GPU build but an explicit CPU index is pinned -- reinstalling "
+        f"CPU torch from {_strip_index_url_credentials(pin)}"
+    )
+    # Pin the supported torch<2.11 family (the /cpu index now serves 2.11+, so a bare
+    # trio could resolve out of range or ABI-mismatched).
+    _torch_pkg, _vision_pkg, _audio_pkg = _CPU_TORCH_PKG_SPEC
+    pip_install(
+        "CPU torch repair",
+        "--force-reinstall",
+        "--no-cache-dir",
+        _torch_pkg,
+        _vision_pkg,
+        _audio_pkg,
+        "--index-url",
+        pin,
+        constrain = False,
+    )
+
+
 def _ensure_rocm_torch() -> None:
     """Reinstall torch with ROCm wheels when the venv received CPU-only torch.
 
@@ -1160,16 +1656,15 @@ def _ensure_rocm_torch() -> None:
     Uses pip_install() to respect uv, constraints, and --python targeting.
     """
     global _rocm_windows_torch_installed
-    # install.sh sets UNSLOTH_TORCH_BACKEND to the resolved wheel family
-    # ("cuda", "rocm", "cpu"). Skip ROCm operations entirely when install.sh
-    # already selected a non-ROCm backend -- this is the authoritative signal
-    # and avoids re-running GPU detection in a subprocess that may see a
-    # different environment (different PATH, CUDA_VISIBLE_DEVICES, etc.).
+    # install.sh's resolved backend is authoritative: skip ROCm when it already chose a
+    # non-ROCm family (avoids re-detecting in a subprocess that may see a different env).
     if _TORCH_BACKEND in ("cuda", "cpu"):
         return
-    # setup.ps1 sets this after installing AMD wheels; skip the probe only when
-    # torch is actually importable as ROCm. If the venv was wiped between runs,
-    # the stale env-var would suppress a needed reinstall.
+    # An explicit unknown-family pin was applied VERBATIM at install time; leave it alone.
+    if _explicit_unknown_family_torch_index_url() is not None:
+        return
+    # setup.ps1 sets this after installing AMD wheels; skip only when torch is actually
+    # importable as ROCm (a wiped venv leaves a stale env-var that must not suppress it).
     if os.environ.get("UNSLOTH_ROCM_TORCH_INSTALLED") == "1":
         _torch_ok = False
         try:
@@ -1193,9 +1688,8 @@ def _ensure_rocm_torch() -> None:
             pass
         if _torch_ok:
             _rocm_windows_torch_installed = True
-            # setup.ps1 already installed ROCm torch, but we still need the AMD
-            # Windows BNB wheel here -- the PyPI bitsandbytes wheel ships only
-            # CUDA DLLs and fails to load on ROCm.
+            # ROCm torch is already installed, but the AMD Windows BNB wheel is still
+            # needed (the PyPI bitsandbytes ships only CUDA DLLs, fails on ROCm).
             _install_bnb_windows_rocm()
             return
         # torch was wiped between runs; fall through to the full install path
@@ -1203,10 +1697,15 @@ def _ensure_rocm_torch() -> None:
         return
 
     if IS_WINDOWS:
-        if _has_usable_nvidia_gpu():
+        # An explicit ROCm-family pin commits to ROCm wheels regardless of the visible
+        # GPU and overrides the public per-arch index (mirrors the Linux pin handling
+        # below): after a pinned setup.ps1 install fails to CPU, this repair must retry
+        # the PINNED index, not repo.amd.com.
+        _win_rocm_pin = _explicit_rocm_torch_index_url()
+        if _win_rocm_pin is None and _has_usable_nvidia_gpu():
             return
         gfx_arch = _detect_windows_gfx_arch()
-        if not gfx_arch:
+        if not gfx_arch and _win_rocm_pin is None:
             return  # no AMD GPU visible via hipinfo
         # Probe whether torch already links against HIP.
         _torch_already_rocm = False
@@ -1231,23 +1730,24 @@ def _ensure_rocm_torch() -> None:
         except (OSError, subprocess.TimeoutExpired):
             pass
         if not _torch_already_rocm:
-            index_url = _windows_rocm_index_url(gfx_arch)
+            index_url = _win_rocm_pin or _windows_rocm_index_url(gfx_arch)
             if index_url is None:
                 print(f"   No AMD Windows torch index for GPU arch {gfx_arch} -- skipping")
                 return
-            print(f"   {gfx_arch} (Windows) -- installing torch from {index_url}")
-            # Pin companions for the arches install.ps1/setup.ps1 pin (gfx120X /
-            # Strix) so the per-arch index resolves an ABI-consistent trio; other
-            # arches stay bare (no published floor), matching the PowerShell side.
+            print(
+                f"   {gfx_arch or 'pinned ROCm index'} (Windows) -- installing torch from "
+                f"{_strip_index_url_credentials(index_url)}"
+            )
+            # Pin companions for the arches install.ps1/setup.ps1 pin (gfx120X / Strix)
+            # so the per-arch index resolves an ABI-consistent trio; other arches stay bare.
             _torch_pkg, _vision_pkg, _audio_pkg = _WINDOWS_ROCM_TORCH_PKG_SPECS.get(
                 gfx_arch, ("torch", "torchvision", "torchaudio")
             )
-            # Nonfatal: a transient AMD-index failure must not abort the whole
-            # install once the PowerShell side has fallen back to CPU torch.
-            # --force-reinstall resolves before uninstalling, so a failed index
-            # leaves the existing build intact; keep it and let the user retry.
+            # Nonfatal: a transient AMD-index failure must not abort the install.
+            # --force-reinstall resolves before uninstalling, so a failed index keeps the
+            # existing build intact; let the user retry.
             if not pip_install_try(
-                f"ROCm torch (Windows, {gfx_arch})",
+                f"ROCm torch (Windows, {gfx_arch or 'pinned'})",
                 "--force-reinstall",
                 "--index-url",
                 index_url,
@@ -1257,7 +1757,7 @@ def _ensure_rocm_torch() -> None:
                 constrain = False,
             ):
                 print(
-                    f"   Warning: AMD Windows ROCm torch install failed for {gfx_arch}; "
+                    f"   Warning: AMD Windows ROCm torch install failed for {gfx_arch or 'the pinned index'}; "
                     "keeping the existing torch build. Re-run 'unsloth studio update' "
                     "later to retry ROCm."
                 )
@@ -1280,26 +1780,32 @@ def _ensure_rocm_torch() -> None:
     # ── Linux x86_64 only: PyTorch ROCm wheels are not published for aarch64 ──
     if platform.machine().lower() not in {"x86_64", "amd64"}:
         return
-    # NVIDIA takes precedence on mixed hosts -- but only if a GPU is usable
-    if _has_usable_nvidia_gpu():
-        return
-    # Use _has_rocm_gpu() (rocminfo / amd-smi GPU data rows) as the
-    # authoritative "is this an AMD ROCm host?" signal. The old gate required
-    # /opt/rocm or hipcc to exist, which breaks runtime-only ROCm installs
-    # (minimal package-managed installs, Radeon software) that ship
-    # amd-smi/rocminfo without /opt/rocm or hipcc, leaving `unsloth studio
-    # update` unable to repair a CPU-only venv on those systems.
-    if not _has_rocm_gpu():
-        return  # no AMD GPU visible
+    # An explicit ROCm pin commits to ROCm wheels regardless of the visible GPU (headless / CI).
+    # Mirror _ensure_cuda_torch: skip the NVIDIA/no-AMD/unreadable gates.
+    _rocm_pin = _explicit_rocm_torch_index_url()
+    _inferred_linux_gfx = (
+        _infer_linux_amd_gfx_arch() if (_rocm_pin is None and not IS_WINDOWS) else None
+    )
+    if _rocm_pin is None:
+        # NVIDIA takes precedence on mixed hosts (only if a GPU is usable).
+        if _has_usable_nvidia_gpu():
+            return
+        # _has_rocm_gpu() (rocminfo / amd-smi rows) is the authoritative AMD-host signal;
+        # the old /opt/rocm-or-hipcc gate broke runtime-only ROCm installs.
+        if not _has_rocm_gpu() and not _inferred_linux_gfx:
+            return  # no AMD GPU visible
 
     ver = _detect_rocm_version()
     if ver is None:
-        print("   ROCm detected but version unreadable -- skipping torch reinstall")
-        return
+        if _rocm_pin is None and not _inferred_linux_gfx:
+            print("   ROCm detected but version unreadable -- skipping torch reinstall")
+            return
+        # Explicit pin or inferred gfx: the index drives the install.
+        ver = (0, 0)
 
-    # Probe whether torch already links against HIP (ROCm already working).
-    # Do NOT skip for CUDA-only builds: they are unusable on AMD-only hosts
-    # (the NVIDIA check above already handled mixed AMD+NVIDIA setups).
+    # Probe whether torch links against HIP, capturing the installed ROCm tag for pin-mismatch
+    # detection. Emit ONE "<hip_marker>|<version>" line: marker (HIP version, "rocm" sentinel,
+    # or empty for CPU/CUDA) before "|", wheel version after.
     try:
         probe = subprocess.run(
             [
@@ -1309,10 +1815,10 @@ def _ensure_rocm_torch() -> None:
                     "import torch; "
                     "hip=getattr(torch.version,'hip','') or ''; "
                     "ver=getattr(torch,'__version__','').lower(); "
-                    # Print the HIP version when present (back-compat), else a
-                    # "rocm" sentinel when only torch.__version__ flags ROCm
-                    # (AMD SDK / Radeon wheels). Empty string = CPU/CUDA.
-                    "print(hip if hip else ('rocm' if 'rocm' in ver else ''))"
+                    # HIP version if present, else a "rocm" sentinel when only the
+                    # version string flags ROCm; empty marker = CPU/CUDA torch.
+                    "marker=hip if hip else ('rocm' if 'rocm' in ver else ''); "
+                    "print(marker + '|' + ver)"
                 ),
             ],
             stdout = subprocess.PIPE,
@@ -1321,29 +1827,80 @@ def _ensure_rocm_torch() -> None:
         )
     except (OSError, subprocess.TimeoutExpired):
         probe = None
-    has_hip_torch = (
-        probe is not None and probe.returncode == 0 and probe.stdout.decode().strip() != ""
+    # Last non-empty line, split on the FIRST "|" so the empty HIP field is preserved.
+    _marker_lines = (
+        [ln.strip() for ln in probe.stdout.decode(errors = "replace").splitlines() if ln.strip()]
+        if (probe is not None and probe.returncode == 0)
+        else []
+    )
+    _hip_marker, _sep, _installed_torch_ver = (
+        _marker_lines[-1].partition("|") if _marker_lines else ("", "", "")
+    )
+    # A "|"-delimited line is required; without it treat HIP as absent -> reinstall.
+    has_hip_torch = bool(_sep) and _hip_marker != ""
+
+    # An explicit ROCm pin whose family differs from the installed torch must reinstall, else a
+    # rocm7.2/gfx* pin over an older +rocm6.4/7.1 build never applies. Version-tag heuristic
+    # only: a same-tag per-arch switch (gfx1151 -> gfx120X-all, both +rocm7.13.0) isn't detectable.
+    _rocm_pin_mismatch = (
+        _rocm_pin_family_mismatch(_rocm_pin, _installed_torch_ver)
+        if (has_hip_torch and _rocm_pin is not None)
+        else False
     )
 
-    rocm_torch_ready = has_hip_torch
+    rocm_torch_ready = has_hip_torch and not _rocm_pin_mismatch
 
-    # Strix Halo / Strix Point (gfx1151 / gfx1150) segfault under ROCm 7.1
-    # in torch._grouped_mm. AMD's per-gfx repo ships torch 2.11.0+rocm7.13.0
-    # with the real fix, so route those hosts there instead of the generic
-    # pytorch.org rocm7.1 wheel. Mirrors install.sh's Strix override.
-    # On mixed hosts (Strix iGPU + non-Strix dGPU), route to the AMD per-gfx
-    # index only when HIP's runtime GPU is the Strix one -- else the dGPU gets
-    # an incompatible wheel. Use HIP_VISIBLE_DEVICES for the runtime target.
+    # Inferred-gfx path: ROCm runtime missing but install.sh would route to AMD wheels.
+    # Gated on the runtime NOT enumerating a GPU: when it can, the runtime-visible
+    # arch (Strix override / generic below) decides, not cpuinfo -- a mixed Strix
+    # APU + dGPU box with HIP_VISIBLE_DEVICES on the dGPU must not get APU wheels.
+    # An explicit UNSLOTH_ROCM_GFX_ARCH is exempt from that runtime gate (mirrors
+    # install.sh): a visible GPU with an unreadable/unsupported ROCm version must
+    # not silently discard the user's named arch and leave CPU torch in place.
+    _gfx_override_env = (os.environ.get("UNSLOTH_ROCM_GFX_ARCH") or "").strip().lower()
+    if (
+        _inferred_linux_gfx
+        and not has_hip_torch
+        and _rocm_pin is None
+        and (_gfx_override_env or not _has_rocm_gpu())
+    ):
+        index_url = _amd_arch_index_url(_inferred_linux_gfx)
+        if index_url is not None:
+            _torch_pkg, _vision_pkg, _audio_pkg = _WINDOWS_ROCM_TORCH_PKG_SPECS.get(
+                _inferred_linux_gfx, ("torch", "torchvision", "torchaudio")
+            )
+            print(
+                f"\n   {_inferred_linux_gfx} inferred (ROCm runtime not visible) -- "
+                f"installing torch from {_strip_index_url_credentials(index_url)}\n"
+                f"   AMD wheels bundle their own ROCm runtime; install the kernel stack "
+                f"for native GPU compute.\n"
+            )
+            pip_install(
+                f"ROCm torch (inferred {_inferred_linux_gfx})",
+                "--force-reinstall",
+                "--no-cache-dir",
+                _torch_pkg,
+                _vision_pkg,
+                _audio_pkg,
+                "--index-url",
+                index_url,
+                constrain = False,
+            )
+            rocm_torch_ready = True
+
+    # Strix Halo / Point (gfx1151 / gfx1150) need torch from AMD's per-gfx index
+    # (2.11+rocm7.13); any generic pytorch.org rocm index lacks the fixes (ROCm 7.1
+    # segfaults in _grouped_mm). See _strix_needs_amd_arch_index for the floor gate.
     _strix_override_url: "str | None" = None
     _strix_override_pkgs: "tuple[str, str, str] | None" = None
-    if ver < (7, 2):
+    # An explicit ROCm pin is authoritative: never auto-reroute it.
+    if _strix_needs_amd_arch_index(ver) and _explicit_rocm_torch_index_url() is None:
         gfx_codes = _detect_amd_gfx_codes()
         _strix_gfx = {"gfx1151", "gfx1150"}
         _detected_strix = _strix_gfx.intersection(gfx_codes)
         if _detected_strix:
-            # Pick the runtime-visible GPU: use the HIP_VISIBLE_DEVICES index
-            # into gfx_codes, else default to the first GPU. Skip the override
-            # unless the resolved GPU is Strix.
+            # Runtime-visible GPU (HIP_VISIBLE_DEVICES index into gfx_codes, else first);
+            # skip the override unless it's Strix.
             _runtime_gfx = gfx_codes[_pick_visible_index(len(gfx_codes))] if gfx_codes else None
             if _runtime_gfx in _strix_gfx:
                 _selected_gfx = _runtime_gfx
@@ -1353,22 +1910,18 @@ def _ensure_rocm_torch() -> None:
                 _strix_override_url = f"{_amd_mirror}/{_selected_gfx}/"
                 _strix_override_pkgs = (
                     "torch>=2.11.0,<2.12.0",
-                    # Pin torchvision/torchaudio to the 2.11.x-compatible range.
-                    # The install uses --index-url (exclusive, no PyPI fallback),
-                    # so bare unversioned names risk resolving an AMD-index build
-                    # targeting a different torch major (e.g. 0.27 built against
-                    # torch 2.12), which fails at runtime with an ABI/version
-                    # mismatch. Matches _ROCM_TORCH_CONSTRAINT["rocm7.2"].
+                    # Pin companions to the 2.11.x range: the exclusive --index-url could
+                    # otherwise resolve a build for a different torch major (ABI mismatch).
                     "torchvision>=0.26.0,<0.27.0",
                     "torchaudio>=2.11.0,<2.12.0",
                 )
                 print(
                     f"\n   {_selected_gfx} (AMD Strix) is the runtime target with ROCm "
                     f"{ver[0]}.{ver[1]}.\n"
-                    f"   ROCm 7.1 has a known _grouped_mm segfault on this GPU;\n"
-                    f"   routing torch install to AMD's arch-specific index\n"
+                    f"   Routing torch install to AMD's arch-specific index\n"
                     f"   ({_strix_override_url}) which serves torch 2.11.0+rocm7.13.0\n"
-                    f"   with the upstream fix.\n"
+                    f"   with AMD's gfx1150/gfx1151 fixes (more reliable than the generic\n"
+                    f"   pytorch.org rocm7.2 index on ROCm 7.3+ hosts).\n"
                 )
             else:
                 _gfx_str = ", ".join(sorted(_detected_strix))
@@ -1378,14 +1931,15 @@ def _ensure_rocm_torch() -> None:
                     f"   skipping AMD per-gfx index override.\n"
                 )
 
-    # Strix override on ROCm 7.1 must fire even when has_hip_torch is True --
-    # an existing torch with `torch.version.hip == "7.1"` is exactly the broken
-    # combo the override repairs, so skipping it leaves users on the known
-    # _grouped_mm segfault.
+    # The Strix override must fire even when has_hip_torch is True: an existing
+    # torch.version.hip == "7.1" is exactly the broken combo it repairs.
     if _strix_override_url is not None and _strix_override_pkgs is not None:
         index_url = _strix_override_url
         _torch_pkg, _vision_pkg, _audio_pkg = _strix_override_pkgs
-        print(f"   Strix ROCm 7.1 override -- installing torch from {index_url}")
+        print(
+            f"   Strix arch-specific override -- installing torch from "
+            f"{_strip_index_url_credentials(index_url)}"
+        )
         pip_install(
             "ROCm torch (Strix arch-specific)",
             "--force-reinstall",
@@ -1398,24 +1952,41 @@ def _ensure_rocm_torch() -> None:
             constrain = False,
         )
         rocm_torch_ready = True
-    elif not has_hip_torch:
-        # Select best matching wheel tag (newest ROCm version <= installed)
-        tag = next(
-            (
-                t
-                for (maj, mn), t in sorted(_ROCM_TORCH_INDEX.items(), reverse = True)
-                if ver >= (maj, mn)
-            ),
-            None,
-        )
-        if tag is None:
-            print(f"   No PyTorch wheel for ROCm {ver[0]}.{ver[1]} -- " f"skipping torch reinstall")
+    elif not rocm_torch_ready:
+        # Reinstall when torch is not ROCm yet, OR a ROCm build's family differs from a pin.
+        # Gate on rocm_torch_ready (not has_hip_torch alone) so a successful inferred-gfx
+        # install above is not overwritten by the generic pytorch.org/rocmX.Y path -- that
+        # would undo the fresh-ROCm/no-/dev/kfd repair this path exists for (Codex P1 #7305).
+        # Honour a ROCm pin verbatim; else pick the newest wheel tag <= host.
+        _override_idx = _explicit_rocm_torch_index_url()
+        if _override_idx is not None:
+            index_url = _override_idx
+            tag = _torch_index_leaf(index_url)
         else:
-            index_url = f"{_PYTORCH_WHL_BASE}/{tag}"
-            print(f"   ROCm {ver[0]}.{ver[1]} -- installing torch from {index_url}")
-            _torch_pkg, _vision_pkg, _audio_pkg = _ROCM_TORCH_PKG_SPECS.get(
-                tag, _ROCM_TORCH_PKG_SPECS["_default"]
+            tag = next(
+                (
+                    t
+                    for (maj, mn), t in sorted(_ROCM_TORCH_INDEX.items(), reverse = True)
+                    if ver >= (maj, mn)
+                ),
+                None,
             )
+        if tag is None:
+            print(f"   No PyTorch wheel for ROCm {ver[0]}.{ver[1]} -- skipping torch reinstall")
+        else:
+            if _override_idx is None:
+                index_url = f"{_PYTORCH_WHL_BASE}/{tag}"
+            print(f"   ROCm torch -- installing from {_strip_index_url_credentials(index_url)}")
+            # Only the _grouped_mm-bug gfx arches need the 2.11 spec; other gfx indexes ship
+            # <2.11 and stay on the default range (matches install.ps1 / setup.ps1).
+            if tag in _ROCM_GFX_TORCH211_LEAVES:
+                _torch_pkg, _vision_pkg, _audio_pkg = _ROCM_TORCH_PKG_SPECS["rocm7.2"]
+            elif tag.startswith("gfx"):
+                _torch_pkg, _vision_pkg, _audio_pkg = _ROCM_TORCH_PKG_SPECS["_default"]
+            else:
+                _torch_pkg, _vision_pkg, _audio_pkg = _ROCM_TORCH_PKG_SPECS.get(
+                    tag, _ROCM_TORCH_PKG_SPECS["_default"]
+                )
             pip_install(
                 f"ROCm torch ({tag})",
                 "--force-reinstall",
@@ -1504,11 +2075,26 @@ def _infer_no_torch() -> bool:
 
 NO_TORCH = _infer_no_torch()
 
-# UNSLOTH_TORCH_BACKEND is set by install.sh after get_torch_index_url() so
-# that this script knows which torch variant was selected without re-running
-# GPU detection. Values: "cuda", "rocm", or "cpu". Empty means unknown
-# (standalone `unsloth studio update` runs, where we re-detect normally).
+# UNSLOTH_TORCH_BACKEND is set by install.sh after get_torch_index_url() ("cuda", "rocm",
+# "cpu"; empty = standalone `studio update`, where we re-detect).
 _TORCH_BACKEND: str = os.environ.get("UNSLOTH_TORCH_BACKEND", "").lower()
+# Standalone update with an explicit pin: derive the backend from the override (classify on
+# the final URL/family segment, mirroring install.sh) instead of re-probing the GPU.
+if not _TORCH_BACKEND:
+    _idx_override = (
+        os.environ.get("UNSLOTH_TORCH_INDEX_URL", "").strip()
+        or os.environ.get("UNSLOTH_TORCH_INDEX_FAMILY", "").strip()
+    )
+    _idx_leaf = _torch_index_leaf(_idx_override)
+    if _idx_leaf.startswith(("rocm", "gfx")):
+        _TORCH_BACKEND = "rocm"
+    elif _idx_leaf == "cpu":
+        _TORCH_BACKEND = "cpu"
+    elif _is_cuda_family_leaf(_idx_leaf):
+        # Require a digit after "cu" so /current or /custom is NOT branded CUDA (a wrong backend
+        # makes _ensure_rocm_torch return early on AMD hosts). An unknown leaf keeps "" so the
+        # helpers probe the GPU.
+        _TORCH_BACKEND = "cuda"
 
 
 def _torch_step_label(suffix: str) -> str:
@@ -1724,12 +2310,15 @@ def run(
         cmd,
         stdout = subprocess.PIPE if quiet else None,
         stderr = subprocess.STDOUT if quiet else None,
+        env = _install_env_for_cmd(cmd),
         **_windows_hidden_subprocess_kwargs(),
     )
     if result.returncode != 0:
         _step("error", f"{label} failed (exit code {result.returncode})", _red)
         if result.stdout:
-            print(result.stdout.decode(errors = "replace"))
+            # Redact before printing: the failing pip command may carry a pinned --index-url
+            # with userinfo/?token= creds, so raw pip error text would leak them.
+            print(_redact_install_output(result.stdout))
         sys.exit(result.returncode)
     return result
 
@@ -1737,15 +2326,13 @@ def run(
 # Packages to skip on Windows (require special build steps)
 WINDOWS_SKIP_PACKAGES = {"triton_kernels"}
 
-# Packages to skip when torch is unavailable (Intel Mac GGUF-only mode).
-# These either *are* torch extensions or have unconditional
-# ``Requires-Dist: torch``, so installing them would pull torch back in.
-# ``librosa`` is here too despite not requiring torch: upstream ``llvmlite``
-# dropped its macOS x86_64 wheel between 0.42.0 and 0.46.0+ (see
-# https://pypi.org/project/llvmlite/0.47.0/#files -- only
-# macosx_arm64 / manylinux / win_amd64 remain), so on Intel Mac the
-# librosa -> numba -> llvmlite chain triggers a from-source build that fails
-# in CI and on hosts without LLVM 14/15 headers. Tracked in unslothai/unsloth#5046.
+# Packages to skip when torch is unavailable (Intel Mac GGUF-only mode). These
+# either *are* torch extensions or have unconditional ``Requires-Dist: torch``, so
+# installing them pulls torch back in. ``librosa`` is here despite not requiring
+# torch: upstream ``llvmlite`` dropped its macOS x86_64 wheel (0.46.0+ ships only
+# macosx_arm64 / manylinux / win_amd64), so on Intel Mac the librosa -> numba ->
+# llvmlite chain triggers a from-source build that fails without LLVM 14/15 headers.
+# Tracked in unslothai/unsloth#5046.
 NO_TORCH_SKIP_PACKAGES = {
     "torch-stoi",
     "timm",
@@ -1767,7 +2354,8 @@ def _build_flash_attn_wheel_url(env: dict[str, str]) -> str | None:
 def _print_optional_install_failure(label: str, result: subprocess.CompletedProcess[str]) -> None:
     _step("warning", f"{label} failed (exit code {result.returncode})", _cyan)
     if result.stdout:
-        print(result.stdout.strip())
+        # Redact any pinned --index-url credentials before printing captured output.
+        print(_redact_install_output(result.stdout).strip())
 
 
 def _flash_attn_install_disabled() -> bool:
@@ -1913,15 +2501,60 @@ def _build_uv_cmd(args: tuple[str, ...]) -> list[str]:
     # Colab and similar).
     cmd.extend(["--python", sys.executable])
     cmd.extend(_translate_pip_args_for_uv(args))
-    # Torch is pre-installed by install.sh/setup.ps1. Do not add
-    # --torch-backend by default -- it can cause solver dead-ends on CPU-only
-    # machines. Callers that need it can set UV_TORCH_BACKEND.
+    # Torch is pre-installed, so don't add --torch-backend by default (solver dead-ends on
+    # CPU-only machines); callers can set UV_TORCH_BACKEND. Never add it to a pinned-index
+    # command: uv's torch backend redirects torch to its own per-backend index, defeating the pin.
     _tb = os.environ.get("UV_TORCH_BACKEND", "")
-    if _tb:
+    if _tb and not _is_pinned_index_cmd(cmd):
         cmd.append(f"--torch-backend={_tb}")
     return cmd
 
 
+# uv resolves --index-url / --default-index at LOWEST priority, so an inherited UV_INDEX /
+# UV_EXTRA_INDEX_URL mirror wins and a pinned torch repair silently ignores the pin.
+# Neutralise these for pinned installs (as install.sh #6898 / install.ps1 / setup.ps1 do).
+# UV_TORCH_BACKEND redirects torch; PIP_* matter for the pip FALLBACK; UV_CONFIG_FILE is
+# stripped + UV_NO_CONFIG=1 (a discovered uv.toml outranks the CLI pin, uv 0.10).
+_UV_INDEX_ENV_VARS = (
+    "UV_CONFIG_FILE",
+    "UV_DEFAULT_INDEX",
+    "UV_INDEX_URL",
+    "UV_INDEX",
+    "UV_EXTRA_INDEX_URL",
+    "UV_TORCH_BACKEND",
+    "UV_FIND_LINKS",
+    "PIP_EXTRA_INDEX_URL",
+    "PIP_FIND_LINKS",
+    # PIP_NO_INDEX=1 makes the pip fallback ignore ALL indexes (defeating --index-url);
+    # PIP_INDEX_URL is dropped too so a stale mirror env can't outrank the pin.
+    "PIP_NO_INDEX",
+    "PIP_INDEX_URL",
+)
+
+
+def _is_pinned_index_cmd(cmd: "list[str] | tuple[str, ...]") -> bool:
+    """True when the command pins an index via --index-url / --default-index."""
+    return any(arg in ("--index-url", "--default-index") for arg in cmd)
+
+
+def _install_env_for_cmd(cmd: "list[str]") -> "dict[str, str] | None":
+    """Return an env with the uv index vars stripped for a pinned-index install.
+
+    None (inherit env) when the command does NOT pin an index, so ordinary installs honour
+    the user's mirror. For pinned commands, the uv index/backend vars are removed,
+    UV_NO_CONFIG=1 set (a discovered uv.toml outranks the CLI pin), and PIP_CONFIG_FILE
+    pointed at os.devnull for the pip fallback. Mirrors install.sh's gate (#6898).
+    """
+    if not _is_pinned_index_cmd(cmd):
+        return None
+    env = os.environ.copy()
+    for name in _UV_INDEX_ENV_VARS:
+        env.pop(name, None)
+    env["UV_NO_CONFIG"] = "1"
+    env["PIP_CONFIG_FILE"] = os.devnull
+    return env
+
+
 def pip_install_try(
     label: str,
     *args: str,
@@ -1948,11 +2581,13 @@ def pip_install_try(
         cmd,
         stdout = subprocess.PIPE,
         stderr = subprocess.STDOUT,
+        env = _install_env_for_cmd(cmd),
     )
     if result.returncode == 0:
         return True
     if VERBOSE and result.stdout:
-        print(result.stdout.decode(errors = "replace"))
+        # pip/uv echo index URLs (credentials included) in failure output.
+        print(_redact_install_output(result.stdout))
     return False
 
 
@@ -2000,13 +2635,14 @@ def pip_install(
                 uv_cmd,
                 stdout = subprocess.PIPE,
                 stderr = subprocess.STDOUT,
+                env = _install_env_for_cmd(uv_cmd),
                 **_windows_hidden_subprocess_kwargs(),
             )
             if result.returncode == 0:
                 return
             print(_red(f"   uv failed, falling back to pip..."))
             if result.stdout:
-                print(result.stdout.decode(errors = "replace"))
+                print(_redact_install_output(result.stdout))
 
         pip_cmd = _build_pip_cmd(args) + constraint_args_pip + req_args_pip
         run(f"{label} (pip)" if USE_UV else label, pip_cmd)
@@ -2054,10 +2690,9 @@ def install_python_stack() -> int:
     global USE_UV, _STEP, _TOTAL
     _STEP = 0
 
-    # install.sh (which already installed unsloth) sets SKIP_STUDIO_BASE=1 to
-    # avoid reinstalling base packages. "unsloth studio update" does NOT set it,
-    # so base packages (unsloth + unsloth-zoo) are reinstalled to pick up new
-    # versions.
+    # install.sh sets SKIP_STUDIO_BASE=1 to avoid reinstalling base packages;
+    # `studio update` does NOT, so unsloth + unsloth-zoo are reinstalled to pick
+    # up new versions.
     skip_base = os.environ.get("SKIP_STUDIO_BASE", "0") == "1"
     # --package installs a different package name (for testing).
     package_name = os.environ.get("STUDIO_PACKAGE_NAME", "unsloth")
@@ -2067,9 +2702,9 @@ def install_python_stack() -> int:
     if IS_MACOS:
         base_total -= 1  # triton step is skipped on macOS
     if not IS_MACOS and not NO_TORCH:
-        base_total += 1  # ROCm torch check (line 1526) -- all non-macOS platforms
+        base_total += 1  # ROCm torch check (step 2b), non-macOS
         if not IS_WINDOWS:
-            base_total += 2  # flash-attn (line 1620) + ROCm torch final (line 1705) -- Linux only
+            base_total += 2  # flash-attn + torch final repair (step 13), Linux
     _TOTAL = (base_total - 1) if skip_base else base_total
 
     # 1. Try uv for faster installs (before pip upgrade -- uv venvs don't
@@ -2134,9 +2769,8 @@ def install_python_stack() -> int:
     if skip_base:
         pass
     elif NO_TORCH:
-        # No-torch update path: install unsloth + unsloth-zoo with --no-deps
-        # (PyPI metadata still declares torch as a hard dep), then runtime deps
-        # with --no-deps (avoids transitive torch).
+        # No-torch update path: install unsloth + unsloth-zoo, then runtime deps,
+        # both with --no-deps (PyPI metadata declares torch a hard dep; avoid it).
         _progress("base packages (no torch)")
         pip_install(
             f"Updating {package_name} + unsloth-zoo (no-torch mode)",
@@ -2149,10 +2783,9 @@ def install_python_stack() -> int:
             package_name,
             "unsloth-zoo",
         )
-        # Resolve pydantic WITH deps so pip pins pydantic-core to the exact
-        # version pydantic's metadata declares. Under --no-deps pip picks the
-        # latest of each and trips pydantic's _ensure_pydantic_core_version
-        # check. Transitive deps are torch-free.
+        # Resolve pydantic WITH deps so pip pins pydantic-core to the exact version
+        # its metadata declares (under --no-deps pip picks the latest of each and
+        # trips pydantic's _ensure_pydantic_core_version check). Deps are torch-free.
         pip_install(
             "Installing pydantic (with deps for compatible core)",
             "--no-cache-dir",
@@ -2244,6 +2877,7 @@ def install_python_stack() -> int:
         _progress(_torch_step_label("check"))
         _ensure_cuda_torch()
         _ensure_rocm_torch()
+        _ensure_cpu_torch()
 
     # Windows + AMD GPU: warn if ROCm torch was not installed (wrong Python
     # version or unknown ROCm version).
@@ -2309,16 +2943,15 @@ def install_python_stack() -> int:
         req = REQ_ROOT / "extras-no-deps.txt",
     )
 
-    # 4. Overrides (torchao) -- force-reinstall. The torchao version is chosen to
-    #    match the torch installed in the venv so its C++ extensions load (see
-    #    _select_torchao_spec). Skip when torch is unavailable (e.g. Intel Mac
-    #    GGUF-only mode): torchao requires torch. Also skipped on Windows ROCm
-    #    (no working build; see below).
+    # 4. Overrides (torchao) -- force-reinstall to a version matching the venv's
+    #    torch so its C++ extensions load (see _select_torchao_spec). Skipped when
+    #    torch is unavailable (Intel Mac GGUF-only) and on Windows ROCm (no working
+    #    build; see below).
     if NO_TORCH:
         _progress("dependency overrides (skipped, no torch)")
     elif _rocm_windows_torch_installed or _installed_torch_is_windows_rocm():
         # No working Windows ROCm torchao build: it imports an absent c10d backend
-        # and crashes transformers.quantizers. Studio stubs it at runtime, so
+        # and crashes transformers.quantizers. Unsloth stubs it at runtime, so
         # installing it only ships a package that crashes on import -- skip it.
         _progress("dependency overrides (skipped, Windows ROCm)")
         _safe_print("   Windows ROCm -- skipping torchao (no working build; stubbed at runtime)")
@@ -2371,7 +3004,7 @@ def install_python_stack() -> int:
     #     "https://raw.githubusercontent.com/unslothai/unsloth/refs/heads/main/unsloth/save.py",
     # )
 
-    # 8. Studio dependencies
+    # 8. Unsloth dependencies
     _progress("studio deps")
     pip_install(
         "Installing studio dependencies",
@@ -2430,14 +3063,12 @@ def install_python_stack() -> int:
         [sys.executable, str(SINGLE_ENV / "patch_metadata.py")],
     )
 
-    # 13. AMD ROCm: final torch repair. Several steps above can pull in CUDA
-    #     torch from PyPI (base packages, extras, overrides, studio deps, etc.).
-    #     Running the repair last ensures ROCm torch is in place at runtime,
-    #     whichever intermediate step clobbered it.
+    # 13. Final torch repair. Steps above can pull CUDA torch from PyPI, so repair last.
     if not IS_WINDOWS and not IS_MACOS and not NO_TORCH:
         _progress(_torch_step_label("final"))
         _ensure_cuda_torch()
         _ensure_rocm_torch()
+        _ensure_cpu_torch()
 
     # 14. Final check (silent; third-party conflicts are expected)
     subprocess.run(
diff --git a/studio/install_whisper_prebuilt.py b/studio/install_whisper_prebuilt.py
new file mode 100644
index 0000000000..f1a7fce5e0
--- /dev/null
+++ b/studio/install_whisper_prebuilt.py
@@ -0,0 +1,1401 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Cross-platform whisper.cpp (whisper-server) prebuilt installer for Unsloth Studio.
+
+Downloads a per-platform whisper.cpp bundle published by the Unsloth fork
+(``unslothai/whisper.cpp``) into an isolated ``<UNSLOTH_HOME>/whisper.cpp``,
+never a system whisper.cpp. The canonical install target matches the
+sidecar/build-script contract in ``stt_ggml_sidecar.py``:
+
+    <install-dir>/build/bin/whisper-server              (Unix)
+    <install-dir>/build/bin/Release/whisper-server.exe  (Windows)
+
+Bundles are dynamically linked: ``whisper-server`` needs ``libwhisper``,
+``libggml*`` and any GPU backend libraries. The binaries carry ``RUNPATH=$ORIGIN``
+so the installer co-locates every shared library from the archive into the same
+``build/bin`` directory and marks the server executable on Unix.
+
+Archives are verified against the release's own ``whisper-prebuilt-sha256.json``
+checksum index (same model as ``install_llama_prebuilt.py``). An asset absent
+from the index, or a release without it, fails closed (setup reports the prebuilt
+unavailable and local dictation uses Transformers STT). Being a same-origin
+checksum it proves integrity, not authenticity; pair the release with GitHub
+artifact attestations for provenance.
+
+Release resolution prefers the download host (``github.com/<repo>/releases/...``),
+fetching the manifest + checksum index with zero ``api.github.com`` calls (that
+API is rate-limited to 60 req/hour unauthenticated); the GitHub API is only a
+fallback on a 404 / malformed asset.
+
+The whole component-agnostic flow (verified downloads, safe extraction, the
+install lock, release resolution, checksum-index handling, the install driver,
+the resolve probe) lives in ``prebuilt_core.py`` and is shared with
+``install_llama_prebuilt.py``. This module keeps only the whisper specifics: the
+host mapping, install-tree layout, slim pairing with the installed llama.cpp ggml
+runtime, the pinned-release CPU escape hatch, the marker filename, and the CLI.
+Every retained public name is a thin wrapper tests can monkeypatch so the core
+observes the patch.
+
+Selection is slim-only for current releases (v1.9.1-unsloth.2+): every published
+bundle is a slim (ggml-less) whisper paired to the llama.cpp prebuilt, which
+provides all ggml backends. The per-accelerator fat selection chain was deleted
+with the fat bundles; the one legacy shape still honored is the published fat CPU
+bundle of an explicitly pinned pre-slim release.
+
+Mirrors ``install_node_prebuilt.py`` / ``install_llama_prebuilt.py``. Exit codes:
+0 success (or already current), 1 error, 2 incompatible paired release, 3 busy. A re-run
+that already matches logs "already matches" and returns 0 without downloading
+(the scripts grep it).
+"""
+
+from __future__ import annotations
+
+import argparse
+import os
+import re
+import shutil
+import subprocess
+import sys
+from dataclasses import dataclass, replace
+from pathlib import Path
+from typing import Any
+
+# Put studio/ on sys.path so install_llama_prebuilt / prebuilt_core resolve
+# whether run as a script (from any cwd) or imported by the tests.
+_STUDIO_DIR = os.path.dirname(os.path.abspath(__file__))
+if _STUDIO_DIR not in sys.path:
+    sys.path.insert(0, _STUDIO_DIR)
+
+import install_llama_prebuilt as llama  # noqa: E402
+import prebuilt_core as core  # noqa: E402
+
+# Shared machinery re-exported as module globals; the wrappers below resolve
+# these by bare name at call time so tests can monkeypatch them here.
+PrebuiltFallback = core.PrebuiltFallback
+BusyInstallConflict = core.BusyInstallConflict
+auth_headers = llama.auth_headers
+download_bytes = llama.download_bytes
+download_file = llama.download_file
+fetch_json = llama.fetch_json
+sha256_file = core.sha256_file
+_URL_OPENER = core._URL_OPENER
+install_lock = core.install_lock
+install_lock_path = core.install_lock_path
+parse_macos_version = core.parse_macos_version
+release_asset_map = core.release_asset_map
+release_asset_download_url = core.release_asset_download_url
+compute_install_fingerprint = core.compute_install_fingerprint
+artifact_coverage = core.artifact_coverage
+emit_resolver_output = core.emit_resolver_output
+_valid_sha256 = core.valid_sha256
+_swap_into_place = core.swap_into_place
+InstallSelection = core.InstallSelection
+ReleaseBundle = core.ReleaseBundle
+llama_detect_host = llama.detect_host
+installed_llama_runtime = llama.installed_llama_runtime
+
+# Late-binding seam for prebuilt_core: name lookups hit this module's globals
+# first (so monkeypatches apply), then the core defaults.
+_OPS = core.ModuleOps(globals())
+
+
+# Resolver mode keeps stdout to the JSON payload only (setup.sh parses it);
+# main() flips this on for the install path so setup surfaces progress.
+_LOG_TO_STDOUT = False
+
+
+class ReleaseCompatibilityError(PrebuiltFallback):
+    """A valid slim release cannot pair with this host's installed runtime."""
+
+
+def log(message: str) -> None:
+    print(f"[whisper-prebuilt] {message}", file = sys.stdout if _LOG_TO_STDOUT else sys.stderr)
+
+
+EXIT_SUCCESS = 0
+EXIT_ERROR = 1
+EXIT_INCOMPATIBLE = 2
+EXIT_BUSY = 3
+
+COMPONENT = "whisper.cpp"
+SCHEMA_VERSION = 1
+USER_AGENT = "unsloth-studio-whisper-prebuilt"
+
+DEFAULT_PUBLISHED_REPO = "unslothai/whisper.cpp"
+# Release assets published by the fork's prebuilt CI.
+MANIFEST_ASSET_NAME = "whisper-prebuilt-manifest.json"
+SHA256_ASSET_NAME = "whisper-prebuilt-sha256.json"
+
+METADATA_FILENAME = "UNSLOTH_WHISPER_PREBUILT_INFO.json"
+
+# Backends the installer can select: accelerator identities for the slim pairing
+# (which llama ggml module must exist) and the marker. Only "cpu" can match a fat
+# artifact (the pinned pre-slim escape hatch).
+SUPPORTED_BACKENDS = ("cpu", "cuda", "metal", "vulkan", "rocm")
+
+# Fallback the core applies on a GPU-selection miss: retry with cpu so the slim
+# bundle can pair via the llama cpu modules, or -- on a pinned pre-slim release --
+# the published fat CPU bundle installs. A miss is an install error unless the
+# valid slim release specifically requires a different paired llama release.
+FALLBACK_BACKEND = "cpu"
+
+# Backends whose slim (ggml-less) whisper bundle can ride the installed llama.cpp
+# prebuilt's ggml runtime. All are eligible: the next whisper release ships only
+# slim bundles, so cpu and metal pair like the GPUs do.
+SLIM_ELIGIBLE_BACKENDS = ("cpu", "cuda", "metal", "rocm", "vulkan")
+
+# ggml backend module the llama bin dir must provide per accelerator, keyed by
+# asset os token, following llama's bundle layout / health globs. A backend with
+# no glob for the host os (metal off macOS) is never slim there. llama's x64 cpu
+# bundles ship per-arch libggml-cpu-<variant> modules, macOS a single
+# libggml-cpu; the cpu globs cover both.
+SLIM_BACKEND_MODULE_GLOBS = {
+    "cpu": {
+        "linux": "libggml-cpu*.so*",
+        "windows": "ggml-cpu*.dll",
+        "macos": "libggml-cpu*.dylib",
+    },
+    "cuda": {"linux": "libggml-cuda.so*", "windows": "ggml-cuda.dll"},
+    "metal": {"macos": "libggml-metal*.dylib"},
+    "rocm": {"linux": "libggml-hip.so*", "windows": "*hip*.dll"},
+    "vulkan": {"linux": "libggml-vulkan.so*", "windows": "ggml-vulkan.dll"},
+}
+
+# Everything the slim wiring mirrors from the llama bin dir: the core ggml
+# sonames plus every dlopen'd backend module (CPU variants included). libggml*
+# matches .so and .dylib alike; ggml*.dll covers Windows. libomp*.dll rides along
+# because llama's clang-built windows-arm64 ggml-base.dll imports
+# libomp140.aarch64.dll, shipped in the llama bundle but never a system DLL, so
+# the loader needs it next to whisper-server.exe (MSVC x64 uses System32
+# vcomp140.dll; Linux ggml needs system libgomp.so.1, which llama already requires).
+SLIM_GGML_LIBRARY_GLOBS = ("libggml*", "ggml*.dll", "libomp*.dll")
+SLIM_ROCM_LIBRARY_GLOBS = (
+    "libamd*.so*",
+    "libhip*.so*",
+    "libhsa*.so*",
+    "libroc*.so*",
+)
+SLIM_ROCM_RUNTIME_DIRS = ("hipblaslt", "rocblas")
+SLIM_RUNTIME_WIRING_VERSION = 2
+
+INSTALL_STAGING_ROOT_NAME = ".staging"
+
+# Master switch for the staged runtime smoke test (start whisper-server + a tiny
+# transcription) before the atomic activate. Off by default so a bundle whose GPU
+# forward pass JIT-compiles kernels does not stall every install; the check and
+# its CPU-asset retry stay intact -- set True to re-enable.
+_RUN_STAGED_PREBUILT_VALIDATION = False
+
+
+# ── Host detection (probes shared with install_llama_prebuilt) ──
+@dataclass(frozen = True)
+class HostInfo:
+    system: str  # platform.system()
+    machine: str  # lowered platform.machine()
+    whisper_os: str  # asset token: linux | macos | windows
+    whisper_arch: str  # asset token: x64 | arm64
+    archive_ext: str  # .tar.gz | .zip
+    is_windows: bool
+    is_macos: bool
+    is_apple_silicon: bool
+    has_usable_nvidia: bool = False
+    has_rocm: bool = False
+    rocm_gfx: str | None = None
+    # (major, minor) from platform.mac_ver(); None off macOS or if unparseable.
+    # Enforces a macOS artifact's min_os so we never pick a bundle that cannot
+    # load on this OS version.
+    macos_version: tuple[int, int] | None = None
+
+
+def host_from_llama(base: Any) -> HostInfo:
+    """Map install_llama_prebuilt's detected host onto the whisper asset tokens.
+    Raises PrebuiltFallback on an unsupported OS/arch."""
+    system = base.system
+    machine = base.machine.lower()
+    if system == "Linux":
+        whisper_os = "linux"
+    elif system == "Darwin":
+        whisper_os = "macos"
+    elif system == "Windows":
+        whisper_os = "windows"
+    else:
+        raise PrebuiltFallback(f"unsupported operating system for whisper.cpp prebuilt: {system}")
+
+    if machine in {"x86_64", "amd64", "x64"}:
+        whisper_arch = "x64"
+    elif machine in {"arm64", "aarch64"}:
+        whisper_arch = "arm64"
+    else:
+        raise PrebuiltFallback(f"unsupported CPU architecture for whisper.cpp prebuilt: {machine}")
+
+    return HostInfo(
+        system = system,
+        machine = machine,
+        whisper_os = whisper_os,
+        whisper_arch = whisper_arch,
+        archive_ext = ".zip" if base.is_windows else ".tar.gz",
+        is_windows = base.is_windows,
+        is_macos = base.is_macos,
+        is_apple_silicon = base.is_macos and whisper_arch == "arm64",
+        has_usable_nvidia = base.has_usable_nvidia,
+        has_rocm = base.has_rocm,
+        rocm_gfx = base.rocm_gfx_target,
+        macos_version = base.macos_version,
+    )
+
+
+def detect_host() -> HostInfo:
+    return host_from_llama(llama_detect_host())
+
+
+def apply_host_overrides(
+    host: HostInfo,
+    *,
+    has_rocm: bool = False,
+    rocm_gfx: str | None = None,
+    force_cpu: bool = False,
+) -> HostInfo:
+    """Apply CLI overrides (setup forwards hardware hints) onto a detected host."""
+    if force_cpu:
+        return replace(
+            host,
+            has_usable_nvidia = False,
+            has_rocm = False,
+            rocm_gfx = None,
+            is_apple_silicon = False,
+        )
+    updates: dict[str, Any] = {}
+    if has_rocm or rocm_gfx:
+        # --rocm-gfx implies --has-rocm (llama parity); otherwise the host stays on
+        # its CUDA/CPU path and never picks the ROCm bundle. Drop CUDA detection too.
+        updates["has_rocm"] = True
+        updates["has_usable_nvidia"] = False
+    if rocm_gfx:
+        updates["rocm_gfx"] = rocm_gfx
+    return replace(host, **updates) if updates else host
+
+
+def host_platform_tokens(host: HostInfo) -> tuple[str, str]:
+    """Canonical (os, arch) asset tokens the core uses for matching/reporting."""
+    return host.whisper_os, host.whisper_arch
+
+
+# ── Backend selection ──
+def auto_detect_backend(host: HostInfo) -> str:
+    return core.auto_detect_backend(_OPS, host)
+
+
+def resolve_backend(host: HostInfo, requested: str | None, *, cpu_fallback: bool) -> str:
+    return core.resolve_backend(_OPS, host, requested, cpu_fallback = cpu_fallback)
+
+
+# ── Asset naming (pure, unit tested) ──
+def whisper_asset_name(release_tag: str, host: HostInfo, accel: str) -> str:
+    """e.g. whisper-v1.9.1-unsloth.1-linux-x64-cpu.tar.gz.
+
+    `accel` is the asset-filename accelerator token (cpu, metal, cuda12, ...),
+    finer-grained than the coarse backend. An install's authoritative asset name
+    comes from the release manifest; this constructor is for defaults/diagnostics.
+    """
+    tag = release_tag if release_tag.startswith("v") else f"v{release_tag}"
+    return f"whisper-{tag}-{host.whisper_os}-{host.whisper_arch}-{accel}{host.archive_ext}"
+
+
+# ── Manifest (release-side artifact catalogue; generic parser in the core) ──
+def validate_schema_version(payload: dict[str, Any], *, label: str) -> None:
+    core.validate_schema_version(
+        payload, label = label, schema_version = SCHEMA_VERSION, error = PrebuiltFallback
+    )
+
+
+def parse_manifest(payload: Any, *, label: str = MANIFEST_ASSET_NAME) -> dict[str, Any]:
+    return core.parse_manifest(_OPS, payload, label = label)
+
+
+def _macos_min_os_ok(host: HostInfo, min_os: Any) -> bool:
+    return core.macos_min_os_ok(_OPS, host, min_os)
+
+
+def macos_min_os_ok(host: HostInfo, min_os: Any) -> bool:
+    return _macos_min_os_ok(host, min_os)
+
+
+def _artifacts_for_host(
+    manifest: dict[str, Any], host: HostInfo, backend: str
+) -> list[dict[str, Any]]:
+    return core.artifacts_for_host(_OPS, manifest, host, backend)
+
+
+def artifacts_for_host(
+    manifest: dict[str, Any], host: HostInfo, backend: str
+) -> list[dict[str, Any]]:
+    return _artifacts_for_host(manifest, host, backend)
+
+
+# ── Slim selection (paired with the installed llama.cpp ggml runtime) ──
+def _llama_ggml_commit(tag: str) -> str | None:
+    """The ggml commit a llama.cpp fork tag was built against. Fork tags are
+    "b<upstream_build>-mix-<ggml_commit>"; the ggml commit after "-mix-" fixes
+    the ggml ABI the slim whisper bundle links against, while the build number
+    only tracks upstream llama / fork PRs outside ggml. None when the tag has no
+    "-mix-" marker (then only an exact tag pairs)."""
+    marker = "-mix-"
+    idx = tag.rfind(marker)
+    end = idx + len(marker)
+    return tag[end:] if idx >= 0 and end < len(tag) else None
+
+
+def llama_runtime_pairs(installed_tag: str, required_tag: Any) -> bool:
+    """Whether an installed llama tag can back a slim bundle needing required_tag.
+    An exact tag always pairs; so does a shared ggml commit, since a newer llama
+    build with the same ggml ships an ABI-identical runtime. requires_ggml_sonames
+    stays the real per-file ABI gate."""
+    if not isinstance(required_tag, str):
+        return False
+    if installed_tag == required_tag:
+        return True
+    commit = _llama_ggml_commit(installed_tag)
+    return commit is not None and commit == _llama_ggml_commit(required_tag)
+
+
+def slim_pairing_for_artifact(
+    artifact: dict[str, Any], host: HostInfo, backend: str
+) -> tuple[Path, str] | None:
+    """(llama bin dir, llama release tag) when the installed llama runtime can
+    back this slim artifact, else None. Each failed gate logs why; the caller
+    then retries via CPU or reports the prebuilt unavailable."""
+    asset = artifact.get("asset")
+    runtime = installed_llama_runtime()
+    if runtime is None:
+        log(f"slim_selection: {asset} skipped: no managed llama.cpp prebuilt install")
+        return None
+    llama_bin_dir, llama_tag, _profile = runtime
+    requires_tag = artifact.get("requires_llama_tag")
+    if not llama_runtime_pairs(llama_tag, requires_tag):
+        log(
+            f"slim_selection: {asset} skipped: installed llama tag {llama_tag!r} "
+            f"does not pair with required {requires_tag!r}"
+        )
+        return None
+    sonames = artifact.get("requires_ggml_sonames")
+    if not isinstance(sonames, list) or not sonames:
+        log(f"slim_selection: {asset} skipped: manifest lists no requires_ggml_sonames")
+        return None
+    missing = [str(name) for name in sonames if not (llama_bin_dir / str(name)).is_file()]
+    if missing:
+        log(f"slim_selection: {asset} skipped: llama runtime missing {', '.join(missing)}")
+        return None
+    module_glob = SLIM_BACKEND_MODULE_GLOBS.get(backend, {}).get(host.whisper_os)
+    if module_glob is None:
+        log(f"slim_selection: {asset} skipped: no {backend} ggml module on {host.whisper_os}")
+        return None
+    if not any(path.is_file() for path in llama_bin_dir.glob(module_glob)):
+        log(f"slim_selection: {asset} skipped: llama runtime has no {module_glob} module")
+        return None
+    log(f"slim_selection: selected {asset} paired with llama {llama_tag} at {llama_bin_dir}")
+    return llama_bin_dir, llama_tag
+
+
+def select_slim_artifact(
+    manifest: dict[str, Any], host: HostInfo, backend: str
+) -> dict[str, Any] | None:
+    """The paired slim artifact for any backend (cpu and metal included), or None.
+    Slim assets carry backend "slim" so the CPU escape hatch's fat os/arch/backend
+    matching never sees them. When the release ships slim candidates but none
+    pair, log the actionable reason: on a slim-only release nothing else selects,
+    setup reports the prebuilt unavailable, and local dictation stays on
+    Transformers STT."""
+    if backend not in SLIM_ELIGIBLE_BACKENDS:
+        return None
+    os_token, arch_token = host_platform_tokens(host)
+    candidates = [
+        artifact
+        for artifact in manifest.get("artifacts", [])
+        if artifact.get("os") == os_token
+        and artifact.get("arch") == arch_token
+        and artifact.get("backend") == "slim"
+        and artifact.get("install_kind") == "slim"
+        and (not host.is_macos or _macos_min_os_ok(host, artifact.get("min_os")))
+    ]
+    for artifact in candidates:
+        if slim_pairing_for_artifact(artifact, host, backend) is not None:
+            return artifact
+    if candidates:
+        required_tag = candidates[0].get("requires_llama_tag")
+        log(f"slim bundle requires llama.cpp {required_tag}; install or update llama.cpp first")
+    return None
+
+
+def select_artifact(
+    manifest: dict[str, Any], host: HostInfo, backend: str
+) -> dict[str, Any] | None:
+    """Slim-only: every backend resolves to the paired slim artifact. The one
+    legacy shape still honored is the published fat CPU bundle of a pinned pre-slim
+    release, reached by a GPU-backend miss through the core's CPU fallback retry.
+    No other fat artifact is ever selected."""
+    slim = select_slim_artifact(manifest, host, backend)
+    if slim is not None:
+        return slim
+    if backend != "cpu":
+        return None
+    candidates = _artifacts_for_host(manifest, host, "cpu")
+    return candidates[0] if candidates else None
+
+
+def select_artifact_with_cpu_fallback(
+    manifest: dict[str, Any], host: HostInfo, backend: str
+) -> tuple[dict[str, Any], str, bool]:
+    try:
+        return core.select_artifact_with_fallback(_OPS, manifest, host, backend)
+    except PrebuiltFallback as exc:
+        reason = _slim_release_incompatibility(manifest, host)
+        if reason is not None:
+            raise ReleaseCompatibilityError(reason) from exc
+        raise
+
+
+def _slim_release_incompatibility(manifest: dict[str, Any], host: HostInfo) -> str | None:
+    """Explain a valid platform slim release that this runtime cannot pair.
+
+    This intentionally excludes missing files, malformed manifests, checksum
+    failures, and unsupported platforms. Those are operational errors and must
+    never be converted into the update path's kept-existing-runtime success.
+    """
+    os_token, arch_token = host_platform_tokens(host)
+    candidates = [
+        artifact
+        for artifact in manifest.get("artifacts", [])
+        if artifact.get("os") == os_token
+        and artifact.get("arch") == arch_token
+        and artifact.get("backend") == "slim"
+        and artifact.get("install_kind") == "slim"
+    ]
+    if not candidates:
+        return None
+    os_compatible = [
+        artifact
+        for artifact in candidates
+        if not host.is_macos or _macos_min_os_ok(host, artifact.get("min_os"))
+    ]
+    if not os_compatible:
+        required = candidates[0].get("min_os")
+        return f"slim bundle requires macOS {required}; this host is older"
+    runtime = installed_llama_runtime()
+    if runtime is None:
+        return None
+    installed_tag = runtime[1]
+    required_tags = {
+        artifact.get("requires_llama_tag")
+        for artifact in os_compatible
+        if isinstance(artifact.get("requires_llama_tag"), str)
+    }
+    if required_tags and not any(llama_runtime_pairs(installed_tag, tag) for tag in required_tags):
+        required_tag = sorted(required_tags)[0]
+        return (
+            f"slim bundle requires llama.cpp {required_tag}; installed llama.cpp is {installed_tag}"
+        )
+    return None
+
+
+def select_artifact_with_fallback(
+    manifest: dict[str, Any], host: HostInfo, backend: str
+) -> tuple[dict[str, Any], str, bool]:
+    return select_artifact_with_cpu_fallback(manifest, host, backend)
+
+
+# ── Release checksum index (trust anchor: the release's own sha256 asset) ──
+def parse_release_checksums(repo: str, release_tag: str, payload: Any) -> dict[str, str]:
+    return core.parse_release_checksums(_OPS, repo, release_tag, payload)
+
+
+def fetch_release_checksums(bundle: ReleaseBundle) -> dict[str, str]:
+    return core.fetch_release_checksums(_OPS, bundle)
+
+
+def expected_sha256_for(
+    checksums: dict[str, str],
+    asset_name: str,
+    *,
+    manifest_sha256: str | None = None,
+) -> str:
+    return core.expected_sha256_for(_OPS, checksums, asset_name, manifest_sha256 = manifest_sha256)
+
+
+# ── Verified download (retries once on checksum mismatch) ──
+def download_file_verified(
+    url: str, destination: Path, *, expected_sha256: str, label: str
+) -> None:
+    core.download_file_verified_strict(
+        _OPS, url, destination, expected_sha256 = expected_sha256, label = label
+    )
+
+
+# ── GitHub release resolution ──
+def github_release(repo: str, tag: str) -> dict[str, Any]:
+    return core.github_release(_OPS, repo, tag, error = PrebuiltFallback)
+
+
+def fetch_release_bundle(repo: str, release_tag: str) -> ReleaseBundle:
+    return core.fetch_release_bundle(_OPS, repo, release_tag)
+
+
+def asset_download_url(bundle: ReleaseBundle, asset_name: str) -> str:
+    return core.asset_download_url(_OPS, bundle, asset_name)
+
+
+# ── Download-host fast path (resolve + fetch the JSON assets with no GitHub API) ──
+def _download_host_latest_release_tag(repo: str) -> str | None:
+    return core.download_host_latest_release_tag(_OPS, repo)
+
+
+def _download_host_json(url: str) -> Any:
+    return core.fetch_download_host_json(_OPS, url)
+
+
+def _resolve_release_via_download_host(
+    repo: str, published_release_tag: str | None
+) -> tuple[ReleaseBundle, dict[str, str]] | None:
+    return core.resolve_release_via_download_host(_OPS, repo, published_release_tag)
+
+
+# ── Archive extraction (core's guarded extractor + tar exec-bit restore) ──
+def extract_archive(archive_path: Path, destination: Path) -> None:
+    """Shared guarded extraction, then restore tar exec bits (the extractor writes
+    plain files; whisper-server must stay executable)."""
+    core.extract_archive(archive_path, destination)
+    core.restore_tar_exec_bits(archive_path, destination)
+
+
+# ── Install layout ──
+def server_binary_name(host: HostInfo) -> str:
+    return "whisper-server.exe" if host.is_windows else "whisper-server"
+
+
+def runtime_bin_dir(install_dir: Path, host: HostInfo) -> Path:
+    """Canonical directory holding whisper-server + its co-located libs."""
+    if host.is_windows:
+        return install_dir / "build" / "bin" / "Release"
+    return install_dir / "build" / "bin"
+
+
+def whisper_server_path(install_dir: Path, host: HostInfo) -> Path:
+    return runtime_bin_dir(install_dir, host) / server_binary_name(host)
+
+
+def installed_server_path(install_dir: Path, host: HostInfo) -> Path:
+    return whisper_server_path(install_dir, host)
+
+
+def _locate_server_in_tree(root: Path, host: HostInfo) -> Path:
+    return core.locate_server_in_tree(_OPS, root, host)
+
+
+def locate_server_in_tree(root: Path, host: HostInfo) -> Path:
+    return _locate_server_in_tree(root, host)
+
+
+def _assemble_install_tree(bundle_root: Path, staged_root: Path, host: HostInfo) -> Path:
+    """Lay out staged_root as a full install: build/bin/<server + libs>.
+
+    Everything beside the server in the archive (shared libs, backend kernel
+    subdirs, license/build-info) is co-located into the canonical bin dir so the
+    server's RUNPATH=$ORIGIN resolves its libs.
+    """
+    bin_dir = runtime_bin_dir(staged_root, host)
+    bin_dir.mkdir(parents = True, exist_ok = True)
+    for entry in sorted(bundle_root.iterdir()):
+        if entry.name == METADATA_FILENAME:
+            continue
+        dest = bin_dir / entry.name
+        if entry.is_dir() and not entry.is_symlink():
+            shutil.copytree(entry, dest, symlinks = True)
+        else:
+            shutil.copy2(entry, dest, follow_symlinks = False)
+    server = bin_dir / server_binary_name(host)
+    if not server.exists():
+        raise PrebuiltFallback("staged install is missing the whisper-server binary")
+    if not host.is_windows:
+        os.chmod(server, server.stat().st_mode | 0o111)
+    return server
+
+
+def assemble_install_tree(bundle_root: Path, staged_root: Path, host: HostInfo) -> Path:
+    return _assemble_install_tree(bundle_root, staged_root, host)
+
+
+def _validate_staged_server(staged_root: Path, host: HostInfo) -> None:
+    """Optional pre-activate smoke test. Gated off by default (see the switch)."""
+    if not _RUN_STAGED_PREBUILT_VALIDATION:
+        return
+    server = whisper_server_path(staged_root, host)
+    env = os.environ.copy()
+    bin_dir = str(runtime_bin_dir(staged_root, host))
+    for var in ("LD_LIBRARY_PATH", "DYLD_LIBRARY_PATH"):
+        env[var] = bin_dir + (os.pathsep + env[var] if env.get(var) else "")
+    try:
+        result = subprocess.run(
+            [str(server), "--help"],
+            capture_output = True,
+            text = True,
+            timeout = 60,
+            env = env,
+            **llama.windows_hidden_subprocess_kwargs(),
+        )
+    except (OSError, subprocess.SubprocessError) as exc:
+        raise PrebuiltFallback(f"staged whisper-server failed to launch: {exc}") from exc
+    if result.returncode != 0:
+        raise PrebuiltFallback(
+            f"staged whisper-server --help exited {result.returncode}: {result.stderr.strip()}"
+        )
+
+
+def validate_staged_server(staged_root: Path, host: HostInfo) -> None:
+    _validate_staged_server(staged_root, host)
+
+
+# ── Slim install wiring (llama ggml runtime into the whisper bin dir) ──
+def _elf_needed(path: Path) -> set[str] | None:
+    """Read ELF DT_NEEDED names when a standard inspection tool is available."""
+    commands = (("readelf", "-d"), ("objdump", "-p"))
+    for command in commands:
+        try:
+            result = subprocess.run(
+                [*command, str(path)], capture_output = True, text = True, timeout = 10
+            )
+        except (OSError, subprocess.SubprocessError):
+            continue
+        if result.returncode != 0:
+            continue
+        needed: set[str] = set()
+        for line in result.stdout.splitlines():
+            match = re.search(r"\(NEEDED\).*\[([^]]+)\]", line)
+            if match:
+                needed.add(match.group(1))
+                continue
+            match = re.match(r"\s*NEEDED\s+(\S+)", line)
+            if match:
+                needed.add(match.group(1))
+        return needed
+    return None
+
+
+def _runtime_library_sources(llama_bin_dir: Path, backend: str | None) -> list[Path]:
+    patterns = list(SLIM_GGML_LIBRARY_GLOBS)
+    sources = {
+        path for pattern in patterns for path in llama_bin_dir.glob(pattern) if path.is_file()
+    }
+    if backend == "rocm":
+        # Windows llama HIP/ROCm prebuilts use a flat *.dll runtime overlay.
+        # Mirror that complete no-SDK closure, not only filenames containing
+        # ggml, hip, or roc: transitive runtime DLLs can have unrelated names.
+        windows_dlls = {path for path in llama_bin_dir.glob("*.dll") if path.is_file()}
+        if windows_dlls:
+            sources.update(windows_dlls)
+            return sorted(sources)
+
+        # Linux can inspect DT_NEEDED and copy the exact packaged closure. Fall
+        # back to the ROCm globs only when standard ELF tools are unavailable.
+        by_name = {path.name: path for path in llama_bin_dir.iterdir() if path.is_file()}
+        pending = list(sources)
+        inspected_hip = False
+        system_libraries = {
+            "libc.so.6",
+            "libdl.so.2",
+            "libgcc_s.so.1",
+            "libm.so.6",
+            "libpthread.so.0",
+            "librt.so.1",
+            "libstdc++.so.6",
+        }
+        while pending:
+            source = pending.pop()
+            needed = _elf_needed(source)
+            if needed is None:
+                continue
+            if source.name.startswith("libggml-hip"):
+                inspected_hip = True
+            for name in needed - system_libraries:
+                dependency = by_name.get(name)
+                if dependency is not None and dependency not in sources:
+                    sources.add(dependency)
+                    pending.append(dependency)
+        if not inspected_hip:
+            sources.update(
+                path
+                for pattern in SLIM_ROCM_LIBRARY_GLOBS
+                for path in llama_bin_dir.glob(pattern)
+                if path.is_file()
+            )
+    return sorted(sources)
+
+
+def _link_or_copy(source: Path, destination: Path) -> None:
+    destination.parent.mkdir(parents = True, exist_ok = True)
+    if destination.exists() or destination.is_symlink():
+        destination.unlink()
+    try:
+        os.link(source, destination)
+    except OSError:
+        shutil.copy2(source, destination)
+
+
+def link_ggml_runtime(
+    llama_bin_dir: Path,
+    whisper_bin_dir: Path,
+    *,
+    backend: str | None = None,
+) -> list[str]:
+    """Hardlink every ggml library from the llama runtime into the whisper bin
+    dir; returns the wired filenames (sorted) for the marker / sidecar launch guard.
+
+    Hardlinks (not symlinks) on purpose: when the llama updater atomically swaps
+    its install dir, the old inodes stay alive under these links, so a
+    not-yet-updated whisper keeps running the exact ggml build it was installed
+    against. Falls back to a copy where linking is unsupported or crosses devices.
+    Re-run on every install/update so the links track the current pairing.
+    """
+    sources = _runtime_library_sources(llama_bin_dir, backend)
+    if not any(source.name.startswith(("libggml", "ggml")) for source in sources):
+        raise PrebuiltFallback(
+            f"no ggml libraries found in {llama_bin_dir} to pair the slim whisper install"
+        )
+    whisper_bin_dir.mkdir(parents = True, exist_ok = True)
+    for source in sources:
+        # Follows a libggml.so.0 -> libggml.so.0.x symlink to its inode, so every
+        # created name is a real hardlink surviving a dir swap.
+        _link_or_copy(source, whisper_bin_dir / source.name)
+    return [source.name for source in sources]
+
+
+def link_runtime_directories(
+    llama_bin_dir: Path, whisper_bin_dir: Path, *, backend: str, host: HostInfo
+) -> list[str]:
+    """Mirror GPU kernel catalogs that packaged ROCm libraries load at runtime."""
+    # Windows ROCm prebuilts are a flat DLL overlay. The hipblaslt/rocblas
+    # catalog directories are part of the Linux ROCm bundle layout only.
+    if backend != "rocm" or host.is_windows:
+        return []
+    linked: list[str] = []
+    for name in SLIM_ROCM_RUNTIME_DIRS:
+        source_root = llama_bin_dir / name
+        if not source_root.is_dir():
+            raise PrebuiltFallback(f"paired ROCm runtime is missing its {name} kernel catalog")
+        files = [path for path in source_root.rglob("*") if path.is_file()]
+        if not files:
+            raise PrebuiltFallback(f"paired ROCm runtime has an empty {name} kernel catalog")
+        for source in files:
+            _link_or_copy(source, whisper_bin_dir / name / source.relative_to(source_root))
+        linked.append(name)
+    return linked
+
+
+def prepare_runtime_payload(staged_root: Path, host: HostInfo, selection: Any) -> Any:
+    """Slim installs wire the paired llama ggml runtime into the staged bin dir
+    before validation so the activated tree is self-contained; the returned
+    selection carries the wired filenames for the marker. Fat installs need
+    nothing (the archive carries its ggml) and return None."""
+    if getattr(selection, "install_kind", None) != "slim" or not selection.linked_from:
+        return None
+    source = Path(selection.linked_from)
+    destination = runtime_bin_dir(staged_root, host)
+    linked = link_ggml_runtime(source, destination, backend = selection.backend)
+    linked_dirs = link_runtime_directories(
+        source,
+        destination,
+        backend = selection.backend,
+        host = host,
+    )
+    log(f"slim install: hardlinked {len(linked)} ggml libraries from {selection.linked_from}")
+    return replace(
+        selection,
+        linked_libraries = tuple(linked),
+        runtime_wiring_version = SLIM_RUNTIME_WIRING_VERSION,
+        linked_runtime_directories = tuple(linked_dirs),
+    )
+
+
+# ── Metadata / marker ──
+def metadata_path(install_dir: Path) -> Path:
+    return install_dir / METADATA_FILENAME
+
+
+def selection_from_artifact(
+    *,
+    published_repo: str,
+    release_tag: str,
+    manifest: dict[str, Any],
+    artifact: dict[str, Any],
+    backend: str,
+    asset_sha256: str,
+) -> InstallSelection:
+    selection = core.selection_from_artifact(
+        _OPS,
+        published_repo = published_repo,
+        release_tag = release_tag,
+        manifest = manifest,
+        artifact = artifact,
+        backend = backend,
+        asset_sha256 = asset_sha256,
+    )
+    if artifact.get("install_kind") != "slim":
+        return selection
+    # A slim selection carries its pairing so the install wiring and marker know
+    # which llama runtime provides the ggml libraries.
+    runtime = installed_llama_runtime()
+    if runtime is None or not llama_runtime_pairs(runtime[1], artifact.get("requires_llama_tag")):
+        raise PrebuiltFallback(
+            "the paired llama.cpp runtime changed underneath the slim whisper selection"
+        )
+    llama_bin_dir, llama_tag, _profile = runtime
+    return replace(
+        selection,
+        install_kind = "slim",
+        paired_llama_tag = llama_tag,
+        linked_from = str(llama_bin_dir),
+    )
+
+
+def write_prebuilt_metadata(install_dir: Path, selection: InstallSelection) -> None:
+    core.write_prebuilt_metadata(_OPS, install_dir, selection)
+
+
+def load_whisper_prebuilt_metadata(install_dir: Path) -> dict[str, Any] | None:
+    return core.load_prebuilt_metadata(_OPS, install_dir)
+
+
+def load_prebuilt_metadata(install_dir: Path) -> dict[str, Any] | None:
+    return load_whisper_prebuilt_metadata(install_dir)
+
+
+def existing_install_matches(
+    install_dir: Path, host: HostInfo, selection: InstallSelection
+) -> bool:
+    """Core fingerprint match, hardened for repairability: a marker-matching
+    install is only "current" when the server is executable (the sidecar refuses
+    non-executable binaries, so setup must repair not skip) and, for slim
+    installs, every wired ggml library is still present (else a deleted/moved
+    llama dir leaves dictation broken while update reports up to date)."""
+    if not core.existing_install_matches(_OPS, install_dir, host, selection):
+        return False
+    server = installed_server_path(install_dir, host)
+    if not host.is_windows and not os.access(server, os.X_OK):
+        log(f"existing install at {install_dir} has a non-executable server; reinstalling")
+        return False
+    marker = load_prebuilt_metadata(install_dir) or {}
+    if marker.get("install_kind") == "slim":
+        bin_dir = server.parent
+        if marker.get("runtime_wiring_version") != SLIM_RUNTIME_WIRING_VERSION:
+            log(f"existing slim install at {install_dir} has stale runtime wiring; reinstalling")
+            return False
+        linked_libraries = marker.get("linked_libraries")
+        if (
+            not isinstance(linked_libraries, list)
+            or not linked_libraries
+            or not all(
+                isinstance(name, str) and name and Path(name).name == name
+                for name in linked_libraries
+            )
+        ):
+            log(f"existing slim install at {install_dir} has invalid runtime wiring; reinstalling")
+            return False
+        missing = [name for name in linked_libraries if not (bin_dir / name).is_file()]
+        if missing:
+            log(
+                f"existing slim install at {install_dir} is missing wired ggml "
+                f"libraries ({', '.join(missing[:4])}); reinstalling"
+            )
+            return False
+        runtime_dirs = marker.get("linked_runtime_directories")
+        if (
+            marker.get("backend") == "rocm"
+            and not host.is_windows
+            and (
+                not isinstance(runtime_dirs, list)
+                or set(runtime_dirs) != set(SLIM_ROCM_RUNTIME_DIRS)
+            )
+        ):
+            log(f"existing ROCm install at {install_dir} lacks kernel catalogs; reinstalling")
+            return False
+        missing_dirs = [
+            name
+            for name in runtime_dirs or []
+            if not isinstance(name, str)
+            or not (bin_dir / name).is_dir()
+            or not any(path.is_file() for path in (bin_dir / name).rglob("*"))
+        ]
+        if missing_dirs:
+            log(
+                f"existing slim install at {install_dir} is missing runtime directories "
+                f"({', '.join(str(name) for name in missing_dirs[:4])}); reinstalling"
+            )
+            return False
+    return True
+
+
+# ── Orchestration ──
+def resolve_newest_release_tag(repo: str) -> str:
+    return core.resolve_newest_release_tag(_OPS, repo)
+
+
+def resolve_release_tag(published_repo: str, *, published_release_tag: str | None) -> str:
+    return core.resolve_release_tag(
+        _OPS, published_repo, published_release_tag = published_release_tag
+    )
+
+
+def fetch_release_for_install(
+    repo: str, *, published_release_tag: str | None
+) -> tuple[ReleaseBundle, dict[str, str]]:
+    return core.fetch_release_for_install(_OPS, repo, published_release_tag = published_release_tag)
+
+
+@dataclass(frozen = True)
+class WhisperReleasePlan:
+    bundle: ReleaseBundle
+    selection: InstallSelection | None
+    artifact: dict[str, Any]
+    resolved_backend: str
+    used_fallback: bool
+
+
+def _normalized_upstream_tag(value: str) -> str:
+    value = value.strip()
+    return value[1:] if value[:1].lower() == "v" else value
+
+
+def _bundle_matches_whisper_tag(bundle: ReleaseBundle, whisper_tag: str) -> bool:
+    requested = whisper_tag.strip()
+    if not requested or requested.lower() == "latest":
+        return True
+    upstream = bundle.manifest.get("upstream_tag")
+    return isinstance(upstream, str) and _normalized_upstream_tag(
+        upstream
+    ) == _normalized_upstream_tag(requested)
+
+
+def _published_release_tags(repo: str) -> list[str]:
+    """Published release tags in newest-first order for compatibility search."""
+    payload = fetch_json(f"https://api.github.com/repos/{repo}/releases?per_page=100")
+    if not isinstance(payload, list):
+        raise PrebuiltFallback(f"unexpected releases payload for {repo}")
+    releases = [
+        release
+        for release in payload
+        if isinstance(release, dict)
+        and not release.get("draft")
+        and not release.get("prerelease")
+        and isinstance(release.get("tag_name"), str)
+        and release.get("tag_name")
+    ]
+    releases.sort(key = lambda release: release.get("published_at") or "", reverse = True)
+    return [str(release["tag_name"]) for release in releases]
+
+
+def _fetch_release_candidate(repo: str, release_tag: str) -> ReleaseBundle:
+    """Fetch one candidate manifest by its deterministic download-host URL."""
+    manifest_url = release_asset_download_url(repo, release_tag, MANIFEST_ASSET_NAME)
+    try:
+        payload = _download_host_json(manifest_url)
+        manifest = parse_manifest(payload, label = f"{MANIFEST_ASSET_NAME} in {repo}@{release_tag}")
+    except Exception as exc:
+        raise PrebuiltFallback(
+            f"could not read {MANIFEST_ASSET_NAME} from {repo}@{release_tag}: {exc}"
+        ) from exc
+    asset_names = {MANIFEST_ASSET_NAME, SHA256_ASSET_NAME}
+    asset_names.update(
+        str(artifact["asset"])
+        for artifact in manifest.get("artifacts", [])
+        if isinstance(artifact, dict) and artifact.get("asset")
+    )
+    asset_urls = {name: release_asset_download_url(repo, release_tag, name) for name in asset_names}
+    return ReleaseBundle(
+        repo = repo,
+        release_tag = release_tag,
+        manifest = manifest,
+        asset_urls = asset_urls,
+    )
+
+
+def _plan_bundle(
+    host: HostInfo,
+    bundle: ReleaseBundle,
+    checksums: dict[str, str],
+    *,
+    published_repo: str,
+    requested_backend: str,
+    verify_checksums: bool,
+) -> WhisperReleasePlan:
+    artifact, resolved_backend, used_fallback = select_artifact_with_cpu_fallback(
+        bundle.manifest, host, requested_backend
+    )
+    selection = (
+        plan_selection(
+            host,
+            bundle,
+            published_repo = published_repo,
+            backend = requested_backend,
+            checksums = checksums,
+        )
+        if verify_checksums
+        else None
+    )
+    return WhisperReleasePlan(
+        bundle = bundle,
+        selection = selection,
+        artifact = artifact,
+        resolved_backend = resolved_backend,
+        used_fallback = used_fallback,
+    )
+
+
+def _release_plan_for_host(
+    host: HostInfo,
+    *,
+    published_repo: str,
+    published_release_tag: str | None,
+    whisper_tag: str,
+    requested_backend: str,
+    verify_checksums: bool = True,
+) -> WhisperReleasePlan:
+    """Select the requested or newest host-compatible published release.
+
+    Explicit published release pins never walk. An upstream ``whisper_tag``
+    searches published manifests for that exact upstream version. An unpinned
+    macOS install may walk older published releases only when the newest
+    manifest has no host-compatible artifact. Checksum and archive failures are
+    outside this search and remain hard failures.
+    """
+    requested_specific_tag = whisper_tag.strip().lower() not in ("", "latest")
+    first_bundle: ReleaseBundle | None = None
+    first_error: PrebuiltFallback | None = None
+    # An upstream version pin searches manifests directly. It must not depend
+    # on the unrelated newest release or its checksum index being healthy.
+    if not requested_specific_tag or published_release_tag:
+        first_bundle, first_checksums = fetch_release_for_install(
+            published_repo, published_release_tag = published_release_tag
+        )
+        if not _bundle_matches_whisper_tag(first_bundle, whisper_tag):
+            first_error = PrebuiltFallback(
+                f"{published_repo}@{first_bundle.release_tag} targets whisper.cpp "
+                f"{first_bundle.manifest.get('upstream_tag')}, not requested {whisper_tag}"
+            )
+        else:
+            try:
+                select_artifact_with_cpu_fallback(first_bundle.manifest, host, requested_backend)
+            except PrebuiltFallback as exc:
+                first_error = exc
+            else:
+                # Integrity validation happens only after compatibility succeeds.
+                # Its failures are never eligible for release walkback.
+                return _plan_bundle(
+                    host,
+                    first_bundle,
+                    first_checksums,
+                    published_repo = published_repo,
+                    requested_backend = requested_backend,
+                    verify_checksums = verify_checksums,
+                )
+
+    if published_release_tag:
+        assert first_error is not None
+        raise first_error
+
+    if not requested_specific_tag and not host.is_macos:
+        assert first_error is not None
+        raise first_error
+
+    for release_tag in _published_release_tags(published_repo):
+        if first_bundle is not None and release_tag == first_bundle.release_tag:
+            continue
+        try:
+            bundle = _fetch_release_candidate(published_repo, release_tag)
+        except PrebuiltFallback:
+            continue
+        if not _bundle_matches_whisper_tag(bundle, whisper_tag):
+            continue
+        try:
+            # Establish host compatibility before fetching or trusting this
+            # candidate's checksum index. Once selected, integrity failures must
+            # stop the install rather than silently downgrade again.
+            select_artifact_with_cpu_fallback(bundle.manifest, host, requested_backend)
+        except PrebuiltFallback:
+            continue
+        checksums = fetch_release_checksums(bundle) if verify_checksums else {}
+        plan = _plan_bundle(
+            host,
+            bundle,
+            checksums,
+            published_repo = published_repo,
+            requested_backend = requested_backend,
+            verify_checksums = verify_checksums,
+        )
+        log(
+            f"selected compatible published release {bundle.release_tag} "
+            f"(upstream {bundle.manifest.get('upstream_tag')})"
+        )
+        return plan
+
+    if requested_specific_tag:
+        raise PrebuiltFallback(
+            f"no published {COMPONENT} release for upstream tag {whisper_tag} supports this host"
+        )
+    assert first_error is not None
+    raise first_error
+
+
+def _install_from_bundle(
+    install_dir: Path, host: HostInfo, bundle: ReleaseBundle, selection: InstallSelection
+) -> None:
+    core.install_from_bundle(_OPS, install_dir, host, bundle, selection)
+
+
+def plan_selection(
+    host: HostInfo,
+    bundle: ReleaseBundle,
+    *,
+    published_repo: str,
+    backend: str,
+    checksums: dict[str, str],
+) -> InstallSelection:
+    return core.plan_selection(
+        _OPS,
+        host,
+        bundle,
+        published_repo = published_repo,
+        backend = backend,
+        checksums = checksums,
+    )
+
+
+def install_prebuilt(
+    install_dir: Path,
+    *,
+    whisper_tag: str = "latest",
+    published_repo: str = DEFAULT_PUBLISHED_REPO,
+    published_release_tag: str | None = None,
+    backend: str | None = "auto",
+    has_rocm: bool = False,
+    rocm_gfx: str | None = None,
+    cpu_fallback: bool = False,
+    force: bool = False,
+) -> int:
+    host = apply_host_overrides(
+        detect_host(), has_rocm = has_rocm, rocm_gfx = rocm_gfx, force_cpu = cpu_fallback
+    )
+    requested_backend = resolve_backend(host, backend, cpu_fallback = cpu_fallback)
+    os_token, arch_token = host_platform_tokens(host)
+    log(
+        f"target {COMPONENT} from {published_repo} "
+        f"({os_token}-{arch_token}, backend {requested_backend})"
+    )
+    plan = _release_plan_for_host(
+        host,
+        published_repo = published_repo,
+        published_release_tag = published_release_tag,
+        whisper_tag = whisper_tag,
+        requested_backend = requested_backend,
+    )
+    if plan.selection is None:  # pragma: no cover - install plans always verify
+        raise PrebuiltFallback("install plan did not validate its checksum entry")
+    return core.install_selected_prebuilt(
+        _OPS,
+        install_dir,
+        host = host,
+        bundle = plan.bundle,
+        selection = plan.selection,
+        force = force,
+    )
+
+
+def resolver_payload_extra(artifact: dict[str, Any]) -> dict[str, Any]:
+    """Additive --resolve-prebuilt field: whether the selected asset installs
+    slim (paired with the llama ggml runtime) or fat (self-contained)."""
+    return {"install_kind": "slim" if artifact.get("install_kind") == "slim" else "fat"}
+
+
+def resolve_prebuilt(
+    host: HostInfo,
+    *,
+    published_repo: str,
+    published_release_tag: str | None,
+    whisper_tag: str = "latest",
+    backend: str | None,
+    cpu_fallback: bool,
+) -> dict[str, Any]:
+    requested_backend = resolve_backend(host, backend, cpu_fallback = cpu_fallback)
+    try:
+        plan = _release_plan_for_host(
+            host,
+            published_repo = published_repo,
+            published_release_tag = published_release_tag,
+            whisper_tag = whisper_tag,
+            requested_backend = requested_backend,
+            verify_checksums = False,
+        )
+    except PrebuiltFallback:
+        return {"prebuilt_available": False, "repo": published_repo}
+    os_token, arch_token = host_platform_tokens(host)
+    payload = {
+        "prebuilt_available": True,
+        "repo": published_repo,
+        "release_tag": plan.bundle.release_tag,
+        "upstream_tag": plan.bundle.manifest.get("upstream_tag"),
+        "backend": plan.resolved_backend,
+        "requested_backend": requested_backend,
+        "cpu_fallback": plan.used_fallback,
+        "asset": str(plan.artifact.get("asset")),
+        "os": os_token,
+        "arch": arch_token,
+        "runtime_line": plan.artifact.get("runtime_line"),
+    }
+    payload.update(resolver_payload_extra(plan.artifact))
+    return payload
+
+
+# The whisper component descriptor: the declarative form of everything above,
+# for descriptor-driven consumers (shared tests, future tooling). The shipped CLI
+# runs through this module's wrappers so monkeypatch seams stay intact.
+DESCRIPTOR = core.ComponentDescriptor(
+    component = COMPONENT,
+    log_prefix = "whisper-prebuilt",
+    published_repo = DEFAULT_PUBLISHED_REPO,
+    manifest_asset_name = MANIFEST_ASSET_NAME,
+    sha256_asset_name = SHA256_ASSET_NAME,
+    metadata_filename = METADATA_FILENAME,
+    user_agent = USER_AGENT,
+    supported_backends = SUPPORTED_BACKENDS,
+    schema_version = SCHEMA_VERSION,
+    fallback_backend = FALLBACK_BACKEND,
+    detect_host = detect_host,
+    host_platform_tokens = host_platform_tokens,
+    server_binary_name = server_binary_name,
+    runtime_bin_dir = runtime_bin_dir,
+)
+
+
+def build_arg_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser(
+        description = "Install a prebuilt whisper.cpp (whisper-server) for Unsloth Studio"
+    )
+    parser.add_argument(
+        "--install-dir",
+        default = None,
+        help = (
+            "managed whisper.cpp directory, e.g. <UNSLOTH_HOME>/whisper.cpp. Required for an "
+            "install; omit it only with --resolve-prebuilt (a read-only probe)."
+        ),
+    )
+    parser.add_argument(
+        "--whisper-tag",
+        default = os.environ.get("UNSLOTH_WHISPER_TAG", "latest"),
+        help = "upstream whisper.cpp tag hint (default 'latest' or $UNSLOTH_WHISPER_TAG)",
+    )
+    parser.add_argument(
+        "--published-repo",
+        default = DEFAULT_PUBLISHED_REPO,
+        help = f"GitHub repo publishing the prebuilt releases (default {DEFAULT_PUBLISHED_REPO})",
+    )
+    parser.add_argument(
+        "--published-release-tag",
+        default = os.environ.get("UNSLOTH_WHISPER_RELEASE_TAG") or None,
+        help = "explicit release tag to install (default: the newest published release)",
+    )
+    parser.add_argument(
+        "--backend",
+        default = os.environ.get("UNSLOTH_WHISPER_BACKEND", "auto"),
+        choices = ("auto", *SUPPORTED_BACKENDS),
+        help = "accelerator backend; 'auto' detects from hardware",
+    )
+    parser.add_argument("--has-rocm", action = "store_true", help = "treat this host as ROCm-capable")
+    parser.add_argument("--rocm-gfx", default = None, help = "ROCm gfx target override, e.g. gfx1100")
+    parser.add_argument(
+        "--cpu-fallback", action = "store_true", help = "force the CPU asset regardless of hardware"
+    )
+    parser.add_argument(
+        "--resolve-prebuilt",
+        nargs = "?",
+        const = "latest",
+        default = None,
+        help = "report whether a prebuilt exists for this host without downloading",
+    )
+    parser.add_argument(
+        "--output-format",
+        choices = ("plain", "json"),
+        default = "plain",
+        help = "resolver output format (default plain)",
+    )
+    parser.add_argument(
+        "--force", action = "store_true", help = "reinstall even if the install already matches"
+    )
+    return parser
+
+
+def main(argv: list[str] | None = None) -> int:
+    global _LOG_TO_STDOUT
+    parser = build_arg_parser()
+    args = parser.parse_args(argv)
+
+    if args.resolve_prebuilt is not None:
+        # Read-only probe: stdout is only the JSON/asset line (setup.sh and
+        # whisper_cpp_update.py parse it), so force diagnostics to stderr and map
+        # any failure to "not available" rather than a traceback.
+        _LOG_TO_STDOUT = False
+        try:
+            host = apply_host_overrides(
+                detect_host(),
+                has_rocm = args.has_rocm,
+                rocm_gfx = args.rocm_gfx,
+                force_cpu = args.cpu_fallback,
+            )
+            payload = resolve_prebuilt(
+                host,
+                published_repo = args.published_repo,
+                published_release_tag = args.published_release_tag,
+                whisper_tag = args.resolve_prebuilt,
+                backend = args.backend,
+                cpu_fallback = args.cpu_fallback,
+            )
+        except PrebuiltFallback:
+            payload = {"prebuilt_available": False, "repo": args.published_repo}
+        except Exception as exc:  # noqa: BLE001 - probe must never crash the caller
+            log(f"resolve failed: {exc}")
+            payload = {"prebuilt_available": False, "repo": args.published_repo}
+        emit_resolver_output(payload, output_format = args.output_format)
+        return EXIT_SUCCESS
+
+    # Install path: progress logs go to stdout so setup surfaces them.
+    _LOG_TO_STDOUT = True
+
+    if not args.install_dir:
+        parser.error("--install-dir is required unless --resolve-prebuilt is used")
+    install_dir = Path(args.install_dir).expanduser().resolve()
+    try:
+        return install_prebuilt(
+            install_dir,
+            whisper_tag = args.whisper_tag,
+            published_repo = args.published_repo,
+            published_release_tag = args.published_release_tag,
+            backend = args.backend,
+            has_rocm = args.has_rocm,
+            rocm_gfx = args.rocm_gfx,
+            cpu_fallback = args.cpu_fallback,
+            force = args.force,
+        )
+    except BusyInstallConflict as exc:
+        log(str(exc))
+        return EXIT_BUSY
+    except ReleaseCompatibilityError as exc:
+        log(f"incompatible release: {exc}")
+        return EXIT_INCOMPATIBLE
+    except PrebuiltFallback as exc:
+        log(f"prebuilt install failed: {exc}")
+        return EXIT_ERROR
+    except Exception as exc:  # noqa: BLE001
+        log(f"unexpected error: {exc}")
+        return EXIT_ERROR
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/studio/prebuilt_core.py b/studio/prebuilt_core.py
new file mode 100644
index 0000000000..5dc85af1c2
--- /dev/null
+++ b/studio/prebuilt_core.py
@@ -0,0 +1,2427 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Component-agnostic machinery shared by the ggml-family prebuilt installers.
+
+``install_llama_prebuilt.py`` and ``install_whisper_prebuilt.py`` both run on
+this module, which owns two layers:
+
+1. Primitives: HTTP fetches with retries and token-safe redirects, verified
+   downloads, safe archive extraction, the install lock, sha256 helpers, and
+   CUDA runtime-line / compute-capability selection. Moved verbatim out of
+   ``install_llama_prebuilt.py``, which re-exports them under their old names.
+
+2. The generic descriptor-driven install flow: release resolution (download
+   host fast path, GitHub API fallback), checksum-index parsing, coverage-aware
+   artifact selection, verified download + extraction + staged atomic
+   activation, marker/fingerprint handling, and the resolve probe. Whisper runs
+   entirely on this flow; a third component plugs in with a ``ComponentDescriptor``.
+
+Seam rule: every function calling a collaborator tests monkeypatch takes an
+``ops`` handle first. ``ops`` resolves names in the calling installer module's
+globals first (so a ``monkeypatch.setattr`` still wins) and falls back to this
+module's defaults, letting a descriptor-only component work with no installer
+module behind it.
+"""
+
+from __future__ import annotations
+
+import errno
+import functools
+import hashlib
+import json
+import os
+import random
+import re
+import shutil
+import socket
+import subprocess
+import sys
+import tarfile
+import tempfile
+import time
+import urllib.error
+import urllib.parse
+import urllib.request
+import zipfile
+from contextlib import contextmanager
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any, Callable, Iterable, Iterator
+
+try:
+    from filelock import FileLock, Timeout as FileLockTimeout
+except ImportError:
+    FileLock = None
+    FileLockTimeout = None
+
+
+class PrebuiltFallback(RuntimeError):
+    pass
+
+
+class BusyInstallConflict(RuntimeError):
+    pass
+
+
+# ── Defaults a component module may override via its own globals ──
+USER_AGENT = "unsloth-studio-prebuilt"
+GITHUB_AUTH_HOSTS = {"api.github.com", "github.com"}
+HF_AUTH_HOSTS = {"huggingface.co", "www.huggingface.co"}
+RETRYABLE_HTTP_STATUS = {408, 429, 500, 502, 503, 504}
+HTTP_FETCH_ATTEMPTS = 4
+HTTP_FETCH_BASE_DELAY_SECONDS = 0.75
+JSON_FETCH_ATTEMPTS = 3
+TTY_PROGRESS_START_DELAY_SECONDS = 0.5
+INSTALL_LOCK_TIMEOUT_SECONDS = 300
+INSTALL_STAGING_ROOT_NAME = ".staging"
+SCHEMA_VERSION = 1
+# Backend to retry when the preferred one has no covering asset; None disables it.
+FALLBACK_BACKEND: str | None = "cpu"
+_RATE_LIMIT_WAIT_CAP_SECONDS = 60.0
+
+# Lowest CUDA major we ship prebuilts for, and highest we probe for installed
+# runtime libraries. Detection and runtime-line derivation are generated per
+# major, so a new toolkit (cuda14, ...) needs no code change while ggml keeps
+# the cudart64_<major>.dll / libcudart.so.<major> naming.
+_MIN_CUDA_MAJOR = 12
+_MAX_PROBE_CUDA_MAJOR = 19
+
+# Blackwell floor is sm_100 (B100/B200 sm_100, B300/GB300 sm_103 below consumer
+# RTX 50 sm_120); the family needs toolkit >= 12.8, sm_103/sm_121 need 12.9.
+_BLACKWELL_MIN_SM = 100
+_BLACKWELL_MIN_TOOLKIT = (12, 8)
+_BLACKWELL_SM_MIN_TOOLKIT = {103: (12, 9), 121: (12, 9)}
+
+
+def log(message: str) -> None:
+    print(f"[prebuilt-core] {message}", file = sys.stderr)
+
+
+def _cuda_runtime_lines_for_major(major: int) -> list[str]:
+    """Runtime lines a driver of this CUDA major can use (its own major and any
+    older one, newest first down to the minimum we ship)."""
+    return [f"cuda{m}" for m in range(major, _MIN_CUDA_MAJOR - 1, -1)]
+
+
+# ── The ops seam ──
+_MISSING = object()
+
+# Core functions expecting an ``ops`` first argument. ModuleOps binds itself when
+# a lookup falls back to the core default, so a descriptor-only component gets
+# working defaults while an installer wrapper (or a test monkeypatch) always wins.
+_OPS_FIRST_NAMES = {
+    "auth_headers",
+    "github_api_headers",
+    "download_bytes",
+    "fetch_json",
+    "download_file",
+    "download_file_verified",
+    "download_file_verified_strict",
+    "github_release",
+    "github_release_assets",
+    "download_host_latest_release_tag",
+    "fetch_download_host_json",
+    "linux_runtime_dirs_for_required_libraries",
+    "detected_linux_runtime_lines",
+    "detected_windows_runtime_lines",
+    "parse_manifest",
+    "parse_release_checksums",
+    "fetch_release_checksums",
+    "expected_sha256_for",
+    "macos_min_os_ok",
+    "artifacts_for_host",
+    "select_artifact",
+    "select_artifact_with_fallback",
+    "auto_detect_backend",
+    "resolve_backend",
+    "fetch_release_bundle",
+    "asset_download_url",
+    "resolve_newest_release_tag",
+    "resolve_release_tag",
+    "resolve_release_via_download_host",
+    "fetch_release_for_install",
+    "write_prebuilt_metadata",
+    "load_prebuilt_metadata",
+    "existing_install_matches",
+    "metadata_path",
+    "selection_from_artifact",
+    "plan_selection",
+    "install_from_bundle",
+    "install_prebuilt",
+    "resolve_prebuilt",
+    "installed_server_path",
+    "assemble_install_tree",
+    "validate_staged_server",
+    "locate_server_in_tree",
+    # Underscored aliases the installer modules expose for their tests.
+    "_download_host_latest_release_tag",
+    "_download_host_json",
+    "_resolve_release_via_download_host",
+    "_install_from_bundle",
+}
+
+
+class ModuleOps:
+    """Late-binding name resolver over an installer module's globals.
+
+    Lookup hits the wrapped globals first (so a ``monkeypatch.setattr`` is always
+    observed), then this module's defaults (ops-first defaults come back bound).
+    """
+
+    def __init__(self, module_globals: dict[str, Any]) -> None:
+        self._globals = module_globals
+
+    def __getattr__(self, name: str) -> Any:
+        value = self._globals.get(name, _MISSING)
+        if value is _MISSING:
+            value = globals().get(name, _MISSING)
+            if value is _MISSING:
+                raise AttributeError(f"prebuilt component namespace has no attribute {name!r}")
+            if name in _OPS_FIRST_NAMES:
+                return functools.partial(value, self)
+        return value
+
+
+@dataclass(frozen = True)
+class ComponentDescriptor:
+    """Everything the generic flow needs about one ggml-family component.
+
+    Hooks mirror the module-level names an installer defines; a descriptor-only
+    component supplies them here and ``component_ops`` builds a namespace with
+    core defaults behind them.
+    """
+
+    component: str  # manifest "component" value, e.g. "whisper.cpp"
+    log_prefix: str  # stderr prefix, e.g. "whisper-prebuilt"
+    published_repo: str  # fork publishing the prebuilt releases
+    manifest_asset_name: str
+    sha256_asset_name: str
+    metadata_filename: str  # marker written into the install dir
+    user_agent: str
+    supported_backends: tuple[str, ...] = ("cpu", "cuda", "metal", "vulkan", "rocm")
+    schema_version: int = SCHEMA_VERSION
+    # Backend to retry when the preferred one has no covering asset: "cpu"
+    # (whisper) ships a CPU bundle in every release; None (llama) reports "no
+    # prebuilt" so the caller falls back to a source build.
+    fallback_backend: str | None = "cpu"
+    staging_root_name: str = INSTALL_STAGING_ROOT_NAME
+    run_staged_validation: bool = False
+    # Hooks. Each mirrors the module-level function it replaces; None keeps the
+    # core default (which raises if truly required).
+    detect_host: Callable[[], Any] | None = None
+    host_platform_tokens: Callable[[Any], tuple[str, str]] | None = None
+    server_binary_name: Callable[[Any], str] | None = None
+    runtime_bin_dir: Callable[[Path, Any], Path] | None = None
+    auto_detect_backend: Callable[[Any], str] | None = None
+
+
+def component_namespace(descriptor: ComponentDescriptor) -> dict[str, Any]:
+    """Materialize a descriptor into the module-like namespace ``ModuleOps``
+    resolves against; core defaults cover anything not listed here."""
+    prefix = descriptor.log_prefix
+
+    def component_log(message: str) -> None:
+        print(f"[{prefix}] {message}", file = sys.stderr)
+
+    namespace: dict[str, Any] = {
+        "COMPONENT": descriptor.component,
+        "SCHEMA_VERSION": descriptor.schema_version,
+        "DEFAULT_PUBLISHED_REPO": descriptor.published_repo,
+        "MANIFEST_ASSET_NAME": descriptor.manifest_asset_name,
+        "SHA256_ASSET_NAME": descriptor.sha256_asset_name,
+        "METADATA_FILENAME": descriptor.metadata_filename,
+        "SUPPORTED_BACKENDS": descriptor.supported_backends,
+        "USER_AGENT": descriptor.user_agent,
+        "FALLBACK_BACKEND": descriptor.fallback_backend,
+        "INSTALL_STAGING_ROOT_NAME": descriptor.staging_root_name,
+        "_RUN_STAGED_PREBUILT_VALIDATION": descriptor.run_staged_validation,
+        "log": component_log,
+    }
+    for hook in (
+        "detect_host",
+        "host_platform_tokens",
+        "server_binary_name",
+        "runtime_bin_dir",
+        "auto_detect_backend",
+    ):
+        value = getattr(descriptor, hook)
+        if value is not None:
+            namespace[hook] = value
+    return namespace
+
+
+def component_ops(descriptor: ComponentDescriptor) -> ModuleOps:
+    return ModuleOps(component_namespace(descriptor))
+
+
+# ── Lock/busy classification ──
+def _os_error_messages(exc: BaseException) -> list[str]:
+    messages: list[str] = []
+    if isinstance(exc, OSError):
+        for value in (
+            getattr(exc, "strerror", None),
+            getattr(exc, "filename", None),
+            getattr(exc, "filename2", None),
+        ):
+            if isinstance(value, str) and value:
+                messages.append(value)
+    text = str(exc)
+    if text:
+        messages.append(text)
+    return [message.lower() for message in messages if message]
+
+
+def is_busy_lock_error(exc: BaseException) -> bool:
+    if isinstance(exc, BusyInstallConflict):
+        return True
+    if isinstance(exc, OSError):
+        if exc.errno in {
+            errno.EACCES,
+            errno.EBUSY,
+            errno.EPERM,
+            errno.ETXTBSY,
+        }:
+            return True
+        if getattr(exc, "winerror", None) in {5, 32, 145}:
+            return True
+    for message in _os_error_messages(exc):
+        if any(
+            needle in message
+            for needle in (
+                "access is denied",
+                "being used by another process",
+                "device or resource busy",
+                "permission denied",
+                "text file busy",
+                "file is in use",
+                "process cannot access the file",
+                "cannot create a file when that file already exists",
+            )
+        ):
+            return True
+    return False
+
+
+# ── HTTP: auth, redirects, retries ──
+def parsed_hostname(url: str | None) -> str | None:
+    if not url:
+        return None
+    try:
+        hostname = urllib.parse.urlparse(url).hostname
+    except Exception:
+        return None
+    if not hostname:
+        return None
+    return hostname.lower()
+
+
+def should_send_github_auth(url: str | None) -> bool:
+    return parsed_hostname(url) in GITHUB_AUTH_HOSTS
+
+
+def should_send_hf_auth(url: str | None) -> bool:
+    return parsed_hostname(url) in HF_AUTH_HOSTS
+
+
+def auth_headers(ops: ModuleOps, url: str | None = None) -> dict[str, str]:
+    headers = {
+        "User-Agent": ops.USER_AGENT,
+    }
+    token = os.environ.get("GH_TOKEN") or os.environ.get("GITHUB_TOKEN")
+    if token and should_send_github_auth(url):
+        headers["Authorization"] = f"Bearer {token}"
+        return headers
+    # Anonymous huggingface.co fetches share a per-IP rate limit CI fleets
+    # exhaust (HTTP 429); authenticate when a token is available.
+    hf_token = os.environ.get("HF_TOKEN") or os.environ.get("HUGGING_FACE_HUB_TOKEN")
+    if hf_token and should_send_hf_auth(url):
+        headers["Authorization"] = f"Bearer {hf_token}"
+    return headers
+
+
+class _CrossHostAuthStrippingRedirectHandler(urllib.request.HTTPRedirectHandler):
+    """Drop Authorization when a redirect leaves the original host.
+
+    huggingface.co redirects downloads to CDN hosts whose signed URLs can reject
+    a foreign Authorization header; urllib forwards headers across redirects by
+    default (requests/huggingface_hub strip them).
+    """
+
+    def redirect_request(self, req, fp, code, msg, headers, newurl):
+        new_request = super().redirect_request(req, fp, code, msg, headers, newurl)
+        if new_request is not None and parsed_hostname(newurl) != parsed_hostname(req.full_url):
+            new_request.headers.pop("Authorization", None)
+            new_request.unredirected_hdrs.pop("Authorization", None)
+        return new_request
+
+
+_URL_OPENER = urllib.request.build_opener(_CrossHostAuthStrippingRedirectHandler())
+
+
+def github_api_headers(ops: ModuleOps, url: str | None = None) -> dict[str, str]:
+    return {
+        "Accept": "application/vnd.github+json",
+        **ops.auth_headers(url),
+    }
+
+
+def is_github_api_url(url: str | None) -> bool:
+    return parsed_hostname(url) == "api.github.com"
+
+
+def is_retryable_url_error(exc: Exception) -> bool:
+    if isinstance(exc, urllib.error.HTTPError):
+        # GitHub returns 403 (not 429) on API rate-limit; anonymous calls share a
+        # 60-req/hour bucket per runner IP that CI fleets exhaust. Treat 403
+        # against api.github.com as retryable so we get a backoff cycle or two
+        # (honouring Retry-After / X-RateLimit-Reset) before the source-build
+        # fallback fires. 403s on other hosts (private downloads, auth) stay non-retryable.
+        if exc.code == 403:
+            return is_github_api_url(getattr(exc, "url", None))
+        return exc.code in RETRYABLE_HTTP_STATUS
+    if isinstance(exc, urllib.error.URLError):
+        return True
+    if isinstance(exc, TimeoutError):
+        return True
+    if isinstance(exc, socket.timeout):
+        return True
+    return False
+
+
+def _http_error_retry_delay(exc: Exception) -> float | None:
+    """Recommended wait from rate-limit headers on a 403/429.
+
+    None when no header is present or the wait exceeds
+    _RATE_LIMIT_WAIT_CAP_SECONDS (the source-build fallback is faster).
+    """
+    if not isinstance(exc, urllib.error.HTTPError):
+        return None
+    headers = getattr(exc, "headers", None)
+    if headers is None:
+        return None
+    retry_after = headers.get("Retry-After")
+    if retry_after and retry_after.strip().isdigit():
+        wait = float(retry_after.strip())
+        return wait if wait <= _RATE_LIMIT_WAIT_CAP_SECONDS else None
+    rate_reset = headers.get("X-RateLimit-Reset")
+    if rate_reset and rate_reset.strip().isdigit():
+        wait = float(rate_reset.strip()) - time.time()
+        if 0.0 < wait <= _RATE_LIMIT_WAIT_CAP_SECONDS:
+            return wait + 1.0  # +1s of slack so the bucket is fresh
+    return None
+
+
+def sleep_backoff(
+    attempt: int,
+    *,
+    base_delay: float = HTTP_FETCH_BASE_DELAY_SECONDS,
+    exc: Exception | None = None,
+) -> None:
+    delay = base_delay * (2 ** max(attempt - 1, 0))
+    header_delay = _http_error_retry_delay(exc) if exc is not None else None
+    if header_delay is not None:
+        delay = max(delay, header_delay)
+    delay += random.uniform(0.0, 0.2)
+    time.sleep(delay)
+
+
+# ── Atomic writes and hashing ──
+def atomic_write_bytes(destination: Path, data: bytes) -> None:
+    destination.parent.mkdir(parents = True, exist_ok = True)
+    with tempfile.NamedTemporaryFile(
+        prefix = destination.name + ".tmp-",
+        dir = destination.parent,
+        delete = False,
+    ) as handle:
+        tmp_path = Path(handle.name)
+        handle.write(data)
+        handle.flush()
+        os.fsync(handle.fileno())
+    os.replace(tmp_path, destination)
+
+
+def atomic_replace_from_tempfile(tmp_path: Path, destination: Path) -> None:
+    destination.parent.mkdir(parents = True, exist_ok = True)
+    os.replace(tmp_path, destination)
+
+
+def sha256_file(path: Path) -> str:
+    digest = hashlib.sha256()
+    with path.open("rb") as handle:
+        for chunk in iter(lambda: handle.read(1024 * 1024), b""):
+            digest.update(chunk)
+    return digest.hexdigest()
+
+
+def sha256_bytes(data: bytes) -> str:
+    return hashlib.sha256(data).hexdigest()
+
+
+def normalize_sha256_digest(value: str | None) -> str | None:
+    if not isinstance(value, str) or not value:
+        return None
+    lowered = value.lower()
+    if lowered.startswith("sha256:"):
+        lowered = lowered.split(":", 1)[1]
+    if len(lowered) != 64 or any(ch not in "0123456789abcdef" for ch in lowered):
+        return None
+    return lowered
+
+
+def validate_schema_version(
+    payload: dict[str, Any],
+    *,
+    label: str,
+    schema_version: int = SCHEMA_VERSION,
+    error: type[Exception] = RuntimeError,
+) -> None:
+    value = payload.get("schema_version")
+    if value is None:
+        return
+    try:
+        normalized = int(value)
+    except (TypeError, ValueError) as exc:
+        raise error(f"{label} schema_version was not an integer") from exc
+    if normalized != schema_version:
+        raise error(f"{label} schema_version={normalized} is unsupported")
+
+
+# ── Download progress ──
+def format_byte_count(num_bytes: float) -> str:
+    units = ["B", "KiB", "MiB", "GiB", "TiB"]
+    value = float(num_bytes)
+    for unit in units:
+        if abs(value) < 1024.0 or unit == units[-1]:
+            if unit == "B":
+                return f"{int(value)} {unit}"
+            return f"{value:.1f} {unit}"
+        value /= 1024.0
+    return f"{num_bytes:.1f} B"
+
+
+def _progress_percent_step() -> int:
+    """Non-tty milestone granularity. The in-app updater sets
+    UNSLOTH_PROGRESS_PERCENT_STEP=5 for finer progress lines."""
+    try:
+        step = int(os.environ.get("UNSLOTH_PROGRESS_PERCENT_STEP", "25"))
+    except ValueError:
+        return 25
+    return min(max(step, 1), 50)
+
+
+class DownloadProgress:
+    def __init__(self, label: str, total_bytes: int | None) -> None:
+        self.label = label
+        self.total_bytes = total_bytes if total_bytes and total_bytes > 0 else None
+        self.start_time = time.monotonic()
+        self.last_emit = 0.0
+        term_ok = os.environ.get("TERM", "").lower() != "dumb"
+        self.stream = (
+            sys.stderr if sys.stderr.isatty() else sys.stdout if sys.stdout.isatty() else sys.stderr
+        )
+        self.is_tty = term_ok and self.stream.isatty()
+        self.completed = False
+        self.milestone_step = _progress_percent_step()
+        self.last_milestone_percent = -1
+        self.last_milestone_bytes = 0
+        self.has_rendered_tty_progress = False
+
+    def _render(
+        self,
+        downloaded_bytes: int,
+        *,
+        final: bool = False,
+    ) -> str:
+        elapsed = max(time.monotonic() - self.start_time, 1e-6)
+        speed = downloaded_bytes / elapsed
+        speed_text = f"{format_byte_count(speed)}/s"
+        if self.total_bytes is not None:
+            percent = min(100.0, (downloaded_bytes / self.total_bytes) * 100.0)
+            return (
+                f"{self.label}: {percent:5.1f}% "
+                f"({format_byte_count(downloaded_bytes)}/{format_byte_count(self.total_bytes)}) "
+                f"at {speed_text}"
+            )
+        if final:
+            return f"{self.label}: {format_byte_count(downloaded_bytes)} downloaded at {speed_text}"
+        return f"{self.label}: {format_byte_count(downloaded_bytes)} downloaded at {speed_text}"
+
+    def update(self, downloaded_bytes: int) -> None:
+        now = time.monotonic()
+        if self.is_tty:
+            elapsed = now - self.start_time
+            if not self.has_rendered_tty_progress:
+                if self.total_bytes is not None and downloaded_bytes >= self.total_bytes:
+                    return
+                if elapsed < TTY_PROGRESS_START_DELAY_SECONDS:
+                    return
+            min_interval = 0.2
+            if (
+                self.has_rendered_tty_progress
+                and not self.completed
+                and (now - self.last_emit) < min_interval
+            ):
+                return
+            self.last_emit = now
+            line = self._render(downloaded_bytes)
+            self.stream.write("\r\033[K" + line)
+            self.stream.flush()
+            self.has_rendered_tty_progress = True
+            return
+
+        should_emit = False
+        if self.total_bytes is not None:
+            percent = int((downloaded_bytes * 100) / max(self.total_bytes, 1))
+            step = self.milestone_step
+            milestone_percent = min((percent // step) * step, 100)
+            if milestone_percent > self.last_milestone_percent and milestone_percent < 100:
+                self.last_milestone_percent = milestone_percent
+                should_emit = True
+        else:
+            byte_step = 25 * 1024 * 1024
+            if (
+                downloaded_bytes - self.last_milestone_bytes >= byte_step
+                and (now - self.last_emit) >= 5.0
+            ):
+                self.last_milestone_bytes = downloaded_bytes
+                should_emit = True
+
+        if not should_emit:
+            return
+
+        self.last_emit = now
+        self.stream.write(self._render(downloaded_bytes) + "\n")
+        self.stream.flush()
+
+    def finish(self, downloaded_bytes: int) -> None:
+        self.completed = True
+        line = self._render(downloaded_bytes, final = True)
+        if self.is_tty:
+            if not self.has_rendered_tty_progress:
+                return
+            self.stream.write("\r\033[K")
+        else:
+            self.stream.write(line + "\n")
+        self.stream.flush()
+
+
+def download_label_from_url(url: str) -> str:
+    name = Path(urllib.parse.urlparse(url).path).name
+    return name or url
+
+
+# ── Downloads ──
+def download_bytes(
+    ops: ModuleOps,
+    url: str,
+    *,
+    timeout: int = 120,
+    attempts: int | None = None,
+    headers: dict[str, str] | None = None,
+    progress_label: str | None = None,
+) -> bytes:
+    if attempts is None:
+        attempts = ops.HTTP_FETCH_ATTEMPTS
+    last_exc: Exception | None = None
+    for attempt in range(1, attempts + 1):
+        try:
+            request = urllib.request.Request(url, headers = headers or ops.auth_headers(url))
+            with ops._URL_OPENER.open(request, timeout = timeout) as response:
+                total_bytes: int | None = None
+                content_length = response.headers.get("Content-Length")
+                if content_length and content_length.isdigit():
+                    total_bytes = int(content_length)
+                progress = DownloadProgress(progress_label, total_bytes) if progress_label else None
+                data = bytearray()
+                while True:
+                    chunk = response.read(1024 * 1024)
+                    if not chunk:
+                        break
+                    data.extend(chunk)
+                    if progress is not None:
+                        progress.update(len(data))
+                if progress is not None:
+                    progress.finish(len(data))
+                return bytes(data)
+        except Exception as exc:
+            last_exc = exc
+            if attempt >= attempts or not is_retryable_url_error(exc):
+                raise
+            ops.log(f"fetch failed ({attempt}/{attempts}) for {url}: {exc}; retrying")
+            sleep_backoff(attempt, exc = exc)
+    assert last_exc is not None
+    raise last_exc
+
+
+def fetch_json(ops: ModuleOps, url: str) -> Any:
+    attempts = ops.JSON_FETCH_ATTEMPTS if is_github_api_url(url) else 1
+    last_decode_exc: Exception | None = None
+    for attempt in range(1, attempts + 1):
+        try:
+            data = ops.download_bytes(
+                url,
+                timeout = 30,
+                headers = ops.github_api_headers(url)
+                if is_github_api_url(url)
+                else ops.auth_headers(url),
+            )
+        except urllib.error.HTTPError as exc:
+            if exc.code == 403 and is_github_api_url(url):
+                hint = ""
+                if not (os.environ.get("GH_TOKEN") or os.environ.get("GITHUB_TOKEN")):
+                    hint = "; set GH_TOKEN or GITHUB_TOKEN to avoid GitHub API rate limits"
+                raise RuntimeError(f"GitHub API returned 403 for {url}{hint}") from exc
+            raise
+        if not data:
+            last_decode_exc = RuntimeError(f"downloaded empty JSON payload from {url}")
+        else:
+            try:
+                payload = json.loads(data.decode("utf-8"))
+            except (UnicodeDecodeError, json.JSONDecodeError) as exc:
+                last_decode_exc = RuntimeError(f"downloaded invalid JSON from {url}: {exc}")
+            else:
+                if not isinstance(payload, dict) and not isinstance(payload, list):
+                    raise RuntimeError(
+                        f"downloaded unexpected JSON type from {url}: {type(payload).__name__}"
+                    )
+                return payload
+        if attempt >= attempts:
+            assert last_decode_exc is not None
+            raise last_decode_exc
+        ops.log(f"json fetch failed ({attempt}/{attempts}) for {url}; retrying")
+        sleep_backoff(attempt)
+    assert last_decode_exc is not None
+    raise last_decode_exc
+
+
+def download_file(ops: ModuleOps, url: str, destination: Path) -> None:
+    destination.parent.mkdir(parents = True, exist_ok = True)
+    attempts = ops.HTTP_FETCH_ATTEMPTS
+    last_exc: Exception | None = None
+    for attempt in range(1, attempts + 1):
+        tmp_path: Path | None = None
+        try:
+            request = urllib.request.Request(url, headers = ops.auth_headers(url))
+            with tempfile.NamedTemporaryFile(
+                prefix = destination.name + ".tmp-",
+                dir = destination.parent,
+                delete = False,
+            ) as handle:
+                tmp_path = Path(handle.name)
+                with ops._URL_OPENER.open(request, timeout = 120) as response:
+                    total_bytes: int | None = None
+                    content_length = response.headers.get("Content-Length")
+                    if content_length and content_length.isdigit():
+                        total_bytes = int(content_length)
+                    progress = DownloadProgress(f"Downloading {destination.name}", total_bytes)
+                    downloaded_bytes = 0
+                    while True:
+                        chunk = response.read(1024 * 1024)
+                        if not chunk:
+                            break
+                        handle.write(chunk)
+                        downloaded_bytes += len(chunk)
+                        progress.update(downloaded_bytes)
+                    progress.finish(downloaded_bytes)
+                handle.flush()
+                os.fsync(handle.fileno())
+            if not tmp_path.exists() or tmp_path.stat().st_size == 0:
+                raise RuntimeError(f"downloaded empty file from {url}")
+            atomic_replace_from_tempfile(tmp_path, destination)
+            return
+        except Exception as exc:
+            last_exc = exc
+            if tmp_path is not None:
+                try:
+                    tmp_path.unlink(missing_ok = True)
+                except Exception:
+                    pass
+            if attempt >= attempts or not is_retryable_url_error(exc):
+                raise
+            ops.log(f"download failed ({attempt}/{attempts}) for {url}: {exc}; retrying")
+            sleep_backoff(attempt, exc = exc)
+    assert last_exc is not None
+    raise last_exc
+
+
+def download_file_verified(
+    ops: ModuleOps, url: str, destination: Path, *, expected_sha256: str | None, label: str
+) -> None:
+    normalized_expected = normalize_sha256_digest(expected_sha256)
+    if not normalized_expected:
+        ops.download_file(url, destination)
+        ops.log(f"downloaded {label} without a published sha256; relying on install validation")
+        return
+
+    for attempt in range(1, 3):
+        ops.download_file(url, destination)
+        actual_sha256 = ops.sha256_file(destination)
+        if actual_sha256 == normalized_expected:
+            ops.log(f"verified {label} sha256={actual_sha256}")
+            return
+
+        ops.log(
+            f"{label} checksum mismatch on attempt {attempt}/2: "
+            f"expected={normalized_expected} actual={actual_sha256}"
+        )
+        destination.unlink(missing_ok = True)
+        if attempt == 2:
+            raise PrebuiltFallback(
+                f"{label} checksum mismatch after retry: expected={normalized_expected} actual={actual_sha256}"
+            )
+        ops.log(f"retrying {label} download after checksum mismatch")
+
+
+def download_file_verified_strict(
+    ops: ModuleOps, url: str, destination: Path, *, expected_sha256: str, label: str
+) -> None:
+    """Verified download with a required digest (the generic flow fails closed on
+    a missing checksum, so None never reaches here)."""
+    for attempt in range(1, 3):
+        ops.download_file(url, destination)
+        actual = ops.sha256_file(destination)
+        if actual == expected_sha256:
+            ops.log(f"verified {label} sha256={actual}")
+            return
+        ops.log(
+            f"{label} checksum mismatch {attempt}/2: expected={expected_sha256} actual={actual}"
+        )
+        destination.unlink(missing_ok = True)
+        if attempt == 2:
+            raise PrebuiltFallback(f"{label} checksum mismatch after retry")
+
+
+# ── GitHub release primitives ──
+def release_asset_map(release: dict[str, Any]) -> dict[str, str]:
+    assets = release.get("assets")
+    if not isinstance(assets, list):
+        return {}
+    return {
+        asset["name"]: asset.get("browser_download_url", "")
+        for asset in assets
+        if isinstance(asset, dict)
+        and isinstance(asset.get("name"), str)
+        and isinstance(asset.get("browser_download_url"), str)
+    }
+
+
+def github_release(
+    ops: ModuleOps,
+    repo: str,
+    tag: str,
+    *,
+    error: type[Exception] = RuntimeError,
+) -> dict[str, Any]:
+    payload = ops.fetch_json(
+        f"https://api.github.com/repos/{repo}/releases/tags/{urllib.parse.quote(tag, safe = '')}"
+    )
+    if not isinstance(payload, dict):
+        raise error(f"unexpected release payload for {repo}@{tag}")
+    return payload
+
+
+def github_release_assets(ops: ModuleOps, repo: str, tag: str) -> dict[str, str]:
+    payload = ops.fetch_json(
+        f"https://api.github.com/repos/{repo}/releases/tags/{urllib.parse.quote(tag, safe = '')}"
+    )
+    if not isinstance(payload, dict):
+        raise RuntimeError(f"unexpected release payload for {repo}@{tag}")
+    return release_asset_map(payload)
+
+
+def release_asset_download_url(repo: str, release_tag: str, asset_name: str) -> str:
+    """Tag-pinned asset URL on the release-assets CDN (github.com redirect, NOT
+    api.github.com, so no 60-req/hour unauthenticated limit)."""
+    return (
+        f"https://github.com/{urllib.parse.quote(repo, safe = '/')}/releases/download/"
+        f"{urllib.parse.quote(release_tag, safe = '')}/"
+        f"{urllib.parse.quote(asset_name, safe = '')}"
+    )
+
+
+def download_host_latest_release_tag(ops: ModuleOps, repo: str) -> str | None:
+    """Latest release tag from github.com/<repo>/releases/latest via its redirect
+    target (no api.github.com call). None on 404 so the caller falls back to the
+    API. /releases/latest resolves by created_at/make_latest, which can lag the
+    published_at newest the freshness check uses -- acceptable for install."""
+    url = f"https://github.com/{urllib.parse.quote(repo, safe = '/')}/releases/latest"
+    request = urllib.request.Request(
+        url,
+        method = "HEAD",
+        headers = {"User-Agent": ops.USER_AGENT},
+    )
+    try:
+        with ops._URL_OPENER.open(request, timeout = 30) as response:
+            final_url = response.geturl()
+    except urllib.error.HTTPError as exc:
+        if exc.code == 404:
+            return None
+        raise
+    marker = "/releases/tag/"
+    index = final_url.find(marker)
+    if index == -1:
+        return None
+    tag = urllib.parse.unquote(final_url[index + len(marker) :]).strip("/")
+    return tag or None
+
+
+def fetch_download_host_json(ops: ModuleOps, url: str) -> Any:
+    # Public CDN asset: plain unauthenticated GET, not the rate-limited API.
+    data = ops.download_bytes(
+        url,
+        timeout = 30,
+        headers = {"User-Agent": ops.USER_AGENT},
+    )
+    return json.loads(data.decode("utf-8"))
+
+
+# ── Archive extraction (traversal/symlink guarded) ──
+def extract_archive(archive_path: Path, destination: Path) -> None:
+    def safe_extract_path(base: Path, member_name: str) -> Path:
+        normalized = member_name.replace("\\", "/")
+        member_path = Path(normalized)
+        if member_path.is_absolute():
+            raise PrebuiltFallback(f"archive member used an absolute path: {member_name}")
+
+        target = (base / member_path).resolve()
+        base_resolved = base.resolve()
+        try:
+            target.relative_to(base_resolved)
+        except ValueError as exc:
+            raise PrebuiltFallback(f"archive member escaped destination: {member_name}") from exc
+        return target
+
+    def _try_repair_missing_slash(
+        member_name: str, link_name: str, archive_names: set[str]
+    ) -> str | None:
+        """Repair a mangled symlink from some upstream llama.cpp Mac releases
+        (e.g. b9165, b9169) whose linkname drops the separator AND the file
+        basename's leading char between the top-level dir and the rest:
+
+            llama-b9165/libggml-rpc.0.dylib -> llama-b9165ibggml-rpc.0.11.1.dylib
+
+        Detect the pattern (linkname starts with the top-level dir but no
+        following slash), then find the archive entry under that dir whose
+        basename ends with the mangled suffix; only accept a unique match.
+        Returns the corrected linkname relative to the member's parent dir --
+        callers join it with `target.parent`, so a full `top/file` path would
+        double the prefix into `top/top/file`."""
+        if "/" not in member_name or "/" in link_name:
+            return None
+        top, _, _ = member_name.partition("/")
+        if not link_name.startswith(top) or len(link_name) <= len(top):
+            return None
+        bad_suffix = link_name[len(top) :]
+        if not bad_suffix or bad_suffix.startswith("/"):
+            return None
+        prefix = f"{top}/"
+        candidates = [
+            name
+            for name in archive_names
+            if name.startswith(prefix)
+            and "/" not in name[len(prefix) :]
+            and name[len(prefix) :].endswith(bad_suffix)
+        ]
+        if len(candidates) != 1:
+            return None
+        # Strip the top-level dir so the caller's `target.parent / Path(...)`
+        # resolves inside the staging dir, not a duplicate `top/top/...` path.
+        return candidates[0][len(prefix) :]
+
+    def safe_link_target(
+        base: Path, member_name: str, link_name: str, target: Path, archive_names: set[str]
+    ) -> tuple[str, Path]:
+        normalized = link_name.replace("\\", "/")
+        repaired = _try_repair_missing_slash(member_name, normalized, archive_names)
+        if repaired is not None:
+            normalized = repaired
+        link_path = Path(normalized)
+        if link_path.is_absolute():
+            raise PrebuiltFallback(
+                f"archive link used an absolute target: {member_name} -> {link_name}"
+            )
+        if not normalized:
+            raise PrebuiltFallback(f"archive link used an empty target: {member_name}")
+
+        resolved = (target.parent / link_path).resolve()
+        base_resolved = base.resolve()
+        try:
+            resolved.relative_to(base_resolved)
+        except ValueError as exc:
+            raise PrebuiltFallback(
+                f"archive link escaped destination: {member_name} -> {link_name}"
+            ) from exc
+        return normalized, resolved
+
+    def extract_zip_safely(source: Path, base: Path) -> None:
+        with zipfile.ZipFile(source) as archive:
+            for member in archive.infolist():
+                target = safe_extract_path(base, member.filename)
+                mode = (member.external_attr >> 16) & 0o170000
+                if mode == 0o120000:
+                    raise PrebuiltFallback(
+                        f"zip archive contained a symlink entry: {member.filename}"
+                    )
+                if member.is_dir():
+                    target.mkdir(parents = True, exist_ok = True)
+                    continue
+                target.parent.mkdir(parents = True, exist_ok = True)
+                with archive.open(member, "r") as src, target.open("wb") as dst:
+                    shutil.copyfileobj(src, dst)
+
+    def extract_tar_safely(source: Path, base: Path) -> None:
+        pending_links: list[tuple[tarfile.TarInfo, Path]] = []
+        archive_names: set[str] = set()
+        with tarfile.open(source, "r:gz") as archive:
+            for member in archive.getmembers():
+                archive_names.add(member.name)
+                target = safe_extract_path(base, member.name)
+                if member.isdir():
+                    target.mkdir(parents = True, exist_ok = True)
+                    continue
+                if member.islnk() or member.issym():
+                    pending_links.append((member, target))
+                    continue
+                if not member.isfile():
+                    raise PrebuiltFallback(
+                        f"tar archive contained an unsupported entry: {member.name}"
+                    )
+                target.parent.mkdir(parents = True, exist_ok = True)
+                extracted = archive.extractfile(member)
+                if extracted is None:
+                    raise PrebuiltFallback(f"tar archive entry could not be read: {member.name}")
+                with extracted, target.open("wb") as dst:
+                    shutil.copyfileobj(extracted, dst)
+
+        unresolved = list(pending_links)
+        while unresolved:
+            next_round: list[tuple[tarfile.TarInfo, Path]] = []
+            progressed = False
+            for member, target in unresolved:
+                normalized_link, resolved_target = safe_link_target(
+                    base, member.name, member.linkname, target, archive_names
+                )
+                if not resolved_target.exists() and not resolved_target.is_symlink():
+                    next_round.append((member, target))
+                    continue
+                if resolved_target.is_dir():
+                    raise PrebuiltFallback(
+                        f"archive link targeted a directory: {member.name} -> {member.linkname}"
+                    )
+
+                target.parent.mkdir(parents = True, exist_ok = True)
+                if target.exists() or target.is_symlink():
+                    target.unlink()
+
+                if member.issym():
+                    target.symlink_to(normalized_link)
+                else:
+                    shutil.copy2(resolved_target, target)
+                progressed = True
+
+            if not progressed:
+                details = ", ".join(
+                    f"{member.name} -> {member.linkname}" for member, _ in next_round
+                )
+                raise PrebuiltFallback(f"tar archive contained unresolved link entries: {details}")
+            unresolved = next_round
+
+    destination.mkdir(parents = True, exist_ok = True)
+    if archive_path.name.endswith(".zip"):
+        extract_zip_safely(archive_path, destination)
+        return
+    if archive_path.name.endswith(".tar.gz"):
+        extract_tar_safely(archive_path, destination)
+        return
+    raise PrebuiltFallback(f"unsupported archive format: {archive_path.name}")
+
+
+def restore_tar_exec_bits(archive_path: Path, destination: Path) -> None:
+    """Re-apply tar exec bits after the guarded extraction writes plain files;
+    server binaries must stay executable on Unix."""
+    if os.name == "nt" or not archive_path.name.endswith(".tar.gz"):
+        return
+    with tarfile.open(archive_path, "r:gz") as archive:
+        for member in archive.getmembers():
+            if not (member.isfile() and member.mode & 0o111):
+                continue
+            # Paths were already traversal-validated by the extractor above.
+            target = destination / Path(member.name.replace("\\", "/"))
+            if target.is_file():
+                os.chmod(target, target.stat().st_mode | 0o111)
+
+
+# ── Install lock ──
+@contextmanager
+def install_lock(lock_path: Path) -> Iterator[None]:
+    lock_path.parent.mkdir(parents = True, exist_ok = True)
+
+    if FileLock is None:
+        # Fallback lock: exclusive file creation, writing our PID so stale locks
+        # from crashed processes can be detected.
+        fd: int | None = None
+        deadline = time.monotonic() + INSTALL_LOCK_TIMEOUT_SECONDS
+        while True:
+            try:
+                fd = os.open(str(lock_path), os.O_CREAT | os.O_EXCL | os.O_RDWR)
+                try:
+                    os.write(fd, f"{os.getpid()}\n".encode())
+                    os.fsync(fd)
+                except Exception:
+                    os.close(fd)
+                    fd = None
+                    lock_path.unlink(missing_ok = True)
+                    raise
+                break
+            except FileExistsError:
+                stale = False
+                try:
+                    raw = lock_path.read_text().strip()
+                except FileNotFoundError:
+                    # Lock vanished between our open and read -- retry
+                    continue
+                if not raw:
+                    # Exists but PID not yet written; wait for the write to land.
+                    if time.monotonic() >= deadline:
+                        raise BusyInstallConflict(
+                            f"timed out after {INSTALL_LOCK_TIMEOUT_SECONDS}s waiting for concurrent install lock: {lock_path}"
+                        )
+                    time.sleep(0.1)
+                    continue
+                try:
+                    holder_pid = int(raw)
+                    os.kill(holder_pid, 0)  # signal 0 = existence check
+                except ValueError:
+                    stale = True  # PID unreadable (corrupted file)
+                except ProcessLookupError:
+                    stale = True  # holder is dead
+                except PermissionError:
+                    pass  # alive but owned by another user -- not stale
+                if stale:
+                    lock_path.unlink(missing_ok = True)
+                    continue
+                if time.monotonic() >= deadline:
+                    raise BusyInstallConflict(
+                        f"timed out after {INSTALL_LOCK_TIMEOUT_SECONDS}s waiting for concurrent install lock: {lock_path}"
+                    )
+                time.sleep(0.5)
+        try:
+            yield
+        finally:
+            if fd is not None:
+                os.close(fd)
+            lock_path.unlink(missing_ok = True)
+        return
+
+    try:
+        with FileLock(lock_path, timeout = INSTALL_LOCK_TIMEOUT_SECONDS):
+            yield
+    except FileLockTimeout as exc:
+        raise BusyInstallConflict(
+            f"timed out after {INSTALL_LOCK_TIMEOUT_SECONDS}s waiting for concurrent install lock: {lock_path}"
+        ) from exc
+
+
+def install_lock_path(install_dir: Path) -> Path:
+    return install_dir.parent / f".{install_dir.name}.install.lock"
+
+
+# ── macOS version parsing ──
+def parse_macos_version(value: str | None) -> tuple[int, int] | None:
+    """Parse a macOS product version into (major, minor).
+
+    Handles "14.7.1", "15.5", "26.0", bare "26". None when empty/unparseable
+    (callers then defer to runtime validation rather than reject every prebuilt)."""
+    if not value:
+        return None
+    match = re.match(r"\s*(\d+)(?:\.(\d+))?", str(value))
+    if not match:
+        return None
+    return int(match.group(1)), int(match.group(2) or 0)
+
+
+# ── GPU and CUDA runtime-line selection primitives ──
+def normalize_compute_cap(value: Any) -> str | None:
+    raw = str(value).strip()
+    if not raw:
+        return None
+    if "." in raw:
+        parts = raw.split(".", 1)
+        if len(parts) != 2:
+            return None
+        major, minor = parts
+        if not major.isdigit() or not minor.isdigit():
+            return None
+        return f"{int(major)}{int(minor)}"
+    if raw.isdigit():
+        return str(int(raw))
+    return None
+
+
+def normalize_compute_caps(compute_caps: Iterable[str]) -> list[str]:
+    normalized: list[str] = []
+    seen: set[str] = set()
+    for raw in compute_caps:
+        normalized_value = normalize_compute_cap(raw)
+        if normalized_value is None:
+            continue
+        if normalized_value in seen:
+            continue
+        seen.add(normalized_value)
+        normalized.append(normalized_value)
+    normalized.sort(key = int)
+    return normalized
+
+
+def parse_cuda_visible_devices(value: str | None) -> list[str] | None:
+    if value is None:
+        return None
+    raw = value.strip()
+    if not raw or raw == "-1":
+        return []
+    return [token.strip() for token in raw.split(",") if token.strip()]
+
+
+def supports_explicit_visible_device_matching(visible_devices: list[str] | None) -> bool:
+    if not visible_devices:
+        return False
+    for token in visible_devices:
+        lowered = token.lower()
+        if token.isdigit() or lowered.startswith("gpu-"):
+            continue
+        return False
+    return True
+
+
+def select_visible_gpu_rows(
+    gpu_rows: Iterable[tuple[str, str, str]], visible_devices: list[str] | None
+) -> list[tuple[str, str, str]]:
+    rows = list(gpu_rows)
+    if visible_devices is None:
+        return rows
+    if not visible_devices:
+        return []
+
+    by_index = {index: (index, uuid, cap) for index, uuid, cap in rows}
+    by_uuid = {uuid.lower(): (index, uuid, cap) for index, uuid, cap in rows}
+    selected: list[tuple[str, str, str]] = []
+    seen_indices: set[str] = set()
+    for token in visible_devices:
+        row = by_index.get(token)
+        if row is None:
+            normalized_token = token.lower()
+            row = by_uuid.get(normalized_token)
+            if row is None and normalized_token.startswith("gpu-"):
+                row = by_uuid.get(normalized_token)
+            if row is None and not normalized_token.startswith("gpu-"):
+                row = by_uuid.get("gpu-" + normalized_token)
+        if row is None:
+            continue
+        index = row[0]
+        if index in seen_indices:
+            continue
+        seen_indices.add(index)
+        selected.append(row)
+    return selected
+
+
+def dir_provides_exact_library(directory: str | Path, library: str) -> bool:
+    if not library:
+        return False
+    candidate = Path(directory) / library
+    return candidate.exists() and (candidate.is_file() or candidate.is_symlink())
+
+
+def linux_runtime_dirs_for_required_libraries(
+    ops: ModuleOps, required_libraries: Iterable[str]
+) -> list[str]:
+    required = [library for library in required_libraries if library]
+    candidates: list[str | Path] = []
+
+    env_dirs = os.environ.get("CUDA_RUNTIME_LIB_DIR", "")
+    if env_dirs:
+        candidates.extend(part for part in env_dirs.split(os.pathsep) if part)
+    ld_library_path = os.environ.get("LD_LIBRARY_PATH", "")
+    if ld_library_path:
+        candidates.extend(part for part in ld_library_path.split(os.pathsep) if part)
+
+    cuda_roots: list[Path] = []
+    for name in ("CUDA_HOME", "CUDA_PATH", "CUDA_ROOT"):
+        value = os.environ.get(name)
+        if value:
+            cuda_roots.append(Path(value))
+    cuda_roots.extend(Path(path) for path in ops.glob_paths("/usr/local/cuda", "/usr/local/cuda-*"))
+
+    for root in cuda_roots:
+        candidates.extend(
+            [
+                root / "lib",
+                root / "lib64",
+                root / "targets" / "x86_64-linux" / "lib",
+            ]
+        )
+
+    candidates.extend(
+        Path(path)
+        for path in ops.glob_paths(
+            "/lib",
+            "/lib64",
+            "/usr/lib",
+            "/usr/lib64",
+            "/usr/local/lib",
+            "/usr/local/lib64",
+            "/lib/x86_64-linux-gnu",
+            "/usr/lib/x86_64-linux-gnu",
+        )
+    )
+    candidates.extend(
+        Path(path) for path in ops.glob_paths("/usr/local/lib/ollama/cuda_v*", "/usr/lib/wsl/lib")
+    )
+    candidates.extend(Path(path) for path in ops.python_runtime_dirs())
+    candidates.extend(Path(path) for path in ops.ldconfig_runtime_dirs(required))
+
+    resolved = ops.dedupe_existing_dirs(candidates)
+    if not required:
+        return resolved
+
+    matched: list[tuple[int, str]] = []
+    for directory in resolved:
+        provided = sum(1 for library in required if dir_provides_exact_library(directory, library))
+        if provided:
+            matched.append((provided, directory))
+
+    matched.sort(key = lambda item: item[0], reverse = True)
+    return [directory for _, directory in matched]
+
+
+def detected_linux_runtime_lines(ops: ModuleOps) -> tuple[list[str], dict[str, list[str]]]:
+    """`cuda<major>` lines with a matching libcudart/libcublas file on disk (glob
+    match, so a versioned-only file counts), plus the dirs that matched."""
+    line_requirements = {
+        f"cuda{m}": [f"libcudart.so.{m}", f"libcublas.so.{m}"]
+        for m in range(_MAX_PROBE_CUDA_MAJOR, _MIN_CUDA_MAJOR - 1, -1)
+    }
+    detected: list[str] = []
+    runtime_dirs: dict[str, list[str]] = {}
+    for line, required in line_requirements.items():
+        dirs = ops.linux_runtime_dirs_for_required_libraries(required)
+        library_matches: dict[str, list[str]] = {}
+        matching_dirs: list[str] = []
+        for library in required:
+            matched_dirs = [
+                directory for directory in dirs if any(Path(directory).glob(f"{library}*"))
+            ]
+            if not matched_dirs:
+                library_matches = {}
+                matching_dirs = []
+                break
+            library_matches[library] = matched_dirs
+            for directory in matched_dirs:
+                if directory not in matching_dirs:
+                    matching_dirs.append(directory)
+        if library_matches:
+            detected.append(line)
+            runtime_dirs[line] = matching_dirs
+    return detected, runtime_dirs
+
+
+def windows_runtime_line_info() -> dict[str, tuple[str, ...]]:
+    # Generated per CUDA major (newest first) so a new toolkit is detected without
+    # a code change while the cudart64_<major>.dll naming holds.
+    return {
+        f"cuda{m}": (
+            f"cudart64_{m}*.dll",
+            f"cublas64_{m}*.dll",
+            f"cublasLt64_{m}*.dll",
+        )
+        for m in range(_MAX_PROBE_CUDA_MAJOR, _MIN_CUDA_MAJOR - 1, -1)
+    }
+
+
+def detected_windows_runtime_lines(ops: ModuleOps) -> tuple[list[str], dict[str, list[str]]]:
+    dirs = ops.windows_runtime_dirs()
+    detected: list[str] = []
+    runtime_dirs: dict[str, list[str]] = {}
+    for runtime_line, required_patterns in windows_runtime_line_info().items():
+        matching_dirs = ops.windows_runtime_dirs_for_patterns(required_patterns, dirs)
+        if matching_dirs:
+            detected.append(runtime_line)
+            runtime_dirs[runtime_line] = matching_dirs
+    return detected, runtime_dirs
+
+
+def compatible_linux_runtime_lines(host: Any) -> list[str]:
+    if not host.driver_cuda_version:
+        return []
+    major, _minor = host.driver_cuda_version
+    if major < _MIN_CUDA_MAJOR:
+        return []
+    return _cuda_runtime_lines_for_major(major)
+
+
+def runtime_line_from_cuda_version(cuda_version: str | None) -> str | None:
+    if not cuda_version:
+        return None
+    raw = str(cuda_version).strip()
+    if not raw:
+        return None
+    major, _, _ = raw.partition(".")
+    if major == "12":
+        return "cuda12"
+    if major == "13":
+        return "cuda13"
+    return None
+
+
+@dataclass
+class CudaRuntimePreference:
+    runtime_line: str | None
+    selection_log: list[str]
+
+
+def detect_torch_cuda_runtime_preference(host: Any) -> CudaRuntimePreference:
+    selection_log: list[str] = []
+    if host.is_macos:
+        selection_log.append("torch_cuda_preference: skipped on macOS")
+        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
+    if not (host.has_usable_nvidia and (host.is_linux or host.is_windows)):
+        selection_log.append(
+            "torch_cuda_preference: skipped because CUDA host prerequisites were not met"
+        )
+        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
+
+    try:
+        import torch
+    except Exception as exc:
+        selection_log.append(f"torch_cuda_preference: import failed: {exc}")
+        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
+
+    cuda_version = getattr(getattr(torch, "version", None), "cuda", None)
+    if not isinstance(cuda_version, str) or not cuda_version.strip():
+        selection_log.append(
+            "torch_cuda_preference: torch.version.cuda missing; skipping Torch shortcut"
+        )
+        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
+
+    try:
+        cuda_available = bool(torch.cuda.is_available())
+    except Exception as exc:
+        selection_log.append(f"torch_cuda_preference: torch.cuda.is_available() failed: {exc}")
+        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
+
+    if not cuda_available:
+        selection_log.append(
+            "torch_cuda_preference: torch.cuda.is_available() returned False; falling back to normal selection"
+        )
+        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
+
+    runtime_line = runtime_line_from_cuda_version(cuda_version)
+    if runtime_line is None:
+        selection_log.append(
+            f"torch_cuda_preference: unsupported torch.version.cuda={cuda_version}; falling back to normal selection"
+        )
+        return CudaRuntimePreference(runtime_line = None, selection_log = selection_log)
+
+    selection_log.append(
+        "torch_cuda_preference: selected runtime_line="
+        f"{runtime_line} from torch.version.cuda={cuda_version}"
+    )
+    return CudaRuntimePreference(runtime_line = runtime_line, selection_log = selection_log)
+
+
+def artifact_covers_sms(artifact: Any, host_sms: Iterable[str]) -> bool:
+    """True when every host SM is in the artifact's supported_sms and within its
+    [min_sm, max_sm] range."""
+    if not artifact.supported_sms or artifact.min_sm is None or artifact.max_sm is None:
+        return False
+    supported = {str(value) for value in artifact.supported_sms}
+    return all(sm in supported and artifact.min_sm <= int(sm) <= artifact.max_sm for sm in host_sms)
+
+
+def sm_range(artifact: Any) -> int:
+    """SM-coverage span as a sort key (tighter range wins). A bundle with no SM
+    metadata gets a max range so it sorts last, never outranking a targeted bundle."""
+    if artifact.min_sm is not None and artifact.max_sm is not None:
+        return artifact.max_sm - artifact.min_sm
+    return 9999
+
+
+def blackwell_capable_linux_runtime_lines(host_sms: list[str], artifacts: list[Any]) -> list[str]:
+    """CUDA runtime lines (highest major first) shipping a bundle covering every
+    visible host SM. Lets a Blackwell host prefer a native sm_120 line over torch's
+    reported line, mirroring the Windows Blackwell preference."""
+    lines: set[str] = set()
+    for artifact in artifacts:
+        line = artifact.runtime_line
+        # Only rank "cuda<major>" lines; skip malformed/future-format values
+        # (e.g. "cuda13.1") rather than crash the major sort.
+        if not (line and line.startswith("cuda") and line[len("cuda") :].isdigit()):
+            continue
+        if not artifact.supported_sms or artifact.min_sm is None or artifact.max_sm is None:
+            continue
+        supported = {str(value) for value in artifact.supported_sms}
+        if all(
+            sm in supported and artifact.min_sm <= int(sm) <= artifact.max_sm for sm in host_sms
+        ):
+            lines.add(line)
+    return sorted(lines, key = lambda line: int(line[len("cuda") :]), reverse = True)
+
+
+def host_is_blackwell(host: Any) -> bool:
+    caps = normalize_compute_caps(host.compute_caps)
+    return bool(caps) and int(caps[-1]) >= _BLACKWELL_MIN_SM
+
+
+def blackwell_min_toolkit_for_host(host: Any) -> tuple[int, int]:
+    """Minimum CUDA toolkit this Blackwell host needs: 12.8 for the family, 12.9
+    if any SM is sm_103/sm_121 (no native target before 12.9)."""
+    req = _BLACKWELL_MIN_TOOLKIT
+    for sm in normalize_compute_caps(host.compute_caps):
+        req = max(req, _BLACKWELL_SM_MIN_TOOLKIT.get(int(sm), _BLACKWELL_MIN_TOOLKIT))
+    return req
+
+
+# ════════════════════════════════════════════════════════════════════════════
+# Generic descriptor-driven install flow (whisper dialect: one release carries
+# a manifest of os/arch/backend artifacts plus a same-origin checksum index).
+# ════════════════════════════════════════════════════════════════════════════
+def host_platform_tokens(host: Any) -> tuple[str, str]:
+    """Default (os, arch) asset tokens; components with their own HostInfo field
+    names override this hook."""
+    return host.os_token, host.arch_token
+
+
+# ── Manifest parsing ──
+def parse_manifest(ops: ModuleOps, payload: Any, *, label: str) -> dict[str, Any]:
+    """Validate a component prebuilt manifest and return it normalized.
+
+    Rejects an unknown schema_version or wrong component. Returns keys:
+    schema_version, component, studio_protocol, upstream_tag, source_commit,
+    artifacts (list of dicts).
+    """
+    component = ops.COMPONENT
+    if not isinstance(payload, dict):
+        raise PrebuiltFallback(f"{label} was not a JSON object")
+    validate_schema_version(
+        payload, label = label, schema_version = ops.SCHEMA_VERSION, error = PrebuiltFallback
+    )
+    manifest_component = payload.get("component")
+    if manifest_component != component:
+        raise PrebuiltFallback(
+            f"{label} describes component {manifest_component!r}, expected {component!r}"
+        )
+
+    artifacts_raw = payload.get("artifacts")
+    if not isinstance(artifacts_raw, list):
+        raise PrebuiltFallback(f"{label} omitted an 'artifacts' list")
+    artifacts: list[dict[str, Any]] = []
+    for index, raw in enumerate(artifacts_raw):
+        if not isinstance(raw, dict):
+            ops.log(f"{label} artifact[{index}] ignored: not an object")
+            continue
+        asset = raw.get("asset")
+        if not isinstance(asset, str) or not asset:
+            ops.log(f"{label} artifact[{index}] ignored: missing asset name")
+            continue
+        artifacts.append(raw)
+
+    studio_protocol = payload.get("studio_protocol")
+    return {
+        "schema_version": ops.SCHEMA_VERSION,
+        "component": component,
+        "studio_protocol": studio_protocol if isinstance(studio_protocol, str) else None,
+        "upstream_tag": payload.get("upstream_tag")
+        if isinstance(payload.get("upstream_tag"), str)
+        else None,
+        "source_commit": payload.get("source_commit")
+        if isinstance(payload.get("source_commit"), str)
+        else None,
+        "artifacts": artifacts,
+    }
+
+
+def macos_min_os_ok(ops: ModuleOps, host: Any, min_os: Any) -> bool:
+    """True if a macOS artifact requiring `min_os` can load here. The manifest
+    labels it `macos-<version>` (e.g. `macos-14.0`); strip that prefix before
+    parsing or every entry parses as None and the guard no-ops. Unknown host or
+    min_os -> True (defer to runtime validation)."""
+    if not isinstance(min_os, str) or not min_os.strip():
+        return True
+    raw = min_os.strip()
+    if raw.lower().startswith("macos-"):
+        raw = raw[len("macos-") :]
+    required = ops.parse_macos_version(raw)
+    if required is None or host.macos_version is None:
+        return True
+    return host.macos_version >= required
+
+
+def artifacts_for_host(
+    ops: ModuleOps, manifest: dict[str, Any], host: Any, backend: str
+) -> list[dict[str, Any]]:
+    """Manifest artifacts matching this host os/arch/backend. On macOS, drop any
+    whose `min_os` exceeds the host version."""
+    os_token, arch_token = ops.host_platform_tokens(host)
+    return [
+        artifact
+        for artifact in manifest.get("artifacts", [])
+        if artifact.get("os") == os_token
+        and artifact.get("arch") == arch_token
+        and artifact.get("backend") == backend
+        and (not host.is_macos or ops.macos_min_os_ok(host, artifact.get("min_os")))
+    ]
+
+
+def select_artifact(
+    ops: ModuleOps, manifest: dict[str, Any], host: Any, backend: str
+) -> dict[str, Any] | None:
+    """First manifest artifact matching this host os/arch and backend, or None
+    (caller then applies the component's fallback policy). No accelerator
+    capability matching here: whisper bundles are slim per os/arch (the paired
+    llama.cpp installer already picked SM/gfx-appropriate ggml backends), and
+    llama keeps its own selection chain in install_llama_prebuilt.py."""
+    candidates = ops.artifacts_for_host(manifest, host, backend)
+    return candidates[0] if candidates else None
+
+
+def select_artifact_with_fallback(
+    ops: ModuleOps, manifest: dict[str, Any], host: Any, backend: str
+) -> tuple[dict[str, Any], str, bool]:
+    """Select the backend artifact, else the descriptor's fallback-backend
+    artifact of the same release (whisper: CPU; llama: none, so a GPU miss
+    surfaces as "no prebuilt" and the caller does a source build).
+
+    Returns (artifact, effective_backend, used_fallback). Raises PrebuiltFallback
+    when neither the requested backend nor the fallback has an asset."""
+    os_token, arch_token = ops.host_platform_tokens(host)
+    artifact = ops.select_artifact(manifest, host, backend)
+    if artifact is not None:
+        return artifact, backend, False
+    fallback_backend = ops.FALLBACK_BACKEND
+    if fallback_backend and backend != fallback_backend:
+        fallback_artifact = ops.select_artifact(manifest, host, fallback_backend)
+        if fallback_artifact is not None:
+            ops.log(
+                f"no '{backend}' asset for {os_token}-{arch_token}; "
+                f"falling back to the {fallback_backend.upper()} asset of the same release"
+            )
+            return fallback_artifact, fallback_backend, True
+    raise PrebuiltFallback(
+        f"no {ops.COMPONENT} prebuilt asset for {os_token}-{arch_token} (backend '{backend}')"
+    )
+
+
+def artifact_coverage(artifact: dict[str, Any]) -> dict[str, Any]:
+    """The sm/gfx/min_os coverage recorded for an artifact (marker/fingerprint)."""
+    coverage: dict[str, Any] = {}
+    for key in ("sm_coverage", "gfx_coverage", "min_os", "sm", "gfx"):
+        if key in artifact and artifact.get(key) is not None:
+            coverage[key] = artifact.get(key)
+    return coverage
+
+
+# ── Backend resolution ──
+def auto_detect_backend(ops: ModuleOps, host: Any) -> str:
+    """Host-preferred backend: Apple Silicon -> metal, usable NVIDIA -> cuda,
+    AMD gfx -> rocm, otherwise cpu."""
+    if host.is_apple_silicon:
+        return "metal"
+    if host.has_usable_nvidia:
+        return "cuda"
+    if host.has_rocm:
+        return "rocm"
+    return "cpu"
+
+
+def resolve_backend(ops: ModuleOps, host: Any, requested: str | None, *, cpu_fallback: bool) -> str:
+    """Resolve the effective backend from --backend / --cpu-fallback and detection."""
+    if cpu_fallback:
+        return "cpu"
+    value = (requested or "auto").strip().lower()
+    if value in {"", "auto"}:
+        return ops.auto_detect_backend(host)
+    if value in ops.SUPPORTED_BACKENDS:
+        return value
+    raise PrebuiltFallback(
+        f"unsupported --backend '{requested}'; choose from auto,{','.join(ops.SUPPORTED_BACKENDS)}"
+    )
+
+
+# ── Release checksum index (trust anchor: the release's own sha256 asset) ──
+def valid_sha256(value: Any) -> str | None:
+    if not isinstance(value, str):
+        return None
+    digest = value.strip().lower()
+    if digest.startswith("sha256:"):
+        digest = digest[len("sha256:") :]
+    if len(digest) == 64 and all(c in "0123456789abcdef" for c in digest):
+        return digest
+    return None
+
+
+def parse_release_checksums(
+    ops: ModuleOps, repo: str, release_tag: str, payload: Any
+) -> dict[str, str]:
+    """Asset name -> sha256 from a release's checksum-index asset.
+
+    That index is the authority for each asset's sha256. It is validated for
+    schema/component and that its ``release_tag`` matches the resolved release,
+    so a redirected or mismatched index is rejected; malformed fails closed."""
+    label = f"{ops.SHA256_ASSET_NAME} in {repo}@{release_tag}"
+    if not isinstance(payload, dict):
+        raise PrebuiltFallback(f"{label} was not a JSON object")
+    if payload.get("schema_version") != ops.SCHEMA_VERSION:
+        raise PrebuiltFallback(f"{label} has an unexpected schema_version")
+    if payload.get("component") != ops.COMPONENT:
+        raise PrebuiltFallback(f"{label} did not describe {ops.COMPONENT}")
+    payload_tag = payload.get("release_tag")
+    if not isinstance(payload_tag, str) or not payload_tag:
+        raise PrebuiltFallback(f"{label} omitted release_tag")
+    if payload_tag != release_tag:
+        raise PrebuiltFallback(
+            f"{label} release_tag={payload_tag} did not match the resolved release {release_tag}"
+        )
+    artifacts = payload.get("artifacts")
+    if not isinstance(artifacts, dict):
+        raise PrebuiltFallback(f"{label} omitted an 'artifacts' map")
+    checksums: dict[str, str] = {}
+    for asset_name, entry in artifacts.items():
+        if not isinstance(asset_name, str) or not asset_name or not isinstance(entry, dict):
+            continue
+        digest = valid_sha256(entry.get("sha256"))
+        if digest is not None:
+            checksums[asset_name] = digest
+    if not checksums:
+        raise PrebuiltFallback(f"{label} carried no usable sha256 entries")
+    return checksums
+
+
+def fetch_release_checksums(ops: ModuleOps, bundle: "ReleaseBundle") -> dict[str, str]:
+    """Download + parse the release's checksum-index asset; fails closed if the
+    release does not publish it."""
+    sha_asset = ops.SHA256_ASSET_NAME
+    url = bundle.asset_urls.get(sha_asset)
+    if not url:
+        raise PrebuiltFallback(
+            f"release {bundle.repo}@{bundle.release_tag} has no {sha_asset}; "
+            f"cannot verify a download"
+        )
+    try:
+        raw = ops.download_bytes(url, timeout = 30, headers = ops.auth_headers(url))
+        payload = json.loads(raw.decode("utf-8"))
+    except (urllib.error.URLError, OSError, socket.timeout) as exc:
+        raise PrebuiltFallback(
+            f"could not fetch {sha_asset} from {bundle.repo}@{bundle.release_tag}: {exc}"
+        ) from exc
+    except (UnicodeDecodeError, json.JSONDecodeError) as exc:
+        raise PrebuiltFallback(
+            f"{sha_asset} in {bundle.repo}@{bundle.release_tag} was not valid JSON"
+        ) from exc
+    return ops.parse_release_checksums(bundle.repo, bundle.release_tag, payload)
+
+
+def expected_sha256_for(
+    ops: ModuleOps,
+    checksums: dict[str, str],
+    asset_name: str,
+    *,
+    manifest_sha256: str | None = None,
+) -> str:
+    """The sha256 the archive must match, from the release checksum-index entry.
+    An asset absent from the index fails closed. Any sha256 the manifest embeds
+    for the asset must agree with the index (a mismatch means a tampered manifest)."""
+    digest = checksums.get(asset_name)
+    if digest is None:
+        raise PrebuiltFallback(
+            f"{asset_name} is not covered by {ops.SHA256_ASSET_NAME}; "
+            f"refusing an unverifiable download"
+        )
+    embedded = valid_sha256(manifest_sha256)
+    if embedded is not None and embedded != digest:
+        raise PrebuiltFallback(
+            f"manifest sha256 for {asset_name} disagrees with {ops.SHA256_ASSET_NAME}; "
+            f"refusing a possibly tampered release"
+        )
+    ops.log(f"verifying {asset_name} against {ops.SHA256_ASSET_NAME} sha256={digest}")
+    return digest
+
+
+# ── Release resolution ──
+@dataclass
+class ReleaseBundle:
+    repo: str
+    release_tag: str
+    manifest: dict[str, Any]
+    asset_urls: dict[str, str]
+
+
+def fetch_release_bundle(ops: ModuleOps, repo: str, release_tag: str) -> ReleaseBundle:
+    """Fetch a fork release, download+validate its manifest, return the bundle.
+
+    The single network seam for API-path release resolution; tests inject a fake
+    to exercise selection/install offline. A missing or unreachable release (404,
+    rate limit, no network) surfaces as PrebuiltFallback so the caller does a
+    source build rather than error out.
+    """
+    manifest_asset = ops.MANIFEST_ASSET_NAME
+    try:
+        release = ops.github_release(repo, release_tag)
+    except PrebuiltFallback:
+        raise
+    except (urllib.error.URLError, OSError, socket.timeout) as exc:
+        raise PrebuiltFallback(f"could not fetch release {repo}@{release_tag}: {exc}") from exc
+    resolved_tag = release.get("tag_name")
+    resolved_tag = resolved_tag if isinstance(resolved_tag, str) and resolved_tag else release_tag
+    asset_urls = ops.release_asset_map(release)
+    manifest_url = asset_urls.get(manifest_asset)
+    if not manifest_url:
+        raise PrebuiltFallback(
+            f"release {repo}@{resolved_tag} has no {manifest_asset}; cannot select a prebuilt"
+        )
+    try:
+        manifest_bytes = ops.download_bytes(
+            manifest_url, timeout = 30, headers = ops.auth_headers(manifest_url)
+        )
+    except (urllib.error.URLError, OSError, socket.timeout) as exc:
+        raise PrebuiltFallback(
+            f"could not fetch {manifest_asset} from {repo}@{resolved_tag}: {exc}"
+        ) from exc
+    try:
+        manifest_payload = json.loads(manifest_bytes.decode("utf-8"))
+    except (UnicodeDecodeError, json.JSONDecodeError) as exc:
+        raise PrebuiltFallback(
+            f"{manifest_asset} in {repo}@{resolved_tag} was not valid JSON"
+        ) from exc
+    manifest = ops.parse_manifest(
+        manifest_payload, label = f"{manifest_asset} in {repo}@{resolved_tag}"
+    )
+    return ReleaseBundle(
+        repo = repo, release_tag = resolved_tag, manifest = manifest, asset_urls = asset_urls
+    )
+
+
+def asset_download_url(ops: ModuleOps, bundle: ReleaseBundle, asset_name: str) -> str:
+    url = bundle.asset_urls.get(asset_name)
+    if url:
+        return url
+    # A manifest can list an asset the release JSON omitted; fall back to the
+    # deterministic release-download URL.
+    return ops.release_asset_download_url(bundle.repo, bundle.release_tag, asset_name)
+
+
+def resolve_newest_release_tag(ops: ModuleOps, repo: str) -> str:
+    """Newest published (non-draft/non-prerelease) release tag for `repo` by
+    ``published_at`` -- what the freshness checks use, NOT GitHub's
+    ``/releases/latest`` pointer (sorts by commit date, can lag the newest build)."""
+    payload = ops.fetch_json(f"https://api.github.com/repos/{repo}/releases?per_page=30")
+    if not isinstance(payload, list):
+        raise PrebuiltFallback(f"unexpected releases payload for {repo}")
+    published = [
+        r
+        for r in payload
+        if isinstance(r, dict)
+        and not r.get("draft")
+        and not r.get("prerelease")
+        and isinstance(r.get("tag_name"), str)
+        and r.get("tag_name")
+    ]
+    if not published:
+        raise PrebuiltFallback(f"{repo} has no published prebuilt release yet")
+    newest = max(published, key = lambda r: r.get("published_at") or "")
+    return newest["tag_name"]
+
+
+def resolve_release_tag(
+    ops: ModuleOps, published_repo: str, *, published_release_tag: str | None
+) -> str:
+    """The release tag to install: an explicit override, else the newest
+    published release resolved at runtime."""
+    override = (published_release_tag or "").strip()
+    if override:
+        return override
+    return ops.resolve_newest_release_tag(published_repo)
+
+
+def resolve_release_via_download_host(
+    ops: ModuleOps, repo: str, published_release_tag: str | None
+) -> tuple[ReleaseBundle, dict[str, str]] | None:
+    """Resolve the release + manifest + checksum index entirely from the download
+    host, with zero api.github.com calls. None (caller falls back to the API) on a
+    missing/renamed asset, a 404, or a tag mismatch. Fetches the checksum index
+    first (an in-progress release can publish it before the manifest)."""
+    manifest_asset = ops.MANIFEST_ASSET_NAME
+    sha_asset = ops.SHA256_ASSET_NAME
+    release_tag = (published_release_tag or "").strip() or ops._download_host_latest_release_tag(
+        repo
+    )
+    if not release_tag:
+        return None
+    sha_url = ops.release_asset_download_url(repo, release_tag, sha_asset)
+    try:
+        sha_payload = ops._download_host_json(sha_url)
+    except urllib.error.HTTPError as exc:
+        if exc.code == 404:
+            return None
+        raise
+    except (
+        urllib.error.URLError,
+        OSError,
+        socket.timeout,
+        UnicodeDecodeError,
+        json.JSONDecodeError,
+    ):
+        return None
+    try:
+        checksums = ops.parse_release_checksums(repo, release_tag, sha_payload)
+    except PrebuiltFallback:
+        return None  # schema/component/tag mismatch -> let the API path decide
+    manifest_url = ops.release_asset_download_url(repo, release_tag, manifest_asset)
+    try:
+        manifest_payload = ops._download_host_json(manifest_url)
+    except urllib.error.HTTPError as exc:
+        if exc.code == 404:
+            return None
+        raise
+    except (
+        urllib.error.URLError,
+        OSError,
+        socket.timeout,
+        UnicodeDecodeError,
+        json.JSONDecodeError,
+    ):
+        return None
+    try:
+        manifest = ops.parse_manifest(
+            manifest_payload, label = f"{manifest_asset} in {repo}@{release_tag}"
+        )
+    except PrebuiltFallback:
+        return None
+    # Tag-pinned CDN URLs for every asset the install may fetch (asset_download_url
+    # reconstructs any missing one), keeping this a pure download-host path.
+    names = {
+        str(a.get("asset"))
+        for a in manifest.get("artifacts", [])
+        if isinstance(a, dict) and a.get("asset")
+    }
+    names |= {manifest_asset, sha_asset}
+    asset_urls = {name: ops.release_asset_download_url(repo, release_tag, name) for name in names}
+    bundle = ReleaseBundle(
+        repo = repo, release_tag = release_tag, manifest = manifest, asset_urls = asset_urls
+    )
+    return bundle, checksums
+
+
+def fetch_release_for_install(
+    ops: ModuleOps, repo: str, *, published_release_tag: str | None
+) -> tuple[ReleaseBundle, dict[str, str]]:
+    """Resolve the release + manifest + checksum index, preferring the download
+    host (no api.github.com rate limit) and falling back to the GitHub API. The
+    single network seam the install/probe paths use."""
+    fast = ops._resolve_release_via_download_host(repo, published_release_tag)
+    if fast is not None:
+        bundle, checksums = fast
+        ops.log(f"resolved {repo}@{bundle.release_tag} via the download host (no GitHub API)")
+        return bundle, checksums
+    release_tag = ops.resolve_release_tag(repo, published_release_tag = published_release_tag)
+    bundle = ops.fetch_release_bundle(repo, release_tag)
+    checksums = ops.fetch_release_checksums(bundle)
+    return bundle, checksums
+
+
+# ── Marker and fingerprint ──
+def compute_install_fingerprint(
+    *,
+    published_repo: str,
+    release_tag: str,
+    upstream_tag: str | None,
+    source_commit: str | None,
+    asset: str,
+    asset_sha256: str,
+    backend: str,
+    runtime_line: str | None,
+    coverage: dict[str, Any],
+) -> str:
+    payload = {
+        "published_repo": published_repo,
+        "release_tag": release_tag,
+        "upstream_tag": upstream_tag,
+        "source_commit": source_commit,
+        "asset": asset,
+        "asset_sha256": asset_sha256,
+        "backend": backend,
+        "runtime_line": runtime_line,
+        "coverage": coverage,
+    }
+    return hashlib.sha256(
+        json.dumps(payload, sort_keys = True, separators = (",", ":")).encode("utf-8")
+    ).hexdigest()
+
+
+@dataclass(frozen = True)
+class InstallSelection:
+    """The identity of a chosen prebuilt: everything the marker/fingerprint record."""
+
+    published_repo: str
+    release_tag: str
+    upstream_tag: str | None
+    source_commit: str | None
+    asset: str
+    asset_sha256: str
+    backend: str
+    runtime_line: str | None
+    coverage: dict[str, Any]
+    studio_protocol: str | None
+    # Slim pairing identity (whisper slim bundles ride the llama ggml runtime);
+    # all None for fat installs, never part of the fingerprint.
+    install_kind: str | None = None
+    paired_llama_tag: str | None = None
+    linked_from: str | None = None
+    # Filenames the slim wiring hardlinked beside the server; the sidecar launch
+    # guard verifies exactly these instead of hardcoded per-OS names.
+    linked_libraries: tuple[str, ...] | None = None
+    runtime_wiring_version: int | None = None
+    linked_runtime_directories: tuple[str, ...] | None = None
+
+    def fingerprint(self) -> str:
+        return compute_install_fingerprint(
+            published_repo = self.published_repo,
+            release_tag = self.release_tag,
+            upstream_tag = self.upstream_tag,
+            source_commit = self.source_commit,
+            asset = self.asset,
+            asset_sha256 = self.asset_sha256,
+            backend = self.backend,
+            runtime_line = self.runtime_line,
+            coverage = self.coverage,
+        )
+
+
+def selection_from_artifact(
+    ops: ModuleOps,
+    *,
+    published_repo: str,
+    release_tag: str,
+    manifest: dict[str, Any],
+    artifact: dict[str, Any],
+    backend: str,
+    asset_sha256: str,
+) -> InstallSelection:
+    return InstallSelection(
+        published_repo = published_repo,
+        release_tag = release_tag,
+        upstream_tag = manifest.get("upstream_tag"),
+        source_commit = manifest.get("source_commit"),
+        asset = str(artifact.get("asset")),
+        asset_sha256 = asset_sha256,
+        backend = backend,
+        runtime_line = artifact.get("runtime_line")
+        if isinstance(artifact.get("runtime_line"), str)
+        else None,
+        coverage = ops.artifact_coverage(artifact),
+        studio_protocol = manifest.get("studio_protocol"),
+    )
+
+
+def metadata_path(ops: ModuleOps, install_dir: Path) -> Path:
+    return install_dir / ops.METADATA_FILENAME
+
+
+def write_prebuilt_metadata(ops: ModuleOps, install_dir: Path, selection: InstallSelection) -> None:
+    coverage = selection.coverage
+    payload = {
+        "schema_version": ops.SCHEMA_VERSION,
+        "component": ops.COMPONENT,
+        "published_repo": selection.published_repo,
+        "release_tag": selection.release_tag,
+        "upstream_tag": selection.upstream_tag,
+        "source_commit": selection.source_commit,
+        "asset": selection.asset,
+        "asset_sha256": selection.asset_sha256,
+        "backend": selection.backend,
+        "runtime_line": selection.runtime_line,
+        "sm_coverage": coverage.get("sm_coverage") or coverage.get("sm"),
+        "gfx_coverage": coverage.get("gfx_coverage") or coverage.get("gfx"),
+        "min_os": coverage.get("min_os"),
+        "studio_protocol": selection.studio_protocol,
+        "install_fingerprint": selection.fingerprint(),
+        "installed_at_utc": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()),
+    }
+    if selection.install_kind == "slim":
+        # Additive slim fields; fat markers keep the legacy payload exactly.
+        payload["install_kind"] = "slim"
+        payload["paired_llama_tag"] = selection.paired_llama_tag
+        payload["linked_from"] = selection.linked_from
+        if selection.linked_libraries is not None:
+            payload["linked_libraries"] = list(selection.linked_libraries)
+        if selection.runtime_wiring_version is not None:
+            payload["runtime_wiring_version"] = selection.runtime_wiring_version
+        if selection.linked_runtime_directories is not None:
+            payload["linked_runtime_directories"] = list(selection.linked_runtime_directories)
+    ops.metadata_path(install_dir).write_text(
+        json.dumps(payload, indent = 2) + "\n", encoding = "utf-8"
+    )
+
+
+def load_prebuilt_metadata(ops: ModuleOps, install_dir: Path) -> dict[str, Any] | None:
+    path = ops.metadata_path(install_dir)
+    if not path.is_file():
+        return None
+    try:
+        payload = json.loads(path.read_text(encoding = "utf-8"))
+    except (json.JSONDecodeError, OSError):
+        return None
+    return payload if isinstance(payload, dict) else None
+
+
+def existing_install_matches(
+    ops: ModuleOps, install_dir: Path, host: Any, selection: InstallSelection
+) -> bool:
+    """True iff the marker records this exact selection and the server binary is on disk."""
+    metadata = ops.load_prebuilt_metadata(install_dir)
+    if metadata is None:
+        return False
+    if not ops.installed_server_path(install_dir, host).is_file():
+        return False
+    recorded = metadata.get("install_fingerprint")
+    if not isinstance(recorded, str) or recorded != selection.fingerprint():
+        return False
+    ops.log(
+        f"existing {ops.COMPONENT} install already matches {selection.release_tag} "
+        f"({selection.backend}); nothing to do"
+    )
+    return True
+
+
+# ── Install tree assembly and staged activation ──
+def locate_server_in_tree(ops: ModuleOps, root: Path, host: Any) -> Path:
+    name = ops.server_binary_name(host)
+    matches = sorted(root.rglob(name))
+    if not matches:
+        raise PrebuiltFallback(f"archive did not contain a {name} binary")
+    return matches[0]
+
+
+def assemble_install_tree(ops: ModuleOps, bundle_root: Path, staged_root: Path, host: Any) -> Path:
+    """Lay out staged_root as a full install: <runtime bin dir>/<server + libs>.
+
+    Everything beside the server in the archive (shared libs, backend kernel
+    subdirs, license/build-info) is co-located into the canonical bin dir so the
+    server's RUNPATH=$ORIGIN resolves its libs.
+    """
+    bin_dir = ops.runtime_bin_dir(staged_root, host)
+    bin_dir.mkdir(parents = True, exist_ok = True)
+    for entry in sorted(bundle_root.iterdir()):
+        dest = bin_dir / entry.name
+        if entry.is_dir() and not entry.is_symlink():
+            shutil.copytree(entry, dest, symlinks = True)
+        else:
+            shutil.copy2(entry, dest, follow_symlinks = False)
+    server = bin_dir / ops.server_binary_name(host)
+    if not server.exists():
+        raise PrebuiltFallback(f"staged install is missing the {ops.COMPONENT} server binary")
+    if not host.is_windows:
+        os.chmod(server, server.stat().st_mode | 0o111)
+    return server
+
+
+def swap_into_place(staged_root: Path, install_dir: Path) -> None:
+    """Atomically replace install_dir with staged_root (same filesystem), with rollback."""
+    install_dir.parent.mkdir(parents = True, exist_ok = True)
+    backup: Path | None = None
+    try:
+        if install_dir.exists():
+            backup = install_dir.parent / f".{install_dir.name}.old-{os.getpid()}"
+            os.replace(install_dir, backup)
+        os.replace(staged_root, install_dir)
+    except OSError as exc:
+        restored = False
+        if backup is not None and backup.exists() and not install_dir.exists():
+            try:
+                os.replace(backup, install_dir)
+                restored = True
+            except OSError as rollback_exc:
+                raise PrebuiltFallback(
+                    "prebuilt activation failed and the previous install could not be restored "
+                    f"({exc}; rollback: {rollback_exc})"
+                ) from rollback_exc
+        if is_busy_lock_error(exc):
+            detail = "; restored the previous install" if restored else ""
+            raise BusyInstallConflict(
+                f"the existing install appears to still be in use{detail} ({exc})"
+            ) from exc
+        raise
+    if backup is not None:
+        shutil.rmtree(backup, ignore_errors = True)
+
+
+def validate_staged_server(ops: ModuleOps, staged_root: Path, host: Any) -> None:
+    """Optional pre-activate smoke test, gated off by default (the component's
+    _RUN_STAGED_PREBUILT_VALIDATION switch)."""
+    if not ops._RUN_STAGED_PREBUILT_VALIDATION:
+        return
+    server = ops.installed_server_path(staged_root, host)
+    env = os.environ.copy()
+    bin_dir = str(ops.runtime_bin_dir(staged_root, host))
+    for var in ("LD_LIBRARY_PATH", "DYLD_LIBRARY_PATH"):
+        env[var] = bin_dir + (os.pathsep + env[var] if env.get(var) else "")
+    try:
+        result = subprocess.run(
+            [str(server), "--help"],
+            capture_output = True,
+            text = True,
+            timeout = 60,
+            env = env,
+            **ops.windows_hidden_subprocess_kwargs(),
+        )
+    except (OSError, subprocess.SubprocessError) as exc:
+        raise PrebuiltFallback(f"staged {ops.COMPONENT} server failed to launch: {exc}") from exc
+    if result.returncode != 0:
+        raise PrebuiltFallback(
+            f"staged {ops.COMPONENT} server --help exited {result.returncode}: "
+            f"{result.stderr.strip()}"
+        )
+
+
+def windows_hidden_subprocess_kwargs() -> dict[str, object]:
+    """Return Windows-only subprocess kwargs that suppress console windows."""
+    if sys.platform != "win32":
+        return {}
+
+    kwargs: dict[str, object] = {}
+    create_no_window = getattr(subprocess, "CREATE_NO_WINDOW", 0)
+    if create_no_window:
+        kwargs["creationflags"] = create_no_window
+
+    startupinfo_factory = getattr(subprocess, "STARTUPINFO", None)
+    startf_use_showwindow = getattr(subprocess, "STARTF_USESHOWWINDOW", 0)
+    sw_hide = getattr(subprocess, "SW_HIDE", 0)
+    if startupinfo_factory is not None and startf_use_showwindow:
+        startupinfo = startupinfo_factory()
+        startupinfo.dwFlags |= startf_use_showwindow
+        startupinfo.wShowWindow = sw_hide
+        kwargs["startupinfo"] = startupinfo
+
+    return kwargs
+
+
+def install_from_bundle(
+    ops: ModuleOps, install_dir: Path, host: Any, bundle: ReleaseBundle, selection: InstallSelection
+) -> None:
+    staging_root = install_dir.parent / ops.INSTALL_STAGING_ROOT_NAME
+    staging_root.mkdir(parents = True, exist_ok = True)
+    staging = Path(tempfile.mkdtemp(prefix = f"{install_dir.name}.staging-", dir = staging_root))
+    try:
+        archive_path = staging / selection.asset
+        url = ops.asset_download_url(bundle, selection.asset)
+        ops.log(f"downloading {url}")
+        ops.download_file_verified(
+            url, archive_path, expected_sha256 = selection.asset_sha256, label = selection.asset
+        )
+        extract_dir = staging / "extracted"
+        ops.extract_archive(archive_path, extract_dir)
+
+        server = ops.locate_server_in_tree(extract_dir, host)
+        bundle_root = server.parent
+
+        staged_root = staging / "staged"
+        ops.assemble_install_tree(bundle_root, staged_root, host)
+        # Component hook (default no-op): slim whisper wires the llama ggml
+        # runtime here so staged validation sees the final linked tree; a returned
+        # selection (with the wired filenames) supersedes the input so the marker
+        # records what was actually linked.
+        updated = ops.prepare_runtime_payload(staged_root, host, selection)
+        if updated is not None:
+            selection = updated
+        ops.validate_staged_server(staged_root, host)
+        ops.write_prebuilt_metadata(staged_root, selection)
+        ops._swap_into_place(staged_root, install_dir)
+    finally:
+        shutil.rmtree(staging, ignore_errors = True)
+        try:
+            staging_root.rmdir()
+        except OSError:
+            pass
+
+
+def plan_selection(
+    ops: ModuleOps,
+    host: Any,
+    bundle: ReleaseBundle,
+    *,
+    published_repo: str,
+    backend: str,
+    checksums: dict[str, str],
+) -> InstallSelection:
+    """Choose an artifact (with the component's fallback policy) and resolve its
+    trusted sha256 from the release checksum index."""
+    artifact, effective_backend, _used_fallback = ops.select_artifact_with_fallback(
+        bundle.manifest, host, backend
+    )
+    asset = str(artifact.get("asset"))
+    manifest_sha256 = artifact.get("sha256") if isinstance(artifact.get("sha256"), str) else None
+    expected_sha = ops.expected_sha256_for(
+        checksums,
+        asset,
+        manifest_sha256 = manifest_sha256,
+    )
+    return ops.selection_from_artifact(
+        published_repo = published_repo,
+        release_tag = bundle.release_tag,
+        manifest = bundle.manifest,
+        artifact = artifact,
+        backend = effective_backend,
+        asset_sha256 = expected_sha,
+    )
+
+
+def install_prebuilt(
+    ops: ModuleOps,
+    install_dir: Path,
+    *,
+    published_repo: str,
+    published_release_tag: str | None = None,
+    backend: str | None = "auto",
+    cpu_fallback: bool = False,
+    force: bool = False,
+    host: Any = None,
+) -> int:
+    if host is None:
+        host = ops.detect_host()
+    effective_backend = ops.resolve_backend(host, backend, cpu_fallback = cpu_fallback)
+    os_token, arch_token = ops.host_platform_tokens(host)
+    ops.log(
+        f"target {ops.COMPONENT} from {published_repo} "
+        f"({os_token}-{arch_token}, backend {effective_backend})"
+    )
+
+    bundle, checksums = ops.fetch_release_for_install(
+        published_repo, published_release_tag = published_release_tag
+    )
+    selection = ops.plan_selection(
+        host,
+        bundle,
+        published_repo = published_repo,
+        backend = effective_backend,
+        checksums = checksums,
+    )
+
+    return install_selected_prebuilt(
+        ops,
+        install_dir,
+        host = host,
+        bundle = bundle,
+        selection = selection,
+        force = force,
+    )
+
+
+def install_selected_prebuilt(
+    ops: ModuleOps,
+    install_dir: Path,
+    *,
+    host: Any,
+    bundle: ReleaseBundle,
+    selection: InstallSelection,
+    force: bool,
+) -> int:
+    """Validate and activate an already selected release plan.
+
+    Components that need to examine more than one published release can keep
+    release selection component-specific while sharing the lock, idempotency,
+    atomic activation, and post-install verification path.
+    """
+
+    if not force and ops.existing_install_matches(install_dir, host, selection):
+        return 0
+
+    with ops.install_lock(ops.install_lock_path(install_dir)):
+        # Re-check under the lock: a concurrent run may have just finished.
+        if not force and ops.existing_install_matches(install_dir, host, selection):
+            return 0
+        ops._install_from_bundle(install_dir, host, bundle, selection)
+
+    server = ops.installed_server_path(install_dir, host)
+    if not server.is_file():
+        raise PrebuiltFallback(f"post-install verification failed: {server} is missing")
+    ops.log(
+        f"installed {ops.COMPONENT} {bundle.release_tag} " f"({selection.backend}) at {install_dir}"
+    )
+    return 0
+
+
+def resolve_prebuilt(
+    ops: ModuleOps,
+    host: Any,
+    *,
+    published_repo: str,
+    published_release_tag: str | None,
+    backend: str | None,
+    cpu_fallback: bool,
+) -> dict[str, Any]:
+    """Host-aware "is a prebuilt available" probe. No archive download."""
+    effective_backend = ops.resolve_backend(host, backend, cpu_fallback = cpu_fallback)
+    try:
+        bundle, _checksums = ops.fetch_release_for_install(
+            published_repo, published_release_tag = published_release_tag
+        )
+        artifact, resolved_backend, used_fallback = ops.select_artifact_with_fallback(
+            bundle.manifest, host, effective_backend
+        )
+    except PrebuiltFallback:
+        return {"prebuilt_available": False, "repo": published_repo}
+    os_token, arch_token = ops.host_platform_tokens(host)
+    payload = {
+        "prebuilt_available": True,
+        "repo": published_repo,
+        "release_tag": bundle.release_tag,
+        "upstream_tag": bundle.manifest.get("upstream_tag"),
+        "backend": resolved_backend,
+        "requested_backend": effective_backend,
+        "cpu_fallback": used_fallback,
+        "asset": str(artifact.get("asset")),
+        "os": os_token,
+        "arch": arch_token,
+        "runtime_line": artifact.get("runtime_line"),
+    }
+    # Component hook (default none): whisper adds install_kind slim|fat. The JSON
+    # emitter sorts keys, so an appended field can't perturb the legacy key order.
+    payload.update(ops.resolver_payload_extra(artifact))
+    return payload
+
+
+def prepare_runtime_payload(staged_root: Path, host: Any, selection: InstallSelection) -> Any:
+    """Post-assemble hook; the core stages nothing extra. Components override it
+    to wire external runtime files into the staged bin dir (whisper slim hardlinks
+    the llama install's ggml libraries) before validation, and may return an
+    updated InstallSelection for the marker to record instead."""
+    return None
+
+
+def resolver_payload_extra(artifact: dict[str, Any]) -> dict[str, Any]:
+    """Additive --resolve-prebuilt payload fields; the core adds none."""
+    return {}
+
+
+def installed_server_path(ops: ModuleOps, install_dir: Path, host: Any) -> Path:
+    return ops.runtime_bin_dir(install_dir, host) / ops.server_binary_name(host)
+
+
+# Underscored aliases so ops lookups that mirror the installer modules' private
+# names still resolve for a descriptor-only component.
+_download_host_latest_release_tag = download_host_latest_release_tag
+_download_host_json = fetch_download_host_json
+_resolve_release_via_download_host = resolve_release_via_download_host
+_install_from_bundle = install_from_bundle
+_swap_into_place = swap_into_place
+
+
+def emit_resolver_output(payload: dict[str, Any], *, output_format: str) -> None:
+    if output_format == "json":
+        print(json.dumps(payload, sort_keys = True))
+        return
+    if "asset" in payload and payload.get("prebuilt_available"):
+        print(payload["asset"])
+        return
+    print(json.dumps(payload, sort_keys = True))
diff --git a/studio/setup.ps1 b/studio/setup.ps1
index dab1e1e73f..c6932121c9 100644
--- a/studio/setup.ps1
+++ b/studio/setup.ps1
@@ -32,6 +32,10 @@ $PackageDir = Split-Path -Parent $ScriptDir
 # (no matching GitHub release), forces a source build, and causes HTTP 422
 # errors. Only use "master" temporarily when the latest release is missing
 # support for a new model architecture.
+#
+# UNSLOTH_LLAMA_CPP_BACKEND : "auto" (default) or "cpu". When "cpu", forces
+# the CPU-only prebuilt bundle on GPU hosts. Fixes Intel iGPU Vulkan
+# crashes (#7213).
 $DefaultLlamaPrForce = ""
 $DefaultLlamaSource = "https://github.com/ggml-org/llama.cpp"
 $DefaultLlamaTag = "latest"
@@ -322,7 +326,7 @@ function Write-CudaDriverToolkitMismatch {
     $driverMajor = $DriverMaxCuda.Split('.')[0]
     substep "CUDA Toolkit $ToolkitVersion is a major-version mismatch: toolkit major $toolkitMajor exceeds driver CUDA major $driverMajor ($DriverMaxCuda)." $Color
     substep "Update the NVIDIA GPU driver to run CUDA Toolkit $ToolkitVersion, or install a CUDA $driverMajor.x toolkit." $Color
-    substep "Or let Studio use the prebuilt CUDA bundle; it does not need the local toolkit." $Color
+    substep "Or let Unsloth use the prebuilt CUDA bundle; it does not need the local toolkit." $Color
 }
 
 # Detect CUDA Compute Capability via nvidia-smi.
@@ -427,6 +431,167 @@ function Get-PytorchCudaTag {
     return "cu126"
 }
 
+# Trim trailing slashes from the URL PATH only, preserving ?query / #fragment: a whole-URL
+# TrimEnd corrupts a token ending in "/", a single strip leaves .../cu128// empty. Shared.
+function Trim-IndexPathSlashes {
+    param([string]$Url)
+    $value = $Url.Trim()
+    $idx = $value.IndexOfAny([char[]]@('?', '#'))
+    if ($idx -lt 0) {
+        return $value.TrimEnd('/')
+    }
+    return $value.Substring(0, $idx).TrimEnd('/') + $value.Substring($idx)
+}
+
+# Explicit torch-index pin (UNSLOTH_TORCH_INDEX_URL / _FAMILY), shared by the stale-venv check
+# and install selection so a pinned index wins over GPU probing (parity with the other
+# installers). URL is verbatim; _FAMILY is the leaf joined to the mirror base.
+function Get-PinnedTorchIndexUrl {
+    if (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_TORCH_INDEX_URL)) {
+        return (Trim-IndexPathSlashes $env:UNSLOTH_TORCH_INDEX_URL)
+    }
+    if (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_TORCH_INDEX_FAMILY)) {
+        $base = if ($env:UNSLOTH_PYTORCH_MIRROR) { $env:UNSLOTH_PYTORCH_MIRROR.TrimEnd('/') } else { "https://download.pytorch.org/whl" }
+        return "$base/$($env:UNSLOTH_TORCH_INDEX_FAMILY.Trim().Trim('/'))"
+    }
+    return $null
+}
+
+# Last path segment of a wheel index URL, query/fragment dropped first so a token-authenticated
+# pin (.../cu128?token=x) classifies as cu128 (else it reinstalls every update). Classification
+# only. Shared with the py / install.sh leaf extractors.
+function Get-TorchIndexLeaf {
+    param([string]$Url)
+    if ([string]::IsNullOrWhiteSpace($Url)) { return $null }
+    $path = ($Url -split '[?#]', 2)[0]
+    if ([string]::IsNullOrWhiteSpace($path)) { return $null }
+    return ($path.TrimEnd('/') -split '/')[-1].ToLowerInvariant()
+}
+
+# Redact index-URL credentials (userinfo + ?query= + #fragment) from captured installer
+# output before printing on failure; uv/pip errors echo the failing --index-url verbatim.
+# Mirrors the other installers. Verbose mode streams uncaptured, so it isn't redacted.
+function Redact-InstallOutput {
+    param([string]$Text)
+    if (-not $Text) { return $Text }
+    $Text = $Text -replace '(https?://)[^/@\s`]+@', '$1<redacted>@'
+    $Text = $Text -replace '([?&][^=\s&`]+)=[^&#\s`]+', '$1=<redacted>'
+    # A #token=... fragment is as sensitive as a query; URL-anchored.
+    return $Text -replace '(https?://[^\s`#]+)#[^\s`]+', '$1#<redacted>'
+}
+
+# AMD per-arch leaves needing the torch 2.11 floor (the _grouped_mm <2.11 bug). MUST match
+# the install-spec path below and the other installers; other leaves ship <2.11 and stay default.
+function Test-RocmGfx211Leaf {
+    param([string]$Leaf)
+    return @('gfx120x-all', 'gfx1151', 'gfx1150') -contains $Leaf
+}
+
+# rocmX.Y versions KNOWN to ship torch 2.11: rocm7.2 only today. Do NOT floor an unknown newer
+# rocm speculatively. MUST match _ROCM_KNOWN_TORCH211_VERSIONS and the rocm7.2 leaf elsewhere.
+function Test-RocmKnown211Version {
+    param([int]$Major, [int]$Minor)
+    return ($Major -eq 7 -and $Minor -eq 2)
+}
+
+# True only for a real CUDA family leaf: "cu" + digits (cu118, cu128, ...). A bare -like 'cu*'
+# would match "custom"/"current" and rebuild the venv every run. Mirrors _is_cuda_family_leaf.
+function Test-CudaFamilyLeaf {
+    param([string]$Leaf)
+    if ([string]::IsNullOrWhiteSpace($Leaf)) { return $false }
+    # EXACT cu+digits: cu128-private routes through the unknown-leaf path instead.
+    return $Leaf -match '^cu[0-9]+$'
+}
+
+# True only for a real pip ROCm family leaf: EXACT rocm<digits>[.<digits>] or a gfx leaf. A leaf
+# that merely STARTS with rocm (rocm-rel-7.2.1, rocm7.2-private) is a custom pin the verbatim
+# path owns, so anchor the match. Mirrors _is_pip_rocm_family_leaf / install.sh.
+function Test-PipRocmFamilyLeaf {
+    param([string]$Leaf)
+    if ([string]::IsNullOrWhiteSpace($Leaf)) { return $false }
+    # gfx must be followed by a digit (an architecture leaf); gfx-private is custom.
+    return ($Leaf -match '^gfx[0-9]') -or ($Leaf -match '^rocm[0-9]+(\.[0-9]+)?$')
+}
+
+# Stale-venv ROCm comparison for a pinned gfx*/rocm* index. Returns @{ Expected; Installed } so
+# the caller rebuilds when they differ. Mirrors _rocm_pin_family_mismatch (same rocmX.Y / gfx
+# cases). An untagged (no +rocm) wheel never satisfies a ROCm pin -> stale.
+function Get-RocmPinStaleTags {
+    param([string]$PinLeaf, [string]$TorchVersion)
+    $_pinRocm = [regex]::Match($PinLeaf, '^rocm(\d+)\.(\d+)')
+    $_pinVer = if ($_pinRocm.Success) { "$($_pinRocm.Groups[1].Value).$($_pinRocm.Groups[2].Value)" } else { $null }
+    # The family classifier accepts a major-only rocm<d> leaf too (rocm7).
+    $_pinMajorOnly = [regex]::Match($PinLeaf, '^rocm(\d+)$')
+    # Installed rocm version and whether the wheel is a per-arch (three-part) build.
+    $_instRocm = [regex]::Match($TorchVersion, '\+rocm(\d+)\.(\d+)')
+    $_instVer = if ($_instRocm.Success) { "$($_instRocm.Groups[1].Value).$($_instRocm.Groups[2].Value)" } else { $null }
+    $_instPerArch = [regex]::IsMatch($TorchVersion, '\+rocm\d+\.\d+\.\d+')
+    # A ROCm build MUST carry a +rocm tag; an untagged wheel can't satisfy any ROCm pin.
+    $_instHasRocm = [regex]::IsMatch($TorchVersion, '\+rocm')
+    $_instRel = [regex]::Match($TorchVersion, '^(\d+)\.(\d+)')
+    $_instIs211 = $false
+    if ($_instRel.Success) {
+        $_instIs211 = ([int]$_instRel.Groups[1].Value -gt 2) -or ([int]$_instRel.Groups[1].Value -eq 2 -and [int]$_instRel.Groups[2].Value -ge 11)
+    }
+
+    if ($PinLeaf -like 'gfx*') {
+        if (Test-RocmGfx211Leaf $PinLeaf) {
+            # Expect the AMD per-arch (three-part) 2.11 wheel: satisfied only when BOTH
+            # a 2.11 release AND a three-part rocm tag are installed.
+            $installed = if ($_instIs211 -and $_instPerArch) { "rocm-perarch(torch>=2.11)" } else { "rocm-generic-or-old" }
+            return @{ Expected = "rocm-perarch(torch>=2.11)"; Installed = $installed }
+        }
+        # Non-2.11 gfx leaf (<2.11 spec): stale on an untagged wheel or a 2.11+ build.
+        $installed = if (-not $_instHasRocm) { "not-rocm" } elseif ($_instIs211) { "rocm(torch>=2.11)" } else { "rocm(torch<2.11)" }
+        return @{
+            Expected  = "rocm(torch<2.11)"
+            Installed = $installed
+        }
+    }
+
+    # Major-only rocm pin (rocm7): compare majors only -- a +rocm6.4 wheel under a rocm7
+    # pin is stale, any +rocm7.x wheel satisfies it (no pinned minor to compare, and the
+    # 2.11-line fallback below would invert both verdicts). Mirrors _rocm_pin_family_mismatch.
+    if ($_pinMajorOnly.Success) {
+        $_pinMaj = [int]$_pinMajorOnly.Groups[1].Value
+        if ($_instVer) {
+            $_instMaj = [int]$_instRocm.Groups[1].Value
+            $expected = if ($_instMaj -eq $_pinMaj) { "rocm$_instVer" } else { "rocm$_pinMaj.x" }
+            return @{ Expected = $expected; Installed = "rocm$_instVer" }
+        }
+        # Untagged wheel never satisfies a ROCm pin; a +rocm tag with an unreadable
+        # version is accepted (matches the lenient unreadable fallback below).
+        $installed = if ($_instHasRocm) { "rocm" } else { "not-rocm" }
+        return @{ Expected = "rocm"; Installed = $installed }
+    }
+
+    # rocmX.Y pin.
+    if ($_pinVer -and $_instVer) {
+        # Both readable: exact compare. When they match AND the pin is KNOWN-2.11, the
+        # installed release must also be 2.11 (a +rocm7.2 wheel drifted to 2.12 shares the
+        # tag but violates the spec), so fold the release into the tag. Mirrors _rocm_pin_family_mismatch.
+        $_pinKnown211 = Test-RocmKnown211Version -Major ([int]$_pinRocm.Groups[1].Value) -Minor ([int]$_pinRocm.Groups[2].Value)
+        $_instOn211 = $_instRel.Success -and [int]$_instRel.Groups[1].Value -eq 2 -and [int]$_instRel.Groups[2].Value -eq 11
+        if ($_pinKnown211 -and -not $_instOn211) {
+            return @{ Expected = "rocm$_pinVer(torch2.11)"; Installed = "rocm$_instVer(torch-off-2.11)" }
+        }
+        return @{ Expected = "rocm$_pinVer"; Installed = "rocm$_instVer" }
+    }
+    $_pinNeeds211 = $false
+    if ($_pinRocm.Success) {
+        # Only KNOWN-2.11 rocm (rocm7.2) is on the 2.11 line (no speculative floor).
+        # Matches _ROCM_KNOWN_TORCH211_VERSIONS.
+        $_pinNeeds211 = Test-RocmKnown211Version -Major ([int]$_pinRocm.Groups[1].Value) -Minor ([int]$_pinRocm.Groups[2].Value)
+    }
+    # Fallback (installed rocm version unreadable): compare on the 2.11 line; an untagged
+    # wheel never satisfies a rocmX.Y pin -> stale.
+    $installed = if (-not $_instHasRocm) { "not-rocm" } elseif ($_instIs211) { "rocm(torch>=2.11)" } else { "rocm(torch<2.11)" }
+    return @{
+        Expected  = if ($_pinNeeds211) { "rocm(torch>=2.11)" } else { "rocm(torch<2.11)" }
+        Installed = $installed
+    }
+}
+
 # VS generator -> MSBuild BuildCustomizations dir; toolset tracks the VS major
 # (18->v180, 17->v170), defaulting to v170 when unparseable.
 function Get-VcBuildCustomizationsDir {
@@ -809,11 +974,14 @@ function Invoke-SetupCommand {
             # Merge stderr into stdout so progress/warning output stays visible
             # without flipping $? on successful native commands (PS 5.1 treats
             # stderr records as errors that set $? = $false even on exit code 0).
-            & $Command 2>&1 | Out-Host
+            # Redact per record: uv/pip echo index URLs (credentials and all) in
+            # their errors, and verbose mode must not bypass the quiet path's
+            # redaction. ForEach-Object/Out-Host leave $LASTEXITCODE untouched.
+            & $Command 2>&1 | ForEach-Object { Redact-InstallOutput "$_" } | Out-Host
         } else {
             $output = & $Command 2>&1 | Out-String
             if ($LASTEXITCODE -ne 0) {
-                Write-Host $output -ForegroundColor Red
+                Write-Host (Redact-InstallOutput $output) -ForegroundColor Red
             }
         }
         return [int]$LASTEXITCODE
@@ -937,13 +1105,13 @@ function Show-NpmRegistryHint {
     Write-Host ""
     step "frontend" "registry.npmjs.org looks blocked (corporate firewall/proxy?)" "Yellow"
     if ($mirror) {
-        substep "Studio pins the public npm registry; your mirror is being ignored."
+        substep "Unsloth pins the public npm registry; your mirror is being ignored."
         substep "Detected a registry in your npm config:"
         substep "  $mirror"
-        substep "Re-run pointing Studio at it:"
+        substep "Re-run pointing Unsloth at it:"
         substep "  `$env:UNSLOTH_NPM_REGISTRY='$mirror'; .\install.ps1 --local"
     } else {
-        substep "If you use a private mirror/proxy, point Studio at it and re-run:"
+        substep "If you use a private mirror/proxy, point Unsloth at it and re-run:"
         substep "  `$env:UNSLOTH_NPM_REGISTRY='https://your-mirror.example/api/npm/'; .\install.ps1 --local"
     }
     substep "(min-release-age and save-exact stay enforced.)"
@@ -1070,7 +1238,7 @@ if (-not $HasNvidiaSmi) {
 }
 # ── Helper: run amd-smi without triggering a UAC elevation prompt ──
 # amd-smi on Windows auto-elevates to read GPU/APU memory, surfacing a confusing
-# DiskPart UAC prompt mid-install (Studio backend amd.py hits the same). RunAsInvoker
+# DiskPart UAC prompt mid-install (Unsloth backend amd.py hits the same). RunAsInvoker
 # forces it (and helpers it spawns) to run un-elevated; on failure the WMI name ->
 # gfx fallback still resolves the arch.
 function Invoke-AmdSmiNoElevate {
@@ -1132,7 +1300,7 @@ if (-not $HasNvidiaSmi) {
         if ([string]::IsNullOrWhiteSpace($HipinfoPath)) { return $false }
         # VenvDir/VIRTUAL_ENV can be unset this early (the update flow probes before
         # VenvDir is set), so also derive the venv from the setup python + default
-        # Studio home, else the venv hipInfo isn't caught.
+        # Unsloth home, else the venv hipInfo isn't caught.
         $venvRoots = @()
         if ($env:VIRTUAL_ENV) { $venvRoots += $env:VIRTUAL_ENV }
         $vd = Get-Variable -Name VenvDir -ValueOnly -ErrorAction SilentlyContinue
@@ -1141,7 +1309,7 @@ if (-not $HasNvidiaSmi) {
             try { $venvRoots += (Split-Path -Parent (Split-Path -Parent $env:UNSLOTH_SETUP_PYTHON)) } catch {}
         }
         if ($env:USERPROFILE) { $venvRoots += (Join-Path $env:USERPROFILE ".unsloth\studio\unsloth_studio") }
-        # A custom Studio home (UNSLOTH_STUDIO_HOME / STUDIO_HOME alias) moves the
+        # A custom Unsloth home (UNSLOTH_STUDIO_HOME / STUDIO_HOME alias) moves the
         # venv off the default path; seed it too or its hipInfo escapes the filter.
         $studioHomeEnv = if (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_STUDIO_HOME)) { $env:UNSLOTH_STUDIO_HOME.Trim() } elseif (-not [string]::IsNullOrWhiteSpace($env:STUDIO_HOME)) { $env:STUDIO_HOME.Trim() } else { $null }
         if ($studioHomeEnv) {
@@ -1330,7 +1498,7 @@ if (-not $HasNvidiaSmi) {
             $nameArchTable = @(
                 @{ P = "9070 XT|9080";                                        A = "gfx1201" }  # RDNA 4 (Radeon RX 9070 XT / 9080)
                 @{ P = "9070|9060";                                           A = "gfx1200" }  # RDNA 4 (Radeon RX 9070 / 9060)
-                @{ P = "8060S|8050S|8040S|Strix Halo|Ryzen AI Max|AI Max"; A = "gfx1151" }  # RDNA 3.5 (Strix Halo: Radeon 8060S/8050S/8040S iGPU, Ryzen AI Max+)
+                @{ P = "8065S|8060S|8050S|8040S|Strix Halo|Ryzen AI Max|AI Max"; A = "gfx1151" }  # RDNA 3.5 (Strix Halo + Gorgon Halo: Radeon 8065S/8060S/8050S/8040S iGPU, Ryzen AI Max / Max+)
                 @{ P = "890M|880M|860M|840M|Strix Point|Krackan|HX 37[05]|AI 9 HX|AI 9 36[05]|AI 7 35[05]|AI 5 34[05]|AI 7 PRO 35|AI 5 33"; A = "gfx1150" }  # RDNA 3.5 (Strix/Krackan Point: Radeon 890M/880M iGPU, Ryzen AI 9 HX 370/375)
                 @{ P = "RX 7900|RX 7800|RX 7700(?!S)|PRO W7900|PRO W7800|PRO W7700"; A = "gfx1100" }  # RDNA 3 desktop / workstation (Navi 31)
                 @{ P = "RX 7600|RX 7700S|RX 7650|PRO W7600|PRO W7500|PRO V710"; A = "gfx1102" }  # RDNA 3 (Navi 33)
@@ -1860,7 +2028,7 @@ $SysNpmVersion = ""
 $NodeSource = $null
 
 if (-not $IsPipInstall) {
-    # Put Node beside the Studio root. OXC can still need npm when the
+    # Put Node beside the Unsloth root. OXC can still need npm when the
     # frontend build is skipped.
     if (-not [string]::IsNullOrWhiteSpace($env:UNSLOTH_STUDIO_HOME)) { $NodeOverride = $env:UNSLOTH_STUDIO_HOME.Trim() }
     elseif (-not [string]::IsNullOrWhiteSpace($env:STUDIO_HOME)) { $NodeOverride = $env:STUDIO_HOME.Trim() }
@@ -2137,17 +2305,17 @@ if ($NeedNodeForSetup) {
             step "frontend" "skipped (no suitable Node; system left untouched)" "Yellow"
         }
         $NeedFrontendBuild = $false
-        substep "found Node='$SysNodeVersion' npm='$SysNpmVersion'; Studio needs Node >=20.19/22.12/23 and npm >= 11" "Yellow"
+        substep "found Node='$SysNodeVersion' npm='$SysNpmVersion'; Unsloth needs Node >=20.19/22.12/23 and npm >= 11" "Yellow"
         substep "install a suitable Node + npm, or unset UNSLOTH_SKIP_NODE_INSTALL to let Unsloth manage an isolated Node" "Yellow"
     } elseif ($NodeSource -eq "bundled") {
         New-Item -ItemType Directory -Force -Path $NodeParent -ErrorAction SilentlyContinue | Out-Null
-        # Minimal ownership guard for a custom-home dir (the full Studio-owned
+        # Minimal ownership guard for a custom-home dir (the full Unsloth-owned
         # helpers are defined later); never os.replace over a user-owned dir.
         if ($NodeOverride -and (Test-Path -LiteralPath $NodeDir -PathType Container)) {
             $nodeOwnedMarker = Join-Path $NodeDir ".unsloth-studio-owned"
             $nodeMeta = Join-Path $NodeDir "UNSLOTH_NODE_PREBUILT_INFO.json"
             if (-not (Test-Path -LiteralPath $nodeOwnedMarker) -and -not (Test-Path -LiteralPath $nodeMeta)) {
-                Write-Host "[ERROR] $NodeDir already exists and is not a Studio-owned Node install." -ForegroundColor Red
+                Write-Host "[ERROR] $NodeDir already exists and is not an Unsloth-owned Node install." -ForegroundColor Red
                 Write-Host "        Move it aside or choose an empty UNSLOTH_STUDIO_HOME before re-running." -ForegroundColor Yellow
                 exit 1
             }
@@ -2160,7 +2328,7 @@ if ($NeedNodeForSetup) {
         $nodeExit = $LASTEXITCODE
         if ($nodeExit -eq 3) {
             Write-Host $nodeOut -ForegroundColor DarkGray
-            step "node" "install blocked by another active Studio install" "Red"
+            step "node" "install blocked by another active Unsloth install" "Red"
             exit 3
         } elseif ($nodeExit -ne 0) {
             Write-Host $nodeOut -ForegroundColor DarkGray
@@ -2486,13 +2654,14 @@ if (Test-Path -LiteralPath $LegacyStudioHome -PathType Container) {
     $LegacyStudioHome = (Resolve-Path -LiteralPath $LegacyStudioHome).Path
 }
 $StudioHomeIsCustom = ($_studioHomeCanon -ne $LegacyStudioHome)
-# Directory-local evidence that Studio created $Path, used to adopt a custom-home
-# llama.cpp predating the .unsloth-studio-owned marker (see setup.sh). Only the
-# prebuilt UNSLOTH_PREBUILT_INFO.json counts; source builds are indistinguishable
-# from a user clone on Windows and stay under the strict guard.
+# Directory-local evidence that Unsloth created $Path, used to adopt a custom-home
+# llama.cpp or whisper.cpp predating the .unsloth-studio-owned marker (see
+# setup.sh). Only Unsloth prebuilt markers count; source builds are
+# indistinguishable from a user clone on Windows and stay under the strict guard.
 function Test-StudioOwnedAdoptable {
     param([Parameter(Mandatory = $true)][string]$Path)
     if (Test-Path -LiteralPath (Join-Path $Path "UNSLOTH_PREBUILT_INFO.json") -PathType Leaf) { return $true }
+    if (Test-Path -LiteralPath (Join-Path $Path "UNSLOTH_WHISPER_PREBUILT_INFO.json") -PathType Leaf) { return $true }
     return $false
 }
 function Assert-StudioOwnedOrAbsent {
@@ -2506,7 +2675,7 @@ function Assert-StudioOwnedOrAbsent {
             Mark-StudioOwned $Path
             return
         }
-        Write-Host "[ERROR] $Path already exists and is not marked as a Studio-owned $Label." -ForegroundColor Red
+        Write-Host "[ERROR] $Path already exists and is not marked as an Unsloth-owned $Label." -ForegroundColor Red
         Write-Host "        Move it aside or choose an empty UNSLOTH_STUDIO_HOME before re-running." -ForegroundColor Yellow
         exit 1
     }
@@ -2531,6 +2700,8 @@ if ((Test-Path -LiteralPath $VenvDir -PathType Container) -and -not $NoTorchMode
     $VenvPyExe = Join-Path $VenvDir "Scripts\python.exe"
     $installedTorchTag = $null
     $shouldRebuild = $false
+    # Set when a stale venv under a pin is repaired in place (force-reinstall) not wiped.
+    $script:PinChangedForceReinstall = $false
 
     if (Test-Path -LiteralPath $VenvPyExe) {
         try {
@@ -2547,10 +2718,14 @@ if ((Test-Path -LiteralPath $VenvDir -PathType Container) -and -not $NoTorchMode
             if ($finished -and $proc.ExitCode -eq 0 -and $torchVer) {
                 if ($torchVer -match '\+(cu\d+)') {
                     $installedTorchTag = $Matches[1]
+                } elseif ($torchVer -match '\+rocm') {
+                    # Any +rocm / gfx wheel -> generic "rocm" flavor (the exact version is
+                    # repaired later by install_python_stack.py; here we only need the flavor).
+                    $installedTorchTag = "rocm"
                 } elseif ($torchVer -match '\+cpu') {
                     $installedTorchTag = "cpu"
                 } else {
-                    # Untagged wheel (plain "2.x.y" from PyPI) -- treat as cpu
+                    # Untagged wheel (plain "2.x.y" from PyPI) -> cpu.
                     $installedTorchTag = "cpu"
                 }
             } else {
@@ -2566,17 +2741,77 @@ if ((Test-Path -LiteralPath $VenvDir -PathType Container) -and -not $NoTorchMode
     }
 
     if (-not $shouldRebuild) {
-        $expectedTorchTag = if ($HasNvidiaSmi) { Get-PytorchCudaTag } else { "cpu" }
-        if ($installedTorchTag -and $installedTorchTag -ne $expectedTorchTag) {
+        $_pinnedIdx = Get-PinnedTorchIndexUrl
+        $_expectedKnown = $true
+        if ($_pinnedIdx) {
+            $_pinLeaf = Get-TorchIndexLeaf $_pinnedIdx
+            # Digit-gated like the install selection: a custom rocm-* leaf (rocm-current /
+            # rocm-rel-7.2.1) is NOT a ROCm family and must not be stale-compared.
+            if (Test-PipRocmFamilyLeaf $_pinLeaf) {
+                # Don't collapse a pinned ROCm/gfx leaf to a generic "rocm" (would mask a family
+                # change, rocm6.4 -> gfx1151). Get-RocmPinStaleTags uses the SAME 2.11 allowlist
+                # as the install path, so a gfx110X-all/gfx90a/gfx908 pin on a <2.11 wheel is NOT stale.
+                $_rocmTags = Get-RocmPinStaleTags -PinLeaf $_pinLeaf -TorchVersion $torchVer
+                $expectedTorchTag  = $_rocmTags.Expected
+                $installedTorchTag = $_rocmTags.Installed
+            } elseif ((Test-CudaFamilyLeaf $_pinLeaf) -or $_pinLeaf -eq 'cpu') {
+                # cu*/cpu leaves stay specific so a cu126-vs-cu128 mismatch rebuilds;
+                # /custom and /current fall through to the unknown-index branch below.
+                $expectedTorchTag = $_pinLeaf
+            } else {
+                # Custom index whose leaf is not a torch flavor (a /simple mirror): the
+                # flavor can't be inferred, so never treat the venv as stale over it.
+                $_expectedKnown = $false
+                $expectedTorchTag = $installedTorchTag
+            }
+        } elseif ($HasNvidiaSmi) {
+            $expectedTorchTag = Get-PytorchCudaTag
+        } elseif ($HasROCm -or $script:ROCmGfxArch) {
+            # AMD/ROCm host with no explicit pin: an existing +rocm wheel is correct (gfx arch
+            # counts even when $HasROCm is false). But only the arches the install path maps to a
+            # repo.amd.com index get ROCm torch; an unmapped arch installs CPU, so expect "cpu"
+            # for those or a correct CPU venv rebuilds every update.
+            $_rocmWheelArches = @(
+                "gfx1201", "gfx1200",           # RDNA 4
+                "gfx1151", "gfx1150",           # RDNA 3.5 (Strix Halo/Point)
+                "gfx1103", "gfx1102", "gfx1101", "gfx1100",  # RDNA 3
+                "gfx1036", "gfx1035", "gfx1034", "gfx1033", "gfx1032", "gfx1031", "gfx1030",  # RDNA 2 (RX 6000)
+                "gfx90a", "gfx908"              # MI200 / MI100
+            )
+            if ($script:ROCmGfxArch -and ($_rocmWheelArches -contains $script:ROCmGfxArch)) {
+                # A correct +rocm wheel is not stale. A CPU wheel on a supported AMD arch is
+                # NOT wiped either (the AMD Windows ROCm override below upgrades it in place);
+                # expect "cpu" for that case. A wrong CUDA wheel still rebuilds.
+                if ($installedTorchTag -eq "cpu") {
+                    $expectedTorchTag = "cpu"
+                } else {
+                    $expectedTorchTag = "rocm"
+                }
+            } else {
+                $expectedTorchTag = "cpu"
+            }
+        } else {
+            $expectedTorchTag = "cpu"
+        }
+        if ($_expectedKnown -and $installedTorchTag -and $installedTorchTag -ne $expectedTorchTag) {
             $shouldRebuild = $true
         }
     }
 
+    # A stale venv under a pin whose torch still imports is repaired IN PLACE (the dependency
+    # pass force-reinstalls from the pin). The rebuild path wipes the venv and would strand a
+    # direct `studio update`; only a broken venv or an unpinned drift wipes.
+    if ($shouldRebuild -and $_pinnedIdx -and $installedTorchTag) {
+        substep "Torch-index pin changed ($installedTorchTag) -- reinstalling torch from the pin in place." "Cyan"
+        $script:PinChangedForceReinstall = $true
+        $shouldRebuild = $false
+    }
+
     if ($shouldRebuild) {
         $reason = if ($installedTorchTag) { "torch $installedTorchTag != required $expectedTorchTag" } else { "torch could not be imported" }
         if ($InstallerManagedSetup) {
             substep "Stale venv detected ($reason)." "Yellow"
-            Write-Host "   [ERROR] The existing Studio environment needs repair." -ForegroundColor Red
+            Write-Host "   [ERROR] The existing Unsloth environment needs repair." -ForegroundColor Red
             Write-Host "           Re-run install.ps1 so it can replace the environment safely with rollback." -ForegroundColor Yellow
             exit 1
         }
@@ -2598,7 +2833,7 @@ if ((Test-Path -LiteralPath $VenvDir -PathType Container) -and -not $NoTorchMode
             Remove-Item -LiteralPath $VenvDir -Recurse -Force -ErrorAction Stop
         } catch {
             Write-Host "   [ERROR] Could not remove stale venv: $($_.Exception.Message)" -ForegroundColor Red
-            Write-Host "           Close any running Studio/Python processes and re-run setup." -ForegroundColor Red
+            Write-Host "           Close any running Unsloth/Python processes and re-run setup." -ForegroundColor Red
             exit 1
         }
     }
@@ -2649,23 +2884,41 @@ if (Get-Command uv -ErrorAction SilentlyContinue) {
 # Helper: install a package, preferring uv with pip fallback
 function Fast-Install {
     param([Parameter(ValueFromRemainingArguments=$true)]$Args_)
-    if ($UseUv) {
-        $VenvPy = (Get-Command python).Source
-        # An explicit --index-url must win. Inherited uv index env vars otherwise
-        # override it and pull CPU torch over the CUDA/ROCm build (#6898), so drop
-        # them only for index-pinned installs; mirrors still apply elsewhere.
-        $saved = @{}
-        if (@($Args_) -contains '--index-url') {
-            foreach ($n in 'UV_DEFAULT_INDEX', 'UV_INDEX_URL', 'UV_INDEX', 'UV_EXTRA_INDEX_URL') {
-                $saved[$n] = [Environment]::GetEnvironmentVariable($n)
-                Remove-Item "Env:$n" -ErrorAction SilentlyContinue
-            }
+    # An explicit --index-url must win: inherited uv index vars otherwise pull CPU torch over
+    # the CUDA/ROCm build (#6898), so drop them for pinned installs (scrub covers the whole
+    # function since the pip fallback honours PIP_* too). UV_TORCH_BACKEND / UV_FIND_LINKS also
+    # reroute; UV_NO_CONFIG=1 (+ dropping UV_CONFIG_FILE) stops a uv.toml index outranking the
+    # pin (uv 0.10); PIP_NO_INDEX / PIP_INDEX_URL would defeat the pinned --index-url in pip.
+    $saved = @{}
+    $pinned = @($Args_) -contains '--index-url'
+    if ($pinned) {
+        foreach ($n in 'UV_DEFAULT_INDEX', 'UV_INDEX_URL', 'UV_INDEX', 'UV_EXTRA_INDEX_URL',
+                       'UV_TORCH_BACKEND', 'UV_FIND_LINKS', 'PIP_EXTRA_INDEX_URL', 'PIP_FIND_LINKS',
+                       'PIP_NO_INDEX', 'PIP_INDEX_URL',
+                       'UV_CONFIG_FILE', 'UV_NO_CONFIG', 'PIP_CONFIG_FILE') {
+            $saved[$n] = [Environment]::GetEnvironmentVariable($n)
+            Remove-Item "Env:$n" -ErrorAction SilentlyContinue
         }
-        try { $result = & uv pip install --python $VenvPy @Args_ 2>&1 }
-        finally { foreach ($n in $saved.Keys) { if ($null -ne $saved[$n]) { Set-Item "Env:$n" $saved[$n] } } }
-        if ($LASTEXITCODE -eq 0) { return }
+        $env:UV_NO_CONFIG = '1'
+        # A `pip config` global.extra-index-url still adds indexes to the pip FALLBACK;
+        # PIP_CONFIG_FILE = 'nul' (Windows devnull) loads NO config (uv ignores pip config).
+        $env:PIP_CONFIG_FILE = 'nul'
+    }
+    try {
+        if ($UseUv) {
+            $VenvPy = (Get-Command python).Source
+            $result = & uv pip install --python $VenvPy @Args_ 2>&1
+            if ($LASTEXITCODE -eq 0) { return }
+        }
+        & python -m pip install @Args_ 2>&1
+    }
+    finally {
+        if ($pinned) {
+            Remove-Item "Env:UV_NO_CONFIG" -ErrorAction SilentlyContinue
+            Remove-Item "Env:PIP_CONFIG_FILE" -ErrorAction SilentlyContinue
+        }
+        foreach ($n in $saved.Keys) { if ($null -ne $saved[$n]) { Set-Item "Env:$n" $saved[$n] } }
     }
-    & python -m pip install @Args_ 2>&1
 }
 
 # ── Check if Python deps need updating ──
@@ -2748,6 +3001,10 @@ sys.exit(0 if (major, minor) >= (4, 14) else 1)
 #     pip install unsloth 2>&1 | Out-Null
 # }
 
+# A torch-index pin change repairs in place: force the dependency pass so the torch install
+# below force-reinstalls from the new pin (else the fast path keeps the old wheel).
+if ($script:PinChangedForceReinstall) { $SkipPythonDeps = $false }
+
 if (-not $SkipPythonDeps) {
 
 if ($script:UnslothVerbose) {
@@ -2764,7 +3021,7 @@ if ($script:UnslothVerbose) {
 # The CUDA tag is chosen based on the driver's max supported CUDA version.
 
 # Triton/inductor filenames are long and can hit Windows MAX_PATH (260). With long
-# paths on, cache under Studio home; else use a short drive-root dir for headroom.
+# paths on, cache under Unsloth home; else use a short drive-root dir for headroom.
 if ($LongPathsEnabled) {
     $TorchCacheDir = Join-Path $StudioHome "TORCHINDUCTOR_CACHE_DIR"
 } else {
@@ -2775,7 +3032,13 @@ $env:TORCHINDUCTOR_CACHE_DIR = $TorchCacheDir
 [Environment]::SetEnvironmentVariable('TORCHINDUCTOR_CACHE_DIR', $TorchCacheDir, 'User')
 substep "TORCHINDUCTOR_CACHE_DIR set to $TorchCacheDir (avoids MAX_PATH issues)"
 
-if ($HasNvidiaSmi) {
+# Explicit pin (URL or family) wins over GPU probing and suppresses the AMD reroute below;
+# matches install.sh / install.ps1 / install_python_stack.py.
+$PinnedTorchIndexUrl = Get-PinnedTorchIndexUrl
+$TorchIndexPinned = [bool]$PinnedTorchIndexUrl
+if ($PinnedTorchIndexUrl) {
+    $CuTag = Get-TorchIndexLeaf $PinnedTorchIndexUrl
+} elseif ($HasNvidiaSmi) {
     $CuTag = Get-PytorchCudaTag
 } else {
     $CuTag = "cpu"
@@ -2793,16 +3056,20 @@ $ROCmIndexUrl = $null
 # Install AMD ROCm PyTorch wheels when ROCm is confirmed OR a gfx arch is known
 # (name-inferred on Adrenalin-only hosts). The per-arch wheels bundle the runtime
 # (rocm-sdk-libraries-<gfx>), so torch.cuda.is_available() is True without a HIP
-# SDK -- which flips Studio out of chat-only (CHAT_ONLY) and enables Train/Export.
+# SDK -- which flips Unsloth out of chat-only (CHAT_ONLY) and enables Train/Export.
 # Gating on $HasROCm alone left Strix Halo / Radeon 8060S on CPU torch; a failed
 # ROCm install still falls back to CPU below, so this is safe.
-if (($HasROCm -or $ROCmGfxArch) -and $CuTag -eq "cpu") {
+if (-not $TorchIndexPinned -and ($HasROCm -or $ROCmGfxArch) -and $CuTag -eq "cpu") {
     $amdIndexBase = if ($env:UNSLOTH_ROCM_WINDOWS_MIRROR) { $env:UNSLOTH_ROCM_WINDOWS_MIRROR.TrimEnd('/') } else { "https://repo.amd.com/rocm/whl" }
     $archFamilyMap = @{
         "gfx1201" = "gfx120X-all"; "gfx1200" = "gfx120X-all"  # RDNA 4
         "gfx1151" = "gfx1151";     "gfx1150" = "gfx1150"      # RDNA 3.5 (Strix Halo/Point)
         "gfx1103" = "gfx110X-all"; "gfx1102" = "gfx110X-all"  # RDNA 3
         "gfx1101" = "gfx110X-all"; "gfx1100" = "gfx110X-all"
+        "gfx1036" = "gfx103X-all"; "gfx1035" = "gfx103X-all"  # RDNA 2 (RX 6000)
+        "gfx1034" = "gfx103X-all"; "gfx1033" = "gfx103X-all"
+        "gfx1032" = "gfx103X-all"; "gfx1031" = "gfx103X-all"
+        "gfx1030" = "gfx103X-all"
         "gfx90a"  = "gfx90a";      "gfx908"  = "gfx908"       # MI200/MI100
     }
     # gfx120X and Strix have a null _grouped_mm kernel on torch <2.11.0.
@@ -2837,7 +3104,7 @@ if (($HasROCm -or $ROCmGfxArch) -and $CuTag -eq "cpu") {
         # GPU arch detected but not in the supported wheel map — warn explicitly
         # so the user knows why they are getting CPU PyTorch instead of ROCm.
         substep "[WARN] AMD GPU ($ROCmGfxArch) not in supported arch list -- falling back to CPU-only PyTorch" "Yellow"
-        substep "       Supported: gfx1200/1201 (RDNA 4), gfx1150/1151 (RDNA 3.5), gfx1100-1103 (RDNA 3), gfx90a, gfx908" "Yellow"
+        substep "       Supported: gfx1200/1201 (RDNA 4), gfx1150/1151 (RDNA 3.5), gfx1100-1103 (RDNA 3), gfx1030-1036 (RDNA 2), gfx90a, gfx908" "Yellow"
     } else {
         # HIP SDK present ($HasROCm=true via amd-smi) but gcnArchName was not
         # readable — warn rather than silently falling back to CPU PyTorch.
@@ -2846,8 +3113,45 @@ if (($HasROCm -or $ROCmGfxArch) -and $CuTag -eq "cpu") {
     }
 }
 
+# A pinned gfx*/rocm index skips the auto-reroute above; route it through the ROCm install path
+# with the same floor/companions the unpinned AMD path uses (mirrors install.ps1), else the CUDA
+# branch installs bare torch and resolves a known-bad wheel for gfx115x/gfx120x/rocm>=7.2.
+if ($TorchIndexPinned -and -not $ROCmIndexUrl -and $PinnedTorchIndexUrl) {
+    $_pinLeaf = Get-TorchIndexLeaf $PinnedTorchIndexUrl
+    $_pinRocm211 = $false
+    # Anchor the match ($) so a suffixed custom leaf (rocm7.2-private) falls through to the
+    # verbatim install instead of being floored by its rocm7.2 prefix.
+    if ($_pinLeaf -match '^rocm(\d+)\.(\d+)$') {
+        # Only KNOWN-2.11 rocm (rocm7.2) gets the floor (no speculative floor). Matches
+        # Test-RocmKnown211Version / _ROCM_KNOWN_TORCH211_VERSIONS.
+        $_pinRocm211 = Test-RocmKnown211Version -Major ([int]$Matches[1]) -Minor ([int]$Matches[2])
+    }
+    # Only the 2.11 gfx arches need the floor; others publish <2.11 and stay bare. Reuse
+    # Test-RocmGfx211Leaf so this allowlist and the stale-venv check never diverge.
+    $_pinGfx211 = Test-RocmGfx211Leaf $_pinLeaf
+    if ($_pinGfx211 -or $_pinRocm211) {
+        $ROCmIndexUrl   = $PinnedTorchIndexUrl
+        $ROCmTorchSpec  = "torch>=2.11.0,<2.12.0"
+        $ROCmVisionSpec = "torchvision>=0.26.0,<0.27.0"
+        $ROCmAudioSpec  = "torchaudio>=2.11.0,<2.12.0"
+        substep "pinned ROCm index ($_pinLeaf) -- enforcing $ROCmTorchSpec" "Cyan"
+    } elseif (Test-PipRocmFamilyLeaf $_pinLeaf) {
+        # Other gfx / older rocm (<=7.1) ship torch <2.11; route via the ROCm path with
+        # bare specs. Only EXACT rocm<digits> and gfx* are --index-url families; a suffixed
+        # leaf stays on the verbatim path. Mirrors install.ps1 / _is_pip_rocm_family_leaf.
+        $ROCmIndexUrl   = $PinnedTorchIndexUrl
+        $ROCmTorchSpec  = "torch"
+        $ROCmVisionSpec = "torchvision"
+        $ROCmAudioSpec  = "torchaudio"
+    }
+}
+
 $PyTorchWhlBase = if ($env:UNSLOTH_PYTORCH_MIRROR) { $env:UNSLOTH_PYTORCH_MIRROR.TrimEnd('/') } else { "https://download.pytorch.org/whl" }
 
+# A full URL pin is used verbatim; a family pin already set $CuTag. A pinned ROCm install
+# goes through $ROCmIndexUrl; on failure the fallback uses the CPU index, not the ROCm pin.
+$TorchInstallIndexUrl = if ($ROCmIndexUrl) { "$PyTorchWhlBase/cpu" } elseif ($PinnedTorchIndexUrl) { $PinnedTorchIndexUrl } else { "$PyTorchWhlBase/$CuTag" }
+
 $ROCmCpuFallback = $false
 if ($ROCmIndexUrl) {
     substep "installing PyTorch (AMD ROCm, $ROCmGfxArch)..."
@@ -2855,7 +3159,7 @@ if ($ROCmIndexUrl) {
         substep "  enforcing $ROCmTorchSpec $ROCmVisionSpec $ROCmAudioSpec (known _grouped_mm bug in older wheels)" "Cyan"
     }
     if ($script:UnslothVerbose) {
-        Fast-Install $ROCmTorchSpec $ROCmVisionSpec $ROCmAudioSpec --force-reinstall --index-url $ROCmIndexUrl
+        Fast-Install $ROCmTorchSpec $ROCmVisionSpec $ROCmAudioSpec --force-reinstall --index-url $ROCmIndexUrl | ForEach-Object { Redact-InstallOutput "$_" } | Out-Host
         $torchInstallExit = $LASTEXITCODE
         $output = ""
     } else {
@@ -2864,7 +3168,7 @@ if ($ROCmIndexUrl) {
     }
     if ($torchInstallExit -ne 0) {
         Write-Host "[WARN] AMD ROCm PyTorch install failed -- falling back to CPU" -ForegroundColor Yellow
-        Write-Host $output -ForegroundColor Yellow
+        Write-Host (Redact-InstallOutput $output) -ForegroundColor Yellow
         $ROCmIndexUrl = $null
         $ROCmCpuFallback = $true
     } else {
@@ -2874,42 +3178,70 @@ if ($ROCmIndexUrl) {
     }
 }
 
-if (-not $ROCmIndexUrl -and $CuTag -eq "cpu") {
+if (-not $ROCmIndexUrl -and ($CuTag -eq "cpu" -or $ROCmCpuFallback)) {
     substep "installing PyTorch (CPU-only)..."
-    # After an AMD ROCm fallback, force-reinstall so a partially-installed ROCm torch
-    # (which still satisfies the CPU torch>= range) is replaced by the CPU build. Skip
-    # the forced reinstall on a genuine CPU-only host so the common path stays fast.
-    # Build the array directly: an if-expression collapses @("x") to a scalar string,
-    # which @splat would then enumerate char-by-char into broken single-letter args.
+    # After an AMD ROCm fallback, force-reinstall so a partial ROCm torch (which satisfies the
+    # CPU torch>= range) is replaced by the CPU build; skip on a genuine CPU host to stay fast.
+    # $ROCmCpuFallback matters when a PINNED ROCm index failed ($CuTag is still the rocm leaf).
+    # Build the array directly: an if-expression collapses @("x") to a scalar @splat would
+    # enumerate char-by-char.
     $cpuForce = @()
     if ($ROCmCpuFallback) { $cpuForce = @("--force-reinstall") }
+    # --force-reinstall on a pin change: a stale +cu / +rocm wheel still satisfies the CPU
+    # torch>= range, so uv would keep it and only swap companions.
+    if ($script:PinChangedForceReinstall) { $cpuForce = @("--force-reinstall") }
+    # A PINNED cpu index installs the bounded trio (parity with _CPU_TORCH_PKG_SPEC): the /cpu
+    # index serves newer torch, and _ensure_cpu_torch keeps any CPU build, so a bare trio could
+    # land an unsupported version. Unpinned CPU hosts keep the bare trio (pre-pin behavior).
+    $cpuTorchSpec = "torch"; $cpuVisionSpec = "torchvision"; $cpuAudioSpec = "torchaudio"
+    if ($TorchIndexPinned) {
+        $cpuTorchSpec  = "torch>=2.4,<2.12.0"
+        $cpuVisionSpec = "torchvision>=0.19,<0.27.0"
+        $cpuAudioSpec  = "torchaudio>=2.4,<2.12.0"
+    }
     if ($script:UnslothVerbose) {
-        Fast-Install torch torchvision torchaudio @cpuForce --index-url "$PyTorchWhlBase/cpu"
+        Fast-Install $cpuTorchSpec $cpuVisionSpec $cpuAudioSpec @cpuForce --index-url $TorchInstallIndexUrl | ForEach-Object { Redact-InstallOutput "$_" } | Out-Host
         $torchInstallExit = $LASTEXITCODE
         $output = ""
     } else {
-        $output = Fast-Install torch torchvision torchaudio @cpuForce --index-url "$PyTorchWhlBase/cpu" | Out-String
+        $output = Fast-Install $cpuTorchSpec $cpuVisionSpec $cpuAudioSpec @cpuForce --index-url $TorchInstallIndexUrl | Out-String
         $torchInstallExit = $LASTEXITCODE
     }
     if ($torchInstallExit -ne 0) {
         Write-Host "[FAILED] PyTorch install failed (exit code $torchInstallExit)" -ForegroundColor Red
-        Write-Host $output -ForegroundColor Red
+        Write-Host (Redact-InstallOutput $output) -ForegroundColor Red
         exit 1
     }
 } elseif (-not $ROCmIndexUrl) {
     substep "installing PyTorch with CUDA support ($CuTag)..."
     substep "(This download is ~2.8 GB -- may take a few minutes)"
+    # --force-reinstall on a pin change: an installed cuXXX wheel satisfies the bare torch
+    # requirement (PEP 440 ignores the +cuXXX tag), so without it a changed CUDA pin (cu126
+    # -> cu128) never applies.
+    $cudaForce = @()
+    if ($script:PinChangedForceReinstall) { $cudaForce = @("--force-reinstall") }
+    # An unknown-leaf custom pin (/simple, /current) routes here with $CuTag as that leaf. Bound
+    # the trio like the fresh custom-pin paths so a mirror can't pull an ABI-newer companion
+    # against the capped torch. Known cu* leaves keep bare specs.
+    $cudaTorchSpec = "torch"
+    $cudaVisionSpec = "torchvision"
+    $cudaAudioSpec = "torchaudio"
+    if ($TorchIndexPinned -and -not (Test-CudaFamilyLeaf $CuTag)) {
+        $cudaTorchSpec = "torch>=2.4,<2.11.0"
+        $cudaVisionSpec = "torchvision>=0.19,<0.26.0"
+        $cudaAudioSpec = "torchaudio>=2.4,<2.11.0"
+    }
     if ($script:UnslothVerbose) {
-        Fast-Install torch torchvision torchaudio --index-url "$PyTorchWhlBase/$CuTag"
+        Fast-Install $cudaTorchSpec $cudaVisionSpec $cudaAudioSpec @cudaForce --index-url $TorchInstallIndexUrl | ForEach-Object { Redact-InstallOutput "$_" } | Out-Host
         $torchInstallExit = $LASTEXITCODE
         $output = ""
     } else {
-        $output = Fast-Install torch torchvision torchaudio --index-url "$PyTorchWhlBase/$CuTag" | Out-String
+        $output = Fast-Install $cudaTorchSpec $cudaVisionSpec $cudaAudioSpec @cudaForce --index-url $TorchInstallIndexUrl | Out-String
         $torchInstallExit = $LASTEXITCODE
     }
     if ($torchInstallExit -ne 0) {
         Write-Host "[FAILED] PyTorch CUDA install failed (exit code $torchInstallExit)" -ForegroundColor Red
-        Write-Host $output -ForegroundColor Red
+        Write-Host (Redact-InstallOutput $output) -ForegroundColor Red
         exit 1
     }
 
@@ -2925,7 +3257,7 @@ if (-not $ROCmIndexUrl -and $CuTag -eq "cpu") {
     }
     if ($tritonInstallExit -ne 0) {
         substep "Triton install failed -- torch.compile may not work" "Yellow"
-        Write-Host $output -ForegroundColor Yellow
+        Write-Host (Redact-InstallOutput $output) -ForegroundColor Yellow
     } else {
         substep "Triton for Windows installed (enables torch.compile)"
     }
@@ -3022,7 +3354,7 @@ foreach ($pkg in @("transformers==5.3.0", "huggingface_hub==1.8.0", "hf_xet==1.4
     }
     if ($t5PkgExit -ne 0) {
         Write-Host "[FAIL] Could not install $pkg into .venv_t5_530/" -ForegroundColor Red
-        Write-Host $output -ForegroundColor Red
+        Write-Host (Redact-InstallOutput $output) -ForegroundColor Red
         $ErrorActionPreference = $prevEAP_t5
         exit 1
     }
@@ -3057,7 +3389,7 @@ foreach ($pkg in @("transformers==5.5.0", "huggingface_hub==1.8.0", "hf_xet==1.4
     }
     if ($t5PkgExit -ne 0) {
         Write-Host "[FAIL] Could not install $pkg into .venv_t5_550/" -ForegroundColor Red
-        Write-Host $output -ForegroundColor Red
+        Write-Host (Redact-InstallOutput $output) -ForegroundColor Red
         $ErrorActionPreference = $prevEAP_t5
         exit 1
     }
@@ -3092,7 +3424,7 @@ foreach ($pkg in @("transformers==5.10.2", "huggingface_hub==1.8.0", "hf_xet==1.
     }
     if ($t5PkgExit -ne 0) {
         Write-Host "[FAIL] Could not install $pkg into .venv_t5_510/" -ForegroundColor Red
-        Write-Host $output -ForegroundColor Red
+        Write-Host (Redact-InstallOutput $output) -ForegroundColor Red
         $ErrorActionPreference = $prevEAP_t5
         exit 1
     }
@@ -3231,7 +3563,7 @@ if ($LocalLlamaCppSrc) {
     # Reusing a local dir disables both the prebuilt download and the source
     # build, so a runnable llama-server.exe must already be present. Accept any
     # layout LlamaCppBackend._layout_candidates() resolves (root-level, build\bin,
-    # or build\bin\Release) so the flag never rejects a tree Studio could run.
+    # or build\bin\Release) so the flag never rejects a tree Unsloth could run.
     $LocalLlamaServerFound = $false
     foreach ($_cand in @(
             (Join-Path $ResolvedLocal "llama-server.exe"),
@@ -3253,7 +3585,7 @@ if ($LocalLlamaCppSrc) {
         }
     } else {
         # Fail clearly rather than junction an unbuilt or wrong-platform checkout
-        # and leave Studio with no usable binary.
+        # and leave Unsloth with no usable binary.
         if (-not $LocalLlamaServerFound) {
             step "llama.cpp" "no llama-server.exe under $ResolvedLocal (looked for .\llama-server.exe, .\build\bin and .\build\bin\Release) -- build llama.cpp there first, or drop --with-llama-cpp-dir" "Red"
             exit 1
@@ -3281,7 +3613,7 @@ if ($LocalLlamaCppSrc) {
             # prebuilt path's active-process handling and stop with a clear message.
             if (Test-Path -LiteralPath $LlamaCppDir) {
                 step "llama.cpp" "install blocked by active llama.cpp process" "Yellow"
-                substep "Close Studio or other llama.cpp users and retry" "Yellow"
+                substep "Close Unsloth or other llama.cpp users and retry" "Yellow"
                 exit 3
             }
         }
@@ -3367,6 +3699,15 @@ if ($LocalLlamaCppLinked) {
         if ($env:UNSLOTH_LLAMA_RELEASE_TAG) {
             $prebuiltArgs += @("--published-release-tag", $env:UNSLOTH_LLAMA_RELEASE_TAG)
         }
+        # UNSLOTH_LLAMA_CPP_BACKEND=cpu (case-insensitive, whitespace-trimmed) forces the
+        # CPU-only prebuilt via --force-cpu (persisted so updates keep it). Fixes Intel
+        # iGPU Vulkan crash (#7213).
+        $llamaBackend = "$($env:UNSLOTH_LLAMA_CPP_BACKEND)".Trim().ToLowerInvariant()
+        if ($llamaBackend -eq "cpu") {
+            $prebuiltArgs += "--force-cpu"
+        } elseif ($llamaBackend -and $llamaBackend -ne "auto") {
+            Write-Host "[WARN] Ignoring UNSLOTH_LLAMA_CPP_BACKEND='$($env:UNSLOTH_LLAMA_CPP_BACKEND)' (expected 'auto' or 'cpu')" -ForegroundColor Yellow
+        }
         $prevEAPPrebuilt = $ErrorActionPreference
         $ErrorActionPreference = "Continue"
         $previousNativeErrorPreference = $null
@@ -3414,7 +3755,7 @@ if ($LocalLlamaCppLinked) {
             if (Test-Path -LiteralPath $LlamaCppDir) {
                 substep "Existing install was restored" "Yellow"
             }
-            substep "Close Studio or other llama.cpp users and retry" "Yellow"
+            substep "Close Unsloth or other llama.cpp users and retry" "Yellow"
             exit 3
         } else {
             step "llama.cpp" "prebuilt install failed (continuing)" "Yellow"
@@ -3427,6 +3768,83 @@ if ($LocalLlamaCppLinked) {
         }
 }
 
+# ==========================================================================
+#  PHASE 3.4: Install the whisper.cpp prebuilt (dictation runtime)
+# ==========================================================================
+# Mirrors the llama.cpp prebuilt install above; current whisper releases are
+# slim bundles that reuse the llama install's ggml runtime, so this runs after
+# llama. Failure is never fatal: local dictation falls back to Transformers STT.
+$WhisperCppDir = Join-Path $UnslothHome "whisper.cpp"
+$WhisperInstaller = Join-Path $PSScriptRoot "install_whisper_prebuilt.py"
+# Same opt-outs as setup.sh: a user-configured binary/dir or an explicit skip
+# disables the managed install entirely.
+if ($env:WHISPER_SERVER_PATH -or $env:UNSLOTH_WHISPER_CPP_PATH) {
+    substep "whisper.cpp: using a user-configured binary/dir; skipping managed install"
+} elseif ($env:UNSLOTH_SKIP_WHISPER_INSTALL -eq "1") {
+    substep "whisper.cpp: install skipped (UNSLOTH_SKIP_WHISPER_INSTALL=1)"
+} elseif (Test-Path -LiteralPath $WhisperInstaller) {
+    # The installer's atomic activation replaces the whole directory, so the
+    # custom-home ownership guard must run first (mirrors the llama block).
+    if ($StudioHomeIsCustom) {
+        Assert-StudioOwnedOrAbsent -Path $WhisperCppDir -Label "whisper.cpp install"
+    }
+    $whisperArgs = @($WhisperInstaller, "--install-dir", $WhisperCppDir)
+    if ($env:UNSLOTH_WHISPER_RELEASE_TAG) {
+        $whisperArgs += @("--published-release-tag", $env:UNSLOTH_WHISPER_RELEASE_TAG)
+    }
+    if ($script:ROCmGfxArch) {
+        $whisperArgs += @("--rocm-gfx", $script:ROCmGfxArch)
+    } elseif ($HasROCm) {
+        $whisperArgs += "--has-rocm"
+    }
+    $prevEAPWhisper = $ErrorActionPreference
+    $ErrorActionPreference = "Continue"
+    $previousNativeErrorPreferenceW = $null
+    $restoreNativeErrorPreferenceW = $false
+    if ($PSVersionTable.PSVersion.Major -ge 7) {
+        $previousNativeErrorPreferenceW = $PSNativeCommandUseErrorActionPreference
+        $PSNativeCommandUseErrorActionPreference = $false
+        $restoreNativeErrorPreferenceW = $true
+    }
+    try {
+        $whisperOutput = & python @whisperArgs 2>&1 | Out-String
+        $whisperExit = $LASTEXITCODE
+    } finally {
+        if ($restoreNativeErrorPreferenceW) {
+            $PSNativeCommandUseErrorActionPreference = $previousNativeErrorPreferenceW
+        }
+    }
+    $ErrorActionPreference = $prevEAPWhisper
+    if ($whisperExit -eq 0) {
+        if ($whisperOutput -match "already matches") {
+            step "whisper.cpp" "prebuilt up to date"
+        } else {
+            step "whisper.cpp" "prebuilt installed"
+        }
+        if ($StudioHomeIsCustom -and (Test-Path -LiteralPath $WhisperCppDir -PathType Container)) {
+            Mark-StudioOwned -Path $WhisperCppDir
+        }
+    } elseif ($whisperExit -eq 3) {
+        step "whisper.cpp" "install busy; keeping existing runtime" "Yellow"
+    } elseif ($whisperExit -eq 2) {
+        $requiredWhisperLlamaTag = "unknown"
+        if ($whisperOutput -match "slim bundle requires llama\.cpp ([^;\s]+)") {
+            $requiredWhisperLlamaTag = $Matches[1]
+        }
+        $installedWhisperLlamaTag = "unknown"
+        $llamaMarker = Join-Path $LlamaCppDir "UNSLOTH_PREBUILT_INFO.json"
+        if (Test-Path -LiteralPath $llamaMarker -PathType Leaf) {
+            try {
+                $markerPayload = Get-Content -LiteralPath $llamaMarker -Raw | ConvertFrom-Json
+                if ($markerPayload.release_tag) { $installedWhisperLlamaTag = $markerPayload.release_tag }
+            } catch {}
+        }
+        step "whisper.cpp" "no compatible prebuilt (installed llama.cpp $installedWhisperLlamaTag; whisper requires $requiredWhisperLlamaTag); curated whisper.cpp dictation is unavailable; publish paired releases in llama.cpp then whisper.cpp order; browser and Transformers dictation remain available" "Yellow"
+    } else {
+        step "whisper.cpp" "prebuilt install failed; curated whisper.cpp dictation is unavailable; retry setup or inspect verbose output; browser and Transformers dictation remain available" "Yellow"
+    }
+}
+
 # ==========================================================================
 #  PHASE 3.5: Install OpenSSL dev (for HTTPS support in llama-server)
 # ==========================================================================
@@ -4003,7 +4421,7 @@ if ($LocalLlamaCppLinked) {
     }
 
     # -- Step E: Build the DiffusionGemma visual server (optional, best-effort) --
-    # An example target present on llama.cpp PR #24423; lets Studio serve
+    # An example target present on llama.cpp PR #24423; lets Unsloth serve
     # DiffusionGemma GGUFs without DG_VISUAL_BIN. No-op when not configured.
     if ($BuildOk) {
         $null = cmake --build $BuildDir --config Release --target llama-diffusion-gemma-visual-server -j $NumCpu 2>&1 | Out-String
diff --git a/studio/setup.sh b/studio/setup.sh
index 3d67db3da7..f6a6bc346b 100755
--- a/studio/setup.sh
+++ b/studio/setup.sh
@@ -36,6 +36,10 @@ fi
 #                             forces a source build, and causes HTTP 422 errors.
 #                             Only use "master" temporarily when the latest release
 #                             is missing support for a new model architecture.
+#
+#   UNSLOTH_LLAMA_CPP_BACKEND : "auto" (default) or "cpu". When "cpu", forces
+#                               the CPU-only prebuilt bundle on GPU hosts.
+#                               Fixes Intel iGPU Vulkan crashes (#7213).
 # ──────────────────────────────────────────────────────────────────────────
 _DEFAULT_LLAMA_PR_FORCE=""
 _DEFAULT_LLAMA_SOURCE="https://github.com/ggml-org/llama.cpp"
@@ -127,13 +131,13 @@ _suggest_npm_registry() {
     printf '\n' >&2
     step "frontend" "registry.npmjs.org looks blocked (corporate firewall/proxy?)" "$C_WARN" >&2
     if [ -n "$_mirror" ]; then
-        substep "Studio pins the public npm registry; your mirror is being ignored." >&2
+        substep "Unsloth pins the public npm registry; your mirror is being ignored." >&2
         substep "Detected a registry in your npm config:" >&2
         substep "  $_mirror" >&2
-        substep "Re-run pointing Studio at it:" >&2
+        substep "Re-run pointing Unsloth at it:" >&2
         substep "  UNSLOTH_NPM_REGISTRY=$_mirror ./install.sh --local" >&2
     else
-        substep "If you use a private mirror/proxy, point Studio at it and re-run:" >&2
+        substep "If you use a private mirror/proxy, point Unsloth at it and re-run:" >&2
         substep "  UNSLOTH_NPM_REGISTRY=https://your-mirror.example/api/npm/ ./install.sh --local" >&2
     fi
     substep "(min-release-age and save-exact stay enforced.)" >&2
@@ -247,6 +251,38 @@ _resolve_cuda_archs() {
     printf '%s' "$_archs"
 }
 
+# Opt-in staged GPU smoke test after a source build (#5854 gap 2). Default off:
+# llama-server's first GPU forward pass JIT-compiles CUDA kernels and stalls
+# installs for minutes on Blackwell. Same env as install_llama_prebuilt.py.
+_staged_validation_enabled() {
+    local _raw="${UNSLOTH_LLAMA_STAGED_VALIDATION:-}"
+    # Match install_llama_prebuilt.py staged_validation_enabled(): strip + lowercase.
+    _raw="$(printf '%s' "$_raw" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//' | tr '[:upper:]' '[:lower:]')"
+    case "$_raw" in
+        1|true|yes|on) return 0 ;;
+        *) return 1 ;;
+    esac
+}
+
+# Map the source-build GPU backend to install_llama_prebuilt --install-kind so
+# validate_server enables --n-gpu-layers for the right backends.
+_source_smoke_install_kind() {
+    if [ "${_TRY_METAL_CPU_FALLBACK:-false}" = true ]; then
+        printf '%s' "macos-arm64"
+        return 0
+    fi
+    case "${GPU_BACKEND:-}" in
+        cuda)
+            case "$(uname -m 2>/dev/null || true)" in
+                aarch64|arm64) printf '%s' "linux-arm64-cuda" ;;
+                *) printf '%s' "linux-cuda" ;;
+            esac
+            ;;
+        rocm) printf '%s' "linux-rocm" ;;
+        *) printf '%s' "" ;;
+    esac
+}
+
 # Run a GPU probe under a 10s timeout when `timeout` is available so a wedged
 # NVIDIA driver cannot hang setup; fall back to a bare call where it is not.
 _setup_run_smi() {
@@ -396,7 +432,7 @@ _print_cuda_driver_toolkit_mismatch() {
     local _driver_major=${_driver_version%%.*}
     substep "CUDA Toolkit $_toolkit_version is a major-version mismatch: toolkit major $_toolkit_major exceeds driver CUDA major $_driver_major ($_driver_version)." "$C_WARN"
     substep "Update the NVIDIA GPU driver to run CUDA Toolkit $_toolkit_version, or install a CUDA $_driver_major.x toolkit." "$C_WARN"
-    substep "Or let Studio use the prebuilt CUDA bundle; it does not need the local toolkit." "$C_WARN"
+    substep "Or let Unsloth use the prebuilt CUDA bundle; it does not need the local toolkit." "$C_WARN"
 }
 
 print_llama_error_log() {
@@ -531,13 +567,15 @@ _STUDIO_HOME_IS_CUSTOM=false
 if [ "$_studio_home_canon" != "$_LEGACY_STUDIO_HOME" ]; then
     _STUDIO_HOME_IS_CUSTOM=true
 fi
-# Directory-local evidence Studio created "$1": only prebuilt-installer metadata
+# Directory-local evidence Unsloth created "$1": only prebuilt-installer metadata
 # counts (UNSLOTH_PREBUILT_INFO.json for llama.cpp, UNSLOTH_NODE_PREBUILT_INFO.json
-# for Node), both written only by our installers. Mirrors the setup.ps1 Node guard.
-# A markerless source build stays strict since this runs right before an rm -rf.
+# for Node, UNSLOTH_WHISPER_PREBUILT_INFO.json for whisper.cpp), all written only
+# by our installers. Mirrors the setup.ps1 Node guard. A markerless source build
+# stays strict since this runs right before an rm -rf.
 _studio_owned_adoptable() {
     [ -f "$1/UNSLOTH_PREBUILT_INFO.json" ] && return 0
     [ -f "$1/UNSLOTH_NODE_PREBUILT_INFO.json" ] && return 0
+    [ -f "$1/UNSLOTH_WHISPER_PREBUILT_INFO.json" ] && return 0
     return 1
 }
 _assert_studio_owned_or_absent() {
@@ -549,7 +587,7 @@ _assert_studio_owned_or_absent() {
             : > "$_aso_dir/$_STUDIO_OWNED_MARKER" 2>/dev/null || true
             return 0
         fi
-        echo "ERROR: $_aso_dir already exists and is not marked as a Studio-owned $_aso_label." >&2
+        echo "ERROR: $_aso_dir already exists and is not marked as an Unsloth-owned $_aso_label." >&2
         echo "       Move it aside or choose an empty UNSLOTH_STUDIO_HOME before re-running." >&2
         exit 1
     fi
@@ -585,7 +623,7 @@ if [ "$_NEED_FRONTEND_BUILD" = false ] && [ ! -d "$_OXC_DIR" ]; then
 else
 
 # ── Node (isolated; never touches the system Node/npm) ──
-# Studio's frontend (Vite 8) needs Node ^20.19 || >=22.12 || >=23 and npm >= 11.
+# Unsloth's frontend (Vite 8) needs Node ^20.19 || >=22.12 || >=23 and npm >= 11.
 # Three sources:
 #   system  -- system Node + npm already satisfy both; used read-only.
 #   bundled -- install a pinned isolated Node under $UNSLOTH_HOME/node, build-only.
@@ -666,9 +704,9 @@ elif [ "$NODE_SOURCE" = bundled ]; then
     fi
     set -e
     if [ "$_NODE_STATUS" -eq 3 ]; then
-        step "node" "install blocked by another active Studio install" "$C_ERR"
+        step "node" "install blocked by another active Unsloth install" "$C_ERR"
         sed 's/^/   | /' "$_NODE_LOG" >&2; rm -f "$_NODE_LOG"
-        substep "close other Studio installs and retry"
+        substep "close other Unsloth installs and retry"
         exit 3
     elif [ "$_NODE_STATUS" -ne 0 ]; then
         step "node" "isolated Node install failed" "$C_ERR"
@@ -692,7 +730,7 @@ elif [ "$NODE_SOURCE" = bundled ]; then
 else
     _FRONTEND_SKIP=true
     step "frontend" "skipped (no suitable Node; system left untouched)" "$C_WARN"
-    substep "found Node='${_SYS_NODE_VER:-none}' npm='${_SYS_NPM_VER:-none}'; Studio needs Node >=20.19/22.12/23 and npm >= 11"
+    substep "found Node='${_SYS_NODE_VER:-none}' npm='${_SYS_NPM_VER:-none}'; Unsloth needs Node >=20.19/22.12/23 and npm >= 11"
     substep "install a suitable Node + npm, or unset UNSLOTH_SKIP_NODE_INSTALL to let Unsloth manage an isolated Node"
 fi
 verbose_substep "node source: $NODE_SOURCE (sys node=${_SYS_NODE_VER:-none} npm=${_SYS_NPM_VER:-none}) dir=$NODE_DIR"
@@ -873,11 +911,11 @@ _remove_agent_instruction_files \
 _COLAB_NO_VENV=false
 if [ ! -x "$VENV_DIR/bin/python" ]; then
     if [ "$IS_COLAB" = true ]; then
-        # On Colab there is no Studio venv -- install backend deps into system Python.
+        # On Colab there is no Unsloth venv -- install backend deps into system Python.
         # Strip all version constraints so pip keeps Colab's pre-installed
         # packages (huggingface-hub, datasets, transformers) and only pulls
         # in genuinely missing ones (structlog, fastapi, etc.).
-        substep "Colab detected, installing Studio backend dependencies..."
+        substep "Colab detected, installing Unsloth backend dependencies..."
         _COLAB_REQS_TMP="$(mktemp)"
         sed 's/[><=!~;].*//' "$SCRIPT_DIR/backend/requirements/studio.txt" \
             | grep -v '^#' | grep -v '^$' > "$_COLAB_REQS_TMP"
@@ -1097,8 +1135,7 @@ if [ "$_setup_nvidia_usable" != true ]; then
         _setup_mkt=$(_setup_run_smi amd-smi static --asic 2>/dev/null | awk -F'[:|]' \
             '/[Mm]arket.?[Nn]ame/{gsub(/^[[:space:]]+|[[:space:]]+$/,"", $2); if($2){print $2; exit}}' || true)
     elif [ -e /dev/kfd ] && \
-         awk 'FNR==1{ gpu=0; amd=0 } /gpu_id/{ gpu=($2+0>0) } /vendor_id/{ amd=($2==4098) } \
-              gpu && amd { found=1 } END{ exit !found }' \
+         awk '/vendor_id/ && $2 == 4098 { found = 1 } END { exit !found }' \
              /sys/class/kfd/kfd/topology/nodes/*/properties 2>/dev/null; then
         # KFD sysfs fallback, AMD vendor_id 4098 only (mirrors install.sh
         # _has_amd_rocm_gpu): covers AMD hosts where rocminfo/amd-smi are
@@ -1132,7 +1169,7 @@ elif [ "$_setup_amd_detected" = true ]; then
         case "$_setup_mkt" in
             *"9070 XT"*|*9080*)                                                                            _setup_gfx="gfx1201" ;;  # RDNA 4
             *9070*|*9060*)                                                                                 _setup_gfx="gfx1200" ;;  # RDNA 4
-            *"8060S"*|*"8050S"*|*"8040S"*|*"Strix Halo"*|*"Ryzen AI Max"*|*"AI Max"*) _setup_gfx="gfx1151" ;;  # RDNA 3.5 (Strix Halo: Radeon 8060S/8050S/8040S iGPU, Ryzen AI Max+)
+            *"8065S"*|*"8060S"*|*"8050S"*|*"8040S"*|*"Strix Halo"*|*"Ryzen AI Max"*|*"AI Max"*) _setup_gfx="gfx1151" ;;  # RDNA 3.5 (Strix Halo + Gorgon Halo: Radeon 8065S/8060S/8050S/8040S iGPU, Ryzen AI Max / Max+)
             *"890M"*|*"880M"*|*"860M"*|*"840M"*|*"Strix Point"*|*"Krackan"*|*"HX 37"*|*"AI 9 HX"*|*"AI 9 36"*|*"AI 7 35"*|*"AI 5 34"*|*"AI 7 PRO 35"*|*"AI 5 33"*) _setup_gfx="gfx1150" ;;  # RDNA 3.5 (Strix/Krackan Point: Radeon 890M/880M iGPU, Ryzen AI 9 HX 370/375)
             *"RX 7600"*|*"RX 7700S"*|*"RX 7650"*|*"PRO W7600"*|*"PRO W7500"*|*"PRO V710"*)                  _setup_gfx="gfx1102" ;;  # RDNA 3 (Navi 33)
             *"RX 7900"*|*"RX 7800"*|*"RX 7700"*|*"PRO W7900"*|*"PRO W7800"*|*"PRO W7700"*)                  _setup_gfx="gfx1100" ;;  # RDNA 3 desktop / workstation (Navi 31)
@@ -1254,7 +1291,7 @@ _link_local_llama_quantize_shim() {
 }
 
 # Accept any layout LlamaCppBackend._layout_candidates() resolves so the flag
-# never rejects a tree Studio could actually run: a root-level llama-server (a
+# never rejects a tree Unsloth could actually run: a root-level llama-server (a
 # `make` build or a flat-extracted release) or the CMake build/bin/llama-server.
 _has_local_llama_server() {
     [ -x "$1/llama-server" ] || [ -x "$1/build/bin/llama-server" ]
@@ -1298,13 +1335,13 @@ if [ -n "${UNSLOTH_LOCAL_LLAMA_CPP_DIR:-}" ]; then
         # Reusing disables BOTH the prebuilt download and the source build, so the
         # linked tree must already contain a runnable llama-server in one of the
         # layouts the backend resolves (root-level or build/bin/). Fail clearly
-        # rather than link an unbuilt or wrong-platform checkout and leave Studio
+        # rather than link an unbuilt or wrong-platform checkout and leave Unsloth
         # with no usable binary.
         if ! _has_local_llama_server "$_RESOLVED_LOCAL"; then
             step "llama.cpp" "no llama-server under $_RESOLVED_LOCAL (looked for ./llama-server and ./build/bin/llama-server) -- build llama.cpp there first, or drop --with-llama-cpp-dir" "$C_ERR"
             exit 1
         fi
-        # A stale link from a previous --with-llama-cpp-dir run isn't Studio-owned
+        # A stale link from a previous --with-llama-cpp-dir run isn't Unsloth-owned
         # content; drop it before the ownership check so re-runs stay idempotent
         # for a custom UNSLOTH_STUDIO_HOME (the assert would otherwise follow the
         # link into the user's dir and reject it as unowned).
@@ -1354,11 +1391,32 @@ else
     # name-inferred arch). Implies --has-rocm on the installer side.
     if [ -n "${_setup_gfx:-}" ]; then
         _PREBUILT_CMD+=(--rocm-gfx "$_setup_gfx")
-    elif [ "$_setup_amd_detected" = true ]; then
-        # AMD was detected but gfx resolution failed; tell the installer ROCm is
-        # present so it can still attempt a prebuilt. Mirrors setup.ps1 behaviour.
+    elif [ "$_setup_amd_detected" = true ] && \
+         { command -v hipcc >/dev/null 2>&1 || [ -x /opt/rocm/bin/hipcc ] || \
+           ls /opt/rocm-*/bin/hipcc >/dev/null 2>&1; }; then
+        # AMD detected but gfx unknown (KFD-only host): forward --has-rocm only when
+        # hipcc can actually build llama.cpp (incl. a versioned /opt/rocm-*/bin, the
+        # same paths the source build uses). With no gfx the prebuilt resolver finds
+        # no ROCm bundle and the source build would fail, so without hipcc fall
+        # through to the CPU prebuilt instead of breaking the install.
         _PREBUILT_CMD+=(--has-rocm)
     fi
+    # UNSLOTH_LLAMA_CPP_BACKEND=cpu (case-insensitive, trimmed) forces the CPU-only
+    # prebuilt via --force-cpu, bypassing Vulkan/CUDA/ROCm. Fixes Intel iGPU crash (#7213).
+    # No effect on macOS: the universal bundle already runs on CPU (Metal is a runtime
+    # -ngl choice), so warn instead of writing a misleading forced-CPU marker.
+    _llama_backend="$(printf '%s' "${UNSLOTH_LLAMA_CPP_BACKEND:-auto}" | awk '{$1=$1; print tolower($0)}')"
+    case "$_llama_backend" in
+        cpu)
+            if [ "$_HOST_SYSTEM" = "Darwin" ]; then
+                step "llama.cpp" "UNSLOTH_LLAMA_CPP_BACKEND=cpu has no effect on macOS (universal build; use -ngl 0 at runtime for CPU-only)" "$C_WARN" >&2
+            else
+                _PREBUILT_CMD+=(--force-cpu)
+            fi
+            ;;
+        ""|auto) ;;
+        *) step "llama.cpp" "Ignoring UNSLOTH_LLAMA_CPP_BACKEND='$UNSLOTH_LLAMA_CPP_BACKEND' (expected 'auto' or 'cpu')" "$C_WARN" >&2 ;;
+    esac
     _PREBUILT_LOG="$(mktemp)"
     set +e
     if _is_verbose; then
@@ -1389,7 +1447,7 @@ else
         if [ -d "$LLAMA_CPP_DIR" ]; then
             substep "existing install was restored"
         fi
-        substep "close Studio or other llama.cpp users and retry"
+        substep "close Unsloth or other llama.cpp users and retry"
         exit 3
     else
         step "llama.cpp" "prebuilt install failed (continuing)" "$C_WARN"
@@ -1874,6 +1932,37 @@ else
             run_quiet_no_exit "build diffusion visual server" cmake --build "$_BUILD_TMP/build" --config Release --target llama-diffusion-gemma-visual-server -j"$NCPU" || true
         fi
 
+        # Opt-in post-build GPU smoke test (#5854 gap 2). Default off (Blackwell
+        # CUDA JIT stalls). On failure, reuse the CPU fallback path so the user
+        # still gets a working llama-server. Runs before the install swap.
+        if [ "$BUILD_OK" = true ] && _staged_validation_enabled; then
+            _FB_LABEL="$(_gpu_fallback_label)"
+            _SMOKE_KIND="$(_source_smoke_install_kind)"
+            if [ -n "$_FB_LABEL" ]; then
+                _SMOKE_CMD=(
+                    python "$SCRIPT_DIR/install_llama_prebuilt.py"
+                    --validate-install "$_BUILD_TMP"
+                )
+                [ -n "$_SMOKE_KIND" ] && _SMOKE_CMD+=(--install-kind "$_SMOKE_KIND")
+                if ! run_quiet_no_exit "validate source llama.cpp" "${_SMOKE_CMD[@]}"; then
+                    substep "$_FB_LABEL source build failed smoke test; retrying CPU build..." "$C_WARN"
+                    _TRY_METAL_CPU_FALLBACK=false
+                    rm -rf "$_BUILD_TMP/build"
+                    if run_quiet_no_exit "cmake llama.cpp (cpu fallback)" cmake $CMAKE_GENERATOR_ARGS -S "$_BUILD_TMP" -B "$_BUILD_TMP/build" $CPU_FALLBACK_CMAKE_ARGS; then
+                        _BUILD_DESC="building (CPU fallback after $_FB_LABEL smoke failed)"
+                        GPU_BACKEND=""
+                        run_quiet_no_exit "build llama-server (cpu fallback)" cmake --build "$_BUILD_TMP/build" --config Release --target llama-server -j"$NCPU" || BUILD_OK=false
+                        if [ "$BUILD_OK" = true ]; then
+                            run_quiet_no_exit "build llama-quantize (cpu fallback)" cmake --build "$_BUILD_TMP/build" --config Release --target llama-quantize -j"$NCPU" || true
+                            run_quiet_no_exit "build diffusion visual server (cpu fallback)" cmake --build "$_BUILD_TMP/build" --config Release --target llama-diffusion-gemma-visual-server -j"$NCPU" || true
+                        fi
+                    else
+                        BUILD_OK=false
+                    fi
+                fi
+            fi
+        fi
+
         # Swap only after build succeeds -- preserves existing install on failure
         if [ "$BUILD_OK" = true ]; then
             _assert_studio_owned_or_absent "$LLAMA_CPP_DIR" "llama.cpp install"
@@ -1886,7 +1975,7 @@ else
                 ln -sf build/bin/llama-quantize "$LLAMA_CPP_DIR/llama-quantize"
             fi
             # DiffusionGemma visual server, if it was built (PR #24423): link next to
-            # llama-server so Studio serves DiffusionGemma GGUFs without DG_VISUAL_BIN.
+            # llama-server so Unsloth serves DiffusionGemma GGUFs without DG_VISUAL_BIN.
             if [ -f "$LLAMA_CPP_DIR/build/bin/llama-diffusion-gemma-visual-server" ]; then
                 ln -sf build/bin/llama-diffusion-gemma-visual-server "$LLAMA_CPP_DIR/llama-diffusion-gemma-visual-server"
             fi
@@ -1941,6 +2030,99 @@ if [ ! -L "$LLAMA_CPP_DIR" ] && {
     _remove_agent_instruction_files "$LLAMA_CPP_DIR"
 fi
 
+# ── whisper.cpp (local speech-to-text dictation engine) ──
+# Optional runtime for local dictation. Fail-open: any failure leaves the
+# Transformers STT engine and browser dictation working, so it never aborts
+# setup (unlike llama.cpp). Runs in 'unsloth studio update' too so the runtime
+# installs/refreshes without a compiler. Installs beside llama.cpp under the
+# same managed home the sidecar's _managed_whisper_cpp_dir() resolves.
+WHISPER_CPP_DIR="$UNSLOTH_HOME/whisper.cpp"
+if [ -n "${WHISPER_SERVER_PATH:-}" ] || [ -n "${UNSLOTH_WHISPER_CPP_PATH:-}" ]; then
+    verbose_substep "whisper.cpp: using a user-configured binary/dir; skipping managed install"
+elif [ "${UNSLOTH_SKIP_WHISPER_INSTALL:-0}" = "1" ]; then
+    verbose_substep "whisper.cpp: install skipped (UNSLOTH_SKIP_WHISPER_INSTALL=1)"
+else
+    if [ "$_STUDIO_HOME_IS_CUSTOM" = true ]; then
+        _assert_studio_owned_or_absent "$WHISPER_CPP_DIR" "whisper.cpp install"
+    fi
+    _WHISPER_CMD=(python "$SCRIPT_DIR/install_whisper_prebuilt.py" --install-dir "$WHISPER_CPP_DIR")
+    if [ -n "${UNSLOTH_WHISPER_RELEASE_TAG:-}" ]; then
+        _WHISPER_CMD+=(--published-release-tag "$UNSLOTH_WHISPER_RELEASE_TAG")
+    fi
+    if [ -n "${_setup_gfx:-}" ]; then
+        _WHISPER_CMD+=(--rocm-gfx "$_setup_gfx")
+    elif [ "$_setup_amd_detected" = true ]; then
+        _WHISPER_CMD+=(--has-rocm)
+    fi
+    _WHISPER_LOG="$(mktemp)"
+    set +e
+    if _is_verbose; then
+        "${_WHISPER_CMD[@]}" 2>&1 | tee "$_WHISPER_LOG"
+        _WHISPER_STATUS=${PIPESTATUS[0]}
+    else
+        "${_WHISPER_CMD[@]}" >"$_WHISPER_LOG" 2>&1
+        _WHISPER_STATUS=$?
+    fi
+    set -e
+    if [ "$_WHISPER_STATUS" -eq 0 ]; then
+        if grep -Fq "already matches" "$_WHISPER_LOG"; then
+            step "whisper.cpp" "prebuilt up to date"
+        else
+            step "whisper.cpp" "prebuilt installed"
+        fi
+        if [ "$_STUDIO_HOME_IS_CUSTOM" = true ] && [ -d "$WHISPER_CPP_DIR" ]; then
+            : > "$WHISPER_CPP_DIR/$_STUDIO_OWNED_MARKER" 2>/dev/null || true
+        fi
+        rm -f "$_WHISPER_LOG"
+    elif [ "$_WHISPER_STATUS" -eq 3 ]; then
+        # A warm dictation server holds the binary; keep the old install.
+        step "whisper.cpp" "install busy; keeping existing runtime" "$C_WARN"
+        rm -f "$_WHISPER_LOG"
+    else
+        # A source build is opt-in. Keep the installer log until fallback has
+        # finished so setup can distinguish release skew from an operational
+        # installer failure and report the exact pairing when available.
+        _WHISPER_RECOVERED=false
+        _WHISPER_BUILD="$SCRIPT_DIR/../scripts/build_whisper_cpp.sh"
+        if [ "${UNSLOTH_WHISPER_FORCE_COMPILE:-0}" = "1" ] && [ -f "$_WHISPER_BUILD" ] \
+                && command -v cmake >/dev/null 2>&1 && command -v git >/dev/null 2>&1; then
+            substep "whisper.cpp prebuilt unavailable; building from source (UNSLOTH_WHISPER_FORCE_COMPILE=1)..."
+            # The source build overwrites whisper-server in the managed dir but
+            # knows nothing about the prebuilt marker; a stale marker would make
+            # a later setup run report "already matches" and skip repairing the
+            # prebuilt over the source binary. Drop it before building.
+            rm -f "$WHISPER_CPP_DIR/UNSLOTH_WHISPER_PREBUILT_INFO.json" 2>/dev/null || true
+            if run_quiet_no_exit "whisper.cpp source build" sh "$_WHISPER_BUILD"; then
+                _WHISPER_RECOVERED=true
+                step "whisper.cpp" "source build installed"
+                if [ "$_STUDIO_HOME_IS_CUSTOM" = true ] && [ -d "$WHISPER_CPP_DIR" ]; then
+                    : > "$WHISPER_CPP_DIR/$_STUDIO_OWNED_MARKER" 2>/dev/null || true
+                fi
+            else
+                :
+            fi
+        fi
+        if [ "$_WHISPER_RECOVERED" != true ]; then
+            if [ "$_WHISPER_STATUS" -eq 2 ]; then
+                _WHISPER_REQUIRED_TAG="$(sed -n 's/.*slim bundle requires llama\.cpp \([^; ]*\).*/\1/p' "$_WHISPER_LOG" | tail -n 1)"
+                _WHISPER_INSTALLED_TAG="$(python - "$UNSLOTH_HOME/llama.cpp/UNSLOTH_PREBUILT_INFO.json" <<'PY' 2>/dev/null || true
+import json, sys
+try:
+    print(json.load(open(sys.argv[1], encoding="utf-8")).get("release_tag", ""))
+except Exception:
+    pass
+PY
+)"
+                _WHISPER_PAIRING="installed llama.cpp ${_WHISPER_INSTALLED_TAG:-unknown}; whisper requires ${_WHISPER_REQUIRED_TAG:-unknown}"
+                step "whisper.cpp" "no compatible prebuilt ($_WHISPER_PAIRING); curated whisper.cpp dictation is unavailable; publish the paired releases in llama.cpp then whisper.cpp order; browser and Transformers dictation remain available" "$C_WARN"
+            else
+                step "whisper.cpp" "prebuilt install failed; curated whisper.cpp dictation is unavailable; retry setup or inspect verbose output; browser and Transformers dictation remain available" "$C_WARN"
+            fi
+        fi
+        rm -f "$_WHISPER_LOG"
+    fi
+fi
+
 # ── Footer ──
 if [ "$_LLAMA_ONLY" = "1" ]; then
     echo ""
@@ -1983,7 +2165,7 @@ echo ""
 # When called from install.sh (SKIP_STUDIO_BASE=1), exit non-zero so the
 # installer can report the GGUF failure after finishing PATH/shortcut setup.
 # When called directly via 'unsloth studio update', keep the install
-# successful -- the footer above already reports the limitation and Studio
+# successful -- the footer above already reports the limitation and Unsloth
 # is still usable for non-GGUF workflows.
 if [ "$_LLAMA_CPP_DEGRADED" = true ] && [ "${SKIP_STUDIO_BASE:-0}" = "1" ]; then
     exit 1
diff --git a/studio/src-tauri/Cargo.lock b/studio/src-tauri/Cargo.lock
index 183cfc1cc8..604bb01525 100644
--- a/studio/src-tauri/Cargo.lock
+++ b/studio/src-tauri/Cargo.lock
@@ -5592,6 +5592,7 @@ dependencies = [
  "tauri-plugin-single-instance",
  "tauri-plugin-updater",
  "tauri-plugin-window-state",
+ "tempfile",
  "tokio",
  "windows 0.62.2",
  "windows-sys 0.61.2",
diff --git a/studio/src-tauri/Cargo.toml b/studio/src-tauri/Cargo.toml
index 438558fe77..826509ce9a 100644
--- a/studio/src-tauri/Cargo.toml
+++ b/studio/src-tauri/Cargo.toml
@@ -29,6 +29,7 @@ tauri-plugin-clipboard-manager = "2"
 tauri-plugin-dialog = "2"
 rand = "0.10.0"
 tauri-plugin-notification = "2.3.3"
+tempfile = "3"
 tauri-plugin-window-state = "2"
 
 [target.'cfg(unix)'.dependencies]
diff --git a/studio/src-tauri/Entitlements.plist b/studio/src-tauri/Entitlements.plist
index 10e6df3427..71b1d2c0f4 100644
--- a/studio/src-tauri/Entitlements.plist
+++ b/studio/src-tauri/Entitlements.plist
@@ -8,6 +8,9 @@
     <!-- Network access for backend health checks and HuggingFace API -->
     <key>com.apple.security.network.client</key>
     <true/>
+    <!-- Permit microphone capture for local dictation -->
+    <key>com.apple.security.device.audio-input</key>
+    <true/>
     <!-- Allow loading Python/venv libraries not signed by us -->
     <key>com.apple.security.cs.disable-library-validation</key>
     <true/>
diff --git a/studio/src-tauri/Info.plist b/studio/src-tauri/Info.plist
new file mode 100644
index 0000000000..e7a280647b
--- /dev/null
+++ b/studio/src-tauri/Info.plist
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>NSMicrophoneUsageDescription</key>
+    <string>Unsloth Studio uses the microphone you select for local voice dictation.</string>
+</dict>
+</plist>
diff --git a/studio/src-tauri/src/app_layout.rs b/studio/src-tauri/src/app_layout.rs
new file mode 100644
index 0000000000..9b9277b48d
--- /dev/null
+++ b/studio/src-tauri/src/app_layout.rs
@@ -0,0 +1,274 @@
+use std::fs;
+use std::path::{Path, PathBuf};
+use tauri::{Manager, WebviewWindow};
+
+use tauri_plugin_window_state::AppHandleExt;
+
+const APP_LAYOUT_MARKER_FILE: &str = "app-layout-initialized-v1";
+const INITIALIZED_MARKER: &[u8] = b"initialized\n";
+const RESET_MARKER: &[u8] = b"reset\n";
+
+const SETUP_WINDOW_WIDTH: f64 = 760.0;
+const SETUP_WINDOW_HEIGHT: f64 = 560.0;
+const MIN_REASONABLE_WINDOW_WIDTH: u64 = 320;
+const MIN_REASONABLE_WINDOW_HEIGHT: u64 = 240;
+
+const SETUP_SIZE_TOLERANCE_PX: f64 = 2.0;
+
+#[derive(serde::Deserialize)]
+struct PersistedWindowState {
+    width: u32,
+    height: u32,
+    #[serde(rename = "x")]
+    _x: i32,
+    #[serde(rename = "y")]
+    _y: i32,
+    #[serde(rename = "prev_x")]
+    _prev_x: i32,
+    #[serde(rename = "prev_y")]
+    _prev_y: i32,
+    #[serde(rename = "maximized")]
+    _maximized: bool,
+    #[serde(rename = "visible")]
+    _visible: bool,
+    #[serde(rename = "decorated")]
+    _decorated: bool,
+    #[serde(rename = "fullscreen")]
+    _fullscreen: bool,
+}
+
+fn marker_path(config_dir: &Path) -> PathBuf {
+    config_dir.join(APP_LAYOUT_MARKER_FILE)
+}
+
+fn marker_matches(config_dir: &Path, expected: &[u8]) -> bool {
+    fs::read(marker_path(config_dir))
+        .map(|contents| contents == expected)
+        .unwrap_or(false)
+}
+
+fn is_initialized(config_dir: &Path) -> bool {
+    marker_matches(config_dir, INITIALIZED_MARKER)
+}
+
+fn is_reset_pending(config_dir: &Path) -> bool {
+    marker_matches(config_dir, RESET_MARKER)
+}
+
+fn write_marker(config_dir: &Path, contents: &[u8]) -> Result<(), String> {
+    fs::create_dir_all(config_dir).map_err(|error| {
+        format!(
+            "Failed to create app configuration directory {}: {error}",
+            config_dir.display()
+        )
+    })?;
+    let path = marker_path(config_dir);
+    fs::write(&path, contents).map_err(|error| {
+        format!(
+            "Failed to write app layout marker {}: {error}",
+            path.display()
+        )
+    })
+}
+
+fn reset_initialized(config_dir: &Path) -> Result<(), String> {
+    write_marker(config_dir, RESET_MARKER)
+}
+
+fn is_setup_window_size(width: u64, height: u64) -> bool {
+    // Window-state persists physical dimensions but not their source scale.
+    let width_scale = width as f64 / SETUP_WINDOW_WIDTH;
+    let height_scale = height as f64 / SETUP_WINDOW_HEIGHT;
+    let scale_tolerance = SETUP_SIZE_TOLERANCE_PX / SETUP_WINDOW_WIDTH
+        + SETUP_SIZE_TOLERANCE_PX / SETUP_WINDOW_HEIGHT;
+    (width_scale - height_scale).abs() <= scale_tolerance
+}
+
+fn saved_main_window_size(config_dir: &Path, state_file_name: &str) -> Option<(u64, u64)> {
+    let contents = fs::read(config_dir.join(state_file_name)).ok()?;
+    let states = serde_json::from_slice::<std::collections::HashMap<String, PersistedWindowState>>(
+        &contents,
+    )
+    .ok()?;
+    let main = states.get("main")?;
+    let width = u64::from(main.width);
+    let height = u64::from(main.height);
+    if width < MIN_REASONABLE_WINDOW_WIDTH || height < MIN_REASONABLE_WINDOW_HEIGHT {
+        return None;
+    }
+    Some((width, height))
+}
+
+fn should_restore_saved_layout(config_dir: &Path, state_file_name: &str) -> bool {
+    if is_reset_pending(config_dir) {
+        return false;
+    }
+    let Some((width, height)) = saved_main_window_size(config_dir, state_file_name) else {
+        return false;
+    };
+    is_initialized(config_dir) || !is_setup_window_size(width, height)
+}
+
+fn mark_initialized(config_dir: &Path) -> Result<(), String> {
+    write_marker(config_dir, INITIALIZED_MARKER)
+}
+
+fn app_config_dir(app: &tauri::AppHandle) -> Result<PathBuf, String> {
+    app.path()
+        .app_config_dir()
+        .map_err(|error| format!("Could not determine app configuration directory: {error}"))
+}
+
+/// Returns whether a full-app layout has previously completed. Legacy state is
+/// migrated unless it matches the fixed setup-window size at any display scale.
+#[tauri::command]
+pub fn has_initialized_app_window_layout(
+    window: WebviewWindow,
+    app: tauri::AppHandle,
+) -> Result<bool, String> {
+    crate::native_intents::ensure_main_window(&window)?;
+    let config_dir = app_config_dir(&app)?;
+    Ok(should_restore_saved_layout(&config_dir, &app.filename()))
+}
+
+/// Persist only after the caller has successfully sized/centered or restored,
+/// shown, constrained, and minimum-sized the full application window.
+#[tauri::command]
+pub fn mark_app_window_layout_initialized(
+    window: WebviewWindow,
+    app: tauri::AppHandle,
+) -> Result<(), String> {
+    crate::native_intents::ensure_main_window(&window)?;
+    mark_initialized(&app_config_dir(&app)?)
+}
+
+/// Force the next full-app transition to use a monitor-safe layout. Setup can
+/// overwrite the plugin's saved full-app dimensions before the process exits.
+#[tauri::command]
+pub fn reset_app_window_layout_initialized(
+    window: WebviewWindow,
+    app: tauri::AppHandle,
+) -> Result<(), String> {
+    crate::native_intents::ensure_main_window(&window)?;
+    reset_initialized(&app_config_dir(&app)?)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::time::{SystemTime, UNIX_EPOCH};
+
+    fn temp_dir(name: &str) -> PathBuf {
+        let nanos = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap()
+            .as_nanos();
+        std::env::temp_dir().join(format!(
+            "unsloth-app-layout-{name}-{}-{nanos}",
+            std::process::id()
+        ))
+    }
+
+    fn window_state(width: u32, height: u32, maximized: bool) -> String {
+        serde_json::json!({
+            "main": {
+                "width": width,
+                "height": height,
+                "x": 0,
+                "y": 0,
+                "prev_x": 0,
+                "prev_y": 0,
+                "maximized": maximized,
+                "visible": true,
+                "decorated": true,
+                "fullscreen": false
+            }
+        })
+        .to_string()
+    }
+
+    #[test]
+    fn marker_is_absent_until_full_layout_is_marked() {
+        let dir = temp_dir("transition");
+        assert!(!is_initialized(&dir));
+        mark_initialized(&dir).unwrap();
+        assert!(is_initialized(&dir));
+        assert_eq!(fs::read(marker_path(&dir)).unwrap(), b"initialized\n");
+        let _ = fs::remove_dir_all(dir);
+    }
+
+    #[test]
+    fn marker_write_and_reset_are_idempotent() {
+        let dir = temp_dir("idempotent");
+        mark_initialized(&dir).unwrap();
+        mark_initialized(&dir).unwrap();
+        assert!(is_initialized(&dir));
+        assert!(!is_reset_pending(&dir));
+
+        reset_initialized(&dir).unwrap();
+        reset_initialized(&dir).unwrap();
+        assert!(!is_initialized(&dir));
+        assert!(is_reset_pending(&dir));
+
+        mark_initialized(&dir).unwrap();
+        assert!(is_initialized(&dir));
+        assert!(!is_reset_pending(&dir));
+        let _ = fs::remove_dir_all(dir);
+    }
+
+    #[test]
+    fn legacy_full_app_state_is_migrated_but_setup_state_at_any_scale_is_not() {
+        let dir = temp_dir("legacy-plugin-state");
+        fs::create_dir_all(&dir).unwrap();
+        let state_file = ".window-state.json";
+        let state_path = dir.join(state_file);
+
+        fs::write(&state_path, window_state(1200, 800, false)).unwrap();
+        assert!(should_restore_saved_layout(&dir, state_file));
+
+        fs::write(&state_path, window_state(760, 560, false)).unwrap();
+        assert!(!should_restore_saved_layout(&dir, state_file));
+
+        fs::write(&state_path, window_state(950, 700, false)).unwrap();
+        assert!(!should_restore_saved_layout(&dir, state_file));
+
+        fs::write(&state_path, window_state(1520, 1120, false)).unwrap();
+        assert!(!should_restore_saved_layout(&dir, state_file));
+
+        fs::write(&state_path, window_state(1520, 1120, true)).unwrap();
+        assert!(!should_restore_saved_layout(&dir, state_file));
+        let _ = fs::remove_dir_all(dir);
+    }
+
+    #[test]
+    fn explicit_reset_blocks_legacy_migration_until_app_layout_completes() {
+        let dir = temp_dir("reset-migration");
+        fs::create_dir_all(&dir).unwrap();
+        let state_file = ".window-state.json";
+        fs::write(dir.join(state_file), window_state(1200, 800, false)).unwrap();
+
+        mark_initialized(&dir).unwrap();
+        assert!(should_restore_saved_layout(&dir, state_file));
+        reset_initialized(&dir).unwrap();
+        assert!(!should_restore_saved_layout(&dir, state_file));
+        mark_initialized(&dir).unwrap();
+        assert!(should_restore_saved_layout(&dir, state_file));
+        let _ = fs::remove_dir_all(dir);
+    }
+
+    #[test]
+    fn corrupt_plugin_state_does_not_restore_even_with_initialized_marker() {
+        let dir = temp_dir("plugin-state");
+        fs::create_dir_all(&dir).unwrap();
+        let state_file = ".window-state.json";
+        fs::write(
+            dir.join(state_file),
+            r#"{"main":{"width":1200,"height":800}}"#,
+        )
+        .unwrap();
+        mark_initialized(&dir).unwrap();
+        assert!(is_initialized(&dir));
+        assert!(!should_restore_saved_layout(&dir, state_file));
+        let _ = fs::remove_dir_all(dir);
+    }
+}
diff --git a/studio/src-tauri/src/commands.rs b/studio/src-tauri/src/commands.rs
index 6bc2116786..72ea9d6985 100644
--- a/studio/src-tauri/src/commands.rs
+++ b/studio/src-tauri/src/commands.rs
@@ -25,12 +25,12 @@ fn should_emit_repair_failed(msg: &str) -> bool {
 fn external_conflict_message(conflict: &crate::preflight::ExternalBackendConflict) -> String {
     if conflict.reason == "desktop_owned_backend_active" {
         return format!(
-            "A desktop-owned Studio server for this install is already running on port {}. Quit the other desktop app instance, then try again.",
+            "A desktop-owned Unsloth server for this install is already running on port {}. Quit the other desktop app instance, then try again.",
             conflict.port
         );
     }
     format!(
-        "A Studio server for this install is already running from a terminal on port {}. Stop that server, or run `unsloth studio update` from that terminal before using desktop repair/update.",
+        "An Unsloth server for this install is already running from a terminal on port {}. Stop that server, or run `unsloth studio update` from that terminal before using desktop repair/update.",
         conflict.port
     )
 }
@@ -339,11 +339,21 @@ pub fn get_server_logs(state: tauri::State<'_, BackendState>) -> Vec<String> {
 
 /// Open an existing directory in the system file manager. Validates the path
 /// up front so callers get a clean error instead of a raw OS failure.
-fn open_existing_dir(dir: &std::path::Path) -> Result<(), String> {
+fn open_existing_dir_with<E>(
+    dir: &std::path::Path,
+    opener: impl FnOnce(&std::path::Path) -> Result<(), E>,
+) -> Result<(), String>
+where
+    E: std::fmt::Display,
+{
     if !dir.is_dir() {
         return Err(format!("Directory does not exist: {}", dir.display()));
     }
-    open::that(dir).map_err(|e| format!("Failed to open directory: {}", e))
+    opener(dir).map_err(|error| format!("Failed to open directory: {error}"))
+}
+
+fn open_existing_dir(dir: &std::path::Path) -> Result<(), String> {
+    open_existing_dir_with(dir, |path| open::that_detached(path))
 }
 
 /// Open the Unsloth Studio directory in the system file manager.
@@ -475,7 +485,7 @@ pub async fn start_backend_update(
         .map_err(|e| format!("Update task panicked: {e}"))?
 }
 
-/// Repair a stale managed Studio install.
+/// Repair a stale managed Unsloth install.
 #[tauri::command]
 pub async fn start_managed_repair(
     app: AppHandle,
@@ -522,7 +532,7 @@ pub async fn start_managed_repair(
     let repair_group_id = install::take_pending_repair_group_for_resume(&install_state)
         .unwrap_or_else(|| diagnostics::begin_repair_group(&diagnostics_state));
 
-    let _ = app.emit("repair-progress", "Updating existing Studio install...");
+    let _ = app.emit("repair-progress", "Updating existing Unsloth install...");
     let update_app = app.clone();
     let update_state = update_state.inner().clone();
     let update_diagnostics = diagnostics_state.clone();
@@ -549,7 +559,7 @@ pub async fn start_managed_repair(
             warn!("Managed repair update finished, but preflight is still not ready; falling back to installer");
             let _ = app.emit(
                 "repair-progress",
-                "Update finished, but Studio is still not ready. Running bundled installer...",
+                "Update finished, but Unsloth is still not ready. Running bundled installer...",
             );
         }
         Err(msg) => {
@@ -627,7 +637,7 @@ pub async fn start_managed_repair(
         return Ok(());
     }
 
-    let msg = "Repair finished, but Studio install is still not desktop-ready.".to_string();
+    let msg = "Repair finished, but Unsloth install is still not desktop-ready.".to_string();
     error!("{}", msg);
     diagnostics::finish_repair_group(
         &diagnostics_state,
@@ -641,7 +651,8 @@ pub async fn start_managed_repair(
 
 #[cfg(test)]
 mod tests {
-    use std::time::Duration;
+    use std::fs;
+    use std::time::{Duration, SystemTime, UNIX_EPOCH};
     use tokio::io::{AsyncReadExt, AsyncWriteExt};
     use tokio::net::TcpListener;
 
@@ -699,6 +710,40 @@ mod tests {
         port
     }
 
+    #[test]
+    fn existing_directory_helper_invokes_opener_and_surfaces_errors() {
+        let nanos = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap()
+            .as_nanos();
+        let dir =
+            std::env::temp_dir().join(format!("unsloth-open-dir-{}-{nanos}", std::process::id()));
+        fs::create_dir_all(&dir).unwrap();
+        let mut opened = false;
+        super::open_existing_dir_with(&dir, |path| {
+            opened = true;
+            assert_eq!(path, dir);
+            Ok::<_, &str>(())
+        })
+        .unwrap();
+        assert!(opened);
+
+        let error = super::open_existing_dir_with(&dir, |_| Err("opener failed")).unwrap_err();
+        assert!(error.contains("opener failed"));
+        let _ = fs::remove_dir_all(dir);
+    }
+
+    #[test]
+    fn existing_directory_helper_rejects_missing_path_without_opening() {
+        let missing = std::env::temp_dir().join("unsloth-definitely-missing-open-dir");
+        let error = super::open_existing_dir_with(&missing, |_| {
+            panic!("opener must not run for an invalid directory");
+            #[allow(unreachable_code)]
+            Ok::<_, &str>(())
+        })
+        .unwrap_err();
+        assert!(error.contains("Directory does not exist"));
+    }
     #[test]
     fn repair_elevation_is_not_a_terminal_repair_failure() {
         assert!(!super::should_emit_repair_failed("NEEDS_ELEVATION"));
diff --git a/studio/src-tauri/src/desktop_auth.rs b/studio/src-tauri/src/desktop_auth.rs
index 33605f6c65..db65b8796f 100644
--- a/studio/src-tauri/src/desktop_auth.rs
+++ b/studio/src-tauri/src/desktop_auth.rs
@@ -201,7 +201,7 @@ async fn exchange_desktop_secret(
 
     if response.status() == reqwest::StatusCode::NOT_FOUND {
         return Err(AuthError::StaleResponder(
-            "Running Studio backend is too old for this desktop app. Update that backend and restart."
+            "Running Unsloth backend is too old for this desktop app. Update that backend and restart."
                 .to_string(),
         ));
     }
@@ -364,7 +364,7 @@ async fn desktop_auth_inner(
     }
 
     Err(
-        "Desktop auth failed. Update or repair the managed Studio install, then restart Studio."
+        "Desktop auth failed. Update or repair the managed Unsloth install, then restart Unsloth."
             .to_string(),
     )
 }
@@ -465,7 +465,7 @@ mod tests {
             .message();
         assert_eq!(
             error,
-            "Running Studio backend is too old for this desktop app. Update that backend and restart."
+            "Running Unsloth backend is too old for this desktop app. Update that backend and restart."
         );
     }
 }
diff --git a/studio/src-tauri/src/main.rs b/studio/src-tauri/src/main.rs
index 4ed12051ed..405b390177 100644
--- a/studio/src-tauri/src/main.rs
+++ b/studio/src-tauri/src/main.rs
@@ -1,5 +1,6 @@
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
 
+mod app_layout;
 mod commands;
 mod desktop_auth;
 mod desktop_backend_owner;
@@ -7,6 +8,7 @@ mod desktop_update_policy;
 mod diagnostics;
 mod install;
 mod native_backend_lease;
+mod native_file_dialogs;
 mod native_intents;
 mod native_path_policy;
 mod preflight;
@@ -107,7 +109,7 @@ fn cleanup_child_processes(app: &tauri::AppHandle) {
 }
 
 fn setup_tray(app: &tauri::App) -> Result<(), Box<dyn std::error::Error>> {
-    let open = MenuItemBuilder::with_id("open", "Open Studio").build(app)?;
+    let open = MenuItemBuilder::with_id("open", "Open Unsloth").build(app)?;
     let toggle = MenuItemBuilder::with_id("toggle", "Start/Stop Server").build(app)?;
     let quit = MenuItemBuilder::with_id("quit", "Quit").build(app)?;
     let menu = MenuBuilder::new(app)
@@ -195,6 +197,9 @@ fn main() {
         .manage(process::new_shutdown_flag())
         .manage(update::new_update_state())
         .invoke_handler(tauri::generate_handler![
+            app_layout::has_initialized_app_window_layout,
+            app_layout::mark_app_window_layout_initialized,
+            app_layout::reset_app_window_layout_initialized,
             commands::check_install_status,
             commands::desktop_preflight,
             commands::start_install,
@@ -213,9 +218,12 @@ fn main() {
             desktop_update_policy::check_desktop_manual_update,
             desktop_update_policy::desktop_update_policy,
             diagnostics::collect_support_diagnostics,
+            native_file_dialogs::save_native_file,
+            native_file_dialogs::pick_native_chat_import,
             native_intents::drain_native_intents,
             native_intents::register_native_model_path,
             native_intents::pick_native_model,
+            native_intents::pick_hugging_face_cache_dir,
             native_intents::consume_native_path_token,
             native_intents::register_artifact_path,
             native_intents::reveal_path_token,
diff --git a/studio/src-tauri/src/native_file_dialogs.rs b/studio/src-tauri/src/native_file_dialogs.rs
new file mode 100644
index 0000000000..d795eb020c
--- /dev/null
+++ b/studio/src-tauri/src/native_file_dialogs.rs
@@ -0,0 +1,320 @@
+use base64::{engine::general_purpose::STANDARD as BASE64, Engine as _};
+
+use serde::Serialize;
+use std::fs::{self, File};
+use std::io::{Read, Write};
+use std::path::{Path, PathBuf};
+use tauri::{AppHandle, WebviewWindow};
+use tauri_plugin_dialog::DialogExt;
+
+const MAX_CHAT_IMPORT_BYTES: u64 = 64 * 1024 * 1024;
+const NATIVE_FILE_NAME_HEADER: &str = "x-unsloth-default-name";
+const CHAT_IMPORT_EXTENSIONS: &[&str] = &["jsonl", "ndjson", "csv"];
+
+#[derive(Debug, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct NativeImportedFile {
+    name: String,
+    content: String,
+}
+
+fn default_file_name(suggested_name: &str) -> String {
+    Path::new(suggested_name)
+        .file_name()
+        .and_then(|name| name.to_str())
+        .filter(|name| !name.is_empty() && *name != "." && *name != "..")
+        .unwrap_or("unsloth-export.json")
+        .to_string()
+}
+fn decode_default_file_name(encoded_name: &str) -> Result<String, String> {
+    let bytes = BASE64
+        .decode(encoded_name)
+        .map_err(|_| "Invalid native export filename.".to_string())?;
+    let name =
+        String::from_utf8(bytes).map_err(|_| "Invalid native export filename.".to_string())?;
+    Ok(default_file_name(&name))
+}
+
+fn save_filter(file_name: &str) -> (&'static str, Vec<&'static str>) {
+    match Path::new(file_name)
+        .extension()
+        .and_then(|extension| extension.to_str())
+        .map(str::to_ascii_lowercase)
+        .as_deref()
+    {
+        Some("json") => ("JSON", vec!["json"]),
+        Some("jsonl") | Some("ndjson") => ("JSON Lines", vec!["jsonl", "ndjson"]),
+        Some("csv") => ("CSV", vec!["csv"]),
+        Some("md") | Some("markdown") => ("Markdown", vec!["md", "markdown"]),
+        Some("zip") => ("ZIP archive", vec!["zip"]),
+        _ => (
+            "Export files",
+            vec!["json", "jsonl", "ndjson", "csv", "md", "markdown", "zip"],
+        ),
+    }
+}
+
+fn local_dialog_path(path: tauri_plugin_dialog::FilePath) -> Result<PathBuf, String> {
+    path.into_path()
+        .map_err(|_| "Only local filesystem paths are supported.".to_string())
+}
+
+fn save_selected_file(
+    selected_path: Option<PathBuf>,
+    content: &[u8],
+) -> Result<Option<String>, String> {
+    let Some(path) = selected_path else {
+        return Ok(None);
+    };
+    let parent = path
+        .parent()
+        .filter(|parent| !parent.as_os_str().is_empty())
+        .unwrap_or_else(|| Path::new("."));
+    let mut builder = tempfile::Builder::new();
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        let permissions = fs::metadata(&path)
+            .map(|metadata| metadata.permissions())
+            .unwrap_or_else(|_| fs::Permissions::from_mode(0o666));
+        builder.permissions(permissions);
+    }
+    let mut temporary = builder
+        .prefix(".unsloth-export-")
+        .tempfile_in(parent)
+        .map_err(|error| format!("Failed to prepare {}: {error}", path.display()))?;
+    temporary
+        .write_all(content)
+        .and_then(|()| temporary.as_file().sync_all())
+        .map_err(|error| format!("Failed to save {}: {error}", path.display()))?;
+    temporary
+        .persist(&path)
+        .map_err(|error| format!("Failed to save {}: {}", path.display(), error.error))?;
+    let file_name = path
+        .file_name()
+        .and_then(|name| name.to_str())
+        .unwrap_or("export")
+        .to_string();
+    Ok(Some(file_name))
+}
+
+fn read_selected_import(
+    selected_path: Option<PathBuf>,
+) -> Result<Option<NativeImportedFile>, String> {
+    let Some(path) = selected_path else {
+        return Ok(None);
+    };
+    let extension = path
+        .extension()
+        .and_then(|extension| extension.to_str())
+        .map(str::to_ascii_lowercase)
+        .ok_or_else(|| "Chat import must be a .jsonl, .ndjson, or .csv file.".to_string())?;
+    if !CHAT_IMPORT_EXTENSIONS.contains(&extension.as_str()) {
+        return Err("Chat import must be a .jsonl, .ndjson, or .csv file.".to_string());
+    }
+
+    let metadata = fs::metadata(&path)
+        .map_err(|error| format!("Failed to inspect {}: {error}", path.display()))?;
+    if !metadata.is_file() {
+        return Err(format!("Selected import is not a file: {}", path.display()));
+    }
+    if metadata.len() > MAX_CHAT_IMPORT_BYTES {
+        return Err(format!(
+            "Chat import is too large (maximum {} MiB).",
+            MAX_CHAT_IMPORT_BYTES / 1024 / 1024
+        ));
+    }
+
+    // Limit the read too, so a file that grows after metadata inspection cannot
+    // make the command allocate without bound.
+    let file =
+        File::open(&path).map_err(|error| format!("Failed to open {}: {error}", path.display()))?;
+    let mut bytes = Vec::with_capacity(metadata.len() as usize);
+    file.take(MAX_CHAT_IMPORT_BYTES + 1)
+        .read_to_end(&mut bytes)
+        .map_err(|error| format!("Failed to read {}: {error}", path.display()))?;
+    if bytes.len() as u64 > MAX_CHAT_IMPORT_BYTES {
+        return Err(format!(
+            "Chat import is too large (maximum {} MiB).",
+            MAX_CHAT_IMPORT_BYTES / 1024 / 1024
+        ));
+    }
+    let content = String::from_utf8(bytes)
+        .map_err(|_| format!("Chat import is not valid UTF-8: {}", path.display()))?;
+    let name = path
+        .file_name()
+        .and_then(|name| name.to_str())
+        .map(str::to_string)
+        .unwrap_or_else(|| format!("chat-import.{extension}"));
+    Ok(Some(NativeImportedFile { name, content }))
+}
+
+#[tauri::command]
+pub async fn save_native_file(
+    window: WebviewWindow,
+    app: AppHandle,
+    request: tauri::ipc::Request<'_>,
+) -> Result<Option<String>, String> {
+    crate::native_intents::ensure_main_window(&window)?;
+    let encoded_name = request
+        .headers()
+        .get(NATIVE_FILE_NAME_HEADER)
+        .ok_or_else(|| "Native export filename is missing.".to_string())?
+        .to_str()
+        .map_err(|_| "Invalid native export filename.".to_string())?;
+    let file_name = decode_default_file_name(encoded_name)?;
+    let content = match request.body() {
+        tauri::ipc::InvokeBody::Raw(content) => content,
+        _ => return Err("Native export content must be binary.".to_string()),
+    };
+    let (filter_name, extensions) = save_filter(&file_name);
+    let (tx, rx) = tokio::sync::oneshot::channel();
+    app.dialog()
+        .file()
+        .set_title("Save Unsloth export")
+        .set_file_name(file_name)
+        .add_filter(filter_name, &extensions)
+        .save_file(move |path| {
+            let _ = tx.send(path);
+        });
+    let selected_path = rx
+        .await
+        .map_err(|_| "Save dialog closed unexpectedly.".to_string())?
+        .map(local_dialog_path)
+        .transpose()?;
+    save_selected_file(selected_path, content)
+}
+
+#[tauri::command]
+pub async fn pick_native_chat_import(
+    window: WebviewWindow,
+    app: AppHandle,
+) -> Result<Option<NativeImportedFile>, String> {
+    crate::native_intents::ensure_main_window(&window)?;
+    let (tx, rx) = tokio::sync::oneshot::channel();
+    app.dialog()
+        .file()
+        .set_title("Import chats")
+        .add_filter("Chat exports", CHAT_IMPORT_EXTENSIONS)
+        .pick_file(move |path| {
+            let _ = tx.send(path);
+        });
+    let selected_path = rx
+        .await
+        .map_err(|_| "Import dialog closed unexpectedly.".to_string())?
+        .map(local_dialog_path)
+        .transpose()?;
+    read_selected_import(selected_path)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::time::{SystemTime, UNIX_EPOCH};
+
+    fn temp_path(name: &str) -> PathBuf {
+        let nanos = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap()
+            .as_nanos();
+        std::env::temp_dir().join(format!(
+            "unsloth-native-files-{name}-{}-{nanos}",
+            std::process::id()
+        ))
+    }
+
+    #[test]
+    fn cancellation_is_quiet_for_save_and_import() {
+        assert!(save_selected_file(None, b"x").unwrap().is_none());
+        assert!(read_selected_import(None).unwrap().is_none());
+    }
+
+    #[test]
+    fn writes_text_and_binary_exactly() {
+        // Overwriting must stage the new content before replacing the destination.
+        let text_path = temp_path("text").with_extension("json");
+        let binary_path = temp_path("binary").with_extension("zip");
+
+        fs::write(&text_path, b"previous export").unwrap();
+        save_selected_file(Some(text_path.clone()), b"{\"ok\":true}").unwrap();
+        save_selected_file(Some(binary_path.clone()), &[0, 1, 2, 255]).unwrap();
+        assert_eq!(fs::read(&text_path).unwrap(), b"{\"ok\":true}");
+        assert_eq!(fs::read(&binary_path).unwrap(), [0, 1, 2, 255]);
+        let _ = fs::remove_file(text_path);
+        let _ = fs::remove_file(binary_path);
+    }
+
+    #[test]
+    fn markdown_exports_use_a_markdown_save_filter() {
+        assert_eq!(
+            save_filter("message.md"),
+            ("Markdown", vec!["md", "markdown"])
+        );
+    }
+
+    #[test]
+    fn reads_supported_import_and_rejects_other_extensions() {
+        let jsonl_path = temp_path("allowed").with_extension("JSONL");
+        fs::write(&jsonl_path, "{\"messages\":[]}").unwrap();
+        let imported = read_selected_import(Some(jsonl_path.clone()))
+            .unwrap()
+            .unwrap();
+        assert_eq!(imported.content, "{\"messages\":[]}");
+
+        let json_path = temp_path("unsupported").with_extension("json");
+        fs::write(&json_path, "{}").unwrap();
+        assert!(read_selected_import(Some(json_path.clone())).is_err());
+        let txt_path = temp_path("denied").with_extension("txt");
+        fs::write(&txt_path, "no").unwrap();
+        assert!(read_selected_import(Some(txt_path.clone()))
+            .unwrap_err()
+            .contains(".json"));
+        let _ = fs::remove_file(jsonl_path);
+        let _ = fs::remove_file(json_path);
+        let _ = fs::remove_file(txt_path);
+    }
+
+    #[test]
+    fn read_limit_and_utf8_errors_are_concrete() {
+        let oversized = temp_path("oversized").with_extension("csv");
+        let file = File::create(&oversized).unwrap();
+        file.set_len(MAX_CHAT_IMPORT_BYTES + 1).unwrap();
+        assert!(read_selected_import(Some(oversized.clone()))
+            .unwrap_err()
+            .contains("too large"));
+
+        let invalid = temp_path("invalid-utf8").with_extension("jsonl");
+        fs::write(&invalid, [0xff]).unwrap();
+        assert!(read_selected_import(Some(invalid.clone()))
+            .unwrap_err()
+            .contains("UTF-8"));
+        let _ = fs::remove_file(oversized);
+        let _ = fs::remove_file(invalid);
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn non_utf8_import_name_preserves_csv_extension() {
+        use std::ffi::OsString;
+        use std::os::unix::ffi::OsStringExt;
+
+        let path = std::env::temp_dir().join(OsString::from_vec(vec![
+            b'u', b'n', b's', b'l', b'o', b't', b'h', 0xff, b'.', b'c', b's', b'v',
+        ]));
+        fs::write(&path, "role,content\nuser,hello\n").unwrap();
+        let imported = read_selected_import(Some(path.clone())).unwrap().unwrap();
+        assert_eq!(imported.name, "chat-import.csv");
+        let _ = fs::remove_file(path);
+    }
+
+    #[test]
+    fn strips_directories_from_suggested_default_name() {
+        assert_eq!(default_file_name("../../chat.jsonl"), "chat.jsonl");
+        assert_eq!(default_file_name(""), "unsloth-export.json");
+
+        assert_eq!(
+            decode_default_file_name("Y2hhdC5qc29ubA==").unwrap(),
+            "chat.jsonl"
+        );
+    }
+}
diff --git a/studio/src-tauri/src/native_intents.rs b/studio/src-tauri/src/native_intents.rs
index dccbba7083..006babfaa7 100644
--- a/studio/src-tauri/src/native_intents.rs
+++ b/studio/src-tauri/src/native_intents.rs
@@ -16,6 +16,25 @@ use tauri_plugin_dialog::DialogExt;
 
 const TOKEN_TTL: Duration = Duration::from_secs(15 * 60);
 
+fn normalize_windows_verbatim_path(path: String) -> String {
+    if let Some(rest) = path.strip_prefix(r"\\?\UNC\") {
+        return format!(r"\\{rest}");
+    }
+    path.strip_prefix(r"\\?\").unwrap_or(&path).to_string()
+}
+
+fn portable_path_string(path: &Path) -> String {
+    let value = path.to_string_lossy().to_string();
+    #[cfg(windows)]
+    {
+        return normalize_windows_verbatim_path(value);
+    }
+    #[cfg(not(windows))]
+    {
+        value
+    }
+}
+
 #[derive(Clone, Debug)]
 struct NativePathEntry {
     token: String,
@@ -311,6 +330,34 @@ pub async fn pick_native_model(
         .map(Some)
 }
 
+#[tauri::command]
+pub async fn pick_hugging_face_cache_dir(
+    window: WebviewWindow,
+    app: AppHandle,
+) -> Result<Option<String>, String> {
+    ensure_main_window(&window)?;
+    let (tx, rx) = tokio::sync::oneshot::channel();
+    app.dialog()
+        .file()
+        .set_title("Choose model download location")
+        .pick_folder(move |path| {
+            let _ = tx.send(path);
+        });
+    let Some(folder_path) = rx.await.map_err(|_| "Dialog closed".to_string())? else {
+        return Ok(None);
+    };
+    let path = folder_path
+        .into_path()
+        .map_err(|_| "Only local filesystem folders are supported.".to_string())?;
+    let canonical = path
+        .canonicalize()
+        .map_err(|e| format!("Could not use the selected folder: {e}"))?;
+    if !canonical.is_dir() {
+        return Err("The selected location is not a folder.".to_string());
+    }
+    Ok(Some(portable_path_string(&canonical)))
+}
+
 #[tauri::command]
 pub fn consume_native_path_token(
     window: WebviewWindow,
@@ -451,6 +498,18 @@ mod tests {
         let _ = fs::remove_file(path);
     }
 
+    #[test]
+    fn windows_verbatim_paths_are_portable() {
+        assert_eq!(
+            normalize_windows_verbatim_path(r"\\?\C:\models\cache".to_string()),
+            r"C:\models\cache"
+        );
+        assert_eq!(
+            normalize_windows_verbatim_path(r"\\?\UNC\server\share\cache".to_string()),
+            r"\\server\share\cache"
+        );
+    }
+
     #[cfg(unix)]
     #[test]
     fn reveal_rejects_symlink_replacement() {
diff --git a/studio/src-tauri/src/native_path_policy.rs b/studio/src-tauri/src/native_path_policy.rs
index b2ebb34621..26d4cdb61a 100644
--- a/studio/src-tauri/src/native_path_policy.rs
+++ b/studio/src-tauri/src/native_path_policy.rs
@@ -130,8 +130,8 @@ fn classify_existing_path(path: &Path) -> Result<ClassifiedPath, String> {
         .canonicalize()
         .map_err(|e| format!("Path could not be resolved: {e}"))?;
     reject_network_or_device_path(&canonical_path)?;
-    let canonical_symlink_metadata = fs::symlink_metadata(&canonical_path)
-        .map_err(|e| format!("Path is not available: {e}"))?;
+    let canonical_symlink_metadata =
+        fs::symlink_metadata(&canonical_path).map_err(|e| format!("Path is not available: {e}"))?;
     if canonical_symlink_metadata.file_type().is_symlink() {
         return Err("Symlink paths are not supported for native intake.".to_string());
     }
@@ -191,7 +191,7 @@ fn reject_sensitive_artifact(path: &Path) -> Result<(), String> {
         "\\pid",
     ] {
         if lowered.contains(needle) {
-            return Err("Sensitive Studio state cannot be registered as an artifact.".to_string());
+            return Err("Sensitive Unsloth state cannot be registered as an artifact.".to_string());
         }
     }
     if let Some(ext) = path.extension().and_then(|ext| ext.to_str()) {
diff --git a/studio/src-tauri/tauri.macos.conf.json b/studio/src-tauri/tauri.macos.conf.json
index 202c9fb505..b1517a6234 100644
--- a/studio/src-tauri/tauri.macos.conf.json
+++ b/studio/src-tauri/tauri.macos.conf.json
@@ -2,6 +2,7 @@
   "bundle": {
     "macOS": {
       "entitlements": "./Entitlements.plist",
+      "infoPlist": "./Info.plist",
       "dmg": {
         "appPosition": { "x": 180, "y": 220 },
         "applicationFolderPosition": { "x": 480, "y": 220 }
diff --git a/tests/python/test_construct_chat_template_validation.py b/tests/python/test_construct_chat_template_validation.py
index 66d3d80920..53d281d435 100644
--- a/tests/python/test_construct_chat_template_validation.py
+++ b/tests/python/test_construct_chat_template_validation.py
@@ -104,3 +104,93 @@ def test_chat_template_does_not_leak_sentinel_when_section_starts_with_it(chat_t
     )
     assert "{INPUT}" not in jinja_template
     assert "{OUTPUT}" not in jinja_template
+
+
+_SYSTEM_CHAT_TEMPLATE = (
+    "{SYSTEM}\n"
+    "### User: {INPUT}\n### Assistant: {OUTPUT}</s>"
+    "### User: {INPUT}\n### Assistant: {OUTPUT}</s>"
+)
+
+
+def _render(jinja_template, messages):
+    from jinja2.sandbox import ImmutableSandboxedEnvironment
+
+    env = ImmutableSandboxedEnvironment()
+    env.globals["raise_exception"] = lambda message: (_ for _ in ()).throw(RuntimeError(message))
+    return env.from_string(jinja_template).render(
+        messages = messages,
+        bos_token = "<s>",
+        eos_token = "</s>",
+        add_generation_prompt = False,
+    )
+
+
+@pytest.mark.parametrize("default_system_message", [None, "You are helpful."])
+def test_system_message_is_consumed_by_the_system_part(default_system_message):
+    """A caller-supplied system message must be rendered by the system part and
+    skipped by the message loop, whatever `default_system_message` is.
+
+    With `default_system_message = None` the generated template used to bind
+    `loop_messages` only inside the `{% if %}` arm. The `Fix missing
+    loop_messages` step then saw no unconditional binding, rewrote the loop back
+    to `messages`, and the system message reached the loop and tripped
+    `raise_exception`.
+    """
+    _, jinja_template, _, _ = construct_chat_template(
+        tokenizer = _SuccessFakeTokenizer(),
+        chat_template = _SYSTEM_CHAT_TEMPLATE,
+        default_system_message = default_system_message,
+        extra_eos_tokens = ["</s>"],
+    )
+    rendered = _render(
+        jinja_template,
+        [
+            {"role": "system", "content": "Be terse."},
+            {"role": "user", "content": "Hi"},
+        ],
+    )
+    assert rendered.count("Be terse.") == 1
+    assert rendered.count("Hi") == 1
+    # A caller system message overrides the default; the default must not leak in.
+    if default_system_message is not None:
+        assert default_system_message not in rendered
+
+
+def test_absent_system_message_still_renders_without_default():
+    """`default_system_message = None` with no system message in the input must
+    keep working -- the `{% else %}` arm has to bind `loop_messages = messages`."""
+    _, jinja_template, _, _ = construct_chat_template(
+        tokenizer = _SuccessFakeTokenizer(),
+        chat_template = _SYSTEM_CHAT_TEMPLATE,
+        default_system_message = None,
+        extra_eos_tokens = ["</s>"],
+    )
+    rendered = _render(jinja_template, [{"role": "user", "content": "Hi"}])
+    assert "Hi" in rendered
+
+
+_NO_SYSTEM_CHAT_TEMPLATE = (
+    "PREAMBLE\n"
+    "### User: {INPUT}\n### Assistant: {OUTPUT}</s>"
+    "### User: {INPUT}\n### Assistant: {OUTPUT}</s>"
+)
+
+
+def test_static_prefix_without_system_still_rejects_system_message():
+    """A template with a static prefix but no {SYSTEM} placeholder cannot render a
+    caller system message, so it must still raise rather than silently drop it."""
+    _, jinja_template, _, _ = construct_chat_template(
+        tokenizer = _SuccessFakeTokenizer(),
+        chat_template = _NO_SYSTEM_CHAT_TEMPLATE,
+        default_system_message = None,
+        extra_eos_tokens = ["</s>"],
+    )
+    with pytest.raises(RuntimeError, match = "Only user and assistant roles are supported!"):
+        _render(
+            jinja_template,
+            [
+                {"role": "system", "content": "Be terse."},
+                {"role": "user", "content": "Hi"},
+            ],
+        )
diff --git a/tests/python/test_cross_platform_parity.py b/tests/python/test_cross_platform_parity.py
index 666ea7ce10..b3a9b99c55 100644
--- a/tests/python/test_cross_platform_parity.py
+++ b/tests/python/test_cross_platform_parity.py
@@ -10,6 +10,8 @@ import pytest
 REPO_ROOT = Path(__file__).resolve().parents[2]
 INSTALL_SH = REPO_ROOT / "install.sh"
 INSTALL_PS1 = REPO_ROOT / "install.ps1"
+SETUP_PS1 = REPO_ROOT / "studio" / "setup.ps1"
+STACK_PY = REPO_ROOT / "studio" / "install_python_stack.py"
 
 
 class TestNoTorchBackendAutoInInstallSh:
@@ -180,3 +182,607 @@ class TestUvBytecodeCompileTimeout:
         assert (
             '$env:UV_COMPILE_BYTECODE_TIMEOUT = "180"' in text
         ), "install.ps1 should default UV_COMPILE_BYTECODE_TIMEOUT"
+
+
+class TestTorchIndexOverrideParity:
+    """Every installer must honor UNSLOTH_TORCH_INDEX_URL / _FAMILY so a pinned wheel
+    index wins over GPU probing on all platforms (no asymmetric, per-OS coverage)."""
+
+    @pytest.mark.parametrize(
+        "path",
+        [INSTALL_SH, INSTALL_PS1, SETUP_PS1, STACK_PY],
+        ids = ["install.sh", "install.ps1", "setup.ps1", "install_python_stack.py"],
+    )
+    def test_installer_reads_override_env(self, path):
+        text = path.read_text(encoding = "utf-8")
+        for var in ("UNSLOTH_TORCH_INDEX_URL", "UNSLOTH_TORCH_INDEX_FAMILY"):
+            assert var in text, f"{path.name} does not honor {var}"
+
+    @pytest.mark.parametrize(
+        "path",
+        [INSTALL_PS1, SETUP_PS1],
+        ids = ["install.ps1", "setup.ps1"],
+    )
+    def test_amd_reroute_guarded_when_pinned(self, path):
+        # The AMD ROCm reroute must be skipped when the index is explicitly pinned,
+        # so an explicit cpu / cu* / rocm pin on an AMD host is not overwritten.
+        text = path.read_text(encoding = "utf-8")
+        assert (
+            "TorchIndexPinned" in text
+        ), f"{path.name} should gate the AMD ROCm reroute on a pinned-index flag"
+
+    def test_cuda_pin_overrides_cvd_hide_gate(self):
+        # A pinned cu* index skips ALL host-GPU probing, so the CUDA repair must clear the
+        # CUDA_VISIBLE_DEVICES hide gate too (else the GPU-less CI case bails).
+        text = STACK_PY.read_text(encoding = "utf-8")
+        m = re.search(r"def _ensure_cuda_torch\(\).*?(?=\ndef )", text, re.DOTALL)
+        assert m, "could not locate _ensure_cuda_torch"
+        body = m.group(0)
+        assert "_cuda_pinned" in body, (
+            "_ensure_cuda_torch should compute a CUDA-pin flag so the pin can "
+            "override the CVD hide gate"
+        )
+        assert re.search(
+            r"if not _cuda_pinned and _cvd is not None", body
+        ), "the CVD hide gate must be bypassed when a CUDA index is pinned"
+
+    def test_cpu_repair_pins_supported_torch_range(self):
+        # The explicit-CPU repair must use the bounded CPU/CUDA spec, not a bare trio (the
+        # /cpu index serves torch 2.11+, so a bare install could resolve out of range).
+        text = STACK_PY.read_text(encoding = "utf-8")
+        m = re.search(r"def _ensure_cpu_torch\(\).*?(?=\ndef )", text, re.DOTALL)
+        assert m, "could not locate _ensure_cpu_torch"
+        body = m.group(0)
+        assert "_CPU_TORCH_PKG_SPEC" in body, (
+            "_ensure_cpu_torch should install the bounded _CPU_TORCH_PKG_SPEC, "
+            "not a bare torch/torchvision/torchaudio trio"
+        )
+
+    def test_setup_ps1_stale_check_gates_rocm_on_supported_arch(self):
+        # The stale check must expect ROCm torch only for arches the install path maps to a
+        # repo.amd.com index; expecting "rocm" for an unmapped arch marks a good CPU venv stale.
+        text = SETUP_PS1.read_text(encoding = "utf-8")
+        assert "_rocmWheelArches" in text, (
+            "setup.ps1 stale check should restrict the ROCm expected-tag to the "
+            "supported gfx wheel arches"
+        )
+
+
+class TestGfx211AllowlistParity:
+    """The gfx per-arch 2.11-floor leaves (gfx120X-all / gfx1151 / gfx1150) must be the
+    SAME set in every installer and its stale/mismatch check. When they diverged, a
+    pinned gfx110X-all / gfx90a / gfx908 wheel (<2.11) was force-reinstalled every update."""
+
+    EXPECTED = {"gfx120x-all", "gfx1151", "gfx1150"}
+
+    def test_install_sh_allowlist(self):
+        text = INSTALL_SH.read_text(encoding = "utf-8").lower()
+        # install.sh: the TORCH_CONSTRAINT case (rocm7.2|gfx120x-all|gfx1151|gfx1150).
+        m = re.search(r"rocm7\.2\|gfx120x-all\|gfx1151\|gfx1150", text)
+        assert m, "install.sh gfx-2.11 allowlist case not found / changed"
+
+    def test_install_ps1_allowlist(self):
+        text = INSTALL_PS1.read_text(encoding = "utf-8").lower()
+        m = re.search(r"@\('gfx120x-all',\s*'gfx1151',\s*'gfx1150'\)", text)
+        assert m, "install.ps1 $_pinGfx211 allowlist not found / changed"
+
+    def test_setup_ps1_defines_single_allowlist_helper(self):
+        # setup.ps1 must define the allowlist once (Test-RocmGfx211Leaf) and reuse it, so
+        # the stale check and install spec can't disagree.
+        text = SETUP_PS1.read_text(encoding = "utf-8")
+        assert (
+            "function Test-RocmGfx211Leaf" in text
+        ), "setup.ps1 should define a single Test-RocmGfx211Leaf allowlist helper"
+        assert re.search(
+            r"@\('gfx120x-all',\s*'gfx1151',\s*'gfx1150'\)", text.lower()
+        ), "Test-RocmGfx211Leaf should hold the gfx-2.11 allowlist"
+        assert "$_pinGfx211 = Test-RocmGfx211Leaf" in text, (
+            "setup.ps1 install-spec path should reuse Test-RocmGfx211Leaf, not "
+            "re-hardcode the allowlist (they must not diverge)"
+        )
+
+    def test_stack_py_allowlist(self):
+        text = STACK_PY.read_text(encoding = "utf-8").lower()
+        assert (
+            '"gfx120x-all", "gfx1151", "gfx1150"' in text
+        ), "install_python_stack.py _ROCM_GFX_TORCH211_LEAVES not found / changed"
+
+
+class TestCudaLeafDigitParity:
+    """A wheel-family leaf is CUDA only when it is "cu" + digits (cu118/cu128/...).
+    A bare cu* glob wrongly catches mirror leaves like /custom or /current; when
+    that happened the venv was marked stale and rebuilt on every run. Every
+    installer must require a digit after "cu" in its family/CUDA classification."""
+
+    def test_stack_py_requires_cu_digit(self):
+        text = STACK_PY.read_text(encoding = "utf-8")
+        # EXACT cu+digits: a custom leaf like cu128-private must route to the
+        # verbatim/unknown path, not be compared against the installed +cu128 tag.
+        assert re.search(
+            r'r"cu\[0-9\]\+"', text
+        ), "install_python_stack.py _is_cuda_family_leaf must fullmatch cu[0-9]+"
+
+    def test_setup_ps1_requires_cu_digit(self):
+        text = SETUP_PS1.read_text(encoding = "utf-8")
+        # EXACT cu+digits: cu128-private must not classify as CUDA (it would become
+        # the expected tag and rebuild the venv on every update).
+        assert re.search(
+            r"'\^cu\[0-9\]\+\$'", text
+        ), "setup.ps1 Test-CudaFamilyLeaf must match ^cu[0-9]+$, not a cu* prefix"
+        # The stale-venv branch must go through the digit-guarded helper.
+        assert (
+            "Test-CudaFamilyLeaf $_pinLeaf" in text
+        ), "setup.ps1 stale check should classify CUDA via Test-CudaFamilyLeaf"
+
+    def test_install_ps1_requires_cu_digit_in_gpu_branch(self):
+        text = INSTALL_PS1.read_text(encoding = "utf-8")
+        assert re.search(
+            r"'\^cu\[0-9\]'", text
+        ), "install.ps1 Get-TauriGpuBranch must require a digit after cu"
+
+    def test_install_sh_requires_cu_digit_in_gpu_branch(self):
+        text = INSTALL_SH.read_text(encoding = "utf-8")
+        # The _tauri_gpu_branch cuda case must be cu[0-9]*, not a bare cu*.
+        assert re.search(
+            r"cu\[0-9\]\*\)\s*echo \"cuda\"", text
+        ), "install.sh _tauri_gpu_branch cuda case must be cu[0-9]*, not cu*"
+
+    def test_install_sh_backend_export_requires_cu_digit(self):
+        text = INSTALL_SH.read_text(encoding = "utf-8")
+        # Brand CUDA only on cu[0-9]*; a bare catch-all *) -> cuda would mis-brand
+        # /current, /custom pins and skip ROCm repair on AMD hosts.
+        assert re.search(
+            r'cu\[0-9\]\*\)\s*export UNSLOTH_TORCH_BACKEND="cuda"', text
+        ), "install.sh backend export must brand cuda only on cu[0-9]*"
+        # An unknown leaf must NOT commit a cuda backend (it unsets instead).
+        assert re.search(
+            r"\*\)\s*unset UNSLOTH_TORCH_BACKEND", text
+        ), "install.sh backend export must unset (not force cuda) on an unknown leaf"
+
+    def test_install_sh_lowercases_backend_leaf(self):
+        text = INSTALL_SH.read_text(encoding = "utf-8")
+        # The leaf feeding both the backend case and the 2.11 floor case must be
+        # lowercased so the canonical gfx120X-all (capital X) matches.
+        assert re.search(
+            r"_torch_index_leaf=\$\(printf '%s' \"\$_torch_index_leaf\" \| tr '\[:upper:\]' '\[:lower:\]'\)",
+            text,
+        ), "install.sh must lowercase _torch_index_leaf before the gfx/rocm/cu case matches"
+
+
+class TestKnown211SetParity:
+    """The KNOWN-2.11 rocm/gfx set must be identical across all four installers:
+    exactly {rocm7.2} plus the gfx allowlist {gfx120x-all, gfx1151, gfx1150}.
+    rocm7.3 / torch 2.12 do not exist, so no side may floor them speculatively."""
+
+    def test_install_sh_known_211_leaf_is_rocm72_and_gfx_allowlist(self):
+        text = INSTALL_SH.read_text(encoding = "utf-8")
+        # The 2.11 floor case matches exactly rocm7.2 + the three gfx leaves.
+        assert re.search(
+            r"rocm7\.2\|gfx120x-all\|gfx1151\|gfx1150\)", text
+        ), "install.sh 2.11 floor must be exactly rocm7.2|gfx120x-all|gfx1151|gfx1150"
+        # No speculative rocm7.3 anywhere.
+        assert "rocm7.3" not in text, "install.sh must not reference a non-existent rocm7.3"
+
+    def test_python_known_211_versions_is_only_rocm72(self):
+        text = STACK_PY.read_text(encoding = "utf-8")
+        assert "_ROCM_KNOWN_TORCH211_VERSIONS" in text
+        # The frozenset literal is exactly {(7, 2)}.
+        m = re.search(r"_ROCM_KNOWN_TORCH211_VERSIONS[^=]*=\s*frozenset\(\{([^}]*)\}\)", text)
+        assert m is not None, "install_python_stack.py must define _ROCM_KNOWN_TORCH211_VERSIONS"
+        assert "(7, 2)" in m.group(1)
+        assert "7, 3" not in m.group(1) and "7, 1" not in m.group(1)
+
+    def test_setup_ps1_known_211_helper_is_only_rocm72(self):
+        text = SETUP_PS1.read_text(encoding = "utf-8")
+        assert "Test-RocmKnown211Version" in text
+        # The predicate is Major -eq 7 -and Minor -eq 2 (only rocm7.2).
+        assert re.search(
+            r"Test-RocmKnown211Version[\s\S]{0,400}\$Major -eq 7 -and \$Minor -eq 2", text
+        ), "setup.ps1 Test-RocmKnown211Version must accept only rocm7.2"
+
+    def test_install_ps1_pin_floor_is_only_rocm72(self):
+        text = INSTALL_PS1.read_text(encoding = "utf-8")
+        # The pinned-ROCm install-spec floor must be Major -eq 7 -and Minor -eq 2,
+        # not the speculative >= 2 that would floor a non-existent rocm7.3.
+        assert re.search(
+            r"\$_pinRocm211 = \(\[int\]\$Matches\[1\] -eq 7 -and \[int\]\$Matches\[2\] -eq 2\)",
+            text,
+        ), "install.ps1 pinned-ROCm floor must be rocm7.2 only (no speculative >= 2)"
+
+    def test_ps1_pin_floor_gate_is_anchored(self):
+        """The floor-selection gate that reads $_pinRocm211 from the raw leaf must anchor
+        the rocm match ($), or a suffixed custom leaf (rocm7.2-private) matches the rocm7.2
+        prefix, takes the 2.11-floor branch, and is force-routed through the ROCm path
+        before the exact-match elseif can send it to the verbatim install (Codex P2)."""
+        for path, label in ((INSTALL_PS1, "install.ps1"), (SETUP_PS1, "setup.ps1")):
+            text = path.read_text(encoding = "utf-8")
+            assert "-match '^rocm(\\d+)\\.(\\d+)$'" in text, (
+                f"{label} floor gate must anchor the rocm match (^rocm(\\d+)\\.(\\d+)$) so a "
+                "suffixed custom leaf is not floored/routed as rocm7.2"
+            )
+            assert (
+                "-match '^rocm(\\d+)\\.(\\d+)'\n" not in text
+            ), f"{label} floor gate must not use the unanchored ^rocm(\\d+)\\.(\\d+) prefix"
+
+    def test_install_ps1_bounds_unknown_leaf_pinned_torch(self):
+        """install.ps1's pinned-torch install must bound BOTH companions on EVERY
+        index, cu<digits> families included: torchaudio 2.11 dropped its exact torch
+        pin from the wheel metadata, so a bare companion beside torch<2.11 can
+        resolve a mismatched 2.11.0 build (Codex P2, then unconditional per the
+        torchaudio 2.11 unpinning)."""
+        text = INSTALL_PS1.read_text(encoding = "utf-8")
+        assert (
+            '$_pinVisionSpec = "torchvision>=0.19,<0.26.0"' in text
+        ), "install.ps1 custom-pin install must bound torchvision (>=0.19,<0.26.0)"
+        assert (
+            '$_pinAudioSpec = "torchaudio>=2.4,<2.11.0"' in text
+        ), "install.ps1 custom-pin install must bound torchaudio (>=2.4,<2.11.0)"
+        # No cu-family exemption: the bounds apply unconditionally.
+        assert (
+            "$_pinCuLeaf" not in text
+        ), "install.ps1 must bound companions on every index (no cu-family exemption)"
+        # The bounded companions must actually be passed to the install command.
+        assert re.search(
+            r'"torch>=2\.4,<2\.11\.0" \$_pinVisionSpec \$_pinAudioSpec --default-index \$TorchIndexUrl',
+            text,
+        ), "install.ps1 custom-pin install must pass the bounded companion specs to uv"
+
+    def test_gfx_allowlist_matches_across_installers(self):
+        # The gfx 2.11 allowlist {gfx120x-all, gfx1151, gfx1150} must appear in each.
+        gfx = ("gfx120x-all", "gfx1151", "gfx1150")
+        for path, label in (
+            (INSTALL_SH, "install.sh"),
+            (INSTALL_PS1, "install.ps1"),
+            (SETUP_PS1, "setup.ps1"),
+            (STACK_PY, "install_python_stack.py"),
+        ):
+            low = path.read_text(encoding = "utf-8").lower()
+            for g in gfx:
+                assert g in low, f"{label} missing gfx 2.11 allowlist member {g}"
+
+
+class TestPinnedRocmLeafDigitParity:
+    """A pinned index is a pip ROCm --default-index family only when its leaf is an
+    EXACT rocm+digits (rocm7 / rocm7.2) or gfx*. A ^rocm[0-9] PREFIX (or a bare rocm*
+    glob) wrongly catches a custom mirror / find-links leaf (rocm-current /
+    rocm-rel-7.2.1) AND a suffixed private-mirror leaf (rocm7.2-private / rocm7-current),
+    routing it through the ROCm install path (which silently falls back to CPU on
+    failure) or skipping the custom-index companion bounds, instead of the verbatim
+    --default-index install. All installers must match the family EXACTLY: Python and
+    install.sh via a shared _is_pip_rocm_family_leaf, setup.ps1 via Test-PipRocmFamilyLeaf,
+    install.ps1 via an anchored ^rocm[0-9]+(\\.[0-9]+)?$ reroute."""
+
+    def test_install_ps1_pinned_reroute_requires_rocm_digit(self):
+        text = INSTALL_PS1.read_text(encoding = "utf-8")
+        # The pinned gfx*/rocm reroute must match rocm EXACTLY (anchored), so a suffixed
+        # rocm7.2-private / rocm-current falls through to the verbatim --default-index path.
+        assert "-match '^rocm[0-9]+(\\.[0-9]+)?$'" in text, (
+            "install.ps1 pinned-index reroute must anchor the rocm match "
+            "(^rocm[0-9]+(\\.[0-9]+)?$), not a bare -like 'rocm*' or an unanchored ^rocm\\d"
+        )
+        # Neither the broad glob nor the unanchored prefix may drive that reroute.
+        assert (
+            "-like 'rocm*'" not in text
+        ), "install.ps1 must not route a pinned index on a bare -like 'rocm*' glob"
+        assert (
+            "-match '^rocm\\d'" not in text
+        ), "install.ps1 must not route a pinned index on an unanchored -match '^rocm\\d'"
+
+    def test_setup_ps1_pinned_reroute_requires_rocm_digit(self):
+        text = SETUP_PS1.read_text(encoding = "utf-8")
+        # setup.ps1 routes every family decision through Test-PipRocmFamilyLeaf, which
+        # anchors the rocm match so a suffixed custom leaf stays on the verbatim path.
+        assert (
+            "function Test-PipRocmFamilyLeaf" in text
+        ), "setup.ps1 must define Test-PipRocmFamilyLeaf (the exact rocm/gfx family gate)"
+        assert "'^rocm[0-9]+(\\.[0-9]+)?$'" in text, (
+            "setup.ps1 Test-PipRocmFamilyLeaf must anchor the rocm match "
+            "(^rocm[0-9]+(\\.[0-9]+)?$) so rocm7.2-private / rocm-current stay verbatim"
+        )
+        pinned_block = text[text.find("$_pinGfx211 = Test-RocmGfx211Leaf") :][:2000]
+        assert (
+            "-like 'rocm*'" not in pinned_block
+        ), "setup.ps1 pinned reroute must not route on a bare -like 'rocm*' glob"
+
+    def test_install_sh_repairable_requires_rocm_digit(self):
+        text = INSTALL_SH.read_text(encoding = "utf-8")
+        # _torch_index_repairable routes rocm/gfx through the exact-match helper.
+        assert (
+            "_is_pip_rocm_family_leaf" in text
+        ), "install.sh must define/use _is_pip_rocm_family_leaf for the exact rocm gate"
+        # gfx needs a following digit: gfx-private / gfxfoo are custom verbatim pins.
+        assert re.search(
+            r'case "\$1" in\n\s*gfx\[0-9\]\*\) return 0', text
+        ), "install.sh _is_pip_rocm_family_leaf must treat only gfx<digit>* as a family"
+        assert not re.search(
+            r'case "\$1" in\n\s*gfx\*\) return 0', text
+        ), "install.sh _is_pip_rocm_family_leaf must not family-match a bare gfx* glob"
+
+    def test_stack_py_pip_rocm_family_requires_digit(self):
+        text = STACK_PY.read_text(encoding = "utf-8")
+        assert re.search(
+            r'fullmatch\(r"rocm\\d\+\(\?:\\\.\\d\+\)\?", leaf\)', text
+        ), "install_python_stack.py _is_pip_rocm_family_leaf must fullmatch rocm\\d+(?:\\.\\d+)?"
+        # The unanchored prefix must be gone from the family/flavor gates.
+        assert (
+            're.match(r"^rocm\\d"' not in text
+        ), "install_python_stack.py must not gate a family on an unanchored re.match(^rocm\\d)"
+
+    def test_install_sh_rocm_side_effects_digit_gated(self):
+        """The AMD bitsandbytes + 'repair ROCm torch' side effects must fire only on
+        an EXACT ROCm family (rocm7.2/gfx*), not a bare */rocm* whole-URL glob nor a
+        ^rocm[0-9] prefix that catches a custom CPU/CUDA index like /rocm-current or a
+        suffixed /rocm7.2-private and force-repairs it from the wrong --default-index."""
+        text = INSTALL_SH.read_text(encoding = "utf-8")
+        assert (
+            'if _is_pip_rocm_family_leaf "$_torch_index_leaf"; then\n    _torch_index_is_rocm_family=true'
+            in text
+        ), "install.sh must set _torch_index_is_rocm_family from the exact-match helper"
+        assert (
+            '[ "$_torch_index_is_rocm_family" = true ]' in text
+        ), "install.sh ROCm bnb/repair hooks must gate on _torch_index_is_rocm_family"
+        assert (
+            "*/rocm*|*/gfx*)\n                _install_bnb_rocm" not in text
+        ), "install.sh must not gate _install_bnb_rocm on a bare */rocm* whole-URL glob"
+
+
+class TestPinnedIndexClearsUvEnvParity:
+    """Every installer must neutralise the uv index env vars for a pinned torch
+    install (#6898). uv treats the default index (--index-url / --default-index) as
+    lowest priority, so an inherited UV_INDEX / UV_EXTRA_INDEX_URL mirror would win
+    under uv's first-index strategy and pull torch from the wrong index -- after
+    which the pinned wheel index is silently never used."""
+
+    UV_VARS = ("UV_DEFAULT_INDEX", "UV_INDEX_URL", "UV_INDEX", "UV_EXTRA_INDEX_URL")
+
+    def test_install_sh_clears_uv_index_vars(self):
+        text = INSTALL_SH.read_text(encoding = "utf-8")
+        assert (
+            "env -u UV_DEFAULT_INDEX -u UV_INDEX_URL -u UV_INDEX -u UV_EXTRA_INDEX_URL" in text
+        ), "install.sh run_install_cmd must clear the uv index vars for --default-index installs"
+
+    def test_install_ps1_clears_uv_index_vars(self):
+        text = INSTALL_PS1.read_text(encoding = "utf-8")
+        for var in self.UV_VARS:
+            assert var in text, f"install.ps1 must clear {var} for pinned installs"
+
+    def test_setup_ps1_clears_uv_index_vars(self):
+        text = SETUP_PS1.read_text(encoding = "utf-8")
+        for var in self.UV_VARS:
+            assert var in text, f"setup.ps1 must clear {var} for pinned installs"
+
+    def test_stack_py_clears_uv_index_vars(self):
+        text = STACK_PY.read_text(encoding = "utf-8")
+        assert "_install_env_for_cmd" in text, (
+            "install_python_stack.py must scrub inherited uv index vars for pinned "
+            "installs via _install_env_for_cmd (parity with install.sh #6898)"
+        )
+        for var in self.UV_VARS:
+            assert var in text, f"install_python_stack.py must clear {var} for pinned installs"
+
+    def test_all_installers_clear_uv_torch_backend(self):
+        """uv's torch backend redirects torch resolution to its own per-backend
+        index even against an explicit pin, so every installer's pinned-install
+        scrub must clear UV_TORCH_BACKEND too."""
+        sh = INSTALL_SH.read_text(encoding = "utf-8")
+        assert "-u UV_TORCH_BACKEND" in sh, "install.sh pinned scrub must clear UV_TORCH_BACKEND"
+        for path in (INSTALL_PS1, SETUP_PS1):
+            text = path.read_text(encoding = "utf-8")
+            assert (
+                "'UV_TORCH_BACKEND'" in text
+            ), f"{path.name} pinned scrub must clear UV_TORCH_BACKEND"
+        stack = STACK_PY.read_text(encoding = "utf-8")
+        assert (
+            '"UV_TORCH_BACKEND",' in stack
+        ), "install_python_stack.py strip tuple must include UV_TORCH_BACKEND"
+
+    def test_stack_py_strips_pip_extra_index_for_pip_fallback(self):
+        """The pip fallback honours PIP_EXTRA_INDEX_URL (pip adds it IN ADDITION
+        to --index-url), so the pinned-command scrub must strip it."""
+        stack = STACK_PY.read_text(encoding = "utf-8")
+        assert (
+            '"PIP_EXTRA_INDEX_URL",' in stack
+        ), "install_python_stack.py strip tuple must include PIP_EXTRA_INDEX_URL"
+
+    def test_all_installers_scrub_find_links(self):
+        """uv's --find-links (env UV_FIND_LINKS) adds candidate locations that can
+        satisfy torch off a pinned index; every pinned-install scrub must clear it."""
+        sh = INSTALL_SH.read_text(encoding = "utf-8")
+        assert "-u UV_FIND_LINKS" in sh
+        for path in (INSTALL_PS1, SETUP_PS1):
+            assert "'UV_FIND_LINKS'" in path.read_text(encoding = "utf-8"), path.name
+        stack = STACK_PY.read_text(encoding = "utf-8")
+        assert '"UV_FIND_LINKS",' in stack and '"PIP_FIND_LINKS",' in stack
+
+    def test_setup_ps1_scrub_covers_pip_fallback(self):
+        """setup.ps1's Fast-Install must keep the scrub active through the pip
+        fallback (pip honours PIP_EXTRA_INDEX_URL / PIP_FIND_LINKS in addition to
+        --index-url); restoring the vars before the fallback reopens the hole."""
+        text = SETUP_PS1.read_text(encoding = "utf-8")
+        fi = text[text.find("function Fast-Install") :][:2500]
+        assert "'PIP_EXTRA_INDEX_URL'" in fi and "'PIP_FIND_LINKS'" in fi
+        # the pip fallback must sit INSIDE the try whose finally restores the vars
+        assert fi.find("python -m pip install") < fi.find(
+            "finally"
+        ), "pip fallback must run before the scrub is restored"
+
+    def test_all_installers_disable_uv_config_for_pinned_installs(self):
+        """A DISCOVERED uv.toml / pyproject [tool.uv] outranks the CLI pin
+        (verified with uv 0.10: [pip] torch-backend = "cpu" and a non-default
+        [[index]] both resolve torch+cpu against an explicit --index-url /
+        --default-index cu126 pin; UV_NO_CONFIG=1 restores the pin). Every
+        installer's pinned scrub must set UV_NO_CONFIG=1 and drop UV_CONFIG_FILE."""
+        sh = INSTALL_SH.read_text(encoding = "utf-8")
+        assert "-u UV_CONFIG_FILE UV_NO_CONFIG=1" in sh, (
+            "install.sh run_install_cmd must set UV_NO_CONFIG=1 and drop "
+            "UV_CONFIG_FILE for --default-index installs"
+        )
+        for path in (INSTALL_PS1, SETUP_PS1):
+            text = path.read_text(encoding = "utf-8")
+            assert "'UV_CONFIG_FILE'" in text, f"{path.name} must drop UV_CONFIG_FILE"
+            assert (
+                "$env:UV_NO_CONFIG = '1'" in text
+            ), f"{path.name} must set UV_NO_CONFIG=1 for pinned installs"
+        stack = STACK_PY.read_text(encoding = "utf-8")
+        assert (
+            '"UV_CONFIG_FILE",' in stack
+        ), "install_python_stack.py strip tuple must include UV_CONFIG_FILE"
+        assert (
+            'env["UV_NO_CONFIG"] = "1"' in stack
+        ), "_install_env_for_cmd must set UV_NO_CONFIG=1 for pinned installs"
+
+    def test_pip_fallbacks_disable_pip_config_files(self):
+        """The pip FALLBACK (uv missing/failed) honours user/site pip config files
+        even with the PIP_* env vars stripped: `pip config set
+        global.extra-index-url` still adds indexes to a pinned install. pip loads
+        NO configuration files when PIP_CONFIG_FILE is the platform devnull, so
+        the two installers that HAVE a pip fallback (install_python_stack.py and
+        setup.ps1's Fast-Install) must set it in their pinned scrub. install.sh
+        and install.ps1 are uv-only (no python -m pip fallback) and need no
+        equivalent."""
+        stack = STACK_PY.read_text(encoding = "utf-8")
+        assert 'env["PIP_CONFIG_FILE"] = os.devnull' in stack, (
+            "_install_env_for_cmd must point PIP_CONFIG_FILE at os.devnull for "
+            "pinned installs (pip fallback isolation)"
+        )
+        setup = SETUP_PS1.read_text(encoding = "utf-8")
+        assert "$env:PIP_CONFIG_FILE = 'nul'" in setup, (
+            "setup.ps1 Fast-Install pinned scrub must point PIP_CONFIG_FILE at nul "
+            "(Windows devnull) so the pip fallback ignores user/site pip config"
+        )
+        assert (
+            "'PIP_CONFIG_FILE'" in setup
+        ), "setup.ps1 must save/restore PIP_CONFIG_FILE around the pinned scrub"
+
+    def test_setup_ps1_bounds_unknown_leaf_pinned_torch(self):
+        """A first-time/changed unknown-leaf custom pin routes through setup.ps1's
+        CUDA branch; install.ps1's fresh pinned install, install.sh, and the Python
+        verbatim path bound the WHOLE trio, so the Windows update path must too -- a
+        private mirror serving newer torch OR newer companions must not lift the venv
+        above the supported range under the pin."""
+        text = SETUP_PS1.read_text(encoding = "utf-8")
+        # The custom-leaf branch bounds torch AND both companions (parity with the
+        # other installers' custom-pin trio bounds), gated on a non-cu-family leaf.
+        for spec in (
+            '$cudaTorchSpec = "torch>=2.4,<2.11.0"',
+            '$cudaVisionSpec = "torchvision>=0.19,<0.26.0"',
+            '$cudaAudioSpec = "torchaudio>=2.4,<2.11.0"',
+        ):
+            assert spec in text, f"setup.ps1 must bound the custom-leaf trio: {spec}"
+        assert (
+            "if ($TorchIndexPinned -and -not (Test-CudaFamilyLeaf $CuTag)) {" in text
+        ), "the custom-leaf trio bounds must be gated on a pinned non-cu-family leaf"
+        assert (
+            "Fast-Install $cudaTorchSpec $cudaVisionSpec $cudaAudioSpec" in text
+        ), "setup.ps1's CUDA branch must install via the bounded spec variables"
+
+    def test_setup_ps1_bounds_pinned_cpu_torch(self):
+        """setup.ps1's CPU branch must bound the trio under an explicit pin (parity with
+        _CPU_TORCH_PKG_SPEC): the /cpu index serves newer torch, and _ensure_cpu_torch
+        keeps any CPU build, so a bare pinned trio could land an unsupported version.
+        An unpinned CPU host keeps the bare trio (pre-pin behavior unchanged)."""
+        text = SETUP_PS1.read_text(encoding = "utf-8")
+        for spec in (
+            '$cpuTorchSpec  = "torch>=2.4,<2.12.0"',
+            '$cpuVisionSpec = "torchvision>=0.19,<0.27.0"',
+            '$cpuAudioSpec  = "torchaudio>=2.4,<2.12.0"',
+        ):
+            assert spec in text, f"setup.ps1 must bound the pinned CPU trio: {spec}"
+        assert (
+            "if ($TorchIndexPinned) {" in text
+        ), "the CPU trio bounds must be gated on an explicit pin"
+        assert (
+            "Fast-Install $cpuTorchSpec $cpuVisionSpec $cpuAudioSpec @cpuForce" in text
+        ), "setup.ps1's CPU branch must install via the spec variables"
+        # The ceilings mirror the Python repair spec exactly.
+        stack = STACK_PY.read_text(encoding = "utf-8")
+        spec_block = re.search(r"_CUDA_TORCH_PKG_SPEC[^(]*\(\s*(.*?)\)", stack, re.DOTALL)
+        assert spec_block and '"torch>=2.4,<2.12.0"' in spec_block.group(1), (
+            "_CPU_TORCH_PKG_SPEC (via _CUDA_TORCH_PKG_SPEC) must keep the torch<2.12 "
+            "ceiling the setup.ps1 pinned CPU branch mirrors"
+        )
+
+    def test_setup_ps1_stale_check_requires_rocm_digit(self):
+        """The stale-venv check must use the same EXACT rocm/gfx gate as the install
+        selection (Test-PipRocmFamilyLeaf), or a custom rocm-* / suffixed rocm7.2-private
+        leaf is stale-compared as a family and force-reinstalls on every studio update."""
+        text = SETUP_PS1.read_text(encoding = "utf-8")
+        anchor = text.find("$_pinLeaf = Get-TorchIndexLeaf $_pinnedIdx")
+        assert anchor >= 0, "setup.ps1 stale check must classify the pinned leaf"
+        stale = text[anchor:][:2500]
+        assert (
+            "Test-PipRocmFamilyLeaf" in stale
+        ), "setup.ps1 stale check must gate rocm leaves via the exact Test-PipRocmFamilyLeaf"
+        assert (
+            stale.count("-like 'rocm*'") == 0
+        ), "setup.ps1 stale check must not use a bare -like 'rocm*' glob"
+        assert (
+            "-match '^rocm\\d'" not in stale
+        ), "setup.ps1 stale check must not use an unanchored -match '^rocm\\d'"
+
+
+class TestIndexPathSlashTrimParity:
+    """Every installer must trim trailing PATH slashes only on the verbatim
+    UNSLOTH_TORCH_INDEX_URL override, preserving a ?query/#fragment token: a whole-URL
+    strip corrupts a base64 token ending in "/", a single strip leaves a double-slash leaf
+    empty. The helper must be DEFINED and WIRED into the override return in all four."""
+
+    def test_helper_defined_in_all_installers(self):
+        assert "def _trim_index_path_slashes(" in STACK_PY.read_text(encoding = "utf-8")
+        assert "_trim_index_path_slashes()" in INSTALL_SH.read_text(encoding = "utf-8")
+        assert "function Trim-IndexPathSlashes" in INSTALL_PS1.read_text(encoding = "utf-8")
+        assert "function Trim-IndexPathSlashes" in SETUP_PS1.read_text(encoding = "utf-8")
+
+    def test_helper_wired_into_override_in_all_installers(self):
+        assert "_trim_index_path_slashes(url)" in STACK_PY.read_text(encoding = "utf-8")
+        assert '_url=$(_trim_index_path_slashes "$_url")' in INSTALL_SH.read_text(encoding = "utf-8")
+        assert "Trim-IndexPathSlashes $env:UNSLOTH_TORCH_INDEX_URL" in INSTALL_PS1.read_text(
+            encoding = "utf-8"
+        )
+        assert "Trim-IndexPathSlashes $env:UNSLOTH_TORCH_INDEX_URL" in SETUP_PS1.read_text(
+            encoding = "utf-8"
+        )
+
+
+class TestInstallOutputRedactionParity:
+    """uv/pip failure text embeds the failing --index-url verbatim, so a captured install
+    log dumped on error can leak a user:token@ or ?token= secret. Every installer must
+    DEFINE a redaction helper and WIRE it into the captured-output print path."""
+
+    def test_helper_defined_in_all_installers(self):
+        assert "def _redact_install_output(" in STACK_PY.read_text(encoding = "utf-8")
+        assert "_redact_install_output()" in INSTALL_SH.read_text(encoding = "utf-8")
+        assert "function Redact-InstallOutput" in INSTALL_PS1.read_text(encoding = "utf-8")
+        assert "function Redact-InstallOutput" in SETUP_PS1.read_text(encoding = "utf-8")
+
+    def test_helper_wired_into_failure_print(self):
+        # install.sh dumps the captured log through the redactor on failure.
+        assert '_redact_install_output "$_log"' in INSTALL_SH.read_text(encoding = "utf-8")
+        # Both ps1 installers redact the captured $output before Write-Host on non-zero exit.
+        assert (
+            "Write-Host (Redact-InstallOutput $output) -ForegroundColor Red"
+            in INSTALL_PS1.read_text(encoding = "utf-8")
+        )
+        assert (
+            "Write-Host (Redact-InstallOutput $output) -ForegroundColor Red"
+            in SETUP_PS1.read_text(encoding = "utf-8")
+        )
+        # Python redacts the captured stdout before printing.
+        assert "_redact_install_output(" in STACK_PY.read_text(encoding = "utf-8")
+
+
+class TestPipNoIndexScrubParity:
+    """The plain-pip fallback honours PIP_*: PIP_NO_INDEX=1 makes it ignore ALL indexes
+    (defeating the pinned --index-url) and PIP_INDEX_URL replaces the pin. The two installers
+    that HAVE a plain-pip fallback (Python + setup.ps1) must scrub both for a pinned install.
+    install.sh / install.ps1 are uv-only (--default-index), which ignores pip config/env."""
+
+    def test_python_scrubs_pip_no_index_and_pip_index_url(self):
+        text = STACK_PY.read_text(encoding = "utf-8")
+        assert '"PIP_NO_INDEX"' in text
+        assert '"PIP_INDEX_URL"' in text
+
+    def test_setup_ps1_scrubs_pip_no_index_and_pip_index_url(self):
+        text = SETUP_PS1.read_text(encoding = "utf-8")
+        assert "'PIP_NO_INDEX'" in text
+        assert "'PIP_INDEX_URL'" in text
diff --git a/tests/python/test_e2e_no_torch_sandbox.py b/tests/python/test_e2e_no_torch_sandbox.py
index f412de2063..bb61af462d 100644
--- a/tests/python/test_e2e_no_torch_sandbox.py
+++ b/tests/python/test_e2e_no_torch_sandbox.py
@@ -30,7 +30,7 @@ VLM_PROCESSING = DATASETS_DIR / "vlm_processing.py"
 ITERABLE = DATASETS_DIR / "iterable.py"
 HARDWARE_PY = HARDWARE_DIR / "hardware.py"
 
-# Studio venv for server tests
+# Unsloth venv for server tests
 STUDIO_VENV = Path.home() / ".unsloth" / "studio" / "unsloth_studio"
 
 sys.path.insert(0, str(STUDIO_DIR))
@@ -957,20 +957,20 @@ server = pytest.mark.server
 
 @server
 class TestLiveServerStartup:
-    """Live server startup against the existing Studio venv with torch made unimportable (pytest -m server)."""
+    """Live server startup against the existing Unsloth venv with torch made unimportable (pytest -m server)."""
 
     @pytest.fixture(autouse = True)
     def _check_studio_venv(self):
         py = _studio_venv_python()
         if py is None:
-            pytest.skip("Studio venv not found at ~/.unsloth/studio/unsloth_studio")
+            pytest.skip("Unsloth venv not found at ~/.unsloth/studio/unsloth_studio")
 
     @pytest.fixture(scope = "class")
     def server_process(self):
         """Start the studio backend server without torch, yield (proc, port), then stop."""
         py = _studio_venv_python()
         if py is None:
-            pytest.skip("Studio venv not found")
+            pytest.skip("Unsloth venv not found")
 
         port = _server_port()
         backend_dir = BACKEND_DIR
diff --git a/tests/python/test_get_lora_parameters_bias_fp8_block_size.py b/tests/python/test_get_lora_parameters_bias_fp8_block_size.py
new file mode 100644
index 0000000000..835ad19542
--- /dev/null
+++ b/tests/python/test_get_lora_parameters_bias_fp8_block_size.py
@@ -0,0 +1,82 @@
+import ast
+from pathlib import Path
+
+
+def _load_function(name):
+    # Extract a function from kernels/utils.py without importing unsloth (which
+    # needs a GPU / torch / bitsandbytes). The functions exercised here only use
+    # getattr and the _FP8_WEIGHT_DTYPES name on the paths under test.
+    source = Path(__file__).parents[2] / "unsloth" / "kernels" / "utils.py"
+    tree = ast.parse(source.read_text(encoding = "utf-8"))
+    funcs = [
+        node for node in ast.walk(tree) if isinstance(node, ast.FunctionDef) and node.name == name
+    ]
+    assert len(funcs) == 1, (name, funcs)
+    namespace = {"getattr": getattr, "_FP8_WEIGHT_DTYPES": ()}
+    module = ast.Module(body = funcs, type_ignores = [])
+    ast.fix_missing_locations(module)
+    exec(compile(module, str(source), "exec"), namespace)
+    return namespace[name]
+
+
+class _Obj:
+    pass
+
+
+def _make_disabled_block_fp8_proj(block_size):
+    # A merged/disabled projection whose base layer is a block-fp8 weight that
+    # ships a non-default block size on its checkpoint.
+    weight = _Obj()
+    weight.quant_state = _Obj()
+    base_layer = _Obj()
+    base_layer.weight = weight
+    base_layer.quant_method = "fp8"
+    base_layer.block_size = block_size
+    base_layer.bias = None
+    proj = _Obj()
+    proj.base_layer = base_layer
+    proj.merged = True
+    proj.disable_adapters = True
+    return proj, weight.quant_state
+
+
+def test_bias_variant_propagates_fp8_block_size_on_disabled_path():
+    # Downstream fp8 kernels read getattr(weight_scale, "block_size", [128, 128]),
+    # so the checkpoint's real block size must survive the merged/disabled path,
+    # exactly as it does for the non-bias sibling get_lora_parameters.
+    get_lora_parameters_bias = _load_function("get_lora_parameters_bias")
+
+    proj, weight_scale = _make_disabled_block_fp8_proj([64, 128])
+    get_lora_parameters_bias(proj)
+
+    assert getattr(weight_scale, "block_size", [128, 128]) == [64, 128]
+
+
+def _make_decompressed_merged_proj():
+    # A merged compressed-tensors layer that was decompressed back to bf16. It keeps
+    # quant_method == "fp8" from the checkpoint metadata, but the live weight is bf16
+    # so there is no quant state to attach a block size to.
+    weight = _Obj()
+    weight.dtype = "bfloat16"
+    base_layer = _Obj()
+    base_layer.weight = weight
+    base_layer.quant_method = "fp8"
+    base_layer.block_size = [128, 128]
+    base_layer.bias = None
+    proj = _Obj()
+    proj.base_layer = base_layer
+    proj.merged = True
+    proj.disable_adapters = True
+    return proj
+
+
+def test_bias_variant_keeps_none_quant_state_for_decompressed_layer():
+    # Such a layer has no quant state, and fast_linear_forward relies on getting
+    # W_quant None back so it can fall back to a plain matmul, so setting the block
+    # size must not assume a quant state is present.
+    get_lora_parameters_bias = _load_function("get_lora_parameters_bias")
+
+    W, W_quant = get_lora_parameters_bias(_make_decompressed_merged_proj())[:2]
+
+    assert W_quant is None
+    assert getattr(W, "block_size", None) == [128, 128]
diff --git a/tests/python/test_get_lora_parameters_fp8_block_size.py b/tests/python/test_get_lora_parameters_fp8_block_size.py
new file mode 100644
index 0000000000..f5f1359125
--- /dev/null
+++ b/tests/python/test_get_lora_parameters_fp8_block_size.py
@@ -0,0 +1,81 @@
+import ast
+from pathlib import Path
+
+
+def _load_function(name):
+    # Extract a function from kernels/utils.py without importing unsloth (which
+    # needs a GPU / torch / bitsandbytes). get_lora_parameters only uses getattr,
+    # hasattr and the _FP8_WEIGHT_DTYPES name on the paths under test.
+    source = Path(__file__).parents[2] / "unsloth" / "kernels" / "utils.py"
+    tree = ast.parse(source.read_text(encoding = "utf-8"))
+    funcs = [
+        node for node in ast.walk(tree) if isinstance(node, ast.FunctionDef) and node.name == name
+    ]
+    assert len(funcs) == 1, (name, funcs)
+    namespace = {"getattr": getattr, "hasattr": hasattr, "_FP8_WEIGHT_DTYPES": ()}
+    module = ast.Module(body = funcs, type_ignores = [])
+    ast.fix_missing_locations(module)
+    exec(compile(module, str(source), "exec"), namespace)
+    return namespace[name]
+
+
+class _Obj:
+    pass
+
+
+def _make_disabled_block_fp8_proj(block_size):
+    # A merged/disabled projection whose base layer is a block-fp8 weight that
+    # ships a non-default block size on its checkpoint.
+    weight = _Obj()
+    weight.quant_state = _Obj()
+    base_layer = _Obj()
+    base_layer.weight = weight
+    base_layer.quant_method = "fp8"
+    base_layer.block_size = block_size
+    proj = _Obj()
+    proj.base_layer = base_layer
+    proj.merged = True
+    proj.disable_adapters = True
+    return proj, weight.quant_state
+
+
+def test_propagates_fp8_block_size_on_disabled_path():
+    # get_lora_parameters already sets block_size before its early return; downstream
+    # fp8 kernels read getattr(weight_scale, "block_size", [128, 128]), so the
+    # checkpoint's real block size must survive the merged/disabled path.
+    get_lora_parameters = _load_function("get_lora_parameters")
+
+    proj, weight_scale = _make_disabled_block_fp8_proj([64, 128])
+    get_lora_parameters(proj)
+
+    assert getattr(weight_scale, "block_size", [128, 128]) == [64, 128]
+
+
+def _make_decompressed_merged_proj():
+    # A merged compressed-tensors layer that was decompressed back to bf16. It keeps
+    # quant_method == "fp8" from the checkpoint metadata, but the live weight is bf16
+    # so there is no quant state to attach a block size to.
+    weight = _Obj()
+    weight.dtype = "bfloat16"
+    base_layer = _Obj()
+    base_layer.weight = weight
+    base_layer.quant_method = "fp8"
+    base_layer.block_size = [128, 128]
+    proj = _Obj()
+    proj.base_layer = base_layer
+    proj.merged = True
+    proj.disable_adapters = True
+    return proj
+
+
+def test_keeps_none_quant_state_for_decompressed_layer():
+    # Mirrors the get_lora_parameters_bias guard: with no quant state, assigning
+    # W_quant.block_size must not assume one is present, or it raises AttributeError
+    # on None. fast_lora relies on getting W_quant None back to fall back to a plain
+    # matmul, so this path must stay crash-free.
+    get_lora_parameters = _load_function("get_lora_parameters")
+
+    W, W_quant = get_lora_parameters(_make_decompressed_merged_proj())[:2]
+
+    assert W_quant is None
+    assert getattr(W, "block_size", None) == [128, 128]
diff --git a/tests/python/test_install_python_stack.py b/tests/python/test_install_python_stack.py
index 9015ff8c9d..3a12e53f95 100644
--- a/tests/python/test_install_python_stack.py
+++ b/tests/python/test_install_python_stack.py
@@ -54,6 +54,24 @@ class TestBuildUvCmdTorchBackend:
             a.startswith("--torch-backend") for a in cmd
         ), f"Empty UV_TORCH_BACKEND should not add flag, got: {cmd}"
 
+    def test_uv_torch_backend_skipped_for_pinned_index(self):
+        """A pinned-index command must NOT get --torch-backend: uv's torch backend
+        redirects torch resolution to its own per-backend index even when
+        --index-url is given (verified: cu128 pin + backend cpu installs
+        torch+cpu), defeating the pin."""
+        for pin_flag in ("--index-url", "--default-index"):
+            with mock.patch.dict(os.environ, {"UV_TORCH_BACKEND": "cpu"}):
+                cmd = self._call(("torch", pin_flag, "https://download.pytorch.org/whl/cu128"))
+            assert not any(
+                a.startswith("--torch-backend") for a in cmd
+            ), f"{pin_flag} command must not carry --torch-backend, got: {cmd}"
+
+    def test_uv_torch_backend_kept_for_unpinned(self):
+        """Non-pinned commands still honour UV_TORCH_BACKEND."""
+        with mock.patch.dict(os.environ, {"UV_TORCH_BACKEND": "cpu"}):
+            cmd = self._call(("somepackage",))
+        assert "--torch-backend=cpu" in cmd
+
 
 class TestUvSafePath:
     """_uv_safe_path hands uv a space-free `-c`/`-r` path (issue #6503)."""
@@ -148,3 +166,119 @@ class TestUvSafePathHardening:
 
         assert " " not in value
         assert Path(value).read_text() == "transformers>=4.57.6\n"
+
+
+class TestPinnedIndexClearsUvEnv:
+    """A pinned torch install (--index-url / --default-index) must neutralise an
+    inherited UV_INDEX / UV_EXTRA_INDEX_URL so the pinned wheel index wins.
+
+    uv treats the default index (--index-url / --default-index) as LOWEST priority,
+    so an inherited UV_INDEX / UV_EXTRA_INDEX_URL (a corporate/CPU mirror) would be
+    searched first and, under uv's default first-index strategy, resolve torch from
+    the wrong mirror -- after which the marker records a wheel index that was never
+    used. install.sh (#6898), install.ps1 and setup.ps1 already clear these for
+    pinned installs; install_python_stack must match (parity across all installers).
+    """
+
+    UV_VARS = ("UV_DEFAULT_INDEX", "UV_INDEX_URL", "UV_INDEX", "UV_EXTRA_INDEX_URL")
+
+    def test_pinned_index_url_strips_uv_index_vars(self):
+        cmd = [
+            "uv",
+            "pip",
+            "install",
+            "--force-reinstall",
+            "torch",
+            "torchvision",
+            "torchaudio",
+            "--index-url",
+            "https://download.pytorch.org/whl/cu128",
+        ]
+        with mock.patch.dict(
+            os.environ,
+            {
+                "UV_INDEX": "https://mirror.corp/simple",
+                "UV_EXTRA_INDEX_URL": "https://mirror.corp/extra",
+                "UV_INDEX_URL": "https://mirror.corp/root",
+                "UV_DEFAULT_INDEX": "https://mirror.corp/default",
+            },
+        ):
+            env = ips._install_env_for_cmd(cmd)
+        assert env is not None, "a --index-url install must run with a scrubbed env"
+        for var in self.UV_VARS:
+            assert var not in env, f"{var} must be cleared for a pinned-index install"
+
+    def test_pinned_default_index_strips_uv_index_vars(self):
+        # --default-index must be gated too (matches install.sh / install.ps1).
+        cmd = ["uv", "pip", "install", "torch", "--default-index", "https://x/cu126"]
+        with mock.patch.dict(os.environ, {"UV_INDEX": "https://mirror.corp/simple"}):
+            env = ips._install_env_for_cmd(cmd)
+        assert env is not None
+        assert "UV_INDEX" not in env
+
+    def test_non_pinned_install_keeps_user_mirror(self):
+        # A plain install (no --index-url) must NOT scrub the env, so a user's mirror
+        # still applies to base packages.
+        cmd = ["uv", "pip", "install", "unsloth", "unsloth-zoo"]
+        with mock.patch.dict(os.environ, {"UV_INDEX": "https://mirror.corp/simple"}):
+            env = ips._install_env_for_cmd(cmd)
+        assert env is None, "non-pinned installs must inherit the caller env unchanged"
+
+    def test_scrubbed_env_preserves_other_vars(self):
+        cmd = ["uv", "pip", "install", "torch", "--index-url", "https://x/cu128"]
+        with mock.patch.dict(
+            os.environ,
+            {"UV_INDEX": "https://mirror.corp/simple", "PATH_SENTINEL_XYZ": "keepme"},
+        ):
+            env = ips._install_env_for_cmd(cmd)
+        assert env is not None
+        assert env.get("PATH_SENTINEL_XYZ") == "keepme", "only uv index vars are removed"
+
+    def test_pinned_cmd_strips_pip_extra_index_url(self):
+        """PIP_EXTRA_INDEX_URL is stripped for pinned commands so the pip
+        fallback cannot satisfy torch from an inherited extra index."""
+        with mock.patch.dict(os.environ, {"PIP_EXTRA_INDEX_URL": "https://mirror/simple"}):
+            env = ips._install_env_for_cmd(
+                ["pip", "install", "torch", "--index-url", "https://x/cu128"]
+            )
+        assert env is not None and "PIP_EXTRA_INDEX_URL" not in env
+
+    def test_pinned_cmd_strips_uv_torch_backend(self):
+        """UV_TORCH_BACKEND is stripped for pinned commands so uv cannot read it
+        from the environment and reroute torch off the pinned index."""
+        with mock.patch.dict(os.environ, {"UV_TORCH_BACKEND": "cpu"}):
+            env = ips._install_env_for_cmd(
+                ["uv", "pip", "install", "torch", "--index-url", "https://x/cu128"]
+            )
+        assert env is not None and "UV_TORCH_BACKEND" not in env
+
+    def test_pinned_cmd_disables_uv_config_discovery(self):
+        """A DISCOVERED uv.toml / pyproject [tool.uv] outranks the CLI pin too
+        (verified with uv 0.10: [pip] torch-backend = "cpu" and a non-default
+        [[index]] both resolve torch+cpu against an explicit --index-url /
+        --default-index cu126 pin). Pinned commands must run with UV_NO_CONFIG=1
+        and without an inherited UV_CONFIG_FILE."""
+        with mock.patch.dict(os.environ, {"UV_CONFIG_FILE": "/etc/uv/uv.toml"}):
+            env = ips._install_env_for_cmd(
+                ["uv", "pip", "install", "torch", "--index-url", "https://x/cu128"]
+            )
+        assert env is not None
+        assert env.get("UV_NO_CONFIG") == "1"
+        assert "UV_CONFIG_FILE" not in env
+
+    def test_pinned_cmd_disables_pip_config_files(self):
+        """The pip FALLBACK honours user/site pip config files (pip config set
+        global.extra-index-url) even with the PIP_* env vars stripped; pip loads
+        NO configuration files when PIP_CONFIG_FILE is os.devnull. Harmless for
+        uv, decisive for the fallback."""
+        env = ips._install_env_for_cmd(
+            ["uv", "pip", "install", "torch", "--index-url", "https://x/cu128"]
+        )
+        assert env is not None
+        assert env.get("PIP_CONFIG_FILE") == os.devnull
+
+    def test_non_pinned_cmd_keeps_uv_config_discovery(self):
+        """Non-pinned installs inherit the caller env unchanged, so a user's uv
+        configuration still applies to base packages."""
+        env = ips._install_env_for_cmd(["uv", "pip", "install", "unsloth"])
+        assert env is None
diff --git a/tests/python/test_studio_import_no_torch.py b/tests/python/test_studio_import_no_torch.py
index c4efbc8cea..f551519de9 100644
--- a/tests/python/test_studio_import_no_torch.py
+++ b/tests/python/test_studio_import_no_torch.py
@@ -1,4 +1,4 @@
-"""Sandbox tests: Studio dataset modules load/run in isolated no-torch venvs."""
+"""Sandbox tests: Unsloth dataset modules load/run in isolated no-torch venvs."""
 
 from __future__ import annotations
 
diff --git a/tests/python/test_tokenizers_and_torch_constraint.py b/tests/python/test_tokenizers_and_torch_constraint.py
index 4322f0c7d6..c58808689b 100644
--- a/tests/python/test_tokenizers_and_torch_constraint.py
+++ b/tests/python/test_tokenizers_and_torch_constraint.py
@@ -69,6 +69,21 @@ class TestStructuralTorchConstraint:
     def test_tightened_assignment_exists(self):
         assert 'TORCH_CONSTRAINT="torch>=2.6,<2.11.0"' in self._sh
 
+    def test_cuda_constraint_widened_to_2_12(self):
+        """A fresh CUDA install widens the ceiling to <2.12.0 so cu12x/cu13x
+        land torch 2.11.x (matches the base image and _CUDA_TORCH_PKG_SPEC);
+        without it cu128/cu130 resolves torch 2.10.x."""
+        assert 'TORCH_CONSTRAINT="torch>=2.4,<2.12.0"' in self._sh
+
+    def test_cuda_case_widens_via_index_leaf(self):
+        """The cu* branch of the _torch_index_leaf case sets the widened
+        constraint (parallel to rocm7.2), anchored on the leaf."""
+        m = re.search(
+            r'cu\[0-9\]\*\)\s*TORCH_CONSTRAINT="torch>=2\.4,<2\.12\.0"',
+            self._sh,
+        )
+        assert m is not None, "CUDA (cu*) TORCH_CONSTRAINT widening case not found"
+
     def test_variable_used_in_pip_install(self):
         """$TORCH_CONSTRAINT must appear in a uv pip install line."""
         assert '"$TORCH_CONSTRAINT"' in self._sh
@@ -384,6 +399,71 @@ class TestTorchConstraintShell:
         logged = log_file.read_text()
         assert "torch>=2.4,<2.11.0" in logged, f"uv log: {logged}"
 
+    # Mirrors the _torch_index_leaf case in install.sh: rocm7.2 -> 2.11.x floor,
+    # CUDA -> widened <2.12.0 ceiling, else (CPU/older ROCm) -> default. Anchored
+    # on the final path segment, so a mirror base path containing cu*/rocm7.2 but
+    # ending in a cpu/older-rocm leaf keeps the default.
+    _INDEX_SNIPPET = textwrap.dedent(r"""
+        #!/bin/bash
+        set -e
+        TORCH_INDEX_URL="{index_url}"
+        TORCH_CONSTRAINT="torch>=2.4,<2.11.0"
+        _torch_index_leaf="${TORCH_INDEX_URL%/}"
+        _torch_index_leaf="${_torch_index_leaf##*/}"
+        case "$_torch_index_leaf" in
+            rocm7.2)  TORCH_CONSTRAINT="torch>=2.11.0,<2.12.0" ;;
+            cu[0-9]*) TORCH_CONSTRAINT="torch>=2.4,<2.12.0" ;;
+        esac
+        echo "$TORCH_CONSTRAINT"
+    """).strip()
+
+    def _resolve_index(self, tmp_path: pathlib.Path, index_url: str) -> str:
+        script_file = tmp_path / "index_snippet.sh"
+        script_file.write_text(self._INDEX_SNIPPET.replace("{index_url}", index_url))
+        script_file.chmod(0o755)
+        result = subprocess.run(
+            ["bash", str(script_file)],
+            capture_output = True,
+            text = True,
+            timeout = 10,
+        )
+        assert result.returncode == 0, f"Script failed: {result.stderr}"
+        return result.stdout.strip()
+
+    @pytest.mark.parametrize("leaf", ["cu118", "cu124", "cu126", "cu128", "cu130"])
+    def test_cuda_index_widens_to_2_12(self, tmp_path, leaf):
+        url = f"https://download.pytorch.org/whl/{leaf}"
+        assert self._resolve_index(tmp_path, url) == "torch>=2.4,<2.12.0"
+
+    def test_rocm72_index_uses_211_floor(self, tmp_path):
+        url = "https://download.pytorch.org/whl/rocm7.2"
+        assert self._resolve_index(tmp_path, url) == "torch>=2.11.0,<2.12.0"
+
+    def test_cpu_index_keeps_default(self, tmp_path):
+        # /cpu must NOT match the */cu[0-9]* branch.
+        url = "https://download.pytorch.org/whl/cpu"
+        assert self._resolve_index(tmp_path, url) == "torch>=2.4,<2.11.0"
+
+    def test_older_rocm_index_keeps_default(self, tmp_path):
+        url = "https://download.pytorch.org/whl/rocm7.1"
+        assert self._resolve_index(tmp_path, url) == "torch>=2.4,<2.11.0"
+
+    def test_cuda_index_custom_mirror_widens(self, tmp_path):
+        url = "https://internal.example.com/pytorch/cu128"
+        assert self._resolve_index(tmp_path, url) == "torch>=2.4,<2.12.0"
+
+    @pytest.mark.parametrize(
+        "url",
+        [
+            "https://internal.example.com/pytorch/cu128/cpu",
+            "https://internal.example.com/cu128/whl/rocm7.1",
+        ],
+    )
+    def test_cuda_in_mirror_path_but_noncuda_leaf_keeps_default(self, tmp_path, url):
+        # A cu128 in the mirror base path must not widen when the leaf is cpu /
+        # older ROCm: the case anchors on _torch_index_leaf, not the whole URL.
+        assert self._resolve_index(tmp_path, url) == "torch>=2.4,<2.11.0"
+
 
 # Group 3 -- E2E tokenizers fix (requires network, ~2-5 min)
 @pytest.mark.e2e
diff --git a/tests/python/test_torchcodec_torch_compat.py b/tests/python/test_torchcodec_torch_compat.py
new file mode 100644
index 0000000000..6ad16a73f4
--- /dev/null
+++ b/tests/python/test_torchcodec_torch_compat.py
@@ -0,0 +1,129 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
+
+"""torch / torchcodec ABI guardrails (unslothai/unsloth#7225)."""
+
+from __future__ import annotations
+
+import importlib.util
+import re
+import sys
+import types
+from pathlib import Path
+
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+PYPROJECT = REPO_ROOT / "pyproject.toml"
+IMPORT_FIXES_PATH = REPO_ROOT / "unsloth" / "import_fixes.py"
+
+
+def _load_import_fixes_module():
+    spec = importlib.util.spec_from_file_location(
+        "unsloth_import_fixes_under_test",
+        IMPORT_FIXES_PATH,
+    )
+    assert spec and spec.loader
+    mod = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(mod)
+    return mod
+
+
+def test_pyproject_declares_torch210_audio_extra_with_python_gate():
+    text = PYPROJECT.read_text(encoding = "utf-8")
+    assert "audio-torch210 = [" in text
+    assert "torchcodec>=0.10.0,<0.11.0" in text
+    assert "python_version >= '3.10'" in text
+    assert "audio-torch290 = [" in text
+    assert "audio-torch280 = [" in text
+    assert "\naudio = [" not in text
+
+
+def _stub_torch(monkeypatch, version: str):
+    torch_mod = types.ModuleType("torch")
+    torch_mod.__version__ = version
+    monkeypatch.setitem(sys.modules, "torch", torch_mod)
+
+
+def test_torch210_extras_bundle_audio_torch210():
+    text = PYPROJECT.read_text(encoding = "utf-8")
+    for extra in (
+        "cu128-torch2100",
+        "cu126-ampere-torch2100",
+        "rocm72-torch2100",
+    ):
+        match = re.search(rf"^{extra} = \[(.*?)^\]", text, re.MULTILINE | re.DOTALL)
+        assert match is not None, extra
+        assert "unsloth[audio-torch210]" in match.group(1)
+
+
+def test_torchcodec_matrix_matches_notebook_validator():
+    from scripts import notebook_validator as nv
+    fixes = _load_import_fixes_module()
+    assert fixes._TORCH_TORCHCODEC_MINORS == nv.TORCH_TORCHCODEC
+
+
+def test_torchcodec_exclusive_upper_bound():
+    fixes = _load_import_fixes_module()
+    assert fixes._torchcodec_exclusive_upper("0.10") == "<0.11.0"
+    assert fixes._torchcodec_exclusive_upper("0.9") == "<0.10.0"
+
+
+def test_torch290_rejects_torchcodec_07(monkeypatch):
+    import importlib.metadata
+
+    fixes = _load_import_fixes_module()
+    _stub_torch(monkeypatch, "2.9.0+cu128")
+    monkeypatch.setattr(importlib.metadata, "version", lambda _name: "0.7.0")
+
+    hint = fixes._torchcodec_version_mismatch_hint()
+    assert hint is not None
+    assert "audio-torch210" not in hint
+
+
+def test_torch280_accepts_torchcodec_07(monkeypatch):
+    import importlib.metadata
+
+    fixes = _load_import_fixes_module()
+    _stub_torch(monkeypatch, "2.8.0+cu128")
+    monkeypatch.setattr(importlib.metadata, "version", lambda _name: "0.7.0")
+
+    assert fixes._torchcodec_version_mismatch_hint() is None
+
+
+def test_torch210_rejects_torchcodec_011(monkeypatch):
+    import importlib.metadata
+
+    fixes = _load_import_fixes_module()
+    _stub_torch(monkeypatch, "2.10.0+cu128")
+    monkeypatch.setattr(
+        importlib.metadata,
+        "version",
+        lambda _name: "0.11.0",
+    )
+
+    hint = fixes._torchcodec_version_mismatch_hint()
+    assert hint is not None
+    assert "torchcodec 0.11.0" in hint
+    assert "audio-torch210" in hint
+    assert "<0.11.0" in hint
+    assert "<11.0" not in hint
+
+
+def test_torch210_accepts_torchcodec_010(monkeypatch):
+    import importlib.metadata
+
+    fixes = _load_import_fixes_module()
+    _stub_torch(monkeypatch, "2.10.0+cu128")
+    monkeypatch.setattr(
+        importlib.metadata,
+        "version",
+        lambda _name: "0.10.0+cu128",
+    )
+
+    assert fixes._torchcodec_version_mismatch_hint() is None
+
+
+def test_import_fixes_loads_on_python39_syntax():
+    """Regression: module must import on 3.9 (postponed annotations for str | None)."""
+    fixes = _load_import_fixes_module()
+    assert callable(fixes._torchcodec_version_mismatch_hint)
diff --git a/tests/run_all.sh b/tests/run_all.sh
index d03f4c4d4f..6eccffc75f 100755
--- a/tests/run_all.sh
+++ b/tests/run_all.sh
@@ -12,10 +12,13 @@ sh "$TESTS_DIR/sh/test_mac_intel_compat.sh"
 sh "$TESTS_DIR/sh/test_torch_constraint.sh"
 sh "$TESTS_DIR/sh/test_nvcc_meets_llama_minimum.sh"
 sh "$TESTS_DIR/sh/test_resolve_cuda_archs.sh"
+sh "$TESTS_DIR/sh/test_staged_validation_enabled.sh"
 sh "$TESTS_DIR/sh/test_strixhalo_wsl_reroute.sh"
 sh "$TESTS_DIR/sh/test_uninstall_shared_icon.sh"
 sh "$TESTS_DIR/sh/test_torch_flavor.sh"
+sh "$TESTS_DIR/sh/test_redact_install_output.sh"
 sh "$TESTS_DIR/sh/test_install_uv_override_space.sh"
+sh "$TESTS_DIR/sh/test_install_rollback_lifecycle.sh"
 
 echo ""
 echo "=== Python tests ==="
diff --git a/tests/saving/test_fix_sentencepiece_tokenizer_guard.py b/tests/saving/test_fix_sentencepiece_tokenizer_guard.py
new file mode 100644
index 0000000000..1ee523d57b
--- /dev/null
+++ b/tests/saving/test_fix_sentencepiece_tokenizer_guard.py
@@ -0,0 +1,307 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+import gc
+import os
+
+os.environ.setdefault("PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION", "python")
+
+import transformers
+from transformers.utils import sentencepiece_model_pb2
+
+from unsloth.tokenizer_utils import fix_sentencepiece_tokenizer
+
+
+NORMAL, CONTROL = 1, 3
+
+
+def _spm_bytes(pieces):
+    m = sentencepiece_model_pb2.ModelProto()
+    for piece, score, typ in pieces:
+        p = m.pieces.add()
+        p.piece = piece
+        p.score = score
+        p.type = typ
+    return m.SerializeToString()
+
+
+def _read_pieces(path):
+    m = sentencepiece_model_pb2.ModelProto()
+    with open(path, "rb") as f:
+        m.ParseFromString(f.read())
+    return [p.piece for p in m.pieces]
+
+
+class _FakeTokenizer:
+    """Minimal stand-in for a sentencepiece-backed slow tokenizer.
+
+    ``save_pretrained`` writes a tokenizer.model, which is what the real slow
+    tokenizers do and what fix_sentencepiece_tokenizer reads back.
+    """
+
+    def __init__(
+        self,
+        name,
+        spm_bytes = None,
+        vocab = None,
+    ):
+        self.name = name
+        self.eos_token = "</s>"
+        self.pad_token = "<pad>"
+        self._spm_bytes = spm_bytes
+        self._vocab = vocab or {}
+        self.saved_to = []
+
+    def save_pretrained(self, location):
+        self.saved_to.append(location)
+        os.makedirs(location, exist_ok = True)
+        if self._spm_bytes is not None:
+            with open(os.path.join(location, "tokenizer.model"), "wb") as f:
+                f.write(self._spm_bytes)
+
+    def __call__(
+        self,
+        texts,
+        add_special_tokens = False,
+    ):
+        class _Encoded:
+            pass
+
+        encoded = _Encoded()
+        encoded.input_ids = [[self._vocab[text]] for text in texts]
+        return encoded
+
+
+def _tokenizers():
+    pieces = [("<s>", 0.0, CONTROL), ("a", -1.0, NORMAL), ("</s>", 0.0, CONTROL)]
+    old = _FakeTokenizer("old", spm_bytes = _spm_bytes(pieces), vocab = {"</s>": 2})
+    new = _FakeTokenizer("new")
+    return old, new
+
+
+class _ReloadedTokenizer:
+    """Weakref-able stand-in for the tokenizer AutoTokenizer.from_pretrained returns."""
+
+    def __init__(self, location):
+        self.location = location
+
+
+def _stub_auto_tokenizer(monkeypatch):
+    """fix_sentencepiece_tokenizer reloads the patched directory through
+    AutoTokenizer at the end; that needs a full tokenizer on disk, which is
+    out of scope here. Record the reload location and hand back a sentinel.
+    """
+    loaded = []
+
+    class _StubAutoTokenizer:
+        @staticmethod
+        def from_pretrained(location, **kwargs):
+            loaded.append(location)
+            return _ReloadedTokenizer(location)
+
+    monkeypatch.setattr(transformers, "AutoTokenizer", _StubAutoTokenizer)
+    return loaded
+
+
+def test_old_tokenizer_is_saved_so_its_model_can_be_read(tmp_path, monkeypatch):
+    """The guard must not skip the body on a fresh temporary directory.
+
+    fix_sentencepiece_tokenizer creates its scratch directory itself and then
+    checks for a tokenizer.model inside it, but that file only appears once
+    old_tokenizer.save_pretrained() has run.
+    """
+    _stub_auto_tokenizer(monkeypatch)
+    old, new = _tokenizers()
+    location = str(tmp_path / "_unsloth_sentencepiece_temp")
+
+    fix_sentencepiece_tokenizer(old, new, {"</s>": "<|im_end|>"}, temporary_location = location)
+
+    assert old.saved_to, "old tokenizer was never saved: the body did not run"
+
+
+def test_token_mapping_is_applied_to_the_sentencepiece_model(tmp_path, monkeypatch):
+    loaded = _stub_auto_tokenizer(monkeypatch)
+    old, new = _tokenizers()
+    location = str(tmp_path / "_unsloth_sentencepiece_temp")
+
+    # Hold the returned tokenizer so its scratch dir survives until we read it.
+    tok = fix_sentencepiece_tokenizer(old, new, {"</s>": "<|im_end|>"}, temporary_location = location)
+
+    assert "<|im_end|>" in _read_pieces(f"{loaded[-1]}/tokenizer.model")
+    assert tok is not None
+
+
+def test_tokenizer_without_a_sentencepiece_model_is_returned_untouched(tmp_path, monkeypatch):
+    """A fast-only tokenizer writes no tokenizer.model, so the guard still
+    short-circuits and the caller gets new_tokenizer back unchanged. Its scratch
+    dir is unreferenced and reclaimed immediately.
+    """
+    _stub_auto_tokenizer(monkeypatch)
+    old = _FakeTokenizer("old", spm_bytes = None)
+    new = _FakeTokenizer("new")
+    location = str(tmp_path / "_unsloth_sentencepiece_temp")
+
+    result = fix_sentencepiece_tokenizer(
+        old, new, {"</s>": "<|im_end|>"}, temporary_location = location
+    )
+
+    assert result is new
+    assert not any(
+        name.startswith("tokenizer_") for name in os.listdir(location)
+    ), "the fast-only scratch dir was not reclaimed"
+
+
+def test_each_call_uses_a_fresh_isolated_subdirectory(tmp_path, monkeypatch):
+    """Each call must work in its own unique subdirectory, so concurrent or
+    repeated calls never share scratch files, stale artifacts never leak into
+    the reload, and nothing the caller left in the scratch location is deleted.
+    """
+    loaded = _stub_auto_tokenizer(monkeypatch)
+    location = str(tmp_path / "_unsloth_sentencepiece_temp")
+    os.makedirs(location, exist_ok = True)
+
+    # A pre-existing artifact in the shared scratch location.
+    marker = os.path.join(location, "leftover.json")
+    with open(marker, "w") as f:
+        f.write("{}")
+
+    old1, new1 = _tokenizers()
+    old2, new2 = _tokenizers()
+    # Hold both returned tokenizers so their scratch dirs stay alive.
+    tok1 = fix_sentencepiece_tokenizer(
+        old1, new1, {"</s>": "<|im_end|>"}, temporary_location = location
+    )
+    tok2 = fix_sentencepiece_tokenizer(
+        old2, new2, {"</s>": "<|im_end|>"}, temporary_location = location
+    )
+
+    work1, work2 = loaded[0], loaded[1]
+    assert work1 != work2, "two calls reused the same directory"
+    assert os.path.dirname(work1) == location and os.path.dirname(work2) == location
+    assert os.path.isdir(work1) and os.path.isdir(work2)
+    # Nothing the caller left behind is deleted, and it never leaks into a work dir.
+    assert os.path.isfile(marker), "a pre-existing scratch file was deleted"
+    assert not os.path.isfile(os.path.join(work1, "leftover.json"))
+    assert not os.path.isfile(os.path.join(work2, "leftover.json"))
+    assert tok1 is not None and tok2 is not None
+
+
+def test_sentencepiece_scratch_dir_is_reclaimed_once_the_tokenizer_is_gone(tmp_path, monkeypatch):
+    """The scratch dir must live as long as the returned tokenizer (its vocab_file
+    points there), then be reclaimed when the tokenizer is garbage collected.
+    """
+    loaded = _stub_auto_tokenizer(monkeypatch)
+    old, new = _tokenizers()
+    location = str(tmp_path / "_unsloth_sentencepiece_temp")
+
+    tok = fix_sentencepiece_tokenizer(old, new, {"</s>": "<|im_end|>"}, temporary_location = location)
+    work = loaded[-1]
+    assert os.path.isdir(work), "scratch dir vanished while the tokenizer was alive"
+
+    del tok
+    gc.collect()
+    assert not os.path.isdir(work), "scratch dir was not reclaimed after the tokenizer was freed"
+
+
+class _CopyFromSubdirTokenizer:
+    """A slow tokenizer whose sentencepiece source lives elsewhere (like the
+    tokenizers convert_to_fast_tokenizer produces under {location}/{name}).
+    save_pretrained copies that source into the destination, as HF slow
+    tokenizers copy their vocab_file.
+    """
+
+    def __init__(self, source_model_path):
+        self.eos_token = "</s>"
+        self.pad_token = "<pad>"
+        self._source_model_path = source_model_path
+
+    def save_pretrained(self, location):
+        os.makedirs(location, exist_ok = True)
+        if os.path.isfile(self._source_model_path):
+            with open(self._source_model_path, "rb") as src:
+                data = src.read()
+            with open(os.path.join(location, "tokenizer.model"), "wb") as dst:
+                dst.write(data)
+
+    def __call__(
+        self,
+        texts,
+        add_special_tokens = False,
+    ):
+        class _Encoded:
+            pass
+
+        encoded = _Encoded()
+        encoded.input_ids = [[2] for _ in texts]
+        return encoded
+
+
+def test_source_vocab_outside_the_work_directory_is_not_disturbed(tmp_path, monkeypatch):
+    """A tokenizer whose sentencepiece source lives elsewhere (e.g. the subtree
+    convert_to_fast_tokenizer created) is copied into the fresh work directory
+    and patched there; the original source is left untouched.
+    """
+    loaded = _stub_auto_tokenizer(monkeypatch)
+    location = str(tmp_path / "_unsloth_sentencepiece_temp")
+    subdir = os.path.join(location, "some_model")
+    os.makedirs(subdir, exist_ok = True)
+
+    pieces = [("<s>", 0.0, CONTROL), ("a", -1.0, NORMAL), ("</s>", 0.0, CONTROL)]
+    source_model = os.path.join(subdir, "tokenizer.model")
+    with open(source_model, "wb") as f:
+        f.write(_spm_bytes(pieces))
+
+    old = _CopyFromSubdirTokenizer(source_model)
+    new = _FakeTokenizer("new")
+    tok = fix_sentencepiece_tokenizer(old, new, {"</s>": "<|im_end|>"}, temporary_location = location)
+
+    assert _read_pieces(source_model) == [
+        "<s>",
+        "a",
+        "</s>",
+    ], "the original source vocab was modified"
+    assert "<|im_end|>" in _read_pieces(f"{loaded[-1]}/tokenizer.model")
+    assert tok is not None
+
+
+def test_swap_mapping_swaps_both_pieces_without_duplicating(tmp_path, monkeypatch):
+    """When the caller swaps eos and stop_word in the fast JSON it must pass both
+    directions here; a one-way mapping would leave two stop_word pieces and no eos.
+    """
+    loaded = _stub_auto_tokenizer(monkeypatch)
+    location = str(tmp_path / "_unsloth_sentencepiece_temp")
+
+    pieces = [("<s>", 0.0, CONTROL), ("<|im_end|>", -1.0, NORMAL), ("</s>", 0.0, CONTROL)]
+    old = _FakeTokenizer("old", spm_bytes = _spm_bytes(pieces), vocab = {"</s>": 2, "<|im_end|>": 1})
+    new = _FakeTokenizer("new")
+
+    tok = fix_sentencepiece_tokenizer(
+        old, new, {"</s>": "<|im_end|>", "<|im_end|>": "</s>"}, temporary_location = location
+    )
+
+    result = _read_pieces(f"{loaded[-1]}/tokenizer.model")
+    assert result.count("<|im_end|>") == 1 and result.count("</s>") == 1, result
+    assert tok is not None
+
+
+def test_only_applied_mappings_are_patched(tmp_path, monkeypatch):
+    """When the caller skips a mapping whose target already exists, it must not
+    pass that mapping here, or the skipped source token gets renamed anyway and
+    duplicates the existing target in the model.
+    """
+    loaded = _stub_auto_tokenizer(monkeypatch)
+    location = str(tmp_path / "_unsloth_sentencepiece_temp")
+
+    pieces = [
+        ("<s>", 0.0, CONTROL),
+        ("aa", -1.0, NORMAL),
+        ("bb", -1.0, NORMAL),
+        ("X", -1.0, NORMAL),
+    ]
+    old = _FakeTokenizer("old", spm_bytes = _spm_bytes(pieces), vocab = {"aa": 1, "bb": 2})
+    new = _FakeTokenizer("new")
+
+    # Caller skipped aa->X (X already exists) and applied bb->Y, so only bb->Y is passed.
+    tok = fix_sentencepiece_tokenizer(old, new, {"bb": "Y"}, temporary_location = location)
+
+    result = _read_pieces(f"{loaded[-1]}/tokenizer.model")
+    assert result.count("X") == 1 and "Y" in result and "aa" in result, result
+    assert tok is not None
diff --git a/tests/saving/test_prewarm_base_model_hub_cache.py b/tests/saving/test_prewarm_base_model_hub_cache.py
index cbb52863ba..4269f9d61c 100644
--- a/tests/saving/test_prewarm_base_model_hub_cache.py
+++ b/tests/saving/test_prewarm_base_model_hub_cache.py
@@ -4,7 +4,7 @@
 """Regression tests for #6890: repeated base-model downloads across checkpoint exports.
 
 merge_and_overwrite_lora downloads missing 16-bit shards with hf_hub_download(local_dir),
-which never populates the persistent HF hub cache; a temporary merge directory (Studio
+which never populates the persistent HF hub cache; a temporary merge directory (Unsloth
 GGUF exports delete it) means every checkpoint export re-downloads the full base model.
 _prewarm_base_model_hub_cache snapshot-downloads the base into the hub cache first so
 the zoo's cache-copy fast path is hit on later exports.
diff --git a/tests/sh/test_apt_distro_prompt.sh b/tests/sh/test_apt_distro_prompt.sh
new file mode 100755
index 0000000000..19601b0065
--- /dev/null
+++ b/tests/sh/test_apt_distro_prompt.sh
@@ -0,0 +1,94 @@
+#!/bin/bash
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+# Unit tests for install.sh's _apt_distro_description helper (#6207).
+# The sudo Accept? prompt should name the detected distro and say packages come
+# from official apt repos. Hermetic: extract the helper and rewrite
+# /etc/os-release to per-test fixtures (same pattern as test_strixhalo_wsl_reroute.sh).
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+INSTALL_SH="$SCRIPT_DIR/../../install.sh"
+PASS=0
+FAIL=0
+
+_TMP_ROOT=$(mktemp -d)
+trap 'rm -rf "$_TMP_ROOT"' EXIT
+
+assert_eq() {
+    _label="$1"; _expected="$2"; _actual="$3"
+    if [ "$_actual" = "$_expected" ]; then
+        echo "  PASS: $_label"; PASS=$((PASS + 1))
+    else
+        echo "  FAIL: $_label (expected '$_expected', got '$_actual')"; FAIL=$((FAIL + 1))
+    fi
+}
+
+assert_contains() {
+    _label="$1"; _hay="$2"; _needle="$3"
+    case "$_hay" in
+        *"$_needle"*) echo "  PASS: $_label"; PASS=$((PASS + 1)) ;;
+        *) echo "  FAIL: $_label (missing '$_needle' in: $_hay)"; FAIL=$((FAIL + 1)) ;;
+    esac
+}
+
+# Extract helper with /etc/os-release rewritten to $1.
+build_func() {
+    _fix="$1"
+    _f=$(mktemp -p "$_TMP_ROOT")
+    sed -n '/^_apt_distro_description()/,/^}/p' "$INSTALL_SH" \
+        | sed -e "s#/etc/os-release#$_fix/os-release#g" \
+        > "$_f"
+    echo "$_f"
+}
+
+run_desc() {
+    _os="$1"
+    _d=$(mktemp -d -p "$_TMP_ROOT")
+    printf '%s\n' "$_os" > "$_d/os-release"
+    _f=$(build_func "$_d")
+    # shellcheck disable=SC1090
+    . "$_f"
+    _apt_distro_description
+}
+
+echo "=== _apt_distro_description ==="
+
+assert_eq "ubuntu name+version debian-like" \
+    "Ubuntu 24.04 (debian-like)" \
+    "$(run_desc "$(printf 'NAME=\"Ubuntu\"\nVERSION_ID=\"24.04\"\nID=ubuntu\nID_LIKE=debian\n')")"
+
+assert_eq "debian name+version debian-like" \
+    "Debian GNU/Linux 12 (debian-like)" \
+    "$(run_desc "$(printf 'NAME=\"Debian GNU/Linux\"\nVERSION_ID=\"12\"\nID=debian\n')")"
+
+assert_eq "pretty_name fallback when name/version missing" \
+    "Linux Mint 22 (debian-like)" \
+    "$(run_desc "$(printf 'PRETTY_NAME=\"Linux Mint 22\"\nID=linuxmint\nID_LIKE=\"ubuntu debian\"\n')")"
+
+# NAME alone (no VERSION_ID) — still prefer NAME over PRETTY_NAME.
+assert_eq "name only" \
+    "Pop!_OS (debian-like)" \
+    "$(run_desc "$(printf 'NAME=\"Pop!_OS\"\nID=pop\nID_LIKE=\"ubuntu debian\"\n')")"
+
+assert_eq "missing os-release file" \
+    "a debian-like system" \
+    "$(
+        _d=$(mktemp -d -p "$_TMP_ROOT")
+        _f=$(build_func "$_d")
+        # shellcheck disable=SC1090
+        . "$_f"
+        _apt_distro_description
+    )"
+
+echo "=== _smart_apt_install prompt contract ==="
+_smart=$(sed -n '/^_smart_apt_install()/,/^}/p' "$INSTALL_SH")
+assert_contains "calls distro helper" "$_smart" '_apt_distro_description'
+assert_contains "names detected distro" "$_smart" 'Detected ${_ad_desc}'
+assert_contains "mentions apt-get" "$_smart" 'sudo apt-get'
+assert_contains "mentions official repos" "$_smart" "official repositories"
+assert_contains "rejects tarball worry" "$_smart" "not a third-party tarball"
+
+echo ""
+echo "Results: $PASS passed, $FAIL failed"
+[ "$FAIL" -eq 0 ]
diff --git a/tests/sh/test_get_torch_index_url.sh b/tests/sh/test_get_torch_index_url.sh
index 6656142625..633d8ca17b 100755
--- a/tests/sh/test_get_torch_index_url.sh
+++ b/tests/sh/test_get_torch_index_url.sh
@@ -14,6 +14,13 @@ FAIL=0
 # controllable path so we can test the "no GPU" scenario on GPU machines.
 _FUNC_FILE=$(mktemp)
 _FAKE_SMI_DIR=$(mktemp -d)
+# The ROCm probe helpers read the real /opt/rocm prefix by ABSOLUTE path
+# (_ensure_rocm_probe_env appends /opt/rocm/bin to PATH and runs the host
+# rocminfo; version detection reads /opt/rocm/.info/version). On a real ROCm
+# host that leaks the host GPU into the minimal-PATH harness and makes the
+# no-GPU / CPU assertions host-dependent. Redirect the whole prefix to an empty
+# temp dir so the probes stay hermetic (same idea as the nvidia-smi rewrite).
+_FAKE_ROCM_DIR=$(mktemp -d)
 {
     sed -n '/^_run_bounded()/,/^}/p' "$INSTALL_SH"
     echo ""
@@ -23,8 +30,28 @@ _FAKE_SMI_DIR=$(mktemp -d)
     echo ""
     sed -n '/^_has_usable_nvidia_gpu()/,/^}/p' "$INSTALL_SH"
     echo ""
+    # ROCm gfx-arch probe helpers that get_torch_index_url / _has_amd_rocm_gpu
+    # now call. These MUST stay in sync with install.sh: if get_torch_index_url
+    # references a helper that is not extracted here, the ROCm branch hits an
+    # undefined function, silently falls through to the CPU wheel index, and the
+    # ROCm assertions below fail.
+    sed -n '/^_ensure_rocm_probe_env()/,/^}/p' "$INSTALL_SH"
+    echo ""
+    sed -n '/^_probe_amd_gfx_arch()/,/^}/p' "$INSTALL_SH"
+    echo ""
+    sed -n '/^_amd_gpu_present_via_pci()/,/^}/p' "$INSTALL_SH"
+    echo ""
+    sed -n '/^_infer_amd_gfx_arch_from_gpu_name()/,/^}/p' "$INSTALL_SH"
+    echo ""
+    sed -n '/^_infer_linux_amd_gfx_arch()/,/^}/p' "$INSTALL_SH"
+    echo ""
+    sed -n '/^_amd_arch_index_family_for_gfx()/,/^}/p' "$INSTALL_SH"
+    echo ""
+    sed -n '/^_trim_index_path_slashes()/,/^}/p' "$INSTALL_SH"
+    echo ""
     sed -n '/^get_torch_index_url()/,/^}/p' "$INSTALL_SH"
-} | sed "s|/usr/bin/nvidia-smi|$_FAKE_SMI_DIR/nvidia-smi-absent|g" \
+} | sed -e "s|/usr/bin/nvidia-smi|$_FAKE_SMI_DIR/nvidia-smi-absent|g" \
+      -e "s|/opt/rocm|$_FAKE_ROCM_DIR|g" \
   > "$_FUNC_FILE"
 
 # Save system PATH so we always have basic tools (uname, grep, head, etc.)
@@ -379,8 +406,64 @@ _result=$(run_func "$_dir" " -1 ")
 assert_eq "CVD=' -1 ' hides NVIDIA -> cpu" "https://download.pytorch.org/whl/cpu" "$_result"
 rm -rf "$_dir"
 
+# --- explicit overrides (headless / container / CI; no GPU probing) ----------
+# 39) UNSLOTH_TORCH_INDEX_FAMILY pins the family with no GPU present (not the cpu fallback).
+_result=$(UNSLOTH_TORCH_INDEX_FAMILY="cu128" run_func "none")
+assert_eq "family override (no GPU) -> cu128" "https://download.pytorch.org/whl/cu128" "$_result"
+
+# 40) Family override beats real detection: an nvidia-smi 12.6 host still gets cu128
+#     (the Docker-build case -- builder sees the host driver but publishes a cu128 image).
+_dir=$(make_mock_smi "12.6")
+_result=$(UNSLOTH_TORCH_INDEX_FAMILY="cu128" run_func "$_dir")
+assert_eq "family override beats detected 12.6 -> cu128" "https://download.pytorch.org/whl/cu128" "$_result"
+rm -rf "$_dir"
+
+# 41) UNSLOTH_TORCH_INDEX_URL is used verbatim and wins over detection.
+_dir=$(make_mock_smi "12.6")
+_result=$(UNSLOTH_TORCH_INDEX_URL="https://mirror.example.com/whl/cu999" run_func "$_dir")
+assert_eq "url override beats detection -> verbatim" "https://mirror.example.com/whl/cu999" "$_result"
+rm -rf "$_dir"
+
+# 42) Family override is appended to UNSLOTH_PYTORCH_MIRROR (mirror still honoured).
+_result=$(UNSLOTH_PYTORCH_MIRROR="https://mirror.example.com/whl" UNSLOTH_TORCH_INDEX_FAMILY="cu128" run_func "none")
+assert_eq "mirror + family override -> mirror/cu128" "https://mirror.example.com/whl/cu128" "$_result"
+
+# 43) Trailing slash in UNSLOTH_TORCH_INDEX_URL is stripped.
+_result=$(UNSLOTH_TORCH_INDEX_URL="https://mirror.example.com/whl/cu128/" run_func "none")
+assert_eq "url override trailing slash stripped" "https://mirror.example.com/whl/cu128" "$_result"
+
+# 44) URL override takes precedence over family override.
+_result=$(UNSLOTH_TORCH_INDEX_URL="https://mirror.example.com/whl/cu130" UNSLOTH_TORCH_INDEX_FAMILY="cu128" run_func "none")
+assert_eq "url override beats family override -> url" "https://mirror.example.com/whl/cu130" "$_result"
+
+# 45) An empty override is ignored (falls through to normal detection).
+_result=$(UNSLOTH_TORCH_INDEX_FAMILY="" UNSLOTH_TORCH_INDEX_URL="" run_func "none")
+assert_eq "empty overrides ignored -> detected cpu" "https://download.pytorch.org/whl/cpu" "$_result"
+
+# 46) ALL trailing slashes are stripped from a URL override (not just one).
+_result=$(UNSLOTH_TORCH_INDEX_URL="https://mirror.example.com/whl/cu128///" run_func "none")
+assert_eq "url override double slash stripped" "https://mirror.example.com/whl/cu128" "$_result"
+
+# 47) Leading and trailing slashes stripped from a family override.
+_result=$(UNSLOTH_TORCH_INDEX_FAMILY="//cu128//" run_func "none")
+assert_eq "family override slashes stripped" "https://download.pytorch.org/whl/cu128" "$_result"
+
+# 48) A ?query token that ends in "/" is PRESERVED: only PATH slashes are trimmed, so a
+# base64 token ending in "/" is not corrupted (path-only trim, not whole-URL rstrip).
+_result=$(UNSLOTH_TORCH_INDEX_URL="https://mirror.example.com/whl/cu128?token=ab12cd/" run_func "none")
+assert_eq "url override preserves query token slash" "https://mirror.example.com/whl/cu128?token=ab12cd/" "$_result"
+
+# 49) Double PATH slash before a query is collapsed while the query survives intact.
+_result=$(UNSLOTH_TORCH_INDEX_URL="https://mirror.example.com/whl/cu128//?token=ab12cd/" run_func "none")
+assert_eq "url override path slash trimmed, query kept" "https://mirror.example.com/whl/cu128?token=ab12cd/" "$_result"
+
+# 50) A #fragment ending in "/" is likewise preserved.
+_result=$(UNSLOTH_TORCH_INDEX_URL="https://mirror.example.com/whl/cu128#anchor/" run_func "none")
+assert_eq "url override preserves fragment slash" "https://mirror.example.com/whl/cu128#anchor/" "$_result"
+
 rm -f "$_FUNC_FILE"
 rm -rf "$_FAKE_SMI_DIR"
+rm -rf "$_FAKE_ROCM_DIR"
 rm -rf "$_TOOLS_DIR"
 
 echo ""
diff --git a/tests/sh/test_install_rollback_lifecycle.sh b/tests/sh/test_install_rollback_lifecycle.sh
new file mode 100644
index 0000000000..d1ccae8e19
--- /dev/null
+++ b/tests/sh/test_install_rollback_lifecycle.sh
@@ -0,0 +1,202 @@
+#!/bin/bash
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+# Exercises install.sh's real rollback helpers without downloading the Studio stack.
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+INSTALL_SH="$SCRIPT_DIR/../../install.sh"
+INSTALL_PS1="$SCRIPT_DIR/../../install.ps1"
+PASS=0
+FAIL=0
+
+ok()  { echo "  PASS: $1"; PASS=$((PASS + 1)); }
+bad() { echo "  FAIL: $1"; FAIL=$((FAIL + 1)); }
+
+ROLLBACK_BLOCK=$(sed -n '/^_VENV_ROLLBACK_DIR=""/,/^trap '\''_on_install_signal 143'\'' TERM$/p' "$INSTALL_SH")
+if ! printf '%s\n' "$ROLLBACK_BLOCK" | grep -q '^_on_install_signal() {'; then
+    echo "  FAIL: could not extract rollback lifecycle block from install.sh"
+    exit 1
+fi
+
+WORK=$(mktemp -d)
+trap 'rm -rf "$WORK"' EXIT
+
+run_signal_case() {
+    _signal="$1"
+    _expected_status="$2"
+    _case_dir="$WORK/signal-$_signal"
+    mkdir -p "$_case_dir/unsloth_studio"
+    printf 'old\n' > "$_case_dir/unsloth_studio/generation"
+    _harness="$_case_dir/harness.sh"
+    {
+        printf '%s\n' 'set -e'
+        printf '%s\n' 'substep() { :; }'
+        printf '%s\n' 'C_WARN=""'
+        printf "STUDIO_HOME='%s'\n" "$_case_dir"
+        printf "VENV_DIR='%s/unsloth_studio'\n" "$_case_dir"
+        printf '%s\n' "$ROLLBACK_BLOCK"
+        printf '%s\n' '_start_studio_venv_replacement "$VENV_DIR"'
+        printf '%s\n' 'mkdir -p "$VENV_DIR"'
+        printf '%s\n' 'printf "partial\n" > "$VENV_DIR/generation"'
+        printf 'kill -%s $$\n' "$_signal"
+        printf '%s\n' 'exit 99'
+    } > "$_harness"
+
+    set +e
+    dash "$_harness" >/dev/null 2>&1
+    _status=$?
+    set -e
+    if [ "$_status" = "$_expected_status" ]; then
+        ok "dash $_signal exits with $_expected_status"
+    else
+        bad "dash $_signal exits with $_expected_status (got $_status)"
+    fi
+    if [ "$(cat "$_case_dir/unsloth_studio/generation" 2>/dev/null)" = "old" ]; then
+        ok "dash $_signal restores the previous environment"
+    else
+        bad "dash $_signal did not restore the previous environment"
+    fi
+    if ! find "$_case_dir" -maxdepth 1 -name 'unsloth_studio.rollback.*' -print -quit | grep -q .; then
+        ok "dash $_signal leaves no rollback copy"
+    else
+        bad "dash $_signal left a rollback copy"
+    fi
+}
+
+echo "=== install.sh signal rollback ==="
+run_signal_case INT 130
+run_signal_case TERM 143
+run_signal_case HUP 129
+
+echo "=== install.sh transition boundaries ==="
+START_BOUNDARY_DIR="$WORK/start-boundary"
+mkdir -p "$START_BOUNDARY_DIR/unsloth_studio"
+printf 'old\n' > "$START_BOUNDARY_DIR/unsloth_studio/generation"
+START_BOUNDARY_HARNESS="$START_BOUNDARY_DIR/harness.sh"
+{
+    printf '%s\n' 'set -e'
+    printf '%s\n' 'substep() { :; }'
+    printf '%s\n' 'C_WARN=""'
+    printf "STUDIO_HOME='%s'\n" "$START_BOUNDARY_DIR"
+    printf "VENV_DIR='%s/unsloth_studio'\n" "$START_BOUNDARY_DIR"
+    printf '%s\n' "$ROLLBACK_BLOCK"
+    printf '%s\n' 'mv() { command mv "$@"; kill -TERM $$; }'
+    printf '%s\n' '_start_studio_venv_replacement "$VENV_DIR"'
+} > "$START_BOUNDARY_HARNESS"
+set +e
+dash "$START_BOUNDARY_HARNESS" >/dev/null 2>&1
+_start_boundary_status=$?
+set -e
+if [ "$_start_boundary_status" -eq 143 ] \
+   && [ "$(cat "$START_BOUNDARY_DIR/unsloth_studio/generation" 2>/dev/null)" = "old" ]; then
+    ok "signal immediately after rollback rename restores the old environment"
+else
+    bad "rollback state was not published before rename"
+fi
+
+COMMIT_BOUNDARY_DIR="$WORK/commit-boundary"
+mkdir -p "$COMMIT_BOUNDARY_DIR/unsloth_studio"
+printf 'old\n' > "$COMMIT_BOUNDARY_DIR/unsloth_studio/generation"
+COMMIT_BOUNDARY_HARNESS="$COMMIT_BOUNDARY_DIR/harness.sh"
+{
+    printf '%s\n' 'set -e'
+    printf '%s\n' 'substep() { :; }'
+    printf '%s\n' 'C_WARN=""'
+    printf "STUDIO_HOME='%s'\n" "$COMMIT_BOUNDARY_DIR"
+    printf "VENV_DIR='%s/unsloth_studio'\n" "$COMMIT_BOUNDARY_DIR"
+    printf '%s\n' "$ROLLBACK_BLOCK"
+    printf '%s\n' '_start_studio_venv_replacement "$VENV_DIR"'
+    printf '%s\n' 'mkdir -p "$VENV_DIR"'
+    printf '%s\n' 'printf "new\n" > "$VENV_DIR/generation"'
+    printf '%s\n' 'rm() { kill -TERM $$; }'
+    printf '%s\n' '_commit_studio_venv_replacement'
+} > "$COMMIT_BOUNDARY_HARNESS"
+set +e
+dash "$COMMIT_BOUNDARY_HARNESS" >/dev/null 2>&1
+_commit_boundary_status=$?
+set -e
+if [ "$_commit_boundary_status" -eq 143 ] \
+   && [ "$(cat "$COMMIT_BOUNDARY_DIR/unsloth_studio/generation" 2>/dev/null)" = "new" ]; then
+    ok "signal during committed-backup deletion keeps the new environment"
+else
+    bad "signal during committed-backup deletion restored a partial backup"
+fi
+
+echo "=== install.sh successful cleanup ==="
+PRUNE_DIR="$WORK/prune"
+mkdir -p "$PRUNE_DIR/unsloth_studio"
+printf 'old\n' > "$PRUNE_DIR/unsloth_studio/generation"
+PRUNE_HARNESS="$PRUNE_DIR/harness.sh"
+{
+    printf '%s\n' 'set -e'
+    printf '%s\n' 'substep() { :; }'
+    printf '%s\n' 'C_WARN=""'
+    printf "STUDIO_HOME='%s'\n" "$PRUNE_DIR"
+    printf "VENV_DIR='%s/unsloth_studio'\n" "$PRUNE_DIR"
+    printf '%s\n' "$ROLLBACK_BLOCK"
+    printf '%s\n' '_start_studio_venv_replacement "$VENV_DIR"'
+    printf '%s\n' 'mkdir -p "$VENV_DIR"'
+    printf '%s\n' 'printf "new\n" > "$VENV_DIR/generation"'
+    printf '%s\n' 'mkdir "$STUDIO_HOME/unsloth_studio.rollback.20000101000000.999999999"'
+    printf '%s\n' 'mkdir "$STUDIO_HOME/unsloth_studio.rollback.20000101000001.$$"'
+    printf '%s\n' 'mkdir "$STUDIO_HOME/unsloth_studio.rollback.user-data"'
+    printf '%s\n' 'mkdir "$STUDIO_HOME/outside"'
+    printf '%s\n' 'ln -s "$STUDIO_HOME/outside" "$STUDIO_HOME/unsloth_studio.rollback.20000101000002.999999998"'
+    printf '%s\n' '_commit_studio_venv_replacement'
+} > "$PRUNE_HARNESS"
+
+sh "$PRUNE_HARNESS" >/dev/null 2>&1
+if [ "$(cat "$PRUNE_DIR/unsloth_studio/generation" 2>/dev/null)" = "new" ]; then
+    ok "successful replacement keeps the new environment"
+else
+    bad "successful replacement lost the new environment"
+fi
+if [ ! -d "$PRUNE_DIR/unsloth_studio.rollback.20000101000000.999999999" ]; then
+    ok "successful install removes an orphan from a dead PID"
+else
+    bad "successful install left an orphan from a dead PID"
+fi
+_active_count=$(find "$PRUNE_DIR" -maxdepth 1 -type d -name 'unsloth_studio.rollback.20000101000001.*' | wc -l)
+if [ "$_active_count" -eq 1 ]; then
+    ok "successful install preserves a concurrent installer's rollback"
+else
+    bad "successful install removed a concurrent installer's rollback"
+fi
+if [ -d "$PRUNE_DIR/unsloth_studio.rollback.user-data" ]; then
+    ok "stale cleanup preserves names outside the generated format"
+else
+    bad "stale cleanup removed a non-generated rollback name"
+fi
+if [ -L "$PRUNE_DIR/unsloth_studio.rollback.20000101000002.999999998" ] \
+   && [ -d "$PRUNE_DIR/outside" ]; then
+    ok "stale cleanup does not follow rollback symlinks"
+else
+    bad "stale cleanup mutated a rollback symlink target"
+fi
+
+echo "=== install.ps1 rollback wiring ==="
+if grep -q '^    function Remove-StaleStudioVenvRollbacks {' "$INSTALL_PS1" \
+   && grep -q '^    Remove-StaleStudioVenvRollbacks$' "$INSTALL_PS1"; then
+    ok "Windows installer prunes stale rollbacks after success"
+else
+    bad "Windows installer does not wire stale rollback cleanup"
+fi
+if grep -q '^    } finally {$' "$INSTALL_PS1" \
+   && grep -A3 '^    } finally {$' "$INSTALL_PS1" | grep -q 'Restore-StudioVenvRollback'; then
+    ok "Windows replacement is protected by finally"
+else
+    bad "Windows replacement lacks finally rollback"
+fi
+if grep -A18 '^    function Remove-StudioVenvTreeWithRetry {' "$INSTALL_PS1" \
+   | grep -q 'ErrorAction Stop'; then
+    ok "Windows rollback deletion failures are observable and retried"
+else
+    bad "Windows rollback deletion still hides failures"
+fi
+
+echo ""
+echo "  PASS: $PASS"
+echo "  FAIL: $FAIL"
+[ "$FAIL" -eq 0 ] || exit 1
+echo "ALL PASSED"
diff --git a/tests/sh/test_previous_torch_pin.sh b/tests/sh/test_previous_torch_pin.sh
new file mode 100644
index 0000000000..f910affc2f
--- /dev/null
+++ b/tests/sh/test_previous_torch_pin.sh
@@ -0,0 +1,137 @@
+#!/bin/bash
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+# Unit tests for install.sh's _previous_torch_pin, which keeps the previous
+# venv's torch RELEASE on a re-run instead of moving the user to a newer one.
+# The release is kept regardless of the old build's flavor tag (PyPI bare,
+# +cuXXX, +rocm, +cpu): the pin installs from the freshly chosen index, so the
+# flavor follows the machine while the release follows the user. Per-leaf
+# windows still win (rocm7.2 / Strix floors, out-of-window manual installs).
+# Helpers are extracted from install.sh and sourced.
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+INSTALL_SH="$SCRIPT_DIR/../../install.sh"
+PASS=0
+FAIL=0
+
+# Extract _previous_torch_pin and its dependency _torch_release_in_window.
+_FUNC_FILE=$(mktemp)
+{
+    sed -n '/^_torch_release_in_window()/,/^}/p' "$INSTALL_SH"
+    echo ""
+    sed -n '/^_previous_torch_pin()/,/^}/p' "$INSTALL_SH"
+} > "$_FUNC_FILE"
+# shellcheck disable=SC1090
+. "$_FUNC_FILE"
+rm -f "$_FUNC_FILE"
+
+assert_eq() {
+    _label="$1"; _expected="$2"; _actual="$3"
+    if [ "$_actual" = "$_expected" ]; then
+        echo "  PASS: $_label"; PASS=$((PASS + 1))
+    else
+        echo "  FAIL: $_label (expected '$_expected', got '$_actual')"; FAIL=$((FAIL + 1))
+    fi
+}
+
+unset UNSLOTH_TORCH_UPGRADE
+
+echo "=== _previous_torch_pin: in-window releases are kept, any flavor ==="
+assert_eq "cu126 wheel"                  "torch==2.10.0" "$(_previous_torch_pin '2.10.0+cu126' 'torch>=2.4,<2.12.0')"
+assert_eq "cu130 wheel"                  "torch==2.10.0" "$(_previous_torch_pin '2.10.0+cu130' 'torch>=2.4,<2.12.0')"
+assert_eq "cpu wheel"                    "torch==2.10.0" "$(_previous_torch_pin '2.10.0+cpu' 'torch>=2.4,<2.12.0')"
+assert_eq "PyPI bare version (CUDA build on Linux)" "torch==2.10.0" "$(_previous_torch_pin '2.10.0' 'torch>=2.4,<2.12.0')"
+assert_eq "rocm wheel"                   "torch==2.10.0" "$(_previous_torch_pin '2.10.0+rocm6.4' 'torch>=2.4,<2.11.0')"
+assert_eq "rocm three-component tag"     "torch==2.9.1"  "$(_previous_torch_pin '2.9.1+rocm7.2.1' 'torch>=2.4,<2.12.0')"
+assert_eq "Intel xpu wheel"              "torch==2.9.0"  "$(_previous_torch_pin '2.9.0+xpu' 'torch>=2.4,<2.12.0')"
+assert_eq "local suffix stripped"        "torch==2.9.1"  "$(_previous_torch_pin '2.9.1+cu128' 'torch>=2.4,<2.12.0')"
+
+echo "=== _previous_torch_pin: raised floors reject older releases ==="
+# rocm7.2 / Strix gfx leaves raise TORCH_CONSTRAINT to >=2.11.0 BEFORE the pin
+# is evaluated, so an old 2.10 is out of window there and the floor wins.
+assert_eq "old 2.10 vs rocm7.2 floor"    "" "$(_previous_torch_pin '2.10.0+rocm7.1' 'torch>=2.11.0,<2.12.0')"
+assert_eq "2.11 passes the rocm7.2 floor" "torch==2.11.0" "$(_previous_torch_pin '2.11.0+rocm7.2' 'torch>=2.11.0,<2.12.0')"
+
+echo "=== _previous_torch_pin: probe noise never becomes a pin ==="
+assert_eq "empty version"                "" "$(_previous_torch_pin '' 'torch>=2.4,<2.12.0')"
+assert_eq "garbage version"              "" "$(_previous_torch_pin 'not-a-version' 'torch>=2.4,<2.12.0')"
+assert_eq "traceback fragment"           "" "$(_previous_torch_pin "ModuleNotFoundError: No module named 'torch'" 'torch>=2.4,<2.12.0')"
+
+echo "=== _previous_torch_pin: nightly / dev / source builds never pin ==="
+# No stable index carries these, so pinning would print "keeping it" and then
+# burn a doomed resolve before the range fallback rescues the install.
+assert_eq "nightly dev build"            "" "$(_previous_torch_pin '2.11.0.dev20250704+cu128' 'torch>=2.4,<2.12.0')"
+assert_eq "source build a0 tag"          "" "$(_previous_torch_pin '2.9.0a0+gitabc1234' 'torch>=2.4,<2.12.0')"
+assert_eq "release candidate"            "" "$(_previous_torch_pin '2.11.0rc1+cu130' 'torch>=2.4,<2.12.0')"
+
+echo "=== _previous_torch_pin: out-of-window releases never pin ==="
+assert_eq "2.3.x below the cu floor"     "" "$(_previous_torch_pin '2.3.1+cu118' 'torch>=2.4,<2.12.0')"
+assert_eq "2.12.x above the cu ceiling"  "" "$(_previous_torch_pin '2.12.0+cu130' 'torch>=2.4,<2.12.0')"
+assert_eq "floor boundary 2.4.0 kept"    "torch==2.4.0"  "$(_previous_torch_pin '2.4.0+cu126' 'torch>=2.4,<2.12.0')"
+assert_eq "ceiling-adjacent 2.11.x kept" "torch==2.11.1" "$(_previous_torch_pin '2.11.1+cu130' 'torch>=2.4,<2.12.0')"
+assert_eq "cpu window excludes 2.11.x"   "" "$(_previous_torch_pin '2.11.0+cpu' 'torch>=2.4,<2.11.0')"
+assert_eq "mac floor excludes 2.5.x"     "" "$(_previous_torch_pin '2.5.1' 'torch>=2.6,<2.11.0')"
+assert_eq "malformed window never pins"  "" "$(_previous_torch_pin '2.10.0+cu126' 'torch')"
+assert_eq "empty window never pins"      "" "$(_previous_torch_pin '2.10.0+cu126' '')"
+
+echo "=== _torch_release_in_window ==="
+assert_eq "in window"            "yes" "$(_torch_release_in_window '2.10.0' 'torch>=2.4,<2.12.0')"
+assert_eq "at floor"             "yes" "$(_torch_release_in_window '2.4.0' 'torch>=2.4,<2.12.0')"
+assert_eq "below floor"          "no"  "$(_torch_release_in_window '2.3.1' 'torch>=2.4,<2.12.0')"
+assert_eq "at ceiling"           "no"  "$(_torch_release_in_window '2.12.0' 'torch>=2.4,<2.12.0')"
+assert_eq "next major"           "no"  "$(_torch_release_in_window '3.0.0' 'torch>=2.4,<2.12.0')"
+assert_eq "patch-level floor"    "yes" "$(_torch_release_in_window '2.11.5' 'torch>=2.11.0,<2.12.0')"
+assert_eq "no ceiling -> no"     "no"  "$(_torch_release_in_window '2.10.0' 'torch>=2.4')"
+assert_eq "garbage minor -> no"  "no"  "$(_torch_release_in_window '2.x' 'torch>=2.4,<2.12.0')"
+
+echo "=== _previous_torch_pin: UNSLOTH_TORCH_UPGRADE=1 opts out ==="
+assert_eq "upgrade env set"    "" "$(UNSLOTH_TORCH_UPGRADE=1 _previous_torch_pin '2.10.0+cu126' 'torch>=2.4,<2.12.0')"
+assert_eq "upgrade env 0"      "torch==2.10.0" "$(UNSLOTH_TORCH_UPGRADE=0 _previous_torch_pin '2.10.0+cu126' 'torch>=2.4,<2.12.0')"
+
+echo "=== install.sh wiring ==="
+# The probe must run against the OLD venv, before it is moved aside for rollback.
+_probe_line=$(grep -n '_PREV_TORCH_VER=\$(' "$INSTALL_SH" | head -1 | cut -d: -f1)
+_move_line=$(grep -n '_start_studio_venv_replacement "\$VENV_DIR"' "$INSTALL_SH" | head -1 | cut -d: -f1)
+assert_eq "probe exists"                  "yes" "$([ -n "$_probe_line" ] && echo yes)"
+assert_eq "probe before venv replacement" "yes" "$([ -n "$_probe_line" ] && [ -n "$_move_line" ] && [ "$_probe_line" -lt "$_move_line" ] && echo yes)"
+# The pin must be evaluated AFTER the last index/constraint decision (the Strix
+# reroute raises the floor), so a raised floor rejects an older kept release.
+_pin_line=$(grep -n '_prev_pin=\$(_previous_torch_pin' "$INSTALL_SH" | head -1 | cut -d: -f1)
+_strix_line=$(grep -n 'Strix Halo / Strix Point:' "$INSTALL_SH" | head -1 | cut -d: -f1)
+assert_eq "pin evaluated after the Strix reroute" "yes" "$([ -n "$_pin_line" ] && [ -n "$_strix_line" ] && [ "$_pin_line" -gt "$_strix_line" ] && echo yes)"
+# A kept release that vanished from the index must fall back to the supported range.
+assert_eq "resolve-failure fallback wired" "yes" "$(grep -q 'TORCH_CONSTRAINT="\$_PREV_FALLBACK_CONSTRAINT"' "$INSTALL_SH" && echo yes)"
+assert_eq "pin gated on SKIP_TORCH"        "yes" "$(grep -q 'if \[ "\$SKIP_TORCH" = false \]; then' "$INSTALL_SH" && echo yes)"
+# Every --default-index torch install path must go through the kept-release
+# helper (definition + default path + three ROCm-index fallbacks + two ROCm
+# repairs + the flavor repair), so a pinned release missing from the index
+# never aborts a rerun.
+_helper_uses=$(grep -c '_install_torch_default_index' "$INSTALL_SH")
+assert_eq "kept-release helper used by all default-index paths" "yes" "$([ "$_helper_uses" -ge 8 ] && echo yes)"
+_repair_uses=$(grep -c '_install_torch_default_index --force-reinstall' "$INSTALL_SH")
+assert_eq "ROCm repairs routed through the kept-release helper" "yes" "$([ "$_repair_uses" -ge 2 ] && echo yes)"
+# The wrong-flavor repair must use the helper too (it runs under set -e, so a
+# direct uv call with an unresolvable pin would abort the whole installer).
+assert_eq "flavor repair routed through the kept-release helper" "yes" "$(grep -q '_install_torch_default_index \\' "$INSTALL_SH" && grep -q -- '--reinstall-package torch --reinstall-package torchvision --reinstall-package torchaudio' "$INSTALL_SH" && echo yes)"
+# The kept-release install must pair the companions with the kept minor:
+# torchaudio no longer exact-pins torch, so unconstrained it resolves a newer
+# mismatched build (verified: torch==2.9.0 pulled torchaudio 2.11.0 on cu130).
+assert_eq "kept-release install pairs torchvision/torchaudio to the kept minor" "yes" "$(grep -q 'torchaudio==2.\${_itdi_minor}.\*' "$INSTALL_SH" && grep -q 'torchvision==0.\$((_itdi_minor + 15)).\*' "$INSTALL_SH" && echo yes)"
+# The Radeon direct-wheel path must also honor the pin: an exact-first kept-trio
+# attempt (exact patch, else the kept minor's newest patch, with paired
+# vision/audio) runs BEFORE the newest-trio search, and the newest-trio search
+# only runs when that attempt did not produce a match, so a kept release can
+# neither drift to another patch/minor nor be undercut by the gap search.
+_radeon_kept_line=$(grep -n '_kept_torch=\$(_pick_radeon_wheel "torch" *"\${_prev_kept_base}"' "$INSTALL_SH" | head -1 | cut -d: -f1)
+_radeon_loop_line=$(grep -n 'Loop downwards to find the first complete matching trio' "$INSTALL_SH" | head -1 | cut -d: -f1)
+assert_eq "Radeon kept-trio attempt before the newest-trio search" "yes" "$([ -n "$_radeon_kept_line" ] && [ -n "$_radeon_loop_line" ] && [ "$_radeon_kept_line" -lt "$_radeon_loop_line" ] && echo yes)"
+assert_eq "Radeon newest-trio search gated on no kept match" "yes" "$(grep -q 'if \[ "\$_radeon_versions_match" != true \] &&' "$INSTALL_SH" && echo yes)"
+assert_eq "Radeon kept-trio gap falls back with a warning" "yes" "$(grep -q 'lacks a complete wheel set for kept' "$INSTALL_SH" && echo yes)"
+
+echo ""
+if [ "$FAIL" -gt 0 ]; then
+    echo "$FAIL check(s) FAILED"
+    exit 1
+fi
+echo "All $PASS checks passed"
diff --git a/tests/sh/test_redact_install_output.sh b/tests/sh/test_redact_install_output.sh
new file mode 100755
index 0000000000..0f10122aea
--- /dev/null
+++ b/tests/sh/test_redact_install_output.sh
@@ -0,0 +1,89 @@
+#!/bin/bash
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+# Unit tests for install.sh's _redact_install_output helper. uv/pip failure text embeds the
+# failing --index-url verbatim, so a captured install log dumped on error can leak a
+# user:token@ or ?token= secret. The helper redacts both before printing. Mirrors
+# _redact_install_output (install_python_stack.py) / Redact-InstallOutput (install.ps1 /
+# setup.ps1).
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+INSTALL_SH="$SCRIPT_DIR/../../install.sh"
+PASS=0
+FAIL=0
+
+_FUNC_FILE=$(mktemp)
+sed -n '/^_redact_install_output()/,/^}/p' "$INSTALL_SH" > "$_FUNC_FILE"
+# shellcheck disable=SC1090
+. "$_FUNC_FILE"
+rm -f "$_FUNC_FILE"
+
+assert_eq() {
+    _label="$1"; _expected="$2"; _actual="$3"
+    if [ "$_actual" = "$_expected" ]; then
+        echo "  PASS: $_label"; PASS=$((PASS + 1))
+    else
+        echo "  FAIL: $_label (expected '$_expected', got '$_actual')"; FAIL=$((FAIL + 1))
+    fi
+}
+
+# Redact from a file (the actual call site passes a captured-log tempfile).
+redact_str() {
+    _rs_tmp=$(mktemp)
+    printf '%s\n' "$1" > "$_rs_tmp"
+    _rs_out=$(_redact_install_output "$_rs_tmp")
+    rm -f "$_rs_tmp"
+    printf '%s' "$_rs_out"
+}
+
+echo "=== _redact_install_output ==="
+assert_eq "userinfo user:token@ redacted" \
+    "ERROR: failed https://<redacted>@download.pytorch.org/whl/cu128" \
+    "$(redact_str 'ERROR: failed https://alice:s3cr3t@download.pytorch.org/whl/cu128')"
+
+assert_eq "bare-token@ userinfo redacted" \
+    "fetch https://<redacted>@host/whl/cu128 failed" \
+    "$(redact_str 'fetch https://ghp_deadbeef@host/whl/cu128 failed')"
+
+assert_eq "single ?token= query redacted" \
+    "url https://host/whl/cu128?token=<redacted> unreachable" \
+    "$(redact_str 'url https://host/whl/cu128?token=abcd1234 unreachable')"
+
+assert_eq "multiple query values redacted" \
+    "https://host/whl/cu128?token=<redacted>&channel=<redacted>" \
+    "$(redact_str 'https://host/whl/cu128?token=abcd1234&channel=beta')"
+
+assert_eq "http (not https) userinfo redacted" \
+    "http://<redacted>@host/simple" \
+    "$(redact_str 'http://u:p@host/simple')"
+
+assert_eq "fragment token redacted" \
+    "ERROR: could not fetch https://mirror.local/whl/cu128#<redacted> (403)" \
+    "$(redact_str 'ERROR: could not fetch https://mirror.local/whl/cu128#token=SECRET123 (403)')"
+
+assert_eq "query and fragment both redacted" \
+    "https://host/whl/cu128?token=<redacted>#<redacted> done" \
+    "$(redact_str 'https://host/whl/cu128?token=abc#sig=xyz done')"
+
+# Non-secret text is untouched (no false positives on ordinary log lines).
+assert_eq "plain line untouched" \
+    "Resolved 42 packages in 1.2s" \
+    "$(redact_str 'Resolved 42 packages in 1.2s')"
+assert_eq "plain url without creds untouched" \
+    "downloading https://download.pytorch.org/whl/cu128/torch-2.8.0.whl" \
+    "$(redact_str 'downloading https://download.pytorch.org/whl/cu128/torch-2.8.0.whl')"
+assert_eq "bare hash comment untouched" \
+    "# retrying with --no-cache-dir" \
+    "$(redact_str '# retrying with --no-cache-dir')"
+
+# Regression guard: no secret substring survives.
+_leak=$(redact_str 'https://alice:s3cr3t@host/whl/cu128?token=SUPERSECRET#frag=ALSOSECRET')
+case "$_leak" in
+    *s3cr3t*|*SUPERSECRET*|*ALSOSECRET*) assert_eq "no secret leak" "clean" "leaked:$_leak" ;;
+    *)                                   assert_eq "no secret leak" "clean" "clean" ;;
+esac
+
+echo ""
+echo "Results: $PASS passed, $FAIL failed"
+[ "$FAIL" -eq 0 ]
diff --git a/tests/sh/test_staged_validation_enabled.sh b/tests/sh/test_staged_validation_enabled.sh
new file mode 100755
index 0000000000..da6a0bdd27
--- /dev/null
+++ b/tests/sh/test_staged_validation_enabled.sh
@@ -0,0 +1,116 @@
+#!/bin/bash
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+# Unit tests for setup.sh staged-validation helpers (#5854 gap 2).
+# Opt-in GPU smoke after a source build; default off (Blackwell JIT stall).
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+SETUP_SH="$SCRIPT_DIR/../../studio/setup.sh"
+PASS=0
+FAIL=0
+
+_FUNC_FILE=$(mktemp)
+{
+    sed -n '/^_staged_validation_enabled()/,/^}/p' "$SETUP_SH"
+    sed -n '/^_source_smoke_install_kind()/,/^}/p' "$SETUP_SH"
+} > "$_FUNC_FILE"
+# shellcheck disable=SC1090
+. "$_FUNC_FILE"
+rm -f "$_FUNC_FILE"
+
+assert_eq() {
+    _label="$1"; _expected="$2"; _actual="$3"
+    if [ "$_actual" = "$_expected" ]; then
+        echo "  PASS: $_label"; PASS=$((PASS + 1))
+    else
+        echo "  FAIL: $_label (expected '$_expected', got '$_actual')"; FAIL=$((FAIL + 1))
+    fi
+}
+
+assert_rc() {
+    _label="$1"; _expected="$2"
+    shift 2
+    set +e
+    "$@" >/dev/null 2>&1
+    _rc=$?
+    set -e
+    if [ "$_rc" -eq "$_expected" ]; then
+        echo "  PASS: $_label"; PASS=$((PASS + 1))
+    else
+        echo "  FAIL: $_label (expected rc $_expected, got $_rc)"; FAIL=$((FAIL + 1))
+    fi
+}
+
+echo "=== _staged_validation_enabled ==="
+unset UNSLOTH_LLAMA_STAGED_VALIDATION
+assert_rc "default off" 1 _staged_validation_enabled
+
+UNSLOTH_LLAMA_STAGED_VALIDATION=0
+assert_rc "0 is off" 1 _staged_validation_enabled
+
+UNSLOTH_LLAMA_STAGED_VALIDATION=1
+assert_rc "1 is on" 0 _staged_validation_enabled
+
+UNSLOTH_LLAMA_STAGED_VALIDATION=true
+assert_rc "true is on" 0 _staged_validation_enabled
+
+UNSLOTH_LLAMA_STAGED_VALIDATION=yes
+assert_rc "yes is on" 0 _staged_validation_enabled
+
+UNSLOTH_LLAMA_STAGED_VALIDATION=on
+assert_rc "on is on" 0 _staged_validation_enabled
+
+UNSLOTH_LLAMA_STAGED_VALIDATION=True
+assert_rc "True is on" 0 _staged_validation_enabled
+
+UNSLOTH_LLAMA_STAGED_VALIDATION='  yes  '
+assert_rc "whitespace yes is on" 0 _staged_validation_enabled
+
+UNSLOTH_LLAMA_STAGED_VALIDATION=maybe
+assert_rc "maybe is off" 1 _staged_validation_enabled
+unset UNSLOTH_LLAMA_STAGED_VALIDATION
+
+echo "=== _source_smoke_install_kind ==="
+_TRY_METAL_CPU_FALLBACK=true
+GPU_BACKEND=""
+assert_eq "metal" "macos-arm64" "$(_source_smoke_install_kind)"
+
+_TRY_METAL_CPU_FALLBACK=false
+GPU_BACKEND=cuda
+_kind="$(_source_smoke_install_kind)"
+case "$(uname -m)" in
+    aarch64|arm64) assert_eq "cuda arm" "linux-arm64-cuda" "$_kind" ;;
+    *) assert_eq "cuda x86" "linux-cuda" "$_kind" ;;
+esac
+
+GPU_BACKEND=rocm
+assert_eq "rocm" "linux-rocm" "$(_source_smoke_install_kind)"
+
+GPU_BACKEND=""
+assert_eq "cpu empty" "" "$(_source_smoke_install_kind)"
+
+echo "=== setup.sh source smoke contract ==="
+assert_contains() {
+    _label="$1"; _hay="$2"; _needle="$3"
+    case "$_hay" in
+        *"$_needle"*) echo "  PASS: $_label"; PASS=$((PASS + 1)) ;;
+        *) echo "  FAIL: $_label (missing '$_needle')"; FAIL=$((FAIL + 1)) ;;
+    esac
+}
+_src=$(cat "$SETUP_SH")
+assert_contains "env gate present" "$_src" "UNSLOTH_LLAMA_STAGED_VALIDATION"
+assert_contains "calls validate-install" "$_src" "--validate-install"
+assert_contains "smoke fail retries CPU" "$_src" "source build failed smoke test; retrying CPU build"
+# Smoke must run before the install swap.
+_smoke_pos=$(printf '%s' "$_src" | awk '/validate source llama.cpp/{print NR; exit}')
+_swap_pos=$(printf '%s' "$_src" | awk '/mv "\$_BUILD_TMP" "\$LLAMA_CPP_DIR"/{print NR; exit}')
+if [ -n "$_smoke_pos" ] && [ -n "$_swap_pos" ] && [ "$_smoke_pos" -lt "$_swap_pos" ]; then
+    echo "  PASS: smoke before install swap"; PASS=$((PASS + 1))
+else
+    echo "  FAIL: smoke before install swap (smoke=$_smoke_pos swap=$_swap_pos)"; FAIL=$((FAIL + 1))
+fi
+
+echo ""
+echo "Results: $PASS passed, $FAIL failed"
+[ "$FAIL" -eq 0 ]
diff --git a/tests/sh/test_torch_constraint.sh b/tests/sh/test_torch_constraint.sh
index 293a709360..bfafbd161b 100644
--- a/tests/sh/test_torch_constraint.sh
+++ b/tests/sh/test_torch_constraint.sh
@@ -108,6 +108,39 @@ assert_eq "\$TORCH_CONSTRAINT used in pip install" "yes" "$_has_var"
 _hardcoded=$(grep -c '"torch>=2.4,<2.11.0"' "$INSTALL_SH" || true)
 assert_eq "hardcoded torch>=2.4 appears exactly once" "1" "$_hardcoded"
 
+# Companions must be bounded to torch's window everywhere: the <2.11 bound appears
+# twice (default assignments + the pinned custom-leaf block), never bare. torchaudio
+# 2.11 dropped its exact torch pin, so a bare companion next to a <2.11-capped torch
+# resolves a mismatched 2.11 build.
+_count=$(grep -c 'TORCHVISION_CONSTRAINT="torchvision>=0.19,<0.26.0"' "$INSTALL_SH" || true)
+assert_eq "torchvision bounded (<0.26) at default + custom-leaf" "2" "$_count"
+_count=$(grep -c 'TORCHAUDIO_CONSTRAINT="torchaudio>=2.4,<2.11.0"' "$INSTALL_SH" || true)
+assert_eq "torchaudio bounded (<2.11) at default + custom-leaf" "2" "$_count"
+_count=$(grep -c 'TORCHVISION_CONSTRAINT="torchvision"$' "$INSTALL_SH" || true)
+assert_eq "no bare torchvision companion remains" "0" "$_count"
+_count=$(grep -c 'TORCHAUDIO_CONSTRAINT="torchaudio"$' "$INSTALL_SH" || true)
+assert_eq "no bare torchaudio companion remains" "0" "$_count"
+# The cu* widen must carry the companions with it (torch <2.12 with torchaudio <2.11
+# would cap a mismatched pair the other way).
+assert_eq "cu widen pairs torchaudio (<2.12)" "1" "$(grep -c 'TORCHAUDIO_CONSTRAINT="torchaudio>=2.4,<2.12.0"' "$INSTALL_SH" || true)"
+_gated=$(grep -c '_expected_torch_flavor_tag "$TORCH_INDEX_URL"' "$INSTALL_SH" || true)
+_has_gate=$([ "$_gated" -ge 1 ] && echo "yes" || echo "no")
+assert_eq "custom-companion bound gated on empty flavor tag" "yes" "$_has_gate"
+
+# A fresh CUDA install widens the ceiling to <2.12.0 so cu12x/cu13x land torch
+# 2.11.x (matches the base image and _CUDA_TORCH_PKG_SPEC).
+_cuda_widen=$(grep -c 'TORCH_CONSTRAINT="torch>=2.4,<2.12.0"' "$INSTALL_SH" || true)
+assert_eq "CUDA TORCH_CONSTRAINT widened to <2.12.0" "1" "$_cuda_widen"
+
+# Widening keys off the final leaf (_torch_index_leaf), not the full URL, so a
+# mirror base path with cu*/rocm7.2 but a cpu/older-rocm leaf is not mis-widened.
+_cuda_case=$(grep -c 'cu\[0-9\]\*)' "$INSTALL_SH" || true)
+_has_cuda_case=$([ "$_cuda_case" -ge 1 ] && echo "yes" || echo "no")
+assert_eq "cu* index case adjusts TORCH_CONSTRAINT" "yes" "$_has_cuda_case"
+_leaf_case=$(grep -c 'case "\$_torch_index_leaf" in' "$INSTALL_SH" || true)
+_has_leaf_constraint=$([ "$_leaf_case" -ge 2 ] && echo "yes" || echo "no")
+assert_eq "constraint case anchors on _torch_index_leaf" "yes" "$_has_leaf_constraint"
+
 echo ""
 echo "=== Structural: tokenizers in no-torch-runtime.txt ==="
 
@@ -271,6 +304,61 @@ bash -c "
 _uv_got2=$(cat "$_UV_LOG2" 2>/dev/null || echo "")
 assert_contains "mock uv arm64+py312 receives torch>=2.4" "$_uv_got2" "torch>=2.4,<2.11.0"
 
+# ======================================================================
+# ROCm 2.11 floor: leaf is lowercased before the gfx*/rocm* allowlist match
+# ======================================================================
+echo ""
+echo "=== ROCm 2.11 floor case (leaf normalization) ==="
+
+# Structural: install.sh lowercases _torch_index_leaf before the floor case, so the
+# canonical gfx120X-all (capital X) matches gfx120x-all.
+_has_lc=$(grep -c '_torch_index_leaf=$(printf .* | tr .\[:upper:\]. .\[:lower:\].)' "$INSTALL_SH" || true)
+_has_lc_ok=$([ "$_has_lc" -ge 1 ] && echo "yes" || echo "no")
+assert_eq "install.sh lowercases _torch_index_leaf" "yes" "$_has_lc_ok"
+
+# Runtime: replicate install.sh's normalization + floor case and assert both gfx120X-all
+# and gfx120x-all get the floor, while non-2.11 leaves keep the default.
+run_floor_case() {
+    _url="$1"
+    bash -c '
+        TORCH_CONSTRAINT="torch>=2.4,<2.11.0"
+        TORCHVISION_CONSTRAINT="torchvision"
+        TORCHAUDIO_CONSTRAINT="torchaudio"
+        _torch_index_leaf="${1%/}"
+        _torch_index_leaf="${_torch_index_leaf##*/}"
+        _torch_index_leaf=$(printf "%s" "$_torch_index_leaf" | tr "[:upper:]" "[:lower:]")
+        case "$_torch_index_leaf" in
+            rocm7.2|gfx120x-all|gfx1151|gfx1150)
+                TORCH_CONSTRAINT="torch>=2.11.0,<2.12.0"
+                TORCHVISION_CONSTRAINT="torchvision>=0.26.0,<0.27.0"
+                TORCHAUDIO_CONSTRAINT="torchaudio>=2.11.0,<2.12.0"
+                ;;
+        esac
+        echo "$TORCH_CONSTRAINT"
+    ' _ "$_url"
+}
+
+assert_eq "gfx120X-all (capital) -> 2.11 floor" "torch>=2.11.0,<2.12.0" \
+    "$(run_floor_case 'https://repo.amd.com/rocm/whl/gfx120X-all')"
+assert_eq "gfx120X-all trailing slash -> 2.11 floor" "torch>=2.11.0,<2.12.0" \
+    "$(run_floor_case 'https://repo.amd.com/rocm/whl/gfx120X-all/')"
+assert_eq "gfx120x-all (lowercase) -> 2.11 floor" "torch>=2.11.0,<2.12.0" \
+    "$(run_floor_case 'https://repo.amd.com/rocm/whl/gfx120x-all')"
+assert_eq "gfx1151 -> 2.11 floor" "torch>=2.11.0,<2.12.0" \
+    "$(run_floor_case 'https://repo.amd.com/rocm/whl/gfx1151')"
+assert_eq "gfx1150 -> 2.11 floor" "torch>=2.11.0,<2.12.0" \
+    "$(run_floor_case 'https://repo.amd.com/rocm/whl/gfx1150')"
+assert_eq "rocm7.2 -> 2.11 floor" "torch>=2.11.0,<2.12.0" \
+    "$(run_floor_case 'https://download.pytorch.org/whl/rocm7.2')"
+assert_eq "gfx110X-all -> default (no floor)" "torch>=2.4,<2.11.0" \
+    "$(run_floor_case 'https://repo.amd.com/rocm/whl/gfx110X-all')"
+assert_eq "rocm6.4 -> default (no floor)" "torch>=2.4,<2.11.0" \
+    "$(run_floor_case 'https://download.pytorch.org/whl/rocm6.4')"
+assert_eq "cu128 -> default (no floor)" "torch>=2.4,<2.11.0" \
+    "$(run_floor_case 'https://download.pytorch.org/whl/cu128')"
+assert_eq "cpu -> default (no floor)" "torch>=2.4,<2.11.0" \
+    "$(run_floor_case 'https://download.pytorch.org/whl/cpu')"
+
 # ======================================================================
 # Summary
 # ======================================================================
diff --git a/tests/sh/test_torch_flavor.sh b/tests/sh/test_torch_flavor.sh
index ead2c4164f..55da2c0f07 100755
--- a/tests/sh/test_torch_flavor.sh
+++ b/tests/sh/test_torch_flavor.sh
@@ -11,14 +11,21 @@ INSTALL_SH="$SCRIPT_DIR/../../install.sh"
 PASS=0
 FAIL=0
 
-# Extract the three helper functions from install.sh and source them.
+# Extract the helper functions from install.sh and source them
+# (_torch_index_url_leaf is the shared leaf extractor the classifiers call).
 _FUNC_FILE=$(mktemp)
 {
     sed -n '/^_torch_flavor_tag()/,/^}/p' "$INSTALL_SH"
     echo ""
+    sed -n '/^_torch_index_url_leaf()/,/^}/p' "$INSTALL_SH"
+    echo ""
+    sed -n '/^_is_pip_rocm_family_leaf()/,/^}/p' "$INSTALL_SH"
+    echo ""
     sed -n '/^_expected_torch_flavor_tag()/,/^}/p' "$INSTALL_SH"
     echo ""
     sed -n '/^_torch_index_repairable()/,/^}/p' "$INSTALL_SH"
+    echo ""
+    sed -n '/^_tauri_torch_index_family()/,/^}/p' "$INSTALL_SH"
 } > "$_FUNC_FILE"
 # shellcheck disable=SC1090
 . "$_FUNC_FILE"
@@ -56,6 +63,26 @@ assert_eq "amd gfx index"      "rocm"  "$(_expected_torch_flavor_tag 'https://re
 assert_eq "mirror cu130 leaf"  "cu130" "$(_expected_torch_flavor_tag 'https://my.mirror/pytorch/whl/cu130')"
 assert_eq "unrecognized leaf"  ""      "$(_expected_torch_flavor_tag 'https://my.mirror/whl/simple')"
 assert_eq "empty url"          ""      "$(_expected_torch_flavor_tag '')"
+# Query/fragment dropped before classification: .../cu128?token=x classifies as cu128,
+# not an opaque leaf that reinstalls every run.
+assert_eq "query-bearing cu128" "cu128" "$(_expected_torch_flavor_tag 'https://m/whl/cu128?token=x')"
+assert_eq "fragment-bearing cpu" "cpu"  "$(_expected_torch_flavor_tag 'https://m/whl/cpu#frag')"
+# A cu-suffixed CUSTOM leaf (cu128-private, cu128x) is NOT the cu128 family (exact
+# cu+digits only). Mirrors Python re.fullmatch(cu[0-9]+) / PowerShell.
+assert_eq "cu-suffix custom leaf" ""    "$(_expected_torch_flavor_tag 'https://m/whl/cu128-private')"
+assert_eq "cu-alnum custom leaf"  ""    "$(_expected_torch_flavor_tag 'https://m/whl/cu128x')"
+assert_eq "bare cu digits stays"  "cu126" "$(_expected_torch_flavor_tag 'https://m/whl/cu126')"
+# A custom leaf merely STARTING with rocm (rocm-current, rocm-rel-7.2.1) is NOT a pip
+# rocm family -> "" (custom); real families (rocm7.2) and gfx indexes stay "rocm".
+assert_eq "custom rocm-current"   ""    "$(_expected_torch_flavor_tag 'https://mirror/whl/rocm-current')"
+assert_eq "radeon rocm-rel leaf"  ""    "$(_expected_torch_flavor_tag 'https://repo.radeon.com/rocm/manylinux/rocm-rel-7.2.1')"
+assert_eq "real rocm7.2 stays"    "rocm" "$(_expected_torch_flavor_tag 'https://download.pytorch.org/whl/rocm7.2')"
+# A rocm<digit>-SUFFIX private mirror (rocm7.2-private, rocm7-current) is a custom pin ->
+# "" (custom); match the family exactly, not the prefix.
+assert_eq "suffixed rocm7.2-private" "" "$(_expected_torch_flavor_tag 'https://co.internal/whl/rocm7.2-private')"
+assert_eq "suffixed rocm7-current"   "" "$(_expected_torch_flavor_tag 'https://co.internal/whl/rocm7-current')"
+assert_eq "two-dot rocm7.2.1"        "" "$(_expected_torch_flavor_tag 'https://co.internal/whl/rocm7.2.1')"
+assert_eq "bare rocm7 stays"       "rocm" "$(_expected_torch_flavor_tag 'https://download.pytorch.org/whl/rocm7')"
 
 echo "=== _torch_index_repairable ==="
 assert_eq "cu130 repairable"   "yes"   "$(_torch_index_repairable 'https://download.pytorch.org/whl/cu130')"
@@ -64,6 +91,66 @@ assert_eq "gfx repairable"     "yes"   "$(_torch_index_repairable 'https://repo.
 assert_eq "gfx1151 repairable" "yes"   "$(_torch_index_repairable 'https://repo.amd.com/rocm/whl/gfx1151/')"
 assert_eq "cpu NOT repairable" "no"    "$(_torch_index_repairable 'https://download.pytorch.org/whl/cpu')"
 assert_eq "unknown NOT repair" "no"    "$(_torch_index_repairable 'https://my.mirror/whl/simple')"
+# A suffixed rocm leaf is a verbatim pin, not a --default-index repairable family.
+assert_eq "rocm-private NOT repair" "no" "$(_torch_index_repairable 'https://co.internal/whl/rocm7.2-private')"
+
+echo "=== _is_pip_rocm_family_leaf ==="
+assert_family() {
+    _label="$1"; _expected="$2"; _leaf="$3"
+    if _is_pip_rocm_family_leaf "$_leaf"; then _actual="yes"; else _actual="no"; fi
+    assert_eq "$_label" "$_expected" "$_actual"
+}
+assert_family "rocm7.2 family"        "yes" "rocm7.2"
+assert_family "rocm6.4 family"        "yes" "rocm6.4"
+assert_family "bare rocm7 family"     "yes" "rocm7"
+assert_family "gfx120x-all family"    "yes" "gfx120x-all"
+assert_family "gfx1151 family"        "yes" "gfx1151"
+assert_family "rocm7.2-private custom" "no" "rocm7.2-private"
+assert_family "rocm7-current custom"  "no"  "rocm7-current"
+assert_family "rocm-current custom"   "no"  "rocm-current"
+assert_family "rocm-rel-7.2.1 custom" "no"  "rocm-rel-7.2.1"
+assert_family "rocm7.2.1 custom"      "no"  "rocm7.2.1"
+# A trailing dot (rocm7.) or leading/double dot is NOT a family: both major and minor must
+# be non-empty all-digits, matching Python re.fullmatch(rocm\d+(?:\.\d+)?). Bash previously
+# accepted rocm7. via a bare %/-style trim while Python rejected it (validator asymmetry).
+assert_family "rocm7. trailing-dot custom" "no" "rocm7."
+assert_family "rocm.7 leading-dot custom"  "no" "rocm.7"
+assert_family "rocm7..2 double-dot custom" "no" "rocm7..2"
+assert_family "cpu not rocm"          "no"  "cpu"
+assert_family "cu128 not rocm"        "no"  "cu128"
+assert_family "simple not rocm"       "no"  "simple"
+
+echo "=== _torch_index_url_leaf (ALL trailing slashes stripped -> non-empty leaf) ==="
+# A double (or triple) trailing slash must yield the real leaf, not an empty string that
+# fails every classifier arm. Python .rstrip("/") drops them all; bash must match (a bare
+# %/ left .../cu128// classifying as "").
+assert_eq "double slash cu128 leaf"   "cu128"   "$(_torch_index_url_leaf 'https://m/whl/cu128//')"
+assert_eq "triple slash rocm7.2 leaf" "rocm7.2" "$(_torch_index_url_leaf 'https://m/whl/rocm7.2///')"
+assert_eq "double slash + token leaf" "cu128"   "$(_torch_index_url_leaf 'https://m/whl/cu128//?token=x')"
+assert_eq "single slash cu128 leaf"   "cu128"   "$(_torch_index_url_leaf 'https://m/whl/cu128/')"
+# The classifier that consumes the leaf must therefore still tag a double-slash index.
+assert_eq "double-slash cu128 tag"    "cu128"   "$(_expected_torch_flavor_tag 'https://m/whl/cu128//')"
+assert_eq "double-slash rocm7.2 tag"  "rocm"    "$(_expected_torch_flavor_tag 'https://m/whl/rocm7.2//')"
+
+echo "=== _tauri_torch_index_family (credential redaction) ==="
+# A token/fragment must be stripped BEFORE classification so it never reaches the
+# [TAURI:DIAG] line (the family is the last path segment, which else carries the query).
+SKIP_TORCH=false
+assert_eq "token stripped from rocm"  "rocm7.2" "$(_tauri_torch_index_family 'https://mirror/whl/rocm7.2?token=SECRET')"
+assert_eq "token-bearing cu classifies" "cu128" "$(_tauri_torch_index_family 'https://m/whl/cu128?token=x')"
+assert_eq "fragment stripped cpu"     "cpu"     "$(_tauri_torch_index_family 'https://m/whl/cpu#frag')"
+assert_eq "plain rocm7.2 unchanged"   "rocm7.2" "$(_tauri_torch_index_family 'https://download.pytorch.org/whl/rocm7.2')"
+# A trailing slash must be stripped too, or the */cu128 and */cpu arms miss .../cu128/
+# and it falls through to "auto".
+assert_eq "trailing slash cu128"      "cu128"   "$(_tauri_torch_index_family 'https://download.pytorch.org/whl/cu128/')"
+assert_eq "slash + token cu128"       "cu128"   "$(_tauri_torch_index_family 'https://m/whl/cu128/?token=x')"
+assert_eq "trailing slash cpu"        "cpu"     "$(_tauri_torch_index_family 'https://m/whl/cpu/')"
+# Regression guard: no secret token substring may survive in any classification.
+_leak=$(_tauri_torch_index_family 'https://mirror/whl/rocm7.2?token=SECRET')
+case "$_leak" in
+    *SECRET*|*token*) assert_eq "no token leak in family" "clean" "leaked:$_leak" ;;
+    *)                assert_eq "no token leak in family" "clean" "clean" ;;
+esac
 
 echo ""
 echo "Results: $PASS passed, $FAIL failed"
diff --git a/tests/sh/test_unsloth_torch_override.sh b/tests/sh/test_unsloth_torch_override.sh
new file mode 100644
index 0000000000..84e52ca287
--- /dev/null
+++ b/tests/sh/test_unsloth_torch_override.sh
@@ -0,0 +1,142 @@
+#!/bin/bash
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+# Tests for the torch-trio --overrides guard on the Step-2 unsloth installs in
+# install.sh. A released unsloth wheel can pin an older torch (2026.7.2 declares
+# torch<2.11.0); without the overrides file a with-deps PyPI resolve downgrades
+# the trio Step 1 installed, and the flavor guard misses it (PyPI's torch 2.10
+# default is itself cu128-flavored). Same assertion pattern as test_torch_constraint.sh.
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+INSTALL_SH="$SCRIPT_DIR/../../install.sh"
+PASS=0
+FAIL=0
+
+assert_true() {
+    _label="$1"; _ok="$2"
+    if [ "$_ok" = "0" ]; then
+        echo "  PASS: $_label"
+        PASS=$((PASS + 1))
+    else
+        echo "  FAIL: $_label"
+        FAIL=$((FAIL + 1))
+    fi
+}
+
+echo "=== test_unsloth_torch_override ==="
+
+# 1. Every with-deps unsloth install carries the overrides expansion (local,
+#    generic, migrated); the --no-deps no-torch paths need no guard.
+_local_block=$(grep -A2 '"install unsloth (local)"' "$INSTALL_SH")
+printf '%s' "$_local_block" | grep -q -- '--overrides "\$_UNSLOTH_TORCH_OVERRIDES"'
+assert_true "local (with-deps) unsloth install passes --overrides" "$?"
+
+_generic_block=$(grep -A2 '"install unsloth" uv pip install' "$INSTALL_SH")
+printf '%s' "$_generic_block" | grep -q -- '--overrides "\$_UNSLOTH_TORCH_OVERRIDES"'
+assert_true "generic (with-deps) unsloth install passes --overrides" "$?"
+
+_migrated_block=$(grep -A3 '"install unsloth (migrated)"' "$INSTALL_SH")
+printf '%s' "$_migrated_block" | grep -q -- '--overrides "\$_UNSLOTH_TORCH_OVERRIDES"'
+assert_true "migrated (with-deps) unsloth install passes --overrides" "$?"
+
+_no_torch_block=$(grep -A2 '"install unsloth (no-torch)"' "$INSTALL_SH")
+if printf '%s' "$_no_torch_block" | grep -q -- '--overrides'; then _rc=1; else _rc=0; fi
+assert_true "no-torch (--no-deps) unsloth install has no overrides" "$_rc"
+
+_migrated_nt_block=$(grep -A2 '"install unsloth (migrated no-torch)"' "$INSTALL_SH")
+if printf '%s' "$_migrated_nt_block" | grep -q -- '--overrides'; then _rc=1; else _rc=0; fi
+assert_true "migrated no-torch (--no-deps) unsloth install has no overrides" "$_rc"
+
+# 2. The overrides file is only built when SKIP_TORCH=false.
+grep -B2 '_torch_trio_pins=\$(' "$INSTALL_SH" | grep -q 'SKIP_TORCH" = false'
+assert_true "overrides file build is gated on SKIP_TORCH=false" "$?"
+
+# 3. The pin-collection snippet emits exact ==pins for the installed trio (run
+#    the embedded python against this test's interpreter).
+_snippet=$(sed -n '/_torch_trio_pins=\$("\$_VENV_PY" -c "/,/^" 2>\/dev\/null)/p' "$INSTALL_SH" \
+    | sed '1s/.*-c "//' | sed '$d')
+_out=$(python3 -c "$_snippet" 2>&1) || true
+# torch may or may not be importable on the test host; the snippet must not
+# crash and every line it does emit must be an exact pkg==version pin.
+if [ -n "$_out" ]; then
+    printf '%s\n' "$_out" | grep -vqE '^(torch|torchvision|torchaudio)==.+$' && _rc=1 || _rc=0
+else
+    _rc=0
+fi
+assert_true "pin snippet emits only exact trio ==pins (or nothing)" "$_rc"
+
+# 4. The temp overrides file is cleaned up after Step 2.
+grep -q 'rm -f "\$_UNSLOTH_TORCH_OVERRIDES"' "$INSTALL_SH"
+assert_true "overrides temp file is removed after the unsloth installs" "$?"
+
+# 5. Any UV_OVERRIDE env file is folded in (the CLI --overrides flag would
+#    otherwise replace it, dropping e.g. the macOS arm64 darwin overrides).
+grep -q 'for _ov_file in \${UV_OVERRIDE:-}' "$INSTALL_SH"
+assert_true "UV_OVERRIDE env files are merged into the overrides file" "$?"
+
+# 6. Exit and signal traps share cleanup, so a failed or interrupted Step 2
+#    cannot leak the overrides file.
+sed -n '/_on_install_exit() {/,/^}/p' "$INSTALL_SH" | grep -q '_cleanup_install_temporaries'
+_exit_cleanup_rc=$?
+sed -n '/_on_install_signal() {/,/^}/p' "$INSTALL_SH" | grep -q '_cleanup_install_temporaries'
+_signal_cleanup_rc=$?
+sed -n '/_cleanup_install_temporaries() {/,/^}/p' "$INSTALL_SH" \
+    | grep -q 'rm -f "\$_UNSLOTH_TORCH_OVERRIDES"'
+_cleanup_body_rc=$?
+if [ "$_exit_cleanup_rc" -eq 0 ] && [ "$_signal_cleanup_rc" -eq 0 ] \
+   && [ "$_cleanup_body_rc" -eq 0 ]; then
+    _rc=0
+else
+    _rc=1
+fi
+assert_true "exit and signal traps remove the overrides temp file" "$_rc"
+
+# 7. The UV_OVERRIDE fold filters inherited files instead of cat-ing them (run
+#    the extracted awk program on sample files): (a) inherited torch-trio lines
+#    are dropped so the generated exact pins win (uv intersects duplicates);
+#    (b) every line is newline-terminated so an unterminated file cannot join
+#    two requirements into one.
+_awk_prog=$(sed -n "s/.*awk '\(.*\)' \"\$_ov_file\".*/\1/p" "$INSTALL_SH")
+[ -n "$_awk_prog" ]
+assert_true "UV_OVERRIDE fold uses the trio-filtering awk program" "$?"
+
+_ov_dir=$(mktemp -d)
+printf '%s' 'transformers>=4.57.6' > "$_ov_dir/ov1.txt" # no trailing newline
+cat > "$_ov_dir/ov2.txt" <<'EOF'
+# comment survives
+torch<2.11.0
+torchvision==0.25.0
+torchaudio!=2.11.0
+torchmetrics==1.0
+anyio<4.14.0
+EOF
+_merged="$_ov_dir/merged.txt"
+printf '%s\n' 'torch==2.11.0+cu128' > "$_merged"
+for _f in "$_ov_dir/ov1.txt" "$_ov_dir/ov2.txt"; do
+    awk "$_awk_prog" "$_f" >> "$_merged"
+done
+
+grep -qx 'transformers>=4.57.6' "$_merged"
+assert_true "no-trailing-newline override stays a separate requirement line" "$?"
+
+if grep -qx 'torchmetrics==1.0' "$_merged" && grep -qx 'anyio<4.14.0' "$_merged"; then
+    _rc=0
+else
+    _rc=1
+fi
+assert_true "unrelated inherited overrides are preserved" "$_rc"
+
+if grep -qE '^(torch|torchvision|torchaudio)([[:space:]<>=!~;@[]|$)' "$_merged" \
+    && [ "$(grep -cE '^(torch|torchvision|torchaudio)([[:space:]<>=!~;@[]|$)' "$_merged")" != "1" ]; then
+    _rc=1
+else
+    _rc=0
+fi
+grep -qx 'torch==2.11.0+cu128' "$_merged" || _rc=1
+assert_true "inherited torch-trio lines are dropped; generated pin wins" "$_rc"
+rm -rf "$_ov_dir"
+
+echo ""
+echo "Results: $PASS passed, $FAIL failed"
+[ "$FAIL" -eq 0 ] || exit 1
diff --git a/tests/studio/_playwright_robust.py b/tests/studio/_playwright_robust.py
index a4590066d4..b2f6df751e 100644
--- a/tests/studio/_playwright_robust.py
+++ b/tests/studio/_playwright_robust.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Shared CI-runner workarounds for the Studio Playwright tests (Chromium flags,
+"""Shared CI-runner workarounds for the Unsloth Playwright tests (Chromium flags,
 view-transition killer, page recovery, post-action response wait). Imported
 directly by the standalone scripts; does NOT depend on pytest.
 """
@@ -130,7 +130,7 @@ def wait_for_health(
             timeout = 3.0,
         )
         last_status, last_body = status, body
-        # Accept any 200 -- different Studio builds report status differently.
+        # Accept any 200 -- different Unsloth builds report status differently.
         if status == 200:
             if info is not None:
                 info(f"health pre-flight OK: status=200, body keys={list((body or {}).keys())}")
diff --git a/tests/studio/install/smoke_test_parallel_studio_home.py b/tests/studio/install/smoke_test_parallel_studio_home.py
index 9d840355e1..55b6df5190 100644
--- a/tests/studio/install/smoke_test_parallel_studio_home.py
+++ b/tests/studio/install/smoke_test_parallel_studio_home.py
@@ -80,7 +80,7 @@ def _launch_backend(
     env = os.environ.copy()
     env["HOME"] = str(fake_home)
     # Pin UNSLOTH_STUDIO_HOME and clear the alias so the child can't inherit a
-    # Studio root from the caller's shell and resolve to the wrong install.
+    # Unsloth root from the caller's shell and resolve to the wrong install.
     env["UNSLOTH_STUDIO_HOME"] = str(studio_home)
     env.pop("STUDIO_HOME", None)
     # Popen dups stdout into the child, so closing the parent's handle here is safe.
diff --git a/tests/studio/install/test_cuda_repair.py b/tests/studio/install/test_cuda_repair.py
index cea4383268..c6d2b95316 100644
--- a/tests/studio/install/test_cuda_repair.py
+++ b/tests/studio/install/test_cuda_repair.py
@@ -64,15 +64,23 @@ def _run_cuda_repair(
     rocm_marker = False,
     smi_path = "/usr/bin/nvidia-smi",
     cvd = None,
+    index_family = None,
+    index_url = None,
 ):
     """Invoke _ensure_cuda_torch under a fully mocked host; return the pip mock.
 
-    cvd controls CUDA_VISIBLE_DEVICES: None removes it from the env, any string sets it."""
+    cvd controls CUDA_VISIBLE_DEVICES: None removes it from the env, any string sets it.
+    index_family sets UNSLOTH_TORCH_INDEX_FAMILY (the explicit wheel-index pin).
+    index_url sets UNSLOTH_TORCH_INDEX_URL (the full-URL pin form)."""
     env = {}
     if rocm_marker:
         env["UNSLOTH_ROCM_TORCH_INSTALLED"] = "1"
     if cvd is not None:
         env["CUDA_VISIBLE_DEVICES"] = cvd
+    if index_family is not None:
+        env["UNSLOTH_TORCH_INDEX_FAMILY"] = index_family
+    if index_url is not None:
+        env["UNSLOTH_TORCH_INDEX_URL"] = index_url
 
     def _which(name, *a, **k):
         if name == "nvidia-smi":
@@ -99,6 +107,10 @@ def _run_cuda_repair(
             stack_mod.os.environ.pop("UNSLOTH_ROCM_TORCH_INSTALLED", None)
         if cvd is None:
             stack_mod.os.environ.pop("CUDA_VISIBLE_DEVICES", None)
+        if index_family is None:
+            stack_mod.os.environ.pop("UNSLOTH_TORCH_INDEX_FAMILY", None)
+        if index_url is None:
+            stack_mod.os.environ.pop("UNSLOTH_TORCH_INDEX_URL", None)
         _ensure_cuda_torch()
     return mock_pip
 
@@ -123,11 +135,74 @@ class TestCudaRepairFires:
         assert mock_pip.call_args.kwargs["constrain"] is False
 
     def test_rocm_in_version_string_triggers_repair(self):
-        # AMD SDK / Radeon wheels may encode rocm in __version__ without
-        # torch.version.hip; the probe prints "hip" for both.
+        # AMD SDK / Radeon wheels may encode rocm in __version__ without torch.version.hip;
+        # the probe prints "hip" for both.
         mock_pip = _run_cuda_repair(torch_state = "hip")
         assert mock_pip.call_count == 1
 
+    def test_no_gpu_but_explicit_cuda_pin_repairs(self):
+        # Headless / CI cross-install: an explicit cu* pin commits to CUDA wheels with no
+        # NVIDIA GPU visible, so a ROCm-poisoned venv is still repaired to the pinned family.
+        mock_pip = _run_cuda_repair(
+            nvidia = False,
+            backend = "cuda",
+            index_family = "cu128",
+            torch_state = "hip",
+        )
+        assert mock_pip.call_count == 1
+        assert "cu128" in _index_url(mock_pip)
+
+    def test_cvd_hidden_but_explicit_cuda_pin_repairs(self):
+        # CVD=-1/"" hides the GPU, but an explicit cu* pin skips ALL host-GPU probing, so the
+        # CVD hide gate must not suppress the repair (GPU-less CI: CVD=-1, FAMILY=cu128).
+        for _cvd in ("-1", ""):
+            mock_pip = _run_cuda_repair(
+                nvidia = False,
+                backend = "cuda",
+                cvd = _cvd,
+                index_family = "cu128",
+                torch_state = "hip",
+            )
+            assert mock_pip.call_count == 1
+            assert "cu128" in _index_url(mock_pip)
+
+    def test_tagged_cuda_mismatch_repairs(self):
+        # A healthy CUDA torch whose +cuXXX differs from the pin is repaired.
+        mock_pip = _run_cuda_repair(
+            index_family = "cu128",
+            torch_state = "cuda|cu126",
+            cuda_version = "12.8",
+        )
+        assert mock_pip.call_count == 1
+        assert "cu128" in _index_url(mock_pip)
+
+    def test_untagged_cuda_build_under_pin_repairs(self):
+        # An untagged CUDA build (no +cuXXX tag -> empty installed cu) can't be confirmed
+        # to match the pin, so the pin is enforced with a reinstall.
+        mock_pip = _run_cuda_repair(
+            index_family = "cu128",
+            torch_state = "cuda",  # marker cuda, empty installed cu
+            cuda_version = "12.8",
+        )
+        assert mock_pip.call_count == 1
+        assert "cu128" in _index_url(mock_pip)
+
+    def test_broken_probe_with_cuda_pin_repairs(self):
+        # torch present but unimportable under a CUDA pin: the base update won't repair a
+        # broken already-installed torch, so reinstall from the pin instead of stranding it.
+        mock_pip = _run_cuda_repair(torch_state = "hip", torch_rc = 1, index_family = "cu128")
+        assert mock_pip.call_count == 1
+        assert "cu128" in _index_url(mock_pip)
+
+    def test_broken_probe_with_cuda_url_pin_repairs(self):
+        mock_pip = _run_cuda_repair(
+            torch_state = "cpu",
+            torch_rc = 1,
+            index_url = "https://mirror.local/cu128",
+        )
+        assert mock_pip.call_count == 1
+        assert "https://mirror.local/cu128" in _index_url(mock_pip)
+
 
 # No-op cases.
 
@@ -157,8 +232,9 @@ class TestCudaRepairSkips:
         mock_pip = _run_cuda_repair(nvidia = False, torch_state = "hip")
         mock_pip.assert_not_called()
 
-    def test_torch_missing_skips(self):
-        # Non-zero probe exit = torch missing / un-importable.
+    def test_torch_missing_no_pin_skips(self):
+        # Non-zero probe exit = torch missing/un-importable. With NO CUDA pin the base
+        # install owns it, so leave it alone (a pinned build reinstalls).
         mock_pip = _run_cuda_repair(torch_state = "hip", torch_rc = 1)
         mock_pip.assert_not_called()
 
@@ -191,6 +267,109 @@ class TestCudaRepairSkips:
         mock_pip = _run_cuda_repair(cvd = "0", torch_state = "hip")
         assert mock_pip.call_count == 1
 
+    def test_matching_tagged_cuda_pin_no_repair(self):
+        # Healthy CUDA torch whose +cuXXX already matches the pin: no reinstall.
+        mock_pip = _run_cuda_repair(
+            index_family = "cu128",
+            torch_state = "cuda|cu128",
+            cuda_version = "12.8",
+        )
+        mock_pip.assert_not_called()
+
+    def test_custom_mirror_leaf_not_treated_as_cuda_pin(self):
+        # A mirror leaf starting with "cu" but not cuXXX (.../custom, .../current) must
+        # NOT be treated as a CUDA pin, so it can't bypass the NVIDIA gate.
+        for _leaf in ("custom", "current"):
+            mock_pip = _run_cuda_repair(
+                nvidia = False,
+                backend = "cuda",
+                index_url = f"https://mymirror.example/{_leaf}",
+                torch_state = "hip",
+            )
+            mock_pip.assert_not_called()
+
+    def test_explicit_cuda_family_leaf_helper(self):
+        # _explicit_cuda_torch_index_url matches cuXXX narrowly, not any cu* leaf.
+        import contextlib
+
+        def _with(url):
+            with patch.dict(stack_mod.os.environ, {"UNSLOTH_TORCH_INDEX_URL": url}, clear = False):
+                stack_mod.os.environ.pop("UNSLOTH_TORCH_INDEX_FAMILY", None)
+                return stack_mod._explicit_cuda_torch_index_url()
+
+        assert _with("https://download.pytorch.org/whl/cu128") is not None
+        assert _with("https://download.pytorch.org/whl/cu126") is not None
+        assert _with("https://mymirror.example/custom") is None
+        assert _with("https://mymirror.example/current") is None
+        assert _with("https://download.pytorch.org/whl/cpu") is None
+        with contextlib.suppress(Exception):
+            stack_mod.os.environ.pop("UNSLOTH_TORCH_INDEX_URL", None)
+
+
+class TestTorchBackendDerivationFromPin:
+    """The module-level _TORCH_BACKEND derivation (standalone `studio update`
+    with no install.sh-set UNSLOTH_TORCH_BACKEND) must classify the pinned index
+    leaf via _is_cuda_family_leaf (^cu[0-9]), NOT a bare startswith("cu"). A
+    full-override URL ending in /current or /custom must fall through to backend
+    "" (probe the GPU) so _ensure_rocm_torch() still repairs a wrong/CPU torch on
+    AMD hosts, instead of being wrongly branded "cuda" and returning early."""
+
+    @staticmethod
+    def _derive(env):
+        # Re-run the module's import-time derivation, using its own _is_cuda_family_leaf
+        # so this stays in lockstep.
+        idx_override = (
+            env.get("UNSLOTH_TORCH_INDEX_URL", "").strip()
+            or env.get("UNSLOTH_TORCH_INDEX_FAMILY", "").strip()
+        )
+        backend = env.get("UNSLOTH_TORCH_BACKEND", "").lower()
+        if not backend:
+            leaf = idx_override.rstrip("/").rsplit("/", 1)[-1].lower()
+            if leaf.startswith(("rocm", "gfx")):
+                backend = "rocm"
+            elif leaf == "cpu":
+                backend = "cpu"
+            elif stack_mod._is_cuda_family_leaf(leaf):
+                backend = "cuda"
+        return backend
+
+    def test_cu128_pin_is_cuda(self):
+        assert (
+            self._derive({"UNSLOTH_TORCH_INDEX_URL": "https://download.pytorch.org/whl/cu128"})
+            == "cuda"
+        )
+
+    def test_cu128_family_is_cuda(self):
+        assert self._derive({"UNSLOTH_TORCH_INDEX_FAMILY": "cu128"}) == "cuda"
+
+    def test_current_leaf_not_cuda(self):
+        # ^cu[0-9] rejects /current -> backend stays "" (probe GPU), so an AMD host still
+        # repairs a CPU/wrong torch instead of short-circuiting.
+        assert self._derive({"UNSLOTH_TORCH_INDEX_URL": "https://mymirror.example/current"}) == ""
+
+    def test_custom_leaf_not_cuda(self):
+        assert self._derive({"UNSLOTH_TORCH_INDEX_URL": "https://mymirror.example/custom"}) == ""
+
+    def test_rocm_and_gfx_pins_are_rocm(self):
+        assert self._derive({"UNSLOTH_TORCH_INDEX_FAMILY": "rocm7.2"}) == "rocm"
+        assert (
+            self._derive({"UNSLOTH_TORCH_INDEX_URL": "https://repo.amd.com/rocm/whl/gfx120X-all"})
+            == "rocm"
+        )
+
+    def test_cpu_pin_is_cpu(self):
+        assert self._derive({"UNSLOTH_TORCH_INDEX_FAMILY": "cpu"}) == "cpu"
+
+    def test_source_uses_helper_not_bare_startswith(self):
+        # Guard against a regression back to elif _idx_leaf.startswith("cu").
+        src = _STACK_PATH.read_text(encoding = "utf-8")
+        assert (
+            "elif _is_cuda_family_leaf(_idx_leaf):" in src
+        ), "_TORCH_BACKEND derivation must classify CUDA via _is_cuda_family_leaf"
+        assert (
+            'elif _idx_leaf.startswith("cu"):' not in src
+        ), "_TORCH_BACKEND derivation must not use a bare startswith('cu')"
+
 
 # CUDA index ladder.
 
diff --git a/tests/studio/install/test_gpu_detection_followups.py b/tests/studio/install/test_gpu_detection_followups.py
index f5ad9566d7..d2fd7ae8db 100644
--- a/tests/studio/install/test_gpu_detection_followups.py
+++ b/tests/studio/install/test_gpu_detection_followups.py
@@ -284,7 +284,9 @@ class TestBackendExportLeafClassification:
     def test_export_block_uses_leaf(self, install_src):
         anchor = install_src.find("_torch_index_leaf=")
         assert anchor >= 0, "backend export must classify on the final path segment"
-        window = install_src[anchor : anchor + 500]
+        # Window spans the leaf-normalization prelude (query/frag drop + all-slash trim loop)
+        # through the export case arms.
+        window = install_src[anchor : anchor + 900]
         assert 'export UNSLOTH_TORCH_BACKEND="rocm"' in window
         assert 'export UNSLOTH_TORCH_BACKEND="cpu"' in window
         assert 'export UNSLOTH_TORCH_BACKEND="cuda"' in window
@@ -459,3 +461,130 @@ class TestHiddenCvdNotUsable:
             cvd,
         )
         assert out == expected
+
+
+class TestRedactInstallOutput:
+    """_redact_install_output scrubs index-URL credentials from a captured install log
+    before it is printed on failure (uv/pip embeds the failing --index-url verbatim)."""
+
+    def test_userinfo_redacted(self):
+        out = stack_mod._redact_install_output(
+            "ERROR: failed https://alice:s3cr3t@download.pytorch.org/whl/cu128"
+        )
+        assert out == "ERROR: failed https://<redacted>@download.pytorch.org/whl/cu128"
+
+    def test_bytes_input_decoded_and_redacted(self):
+        out = stack_mod._redact_install_output(b"fetch https://ghp_deadbeef@host/whl/cu128 failed")
+        assert out == "fetch https://<redacted>@host/whl/cu128 failed"
+
+    def test_query_values_redacted(self):
+        out = stack_mod._redact_install_output(
+            "url https://host/whl/cu128?token=abcd1234&channel=beta unreachable"
+        )
+        assert out == "url https://host/whl/cu128?token=<redacted>&channel=<redacted> unreachable"
+
+    def test_fragment_redacted(self):
+        out = stack_mod._redact_install_output(
+            "ERROR: could not fetch https://mirror.local/whl/cu128#token=SECRET123 (403)"
+        )
+        assert out == "ERROR: could not fetch https://mirror.local/whl/cu128#<redacted> (403)"
+
+    def test_query_and_fragment_both_redacted(self):
+        out = stack_mod._redact_install_output("https://host/whl/cu128?token=abc#sig=xyz done")
+        assert out == "https://host/whl/cu128?token=<redacted>#<redacted> done"
+
+    def test_bare_hash_comment_untouched(self):
+        # The fragment redaction is URL-anchored: a shell comment in tool output survives.
+        assert (
+            stack_mod._redact_install_output("# retrying with --no-cache-dir")
+            == "# retrying with --no-cache-dir"
+        )
+
+    def test_plain_line_untouched(self):
+        assert (
+            stack_mod._redact_install_output("Resolved 42 packages in 1.2s")
+            == "Resolved 42 packages in 1.2s"
+        )
+
+    def test_no_secret_substring_survives(self):
+        out = stack_mod._redact_install_output(
+            "https://alice:s3cr3t@host/whl/cu128?token=SUPERSECRET#frag=ALSOSECRET"
+        )
+        assert "s3cr3t" not in out and "SUPERSECRET" not in out and "ALSOSECRET" not in out
+
+
+class TestTrimIndexPathSlashes:
+    """_trim_index_path_slashes strips trailing PATH slashes only; a ?query/#fragment token
+    ending in "/" must survive (a whole-URL rstrip would corrupt a base64 token)."""
+
+    def test_double_path_slash_collapsed(self):
+        assert stack_mod._trim_index_path_slashes("https://h/whl/cu128//") == "https://h/whl/cu128"
+
+    def test_query_token_slash_preserved(self):
+        assert (
+            stack_mod._trim_index_path_slashes("https://h/whl/cu128?token=ab12cd/")
+            == "https://h/whl/cu128?token=ab12cd/"
+        )
+
+    def test_path_slash_trimmed_query_kept(self):
+        assert (
+            stack_mod._trim_index_path_slashes("https://h/whl/cu128//?token=ab12cd/")
+            == "https://h/whl/cu128?token=ab12cd/"
+        )
+
+    def test_fragment_slash_preserved(self):
+        assert (
+            stack_mod._trim_index_path_slashes("https://h/whl/cu128#anchor/")
+            == "https://h/whl/cu128#anchor/"
+        )
+
+
+class TestRocmFamilyLeafParity:
+    """_is_pip_rocm_family_leaf must match re.fullmatch(rocm\\d+(?:\\.\\d+)?): a trailing dot
+    (rocm7.) is a CUSTOM pin, not a family (the historical bash/py validator asymmetry)."""
+
+    @pytest.mark.parametrize(
+        "leaf, expected",
+        [
+            ("rocm7", True),
+            ("rocm7.2", True),
+            ("gfx1151", True),
+            ("rocm7.", False),
+            ("rocm.7", False),
+            ("rocm7..2", False),
+            ("rocm7.2.1", False),
+            ("rocm7.2-private", False),
+            ("cpu", False),
+            ("cu128", False),
+        ],
+    )
+    def test_family_classification(self, leaf, expected):
+        assert stack_mod._is_pip_rocm_family_leaf(leaf) is expected
+
+
+class TestTorchIndexLeafAllSlashes:
+    """_torch_index_leaf drops query/fragment then strips ALL trailing slashes, so a
+    double-slash index still yields the real leaf (not an empty string)."""
+
+    @pytest.mark.parametrize(
+        "url, expected",
+        [
+            ("https://m/whl/cu128//", "cu128"),
+            ("https://m/whl/rocm7.2///", "rocm7.2"),
+            ("https://m/whl/cu128//?token=x", "cu128"),
+            ("https://m/whl/cu128/", "cu128"),
+        ],
+    )
+    def test_leaf_never_empty_on_double_slash(self, url, expected):
+        assert stack_mod._torch_index_leaf(url) == expected
+
+
+class TestUvIndexEnvVarsScrub:
+    """The pinned-install env scrub must drop PIP_NO_INDEX (which makes the pip fallback
+    ignore ALL indexes, defeating the pin) and PIP_INDEX_URL (replaces the pinned index)."""
+
+    def test_pip_no_index_scrubbed(self):
+        assert "PIP_NO_INDEX" in stack_mod._UV_INDEX_ENV_VARS
+
+    def test_pip_index_url_scrubbed(self):
+        assert "PIP_INDEX_URL" in stack_mod._UV_INDEX_ENV_VARS
diff --git a/tests/studio/install/test_install_llama_prebuilt_logic.py b/tests/studio/install/test_install_llama_prebuilt_logic.py
index e995e5033e..3eaf56d15c 100644
--- a/tests/studio/install/test_install_llama_prebuilt_logic.py
+++ b/tests/studio/install/test_install_llama_prebuilt_logic.py
@@ -22,7 +22,6 @@ sys.modules[SPEC.name] = INSTALL_LLAMA_PREBUILT
 SPEC.loader.exec_module(INSTALL_LLAMA_PREBUILT)
 
 PrebuiltFallback = INSTALL_LLAMA_PREBUILT.PrebuiltFallback
-extract_archive = INSTALL_LLAMA_PREBUILT.extract_archive
 binary_env = INSTALL_LLAMA_PREBUILT.binary_env
 is_secret_env_name = INSTALL_LLAMA_PREBUILT.is_secret_env_name
 scrub_env = INSTALL_LLAMA_PREBUILT.scrub_env
@@ -105,105 +104,10 @@ def approved_checksums_for(
     )
 
 
-def test_extract_archive_allows_safe_tar_symlink_chain(tmp_path: Path):
-    archive_path = tmp_path / "bundle.tar.gz"
-    payload = b"shared-object"
-
-    with tarfile.open(archive_path, "w:gz") as archive:
-        versioned = tarfile.TarInfo("libllama.so.0.0.1")
-        versioned.size = len(payload)
-        archive.addfile(versioned, io_bytes(payload))
-
-        soname = tarfile.TarInfo("libllama.so.0")
-        soname.type = tarfile.SYMTYPE
-        soname.linkname = "libllama.so.0.0.1"
-        archive.addfile(soname)
-
-        linker_name = tarfile.TarInfo("libllama.so")
-        linker_name.type = tarfile.SYMTYPE
-        linker_name.linkname = "libllama.so.0"
-        archive.addfile(linker_name)
-
-    destination = tmp_path / "extract"
-    extract_archive(archive_path, destination)
-
-    assert (destination / "libllama.so.0.0.1").read_bytes() == payload
-    assert (destination / "libllama.so.0").is_symlink()
-    assert (destination / "libllama.so").is_symlink()
-    assert (destination / "libllama.so").resolve().read_bytes() == payload
-
-
-def test_extract_archive_allows_safe_tar_hardlink(tmp_path: Path):
-    archive_path = tmp_path / "bundle.tar.gz"
-    payload = b"quantize"
-
-    with tarfile.open(archive_path, "w:gz") as archive:
-        target = tarfile.TarInfo("llama-quantize")
-        target.size = len(payload)
-        archive.addfile(target, io_bytes(payload))
-
-        hardlink = tarfile.TarInfo("llama-quantize-copy")
-        hardlink.type = tarfile.LNKTYPE
-        hardlink.linkname = "llama-quantize"
-        archive.addfile(hardlink)
-
-    destination = tmp_path / "extract"
-    extract_archive(archive_path, destination)
-
-    assert (destination / "llama-quantize-copy").read_bytes() == payload
-    assert not (destination / "llama-quantize-copy").is_symlink()
-
-
-def test_extract_archive_rejects_absolute_tar_symlink_target(tmp_path: Path):
-    archive_path = tmp_path / "bundle.tar.gz"
-
-    with tarfile.open(archive_path, "w:gz") as archive:
-        entry = tarfile.TarInfo("libllama.so")
-        entry.type = tarfile.SYMTYPE
-        entry.linkname = "/tmp/libllama.so.0"
-        archive.addfile(entry)
-
-    with pytest.raises(PrebuiltFallback, match = "archive link used an absolute target"):
-        extract_archive(archive_path, tmp_path / "extract")
-
-
-def test_extract_archive_rejects_escaping_tar_symlink_target(tmp_path: Path):
-    archive_path = tmp_path / "bundle.tar.gz"
-
-    with tarfile.open(archive_path, "w:gz") as archive:
-        entry = tarfile.TarInfo("libllama.so")
-        entry.type = tarfile.SYMTYPE
-        entry.linkname = "../outside/libllama.so.0"
-        archive.addfile(entry)
-
-    with pytest.raises(PrebuiltFallback, match = "archive link escaped destination"):
-        extract_archive(archive_path, tmp_path / "extract")
-
-
-def test_extract_archive_rejects_unresolved_tar_symlink_target(tmp_path: Path):
-    archive_path = tmp_path / "bundle.tar.gz"
-
-    with tarfile.open(archive_path, "w:gz") as archive:
-        entry = tarfile.TarInfo("libllama.so")
-        entry.type = tarfile.SYMTYPE
-        entry.linkname = "libllama.so.0"
-        archive.addfile(entry)
-
-    with pytest.raises(PrebuiltFallback, match = "unresolved link entries"):
-        extract_archive(archive_path, tmp_path / "extract")
-
-
-def test_extract_archive_rejects_zip_symlink_entry(tmp_path: Path):
-    archive_path = tmp_path / "bundle.zip"
-
-    with zipfile.ZipFile(archive_path, "w") as archive:
-        info = zipfile.ZipInfo("libllama.so")
-        info.create_system = 3
-        info.external_attr = 0o120777 << 16
-        archive.writestr(info, "libllama.so.0")
-
-    with pytest.raises(PrebuiltFallback, match = "zip archive contained a symlink entry"):
-        extract_archive(archive_path, tmp_path / "extract")
+# The extract_archive guard tests (safe symlink chain / hardlink, absolute or
+# escaping or unresolved symlink targets, zip symlink entries) moved verbatim
+# to tests/studio/install/test_prebuilt_core.py: extract_archive is the shared
+# prebuilt_core implementation, re-exported by this installer.
 
 
 def test_remove_agent_instruction_files_does_not_follow_links(tmp_path: Path):
@@ -1348,6 +1252,7 @@ def test_install_prebuilt_falls_back_to_older_release_plan(
         approved_checksums,
         initial_fallback_used = False,
         existing_install_dir = None,
+        force_cpu = False,
     ):
         call_log.append((llama_tag, initial_fallback_used))
         if llama_tag == "b9002":
@@ -2551,6 +2456,7 @@ def test_install_prebuilt_skips_when_older_release_fallback_matches_existing_ins
         approved_checksums,
         initial_fallback_used = False,
         existing_install_dir = None,
+        force_cpu = False,
     ):
         call_log.append(llama_tag)
         raise PrebuiltFallback("validation failed for latest release")
@@ -2698,6 +2604,7 @@ def test_install_prebuilt_skips_same_release_fallback_attempt_when_installed(
         approved_checksums,
         prebuilt_fallback_used,
         quantized_path,
+        force_cpu = False,
     ):
         attempted_names.append(choice.name)
         if choice.name == first_choice.name:
@@ -2824,6 +2731,7 @@ def test_install_prebuilt_same_tag_upstream_failure_uses_older_unsloth_release_p
         approved_checksums,
         initial_fallback_used = False,
         existing_install_dir = None,
+        force_cpu = False,
     ):
         attempted.append((llama_tag, release_tag, attempts[0].source_label))
         if llama_tag == "b9002":
@@ -3416,6 +3324,66 @@ def test_validate_prebuilt_choice_approved_validation_runs_when_flag_enabled(tmp
     assert calls == {"quantize": 1, "server": 1}
 
 
+def test_staged_validation_enabled_default_off(monkeypatch):
+    monkeypatch.setattr(INSTALL_LLAMA_PREBUILT, "_RUN_STAGED_PREBUILT_VALIDATION", False)
+    monkeypatch.delenv("UNSLOTH_LLAMA_STAGED_VALIDATION", raising = False)
+    assert INSTALL_LLAMA_PREBUILT.staged_validation_enabled() is False
+
+
+@pytest.mark.parametrize("value", ["1", "true", "YES", "on"])
+def test_staged_validation_enabled_env_opt_in(monkeypatch, value):
+    monkeypatch.setattr(INSTALL_LLAMA_PREBUILT, "_RUN_STAGED_PREBUILT_VALIDATION", False)
+    monkeypatch.setenv("UNSLOTH_LLAMA_STAGED_VALIDATION", value)
+    assert INSTALL_LLAMA_PREBUILT.staged_validation_enabled() is True
+
+
+def test_validate_prebuilt_choice_approved_validation_runs_when_env_enabled(tmp_path, monkeypatch):
+    monkeypatch.setattr(INSTALL_LLAMA_PREBUILT, "_RUN_STAGED_PREBUILT_VALIDATION", False)
+    monkeypatch.setenv("UNSLOTH_LLAMA_STAGED_VALIDATION", "1")
+    calls = _run_validate_prebuilt_choice(monkeypatch, tmp_path, expected_sha256 = "ab" * 32)
+    assert calls == {"quantize": 1, "server": 1}
+
+
+def test_validate_existing_install_runs_server_smoke(tmp_path, monkeypatch):
+    # setup.sh --validate-install path: exercise smoke helpers without a real GPU.
+    install_dir = tmp_path / "llama.cpp"
+    bin_dir = install_dir / "build" / "bin"
+    bin_dir.mkdir(parents = True)
+    (bin_dir / "llama-server").write_text("#!/bin/sh\n", encoding = "utf-8")
+    (bin_dir / "llama-quantize").write_text("#!/bin/sh\n", encoding = "utf-8")
+    calls: dict[str, int] = {"quantize": 0, "server": 0, "download": 0}
+
+    monkeypatch.setattr(
+        INSTALL_LLAMA_PREBUILT,
+        "download_validation_model",
+        lambda path, cache = None: calls.__setitem__("download", calls["download"] + 1),
+    )
+    monkeypatch.setattr(
+        INSTALL_LLAMA_PREBUILT,
+        "validate_quantize",
+        lambda *a, **k: calls.__setitem__("quantize", calls["quantize"] + 1),
+    )
+    monkeypatch.setattr(
+        INSTALL_LLAMA_PREBUILT,
+        "validate_server",
+        lambda *a, **k: calls.__setitem__("server", calls["server"] + 1),
+    )
+    monkeypatch.setattr(
+        INSTALL_LLAMA_PREBUILT,
+        "detect_host",
+        lambda: linux_host(),
+    )
+
+    INSTALL_LLAMA_PREBUILT.validate_existing_install(install_dir, install_kind = "linux-cuda")
+    assert calls == {"quantize": 1, "server": 1, "download": 1}
+
+
+def test_validate_existing_install_missing_server_raises(tmp_path, monkeypatch):
+    monkeypatch.setattr(INSTALL_LLAMA_PREBUILT, "detect_host", lambda: linux_host())
+    with pytest.raises(INSTALL_LLAMA_PREBUILT.PrebuiltFallback, match = "llama-server not found"):
+        INSTALL_LLAMA_PREBUILT.validate_existing_install(tmp_path / "missing")
+
+
 def test_diffusion_visual_server_uses_approved_checksum_download(monkeypatch, tmp_path: Path):
     asset_name = "llama-diffusion-gemma-visual-server-linux-x64"
     expected_sha = "a" * 64
diff --git a/tests/studio/install/test_install_whisper_prebuilt_logic.py b/tests/studio/install/test_install_whisper_prebuilt_logic.py
new file mode 100644
index 0000000000..0a5541b27c
--- /dev/null
+++ b/tests/studio/install/test_install_whisper_prebuilt_logic.py
@@ -0,0 +1,1402 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Logic tests for studio/install_whisper_prebuilt.py -- the prebuilt whisper-server installer.
+# No network/GPU: release resolution is injected and archives are built on disk in a tmp dir.
+
+import importlib.util
+import io
+import json
+import sys
+import tarfile
+import zipfile
+from pathlib import Path
+
+import pytest
+
+
+PACKAGE_ROOT = Path(__file__).resolve().parents[3]
+MODULE_PATH = PACKAGE_ROOT / "studio" / "install_whisper_prebuilt.py"
+# The installer imports install_llama_prebuilt (same directory); make studio/
+# importable so that resolves under spec-based loading.
+_STUDIO_DIR = str(MODULE_PATH.parent)
+if _STUDIO_DIR not in sys.path:
+    sys.path.insert(0, _STUDIO_DIR)
+SPEC = importlib.util.spec_from_file_location("studio_install_whisper_prebuilt", MODULE_PATH)
+assert SPEC is not None and SPEC.loader is not None
+M = importlib.util.module_from_spec(SPEC)
+sys.modules[SPEC.name] = M
+SPEC.loader.exec_module(M)
+
+HostInfo = M.HostInfo
+PrebuiltFallback = M.PrebuiltFallback
+ReleaseCompatibilityError = M.ReleaseCompatibilityError
+BusyInstallConflict = M.BusyInstallConflict
+
+RELEASE_TAG = "v1.9.1-unsloth.1"
+UPSTREAM_TAG = "v1.9.1"
+SOURCE_COMMIT = "0" * 40
+STUDIO_PROTOCOL = "inference/multipart-v1"
+
+
+def _host(
+    whisper_os: str,
+    whisper_arch: str,
+    *,
+    has_usable_nvidia: bool = False,
+    has_rocm: bool = False,
+    rocm_gfx: str | None = None,
+    macos_version: tuple[int, int] | None = None,
+) -> HostInfo:
+    ext = ".zip" if whisper_os == "windows" else ".tar.gz"
+    return HostInfo(
+        system = {"linux": "Linux", "macos": "Darwin", "windows": "Windows"}[whisper_os],
+        machine = whisper_arch,
+        whisper_os = whisper_os,
+        whisper_arch = whisper_arch,
+        archive_ext = ext,
+        is_windows = whisper_os == "windows",
+        is_macos = whisper_os == "macos",
+        is_apple_silicon = whisper_os == "macos" and whisper_arch == "arm64",
+        has_usable_nvidia = has_usable_nvidia,
+        has_rocm = has_rocm,
+        rocm_gfx = rocm_gfx,
+        macos_version = macos_version,
+    )
+
+
+def _artifact(os_: str, arch: str, backend: str, asset: str, sha256: str, **extra) -> dict:
+    art = {
+        "os": os_,
+        "arch": arch,
+        "backend": backend,
+        "asset": asset,
+        "sha256": sha256,
+        "runtime_line": extra.get("runtime_line"),
+    }
+    art.update(extra)
+    return art
+
+
+def _manifest(
+    artifacts: list[dict],
+    *,
+    component: str = "whisper.cpp",
+    schema_version: int = 1,
+) -> dict:
+    return {
+        "schema_version": schema_version,
+        "component": component,
+        "studio_protocol": STUDIO_PROTOCOL,
+        "upstream_tag": UPSTREAM_TAG,
+        "source_commit": SOURCE_COMMIT,
+        "artifacts": artifacts,
+    }
+
+
+# ── Host detection (probes come from install_llama_prebuilt.detect_host) ──
+def _llama_host(
+    system: str,
+    machine: str,
+    *,
+    has_usable_nvidia: bool = False,
+    compute_caps: list[str] | None = None,
+    driver_cuda_version: tuple[int, int] | None = None,
+    has_rocm: bool = False,
+    rocm_gfx: str | None = None,
+    macos_version: tuple[int, int] | None = None,
+):
+    """A fake install_llama_prebuilt HostInfo, as llama_detect_host would return."""
+    lowered = machine.lower()
+    return M.llama.HostInfo(
+        system = system,
+        machine = machine,
+        is_windows = system == "Windows",
+        is_linux = system == "Linux",
+        is_macos = system == "Darwin",
+        is_x86_64 = lowered in {"x86_64", "amd64"},
+        is_arm64 = lowered in {"arm64", "aarch64"},
+        nvidia_smi = None,
+        driver_cuda_version = driver_cuda_version,
+        compute_caps = list(compute_caps or []),
+        visible_cuda_devices = None,
+        has_physical_nvidia = has_usable_nvidia,
+        has_usable_nvidia = has_usable_nvidia,
+        has_rocm = has_rocm,
+        rocm_gfx_target = rocm_gfx,
+        macos_version = macos_version,
+    )
+
+
+@pytest.mark.parametrize(
+    "system,machine,exp_os,exp_arch,exp_ext",
+    [
+        ("Linux", "x86_64", "linux", "x64", ".tar.gz"),
+        ("Linux", "aarch64", "linux", "arm64", ".tar.gz"),
+        ("Darwin", "x86_64", "macos", "x64", ".tar.gz"),
+        ("Darwin", "arm64", "macos", "arm64", ".tar.gz"),
+        ("Windows", "AMD64", "windows", "x64", ".zip"),
+        ("Windows", "ARM64", "windows", "arm64", ".zip"),
+    ],
+)
+def test_detect_host(monkeypatch, system, machine, exp_os, exp_arch, exp_ext):
+    monkeypatch.setattr(M, "llama_detect_host", lambda: _llama_host(system, machine))
+    host = M.detect_host()
+    assert (host.whisper_os, host.whisper_arch, host.archive_ext) == (exp_os, exp_arch, exp_ext)
+    assert host.is_windows == (exp_os == "windows")
+    assert host.is_apple_silicon == (exp_os == "macos" and exp_arch == "arm64")
+
+
+def test_detect_host_maps_rocm_fields(monkeypatch):
+    monkeypatch.setattr(
+        M,
+        "llama_detect_host",
+        lambda: _llama_host("Linux", "x86_64", has_rocm = True, rocm_gfx = "gfx1100"),
+    )
+    host = M.detect_host()
+    assert host.has_rocm is True
+    assert host.rocm_gfx == "gfx1100"
+    assert host.has_usable_nvidia is False
+
+
+@pytest.mark.parametrize(
+    "system,machine",
+    [("Plan9", "x86_64"), ("Linux", "sparc64"), ("Linux", "armv7l")],
+)
+def test_detect_host_unsupported(monkeypatch, system, machine):
+    monkeypatch.setattr(M, "llama_detect_host", lambda: _llama_host(system, machine))
+    with pytest.raises(PrebuiltFallback):
+        M.detect_host()
+
+
+# ── Asset naming (pure) ──
+def test_whisper_asset_name():
+    assert (
+        M.whisper_asset_name(RELEASE_TAG, _host("linux", "x64"), "cpu")
+        == "whisper-v1.9.1-unsloth.1-linux-x64-cpu.tar.gz"
+    )
+    assert (
+        M.whisper_asset_name(RELEASE_TAG, _host("macos", "arm64"), "metal")
+        == "whisper-v1.9.1-unsloth.1-macos-arm64-metal.tar.gz"
+    )
+    assert (
+        M.whisper_asset_name(RELEASE_TAG, _host("windows", "x64"), "cuda12")
+        == "whisper-v1.9.1-unsloth.1-windows-x64-cuda12.zip"
+    )
+
+
+# ── Install layout ──
+def test_whisper_server_path_layout():
+    nix = _host("linux", "x64")
+    win = _host("windows", "x64")
+    assert M.whisper_server_path(Path("/w"), nix) == Path("/w/build/bin/whisper-server")
+    assert M.whisper_server_path(Path("/w"), win) == Path("/w/build/bin/Release/whisper-server.exe")
+
+
+# ── Manifest parse + basic selection (wiring pin; the rejection matrix,
+# extraction guards, resolver payload shape and macOS min_os gating are
+# asserted against the real whisper descriptor in
+# tests/studio/install/test_prebuilt_core.py) ──
+def test_parse_manifest_ok_and_basic_selection():
+    cpu_asset = "whisper-v1.9.1-unsloth.1-linux-x64-cpu.tar.gz"
+    manifest = M.parse_manifest(_manifest([_artifact("linux", "x64", "cpu", cpu_asset, "a" * 64)]))
+    assert manifest["component"] == "whisper.cpp"
+    assert manifest["studio_protocol"] == STUDIO_PROTOCOL
+    host = _host("linux", "x64")
+    # The pinned pre-slim escape hatch: only the fat CPU bundle ever matches.
+    assert M.select_artifact(manifest, host, "cpu")["asset"] == cpu_asset
+    assert M.select_artifact(manifest, host, "metal") is None
+
+
+def test_select_artifact_never_picks_fat_gpu_bundles():
+    # A pinned pre-slim release's fat GPU bundles are dead shapes: a cuda/rocm
+    # backend selects nothing (the core then retries with cpu), never the fat
+    # per-accelerator artifact.
+    manifest = M.parse_manifest(
+        _manifest(
+            [
+                _artifact("linux", "x64", "cpu", "whisper-linux-x64-cpu.tar.gz", "a" * 64),
+                _artifact("linux", "x64", "cuda", "whisper-linux-x64-cuda13.tar.gz", "b" * 64),
+                _artifact("linux", "x64", "rocm", "whisper-linux-x64-rocm.tar.gz", "c" * 64),
+            ]
+        )
+    )
+    cuda_host = _host("linux", "x64", has_usable_nvidia = True)
+    assert M.select_artifact(manifest, cuda_host, "cuda") is None
+    rocm_host = _host("linux", "x64", has_rocm = True, rocm_gfx = "gfx1100")
+    assert M.select_artifact(manifest, rocm_host, "rocm") is None
+    artifact, backend, used_fallback = M.select_artifact_with_fallback(manifest, cuda_host, "cuda")
+    assert artifact["asset"] == "whisper-linux-x64-cpu.tar.gz"
+    assert backend == "cpu" and used_fallback is True
+
+
+# ── Traversal-safe extraction ──
+def _add_file(
+    tar: tarfile.TarFile,
+    name: str,
+    data: bytes,
+    mode: int = 0o644,
+):
+    info = tarfile.TarInfo(name)
+    info.size = len(data)
+    info.mode = mode
+    tar.addfile(info, io.BytesIO(data))
+
+
+# ── Fixture archive + full staging/activate install ──
+def _build_cpu_bundle(tmp_path: Path, host: HostInfo) -> tuple[Path, str, str]:
+    """Build a fake CPU bundle archive with a dummy server + lib; return (path, name, sha256)."""
+    asset = M.whisper_asset_name(RELEASE_TAG, host, "cpu")
+    archive = tmp_path / asset
+    server_name = M.server_binary_name(host)
+    with tarfile.open(archive, "w:gz") as tar:
+        _add_file(tar, server_name, b"#!/bin/sh\necho whisper\n", mode = 0o755)
+        _add_file(tar, "libwhisper.so", b"dummy-libwhisper")
+        _add_file(tar, "libggml-base.so", b"dummy-libggml")
+    return archive, asset, M.sha256_file(archive)
+
+
+def _install_env(
+    monkeypatch,
+    tmp_path,
+    host,
+    *,
+    asset,
+    sha256,
+    backend_in_manifest = "cpu",
+):
+    """Wire monkeypatches so install_prebuilt runs fully offline against a local
+    archive, injecting the release bundle + checksum index (the checksum trust
+    model) via the single fetch_release_for_install seam."""
+    manifest = M.parse_manifest(
+        _manifest(
+            [_artifact(host.whisper_os, host.whisper_arch, backend_in_manifest, asset, sha256)]
+        )
+    )
+    bundle = M.ReleaseBundle(
+        repo = "unslothai/whisper.cpp",
+        release_tag = RELEASE_TAG,
+        manifest = manifest,
+        asset_urls = {asset: f"https://example.invalid/{asset}"},
+    )
+    checksums = {asset: sha256}
+    monkeypatch.setattr(
+        M,
+        "fetch_release_for_install",
+        lambda repo, *, published_release_tag = None: (bundle, checksums),
+    )
+    return bundle
+
+
+def test_install_produces_colocated_layout_and_marker(tmp_path, monkeypatch):
+    host = _host("linux", "x64")
+    archive, asset, sha256 = _build_cpu_bundle(tmp_path, host)
+
+    def fake_download(url, destination):
+        destination.parent.mkdir(parents = True, exist_ok = True)
+        destination.write_bytes(archive.read_bytes())
+
+    monkeypatch.setattr(M, "detect_host", lambda: host)
+    monkeypatch.setattr(M, "download_file", fake_download)
+    _install_env(monkeypatch, tmp_path, host, asset = asset, sha256 = sha256)
+
+    install_dir = tmp_path / "whisper.cpp"
+    rc = M.install_prebuilt(install_dir, backend = "cpu")
+    assert rc == M.EXIT_SUCCESS
+
+    server = install_dir / "build" / "bin" / "whisper-server"
+    assert server.is_file()
+    assert server.stat().st_mode & 0o111  # +x set on unix
+    # every shared lib from the archive is co-located next to the server
+    assert (install_dir / "build" / "bin" / "libwhisper.so").is_file()
+    assert (install_dir / "build" / "bin" / "libggml-base.so").is_file()
+    # marker written at the component root
+    marker = json.loads((install_dir / M.METADATA_FILENAME).read_text())
+    assert marker["component"] == "whisper.cpp"
+    assert marker["release_tag"] == RELEASE_TAG
+    assert marker["backend"] == "cpu"
+    assert marker["studio_protocol"] == STUDIO_PROTOCOL
+    assert marker["install_fingerprint"]
+
+
+def test_install_is_idempotent(tmp_path, monkeypatch):
+    host = _host("linux", "x64")
+    archive, asset, sha256 = _build_cpu_bundle(tmp_path, host)
+
+    calls = {"n": 0}
+
+    def fake_download(url, destination):
+        calls["n"] += 1
+        destination.parent.mkdir(parents = True, exist_ok = True)
+        destination.write_bytes(archive.read_bytes())
+
+    monkeypatch.setattr(M, "detect_host", lambda: host)
+    monkeypatch.setattr(M, "download_file", fake_download)
+    _install_env(monkeypatch, tmp_path, host, asset = asset, sha256 = sha256)
+
+    install_dir = tmp_path / "whisper.cpp"
+    assert M.install_prebuilt(install_dir, backend = "cpu") == M.EXIT_SUCCESS
+    assert calls["n"] == 1
+    # Second run: marker + binary already match -> "already matches", no download.
+    assert M.install_prebuilt(install_dir, backend = "cpu") == M.EXIT_SUCCESS
+    assert calls["n"] == 1
+
+
+def test_install_sha_mismatch_then_retry_fails_closed(tmp_path, monkeypatch):
+    host = _host("linux", "x64")
+    archive, asset, _real_sha = _build_cpu_bundle(tmp_path, host)
+    wrong_sha = "f" * 64  # the checksum index claims a different sha than the archive
+
+    def fake_download(url, destination):
+        destination.parent.mkdir(parents = True, exist_ok = True)
+        destination.write_bytes(archive.read_bytes())
+
+    monkeypatch.setattr(M, "detect_host", lambda: host)
+    monkeypatch.setattr(M, "download_file", fake_download)
+    _install_env(monkeypatch, tmp_path, host, asset = asset, sha256 = wrong_sha)
+
+    install_dir = tmp_path / "whisper.cpp"
+    with pytest.raises(PrebuiltFallback):
+        M.install_prebuilt(install_dir, backend = "cpu")
+    # A failed verify never activates a binary.
+    assert not (install_dir / "build" / "bin" / "whisper-server").exists()
+
+
+# ── Busy lock -> exit 3 ──
+def test_busy_lock_maps_to_exit_busy(tmp_path, monkeypatch):
+    host = _host("linux", "x64")
+    archive, asset, sha256 = _build_cpu_bundle(tmp_path, host)
+    monkeypatch.setattr(M, "detect_host", lambda: host)
+    monkeypatch.setattr(M, "download_file", lambda u, d: None)
+    _install_env(monkeypatch, tmp_path, host, asset = asset, sha256 = sha256)
+
+    from contextlib import contextmanager
+
+    @contextmanager
+    def busy_lock(_path):
+        raise BusyInstallConflict("held by another process")
+        yield  # pragma: no cover
+
+    monkeypatch.setattr(M, "install_lock", busy_lock)
+    rc = M.main(["--install-dir", str(tmp_path / "whisper.cpp"), "--backend", "cpu"])
+    assert rc == M.EXIT_BUSY
+
+
+# ── Resolver JSON shape ──
+def test_resolve_mode_keeps_stdout_json_only(tmp_path, monkeypatch, capsys):
+    # Even when the slim pairing emits diagnostics, --resolve-prebuilt must keep
+    # stdout to exactly the JSON line (setup.sh / whisper_cpp_update.py parse
+    # it); the slim_selection log noise belongs on stderr.
+    host = _cuda_host()
+    bin_dir = _fake_llama_bin(tmp_path)
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, SLIM_LLAMA_TAG, "cuda13-newer")
+    )
+    manifest = _slim_manifest()
+    bundle = M.ReleaseBundle(
+        repo = "unslothai/whisper.cpp",
+        release_tag = RELEASE_TAG,
+        manifest = manifest,
+        asset_urls = {
+            a["asset"]: f"https://example.invalid/{a['asset']}" for a in manifest["artifacts"]
+        },
+    )
+    monkeypatch.setattr(M, "detect_host", lambda: host)
+    monkeypatch.setattr(
+        M, "fetch_release_for_install", lambda repo, *, published_release_tag = None: (bundle, {})
+    )
+    # A prior install test may have left the module flag True; the resolver must
+    # force it back to stderr regardless.
+    monkeypatch.setattr(M, "_LOG_TO_STDOUT", True, raising = False)
+
+    rc = M.main(["--resolve-prebuilt", "--output-format", "json"])
+    assert rc == M.EXIT_SUCCESS
+    captured = capsys.readouterr()
+    payload = json.loads(captured.out.strip())  # exactly one JSON line, parseable
+    assert payload["asset"] == SLIM_ASSET
+    assert "[whisper-prebuilt]" not in captured.out  # no log noise on stdout
+    assert "slim_selection:" in captured.err  # diagnostics routed to stderr
+
+
+def test_main_maps_prebuilt_fallback_to_exit_error(tmp_path, monkeypatch):
+    def boom(*a, **kw):
+        raise PrebuiltFallback("no prebuilt")
+
+    monkeypatch.setattr(M, "install_prebuilt", boom)
+    rc = M.main(["--install-dir", str(tmp_path / "whisper.cpp"), "--backend", "cpu"])
+    assert rc == M.EXIT_ERROR
+
+
+def test_main_forwards_requested_whisper_tags(tmp_path, monkeypatch):
+    seen = {}
+
+    def install(*args, **kwargs):
+        seen.update(kwargs)
+        return M.EXIT_SUCCESS
+
+    monkeypatch.setattr(M, "install_prebuilt", install)
+    rc = M.main(["--install-dir", str(tmp_path / "whisper.cpp"), "--whisper-tag", "v1.9.0"])
+    assert rc == M.EXIT_SUCCESS
+    assert seen["whisper_tag"] == "v1.9.0"
+
+    monkeypatch.setattr(M, "detect_host", lambda: _host("linux", "x64"))
+    monkeypatch.setattr(
+        M,
+        "resolve_prebuilt",
+        lambda host, **kwargs: (
+            seen.update(kwargs) or {"prebuilt_available": False, "repo": "unslothai/whisper.cpp"}
+        ),
+    )
+    assert M.main(["--resolve-prebuilt", "v1.8.0", "--output-format", "json"]) == 0
+    assert seen["whisper_tag"] == "v1.8.0"
+
+
+def test_main_reserves_exit_2_for_release_incompatibility(tmp_path, monkeypatch):
+    def boom(*a, **kw):
+        raise ReleaseCompatibilityError("slim bundle requires llama.cpp b2; installed b1")
+
+    monkeypatch.setattr(M, "install_prebuilt", boom)
+    rc = M.main(["--install-dir", str(tmp_path / "whisper.cpp"), "--backend", "cpu"])
+    assert rc == M.EXIT_INCOMPATIBLE
+
+
+def test_main_maps_unexpected_error_to_exit_error(tmp_path, monkeypatch):
+    def boom(*a, **kw):
+        raise RuntimeError("kaboom")
+
+    monkeypatch.setattr(M, "install_prebuilt", boom)
+    rc = M.main(["--install-dir", str(tmp_path / "whisper.cpp"), "--backend", "cpu"])
+    assert rc == M.EXIT_ERROR
+
+
+def test_resolve_mode_unexpected_error_reports_unavailable(monkeypatch, capsys):
+    # An unexpected failure inside the probe maps to prebuilt_available=False, not
+    # a traceback, so the caller falls back cleanly.
+    host = _host("linux", "x64")
+    monkeypatch.setattr(M, "detect_host", lambda: host)
+
+    def boom(repo, *, published_release_tag = None):
+        raise RuntimeError("network down")
+
+    monkeypatch.setattr(M, "fetch_release_for_install", boom)
+    rc = M.main(["--resolve-prebuilt", "--output-format", "json"])
+    assert rc == M.EXIT_SUCCESS
+    payload = json.loads(capsys.readouterr().out.strip())
+    assert payload == {"prebuilt_available": False, "repo": "unslothai/whisper.cpp"}
+
+
+# ── --rocm-gfx / --has-rocm overrides (llama parity) ──
+def test_rocm_gfx_override_implies_has_rocm():
+    # --rocm-gfx alone (no --has-rocm) must enable ROCm and clear NVIDIA, else the
+    # host stays on its CUDA/CPU path and never picks the ROCm bundle.
+    base = _host("linux", "x64", has_usable_nvidia = True)
+    out = M.apply_host_overrides(base, rocm_gfx = "gfx1100")
+    assert out.has_rocm is True
+    assert out.rocm_gfx == "gfx1100"
+    assert out.has_usable_nvidia is False
+    assert M.auto_detect_backend(out) == "rocm"
+
+
+# ── Slim bundles paired with the installed llama.cpp ggml runtime ──
+SLIM_LLAMA_TAG = "b10069-mix-fb3d4ca"
+SLIM_ASSET = "whisper-v1.9.1-unsloth.1-linux-x64-slim.tar.gz"
+CPU_ASSET = "whisper-v1.9.1-unsloth.1-linux-x64-cpu.tar.gz"
+
+
+def _fake_llama_bin(
+    tmp_path: Path,
+    *,
+    backend_module: str | None = "libggml-cuda.so",
+    sonames: tuple[str, ...] = ("libggml.so.0", "libggml-base.so.0"),
+) -> Path:
+    bin_dir = tmp_path / "llama.cpp" / "build" / "bin"
+    bin_dir.mkdir(parents = True, exist_ok = True)
+    for name in sonames:
+        (bin_dir / name).write_bytes(b"ggml-old-" + name.encode())
+    if backend_module:
+        (bin_dir / backend_module).write_bytes(b"ggml-backend-old")
+    (bin_dir / "libggml-cpu-x64.so").write_bytes(b"ggml-cpu-old")
+    (bin_dir / "libllama.so").write_bytes(b"not-ggml")  # must never be linked
+    return bin_dir
+
+
+def _slim_artifact(**extra) -> dict:
+    art = {
+        "os": "linux",
+        "arch": "x64",
+        "backend": "slim",
+        "asset": SLIM_ASSET,
+        "sha256": "c" * 64,
+        "install_kind": "slim",
+        "requires_llama_tag": SLIM_LLAMA_TAG,
+        "requires_ggml_version": "0.17.0",
+        "requires_ggml_sonames": ["libggml.so.0", "libggml-base.so.0"],
+        "min_os": None,
+    }
+    art.update(extra)
+    return art
+
+
+def _slim_manifest(slim_extra: dict | None = None) -> dict:
+    """The transition-release shape: a slim bundle beside the published fat CPU
+    bundle (the pinned pre-slim escape hatch)."""
+    artifacts = [
+        _artifact("linux", "x64", "cpu", CPU_ASSET, "a" * 64),
+        _slim_artifact(**(slim_extra or {})),
+    ]
+    return M.parse_manifest(_manifest(artifacts))
+
+
+def _cuda_host() -> HostInfo:
+    return _host("linux", "x64", has_usable_nvidia = True)
+
+
+def test_installed_llama_runtime_reads_marker(tmp_path):
+    root = tmp_path / "llama.cpp"
+    bin_dir = root / "build" / "bin"
+    bin_dir.mkdir(parents = True)
+    (root / "UNSLOTH_PREBUILT_INFO.json").write_text(
+        json.dumps({"release_tag": SLIM_LLAMA_TAG, "bundle_profile": "cuda13-newer"})
+    )
+    assert M.llama.installed_llama_runtime(root) == (bin_dir, SLIM_LLAMA_TAG, "cuda13-newer")
+
+
+@pytest.mark.parametrize(
+    "prepare",
+    [
+        lambda root: None,  # no marker at all
+        lambda root: (root / "UNSLOTH_PREBUILT_INFO.json").write_text("{}"),  # no release_tag
+        lambda root: (root / "UNSLOTH_PREBUILT_INFO.json").write_text("not json"),
+    ],
+)
+def test_installed_llama_runtime_rejects_incomplete_installs(tmp_path, prepare):
+    root = tmp_path / "llama.cpp"
+    (root / "build" / "bin").mkdir(parents = True)
+    prepare(root)
+    assert M.llama.installed_llama_runtime(root) is None
+
+
+def test_installed_llama_runtime_requires_bin_dir(tmp_path):
+    root = tmp_path / "llama.cpp"
+    root.mkdir()
+    (root / "UNSLOTH_PREBUILT_INFO.json").write_text(json.dumps({"release_tag": SLIM_LLAMA_TAG}))
+    assert M.llama.installed_llama_runtime(root) is None  # marker but no build/bin
+
+
+def test_slim_selected_when_all_pairing_checks_pass(tmp_path, monkeypatch):
+    bin_dir = _fake_llama_bin(tmp_path)
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, SLIM_LLAMA_TAG, "cuda13-newer")
+    )
+    artifact, backend, used_fallback = M.select_artifact_with_fallback(
+        _slim_manifest(), _cuda_host(), "cuda"
+    )
+    assert artifact["asset"] == SLIM_ASSET
+    assert backend == "cuda" and used_fallback is False
+
+
+@pytest.mark.parametrize(
+    "runtime,slim_extra",
+    [
+        # No llama install at all.
+        (lambda bin_dir: None, None),
+        # Installed llama tag does not match requires_llama_tag.
+        (lambda bin_dir: (bin_dir, "b99999-mix-0000000", "cuda13-newer"), None),
+        # A required soname is missing from the llama bin dir.
+        (
+            lambda bin_dir: (bin_dir, SLIM_LLAMA_TAG, "cuda13-newer"),
+            {"requires_ggml_sonames": ["libggml.so.0", "libggml-base.so.0", "libggml-extra.so.9"]},
+        ),
+        # Manifest omits the soname contract entirely.
+        (lambda bin_dir: (bin_dir, SLIM_LLAMA_TAG, "cuda13-newer"), {"requires_ggml_sonames": []}),
+    ],
+)
+def test_slim_pairing_failure_falls_back_to_pinned_cpu(tmp_path, monkeypatch, runtime, slim_extra):
+    # With the fat per-accelerator chain gone, a failed pairing degrades to the
+    # one legacy shape: the release's published fat CPU bundle.
+    bin_dir = _fake_llama_bin(tmp_path)
+    monkeypatch.setattr(M, "installed_llama_runtime", lambda: runtime(bin_dir))
+    artifact, backend, used_fallback = M.select_artifact_with_fallback(
+        _slim_manifest(slim_extra), _cuda_host(), "cuda"
+    )
+    assert artifact["asset"] == CPU_ASSET
+    assert backend == "cpu" and used_fallback is True
+
+
+def test_slim_missing_accel_module_rides_the_cpu_module(tmp_path, monkeypatch):
+    # Sonames present but no libggml-cuda.so in the llama bin dir: the cuda
+    # pairing fails, and the cpu retry still serves the same slim bundle via
+    # the llama cpu modules.
+    bin_dir = _fake_llama_bin(tmp_path, backend_module = None)
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, SLIM_LLAMA_TAG, "cuda13-newer")
+    )
+    artifact, backend, used_fallback = M.select_artifact_with_fallback(
+        _slim_manifest(), _cuda_host(), "cuda"
+    )
+    assert artifact["asset"] == SLIM_ASSET
+    assert backend == "cpu" and used_fallback is True
+
+
+def test_slim_selected_for_cpu_backend_on_linux(tmp_path, monkeypatch):
+    # Slim-only releases must serve cpu too: with the llama cpu modules present
+    # the cpu backend rides the same slim bundle as the GPUs.
+    bin_dir = _fake_llama_bin(tmp_path)
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, SLIM_LLAMA_TAG, "cuda13-newer")
+    )
+    artifact, backend, _fb = M.select_artifact_with_fallback(
+        _slim_manifest(), _host("linux", "x64"), "cpu"
+    )
+    assert artifact["asset"] == SLIM_ASSET and backend == "cpu"
+
+
+def test_slim_cpu_requires_a_cpu_module(tmp_path, monkeypatch):
+    # Sonames present but no libggml-cpu* variant in the llama bin dir -> fat cpu.
+    bin_dir = tmp_path / "llama.cpp" / "build" / "bin"
+    bin_dir.mkdir(parents = True)
+    for name in ("libggml.so.0", "libggml-base.so.0"):
+        (bin_dir / name).write_bytes(b"ggml")
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, SLIM_LLAMA_TAG, "linux-cpu")
+    )
+    artifact, backend, _fb = M.select_artifact_with_fallback(
+        _slim_manifest(), _host("linux", "x64"), "cpu"
+    )
+    assert artifact["asset"] == CPU_ASSET and backend == "cpu"
+
+
+WIN_SLIM_ASSET = "whisper-v1.9.1-unsloth.1-windows-x64-slim.zip"
+
+
+def test_slim_selected_for_cpu_backend_on_windows(tmp_path, monkeypatch):
+    bin_dir = tmp_path / "llama.cpp" / "build" / "bin" / "Release"
+    bin_dir.mkdir(parents = True)
+    for name in ("ggml.dll", "ggml-base.dll", "ggml-cpu-haswell.dll"):
+        (bin_dir / name).write_bytes(b"ggml")
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, SLIM_LLAMA_TAG, "windows-cpu")
+    )
+    manifest = M.parse_manifest(
+        _manifest(
+            [
+                _slim_artifact(
+                    os = "windows",
+                    arch = "x64",
+                    asset = WIN_SLIM_ASSET,
+                    requires_ggml_sonames = ["ggml.dll", "ggml-base.dll"],
+                )
+            ]
+        )
+    )
+    artifact, backend, _fb = M.select_artifact_with_fallback(
+        manifest, _host("windows", "x64"), "cpu"
+    )
+    assert artifact["asset"] == WIN_SLIM_ASSET and backend == "cpu"
+
+
+MAC_SLIM_ASSET = "whisper-v1.9.1-unsloth.1-macos-arm64-slim.tar.gz"
+
+
+def _fake_llama_bin_macos(tmp_path: Path) -> Path:
+    """The dylib names the live llama macos bundle ships (core + cpu + metal)."""
+    bin_dir = tmp_path / "llama.cpp" / "build" / "bin"
+    bin_dir.mkdir(parents = True, exist_ok = True)
+    for name in (
+        "libggml.dylib",
+        "libggml-base.dylib",
+        "libggml-cpu.dylib",
+        "libggml-metal.dylib",
+        "libggml-blas.dylib",
+    ):
+        (bin_dir / name).write_bytes(b"ggml-" + name.encode())
+    (bin_dir / "libllama.dylib").write_bytes(b"not-ggml")
+    return bin_dir
+
+
+def _macos_slim_manifest(arch: str = "arm64") -> dict:
+    return M.parse_manifest(
+        _manifest(
+            [
+                _slim_artifact(
+                    os = "macos",
+                    arch = arch,
+                    asset = MAC_SLIM_ASSET,
+                    requires_ggml_sonames = ["libggml.dylib", "libggml-base.dylib"],
+                )
+            ]
+        )
+    )
+
+
+@pytest.mark.parametrize("backend", ["metal", "cpu"])
+def test_slim_selected_for_metal_and_cpu_on_macos(tmp_path, monkeypatch, backend):
+    bin_dir = _fake_llama_bin_macos(tmp_path)
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, SLIM_LLAMA_TAG, "macos-metal-arm64")
+    )
+    host = _host("macos", "arm64", macos_version = (14, 0))
+    artifact, effective, _fb = M.select_artifact_with_fallback(
+        _macos_slim_manifest(), host, backend
+    )
+    assert artifact["asset"] == MAC_SLIM_ASSET
+    assert effective == backend  # the accel identity, never "slim"
+
+
+def test_macos_auto_backends_route_to_slim(tmp_path, monkeypatch):
+    # auto -> metal on Apple Silicon, cpu on Intel macs; both must pick slim.
+    bin_dir = _fake_llama_bin_macos(tmp_path)
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, SLIM_LLAMA_TAG, "macos-metal-arm64")
+    )
+    silicon = _host("macos", "arm64", macos_version = (14, 0))
+    assert M.resolve_backend(silicon, "auto", cpu_fallback = False) == "metal"
+    artifact, backend, _fb = M.select_artifact_with_fallback(
+        _macos_slim_manifest(), silicon, "metal"
+    )
+    assert artifact["asset"] == MAC_SLIM_ASSET and backend == "metal"
+
+    intel = _host("macos", "x64", macos_version = (14, 0))
+    assert M.resolve_backend(intel, "auto", cpu_fallback = False) == "cpu"
+    artifact, backend, _fb = M.select_artifact_with_fallback(
+        _macos_slim_manifest(arch = "x64"), intel, "cpu"
+    )
+    assert artifact["asset"] == MAC_SLIM_ASSET and backend == "cpu"
+
+
+def test_slim_metal_requires_the_metal_module(tmp_path, monkeypatch):
+    # A macos llama runtime without libggml-metal*.dylib cannot back metal; the
+    # cpu fallback still rides the same slim bundle via the cpu module.
+    bin_dir = tmp_path / "llama.cpp" / "build" / "bin"
+    bin_dir.mkdir(parents = True)
+    for name in ("libggml.dylib", "libggml-base.dylib", "libggml-cpu.dylib"):
+        (bin_dir / name).write_bytes(b"ggml")
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, SLIM_LLAMA_TAG, "macos-cpu-x64")
+    )
+    host = _host("macos", "arm64", macos_version = (14, 0))
+    artifact, backend, used_fallback = M.select_artifact_with_fallback(
+        _macos_slim_manifest(), host, "metal"
+    )
+    assert artifact["asset"] == MAC_SLIM_ASSET
+    assert backend == "cpu" and used_fallback is True
+
+
+def test_slim_only_release_pairing_failure_is_actionable(tmp_path, monkeypatch):
+    # A slim-only release with no llama install is an operational failure, not
+    # the narrowly handled installed-version skew.
+    lines: list[str] = []
+    monkeypatch.setattr(M, "log", lines.append)
+    monkeypatch.setattr(M, "installed_llama_runtime", lambda: None)
+    manifest = M.parse_manifest(_manifest([_slim_artifact()]))
+    with pytest.raises(PrebuiltFallback):
+        M.select_artifact_with_fallback(manifest, _cuda_host(), "cuda")
+    assert any(
+        f"slim bundle requires llama.cpp {SLIM_LLAMA_TAG}; "
+        "install or update llama.cpp first" in line
+        for line in lines
+    )
+
+
+def test_slim_release_tag_skew_has_distinct_compatibility_error(tmp_path, monkeypatch):
+    bin_dir = _fake_llama_bin(tmp_path)
+    monkeypatch.setattr(
+        M,
+        "installed_llama_runtime",
+        lambda: (bin_dir, "b10068-mix-old", "cuda13-newer"),
+    )
+    manifest = M.parse_manifest(_manifest([_slim_artifact()]))
+    with pytest.raises(ReleaseCompatibilityError, match = SLIM_LLAMA_TAG):
+        M.select_artifact_with_fallback(manifest, _cuda_host(), "cuda")
+
+
+# A newer llama build that keeps the same ggml commit as SLIM_LLAMA_TAG.
+NEWER_LLAMA_TAG = "b10079-mix-fb3d4ca"
+
+
+@pytest.mark.parametrize(
+    "installed,required,pairs",
+    [
+        (SLIM_LLAMA_TAG, SLIM_LLAMA_TAG, True),  # exact tag
+        (NEWER_LLAMA_TAG, SLIM_LLAMA_TAG, True),  # newer build, same ggml commit
+        ("b10069-mix-0000000", SLIM_LLAMA_TAG, False),  # same build, different ggml
+        (SLIM_LLAMA_TAG, None, False),  # no requirement recorded
+        ("b10069", "b10069", True),  # tag without -mix-, exact only
+        ("b10070", "b10069", False),  # tag without -mix-, no shared key
+    ],
+)
+def test_llama_runtime_pairs_keys_on_ggml_commit(installed, required, pairs):
+    assert M.llama_runtime_pairs(installed, required) is pairs
+
+
+def test_slim_pairs_across_llama_build_bump_with_same_ggml(tmp_path, monkeypatch):
+    # The live failure: the llama installer advances to a newer build that keeps
+    # the same ggml commit, so the slim bundle's paired runtime is ABI-identical
+    # and must still select rather than degrade to CPU or report unavailable.
+    bin_dir = _fake_llama_bin(tmp_path)
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, NEWER_LLAMA_TAG, "cuda13-newer")
+    )
+    artifact, backend, used_fallback = M.select_artifact_with_fallback(
+        _slim_manifest(), _cuda_host(), "cuda"
+    )
+    assert artifact["asset"] == SLIM_ASSET
+    assert backend == "cuda" and used_fallback is False
+
+
+def test_slim_build_bump_same_ggml_is_not_a_compatibility_error(tmp_path, monkeypatch):
+    # A same-ggml build bump must not surface as a release incompatibility (the
+    # update path reports that as unavailable); only a real ggml skew does.
+    bin_dir = _fake_llama_bin(tmp_path)
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, NEWER_LLAMA_TAG, "cuda13-newer")
+    )
+    assert M._slim_release_incompatibility(_slim_manifest(), _cuda_host()) is None
+
+
+def test_link_ggml_runtime_hardlinks_every_ggml_library(tmp_path):
+    bin_dir = _fake_llama_bin(tmp_path)
+    whisper_bin = tmp_path / "whisper.cpp" / "build" / "bin"
+    linked = M.link_ggml_runtime(bin_dir, whisper_bin)
+    assert linked == [
+        "libggml-base.so.0",
+        "libggml-cpu-x64.so",
+        "libggml-cuda.so",
+        "libggml.so.0",
+    ]
+    for name in ("libggml.so.0", "libggml-base.so.0", "libggml-cuda.so", "libggml-cpu-x64.so"):
+        source, dest = bin_dir / name, whisper_bin / name
+        assert dest.is_file() and not dest.is_symlink()
+        assert dest.stat().st_ino == source.stat().st_ino  # a true hardlink
+    assert not (whisper_bin / "libllama.so").exists()  # only ggml libraries wire over
+
+
+def test_link_ggml_runtime_copy_fallback(tmp_path, monkeypatch):
+    def no_link(src, dst, **kwargs):
+        raise OSError("cross-device link")
+
+    monkeypatch.setattr(M.os, "link", no_link)
+    bin_dir = _fake_llama_bin(tmp_path)
+    whisper_bin = tmp_path / "whisper.cpp" / "build" / "bin"
+    assert len(M.link_ggml_runtime(bin_dir, whisper_bin)) == 4
+    dest = whisper_bin / "libggml.so.0"
+    assert dest.read_bytes() == (bin_dir / "libggml.so.0").read_bytes()
+    assert dest.stat().st_nlink == 1  # a copy, not a link
+
+
+def test_link_ggml_runtime_hardlinks_dylibs(tmp_path):
+    # macOS wiring: the libggml* glob must take the .dylib names too.
+    bin_dir = _fake_llama_bin_macos(tmp_path)
+    whisper_bin = tmp_path / "whisper.cpp" / "build" / "bin"
+    linked = M.link_ggml_runtime(bin_dir, whisper_bin)
+    assert linked == [
+        "libggml-base.dylib",
+        "libggml-blas.dylib",
+        "libggml-cpu.dylib",
+        "libggml-metal.dylib",
+        "libggml.dylib",
+    ]
+    for name in linked:
+        source, dest = bin_dir / name, whisper_bin / name
+        assert dest.is_file() and not dest.is_symlink()
+        assert dest.stat().st_ino == source.stat().st_ino  # a true hardlink
+    assert not (whisper_bin / "libllama.dylib").exists()
+
+
+def test_link_ggml_runtime_fails_closed_on_empty_runtime(tmp_path):
+    empty = tmp_path / "empty"
+    empty.mkdir()
+    with pytest.raises(PrebuiltFallback):
+        M.link_ggml_runtime(empty, tmp_path / "whisper_bin")
+
+
+def test_link_ggml_runtime_wires_windows_libomp(tmp_path):
+    # llama's clang-built windows-arm64 ggml-base.dll imports
+    # libomp140.aarch64.dll (bundled, not a system DLL): the wiring must place
+    # it next to whisper-server.exe or the loader dies with DLL_NOT_FOUND.
+    bin_dir = tmp_path / "llama_bin"
+    bin_dir.mkdir()
+    for name in ("ggml.dll", "ggml-base.dll", "ggml-cpu.dll", "libomp140.aarch64.dll"):
+        (bin_dir / name).write_bytes(b"x")
+    (bin_dir / "llama.dll").write_bytes(b"x")  # never wired
+    whisper_bin = tmp_path / "whisper_bin"
+    linked = M.link_ggml_runtime(bin_dir, whisper_bin)
+    assert linked == ["ggml-base.dll", "ggml-cpu.dll", "ggml.dll", "libomp140.aarch64.dll"]
+    assert not (whisper_bin / "llama.dll").exists()
+
+
+def test_rocm_runtime_wires_complete_windows_dll_overlay(tmp_path):
+    bin_dir = tmp_path / "llama_bin"
+    bin_dir.mkdir()
+    dlls = {
+        "ggml.dll",
+        "ggml-base.dll",
+        "ggml-hip.dll",
+        "amdhip64.dll",
+        "rocblas.dll",
+        "hipblaslt.dll",
+        "hsa-runtime64.dll",
+        # The llama Windows ROCm archive can carry transitive DLLs whose names
+        # do not contain hip/roc/amd. Its installer overlays every DLL.
+        "runtime-support.dll",
+    }
+    for name in dlls:
+        (bin_dir / name).write_bytes(name.encode())
+    (bin_dir / "not-a-runtime.txt").write_text("ignored")
+
+    whisper_bin = tmp_path / "whisper_bin"
+    linked = M.link_ggml_runtime(bin_dir, whisper_bin, backend = "rocm")
+    linked_dirs = M.link_runtime_directories(
+        bin_dir,
+        whisper_bin,
+        backend = "rocm",
+        host = _host("windows", "x64"),
+    )
+
+    assert set(linked) == dlls
+    assert linked_dirs == []
+    assert all((whisper_bin / name).is_file() for name in dlls)
+    assert not (whisper_bin / "not-a-runtime.txt").exists()
+
+
+def test_assemble_does_not_copy_packaging_marker_beside_server(tmp_path):
+    host = _host("linux", "x64")
+    bundle = tmp_path / "bundle"
+    bundle.mkdir()
+    (bundle / "whisper-server").write_text("server")
+    (bundle / M.METADATA_FILENAME).write_text('{"backend":"slim"}')
+    staged = tmp_path / "staged"
+    M.assemble_install_tree(bundle, staged, host)
+    assert not (staged / "build" / "bin" / M.METADATA_FILENAME).exists()
+
+
+def test_rocm_runtime_wires_packaged_dependency_closure_and_catalogs(tmp_path, monkeypatch):
+    llama_bin = _fake_llama_bin(tmp_path, backend_module = "libggml-hip.so")
+    for name in ("libamdhip64.so.6", "libhipblas.so.2", "libcustomrocm.so.1"):
+        (llama_bin / name).write_bytes(name.encode())
+    for directory in M.SLIM_ROCM_RUNTIME_DIRS:
+        catalog = llama_bin / directory / "library" / "gfx1100"
+        catalog.mkdir(parents = True)
+        (catalog / "kernel.dat").write_bytes(directory.encode())
+
+    dependencies = {
+        "libggml-hip.so": {"libamdhip64.so.6", "libcustomrocm.so.1"},
+        "libamdhip64.so.6": {"libhipblas.so.2"},
+    }
+    monkeypatch.setattr(M, "_elf_needed", lambda path: dependencies.get(path.name, set()))
+    whisper_bin = tmp_path / "whisper-bin"
+    linked = M.link_ggml_runtime(llama_bin, whisper_bin, backend = "rocm")
+    linked_dirs = M.link_runtime_directories(
+        llama_bin,
+        whisper_bin,
+        backend = "rocm",
+        host = _host("linux", "x64"),
+    )
+
+    assert "libcustomrocm.so.1" in linked
+    assert "libhipblas.so.2" in linked
+    assert linked_dirs == ["hipblaslt", "rocblas"]
+    for directory in linked_dirs:
+        linked_catalog = whisper_bin / directory / "library" / "gfx1100" / "kernel.dat"
+        source_catalog = llama_bin / directory / "library" / "gfx1100" / "kernel.dat"
+        assert linked_catalog.stat().st_ino == source_catalog.stat().st_ino
+
+
+def test_rocm_runtime_requires_both_kernel_catalogs(tmp_path):
+    llama_bin = _fake_llama_bin(tmp_path, backend_module = "libggml-hip.so")
+    (llama_bin / "hipblaslt").mkdir()
+    (llama_bin / "hipblaslt" / "kernel.dat").write_bytes(b"kernel")
+    with pytest.raises(PrebuiltFallback, match = "rocblas"):
+        M.link_runtime_directories(
+            llama_bin,
+            tmp_path / "whisper-bin",
+            backend = "rocm",
+            host = _host("linux", "x64"),
+        )
+
+
+def test_rocm_runtime_catalog_copy_fallback(tmp_path, monkeypatch):
+    llama_bin = _fake_llama_bin(tmp_path, backend_module = "libggml-hip.so")
+    for directory in M.SLIM_ROCM_RUNTIME_DIRS:
+        catalog = llama_bin / directory
+        catalog.mkdir()
+        (catalog / "kernel.dat").write_bytes(directory.encode())
+    monkeypatch.setattr(M.os, "link", lambda *args: (_ for _ in ()).throw(OSError("xdev")))
+    whisper_bin = tmp_path / "whisper-bin"
+    M.link_runtime_directories(
+        llama_bin,
+        whisper_bin,
+        backend = "rocm",
+        host = _host("linux", "x64"),
+    )
+    for directory in M.SLIM_ROCM_RUNTIME_DIRS:
+        assert (whisper_bin / directory / "kernel.dat").read_bytes() == directory.encode()
+
+
+def test_existing_install_requires_executable_server(tmp_path, monkeypatch):
+    # A marker-matching install with a non-executable server must reinstall:
+    # the sidecar refuses it via os.access(X_OK), so "already matches" would
+    # otherwise leave dictation permanently broken.
+    host = _host("linux", "x64")
+    selection = object()
+    monkeypatch.setattr(M.core, "existing_install_matches", lambda *a: True)
+    server = tmp_path / "build" / "bin" / "whisper-server"
+    server.parent.mkdir(parents = True)
+    server.write_text("bin")
+    monkeypatch.setattr(M, "installed_server_path", lambda d, h: server)
+    monkeypatch.setattr(M, "load_prebuilt_metadata", lambda d: {})
+    server.chmod(0o644)
+    assert M.existing_install_matches(tmp_path, host, selection) is False
+    server.chmod(0o755)
+    assert M.existing_install_matches(tmp_path, host, selection) is True
+
+
+def test_existing_slim_install_requires_wired_libraries(tmp_path, monkeypatch):
+    # A slim install whose hardlinked ggml files vanished (llama dir deleted)
+    # must reinstall so update re-wires instead of reporting up to date.
+    host = _host("linux", "x64")
+    monkeypatch.setattr(M.core, "existing_install_matches", lambda *a: True)
+    server = tmp_path / "build" / "bin" / "whisper-server"
+    server.parent.mkdir(parents = True)
+    server.write_text("bin")
+    server.chmod(0o755)
+    monkeypatch.setattr(M, "installed_server_path", lambda d, h: server)
+    marker = {
+        "install_kind": "slim",
+        "runtime_wiring_version": M.SLIM_RUNTIME_WIRING_VERSION,
+        "linked_libraries": ["libggml.so.0"],
+    }
+    monkeypatch.setattr(M, "load_prebuilt_metadata", lambda d: marker)
+    marker.pop("runtime_wiring_version")
+    assert M.existing_install_matches(tmp_path, host, object()) is False
+    marker["runtime_wiring_version"] = M.SLIM_RUNTIME_WIRING_VERSION
+    assert M.existing_install_matches(tmp_path, host, object()) is False
+    (server.parent / "libggml.so.0").write_text("lib")
+    assert M.existing_install_matches(tmp_path, host, object()) is True
+    marker.update(backend = "rocm", linked_runtime_directories = [])
+    assert M.existing_install_matches(tmp_path, _host("windows", "x64"), object()) is True
+
+
+def test_link_ggml_runtime_libomp_alone_is_not_a_pairing(tmp_path):
+    # A libomp without any ggml library is not a usable llama runtime.
+    bin_dir = tmp_path / "llama_bin"
+    bin_dir.mkdir()
+    (bin_dir / "libomp140.aarch64.dll").write_bytes(b"x")
+    with pytest.raises(PrebuiltFallback):
+        M.link_ggml_runtime(bin_dir, tmp_path / "whisper_bin")
+
+
+def _build_slim_bundle(tmp_path: Path, host: HostInfo) -> tuple[Path, str]:
+    """Slim archive per the CI contract: whisper-server + libwhisper only."""
+    archive = tmp_path / SLIM_ASSET
+    with tarfile.open(archive, "w:gz") as tar:
+        _add_file(tar, M.server_binary_name(host), b"#!/bin/sh\necho whisper\n", mode = 0o755)
+        _add_file(tar, "libwhisper.so.1", b"dummy-libwhisper")
+    return archive, M.sha256_file(archive)
+
+
+def _slim_install_env(monkeypatch, tmp_path, host, *, sha256: str) -> Path:
+    llama_bin = _fake_llama_bin(tmp_path)
+    monkeypatch.setattr(
+        M,
+        "installed_llama_runtime",
+        lambda install_dir = None: (llama_bin, SLIM_LLAMA_TAG, "cuda13-newer"),
+    )
+    manifest = M.parse_manifest(
+        _manifest(
+            [
+                _artifact("linux", "x64", "cpu", CPU_ASSET, "a" * 64),
+                _slim_artifact(sha256 = sha256),
+            ]
+        )
+    )
+    bundle = M.ReleaseBundle(
+        repo = "unslothai/whisper.cpp",
+        release_tag = RELEASE_TAG,
+        manifest = manifest,
+        asset_urls = {SLIM_ASSET: f"https://example.invalid/{SLIM_ASSET}"},
+    )
+    checksums = {SLIM_ASSET: sha256, CPU_ASSET: "a" * 64}
+    monkeypatch.setattr(
+        M,
+        "fetch_release_for_install",
+        lambda repo, *, published_release_tag = None: (bundle, checksums),
+    )
+    return llama_bin
+
+
+def test_slim_install_wires_links_and_marker(tmp_path, monkeypatch):
+    host = _cuda_host()
+    archive, sha256 = _build_slim_bundle(tmp_path, host)
+
+    def fake_download(url, destination):
+        destination.parent.mkdir(parents = True, exist_ok = True)
+        destination.write_bytes(archive.read_bytes())
+
+    monkeypatch.setattr(M, "detect_host", lambda: host)
+    monkeypatch.setattr(M, "download_file", fake_download)
+    llama_bin = _slim_install_env(monkeypatch, tmp_path, host, sha256 = sha256)
+
+    install_dir = tmp_path / "whisper.cpp"
+    assert M.install_prebuilt(install_dir, backend = "cuda") == M.EXIT_SUCCESS
+
+    whisper_bin = install_dir / "build" / "bin"
+    assert (whisper_bin / "whisper-server").is_file()
+    assert (whisper_bin / "libwhisper.so.1").is_file()
+    for name in ("libggml.so.0", "libggml-base.so.0", "libggml-cuda.so", "libggml-cpu-x64.so"):
+        dest = whisper_bin / name
+        assert dest.is_file() and not dest.is_symlink()
+        assert dest.stat().st_ino == (llama_bin / name).stat().st_ino
+
+    marker = json.loads((install_dir / M.METADATA_FILENAME).read_text())
+    assert marker["backend"] == "cuda"  # the accel identity, not "slim"
+    assert marker["asset"] == SLIM_ASSET
+    assert marker["install_kind"] == "slim"
+    assert marker["paired_llama_tag"] == SLIM_LLAMA_TAG
+    assert marker["linked_from"] == str(llama_bin)
+    # The wired filenames land in the marker; the sidecar launch guard
+    # verifies exactly these names instead of hardcoded per-OS globs.
+    assert marker["linked_libraries"] == [
+        "libggml-base.so.0",
+        "libggml-cpu-x64.so",
+        "libggml-cuda.so",
+        "libggml.so.0",
+    ]
+    assert marker["runtime_wiring_version"] == M.SLIM_RUNTIME_WIRING_VERSION
+    assert marker["linked_runtime_directories"] == []
+
+
+def test_slim_links_survive_a_llama_dir_swap(tmp_path, monkeypatch):
+    # The whole point of hardlinks: replace the llama dir contents after wiring
+    # and whisper's links must still hold the OLD inodes/content.
+    host = _cuda_host()
+    archive, sha256 = _build_slim_bundle(tmp_path, host)
+
+    def fake_download(url, destination):
+        destination.parent.mkdir(parents = True, exist_ok = True)
+        destination.write_bytes(archive.read_bytes())
+
+    monkeypatch.setattr(M, "detect_host", lambda: host)
+    monkeypatch.setattr(M, "download_file", fake_download)
+    llama_bin = _slim_install_env(monkeypatch, tmp_path, host, sha256 = sha256)
+
+    install_dir = tmp_path / "whisper.cpp"
+    assert M.install_prebuilt(install_dir, backend = "cuda") == M.EXIT_SUCCESS
+    whisper_lib = install_dir / "build" / "bin" / "libggml.so.0"
+    old_inode = whisper_lib.stat().st_ino
+    old_content = whisper_lib.read_bytes()
+
+    # Simulate the llama updater swapping in a new release's libraries.
+    for path in llama_bin.iterdir():
+        path.unlink()
+    (llama_bin / "libggml.so.0").write_bytes(b"ggml-NEW")
+
+    assert whisper_lib.stat().st_ino == old_inode  # old inode survives the swap
+    assert whisper_lib.read_bytes() == old_content
+    assert whisper_lib.stat().st_nlink == 1  # the llama side is gone; ours remains
+
+
+# The exact resolver key set shipped before slim existed; install_kind is the
+# one additive field and must stay the only difference.
+_LEGACY_RESOLVER_KEYS = {
+    "prebuilt_available",
+    "repo",
+    "release_tag",
+    "upstream_tag",
+    "backend",
+    "requested_backend",
+    "cpu_fallback",
+    "asset",
+    "os",
+    "arch",
+    "runtime_line",
+}
+
+
+def _resolver_payload(monkeypatch, capsys, manifest, host) -> dict:
+    bundle = M.ReleaseBundle(
+        repo = "unslothai/whisper.cpp",
+        release_tag = RELEASE_TAG,
+        manifest = manifest,
+        asset_urls = {},
+    )
+    monkeypatch.setattr(M, "detect_host", lambda: host)
+    monkeypatch.setattr(
+        M, "fetch_release_for_install", lambda repo, *, published_release_tag = None: (bundle, {})
+    )
+    assert M.main(["--resolve-prebuilt", "--output-format", "json"]) == M.EXIT_SUCCESS
+    return json.loads(capsys.readouterr().out.strip())
+
+
+def test_resolver_reports_install_kind_fat_additively(monkeypatch, capsys):
+    # The pinned pre-slim escape hatch resolves the published fat CPU bundle.
+    manifest = M.parse_manifest(_manifest([_artifact("linux", "x64", "cpu", CPU_ASSET, "a" * 64)]))
+    payload = _resolver_payload(monkeypatch, capsys, manifest, _host("linux", "x64"))
+    assert set(payload) == _LEGACY_RESOLVER_KEYS | {"install_kind"}
+    assert payload["install_kind"] == "fat"
+    assert payload["asset"] == CPU_ASSET
+
+
+def _release_for_selection(release_tag: str, upstream_tag: str, artifact: dict) -> M.ReleaseBundle:
+    payload = _manifest([artifact])
+    payload["upstream_tag"] = upstream_tag
+    return M.ReleaseBundle(
+        repo = "unslothai/whisper.cpp",
+        release_tag = release_tag,
+        manifest = M.parse_manifest(payload),
+        asset_urls = {},
+    )
+
+
+def test_whisper_tag_selects_matching_published_upstream(monkeypatch):
+    latest_asset = "latest-linux-x64-cpu.tar.gz"
+    pinned_asset = "pinned-linux-x64-cpu.tar.gz"
+    latest = _release_for_selection(
+        "v1.9.2-unsloth.1",
+        "v1.9.2",
+        _artifact("linux", "x64", "cpu", latest_asset, "a" * 64),
+    )
+    pinned = _release_for_selection(
+        "v1.9.0-unsloth.3",
+        "v1.9.0",
+        _artifact("linux", "x64", "cpu", pinned_asset, "b" * 64),
+    )
+    monkeypatch.setattr(
+        M,
+        "fetch_release_for_install",
+        lambda *args, **kwargs: (_ for _ in ()).throw(
+            AssertionError("an upstream pin consulted the unrelated newest release")
+        ),
+    )
+    monkeypatch.setattr(
+        M,
+        "_published_release_tags",
+        lambda repo: [latest.release_tag, pinned.release_tag],
+    )
+    monkeypatch.setattr(
+        M,
+        "_fetch_release_candidate",
+        lambda repo, tag: latest if tag == latest.release_tag else pinned,
+    )
+    monkeypatch.setattr(M, "fetch_release_checksums", lambda bundle: {pinned_asset: "b" * 64})
+
+    payload = M.resolve_prebuilt(
+        _host("linux", "x64"),
+        published_repo = "unslothai/whisper.cpp",
+        published_release_tag = None,
+        whisper_tag = "v1.9.0",
+        backend = "cpu",
+        cpu_fallback = False,
+    )
+    assert payload["prebuilt_available"] is True
+    assert payload["release_tag"] == pinned.release_tag
+    assert payload["upstream_tag"] == "v1.9.0"
+
+
+def test_macos_walks_back_to_newest_compatible_release(monkeypatch):
+    latest_asset = "latest-macos-arm64-cpu.tar.gz"
+    compatible_asset = "compatible-macos-arm64-cpu.tar.gz"
+    latest = _release_for_selection(
+        "v1.9.2-unsloth.1",
+        "v1.9.2",
+        _artifact(
+            "macos",
+            "arm64",
+            "cpu",
+            latest_asset,
+            "a" * 64,
+            min_os = "macos-15.0",
+        ),
+    )
+    compatible = _release_for_selection(
+        "v1.9.1-unsloth.1",
+        "v1.9.1",
+        _artifact(
+            "macos",
+            "arm64",
+            "cpu",
+            compatible_asset,
+            "b" * 64,
+            min_os = "macos-13.0",
+        ),
+    )
+    monkeypatch.setattr(
+        M,
+        "fetch_release_for_install",
+        lambda repo, *, published_release_tag = None: (latest, {latest_asset: "a" * 64}),
+    )
+    monkeypatch.setattr(
+        M,
+        "_published_release_tags",
+        lambda repo: [latest.release_tag, compatible.release_tag],
+    )
+    monkeypatch.setattr(M, "_fetch_release_candidate", lambda repo, tag: compatible)
+    monkeypatch.setattr(
+        M,
+        "fetch_release_checksums",
+        lambda bundle: {compatible_asset: "b" * 64},
+    )
+
+    payload = M.resolve_prebuilt(
+        _host("macos", "arm64", macos_version = (14, 7)),
+        published_repo = "unslothai/whisper.cpp",
+        published_release_tag = None,
+        backend = "cpu",
+        cpu_fallback = False,
+    )
+    assert payload["prebuilt_available"] is True
+    assert payload["release_tag"] == compatible.release_tag
+
+
+def test_macos_walkback_never_masks_checksum_failure(monkeypatch):
+    asset = "latest-macos-arm64-cpu.tar.gz"
+    latest = _release_for_selection(
+        "v1.9.2-unsloth.1",
+        "v1.9.2",
+        _artifact("macos", "arm64", "cpu", asset, "a" * 64, min_os = "macos-13.0"),
+    )
+    monkeypatch.setattr(
+        M,
+        "fetch_release_for_install",
+        lambda repo, *, published_release_tag = None: (latest, {asset: "b" * 64}),
+    )
+    monkeypatch.setattr(
+        M,
+        "_published_release_tags",
+        lambda repo: (_ for _ in ()).throw(AssertionError("integrity failure walked back")),
+    )
+
+    with pytest.raises(PrebuiltFallback, match = "disagrees"):
+        M._release_plan_for_host(
+            _host("macos", "arm64", macos_version = (14, 7)),
+            published_repo = "unslothai/whisper.cpp",
+            published_release_tag = None,
+            whisper_tag = "latest",
+            requested_backend = "cpu",
+        )
+
+
+def test_resolver_reports_install_kind_slim_when_paired(tmp_path, monkeypatch, capsys):
+    bin_dir = _fake_llama_bin(tmp_path)
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, SLIM_LLAMA_TAG, "cuda13-newer")
+    )
+    payload = _resolver_payload(monkeypatch, capsys, _slim_manifest(), _cuda_host())
+    assert set(payload) == _LEGACY_RESOLVER_KEYS | {"install_kind"}
+    assert payload["install_kind"] == "slim"
+    assert payload["asset"] == SLIM_ASSET
+    assert payload["backend"] == "cuda"
+
+
+def test_resolver_reports_metal_slim_on_macos(tmp_path, monkeypatch, capsys):
+    # Same contract shape on macs: backend stays the accel (metal), the one
+    # additive field says the asset installs slim.
+    bin_dir = _fake_llama_bin_macos(tmp_path)
+    monkeypatch.setattr(
+        M, "installed_llama_runtime", lambda: (bin_dir, SLIM_LLAMA_TAG, "macos-metal-arm64")
+    )
+    host = _host("macos", "arm64", macos_version = (14, 0))
+    payload = _resolver_payload(monkeypatch, capsys, _macos_slim_manifest(), host)
+    assert set(payload) == _LEGACY_RESOLVER_KEYS | {"install_kind"}
+    assert payload["install_kind"] == "slim"
+    assert payload["asset"] == MAC_SLIM_ASSET
+    assert payload["backend"] == "metal"
+    assert payload["requested_backend"] == "metal"
diff --git a/tests/studio/install/test_launch_studio_launcher.py b/tests/studio/install/test_launch_studio_launcher.py
index a7396aaf5d..1c12024f6d 100644
--- a/tests/studio/install/test_launch_studio_launcher.py
+++ b/tests/studio/install/test_launch_studio_launcher.py
@@ -1,4 +1,4 @@
-"""Guard install.ps1's Studio launcher against the AV-heuristic shape (Kaspersky
+"""Guard install.ps1's Unsloth launcher against the AV-heuristic shape (Kaspersky
 HEUR:Trojan.VBS.Agent.gen): a WScript .vbs spawning a hidden ExecutionPolicy-Bypass PowerShell.
 The shortcut must stay windowless via powershell.exe -WindowStyle Hidden over launch-studio.ps1,
 never a .vbs/WScript.Shell.Run wrapper, and any pre-existing .vbs must be deleted on upgrade."""
diff --git a/tests/studio/install/test_managed_node_runtime.py b/tests/studio/install/test_managed_node_runtime.py
index 0dbc6788ca..17c7e3e60f 100644
--- a/tests/studio/install/test_managed_node_runtime.py
+++ b/tests/studio/install/test_managed_node_runtime.py
@@ -3,7 +3,7 @@
 
 """Tests for the runtime managed-Node resolver (studio/backend/utils/node_runtime.py).
 
-The Studio frontend installer may provision an isolated Node under
+The Unsloth frontend installer may provision an isolated Node under
 ``<UNSLOTH_HOME>/node`` that is never added to the user's PATH. The backend OXC
 validator must still find a usable Node at runtime: a version-adequate system
 Node, else the managed isolated one. These tests pin that resolution and the
diff --git a/tests/studio/install/test_pr5940_followups.py b/tests/studio/install/test_pr5940_followups.py
index ac6a96167a..dd2a7ec487 100644
--- a/tests/studio/install/test_pr5940_followups.py
+++ b/tests/studio/install/test_pr5940_followups.py
@@ -420,7 +420,7 @@ def test_ps_installers_gate_amd_smi_on_windows():
         assert (
             "UNSLOTH_SETUP_PYTHON" in text
         ), f"{ps.name} venv-internal check must seed the venv root from UNSLOTH_SETUP_PYTHON"
-        # A custom Studio home moves the venv off the default path; it must be
+        # A custom Unsloth home moves the venv off the default path; it must be
         # seeded too or its hipInfo escapes the filter and reopens the gate.
         assert (
             "UNSLOTH_STUDIO_HOME" in text
@@ -429,7 +429,7 @@ def test_ps_installers_gate_amd_smi_on_windows():
 
 @pytest.mark.parametrize("ps", [_INSTALL_PS1, _SETUP_PS1], ids = ["install.ps1", "setup.ps1"])
 def test_ps_venv_probe_expands_tilde_for_custom_studio_home(ps):
-    # The probe seeds the venv root from a custom Studio home; a ~\studio form
+    # The probe seeds the venv root from a custom Unsloth home; a ~\studio form
     # must expand to USERPROFILE like the canonical resolver, else GetFullPath
     # keeps the literal ~ (cwd-relative) and the hipInfo escapes the filter.
     text = ps.read_text(encoding = "utf-8")
@@ -439,7 +439,7 @@ def test_ps_venv_probe_expands_tilde_for_custom_studio_home(ps):
     block = text[i:j]
     assert "USERPROFILE" in block and ".Substring(1)" in block, (
         f"{ps.name}: the venv-internal probe must expand a leading ~ in the custom "
-        "Studio home before seeding the venv root (mirroring the canonical resolver)"
+        "Unsloth home before seeding the venv root (mirroring the canonical resolver)"
     )
     # The ~ expansion must be guarded on a non-empty USERPROFILE; otherwise
     # Join-Path $env:USERPROFILE throws on a service/SYSTEM account with no profile,
@@ -784,7 +784,7 @@ def test_install_python_stack_windows_rocm_repair_pins_and_is_nonfatal():
         assert re.search(
             r'"' + gfx + r'":\s*_ROCM_TORCH_PKG_SPECS\["rocm7\.2"\]', text
         ), f"{gfx} must pin to the rocm7.2 trio like install.ps1/setup.ps1"
-    i = text.find('f"ROCm torch (Windows, {gfx_arch})"')
+    i = text.find("f\"ROCm torch (Windows, {gfx_arch or 'pinned'})\"")
     assert i != -1, "Windows ROCm repair pip call not found"
     # The nearest preceding call must be the nonfatal pip_install_try, not pip_install.
     j = text.rfind("pip_install_try(", 0, i)
diff --git a/tests/studio/install/test_prebuilt_core.py b/tests/studio/install/test_prebuilt_core.py
new file mode 100644
index 0000000000..4d1c37b8da
--- /dev/null
+++ b/tests/studio/install/test_prebuilt_core.py
@@ -0,0 +1,918 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Shared descriptor-parameterized tests for studio/prebuilt_core.py.
+
+Runs the component-agnostic core against BOTH shipped descriptors -- the real
+whisper descriptor exported by install_whisper_prebuilt and a llama-flavored
+descriptor built here the way a hypothetical third ggml-family component would
+plug in (descriptor only, no installer module). Covers os/arch selection,
+checksum fail-closed behavior, extraction guards, the resolver payload, and the
+ops monkeypatch seam, so a new component gets this coverage for free.
+
+The llama installer's shipped release-plan machinery is intentionally NOT
+routed through the generic flow (its characterization suites pin it); the
+llama descriptor here exercises the canonical dialect a future migration
+would use, including the "no fallback backend -> report no prebuilt" policy.
+"""
+
+import importlib.util
+import io
+import json
+import sys
+import tarfile
+import zipfile
+from pathlib import Path
+from types import SimpleNamespace
+
+import pytest
+
+PACKAGE_ROOT = Path(__file__).resolve().parents[3]
+STUDIO_DIR = PACKAGE_ROOT / "studio"
+if str(STUDIO_DIR) not in sys.path:
+    sys.path.insert(0, str(STUDIO_DIR))
+
+SPEC = importlib.util.spec_from_file_location(
+    "studio_prebuilt_core", STUDIO_DIR / "prebuilt_core.py"
+)
+assert SPEC is not None and SPEC.loader is not None
+core = importlib.util.module_from_spec(SPEC)
+sys.modules[SPEC.name] = core
+SPEC.loader.exec_module(core)
+
+WSPEC = importlib.util.spec_from_file_location(
+    "studio_install_whisper_prebuilt_for_core", STUDIO_DIR / "install_whisper_prebuilt.py"
+)
+assert WSPEC is not None and WSPEC.loader is not None
+iwp = importlib.util.module_from_spec(WSPEC)
+sys.modules[WSPEC.name] = iwp
+WSPEC.loader.exec_module(iwp)
+
+
+LLAMA_DESCRIPTOR = core.ComponentDescriptor(
+    component = "llama.cpp",
+    log_prefix = "llama-prebuilt",
+    published_repo = "unslothai/llama.cpp",
+    manifest_asset_name = "llama-prebuilt-manifest.json",
+    sha256_asset_name = "llama-prebuilt-sha256.json",
+    metadata_filename = "UNSLOTH_LLAMA_PREBUILT_INFO.json",
+    user_agent = "unsloth-studio-llama-prebuilt",
+    # A GPU-selection miss reports "no prebuilt" so the caller can fall back to
+    # a source build instead of silently degrading to CPU.
+    fallback_backend = None,
+    server_binary_name = lambda host: "llama-server",
+    runtime_bin_dir = lambda install_dir, host: install_dir / "build" / "bin",
+)
+
+
+class Component:
+    """One descriptor under test plus the mutable namespace behind its ops."""
+
+    def __init__(self, descriptor):
+        self.descriptor = descriptor
+        self.namespace = core.component_namespace(descriptor)
+        self.namespace["log"] = lambda message: None  # keep test output quiet
+        self.ops = core.ModuleOps(self.namespace)
+
+    @property
+    def falls_back_to_cpu(self):
+        return self.descriptor.fallback_backend == "cpu"
+
+
+@pytest.fixture(params = ["whisper", "llama"])
+def component(request):
+    if request.param == "whisper":
+        return Component(iwp.DESCRIPTOR)
+    return Component(LLAMA_DESCRIPTOR)
+
+
+def make_host(
+    component,
+    *,
+    os_token = "linux",
+    arch_token = "x64",
+    is_windows = False,
+    is_macos = False,
+    is_apple_silicon = False,
+    has_usable_nvidia = False,
+    has_rocm = False,
+    rocm_gfx = None,
+    macos_version = None,
+):
+    if component.descriptor is iwp.DESCRIPTOR:
+        return iwp.HostInfo(
+            system = {"linux": "Linux", "macos": "Darwin", "windows": "Windows"}[os_token],
+            machine = "x86_64" if arch_token == "x64" else "arm64",
+            whisper_os = os_token,
+            whisper_arch = arch_token,
+            archive_ext = ".zip" if is_windows else ".tar.gz",
+            is_windows = is_windows,
+            is_macos = is_macos,
+            is_apple_silicon = is_apple_silicon,
+            has_usable_nvidia = has_usable_nvidia,
+            has_rocm = has_rocm,
+            rocm_gfx = rocm_gfx,
+            macos_version = macos_version,
+        )
+    # Descriptor-only component: the core default host_platform_tokens hook
+    # reads .os_token/.arch_token off a plain host object.
+    return SimpleNamespace(
+        os_token = os_token,
+        arch_token = arch_token,
+        is_windows = is_windows,
+        is_macos = is_macos,
+        is_apple_silicon = is_apple_silicon,
+        has_usable_nvidia = has_usable_nvidia,
+        has_rocm = has_rocm,
+        rocm_gfx = rocm_gfx,
+        macos_version = macos_version,
+    )
+
+
+def artifact(
+    os_ = "linux",
+    arch = "x64",
+    backend = "cpu",
+    asset = "bundle.tar.gz",
+    **extra,
+):
+    payload = {"os": os_, "arch": arch, "backend": backend, "asset": asset}
+    payload.update(extra)
+    return payload
+
+
+def manifest_for(component, artifacts, **extra):
+    payload = {
+        "schema_version": 1,
+        "component": extra.pop("component_name", component.descriptor.component),
+        "upstream_tag": "v1.0.0",
+        "source_commit": "a" * 40,
+        "artifacts": artifacts,
+    }
+    payload.update(extra)
+    return payload
+
+
+# ── Manifest parsing ──
+def test_parse_manifest_normalizes(component):
+    manifest = component.ops.parse_manifest(
+        manifest_for(component, [artifact(), "not-a-dict", {"os": "linux"}]), label = "m"
+    )
+    assert manifest["component"] == component.descriptor.component
+    assert manifest["upstream_tag"] == "v1.0.0"
+    # Non-dict entries and entries without an asset name are dropped.
+    assert [a["asset"] for a in manifest["artifacts"]] == ["bundle.tar.gz"]
+
+
+def test_parse_manifest_rejects_wrong_component(component):
+    with pytest.raises(core.PrebuiltFallback):
+        component.ops.parse_manifest(
+            manifest_for(component, [artifact()], component_name = "other.cpp"), label = "m"
+        )
+
+
+def test_parse_manifest_rejects_unknown_schema(component):
+    with pytest.raises(core.PrebuiltFallback):
+        component.ops.parse_manifest(
+            manifest_for(component, [artifact()], schema_version = 99), label = "m"
+        )
+
+
+def test_parse_manifest_rejects_non_object(component):
+    with pytest.raises(core.PrebuiltFallback):
+        component.ops.parse_manifest(["nope"], label = "m")
+    # An object without an 'artifacts' list is rejected too.
+    with pytest.raises(core.PrebuiltFallback):
+        component.ops.parse_manifest(
+            {"schema_version": 1, "component": component.descriptor.component}, label = "m"
+        )
+
+
+# ── Selection matrix ──
+def test_select_cpu_first_match(component):
+    manifest = component.ops.parse_manifest(
+        manifest_for(
+            component,
+            [
+                artifact(backend = "cpu", asset = "first-cpu.tar.gz"),
+                artifact(backend = "cpu", asset = "second-cpu.tar.gz"),
+            ],
+        ),
+        label = "m",
+    )
+    host = make_host(component)
+    chosen = component.ops.select_artifact(manifest, host, "cpu")
+    assert chosen["asset"] == "first-cpu.tar.gz"
+
+
+def test_select_respects_os_arch(component):
+    manifest = component.ops.parse_manifest(
+        manifest_for(component, [artifact(os_ = "windows", backend = "cpu")]), label = "m"
+    )
+    host = make_host(component)
+    assert component.ops.select_artifact(manifest, host, "cpu") is None
+
+
+def test_fallback_policy_differs_per_descriptor(component):
+    # No asset for the requested backend: whisper degrades to the CPU asset of
+    # the same release, the llama-flavored descriptor reports no prebuilt
+    # (source-build fallback).
+    manifest = component.ops.parse_manifest(
+        manifest_for(component, [artifact(backend = "cpu", asset = "cpu.tar.gz")]), label = "m"
+    )
+    host = make_host(component, has_usable_nvidia = True)
+    assert component.ops.select_artifact(manifest, host, "cuda") is None
+    if component.falls_back_to_cpu:
+        chosen, backend, used_fallback = component.ops.select_artifact_with_fallback(
+            manifest, host, "cuda"
+        )
+        assert (chosen["asset"], backend, used_fallback) == ("cpu.tar.gz", "cpu", True)
+    else:
+        with pytest.raises(core.PrebuiltFallback):
+            component.ops.select_artifact_with_fallback(manifest, host, "cuda")
+
+
+def test_macos_min_os_gate(component):
+    manifest = component.ops.parse_manifest(
+        manifest_for(
+            component,
+            [
+                artifact(
+                    os_ = "macos",
+                    arch = "arm64",
+                    backend = "metal",
+                    asset = "metal-new.tar.gz",
+                    min_os = "macos-15.0",
+                )
+            ],
+        ),
+        label = "m",
+    )
+    old_host = make_host(
+        component,
+        os_token = "macos",
+        arch_token = "arm64",
+        is_macos = True,
+        is_apple_silicon = True,
+        macos_version = (14, 7),
+    )
+    new_host = make_host(
+        component,
+        os_token = "macos",
+        arch_token = "arm64",
+        is_macos = True,
+        is_apple_silicon = True,
+        macos_version = (15, 1),
+    )
+    assert component.ops.select_artifact(manifest, old_host, "metal") is None
+    chosen = component.ops.select_artifact(manifest, new_host, "metal")
+    assert chosen["asset"] == "metal-new.tar.gz"
+
+
+def _metal_artifact(asset, min_os):
+    return artifact(
+        os_ = "macos",
+        arch = "arm64",
+        backend = "metal",
+        asset = asset,
+        min_os = min_os,
+    )
+
+
+def _arm_mac_host(component, macos_version):
+    return make_host(
+        component,
+        os_token = "macos",
+        arch_token = "arm64",
+        is_macos = True,
+        is_apple_silicon = True,
+        macos_version = macos_version,
+    )
+
+
+def test_macos_min_os_filters_to_compatible_bundle(component):
+    # host 14.0 can't load the 15.0 bundle; the 13.0 bundle is picked instead.
+    manifest = component.ops.parse_manifest(
+        manifest_for(
+            component,
+            [
+                _metal_artifact("metal-new.tar.gz", "macos-15.0"),
+                _metal_artifact("metal.tar.gz", "macos-13.0"),
+            ],
+        ),
+        label = "m",
+    )
+    host = _arm_mac_host(component, (14, 0))
+    assert component.ops.select_artifact(manifest, host, "metal")["asset"] == "metal.tar.gz"
+
+
+def test_macos_min_os_unknown_host_version_keeps_artifact(component):
+    # Unknown host macOS version -> defer to runtime validation, don't reject.
+    manifest = component.ops.parse_manifest(
+        manifest_for(component, [_metal_artifact("metal-new.tar.gz", "macos-15.0")]), label = "m"
+    )
+    host = _arm_mac_host(component, None)
+    assert component.ops.select_artifact(manifest, host, "metal")["asset"] == "metal-new.tar.gz"
+
+
+def test_macos_min_os_accepts_bare_version_format(component):
+    # A bare "14.0" (no 'macos-' prefix) must still parse, for forward-compat.
+    manifest = component.ops.parse_manifest(
+        manifest_for(component, [_metal_artifact("metal.tar.gz", "14.0")]), label = "m"
+    )
+    host = _arm_mac_host(component, (13, 0))
+    assert component.ops.select_artifact(manifest, host, "metal") is None  # 13.0 < 14.0
+
+
+def test_macos_min_os_ok_helper_handles_prefix_and_bare(component):
+    host14 = _arm_mac_host(component, (14, 0))
+    # The live manifest format is 'macos-<ver>'; the prefix must be stripped.
+    assert component.ops.macos_min_os_ok(host14, "macos-14.0") is True
+    assert component.ops.macos_min_os_ok(host14, "macos-15.0") is False
+    assert component.ops.macos_min_os_ok(host14, "13.3") is True  # bare also parses
+    assert component.ops.macos_min_os_ok(host14, None) is True  # unknown -> defer
+    host_unknown = _arm_mac_host(component, None)
+    assert component.ops.macos_min_os_ok(host_unknown, "macos-15.0") is True
+
+
+# ── Backend resolution ──
+def test_resolve_backend_auto_and_validation(component):
+    gpu_host = make_host(component, has_usable_nvidia = True)
+    assert component.ops.resolve_backend(gpu_host, "auto", cpu_fallback = False) == "cuda"
+    assert component.ops.resolve_backend(gpu_host, "auto", cpu_fallback = True) == "cpu"
+    # --cpu-fallback wins over an explicit backend too.
+    assert component.ops.resolve_backend(gpu_host, "cuda", cpu_fallback = True) == "cpu"
+    # An explicit supported backend passes through untouched.
+    assert component.ops.resolve_backend(gpu_host, "vulkan", cpu_fallback = False) == "vulkan"
+    mac_host = make_host(
+        component, os_token = "macos", arch_token = "arm64", is_macos = True, is_apple_silicon = True
+    )
+    assert component.ops.resolve_backend(mac_host, None, cpu_fallback = False) == "metal"
+    # Intel mac has no Metal bundle in the P0 matrix -> cpu.
+    intel_mac = make_host(component, os_token = "macos", arch_token = "x64", is_macos = True)
+    assert component.ops.resolve_backend(intel_mac, "auto", cpu_fallback = False) == "cpu"
+    rocm_host = make_host(component, has_rocm = True, rocm_gfx = "gfx1100")
+    assert component.ops.resolve_backend(rocm_host, "auto", cpu_fallback = False) == "rocm"
+    bare_host = make_host(component)
+    assert component.ops.resolve_backend(bare_host, None, cpu_fallback = False) == "cpu"
+    with pytest.raises(core.PrebuiltFallback):
+        component.ops.resolve_backend(gpu_host, "tpu", cpu_fallback = False)
+
+
+# ── Checksum index: fail closed ──
+def _index_for(
+    component,
+    tag = "v1",
+    artifacts = None,
+):
+    return {
+        "schema_version": 1,
+        "component": component.descriptor.component,
+        "release_tag": tag,
+        "artifacts": artifacts
+        if artifacts is not None
+        else {"bundle.tar.gz": {"sha256": "0" * 64}},
+    }
+
+
+def test_parse_release_checksums_valid(component):
+    out = component.ops.parse_release_checksums("r", "v1", _index_for(component))
+    assert out == {"bundle.tar.gz": "0" * 64}
+
+
+@pytest.mark.parametrize(
+    "mutation",
+    [
+        {"component": "other.cpp"},
+        {"schema_version": 99},
+        {"release_tag": "v2"},
+        {"artifacts": {"bundle.tar.gz": {"sha256": "nope"}}},
+        {"artifacts": "not-a-map"},
+    ],
+)
+def test_parse_release_checksums_fails_closed(component, mutation):
+    payload = _index_for(component)
+    payload.update(mutation)
+    with pytest.raises(core.PrebuiltFallback):
+        component.ops.parse_release_checksums("r", "v1", payload)
+
+
+def test_parse_release_checksums_rejects_non_object(component):
+    with pytest.raises(core.PrebuiltFallback):
+        component.ops.parse_release_checksums("r", "v1", ["not", "a", "dict"])
+
+
+def test_expected_sha256_covered_asset_plain_lookup(component):
+    assert component.ops.expected_sha256_for({"a.tar.gz": "0" * 64}, "a.tar.gz") == "0" * 64
+
+
+def test_expected_sha256_missing_asset_fails_closed(component):
+    with pytest.raises(core.PrebuiltFallback):
+        component.ops.expected_sha256_for({"a.tar.gz": "0" * 64}, "b.tar.gz")
+
+
+def test_expected_sha256_manifest_disagreement_fails_closed(component):
+    with pytest.raises(core.PrebuiltFallback):
+        component.ops.expected_sha256_for(
+            {"a.tar.gz": "0" * 64}, "a.tar.gz", manifest_sha256 = "1" * 64
+        )
+    assert (
+        component.ops.expected_sha256_for(
+            {"a.tar.gz": "0" * 64}, "a.tar.gz", manifest_sha256 = "0" * 64
+        )
+        == "0" * 64
+    )
+
+
+# ── Extraction guards ──
+def test_extract_archive_rejects_traversal(tmp_path):
+    archive = tmp_path / "evil.tar.gz"
+    with tarfile.open(archive, "w:gz") as tar:
+        data = b"x"
+        info = tarfile.TarInfo("../escape.txt")
+        info.size = len(data)
+        tar.addfile(info, io.BytesIO(data))
+    with pytest.raises(core.PrebuiltFallback):
+        core.extract_archive(archive, tmp_path / "out")
+
+
+def test_extract_archive_rejects_absolute_member(tmp_path):
+    archive = tmp_path / "abs.tar.gz"
+    with tarfile.open(archive, "w:gz") as tar:
+        data = b"x"
+        info = tarfile.TarInfo("/abs.txt")
+        info.size = len(data)
+        tar.addfile(info, io.BytesIO(data))
+    with pytest.raises(core.PrebuiltFallback):
+        core.extract_archive(archive, tmp_path / "out")
+
+
+def test_extract_archive_rejects_zip_symlink(tmp_path):
+    archive = tmp_path / "link.zip"
+    with zipfile.ZipFile(archive, "w") as zf:
+        info = zipfile.ZipInfo("link")
+        info.create_system = 3
+        info.external_attr = 0o120777 << 16
+        zf.writestr(info, "target")
+    with pytest.raises(core.PrebuiltFallback, match = "zip archive contained a symlink entry"):
+        core.extract_archive(archive, tmp_path / "out")
+
+
+def test_extract_archive_rejects_absolute_zip_member(tmp_path):
+    archive = tmp_path / "abs.zip"
+    with zipfile.ZipFile(archive, "w") as zf:
+        zf.writestr("/etc/passwd", b"pwn")
+    with pytest.raises(core.PrebuiltFallback):
+        core.extract_archive(archive, tmp_path / "out")
+
+
+def test_extract_archive_allows_safe_tar_symlink_chain(tmp_path):
+    archive = tmp_path / "bundle.tar.gz"
+    payload = b"shared-object"
+    with tarfile.open(archive, "w:gz") as tar:
+        versioned = tarfile.TarInfo("libllama.so.0.0.1")
+        versioned.size = len(payload)
+        tar.addfile(versioned, io.BytesIO(payload))
+        soname = tarfile.TarInfo("libllama.so.0")
+        soname.type = tarfile.SYMTYPE
+        soname.linkname = "libllama.so.0.0.1"
+        tar.addfile(soname)
+        linker_name = tarfile.TarInfo("libllama.so")
+        linker_name.type = tarfile.SYMTYPE
+        linker_name.linkname = "libllama.so.0"
+        tar.addfile(linker_name)
+    destination = tmp_path / "extract"
+    core.extract_archive(archive, destination)
+    assert (destination / "libllama.so.0.0.1").read_bytes() == payload
+    assert (destination / "libllama.so.0").is_symlink()
+    assert (destination / "libllama.so").is_symlink()
+    assert (destination / "libllama.so").resolve().read_bytes() == payload
+
+
+def test_extract_archive_allows_safe_tar_hardlink(tmp_path):
+    archive = tmp_path / "bundle.tar.gz"
+    payload = b"quantize"
+    with tarfile.open(archive, "w:gz") as tar:
+        target = tarfile.TarInfo("llama-quantize")
+        target.size = len(payload)
+        tar.addfile(target, io.BytesIO(payload))
+        hardlink = tarfile.TarInfo("llama-quantize-copy")
+        hardlink.type = tarfile.LNKTYPE
+        hardlink.linkname = "llama-quantize"
+        tar.addfile(hardlink)
+    destination = tmp_path / "extract"
+    core.extract_archive(archive, destination)
+    assert (destination / "llama-quantize-copy").read_bytes() == payload
+    assert not (destination / "llama-quantize-copy").is_symlink()
+
+
+def test_extract_archive_rejects_absolute_tar_symlink_target(tmp_path):
+    archive = tmp_path / "bundle.tar.gz"
+    with tarfile.open(archive, "w:gz") as tar:
+        entry = tarfile.TarInfo("libllama.so")
+        entry.type = tarfile.SYMTYPE
+        entry.linkname = "/tmp/libllama.so.0"
+        tar.addfile(entry)
+    with pytest.raises(core.PrebuiltFallback, match = "archive link used an absolute target"):
+        core.extract_archive(archive, tmp_path / "extract")
+
+
+def test_extract_archive_rejects_escaping_tar_symlink_target(tmp_path):
+    archive = tmp_path / "bundle.tar.gz"
+    with tarfile.open(archive, "w:gz") as tar:
+        entry = tarfile.TarInfo("libllama.so")
+        entry.type = tarfile.SYMTYPE
+        entry.linkname = "../outside/libllama.so.0"
+        tar.addfile(entry)
+    with pytest.raises(core.PrebuiltFallback, match = "archive link escaped destination"):
+        core.extract_archive(archive, tmp_path / "extract")
+
+
+def test_extract_archive_rejects_unresolved_tar_symlink_target(tmp_path):
+    archive = tmp_path / "bundle.tar.gz"
+    with tarfile.open(archive, "w:gz") as tar:
+        entry = tarfile.TarInfo("libllama.so")
+        entry.type = tarfile.SYMTYPE
+        entry.linkname = "libllama.so.0"
+        tar.addfile(entry)
+    with pytest.raises(core.PrebuiltFallback, match = "unresolved link entries"):
+        core.extract_archive(archive, tmp_path / "extract")
+
+
+def test_extract_archive_rejects_unknown_format(tmp_path):
+    archive = tmp_path / "blob.xz"
+    archive.write_bytes(b"data")
+    with pytest.raises(core.PrebuiltFallback):
+        core.extract_archive(archive, tmp_path / "out")
+
+
+def test_restore_tar_exec_bits(tmp_path):
+    payload = tmp_path / "server"
+    payload.write_bytes(b"#!/bin/sh\n")
+    payload.chmod(0o755)
+    archive = tmp_path / "bundle.tar.gz"
+    with tarfile.open(archive, "w:gz") as tar:
+        tar.add(payload, arcname = "bundle/server")
+    out = tmp_path / "out"
+    core.extract_archive(archive, out)
+    extracted = out / "bundle" / "server"
+    assert extracted.is_file()
+    core.restore_tar_exec_bits(archive, out)
+    assert extracted.stat().st_mode & 0o111
+
+
+# ── Resolver payload ──
+def _fake_release(component, artifacts):
+    ns = component.namespace
+    manifest = component.ops.parse_manifest(manifest_for(component, artifacts), label = "m")
+    bundle = core.ReleaseBundle(
+        repo = component.descriptor.published_repo,
+        release_tag = "v1",
+        manifest = manifest,
+        asset_urls = {},
+    )
+    checksums = {str(a["asset"]): "0" * 64 for a in artifacts}
+    ns["fetch_release_for_install"] = lambda repo, *, published_release_tag: (bundle, checksums)
+    return bundle
+
+
+def test_resolve_prebuilt_payload_keys(component):
+    _fake_release(component, [artifact(backend = "cpu", asset = "cpu.tar.gz")])
+    host = make_host(component)
+    payload = component.ops.resolve_prebuilt(
+        host,
+        published_repo = component.descriptor.published_repo,
+        published_release_tag = None,
+        backend = "cpu",
+        cpu_fallback = True,
+    )
+    assert payload == {
+        "prebuilt_available": True,
+        "repo": component.descriptor.published_repo,
+        "release_tag": "v1",
+        "upstream_tag": "v1.0.0",
+        "backend": "cpu",
+        "requested_backend": "cpu",
+        "cpu_fallback": False,
+        "asset": "cpu.tar.gz",
+        "os": "linux",
+        "arch": "x64",
+        "runtime_line": None,
+    }
+
+
+def test_resolve_prebuilt_unavailable_payload(component):
+    ns = component.namespace
+
+    def boom(repo, *, published_release_tag):
+        raise core.PrebuiltFallback("no release")
+
+    ns["fetch_release_for_install"] = boom
+    host = make_host(component)
+    payload = component.ops.resolve_prebuilt(
+        host,
+        published_repo = component.descriptor.published_repo,
+        published_release_tag = None,
+        backend = "cpu",
+        cpu_fallback = True,
+    )
+    assert payload == {"prebuilt_available": False, "repo": component.descriptor.published_repo}
+
+
+def test_emit_resolver_output_formats(capsys):
+    payload = {"prebuilt_available": True, "asset": "a.tar.gz"}
+    core.emit_resolver_output(payload, output_format = "json")
+    assert json.loads(capsys.readouterr().out) == payload
+    core.emit_resolver_output(payload, output_format = "plain")
+    assert capsys.readouterr().out.strip() == "a.tar.gz"
+    core.emit_resolver_output({"prebuilt_available": False}, output_format = "plain")
+    assert json.loads(capsys.readouterr().out) == {"prebuilt_available": False}
+
+
+# ── Marker / fingerprint ──
+def test_install_fingerprint_is_stable_and_sensitive(component):
+    kwargs = dict(
+        published_repo = component.descriptor.published_repo,
+        release_tag = "v1",
+        upstream_tag = "v1.0.0",
+        source_commit = "a" * 40,
+        asset = "cpu.tar.gz",
+        asset_sha256 = "0" * 64,
+        backend = "cpu",
+        runtime_line = None,
+        coverage = {},
+    )
+    first = core.compute_install_fingerprint(**kwargs)
+    assert first == core.compute_install_fingerprint(**kwargs)
+    changed = core.compute_install_fingerprint(**{**kwargs, "asset_sha256": "1" * 64})
+    assert changed != first
+
+
+def test_write_and_match_marker(component, tmp_path):
+    host = make_host(component)
+    install_dir = tmp_path / "install"
+    manifest = component.ops.parse_manifest(
+        manifest_for(component, [artifact(backend = "cpu", asset = "cpu.tar.gz")]), label = "m"
+    )
+    selection = component.ops.selection_from_artifact(
+        published_repo = component.descriptor.published_repo,
+        release_tag = "v1",
+        manifest = manifest,
+        artifact = manifest["artifacts"][0],
+        backend = "cpu",
+        asset_sha256 = "0" * 64,
+    )
+    # No marker on disk yet -> not a match.
+    assert not component.ops.existing_install_matches(install_dir, host, selection)
+    bin_dir = component.ops.runtime_bin_dir(install_dir, host)
+    bin_dir.mkdir(parents = True)
+    component.ops.write_prebuilt_metadata(install_dir, selection)
+    # Marker alone is not enough: the server binary must exist too.
+    assert not component.ops.existing_install_matches(install_dir, host, selection)
+    (bin_dir / component.ops.server_binary_name(host)).write_bytes(b"bin")
+    marker = json.loads((install_dir / component.descriptor.metadata_filename).read_text())
+    assert marker["component"] == component.descriptor.component
+    assert marker["install_fingerprint"] == selection.fingerprint()
+    assert component.ops.existing_install_matches(install_dir, host, selection)
+    # A different selection (new sha) must force a reinstall.
+    other = core.InstallSelection(
+        **{
+            **selection.__dict__,
+            "asset_sha256": "1" * 64,
+        }
+    )
+    assert not component.ops.existing_install_matches(install_dir, host, other)
+
+
+def test_slim_selection_fields_are_additive(component, tmp_path):
+    """The slim pairing identity rides InstallSelection additively: it never
+    enters the fingerprint, and only a slim selection writes marker fields."""
+    manifest = component.ops.parse_manifest(
+        manifest_for(component, [artifact(backend = "cpu", asset = "cpu.tar.gz")]), label = "m"
+    )
+    selection = component.ops.selection_from_artifact(
+        published_repo = component.descriptor.published_repo,
+        release_tag = "v1",
+        manifest = manifest,
+        artifact = manifest["artifacts"][0],
+        backend = "cpu",
+        asset_sha256 = "0" * 64,
+    )
+    import dataclasses
+
+    slim = dataclasses.replace(
+        selection,
+        install_kind = "slim",
+        paired_llama_tag = "b10069-mix-fb3d4ca",
+        linked_from = "/llama/build/bin",
+        linked_libraries = ("libggml.so.0", "libggml-base.so.0"),
+    )
+    assert slim.fingerprint() == selection.fingerprint()  # no change to the computation
+
+    fat_dir, slim_dir = tmp_path / "fat", tmp_path / "slim"
+    fat_dir.mkdir(), slim_dir.mkdir()
+    component.ops.write_prebuilt_metadata(fat_dir, selection)
+    fat_marker = json.loads((fat_dir / component.descriptor.metadata_filename).read_text())
+    for key in ("install_kind", "paired_llama_tag", "linked_from", "linked_libraries"):
+        assert key not in fat_marker
+    component.ops.write_prebuilt_metadata(slim_dir, slim)
+    slim_marker = json.loads((slim_dir / component.descriptor.metadata_filename).read_text())
+    assert slim_marker["install_kind"] == "slim"
+    assert slim_marker["paired_llama_tag"] == "b10069-mix-fb3d4ca"
+    assert slim_marker["linked_from"] == "/llama/build/bin"
+    assert slim_marker["linked_libraries"] == ["libggml.so.0", "libggml-base.so.0"]
+    assert set(slim_marker) == set(fat_marker) | {
+        "install_kind",
+        "paired_llama_tag",
+        "linked_from",
+        "linked_libraries",
+    }
+
+
+def test_core_slim_hooks_default_inert(component, tmp_path):
+    # A component without its own hooks stages nothing extra and adds no
+    # resolver fields (llama's probe output must stay byte-identical).
+    assert component.ops.resolver_payload_extra({"install_kind": "slim"}) == {}
+    host = make_host(component)
+    selection = object()
+    assert component.ops.prepare_runtime_payload(tmp_path, host, selection) is None
+
+
+def test_busy_activation_restores_previous_install(monkeypatch, tmp_path):
+    install_dir = tmp_path / "whisper.cpp"
+    staged_root = tmp_path / "staged"
+    install_dir.mkdir()
+    staged_root.mkdir()
+    (install_dir / "version").write_text("old")
+    (staged_root / "version").write_text("new")
+    real_replace = core.os.replace
+
+    def locked_activation(source, destination):
+        if Path(source) == staged_root:
+            raise PermissionError(13, "Permission denied")
+        return real_replace(source, destination)
+
+    monkeypatch.setattr(core.os, "replace", locked_activation)
+    with pytest.raises(core.BusyInstallConflict):
+        core.swap_into_place(staged_root, install_dir)
+
+    assert (install_dir / "version").read_text() == "old"
+    assert staged_root.is_dir()
+    assert not list(tmp_path.glob(".whisper.cpp.old-*"))
+
+
+# ── Host/GPU token helpers (component-independent core functions) ──
+# Value tables moved verbatim from the llama characterization suite; these are
+# pure functions with no descriptor sensitivity, so they run unparameterized.
+@pytest.mark.parametrize(
+    "value,expected",
+    [
+        ("8.6", "86"),
+        ("07.05", "75"),
+        ("75", "75"),
+        (86, "86"),
+        ("", None),
+        ("  ", None),
+        ("x.y", None),
+        ("8.6.0", None),
+        ("9.0", "90"),
+    ],
+)
+def test_normalize_compute_cap(value, expected):
+    assert core.normalize_compute_cap(value) == expected
+
+
+@pytest.mark.parametrize(
+    "values,expected",
+    [
+        (["8.6", "86", "8.6"], ["86"]),  # deduplication
+        (["9.0", "7.5", "8.6"], ["75", "86", "90"]),  # numeric sort
+        (["8.6", "bad", "", "7.5"], ["75", "86"]),  # drops invalid
+        ([], []),
+    ],
+)
+def test_normalize_compute_caps(values, expected):
+    assert core.normalize_compute_caps(values) == expected
+
+
+@pytest.mark.parametrize(
+    "value,expected",
+    [
+        (None, None),
+        ("", []),
+        ("-1", []),
+        ("0", ["0"]),
+        ("0,1,2", ["0", "1", "2"]),
+        (" 0 , 1 ", ["0", "1"]),
+    ],
+)
+def test_parse_cuda_visible_devices(value, expected):
+    assert core.parse_cuda_visible_devices(value) == expected
+
+
+@pytest.mark.parametrize(
+    "visible,expected",
+    [
+        (["0", "1", "2"], True),
+        (["GPU-abc123"], True),
+        (None, False),
+        ([], False),
+        (["0", "MIG-device"], False),
+    ],
+)
+def test_supports_explicit_visible_device_matching(visible, expected):
+    assert core.supports_explicit_visible_device_matching(visible) is expected
+
+
+_GPU_ROWS = [
+    ("0", "GPU-aaa", "8.6"),
+    ("1", "GPU-bbb", "7.5"),
+    ("2", "GPU-ccc", "8.9"),
+]
+
+
+@pytest.mark.parametrize(
+    "visible,expected_indices",
+    [
+        (None, [0, 1, 2]),  # no filter returns all
+        ([], []),
+        (["0", "2"], [0, 2]),  # filter by index
+        (["gpu-bbb"], [1]),  # UUID match is case insensitive
+        (["0", "0"], [0]),  # same device requested twice is deduplicated
+        (["99"], []),  # unknown token matches nothing
+    ],
+)
+def test_select_visible_gpu_rows(visible, expected_indices):
+    expected = [_GPU_ROWS[i] for i in expected_indices]
+    assert core.select_visible_gpu_rows(_GPU_ROWS, visible) == expected
+
+
+@pytest.mark.parametrize(
+    "driver,expected",
+    [
+        (None, []),
+        ((11, 8), []),
+        ((12, 4), ["cuda12"]),
+        ((13, 0), ["cuda13", "cuda12"]),
+        ((14, 0), ["cuda14", "cuda13", "cuda12"]),  # future major derives lines
+    ],
+)
+def test_compatible_linux_runtime_lines(driver, expected):
+    host = SimpleNamespace(driver_cuda_version = driver)
+    assert core.compatible_linux_runtime_lines(host) == expected
+
+
+@pytest.mark.parametrize(
+    "value,expected",
+    [
+        ("12.6", "cuda12"),
+        ("13.0", "cuda13"),
+        ("11.8", None),
+        (None, None),
+        ("", None),
+    ],
+)
+def test_runtime_line_from_cuda_version(value, expected):
+    assert core.runtime_line_from_cuda_version(value) == expected
+
+
+def _caps_host(caps):
+    return SimpleNamespace(compute_caps = list(caps))
+
+
+def test_host_is_blackwell_includes_datacenter_parts():
+    assert core.host_is_blackwell(_caps_host(["10.0"])) is True  # B200 sm_100
+    assert core.host_is_blackwell(_caps_host(["10.3"])) is True  # B300 sm_103
+    assert core.host_is_blackwell(_caps_host(["12.0"])) is True  # RTX 50 sm_120
+    assert core.host_is_blackwell(_caps_host(["12.1"])) is True  # DGX Spark sm_121
+    assert core.host_is_blackwell(_caps_host(["9.0"])) is False  # Hopper
+    assert core.host_is_blackwell(_caps_host(["8.0"])) is False  # Ampere
+    assert core.host_is_blackwell(_caps_host(["9.0", "10.0"])) is True  # highest cap wins
+
+
+def test_blackwell_min_toolkit_is_sm_aware():
+    # Family floor is 12.8; sm_103/sm_121 (no native target before 12.9) lift it.
+    f = core.blackwell_min_toolkit_for_host
+    assert f(_caps_host(["10.0"])) == (12, 8)  # B200
+    assert f(_caps_host(["12.0"])) == (12, 8)  # RTX 50
+    assert f(_caps_host(["10.3"])) == (12, 9)  # B300
+    assert f(_caps_host(["12.1"])) == (12, 9)  # DGX Spark
+    assert f(_caps_host(["10.0", "10.3"])) == (12, 9)  # max across SMs wins
+
+
+# ── The ops seam ──
+def test_module_ops_prefers_module_globals_over_core_defaults(component):
+    ns = dict(component.namespace)
+    calls = []
+
+    def fake_download_file(url, destination):
+        calls.append(url)
+        destination.write_bytes(b"data")
+
+    ns["download_file"] = fake_download_file
+    ops = core.ModuleOps(ns)
+    assert ops.download_file is fake_download_file
+    # Core defaults still resolve (and come back bound) for everything else.
+    assert callable(ops.fetch_json)
+    with pytest.raises(AttributeError):
+        _ = ops.does_not_exist_anywhere
diff --git a/tests/studio/install/test_rocm_support.py b/tests/studio/install/test_rocm_support.py
index 5cabf41f57..b919206120 100644
--- a/tests/studio/install/test_rocm_support.py
+++ b/tests/studio/install/test_rocm_support.py
@@ -3,9 +3,13 @@
 import importlib.util
 import json
 import os
+import re
+import shutil
 import subprocess
 import sys
+import tempfile
 from pathlib import Path
+from types import SimpleNamespace
 from unittest.mock import MagicMock, mock_open, patch, PropertyMock
 
 import pytest
@@ -228,6 +232,10 @@ UPSTREAM_ASSETS = {
 class TestResolveUpstreamAssetChoice:
     """Verify that the asset selection logic picks the right binary for each platform."""
 
+    # The plain cpu-linux / windows-cpu / macos-arm64 routing cases live in
+    # test_selection_logic.py::TestResolveUpstreamAssetChoice (exact-name pins);
+    # this class keeps the ROCm/NVIDIA-precedence dialect only.
+
     @patch.object(prebuilt_mod, "github_release_assets", return_value = UPSTREAM_ASSETS)
     def test_nvidia_linux_gets_cpu_asset(self, mock_assets):
         """NVIDIA host should NOT hit the ROCm path -- gets CPU asset (CUDA handled elsewhere)."""
@@ -245,30 +253,6 @@ class TestResolveUpstreamAssetChoice:
         assert choice.install_kind == "linux-rocm"
         assert "rocm" in choice.name
 
-    @patch.object(prebuilt_mod, "github_release_assets", return_value = UPSTREAM_ASSETS)
-    def test_cpu_linux_gets_cpu_asset(self, mock_assets):
-        """CPU-only Linux host should get CPU asset."""
-        host = cpu_host()
-        choice = resolve_upstream_asset_choice(host, LLAMA_TAG)
-        assert choice.install_kind == "linux-cpu"
-        assert "ubuntu-x64" in choice.name
-
-    @patch.object(prebuilt_mod, "github_release_assets", return_value = UPSTREAM_ASSETS)
-    def test_macos_arm64_gets_macos_asset(self, mock_assets):
-        """macOS arm64 host should get macOS asset."""
-        host = macos_host()
-        choice = resolve_upstream_asset_choice(host, LLAMA_TAG)
-        assert choice.install_kind == "macos-arm64"
-        assert "macos-arm64" in choice.name
-
-    @patch.object(prebuilt_mod, "github_release_assets", return_value = UPSTREAM_ASSETS)
-    def test_windows_cpu_gets_cpu_asset(self, mock_assets):
-        """Windows CPU-only host should get Windows CPU asset."""
-        host = windows_host()
-        choice = resolve_upstream_asset_choice(host, LLAMA_TAG)
-        assert choice.install_kind == "windows-cpu"
-        assert "win-cpu" in choice.name
-
     @patch.object(prebuilt_mod, "github_release_assets", return_value = UPSTREAM_ASSETS)
     def test_windows_rocm_gets_hip_asset(self, mock_assets):
         """Windows ROCm host should get Windows HIP asset."""
@@ -360,7 +344,7 @@ class TestRuntimePatterns:
             install_kind = "windows-hip",
         )
         patterns = runtime_patterns_for_choice(choice)
-        # Narrowed from "*.exe" to the two binaries Studio actually invokes.
+        # Narrowed from "*.exe" to the two binaries Unsloth actually invokes.
         assert "llama-server.exe" in patterns
         assert "llama-quantize.exe" in patterns
         assert "*.dll" in patterns
@@ -378,7 +362,7 @@ class TestRuntimePatterns:
         assert "lib*.dylib" in patterns
 
     def test_diffusion_visual_server_kept(self):
-        # The DiffusionGemma visual-server must survive the prune so Studio can
+        # The DiffusionGemma visual-server must survive the prune so Unsloth can
         # serve DiffusionGemma GGUFs natively.
         for kind, name in (
             ("linux-cuda", "llama-diffusion-gemma-visual-server"),
@@ -557,9 +541,13 @@ class TestDetectRocmVersion:
 class TestEnsureRocmTorch:
     """Verify ROCm torch reinstall logic."""
 
+    # _infer_linux_amd_gfx_arch mocked to None: on a real Strix host the live
+    # /proc/cpuinfo would otherwise take the inferred-install path and break
+    # these "must not install" hosts (environment leak, not the code under test).
     @patch.object(stack_mod, "pip_install")
     @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
-    def test_no_rocm_skips(self, mock_nvidia, mock_pip):
+    @patch.object(stack_mod, "_infer_linux_amd_gfx_arch", return_value = None)
+    def test_no_rocm_skips(self, mock_infer, mock_nvidia, mock_pip):
         """No ROCm toolchain should skip entirely."""
         # Pin _detect_windows_gfx_arch to None so a real AMD test host's WMI
         # fallback can't defeat the "no ROCm anywhere" premise.
@@ -569,19 +557,126 @@ class TestEnsureRocmTorch:
                     _ensure_rocm_torch()
         mock_pip.assert_not_called()
 
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install_try", return_value = True)
+    @patch.object(stack_mod, "pip_install")
+    @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
+    @patch.object(stack_mod, "_has_rocm_gpu", return_value = False)
+    @patch.object(stack_mod, "_infer_linux_amd_gfx_arch", return_value = "gfx1151")
+    @patch.object(stack_mod, "_detect_rocm_version", return_value = None)
+    def test_inferred_gfx_without_rocm_runtime_installs_amd_index(
+        self, mock_ver, mock_infer, mock_gpu, mock_nvidia, mock_pip, mock_pip_try
+    ):
+        """Strix Halo without /dev/kfd must still get AMD gfx1151 wheels (unslothai#7301)."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 0
+        mock_probe.stdout = b"|2.10.0+cpu\n"
+        with patch("os.path.isdir", return_value = True):
+            with patch("subprocess.run", return_value = mock_probe):
+                _ensure_rocm_torch()
+        torch_call = str(mock_pip.call_args_list[0])
+        assert "gfx1151" in torch_call
+        assert "torch>=2.11.0,<2.12.0" in torch_call
+
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install_try", return_value = True)
+    @patch.object(stack_mod, "pip_install")
+    @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
+    @patch.object(stack_mod, "_has_rocm_gpu", return_value = False)
+    @patch.object(stack_mod, "_infer_linux_amd_gfx_arch", return_value = "gfx1151")
+    @patch.object(stack_mod, "_detect_amd_gfx_codes", return_value = [])
+    @patch.object(stack_mod, "_detect_rocm_version", return_value = (7, 1))
+    def test_inferred_gfx_not_overwritten_when_rocm_userland_readable(
+        self, mock_ver, mock_gfx, mock_infer, mock_gpu, mock_nvidia, mock_pip, mock_pip_try
+    ):
+        """Codex P1 #7305: after an inferred per-arch install, do not fall through to the
+        generic pytorch.org/rocmX.Y reinstall just because has_hip_torch is still False.
+        Readable ROCm userland without /dev/kfd is exactly the case that used to overwrite
+        the AMD gfx wheels."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 0
+        mock_probe.stdout = b"|2.10.0+cpu\n"
+        with patch("os.path.isdir", return_value = True):
+            with patch("subprocess.run", return_value = mock_probe):
+                _ensure_rocm_torch()
+        assert mock_pip.call_count == 1, mock_pip.call_args_list
+        torch_call = str(mock_pip.call_args_list[0])
+        assert "gfx1151" in torch_call
+        assert "rocm7.1" not in torch_call
+        assert "download.pytorch.org" not in torch_call
+
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install_try", return_value = True)
+    @patch.object(stack_mod, "pip_install")
+    @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
+    @patch.object(stack_mod, "_has_rocm_gpu", return_value = True)
+    @patch.object(stack_mod, "_infer_linux_amd_gfx_arch", return_value = "gfx1151")
+    @patch.object(stack_mod, "_detect_amd_gfx_codes", return_value = ["gfx1100"])
+    @patch.object(stack_mod, "_detect_rocm_version", return_value = (7, 1))
+    def test_inference_yields_to_runtime_visible_gpu(
+        self, mock_ver, mock_gfx, mock_infer, mock_gpu, mock_nvidia, mock_pip, mock_pip_try
+    ):
+        """When the runtime CAN enumerate a GPU, the cpuinfo inference must not
+        install wheels: a mixed Strix APU + dGPU box with the dGPU selected would
+        otherwise get gfx1151 wheels for a gfx1100 GPU. The runtime-visible arch
+        (Strix override / generic branch) decides instead."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 0
+        mock_probe.stdout = b"|2.10.0+cpu\n"
+        with patch("os.path.isdir", return_value = True):
+            with patch("subprocess.run", return_value = mock_probe):
+                _ensure_rocm_torch()
+        all_calls = str(mock_pip.call_args_list) + str(mock_pip_try.call_args_list)
+        assert "gfx1151" not in all_calls, all_calls
+        assert "rocm7.1" in all_calls, all_calls
+
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install_try", return_value = True)
+    @patch.object(stack_mod, "pip_install")
+    @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
+    @patch.object(stack_mod, "_has_rocm_gpu", return_value = True)
+    @patch.object(stack_mod, "_detect_amd_gfx_codes", return_value = [])
+    @patch.object(stack_mod, "_detect_rocm_version", return_value = None)
+    def test_gfx_override_installs_despite_visible_rocm(
+        self, mock_ver, mock_gfx, mock_gpu, mock_nvidia, mock_pip, mock_pip_try
+    ):
+        """#7305 review: an explicit UNSLOTH_ROCM_GFX_ARCH is exempt from the
+        not-_has_rocm_gpu() gate (mirrors install.sh). A visible GPU with an
+        unreadable ROCm version must not silently discard the user's named arch
+        and leave CPU torch in place -- the per-arch install runs."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 0
+        mock_probe.stdout = b"|2.10.0+cpu\n"
+        with patch.dict(os.environ, {"UNSLOTH_ROCM_GFX_ARCH": "gfx1151"}):
+            with patch("os.path.isdir", return_value = True):
+                with patch("subprocess.run", return_value = mock_probe):
+                    _ensure_rocm_torch()
+        assert mock_pip.call_count == 1, mock_pip.call_args_list
+        torch_call = str(mock_pip.call_args_list[0])
+        assert "gfx1151" in torch_call
+        assert "download.pytorch.org" not in torch_call
+
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install_try", return_value = True)
     @patch.object(stack_mod, "pip_install")
     @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
     @patch.object(stack_mod, "_has_rocm_gpu", return_value = True)
     @patch.object(stack_mod, "_detect_rocm_version", return_value = (7, 1))
-    def test_torch_already_has_cuda_skips(self, mock_ver, mock_gpu, mock_nvidia, mock_pip):
-        """If torch already has CUDA, should skip ROCm reinstall."""
+    def test_cuda_torch_on_amd_host_reinstalls(
+        self, mock_ver, mock_gpu, mock_nvidia, mock_pip, mock_pip_try
+    ):
+        """A CUDA-only torch build is unusable on an AMD-only host, so it must be
+        reinstalled to ROCm (has_hip_torch is driven by the empty HIP marker, not
+        by treating the CUDA version string as a HIP marker)."""
         mock_probe = MagicMock()
         mock_probe.returncode = 0
-        mock_probe.stdout = b"12.6\n"  # CUDA version
+        # Single-line probe: empty HIP marker before "|" for a CUDA build.
+        mock_probe.stdout = b"|2.10.0+cu126\n"
         with patch("os.path.isdir", return_value = True):
             with patch("subprocess.run", return_value = mock_probe):
                 _ensure_rocm_torch()
-        mock_pip.assert_not_called()
+        assert mock_pip.call_count == 1
+        assert "rocm7.1" in str(mock_pip.call_args_list[0])
 
     @patch.object(stack_mod, "pip_install")
     @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
@@ -591,12 +686,31 @@ class TestEnsureRocmTorch:
         """If torch already has HIP, should skip ROCm reinstall."""
         mock_probe = MagicMock()
         mock_probe.returncode = 0
-        mock_probe.stdout = b"7.1.12345\n"  # HIP version
+        mock_probe.stdout = b"7.1.12345|2.10.0+rocm7.1\n"  # HIP marker + version
         with patch("os.path.isdir", return_value = True):
             with patch("subprocess.run", return_value = mock_probe):
                 _ensure_rocm_torch()
         mock_pip.assert_not_called()
 
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install")
+    @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
+    @patch.object(stack_mod, "_has_rocm_gpu", return_value = True)
+    @patch.object(stack_mod, "_detect_rocm_version", return_value = (7, 1))
+    def test_cpu_torch_probe_line_not_read_as_hip(self, mock_ver, mock_gpu, mock_nvidia, mock_pip):
+        """A CPU build's probe line ("|2.10.0+cpu") must not read as HIP: the version
+        after the "|" separator is data, not a HIP marker, so has_hip_torch stays False
+        and the reinstall fires."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 0
+        mock_probe.stdout = b"|2.10.0+cpu\n"
+        with patch("os.path.isdir", return_value = True):
+            with patch("subprocess.run", return_value = mock_probe):
+                with patch.object(stack_mod, "pip_install_try", return_value = True):
+                    _ensure_rocm_torch()
+        assert mock_pip.call_count == 1
+        assert "rocm7.1" in str(mock_pip.call_args_list[0])
+
     @patch.object(stack_mod, "IS_WINDOWS", False)
     @patch.object(stack_mod, "pip_install_try", return_value = True)
     @patch.object(stack_mod, "pip_install")
@@ -653,9 +767,10 @@ class TestEnsureRocmTorch:
     @patch.object(stack_mod, "pip_install")
     @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
     @patch.object(stack_mod, "_has_rocm_gpu", return_value = True)
+    @patch.object(stack_mod, "_infer_linux_amd_gfx_arch", return_value = None)
     @patch.object(stack_mod, "_detect_rocm_version", return_value = None)
     def test_version_unreadable_prints_warning(
-        self, mock_ver, mock_gpu, mock_nvidia, mock_pip, capsys
+        self, mock_ver, mock_infer, mock_gpu, mock_nvidia, mock_pip, capsys
     ):
         """ROCm detected but version unreadable should print warning and skip."""
         with patch("os.path.isdir", return_value = True):
@@ -680,6 +795,316 @@ class TestEnsureRocmTorch:
         torch_call = mock_pip.call_args_list[0]
         assert "rocm7.2" in str(torch_call)
 
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install_try", return_value = True)
+    @patch.object(stack_mod, "pip_install")
+    @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
+    @patch.object(stack_mod, "_has_rocm_gpu", return_value = True)
+    @patch.object(stack_mod, "_detect_rocm_version", return_value = (7, 14))
+    @patch.object(stack_mod, "_detect_amd_gfx_codes", return_value = ["gfx1150"])
+    def test_rocm_714_strix_routes_to_amd_arch_index(
+        self, mock_gfx, mock_ver, mock_gpu, mock_nvidia, mock_pip, mock_pip_try
+    ):
+        """ROCm 7.14 caps to rocm7.2 on pytorch.org; Strix must use AMD gfx index."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 0
+        mock_probe.stdout = b"7.14.60850|2.11.0+rocm7.2\n"
+        with patch("os.path.isdir", return_value = True):
+            with patch("subprocess.run", return_value = mock_probe):
+                _ensure_rocm_torch()
+        torch_call = str(mock_pip.call_args_list[0])
+        assert "gfx1150" in torch_call
+        assert "torch>=2.11.0,<2.12.0" in torch_call
+
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install_try", return_value = True)
+    @patch.object(stack_mod, "pip_install")
+    @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
+    @patch.object(stack_mod, "_has_rocm_gpu", return_value = True)
+    @patch.object(stack_mod, "_detect_rocm_version", return_value = (6, 4))
+    def test_explicit_gfx_index_honored_and_skips_strix_reroute(
+        self, mock_ver, mock_gpu, mock_nvidia, mock_pip, mock_pip_try
+    ):
+        """An explicit gfx wheel-index pin is authoritative: install from it verbatim
+        with torch 2.11, and never re-probe gfx codes to second-guess it (host ROCm 6.4
+        would otherwise pick the rocm6.4 wheel / trigger the Strix re-route)."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 0
+        mock_probe.stdout = b"\n"  # cpu torch -> reinstall
+        env = {"UNSLOTH_TORCH_INDEX_URL": "https://repo.amd.com/rocm/whl/gfx1151"}
+        with patch.dict(stack_mod.os.environ, env, clear = False):
+            stack_mod.os.environ.pop("UNSLOTH_TORCH_INDEX_FAMILY", None)
+            with patch("os.path.isdir", return_value = True):
+                with patch("subprocess.run", return_value = mock_probe):
+                    # Would raise if the Strix block ran (it is skipped on an explicit pin).
+                    with patch.object(
+                        stack_mod, "_detect_amd_gfx_codes", side_effect = AssertionError
+                    ):
+                        _ensure_rocm_torch()
+        assert mock_pip.call_count == 1
+        torch_call = str(mock_pip.call_args_list[0])
+        assert "gfx1151" in torch_call
+        assert "torch>=2.11.0,<2.12.0" in torch_call
+
+    def test_rocm_pin_family_mismatch_helper(self):
+        """_rocm_pin_family_mismatch: exact rocm compare, else the 2.11 line."""
+        f = stack_mod._rocm_pin_family_mismatch
+        base = "https://download.pytorch.org/whl"
+        amd = "https://repo.amd.com/rocm/whl"
+        # Exact rocm version comparison.
+        assert f(f"{base}/rocm7.2", "2.11.0+rocm7.2") is False
+        assert f(f"{base}/rocm7.2", "2.10.0+rocm6.4") is True
+        assert f(f"{base}/rocm6.4", "2.10.0+rocm6.4") is False
+        # rocm7.2 is KNOWN-2.11. A +rocm7.2 wheel whose RELEASE drifted off 2.11 shares the
+        # tag but violates the spec -> mismatch (a plain version compare would accept it).
+        assert f(f"{base}/rocm7.2", "2.12.0+rocm7.2") is True
+        assert f(f"{base}/rocm7.2", "2.13.0+rocm7.2") is True
+        assert f(f"{base}/rocm7.2", "2.11.5+rocm7.2") is False  # patch on 2.11 is in-spec
+        # An UNKNOWN newer rocm (not on the 2.11 allowlist) is not floored to 2.11, so a
+        # matching rocm version at any release line is NOT a mismatch on this branch.
+        assert f(f"{base}/rocm8.0", "2.12.0+rocm8.0") is False
+        # gfx pin (2.11 line) vs installed release line.
+        assert f(f"{amd}/gfx1151", "2.10.0+rocm6.4") is True
+        assert f(f"{amd}/gfx1151", "2.11.0+rocm7.13.0") is False
+        # rocm7.2 pin vs an untagged (no +rocm) wheel: a CPU/CUDA build never
+        # satisfies a ROCm pin, regardless of its release line -> always a mismatch.
+        assert f(f"{base}/rocm7.2", "2.10.0") is True
+        assert f(f"{base}/rocm7.2", "2.11.0") is True
+        assert f(f"{base}/rocm6.4", "2.10.0") is True
+        # A 2.11-allowlist gfx pin over a GENERIC (two-part +rocm7.2) 2.11 wheel mismatches:
+        # the user wants AMD's per-arch (three-part) wheel, not the generic one.
+        assert f(f"{amd}/gfx1151", "2.11.0+rocm7.2") is True
+        assert f(f"{amd}/gfx120X-all", "2.11.0+rocm7.2") is True
+        # ...but an already-installed per-arch (three-part) wheel is NOT re-flagged
+        # (no reinstall loop once the correct gfx wheel is present).
+        assert f(f"{amd}/gfx120X-all", "2.11.0+rocm7.13.0") is False
+        assert f(f"{amd}/gfx1150", "2.11.0+rocm7.13.0") is False
+        # A NON-2.11 gfx pin (gfx110X-all/gfx90a/gfx908) tracks the default <2.11 spec: a
+        # correct 2.10+rocm wheel is NOT a mismatch, a 2.11 build is.
+        assert f(f"{amd}/gfx110X-all", "2.10.0+rocm6.4") is False
+        assert f(f"{amd}/gfx90a", "2.10.0+rocm6.3") is False
+        assert f(f"{amd}/gfx908", "2.10.0+rocm7.0") is False
+        assert f(f"{amd}/gfx110X-all", "2.11.0+rocm7.2") is True
+        # A non-2.11 gfx pin over an untagged (no +rocm) wheel is a mismatch even
+        # when torch is already <2.11: a CPU/CUDA build never satisfies the ROCm pin.
+        assert f(f"{amd}/gfx110X-all", "2.10.0") is True
+        assert f(f"{amd}/gfx90a", "2.10.0") is True
+        # A major-only rocm pin (rocm7) compares on the major alone: rocm6.x mismatches,
+        # any rocm7.x satisfies it, an untagged wheel never does, a bare +rocm is lenient.
+        assert f(f"{base}/rocm7", "2.10.0+rocm6.4") is True
+        assert f(f"{base}/rocm7", "2.11.0+rocm7.2") is False
+        assert f(f"{base}/rocm7", "2.11.0+rocm7.13.0") is False
+        assert f(f"{base}/rocm7", "2.10.0") is True
+        assert f(f"{base}/rocm7", "2.10.0+rocm") is False
+
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install_try", return_value = True)
+    @patch.object(stack_mod, "pip_install")
+    @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
+    @patch.object(stack_mod, "_has_rocm_gpu", return_value = True)
+    @patch.object(stack_mod, "_detect_rocm_version", return_value = (7, 2))
+    def test_rocm_pin_mismatch_over_installed_rocm_reinstalls(
+        self, mock_ver, mock_gpu, mock_nvidia, mock_pip, mock_pip_try
+    ):
+        """A rocm7.2 pin over an already-installed OLDER +rocm6.4 build must reinstall,
+        even though has_hip_torch is True (the ROCm analogue of the CUDA cuXXX mismatch)."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 0
+        # HIP marker present (has_hip_torch=True) + installed +rocm6.4 wheel.
+        mock_probe.stdout = b"6.4.12345|2.10.0+rocm6.4\n"
+        env = {"UNSLOTH_TORCH_INDEX_FAMILY": "rocm7.2"}
+        with patch.dict(stack_mod.os.environ, env, clear = False):
+            stack_mod.os.environ.pop("UNSLOTH_TORCH_INDEX_URL", None)
+            with patch("os.path.isdir", return_value = True):
+                with patch("subprocess.run", return_value = mock_probe):
+                    _ensure_rocm_torch()
+        torch_call = str(mock_pip.call_args_list[0])
+        assert "rocm7.2" in torch_call
+        assert "torch>=2.11.0,<2.12.0" in torch_call
+
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install_try", return_value = True)
+    @patch.object(stack_mod, "pip_install")
+    @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
+    @patch.object(stack_mod, "_has_rocm_gpu", return_value = True)
+    @patch.object(stack_mod, "_detect_rocm_version", return_value = (6, 4))
+    def test_gfx_pin_over_installed_pre211_rocm_reinstalls(
+        self, mock_ver, mock_gpu, mock_nvidia, mock_pip, mock_pip_try
+    ):
+        """A gfx* pin (2.11 line) over an installed pre-2.11 +rocm6.4 build reinstalls."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 0
+        mock_probe.stdout = b"6.4.12345|2.10.0+rocm6.4\n"
+        env = {"UNSLOTH_TORCH_INDEX_URL": "https://repo.amd.com/rocm/whl/gfx1151"}
+        with patch.dict(stack_mod.os.environ, env, clear = False):
+            stack_mod.os.environ.pop("UNSLOTH_TORCH_INDEX_FAMILY", None)
+            with patch("os.path.isdir", return_value = True):
+                with patch("subprocess.run", return_value = mock_probe):
+                    with patch.object(
+                        stack_mod, "_detect_amd_gfx_codes", side_effect = AssertionError
+                    ):
+                        _ensure_rocm_torch()
+        torch_call = str(mock_pip.call_args_list[0])
+        assert "gfx1151" in torch_call
+        assert "torch>=2.11.0,<2.12.0" in torch_call
+
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install_try", return_value = True)
+    @patch.object(stack_mod, "pip_install")
+    @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
+    @patch.object(stack_mod, "_has_rocm_gpu", return_value = True)
+    @patch.object(stack_mod, "_detect_rocm_version", return_value = (7, 2))
+    def test_rocm_pin_matches_installed_no_torch_reinstall(
+        self, mock_ver, mock_gpu, mock_nvidia, mock_pip, mock_pip_try
+    ):
+        """A rocm7.2 pin over an already-matching +rocm7.2 build must NOT reinstall torch
+        (no false reinstall of a correct ROCm venv)."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 0
+        mock_probe.stdout = b"7.2.12345|2.11.0+rocm7.2\n"
+        env = {"UNSLOTH_TORCH_INDEX_FAMILY": "rocm7.2"}
+        with patch.dict(stack_mod.os.environ, env, clear = False):
+            stack_mod.os.environ.pop("UNSLOTH_TORCH_INDEX_URL", None)
+            with patch("os.path.isdir", return_value = True):
+                with patch("subprocess.run", return_value = mock_probe):
+                    _ensure_rocm_torch()
+        # No torch reinstall: any pip_install call must not target a torch index.
+        for _call in mock_pip.call_args_list:
+            _args = [str(a) for a in _call.args]
+            if "--index-url" in _args:
+                _url = _args[_args.index("--index-url") + 1]
+                assert "rocm7.2" not in _url or "torch" not in " ".join(
+                    _args
+                ), "torch must not be reinstalled when the pin already matches"
+        # A torch reinstall would pass torch>=... as a positional; assert none did.
+        assert not any(
+            any(str(a).startswith("torch") for a in _c.args) for _c in mock_pip.call_args_list
+        )
+
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install_try", return_value = True)
+    @patch.object(stack_mod, "pip_install")
+    @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
+    @patch.object(stack_mod, "_has_rocm_gpu", return_value = True)
+    @patch.object(stack_mod, "_detect_rocm_version", return_value = (6, 4))
+    def test_non211_gfx_pin_over_210_rocm_no_reinstall(
+        self, mock_ver, mock_gpu, mock_nvidia, mock_pip, mock_pip_try
+    ):
+        """A gfx110X-all pin (NOT in the 2.11 allowlist) over a correct 2.10+rocm
+        wheel must NOT be flagged stale -- the install path uses the default <2.11
+        specs for that arch, so re-flagging would reinstall-loop on every update."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 0
+        mock_probe.stdout = b"6.4.12345|2.10.0+rocm6.4\n"
+        env = {"UNSLOTH_TORCH_INDEX_URL": "https://repo.amd.com/rocm/whl/gfx110X-all"}
+        with patch.dict(stack_mod.os.environ, env, clear = False):
+            stack_mod.os.environ.pop("UNSLOTH_TORCH_INDEX_FAMILY", None)
+            with patch("os.path.isdir", return_value = True):
+                with patch("subprocess.run", return_value = mock_probe):
+                    _ensure_rocm_torch()
+        # has_hip_torch True + no mismatch -> torch must NOT be reinstalled.
+        assert not any(
+            any(str(a).startswith("torch") for a in _c.args) for _c in mock_pip.call_args_list
+        )
+
+    @patch.object(stack_mod, "IS_WINDOWS", False)
+    @patch.object(stack_mod, "pip_install_try", return_value = True)
+    @patch.object(stack_mod, "pip_install")
+    @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
+    @patch.object(stack_mod, "_has_rocm_gpu", return_value = True)
+    @patch.object(stack_mod, "_detect_rocm_version", return_value = (7, 2))
+    def test_gfx_pin_over_generic_rocm211_reinstalls(
+        self, mock_ver, mock_gpu, mock_nvidia, mock_pip, mock_pip_try
+    ):
+        """A gfx1151 pin over a GENERIC (two-part +rocm7.2) 2.11 wheel must reinstall
+        the AMD per-arch wheel -- even though both are torch 2.11, the generic wheel
+        is not the per-arch build the user pinned (Strix stays off the generic wheel)."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 0
+        mock_probe.stdout = b"7.2.12345|2.11.0+rocm7.2\n"
+        env = {"UNSLOTH_TORCH_INDEX_URL": "https://repo.amd.com/rocm/whl/gfx1151"}
+        with patch.dict(stack_mod.os.environ, env, clear = False):
+            stack_mod.os.environ.pop("UNSLOTH_TORCH_INDEX_FAMILY", None)
+            with patch("os.path.isdir", return_value = True):
+                with patch("subprocess.run", return_value = mock_probe):
+                    with patch.object(
+                        stack_mod, "_detect_amd_gfx_codes", side_effect = AssertionError
+                    ):
+                        _ensure_rocm_torch()
+        torch_call = str(mock_pip.call_args_list[0])
+        assert "gfx1151" in torch_call
+        assert "torch>=2.11.0,<2.12.0" in torch_call
+
+    def test_radeon_url_not_classified_as_pip_rocm_family(self):
+        """A repo.radeon.com find-links dir (leaf rocm-rel-7.2.1) starts with "rocm" but is
+        NOT a pip --index-url ROCm family: it must route to the verbatim path, not a
+        --index-url reinstall that fails against a find-links listing."""
+        leaf_f = stack_mod._is_pip_rocm_family_leaf
+        # Real pip ROCm families (download.pytorch.org/whl/rocmX.Y, repo.amd.com gfx).
+        assert leaf_f("rocm7.2") is True
+        assert leaf_f("rocm6.4") is True
+        assert leaf_f("gfx120x-all") is True
+        assert leaf_f("gfx1151") is True
+        # A bare rocm<digits> (no minor) is still an exact family.
+        assert leaf_f("rocm7") is True
+        # A Radeon find-links dir leaf, a custom mirror, cpu and cuda are NOT pip rocm.
+        assert leaf_f("rocm-rel-7.2.1") is False
+        assert leaf_f("simple") is False
+        assert leaf_f("current") is False
+        assert leaf_f("cpu") is False
+        assert leaf_f("cu128") is False
+        # A rocm<digit>-SUFFIX private mirror shares the family prefix but is a custom pin
+        # the verbatim path owns: a ^rocm\d PREFIX match would wrongly treat it as a
+        # --index-url family. Match EXACTLY.
+        assert leaf_f("rocm7.2-private") is False
+        assert leaf_f("rocm7-current") is False
+        assert leaf_f("rocm7.2.1") is False  # two-part local suffix -> custom, not rocm7.2
+
+        radeon = "https://repo.radeon.com/rocm/manylinux/rocm-rel-7.2.1"
+        pip_rocm = "https://download.pytorch.org/whl/rocm7.2"
+        amd_gfx = "https://repo.amd.com/rocm/whl/gfx120X-all"
+
+        def _classify(url, fn):
+            with patch.dict(stack_mod.os.environ, {"UNSLOTH_TORCH_INDEX_URL": url}, clear = False):
+                stack_mod.os.environ.pop("UNSLOTH_TORCH_INDEX_FAMILY", None)
+                return fn()
+
+        rocm_fn = stack_mod._explicit_rocm_torch_index_url
+        unk_fn = stack_mod._explicit_unknown_family_torch_index_url
+        # Real pip rocm/gfx pins ARE a ROCm family (reinstallable via --index-url) and
+        # are NOT "unknown".
+        assert _classify(pip_rocm, rocm_fn) == pip_rocm
+        assert _classify(amd_gfx, rocm_fn) == amd_gfx
+        assert _classify(pip_rocm, unk_fn) is None
+        assert _classify(amd_gfx, unk_fn) is None
+        # The Radeon find-links URL is NOT a pip ROCm family (so _ensure_rocm_torch skips
+        # it) and IS unknown, so the family repair helpers leave it alone.
+        assert _classify(radeon, rocm_fn) is None
+        assert _classify(radeon, unk_fn) == radeon
+
+        # A rocm<digit>-suffix private mirror routes the same way: NOT a pip rocm family,
+        # IS an unknown-family (verbatim) pin.
+        suffixed = "https://co.internal/whl/rocm7.2-private"
+        assert _classify(suffixed, rocm_fn) is None
+        assert _classify(suffixed, unk_fn) == suffixed
+
+    @patch.object(stack_mod, "pip_install")
+    def test_ensure_cpu_torch_broken_probe_reinstalls(self, mock_pip):
+        """_ensure_cpu_torch: torch present but unimportable (probe exit != 0) under an
+        explicit CPU pin must reinstall from the pin, not return -- the base update does
+        not repair a broken installed torch, so returning would strand it (Codex P2)."""
+        mock_probe = MagicMock()
+        mock_probe.returncode = 1  # torch present but cannot import
+        mock_probe.stdout = b""
+        env = {"UNSLOTH_TORCH_INDEX_URL": "https://mirror.local/cpu"}
+        with patch.dict(stack_mod.os.environ, env, clear = False):
+            stack_mod.os.environ.pop("UNSLOTH_TORCH_INDEX_FAMILY", None)
+            with patch("subprocess.run", return_value = mock_probe):
+                with patch.object(stack_mod, "NO_TORCH", False):
+                    stack_mod._ensure_cpu_torch()
+        assert mock_pip.call_count == 1
+        assert "https://mirror.local/cpu" in str(mock_pip.call_args)
+
     @patch.object(stack_mod, "IS_WINDOWS", False)
     @patch.object(stack_mod, "pip_install_try", return_value = True)
     @patch.object(stack_mod, "pip_install")
@@ -702,7 +1127,8 @@ class TestEnsureRocmTorch:
     @patch.object(stack_mod, "pip_install")
     @patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = False)
     @patch.object(stack_mod, "_has_rocm_gpu", return_value = False)
-    def test_no_gpu_with_rocm_tools_skips(self, mock_gpu, mock_nvidia, mock_pip):
+    @patch.object(stack_mod, "_infer_linux_amd_gfx_arch", return_value = None)
+    def test_no_gpu_with_rocm_tools_skips(self, mock_infer, mock_gpu, mock_nvidia, mock_pip):
         """ROCm tools present but no actual AMD GPU should skip entirely."""
         # Pin the Windows arch probe to None so a real AMD host's WMI fallback
         # can't defeat the "no actual GPU" premise.
@@ -732,7 +1158,7 @@ class TestEnsureRocmTorch:
         mock_pip.assert_not_called()
 
 
-# TEST: install_python_stack.py -- _has_rocm_gpu KFD sysfs vendor_id guard
+# TEST: install_python_stack.py -- torch-index MARKER mechanism (PR #6692)
 
 
 class TestHasRocmGpuKfdVendorGuard:
@@ -1013,6 +1439,59 @@ class TestInstallShStructure:
         sh_path = PACKAGE_ROOT / "install.sh"
         source = sh_path.read_text(encoding = "utf-8")
         assert "amd-smi" in source
+
+    def test_cpu_index_note_respects_explicit_pin(self):
+        """An explicit UNSLOTH_TORCH_INDEX_URL/_FAMILY CPU pin is a request, not
+        a detection failure: the */cpu wheel note must report the pin instead of
+        claiming ROCm/HIP is unusable, the WSL setup guidance must be skipped,
+        and the gpu summary must not label a pinned AMD host "no usable ROCm"."""
+        sh_path = PACKAGE_ROOT / "install.sh"
+        source = sh_path.read_text(encoding = "utf-8")
+        note = source.find('substep "AMD GPU detected, but no usable ROCm/HIP install')
+        assert note != -1
+        assert (
+            '[ "$_torch_index_pinned" = true ]' in source[note - 400 : note]
+        ), "the */cpu note must check the explicit pin before diagnosing ROCm"
+        assert (
+            '[ "$OS" = "wsl" ] && [ "$_torch_index_pinned" = false ]' in source
+        ), "ROCm-on-WSL guidance is detection advice; skip it for pinned installs"
+        summary = source.find('step "gpu" "AMD GPU (no usable ROCm -- CPU fallback)"')
+        assert summary != -1
+        assert (
+            '[ "$_torch_index_pinned" = true ]' in source[summary - 700 : summary]
+        ), "the gpu summary must not claim no usable ROCm for a pinned index"
+
+    def test_rocm_version_chain_survives_no_source_under_set_e(self):
+        """When every ROCm version source is missing (e.g. rocminfo present but
+        rocm-core not installed, so dpkg-query/rpm exit 1), the _rocm_tag ||
+        chain fails as a whole; without the || guard set -e kills the installer
+        BEFORE the actionable no-version WARN it feeds. Executed, not text."""
+        shell = shutil.which("bash")
+        if not shell:
+            pytest.skip("bash needed to execute the version chain")
+        sh_path = PACKAGE_ROOT / "install.sh"
+        source = sh_path.read_text(encoding = "utf-8")
+        chain = re.search(
+            r'^        _rocm_tag=\$\(\{ command -v amd-smi.*?\|\| _rocm_tag=""\n',
+            source,
+            re.S | re.M,
+        )
+        assert chain, "could not extract the guarded _rocm_tag chain"
+        with tempfile.TemporaryDirectory() as d:
+            # Tools exist on PATH but yield nothing usable, like a box with the
+            # probe tools installed and no rocm-core package.
+            for name in ("amd-smi", "hipconfig", "dpkg-query", "rpm"):
+                p = os.path.join(d, name)
+                with open(p, "w", encoding = "utf-8") as f:
+                    f.write("#!/bin/sh\nexit 1\n")
+                os.chmod(p, 0o755)
+            script = (
+                "set -euo pipefail\n" + chain.group(0) + '\nprintf "SURVIVED:%s\\n" "$_rocm_tag"\n'
+            )
+            env = dict(os.environ, PATH = d + os.pathsep + os.environ.get("PATH", ""))
+            r = subprocess.run([shell, "-c", script], env = env, capture_output = True, text = True)
+            assert r.returncode == 0, f"version chain aborted under set -e: {r.stderr}"
+            assert r.stdout.startswith("SURVIVED:"), r.stdout
         assert "rocm" in source.lower()
 
     def test_cuda_precedence(self):
@@ -1144,17 +1623,446 @@ class TestInstallShStructure:
             "4098" in func_body
         ), "_has_amd_rocm_gpu sysfs fallback must require AMD vendor_id 4098 (0x1002)"
 
-    def test_kfd_awk_resets_state_per_file(self):
-        """KFD sysfs awk must reset gpu/amd state per file (FNR==1) to avoid Ryzen+NVIDIA false positives."""
+    def test_kfd_awk_vendor_check_is_per_line(self):
+        """KFD sysfs awk must decide on a single vendor_id line, with no cross-node state.
+
+        The old awk paired two per-node flags (gpu_id + vendor_id) and needed an FNR==1
+        reset so flags from different KFD nodes could not combine into a Ryzen+NVIDIA
+        false positive. gpu_id is a sibling sysfs file and never appears inside
+        properties, so that pairing also never matched at all (every ROCm-less AMD host
+        was reported as no-GPU). The replacement keys on one atomic line: only an AMD
+        GPU node reports `vendor_id 4098` (KFD CPU nodes report 0, NVIDIA's open kernel
+        module registers 4318), so there is no cross-file state left to reset.
+        """
         sh_path = PACKAGE_ROOT / "install.sh"
         source = sh_path.read_text(encoding = "utf-8")
         func_start = source.find("_has_amd_rocm_gpu()")
         func_end = source.find("\n}", func_start)
         func_body = source[func_start:func_end]
-        assert "FNR==1" in func_body, (
-            "_has_amd_rocm_gpu KFD awk must reset state per file with FNR==1 "
-            "to avoid false positives on Ryzen+NVIDIA hosts with multiple KFD nodes"
+        assert "$2 == 4098" in func_body, (
+            "_has_amd_rocm_gpu KFD awk must match `vendor_id 4098` as a single-line "
+            "condition so no per-node state can leak across KFD nodes"
         )
+        assert "/gpu_id/" not in func_body, (
+            "_has_amd_rocm_gpu KFD awk must not key on a gpu_id line: gpu_id is a "
+            "sibling sysfs file, not a line in properties, so it never matches there"
+        )
+
+    def test_setup_sh_kfd_awk_matches_install_sh(self):
+        """setup.sh's KFD fallback must use the same per-line vendor_id check as install.sh.
+
+        setup.sh re-probes AMD detection independently of install.sh; if its copy keeps
+        the dead gpu_id-inside-properties pairing, a host that install.sh routes to ROCm
+        still gets a CPU llama.cpp from the setup step (_setup_amd_detected stays false).
+        """
+        source = (PACKAGE_ROOT / "studio" / "setup.sh").read_text(encoding = "utf-8")
+        assert (
+            "$2 == 4098" in source
+        ), "setup.sh KFD awk must match `vendor_id 4098` as a single-line condition"
+        assert (
+            "/gpu_id/" not in source
+        ), "setup.sh KFD awk must not key on a gpu_id line inside properties"
+
+    def test_kfd_only_torch_falls_back_to_cpu(self):
+        """An AMD host whose gfx arch can't be read (rocminfo/amd-smi missing, or
+        present but not enumerating the GPU) must route torch to CPU, not a generic
+        rocm index: a Strix box (gfx1150/1151) would otherwise get the broken
+        _grouped_mm wheels because the reroute has no gfx to correct it."""
+        source = (PACKAGE_ROOT / "install.sh").read_text(encoding = "utf-8")
+        body = _extract_sh_function_body(source, "get_torch_index_url")
+        probe = body.find("_amd_gfx_probe=$(_probe_amd_gfx_arch)")
+        assert probe >= 0, "get_torch_index_url must probe the gfx arch before picking a rocm index"
+        # The shared probe reads gfx (not just tests binary presence), from rocminfo
+        # AND amd-smi, so an installed-but-not-enumerating probe still falls to CPU.
+        helper = _extract_sh_function_body(source, "_probe_amd_gfx_arch")
+        assert helper, "install.sh must define the shared _probe_amd_gfx_arch helper"
+        assert (
+            "rocminfo 2>/dev/null) | grep -oE 'gfx" in helper
+        ), "probe must read gfx from rocminfo"
+        assert (
+            "amd-smi list 2>/dev/null) | grep -oE 'gfx" in helper
+        ), "probe must read gfx from amd-smi"
+        # The probe clears ROCR/HIP_VISIBLE_DEVICES so a container mask
+        # (ROCR_VISIBLE_DEVICES=-1) can't blind the env-independent KFD detection.
+        assert (
+            "unset ROCR_VISIBLE_DEVICES HIP_VISIBLE_DEVICES" in helper
+        ), "the gfx probe must clear the visibility masks so a mask can't force CPU"
+        cpu_guard = body.find('if [ -z "$_amd_gfx_probe" ]')
+        assert cpu_guard >= 0, "unreadable gfx must fall back to CPU"
+        assert cpu_guard < body.find(
+            "_rocm_tag="
+        ), "the gfx gate must run before the ROCm version/index selection"
+
+    def test_kfd_only_llama_requires_hipcc(self):
+        """setup.sh must forward --has-rocm for a gfx-unknown (KFD-only) host only when
+        hipcc is present. With no gfx the prebuilt resolver finds no ROCm bundle and the
+        source build would fail, so without a HIP toolchain the host keeps the CPU
+        prebuilt rather than breaking the llama.cpp install."""
+        source = (PACKAGE_ROOT / "studio" / "setup.sh").read_text(encoding = "utf-8")
+        idx = source.find("_PREBUILT_CMD+=(--has-rocm)")
+        assert idx >= 0, "setup.sh must still be able to forward --has-rocm"
+        window = source[max(0, idx - 900) : idx]
+        assert (
+            "hipcc" in window
+        ), "the gfx-unknown --has-rocm branch must gate on hipcc (a usable HIP toolchain)"
+        assert (
+            "command -v hipcc" in window or "/opt/rocm/bin/hipcc" in window
+        ), "hipcc presence must be checked via command -v or the rocm bin path"
+        assert (
+            "/opt/rocm-*/bin/hipcc" in window
+        ), "the hipcc gate must also accept a versioned /opt/rocm-*/bin/hipcc toolchain"
+
+    def test_gfx_unknown_guard_honors_override(self):
+        """A user-set UNSLOTH_ROCM_GFX_ARCH must seed the gfx probe before the CPU
+        fallback: an air-gapped/rocminfo-less Strix host that names its arch should
+        still reach a rocm index instead of being forced to CPU."""
+        source = (PACKAGE_ROOT / "install.sh").read_text(encoding = "utf-8")
+        helper = _extract_sh_function_body(source, "_probe_amd_gfx_arch")
+        assert helper, "install.sh must define the shared _probe_amd_gfx_arch helper"
+        seed = helper.find("$(printf")
+        assert seed >= 0, "the gfx probe must seed from UNSLOTH_ROCM_GFX_ARCH"
+        assert "UNSLOTH_ROCM_GFX_ARCH" in helper[seed : seed + 80]
+        assert seed < helper.find(
+            "rocminfo 2>/dev/null) | grep -oE 'gfx"
+        ), "the override must be read before probing rocminfo"
+        body = _extract_sh_function_body(source, "get_torch_index_url")
+        call = body.find("_amd_gfx_probe=$(_probe_amd_gfx_arch)")
+        assert call >= 0, "get_torch_index_url must call the shared probe"
+        assert call < body.find(
+            'if [ -z "$_amd_gfx_probe" ]; then'
+        ), "the probe must run before the CPU fallback guard"
+
+    def test_gfx_override_seeds_reroute_without_tools(self):
+        """The Strix reroute must honour UNSLOTH_ROCM_GFX_ARCH even when rocminfo and
+        amd-smi are absent, so a manual override reaches the arch index; with no
+        override and no tools it must stay empty (no false Strix routing)."""
+        shell = shutil.which("bash")
+        if not shell:
+            pytest.skip("bash needed to execute the probe block")
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        block = re.search(
+            r'^        _gfx_all=\$\(printf[^\n]*\n.*?(?=^        _strix_gfx="")',
+            source,
+            re.S | re.M,
+        )
+        assert block, "could not extract the gfx-detection block"
+        with tempfile.TemporaryDirectory() as d:
+            # Shim rocminfo/amd-smi to enumerate nothing, so only the override can
+            # supply a gfx (keeps coreutils on PATH for tr/grep/printf).
+            for name in ("rocminfo", "amd-smi"):
+                p = os.path.join(d, name)
+                with open(p, "w", encoding = "utf-8") as f:
+                    f.write("#!/bin/sh\nexit 0\n")
+                os.chmod(p, 0o755)
+            script = (
+                'set -euo pipefail\nHIP_VISIBLE_DEVICES=""\nROCR_VISIBLE_DEVICES=""\n'
+                + block.group(0)
+                + '\nprintf "OK:%s\\n" "$_gfx_all"\n'
+            )
+
+            def run(**extra):
+                env = dict(os.environ, PATH = d + os.pathsep + os.environ.get("PATH", ""), **extra)
+                return subprocess.run(
+                    [shell, "-c", script], env = env, capture_output = True, text = True
+                )
+
+            r = run(UNSLOTH_ROCM_GFX_ARCH = "GFX1151")
+            assert r.returncode == 0, f"override probe aborted: {r.stderr}"
+            assert "OK:gfx1151" in r.stdout, f"override not honoured/lowercased: {r.stdout!r}"
+            r2 = run()
+            assert r2.returncode == 0, f"empty probe aborted: {r2.stderr}"
+            assert (
+                "OK:\n" in r2.stdout or r2.stdout.strip() == "OK:"
+            ), f"no override + no tools must leave gfx empty: {r2.stdout!r}"
+
+    def test_gfx_probe_ignores_visibility_mask(self):
+        """A container visibility mask (ROCR_VISIBLE_DEVICES=-1) must not blind the
+        gfx probe: rocminfo honours the mask and would enumerate nothing, but KFD
+        detection is env-independent, so the probe clears the mask and still reads
+        the arch (else a masked host is wrongly forced to CPU)."""
+        shell = shutil.which("bash")
+        if not shell:
+            pytest.skip("bash needed to execute the probe block")
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        probe_fn = _extract_sh_function_body(source, "_probe_amd_gfx_arch")
+        assert probe_fn, "could not extract _probe_amd_gfx_arch"
+        with tempfile.TemporaryDirectory() as d:
+            # rocminfo that mimics ROCR_VISIBLE_DEVICES=-1 hiding all agents.
+            with open(os.path.join(d, "rocminfo"), "w", encoding = "utf-8") as f:
+                f.write(
+                    "#!/bin/sh\n"
+                    'if [ "${ROCR_VISIBLE_DEVICES:-}" = "-1" ]; then echo "no agents"; exit 0; fi\n'
+                    'echo "  Name:  gfx1151"\n'
+                )
+            os.chmod(os.path.join(d, "rocminfo"), 0o755)
+            script = (
+                "set -euo pipefail\n"
+                "_ensure_rocm_probe_env() { :; }\n"
+                + probe_fn
+                + '\n_amd_gfx_probe=$(_probe_amd_gfx_arch)\nprintf "OK:%s\\n" "$_amd_gfx_probe"\n'
+            )
+
+            def run(**extra):
+                env = dict(os.environ, PATH = d + os.pathsep + os.environ.get("PATH", ""), **extra)
+                return subprocess.run(
+                    [shell, "-c", script], env = env, capture_output = True, text = True
+                )
+
+            r = run(ROCR_VISIBLE_DEVICES = "-1")
+            assert r.returncode == 0, f"masked probe aborted: {r.stderr}"
+            assert (
+                "OK:gfx1151" in r.stdout
+            ), f"a visibility mask must not blind the gfx probe: {r.stdout!r}"
+
+    def test_kfd_only_inferable_gfx_defers_to_reroute(self):
+        """A KFD-only host (GPU detected, gfx unreadable) whose arch IS inferable
+        from hardware IDs must not print the 'installing CPU-only PyTorch' warning:
+        get_torch_index_url returns the cpu index quietly and the runtime-less
+        reroute upgrades it to AMD per-arch wheels. Only when inference also fails
+        (or maps to no supported family) is CPU final, with the actionable hint."""
+        shell = shutil.which("bash")
+        if not shell:
+            pytest.skip("bash needed to execute get_torch_index_url")
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        fn = _extract_sh_function_body(source, "get_torch_index_url")
+        probe_fn = _extract_sh_function_body(source, "_probe_amd_gfx_arch")
+        family_fn = _extract_sh_function_body(source, "_amd_arch_index_family_for_gfx")
+        assert fn and probe_fn and family_fn
+        with tempfile.TemporaryDirectory() as d:
+            # uname -> Linux/x86_64 so the AMD branch runs on any dev host; the
+            # rocminfo/amd-smi shims enumerate nothing (KFD-only host).
+            with open(os.path.join(d, "uname"), "w", encoding = "utf-8", newline = "\n") as f:
+                f.write('#!/bin/sh\ncase "${1:-}" in -m) echo x86_64 ;; *) echo Linux ;; esac\n')
+            for name in ("rocminfo", "amd-smi"):
+                with open(os.path.join(d, name), "w", encoding = "utf-8", newline = "\n") as f:
+                    f.write("#!/bin/sh\nexit 0\n")
+            for name in ("uname", "rocminfo", "amd-smi"):
+                os.chmod(os.path.join(d, name), 0o755)
+
+            def run(infer_stub):
+                script = (
+                    "set -euo pipefail\n"
+                    "_ensure_rocm_probe_env() { :; }\n"
+                    "_trim_index_path_slashes() { printf '%s\\n' \"$1\"; }\n"
+                    "_has_usable_nvidia_gpu() { return 1; }\n"
+                    "_has_amd_rocm_gpu() { return 0; }\n"
+                    + infer_stub
+                    + "\n"
+                    + probe_fn
+                    + "\n"
+                    + family_fn
+                    + "\n"
+                    + fn
+                    + "\n"
+                    "get_torch_index_url\n"
+                )
+                # Run from a file, not -c: Windows bash mangles multi-KB -c strings.
+                sp = os.path.join(d, "gtiu.sh")
+                with open(sp, "w", encoding = "utf-8", newline = "\n") as f:
+                    f.write(script)
+                env = dict(os.environ, PATH = d + os.pathsep + os.environ.get("PATH", ""))
+                for var in (
+                    "UNSLOTH_ROCM_GFX_ARCH",
+                    "UNSLOTH_TORCH_INDEX_URL",
+                    "UNSLOTH_TORCH_INDEX_FAMILY",
+                    "UNSLOTH_PYTORCH_MIRROR",
+                    "ROCR_VISIBLE_DEVICES",
+                    "HIP_VISIBLE_DEVICES",
+                ):
+                    env.pop(var, None)
+                return subprocess.run(
+                    [shell, sp.replace("\\", "/")], env = env, capture_output = True, text = True
+                )
+
+            r = run("_infer_linux_amd_gfx_arch() { echo gfx1100; }")
+            assert r.returncode == 0, f"inferable case aborted: {r.stderr}"
+            assert r.stdout.strip().endswith(
+                "/cpu"
+            ), f"must hand */cpu to the reroute: {r.stdout!r}"
+            assert (
+                "inferring gfx1100" in r.stderr
+            ), f"must announce the inference handoff: {r.stderr!r}"
+            assert (
+                "installing CPU-only PyTorch" not in r.stderr
+            ), f"must not promise a CPU-only install the reroute will override: {r.stderr!r}"
+            r2 = run("_infer_linux_amd_gfx_arch() { return 1; }")
+            assert r2.returncode == 0, f"uninferable case aborted: {r2.stderr}"
+            assert r2.stdout.strip().endswith("/cpu")
+            assert (
+                "installing CPU-only PyTorch" in r2.stderr
+            ), f"uninferable gfx must keep the actionable CPU warning: {r2.stderr!r}"
+            r3 = run("_infer_linux_amd_gfx_arch() { echo gfx906; }")
+            assert r3.returncode == 0, f"unsupported-family case aborted: {r3.stderr}"
+            assert r3.stdout.strip().endswith("/cpu")
+            assert (
+                "installing CPU-only PyTorch" in r3.stderr
+            ), f"an inferred arch with no wheel family must keep the CPU warning: {r3.stderr!r}"
+
+    def test_no_version_cpu_warning_respects_gfx_override(self):
+        """With UNSLOTH_ROCM_GFX_ARCH set on a KFD-only host that has no ROCm
+        version sources, the gfx probe is seeded by the override, so the
+        no-version endpoint used to print 'falling back to CPU-only PyTorch'
+        even though the reroute then installs the per-arch wheels (Codex P3).
+        A supported override must defer; an unsupported override, or a
+        readable-gfx host without an override, keeps the CPU warning."""
+        shell = shutil.which("bash")
+        if not shell:
+            pytest.skip("bash needed to execute get_torch_index_url")
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        fn = _extract_sh_function_body(source, "get_torch_index_url")
+        probe_fn = _extract_sh_function_body(source, "_probe_amd_gfx_arch")
+        family_fn = _extract_sh_function_body(source, "_amd_arch_index_family_for_gfx")
+        assert fn and probe_fn and family_fn
+        with tempfile.TemporaryDirectory() as d:
+            with open(os.path.join(d, "uname"), "w", encoding = "utf-8", newline = "\n") as f:
+                f.write('#!/bin/sh\ncase "${1:-}" in -m) echo x86_64 ;; *) echo Linux ;; esac\n')
+            # Silence every ROCm version source, not just amd-smi: a dev box with
+            # a real hipconfig/dpkg would otherwise resolve a version and skip
+            # the no-version endpoint this test exercises.
+            with open(os.path.join(d, "amd-smi"), "w", encoding = "utf-8", newline = "\n") as f:
+                f.write("#!/bin/sh\nexit 0\n")
+            for name in ("hipconfig", "dpkg-query", "rpm"):
+                with open(os.path.join(d, name), "w", encoding = "utf-8", newline = "\n") as f:
+                    f.write("#!/bin/sh\nexit 1\n")
+            for name in ("uname", "amd-smi", "hipconfig", "dpkg-query", "rpm"):
+                os.chmod(os.path.join(d, name), 0o755)
+            script = (
+                "set -euo pipefail\n"
+                "_ensure_rocm_probe_env() { :; }\n"
+                "_trim_index_path_slashes() { printf '%s\\n' \"$1\"; }\n"
+                "_has_usable_nvidia_gpu() { return 1; }\n"
+                "_has_amd_rocm_gpu() { return 0; }\n"
+                "_infer_linux_amd_gfx_arch() { return 1; }\n"
+                + probe_fn
+                + "\n"
+                + family_fn
+                + "\n"
+                + fn
+                + "\n"
+                "get_torch_index_url\n"
+            )
+            sp = os.path.join(d, "gtiu.sh")
+            with open(sp, "w", encoding = "utf-8", newline = "\n") as f:
+                f.write(script)
+
+            def run(rocminfo_body, **extra):
+                with open(os.path.join(d, "rocminfo"), "w", encoding = "utf-8", newline = "\n") as f:
+                    f.write("#!/bin/sh\n" + rocminfo_body)
+                os.chmod(os.path.join(d, "rocminfo"), 0o755)
+                env = dict(os.environ, PATH = d + os.pathsep + os.environ.get("PATH", ""), **extra)
+                for var in (
+                    "UNSLOTH_TORCH_INDEX_URL",
+                    "UNSLOTH_TORCH_INDEX_FAMILY",
+                    "UNSLOTH_PYTORCH_MIRROR",
+                    "ROCR_VISIBLE_DEVICES",
+                    "HIP_VISIBLE_DEVICES",
+                ):
+                    env.pop(var, None)
+                if "UNSLOTH_ROCM_GFX_ARCH" not in extra:
+                    env.pop("UNSLOTH_ROCM_GFX_ARCH", None)
+                return subprocess.run(
+                    [shell, sp.replace("\\", "/")], env = env, capture_output = True, text = True
+                )
+
+            # Supported override on a tool-blind host: defer to the reroute.
+            r = run("exit 0\n", UNSLOTH_ROCM_GFX_ARCH = "gfx1151")
+            assert r.returncode == 0, f"override case aborted: {r.stderr}"
+            assert r.stdout.strip().endswith("/cpu")
+            assert (
+                "falling back to CPU-only PyTorch" not in r.stderr
+            ), f"a supported override must not get the false CPU warning: {r.stderr!r}"
+            assert (
+                "UNSLOTH_ROCM_GFX_ARCH=gfx1151 is set" in r.stderr
+            ), f"the override deferral must be announced: {r.stderr!r}"
+            # Unsupported override: the reroute can't map it -> CPU warning stays.
+            r2 = run("exit 0\n", UNSLOTH_ROCM_GFX_ARCH = "gfx906")
+            assert r2.returncode == 0, f"unsupported-override case aborted: {r2.stderr}"
+            assert (
+                "falling back to CPU-only PyTorch" in r2.stderr
+            ), f"an unmappable override must keep the CPU warning: {r2.stderr!r}"
+            # Readable gfx, no override, no version: deliberate CPU fallback.
+            r3 = run('echo "  Name:  gfx1151"\n')
+            assert r3.returncode == 0, f"readable-gfx case aborted: {r3.stderr}"
+            assert (
+                "falling back to CPU-only PyTorch" in r3.stderr
+            ), f"a readable-gfx host without a version keeps the CPU warning: {r3.stderr!r}"
+
+    def test_reroute_gate_covers_kfd_only(self):
+        """The runtime-less reroute must fire for a KFD-only host: _has_amd_rocm_gpu
+        is now true via the KFD topology, so the gate also accepts a detected GPU
+        whose gfx probe is empty (unslothai#7314 P2). A */cpu index chosen with a
+        READABLE gfx (deliberate ROCm-version fallback) must stay un-rerouted."""
+        shell = shutil.which("bash")
+        if not shell:
+            pytest.skip("bash needed to execute the reroute block")
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        block = re.search(
+            r'^if \[ "\$_torch_index_pinned" = false \] && \[ "\$SKIP_TORCH" = false \] && \\\n'
+            r".*?^fi\n",
+            source,
+            re.S | re.M,
+        )
+        assert block, "could not extract the runtime-less reroute block"
+        family_fn = _extract_sh_function_body(source, "_amd_arch_index_family_for_gfx")
+        assert family_fn
+        with tempfile.TemporaryDirectory() as d:
+            with open(os.path.join(d, "uname"), "w", encoding = "utf-8", newline = "\n") as f:
+                f.write('#!/bin/sh\ncase "${1:-}" in -m) echo x86_64 ;; *) echo Linux ;; esac\n')
+            os.chmod(os.path.join(d, "uname"), 0o755)
+
+            def run(gpu_stub, probe_stub):
+                script = (
+                    "set -euo pipefail\n"
+                    "_has_usable_nvidia_gpu() { return 1; }\n"
+                    f"_has_amd_rocm_gpu() {{ {gpu_stub}; }}\n"
+                    f"_probe_amd_gfx_arch() {{ {probe_stub}; }}\n"
+                    "_infer_linux_amd_gfx_arch() { echo gfx1100; }\n"
+                    "_strip_index_url_credentials() { printf '%s\\n' \"$1\"; }\n" + family_fn + "\n"
+                    "_torch_index_pinned=false\nSKIP_TORCH=false\n_ARCH=x86_64\n"
+                    "TORCH_INDEX_URL=https://download.pytorch.org/whl/cpu\n"
+                    + block.group(0)
+                    + 'printf "URL:%s GFX:%s\\n" "$TORCH_INDEX_URL" "${UNSLOTH_ROCM_GFX_ARCH:-}"\n'
+                )
+                # Run from a file, not -c: Windows bash mangles multi-KB -c strings.
+                sp = os.path.join(d, "reroute.sh")
+                with open(sp, "w", encoding = "utf-8", newline = "\n") as f:
+                    f.write(script)
+                env = dict(os.environ, PATH = d + os.pathsep + os.environ.get("PATH", ""))
+                for var in ("UNSLOTH_ROCM_GFX_ARCH", "UNSLOTH_AMD_ROCM_MIRROR"):
+                    env.pop(var, None)
+                return subprocess.run(
+                    [shell, sp.replace("\\", "/")], env = env, capture_output = True, text = True
+                )
+
+            # KFD-only: GPU detected, probe empty -> reroute to per-arch wheels.
+            r = run("return 0", "printf '\\n'")
+            assert r.returncode == 0, f"kfd-only reroute aborted: {r.stderr}"
+            assert (
+                "URL:https://repo.amd.com/rocm/whl/gfx110X-all/ GFX:gfx1100" in r.stdout
+            ), f"KFD-only host must reach the AMD arch index: {r.stdout!r}"
+            # The diagnostic must not claim /dev/kfd is missing: KFD visibility is
+            # exactly what detected this host (Codex P3).
+            assert (
+                "ROCm runtime not visible" not in r.stderr
+            ), f"KFD-only reroute must not claim /dev/kfd is missing: {r.stderr!r}"
+            assert (
+                "visible via the kernel driver (KFD)" in r.stderr
+            ), f"KFD-only reroute must name the tooling gap: {r.stderr!r}"
+            # Readable gfx: the */cpu index is a deliberate fallback -> untouched.
+            r2 = run("return 0", "echo gfx1151")
+            assert r2.returncode == 0, f"readable-gfx case aborted: {r2.stderr}"
+            assert (
+                "URL:https://download.pytorch.org/whl/cpu GFX:" in r2.stdout
+            ), f"a deliberate CPU fallback must not be rerouted: {r2.stdout!r}"
+            # No AMD GPU detected at all: the pre-KFD-fix path still reroutes.
+            r3 = run("return 1", "printf '\\n'")
+            assert r3.returncode == 0, f"undetected-GPU case aborted: {r3.stderr}"
+            assert (
+                "URL:https://repo.amd.com/rocm/whl/gfx110X-all/ GFX:gfx1100" in r3.stdout
+            ), f"the original undetected-GPU reroute must keep working: {r3.stdout!r}"
+            assert (
+                "ROCm runtime not visible" in r3.stderr
+            ), f"a truly runtime-invisible host keeps the original diagnostic: {r3.stderr!r}"
 
     def test_get_torch_index_url_uses_nvidia_detected_flag(self):
         """get_torch_index_url must track NVIDIA via _nvidia_detected (proc-only NVIDIA still picks CUDA)."""
@@ -1241,7 +2149,7 @@ class TestWorkerRocmMambaSsm:
         assert "getattr(torch.version, 'hip', None)" in source
 
     def test_direct_wheel_url_returns_none_without_cuda_major(self, monkeypatch):
-        """_direct_wheel_url should return None when cuda_major is empty (ROCm)."""
+        """direct_wheel_url should return None when cuda_major is empty (ROCm)."""
         _worker_spec = importlib.util.spec_from_file_location("test_worker", _WORKER_PATH)
         assert _worker_spec is not None and _worker_spec.loader is not None
         worker_mod = importlib.util.module_from_spec(_worker_spec)
@@ -1267,7 +2175,7 @@ class TestWorkerRocmMambaSsm:
             "hip_version": "7.1.12345",
             "cxx11abi": "TRUE",
         }
-        result = worker_mod._direct_wheel_url(
+        result = worker_mod.direct_wheel_url(
             filename_prefix = "causal_conv1d",
             package_version = "1.6.1",
             release_tag = "v1.6.1.post4",
@@ -1716,9 +2624,8 @@ class TestDetectWindowsGfxArch:
         assert result == "gfx1200"
 
     def test_returns_arch_on_crash_with_gcnarchname_in_output(self):
-        # Regression #6043: hipinfo may crash (0xC0000005 on RDNA 4) after
-        # printing gcnArchName. Accept the arch whenever gcnArchName is in
-        # stdout, regardless of exit code (previously a CPU fallback).
+        # Regression #6043: hipinfo may crash (0xC0000005 on RDNA 4) after printing
+        # gcnArchName. Accept the arch whenever gcnArchName is in stdout, any exit code.
         mock_result = MagicMock()
         mock_result.returncode = -1073741819  # 0xC0000005 STATUS_ACCESS_VIOLATION
         mock_result.stdout = b"gcnArchName : gfx1200\nsome other line\n"
@@ -1783,6 +2690,7 @@ class TestGfxArchNameFallback:
         "name, expected",
         [
             ("AMD Radeon(TM) 8060S Graphics", "gfx1151"),
+            ("AMD Radeon(TM) 8065S Graphics", "gfx1151"),
             ("AMD Ryzen AI MAX+ 395 w/ Radeon 8060S", "gfx1151"),
             ("AMD Radeon(TM) 890M", "gfx1150"),
             ("AMD Ryzen AI 9 HX 370 w/ Radeon 890M", "gfx1150"),
@@ -2360,6 +3268,49 @@ class TestWindowsRocmTorchaoGuard:
         assert not any("torchao" in arg for arg in installed_specs)
 
 
+class TestProgressStepCountMatchesTotal:
+    """The progress bar must reach exactly _TOTAL: every _progress() step is counted in
+    base_total. Regression for a repair step added without incrementing base_total,
+    which pushed _STEP past _TOTAL (Codex P2)."""
+
+    def _run_stack(self, tmp_path, *, is_windows, is_macos, is_mac_arm):
+        unstructured_plugin = tmp_path / "unstructured"
+        github_plugin = tmp_path / "github"
+        unstructured_plugin.mkdir()
+        github_plugin.mkdir()
+        sub = MagicMock()
+        sub.returncode = 0
+        sub.stdout = ""
+        with (
+            patch.dict(os.environ, {"SKIP_STUDIO_BASE": "1"}),
+            patch.object(stack_mod, "IS_WINDOWS", is_windows),
+            patch.object(stack_mod, "IS_MACOS", is_macos),
+            patch.object(stack_mod, "IS_MAC_ARM", is_mac_arm),
+            patch.object(stack_mod, "NO_TORCH", False),
+            patch.object(stack_mod, "_rocm_windows_torch_installed", False),
+            patch.object(stack_mod, "_bootstrap_uv", return_value = False),
+            patch.object(stack_mod, "_installed_torch_is_windows_rocm", return_value = False),
+            patch.object(stack_mod, "_has_usable_nvidia_gpu", return_value = True),
+            patch.object(stack_mod, "_repair_bad_anyio"),
+            patch.object(stack_mod, "_ensure_cuda_torch"),
+            patch.object(stack_mod, "_ensure_rocm_torch"),
+            patch.object(stack_mod, "_ensure_cpu_torch"),
+            patch.object(stack_mod, "LOCAL_DD_UNSTRUCTURED_PLUGIN", unstructured_plugin),
+            patch.object(stack_mod, "LOCAL_DD_GITHUB_PLUGIN", github_plugin),
+            patch.object(stack_mod.subprocess, "run", return_value = sub),
+        ):
+            assert stack_mod.install_python_stack() == 0
+            return stack_mod._STEP, stack_mod._TOTAL
+
+    def test_windows_progress_reaches_total(self, tmp_path):
+        step, total = self._run_stack(tmp_path, is_windows = True, is_macos = False, is_mac_arm = False)
+        assert step == total, f"Windows progress {step} != total {total} (final step uncounted)"
+
+    def test_linux_progress_reaches_total(self, tmp_path):
+        step, total = self._run_stack(tmp_path, is_windows = False, is_macos = False, is_mac_arm = False)
+        assert step == total, f"Linux progress {step} != total {total}"
+
+
 # TEST: worker.py -- Windows ROCm patches (source-level checks)
 
 
@@ -2807,6 +3758,286 @@ _SETUP_SH_PATH = PACKAGE_ROOT / "studio" / "setup.sh"
 class TestStrixRocm71Override:
     """install.sh routes gfx1151/gfx1150 to AMD's arch index instead of ROCm 7.1 (_grouped_mm segfault)."""
 
+    def test_linux_gfx_inference_helpers_present(self):
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        assert "_infer_linux_amd_gfx_arch" in source
+        assert "_amd_arch_index_family_for_gfx" in source
+        assert "_amd_gpu_present_via_pci" in source
+        assert "unslothai#7301" in source
+
+    def test_infer_linux_amd_gfx_from_cpuinfo(self):
+        assert stack_mod._linux_amd_gfx_from_cpuinfo is not None
+        with patch.object(
+            Path,
+            "read_text",
+            return_value = "model name : AMD Ryzen AI Max+ 395 w/ Radeon 8060S\n",
+        ):
+            assert stack_mod._linux_amd_gfx_from_cpuinfo() == "gfx1151"
+        # 8065S (Gorgon Halo) must match on the Radeon name alone, even without the
+        # "Ryzen AI Max" branding (mirrors setup.sh / setup.ps1 which list 8065S).
+        with patch.object(Path, "read_text", return_value = "model name : AMD Radeon 8065S\n"):
+            assert stack_mod._linux_amd_gfx_from_cpuinfo() == "gfx1151"
+
+    def test_infer_gfx_gated_out_of_wsl_without_runtime(self):
+        """On WSL the cpuinfo/lspci inference must be skipped unless the WSL ROCDXG
+        runtime (librocdxg) is present: a bare `unsloth studio update` must not
+        install per-arch ROCm wheels into an env that still can't expose the GPU.
+        An explicit UNSLOTH_ROCM_GFX_ARCH override stays authoritative regardless."""
+        m = stack_mod
+        with (
+            patch.object(m, "_linux_amd_gfx_from_cpuinfo", return_value = "gfx1151"),
+            patch.object(m, "_linux_amd_gfx_from_lspci", return_value = None),
+            # PCI evidence present (the WSL branch never consults it anyway).
+            patch.object(m, "_linux_amd_display_device_present", return_value = True),
+            patch.dict(os.environ, {"UNSLOTH_ROCM_GFX_ARCH": ""}),
+        ):
+            # WSL + no runtime -> inference suppressed (CPU torch stays).
+            with (
+                patch.object(m, "_is_wsl", return_value = True),
+                patch.object(m, "_wsl_rocm_runtime_present", return_value = False),
+            ):
+                assert m._infer_linux_amd_gfx_arch() is None
+            # WSL + runtime present (this dev box) -> inference still runs.
+            with (
+                patch.object(m, "_is_wsl", return_value = True),
+                patch.object(m, "_wsl_rocm_runtime_present", return_value = True),
+            ):
+                assert m._infer_linux_amd_gfx_arch() == "gfx1151"
+            # Native Linux (not WSL) -> the gate never applies.
+            with (
+                patch.object(m, "_is_wsl", return_value = False),
+                patch.object(m, "_wsl_rocm_runtime_present", return_value = False),
+            ):
+                assert m._infer_linux_amd_gfx_arch() == "gfx1151"
+        # Explicit override wins even on a bare WSL box (no runtime).
+        with (
+            patch.object(m, "_is_wsl", return_value = True),
+            patch.object(m, "_wsl_rocm_runtime_present", return_value = False),
+            patch.dict(os.environ, {"UNSLOTH_ROCM_GFX_ARCH": "gfx1151"}),
+        ):
+            assert m._infer_linux_amd_gfx_arch() == "gfx1151"
+
+    def test_infer_gfx_requires_amd_display_device_on_native_linux(self):
+        """A VM/container on a Strix host still shows the host CPU model in
+        /proc/cpuinfo while receiving no AMD GPU, so on native Linux the
+        CPU-model inference must require an AMD PCI display device (#7305
+        review). WSL is exempt (no PCI enumeration there; the librocdxg gate is
+        the evidence) and the explicit override stays authoritative."""
+        m = stack_mod
+        with (
+            patch.object(m, "_linux_amd_gfx_from_cpuinfo", return_value = "gfx1151"),
+            patch.object(m, "_linux_amd_gfx_from_lspci", return_value = None),
+            patch.object(m, "_is_wsl", return_value = False),
+            patch.dict(os.environ, {"UNSLOTH_ROCM_GFX_ARCH": ""}),
+        ):
+            # No AMD display device -> the CPU-model text alone must not infer.
+            with patch.object(m, "_linux_amd_display_device_present", return_value = False):
+                assert m._infer_linux_amd_gfx_arch() is None
+            # Device present -> inference unchanged.
+            with patch.object(m, "_linux_amd_display_device_present", return_value = True):
+                assert m._infer_linux_amd_gfx_arch() == "gfx1151"
+        # Explicit override needs no device evidence (headless/cross-install).
+        with (
+            patch.object(m, "_is_wsl", return_value = False),
+            patch.object(m, "_linux_amd_display_device_present", return_value = False),
+            patch.dict(os.environ, {"UNSLOTH_ROCM_GFX_ARCH": "GFX1151"}),
+        ):
+            assert m._infer_linux_amd_gfx_arch() == "gfx1151"
+
+    def test_install_sh_cpuinfo_inference_requires_pci_evidence(self):
+        """install.sh mirror of the VM/container guard: both cpuinfo greps must be
+        gated on _gpu_evidence (AMD PCI display device via _amd_gpu_present_via_pci,
+        or the WSL librocdxg gate), and the gate must sit before the first grep."""
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        body = _extract_sh_function_body(source, "_infer_linux_amd_gfx_arch")
+        assert body, "could not extract _infer_linux_amd_gfx_arch"
+        pci = body.find("_amd_gpu_present_via_pci")
+        infer = body.find("grep -qiE 'Ryzen AI Max")
+        assert pci >= 0 and infer >= 0
+        assert pci < infer, "the PCI evidence check must run before the cpuinfo inference"
+        assert (
+            body.count('[ -n "$_gpu_evidence" ] && grep -qiE') == 2
+        ), "both cpuinfo greps (gfx1151 and gfx1150) must be gated on _gpu_evidence"
+
+    def test_lspci_scan_covers_all_display_controllers(self):
+        """The lspci fallback must scan every display-class line, not just the
+        first: a non-AMD controller (Intel iGPU, ASPEED BMC) often enumerates
+        before the AMD dGPU. Non-AMD vendors must never map (an NVIDIA GeForce
+        GTX 860M would otherwise hit the AMD 860M pattern), and a 0000: PCI
+        domain prefix must not break matching."""
+        m = stack_mod
+
+        def fake_lspci(stdout):
+            result = SimpleNamespace(returncode = 0, stdout = stdout)
+            return (
+                patch.object(m.shutil, "which", return_value = "/usr/bin/lspci"),
+                patch.object(m.subprocess, "run", return_value = result),
+            )
+
+        intel_then_amd = (
+            "00:02.0 VGA compatible controller [0300]: Intel Corporation Raptor Lake-S GT1 [8086:a780]\n"
+            "03:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI]"
+            " Navi 31 [Radeon RX 7900 XT] [1002:744c]\n"
+        )
+        nvidia_only = "01:00.0 3D controller [0302]: NVIDIA Corporation GM107M [GeForce GTX 860M] [10de:1392]\n"
+        domain_prefixed = (
+            "0000:c5:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI]"
+            " Strix Halo [Radeon Graphics / Radeon 8060S] [1002:150e]\n"
+        )
+        unmapped_then_mapped = (
+            "03:00.0 Display controller [0380]: Advanced Micro Devices, Inc. [AMD/ATI]"
+            " Cape Verde [FirePro W600] [1002:6821]\n"
+            "04:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI]"
+            " Navi 33 [Radeon RX 7600] [1002:7480]\n"
+        )
+        for stdout, expected in (
+            (intel_then_amd, "gfx1100"),
+            (nvidia_only, None),
+            (domain_prefixed, "gfx1151"),
+            (unmapped_then_mapped, "gfx1102"),
+        ):
+            w, r = fake_lspci(stdout)
+            with w, r:
+                assert m._linux_amd_gfx_from_lspci() == expected, stdout
+
+    def test_install_sh_lspci_scan_covers_all_display_controllers(self):
+        """install.sh mirror of the scan-all behaviour, executed with a shimmed
+        lspci: Intel-first still finds the AMD dGPU, NVIDIA-only maps nothing
+        (860M collision), a domain-prefixed AMD line still maps."""
+        shell = shutil.which("bash")
+        if not shell:
+            pytest.skip("bash needed to execute the probe block")
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        name_fn = re.search(
+            r"^_infer_amd_gfx_arch_from_gpu_name\(\) \{\n.*?\n\}\n", source, re.S | re.M
+        )
+        scan = re.search(
+            r"^    if command -v lspci[^\n]*\n.*?\nEOF\n    fi\n    return 1\n", source, re.S | re.M
+        )
+        assert name_fn and scan, "could not extract the lspci scan block"
+        cases = (
+            (
+                "00:02.0 VGA compatible controller [0300]: Intel Corporation UHD [8086:a780]\n"
+                "03:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI]"
+                " Navi 31 [Radeon RX 7900 XT] [1002:744c]",
+                "OK:gfx1100",
+            ),
+            (
+                "01:00.0 3D controller [0302]: NVIDIA Corporation GM107M [GeForce GTX 860M] [10de:1392]",
+                "OK:",
+            ),
+            (
+                "0000:c5:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc."
+                " [AMD/ATI] Strix Halo [Radeon 8060S] [1002:150e]",
+                "OK:gfx1151",
+            ),
+        )
+        for lspci_out, expected in cases:
+            with tempfile.TemporaryDirectory() as d:
+                p = os.path.join(d, "lspci")
+                with open(p, "w", encoding = "utf-8") as f:
+                    f.write(f'#!/bin/sh\ncat <<"EOT"\n{lspci_out}\nEOT\n')
+                os.chmod(p, 0o755)
+                script = (
+                    "set -euo pipefail\n"
+                    + name_fn.group(0)
+                    + "probe() {\n"
+                    + scan.group(0)
+                    + "}\nprintf 'OK:%s\\n' \"$(probe || true)\"\n"
+                )
+                env = dict(os.environ, PATH = d + os.pathsep + os.environ.get("PATH", ""))
+                r = subprocess.run([shell, "-c", script], env = env, capture_output = True, text = True)
+                assert r.returncode == 0, f"scan aborted: {r.stderr}"
+                assert (
+                    r.stdout.splitlines()[-1] == expected
+                ), f"lspci scan wrong for {lspci_out!r}: {r.stdout!r}"
+
+    def test_install_sh_infer_gfx_gated_on_wsl_runtime(self):
+        """install.sh's _infer_linux_amd_gfx_arch must, like the Python side, skip
+        the cpuinfo/lspci inference on WSL unless librocdxg is present -- the
+        override still returns first, so it stays authoritative."""
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        body = _extract_sh_function_body(source, "_infer_linux_amd_gfx_arch")
+        assert body, "could not extract _infer_linux_amd_gfx_arch"
+        override = body.find("UNSLOTH_ROCM_GFX_ARCH")
+        dxg = body.find("/dev/dxg")
+        rocdxg = body.find("librocdxg")
+        # Anchor on the first cpuinfo *inference* (the grep), not a comment mention.
+        infer = body.find("grep -qiE 'Ryzen AI Max")
+        assert override >= 0 and dxg >= 0 and rocdxg >= 0 and infer >= 0
+        assert "microsoft" in body, "WSL gate must also detect WSL via /proc/version"
+        assert override < dxg, "the explicit override must return before the WSL gate"
+        assert (
+            dxg < infer and rocdxg < infer
+        ), "the WSL/librocdxg gate must run before the cpuinfo/lspci inference"
+
+    def test_install_sh_reroute_is_x86_64_only(self):
+        """The Linux inferred-gfx reroute must be x86_64-only: ROCm torch wheels are
+        not published for arm64, so an inferred/overridden gfx must not push an
+        arm64 host to the AMD arch index (get_torch_index_url returns CPU there)."""
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        idx = source.find("_linux_inferred_gfx=$(_infer_linux_amd_gfx_arch")
+        assert idx >= 0, "reroute consumer not found"
+        window = source[max(0, idx - 400) : idx]
+        assert (
+            'case "$_ARCH" in x86_64|amd64)' in window
+        ), "the inferred-gfx reroute must guard on x86_64|amd64 arch"
+
+    def test_install_sh_reroute_skips_visible_rocm_gpu(self):
+        """A */cpu index on a host whose AMD GPU IS visible to the ROCm probes is a
+        deliberate fallback (unsupported/unreadable ROCm version, warned about in
+        get_torch_index_url), not a missing runtime: the reroute must not override
+        it with inferred per-arch wheels. The explicit UNSLOTH_ROCM_GFX_ARCH
+        override must still win either way."""
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        idx = source.find("_linux_inferred_gfx=$(_infer_linux_amd_gfx_arch")
+        assert idx >= 0, "reroute consumer not found"
+        window = source[max(0, idx - 700) : idx]
+        assert (
+            "! _has_amd_rocm_gpu" in window
+        ), "the reroute must be gated on _has_amd_rocm_gpu being false"
+        assert (
+            '[ -n "${UNSLOTH_ROCM_GFX_ARCH:-}" ] || ! _has_amd_rocm_gpu' in window
+        ), "an explicit UNSLOTH_ROCM_GFX_ARCH override must bypass the visible-GPU gate"
+
+    def test_install_sh_reroute_exports_gfx_for_setup_sh(self):
+        """The inferred arch must be exported as UNSLOTH_ROCM_GFX_ARCH so the
+        downstream setup.sh run (which re-probes ROCm independently and finds
+        nothing on these runtime-less hosts) routes llama.cpp to the matching
+        ROCm prebuilt instead of the CPU one -- setup.sh and
+        install_llama_prebuilt.py both read that env var."""
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        assign = source.find('TORCH_INDEX_URL="${_amd_mirror}/${_amd_family}/"')
+        assert assign >= 0, "inferred-gfx index assignment not found"
+        block_end = source.find("esac", assign)
+        assert (
+            'export UNSLOTH_ROCM_GFX_ARCH="$_linux_inferred_gfx"' in source[assign:block_end]
+        ), "the reroute must export the inferred gfx for the setup.sh handoff"
+        # setup.sh's side of the handoff must still exist.
+        setup_source = (PACKAGE_ROOT / "studio" / "setup.sh").read_text(encoding = "utf-8")
+        assert "UNSLOTH_ROCM_GFX_ARCH" in setup_source
+
+    def test_amd_arch_index_url_linux_honors_amd_mirror(self):
+        """On Linux the inferred-gfx repair must honour UNSLOTH_AMD_ROCM_MIRROR (the
+        var install.sh uses), not the Windows mirror var, so a mirrored/air-gapped
+        Linux install does not silently fall back to repo.amd.com. Windows still
+        delegates to the Windows mirror path."""
+        m = stack_mod
+        with (
+            patch.object(m, "IS_WINDOWS", False),
+            patch.dict(os.environ, {"UNSLOTH_AMD_ROCM_MIRROR": "https://mirror.local/rocm"}),
+        ):
+            assert m._amd_arch_index_url("gfx1151") == "https://mirror.local/rocm/gfx1151/"
+        with (
+            patch.object(m, "IS_WINDOWS", False),
+            patch.dict(os.environ, {"UNSLOTH_AMD_ROCM_MIRROR": ""}),
+        ):
+            assert m._amd_arch_index_url("gfx1151") == "https://repo.amd.com/rocm/whl/gfx1151/"
+            assert m._amd_arch_index_url("gfx9999") is None
+        # Windows path is unchanged: delegate to the Windows mirror helper.
+        with patch.object(m, "IS_WINDOWS", True):
+            assert m._amd_arch_index_url("gfx1151") == m._windows_rocm_index_url("gfx1151")
+
     def test_strix_gfx_detection_in_install_sh(self):
         """install.sh must detect gfx1151 and gfx1150 for the override."""
         source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
@@ -2833,19 +4064,160 @@ class TestStrixRocm71Override:
         source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
         assert "moe_utils" in source or "_grouped_mm" in source
 
-    def test_strix_override_only_fires_on_rocm71(self):
-        """install.sh must scope the Strix override to rocm7.1 only (not rocm7.2+)."""
+    def test_strix_override_scoped_below_arch_floor(self):
+        """Strix reroute must fire for rocm leaves BELOW the arch floor (7.13) and
+        NOT at/above it. Executed via _rocm_leaf_below so it verifies the actual
+        version comparison, not a text match that a comment could satisfy."""
         source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
-        strix_idx = source.find("_strix_gfx")
-        assert strix_idx != -1
-        context_before = source[max(0, strix_idx - 2400) : strix_idx]
-        assert "rocm7.1" in context_before
+        # Selector + gate must switch on the index LEAF, not the whole URL (a mirror
+        # base path with its own rocm token would false-positive otherwise).
+        assert 'case "$_torch_index_leaf" in' in source
+        assert '_rocm_leaf_below "$_torch_index_leaf" 7 13' in source
+        shell = shutil.which("sh") or shutil.which("bash")
+        if not shell:
+            pytest.skip("no POSIX shell to execute _rocm_leaf_below")
+        match = re.search(r"^_rocm_leaf_below\(\) \{.*?^\}", source, re.S | re.M)
+        assert match, "could not extract _rocm_leaf_below from install.sh"
+        fn = match.group(0)
+
+        def below(leaf):
+            return (
+                subprocess.run(
+                    [shell, "-c", f'{fn}\n_rocm_leaf_below "$1" 7 13', "_", leaf]
+                ).returncode
+                == 0
+            )
+
+        for leaf in ("rocm6.0", "rocm7.0", "rocm7.1", "rocm7.2", "rocm7.12"):
+            assert below(leaf), f"{leaf} must reroute (below arch floor 7.13)"
+        for leaf in ("rocm7.13", "rocm7.14", "rocm8.0", "gfx1151", "cu128", "cpu"):
+            assert not below(leaf), f"{leaf} must NOT reroute (>= floor or non-rocm)"
+
+    def test_gfx_probe_survives_no_match_under_set_e(self):
+        """A gfx probe whose grep finds no match must not abort install.sh under
+        set -euo pipefail before the amd-smi fallback runs. The reroute case now
+        matches every rocm* index, so this would break ordinary 6.x/7.2 installs
+        with a flaky rocminfo. Executed with shimmed tools, not a text match."""
+        shell = shutil.which("bash")
+        if not shell:
+            pytest.skip("bash needed to execute the probe block")
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        block = re.search(
+            r'^        _gfx_all=\$\(printf[^\n]*\n.*?(?=^        _strix_gfx="")',
+            source,
+            re.S | re.M,
+        )
+        assert block, "could not extract the gfx-detection block"
+        with tempfile.TemporaryDirectory() as d:
+            # rocminfo emits no gfx token; amd-smi supplies gfx1151 (the fallback)
+            for name, out in (("rocminfo", "no gpu here"), ("amd-smi", "GPU: gfx1151")):
+                p = os.path.join(d, name)
+                with open(p, "w", encoding = "utf-8") as f:
+                    f.write(f'#!/bin/sh\ncat <<"EOT"\n{out}\nEOT\n')
+                os.chmod(p, 0o755)
+            script = (
+                'set -euo pipefail\nHIP_VISIBLE_DEVICES=""\nROCR_VISIBLE_DEVICES=""\n'
+                + block.group(0)
+                + '\nprintf "OK:%s\\n" "$_gfx_all"\n'
+            )
+            env = dict(os.environ, PATH = d + os.pathsep + os.environ.get("PATH", ""))
+            r = subprocess.run([shell, "-c", script], env = env, capture_output = True, text = True)
+            assert r.returncode == 0, f"probe aborted under set -e: {r.stderr}"
+            assert "OK:gfx1151" in r.stdout, f"amd-smi fallback not reached: {r.stdout!r}"
+
+    def test_strix_reroute_reprobes_when_mask_hides_all(self):
+        """A visibility mask hiding every agent (ROCR_VISIBLE_DEVICES=-1) must not
+        skip the Strix reroute: get_torch_index_url reads the arch unmasked, so
+        the reroute must re-probe unmasked too or a masked Strix box gets the
+        broken generic wheels. A partial mask must keep its per-GPU selection.
+        Executed with mask-honouring shims, not a text match."""
+        shell = shutil.which("bash")
+        if not shell:
+            pytest.skip("bash needed to execute the probe block")
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        block = re.search(
+            r'^        _gfx_all=\$\(printf[^\n]*\n.*?(?=^        _strix_gfx="")',
+            source,
+            re.S | re.M,
+        )
+        assert block, "could not extract the gfx-detection block"
+        with tempfile.TemporaryDirectory() as d:
+            # rocminfo honours ROCR_VISIBLE_DEVICES like the real tool: -1 and
+            # set-but-empty hide both agents, 1 renumbers to the dGPU only,
+            # unset shows both.
+            rocminfo = (
+                "#!/bin/sh\n"
+                'case "${ROCR_VISIBLE_DEVICES-__unset__}" in\n'
+                '  __unset__) printf "Name: gfx1151\\nName: gfx1201\\n" ;;\n'
+                '  ""|-1) echo "no visible agents" ;;\n'
+                '  1) printf "Name: gfx1201\\n" ;;\n'
+                '  *) printf "Name: gfx1151\\nName: gfx1201\\n" ;;\n'
+                "esac\n"
+            )
+            for name, body in (("rocminfo", rocminfo), ("amd-smi", "#!/bin/sh\nexit 0\n")):
+                p = os.path.join(d, name)
+                with open(p, "w", encoding = "utf-8") as f:
+                    f.write(body)
+                os.chmod(p, 0o755)
+            script = (
+                "set -euo pipefail\n" + block.group(0) + '\nprintf "OK:%s\\n" "$_runtime_gfx"\n'
+            )
+
+            def run(**extra):
+                env = dict(os.environ, PATH = d + os.pathsep + os.environ.get("PATH", ""), **extra)
+                env.pop("UNSLOTH_ROCM_GFX_ARCH", None)
+                env.pop("HIP_VISIBLE_DEVICES", None)
+                return subprocess.run(
+                    [shell, "-c", script], env = env, capture_output = True, text = True
+                )
+
+            # Mask hides everything: re-probe must recover the first GPU (Strix).
+            r = run(ROCR_VISIBLE_DEVICES = "-1")
+            assert r.returncode == 0, f"masked probe aborted: {r.stderr}"
+            assert "OK:gfx1151" in r.stdout, f"reroute blinded by full mask: {r.stdout!r}"
+            # A SET-but-empty mask also hides every agent and must re-probe too
+            # (the ${VAR+x} guard, not ${VAR:-}).
+            r0 = run(ROCR_VISIBLE_DEVICES = "")
+            assert r0.returncode == 0, f"empty-mask probe aborted: {r0.stderr}"
+            assert "OK:gfx1151" in r0.stdout, f"reroute blinded by empty mask: {r0.stdout!r}"
+            # Partial mask: enumeration already reflects it; the dGPU selection
+            # must survive (no unmasked re-probe overriding the user's pick).
+            r2 = run(ROCR_VISIBLE_DEVICES = "1")
+            assert r2.returncode == 0, f"partial-mask probe aborted: {r2.stderr}"
+            assert "OK:gfx1201" in r2.stdout, f"partial mask selection lost: {r2.stdout!r}"
+
+    def test_strix_routing_helpers_cover_rocm714(self):
+        # Reroute for any generic pytorch.org index below the 7.13 arch floor (7.0,
+        # 7.2, a future 7.3+), never at/above it -- mirrors install.sh _rocm_leaf_below.
+        assert stack_mod._generic_pytorch_rocm_tag((7, 14)) == "rocm7.2"
+        assert stack_mod._strix_needs_amd_arch_index((7, 14)) is True
+        assert stack_mod._strix_needs_amd_arch_index((7, 0)) is True
+        assert stack_mod._strix_needs_amd_arch_index((6, 0)) is True
+        assert stack_mod._strix_needs_amd_arch_index((5, 0)) is False
 
     def test_torch_constraint_updated_for_strix_amd_index(self):
         """install.sh must set TORCH_CONSTRAINT>=2.11 when routing Strix to AMD index."""
         source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
         assert "TORCH_CONSTRAINT" in source and "2.11" in source
 
+    def test_torch_constraint_211_matches_leaf_not_whole_url(self):
+        """The 2.11 constraint case must match the index LEAF, not the whole URL.
+
+        A custom UNSLOTH_PYTORCH_MIRROR whose base path contains a gfx/rocm7.2
+        segment (e.g. https://mirror.local/gfx-cache) with a cu*/cpu family must
+        not be pushed to the torch 2.11 line -- same leaf-only reasoning the
+        UNSLOTH_TORCH_BACKEND classification uses.
+        """
+        source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
+        # The 2.11 constraint block must switch on $_torch_index_leaf, not the full
+        # $TORCH_INDEX_URL (a */gfx* match false-positives on a mirror base path). Only the
+        # _grouped_mm-bug gfx families (gfx120X-all / gfx1151 / gfx1150) are pushed to 2.11;
+        # a bare gfx* would also floor gfx110X-all/gfx90a/gfx908, left bare on purpose.
+        assert 'case "$_torch_index_leaf" in\n    rocm7.2|gfx120x-all|gfx1151|gfx1150)' in source, (
+            "the torch>=2.11 constraint must match the specific gfx leaves that need "
+            "it (rocm7.2|gfx120x-all|gfx1151|gfx1150), not a bare gfx* or the whole URL"
+        )
+
     def test_amd_rocm_mirror_env_var_respected(self):
         """install.sh must honour UNSLOTH_AMD_ROCM_MIRROR for air-gapped installs."""
         source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
@@ -2934,9 +4306,9 @@ class TestServerStartupRocmFixes:
         assert '"BNB_ROCM_VERSION" not in os.environ' in source
 
     # ── hipInfo.exe PATH prepend (bitsandbytes arch-probe fix) ────────────────
-    # bnb's get_rocm_gpu_arch() runs hipinfo.exe via PATH at import; the AMD
-    # wheel ships it in venv Scripts (on PATH only for activated venvs), so
-    # without the prepend bnb logs "[WinError 2]" when launched directly.
+    # bnb's get_rocm_gpu_arch() runs hipinfo.exe via PATH at import; the AMD wheel ships it
+    # in venv Scripts (on PATH only for activated venvs), so without the prepend bnb logs
+    # "[WinError 2]" when launched directly.
 
     def test_main_py_prepends_hipinfo_dir_to_path(self):
         """main.py must make hipInfo.exe resolvable before bnb imports."""
@@ -3178,11 +4550,10 @@ class TestRocmGfxForwarding:
         assert '$HelperReleaseRepo = "unslothai/llama.cpp"' in source
         assert "$HelperReleaseRepo = if (" not in source
 
-    # The text pins above guard the literal. The tests below *execute* the real
-    # routing line from setup.sh / setup.ps1 and assert the resolved release repo,
-    # so a refactor that reintroduces a conditional (or a ggml-org branch) is still
-    # caught. Inputs are varied -- CPU-only, inferred/forwarded gfx, usable NVIDIA --
-    # to prove no host slips back onto ggml-org. No GPU, no tooling, no network.
+    # The text pins above guard the literal. The tests below execute the real routing line
+    # from setup.sh / setup.ps1 and assert the resolved release repo, so a refactor that
+    # reintroduces a conditional (or a ggml-org branch) is still caught. Inputs vary
+    # (CPU-only, inferred/forwarded gfx, usable NVIDIA) to prove no host hits ggml-org.
 
     @staticmethod
     def _resolve_setup_sh_repo(
@@ -3277,8 +4648,8 @@ class TestRocmGfxForwarding:
 
 
 # TEST: _pick_rocm_gfx_target -- visible-device selection from rocminfo output.
-# Honours CUDA/HIP_VISIBLE_DEVICES so a mixed-arch host installs the prebuilt
-# for the selected GPU, not GPU 0.
+# Honours CUDA/HIP_VISIBLE_DEVICES so a mixed-arch host installs the prebuilt for the
+# selected GPU, not GPU 0.
 
 _pick_rocm_gfx_target = prebuilt_mod._pick_rocm_gfx_target
 
@@ -3454,7 +4825,11 @@ class TestWslRerouteNvidiaGuard:
         source = _INSTALL_SH_PATH.read_text(encoding = "utf-8")
         start = source.find("_maybe_reroute_strixhalo_to_2404()")
         assert start != -1
-        body = source[start : start + 1200]
+        # Slice the WHOLE function body (to its closing brace at column 0), not a
+        # fixed-length window: preamble growth must not push the signals out of view.
+        end = source.find("\n}", start)
+        assert end != -1
+        body = source[start:end]
         nv = body.find("_has_usable_nvidia_gpu")
         wmi = body.find("_wsl_amd_gpu_name")
         assert nv != -1, "reroute must consult _has_usable_nvidia_gpu before deciding to reroute"
diff --git a/tests/studio/install/test_selection_logic.py b/tests/studio/install/test_selection_logic.py
index 7575dea581..8ebcd6cc86 100644
--- a/tests/studio/install/test_selection_logic.py
+++ b/tests/studio/install/test_selection_logic.py
@@ -31,17 +31,8 @@ PrebuiltFallback = INSTALL_LLAMA_PREBUILT.PrebuiltFallback
 LinuxCudaSelection = INSTALL_LLAMA_PREBUILT.LinuxCudaSelection
 UPSTREAM_REPO = INSTALL_LLAMA_PREBUILT.UPSTREAM_REPO
 
-normalize_compute_cap = INSTALL_LLAMA_PREBUILT.normalize_compute_cap
-normalize_compute_caps = INSTALL_LLAMA_PREBUILT.normalize_compute_caps
-parse_cuda_visible_devices = INSTALL_LLAMA_PREBUILT.parse_cuda_visible_devices
-supports_explicit_visible_device_matching = (
-    INSTALL_LLAMA_PREBUILT.supports_explicit_visible_device_matching
-)
-select_visible_gpu_rows = INSTALL_LLAMA_PREBUILT.select_visible_gpu_rows
-compatible_linux_runtime_lines = INSTALL_LLAMA_PREBUILT.compatible_linux_runtime_lines
 pick_windows_cuda_runtime = INSTALL_LLAMA_PREBUILT.pick_windows_cuda_runtime
 compatible_windows_runtime_lines = INSTALL_LLAMA_PREBUILT.compatible_windows_runtime_lines
-runtime_line_from_cuda_version = INSTALL_LLAMA_PREBUILT.runtime_line_from_cuda_version
 apply_approved_hashes = INSTALL_LLAMA_PREBUILT.apply_approved_hashes
 linux_cuda_choice_from_release = INSTALL_LLAMA_PREBUILT.linux_cuda_choice_from_release
 windows_cuda_attempts = INSTALL_LLAMA_PREBUILT.windows_cuda_attempts
@@ -270,13 +261,13 @@ def mock_windows_runtime(monkeypatch, lines):
 
 
 # ===========================================================================
-# Studio run.py localhost warning
+# Unsloth run.py localhost warning
 # ===========================================================================
 
 
 class TestStudioLocalhostIpv6Warning:
     def _prepare_loopback(self, run_module, monkeypatch):
-        # Studio confirmed answering on the IPv4 loopback.
+        # Unsloth confirmed answering on the IPv4 loopback.
         monkeypatch.setattr(
             run_module,
             "_working_local_url",
@@ -327,7 +318,7 @@ class TestStudioLocalhostIpv6Warning:
         assert "http://localhost:8888" in captured.out
 
     def test_ipv6_listener_does_not_suppress_warning(self, monkeypatch):
-        # A process on ::1 is NOT Studio (binds 127.0.0.1 only), so the warning must
+        # A process on ::1 is NOT Unsloth (binds 127.0.0.1 only), so the warning must
         # still fire -- that is exactly when http://localhost opens the wrong service.
         run_module = load_studio_run_module(monkeypatch)
         self._prepare_loopback(run_module, monkeypatch)
@@ -356,7 +347,7 @@ class TestStudioLocalhostIpv6Warning:
         assert run_module._localhost_ipv6_mismatch_url("127.0.0.1", port) is None
 
     def test_ipv4_not_answering_suppresses_warning(self, monkeypatch):
-        # Studio not confirmed on 127.0.0.1 -> no warning.
+        # Unsloth not confirmed on 127.0.0.1 -> no warning.
         run_module = load_studio_run_module(monkeypatch)
         monkeypatch.setattr(run_module, "_working_local_url", lambda port: None)
         self._set_getaddrinfo(monkeypatch, [self._ipv6()])
@@ -452,165 +443,25 @@ class TestStudioLocalhostIpv6Warning:
 
 
 # ===========================================================================
-# A. normalize_compute_cap
+# A-F, H. Component-independent GPU/token helpers: the behavior tables live in
+# tests/studio/install/test_prebuilt_core.py (they are pure prebuilt_core
+# functions). This pin proves the installer still re-exports them from core, so
+# the master tables keep covering the names this module and its callers use.
 # ===========================================================================
 
 
-class TestNormalizeComputeCap:
-    def test_dotted_86(self):
-        assert normalize_compute_cap("8.6") == "86"
-
-    def test_dotted_leading_zero(self):
-        assert normalize_compute_cap("07.05") == "75"
-
-    def test_already_normalized(self):
-        assert normalize_compute_cap("75") == "75"
-
-    def test_int_input(self):
-        assert normalize_compute_cap(86) == "86"
-
-    def test_empty_string(self):
-        assert normalize_compute_cap("") is None
-
-    def test_whitespace(self):
-        assert normalize_compute_cap("  ") is None
-
-    def test_non_numeric(self):
-        assert normalize_compute_cap("x.y") is None
-
-    def test_triple_part(self):
-        assert normalize_compute_cap("8.6.0") is None
-
-    def test_zero_minor(self):
-        assert normalize_compute_cap("9.0") == "90"
-
-
-# ===========================================================================
-# B. normalize_compute_caps
-# ===========================================================================
-
-
-class TestNormalizeComputeCaps:
-    def test_deduplication(self):
-        assert normalize_compute_caps(["8.6", "86", "8.6"]) == ["86"]
-
-    def test_numeric_sort(self):
-        assert normalize_compute_caps(["9.0", "7.5", "8.6"]) == ["75", "86", "90"]
-
-    def test_drops_invalid(self):
-        assert normalize_compute_caps(["8.6", "bad", "", "7.5"]) == ["75", "86"]
-
-    def test_empty_input(self):
-        assert normalize_compute_caps([]) == []
-
-
-# ===========================================================================
-# C. parse_cuda_visible_devices
-# ===========================================================================
-
-
-class TestParseCudaVisibleDevices:
-    def test_none(self):
-        assert parse_cuda_visible_devices(None) is None
-
-    def test_empty(self):
-        assert parse_cuda_visible_devices("") == []
-
-    def test_minus_one(self):
-        assert parse_cuda_visible_devices("-1") == []
-
-    def test_single(self):
-        assert parse_cuda_visible_devices("0") == ["0"]
-
-    def test_multi(self):
-        assert parse_cuda_visible_devices("0,1,2") == ["0", "1", "2"]
-
-    def test_whitespace_stripped(self):
-        assert parse_cuda_visible_devices(" 0 , 1 ") == ["0", "1"]
-
-
-# ===========================================================================
-# D. supports_explicit_visible_device_matching
-# ===========================================================================
-
-
-class TestSupportsExplicitVisibleDeviceMatching:
-    def test_all_digits(self):
-        assert supports_explicit_visible_device_matching(["0", "1", "2"]) is True
-
-    def test_gpu_prefix(self):
-        assert supports_explicit_visible_device_matching(["GPU-abc123"]) is True
-
-    def test_none(self):
-        assert supports_explicit_visible_device_matching(None) is False
-
-    def test_empty(self):
-        assert supports_explicit_visible_device_matching([]) is False
-
-    def test_mixed_invalid(self):
-        assert supports_explicit_visible_device_matching(["0", "MIG-device"]) is False
-
-
-# ===========================================================================
-# E. select_visible_gpu_rows
-# ===========================================================================
-
-
-class TestSelectVisibleGpuRows:
-    ROWS = [
-        ("0", "GPU-aaa", "8.6"),
-        ("1", "GPU-bbb", "7.5"),
-        ("2", "GPU-ccc", "8.9"),
-    ]
-
-    def test_none_returns_all(self):
-        assert select_visible_gpu_rows(self.ROWS, None) == list(self.ROWS)
-
-    def test_empty_returns_empty(self):
-        assert select_visible_gpu_rows(self.ROWS, []) == []
-
-    def test_filter_by_index(self):
-        result = select_visible_gpu_rows(self.ROWS, ["0", "2"])
-        assert result == [("0", "GPU-aaa", "8.6"), ("2", "GPU-ccc", "8.9")]
-
-    def test_filter_by_uuid_case_insensitive(self):
-        result = select_visible_gpu_rows(self.ROWS, ["gpu-bbb"])
-        assert result == [("1", "GPU-bbb", "7.5")]
-
-    def test_dedup_same_device(self):
-        result = select_visible_gpu_rows(self.ROWS, ["0", "0"])
-        assert result == [("0", "GPU-aaa", "8.6")]
-
-    def test_missing_token(self):
-        result = select_visible_gpu_rows(self.ROWS, ["99"])
-        assert result == []
-
-
-# ===========================================================================
-# F. compatible_linux_runtime_lines
-# ===========================================================================
-
-
-class TestCompatibleLinuxRuntimeLines:
-    def test_no_driver(self):
-        host = make_host(driver_cuda_version = None)
-        assert compatible_linux_runtime_lines(host) == []
-
-    def test_driver_11_8(self):
-        host = make_host(driver_cuda_version = (11, 8))
-        assert compatible_linux_runtime_lines(host) == []
-
-    def test_driver_12_4(self):
-        host = make_host(driver_cuda_version = (12, 4))
-        assert compatible_linux_runtime_lines(host) == ["cuda12"]
-
-    def test_driver_13_0(self):
-        host = make_host(driver_cuda_version = (13, 0))
-        assert compatible_linux_runtime_lines(host) == ["cuda13", "cuda12"]
-
-    def test_future_major_derives_lines(self):
-        host = make_host(driver_cuda_version = (14, 0))
-        assert compatible_linux_runtime_lines(host) == ["cuda14", "cuda13", "cuda12"]
+def test_core_helper_aliases_bound_to_prebuilt_core():
+    import prebuilt_core as _core
+    for name in (
+        "normalize_compute_cap",
+        "normalize_compute_caps",
+        "parse_cuda_visible_devices",
+        "supports_explicit_visible_device_matching",
+        "select_visible_gpu_rows",
+        "compatible_linux_runtime_lines",
+        "runtime_line_from_cuda_version",
+    ):
+        assert getattr(INSTALL_LLAMA_PREBUILT, name) is getattr(_core, name), name
 
 
 # ===========================================================================
@@ -669,28 +520,6 @@ class TestCompatibleWindowsRuntimeLines:
         assert compatible_windows_runtime_lines(host) == ["cuda14", "cuda13", "cuda12"]
 
 
-# ===========================================================================
-# H. runtime_line_from_cuda_version
-# ===========================================================================
-
-
-class TestRuntimeLineFromCudaVersion:
-    def test_cuda_12(self):
-        assert runtime_line_from_cuda_version("12.6") == "cuda12"
-
-    def test_cuda_13(self):
-        assert runtime_line_from_cuda_version("13.0") == "cuda13"
-
-    def test_cuda_11(self):
-        assert runtime_line_from_cuda_version("11.8") is None
-
-    def test_none(self):
-        assert runtime_line_from_cuda_version(None) is None
-
-    def test_empty(self):
-        assert runtime_line_from_cuda_version("") is None
-
-
 # ===========================================================================
 # I. apply_approved_hashes
 # ===========================================================================
@@ -3668,7 +3497,7 @@ class TestCpuFallback:
 # ===========================================================================
 
 
-@pytest.mark.skipif(sys.platform == "win32", reason = "bash-only Studio installer tests")
+@pytest.mark.skipif(sys.platform == "win32", reason = "bash-only Unsloth installer tests")
 class TestCudaDriverToolkitMismatchMessage:
     _SETUP_SH = PACKAGE_ROOT / "studio" / "setup.sh"
     _SETUP_PS1 = PACKAGE_ROOT / "studio" / "setup.ps1"
@@ -3873,7 +3702,7 @@ class TestCudaDriverToolkitMismatchMessage:
             "or install a CUDA $driverMajor.x toolkit." in source
         )
         assert (
-            "Or let Studio use the prebuilt CUDA bundle; it does not need the local toolkit."
+            "Or let Unsloth use the prebuilt CUDA bundle; it does not need the local toolkit."
         ) in source
         assert (
             "Write-CudaDriverToolkitMismatch -ToolkitVersion $IncompatibleToolkit "
diff --git a/tests/studio/install/test_setup_whisper_status.py b/tests/studio/install/test_setup_whisper_status.py
new file mode 100644
index 0000000000..fd3bd82507
--- /dev/null
+++ b/tests/studio/install/test_setup_whisper_status.py
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+"""Contract checks for actionable whisper prebuilt setup outcomes."""
+
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[3]
+
+
+def test_shell_setup_distinguishes_release_skew_from_install_failure():
+    script = (ROOT / "studio" / "setup.sh").read_text(encoding = "utf-8")
+    assert 'if [ "$_WHISPER_STATUS" -eq 2 ]' in script
+    assert "installed llama.cpp ${_WHISPER_INSTALLED_TAG:-unknown}" in script
+    assert "whisper requires ${_WHISPER_REQUIRED_TAG:-unknown}" in script
+    assert "prebuilt install failed" in script
+    assert "retry setup or inspect verbose output" in script
+    assert "curated whisper.cpp dictation is unavailable" in script
+    assert "browser and Transformers dictation remain available" in script
+
+
+def test_powershell_setup_distinguishes_release_skew_from_install_failure():
+    script = (ROOT / "studio" / "setup.ps1").read_text(encoding = "utf-8")
+    assert "elseif ($whisperExit -eq 2)" in script
+    assert "installed llama.cpp $installedWhisperLlamaTag" in script
+    assert "whisper requires $requiredWhisperLlamaTag" in script
+    assert "prebuilt install failed" in script
+    assert "retry setup or inspect verbose output" in script
+    assert "curated whisper.cpp dictation is unavailable" in script
+    assert "browser and Transformers dictation remain available" in script
diff --git a/tests/studio/playwright_chat_ime_i18n.py b/tests/studio/playwright_chat_ime_i18n.py
index 9c01e95fd4..5bebf0a9e8 100644
--- a/tests/studio/playwright_chat_ime_i18n.py
+++ b/tests/studio/playwright_chat_ime_i18n.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Studio chat composer IME + multilingual regression smoke.
+"""Unsloth chat composer IME + multilingual regression smoke.
 
 Covers: stuck IME composition (#5318 / PR #5327), multilingual paste round-trip,
 stuck compositionend (#5546), and Mac input-method switch recovery (keydown/blur).
diff --git a/tests/studio/playwright_chat_ui.py b/tests/studio/playwright_chat_ui.py
index 065ba7a745..a06e559100 100644
--- a/tests/studio/playwright_chat_ui.py
+++ b/tests/studio/playwright_chat_ui.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Comprehensive Studio chat UI test, run locally + in CI."""
+"""Comprehensive Unsloth chat UI test, run locally + in CI."""
 
 import json
 import os
@@ -52,6 +52,14 @@ TURN_TIMEOUT_MS = int(os.environ.get("STUDIO_UI_TURN_TIMEOUT_MS", "180000"))
 # Wall-clock cap for the whole script (healthy run is 5-9 min).
 WALL_TIMEOUT_S = float(os.environ.get("STUDIO_UI_WALL_TIMEOUT_S", "720"))
 
+# Run only bootstrap plus permission controls for fast cross-browser checks.
+PERMISSION_ONLY = os.environ.get("STUDIO_UI_PERMISSION_ONLY", "0") == "1"
+
+# Default stays Chromium for CI. Local runs can select firefox/webkit or a
+# Chromium channel such as chrome/msedge.
+PLAYWRIGHT_BROWSER = os.environ.get("STUDIO_PLAYWRIGHT_BROWSER", "chromium").lower()
+PLAYWRIGHT_CHANNEL = os.environ.get("STUDIO_PLAYWRIGHT_CHANNEL") or None
+
 # Per-fetch budget; /api/inference/load is the slowest (cold-cache GGUF load).
 FETCH_TIMEOUT_MS = int(os.environ.get("STUDIO_UI_FETCH_TIMEOUT_MS", "30000"))
 LOAD_FETCH_TIMEOUT_MS = int(os.environ.get("STUDIO_UI_LOAD_TIMEOUT_MS", "180000"))
@@ -116,6 +124,126 @@ def soft_fail(m):
     info(f"WARN (strict-off): {m}")
 
 
+def exercise_permission_mode_controls(page, shoot):
+    """Exercise labels, migration, persistence, confirmation, and focus."""
+    step("permission levels: labels, persistence, confirmation, and focus")
+    pill = page.locator('button[aria-label="Permission level for tool calls"]:visible').first
+    expect(pill).to_be_visible()
+
+    def expect_mode(label):
+        expect(pill).to_have_attribute("data-pill-label", label)
+        expect(pill).to_contain_text(label)
+
+    def open_menu():
+        pill.click()
+        menu = page.get_by_role("menu").last
+        expect(menu).to_be_visible()
+        return menu
+
+    def choose(label):
+        menu = open_menu()
+        item = menu.get_by_role("menuitem").filter(has_text = label).first
+        expect(item).to_be_visible()
+        item.click()
+
+    # Fresh profiles default to Approve for me.
+    expect_mode("Approve for me")
+    menu = open_menu()
+    for label in (
+        "Ask for approval",
+        "Approve for me",
+        "Run automatically",
+        "Full access",
+    ):
+        expect(menu.get_by_role("menuitem").filter(has_text = label).first).to_be_visible()
+    if menu.get_by_text("Off", exact = True).count() != 0:
+        fail("legacy Off label is still visible")
+    if menu.locator('[role="menuitem"] button, [role="menuitem"] [role="button"]').count():
+        fail("permission menu contains nested interactive controls")
+    page.keyboard.press("Escape")
+    expect(pill).to_be_focused()
+
+    # The active row is a no-op and must not open the Full access dialog.
+    choose("Approve for me")
+    expect_mode("Approve for me")
+    expect(page.get_by_role("alertdialog")).to_have_count(0)
+
+    # Pointer and compact-layout coverage.
+    page.set_viewport_size({"width": 390, "height": 844})
+    expect(pill).to_be_visible()
+    box = pill.bounding_box()
+    if box is None or box["x"] < 0 or box["x"] + box["width"] > 390:
+        fail(f"permission pill is clipped in compact layout: {box!r}")
+    page.set_viewport_size({"width": 1280, "height": 900})
+
+    # Legacy setting migration: true -> ask, false -> off, absent -> auto.
+    migration_cases = (
+        ("true", "Ask for approval"),
+        ("false", "Run automatically"),
+        (None, "Approve for me"),
+    )
+    for legacy_value, expected_label in migration_cases:
+        page.evaluate(
+            """(legacyValue) => {
+                localStorage.removeItem("unsloth_chat_permission_mode");
+                if (legacyValue === null) {
+                    localStorage.removeItem("unsloth_chat_confirm_tool_calls");
+                } else {
+                    localStorage.setItem(
+                        "unsloth_chat_confirm_tool_calls",
+                        legacyValue,
+                    );
+                }
+            }""",
+            legacy_value,
+        )
+        page.reload(wait_until = "domcontentloaded")
+        expect(pill).to_be_visible()
+        expect_mode(expected_label)
+
+    choose("Run automatically")
+    expect_mode("Run automatically")
+    expect(page.locator('button[data-pill-label="Search"]:visible').first).to_be_visible()
+    expect(page.locator('button[data-pill-label="Code"]:visible').first).to_be_visible()
+    stored = page.evaluate("() => localStorage.getItem('unsloth_chat_permission_mode')")
+    if stored != "off":
+        fail(f"Run automatically persisted {stored!r}, expected 'off'")
+
+    # Full access requires explicit consent and never overwrites persistence.
+    choose("Full access")
+    dialog = page.get_by_role("alertdialog")
+    expect(dialog).to_be_visible()
+    expect(dialog.get_by_role("heading", name = "Enable Full access?")).to_be_visible()
+    expect(dialog).to_contain_text("the code sandbox")
+    dialog.get_by_role("button", name = "Cancel").click()
+    expect(dialog).to_be_hidden()
+    expect_mode("Run automatically")
+
+    choose("Full access")
+    expect(dialog).to_be_visible()
+    dialog.get_by_role("button", name = "I understand").click()
+    expect_mode("Full access")
+    expect(pill).to_have_attribute("data-variant", "danger")
+    active_icon = pill.locator(".composer-pill-glyph > :first-child")
+    pill.hover()
+    page.wait_for_timeout(200)
+    icon_opacity = float(active_icon.evaluate("el => getComputedStyle(el).opacity"))
+    if icon_opacity < 0.5:
+        fail(f"Full access icon disappeared on hover (opacity={icon_opacity})")
+    stored = page.evaluate("() => localStorage.getItem('unsloth_chat_permission_mode')")
+    if stored != "off":
+        fail(f"Full access overwrote persisted mode with {stored!r}")
+
+    page.reload(wait_until = "domcontentloaded")
+    expect(pill).to_be_visible()
+    expect_mode("Run automatically")
+
+    # Leave the full chat smoke in the fresh-install default.
+    choose("Approve for me")
+    expect_mode("Approve for me")
+    shoot("04-permission-levels")
+
+
 def login_via_api(pw):
     req = urllib.request.Request(
         f"{BASE}/api/auth/login",
@@ -145,18 +273,24 @@ with sync_playwright() as p:
     # DB is still migrating; this 30s probe catches that gap before we
     # sink 60s into a change-password timeout. Diagnostic only.
     wait_for_health(BASE, timeout = 30.0, info = info)
-    # Chromium launch args: see `tests/studio/_playwright_robust.py`.
-    browser = p.chromium.launch(
-        headless = True,
-        args = chromium_launch_args(),
-    )
+    if PLAYWRIGHT_BROWSER not in ("chromium", "firefox", "webkit"):
+        fail(f"unsupported STUDIO_PLAYWRIGHT_BROWSER={PLAYWRIGHT_BROWSER!r}")
+    browser_type = getattr(p, PLAYWRIGHT_BROWSER)
+    launch_kwargs = {"headless": True}
+    if PLAYWRIGHT_BROWSER == "chromium":
+        launch_kwargs["args"] = chromium_launch_args()
+        if PLAYWRIGHT_CHANNEL:
+            launch_kwargs["channel"] = PLAYWRIGHT_CHANNEL
+    elif PLAYWRIGHT_CHANNEL:
+        fail("STUDIO_PLAYWRIGHT_CHANNEL requires chromium")
+    browser = browser_type.launch(**launch_kwargs)
     ctx = browser.new_context(
         viewport = {"width": 1280, "height": 900},
         # Reduce motion so view-transition animations don't intercept
         # pointer events and break Playwright's actionability check.
         reduced_motion = "reduce",
     )
-    # Hard-disable CSS view-transitions: Studio's theme toggle + sidebar
+    # Hard-disable CSS view-transitions: Unsloth's theme toggle + sidebar
     # collapse run startViewTransition() which can leave <html> intercepting
     # pointer events for a beat after each route swap. See _playwright_robust.py.
     install_view_transition_killer(ctx)
@@ -364,6 +498,15 @@ with sync_playwright() as p:
         raise last_err
     shoot("03-chat-loaded")
 
+    exercise_permission_mode_controls(page, shoot)
+    if PERMISSION_ONLY:
+        info(
+            "permission-only run passed "
+            f"(browser={PLAYWRIGHT_BROWSER}, channel={PLAYWRIGHT_CHANNEL or 'bundled'})"
+        )
+        browser.close()
+        sys.exit(0)
+
     # /api/models/list and /api/inference/load need a bearer; the
     # frontend stores it under "unsloth_auth_token" (auth/session.ts).
     token = robust_evaluate(
@@ -477,7 +620,7 @@ with sync_playwright() as p:
         fail(f"/api/inference/load returned {load_resp['status']}: {load_resp.get('body')!r}")
     info(f"loaded model: {(load_resp['body'] or {}).get('display_name')}")
 
-    # Studio caches model state in zustand; reload so the composer picks
+    # Unsloth caches model state in zustand; reload so the composer picks
     # up the loaded model.
     page.reload()
     composer = page.locator('textarea[aria-label="Message input"]')
@@ -493,7 +636,7 @@ with sync_playwright() as p:
     # (app-sidebar.tsx) -- as stable as anything in the codebase.
     picker_btn = page.locator('[data-tour="chat-model-selector"]').first
     if picker_btn.count() == 0:
-        # Fall back to text-based locators for older Studio builds.
+        # Fall back to text-based locators for older Unsloth builds.
         picker_btn = page.locator(
             'button:has-text("gemma-3-270m"), '
             'button:has-text("Gemma 3"), '
@@ -678,10 +821,16 @@ with sync_playwright() as p:
     last_assistant = page.locator('[data-role="assistant"]').last
     last_assistant.hover()
     page.wait_for_timeout(400)
-    regen_btn = page.get_by_role(
-        "button",
-        name = re.compile(r"(reload|regenerate)", re.I),
-    ).first
+    # Exclude disabled controls: the picker's new disabled "Reload model"
+    # button also matches and sorts first, so .first would target it.
+    regen_btn = (
+        page.get_by_role(
+            "button",
+            name = re.compile(r"(reload|regenerate)", re.I),
+        )
+        .and_(page.locator("button:not([disabled])"))
+        .first
+    )
     if regen_btn.count() > 0:
         regen_btn.click()
         try:
@@ -787,6 +936,70 @@ with sync_playwright() as p:
             page.keyboard.press("Escape")
         page.wait_for_timeout(300)
 
+    def read_chat_typography():
+        """Read message typography after a user-driven theme transition."""
+        return robust_evaluate(
+            page,
+            """() => {
+                const root = document.documentElement;
+                const assistant = Array.from(
+                    document.querySelectorAll('.aui-assistant-message-root')
+                );
+                const user = Array.from(
+                    document.querySelectorAll('.aui-user-message-root')
+                );
+                if (assistant.length === 0 || user.length === 0) {
+                    return { error: 'chat message roots are missing' };
+                }
+                const ua = navigator.userAgent.toLowerCase();
+                const role = (nodes) => {
+                    const styles = nodes.map((node) => getComputedStyle(node));
+                    return {
+                        fontWeight: [...new Set(styles.map((style) => style.fontWeight))],
+                        letterSpacing: [...new Set(styles.map((style) => style.letterSpacing))],
+                    };
+                };
+                return {
+                    actualRenderLinux: root.classList.contains('render-linux'),
+                    isDesktopLinux: ua.includes('linux') && !ua.includes('android'),
+                    isDark: root.classList.contains('dark'),
+                    usesBaselineTypography: (
+                        root.classList.contains('no-font-smoothing') ||
+                        root.hasAttribute('data-chat-font') ||
+                        root.hasAttribute('data-ui-font')
+                    ),
+                    assistant: role(assistant),
+                    user: role(user),
+                };
+            }""",
+        )
+
+    def assert_chat_typography(label, typography):
+        if typography.get("error"):
+            fail(typography["error"])
+        if typography["actualRenderLinux"] != typography["isDesktopLinux"]:
+            fail(f"desktop Linux detection mismatch: {typography!r}")
+        is_dark = typography["isDark"]
+        expected_spacing = "0.31px" if is_dark else "0.155px"
+        if typography["isDesktopLinux"] and not typography["usesBaselineTypography"]:
+            expected_weight = "350" if is_dark else "390"
+            if is_dark:
+                expected_spacing = "0.3565px"
+        else:
+            expected_weight = "410"
+        for role in ("assistant", "user"):
+            actual = typography[role]
+            if actual["fontWeight"] != [expected_weight]:
+                fail(
+                    f"chat font weight {label}/{role}: expected {expected_weight}, "
+                    f"got {actual['fontWeight']!r}"
+                )
+            if actual["letterSpacing"] != [expected_spacing]:
+                fail(
+                    f"chat letter spacing {label}/{role}: expected {expected_spacing}, "
+                    f"got {actual['letterSpacing']!r}"
+                )
+
     # ─────────────────────────────────────────────────────
     # 9. Theme toggle -- multiple cycles + computed-bg-color check
     # (light is near-white >240; dark is near-black <40).
@@ -795,6 +1008,7 @@ with sync_playwright() as p:
     if acct.count() > 0:
         step("theme toggle x3 with computed-color assertion")
         observed = []
+        typography_states = []
         for cycle in range(3):
             # Wait for any prior dropdown to fully detach: clicking while
             # the view-transition is still open no-ops silently. The
@@ -883,6 +1097,9 @@ with sync_playwright() as p:
             }""",
             )
             observed.append(bg)
+            typography = read_chat_typography()
+            assert_chat_typography(f"theme-cycle-{cycle + 1}", typography)
+            typography_states.append(typography)
             shoot(f"10-theme-cycle-{cycle + 1}")
             info(f"  cycle {cycle + 1}: dark={bg['isDark']} body bg={bg['bg']!r}")
         # Across cycles we should see both a near-white (light) and a
@@ -893,7 +1110,7 @@ with sync_playwright() as p:
         if len(observed) < 3:
             soft_fail(f"theme toggle ran only {len(observed)} cycle(s), expected 3")
         # Don't strict-fail on both polarities: the runner's
-        # prefers-color-scheme + Studio's "system" default can collapse
+        # prefers-color-scheme + Unsloth's "system" default can collapse
         # to one polarity even when .dark toggles correctly. The 3-cycle
         # completion above is the real invariant.
         if light_seen and dark_seen:
@@ -905,6 +1122,20 @@ with sync_playwright() as p:
                 "(toggle may not flip on this runner's color-scheme)"
             )
 
+        # These are user-driven theme transitions, not synthetic class
+        # changes. A completed three-cycle toggle must expose both typography
+        # states before we check the Linux selector.
+        if len(typography_states) != 3:
+            soft_fail(
+                f"chat typography observed {len(typography_states)} theme state(s), expected 3"
+            )
+        elif {state["isDark"] for state in typography_states} != {False, True}:
+            soft_fail(f"chat typography did not observe both themes: {typography_states!r}")
+        else:
+            info("OK chat typography platform and theme behavior")
+    else:
+        soft_fail("chat typography requires the account-menu theme control")
+
     # ─────────────────────────────────────────────────────
     # 10. Sidebar nav: New Chat, Compare, Search, Recipes.
     # ─────────────────────────────────────────────────────
diff --git a/tests/studio/playwright_extra_ui.py b/tests/studio/playwright_extra_ui.py
index 209a8a06f1..e4de62fd2e 100644
--- a/tests/studio/playwright_extra_ui.py
+++ b/tests/studio/playwright_extra_ui.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Studio extra-UI Playwright test: Compare tab, Recipes editor, /export, /studio, Settings tabs."""
+"""Unsloth extra-UI Playwright test: Compare tab, Recipes editor, /export, /studio, Settings tabs."""
 
 import json
 import os
@@ -36,6 +36,9 @@ ART_DIR = os.environ.get("PW_ART_DIR", "logs/playwright_extra")
 ART = Path(ART_DIR)
 ART.mkdir(parents = True, exist_ok = True)
 STRICT = os.environ.get("STUDIO_UI_STRICT", "0") == "1"
+# The Voice-picker media-access crash is specific to headless Chromium on macos-14; only there do we
+# downgrade a renderer crash to a warning. Linux/Windows strict smoke jobs keep hard crash coverage.
+MACOS_RUNNER = os.environ.get("RUNNER_OS", "").lower() == "macos" or sys.platform == "darwin"
 # Longer turn timeout: gemma-3-270m CPU inference is 3-5x slower on macos-14 runners.
 TURN_TIMEOUT_MS = int(os.environ.get("STUDIO_UI_TURN_TIMEOUT_MS", "180000"))
 WALL_TIMEOUT_S = float(os.environ.get("STUDIO_UI_WALL_TIMEOUT_S", "720"))
@@ -71,6 +74,18 @@ def runtime_warn(m: str) -> None:
     info(f"WARN (runtime): {m}")
 
 
+def page_crashed(pg, exc: Exception) -> bool:
+    """True when the browser/page/context died (a macos-14 renderer crash) rather than a live-page
+    assertion failing -- so the caller can downgrade CI-environment flakiness to a runtime warning."""
+    try:
+        if pg.is_closed():
+            return True
+    except Exception:
+        return True
+    msg = str(exc).lower()
+    return "has been closed" in msg or "target closed" in msg or "crash" in msg
+
+
 with sync_playwright() as p:
     _watchdog = install_wall_clock_watchdog(
         WALL_TIMEOUT_S,
@@ -90,11 +105,11 @@ with sync_playwright() as p:
     )
     install_view_transition_killer(ctx)
     page = ctx.new_page()
-    # 60s default for slow macos-14 --single-process Chromium (second Studio boot of the job).
+    # 60s default for slow macos-14 --single-process Chromium (second Unsloth boot of the job).
     page.set_default_timeout(60_000)
     page_errors = []
 
-    # Filter out known-benign React errors (timing artefacts on slow CI runners, not Studio bugs);
+    # Filter out known-benign React errors (timing artefacts on slow CI runners, not Unsloth bugs);
     # shared base list lives in _playwright_robust.BENIGN_PAGE_ERROR_PATTERNS.
     def _on_pageerror(e):
         msg = str(e)
@@ -451,9 +466,9 @@ with sync_playwright() as p:
             )
 
     # ─────────────────────────────────────────────────────
-    # 4. Studio training route.
+    # 4. Unsloth training route.
     # ─────────────────────────────────────────────────────
-    step(f"Studio route ({'chat-only redirect' if chat_only else 'tabs + sections'})")
+    step(f"Unsloth route ({'chat-only redirect' if chat_only else 'tabs + sections'})")
     page.goto(f"{BASE}/studio")
     page.wait_for_timeout(1500)
     shoot("08-studio")
@@ -482,6 +497,14 @@ with sync_playwright() as p:
     step("Settings dialog: cycle through tabs")
     page.goto(f"{BASE}/chat")
     composer.wait_for(state = "visible", timeout = 60_000)
+    dictate = page.get_by_role("button", name = "Dictate").first
+    if dictate.count() == 0:
+        fail("Chat Dictate button not found")
+    elif dictate.get_attribute("type") != "button":
+        fail("Chat Dictate control must use type=button, not submit the composer")
+    else:
+        info("OK Chat Dictate control is type=button")
+
     page.keyboard.press("Control+,")
     page.wait_for_timeout(800)
     settings = page.get_by_role("dialog").first
@@ -501,6 +524,7 @@ with sync_playwright() as p:
             "Appearance",
             "Chat",
             "Developer",
+            "Voice",
             "About",
         )
         seen_tabs = []
@@ -528,9 +552,59 @@ with sync_playwright() as p:
                     soft_fail(f"Settings tab '{tab_name}' body suspiciously short: {body_text}")
             except Exception as exc:
                 soft_fail(f"Settings tab '{tab_name}' click failed: {exc!r}")
-        shoot("10-settings-tabs-visited")
-        page.keyboard.press("Escape")
-        page.wait_for_timeout(300)
+        step("Voice model picker: real mouse-wheel scrolling")
+        voice_tab = page.get_by_role(
+            "button", name = re.compile(r"^\s*Voice(?:\s+New)?\s*$", re.I)
+        ).first
+        if voice_tab.count() == 0:
+            fail("Voice settings tab not found")
+        else:
+            # The dictation-engine dropdown touches a media-access path that can crash headless
+            # Chromium on macos-14 (CheckMediaAccessPermission). A resulting TargetClosedError is CI
+            # flakiness there, not a product bug, so on macOS a crash is a runtime warning + page
+            # recovery; on Linux/Windows a crash and any live-page failure stay a hard fail.
+            try:
+                voice_tab.click()
+                page.get_by_label("Dictation engine").click()
+                page.get_by_role("option", name = "Local transcription").click()
+                page.get_by_label("Speech recognition model").click()
+                page.get_by_placeholder("Search model").fill("whisper")
+                results = page.get_by_test_id("stt-model-results")
+                page.wait_for_function(
+                    """() => {
+                        const node = document.querySelector('[data-testid="stt-model-results"]');
+                        return !!node && node.scrollHeight > node.clientHeight;
+                    }""",
+                    timeout = 30_000,
+                )
+                results.hover()
+                page.mouse.wheel(0, 700)
+                page.wait_for_function(
+                    """() => {
+                        const node = document.querySelector('[data-testid="stt-model-results"]');
+                        return !!node && node.scrollTop > 0;
+                    }""",
+                    timeout = 5_000,
+                )
+                info("OK Voice model picker mouse wheel changed scrollTop")
+            except Exception as exc:
+                if page_crashed(page, exc) and MACOS_RUNNER:
+                    runtime_warn(f"Voice model picker aborted (browser/page unstable): {exc!r}")
+                    page = recover_or_replace_page(
+                        page,
+                        ctx,
+                        default_timeout_ms = 60_000,
+                        info = lambda m: info(f"recovery: {m}"),
+                    )
+                else:
+                    fail(f"Voice model picker did not wheel-scroll: {exc!r}")
+        # When the crash closed the context/browser (not just the page), recover_or_replace_page
+        # cannot mint a replacement and hands back the closed page; skip the cosmetic teardown rather
+        # than re-raise TargetClosedError on it. is_closed() is a local check and never raises.
+        if not page.is_closed():
+            shoot("10-settings-tabs-visited")
+            page.keyboard.press("Escape")
+            page.wait_for_timeout(300)
         info(f"visited Settings tabs: {seen_tabs}")
         if not seen_tabs:
             soft_fail("no Settings tabs were visitable")
@@ -549,4 +623,7 @@ with sync_playwright() as p:
         sys.exit(1)
     info("PASS extra UI flow")
     _watchdog.cancel()
-    browser.close()
+    try:
+        browser.close()
+    except Exception:
+        pass  # a crashed browser may already be gone; never fail teardown after PASS
diff --git a/tests/studio/playwright_model_config.py b/tests/studio/playwright_model_config.py
new file mode 100644
index 0000000000..a8d143a253
--- /dev/null
+++ b/tests/studio/playwright_model_config.py
@@ -0,0 +1,740 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Model-picker per-model-config Playwright regression test (GPU-free, CPU gemma).
+
+Guards, end to end against the real frontend, the exact regressions that got the
+predecessor PR reverted:
+
+  - Context Length persists: set a distinctive per-model Context Length + tick
+    "Remember for this model" + Load; the value reaches the /api/inference/load
+    request (max_seq_length) AND lands in localStorage (unsloth_model_configs),
+    and survives a full browser reload (HARD).
+  - Reset clears: after customizing, Reset must clear the stored override, never
+    pin the context to a fixed number (the "Reset pins context" regression) (HARD).
+  - Hidden infra models absent: the RAG embedder (bge-small-en-v1.5) and the
+    llama.cpp validation probe (stories260K) never appear in the picker. The
+    probe GGUF is primed into the HF cache by the CI job, so "absent" proves
+    "hidden", not "not downloaded" (HARD).
+  - Legacy migration is idempotent: a pre-feature unsloth_load_settings store
+    migrates once into the versioned unsloth_model_configs map with the value
+    preserved, and a second reload with a fresh legacy seed present does not
+    re-migrate, duplicate, or clobber (gates under STUDIO_UI_STRICT via soft_fail).
+  - Advanced settings persist: KV cache dtype / tensor-parallel toggled under
+    Advanced + Remember land in unsloth_model_configs (best-effort).
+
+Runs as a plain script (not via pytest), mirroring tests/studio/playwright_extra_ui.py:
+accumulate failures in `_failed`, exit non-zero if any HARD gate failed. With
+STUDIO_UI_STRICT=1 (as CI sets), soft_fail also gates; genuinely-optional checks
+use runtime_warn so they never flake the merge gate.
+"""
+
+import json
+import re
+import sys
+import os
+import time
+from pathlib import Path
+
+from playwright.sync_api import sync_playwright
+
+# Run as a plain script (not via pytest), so prepend the dir to sys.path.
+sys.path.insert(0, str(Path(__file__).resolve().parent))
+from _playwright_robust import (  # noqa: E402
+    chromium_launch_args,
+    click_and_wait_for_response,
+    evaluate_fetch,
+    install_view_transition_killer,
+    install_wall_clock_watchdog,
+    is_benign_page_error,
+    recover_or_replace_page,
+    robust_evaluate,
+    wait_for_health,
+)
+
+BASE = os.environ["BASE_URL"]
+NEW = os.environ.get("STUDIO_NEW_PW", "ModelCfg-NEW-2026!")
+# Attach mode: log into an already-provisioned Studio with an existing password
+# instead of the first-boot change-password dance. CI leaves STUDIO_LOGIN_PW unset
+# to exercise the real change-password flow; local runs can set it to skip re-provisioning.
+LOGIN_PW = os.environ.get("STUDIO_LOGIN_PW")
+LOGIN_USER = os.environ.get("STUDIO_LOGIN_USER", "unsloth")
+GGUF_REPO = os.environ.get("GGUF_REPO", "unsloth/gemma-3-270m-it-GGUF")
+GGUF_VARIANT = os.environ.get("GGUF_VARIANT", "UD-Q4_K_XL")
+# Substring of the On Device picker row for the loaded model.
+MODEL_HINT = os.environ.get("STUDIO_MODEL_HINT", "gemma-3-270m")
+# A distinctive valid (>=128, multiple of 128, below the model's 32768 ceiling)
+# Context Length, clearly not a default, so persistence is unambiguous.
+DISTINCT_CTX = int(os.environ.get("STUDIO_DISTINCT_CTX", "4096"))
+ART_DIR = os.environ.get("PW_ART_DIR", "logs/playwright_modelcfg")
+ART = Path(ART_DIR)
+ART.mkdir(parents = True, exist_ok = True)
+STRICT = os.environ.get("STUDIO_UI_STRICT", "0") == "1"
+TURN_TIMEOUT_MS = int(os.environ.get("STUDIO_UI_TURN_TIMEOUT_MS", "180000"))
+WALL_TIMEOUT_S = float(os.environ.get("STUDIO_UI_WALL_TIMEOUT_S", "720"))
+FETCH_TIMEOUT_MS = int(os.environ.get("STUDIO_UI_FETCH_TIMEOUT_MS", "30000"))
+LOAD_FETCH_TIMEOUT_MS = int(os.environ.get("STUDIO_UI_LOAD_TIMEOUT_MS", "180000"))
+
+_n = [0]
+_failed: list[str] = []
+
+
+def step(s: str) -> None:
+    print(f"[ui-modelcfg] STEP {s}", flush = True)
+
+
+def info(s: str) -> None:
+    print(f"[ui-modelcfg] {s}", flush = True)
+
+
+def fail(m: str) -> None:
+    print(f"[ui-modelcfg] FAIL: {m}", flush = True)
+    _failed.append(m)
+
+
+def soft_fail(m: str) -> None:
+    if STRICT:
+        fail(m)
+    else:
+        info(f"WARN (strict-off): {m}")
+
+
+def runtime_warn(m: str) -> None:
+    """Warn about a genuinely-optional check that STRICT does not gate."""
+    info(f"WARN (runtime): {m}")
+
+
+def _count(loc) -> int:
+    try:
+        return loc.count()
+    except Exception:
+        return 0
+
+
+def _as_int(value) -> int | None:
+    """Parse an input value to int, tolerating commas/whitespace. Comparisons
+    must be numeric, never substring: '40960' (a model's native default) would
+    spuriously "contain" '4096'."""
+    if value is None:
+        return None
+    try:
+        return int(str(value).replace(",", "").strip())
+    except Exception:
+        return None
+
+
+def _login_token_via_api(base: str, user: str, pw: str) -> str:
+    """POST /api/auth/login -> access_token (attach-mode helper, stdlib only)."""
+    import urllib.request
+
+    req = urllib.request.Request(
+        f"{base}/api/auth/login",
+        data = json.dumps({"username": user, "password": pw}).encode(),
+        headers = {"Content-Type": "application/json"},
+        method = "POST",
+    )
+    with urllib.request.urlopen(req, timeout = 15) as r:
+        return json.loads(r.read().decode())["access_token"]
+
+
+with sync_playwright() as p:
+    _watchdog = install_wall_clock_watchdog(
+        WALL_TIMEOUT_S,
+        label = "ui-modelcfg",
+        info = info,
+    )
+    # Health pre-flight: bash-side health wait can pass before the auth DB migrates.
+    wait_for_health(BASE, timeout = 30.0, info = info)
+    browser = p.chromium.launch(
+        headless = True,
+        args = chromium_launch_args(),
+    )
+    ctx = browser.new_context(
+        viewport = {"width": 1280, "height": 900},
+        reduced_motion = "reduce",
+    )
+    install_view_transition_killer(ctx)
+    page = ctx.new_page()
+    page.set_default_timeout(60_000)
+    page_errors = []
+
+    def _on_pageerror(e):
+        msg = str(e)
+        if is_benign_page_error(msg):
+            info(f"WARN ignoring benign pageerror: {msg!r}")
+            return
+        page_errors.append(msg)
+
+    page.on("pageerror", _on_pageerror)
+
+    # Record every /api/inference/load POST payload so the persistence gate can
+    # assert max_seq_length.
+    load_posts: list[str] = []
+
+    def _on_request(req):
+        try:
+            if req.method == "POST" and "/api/inference/load" in req.url:
+                load_posts.append(req.post_data or "")
+        except Exception:
+            pass
+
+    page.on("request", _on_request)
+
+    def shoot(name: str) -> None:
+        _n[0] += 1
+        try:
+            page.screenshot(
+                path = str(ART / f"{_n[0]:02d}-{name}.png"),
+                full_page = True,
+                timeout = 90_000,
+                animations = "disabled",
+            )
+        except Exception as _shoot_err:
+            info(f"WARN: screenshot {name} failed: {_shoot_err}")
+
+    def read_configs() -> dict:
+        """Return the parsed unsloth_model_configs map (or {} if absent/invalid)."""
+        raw = robust_evaluate(page, "() => localStorage.getItem('unsloth_model_configs')")
+        if not raw:
+            return {}
+        try:
+            data = json.loads(raw)
+            return data if isinstance(data, dict) else {}
+        except Exception:
+            return {}
+
+    def config_entries(cfg: dict) -> list[dict]:
+        """The per-model entries (dict values) of the stored map, schema-tolerant."""
+        return [v for v in cfg.values() if isinstance(v, dict)]
+
+    # ─────────────────────────────────────────────────────
+    # Setup: authenticate + model load.
+    # ─────────────────────────────────────────────────────
+    if LOGIN_PW:
+        # Attach mode: log in via the API and seed the token before navigation,
+        # skipping the first-boot change-password dance.
+        step("setup: API login + token seed (attach to running Studio)")
+        _tok = _login_token_via_api(BASE, LOGIN_USER, LOGIN_PW)
+        ctx.add_init_script(
+            f"try{{localStorage.setItem('unsloth_auth_token', {json.dumps(_tok)});}}"
+            f"catch(e){{}}"
+        )
+        page.goto(BASE, wait_until = "domcontentloaded", timeout = 60_000)
+    else:
+        step("setup: change-password")
+        # 3-attempt retry: the form can re-render mid-fill on slow runners and
+        # detach the password fields; each retry re-navigates with a fresh page.
+        form_err: Exception | None = None
+        for _form_attempt in range(3):
+            try:
+                page.goto(f"{BASE}/change-password", wait_until = "domcontentloaded", timeout = 60_000)
+                try:
+                    page.wait_for_load_state("networkidle", timeout = 30_000)
+                except Exception:
+                    pass
+                pw_field = page.locator("#new-password")
+                pw_field.wait_for(state = "visible", timeout = 60_000)
+                pw_field.fill(NEW, timeout = 60_000)
+                page.fill("#confirm-password", NEW, timeout = 60_000)
+                status, _ = click_and_wait_for_response(
+                    page,
+                    url_substr = "/api/auth/change-password",
+                    method = "POST",
+                    do_click = lambda: page.locator('button[type="submit"]').click(),
+                    timeout_ms = 30_000,
+                    info = lambda m: print(f"[ui-modelcfg]   {m}", flush = True),
+                )
+                if status is not None and status >= 400:
+                    raise AssertionError(
+                        f"change-password POST returned {status}; page_errors={page_errors[:1]!r}"
+                    )
+                form_err = None
+                break
+            except Exception as e:
+                form_err = e
+                try:
+                    cur_url = page.url
+                except Exception:
+                    cur_url = "<page closed>"
+                print(
+                    f"[ui-modelcfg]   change-password attempt {_form_attempt + 1} failed: "
+                    f"{type(e).__name__}: {str(e)[:200]}; page.url={cur_url}; "
+                    f"page_errors={len(page_errors)}",
+                    flush = True,
+                )
+                if _form_attempt < 2:
+                    if "ERR_NO_BUFFER_SPACE" in str(e):
+                        backoff_s = 5 if _form_attempt == 0 else 15
+                        time.sleep(backoff_s)
+                    page = recover_or_replace_page(
+                        page,
+                        ctx,
+                        default_timeout_ms = 60_000,
+                        info = lambda m: print(f"[ui-modelcfg]   recovery: {m}", flush = True),
+                    )
+                    page.on("request", _on_request)
+        if form_err is not None:
+            raise form_err
+
+    try:
+        page.wait_for_load_state("networkidle", timeout = 30_000)
+    except Exception:
+        pass
+    composer = page.locator('textarea[aria-label="Message input"]')
+    last_err: Exception | None = None
+    for _attempt in range(2):
+        try:
+            composer.wait_for(state = "visible", timeout = 60_000)
+            last_err = None
+            break
+        except Exception as e:
+            last_err = e
+            try:
+                shoot(f"00-composer-wait-attempt-{_attempt + 1}-fail")
+            except Exception:
+                pass
+            if _attempt == 0:
+                page = recover_or_replace_page(
+                    page,
+                    ctx,
+                    default_timeout_ms = 60_000,
+                    goto_url = BASE,
+                    settle_networkidle = True,
+                    info = lambda m: print(f"[ui-modelcfg]   recovery: {m}", flush = True),
+                )
+                page.on("request", _on_request)
+                composer = page.locator('textarea[aria-label="Message input"]')
+    if last_err is not None:
+        raise last_err
+    shoot("01-chat-loaded")
+
+    token = robust_evaluate(page, "() => localStorage.getItem('unsloth_auth_token')")
+    if not token:
+        fail("no access token after auth setup")
+        sys.exit(1)
+
+    # Load the tiny GGUF so it is a live "On Device" model in the picker.
+    load_resp = evaluate_fetch(
+        page,
+        f"{BASE}/api/inference/load",
+        method = "POST",
+        headers = {
+            "Authorization": f"Bearer {token}",
+            "Content-Type": "application/json",
+        },
+        body = {
+            "model_path": GGUF_REPO,
+            "gguf_variant": GGUF_VARIANT,
+            "is_lora": False,
+            "max_seq_length": 2048,
+        },
+        timeout_ms = LOAD_FETCH_TIMEOUT_MS,
+    )
+    if load_resp.get("error"):
+        fail(f"/api/inference/load wedged: {load_resp['error']!r}")
+        sys.exit(1)
+    if load_resp["status"] != 200:
+        fail(f"/api/inference/load -> {load_resp['status']}: {load_resp.get('body')!r}")
+        sys.exit(1)
+    info(f"loaded model: {(load_resp['body'] or {}).get('display_name')}")
+    page.reload()
+    composer = page.locator('textarea[aria-label="Message input"]')
+    composer.wait_for(state = "visible", timeout = 60_000)
+    load_posts.clear()  # drop the setup load; keep only UI-driven loads below.
+
+    # ─────────────────────────────────────────────────────
+    # Picker helpers (proven selectors).
+    # ─────────────────────────────────────────────────────
+    POPOVER = '[data-tour="chat-model-selector-popover"]'
+    TRIGGER = '[data-tour="chat-model-selector"]'
+
+    def open_picker():
+        popover = page.locator(POPOVER).first
+        if _count(popover) == 0 or not popover.is_visible():
+            page.locator(TRIGGER).first.click()
+            page.wait_for_timeout(900)
+            popover = page.locator(POPOVER).first
+        popover.wait_for(state = "visible", timeout = 30_000)
+        return popover
+
+    def close_picker():
+        try:
+            page.keyboard.press("Escape")
+            page.wait_for_timeout(400)
+        except Exception:
+            pass
+
+    def select_on_device_row(popover, hint):
+        od = page.get_by_role("tab", name = "On Device").first
+        if _count(od):
+            od.click()
+            page.wait_for_timeout(700)
+        row = popover.locator("[data-model-picker-option]", has_text = hint).first
+        if _count(row) == 0:
+            # Fall back to search filtering.
+            search = popover.locator("[data-model-picker-search-input]").first
+            if _count(search):
+                search.click()
+                search.fill(hint)
+                page.wait_for_timeout(700)
+                row = popover.locator("[data-model-picker-option]", has_text = hint).first
+        if _count(row) == 0:
+            return None
+        row.click()
+        page.wait_for_timeout(800)
+        return row
+
+    def open_config(popover, hint):
+        if select_on_device_row(popover, hint) is None:
+            return None
+        gear = popover.locator('button[aria-label^="Inference settings for"]').first
+        if _count(gear) == 0:
+            return None
+        gear.click()
+        page.wait_for_timeout(800)
+        return popover
+
+    def context_input(popover):
+        for role in ("textbox", "spinbutton"):
+            loc = popover.get_by_role(role, name = "Context Length").first
+            if _count(loc):
+                return loc
+        loc = popover.locator('input[aria-label="Context Length"]').first
+        return loc if _count(loc) else None
+
+    def primary_button(popover):
+        for name in ("Load model", "Reload model", "Save settings", "Forget settings"):
+            b = popover.get_by_role("button", name = name).first
+            if _count(b):
+                return b
+        return None
+
+    # ─────────────────────────────────────────────────────
+    # 1. Hidden infra models absent from the picker (HARD).
+    # ─────────────────────────────────────────────────────
+    step("hidden infra models absent from picker")
+    popover = open_picker()
+    shoot("02-picker-open")
+    needles = ["bge-small-en-v1.5", "stories260"]
+    tabs = ["Recommended", "On Device", "Connected"]
+    hidden_ok = True
+    for needle in needles:
+        for tab_name in tabs:
+            tab = page.get_by_role("tab", name = tab_name).first
+            if _count(tab) == 0:
+                continue
+            try:
+                tab.click()
+                page.wait_for_timeout(400)
+            except Exception:
+                continue
+            search = popover.locator("[data-model-picker-search-input]").first
+            if _count(search):
+                search.click()
+                search.fill(needle)
+                page.wait_for_timeout(600)
+            hit = popover.locator(
+                "[data-model-picker-option]",
+                has_text = re.compile(re.escape(needle), re.I),
+            )
+            c = _count(hit)
+            if c > 0:
+                hidden_ok = False
+                fail(f"infra model {needle!r} visible in picker '{tab_name}' tab ({c} rows)")
+            if _count(search):
+                search.fill("")
+                page.wait_for_timeout(300)
+    if hidden_ok:
+        info("OK hidden: bge-small-en-v1.5 + stories260K absent from every picker tab")
+    shoot("03-hidden-check")
+    close_picker()
+
+    # ─────────────────────────────────────────────────────
+    # 2. Context Length persists (load + request + reload) (HARD).
+    # ─────────────────────────────────────────────────────
+    step(f"context length {DISTINCT_CTX} persists")
+    popover = open_picker()
+    if open_config(popover, MODEL_HINT) is None:
+        fail(f"could not open run-settings for a model matching {MODEL_HINT!r}")
+    else:
+        shoot("04-config-open")
+        ctx_in = context_input(popover)
+        if ctx_in is None:
+            fail("Context Length input not found in run-settings")
+        else:
+            default_ctx = ctx_in.input_value()
+            info(f"default Context Length shown: {default_ctx!r}")
+            ctx_in.click()
+            ctx_in.fill(str(DISTINCT_CTX))
+            page.wait_for_timeout(300)
+            page.keyboard.press("Tab")  # blur to commit
+            page.wait_for_timeout(300)
+            remember = popover.get_by_label("Remember for this model").first
+            if _count(remember):
+                try:
+                    remember.check()
+                except Exception:
+                    remember.click()
+            else:
+                fail("'Remember for this model' checkbox not found")
+            page.wait_for_timeout(300)
+            shoot("05-ctx-set")
+            btn = primary_button(popover)
+            if btn is None:
+                fail("primary Load/Save button not found in run-settings")
+            else:
+                btn.click()
+                page.wait_for_timeout(2500)
+                shoot("06-after-load")
+
+                # (a) localStorage stored the distinctive context.
+                cfg = read_configs()
+                entries = config_entries(cfg)
+                got_ls = any(e.get("customContextLength") == DISTINCT_CTX for e in entries)
+                if got_ls:
+                    info(f"OK persist(localStorage): customContextLength={DISTINCT_CTX} stored")
+                else:
+                    fail(
+                        "context not stored in unsloth_model_configs "
+                        f"(entries={json.dumps(entries)[:400]})"
+                    )
+
+                # (b) the load request carried max_seq_length == distinctive value.
+                got_req = False
+                for body in load_posts:
+                    try:
+                        payload = json.loads(body) if body else {}
+                    except Exception:
+                        payload = {}
+                    if payload.get("max_seq_length") == DISTINCT_CTX:
+                        got_req = True
+                        break
+                if got_req:
+                    info(f"OK persist(request): /api/inference/load max_seq_length={DISTINCT_CTX}")
+                else:
+                    # The UI may debounce the load; localStorage is the primary
+                    # proof, so only warn if the request was missed.
+                    runtime_warn(
+                        "no /api/inference/load carried "
+                        f"max_seq_length={DISTINCT_CTX}; posts={load_posts!r}"
+                    )
+
+    # (c) survives a full browser reload.
+    close_picker()
+    page.reload()
+    composer = page.locator('textarea[aria-label="Message input"]')
+    composer.wait_for(state = "visible", timeout = 60_000)
+    popover = open_picker()
+    if open_config(popover, MODEL_HINT) is None:
+        fail("could not reopen run-settings after reload")
+    else:
+        ctx_in = context_input(popover)
+        val = ctx_in.input_value() if ctx_in else None
+        if _as_int(val) == DISTINCT_CTX:
+            info(f"OK persist(reload): Context Length still {val!r} after reload")
+        else:
+            fail(f"Context Length did not persist across reload (got {val!r})")
+        shoot("07-after-reload")
+
+    # ─────────────────────────────────────────────────────
+    # 3. Reset clears the override (never pins context) (HARD).
+    # ─────────────────────────────────────────────────────
+    step("reset clears the per-model override")
+    # (popover + config still open from the reload check.)
+    reset_btn = popover.get_by_role("button", name = "Reset").first
+    if _count(reset_btn) == 0:
+        fail("Reset button not found in run-settings")
+    else:
+        try:
+            reset_btn.click()
+            page.wait_for_timeout(500)
+        except Exception as e:
+            fail(f"Reset click failed: {e}")
+        # The input after Reset is informational only: a live-loaded model can still
+        # echo its context even with the stored override gone. The regression we
+        # guard ("Reset PINS the override") lives in localStorage, asserted below.
+        ctx_in = context_input(popover)
+        after_reset = ctx_in.input_value() if ctx_in else None
+        info(f"reset: Context Length input now shows {after_reset!r}")
+        # Commit the reset so the stored override is dropped, then assert storage.
+        btn = primary_button(popover)
+        if btn is not None and btn.is_enabled():
+            btn.click()
+            page.wait_for_timeout(1500)
+        cfg = read_configs()
+        pinned = any(
+            _as_int(e.get("customContextLength")) == DISTINCT_CTX for e in config_entries(cfg)
+        )
+        if pinned:
+            fail("Reset left the distinctive context pinned in unsloth_model_configs")
+        else:
+            info("OK reset: distinctive context cleared from unsloth_model_configs")
+        shoot("08-after-reset")
+    close_picker()
+
+    # ─────────────────────────────────────────────────────
+    # 4. Advanced settings persist (best-effort, never gates).
+    # ─────────────────────────────────────────────────────
+    step("advanced (KV cache dtype / tensor parallel) persists")
+    try:
+        popover = open_picker()
+        if open_config(popover, MODEL_HINT) is not None:
+            adv = popover.get_by_role("switch", name = re.compile("advanced settings", re.I)).first
+            if _count(adv):
+                try:
+                    adv.check()
+                except Exception:
+                    adv.click()
+                page.wait_for_timeout(500)
+            # The Tensor Parallelism Radix Switch has no aria-label, so target the
+            # first switch after the "Tensor Parallelism" text.
+            tp = popover.locator(
+                'xpath=.//span[contains(text(),"Tensor Parallelism")]'
+                '/following::*[@role="switch"][1]'
+            ).first
+            toggled = False
+            if _count(tp):
+                try:
+                    tp.click()
+                    toggled = True
+                except Exception:
+                    pass
+            remember = popover.get_by_label("Remember for this model").first
+            if _count(remember):
+                try:
+                    remember.check()
+                except Exception:
+                    remember.click()
+            btn = primary_button(popover)
+            if btn is not None and btn.is_enabled():
+                btn.click()
+                page.wait_for_timeout(1500)
+            cfg = read_configs()
+            has_adv = any(
+                e.get("tensorParallel") or e.get("kvCacheDtype") for e in config_entries(cfg)
+            )
+            if toggled and has_adv:
+                info("OK advanced: tensorParallel/kvCacheDtype persisted")
+            else:
+                runtime_warn(
+                    f"advanced persistence not observed (toggled={toggled}, "
+                    f"entries={json.dumps(config_entries(cfg))[:300]})"
+                )
+        else:
+            runtime_warn("could not open run-settings for the advanced-persist check")
+        close_picker()
+    except Exception as e:
+        runtime_warn(f"advanced-persist check errored: {e}")
+
+    # ─────────────────────────────────────────────────────
+    # 5. Legacy migration is idempotent (gates in CI via soft_fail).
+    #    Seed a pre-feature unsloth_load_settings store, confirm it migrates once
+    #    with the value preserved, then reload with a fresh legacy seed and confirm
+    #    the migration does not re-run, duplicate, or clobber. Re-running on every
+    #    reload was the regression that reverted the predecessor PR.
+    # ─────────────────────────────────────────────────────
+    step("legacy unsloth_load_settings migrates once and stays idempotent")
+    try:
+        legacy_key = f"{GGUF_REPO}::{GGUF_VARIANT}"
+        legacy = {
+            legacy_key: {
+                "contextLength": DISTINCT_CTX,
+                "kvCacheDtype": "q8_0",
+                "tensorParallel": True,
+            }
+        }
+        robust_evaluate(
+            page,
+            "(seed) => {"
+            "  localStorage.setItem('unsloth_load_settings', JSON.stringify(seed));"
+            "  localStorage.removeItem('unsloth_model_configs');"
+            "  localStorage.removeItem('unsloth_model_configs_migrated');"
+            "  return true;"
+            "}",
+            arg = legacy,
+        )
+        page.reload()
+        composer = page.locator('textarea[aria-label="Message input"]')
+        composer.wait_for(state = "visible", timeout = 60_000)
+        # Opening the picker config forces the store to read (which migrates).
+        popover = open_picker()
+        open_config(popover, MODEL_HINT)
+        page.wait_for_timeout(800)
+        cfg_first = read_configs()
+        migrated_ctx = any(
+            e.get("customContextLength") == DISTINCT_CTX for e in config_entries(cfg_first)
+        )
+        if migrated_ctx:
+            info(f"OK migration: legacy context {DISTINCT_CTX} preserved after migrating")
+        else:
+            soft_fail(
+                f"legacy context {DISTINCT_CTX} not migrated into unsloth_model_configs "
+                f"(got {json.dumps(cfg_first)[:400]})"
+            )
+        flag_first = robust_evaluate(
+            page, "() => localStorage.getItem('unsloth_model_configs_migrated')"
+        )
+        if flag_first != "1":
+            soft_fail(f"migration flag not set after migrating (got {flag_first!r})")
+        shoot("09-after-migration")
+        close_picker()
+
+        # Idempotency: a second reload with a DIFFERENT legacy entry must not re-run
+        # the migration (the persistent flag blocks it), so the new key must not leak
+        # in, nothing duplicates, and the migrated value is untouched.
+        if migrated_ctx:
+            probe_key = "unsloth/__idem_probe__::Q4_K_M"
+            robust_evaluate(
+                page,
+                "(seed) => {"
+                "  localStorage.setItem('unsloth_load_settings', JSON.stringify(seed));"
+                "  return true;"
+                "}",
+                arg = {probe_key: {"contextLength": DISTINCT_CTX + 2048, "tensorParallel": True}},
+            )
+            page.reload()
+            composer.wait_for(state = "visible", timeout = 60_000)
+            popover = open_picker()
+            open_config(popover, MODEL_HINT)
+            page.wait_for_timeout(800)
+            cfg_second = read_configs()
+            keys_first = set(cfg_first.keys())
+            keys_second = set(cfg_second.keys())
+            new_keys = keys_second - keys_first
+            still_has_ctx = any(
+                e.get("customContextLength") == DISTINCT_CTX for e in config_entries(cfg_second)
+            )
+            if new_keys:
+                soft_fail(
+                    "legacy migration re-ran on a second reload (persistent flag "
+                    f"ignored): new keys {sorted(new_keys)}"
+                )
+            elif keys_second != keys_first:
+                soft_fail(
+                    "legacy migration dropped entries on a second reload: "
+                    f"{sorted(keys_first)} -> {sorted(keys_second)}"
+                )
+            elif not still_has_ctx:
+                soft_fail("legacy migration clobbered the migrated context on a second reload")
+            else:
+                info(
+                    "OK migration idempotent: second reload did not re-migrate, duplicate, or clobber"
+                )
+            shoot("10-after-second-reload")
+            close_picker()
+    except Exception as e:
+        soft_fail(f"migration idempotency check errored: {e}")
+
+    # ─────────────────────────────────────────────────────
+    if page_errors:
+        fail(f"page errors during run: {page_errors[:3]!r}")
+
+    browser.close()
+
+if _failed:
+    print(f"[ui-modelcfg] RESULT: FAIL ({len(_failed)} issue(s))", flush = True)
+    for m in _failed:
+        print(f"[ui-modelcfg]   - {m}", flush = True)
+    sys.exit(1)
+print("[ui-modelcfg] RESULT: PASS", flush = True)
+sys.exit(0)
diff --git a/tests/studio/playwright_ui_font_scale.py b/tests/studio/playwright_ui_font_scale.py
new file mode 100644
index 0000000000..0f14c42422
--- /dev/null
+++ b/tests/studio/playwright_ui_font_scale.py
@@ -0,0 +1,232 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""UI font size scaling regression (Settings > Appearance).
+
+Drives the real appearance controls and asserts the typography-scale
+contract: text and line heights scale by size/16, the root font size and
+layout geometry never move, an explicit Code font size stays fixed, and an
+overflowing Radix select scrolls its viewport by keyboard and wheel.
+
+Runs against an already-booted, already-bootstrapped Unsloth:
+    BASE_URL=http://127.0.0.1:18894 STUDIO_PW=... python tests/studio/playwright_ui_font_scale.py
+"""
+
+import os
+import sys
+from pathlib import Path
+
+from playwright.sync_api import sync_playwright
+
+sys.path.insert(0, str(Path(__file__).resolve().parent))
+from _playwright_robust import wait_for_health  # noqa: E402
+
+BASE = os.environ["BASE_URL"]
+PW = os.environ["STUDIO_PW"]
+ART = Path(os.environ.get("PW_ART_DIR", "logs/playwright_fontscale"))
+ART.mkdir(parents = True, exist_ok = True)
+
+SIZES = (12, 20)
+DEFAULT = 16
+
+
+def step(s):
+    print(f"[font-scale] STEP {s}", flush = True)
+
+
+def fail(m):
+    raise AssertionError(f"[font-scale] FAIL: {m}")
+
+
+def near(
+    a,
+    b,
+    tol = 0.35,
+):
+    return a is not None and b is not None and abs(a - b) <= tol
+
+
+MEASURE_JS = """
+() => {
+  const fs = (el) => (el ? parseFloat(getComputedStyle(el).fontSize) : null);
+  const lh = (el) => (el ? parseFloat(getComputedStyle(el).lineHeight) : null);
+  const byText = (txt) =>
+    [...document.querySelectorAll("span, h2, label, p")].find(
+      (e) => e.textContent.trim() === txt,
+    );
+  const nav = byText("New chat");
+  const sidebar =
+    document.querySelector("[data-slot='sidebar-container']") ??
+    document.querySelector("aside") ??
+    document.querySelector("nav");
+  return {
+    root: parseFloat(getComputedStyle(document.documentElement).fontSize),
+    uiAttr: document.documentElement.getAttribute("data-ui-font-size"),
+    navFont: fs(nav),
+    navLine: lh(nav),
+    sidebarW: sidebar ? sidebar.getBoundingClientRect().width : null,
+  };
+}
+"""
+
+
+def measure(page):
+    return page.evaluate(MEASURE_JS)
+
+
+def set_input(page, label, value):
+    field = page.locator(f"input[aria-label='{label}']")
+    field.scroll_into_view_if_needed()
+    field.fill(str(value))
+    page.keyboard.press("Enter")
+    page.wait_for_timeout(600)
+
+
+def open_appearance(page):
+    page.keyboard.press("Control+,")
+    page.wait_for_timeout(700)
+    if page.get_by_role("dialog").count() == 0:
+        page.keyboard.press("Meta+,")
+        page.wait_for_timeout(700)
+    if page.get_by_role("dialog").count() == 0:
+        fail("settings dialog did not open")
+    page.get_by_role("dialog").get_by_role("button").filter(has_text = "Appearance").first.click()
+    page.wait_for_timeout(600)
+
+
+def main():
+    wait_for_health(BASE)
+    with sync_playwright() as p:
+        browser = p.chromium.launch()
+        page = browser.new_page(viewport = {"width": 1440, "height": 900})
+        page.goto(BASE, wait_until = "networkidle")
+        pw_field = page.locator("input[type='password']")
+        if pw_field.count():
+            pw_field.first.fill(PW)
+            page.keyboard.press("Enter")
+            page.wait_for_load_state("networkidle")
+            page.wait_for_timeout(1500)
+
+        step("baseline at the default size")
+        open_appearance(page)
+        set_input(page, "UI font size", DEFAULT)
+        base = measure(page)
+        if base["root"] != 16:
+            fail(f"root font size not 16 at default: {base['root']}")
+        if base["navFont"] is None or base["sidebarW"] is None:
+            fail(f"baseline samples missing: {base}")
+
+        for size in SIZES:
+            step(f"UI font size {size}")
+            set_input(page, "UI font size", size)
+            m = measure(page)
+            ratio = size / DEFAULT
+            if m["root"] != 16:
+                fail(f"root font size moved at {size}: {m['root']}")
+            if m["uiAttr"] != str(size):
+                fail(f"data-ui-font-size wrong at {size}: {m['uiAttr']}")
+            if not near(m["navFont"], base["navFont"] * ratio):
+                fail(f"nav font at {size}: {base['navFont']} -> {m['navFont']}")
+            if not near(m["navLine"], base["navLine"] * ratio):
+                fail(f"nav line-height at {size}: {base['navLine']} -> {m['navLine']}")
+            if not near(m["sidebarW"], base["sidebarW"], 0.75):
+                fail(f"sidebar width moved at {size}: {base['sidebarW']} -> {m['sidebarW']}")
+            page.screenshot(path = str(ART / f"scale-{size}.png"))
+
+        step("explicit Code font size stays fixed under UI 20")
+        set_input(page, "Code font size", 13)
+        res = page.evaluate(
+            """
+            () => {
+              const pre = document.createElement("pre");
+              pre.textContent = "sample";
+              document.body.appendChild(pre);
+              const size = getComputedStyle(pre).fontSize;
+              pre.remove();
+              return size;
+            }
+            """
+        )
+        if res != "13px":
+            fail(f"explicit code font size scaled: {res}")
+        code_field = page.locator("input[aria-label='Code font size']")
+        code_field.fill("")
+        page.keyboard.press("Enter")
+        page.wait_for_timeout(400)
+
+        step("overflowing select scrolls its Radix viewport")
+        page.get_by_role("dialog").get_by_role("button").filter(has_text = "Voice").first.click()
+        page.wait_for_timeout(600)
+        page.set_viewport_size({"width": 1440, "height": 480})
+        page.locator("[aria-label='Dictation language']").click()
+        page.wait_for_timeout(700)
+        state = page.evaluate(
+            """
+            () => {
+              const vp = document.querySelector("[data-radix-select-viewport]");
+              return vp
+                ? { scrollable: vp.scrollHeight > vp.clientHeight, top: vp.scrollTop }
+                : null;
+            }
+            """
+        )
+        if not state or not state["scrollable"]:
+            fail(f"select viewport not scrollable: {state}")
+        for _ in range(6):
+            page.keyboard.press("ArrowDown")
+            page.wait_for_timeout(100)
+        kb_top = page.evaluate(
+            "() => document.querySelector('[data-radix-select-viewport]').scrollTop"
+        )
+        if not kb_top > 0:
+            fail(f"keyboard did not scroll the select viewport: {kb_top}")
+        vp_box = page.locator("[data-radix-select-viewport]").bounding_box()
+        page.mouse.move(vp_box["x"] + vp_box["width"] / 2, vp_box["y"] + 40)
+        page.mouse.wheel(0, -400)
+        page.wait_for_timeout(300)
+        wheel_top = page.evaluate(
+            "() => document.querySelector('[data-radix-select-viewport]').scrollTop"
+        )
+        if not wheel_top < kb_top:
+            fail(f"wheel did not scroll the select viewport: {kb_top} -> {wheel_top}")
+        page.keyboard.press("Escape")
+        page.set_viewport_size({"width": 1440, "height": 900})
+        page.wait_for_timeout(400)
+
+        step("cn keeps text-ui-* next to color classes (hub tabs)")
+        page.keyboard.press("Escape")
+        page.wait_for_timeout(400)
+        page.goto(f"{BASE}/hub", wait_until = "domcontentloaded")
+        page.wait_for_timeout(2000)
+        open_appearance(page)
+        set_input(page, "UI font size", 12)
+        page.keyboard.press("Escape")
+        page.wait_for_timeout(400)
+        tab = page.get_by_role("radio").filter(has_text = "Discover").first
+        tab.wait_for(state = "visible", timeout = 15000)
+        tab_font = tab.evaluate("el => parseFloat(getComputedStyle(el).fontSize)")
+        # text-ui-12p5 at scale 0.75; 16px means twMerge dropped the token.
+        if not near(tab_font, 12.5 * 12 / 16):
+            fail(f"hub tab font did not scale (twMerge drop?): {tab_font}")
+        page.goto(BASE, wait_until = "domcontentloaded")
+        page.wait_for_timeout(1500)
+        open_appearance(page)
+
+        step("default restores exactly")
+        page.get_by_role("dialog").get_by_role("button").filter(has_text = "Appearance").first.click()
+        page.wait_for_timeout(500)
+        set_input(page, "UI font size", DEFAULT)
+        final = measure(page)
+        for key in ("root", "navFont", "navLine", "sidebarW"):
+            if not near(final[key], base[key], 0.35):
+                fail(f"default drifted for {key}: {base[key]} -> {final[key]}")
+        if final["uiAttr"] is not None:
+            fail(f"data-ui-font-size present at default: {final['uiAttr']}")
+
+        page.screenshot(path = str(ART / "restored-default.png"))
+        browser.close()
+    print("[font-scale] PASS", flush = True)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/tests/studio/run_real_mlx_smoke.py b/tests/studio/run_real_mlx_smoke.py
index 275fe7ac57..63bc0dbba9 100644
--- a/tests/studio/run_real_mlx_smoke.py
+++ b/tests/studio/run_real_mlx_smoke.py
@@ -106,7 +106,7 @@ def _compute_loss_and_grad_norm(model, tokenizer, text: str) -> tuple[float, flo
     import mlx.nn as nn
     from mlx.utils import tree_flatten
 
-    # Match Studio's text dataset path: no EOS appended behind the user's back.
+    # Match Unsloth's text dataset path: no EOS appended behind the user's back.
     ids = list(tokenizer.encode(text))
     if len(ids) < 2:
         raise RuntimeError(f"text too short to compute loss: {len(ids)} tokens")
diff --git a/tests/studio/studio_api_smoke.py b/tests/studio/studio_api_smoke.py
index 845a9ed021..d30bd11dca 100644
--- a/tests/studio/studio_api_smoke.py
+++ b/tests/studio/studio_api_smoke.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""End-to-end Studio API & Auth HTTP integration tests against an externally-booted Studio."""
+"""End-to-end Unsloth API & Auth HTTP integration tests against an externally-booted Unsloth."""
 
 import json
 import os
@@ -571,7 +571,7 @@ EXPECTED_AUTH_ENDPOINTS = [
 for method, path in EXPECTED_AUTH_ENDPOINTS:
     if (method, path) in PUBLIC:
         continue
-    # Don't actually shut Studio down: an unauthenticated call must 401/403 before the trigger fires.
+    # Don't actually shut Unsloth down: an unauthenticated call must 401/403 before the trigger fires.
     if path == "/api/shutdown":
         code, _ = http(method, path)
         if code in (401, 403):
@@ -610,6 +610,6 @@ if _failed:
     sys.exit(1)
 _emit(
     "",
-    "PASS all Studio API & Auth assertions"
+    "PASS all Unsloth API & Auth assertions"
     + (f" ({len(_warned)} audit findings logged)" if _warned else ""),
 )
diff --git a/tests/studio/test_auth_form_input_count.py b/tests/studio/test_auth_form_input_count.py
index 4d5d72d20b..75e6cfd1fb 100644
--- a/tests/studio/test_auth_form_input_count.py
+++ b/tests/studio/test_auth_form_input_count.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 
-"""Fast source and runtime contracts for Studio's frontend authentication flows.
+"""Fast source and runtime contracts for Unsloth's frontend authentication flows.
 
 PR #5490 added a third "Current password" input, regressing first-boot UX to
 three inputs; PR #5545 restores two by rendering it only when BOOTSTRAP is absent.
diff --git a/tests/studio/test_cached_model_path_selection.py b/tests/studio/test_cached_model_path_selection.py
new file mode 100644
index 0000000000..2b6b9c7829
--- /dev/null
+++ b/tests/studio/test_cached_model_path_selection.py
@@ -0,0 +1,241 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Variant-file selection guards for the cached-model-path endpoint.
+
+The Copy path / Reveal endpoint must resolve a quant label to the same file
+the variant menus offer: MTP drafters, mmproj vision adapters, and big-endian
+builds are excluded, and directory layouts (``BF16/model-00001-of-....gguf``)
+resolve their label from the snapshot-relative path, not the basename.
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+from pathlib import Path
+from types import SimpleNamespace
+
+import pytest
+
+
+def _find_repo_root() -> Path | None:
+    env = os.environ.get("UNSLOTH_REPO_ROOT")
+    if env:
+        p = Path(env).resolve()
+        if (p / "studio" / "backend").is_dir():
+            return p
+    here = Path(__file__).resolve()
+    for parent in (here, *here.parents):
+        if (parent / "studio" / "backend").is_dir():
+            return parent
+    return None
+
+
+_REPO_ROOT = _find_repo_root()
+if _REPO_ROOT is None:
+    pytest.skip(
+        "Could not locate studio/backend. Set UNSLOTH_REPO_ROOT or run from "
+        "the repository checkout.",
+        allow_module_level = True,
+    )
+
+_STUDIO_BACKEND = _REPO_ROOT / "studio" / "backend"
+if str(_STUDIO_BACKEND) not in sys.path:
+    sys.path.insert(0, str(_STUDIO_BACKEND))
+
+pytest.importorskip("fastapi")
+pytest.importorskip("huggingface_hub")
+
+try:
+    from routes import models as routes_models
+except Exception as exc:
+    pytest.skip(f"studio backend import unavailable: {exc}", allow_module_level = True)
+
+from fastapi import HTTPException
+
+
+def test_plain_quant_label_resolves():
+    assert routes_models._main_variant_gguf_label("Model-Q8_0.gguf") == "Q8_0"
+
+
+def test_mtp_drafter_in_subdir_is_excluded():
+    assert routes_models._main_variant_gguf_label("MTP/Model-Q8_0-MTP.gguf") is None
+
+
+def test_mtp_drafter_root_prefix_is_excluded():
+    assert routes_models._main_variant_gguf_label("mtp-Model-Q8_0.gguf") is None
+
+
+def test_mmproj_adapter_is_excluded():
+    assert routes_models._main_variant_gguf_label("mmproj-Model-F16.gguf") is None
+
+
+def test_directory_layout_quant_resolves_from_parent_dir():
+    assert routes_models._main_variant_gguf_label("BF16/Model-00001-of-00002.gguf") == "BF16"
+
+
+def test_big_endian_build_is_excluded():
+    assert routes_models._main_variant_gguf_label("Model-Q8_0-BE.gguf") is None
+
+
+def test_non_gguf_file_is_excluded():
+    assert routes_models._main_variant_gguf_label("config.json") is None
+
+
+def test_normalized_quant_label_ignores_separators():
+    assert routes_models._normalized_quant_label("UD-Q4_K_XL") == "udq4kxl"
+    assert routes_models._normalized_quant_label("Q8-0") == routes_models._normalized_quant_label(
+        "Q8_0"
+    )
+
+
+def _revision(
+    snapshot: Path,
+    last_modified: float,
+    names: list[str],
+    size_on_disk: int = 4,
+) -> SimpleNamespace:
+    files = []
+    for name in names:
+        path = snapshot / name
+        path.parent.mkdir(parents = True, exist_ok = True)
+        path.write_bytes(b"x" * size_on_disk)
+        files.append(
+            SimpleNamespace(
+                file_name = name,
+                file_path = path,
+                blob_path = path,
+                size_on_disk = size_on_disk,
+            )
+        )
+    return SimpleNamespace(snapshot_path = snapshot, last_modified = last_modified, files = files)
+
+
+def _patch_cache(monkeypatch, tmp_path: Path, revisions: list[SimpleNamespace]) -> None:
+    repo = SimpleNamespace(
+        repo_id = "Org/Repo",
+        repo_type = "model",
+        repo_path = tmp_path,
+        revisions = revisions,
+    )
+    monkeypatch.setattr(
+        routes_models, "_all_hf_cache_scans", lambda: [SimpleNamespace(repos = [repo])]
+    )
+
+
+def _repo(root: Path, revisions: list[SimpleNamespace]) -> SimpleNamespace:
+    return SimpleNamespace(
+        repo_id = "Org/Repo",
+        repo_type = "model",
+        repo_path = root,
+        revisions = revisions,
+    )
+
+
+def _patch_caches(monkeypatch, repos: list[SimpleNamespace]) -> None:
+    monkeypatch.setattr(
+        routes_models,
+        "_all_hf_cache_scans",
+        lambda: [SimpleNamespace(repos = [repo]) for repo in repos],
+    )
+
+
+@pytest.mark.parametrize("newest_first", [True, False])
+def test_variant_resolves_from_newest_revision(monkeypatch, tmp_path, newest_first):
+    old = _revision(tmp_path / "snapshots" / "aaa", 1_000.0, ["Model-Q4_K_M.gguf"])
+    new = _revision(tmp_path / "snapshots" / "bbb", 2_000.0, ["Model-Q4_K_M.gguf"])
+    _patch_cache(monkeypatch, tmp_path, [new, old] if newest_first else [old, new])
+    resolved = routes_models._resolve_cached_model_path("Org/Repo", "Q4_K_M")
+    assert resolved == tmp_path / "snapshots" / "bbb" / "Model-Q4_K_M.gguf"
+
+
+def test_sharded_variant_resolves_first_split(monkeypatch, tmp_path):
+    rev = _revision(
+        tmp_path / "snapshots" / "aaa",
+        1_000.0,
+        ["Model-Q4_K_M-00002-of-00002.gguf", "Model-Q4_K_M-00001-of-00002.gguf"],
+    )
+    _patch_cache(monkeypatch, tmp_path, [rev])
+    resolved = routes_models._resolve_cached_model_path("Org/Repo", "Q4_K_M")
+    assert resolved.name == "Model-Q4_K_M-00001-of-00002.gguf"
+
+
+def test_variant_only_in_older_revision_resolves(monkeypatch, tmp_path):
+    old = _revision(tmp_path / "snapshots" / "aaa", 1_000.0, ["Model-Q4_K_M.gguf"])
+    new = _revision(tmp_path / "snapshots" / "bbb", 2_000.0, ["Model-Q8_0.gguf"])
+    _patch_cache(monkeypatch, tmp_path, [new, old])
+    resolved = routes_models._resolve_cached_model_path("Org/Repo", "Q4_K_M")
+    assert resolved == tmp_path / "snapshots" / "aaa" / "Model-Q4_K_M.gguf"
+
+
+def test_missing_newest_file_falls_back_to_older_revision(monkeypatch, tmp_path):
+    old = _revision(tmp_path / "snapshots" / "aaa", 1_000.0, ["Model-Q4_K_M.gguf"])
+    new_snapshot = tmp_path / "snapshots" / "bbb"
+    new_snapshot.mkdir(parents = True)
+    new = SimpleNamespace(
+        snapshot_path = new_snapshot,
+        last_modified = 2_000.0,
+        files = [
+            SimpleNamespace(
+                file_name = "Model-Q4_K_M.gguf",
+                file_path = new_snapshot / "Model-Q4_K_M.gguf",
+            )
+        ],
+    )
+    _patch_cache(monkeypatch, tmp_path, [new, old])
+    resolved = routes_models._resolve_cached_model_path("Org/Repo", "Q4_K_M")
+    assert resolved == tmp_path / "snapshots" / "aaa" / "Model-Q4_K_M.gguf"
+
+
+def test_variant_resolves_across_all_cache_roots(monkeypatch, tmp_path):
+    first_root = tmp_path / "active"
+    second_root = tmp_path / "default"
+    old = _revision(
+        first_root / "snapshots" / "aaa",
+        1_000.0,
+        ["Model-Q4_K_M.gguf"],
+    )
+    new = _revision(
+        second_root / "snapshots" / "bbb",
+        2_000.0,
+        ["Model-Q4_K_M.gguf"],
+    )
+    _patch_caches(
+        monkeypatch,
+        [_repo(first_root, [old]), _repo(second_root, [new])],
+    )
+    resolved = routes_models._resolve_cached_model_path("Org/Repo", "Q4_K_M")
+    assert resolved == second_root / "snapshots" / "bbb" / "Model-Q4_K_M.gguf"
+
+
+def test_repo_path_matches_largest_visible_cache_entry(monkeypatch, tmp_path):
+    first_root = tmp_path / "active"
+    second_root = tmp_path / "default"
+    small = _revision(
+        first_root / "snapshots" / "aaa",
+        2_000.0,
+        ["Model-Q8_0.gguf"],
+        size_on_disk = 4,
+    )
+    large = _revision(
+        second_root / "snapshots" / "bbb",
+        1_000.0,
+        ["Model-Q8_0.gguf"],
+        size_on_disk = 8,
+    )
+    _patch_caches(
+        monkeypatch,
+        [_repo(first_root, [small]), _repo(second_root, [large])],
+    )
+    resolved = routes_models._resolve_cached_model_path("Org/Repo", None)
+    assert resolved == second_root / "snapshots" / "bbb"
+
+
+def test_unknown_variant_raises_404(monkeypatch, tmp_path):
+    rev = _revision(tmp_path / "snapshots" / "aaa", 1_000.0, ["Model-Q8_0.gguf"])
+    _patch_cache(monkeypatch, tmp_path, [rev])
+    with pytest.raises(HTTPException) as excinfo:
+        routes_models._resolve_cached_model_path("Org/Repo", "Q4_K_M")
+    assert excinfo.value.status_code == 404
+    assert "Q4_K_M" in excinfo.value.detail
diff --git a/tests/studio/test_chat_preset_load_config.py b/tests/studio/test_chat_preset_load_config.py
new file mode 100644
index 0000000000..1588c7d96d
--- /dev/null
+++ b/tests/studio/test_chat_preset_load_config.py
@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Contract coverage for preset load settings (#7347)."""
+
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[2]
+
+
+def _read(relative: str) -> str:
+    path = ROOT / relative
+    if not path.exists():
+        path = ROOT / "unsloth_repo" / relative
+    return path.read_text(encoding = "utf-8")
+
+
+def test_preset_interface_includes_load_config():
+    policy = _read("studio/frontend/src/features/chat/presets/preset-policy.ts")
+    assert "loadConfig?: PresetLoadConfig" in policy
+
+
+def test_preset_save_captures_load_config():
+    sheet = _read("studio/frontend/src/features/chat/chat-settings-sheet.tsx")
+    assert "capturePresetLoadConfig()" in sheet
+    assert "applyPresetLoadConfig" in sheet
+
+
+def test_preset_apply_restores_load_config():
+    sheet = _read("studio/frontend/src/features/chat/chat-settings-sheet.tsx")
+    assert "if (p.loadConfig)" in sheet
+    assert "applyPresetLoadConfig(p.loadConfig)" in sheet
+
+
+def test_persisted_preset_serializes_load_config():
+    storage = _read("studio/frontend/src/features/chat/utils/chat-settings-storage.ts")
+    assert "normalizePresetLoadConfig(item.loadConfig)" in storage
+    api = _read("studio/frontend/src/features/chat/api/chat-settings-api.ts")
+    assert "loadConfig?: Record<string, unknown>" in api
+
+
+def test_capture_reads_gguf_loaded_context():
+    source = _read("studio/frontend/src/features/chat/presets/preset-load-config.ts")
+    assert "store.ggufContextLength" in source
+    assert "effectiveContextLength" in source
+
+
+def test_apply_skips_missing_load_config():
+    source = _read("studio/frontend/src/features/chat/presets/preset-load-config.ts")
+    assert "if (config == null)" in source
+    assert "selectedGpuIds: store.selectedGpuIds" in source
+    sheet = _read("studio/frontend/src/features/chat/chat-settings-sheet.tsx")
+    assert "if (p.loadConfig)" in sheet
+
+
+def test_hydration_does_not_replay_preset_load_config():
+    store = _read("studio/frontend/src/features/chat/stores/chat-runtime-store.ts")
+    assert "applyPresetLoadConfig(activeDefinition.loadConfig)" not in store
+
+
+def test_capture_coalesces_default_load_knobs():
+    source = _read("studio/frontend/src/features/chat/presets/preset-load-config.ts")
+    assert "coalesceDefaultLoadKnobs" in source
+    assert "DEFAULT_MAX_SEQ_LENGTH" in source
+
+
+def test_backend_chat_preset_accepts_load_config():
+    routes = _read("studio/backend/routes/chat_history.py")
+    assert "class ChatPresetLoadConfig" in routes
+    assert "loadConfig: Optional[ChatPresetLoadConfig]" in routes
diff --git a/tests/studio/test_chat_title_generation.py b/tests/studio/test_chat_title_generation.py
index b568a51400..6a47cfbce4 100644
--- a/tests/studio/test_chat_title_generation.py
+++ b/tests/studio/test_chat_title_generation.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved.
 
-"""Regression checks for Studio chat title generation context."""
+"""Regression checks for Unsloth chat title generation context."""
 
 from __future__ import annotations
 
diff --git a/tests/studio/test_cli_studio_stop_windows.py b/tests/studio/test_cli_studio_stop_windows.py
index 778679c73b..2267d7feda 100644
--- a/tests/studio/test_cli_studio_stop_windows.py
+++ b/tests/studio/test_cli_studio_stop_windows.py
@@ -5,7 +5,7 @@
 
 `stop` once used `os.kill(pid, 0)`, which raises WinError 87 on Windows before
 reaching taskkill; the fix adds cross-platform `_pid_alive` (tasklist on Windows,
-signal-0 elsewhere). AST + mock-only; no real processes, no Studio deps imported.
+signal-0 elsewhere). AST + mock-only; no real processes, no Unsloth deps imported.
 """
 
 import ast
diff --git a/tests/studio/test_compact_dropdown_submenus.py b/tests/studio/test_compact_dropdown_submenus.py
index c82b1e4751..a02b0d8254 100644
--- a/tests/studio/test_compact_dropdown_submenus.py
+++ b/tests/studio/test_compact_dropdown_submenus.py
@@ -22,7 +22,7 @@ def test_shared_submenu_uses_its_layout_width_on_mobile():
 
 def test_shared_submenu_never_exceeds_the_compact_viewport():
     source = DROPDOWN_MENU.read_text(encoding = "utf-8")
-    assert "max-w-[calc(100vw-2rem)]" in source
+    assert "max-w-[calc(100vw-32px)]" in source
 
 
 def test_consumers_do_not_duplicate_compact_offset_logic():
diff --git a/tests/studio/test_desktop_reliability_frontend_contract.py b/tests/studio/test_desktop_reliability_frontend_contract.py
new file mode 100644
index 0000000000..2552b6c1d8
--- /dev/null
+++ b/tests/studio/test_desktop_reliability_frontend_contract.py
@@ -0,0 +1,155 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Static contracts for focused packaged-desktop reliability behavior."""
+
+from pathlib import Path
+
+
+REPO = Path(__file__).resolve().parents[2]
+FRONTEND = REPO / "studio/frontend/src"
+NATIVE_FILES = FRONTEND / "lib/native-files.ts"
+CHAT_EXPORT = FRONTEND / "features/chat/utils/export-chat-history.ts"
+DATA_TAB = FRONTEND / "features/settings/tabs/data-tab.tsx"
+PROMPT_STORAGE = FRONTEND / "features/chat/prompt-storage/prompt-storage-dialog.tsx"
+
+APP_SIDEBAR = FRONTEND / "components/app-sidebar.tsx"
+INDEX_CSS = FRONTEND / "index.css"
+THREAD = FRONTEND / "components/assistant-ui/thread.tsx"
+THREAD_SIDEBAR = FRONTEND / "features/chat/thread-sidebar.tsx"
+SHARED_COMPOSER = FRONTEND / "features/chat/shared-composer.tsx"
+TITLEBAR = FRONTEND / "components/tauri/window-titlebar.tsx"
+NATIVE_DIALOGS = REPO / "studio/src-tauri/src/native_file_dialogs.rs"
+
+
+APP_PROVIDER = FRONTEND / "app/provider.tsx"
+
+
+def test_file_actions_route_through_native_commands_only_in_tauri():
+    helper = NATIVE_FILES.read_text(encoding = "utf-8")
+    history = CHAT_EXPORT.read_text(encoding = "utf-8")
+    data_tab = DATA_TAB.read_text(encoding = "utf-8")
+    prompt_storage = PROMPT_STORAGE.read_text(encoding = "utf-8")
+
+    projects = (FRONTEND / "features/chat/projects-page.tsx").read_text(encoding = "utf-8")
+
+    assert 'invoke<string | null>("save_native_file", bytes, {' in helper
+    assert '"x-unsloth-default-name"' in helper
+    assert "Array.from(new Uint8Array" not in helper
+    assert 'invoke<NativeChatImport | null>("pick_native_chat_import")' in helper
+    assert "if (isTauri)" in helper
+    assert 'document.createElement("a")' in helper
+    assert "DownloadCancelledError" in helper
+    assert "throw new DownloadCancelledError()" in helper
+    assert "return savedPath !== null" not in helper
+
+    assert helper.index("if (isTauri)") < helper.index("  const blob =")
+    assert "downloadFile(" in history
+    assert "downloadFile(" in prompt_storage
+    assert "pickNativeChatImport" in data_tab
+    assert "if (!isTauri)" in data_tab
+
+    assert "pickNativeChatImport" in projects
+    assert "if (!isTauri)" in projects
+    # Browser builds retain the existing hidden-input route.
+    assert 'type="file"' in data_tab
+    assert 'accept=".jsonl,.ndjson,.csv"' in data_tab
+
+    native_dialogs = NATIVE_DIALOGS.read_text(encoding = "utf-8")
+    assert 'CHAT_IMPORT_EXTENSIONS: &[&str] = &["jsonl", "ndjson", "csv"]' in native_dialogs
+    assert "InvokeBody::Raw" in native_dialogs
+
+    assert ".tempfile_in(parent)" in native_dialogs
+    assert ".persist(&path)" in native_dialogs
+    assert "fs::write(&path, content)" not in native_dialogs
+
+
+def test_chat_exports_await_native_saves_and_markdown_uses_shared_helper():
+    app_sidebar = APP_SIDEBAR.read_text(encoding = "utf-8")
+    prompt_storage = PROMPT_STORAGE.read_text(encoding = "utf-8")
+    thread = THREAD.read_text(encoding = "utf-8")
+    thread_sidebar = THREAD_SIDEBAR.read_text(encoding = "utf-8")
+    shared_composer = SHARED_COMPOSER.read_text(encoding = "utf-8")
+
+    data_tab = DATA_TAB.read_text(encoding = "utf-8")
+    projects = (FRONTEND / "features/chat/projects-page.tsx").read_text(encoding = "utf-8")
+    assert "async function downloadBlob(" in prompt_storage
+    download_blob = prompt_storage.split("async function downloadBlob(", 1)[1].split("\n}\n", 1)[0]
+    assert "return downloadFile(" in download_blob
+    assert "catch (error)" not in download_blob
+    assert "isDownloadCancelled(error)" in prompt_storage
+
+    for source in (app_sidebar, thread, thread_sidebar, shared_composer, data_tab, projects):
+        assert "isDownloadCancelled(error)" in source
+    assert "const handleExport = useCallback(async () =>" in prompt_storage
+    assert prompt_storage.count("await export") >= 12
+    assert "await Promise.all(" not in app_sidebar
+    assert "for (const id of ids)" in app_sidebar
+    assert prompt_storage.count("await downloadBlob(") >= 5
+
+    assert "await downloadBlob(zipped," in prompt_storage
+    assert "new Blob([zipped]" not in prompt_storage
+    assert "Promise.all(ids.map((id) => fn(id)))" not in thread_sidebar
+    assert "for (const id of ids)" in thread_sidebar
+    assert "Promise.all(exportThreadIds.map((id) => fn(id)))" not in shared_composer
+    assert "for (const id of exportThreadIds)" in shared_composer
+    assert "onExport={exportMessageMarkdown}" in thread
+    assert '"text/markdown"' in thread
+    assert "downloadFile(" in thread
+
+
+def test_full_app_layout_uses_its_own_initialized_marker():
+    source = APP_PROVIDER.read_text(encoding = "utf-8")
+
+    assert 'invoke<boolean>("has_initialized_app_window_layout")' in source
+    setup_layout = source.split("async function showSetupWindow", 1)[1].split(
+        "async function enforceMinimumWindowSize", 1
+    )[0]
+    reset_call = 'invoke("reset_app_window_layout_initialized")'
+    assert reset_call in setup_layout
+    assert setup_layout.index(reset_call) < setup_layout.index("win.setSize")
+    assert 'invoke("mark_app_window_layout_initialized")' in source
+    assert "hasInitializedAppLayout && hasSavedState" in source
+
+
+def test_expanded_titlebar_button_and_corner_match_sidebar_edge():
+    source = TITLEBAR.read_text(encoding = "utf-8")
+
+    assert 'pinned ? "gap-2 pl-3" : "justify-center"' in source
+    assert "gap-2 px-3" not in source
+    assert "const contentBorderLeft = pinned" in source
+    assert ': "0px";' in source
+    # The curved transition and sidebar-colored backing are expanded-only;
+    # collapsed content is square and its divider spans the sidebar too.
+    assert source.count("{showSidebarSurface && pinned && (") == 2
+    assert (
+        'className="pointer-events-none absolute top-full size-3 -translate-x-px bg-sidebar"'
+        in source
+    )
+    assert (
+        'className="pointer-events-none absolute top-full size-3 -translate-x-px rounded-tl-[12px] border-l border-t border-sidebar-border bg-background"'
+        in source
+    )
+
+
+def test_chat_sidebar_row_actions_visible_on_coarse_pointers():
+    """unslothai/unsloth#7276: Recents chat kebab must be tappable on iPad."""
+    sidebar_source = APP_SIDEBAR.read_text(encoding = "utf-8")
+    css_source = INDEX_CSS.read_text(encoding = "utf-8")
+    assert "renderChatSidebarItem" in sidebar_source
+    block = sidebar_source.split("function renderChatSidebarItem", 1)[1].split("\n  function ", 1)[
+        0
+    ]
+    assert "[@media(pointer:coarse)]:pr-10" in block
+    assert "sidebar-touch-reveal" in block
+    # Coarse-pointer visibility must come after .sidebar-row-action { opacity-0 }.
+    coarse_idx = css_source.index("@media (pointer: coarse)")
+    base_idx = css_source.index(".sidebar-row-action {")
+    assert coarse_idx > base_idx
+    coarse_block = css_source[coarse_idx : coarse_idx + 280]
+    assert "sidebar-touch-reveal" in coarse_block
+    assert "opacity-100" in coarse_block
+    assert "pointer-events-auto" in coarse_block
+    # Must not reveal every sidebar-row-action (project/run/nav rows lack padding).
+    assert ".sidebar-row-action {\n\t\t\t@apply opacity-100" not in coarse_block
+    assert ".sidebar-row-action.sidebar-touch-reveal" in coarse_block
diff --git a/tests/studio/test_gpu_inference_smoke.py b/tests/studio/test_gpu_inference_smoke.py
new file mode 100644
index 0000000000..a28166e1e0
--- /dev/null
+++ b/tests/studio/test_gpu_inference_smoke.py
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Fast, GPU-gated real-inference smoke.
+
+GitHub-hosted CI runners have no GPU, so this AUTO-SKIPS there; the full picker
+-> load -> chat flow is covered on CPU by tests/studio/playwright_model_config.py
+and studio-ui-smoke.yml. This test adds a quick real-generation check for local
+dev and self-hosted GPU runners: it loads the smallest model (gemma-3-270m-it)
+on the GPU and does a single short greedy generation, asserting a non-empty
+reply. Kept deliberately short (a handful of new tokens) so it is a confidence
+check, not a benchmark. Select/deselect it by name, e.g. `-k gpu_generation`.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+torch = pytest.importorskip("torch")
+
+# Smallest instruct model in the CI fixture family; ~270M params loads and
+# generates a few tokens in seconds on any GPU.
+MODEL_ID = "unsloth/gemma-3-270m-it"
+# A handful of forced real tokens: enough to prove GPU decode produced content,
+# short enough to stay a few seconds.
+MIN_NEW_TOKENS = 4
+MAX_NEW_TOKENS = 16
+
+
+@pytest.mark.skipif(not torch.cuda.is_available(), reason = "requires a CUDA GPU")
+def test_gpu_generation_smoke():
+    try:
+        from transformers import AutoModelForCausalLM, AutoTokenizer
+    except Exception as exc:  # pragma: no cover - env without transformers
+        pytest.skip(f"transformers unavailable: {exc}")
+
+    # Gemma is numerically unstable in fp16 (it emits only <pad>); use bf16 where
+    # supported, else fp32. The model is tiny, so fp32 is still fast.
+    dtype = torch.bfloat16 if torch.cuda.is_bf16_supported() else torch.float32
+    try:
+        tokenizer = AutoTokenizer.from_pretrained(MODEL_ID)
+        model = AutoModelForCausalLM.from_pretrained(MODEL_ID, dtype = dtype).to("cuda")
+    except Exception as exc:  # offline / gated / download failure is not a code defect
+        pytest.skip(f"could not fetch/load {MODEL_ID}: {exc}")
+
+    model.eval()
+    messages = [{"role": "user", "content": "Say hello in one word."}]
+    inputs = tokenizer.apply_chat_template(
+        messages, add_generation_prompt = True, return_dict = True, return_tensors = "pt"
+    ).to("cuda")
+    prompt_len = inputs["input_ids"].shape[1]
+
+    with torch.no_grad():
+        output = model.generate(
+            **inputs,
+            min_new_tokens = MIN_NEW_TOKENS,
+            max_new_tokens = MAX_NEW_TOKENS,
+            do_sample = False,
+        )
+
+    # The model produced new tokens on the GPU (the real inference proof)...
+    assert output.shape[1] > prompt_len, "no tokens were generated on the GPU"
+    # ...and they decode to non-empty text (min_new_tokens forces real content).
+    reply = tokenizer.decode(output[0][prompt_len:], skip_special_tokens = True)
+    assert reply.strip(), "expected a non-empty GPU generation"
diff --git a/tests/studio/test_hardware_dispatch_matrix.py b/tests/studio/test_hardware_dispatch_matrix.py
index bccddac967..19619bc318 100644
--- a/tests/studio/test_hardware_dispatch_matrix.py
+++ b/tests/studio/test_hardware_dispatch_matrix.py
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: AGPL-3.0-only
-"""Studio hardware dispatch matrix: spoofs platform/torch/mlx per PROFILES to exercise CUDA/ROCm/XPU/MLX/CPU paths without real hardware."""
+"""Unsloth hardware dispatch matrix: spoofs platform/torch/mlx per PROFILES to exercise CUDA/ROCm/XPU/MLX/CPU paths without real hardware."""
 
 from __future__ import annotations
 
@@ -31,9 +31,9 @@ class HardwareProfile:
     mps_available: bool  # torch.backends.mps.is_available() value
 
     expect_is_mlx: bool  # unsloth._IS_MLX
-    expect_device_type: str  # Studio DeviceType (uppercased name: "CUDA"/"XPU"/"MLX"/"CPU")
-    expect_is_rocm: bool  # Studio IS_ROCM
-    expect_apple_silicon: bool  # Studio is_apple_silicon()
+    expect_device_type: str  # Unsloth DeviceType (uppercased name: "CUDA"/"XPU"/"MLX"/"CPU")
+    expect_is_rocm: bool  # Unsloth IS_ROCM
+    expect_apple_silicon: bool  # Unsloth is_apple_silicon()
     extra_notes: str = ""
 
 
@@ -66,7 +66,7 @@ PROFILES = [
         expect_is_rocm = True,
         expect_apple_silicon = False,
         extra_notes = "PyTorch ROCm reuses torch.cuda.* over HIP; "
-        "Studio still uses DeviceType.CUDA but flips IS_ROCM=True.",
+        "Unsloth still uses DeviceType.CUDA but flips IS_ROCM=True.",
     ),
     HardwareProfile(
         name = "intel_xpu",
@@ -154,7 +154,7 @@ def spoof_hardware(monkeypatch):
         import platform
         import torch
 
-        # platform spoof (used by both the unsloth gate and Studio's helpers)
+        # platform spoof (used by both the unsloth gate and Unsloth's helpers)
         monkeypatch.setattr(platform, "system", lambda: profile.system)
         monkeypatch.setattr(platform, "machine", lambda: profile.machine)
 
@@ -227,7 +227,7 @@ def spoof_hardware(monkeypatch):
 
             monkeypatch.setattr(importlib.util, "find_spec", _no_mlx)
 
-            # Studio's _has_mlx() does `import mlx.core`, not find_spec; block it
+            # Unsloth's _has_mlx() does `import mlx.core`, not find_spec; block it
             # with a meta_path finder that raises ImportError for mlx.*.
             class _BlockMLXFinder:
                 def find_spec(
@@ -266,7 +266,7 @@ def _evaluate_unsloth_is_mlx_gate() -> bool:
 
 
 def _import_studio_hardware_module():
-    """Lazy-load Studio's hardware module under the bare-imports layout."""
+    """Lazy-load Unsloth's hardware module under the bare-imports layout."""
     if str(STUDIO_BACKEND) not in sys.path:
         sys.path.insert(0, str(STUDIO_BACKEND))
     # Fresh import so detect_hardware re-runs under the current spoofs.
@@ -290,7 +290,7 @@ def test_unsloth_is_mlx_gate_matches_profile(profile, spoof_hardware):
 
 @pytest.mark.parametrize("profile", PROFILES, ids = PROFILE_IDS)
 def test_studio_detect_hardware_matches_profile(profile, spoof_hardware):
-    """Studio's detect_hardware() routes to the right DeviceType per profile."""
+    """Unsloth's detect_hardware() routes to the right DeviceType per profile."""
     spoof_hardware(profile)
     hw = _import_studio_hardware_module()
     detected = hw.detect_hardware()
@@ -306,7 +306,7 @@ def test_studio_detect_hardware_matches_profile(profile, spoof_hardware):
 
 @pytest.mark.parametrize("profile", PROFILES, ids = PROFILE_IDS)
 def test_studio_is_apple_silicon_matches_profile(profile, spoof_hardware):
-    """Studio's is_apple_silicon() helper agrees with platform spoof."""
+    """Unsloth's is_apple_silicon() helper agrees with platform spoof."""
     spoof_hardware(profile)
     hw = _import_studio_hardware_module()
     assert hw.is_apple_silicon() is profile.expect_apple_silicon, (
diff --git a/tests/studio/test_hf_token_validation_tick_contract.py b/tests/studio/test_hf_token_validation_tick_contract.py
new file mode 100644
index 0000000000..a381101801
--- /dev/null
+++ b/tests/studio/test_hf_token_validation_tick_contract.py
@@ -0,0 +1,28 @@
+"""Contracts for the Hugging Face token validation indicator."""
+
+from pathlib import Path
+
+
+REPO = Path(__file__).resolve().parents[2]
+GENERAL_TAB = REPO / "studio/frontend/src/features/settings/tabs/general-tab.tsx"
+VALIDATION_HOOK = REPO / "studio/frontend/src/hooks/use-hf-token-validation.ts"
+
+
+def test_success_tick_requires_the_current_token_to_be_validated():
+    source = GENERAL_TAB.read_text(encoding = "utf-8")
+
+    assert "tokenIsCurrent && tokenValidation.isValid === true" in source
+    assert 'tokenValidated ? "pr-14" : "pr-8"' in source
+    assert "{tokenValidated ? (" in source
+    assert 'aria-label={t("settings.general.tokenValidated")}' in source
+    assert 'aria-label={t("settings.general.tokenSaved")}' not in source
+
+
+def test_validation_result_must_belong_to_the_current_normalized_token():
+    source = VALIDATION_HOOK.read_text(encoding = "utf-8")
+
+    assert "const normalizedToken = token.trim()" in source
+    assert "useDebouncedValue(normalizedToken, 500)" in source
+    assert "if (!COMPLETE_HF_TOKEN.test(normalizedToken)) return INITIAL" in source
+    assert "if (completed.token !== normalizedToken)" in source
+    assert "if (completed.token !== debouncedToken)" not in source
diff --git a/tests/studio/test_install_rollback_lifecycle.ps1 b/tests/studio/test_install_rollback_lifecycle.ps1
new file mode 100644
index 0000000000..d70f384ca7
--- /dev/null
+++ b/tests/studio/test_install_rollback_lifecycle.ps1
@@ -0,0 +1,126 @@
+#!/usr/bin/env pwsh
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+# Unit tests for install.ps1's venv rollback helpers. The functions are AST-extracted
+# so the top-level installer is never executed.
+
+$ErrorActionPreference = "Stop"
+$installPath = [System.IO.Path]::Combine($PSScriptRoot, "..", "..", "install.ps1")
+$installPath = (Resolve-Path $installPath).Path
+
+$tokens = $null; $errors = $null
+$ast = [System.Management.Automation.Language.Parser]::ParseFile($installPath, [ref]$tokens, [ref]$errors)
+if ($errors) { $errors | ForEach-Object { $_.ToString() }; throw "install.ps1 has parse errors" }
+
+$helperNames = @(
+    "Start-StudioVenvRollback",
+    "Remove-StudioVenvTreeWithRetry",
+    "Test-StudioVenvRollbackMustBePreserved",
+    "Remove-StaleStudioVenvRollbacks",
+    "Restore-StudioVenvRollback",
+    "Complete-StudioVenvRollback"
+)
+foreach ($name in $helperNames) {
+    $fn = $ast.FindAll({ param($node)
+        $node -is [System.Management.Automation.Language.FunctionDefinitionAst] -and $node.Name -eq $name
+    }, $true)
+    if ($fn.Count -ne 1) { throw "expected exactly one $name in install.ps1, found $($fn.Count)" }
+    Invoke-Expression $fn[0].Extent.Text
+}
+
+function substep { param([string]$Message, [string]$Color) }
+
+$failures = 0
+function Check($name, $condition) {
+    if ($condition) { Write-Host "  PASS  $name" }
+    else { Write-Host "  FAIL  $name" -ForegroundColor Red; $script:failures++ }
+}
+
+function Reset-RollbackState($target) {
+    $script:StudioVenvRollbackDir = $null
+    $script:StudioVenvRollbackTarget = $target
+    $script:StudioVenvRollbackActive = $false
+}
+
+$StudioHome = Join-Path ([System.IO.Path]::GetTempPath()) "unsloth-rollback-$([guid]::NewGuid().ToString('N'))"
+$VenvDir = Join-Path $StudioHome "unsloth_studio"
+[System.IO.Directory]::CreateDirectory($VenvDir) | Out-Null
+
+try {
+    Write-Host "Successful replacement"
+    [System.IO.File]::WriteAllText((Join-Path $VenvDir "generation"), "old")
+    Reset-RollbackState $VenvDir
+    Start-StudioVenvRollback -ExistingDir $VenvDir
+    [System.IO.Directory]::CreateDirectory($VenvDir) | Out-Null
+    [System.IO.File]::WriteAllText((Join-Path $VenvDir "generation"), "new")
+    Complete-StudioVenvRollback
+    Check "new environment remains" ((Get-Content -LiteralPath (Join-Path $VenvDir "generation") -Raw) -eq "new")
+    Check "current rollback is removed" (-not @(Get-ChildItem -LiteralPath $StudioHome -Directory |
+        Where-Object { $_.Name -like "unsloth_studio.rollback.*" }))
+
+    Write-Host "Stale cleanup"
+    $stale = Join-Path $StudioHome "unsloth_studio.rollback.20000101000000.2147483647"
+    $active = Join-Path $StudioHome "unsloth_studio.rollback.20000101000001.$PID"
+    $unrecognized = Join-Path $StudioHome "unsloth_studio.rollback.user-data"
+    [System.IO.Directory]::CreateDirectory($stale) | Out-Null
+    [System.IO.Directory]::CreateDirectory($active) | Out-Null
+    [System.IO.Directory]::CreateDirectory($unrecognized) | Out-Null
+    Remove-StaleStudioVenvRollbacks
+    Check "dead-owner rollback is removed" (-not (Test-Path -LiteralPath $stale))
+    Check "live-owner rollback is preserved" (Test-Path -LiteralPath $active)
+    Check "unrecognized rollback name is preserved" (Test-Path -LiteralPath $unrecognized)
+    Microsoft.PowerShell.Management\Remove-Item -LiteralPath $active -Recurse -Force
+    Microsoft.PowerShell.Management\Remove-Item -LiteralPath $unrecognized -Recurse -Force
+
+    Write-Host "Failure restoration"
+    [System.IO.File]::WriteAllText((Join-Path $VenvDir "generation"), "old-again")
+    Reset-RollbackState $VenvDir
+    $committed = $false
+    try {
+        try {
+            Start-StudioVenvRollback -ExistingDir $VenvDir
+            [System.IO.Directory]::CreateDirectory($VenvDir) | Out-Null
+            [System.IO.File]::WriteAllText((Join-Path $VenvDir "generation"), "partial")
+            throw "simulated install failure"
+        } finally {
+            if (-not $committed) { Restore-StudioVenvRollback }
+        }
+    } catch {
+        if ($_.Exception.Message -ne "simulated install failure") { throw }
+    }
+    Check "finally restores the previous environment" (
+        (Get-Content -LiteralPath (Join-Path $VenvDir "generation") -Raw) -eq "old-again"
+    )
+    Check "failure restoration consumes the rollback" (-not @(Get-ChildItem -LiteralPath $StudioHome -Directory |
+        Where-Object { $_.Name -like "unsloth_studio.rollback.*" }))
+
+    Write-Host "Locked-file retry"
+    $retryDir = Join-Path $StudioHome "retry"
+    [System.IO.Directory]::CreateDirectory($retryDir) | Out-Null
+    $script:removeAttempts = 0
+    function Remove-Item {
+        param(
+            [string]$LiteralPath,
+            [switch]$Recurse,
+            [switch]$Force,
+            [object]$ErrorAction
+        )
+        $script:removeAttempts++
+        if ($script:removeAttempts -lt 3) { throw "simulated lock" }
+        Microsoft.PowerShell.Management\Remove-Item -LiteralPath $LiteralPath -Recurse:$Recurse -Force:$Force
+    }
+    try {
+        $removed = Remove-StudioVenvTreeWithRetry -Path $retryDir -Label "test rollback"
+    } finally {
+        Microsoft.PowerShell.Management\Remove-Item -LiteralPath Function:\Remove-Item -Force
+    }
+    Check "locked rollback deletion retries" ($removed -and $script:removeAttempts -eq 3)
+} finally {
+    if (Test-Path -LiteralPath $StudioHome) {
+        Microsoft.PowerShell.Management\Remove-Item -LiteralPath $StudioHome -Recurse -Force
+    }
+}
+
+Write-Host ""
+if ($failures -gt 0) { Write-Host "$failures check(s) FAILED" -ForegroundColor Red; exit 1 }
+Write-Host "All checks passed" -ForegroundColor Green
diff --git a/tests/studio/test_is_mlx_dispatch_gate.py b/tests/studio/test_is_mlx_dispatch_gate.py
index f31f6d1655..0e5de1b789 100644
--- a/tests/studio/test_is_mlx_dispatch_gate.py
+++ b/tests/studio/test_is_mlx_dispatch_gate.py
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
-"""Regression tests for the CUDA-vs-MLX dispatch gates Studio relies on.
+"""Regression tests for the CUDA-vs-MLX dispatch gates Unsloth relies on.
 
 Two gates: (1) ``unsloth._IS_MLX`` (import-time, delegates to the zoo MLX
 runtime gate behind a local precheck barrier); (2)
@@ -147,7 +147,7 @@ def test_is_mlx_gate_false_on_non_apple_silicon():
 
 
 def _import_studio_hardware():
-    """Lazy import of the Studio hardware module (studio/backend on sys.path)."""
+    """Lazy import of the Unsloth hardware module (studio/backend on sys.path)."""
     studio_backend = REPO_ROOT / "studio" / "backend"
     if str(studio_backend) not in sys.path:
         sys.path.insert(0, str(studio_backend))
diff --git a/tests/studio/test_llama_cpp_wall_clock_cap.py b/tests/studio/test_llama_cpp_wall_clock_cap.py
index f173cfbc55..b7b6917092 100644
--- a/tests/studio/test_llama_cpp_wall_clock_cap.py
+++ b/tests/studio/test_llama_cpp_wall_clock_cap.py
@@ -1,4 +1,4 @@
-"""Timeout policy checks for Studio's local llama-server path."""
+"""Timeout policy checks for Unsloth's local llama-server path."""
 
 from __future__ import annotations
 
diff --git a/tests/studio/test_locale_root_direction_contract.py b/tests/studio/test_locale_root_direction_contract.py
index 1baabdbbca..20d10aa805 100644
--- a/tests/studio/test_locale_root_direction_contract.py
+++ b/tests/studio/test_locale_root_direction_contract.py
@@ -1,4 +1,4 @@
-"""Regression guard for locale changes affecting the entire Studio layout."""
+"""Regression guard for locale changes affecting the entire Unsloth layout."""
 
 from pathlib import Path
 
diff --git a/tests/studio/test_model_picker_contracts.py b/tests/studio/test_model_picker_contracts.py
new file mode 100644
index 0000000000..3934b72d83
--- /dev/null
+++ b/tests/studio/test_model_picker_contracts.py
@@ -0,0 +1,475 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Source-contract guards for the model-picker per-model-config feature.
+
+These are cheap, CPU-only, no-browser checks that read the frontend source and
+assert the specific fixes that got the predecessor PR reverted stay in place. If
+a future edit reverts one of them (e.g. rounds the context ceiling up again, or
+puts the HF token back in the URL), the matching assertion reddens. They pair
+with the runtime Playwright checks (which prove the behavior end to end) and the
+backend pytest checks (which prove the backend logic).
+"""
+
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+WORKDIR = Path(__file__).resolve().parents[2]
+FRONTEND = WORKDIR / "studio" / "frontend" / "src"
+
+
+def _read(rel: str) -> str:
+    path = FRONTEND / rel
+    assert path.exists(), f"missing source file: {path}"
+    return path.read_text()
+
+
+def test_models_api_sends_token_via_header_not_query():
+    """getModelConfig / checkVisionModel / checkEmbeddingModel must pass the HF
+    token through hubTokenHeader, never as a ?hf_token= query param (which leaks
+    the credential into server/proxy access logs)."""
+    src = _read("features/training/api/models-api.ts")
+    assert src.count("hubTokenHeader(") >= 3
+    assert "hf_token=" not in src
+    assert '"hf_token"' not in src and "'hf_token'" not in src
+
+
+def test_model_metadata_probe_never_puts_token_in_query():
+    src = _read("features/model-picker/api/model-metadata.ts")
+    assert "hf_token=" not in src
+    assert '"hf_token"' not in src and "'hf_token'" not in src
+
+
+def test_model_config_page_floors_the_context_ceiling():
+    """The model's native max-context must be FLOORED to the step grid, never
+    rounded up (rounding up can offer/persist a length above the model's real
+    ceiling and break loading)."""
+    src = _read("features/model-picker/components/model-config-page.tsx")
+    assert "floorMaxSeqLength(modelMaxPosition.maxPositionEmbeddings)" in src
+    assert "normalizeMaxSeqLength(modelMaxPosition.maxPositionEmbeddings)" not in src
+
+
+def test_compare_load_clears_stale_native_lease():
+    """A compare-pane load never comes from the desktop file picker, so it must
+    clear any prior picked file's lease token + expiry, otherwise a reload can
+    send a stale lease for the now-active model."""
+    src = _read("features/chat/shared-composer.tsx")
+    assert "activeNativePathToken: null" in src
+    assert "activeNativePathExpiresAtMs: null" in src
+
+
+def test_autoload_records_backend_loaded_model_identity():
+    """An inactive-cache inventory row loads by local path, so startup autoload
+    must key both the active checkpoint and its summary by the backend's loaded
+    model identity instead of the catalog repo id."""
+    src = _read("features/chat/api/chat-adapter.ts")
+    autoload = src.split("async function loadAutoLoadCandidate", 1)[1]
+    autoload = autoload.split("\n  try {", 1)[0]
+    assert "const loadedModelId = loadResp.model || modelPath" in autoload
+    assert "setCheckpoint(loadedModelId," in autoload
+    assert "id: loadedModelId" in autoload
+    assert "m.id === loadedModelId" in autoload
+
+
+def test_rollback_restores_native_lease_expiry_with_token():
+    """A failed model switch that rolls back to a previously loaded picked GGUF
+    must restore the lease expiry paired with the token, never the token alone
+    (which would look non-expiring and skip the expiry guard)."""
+    src = _read("features/chat/hooks/use-chat-model-runtime.ts")
+    assert "previousActiveNativePathExpiresAtMs" in src
+    assert re.search(
+        r"activeNativePathExpiresAtMs:\s*previousActiveNativePathToken", src
+    ), "rollback must restore the expiry alongside the token"
+
+
+def test_default_caches_keyed_on_inventory_version():
+    """The chat-template and max-position caches must key on the inventory
+    version so a model update in the same session invalidates the cached value
+    instead of showing the stale revision."""
+    src = _read("features/model-picker/hooks/use-model-defaults.ts")
+    # Both cache keys (template + max-position) end with the inventory version.
+    assert src.count("${inventoryVersion}") >= 2
+
+
+def test_hidden_infra_model_needles_present():
+    """The frontend static needle list must keep hiding the RAG embedder and the
+    llama.cpp validation probe."""
+    src = _read("features/hub/lib/hidden-models.ts")
+    assert '"bge-small-en-v1.5"' in src
+    assert '"ggml-org/models"' in src
+    assert '"stories260k.gguf"' in src
+
+
+def test_hidden_models_dynamic_exact_ids_wired():
+    """The configured embedder arrives from /api/hub/hidden-models as exact
+    repo ids; a substring needle would let a generic basename like "model"
+    hide unrelated chat models."""
+    src = _read("features/hub/lib/hidden-models.ts")
+    assert "toLowerStrings(data.exact_ids)" in src
+    assert "dynamicExactIds.includes(lower)" in src
+
+
+def test_hidden_model_matchers_refresh_with_inventory_version():
+    src = _read("features/hub/lib/hidden-models.ts")
+    assert "const version = getInventoryVersion()" in src
+    assert "matchersFetchVersion === version" in src
+    assert "getInventoryVersion() !== version" in src
+
+
+def test_diffusion_capability_labeled_image_generation():
+    """The diffusion capability detects image GENERATORS (FLUX, SDXL,
+    text-to-image tags); labeling it "Image to text" showed generators when
+    users asked for captioning models."""
+    for rel in (
+        "features/hub/lib/model-capabilities.ts",
+        "features/hub/lib/model-type-filter.ts",
+        "features/hub/lib/view-models.ts",
+    ):
+        src = _read(rel)
+        assert "Image to text" not in src, rel
+        assert "Image generation" in src, rel
+
+
+def test_active_model_config_round_trips_gpu_fields():
+    """The active model's config must carry the GPU Memory knobs (GGUF only) so
+    a sidebar/hub-gear reload cannot silently reset manual GPU settings, and
+    "Remember settings" cannot persist a GPU-less config over a saved one."""
+    src = _read("features/model-picker/hooks/use-active-model-config.ts")
+    for field in ("gpuMemoryMode", "gpuLayers", "nCpuMoe", "selectedGpuIds"):
+        assert field in src, field
+    assert "if (!isGguf)" in src and "return base" in src
+    for rel in (
+        "features/chat/chat-page.tsx",
+        "features/hub/catalog/sampling-settings-dialog.tsx",
+    ):
+        assert "useActiveModelConfig(" in _read(rel), rel
+    signature = _read("features/model-picker/components/sidebar-model-config.tsx")
+    assert "gpuFieldsSignature(config)" in signature
+    shared = _read("features/model-picker/model-config/apply-per-model-config.ts")
+    assert "export function gpuFieldsSignature" in shared
+
+
+def test_gpu_picker_round_trips_requested_pool_not_fitted_subset():
+    """A GGUF fit may narrow [0, 1] to [0], but load/status hydration must keep
+    [0, 1] as the editable pool so a later reload can grow back onto GPU 1."""
+    types = _read("features/chat/types/api.ts")
+    assert types.count("requested_gpu_ids?: number[] | null") >= 2
+
+    store = _read("features/chat/stores/chat-runtime-store.ts")
+    assert "resp.requested_gpu_ids ?? resp.gpu_ids ?? null" in store
+
+    status = _read("features/chat/lib/apply-inference-status-to-store.ts")
+    assert "status.requested_gpu_ids ?? status.gpu_ids ?? null" in status
+
+
+def test_compare_load_uses_each_models_gpu_config():
+    src = _read("features/chat/shared-composer.tsx")
+    assert "ownConfig.gpuMemoryMode ?? compareLoadKnobs.gpuMemoryMode" in src
+    assert "ownConfig.gpuLayers ?? compareLoadKnobs.gpuLayers" in src
+    assert "ownConfig.nCpuMoe ?? compareLoadKnobs.nCpuMoe" in src
+    assert "if (ownConfig.selectedGpuIds != null)" in src
+    assert "reconcilePersistedGpuIds(ownConfig.selectedGpuIds)" in src
+    for field in (
+        "gpu_memory_mode: effectiveGpuMemoryMode",
+        "gpu_layers: effectiveGpuLayers",
+        "n_cpu_moe: effectiveNCpuMoe",
+        "gpu_ids: effectiveSelectedGpuIds ?? undefined",
+    ):
+        assert field in src
+
+
+def test_active_native_gguf_metadata_uses_path_token():
+    src = _read("features/model-picker/components/model-config-page.tsx")
+    assert "(isActiveModel ? activeNativePathToken : null)" in src
+    assert "target.meta.nativePathToken ??" in src
+    assert "nativePathToken," in src
+    assert '${nativePathToken ?? ""}' in src
+
+
+def test_model_default_hooks_do_not_reset_state_in_effect():
+    src = _read("features/model-picker/hooks/use-model-defaults.ts")
+    assert "setFetched(null)" not in src
+
+
+def test_variant_expander_refreshes_after_delete():
+    """Deleting a downloaded quant from an expanded repo that still has other
+    cached quants must bump the expander refresh key, or the deleted quant stays
+    shown as downloaded and clickable and tries to reload the removed file."""
+    src = _read("features/model-picker/components/model-selector/pickers.tsx")
+    del_confirm = re.search(
+        r"await onDeleteVariant\(v\.quant\);.*?setRefreshKey\(\(key\) => key \+ 1\)",
+        src,
+        re.S,
+    )
+    assert del_confirm, "delete onConfirm must bump refreshKey after a successful delete"
+
+
+def test_local_picker_rows_require_chat_capability():
+    """Local inventory rows can be classified non-chat (canChat false, e.g. a
+    folder with only config.json). The picker must filter those out, or selecting
+    one loads a weightless path; toLocalModelInfo drops capabilities so the memo
+    is the only place the guard can live."""
+    src = _read("features/model-picker/inventory/use-chat-picker-inventory.ts")
+    memo = re.search(r"const localModels = useMemo\(.*?\[inventory\.localRows\]", src, re.S)
+    assert memo, "localModels memo not found"
+    assert "row.capabilities.canChat" in memo.group(0)
+
+
+def test_model_picker_toolbar_reflows_before_crossing_picker_edge():
+    """The content-sized section tabs and fixed-width dropdowns must reflow,
+    while an oversized tab group must shrink labels but preserve its icons."""
+    picker = _read("features/model-picker/components/model-selector/pickers.tsx")
+    assert '"flex flex-wrap items-center gap-2"' in picker
+    assert 'hasConnected ? "-mr-4" : "-mr-2"' in picker
+    assert '"flex max-w-full min-w-0 flex-wrap items-center gap-2"' in picker
+
+    tabs = _read("features/model-picker/components/model-selector/pill-tabs.tsx")
+    assert 'fit ? "min-w-0 shrink" : "min-w-0 flex-1"' in tabs
+    assert '<span className="min-w-0 truncate">{tab.label}</span>' in tabs
+
+    selector = _read("features/model-picker/components/model-selector.tsx")
+    assert 'icon={StarIcon} className="size-3.5 shrink-0"' in selector
+    assert 'icon={Download01Icon} className="size-3.5 shrink-0"' in selector
+    assert 'icon={CloudIcon} className="size-3.5 shrink-0"' in selector
+
+
+def test_native_picked_gguf_template_read_through_lease():
+    """A native (picked / drag-drop) GGUF's path lives only in its signed lease,
+    and the picker chat-template GET has no lease plumbing, so the default
+    template must be read through the lease-aware validate probe: mint a
+    validate-model lease and post include_chat_template. The native token also
+    has to reach the fetch (threaded through the hook) and be part of the cache
+    key so two picks of the same basename don't share a template."""
+    api = _read("features/model-picker/api/templates.ts")
+    assert 'consumeNativePathToken(nativePathToken, "validate-model")' in api
+    assert "include_chat_template: true" in api
+    assert "/api/inference/validate" in api
+    hook = _read("features/model-picker/hooks/use-model-defaults.ts")
+    assert "nativePathToken," in hook
+    assert '${nativePathToken ?? ""}' in hook
+
+
+def test_model_load_guard_is_cross_instance():
+    """The in-flight load guard must consult the shared store pick (not only the
+    per-hook ref) and ejectModel must refuse while any instance is loading:
+    three live useChatModelRuntime instances exist (chat page, hub page, hub
+    gear dialog)."""
+    src = _read("features/chat/hooks/use-chat-model-runtime.ts")
+    assert "useChatRuntimeStore.getState().loadingModelPick" in src
+    assert "clearLoadingModelPick" in src
+    eject_body = src.split("const ejectModel", 1)[1]
+    assert "loadingModelPick" in eject_body.split("ejectModel,", 1)[0]
+
+
+def test_partial_safetensors_download_keeps_delete_menu():
+    """A stopped partial safetensors download must keep its options menu (the
+    Delete affordance) like the GGUF card does, or partial downloads can only
+    be cleaned up by finishing or leaving them. During an ACTIVE download the
+    menu stays hidden (every item would be disabled: no Copy path while not
+    downloaded, no Delete while downloading, pin suppressed in the run bar)."""
+    src = _read("features/hub/catalog/safetensors-download-card.tsx")
+    assert "(isDownloaded || (isPartial && !downloading))" in src
+
+
+def test_pinned_validation_uses_cached_local_variant_listing():
+    """Pinned-quant validation must use the TTL-cached hub client with
+    preferLocalCache (downloaded-ness is local state) instead of one uncached
+    round-trip per pinned repo on every picker open. Picker deletes must go
+    through the hub inventory client, whose delete invalidates both the
+    variants TTL cache and the server-side HF cache scan (the legacy
+    /api/models/delete-cached route invalidates neither, so a post-delete
+    inventory refresh would resurrect the deleted row until the scan TTL)."""
+    src = _read("features/model-picker/components/model-selector/pickers.tsx")
+    assert "listGgufVariantsCached(" in src
+    assert "preferLocalCache: true" in src
+    assert re.search(r'import \{[^}]*\bdeleteCachedModel\b[^}]*\} from "@/features/hub"', src)
+    hub_api = _read("features/hub/inventory/api.ts")
+    delete_fn = hub_api.split("export async function deleteCachedModel", 1)[1]
+    delete_fn = delete_fn.split("export ", 1)[0]
+    assert "invalidateGgufVariantsCache(" in delete_fn
+    assert "bumpInventoryVersion(" in delete_fn
+
+
+def test_chat_autoload_scopes_variant_lookup_to_cached_repo_path():
+    """Autoload must probe the exact cache row it will load, including rows
+    retained from a previously selected Hugging Face cache."""
+    src = _read("features/chat/api/chat-adapter.ts")
+    auto_load = src.split("async function autoLoadSmallestModel", 1)[1]
+    assert auto_load.count("preferLocalCache: true") >= 2
+    assert auto_load.count("localPath: repo.cache_path") >= 2
+
+    chat_api = _read("features/chat/api/chat-api.ts")
+    variants_fn = chat_api.split("export async function listGgufVariants", 1)[1]
+    variants_fn = variants_fn.split("export interface KvCacheEstimate", 1)[0]
+    assert 'params.set("prefer_local_cache", "true")' in variants_fn
+    assert 'params.set("local_path", localPath)' in variants_fn
+
+
+def test_cache_location_update_invalidates_frontend_inventory():
+    """A successful cache switch must refresh both inventory rows and cached
+    GGUF variant results before any stale active-cache identity can be reused."""
+    src = _read("features/settings/api/hugging-face-cache.ts")
+    update_fn = src.split("export async function updateHuggingFaceCacheSettings", 1)[1]
+    assert "bumpInventoryVersion();" in update_fn
+    assert "invalidateGgufVariantsCache();" in update_fn
+
+
+def test_downloaded_list_offsets_virtual_rows():
+    """The On Device virtualized list sits below the Pinned block in the same
+    scroll element, so it must pass its measured offset as scrollMargin or rows
+    past the overscan render blank."""
+    src = _read("features/hub/catalog/models-catalog-lists.tsx")
+    assert "scrollMargin={scrollMargin}" in src
+
+
+def test_local_gguf_diagnostics_gate_on_broad_is_gguf():
+    """The MTP fallback note and the context/VRAM warning must gate on the broad
+    isGguf (variant, loaded gguf context, or .gguf suffix), not the variant-only
+    isLoadedGguf, so direct-file and custom-folder GGUF loads keep those
+    diagnostics."""
+    src = _read("features/chat/chat-settings-sheet.tsx")
+    spec = re.search(r"const showSpecFallback =.*?;", src, re.S)
+    vram = re.search(r"const showContextVramWarning =.*?;", src, re.S)
+    assert spec and "isGguf &&" in spec.group(0) and "isLoadedGguf" not in spec.group(0)
+    assert vram and "isGguf &&" in vram.group(0) and "isLoadedGguf" not in vram.group(0)
+
+
+def test_fixed_layer_gguf_pins_displayed_context():
+    """An already-loaded auto-fit GGUF saved with Manual fixed GPU layers must
+    pin the shown context, so a later fresh load keeps the fitted placement
+    instead of sending native/0 and recreating the OOM."""
+    src = _read("features/model-picker/components/model-config-page.tsx")
+    assert "const pinFixedLayerContext =" in src
+    assert 'config.gpuMemoryMode === "manual"' in src
+    assert "customContextLength: activeLoadedContext" in src
+
+
+def test_auto_defaults_not_persisted_as_overrides():
+    """Auto GPU memory mode and Auto/default speculative type are follow-global
+    defaults; normalization must not persist them as per-model overrides, else a
+    model stops following later changes to the global preference."""
+    src = _read("features/model-picker/model-config/per-model-config.ts")
+    assert 'if (partial.gpuMemoryMode === "manual") {' in src
+    assert 'partial.gpuMemoryMode === "auto" || partial.gpuMemoryMode === "manual"' not in src
+    spec = re.search(r'if \(s === "auto" \|\| s === "default"\) \{\s*return ([^;]+);', src)
+    assert spec and spec.group(1).strip() == "null"
+
+
+def test_compare_pane_context_from_own_config_only():
+    """A compare pane's context comes from its own config only (a saved pin, else
+    null for Auto/native); it must not inherit the active model's shared snapshot,
+    which resolveFitMaxSeqLength would treat as an explicit pin (VRAM/OOM)."""
+    src = _read("features/chat/shared-composer.tsx")
+    assert "const effectiveCustomContextLength = ownConfig.customContextLength;" in src
+    assert "compareLoadKnobs.customContextLength" not in src
+
+
+def test_reset_max_seq_length_falls_back_to_app_default():
+    """After Reset clears maxSeqLength (null), a non-GGUF active model's shown
+    max sequence length must fall back to the app default, never the loaded
+    runtime snapshot, or a remembered/active override can never be cleared."""
+    src = _read("features/model-picker/components/model-config-page.tsx")
+    # The null fallback resolves to the app-default constant, not a runtime value.
+    assert "clampMaxSeqLength(DEFAULT_MAX_SEQ_LENGTH, nativeMaxSeqLength)" in src
+    # The buggy runtime-seeded fallback must not come back.
+    assert "clampMaxSeqLength(initialMaxSeqLength" not in src
+
+
+def test_reset_persists_null_max_length_and_substitutes_only_for_load():
+    """The persisted per-model record must keep config.maxSeqLength (null after
+    Reset) so isDefaultConfig can clear a remembered override; the concrete
+    fallback is substituted only into the load request, not the saved record."""
+    src = _read("features/model-picker/components/model-config-page.tsx")
+    # Load-only substitution of the resolved value.
+    assert "maxSeqLength: maxSeqLengthValue" in src
+    assert "const loadConfig" in src
+    # The persisted record is loaded via onRun(loadConfig), and save uses the
+    # untouched runtimeConfig (so a reset/default config stays default).
+    assert "onRun(loadConfig)" in src
+    assert "savePerModelConfig(" in src
+
+
+def test_reset_enabled_for_explicit_context_pin_at_native():
+    """An explicit customContextLength that equals the native ceiling is still a
+    user override, so contextAtDefault must require customContextLength == null.
+    The buggy form treated `contextValue === native` alone as default, wedging
+    the Reset button disabled for a deliberate pin-to-native."""
+    src = " ".join(_read("features/model-picker/components/model-config-page.tsx").split())
+    assert (
+        "const contextAtDefault = !target.isGguf || "
+        "(config.customContextLength == null && "
+        "(nativeContextLength == null || contextValue === nativeContextLength));" in src
+    )
+    # The old form that ignored an explicit pin equal to native must not return.
+    assert (
+        "(nativeContextLength == null ? config.customContextLength == null : "
+        "contextValue === nativeContextLength)" not in src
+    )
+    # The app-default constant is the single source of truth (imported, not local).
+    assert "DEFAULT_MAX_SEQ_LENGTH," in src
+    assert "const DEFAULT_MAX_SEQ_LENGTH = 4096" not in src
+
+
+def test_compare_pane_non_gguf_falls_back_to_app_default():
+    """A non-GGUF compare pane with no saved maxSeqLength must fall back to the
+    shared app default, not the active model's runtime snapshot; otherwise an
+    unconfigured pane inherits a saved 128K neighbor's context and can OOM."""
+    per_model = _read("features/model-picker/model-config/per-model-config.ts")
+    assert "export const DEFAULT_MAX_SEQ_LENGTH = 4096;" in per_model
+    barrel = _read("features/model-picker/index.ts")
+    assert "DEFAULT_MAX_SEQ_LENGTH," in barrel
+    src = " ".join(_read("features/chat/shared-composer.tsx").split())
+    assert "DEFAULT_MAX_SEQ_LENGTH," in src
+    assert (
+        "const effectiveMaxSeqLength = ownConfig.customContextLength ?? "
+        "normalizeMaxSeqLength(ownConfig.maxSeqLength) ?? "
+        "(isGgufLoad ? 0 : DEFAULT_MAX_SEQ_LENGTH);" in src
+    )
+    # The buggy fallback to the active model's shared runtime value must not return.
+    assert "(isGgufLoad ? 0 : maxSeqLength)" not in src
+    assert "const maxSeqLength = store.params.maxSeqLength;" not in src
+
+
+def test_default_gpu_mode_clears_manual_knobs():
+    """Switching GPU Memory back to Default must clear the Manual-only knobs
+    (gpuLayers/nCpuMoe/selectedGpuIds); otherwise a remembered config keeps stale
+    pins that a later load re-applies when the global preference is Manual."""
+    src = _read("features/model-picker/components/model-config-page.tsx")
+    assert 'gpuMemoryMode: "auto",' in src
+    assert "gpuLayers: undefined," in src
+    assert "nCpuMoe: undefined," in src
+    assert "selectedGpuIds: undefined," in src
+
+
+def test_legacy_migration_is_idempotent_and_non_destructive():
+    """The v1->v2 localStorage migration (unsloth_load_settings ->
+    unsloth_model_configs) is invoked on every store read, so it must be
+    idempotent: repeated reads, browser reloads, and Studio restarts must never
+    re-migrate, duplicate records, or overwrite a newer per-model config. This
+    was the class of regression that reverted the predecessor PR, so pin all
+    three idempotency layers at source level; dropping any of them reddens here.
+    """
+    raw = _read("features/model-picker/model-config/per-model-config.ts")
+    src = " ".join(raw.split())
+    # Migration runs from readMap (every store read), so it must be safe to repeat.
+    assert (
+        "function readMap(): StoredMap { migrateLegacyLoadSettingsOnce(); "
+        "return readMapRaw(); }" in src
+    )
+    # Layer 1: in-memory once-per-session guard so repeated readMap() calls
+    # migrate at most once.
+    assert "let legacyMigrationChecked = false;" in src
+    assert "if (legacyMigrationChecked || !canUseStorage()) {" in src
+    assert "legacyMigrationChecked = true;" in src
+    # Layer 2: persistent cross-session flag so a completed migration is never
+    # redone. Set in every terminal branch (malformed data, nothing to migrate,
+    # successful write); a failed quota write leaves it unset so the next session
+    # retries. Three set-sites encode exactly that.
+    assert 'const LEGACY_MIGRATION_FLAG = "unsloth_model_configs_migrated";' in src
+    assert "if (localStorage.getItem(LEGACY_MIGRATION_FLAG)) {" in src
+    assert src.count('localStorage.setItem(LEGACY_MIGRATION_FLAG, "1");') >= 3
+    # Layer 3: non-overwriting merge skips an existing (or default) key, so even a
+    # forced re-run cannot duplicate or clobber a user's config.
+    assert "if (isDefaultConfig(migrated) || Object.hasOwn(map, key)) {" in src
diff --git a/tests/studio/test_node_decision.ps1 b/tests/studio/test_node_decision.ps1
index bd5d5c8677..44f3ef0e1e 100644
--- a/tests/studio/test_node_decision.ps1
+++ b/tests/studio/test_node_decision.ps1
@@ -60,7 +60,7 @@ $globalBunOffset = $source.IndexOf('npm install -g bun')
 Check "NodeSource initialized before SKIP_STUDIO_FRONTEND branch" (
     $nodeSourceOffset -ge 0 -and $skipFrontendBranchOffset -ge 0 -and $nodeSourceOffset -lt $skipFrontendBranchOffset
 )
-Check "custom Studio home validated before Node parent creation" (
+Check "custom Unsloth home validated before Node parent creation" (
     $customHomeErrorOffset -ge 0 -and $nodeParentMkdirOffset -ge 0 -and $customHomeErrorOffset -lt $nodeParentMkdirOffset
 )
 Check "bundled Node pins npm prefix and clears NODE_PATH" (
diff --git a/tests/studio/test_remote_connection_models_contract.py b/tests/studio/test_remote_connection_models_contract.py
new file mode 100644
index 0000000000..47124541e0
--- /dev/null
+++ b/tests/studio/test_remote_connection_models_contract.py
@@ -0,0 +1,61 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Static contracts for remote connection model persistence (#7281)."""
+
+from pathlib import Path
+
+
+REPO = Path(__file__).resolve().parents[2]
+FRONTEND = REPO / "studio/frontend/src"
+PROVIDERS_API = FRONTEND / "features/chat/api/providers-api.ts"
+SYNC_PROVIDERS = FRONTEND / "features/chat/sync-external-providers.ts"
+CHAT_PAGE = FRONTEND / "features/chat/chat-page.tsx"
+PROVIDERS_DB = REPO / "studio/backend/storage/providers_db.py"
+PROVIDERS_MODELS = REPO / "studio/backend/models/providers.py"
+
+
+def test_providers_db_stores_model_json_columns():
+    source = PROVIDERS_DB.read_text(encoding = "utf-8")
+    assert "models_json" in source
+    assert "available_models_json" in source
+    assert "ALTER TABLE llm_providers ADD COLUMN models_json" in source
+
+
+def test_provider_api_schemas_expose_models():
+    source = PROVIDERS_MODELS.read_text(encoding = "utf-8")
+    assert "models: list[str]" in source
+    assert "available_models: list[str]" in source
+
+
+def test_frontend_sync_prefers_server_models_on_remote_clients():
+    source = SYNC_PROVIDERS.read_text(encoding = "utf-8")
+    assert "config.models" in source
+    assert "config.available_models" in source
+    assert "serverModels.length > 0" in source
+
+
+def test_frontend_sync_backfills_local_models_to_backend():
+    source = SYNC_PROVIDERS.read_text(encoding = "utf-8")
+    assert "updateProviderConfig" in source
+    assert "needsModelBackfill" in source
+    assert "Promise.allSettled(backfillTasks)" in source
+
+
+def test_frontend_sync_preserves_local_provider_options():
+    source = SYNC_PROVIDERS.read_text(encoding = "utf-8")
+    assert "mergeLocalProviderOptions" in source
+    assert "promptCacheTtl" in source
+    assert "openaiContainerTtlMinutes" in source
+
+
+def test_chat_page_hydrates_connections_on_startup():
+    source = CHAT_PAGE.read_text(encoding = "utf-8")
+    assert "syncExternalProvidersFromBackend" in source
+    assert "await hydratePersistedSettings()" in source
+
+
+def test_providers_api_sends_models_to_backend():
+    source = PROVIDERS_API.read_text(encoding = "utf-8")
+    assert "available_models: payload.availableModels" in source
+    assert "models: payload.models" in source
diff --git a/tests/studio/test_reveal_file_manager.py b/tests/studio/test_reveal_file_manager.py
new file mode 100644
index 0000000000..8a1df586e5
--- /dev/null
+++ b/tests/studio/test_reveal_file_manager.py
@@ -0,0 +1,128 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Platform guards for the reveal-in-file-manager endpoint.
+
+A stock WSL distro has no Linux desktop, so the generic Linux branch
+(``xdg-open``) fails there. Under WSL the reveal must route through Windows
+interop (``wslpath -w`` + ``explorer.exe``), fall back to ``xdg-open`` when
+interop is unavailable, and leave native Linux behavior unchanged.
+"""
+
+from __future__ import annotations
+
+import os
+import subprocess
+import sys
+import types
+from pathlib import Path
+
+import pytest
+
+
+def _find_repo_root() -> Path | None:
+    env = os.environ.get("UNSLOTH_REPO_ROOT")
+    if env:
+        p = Path(env).resolve()
+        if (p / "studio" / "backend").is_dir():
+            return p
+    here = Path(__file__).resolve()
+    for parent in (here, *here.parents):
+        if (parent / "studio" / "backend").is_dir():
+            return parent
+    return None
+
+
+_REPO_ROOT = _find_repo_root()
+if _REPO_ROOT is None:
+    pytest.skip(
+        "Could not locate studio/backend. Set UNSLOTH_REPO_ROOT or run from "
+        "the repository checkout.",
+        allow_module_level = True,
+    )
+
+_STUDIO_BACKEND = _REPO_ROOT / "studio" / "backend"
+if str(_STUDIO_BACKEND) not in sys.path:
+    sys.path.insert(0, str(_STUDIO_BACKEND))
+
+pytest.importorskip("fastapi")
+pytest.importorskip("huggingface_hub")
+
+try:
+    from routes import models as routes_models
+    from utils.paths import path_utils
+except Exception as exc:
+    pytest.skip(f"studio backend import unavailable: {exc}", allow_module_level = True)
+
+_WINDOWS_PATH = r"\\wsl.localhost\Distro\cache\model.gguf"
+
+
+@pytest.fixture()
+def linux_host(monkeypatch):
+    monkeypatch.setattr(sys, "platform", "linux")
+    monkeypatch.setattr(os, "name", "posix")
+
+
+@pytest.fixture()
+def spawned(monkeypatch):
+    calls = types.SimpleNamespace(run = [], popen = [], run_error = None)
+
+    def fake_run(cmd, **kwargs):
+        calls.run.append(list(cmd))
+        if calls.run_error is not None:
+            raise calls.run_error
+        return types.SimpleNamespace(stdout = _WINDOWS_PATH + "\n")
+
+    def fake_popen(cmd, **kwargs):
+        calls.popen.append(list(cmd))
+        return types.SimpleNamespace()
+
+    monkeypatch.setattr(subprocess, "run", fake_run)
+    monkeypatch.setattr(subprocess, "Popen", fake_popen)
+    return calls
+
+
+def test_wsl_file_is_selected_in_explorer(linux_host, spawned, monkeypatch, tmp_path):
+    monkeypatch.setattr(path_utils, "_IS_WSL", True)
+    target = tmp_path / "model.gguf"
+    target.write_bytes(b"gguf")
+    routes_models._reveal_in_file_manager(target)
+    assert spawned.run == [["wslpath", "-w", str(target)]]
+    assert spawned.popen == [["explorer.exe", f"/select,{_WINDOWS_PATH}"]]
+
+
+def test_wsl_directory_opens_in_explorer(linux_host, spawned, monkeypatch, tmp_path):
+    monkeypatch.setattr(path_utils, "_IS_WSL", True)
+    routes_models._reveal_in_file_manager(tmp_path)
+    assert spawned.popen == [["explorer.exe", _WINDOWS_PATH]]
+
+
+def test_wsl_without_interop_falls_back_to_xdg_open(linux_host, spawned, monkeypatch, tmp_path):
+    monkeypatch.setattr(path_utils, "_IS_WSL", True)
+    spawned.run_error = FileNotFoundError("wslpath")
+    target = tmp_path / "model.gguf"
+    target.write_bytes(b"gguf")
+    routes_models._reveal_in_file_manager(target)
+    assert spawned.popen == [["xdg-open", str(tmp_path)]]
+
+
+def test_wsl_empty_conversion_falls_back_to_xdg_open(linux_host, spawned, monkeypatch, tmp_path):
+    monkeypatch.setattr(path_utils, "_IS_WSL", True)
+
+    def empty_run(cmd, **kwargs):
+        return types.SimpleNamespace(stdout = "\n")
+
+    monkeypatch.setattr(subprocess, "run", empty_run)
+    routes_models._reveal_in_file_manager(tmp_path)
+    assert spawned.popen == [["xdg-open", str(tmp_path)]]
+
+
+def test_native_linux_keeps_xdg_open_on_parent_directory(
+    linux_host, spawned, monkeypatch, tmp_path
+):
+    monkeypatch.setattr(path_utils, "_IS_WSL", False)
+    target = tmp_path / "model.gguf"
+    target.write_bytes(b"gguf")
+    routes_models._reveal_in_file_manager(target)
+    assert spawned.run == []
+    assert spawned.popen == [["xdg-open", str(tmp_path)]]
diff --git a/tests/studio/test_setup_pin_stale.ps1 b/tests/studio/test_setup_pin_stale.ps1
new file mode 100644
index 0000000000..2c92ae317f
--- /dev/null
+++ b/tests/studio/test_setup_pin_stale.ps1
@@ -0,0 +1,114 @@
+#!/usr/bin/env pwsh
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+# Unit test for studio/setup.ps1's pinned-torch-index stale-venv helpers
+# (Test-RocmGfx211Leaf, Test-CudaFamilyLeaf, Get-RocmPinStaleTags). Pure helpers,
+# AST-extracted and run in-process. Mirrors the Python _rocm_pin_family_mismatch /
+# _is_cuda_family_leaf tests.
+# Run: pwsh -NoProfile -File tests/studio/test_setup_pin_stale.ps1
+
+$ErrorActionPreference = "Stop"
+$setupPath = [System.IO.Path]::Combine($PSScriptRoot, "..", "..", "studio", "setup.ps1")
+$setupPath = (Resolve-Path $setupPath).Path
+
+# --- Parse setup.ps1 (also serves as a syntax gate) and extract the helpers ---
+$tokens = $null; $errors = $null
+$ast = [System.Management.Automation.Language.Parser]::ParseFile($setupPath, [ref]$tokens, [ref]$errors)
+if ($errors) { $errors | ForEach-Object { $_.ToString() }; throw "setup.ps1 has parse errors" }
+
+foreach ($name in @("Test-RocmGfx211Leaf", "Test-RocmKnown211Version", "Test-CudaFamilyLeaf", "Get-RocmPinStaleTags")) {
+    $fn = $ast.FindAll({ param($n)
+        $n -is [System.Management.Automation.Language.FunctionDefinitionAst] -and $n.Name -eq $name
+    }, $true)
+    if ($fn.Count -ne 1) { throw "expected exactly one $name in setup.ps1, found $($fn.Count)" }
+    # Pure helpers (no exit / external calls) -- safe to define in this scope.
+    Invoke-Expression $fn[0].Extent.Text
+}
+
+$failures = 0
+function Check($name, $cond) {
+    if ($cond) { Write-Host "  PASS  $name" }
+    else { Write-Host "  FAIL  $name" -ForegroundColor Red; $script:failures++ }
+}
+
+# A pinned gfx/rocm index is stale when Expected != Installed.
+function IsStale($leaf, $ver) {
+    $t = Get-RocmPinStaleTags -PinLeaf $leaf -TorchVersion $ver
+    return $t.Expected -ne $t.Installed
+}
+
+Write-Host "Test-RocmGfx211Leaf (the 2.11 gfx allowlist)"
+Check "gfx1151 -> true"        (Test-RocmGfx211Leaf "gfx1151")
+Check "gfx1150 -> true"        (Test-RocmGfx211Leaf "gfx1150")
+Check "gfx120x-all -> true"    (Test-RocmGfx211Leaf "gfx120x-all")
+Check "gfx110x-all -> false"   (-not (Test-RocmGfx211Leaf "gfx110x-all"))
+Check "gfx90a -> false"        (-not (Test-RocmGfx211Leaf "gfx90a"))
+Check "gfx908 -> false"        (-not (Test-RocmGfx211Leaf "gfx908"))
+
+Write-Host "Test-CudaFamilyLeaf (^cu[0-9])"
+Check "cu118 -> true"          (Test-CudaFamilyLeaf "cu118")
+Check "cu128 -> true"          (Test-CudaFamilyLeaf "cu128")
+Check "cu130 -> true"          (Test-CudaFamilyLeaf "cu130")
+Check "custom -> false"        (-not (Test-CudaFamilyLeaf "custom"))
+Check "current -> false"       (-not (Test-CudaFamilyLeaf "current"))
+Check "cpu -> false"           (-not (Test-CudaFamilyLeaf "cpu"))
+Check "empty -> false"         (-not (Test-CudaFamilyLeaf ""))
+
+Write-Host "Get-RocmPinStaleTags (mirror of _rocm_pin_family_mismatch)"
+# Exact rocm version comparison.
+Check "rocm7.2 pin + 2.11.0+rocm7.2 -> not stale"  (-not (IsStale "rocm7.2" "2.11.0+rocm7.2"))
+Check "rocm7.2 pin + 2.10.0+rocm6.4 -> stale"      (IsStale "rocm7.2" "2.10.0+rocm6.4")
+Check "rocm6.4 pin + 2.10.0+rocm6.4 -> not stale"  (-not (IsStale "rocm6.4" "2.10.0+rocm6.4"))
+# rocm7.2 is a KNOWN-2.11 index. A +rocm7.2 wheel whose RELEASE drifted off 2.11 shares
+# the tag but violates the spec -> stale (mirror of _rocm_pin_family_mismatch).
+Check "rocm7.2 pin + 2.12.0+rocm7.2 -> stale"      (IsStale "rocm7.2" "2.12.0+rocm7.2")
+Check "rocm7.2 pin + 2.13.0+rocm7.2 -> stale"      (IsStale "rocm7.2" "2.13.0+rocm7.2")
+Check "rocm7.2 pin + 2.11.5+rocm7.2 -> not stale"  (-not (IsStale "rocm7.2" "2.11.5+rocm7.2"))
+# An UNKNOWN newer rocm (off the 2.11 allowlist) isn't floored, so a matching version at
+# any release line is NOT stale on this exact-compare branch.
+Check "rocm8.0 pin + 2.12.0+rocm8.0 -> not stale"  (-not (IsStale "rocm8.0" "2.12.0+rocm8.0"))
+# An untagged (no +rocm) wheel never satisfies a ROCm pin -> always stale.
+Check "rocm7.2 pin + 2.10.0 (untagged) -> stale"   (IsStale "rocm7.2" "2.10.0")
+Check "rocm7.2 pin + 2.11.0 (untagged) -> stale"   (IsStale "rocm7.2" "2.11.0")
+Check "rocm6.4 pin + 2.10.0 (untagged) -> stale"   (IsStale "rocm6.4" "2.10.0")
+# 2.11-allowlist gfx pin: per-arch (three-part) wheel is satisfied, generic is stale.
+Check "gfx1151 pin + 2.11.0+rocm7.13.0 -> not stale"   (-not (IsStale "gfx1151" "2.11.0+rocm7.13.0"))
+Check "gfx1150 pin + 2.11.0+rocm7.13.0 -> not stale"   (-not (IsStale "gfx1150" "2.11.0+rocm7.13.0"))
+Check "gfx120x-all pin + 2.11.0+rocm7.13.0 -> not stale" (-not (IsStale "gfx120x-all" "2.11.0+rocm7.13.0"))
+Check "gfx1151 pin + 2.11.0+rocm7.2 (generic) -> stale" (IsStale "gfx1151" "2.11.0+rocm7.2")
+Check "gfx1151 pin + 2.10.0+rocm6.4 -> stale"           (IsStale "gfx1151" "2.10.0+rocm6.4")
+# Non-2.11 gfx pin (gfx110X-all/gfx90a/gfx908): a valid <2.11 wheel is NOT stale.
+Check "gfx110x-all pin + 2.10.0+rocm6.4 -> not stale"  (-not (IsStale "gfx110x-all" "2.10.0+rocm6.4"))
+Check "gfx90a pin + 2.10.0+rocm6.3 -> not stale"       (-not (IsStale "gfx90a" "2.10.0+rocm6.3"))
+Check "gfx908 pin + 2.10.0+rocm7.0 -> not stale"       (-not (IsStale "gfx908" "2.10.0+rocm7.0"))
+Check "gfx110x-all pin + 2.11.0+rocm7.2 -> stale"      (IsStale "gfx110x-all" "2.11.0+rocm7.2")
+# Non-2.11 gfx pin over an untagged wheel: never satisfies the pin -> stale, so the
+# explicit ROCm index is applied even when torch is already <2.11.
+Check "gfx110x-all pin + 2.10.0 (untagged) -> stale"   (IsStale "gfx110x-all" "2.10.0")
+Check "gfx90a pin + 2.10.0 (untagged) -> stale"        (IsStale "gfx90a" "2.10.0")
+# Capital gfx120X-all is lowercased by Get-TorchIndexLeaf before this helper, so the
+# 2.11-allowlist branch fires and a generic/untagged wheel is stale.
+Check "gfx120x-all pin + 2.11.0+rocm7.2 (generic) -> stale" (IsStale "gfx120x-all" "2.11.0+rocm7.2")
+Check "gfx120x-all pin + 2.10.0 (untagged) -> stale"        (IsStale "gfx120x-all" "2.10.0")
+
+# Major-only rocm pin (rocm7): majors compared alone; mirrors _rocm_pin_family_mismatch.
+Check "rocm7 pin + 2.10.0+rocm6.4 -> stale"           (IsStale "rocm7" "2.10.0+rocm6.4")
+Check "rocm7 pin + 2.11.0+rocm7.2 -> not stale"       (-not (IsStale "rocm7" "2.11.0+rocm7.2"))
+Check "rocm7 pin + 2.11.0+rocm7.13.0 -> not stale"    (-not (IsStale "rocm7" "2.11.0+rocm7.13.0"))
+Check "rocm7 pin + 2.10.0 (untagged) -> stale"        (IsStale "rocm7" "2.10.0")
+Check "rocm7 pin + 2.10.0+rocm (unreadable) -> not stale" (-not (IsStale "rocm7" "2.10.0+rocm"))
+
+Write-Host "Test-RocmKnown211Version + KNOWN-2.11 fallback (rocm7.2 only; no speculative rocm7.3)"
+Check "rocm7.2 -> known 2.11"  (Test-RocmKnown211Version -Major 7 -Minor 2)
+Check "rocm7.1 -> not known"   (-not (Test-RocmKnown211Version -Major 7 -Minor 1))
+Check "rocm7.3 -> not known"   (-not (Test-RocmKnown211Version -Major 7 -Minor 3))
+Check "rocm8.0 -> not known"   (-not (Test-RocmKnown211Version -Major 8 -Minor 0))
+# Unreadable-installed fallback: a rocm7.3 pin (unknown -> <2.11 line) over a <2.11 +rocm
+# wheel with an unreadable version is NOT stale; rocm7.2 (KNOWN-2.11) over the same wheel
+# IS stale (#2534 alignment).
+Check "rocm7.3 pin + 2.10.0+rocm (unreadable ver) -> not stale" (-not (IsStale "rocm7.3" "2.10.0+rocm"))
+Check "rocm7.2 pin + 2.10.0+rocm (unreadable ver) -> stale"     (IsStale "rocm7.2" "2.10.0+rocm")
+
+Write-Host ""
+if ($failures -gt 0) { Write-Host "$failures check(s) FAILED" -ForegroundColor Red; exit 1 }
+Write-Host "All checks passed" -ForegroundColor Green
diff --git a/tests/studio/test_studio_gguf_export_script_pin.py b/tests/studio/test_studio_gguf_export_script_pin.py
index 1f7e7adaa4..defd0d49d4 100644
--- a/tests/studio/test_studio_gguf_export_script_pin.py
+++ b/tests/studio/test_studio_gguf_export_script_pin.py
@@ -1,4 +1,4 @@
-"""Studio GGUF export pins convert_hf_to_gguf.py via UNSLOTH_LLAMA_CPP_SCRIPTS_DIR, with a once-per-process warning fallback when unsloth_zoo lacks the local-script resolver."""
+"""Unsloth GGUF export pins convert_hf_to_gguf.py via UNSLOTH_LLAMA_CPP_SCRIPTS_DIR, with a once-per-process warning fallback when unsloth_zoo lacks the local-script resolver."""
 
 from __future__ import annotations
 
diff --git a/tests/studio/test_studio_text_descender_clipping.py b/tests/studio/test_studio_text_descender_clipping.py
index 7cad6cacfe..98fb3b4b13 100644
--- a/tests/studio/test_studio_text_descender_clipping.py
+++ b/tests/studio/test_studio_text_descender_clipping.py
@@ -1,4 +1,4 @@
-"""Regression guard: Studio text spans must not pair `leading-none` with
+"""Regression guard: Unsloth text spans must not pair `leading-none` with
 `truncate`, which clips glyph descenders (g, p, q, y, j) in visible labels.
 """
 
@@ -10,7 +10,14 @@ from pathlib import Path
 
 WORKDIR = Path(__file__).resolve().parents[2]
 MODEL_SELECTOR = (
-    WORKDIR / "studio" / "frontend" / "src" / "components" / "assistant-ui" / "model-selector.tsx"
+    WORKDIR
+    / "studio"
+    / "frontend"
+    / "src"
+    / "features"
+    / "model-picker"
+    / "components"
+    / "model-selector.tsx"
 )
 APP_SIDEBAR = WORKDIR / "studio" / "frontend" / "src" / "components" / "app-sidebar.tsx"
 
@@ -23,7 +30,7 @@ def _read(path: Path) -> str:
 def test_model_selector_trigger_label_uses_leading_tight():
     src = _read(MODEL_SELECTOR)
     pattern = re.compile(
-        r'<span\s+className="[^"]*\bmin-w-0\b[^"]*\bflex-1\b[^"]*\btruncate\b[^"]*\bfont-heading\b[^"]*\btext-\[16px\][^"]*"',
+        r'<span\s+className="[^"]*\bmin-w-0\b[^"]*\bflex-1\b[^"]*\btruncate\b[^"]*\bfont-heading\b[^"]*\btext-ui-16[^"]*"',
     )
     matches = pattern.findall(src)
     assert matches, "could not find ModelSelectorTrigger model-name span"
@@ -34,17 +41,22 @@ def test_model_selector_trigger_label_uses_leading_tight():
 
 def test_sidebar_account_block_uses_leading_tight():
     src = _read(APP_SIDEBAR)
-    # Match the account-block parent div regardless of its gap utility; this
-    # guard is about the leading-* class, not the spacing.
-    pattern = re.compile(
-        r'<div\s+className="flex\s+flex-col\s+gap-\S+\s+(\S+)\s+group-data-\[collapsible=icon\]:hidden">',
-    )
-    matches = pattern.findall(src)
+    class_names = re.findall(r'<div\s+className="([^"]+)"', src)
+    required = {
+        "flex",
+        "flex-1",
+        "flex-col",
+        "group-data-[collapsible=icon]:hidden",
+    }
+    matches = [classes for classes in class_names if required <= set(classes.split())]
     assert matches, "could not find sidebar account-block parent div"
-    leading_classes = [m for m in matches if m.startswith("leading-")]
-    assert leading_classes, f"no leading-* class on sidebar account-block parent: {matches}"
-    for cls in leading_classes:
-        assert cls == "leading-tight", f"sidebar account-block must use leading-tight, got: {cls}"
+    for classes in matches:
+        leading_classes = [cls for cls in classes.split() if cls.startswith("leading-")]
+        assert leading_classes, f"no leading-* class on sidebar account-block parent: {classes}"
+        for cls in leading_classes:
+            assert (
+                cls == "leading-tight"
+            ), f"sidebar account-block must use leading-tight, got: {cls}"
 
 
 def test_no_truncate_plus_leading_none_in_changed_files():
diff --git a/tests/studio/test_torch_flavor.ps1 b/tests/studio/test_torch_flavor.ps1
index 50be4814b0..f2cc55c21c 100644
--- a/tests/studio/test_torch_flavor.ps1
+++ b/tests/studio/test_torch_flavor.ps1
@@ -15,7 +15,7 @@ $tokens = $null; $errors = $null
 $ast = [System.Management.Automation.Language.Parser]::ParseFile($installPath, [ref]$tokens, [ref]$errors)
 if ($errors) { $errors | ForEach-Object { $_.ToString() }; throw "install.ps1 has parse errors" }
 
-foreach ($name in @("ConvertTo-TorchFlavorTag", "Get-ExpectedTorchFlavorTag")) {
+foreach ($name in @("ConvertTo-TorchFlavorTag", "Get-ExpectedTorchFlavorTag", "Trim-IndexPathSlashes", "Redact-InstallOutput")) {
     $fn = $ast.FindAll({ param($n)
         $n -is [System.Management.Automation.Language.FunctionDefinitionAst] -and $n.Name -eq $name
     }, $true)
@@ -49,6 +49,19 @@ Check "mirror cu130 leaf -> cu130"   ((Get-ExpectedTorchFlavorTag -TorchIndexUrl
 Check "unrecognized leaf -> null"    ($null -eq (Get-ExpectedTorchFlavorTag -TorchIndexUrl "https://my.mirror/whl/simple"))
 Check "empty url -> null"            ($null -eq (Get-ExpectedTorchFlavorTag -TorchIndexUrl ""))
 
+Write-Host "Trim-IndexPathSlashes (install.ps1 parity: path-only, token-preserving)"
+Check "double path slash collapsed"      ((Trim-IndexPathSlashes "https://h/whl/cu128//") -eq "https://h/whl/cu128")
+Check "single trailing slash trimmed"    ((Trim-IndexPathSlashes "https://h/whl/cu128/") -eq "https://h/whl/cu128")
+Check "query token slash preserved"      ((Trim-IndexPathSlashes "https://h/whl/cu128?token=ab12cd/") -eq "https://h/whl/cu128?token=ab12cd/")
+Check "path slash trimmed, query kept"   ((Trim-IndexPathSlashes "https://h/whl/cu128//?token=ab12cd/") -eq "https://h/whl/cu128?token=ab12cd/")
+
+Write-Host "Redact-InstallOutput (install.ps1 parity: credential redaction)"
+Check "userinfo redacted"                ((Redact-InstallOutput "ERROR https://alice:s3cr3t@download.pytorch.org/whl/cu128") -eq "ERROR https://<redacted>@download.pytorch.org/whl/cu128")
+Check "query value redacted"             ((Redact-InstallOutput "https://host/whl/cu128?token=abcd1234&channel=beta") -eq "https://host/whl/cu128?token=<redacted>&channel=<redacted>")
+Check "fragment token redacted"          ((Redact-InstallOutput "ERROR https://mirror.local/whl/cu128#token=SECRET123 (403)") -eq "ERROR https://mirror.local/whl/cu128#<redacted> (403)")
+Check "bare hash comment untouched"      ((Redact-InstallOutput "# retrying with --no-cache-dir") -eq "# retrying with --no-cache-dir")
+Check "plain line untouched"             ((Redact-InstallOutput "Resolved 42 packages in 1.2s") -eq "Resolved 42 packages in 1.2s")
+
 Write-Host ""
 if ($failures -gt 0) { Write-Host "$failures check(s) FAILED" -ForegroundColor Red; exit 1 }
 Write-Host "All checks passed" -ForegroundColor Green
diff --git a/tests/studio/test_torch_index_pin_hardening.ps1 b/tests/studio/test_torch_index_pin_hardening.ps1
new file mode 100644
index 0000000000..b8edf3da25
--- /dev/null
+++ b/tests/studio/test_torch_index_pin_hardening.ps1
@@ -0,0 +1,78 @@
+#!/usr/bin/env pwsh
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+# Unit tests for setup.ps1's torch-index pin-hardening helpers: Trim-IndexPathSlashes
+# (path-only slash trim, token-preserving), Redact-InstallOutput (credential redaction of
+# captured install logs), Get-TorchIndexLeaf (ALL trailing slashes stripped) and
+# Test-PipRocmFamilyLeaf (rocm7. is a custom pin, not a family). Pure helpers, AST-extracted
+# and run in-process. Run: pwsh -NoProfile -File tests/studio/test_torch_index_pin_hardening.ps1
+
+$ErrorActionPreference = "Stop"
+$setupPath = [System.IO.Path]::Combine($PSScriptRoot, "..", "..", "studio", "setup.ps1")
+$setupPath = (Resolve-Path $setupPath).Path
+$setupText = Get-Content -Raw $setupPath
+
+# --- Parse setup.ps1 (also a syntax gate) and extract the pure helpers ---
+$tokens = $null; $errors = $null
+$ast = [System.Management.Automation.Language.Parser]::ParseFile($setupPath, [ref]$tokens, [ref]$errors)
+if ($errors) { $errors | ForEach-Object { $_.ToString() }; throw "setup.ps1 has parse errors" }
+
+foreach ($name in @("Trim-IndexPathSlashes", "Redact-InstallOutput", "Get-TorchIndexLeaf", "Test-PipRocmFamilyLeaf")) {
+    $fn = $ast.FindAll({ param($n)
+        $n -is [System.Management.Automation.Language.FunctionDefinitionAst] -and $n.Name -eq $name
+    }, $true)
+    if ($fn.Count -ne 1) { throw "expected exactly one $name in setup.ps1, found $($fn.Count)" }
+    Invoke-Expression $fn[0].Extent.Text
+}
+
+$failures = 0
+function Check($name, $cond) {
+    if ($cond) { Write-Host "  PASS  $name" }
+    else { Write-Host "  FAIL  $name" -ForegroundColor Red; $script:failures++ }
+}
+
+Write-Host "Trim-IndexPathSlashes (path-only, token-preserving)"
+Check "double path slash collapsed"      ((Trim-IndexPathSlashes "https://h/whl/cu128//") -eq "https://h/whl/cu128")
+Check "single trailing slash trimmed"    ((Trim-IndexPathSlashes "https://h/whl/cu128/") -eq "https://h/whl/cu128")
+Check "no slash unchanged"               ((Trim-IndexPathSlashes "https://h/whl/cu128") -eq "https://h/whl/cu128")
+Check "query token slash preserved"      ((Trim-IndexPathSlashes "https://h/whl/cu128?token=ab12cd/") -eq "https://h/whl/cu128?token=ab12cd/")
+Check "path slash trimmed, query kept"   ((Trim-IndexPathSlashes "https://h/whl/cu128//?token=ab12cd/") -eq "https://h/whl/cu128?token=ab12cd/")
+Check "fragment slash preserved"         ((Trim-IndexPathSlashes "https://h/whl/cu128#anchor/") -eq "https://h/whl/cu128#anchor/")
+
+Write-Host "Redact-InstallOutput (credential redaction)"
+Check "userinfo redacted"                ((Redact-InstallOutput "ERROR https://alice:s3cr3t@download.pytorch.org/whl/cu128") -eq "ERROR https://<redacted>@download.pytorch.org/whl/cu128")
+Check "bare-token@ redacted"             ((Redact-InstallOutput "fetch https://ghp_deadbeef@host/whl/cu128 failed") -eq "fetch https://<redacted>@host/whl/cu128 failed")
+Check "single query value redacted"      ((Redact-InstallOutput "url https://host/whl/cu128?token=abcd1234 unreachable") -eq "url https://host/whl/cu128?token=<redacted> unreachable")
+Check "multiple query values redacted"   ((Redact-InstallOutput "https://host/whl/cu128?token=abcd1234&channel=beta") -eq "https://host/whl/cu128?token=<redacted>&channel=<redacted>")
+Check "fragment token redacted"          ((Redact-InstallOutput "ERROR https://mirror.local/whl/cu128#token=SECRET123 (403)") -eq "ERROR https://mirror.local/whl/cu128#<redacted> (403)")
+Check "query and fragment both redacted" ((Redact-InstallOutput "https://host/whl/cu128?token=abc#sig=xyz done") -eq "https://host/whl/cu128?token=<redacted>#<redacted> done")
+Check "bare hash comment untouched"      ((Redact-InstallOutput "# retrying with --no-cache-dir") -eq "# retrying with --no-cache-dir")
+Check "plain line untouched"             ((Redact-InstallOutput "Resolved 42 packages in 1.2s") -eq "Resolved 42 packages in 1.2s")
+$leak = Redact-InstallOutput "https://alice:s3cr3t@host/whl/cu128?token=SUPERSECRET#frag=ALSOSECRET"
+Check "no secret substring survives"     (($leak -notmatch "s3cr3t") -and ($leak -notmatch "SUPERSECRET") -and ($leak -notmatch "ALSOSECRET"))
+
+Write-Host "Get-TorchIndexLeaf (ALL trailing slashes stripped)"
+Check "double slash cu128 -> cu128"      ((Get-TorchIndexLeaf "https://m/whl/cu128//") -eq "cu128")
+Check "triple slash rocm7.2 -> rocm7.2"  ((Get-TorchIndexLeaf "https://m/whl/rocm7.2///") -eq "rocm7.2")
+Check "double slash + token -> cu128"    ((Get-TorchIndexLeaf "https://m/whl/cu128//?token=x") -eq "cu128")
+Check "single slash cu128 -> cu128"      ((Get-TorchIndexLeaf "https://m/whl/cu128/") -eq "cu128")
+
+Write-Host "Test-PipRocmFamilyLeaf (rocm7. is a custom pin, not a family)"
+Check "rocm7 family"                     (Test-PipRocmFamilyLeaf "rocm7")
+Check "rocm7.2 family"                    (Test-PipRocmFamilyLeaf "rocm7.2")
+Check "gfx1151 family"                    (Test-PipRocmFamilyLeaf "gfx1151")
+Check "rocm7. trailing-dot NOT family"   (-not (Test-PipRocmFamilyLeaf "rocm7."))
+Check "rocm.7 leading-dot NOT family"    (-not (Test-PipRocmFamilyLeaf "rocm.7"))
+Check "rocm7.2.1 two-dot NOT family"     (-not (Test-PipRocmFamilyLeaf "rocm7.2.1"))
+Check "rocm7.2-private NOT family"       (-not (Test-PipRocmFamilyLeaf "rocm7.2-private"))
+Check "cu128 NOT family"                 (-not (Test-PipRocmFamilyLeaf "cu128"))
+
+Write-Host "Fast-Install pinned-install env scrub (source assertion)"
+# The pip fallback honours PIP_*; PIP_NO_INDEX=1 would make it ignore the pinned --index-url
+# and PIP_INDEX_URL would replace it, so both must be scrubbed for a pinned install.
+Check "PIP_NO_INDEX scrubbed"            ($setupText -match "'PIP_NO_INDEX'")
+Check "PIP_INDEX_URL scrubbed"           ($setupText -match "'PIP_INDEX_URL'")
+
+Write-Host ""
+if ($failures -gt 0) { Write-Host "$failures check(s) FAILED" -ForegroundColor Red; exit 1 }
+Write-Host "All checks passed" -ForegroundColor Green
diff --git a/tests/studio/test_ui_font_scale_contract.py b/tests/studio/test_ui_font_scale_contract.py
new file mode 100644
index 0000000000..1153eea643
--- /dev/null
+++ b/tests/studio/test_ui_font_scale_contract.py
@@ -0,0 +1,156 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""UI font size scaling contracts (Settings > Appearance).
+
+The preference must scale typography through the --ui-font-scale tokens,
+never by mutating the root font size, so rem-based layout stays put. These
+contracts also act as the guard against reintroducing raw pixel typography
+that would silently ignore the preference.
+"""
+
+import re
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[2]
+SRC = REPO / "studio/frontend/src"
+INDEX_CSS = (SRC / "index.css").read_text(encoding = "utf-8")
+STORE = (SRC / "features/settings/stores/appearance-custom-store.ts").read_text(encoding = "utf-8")
+SELECT = (SRC / "components/ui/select.tsx").read_text(encoding = "utf-8")
+UTILS = (SRC / "lib/utils.ts").read_text(encoding = "utf-8")
+
+# Raw numeric fontSize props are only allowed where a scaled stylesheet rule
+# (.recharts-text) overrides the presentation attribute at render time.
+FONTSIZE_PROP_ALLOWED_DIRS = (
+    "features/studio/sections/charts",
+    "features/studio/sections/training-section.tsx",
+)
+
+# Non-visible typography that intentionally stays fixed.
+FONTSIZE_STYLE_ALLOWLIST = {
+    # Offscreen textarea; 12pt+ suppresses the iOS focus zoom. Never rendered.
+    "lib/copy-to-clipboard.ts",
+}
+
+
+def _frontend_sources():
+    for path in sorted(SRC.rglob("*")):
+        if path.suffix in {".ts", ".tsx", ".css"}:
+            yield path
+
+
+def test_preference_writes_a_scale_not_the_root_font_size():
+    assert 'setVar("--ui-font-scale"' in STORE
+    assert 'el.setAttribute("data-ui-font-size"' in STORE
+    # Older builds set an inline root font-size; the applier must clear it.
+    assert 'style.removeProperty("font-size")' in STORE
+    assert "style.fontSize" not in STORE
+
+
+def test_named_text_tokens_scale():
+    for token, rem in (
+        ("--text-xs", "0.75rem"),
+        ("--text-sm", "0.875rem"),
+        ("--text-base", "1rem"),
+        ("--text-lg", "1.125rem"),
+    ):
+        assert f"{token}: calc({rem} * var(--ui-font-scale, 1));" in INDEX_CSS
+
+
+def test_numeric_leading_scales_with_the_preference():
+    for n, rem in ((3, "0.75rem"), (5, "1.25rem"), (6, "1.5rem")):
+        assert f"--leading-{n}: calc({rem} * var(--ui-font-scale, 1));" in INDEX_CSS
+
+
+def test_ui_token_families_exist():
+    assert "--text-ui-11: calc(0.6875rem * var(--ui-font-scale, 1));" in INDEX_CSS
+    assert "--text-ui-10p5: calc(0.65625rem * var(--ui-font-scale, 1));" in INDEX_CSS
+    assert "--leading-ui-17: calc(1.0625rem * var(--ui-font-scale, 1));" in INDEX_CSS
+
+
+def test_explicit_code_font_size_is_never_multiplied():
+    match = re.search(r"html\[data-code-font-size\][^{]*\{([^}]*)\}", INDEX_CSS)
+    assert match is not None
+    body = match.group(1)
+    assert "var(--custom-code-font-size)" in body
+    assert "--ui-font-scale" not in body
+
+
+def test_radix_select_viewport_owns_the_scroll_state():
+    viewport = SELECT[SELECT.index("SelectPrimitive.Viewport") :]
+    assert "overflow-y-auto" in viewport.split("</SelectPrimitive.Viewport>")[0]
+    # The rounded surface itself must not scroll (WebKit squares its corners).
+    content_cls = re.search(
+        r"SelectPrimitive\.Content[\s\S]*?className=\{cn\(\s*\"([^\"]+)\"", SELECT
+    )
+    assert content_cls is not None
+    assert "overflow-hidden" in content_cls.group(1)
+    assert "overflow-y-auto" not in content_cls.group(1)
+
+
+def test_cn_knows_the_ui_typography_tokens():
+    """Stock tailwind-merge classifies text-ui-* as a text color and deletes
+    it whenever a real color class follows in the same cn() call, so the
+    element falls back to the unscaled inherited font size."""
+    assert "extendTailwindMerge" in UTILS
+    assert '"font-size": [{ text: [isUiToken] }]' in UTILS
+    assert "leading: [{ leading: [isUiToken] }]" in UTILS
+    assert "/^ui-\\d+(p5)?$/.test(value)" in UTILS
+
+
+def test_no_raw_pixel_text_utilities():
+    offenders = []
+    for path in _frontend_sources():
+        text = path.read_text(encoding = "utf-8")
+        for m in re.finditer(r"(?<![\w-])(?:text|leading)-\[[0-9.]+px\]", text):
+            offenders.append(f"{path.relative_to(SRC)}: {m.group(0)}")
+    assert offenders == [], (
+        "Raw px text utilities ignore the UI font size preference; use the "
+        f"text-ui-* / leading-ui-* tokens in index.css instead: {offenders[:10]}"
+    )
+
+
+def test_css_font_sizes_reference_the_scale():
+    offenders = []
+    for path in _frontend_sources():
+        if path.suffix != ".css":
+            continue
+        text = path.read_text(encoding = "utf-8")
+        for m in re.finditer(r"(font-size|line-height):[^;{}]*;", text):
+            decl = m.group(0)
+            if re.search(r"[0-9.]+(px|rem)", decl) is None:
+                continue  # unitless ratios and vars scale naturally
+            if "--ui-font-scale" in decl:
+                continue
+            if "1px" in decl:
+                continue  # library layout tricks (KaTeX-style), not text
+            offenders.append(f"{path.relative_to(SRC)}: {decl.strip()[:80]}")
+    assert offenders == [], (
+        "CSS typography must multiply by var(--ui-font-scale, 1) or be "
+        f"allowlisted here with a reason: {offenders[:10]}"
+    )
+
+
+def test_inline_font_size_styles_reference_the_scale():
+    offenders = []
+    for path in _frontend_sources():
+        rel = str(path.relative_to(SRC))
+        if rel in FONTSIZE_STYLE_ALLOWLIST:
+            continue
+        text = path.read_text(encoding = "utf-8")
+        for m in re.finditer(r"fontSize:\s*([\"'][^\"']+[\"']|[0-9.]+)", text):
+            value = m.group(1)
+            if "--ui-font-scale" in value:
+                continue
+            if value.replace(".", "").isdigit() and any(
+                rel.startswith(d) for d in FONTSIZE_PROP_ALLOWED_DIRS
+            ):
+                continue  # covered by the .recharts-text override
+            offenders.append(f"{rel}: fontSize {value}")
+        for m in re.finditer(r"fontSize=\{?([0-9.]+)\}?", text):
+            if not any(rel.startswith(d) for d in FONTSIZE_PROP_ALLOWED_DIRS):
+                offenders.append(f"{rel}: fontSize={m.group(1)}")
+    assert offenders == [], (
+        "Inline font sizes must scale with var(--ui-font-scale, 1) or be "
+        f"documented in the allowlist: {offenders[:10]}"
+    )
diff --git a/tests/studio/test_voice_settings_select_width.py b/tests/studio/test_voice_settings_select_width.py
new file mode 100644
index 0000000000..2f657b851e
--- /dev/null
+++ b/tests/studio/test_voice_settings_select_width.py
@@ -0,0 +1,16 @@
+"""Width contract for voice settings selects."""
+
+from pathlib import Path
+
+
+REPO = Path(__file__).resolve().parents[2]
+VOICE_TAB = REPO / "studio/frontend/src/features/settings/tabs/voice-tab.tsx"
+SELECT = REPO / "studio/frontend/src/components/ui/select.tsx"
+
+
+def test_voice_selects_grow_without_overflowing_the_dialog():
+    source = VOICE_TAB.read_text(encoding = "utf-8")
+    assert source.count('className="min-w-56 max-w-72"') == 4
+
+    select_source = SELECT.read_text(encoding = "utf-8")
+    assert "*:data-[slot=select-value]:line-clamp-1" in select_source
diff --git a/tests/studio/test_xpu_spoof_pipeline.py b/tests/studio/test_xpu_spoof_pipeline.py
new file mode 100644
index 0000000000..4a458a545d
--- /dev/null
+++ b/tests/studio/test_xpu_spoof_pipeline.py
@@ -0,0 +1,538 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+"""Full Intel XPU spoof pipeline: fake torch.xpu on a GPU-less/NVIDIA runner so
+Studio's hardware selection + training-device path (detect -> select -> apply ->
+device_map -> cache clear) runs exactly as the CUDA path does, with no real
+Intel hardware. The XPU sibling of tests/_zoo_aggressive_cuda_spoof.py.
+
+State-sensitive: it fresh-imports the Studio hardware module under the spoof and
+mutates its module globals, so studio-backend-ci.yml runs it in the isolated
+"Hardware-spoof tests" step (never alongside tests that import hardware).
+
+torch.xpu surface faked here mirrors the PyTorch 2.6+ API hardware.py calls:
+is_available, device_count, current_device, get_device_name,
+get_device_properties(idx).total_memory, memory_allocated/reserved, mem_get_info
+(incl. the Arc B580 / Lunar Lake RuntimeError), is_initialized, synchronize,
+empty_cache, plus torch.version.xpu.
+"""
+
+from __future__ import annotations
+
+import sys
+import types
+from pathlib import Path
+
+import pytest
+
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+STUDIO_BACKEND = REPO_ROOT / "studio" / "backend"
+
+
+def _make_fake_xpu(
+    *,
+    available: bool = True,
+    device_count: int = 2,
+    total_gb: float = 16.0,
+    used_gb: float = 1.0,
+    device_name: str = "Intel(R) Arc(TM) B580 Graphics (spoofed)",
+    mem_get_info: str = "ok",  # "ok" | "raise" | "absent"
+    is_initialized: bool = False,
+):
+    """Build a fake torch.xpu namespace + a call counter for synchronize/empty_cache.
+
+    mem_get_info: "ok" returns (free, total); "raise" models the Arc B580 / Lunar
+    Lake "device doesn't support querying free memory" RuntimeError; "absent"
+    omits the attribute so the memory_allocated fallback path is exercised.
+    """
+    total_bytes = int(total_gb * 1024**3)
+    used_bytes = int(used_gb * 1024**3)
+    calls = {"synchronize": 0, "empty_cache": 0}
+    props = types.SimpleNamespace(name = device_name, total_memory = total_bytes)
+
+    def _mem_get_info(idx = 0):
+        if mem_get_info == "raise":
+            raise RuntimeError(
+                "The device (Intel(R) Arc(TM) B580 Graphics) doesn't support "
+                "querying the available free memory."
+            )
+        return (total_bytes - used_bytes, total_bytes)
+
+    def _sync(*a, **k):
+        calls["synchronize"] += 1
+
+    def _empty(*a, **k):
+        calls["empty_cache"] += 1
+
+    xpu = types.SimpleNamespace(
+        is_available = lambda: available,
+        device_count = lambda: device_count,
+        current_device = lambda: 0,
+        get_device_name = lambda idx = 0: device_name,
+        get_device_properties = lambda idx = 0: props,
+        memory_allocated = lambda idx = 0: used_bytes,
+        memory_reserved = lambda idx = 0: used_bytes,
+        is_initialized = lambda: is_initialized,
+        synchronize = _sync,
+        empty_cache = _empty,
+    )
+    if mem_get_info != "absent":
+        xpu.mem_get_info = _mem_get_info
+    return xpu, calls
+
+
+def _import_studio_hardware_module():
+    """Fresh-import Studio's hardware module so detect_hardware re-runs under the
+    current spoofs (mirrors test_hardware_dispatch_matrix.py)."""
+    if str(STUDIO_BACKEND) not in sys.path:
+        sys.path.insert(0, str(STUDIO_BACKEND))
+    sys.modules.pop("utils.hardware.hardware", None)
+    sys.modules.pop("utils.hardware", None)
+    from utils.hardware import hardware as hw  # type: ignore
+
+    return hw
+
+
+@pytest.fixture
+def spoof_xpu(monkeypatch):
+    """Apply a full torch.xpu spoof and return (hardware_module, xpu_call_counter).
+
+    Defaults present an unambiguous "prefer XPU" host: CUDA hidden, a numeric
+    ZE_AFFINITY_MASK, and torch.xpu reporting devices. Override cuda_available /
+    cuda_visible / force_xpu / ze_mask to model hybrid or canary hosts.
+    """
+
+    def _apply(
+        *,
+        cuda_available: bool = False,
+        cuda_visible: str = "",  # "" hides CUDA; None unsets; else passthrough
+        ze_mask: str = "0,1",  # None unsets the mask
+        force_xpu: bool = False,
+        xpu_version = "2.7",
+        **xpu_kwargs,
+    ):
+        import torch
+
+        monkeypatch.setattr(torch.cuda, "is_available", lambda: cuda_available)
+        if cuda_available:
+            monkeypatch.setattr(
+                torch.cuda,
+                "get_device_properties",
+                lambda i = 0: types.SimpleNamespace(name = "Stub NVIDIA GPU"),
+                raising = False,
+            )
+        fake_xpu, calls = _make_fake_xpu(**xpu_kwargs)
+        monkeypatch.setattr(torch, "xpu", fake_xpu, raising = False)
+        monkeypatch.setattr(torch.version, "xpu", xpu_version, raising = False)
+
+        if ze_mask is None:
+            monkeypatch.delenv("ZE_AFFINITY_MASK", raising = False)
+        else:
+            monkeypatch.setenv("ZE_AFFINITY_MASK", ze_mask)
+        if cuda_visible is None:
+            monkeypatch.delenv("CUDA_VISIBLE_DEVICES", raising = False)
+        else:
+            monkeypatch.setenv("CUDA_VISIBLE_DEVICES", cuda_visible)
+        if force_xpu:
+            monkeypatch.setenv("UNSLOTH_FORCE_XPU", "1")
+        else:
+            monkeypatch.delenv("UNSLOTH_FORCE_XPU", raising = False)
+        # FLAT is the oneAPI default; pin it so the test is host-independent.
+        monkeypatch.delenv("ZE_FLAT_DEVICE_HIERARCHY", raising = False)
+
+        hw = _import_studio_hardware_module()
+        hw._visible_gpu_count = None
+        return hw, calls
+
+    return _apply
+
+
+# ---------- detection ----------
+
+
+def test_detect_hardware_routes_to_xpu(spoof_xpu):
+    hw, _ = spoof_xpu()
+    assert hw.detect_hardware() == hw.DeviceType.XPU
+    assert hw.CHAT_ONLY is False
+    assert hw.IS_ROCM is False
+
+
+def test_force_xpu_env_routes_to_xpu_even_without_mask(spoof_xpu):
+    hw, _ = spoof_xpu(force_xpu = True, ze_mask = None, cuda_visible = None)
+    assert hw.detect_hardware() == hw.DeviceType.XPU
+
+
+def test_bare_mask_with_cuda_present_stays_cuda(spoof_xpu):
+    # Canary: a stray inherited ZE_AFFINITY_MASK must NOT steal a CUDA host.
+    hw, _ = spoof_xpu(cuda_available = True, cuda_visible = None, ze_mask = "0,1")
+    assert hw.detect_hardware() == hw.DeviceType.CUDA
+
+
+def test_force_xpu_on_hybrid_hides_cuda_for_workers(spoof_xpu):
+    # Forced XPU with CUDA still visible must hide CUDA: unsloth's
+    # device_type picks CUDA before XPU and ignores UNSLOTH_FORCE_XPU,
+    # so workers would otherwise silently train on CUDA.
+    hw, _ = spoof_xpu(force_xpu = True, cuda_available = True, cuda_visible = None, ze_mask = None)
+    assert hw.detect_hardware() == hw.DeviceType.XPU
+    import os
+
+    assert os.environ["CUDA_VISIBLE_DEVICES"] == ""
+
+
+def test_force_xpu_without_working_xpu_leaves_cuda_untouched(spoof_xpu):
+    # Canary: FORCE_XPU on a CUDA host with no working XPU must fall
+    # through to CUDA and must NOT hide it.
+    hw, _ = spoof_xpu(
+        force_xpu = True,
+        cuda_available = True,
+        cuda_visible = None,
+        ze_mask = None,
+        available = False,
+    )
+    assert hw.detect_hardware() == hw.DeviceType.CUDA
+    import os
+
+    assert "CUDA_VISIBLE_DEVICES" not in os.environ
+
+
+def test_apply_gpu_ids_predetect_never_probes_torch(spoof_xpu, monkeypatch):
+    # Workers call apply_gpu_ids() BEFORE detect_hardware(); a lazy detect
+    # would probe torch.cuda against the unmasked parent env, latching device
+    # enumeration before the mask is written. Pre-detect it must decide from
+    # env/build attributes only.
+    import torch
+
+    hw, _ = spoof_xpu(ze_mask = None, cuda_visible = None)
+    assert hw.DEVICE is None  # fresh import, pre-detect
+
+    def _poisoned_detect():
+        raise AssertionError("apply_gpu_ids triggered detect_hardware pre-mask")
+
+    monkeypatch.setattr(hw, "detect_hardware", _poisoned_detect)
+    monkeypatch.setattr(torch.cuda, "is_available", _poisoned_detect, raising = False)
+    # CUDA-build torch (torch.version.cuda set on this box or spoofed):
+    monkeypatch.setattr(torch.version, "cuda", "12.8", raising = False)
+    monkeypatch.setattr(torch.version, "xpu", None, raising = False)
+    hw.apply_gpu_ids([1])
+    import os
+
+    assert os.environ["CUDA_VISIBLE_DEVICES"] == "1"
+    assert "ZE_AFFINITY_MASK" not in os.environ
+
+
+def test_apply_gpu_ids_predetect_xpu_build_writes_ze_mask(spoof_xpu, monkeypatch):
+    # Pre-detect on an XPU-build torch (version.xpu set, no cuda/hip):
+    # the mask must go to ZE_AFFINITY_MASK without any runtime probe.
+    import torch
+
+    hw, _ = spoof_xpu(ze_mask = None, cuda_visible = None)
+    assert hw.DEVICE is None
+
+    def _poisoned_detect():
+        raise AssertionError("apply_gpu_ids triggered detect_hardware pre-mask")
+
+    monkeypatch.setattr(hw, "detect_hardware", _poisoned_detect)
+    monkeypatch.setattr(torch.version, "cuda", None, raising = False)
+    monkeypatch.setattr(torch.version, "hip", None, raising = False)
+    monkeypatch.setattr(torch.version, "xpu", "2.7", raising = False)
+    hw.apply_gpu_ids([0])
+    import os
+
+    assert os.environ["ZE_AFFINITY_MASK"] == "0"
+    assert "CUDA_VISIBLE_DEVICES" not in os.environ
+
+
+def test_apply_gpu_ids_predetect_xpu_compiled_with_null_version(spoof_xpu, monkeypatch):
+    # version.xpu can be None on a working XPU build; torch.xpu._is_compiled()
+    # must be accepted as the build signal so the mask still goes to
+    # ZE_AFFINITY_MASK.
+    import torch
+
+    hw, _ = spoof_xpu(ze_mask = None, cuda_visible = None)
+    assert hw.DEVICE is None
+    monkeypatch.setattr(
+        hw, "detect_hardware", lambda: (_ for _ in ()).throw(AssertionError("detect ran"))
+    )
+    monkeypatch.setattr(torch.version, "cuda", None, raising = False)
+    monkeypatch.setattr(torch.version, "hip", None, raising = False)
+    monkeypatch.setattr(torch.version, "xpu", None, raising = False)
+    monkeypatch.setattr(torch.xpu, "_is_compiled", lambda: True, raising = False)
+    hw.apply_gpu_ids([0])
+    import os
+
+    assert os.environ["ZE_AFFINITY_MASK"] == "0"
+    assert "CUDA_VISIBLE_DEVICES" not in os.environ
+
+
+def test_apply_gpu_ids_predetect_force_on_cuda_build_writes_cvd(spoof_xpu, monkeypatch):
+    # UNSLOTH_FORCE_XPU=1 on a CUDA build (no XPU compiled in): detect falls
+    # back to CUDA, so the pre-detect mask must go to CUDA_VISIBLE_DEVICES,
+    # not ZE_AFFINITY_MASK.
+    import torch
+
+    hw, _ = spoof_xpu(force_xpu = True, ze_mask = None, cuda_visible = None)
+    assert hw.DEVICE is None
+    monkeypatch.setattr(
+        hw, "detect_hardware", lambda: (_ for _ in ()).throw(AssertionError("detect ran"))
+    )
+    monkeypatch.setattr(torch.version, "cuda", "12.8", raising = False)
+    monkeypatch.setattr(torch.version, "xpu", None, raising = False)
+    monkeypatch.setattr(torch.xpu, "_is_compiled", lambda: False, raising = False)
+    hw.apply_gpu_ids([1])
+    import os
+
+    assert os.environ["CUDA_VISIBLE_DEVICES"] == "1"
+    assert "ZE_AFFINITY_MASK" not in os.environ
+
+
+def test_apply_gpu_ids_predetect_dual_build_honors_xpu_hint(spoof_xpu, monkeypatch):
+    # Dual CUDA+XPU build launched the documented XPU way (CUDA hidden + ZE
+    # mask): the mask must narrow ZE_AFFINITY_MASK, not re-expose the hidden
+    # CUDA via CUDA_VISIBLE_DEVICES. Mirrors detect_hardware's hint.
+    import torch
+
+    hw, _ = spoof_xpu(ze_mask = "0,1", cuda_visible = "")
+    assert hw.DEVICE is None
+    monkeypatch.setattr(
+        hw, "detect_hardware", lambda: (_ for _ in ()).throw(AssertionError("detect ran"))
+    )
+    monkeypatch.setattr(torch.version, "cuda", "12.8", raising = False)
+    monkeypatch.setattr(torch.version, "xpu", "2.7", raising = False)
+    hw.apply_gpu_ids([0])
+    import os
+
+    assert os.environ["ZE_AFFINITY_MASK"] == "0"
+    assert os.environ["CUDA_VISIBLE_DEVICES"] == ""  # stays hidden
+
+
+def test_apply_gpu_ids_predetect_dual_build_cuda_active_writes_cvd(spoof_xpu, monkeypatch):
+    # Canary: dual build with CUDA active (no hint) keeps CUDA masking, same
+    # as detect_hardware picking CUDA on a hybrid host.
+    import torch
+
+    hw, _ = spoof_xpu(ze_mask = "0,1", cuda_visible = None)
+    assert hw.DEVICE is None
+    monkeypatch.setattr(
+        hw, "detect_hardware", lambda: (_ for _ in ()).throw(AssertionError("detect ran"))
+    )
+    monkeypatch.setattr(torch.version, "cuda", "12.8", raising = False)
+    monkeypatch.setattr(torch.version, "xpu", "2.7", raising = False)
+    hw.apply_gpu_ids([1])
+    import os
+
+    assert os.environ["CUDA_VISIBLE_DEVICES"] == "1"
+    assert os.environ["ZE_AFFINITY_MASK"] == "0,1"  # untouched
+
+
+def test_apply_gpu_ids_trusts_parent_backend_param(spoof_xpu, monkeypatch):
+    # Workers pass the parent's detected backend (config["device_backend"]):
+    # it must win over build heuristics in both directions, mirroring
+    # detect_hardware's availability check and CUDA fallback exactly.
+    import torch
+
+    hw, _ = spoof_xpu(ze_mask = None, cuda_visible = None, force_xpu = True)
+    assert hw.DEVICE is None
+    monkeypatch.setattr(
+        hw, "detect_hardware", lambda: (_ for _ in ()).throw(AssertionError("detect ran"))
+    )
+    # Forced XPU + XPU build, but the parent detected CUDA (xpu had no
+    # device): backend="cuda" must route to CUDA_VISIBLE_DEVICES.
+    monkeypatch.setattr(torch.version, "cuda", "12.8", raising = False)
+    monkeypatch.setattr(torch.version, "xpu", "2.7", raising = False)
+    hw.apply_gpu_ids([1], backend = "cuda")
+    import os
+
+    assert os.environ["CUDA_VISIBLE_DEVICES"] == "1"
+    assert "ZE_AFFINITY_MASK" not in os.environ
+
+    # And backend="xpu" routes to ZE_AFFINITY_MASK even on a CUDA build.
+    monkeypatch.delenv("CUDA_VISIBLE_DEVICES", raising = False)
+    monkeypatch.setattr(torch.version, "xpu", None, raising = False)
+    hw.apply_gpu_ids([0], backend = "xpu")
+    assert os.environ["ZE_AFFINITY_MASK"] == "0"
+    assert "CUDA_VISIBLE_DEVICES" not in os.environ
+
+
+def test_apply_gpu_ids_predetect_hidden_cuda_without_mask_prefers_xpu(spoof_xpu, monkeypatch):
+    # Hidden CUDA on an XPU-capable build prefers XPU even with NO ZE mask
+    # set (detection falls through to XPU in that state); writing the ids to
+    # CUDA_VISIBLE_DEVICES would re-expose the hidden CUDA.
+    import torch
+
+    hw, _ = spoof_xpu(ze_mask = None, cuda_visible = "")
+    assert hw.DEVICE is None
+    monkeypatch.setattr(
+        hw, "detect_hardware", lambda: (_ for _ in ()).throw(AssertionError("detect ran"))
+    )
+    monkeypatch.setattr(torch.version, "cuda", "12.8", raising = False)
+    monkeypatch.setattr(torch.version, "xpu", "2.7", raising = False)
+    hw.apply_gpu_ids([0])
+    import os
+
+    assert os.environ["ZE_AFFINITY_MASK"] == "0"
+    assert os.environ["CUDA_VISIBLE_DEVICES"] == ""  # stays hidden
+
+
+# ---------- visibility / selection ----------
+
+
+def test_apply_gpu_ids_writes_ze_affinity_mask(spoof_xpu, monkeypatch):
+    hw, _ = spoof_xpu()
+    hw.detect_hardware()
+    monkeypatch.setenv("CUDA_VISIBLE_DEVICES", "sentinel")
+    hw.apply_gpu_ids([0, 1])
+    import os
+
+    assert os.environ["ZE_AFFINITY_MASK"] == "0,1"
+    # XPU pinning must not touch CUDA_VISIBLE_DEVICES (hybrid-host safety).
+    assert os.environ["CUDA_VISIBLE_DEVICES"] == "sentinel"
+
+
+def test_get_visible_gpu_count_uses_device_count(spoof_xpu):
+    hw, _ = spoof_xpu(ze_mask = "0,1", device_count = 2)
+    hw.detect_hardware()
+    assert hw.get_visible_gpu_count() == 2
+
+
+def test_get_visible_gpu_count_empty_mask_is_zero(spoof_xpu):
+    hw, _ = spoof_xpu(ze_mask = "")
+    hw.detect_hardware()
+    assert hw.get_visible_gpu_count() == 0
+
+
+def test_flat_numeric_mask_reports_relative_ordinals(spoof_xpu):
+    hw, _ = spoof_xpu(ze_mask = "4,7", device_count = 2)
+    hw.detect_hardware()
+
+    spec = hw._get_parent_visible_gpu_spec()
+    assert spec["numeric_ids"] is None
+    assert spec["supports_explicit_gpu_ids"] is False
+
+    for result in (hw.get_visible_gpu_utilization(), hw.get_backend_visible_gpu_info()):
+        assert result["available"] is True
+        assert result["index_kind"] == "relative"
+        assert result["parent_visible_gpu_ids"] == []
+        assert [device["index"] for device in result["devices"]] == [0, 1]
+
+
+def test_composite_numeric_mask_reports_physical_ids(spoof_xpu, monkeypatch):
+    hw, _ = spoof_xpu(ze_mask = "4,7", device_count = 2)
+    monkeypatch.setenv("ZE_FLAT_DEVICE_HIERARCHY", "COMPOSITE")
+    hw.detect_hardware()
+
+    spec = hw._get_parent_visible_gpu_spec()
+    assert spec["numeric_ids"] == [4, 7]
+    assert spec["supports_explicit_gpu_ids"] is True
+
+    for result in (hw.get_visible_gpu_utilization(), hw.get_backend_visible_gpu_info()):
+        assert result["available"] is True
+        assert result["index_kind"] == "physical"
+        assert result["parent_visible_gpu_ids"] == [4, 7]
+        assert [device["index"] for device in result["devices"]] == [4, 7]
+
+
+def test_get_device_map_multi_is_balanced(spoof_xpu):
+    hw, _ = spoof_xpu(ze_mask = "0,1", device_count = 2)
+    hw.detect_hardware()
+    assert hw.get_device_map([0, 1]) == "balanced"
+
+
+def test_get_device_map_explicit_single_is_sequential(spoof_xpu):
+    hw, _ = spoof_xpu(ze_mask = "0,1", device_count = 2)
+    hw.detect_hardware()
+    # Explicit gpu_ids=[0] is a deliberate single-device request.
+    assert hw.get_device_map([0]) == "sequential"
+
+
+# ---------- cache / telemetry / versions ----------
+
+
+def test_clear_gpu_cache_calls_xpu(spoof_xpu):
+    hw, calls = spoof_xpu()
+    hw.detect_hardware()
+    hw.clear_gpu_cache()
+    assert calls["synchronize"] >= 1
+    assert calls["empty_cache"] >= 1
+
+
+def test_package_versions_survive_broken_xpu_runtime(spoof_xpu, monkeypatch):
+    # A broken Intel runtime raising in is_available() must not blank the
+    # CUDA/ROCm versions on NVIDIA/AMD hosts.
+    import torch
+
+    hw, _ = spoof_xpu(cuda_available = True, cuda_visible = None, ze_mask = None)
+    monkeypatch.setattr(torch.version, "cuda", "12.8", raising = False)
+
+    def _broken():
+        raise RuntimeError("Level Zero init failed")
+
+    monkeypatch.setattr(torch.xpu, "is_available", _broken)
+    versions = hw.get_package_versions()
+    assert versions["cuda"] == "12.8"
+    assert versions.get("xpu") is None
+
+
+def test_package_versions_reports_xpu(spoof_xpu):
+    hw, _ = spoof_xpu(xpu_version = "2.7")
+    hw.detect_hardware()
+    assert hw.get_package_versions().get("xpu") == "2.7"
+
+
+def test_package_versions_xpu_available_fallback(spoof_xpu):
+    hw, _ = spoof_xpu(xpu_version = None)
+    hw.detect_hardware()
+    assert hw.get_package_versions().get("xpu") == "available"
+
+
+def test_per_device_info_mem_get_info_ok(spoof_xpu):
+    hw, _ = spoof_xpu(total_gb = 16.0, used_gb = 1.0)
+    hw.detect_hardware()
+    info = hw._torch_get_per_device_info([0])
+    assert len(info) == 1
+    assert info[0]["total_gb"] == pytest.approx(16.0, abs = 0.1)
+    assert info[0]["used_gb"] == pytest.approx(1.0, abs = 0.1)
+
+
+def test_mem_get_info_runtimeerror_keeps_device_with_unknown_usage(spoof_xpu):
+    # Arc B580 and Lunar Lake can reject mem_get_info while remaining usable.
+    hw, _ = spoof_xpu(mem_get_info = "raise", total_gb = 16.0, device_count = 2)
+    hw.detect_hardware()
+
+    info = hw._torch_get_per_device_info([0])
+    assert len(info) == 1
+    assert info[0]["total_gb"] == pytest.approx(16.0, abs = 0.1)
+    assert info[0]["used_gb"] is None
+
+    utilization = hw.get_visible_gpu_utilization()
+    assert utilization["available"] is True
+    assert len(utilization["devices"]) == 2
+    assert all(device["vram_total_gb"] == pytest.approx(16.0) for device in utilization["devices"])
+    assert all(device["vram_used_gb"] is None for device in utilization["devices"])
+
+    visibility = hw.get_backend_visible_gpu_info()
+    assert visibility["available"] is True
+    assert len(visibility["devices"]) == 2
+    assert all(device["memory_total_gb"] == pytest.approx(16.0) for device in visibility["devices"])
+
+
+def test_per_device_info_no_mem_get_info_uses_none(spoof_xpu):
+    hw, _ = spoof_xpu(mem_get_info = "absent")
+    hw.detect_hardware()
+    info = hw._torch_get_per_device_info([0])
+    assert len(info) == 1
+    assert info[0]["used_gb"] is None
+
+
+# ---------- training-device wiring ----------
+
+
+def test_get_torch_device_str_is_xpu(spoof_xpu):
+    hw, _ = spoof_xpu()
+    hw.detect_hardware()
+    assert hw.get_torch_device_str() == "xpu"
+
+
+def test_dataset_map_num_proc_none_after_xpu_init(spoof_xpu):
+    # os.fork() after Level-Zero init corrupts the XPU context -> force in-process.
+    hw, _ = spoof_xpu(is_initialized = True)
+    hw.detect_hardware()
+    assert hw.dataset_map_num_proc(4) is None
diff --git a/tests/test_installer_unsloth_version.py b/tests/test_installer_unsloth_version.py
new file mode 100644
index 0000000000..5ee1cfac71
--- /dev/null
+++ b/tests/test_installer_unsloth_version.py
@@ -0,0 +1,75 @@
+"""Regression coverage for installer version reporting."""
+
+from __future__ import annotations
+
+import re
+import shutil
+import subprocess
+import sys
+from importlib.metadata import version
+from pathlib import Path
+
+import pytest
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+INSTALL_SH = REPO_ROOT / "install.sh"
+INSTALL_PS1 = REPO_ROOT / "install.ps1"
+
+
+def _extract(pattern: str, source: str) -> str:
+    match = re.search(pattern, source, flags = re.DOTALL | re.MULTILINE)
+    assert match is not None, f"installer block not found: {pattern}"
+    return match.group(0)
+
+
+@pytest.mark.skipif(shutil.which("sh") is None, reason = "POSIX shell is unavailable")
+def test_posix_installer_reports_installed_distribution_version():
+    source = INSTALL_SH.read_text(encoding = "utf-8")
+    reporter = _extract(
+        r"_installed_package_version=\$\(.*?^fi",
+        source,
+    )
+    result = subprocess.run(
+        [
+            "sh",
+            "-c",
+            (
+                'step() { printf "%s %s\\n" "$1" "$2"; }\n'
+                'substep() { printf "WARN %s\\n" "$1"; }\n'
+                f"_VENV_PY={sys.executable!r}\n"
+                "PACKAGE_NAME=pytest\n"
+                f"{reporter}"
+            ),
+        ],
+        check = True,
+        capture_output = True,
+        text = True,
+    )
+    assert result.stdout.strip() == f"pytest {version('pytest')} installed"
+
+
+@pytest.mark.skipif(shutil.which("pwsh") is None, reason = "PowerShell is unavailable")
+def test_windows_version_reporter_uses_distribution_metadata():
+    source = INSTALL_PS1.read_text(encoding = "utf-8")
+    reporter = _extract(
+        r"    \$installedPackageVersion = .*?^    if .*?^    \} else \{.*?^    \}",
+        source,
+    )
+    result = subprocess.run(
+        [
+            "pwsh",
+            "-NoProfile",
+            "-NonInteractive",
+            "-Command",
+            (
+                'function step { param($Label, $Value) Write-Output "$Label $Value" }; '
+                'function substep { param($Message, $Color) Write-Output "WARN $Message" }; '
+                f"$VenvPython = '{sys.executable}'; $PackageName = 'pytest'; "
+                f"{reporter}"
+            ),
+        ],
+        check = True,
+        capture_output = True,
+        text = True,
+    )
+    assert result.stdout.strip() == f"pytest {version('pytest')} installed"
diff --git a/tests/test_model_registry.py b/tests/test_model_registry.py
index 283b099107..76f462c5cf 100644
--- a/tests/test_model_registry.py
+++ b/tests/test_model_registry.py
@@ -1,5 +1,8 @@
 """Register each model set and check the registered ids exist on the HF Hub."""
 
+import os
+import subprocess
+import sys
 from dataclasses import dataclass
 
 import pytest
@@ -77,3 +80,85 @@ def test_quant_type():
     assert all(m.quant_type == QuantType.UNSLOTH for m in dynamic_quant_models)
     quant_tag = QUANT_TAG_MAP[QuantType.UNSLOTH]
     assert all(quant_tag in m.model_path for m in dynamic_quant_models)
+
+
+def _run_registry_child(body: str) -> subprocess.CompletedProcess:
+    """Run ``body`` in a fresh interpreter that first imports this directory's
+    ``conftest`` so it inherits the same GPU-free harness the pytest session
+    uses (device_type stubs plus torch.cuda probe patches). Without it,
+    ``import unsloth.registry`` raises ``NotImplementedError`` from
+    ``unsloth_zoo.device_type`` on no-accelerator CI runners, so the child
+    would exit non-zero and the test would fail even though the registry code
+    is correct. A fresh process also keeps each check independent of any
+    ``register_models()`` calls other tests make on the shared registry.
+    """
+    tests_dir = os.path.dirname(os.path.abspath(__file__))
+    prelude = (
+        f"import sys; sys.path.insert(0, {tests_dir!r})\n"
+        "try:\n"
+        "    import conftest  # noqa: F401  GPU-free harness on no-accelerator runners\n"
+        "except Exception:\n"
+        "    pass\n"
+    )
+    return subprocess.run(
+        [sys.executable, "-c", prelude + body],
+        capture_output = True,
+        text = True,
+        check = False,
+    )
+
+
+def test_importing_registry_does_not_register_models():
+    """Importing the registry must not populate MODEL_REGISTRY on its own.
+
+    ``_deepseek`` used to call ``register_deepseek_models(...)`` at module
+    scope, so merely importing ``unsloth.registry`` registered models as an
+    import side effect, unlike every other family which only registers on
+    demand.
+    """
+    result = _run_registry_child(
+        "import unsloth.registry\n"
+        "from unsloth.registry.registry import MODEL_REGISTRY\n"
+        "print('REGISTRY_SIZE', len(MODEL_REGISTRY))"
+    )
+    assert result.returncode == 0, (
+        f"registry import subprocess exited {result.returncode}\n"
+        f"stdout:\n{result.stdout}\nstderr:\n{result.stderr}"
+    )
+    size_lines = [line for line in result.stdout.splitlines() if line.startswith("REGISTRY_SIZE")]
+    assert size_lines == ["REGISTRY_SIZE 0"], result.stdout + result.stderr
+
+
+def test_register_models_registers_no_upstream_originals():
+    """``register_models()`` must register each family's ``unsloth``-org models
+    and must NOT leak upstream vendor "original" models.
+
+    Before the fix, ``_deepseek``'s import-time
+    ``register_deepseek_models(include_original_model = True)`` set the
+    ``_IS_DEEPSEEK_*_REGISTERED`` guards, so the later default
+    ``register_models()`` early-returned for deepseek and its 10 ``deepseek-ai``
+    originals leaked permanently (129 -> 139). This asserts the whole registry
+    is ``unsloth``-org after ``register_models()`` while deepseek is still
+    registered via the normal path. Runs in a fresh interpreter so it is
+    independent of other tests' registry mutations.
+    """
+    result = _run_registry_child(
+        "import unsloth.registry\n"
+        "from unsloth.registry import register_models\n"
+        "from unsloth.registry.registry import MODEL_REGISTRY\n"
+        "register_models()\n"
+        "orgs = sorted({m.org for m in MODEL_REGISTRY.values()})\n"
+        "deepseek = [k for k in MODEL_REGISTRY if 'deepseek' in k.lower()]\n"
+        "print('ORGS', orgs)\n"
+        "print('NUM_DEEPSEEK', len(deepseek))"
+    )
+    assert result.returncode == 0, (
+        f"register_models subprocess exited {result.returncode}\n"
+        f"stdout:\n{result.stdout}\nstderr:\n{result.stderr}"
+    )
+    out = result.stdout
+    # Every registered model is unsloth-org: no upstream "original" leaked.
+    assert "ORGS ['unsloth']" in out, out + result.stderr
+    # Deepseek is still registered via the normal path, just without originals.
+    deepseek_lines = [line for line in out.splitlines() if line.startswith("NUM_DEEPSEEK")]
+    assert deepseek_lines and int(deepseek_lines[0].split()[1]) > 0, out + result.stderr
diff --git a/tests/test_raw_text.py b/tests/test_raw_text.py
index ba16e0cfc4..bc75c2e44d 100644
--- a/tests/test_raw_text.py
+++ b/tests/test_raw_text.py
@@ -295,7 +295,117 @@ def test_smart_chunk_text_single_chunk_no_eos_returns_plain_list():
     return True
 
 
+def test_load_from_file_skips_non_object_json_lines():
+    """Non-object .jsonl lines (valid JSON, not dicts) are skipped, not fatal."""
+    # "context" contains "text", ["text"] holds it, 42 isn't iterable -- each
+    # would reach data[field] and raise TypeError without the isinstance guard.
+    with tempfile.NamedTemporaryFile("w", suffix = ".jsonl", delete = False) as f:
+        f.write('"context"\n["text", "x"]\n42\n{"text": "keep this"}\n')
+        path = f.name
+    try:
+        text = RawTextDataLoader(None)._read_file_by_format(path, "json_lines")
+        assert text == "keep this", text
+    finally:
+        os.unlink(path)
+
+    print("test_load_from_file_skips_non_object_json_lines passed")
+    return True
+
+
+def test_smart_chunk_text_empty_input_returns_no_chunks():
+    """Empty/whitespace text must yield no chunks. This tokenizer keeps one token
+    per char (like BPE/SentencePiece keeping spaces), so a len(tokens)==0 check
+    would miss whitespace; the fix guards on text.strip() before tokenizing."""
+
+    class WhitespacePreservingTokenizer:
+        def __init__(self, eos_token_id):
+            self.eos_token = "</s>" if eos_token_id is not None else None
+            self.eos_token_id = eos_token_id
+
+        def __call__(
+            self,
+            text,
+            return_tensors = None,
+            add_special_tokens = False,
+        ):
+            token_ids = [ord(c) % 100 for c in text]  # whitespace -> real tokens
+            if return_tensors == "pt":
+                return {"input_ids": [token_ids]}
+            return {"input_ids": token_ids}
+
+        def decode(
+            self,
+            token_ids,
+            skip_special_tokens = False,
+        ):
+            return "".join(chr(32 + (t % 90)) for t in token_ids)
+
+    for eos_token_id in (2, None):
+        loader = RawTextDataLoader(
+            WhitespacePreservingTokenizer(eos_token_id), chunk_size = 2048, stride = 512
+        )
+        # Whitespace tokenizes to >0 tokens, so [] proves the pre-tokenize guard.
+        assert len(loader.tokenizer("   \n\t  ")["input_ids"]) > 0
+        for text in ("", "   \n\t  "):
+            for return_tokenized in (True, False):
+                assert (
+                    loader.smart_chunk_text(
+                        text, chunk_size = 2048, stride = 512, return_tokenized = return_tokenized
+                    )
+                    == []
+                ), f"no chunks for empty input (eos={eos_token_id}, text={text!r}, tokenized={return_tokenized})"
+                assert loader.chunk_text(text, return_tokenized = return_tokenized) == [], (
+                    f"chunk_text: no chunks for empty input "
+                    f"(eos={eos_token_id}, text={text!r}, tokenized={return_tokenized})"
+                )
+    print("test_smart_chunk_text_empty_input_returns_no_chunks passed")
+    return True
+
+
+def test_load_from_files_all_empty_raises():
+    """All-empty file list must raise (like load_from_file) instead of returning
+    a 0-row text-column dataset in return_tokenized mode."""
+
+    class WhitespacePreservingTokenizer:
+        eos_token = "</s>"
+        eos_token_id = 2
+
+        def __call__(
+            self,
+            text,
+            return_tensors = None,
+            add_special_tokens = False,
+        ):
+            token_ids = [ord(c) % 100 for c in text]
+            if return_tensors == "pt":
+                return {"input_ids": [token_ids]}
+            return {"input_ids": token_ids}
+
+    loader = RawTextDataLoader(WhitespacePreservingTokenizer(), chunk_size = 2048, stride = 512)
+    paths = []
+    try:
+        for content in ("", "   \n\t  "):
+            with tempfile.NamedTemporaryFile("w", suffix = ".txt", delete = False) as f:
+                f.write(content)
+                paths.append(f.name)
+        raised = False
+        try:
+            loader.load_from_files(paths, return_tokenized = True)
+        except ValueError as e:
+            raised = True
+            assert "empty" in str(e).lower() or "whitespace" in str(e).lower(), str(e)
+        assert raised, "load_from_files must raise when all files are empty/whitespace"
+    finally:
+        for p in paths:
+            os.unlink(p)
+    print("test_load_from_files_all_empty_raises passed")
+    return True
+
+
 if __name__ == "__main__":
     success = test_raw_text_loader()
     success = test_smart_chunk_text_single_chunk_no_eos_returns_plain_list() and success
+    success = test_load_from_file_skips_non_object_json_lines() and success
+    success = test_smart_chunk_text_empty_input_returns_no_chunks() and success
+    success = test_load_from_files_all_empty_raises() and success
     sys.exit(0 if success else 1)
diff --git a/tests/test_studio_install_workspace_guard.py b/tests/test_studio_install_workspace_guard.py
index 89836cfb0d..18678a9b4a 100644
--- a/tests/test_studio_install_workspace_guard.py
+++ b/tests/test_studio_install_workspace_guard.py
@@ -1,4 +1,4 @@
-"""install.sh/install.ps1 must refuse to rm -rf an existing Studio venv in env-mode without a sentinel."""
+"""install.sh/install.ps1 must refuse to rm -rf an existing Unsloth venv in env-mode without a sentinel."""
 
 from __future__ import annotations
 
@@ -127,7 +127,7 @@ def test_install_ps1_has_matching_env_mode_guard():
     ), "install.ps1 must gate Remove-Item $VenvDir on env-mode"
     assert "share\\studio.conf" in block, "install.ps1 guard must check share\\studio.conf sentinel"
     assert "bin\\unsloth.exe" in block, "install.ps1 guard must check bin\\unsloth.exe sentinel"
-    assert "Refusing to delete non-Studio venv" in block
+    assert "Refusing to delete non-Unsloth venv" in block
 
 
 def test_setup_ps1_has_writability_probe():
@@ -160,7 +160,7 @@ def test_env_mode_blocks_when_bin_unsloth_is_a_directory(tmp_path):
         capture_output = True,
     )
     assert res.returncode != 0, (
-        "directory at bin/unsloth must NOT satisfy the Studio sentinel; "
+        "directory at bin/unsloth must NOT satisfy the Unsloth sentinel; "
         f"stdout={res.stdout!r} stderr={res.stderr!r}"
     )
     assert (venv / "important.txt").is_file(), "unrelated workspace data must survive"
@@ -205,7 +205,7 @@ def test_install_ps1_sentinel_uses_pathtype_leaf():
 
 
 def test_setup_ps1_stale_venv_has_env_mode_guard():
-    """setup.ps1 stale-venv branch must gate Remove-Item $VenvDir on a custom-root Studio sentinel."""
+    """setup.ps1 stale-venv branch must gate Remove-Item $VenvDir on a custom-root Unsloth sentinel."""
     src = SETUP_PS1.read_text()
     idx = src.index("Stale venv detected")
     block = src[idx : idx + 1500]
@@ -254,6 +254,14 @@ def test_setup_ps1_prebuilt_llama_cpp_has_ownership_guard():
     ), "Assert-StudioOwnedOrAbsent must precede the install_llama_prebuilt.py call"
 
 
+def test_setup_ps1_adopts_existing_whisper_prebuilt_marker():
+    text = SETUP_PS1.read_text(encoding = "utf-8")
+    helper_start = text.index("function Test-StudioOwnedAdoptable")
+    helper_end = text.index("function Assert-StudioOwnedOrAbsent", helper_start)
+    helper = text[helper_start:helper_end]
+    assert "UNSLOTH_WHISPER_PREBUILT_INFO.json" in helper
+
+
 def test_env_mode_passes_when_venv_marker_present(tmp_path):
     """install.sh env-mode guard must accept the in-VENV .unsloth-studio-owned marker as a sentinel."""
     studio_home = tmp_path / "ws"
diff --git a/tests/test_studio_root_resilience.py b/tests/test_studio_root_resilience.py
index 0dfb826376..779ff2f3f1 100644
--- a/tests/test_studio_root_resilience.py
+++ b/tests/test_studio_root_resilience.py
@@ -1,4 +1,4 @@
-"""Studio install-root inference must not crash under hostile filesystem conditions (PermissionError/OSError swallowed; custom root kept when resolve() fails)."""
+"""Unsloth install-root inference must not crash under hostile filesystem conditions (PermissionError/OSError swallowed; custom root kept when resolve() fails)."""
 
 from __future__ import annotations
 
diff --git a/tests/test_studio_shutdown_thread_wait.py b/tests/test_studio_shutdown_thread_wait.py
index 4ec2afc0f0..8299116d9a 100644
--- a/tests/test_studio_shutdown_thread_wait.py
+++ b/tests/test_studio_shutdown_thread_wait.py
@@ -130,4 +130,4 @@ def test_cli_entrypoints_wait_before_returning_to_shell():
 
     assert (
         _calls_shutdown_wait_getattr(tree) >= 3
-    ), "Studio CLI terminal paths must wait for the backend thread after requesting shutdown"
+    ), "Unsloth CLI terminal paths must wait for the backend thread after requesting shutdown"
diff --git a/tests/test_uma_safetensors_load.py b/tests/test_uma_safetensors_load.py
new file mode 100644
index 0000000000..c6d304ab4f
--- /dev/null
+++ b/tests/test_uma_safetensors_load.py
@@ -0,0 +1,229 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2023-present Daniel Han-Chen & the Unsloth team. All rights reserved.
+
+"""Unit tests for the UMA safetensors clone-then-move fast load.
+
+The module loads in isolation with a fake ``transformers.modeling_utils``. The
+CUDA correctness check needs a GPU; gating, passthrough, idempotency and opt-out
+are GPU-free. The gate is lazy (wrapper-time), so the wrapper installs
+everywhere and passes through when it's off.
+"""
+
+from __future__ import annotations
+
+import importlib.util
+import sys
+import types
+from pathlib import Path
+
+import pytest
+
+torch = pytest.importorskip("torch")
+safetensors_torch = pytest.importorskip("safetensors.torch")
+import safetensors  # noqa: E402
+
+_MODULE_PATH = Path(__file__).resolve().parent.parent / "unsloth" / "models" / "_uma_safetensors.py"
+
+
+def _load_module():
+    spec = importlib.util.spec_from_file_location("uma_safetensors_under_test", _MODULE_PATH)
+    assert spec is not None and spec.loader is not None
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module
+
+
+@pytest.fixture()
+def uma():
+    return _load_module()
+
+
+@pytest.fixture()
+def force_uma(uma, monkeypatch):
+    """Force the UMA gate on (or off) and keep the lru_cache from sticking."""
+
+    def _set(on):
+        monkeypatch.setenv("UNSLOTH_FORCE_UMA", "1" if on else "0")
+        uma.is_integrated_unified_memory_gpu.cache_clear()
+
+    yield _set
+    uma.is_integrated_unified_memory_gpu.cache_clear()
+
+
+@pytest.fixture()
+def tiny_safetensors(tmp_path):
+    tensors = {
+        "w": torch.arange(32, dtype = torch.float32).reshape(4, 8),
+        "b": torch.tensor([1.0, 2.0, 3.0, 4.0], dtype = torch.float32),
+    }
+    path = tmp_path / "model.safetensors"
+    safetensors_torch.save_file(tensors, str(path))
+    return path, tensors
+
+
+def _install_fake_modeling_utils(monkeypatch, safe_open_fn):
+    fake_transformers = types.ModuleType("transformers")
+    fake_mu = types.ModuleType("transformers.modeling_utils")
+    fake_mu.safe_open = safe_open_fn
+    fake_transformers.modeling_utils = fake_mu
+    monkeypatch.setitem(sys.modules, "transformers", fake_transformers)
+    monkeypatch.setitem(sys.modules, "transformers.modeling_utils", fake_mu)
+    return fake_mu
+
+
+# --- detection / gate ---
+
+
+def test_force_uma_on(uma, monkeypatch):
+    monkeypatch.setenv("UNSLOTH_FORCE_UMA", "1")
+    uma.is_integrated_unified_memory_gpu.cache_clear()
+    assert uma.is_integrated_unified_memory_gpu() is True
+
+
+def test_force_uma_off(uma, monkeypatch):
+    monkeypatch.setenv("UNSLOTH_FORCE_UMA", "0")
+    uma.is_integrated_unified_memory_gpu.cache_clear()
+    assert uma.is_integrated_unified_memory_gpu() is False
+
+
+@pytest.mark.parametrize(
+    "device,expected",
+    [
+        (0, True),
+        ("cuda", True),
+        ("cuda:0", True),
+        ("cpu", False),
+        ("disk", False),
+        (None, False),
+        (True, False),  # a bool is not a device index
+    ],
+)
+def test_is_cuda_target(uma, device, expected):
+    assert uma._is_cuda_target(device) is expected
+
+
+def test_is_cuda_target_torch_device(uma):
+    assert uma._is_cuda_target(torch.device("cuda", 0)) is True
+    assert uma._is_cuda_target(torch.device("cpu")) is False
+
+
+# --- patch gating ---
+
+
+def test_wrapper_passes_through_off_uma(uma, force_uma, monkeypatch):
+    """Gate OFF: every call -- including CUDA targets -- passes straight through
+    to the real safe_open (the gate is evaluated lazily inside the wrapper)."""
+    force_uma(False)
+    sentinel = object()
+    calls = []
+
+    def fake_safe_open(*args, **kwargs):
+        calls.append((args, kwargs))
+        return sentinel
+
+    fake_mu = _install_fake_modeling_utils(monkeypatch, fake_safe_open)
+    assert uma.patch_unified_memory_safetensors_load() is True
+    assert getattr(fake_mu.safe_open, "_unsloth_uma_clone", False) is True
+    out = fake_mu.safe_open("shard.safetensors", "pt", "cuda:0")
+    assert out is sentinel
+    assert calls == [(("shard.safetensors", "pt", "cuda:0"), {})]
+
+
+def test_patch_install_does_not_evaluate_gate(uma, monkeypatch):
+    """Installing the wrapper must NOT query the integrated-GPU property -- that
+    would init CUDA at ``import unsloth`` (fork-unsafe, and before the Spark
+    allocator config is set)."""
+
+    def _boom():
+        raise AssertionError("gate must not be evaluated at install time")
+
+    _install_fake_modeling_utils(monkeypatch, safetensors.safe_open)
+    monkeypatch.setattr(uma, "is_integrated_unified_memory_gpu", _boom)
+    assert uma.patch_unified_memory_safetensors_load() is True
+
+
+def test_patch_noop_when_opted_out(uma, force_uma, monkeypatch):
+    force_uma(True)
+    monkeypatch.setenv("UNSLOTH_DISABLE_UMA_CLONE_LOAD", "1")
+    real = object()
+    fake_mu = _install_fake_modeling_utils(monkeypatch, real)
+    assert uma.patch_unified_memory_safetensors_load() is False
+    assert fake_mu.safe_open is real
+
+
+def test_patch_installs_and_is_idempotent(uma, force_uma, monkeypatch):
+    force_uma(True)
+    fake_mu = _install_fake_modeling_utils(monkeypatch, safetensors.safe_open)
+    assert uma.patch_unified_memory_safetensors_load() is True
+    wrapped = fake_mu.safe_open
+    assert getattr(wrapped, "_unsloth_uma_clone", False) is True
+    # second call must not double-wrap
+    assert uma.patch_unified_memory_safetensors_load() is True
+    assert fake_mu.safe_open is wrapped
+
+
+# --- correctness ---
+
+
+def test_cpu_target_is_passthrough(uma, force_uma, monkeypatch, tiny_safetensors):
+    path, tensors = tiny_safetensors
+    force_uma(True)
+    fake_mu = _install_fake_modeling_utils(monkeypatch, safetensors.safe_open)
+    uma.patch_unified_memory_safetensors_load()
+    # device="cpu" must NOT be intercepted -> identical data, still on CPU.
+    with fake_mu.safe_open(str(path), framework = "pt", device = "cpu") as f:
+        for key, expected in tensors.items():
+            got = f.get_slice(key)[:]
+            assert got.device.type == "cpu"
+            assert torch.equal(got, expected)
+
+
+@pytest.mark.skipif(
+    not (hasattr(torch, "cuda") and torch.cuda.is_available()),
+    reason = "needs a GPU for the host->device clone-and-move path",
+)
+def test_cuda_target_clones_and_moves(uma, force_uma, monkeypatch, tiny_safetensors):
+    path, tensors = tiny_safetensors
+    force_uma(True)
+    fake_mu = _install_fake_modeling_utils(monkeypatch, safetensors.safe_open)
+    uma.patch_unified_memory_safetensors_load()
+    # device="cuda" IS intercepted -> tensors land on cuda, byte-identical.
+    with fake_mu.safe_open(str(path), framework = "pt", device = "cuda") as f:
+        for key, expected in tensors.items():
+            got = f.get_slice(key)[:]
+            assert got.device.type == "cuda"
+            assert torch.equal(got.cpu(), expected)
+            got_full = f.get_tensor(key)
+            assert got_full.device.type == "cuda"
+            assert torch.equal(got_full.cpu(), expected)
+
+
+@pytest.mark.skipif(
+    not (hasattr(torch, "cuda") and torch.cuda.is_available()),
+    reason = "needs a GPU for the low-memory fallback path",
+)
+def test_low_memory_falls_back_to_direct_move(uma, force_uma, monkeypatch, tiny_safetensors):
+    path, tensors = tiny_safetensors
+    force_uma(True)
+    fake_mu = _install_fake_modeling_utils(monkeypatch, safetensors.safe_open)
+    uma.patch_unified_memory_safetensors_load()
+    # Clone OOMs (transient CPU doubling on a constrained UMA box): the wrapper
+    # must fall back to the direct move and still succeed.
+    real_clone = torch.Tensor.clone
+
+    def _oom_clone(self, *a, **k):
+        raise RuntimeError("[enforce fail] not enough memory")
+
+    monkeypatch.setattr(torch.Tensor, "clone", _oom_clone)
+    try:
+        with fake_mu.safe_open(str(path), framework = "pt", device = "cuda") as f:
+            for key, expected in tensors.items():
+                got = f.get_slice(key)[:]
+                assert got.device.type == "cuda"
+                got_full = f.get_tensor(key)
+                assert got_full.device.type == "cuda"
+    finally:
+        monkeypatch.setattr(torch.Tensor, "clone", real_clone)
+    for key, expected in tensors.items():
+        with fake_mu.safe_open(str(path), framework = "pt", device = "cuda") as f:
+            assert torch.equal(f.get_tensor(key).cpu(), expected)
diff --git a/tests/utils/test_packing.py b/tests/utils/test_packing.py
index a8557d8533..1b8bb65058 100644
--- a/tests/utils/test_packing.py
+++ b/tests/utils/test_packing.py
@@ -14,6 +14,8 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 from unsloth import FastLanguageModel
+import unsloth.trainer as trainer_module
+import unsloth.utils.packing as packing_module
 from unsloth.utils import attention_dispatch as attention_dispatch_utils
 from unsloth.utils.packing import (
     configure_padding_free,
@@ -21,6 +23,7 @@ from unsloth.utils.packing import (
     enable_padding_free_metadata,
     enable_sample_packing,
     mask_packed_sequence_boundaries,
+    patch_hybrid_linear_attention_varlen,
 )
 
 from contextlib import ExitStack
@@ -29,7 +32,7 @@ from unittest.mock import patch
 
 import pytest
 import torch
-from datasets import Dataset
+from datasets import Dataset, IterableDataset
 from trl import SFTConfig, SFTTrainer
 from trl.trainer.sft_trainer import DataCollatorForLanguageModeling
 
@@ -160,6 +163,724 @@ def test_configure_padding_free():
     assert config.remove_unused_columns is False
 
 
+# --- Hybrid linear-attention guard + varlen shim (PR #7211 / #7249) ---------------
+
+
+def _hybrid_config_model():
+    # Qwen3.5 / Qwen3-Next style: explicit linear_attention layer schedule.
+    return SimpleNamespace(
+        config = SimpleNamespace(layer_types = ["linear_attention", "full_attention"])
+    )
+
+
+def _gemma3_model():
+    # Has layer_types but no linear_attention -> must NOT be flagged as hybrid.
+    return SimpleNamespace(
+        config = SimpleNamespace(
+            model_type = "gemma3", layer_types = ["sliding_attention", "full_attention"]
+        ),
+    )
+
+
+def _dense_qwen3_model():
+    return SimpleNamespace(
+        config = SimpleNamespace(model_type = "qwen3", architectures = ["Qwen3ForCausalLM"])
+    )
+
+
+class _FakeGatedDeltaNet(torch.nn.Module):
+    def __init__(self):
+        super().__init__()
+        self.conv1d = torch.nn.Conv1d(4, 4, 3, groups = 4)
+        self.A_log = torch.nn.Parameter(torch.zeros(4))
+
+    def forward(self, hidden_states, **kwargs):  # dispatch through self.<kernel>
+        return self.chunk_gated_delta_rule(self.causal_conv1d_fn(hidden_states))
+
+
+class _FakeHybridModel(torch.nn.Module):
+    def __init__(self):
+        super().__init__()
+        self.config = SimpleNamespace()  # no markers -> forces module-level detection
+        self.linear_attn = _FakeGatedDeltaNet()
+
+
+def test_is_hybrid_linear_attention_detects_and_excludes():
+    is_hybrid = trainer_module._is_hybrid_linear_attention_model
+    assert is_hybrid(_hybrid_config_model()) is True
+    assert is_hybrid(_FakeHybridModel()) is True  # module-structural evidence
+    assert is_hybrid(_text_model()) is False  # Llama
+    assert is_hybrid(_gemma3_model()) is False  # layer_types without linear_attention
+    assert is_hybrid(_dense_qwen3_model()) is False  # dense Qwen3
+    assert is_hybrid(None) is False
+
+
+def test_varlen_from_position_ids():
+    cu, seq_idx = packing_module._varlen_from_position_ids(torch.tensor([[0, 1, 0, 0, 1, 2]]))
+    assert cu.tolist() == [0, 2, 3, 6]
+    assert seq_idx.tolist() == [[0, 0, 1, 2, 2, 2]]
+    assert (
+        packing_module._varlen_from_position_ids(torch.tensor([[0, 1, 2, 3]])) is None
+    )  # single sequence
+    assert packing_module._varlen_from_position_ids(torch.tensor([[1, 2, 3]])) is None  # first != 0
+    assert (
+        packing_module._varlen_from_position_ids(torch.tensor([[0, 1], [0, 1]])) is None
+    )  # normal 2-row batch
+    assert packing_module._varlen_from_position_ids(None) is None
+
+
+def test_seq_idx_from_cu_seqlens_handles_trailing_pad():
+    cu = torch.tensor([0, 2, 5], dtype = torch.int32)
+    boundaries, seq_idx = packing_module._seq_idx_from_cu_seqlens(cu, total = 8)  # pad_to_multiple_of
+    assert boundaries.tolist() == [0, 2, 5, 8]
+    assert seq_idx.tolist() == [[0, 0, 1, 1, 1, 2, 2, 2]]
+    boundaries2, _ = packing_module._seq_idx_from_cu_seqlens(cu, total = 5)  # exact fit
+    assert boundaries2.tolist() == [0, 2, 5]
+    assert (
+        packing_module._seq_idx_from_cu_seqlens(torch.tensor([1, 2], dtype = torch.int32), total = 2)
+        is None
+    )
+    assert packing_module._seq_idx_from_cu_seqlens(cu, total = 3) is None  # boundaries exceed total
+
+
+def test_hybrid_varlen_metadata_prefers_packed_seq_lengths():
+    # A competing position_ids would segment [0, 3, 6]; packed_seq_lengths must win.
+    kwargs = {
+        "input_ids": torch.zeros(1, 6, dtype = torch.long),
+        "packed_seq_lengths": torch.tensor([2, 1, 3], dtype = torch.int32),
+        "position_ids": torch.tensor([[0, 1, 2, 0, 1, 2]]),
+    }
+    cu, seq_idx = packing_module._hybrid_varlen_metadata(kwargs)
+    assert cu.tolist() == [0, 2, 3, 6]
+    assert seq_idx.tolist() == [[0, 0, 1, 2, 2, 2]]
+
+
+def test_hybrid_varlen_metadata_suppressed_when_cached():
+    base = {
+        "input_ids": torch.zeros(1, 6, dtype = torch.long),
+        "packed_seq_lengths": torch.tensor([2, 1, 3], dtype = torch.int32),
+    }
+    assert packing_module._hybrid_varlen_metadata({**base, "use_cache": True}) is None
+    assert packing_module._hybrid_varlen_metadata({**base, "past_key_values": object()}) is None
+
+
+def test_hybrid_varlen_metadata_none_for_plain_batch():
+    kwargs = {
+        "input_ids": torch.zeros(1, 4, dtype = torch.long),
+        "position_ids": torch.tensor([[0, 1, 2, 3]]),
+    }
+    assert packing_module._hybrid_varlen_metadata(kwargs) is None
+
+
+def _make_fake_kernels():
+    def causal_conv1d_fn(
+        x,
+        weight = None,
+        bias = None,
+        activation = None,
+        seq_idx = None,
+    ):
+        causal_conv1d_fn.calls.append(seq_idx)
+        return x
+
+    causal_conv1d_fn.calls = []
+
+    def chunk_gated_delta_rule(
+        q,
+        k = None,
+        v = None,
+        cu_seqlens = None,
+        **kw,
+    ):
+        chunk_gated_delta_rule.calls.append(cu_seqlens)
+        return q
+
+    chunk_gated_delta_rule.calls = []
+    return causal_conv1d_fn, chunk_gated_delta_rule
+
+
+class _ShimGatedDeltaNet(torch.nn.Module):
+    def __init__(self):
+        super().__init__()
+        self.conv1d = torch.nn.Conv1d(4, 4, 3, groups = 4)
+        self.causal_conv1d_fn, self.chunk_gated_delta_rule = _make_fake_kernels()
+
+    def forward(self, hidden_states, **kwargs):
+        return self.chunk_gated_delta_rule(self.causal_conv1d_fn(hidden_states))
+
+
+class _ShimHybridModel(torch.nn.Module):
+    def __init__(self):
+        super().__init__()
+        self.config = SimpleNamespace(layer_types = ["linear_attention", "full_attention"])
+        self.linear_attn = _ShimGatedDeltaNet()
+
+    def forward(
+        self,
+        input_ids = None,
+        position_ids = None,
+        packed_seq_lengths = None,
+        use_cache = None,
+        **kwargs,
+    ):
+        return self.linear_attn(input_ids.float())
+
+
+def test_patch_hybrid_varlen_flag_off(monkeypatch):
+    monkeypatch.delenv("UNSLOTH_EXPERIMENTAL_HYBRID_PACKING", raising = False)
+    model = _ShimHybridModel()
+    assert patch_hybrid_linear_attention_varlen(model) is False
+    assert not getattr(model, "_unsloth_varlen_forward_wrapped", False)
+
+
+def test_patch_hybrid_varlen_active_and_idempotent(monkeypatch):
+    monkeypatch.setenv("UNSLOTH_EXPERIMENTAL_HYBRID_PACKING", "1")
+    model = _ShimHybridModel()
+    conv_orig, scan_orig = (
+        model.linear_attn.causal_conv1d_fn,
+        model.linear_attn.chunk_gated_delta_rule,
+    )
+
+    assert patch_hybrid_linear_attention_varlen(model) is True
+    assert model._unsloth_varlen_forward_wrapped is True
+    assert model.linear_attn._unsloth_varlen_wrapped is True
+    assert patch_hybrid_linear_attention_varlen(model) is True  # idempotent, no double-wrap
+
+    conv_orig.calls.clear()
+    scan_orig.calls.clear()
+    packing_module._HYBRID_WARNED.clear()
+    ids = torch.zeros(1, 6, dtype = torch.long)
+    model(
+        input_ids = ids,
+        packed_seq_lengths = torch.tensor([2, 1, 3], dtype = torch.int32),
+        use_cache = False,
+    )
+    assert conv_orig.calls[-1] is not None  # seq_idx injected
+    assert scan_orig.calls[-1].tolist() == [0, 2, 3, 6]  # cu_seqlens injected
+    assert not packing_module._HYBRID_WARNED  # handshake passed, no rejection
+
+    conv_orig.calls.clear()
+    scan_orig.calls.clear()
+    model(
+        input_ids = ids, packed_seq_lengths = torch.tensor([2, 1, 3], dtype = torch.int32), use_cache = True
+    )
+    assert conv_orig.calls[-1] is None  # cached forward -> no injection
+    assert scan_orig.calls[-1] is None
+
+
+def test_patch_hybrid_varlen_torch_fallback_fail_closed(monkeypatch):
+    monkeypatch.setenv("UNSLOTH_EXPERIMENTAL_HYBRID_PACKING", "1")
+    model = _ShimHybridModel()
+
+    def torch_chunk_gated_delta_rule(
+        q,
+        cu_seqlens = None,
+        **kw,
+    ):
+        return q
+
+    model.linear_attn.chunk_gated_delta_rule = torch_chunk_gated_delta_rule
+    assert patch_hybrid_linear_attention_varlen(model) is False
+    assert not getattr(model, "_unsloth_varlen_forward_wrapped", False)
+
+
+def test_patch_hybrid_varlen_bad_signature_fail_closed(monkeypatch):
+    monkeypatch.setenv("UNSLOTH_EXPERIMENTAL_HYBRID_PACKING", "1")
+    model = _ShimHybridModel()
+
+    def scan_no_cu(q, **kw):  # missing cu_seqlens
+        return q
+
+    model.linear_attn.chunk_gated_delta_rule = scan_no_cu
+    assert patch_hybrid_linear_attention_varlen(model) is False
+
+
+def _hybrid_model_with_gdn(gdn_forward):
+    # Build a fake hybrid model whose gated-delta mixer forward is `gdn_forward`.
+    class _GatedDeltaNet(torch.nn.Module):
+        def __init__(self):
+            super().__init__()
+            self.conv1d = torch.nn.Conv1d(4, 4, 3, groups = 4)
+            self.causal_conv1d_fn, self.chunk_gated_delta_rule = _make_fake_kernels()
+
+        forward = gdn_forward
+
+    class _Model(torch.nn.Module):
+        def __init__(self):
+            super().__init__()
+            self.config = SimpleNamespace(layer_types = ["linear_attention", "full_attention"])
+            self.linear_attn = _GatedDeltaNet()
+
+        def forward(
+            self,
+            input_ids = None,
+            packed_seq_lengths = None,
+            use_cache = None,
+            **kwargs,
+        ):
+            return self.linear_attn(input_ids.float())
+
+    return _Model()
+
+
+def test_patch_hybrid_varlen_no_dispatch_aborts(monkeypatch):
+    # Dispatch is verified at runtime, not statically. A mixer that never calls
+    # self.<kernel> installs the shim, but the first packed forward aborts (both
+    # boundary kernels are load-bearing).
+    monkeypatch.setenv("UNSLOTH_EXPERIMENTAL_HYBRID_PACKING", "1")
+    model = _hybrid_model_with_gdn(lambda self, hidden_states, **kw: hidden_states)
+    assert patch_hybrid_linear_attention_varlen(model) is True  # kernels valid -> installs
+    with pytest.raises(RuntimeError, match = "both invoked"):
+        model(
+            input_ids = torch.zeros(1, 6),
+            packed_seq_lengths = torch.tensor([2, 1, 3], dtype = torch.int32),
+            use_cache = False,
+        )
+
+
+def test_patch_hybrid_varlen_partial_dispatch_aborts(monkeypatch):
+    # Only the conv fires; the scan would leak state. Both must be invoked, so abort.
+    monkeypatch.setenv("UNSLOTH_EXPERIMENTAL_HYBRID_PACKING", "1")
+    conv_only = _hybrid_model_with_gdn(
+        lambda self, hidden_states, **kw: self.causal_conv1d_fn(hidden_states)
+    )
+    assert patch_hybrid_linear_attention_varlen(conv_only) is True
+    with pytest.raises(RuntimeError, match = "both invoked"):
+        conv_only(
+            input_ids = torch.zeros(1, 6),
+            packed_seq_lengths = torch.tensor([2, 1, 3], dtype = torch.int32),
+            use_cache = False,
+        )
+
+    scan_only = _hybrid_model_with_gdn(
+        lambda self, hidden_states, **kw: self.chunk_gated_delta_rule(hidden_states)
+    )
+    assert patch_hybrid_linear_attention_varlen(scan_only) is True
+    with pytest.raises(RuntimeError, match = "both invoked"):
+        scan_only(
+            input_ids = torch.zeros(1, 6),
+            packed_seq_lengths = torch.tensor([2, 1, 3], dtype = torch.int32),
+            use_cache = False,
+        )
+
+
+def test_varlen_from_position_ids_mrope_3d():
+    pos = (
+        torch.tensor([[0, 1, 0, 0, 1, 2]]).unsqueeze(0).expand(3, 1, 6).clone()
+    )  # [3,1,T] text plane
+    cu, seq_idx = packing_module._varlen_from_position_ids(pos)
+    assert cu.tolist() == [0, 2, 3, 6]
+    assert seq_idx.tolist() == [[0, 0, 1, 2, 2, 2]]
+
+
+def test_hybrid_varlen_metadata_trailing_pad():
+    # packed_seq_lengths sum to 6 but the flattened input is 8 (pad_to_multiple_of).
+    kwargs = {
+        "input_ids": torch.zeros(1, 8, dtype = torch.long),
+        "packed_seq_lengths": torch.tensor([2, 1, 3], dtype = torch.int32),
+    }
+    cu, seq_idx = packing_module._hybrid_varlen_metadata(kwargs)
+    assert cu.tolist() == [0, 2, 3, 6, 8]
+    assert seq_idx.tolist() == [[0, 0, 1, 2, 2, 2, 3, 3]]
+
+
+def _patch_fake_sft_trainer():
+    class FakeSFTTrainer:
+        def __init__(self, *args, **kwargs):
+            self.model = args[0] if len(args) >= 1 else kwargs["model"]
+            self.args = args[1] if len(args) >= 2 else kwargs["args"]
+            self.data_collator = args[2] if len(args) >= 3 else kwargs.get("data_collator")
+
+    trainer_module._patch_sft_trainer_auto_packing(SimpleNamespace(SFTTrainer = FakeSFTTrainer))
+    return FakeSFTTrainer
+
+
+def _vlm_model():
+    return SimpleNamespace(
+        config = SimpleNamespace(
+            architectures = ["Gemma4ForConditionalGeneration"],
+            model_type = "gemma4",
+            vision_config = SimpleNamespace(),
+        ),
+        max_seq_length = 16,
+    )
+
+
+def _text_model():
+    return SimpleNamespace(
+        config = SimpleNamespace(
+            architectures = ["LlamaForCausalLM"],
+            model_type = "llama",
+        ),
+        max_seq_length = 16,
+    )
+
+
+class _CharacterTokenizer:
+    bos_token = None
+    eos_token = None
+    chat_template = None
+
+    def __call__(self, texts, **kwargs):
+        is_batched = isinstance(texts, list)
+        if not is_batched:
+            texts = [texts]
+        input_ids = [[ord(char) for char in text] for text in texts]
+        if kwargs.get("truncation") and kwargs.get("max_length") is not None:
+            input_ids = [ids[: kwargs["max_length"]] for ids in input_ids]
+        return {"input_ids": input_ids if is_batched else input_ids[0]}
+
+
+def test_vlm_text_dataset_allows_explicit_packing():
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+
+    trainer = fake_trainer(
+        model = _vlm_model(),
+        args = config,
+        processing_class = object(),
+        train_dataset = Dataset.from_dict({"text": ["text-only CPT sample"]}),
+    )
+
+    assert config.packing is True
+    assert config.padding_free is True
+    assert trainer.model._unsloth_allow_packed_overlength is True
+
+
+def test_vlm_without_processing_class_still_disables_packing():
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+
+    fake_trainer(
+        _vlm_model(),
+        config,
+        None,
+        Dataset.from_dict({"text": ["text-only sample"]}),
+    )
+
+    assert config.packing is False
+    assert config.padding_free is False
+
+
+@pytest.mark.parametrize(
+    ("model_type", "architecture"),
+    (
+        ("t5", "T5ForConditionalGeneration"),
+        ("bart", "BartForConditionalGeneration"),
+        ("whisper", "WhisperForConditionalGeneration"),
+    ),
+)
+def test_encoder_decoder_disables_packing(model_type, architecture):
+    # Text-only encoder-decoder models are not VLMs, but their bidirectional encoder
+    # attends across concatenated samples once padding-free drops attention_mask.
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    model = SimpleNamespace(
+        config = SimpleNamespace(
+            model_type = model_type,
+            architectures = [architecture],
+            is_encoder_decoder = True,
+        ),
+        max_seq_length = 16,
+    )
+
+    trainer = fake_trainer(model, config, None, Dataset.from_dict({"text": ["text-only sample"]}))
+
+    assert config.packing is False
+    assert config.padding_free is False
+
+
+def test_decoder_only_conditional_generation_keeps_packing():
+    # CSM is decoder-only despite the ForConditionalGeneration name -> packing stays on.
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    model = SimpleNamespace(
+        config = SimpleNamespace(
+            model_type = "csm",
+            architectures = ["CsmForConditionalGeneration"],
+            is_encoder_decoder = False,
+        ),
+        max_seq_length = 16,
+    )
+
+    trainer = fake_trainer(model, config, None, Dataset.from_dict({"text": ["text-only sample"]}))
+
+    assert config.packing is True
+    assert config.padding_free is True
+    assert trainer.model._unsloth_allow_packed_overlength is True
+
+
+def _hybrid_trainer_model():
+    return SimpleNamespace(
+        config = SimpleNamespace(
+            model_type = "qwen3_next",
+            architectures = ["Qwen3NextForCausalLM"],
+            layer_types = ["linear_attention", "full_attention"],
+        ),
+        max_seq_length = 16,
+    )
+
+
+def test_hybrid_varlen_active_enables_packing(monkeypatch):
+    # Baseline: shim active + no forward bypass -> hybrid packing is allowed.
+    monkeypatch.setattr(trainer_module, "_chunked_loss_bypasses_forward", lambda config: False)
+    monkeypatch.setattr(trainer_module, "patch_hybrid_linear_attention_varlen", lambda model: True)
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    fake_trainer(_hybrid_trainer_model(), config, None, Dataset.from_dict({"text": ["x"]}))
+    assert config.packing is True
+    assert config.padding_free is True
+
+
+def test_hybrid_chunked_loss_stays_on_padded_path(monkeypatch):
+    # TRL's chunked-loss forward bypass leaves the varlen shim off -> block packing.
+    monkeypatch.setattr(trainer_module, "_chunked_loss_bypasses_forward", lambda config: True)
+    monkeypatch.setattr(trainer_module, "patch_hybrid_linear_attention_varlen", lambda model: True)
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    fake_trainer(_hybrid_trainer_model(), config, None, Dataset.from_dict({"text": ["x"]}))
+    assert config.packing is False
+    assert config.padding_free is False
+
+
+def test_string_hybrid_model_disables_packing(monkeypatch):
+    # A string model= is materialized after init; a hybrid string is blocked because the
+    # shim cannot patch a not-yet-built model.
+    monkeypatch.setattr(
+        trainer_module,
+        "_resolve_string_model_config",
+        lambda name, cfg: SimpleNamespace(
+            model_type = "qwen3_next",
+            architectures = ["Qwen3NextForCausalLM"],
+            layer_types = ["linear_attention", "full_attention"],
+        ),
+    )
+    monkeypatch.setattr(trainer_module, "patch_hybrid_linear_attention_varlen", lambda model: True)
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    fake_trainer("Qwen/Qwen3-Next-80B-A3B", config, None, Dataset.from_dict({"text": ["x"]}))
+    assert config.packing is False
+    assert config.padding_free is False
+
+
+def test_vlm_vision_dataset_still_disables_packing():
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+
+    fake_trainer(
+        _vlm_model(),
+        config,
+        None,
+        Dataset.from_dict({"images": [None], "text": ["multimodal sample"]}),
+        None,
+        object(),
+    )
+
+    assert config.packing is False
+    assert config.padding_free is False
+
+
+@pytest.mark.parametrize(
+    "vision_column",
+    ("pixel_values", "pixel_attention_mask", "image_grid_thw"),
+)
+def test_vlm_preprocessed_vision_dataset_disables_packing(vision_column):
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+
+    fake_trainer(
+        model = _vlm_model(),
+        args = config,
+        processing_class = object(),
+        train_dataset = Dataset.from_dict({"input_ids": [[1]], vision_column: [None]}),
+    )
+
+    assert config.packing is False
+    assert config.padding_free is False
+
+
+@pytest.mark.parametrize("dict_eval", (False, True))
+def test_vlm_vision_eval_dataset_disables_packing(dict_eval):
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    eval_dataset = Dataset.from_dict({"input_ids": [[1]], "pixel_values": [None]})
+    if dict_eval:
+        eval_dataset = {"vision": eval_dataset}
+
+    fake_trainer(
+        model = _vlm_model(),
+        args = config,
+        processing_class = object(),
+        train_dataset = Dataset.from_dict({"text": ["text-only training sample"]}),
+        eval_dataset = eval_dataset,
+    )
+
+    assert config.packing is False
+    assert config.padding_free is False
+
+
+def test_vlm_streaming_vision_dataset_without_metadata_disables_packing():
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    dataset = IterableDataset.from_generator(
+        lambda: iter([{"images": [None], "text": "multimodal sample"}])
+    )
+    assert dataset.column_names is None
+
+    fake_trainer(
+        model = _vlm_model(),
+        args = config,
+        processing_class = object(),
+        train_dataset = dataset,
+    )
+
+    assert config.packing is False
+    assert config.padding_free is False
+    assert next(iter(dataset))["text"] == "multimodal sample"
+
+
+@pytest.mark.parametrize("data_collator", (None, object()))
+def test_stateful_stream_is_not_consumed_during_detection(data_collator):
+    class StatefulDataset:
+        def __init__(self):
+            self.rows = iter([{"text": "first"}, {"text": "second"}])
+
+        def __iter__(self):
+            return (row for row in self.rows)
+
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    dataset = StatefulDataset()
+
+    fake_trainer(
+        model = _vlm_model(),
+        args = config,
+        processing_class = object(),
+        data_collator = data_collator,
+        train_dataset = dataset,
+    )
+
+    assert config.packing is False
+    assert config.padding_free is False
+    assert next(iter(dataset))["text"] == "first"
+
+
+def test_text_model_stream_without_metadata_keeps_packing():
+    class StatefulDataset:
+        def __init__(self):
+            self.rows = iter([{"text": "first"}, {"text": "second"}])
+
+        def __iter__(self):
+            return (row for row in self.rows)
+
+    fake_trainer = _patch_fake_sft_trainer()
+    config = SimpleNamespace(packing = True, padding_free = None, remove_unused_columns = True)
+    dataset = StatefulDataset()
+
+    trainer = fake_trainer(
+        model = _text_model(),
+        args = config,
+        processing_class = object(),
+        train_dataset = dataset,
+    )
+
+    assert config.packing is True
+    assert config.padding_free is True
+    assert trainer.model._unsloth_allow_packed_overlength is True
+    assert next(iter(dataset))["text"] == "first"
+
+
+def test_bfd_packing_truncates_before_packing(monkeypatch):
+    args = SimpleNamespace(
+        dataset_num_proc = 1,
+        dataset_text_field = "text",
+        max_length = 4,
+        packing_strategy = "bfd",
+    )
+    trainer = SimpleNamespace(model = None)
+    dataset = Dataset.from_dict({"prompt": ["abc"], "completion": ["defghij"]})
+    prepare_globals = SFTTrainer._prepare_dataset.__globals__
+
+    def passthrough_pack_dataset(dataset, seq_length, strategy, map_kwargs):
+        return dataset
+
+    monkeypatch.setitem(prepare_globals, "pack_dataset", passthrough_pack_dataset)
+    packed = SFTTrainer._prepare_dataset(
+        trainer,
+        dataset,
+        _CharacterTokenizer(),
+        args,
+        True,
+        None,
+        "train",
+    )
+
+    assert len(packed["input_ids"][0]) == args.max_length
+
+
+def test_wrapped_strategy_without_packing_still_truncates():
+    args = SimpleNamespace(
+        dataset_num_proc = 1,
+        dataset_text_field = "text",
+        max_length = 4,
+        packing_strategy = "wrapped",
+    )
+    trainer = SimpleNamespace(model = None)
+    dataset = Dataset.from_dict({"text": ["abcdefghi"]})
+
+    prepared = SFTTrainer._prepare_dataset(
+        trainer,
+        dataset,
+        _CharacterTokenizer(),
+        args,
+        False,
+        None,
+        "train",
+    )
+
+    assert len(prepared["input_ids"][0]) == args.max_length
+
+
+@pytest.mark.parametrize("legacy_api", (False, True))
+def test_wrapped_packing_preserves_overlength_tokens(monkeypatch, legacy_api):
+    args_kwargs = {
+        "dataset_num_proc": 1,
+        "dataset_text_field": "text",
+        "max_length": 4,
+    }
+    if not legacy_api:
+        args_kwargs["packing_strategy"] = "wrapped"
+    args = SimpleNamespace(**args_kwargs)
+    trainer = SimpleNamespace(model = None)
+    dataset = Dataset.from_dict({"text": ["abcdefghi"]})
+    prepare_globals = SFTTrainer._prepare_dataset.__globals__
+    pack_dataset = prepare_globals["pack_dataset"]
+
+    def legacy_pack_dataset(
+        dataset,
+        seq_length,
+        map_kwargs = None,
+    ):
+        return pack_dataset(dataset, seq_length, "wrapped", map_kwargs)
+
+    if legacy_api:
+        monkeypatch.setitem(prepare_globals, "pack_dataset", legacy_pack_dataset)
+
+    packed = SFTTrainer._prepare_dataset(
+        trainer,
+        dataset,
+        _CharacterTokenizer(),
+        args,
+        True,
+        None,
+        "train",
+    )
+
+    packed_ids = packed["input_ids"]
+    assert sum(len(input_ids) for input_ids in packed_ids) == 9
+    assert all(len(input_ids) <= args.max_length for input_ids in packed_ids)
+
+
 class _DummyChild(torch.nn.Module):
     def __init__(self):
         super().__init__()
@@ -390,3 +1111,128 @@ def test_packing_sdpa(tmp_path):
 
     if hasattr(trainer, "accelerator"):
         trainer.accelerator.free_memory()
+
+
+# --- wrapped-packing source-injection robustness (reviewer.py / fork findings) --------
+
+
+# fmt: off
+# Named to match the unsloth_zoo helper (sourced by name, "def sft_prepare_dataset" ->
+# "def _prepare_dataset"). Deliberately OMITS the "licensed under LGPLv3" header to
+# emulate a newer Zoo whose header moved (dependency is only lower-bounded). Source only.
+def sft_prepare_dataset(
+    self, dataset, processing_class, args, packing, formatting_func, dataset_text_field
+):
+    do_truncation = True
+    max_seq_length = 4
+    used_column_names = ["text"]
+    map_kwargs = {}
+    dataset = processing_class(dataset, truncation = do_truncation,)
+    if do_truncation and max_seq_length > 0:
+        pass
+    if packing:
+        dataset = pack_dataset(
+            dataset.select_columns(used_column_names),
+            max_seq_length,
+            getattr(args, "packing_strategy", "bfd"),
+            map_kwargs,
+        )
+    return dataset
+# fmt: on
+
+
+def test_wrapped_packing_injection_is_drift_resistant(monkeypatch):
+    # Regression: the setup used to anchor on the Zoo license comment, so a header
+    # change silently no-op'd it while the truncation/pack edits still referenced its
+    # variables -> NameError on every SFT prep. It must now install via the signature
+    # before those references, and the pack edit must reuse the guarded
+    # _unsloth_pack_has_strategy instead of re-calling _inspect.signature(pack_dataset).
+    import ast
+    import textwrap
+    import unsloth.models.rl_replacements as rlr
+
+    monkeypatch.setitem(rlr.RL_REPLACEMENTS, "sft_prepare_dataset", sft_prepare_dataset)
+
+    source = (
+        "def _prepare_dataset(self, dataset, processing_class, args, packing, "
+        "formatting_func, dataset_text_field):\n    return dataset\n"
+    )
+    patched = rlr.sft_trainer_prepare_dataset("_prepare_dataset", source)
+
+    # setup installed despite the missing header, and before it is referenced
+    assert "_unsloth_wrapped_packing = packing" in patched
+    assert "import inspect as _inspect" in patched
+    assert patched.index("_unsloth_wrapped_packing = packing") < patched.index(
+        "truncation = do_truncation and not _unsloth_wrapped_packing"
+    )
+    # the pack edit reuses the guarded flag (signature inspected exactly once, in setup)
+    assert "if _unsloth_pack_has_strategy:" in patched
+    assert patched.count("_inspect.signature(pack_dataset)") == 1
+    ast.parse(textwrap.dedent(patched))
+
+
+def test_require_replace_raises_on_missing_anchor():
+    from unsloth.models.rl_replacements import _require_replace
+
+    assert _require_replace("abc", "b", "B") == "aBc"
+    with pytest.raises(RuntimeError):
+        _require_replace("abc", "z", "Z", where = "unit test")
+    # an optional edit warns once and returns the source unchanged (no dangling ref)
+    assert _require_replace("abc", "z", "Z", required = False, where = "optional") == "abc"
+
+
+def test_resolve_string_model_config_forwards_token(monkeypatch):
+    import transformers
+
+    captured = {}
+
+    class _FakeAutoConfig:
+        @staticmethod
+        def from_pretrained(name, **kwargs):
+            captured.update(kwargs)
+            return SimpleNamespace(is_encoder_decoder = False)
+
+    monkeypatch.setattr(transformers, "AutoConfig", _FakeAutoConfig)
+
+    config_arg = SimpleNamespace(
+        model_init_kwargs = {
+            "token": "hf_secret",
+            "trust_remote_code": True,
+            "cache_dir": "/tmp/cache",
+            "torch_dtype": "bfloat16",  # not a config arg -> must NOT be forwarded
+        }
+    )
+    result = trainer_module._resolve_string_model_config("org/private-hybrid", config_arg)
+
+    assert result is not None
+    assert captured.get("token") == "hf_secret"
+    assert captured.get("trust_remote_code") is True
+    assert captured.get("cache_dir") == "/tmp/cache"
+    assert "torch_dtype" not in captured
+
+
+def test_resolve_string_model_config_merges_top_level_trust_remote_code(monkeypatch):
+    import transformers
+
+    captured = {}
+
+    class _FakeAutoConfig:
+        @staticmethod
+        def from_pretrained(name, **kwargs):
+            captured.update(kwargs)
+            return SimpleNamespace(is_encoder_decoder = False)
+
+    monkeypatch.setattr(transformers, "AutoConfig", _FakeAutoConfig)
+
+    # SFTConfig(trust_remote_code=True) with no model_init_kwargs entry is honored
+    config_arg = SimpleNamespace(model_init_kwargs = {}, trust_remote_code = True)
+    trainer_module._resolve_string_model_config("org/remote-hybrid", config_arg)
+    assert captured.get("trust_remote_code") is True
+
+    # model_init_kwargs wins over the top-level flag (mirrors TRL's setdefault)
+    captured.clear()
+    config_arg = SimpleNamespace(
+        model_init_kwargs = {"trust_remote_code": False}, trust_remote_code = True
+    )
+    trainer_module._resolve_string_model_config("org/remote-hybrid", config_arg)
+    assert captured.get("trust_remote_code") is False
diff --git a/tests/version_compat/test_trl_fake_train_cpu.py b/tests/version_compat/test_trl_fake_train_cpu.py
index 4dae696282..2f7b469428 100644
--- a/tests/version_compat/test_trl_fake_train_cpu.py
+++ b/tests/version_compat/test_trl_fake_train_cpu.py
@@ -158,6 +158,37 @@ except Exception:
 _MODEL = "hf-internal-testing/tiny-random-LlamaForCausalLM"
 
 
+def _guard_finite_logits(model):
+    """Keep the LM head logits finite so GRPO sampling can't crash.
+
+    ``test_grpo_trains_on_cpu`` samples completions from a tiny, *untrained*
+    random model on CPU. Driven autoregressively -- and nudged by the fake
+    reward's optimizer step between the two train steps -- such a model can emit
+    non-finite logits, so ``torch.multinomial`` inside ``generate()``
+    intermittently raises "probability tensor contains either `inf`, `nan` or
+    element < 0". That is a well-known nondeterministic sampling failure, not an
+    Unsloth/TRL regression: the Trainer already fixes the seed, but CPU reduction
+    order is not bit-reproducible, so the blow-up still surfaces every so often.
+
+    Sanitize the logits to a finite, bounded range (out of place, so autograd
+    stays valid) before they reach the sampler. This test asserts the train loop
+    runs end to end, not the (deliberately meaningless) numerics, so bounding the
+    logits changes nothing it checks while making the run reliable.
+    """
+
+    def _finite_logits_hook(_module, _inputs, output):
+        logits = getattr(output, "logits", None)
+        if logits is None:
+            return output
+        # nan_to_num maps nan -> 0 and the infinities to large finite values;
+        # clamp then bounds everything to [-30, 30].
+        output.logits = torch.nan_to_num(logits).clamp(-30.0, 30.0)
+        return output
+
+    model.register_forward_hook(_finite_logits_hook)
+    return model
+
+
 def _load_plain():
     """Tiny plain HF model + tokenizer on CPU. Skips (not fails) if the model
     cannot be fetched -- that is a network/hub issue, not an unsloth regression."""
@@ -233,6 +264,11 @@ def test_grpo_trains_on_cpu(tmp_path):
 
     assert GRPOTrainer.__name__ == "UnslothGRPOTrainer", "GRPO patch did not apply"
     model, tok = _load_plain()
+    # GRPO is the only canary that autoregressively samples completions, so it is
+    # the only one that can hit the non-finite-logits multinomial crash. Install
+    # the guard here (not in _load_plain) so the SFT/DPO canaries keep asserting
+    # against the model's true, unclamped outputs.
+    _guard_finite_logits(model)
     ds = Dataset.from_list([{"prompt": "hi there"}] * 4)
     cfg = GRPOConfig(
         output_dir = str(tmp_path / "ci_grpo"),
diff --git a/unsloth-cli.py b/unsloth-cli.py
index be48893d8d..a8a9fa78d0 100644
--- a/unsloth-cli.py
+++ b/unsloth-cli.py
@@ -189,6 +189,10 @@ def run(args):
 
     is_mlx = _is_mlx_backend(unsloth)
 
+    # MLX routes get_peft_model to FastMLXModel, which ignores use_dora (plain LoRA).
+    if args.use_dora and is_mlx:
+        raise NotImplementedError("DoRA is not supported for MLX training yet.")
+
     # Load model and tokenizer
     device_map, distributed = _prepare_device_map(is_mlx)
     model, tokenizer = FastLanguageModel.from_pretrained(
@@ -219,6 +223,7 @@ def run(args):
         random_state = args.random_state,
         use_rslora = args.use_rslora,
         loftq_config = args.loftq_config,
+        use_dora = args.use_dora,
     )
 
     alpaca_prompt = """Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.
@@ -374,6 +379,11 @@ if __name__ == "__main__":
         default = None,
         help = "Configuration for LoftQ",
     )
+    lora_group.add_argument(
+        "--use_dora",
+        action = "store_true",
+        help = "Use DoRA (Weight-Decomposed LoRA)",
+    )
 
     training_group = parser.add_argument_group("🎓 Training Options")
     training_group.add_argument(
diff --git a/unsloth/chat_templates.py b/unsloth/chat_templates.py
index 2d3674fb04..b857c34bcb 100644
--- a/unsloth/chat_templates.py
+++ b/unsloth/chat_templates.py
@@ -1929,6 +1929,9 @@ def get_chat_template(
             string_vocab = tokenizer._tokenizer.to_str()
 
             skipped = 0
+            # Only mirror applied mappings into the spm model; a skipped one would
+            # rename a piece the JSON never changed and desync the two.
+            applied_mapping = {}
             for old_token, new_token in token_mapping.items():
                 old_count = string_vocab.count(f'"{old_token}"')
                 new_count = string_vocab.count(f'"{new_token}"')
@@ -1939,6 +1942,7 @@ def get_chat_template(
                     raise RuntimeError(f"{old_token} was not part of the tokenizer!")
                 else:
                     string_vocab = string_vocab.replace(f'"{old_token}"', f'"{new_token}"')
+                    applied_mapping[old_token] = new_token
                 pass
             pass
 
@@ -1973,7 +1977,7 @@ def get_chat_template(
 
                 # Must fix the sentence piece tokenizer since there's no tokenizer.model file!
                 from .tokenizer_utils import fix_sentencepiece_tokenizer
-                tokenizer = fix_sentencepiece_tokenizer(tokenizer, new_tokenizer, token_mapping,)
+                tokenizer = fix_sentencepiece_tokenizer(tokenizer, new_tokenizer, applied_mapping,)
             else:
                 pass
 
@@ -1997,8 +2001,11 @@ def get_chat_template(
                 string_vocab = string_vocab.replace(old_eos_token, temporary_stop_token)
                 string_vocab = string_vocab.replace(stop_word, old_eos_token)
                 string_vocab = string_vocab.replace(temporary_stop_token, stop_word)
+                # JSON swapped both, so swap both here too; a one-way map leaves two stop_word pieces.
+                sentencepiece_mapping = { old_eos_token : stop_word, stop_word : old_eos_token, }
             else:
                 string_vocab = string_vocab.replace(old_eos_token, stop_word)
+                sentencepiece_mapping = { old_eos_token : stop_word, }
             pass
             new_tokenizer = tokenizer._tokenizer.from_str(string_vocab)
 
@@ -2017,9 +2024,8 @@ def get_chat_template(
             )
 
             # Must fix the sentence piece tokenizer since there's no tokenizer.model file!
-            token_mapping = { old_eos_token : stop_word, }
             from .tokenizer_utils import fix_sentencepiece_tokenizer
-            tokenizer = fix_sentencepiece_tokenizer(tokenizer, new_tokenizer, token_mapping,)
+            tokenizer = fix_sentencepiece_tokenizer(tokenizer, new_tokenizer, sentencepiece_mapping,)
         pass
 
     else:
@@ -2041,7 +2047,7 @@ def get_chat_template(
         .replace("'assistant'", "'" + mapping["assistant"] + "'")
 
     if use_zoo_tokenizer_patch:
-        # Studio MLX avoids the model-utils tokenizer wrapper because that
+        # Unsloth MLX avoids the model-utils tokenizer wrapper because that
         # import path pulls in Torch/GPU-specific modules before MLX training.
         from unsloth_zoo.tokenizer_utils import patch_tokenizer
     else:
@@ -2646,6 +2652,12 @@ extra_eos_tokens = None,
                 "{{ '" + full_system + "' }}"\
                 "{% set loop_messages = messages %}"\
             "{% endif %}"
+        elif "{SYSTEM}" in system_part:
+            # Only bind loop_messages when the template can render a caller system
+            # message. A static prefix with no {SYSTEM} must still raise, not drop it.
+            partial_system += "{% else %}"\
+                "{% set loop_messages = messages %}"\
+            "{% endif %}"
         else:
             partial_system += "{% endif %}"
 
diff --git a/unsloth/dataprep/raw_text.py b/unsloth/dataprep/raw_text.py
index 128d966ecd..fdaba181f1 100644
--- a/unsloth/dataprep/raw_text.py
+++ b/unsloth/dataprep/raw_text.py
@@ -87,6 +87,10 @@ class RawTextDataLoader:
                 text_content, self.chunk_size, self.stride, return_tokenized
             )
             all_chunks.extend(chunks)
+        if not all_chunks:
+            # All files empty/whitespace: raise like load_from_file instead of
+            # create_causal_dataset([]) returning a 0-row text-column dataset.
+            raise ValueError("All files are empty or contain only whitespace")
         return self.create_causal_dataset(all_chunks)
 
     def chunk_text(
@@ -139,6 +143,12 @@ class RawTextDataLoader:
                 f"stride ({stride}) must be smaller than chunk_size ({chunk_size}) to progress the chunking loop"
             )
 
+        # Skip empty/whitespace text before tokenizing: BPE/SentencePiece emit
+        # real tokens for spaces/newlines, so a len(tokens)==0 check misses it
+        # and would yield a degenerate lone-EOS sample. Mirrors load_from_file.
+        if not text or not text.strip():
+            return []
+
         # Tokenize the whole text once for accurate token counts
         tokenized = self.tokenizer(text, return_tensors = "pt", add_special_tokens = False)
         tokens = tokenized["input_ids"]
@@ -236,6 +246,10 @@ class RawTextDataLoader:
 
     def _extract_text_from_json(self, data):
         """Extract text from JSON object using common field names."""
+        # Skip non-object lines (str/list/number): `field in data` would be a
+        # substring/membership test, not a key lookup, and `data[field]` raises.
+        if not isinstance(data, dict):
+            return ""
         for field in self._TEXT_FIELDS:
             if field in data and isinstance(data[field], str):
                 return data[field]
diff --git a/unsloth/import_fixes.py b/unsloth/import_fixes.py
index 09de248c7b..9cd5e7243a 100644
--- a/unsloth/import_fixes.py
+++ b/unsloth/import_fixes.py
@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from __future__ import annotations
+
 import os
 import importlib.abc
 import importlib.machinery
@@ -1525,6 +1527,59 @@ def patch_torchcodec_audio_decoder():
         pass
 
 
+# torch.minor -> compatible torchcodec.minor strings (see notebook_validator.py).
+_TORCH_TORCHCODEC_MINORS: dict[str, set[str]] = {
+    "2.10": {"0.10"},
+    "2.9": {"0.8", "0.9"},
+    "2.8": {"0.6", "0.7"},
+    "2.7": {"0.3", "0.4", "0.5"},
+    "2.6": {"0.2", "0.3"},
+    "2.5": {"0.1", "0.2"},
+}
+
+
+def _torchcodec_exclusive_upper(pin: str) -> str:
+    """Next torchcodec minor as an exclusive pip upper bound (0.10 -> <0.11.0)."""
+    major, minor = pin.split(".", 1)
+    return f"<{major}.{int(minor) + 1}.0"
+
+
+def _torchcodec_version_mismatch_hint() -> str | None:
+    """Return a user-facing hint when installed torchcodec mismatches torch."""
+    try:
+        import importlib.metadata as importlib_metadata
+        import torch
+        from packaging.version import Version
+
+        torchcodec_version = importlib_metadata.version("torchcodec")
+    except Exception:
+        return None
+
+    def _minor(version: str) -> str:
+        parts = Version(version.split("+", 1)[0]).release
+        return ".".join(str(p) for p in parts[:2])
+
+    try:
+        torch_minor = _minor(torch.__version__)
+        codec_minor = _minor(torchcodec_version)
+    except Exception:
+        # Non-PEP440 version strings must never break `import unsloth`.
+        return None
+    allowed = _TORCH_TORCHCODEC_MINORS.get(torch_minor)
+    if allowed is None or codec_minor in allowed:
+        return None
+
+    pin = sorted(allowed)[-1]
+    upper = _torchcodec_exclusive_upper(pin)
+    install_hint = f"`pip install 'torchcodec>={pin},{upper}'`"
+    if torch_minor == "2.10":
+        install_hint += " or `pip install 'unsloth[audio-torch210]'`"
+    return (
+        f"torchcodec {torchcodec_version} is incompatible with torch {torch.__version__}; "
+        f"install a matching build with {install_hint}."
+    )
+
+
 def disable_torchcodec_if_broken():
     """Make broken torchcodec behave as if uninstalled (#5446).
 
@@ -1533,6 +1588,15 @@ def disable_torchcodec_if_broken():
     flags and seat a sys.modules sentinel so downstream imports fall through
     their existing except ImportError handlers cleanly.
     """
+    mismatch_hint = _torchcodec_version_mismatch_hint()
+    if mismatch_hint is not None:
+        try:
+            import warnings
+            warnings.warn(mismatch_hint, stacklevel = 2)
+        except Exception:
+            # Warning filters promoted to errors must not abort the disable
+            # fallback below (e.g. PYTHONWARNINGS=error, pytest -W error).
+            pass
     try:
         import importlib.util
         if importlib.util.find_spec("torchcodec") is None:
@@ -3008,7 +3072,7 @@ def maybe_set_windows_rocm_bnb_version():
 
     No-op unless ALL of: Windows, a real HIP torch build (env hints like
     HIP_PATH do not count), a ROCm DLL installed, and no explicit user value.
-    Linux is untouched. Values seeded by Studio's venv sitecustomize.py
+    Linux is untouched. Values seeded by Unsloth's venv sitecustomize.py
     (marked ``UNSLOTH_BNB_ROCM_VERSION_SOURCE=sitecustomize``) are
     redetectable defaults, not overrides; ``UNSLOTH_SKIP_BNB_ROCM_VERSION=1``
     opts out and drops a seeded default. Returns the value set, else None.
diff --git a/unsloth/kernels/utils.py b/unsloth/kernels/utils.py
index 1b0b5ce12e..ccfedfdef0 100644
--- a/unsloth/kernels/utils.py
+++ b/unsloth/kernels/utils.py
@@ -325,7 +325,10 @@ def get_lora_parameters(proj):
     if getattr(base_layer, "quant_method", None) == "fp8":
         # we need to somehow store and pass this information :)
         W.block_size = getattr(base_layer, "block_size", [128, 128])
-        W_quant.block_size = W.block_size
+        # A decompressed compressed-tensors layer keeps quant_method == "fp8" while its
+        # weight is back to bf16, so it has no quant state to carry the block size.
+        if W_quant is not None:
+            W_quant.block_size = W.block_size
 
     # if not hasattr(proj, "disable_adapters") or proj.disable_adapters or proj.merged:
     if getattr(proj, "disable_adapters", True) or proj.merged:
@@ -375,14 +378,17 @@ def get_lora_parameters_bias(proj):
         if W_quant is None:
             W_quant = getattr(base_layer, "weight_scale", None)
 
-    # if not hasattr(proj, "disable_adapters") or proj.disable_adapters or proj.merged:
-    if getattr(proj, "disable_adapters", True) or proj.merged:
-        return W, W_quant, None, None, None, base_layer.bias
-
     if getattr(base_layer, "quant_method", None) == "fp8":
         # we need to somehow store and pass this information :)
         W.block_size = getattr(base_layer, "block_size", [128, 128])
-        W_quant.block_size = W.block_size
+        # A decompressed compressed-tensors layer keeps quant_method == "fp8" while its
+        # weight is back to bf16, so it has no quant state to carry the block size.
+        if W_quant is not None:
+            W_quant.block_size = W.block_size
+
+    # if not hasattr(proj, "disable_adapters") or proj.disable_adapters or proj.merged:
+    if getattr(proj, "disable_adapters", True) or proj.merged:
+        return W, W_quant, None, None, None, base_layer.bias
 
     adapter = getattr(proj, "active_adapters", None)
     if adapter is None:
diff --git a/unsloth/models/_uma_safetensors.py b/unsloth/models/_uma_safetensors.py
new file mode 100644
index 0000000000..38d8b7d33a
--- /dev/null
+++ b/unsloth/models/_uma_safetensors.py
@@ -0,0 +1,169 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2023-present Daniel Han-Chen & the Unsloth team. All rights reserved.
+
+"""Faster safetensors weight loading on unified-memory (integrated) GPUs.
+
+A direct ``safe_open(..., device=<cuda>)`` on CUDA/HIP UMA GPUs (AMD APUs,
+NVIDIA GB10 Spark) misses torch's fast pinned-DMA path: the mmap-backed
+safetensors buffers aren't recognized, so it falls to a slow per-tensor copy
+with page faults. Cloning each tensor into a normal torch CPU allocation before
+moving it restores the fast path; outputs are bit-identical.
+
+CUDA/HIP only, and only for loads that pass a CUDA device to ``safe_open``
+directly: Intel XPU iGPUs and the CPU-open + later ``.to()`` flows (e.g. bnb /
+HQQ quantized loads) keep the stock path until they can be validated on real
+hardware.
+"""
+
+import os
+import functools
+
+import torch
+
+__all__ = [
+    "is_integrated_unified_memory_gpu",
+    "patch_unified_memory_safetensors_load",
+]
+
+
+@functools.lru_cache(maxsize = None)
+def is_integrated_unified_memory_gpu():
+    """True only when EVERY visible CUDA/HIP device is integrated (UMA).
+
+    Discrete and mixed discrete+iGPU boxes return False (pinned-DMA already
+    works there). Test override: ``UNSLOTH_FORCE_UMA=1`` / ``=0``.
+    """
+    _force = os.environ.get("UNSLOTH_FORCE_UMA")
+    if _force == "1":
+        return True
+    if _force == "0":
+        return False
+    try:
+        if not (hasattr(torch, "cuda") and torch.cuda.is_available()):
+            return False
+        count = torch.cuda.device_count()
+        if count == 0:
+            return False
+        for index in range(count):
+            props = torch.cuda.get_device_properties(index)
+            if not getattr(props, "is_integrated", 0):
+                return False
+        return True
+    except Exception:
+        return False
+
+
+def _is_cuda_target(device):
+    """Does a ``safe_open`` ``device=`` arg name a CUDA/HIP device?"""
+    if isinstance(device, bool):
+        return False
+    if isinstance(device, int):
+        return True
+    if isinstance(device, str):
+        return device == "cuda" or device.startswith("cuda:")
+    try:
+        return isinstance(device, torch.device) and device.type == "cuda"
+    except Exception:
+        return False
+
+
+def patch_unified_memory_safetensors_load():
+    """Wrap ``transformers.modeling_utils.safe_open`` so CUDA-target shard loads
+    open on CPU then clone+``.to(device)``, restoring the UMA fast path.
+
+    Gated to integrated GPUs (no-op on discrete/CPU/XPU/MLX), ``framework="pt"``
+    CUDA targets only, idempotent. Opt out: ``UNSLOTH_DISABLE_UMA_CLONE_LOAD=1``.
+
+    The gate runs lazily inside the wrapper, never here: probing device
+    properties at install would init CUDA during ``import unsloth`` -- breaking
+    fork multiprocessing and preempting ``patch_dgx_spark_memory_config``'s
+    allocator config. Returns ``True`` if the wrapper was installed.
+    """
+    if os.environ.get("UNSLOTH_DISABLE_UMA_CLONE_LOAD") == "1":
+        return False
+    try:
+        from transformers import modeling_utils as _mu
+    except Exception:
+        return False
+    real_safe_open = getattr(_mu, "safe_open", None)
+    if real_safe_open is None:
+        return False
+    if getattr(real_safe_open, "_unsloth_uma_clone", False):
+        return True
+
+    def _clone_move(tensor, device):
+        # Clone into a regular CPU allocation to restore fast pinned-DMA, then
+        # move. The clone transiently doubles the tensor's CPU footprint and can
+        # OOM a low-memory UMA box; fall back to the direct, allocation-free move
+        # (a genuine non-memory error re-raises identically from it).
+        try:
+            return tensor.clone().to(device, non_blocking = False)
+        except (MemoryError, RuntimeError):
+            return tensor.to(device, non_blocking = False)
+
+    class _ClonedSlice:
+        """Proxy over a safetensors ``PySafeSlice`` that clones+moves on read."""
+
+        __slots__ = ("_real", "_device")
+
+        def __init__(self, real, device):
+            self._real = real
+            self._device = device
+
+        def __getattr__(self, name):
+            if name in ("_real", "_device"):
+                raise AttributeError(name)
+            return getattr(self._real, name)
+
+        def __getitem__(self, key):
+            return _clone_move(self._real[key], self._device)
+
+    class _ClonedSafeOpen:
+        """Safetensors-handle proxy: load on CPU, clone+move tensors to CUDA."""
+
+        __slots__ = ("_real", "_device")
+
+        def __init__(self, args, kwargs):
+            self._device = kwargs.get("device", args[2] if len(args) > 2 else "cpu")
+            # Open on CPU; move ourselves.
+            if len(args) > 2:
+                args = args[:2] + ("cpu",) + tuple(args[3:])
+            else:
+                kwargs = dict(kwargs)
+                kwargs["device"] = "cpu"
+            self._real = real_safe_open(*args, **kwargs)
+
+        def __enter__(self):
+            self._real.__enter__()
+            return self
+
+        def __exit__(self, *exc):
+            return self._real.__exit__(*exc)
+
+        def __getattr__(self, name):
+            if name in ("_real", "_device"):
+                raise AttributeError(name)
+            return getattr(self._real, name)
+
+        def get_slice(self, name):
+            return _ClonedSlice(self._real.get_slice(name), self._device)
+
+        def get_tensor(self, name):
+            return _clone_move(self._real.get_tensor(name), self._device)
+
+    @functools.wraps(real_safe_open)
+    def _uma_safe_open(*args, **kwargs):
+        framework = kwargs.get("framework", args[1] if len(args) > 1 else None)
+        device = kwargs.get("device", args[2] if len(args) > 2 else "cpu")
+        # Device check first: non-CUDA loads must not trigger the CUDA-init gate.
+        if (
+            framework in ("pt", "pytorch")
+            and _is_cuda_target(device)
+            and is_integrated_unified_memory_gpu()
+        ):
+            return _ClonedSafeOpen(args, kwargs)
+        return real_safe_open(*args, **kwargs)
+
+    _uma_safe_open._unsloth_uma_clone = True
+    _mu.safe_open = _uma_safe_open
+    return True
diff --git a/unsloth/models/_utils.py b/unsloth/models/_utils.py
index 3d41b505df..0b3a3698c2 100644
--- a/unsloth/models/_utils.py
+++ b/unsloth/models/_utils.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "2026.7.3"
+__version__ = "2026.7.5"
 
 __all__ = [
     "SUPPORTS_BFLOAT16",
@@ -1670,6 +1670,13 @@ except:
 from transformers.modeling_utils import logger as transformers_logger
 
 
+# Faster safetensors loads on UMA (integrated) GPUs; lazy gate keeps this import
+# fork-safe (no CUDA init). No-op off-UMA. Opt out: UNSLOTH_DISABLE_UMA_CLONE_LOAD=1.
+from ._uma_safetensors import patch_unified_memory_safetensors_load
+
+patch_unified_memory_safetensors_load()
+
+
 def _all_missing_keys_are_position_ids(record_str):
     """True only when EVERY key in the 'newly initialized: [...]' list is a position_ids
     buffer.
diff --git a/unsloth/models/diffusion.py b/unsloth/models/diffusion.py
index 955bf55987..85026802d8 100644
--- a/unsloth/models/diffusion.py
+++ b/unsloth/models/diffusion.py
@@ -290,6 +290,10 @@ class FastDiffusionModel:
         if target_modules is None:
             target_modules = DIFFUSION_LORA_TARGETS
 
+        # NOTE: use_dora (and any other LoraConfig kwarg outside this allowlist,
+        # e.g. use_rslora) is silently dropped here. Studio does not reach this
+        # path today, so it's untested/unsupported on diffusion models; add it
+        # to the allowlist below if that changes.
         lora_kwargs = dict(
             r = r,
             lora_alpha = lora_alpha,
diff --git a/unsloth/models/llama.py b/unsloth/models/llama.py
index defacadfee..4d4daec59f 100644
--- a/unsloth/models/llama.py
+++ b/unsloth/models/llama.py
@@ -3140,6 +3140,15 @@ class FastLlamaModel:
             for param in check_parameters:
                 check_all = check_all and (peft_config[param] == eval(param))
 
+            # use_dora arrives via **kwargs, not a named parameter of this
+            # function, so it can't go in check_parameters (which uses
+            # eval(param) and needs each entry to be a bound local name).
+            # Compare it explicitly so a DoRA request against an existing
+            # plain-LoRA adapter doesn't silently pass through unchanged.
+            check_all = check_all and (
+                bool(peft_config.get("use_dora", False)) == bool(kwargs.get("use_dora", False))
+            )
+
             # Check save_modules
             old_target_modules = list(peft_config["target_modules"])
             modules_to_save = peft_config["modules_to_save"]
diff --git a/unsloth/models/loader_utils.py b/unsloth/models/loader_utils.py
index 1e9cc641e9..7661b0d714 100644
--- a/unsloth/models/loader_utils.py
+++ b/unsloth/models/loader_utils.py
@@ -821,7 +821,7 @@ def _exclude_rope_inv_freq_from_ddp(model):
 
 # =============================================================================
 # Offline loading - single source of truth (shared by vision.py, loader.py and
-# the Studio exporter). Decide offline ONCE at the load boundary and force it
+# the Unsloth exporter). Decide offline ONCE at the load boundary and force it
 # ONCE around the whole load, so every nested HF call inherits it.
 # =============================================================================
 
diff --git a/unsloth/models/rl_replacements.py b/unsloth/models/rl_replacements.py
index ffb845b04f..4ef3af6add 100644
--- a/unsloth/models/rl_replacements.py
+++ b/unsloth/models/rl_replacements.py
@@ -276,17 +276,13 @@ def dpo_trainer_vision_signature_columns(function_name, function):
     _extra_columns = "".join(f'                "{_k}",\n' for _k in _DPO_VISION_KEYS)
     new_function = function.replace(
         '                "image_sizes",\n                "token_type_ids",\n',
-        f'                "image_sizes",\n'
-        f"{_extra_columns}"
-        f'                "token_type_ids",\n',
+        f'                "image_sizes",\n{_extra_columns}                "token_type_ids",\n',
     )
     if new_function != function:
         return new_function
     return function.replace(
         '                "image_sizes",\n                "ref_chosen_logps",\n',
-        f'                "image_sizes",\n'
-        f"{_extra_columns}"
-        f'                "ref_chosen_logps",\n',
+        f'                "image_sizes",\n{_extra_columns}                "ref_chosen_logps",\n',
     )
 
 
@@ -441,6 +437,52 @@ RL_FUNCTIONS["dpo_trainer"].append(dpo_trainer_compute_loss_liger)
 RL_EXTRA_ARGS["dpo_trainer"].append(dpo_trainer_data_collator_vision_keys)
 
 
+_WRAPPED_PACKING_SETUP = (
+    "    import inspect as _inspect\n"
+    "    try:\n"
+    '        _unsloth_pack_has_strategy = "strategy" in _inspect.signature(pack_dataset).parameters\n'
+    "    except Exception:\n"
+    "        _unsloth_pack_has_strategy = True\n"
+    "    _unsloth_wrapped_packing = packing and (\n"
+    '        getattr(args, "packing_strategy", None) == "wrapped"\n'
+    "        or not _unsloth_pack_has_strategy\n"
+    "    )\n"
+)
+
+_WARNED_MISSING_ANCHORS = set()
+
+
+def _require_replace(
+    function,
+    old,
+    new,
+    *,
+    count = 1,
+    required = True,
+    where = "",
+):
+    """str.replace that never silently no-ops a load-bearing source edit.
+
+    Plain str.replace returns the source unchanged when the anchor is absent, so a
+    drifted anchor in a newer TRL / unsloth_zoo would skip the edit while later edits
+    still reference helper variables it should have introduced (NameError at runtime).
+    Fail loudly for a required edit, warn once and skip for an optional one, so a
+    drifted source can never corrupt the patched function silently.
+    """
+    if old not in function:
+        detail = f" ({where})" if where else ""
+        if required:
+            raise RuntimeError(
+                f"Unsloth: source anchor not found{detail}; the patched function is out "
+                "of sync with this TRL / unsloth_zoo version. Please file a bug report."
+            )
+        if where not in _WARNED_MISSING_ANCHORS:
+            _WARNED_MISSING_ANCHORS.add(where)
+            logger.warning(f"Unsloth: skipped an optional source edit{detail} (anchor not found).")
+        return function
+    return function.replace(old, new, count)
+
+
 # Fix tokenizer double BOS
 def sft_trainer_prepare_dataset(function_name, function):
     if function_name != "_prepare_non_packed_dataloader" and function_name != "_prepare_dataset":
@@ -458,6 +500,58 @@ def sft_trainer_prepare_dataset(function_name, function):
         if matched:
             # Use fast version!
             function = inspect.getsource(fast_sft_prepare_dataset)
+            # why: anchor the wrapped-packing setup on the function signature -- a
+            # structural anchor that always exists -- not the unsloth_zoo license comment,
+            # which is only lower-bounded and a newer Zoo may move or drop. Anchoring there
+            # let the setup silently no-op while edits below referenced its variables,
+            # NameError-ing every SFT dataset prep. Fail loudly if the signature is missing.
+            function, _n_setup = re.subn(
+                r"(def sft_prepare_dataset\s*\(.*?\)\s*(?:->[^:\n]*)?:[ \t]*\n)",
+                lambda match: match.group(1) + _WRAPPED_PACKING_SETUP,
+                function,
+                count = 1,
+                flags = re.DOTALL,
+            )
+            if _n_setup != 1:
+                raise RuntimeError(
+                    "Unsloth: failed to install wrapped-packing support into "
+                    "sft_prepare_dataset (signature not found); please file a bug report."
+                )
+            # why: route each edit through _require_replace so a drifted anchor fails
+            # loudly instead of leaving a dangling reference to the setup variables.
+            function = _require_replace(
+                function,
+                "truncation = do_truncation,",
+                "truncation = do_truncation and not _unsloth_wrapped_packing,",
+                where = "sft_prepare_dataset truncation flag",
+            )
+            function = _require_replace(
+                function,
+                "if do_truncation and max_seq_length > 0:",
+                "if do_truncation and not _unsloth_wrapped_packing and max_seq_length > 0:",
+                where = "sft_prepare_dataset truncation guard",
+            )
+            # why: reuse the guarded _unsloth_pack_has_strategy from the setup instead of
+            # re-calling _inspect.signature(pack_dataset) here -- the setup wraps that call
+            # in try/except, so a non-introspectable pack_dataset must not crash here.
+            function = _require_replace(
+                function,
+                """dataset = pack_dataset(
+            dataset.select_columns(used_column_names),
+            max_seq_length,
+            getattr(args, "packing_strategy", "bfd"),
+            map_kwargs,
+        )""",
+                """_pack_kwargs = {"map_kwargs": map_kwargs}
+        if _unsloth_pack_has_strategy:
+            _pack_kwargs["strategy"] = getattr(args, "packing_strategy", "bfd")
+        dataset = pack_dataset(
+            dataset.select_columns(used_column_names),
+            max_seq_length,
+            **_pack_kwargs,
+        )""",
+                where = "sft_prepare_dataset pack_dataset call",
+            )
             function = function.split("\n")
             function = "\n".join(" " * 4 + x for x in function)
             function = function.replace("def sft_prepare_dataset", "def _prepare_dataset")
@@ -2120,19 +2214,21 @@ def grpo_trainer_compute_loss(function_name, function):
             logits_to_keep,
             batch_size = None,
             compute_entropy = False,
-            compute_efficient = False: self._get_per_token_logps(
-                model, input_ids, attention_mask, logits_to_keep, compute_efficient
+            compute_efficient = False: (
+                self._get_per_token_logps(
+                    model, input_ids, attention_mask, logits_to_keep, compute_efficient
+                )
+                if hasattr(self, "_get_per_token_logps")
+                else self._get_per_token_logps_and_entropies(
+                    model,
+                    input_ids,
+                    attention_mask,
+                    logits_to_keep,
+                    batch_size,
+                    compute_entropy,
+                    compute_efficient,
+                )[0]
             )
-            if hasattr(self, "_get_per_token_logps")
-            else self._get_per_token_logps_and_entropies(
-                model,
-                input_ids,
-                attention_mask,
-                logits_to_keep,
-                batch_size,
-                compute_entropy,
-                compute_efficient,
-            )[0]
         )  # logps
 
         per_token_logps = get_logps_func(
diff --git a/unsloth/models/sentence_transformer.py b/unsloth/models/sentence_transformer.py
index 4a1a555bcf..006dbf6c3d 100644
--- a/unsloth/models/sentence_transformer.py
+++ b/unsloth/models/sentence_transformer.py
@@ -1968,6 +1968,7 @@ class FastSentenceTransformer(FastModel):
         random_state = 3407,
         max_seq_length = 2048,
         use_rslora = False,
+        use_dora = False,
         modules_to_save = None,
         init_lora_weights = True,
         loftq_config = {},
@@ -2061,6 +2062,7 @@ class FastSentenceTransformer(FastModel):
                     target_modules = target_modules,
                     lora_dropout = lora_dropout,
                     bias = bias,
+                    use_dora = use_dora,
                     task_type = kwargs.get("task_type", "FEATURE_EXTRACTION"),
                 )
 
@@ -2129,6 +2131,7 @@ class FastSentenceTransformer(FastModel):
                 random_state = random_state,
                 max_seq_length = max_seq_length,
                 use_rslora = use_rslora,
+                use_dora = use_dora,
                 modules_to_save = modules_to_save,
                 init_lora_weights = init_lora_weights,
                 loftq_config = loftq_config,
@@ -2160,6 +2163,7 @@ class FastSentenceTransformer(FastModel):
                 random_state = random_state,
                 max_seq_length = max_seq_length,
                 use_rslora = use_rslora,
+                use_dora = use_dora,
                 modules_to_save = modules_to_save,
                 init_lora_weights = init_lora_weights,
                 loftq_config = loftq_config,
diff --git a/unsloth/registry/_deepseek.py b/unsloth/registry/_deepseek.py
index e29190f0f2..618453fb82 100644
--- a/unsloth/registry/_deepseek.py
+++ b/unsloth/registry/_deepseek.py
@@ -171,8 +171,6 @@ def _list_deepseek_r1_distill_models():
     return distill_models
 
 
-register_deepseek_models(include_original_model = True)
-
 if __name__ == "__main__":
     from unsloth.registry.registry import MODEL_REGISTRY, _check_model_info
 
diff --git a/unsloth/save.py b/unsloth/save.py
index 7d5774aa97..0e2650b174 100644
--- a/unsloth/save.py
+++ b/unsloth/save.py
@@ -228,7 +228,7 @@ def _loaded_via_remote_code(obj):
 
     Transformers loads auto_map code into the ``transformers_modules`` package, so a
     ``transformers_modules`` class proves the original load actually ran that remote code
-    (which the caller's / Studio's consent gate scans at load time). Export paths derive their
+    (which the caller's / Unsloth's consent gate scans at load time). Export paths derive their
     reload trust_remote_code from this - the already approved load decision - instead of from a
     checkpoint's static ``auto_map``: a model that loads with built-in classes must not have its
     unvetted remote code run when it is re-read during quantization export. Walks PEFT / wrapper
@@ -3858,7 +3858,7 @@ def _prewarm_base_model_hub_cache(
         from huggingface_hub import HfFileSystem, hf_hub_download, snapshot_download
 
         # Resolve the cache from the live env like the merge, not huggingface_hub's frozen
-        # constants: a runtime cache redirect (read-only default, Studio) would else miss (#6890).
+        # constants: a runtime cache redirect (read-only default, Unsloth) would else miss (#6890).
         try:
             from unsloth_zoo.hf_cache import _active_caches
             _hub_cache = _active_caches()[1]
diff --git a/unsloth/tokenizer_utils.py b/unsloth/tokenizer_utils.py
index 3a91ef188d..c7f61288d5 100644
--- a/unsloth/tokenizer_utils.py
+++ b/unsloth/tokenizer_utils.py
@@ -17,6 +17,9 @@ from transformers.convert_slow_tokenizer import convert_slow_tokenizer
 from transformers import PreTrainedTokenizerFast
 import re
 import os
+import shutil
+import tempfile
+import weakref
 from transformers.models.llama.modeling_llama import logger
 from peft import PeftModelForCausalLM
 import torch
@@ -370,13 +373,19 @@ def fix_sentencepiece_tokenizer(
     if not os.path.exists(temporary_location):
         os.makedirs(temporary_location)
 
-    # Check if tokenizer.model exists
-    if not os.path.isfile(f"{temporary_location}/tokenizer.model"):
-        return new_tokenizer
+    # Fresh per-call subdir so concurrent/repeated calls can't clobber each other's
+    # tokenizer.model or leak stale files, without deleting anything the caller owns.
+    temporary_location = tempfile.mkdtemp(prefix = "tokenizer_", dir = temporary_location)
 
     # First save the old tokenizer
     old_tokenizer.save_pretrained(temporary_location)
 
+    # Only sentencepiece tokenizers write tokenizer.model, so check after the save.
+    if not os.path.isfile(f"{temporary_location}/tokenizer.model"):
+        # new_tokenizer was built in memory and never references this dir, so drop it.
+        shutil.rmtree(temporary_location, ignore_errors = True)
+        return new_tokenizer
+
     tokenizer_file = sentencepiece_model_pb2.ModelProto()
     tokenizer_file.ParseFromString(open(f"{temporary_location}/tokenizer.model", "rb").read())
 
@@ -414,6 +423,9 @@ def fix_sentencepiece_tokenizer(
         eos_token = new_tokenizer.eos_token,
         pad_token = new_tokenizer.pad_token,
     )
+    # vocab_file points here, so the dir must outlive the tokenizer (a later
+    # save_pretrained copies the patched tokenizer.model from it); reclaim it on GC.
+    weakref.finalize(tokenizer, shutil.rmtree, temporary_location, ignore_errors = True)
     return tokenizer
 
 
@@ -1464,7 +1476,7 @@ def get_tokenizer_info(tokenizer) -> dict:
     """Return a concise diagnostic summary of a tokenizer instance.
 
     Collects key properties into a JSON-safe dict for logging, debugging, or the
-    Studio UI. Missing attributes fall back to ``None`` rather than raising.
+    Unsloth UI. Missing attributes fall back to ``None`` rather than raising.
 
     Example output::
 
diff --git a/unsloth/trainer.py b/unsloth/trainer.py
index 8c641b4c71..7b6ff7505a 100644
--- a/unsloth/trainer.py
+++ b/unsloth/trainer.py
@@ -17,6 +17,7 @@ import os
 import psutil
 import warnings
 from dataclasses import dataclass, field
+from types import SimpleNamespace
 from typing import Optional, List
 from functools import wraps
 
@@ -32,6 +33,7 @@ from unsloth.utils import (
     enable_padding_free_metadata,
     enable_sample_packing,
 )
+from unsloth.utils.packing import patch_hybrid_linear_attention_varlen
 from unsloth_zoo.training_utils import (
     unsloth_train as _unsloth_train,
 )
@@ -102,6 +104,10 @@ PADDING_FREE_BLOCKLIST = {
     "gemma2",  # - gemma2:  Uses slow_attention_softcapping which has torch.compile issues
     "gpt_oss",  # - gpt_oss: Uses Flex Attention which doesn't handle padding_free correctly
 }
+# Hybrid linear-attention / state-space models (Qwen3.5, Qwen3-Next, ...) carry a
+# recurrent gated-delta state plus a causal conv1d that leak across sequence
+# boundaries once packing flattens the batch. Detected structurally by
+# _is_hybrid_linear_attention_model, not by model name.
 
 
 def _should_pack(config) -> bool:
@@ -139,6 +145,183 @@ def _should_skip_auto_packing_error(exc: Exception) -> bool:
     return any(msg in message for msg in _AUTO_PACK_SKIP_MESSAGES)
 
 
+_VISION_DATASET_KEYS = frozenset(
+    {
+        "image",
+        "images",
+        "image_grid_thw",
+        "image_position_ids",
+        "image_sizes",
+        "mm_token_type_ids",
+        "pixel_attention_mask",
+        "pixel_position_ids",
+        "pixel_values",
+        "pixel_values_videos",
+        "video",
+        "videos",
+        "video_grid_thw",
+    }
+)
+
+
+def _is_vlm_config(config, model_types = ()) -> bool:
+    if any(
+        hasattr(config, attr)
+        for attr in ("vision_config", "img_processor", "image_token_index", "projector_config")
+    ):
+        return True
+
+    architectures = getattr(config, "architectures", None) or ()
+    try:
+        from transformers.models.auto import modeling_auto
+
+        mappings = (
+            getattr(modeling_auto, "MODEL_FOR_IMAGE_TEXT_TO_TEXT_MAPPING_NAMES", {}) or {},
+            getattr(modeling_auto, "MODEL_FOR_VISION_2_SEQ_MAPPING_NAMES", {}) or {},
+        )
+        registry_types = set().union(*(mapping.keys() for mapping in mappings))
+        registry_classes = set().union(*(mapping.values() for mapping in mappings))
+        config_types = set(model_types or ())
+        model_type = getattr(config, "model_type", None)
+        if model_type is not None:
+            config_types.add(model_type)
+        if not config_types.isdisjoint(registry_types) or any(
+            architecture in registry_classes for architecture in architectures
+        ):
+            return True
+    except Exception:
+        pass
+    return any(
+        isinstance(architecture, str) and architecture.endswith("ForVisionText2Text")
+        for architecture in architectures
+    )
+
+
+def _is_vision_dataset(dataset, *, unknown_is_vision = False) -> bool:
+    if dataset is None:
+        return False
+    column_names = getattr(dataset, "column_names", None)
+    if column_names is not None:
+        return not _VISION_DATASET_KEYS.isdisjoint(column_names)
+    # Unknown-schema streams cannot be safely probed without potentially dropping a sample.
+    return unknown_is_vision
+
+
+def _is_vision_eval_dataset(dataset, *, unknown_is_vision = False) -> bool:
+    if isinstance(dataset, dict):
+        return any(
+            _is_vision_dataset(split, unknown_is_vision = unknown_is_vision)
+            for split in dataset.values()
+        )
+    return _is_vision_dataset(dataset, unknown_is_vision = unknown_is_vision)
+
+
+_HYBRID_CONFIG_MARKERS = (
+    "linear_conv_kernel_dim",
+    "linear_key_head_dim",
+    "linear_value_head_dim",
+    "full_attention_interval",
+)
+
+
+def _is_hybrid_linear_attention_model(model) -> bool:
+    """Detect models mixing linear-attention / state-space mixers (gated-delta,
+    Mamba-style) with a causal conv1d, e.g. Qwen3.5 / Qwen3-Next. Packing and
+    padding-free flatten the batch, and those recurrent + conv ops leak state
+    across sequence boundaries, so they must not be packed. Uses composite
+    structural evidence rather than a model-name match."""
+    if model is None:
+        return False
+
+    # Config-level: explicit hybrid layer schedule or linear-attn markers.
+    for config in (
+        getattr(model, "config", None),
+        getattr(getattr(model, "config", None), "text_config", None),
+    ):
+        if config is None:
+            continue
+        layer_types = getattr(config, "layer_types", None)
+        if isinstance(layer_types, (list, tuple)) and any(
+            isinstance(t, str) and "linear_attention" in t for t in layer_types
+        ):
+            return True
+        if any(hasattr(config, marker) for marker in _HYBRID_CONFIG_MARKERS):
+            return True
+
+    # Module-level: a mixer carrying a recurrent gated-delta op plus a conv1d.
+    named_modules = getattr(model, "named_modules", None)
+    if named_modules is None:
+        return False
+    seen = set()
+    for _, module in named_modules():
+        if id(module) in seen:
+            continue
+        seen.add(id(module))
+        cls = type(module).__name__
+        if not (
+            cls.endswith("GatedDeltaNet") or "LinearAttention" in cls or cls.endswith("Mamba2Mixer")
+        ):
+            continue
+        has_recurrent = any(
+            hasattr(module, attr)
+            for attr in ("chunk_gated_delta_rule", "recurrent_gated_delta_rule", "A_log")
+        )
+        if has_recurrent and hasattr(module, "conv1d"):
+            return True
+    return False
+
+
+def _resolve_string_model_config(model_name, config_arg):
+    """TRL materializes a string ``model=`` inside ``__init__``; resolve its config
+    up front so the packing guards run before the dataset is packed. Best-effort:
+    returns None if the config cannot be loaded."""
+    try:
+        from transformers import AutoConfig
+
+        init_kwargs = getattr(config_arg, "model_init_kwargs", None) or {}
+        # why: forward auth + cache args too. Dropping token/use_auth_token made a
+        # private hybrid fail to load (resolve as None) -> treated as non-hybrid ->
+        # packing enabled without the shim even though TRL later loads it with the token.
+        forward = {
+            key: init_kwargs[key]
+            for key in (
+                "trust_remote_code",
+                "revision",
+                "subfolder",
+                "token",
+                "use_auth_token",
+                "cache_dir",
+                "code_revision",
+            )
+            if key in init_kwargs
+        }
+        # why: TRL merges top-level args.trust_remote_code into the load via setdefault
+        # before create_model_from_path, so honor it here (model_init_kwargs wins), else
+        # a remote-code hybrid with SFTConfig(trust_remote_code=True) resolves as None
+        # and skips the guard.
+        top_level_trust_remote_code = getattr(config_arg, "trust_remote_code", None)
+        if top_level_trust_remote_code is not None:
+            forward.setdefault("trust_remote_code", top_level_trust_remote_code)
+        return AutoConfig.from_pretrained(model_name, **forward)
+    except Exception:
+        return None
+
+
+def _chunked_loss_bypasses_forward(config) -> bool:
+    """TRL's default ``loss_type="chunked_nll"`` patches the model forward and calls
+    the backbone directly, so a forward wrapper never runs. Detect it so hybrid
+    packing stays on the padded path instead of silently skipping the varlen shim."""
+    try:
+        import trl.trainer.sft_trainer as _sft_trainer
+    except Exception:
+        return False
+    if not hasattr(_sft_trainer, "_patch_chunked_ce_lm_head"):
+        return False  # TRL has no chunked-CE path -> forward is not bypassed
+    if getattr(config, "use_liger_kernel", False):
+        return False  # liger forces loss_type="nll" -> normal forward
+    return getattr(config, "loss_type", None) in (None, "chunked_nll")
+
+
 # Unsloth gradient accumulation fix:
 from transformers import __version__ as transformers_version, ProcessorMixin
 
@@ -643,30 +826,69 @@ def _patch_sft_trainer_auto_packing(trl_module):
         else:
             config_arg = kwargs.get("args")
 
-        model = kwargs.get("model")
-        is_unsupported_model = False
+        model = args[0] if len(args) >= 1 else kwargs.get("model")
         is_vlm = False
+        is_unsupported_model = False
+        is_hybrid = False
+        is_encoder_decoder = False
+        hybrid_varlen_active = False
         if model is not None:
             model_config = getattr(model, "config", None)
+            if model_config is None and isinstance(model, str):
+                # TRL builds a string model inside __init__; resolve its config now.
+                model_config = _resolve_string_model_config(model, config_arg)
             if model_config is not None:
                 model_types = get_transformers_model_type(model_config)
                 is_unsupported_model = any(x in PADDING_FREE_BLOCKLIST for x in model_types)
+                is_vlm = _is_vlm_config(model_config, model_types)
+                is_encoder_decoder = bool(getattr(model_config, "is_encoder_decoder", False))
+            hybrid_target = (
+                SimpleNamespace(config = model_config)
+                if isinstance(model, str) and model_config is not None
+                else model
+            )
+            is_hybrid = _is_hybrid_linear_attention_model(hybrid_target)
+            # Hybrid models corrupt packed batches unless the gated-delta conv + scan
+            # reset at sequence boundaries. Enable the experimental varlen shim (flag +
+            # kernels) so packing stays correct, else keep them blocked. A string model
+            # (patched only after init) and TRL's chunked-loss forward bypass both leave
+            # the shim off, so hybrid packing falls back to the padded path.
+            if (
+                is_hybrid
+                and not isinstance(model, str)
+                and not _chunked_loss_bypasses_forward(config_arg)
+            ):
+                try:
+                    hybrid_varlen_active = patch_hybrid_linear_attention_varlen(model)
+                except Exception:
+                    hybrid_varlen_active = False
 
-                architectures = getattr(model_config, "architectures", None)
-                if architectures is None:
-                    architectures = []
-                is_vlm = any(x.endswith("ForConditionalGeneration") for x in architectures)
-                is_vlm = is_vlm or hasattr(model_config, "vision_config")
-
-        processing_class = kwargs.get("processing_class") or kwargs.get("tokenizer")
-        data_collator = kwargs.get("data_collator")
+        processing_class = (
+            args[5] if len(args) >= 6 else kwargs.get("processing_class") or kwargs.get("tokenizer")
+        )
+        data_collator = args[2] if len(args) >= 3 else kwargs.get("data_collator")
+        train_dataset = args[3] if len(args) >= 4 else kwargs.get("train_dataset")
+        eval_dataset = args[4] if len(args) >= 5 else kwargs.get("eval_dataset")
+        is_processor = isinstance(processing_class, ProcessorMixin)
+        is_auto_processor_vlm = is_vlm and processing_class is None
+        is_vision_dataset = (
+            data_collator is None
+            and not is_processor
+            and (
+                _is_vision_dataset(train_dataset, unknown_is_vision = is_vlm)
+                or _is_vision_eval_dataset(eval_dataset, unknown_is_vision = is_vlm)
+            )
+        )
 
         # Disable padding-free for VLMs / custom collators / blocklisted models
         blocked = (
             (data_collator is not None)
-            or isinstance(processing_class, ProcessorMixin)
-            or is_vlm
+            or is_processor
+            or is_auto_processor_vlm
+            or is_vision_dataset
             or is_unsupported_model
+            or is_encoder_decoder
+            or (is_hybrid and not hybrid_varlen_active)
             or (
                 os.environ.get("UNSLOTH_RETURN_LOGITS", "0") == "1"
             )  # Disable padding free on forced logits
@@ -680,10 +902,16 @@ def _patch_sft_trainer_auto_packing(trl_module):
 
         if blocked and requested_pack:
             reason = "custom data collator"
-            if data_collator is None and isinstance(processing_class, ProcessorMixin):
+            if data_collator is None and is_processor:
                 reason = "processor-based model"
-            elif is_vlm:
-                reason = "vision-language model"
+            elif is_auto_processor_vlm:
+                reason = "vision-language model with auto processor"
+            elif is_vision_dataset:
+                reason = "vision dataset"
+            elif is_encoder_decoder:
+                reason = "encoder-decoder model"
+            elif is_hybrid and not hybrid_varlen_active:
+                reason = "hybrid linear-attention model"
             elif is_unsupported_model:
                 reason = f"unsupported model type(s): {', '.join(model_types)}"
             message = f"Unsloth: Sample packing skipped ({reason} detected)."
diff --git a/unsloth/utils/packing.py b/unsloth/utils/packing.py
index dd0a1bfb62..f8d539fb93 100644
--- a/unsloth/utils/packing.py
+++ b/unsloth/utils/packing.py
@@ -17,8 +17,11 @@
 
 from __future__ import annotations
 
+import inspect
 import logging
+import os
 from collections import OrderedDict
+from functools import wraps
 from typing import Any, Iterable, Optional, Sequence, Tuple
 
 import torch
@@ -218,6 +221,305 @@ def enable_padding_free_metadata(model, trainer):
     collator._unsloth_padding_free_lengths_wrapped = True
 
 
+# --- Experimental: correct packing / padding-free for hybrid linear-attention ---
+# Qwen3.5 / Qwen3-Next mix a gated-delta recurrence with a causal conv1d. Packing
+# flattens the batch, and both ops leak state across sequence boundaries unless we
+# pass seq_idx (conv) and cu_seqlens (scan). Only the accelerated kernels accept
+# these, so we fail closed on the pure-torch fallbacks. Gated behind an env flag.
+#
+# Overrides only the per-module prefill kernels (causal_conv1d_fn /
+# chunk_gated_delta_rule), leaving decode untouched so generation is unaffected.
+# Recompute-safe under gradient checkpointing; never fires for cached forwards.
+# Feature-detect (never version-detect), fail closed, idempotent, one deduped
+# diagnostic when it declines to activate.
+_HYBRID_PACKING_ENV_VAR = "UNSLOTH_EXPERIMENTAL_HYBRID_PACKING"
+_HYBRID_LOGGER = logging.getLogger("unsloth.hybrid_packing")
+_HYBRID_WARNED: set = set()
+
+
+def _hybrid_packing_enabled() -> bool:
+    # Read at call time so setting the flag after `import unsloth` still takes effect.
+    return os.environ.get(_HYBRID_PACKING_ENV_VAR, "0").strip().lower() in {
+        "1",
+        "true",
+        "yes",
+        "on",
+    }
+
+
+def _hybrid_reject(reason: str) -> bool:
+    # One deduped diagnostic explaining why hybrid packing stayed on the padded path.
+    if reason not in _HYBRID_WARNED:
+        _HYBRID_WARNED.add(reason)
+        _HYBRID_LOGGER.warning(
+            "Unsloth: hybrid linear-attention packing disabled (padded path): %s.",
+            reason,
+        )
+    return False
+
+
+def _iter_gated_delta_modules(model):
+    modules, seen = [], set()
+    for module in model.modules():
+        if id(module) in seen:
+            continue
+        seen.add(id(module))
+        if type(module).__name__.endswith("GatedDeltaNet") and hasattr(module, "conv1d"):
+            modules.append(module)
+    return modules
+
+
+def _hybrid_varlen_kernels_available(gated_delta_modules) -> Optional[str]:
+    """None if every module can use the accelerated varlen path, else a short
+    reason string. All modules are validated before any are mutated; signatures
+    are read off the captured originals when already wrapped.
+
+    Dispatch (the mixer actually calling self.causal_conv1d_fn /
+    self.chunk_gated_delta_rule) is verified at RUNTIME by the forward-wrapper
+    handshake, not statically: Unsloth's compile-disable shim hides it from
+    inspect.getsource, and every supported transformers release dispatches
+    through the instance attribute."""
+    if not gated_delta_modules:
+        return "no gated-delta modules found"
+    for module in gated_delta_modules:
+        conv = getattr(module, "_unsloth_varlen_orig_conv", None) or getattr(
+            module,
+            "causal_conv1d_fn",
+            None,
+        )
+        scan = getattr(module, "_unsloth_varlen_orig_scan", None) or getattr(
+            module,
+            "chunk_gated_delta_rule",
+            None,
+        )
+        if conv is None or scan is None:
+            return "accelerated kernels missing (install causal_conv1d and fla)"
+        if getattr(scan, "__name__", "").startswith("torch_") or getattr(
+            conv,
+            "__name__",
+            "",
+        ).startswith("torch_"):
+            return "pure-torch kernel fallback in use"
+        try:
+            if "seq_idx" not in inspect.signature(conv).parameters:
+                return "conv kernel does not accept seq_idx"
+            if "cu_seqlens" not in inspect.signature(scan).parameters:
+                return "scan kernel does not accept cu_seqlens"
+        except (TypeError, ValueError):
+            return "kernel signature not introspectable"
+    return None
+
+
+def _varlen_from_position_ids(position_ids):
+    """(cu_seqlens int32[n+1], seq_idx int32[1,T]) for a flattened padding-free
+    batch, else None. Padding-free position_ids reset to 0 at each sequence start;
+    accepts only a validated single-row pack (normal batch or single sequence ->
+    None). Fallback used only when packed_seq_lengths is absent: it assumes
+    right-packed reset position_ids and would mis-segment a left-padded row, which
+    is why packed_seq_lengths is always preferred."""
+    if position_ids is None:
+        return None
+    pos = position_ids
+    if pos.dim() == 3:  # MRoPE [n_planes, 1, T] -> text plane is index 0
+        pos = pos[0]
+    if pos.dim() != 2 or pos.shape[0] != 1:
+        return None
+    row = pos[0]
+    total = row.shape[0]
+    starts = (row == 0).nonzero(as_tuple = False).flatten()
+    if starts.numel() <= 1 or int(starts[0].item()) != 0:
+        return None
+    cu_seqlens = torch.cat(
+        [
+            starts.to(torch.int32),
+            torch.tensor([total], dtype = torch.int32, device = row.device),
+        ]
+    )
+    return _seq_idx_from_cu_seqlens(cu_seqlens, total)
+
+
+def _seq_idx_from_cu_seqlens(cu_seqlens, total):
+    """(cu_seqlens int32[n+1], seq_idx int32[1,total]) partitioning [0, total),
+    else None. Appends a trailing segment for pad_to_multiple_of zero tokens so the
+    boundaries always cover the full flattened length the kernels see."""
+    if cu_seqlens is None or cu_seqlens.numel() < 2 or int(cu_seqlens[0].item()) != 0:
+        return None
+    boundaries = cu_seqlens.to(torch.int32)
+    last = int(boundaries[-1].item())
+    if last > total:
+        return None
+    if last < total:  # trailing pad tokens -> one final segment
+        boundaries = torch.cat(
+            [
+                boundaries,
+                torch.tensor([total], dtype = torch.int32, device = boundaries.device),
+            ]
+        )
+    lengths = boundaries[1:] - boundaries[:-1]
+    if not bool((lengths > 0).all()):
+        return None
+    seq_idx = torch.repeat_interleave(
+        torch.arange(lengths.numel(), dtype = torch.int32, device = boundaries.device),
+        lengths.to(torch.int64),
+    ).unsqueeze(0)
+    return boundaries, seq_idx
+
+
+def _hybrid_varlen_metadata(kwargs):
+    """Boundary metadata (cu_seqlens, seq_idx) for one flattened packed forward,
+    else None. Prefers the authoritative packed_seq_lengths, falls back to
+    reset-style position_ids. Returns None for cached forwards and non-packed
+    batches so decode / eval / normal batches are a strict no-op."""
+    if kwargs.get("use_cache"):
+        return None
+    if kwargs.get("past_key_values") is not None or kwargs.get("cache_params") is not None:
+        return None
+    total, device = None, None
+    for key in ("input_ids", "inputs_embeds", "position_ids"):
+        tensor = kwargs.get(key)
+        if tensor is not None and hasattr(tensor, "shape"):
+            total = tensor.shape[1] if key == "inputs_embeds" else tensor.shape[-1]
+            device = tensor.device
+            break
+    if total is None:
+        return None
+    psl = kwargs.get("packed_seq_lengths")
+    if psl is not None and getattr(psl, "numel", lambda: 1)() > 0:  # skip empty (no max())
+        info = get_packed_info_from_kwargs(kwargs, device)
+        if info is not None:
+            _, cu_seqlens, _ = info
+            built = _seq_idx_from_cu_seqlens(cu_seqlens, total)
+            if built is not None:
+                return built
+    return _varlen_from_position_ids(kwargs.get("position_ids"))
+
+
+def patch_hybrid_linear_attention_varlen(model) -> bool:
+    """Feed seq_idx / cu_seqlens to the gated-delta conv + scan so packing and
+    padding-free reset state at sequence boundaries. Gated by
+    UNSLOTH_EXPERIMENTAL_HYBRID_PACKING and fail-closed. Returns True when the
+    varlen path is active, so the caller may allow packing for the model.
+    Idempotent: repeat calls on an already-patched model return True."""
+    if not _hybrid_packing_enabled():
+        return False
+    gated_delta_modules = _iter_gated_delta_modules(model)
+
+    # Idempotency: an already fully-patched model stays active without re-validation.
+    if (
+        getattr(model, "_unsloth_varlen_forward_wrapped", False)
+        and gated_delta_modules
+        and all(getattr(m, "_unsloth_varlen_wrapped", False) for m in gated_delta_modules)
+    ):
+        return True
+
+    reason = _hybrid_varlen_kernels_available(gated_delta_modules)
+    if reason is not None:
+        return _hybrid_reject(reason)
+
+    # Transactional: every module validated above, now wrap each and stash originals.
+    for module in gated_delta_modules:
+        if getattr(module, "_unsloth_varlen_wrapped", False):
+            continue
+        conv_orig, scan_orig = module.causal_conv1d_fn, module.chunk_gated_delta_rule
+        module._unsloth_varlen_orig_conv = conv_orig
+        module._unsloth_varlen_orig_scan = scan_orig
+
+        @wraps(conv_orig)
+        def conv_fn(
+            *args,
+            _orig = conv_orig,
+            _module = module,
+            **kwargs,
+        ):
+            varlen = getattr(_module, "_unsloth_varlen", None)
+            if varlen is not None:
+                _module._unsloth_varlen_conv_hit = True  # runtime dispatch handshake
+                if kwargs.get("seq_idx") is None:
+                    kwargs["seq_idx"] = varlen[1]
+            return _orig(*args, **kwargs)
+
+        @wraps(scan_orig)
+        def scan_fn(
+            *args,
+            _orig = scan_orig,
+            _module = module,
+            **kwargs,
+        ):
+            varlen = getattr(_module, "_unsloth_varlen", None)
+            if varlen is not None:
+                _module._unsloth_varlen_scan_hit = True
+                if kwargs.get("cu_seqlens") is None:
+                    kwargs["cu_seqlens"] = varlen[0]
+            return _orig(*args, **kwargs)
+
+        module.causal_conv1d_fn = conv_fn
+        module.chunk_gated_delta_rule = scan_fn
+        module._unsloth_varlen = None
+        module._unsloth_varlen_wrapped = True
+
+    # Refresh the boundary stash on the outermost forward (once per step, outside
+    # gradient-checkpoint recompute, so it stays valid for recomputed inner
+    # forwards). Read from both positional and keyword args via the bound signature.
+    if not getattr(model, "_unsloth_varlen_forward_wrapped", False):
+        forward_orig = model.forward
+        try:
+            forward_sig = inspect.signature(forward_orig)
+        except (TypeError, ValueError):
+            forward_sig = None
+
+        @wraps(forward_orig)
+        def forward_with_varlen(*args, **kwargs):
+            try:
+                bound = dict(kwargs)
+                if forward_sig is not None and args:
+                    bound.update(forward_sig.bind_partial(*args).arguments)
+                varlen = _hybrid_varlen_metadata(bound)
+            except Exception:
+                varlen = None
+            first_pack = varlen is not None and not getattr(
+                model,
+                "_unsloth_varlen_handshake_done",
+                False,
+            )
+            for module in gated_delta_modules:
+                module._unsloth_varlen = varlen
+                if first_pack:
+                    module._unsloth_varlen_conv_hit = False
+                    module._unsloth_varlen_scan_hit = False
+            out = forward_orig(*args, **kwargs)
+            # Runtime dispatch handshake: on the first packed forward, confirm BOTH
+            # boundary kernels ran for EVERY module. seq_idx (conv) and cu_seqlens
+            # (scan) are both load-bearing, so a partial/absent dispatch (a future
+            # version no longer routing through self.<kernel>) leaves cross-sequence
+            # contamination. The batch is already flattened with no padded recovery,
+            # so abort before loss/backward rather than train on corrupted data.
+            if first_pack:
+                model._unsloth_varlen_handshake_done = True
+                missing = [
+                    type(m).__name__
+                    for m in gated_delta_modules
+                    if not (
+                        getattr(m, "_unsloth_varlen_conv_hit", False)
+                        and getattr(m, "_unsloth_varlen_scan_hit", False)
+                    )
+                ]
+                if missing:
+                    for m in gated_delta_modules:
+                        m._unsloth_varlen = None
+                    _hybrid_reject("varlen conv/scan not both dispatched (dispatch changed?)")
+                    raise RuntimeError(
+                        "Unsloth: experimental hybrid packing cannot continue because the "
+                        "varlen conv/scan wrappers were not both invoked for "
+                        f"{sorted(set(missing))}. Unset UNSLOTH_EXPERIMENTAL_HYBRID_PACKING "
+                        "to train these models on the padded path."
+                    )
+            return out
+
+        model.forward = forward_with_varlen
+        model._unsloth_varlen_forward_wrapped = True
+    return True
+
+
 def get_packed_info_from_kwargs(
     kwargs: dict, device: torch.device
 ) -> Optional[Tuple[torch.Tensor, torch.Tensor, int]]:
diff --git a/unsloth_cli/__init__.py b/unsloth_cli/__init__.py
index b3831f5314..121b26f03f 100644
--- a/unsloth_cli/__init__.py
+++ b/unsloth_cli/__init__.py
@@ -81,7 +81,7 @@ app.add_typer(studio_app, name = "studio", help = "Unsloth Studio commands.")
 app.add_typer(
     start_app,
     name = "start",
-    help = "Start a coding agent (Claude, Codex, OpenClaw, OpenCode, Hermes, Pi) against Studio.",
+    help = "Start a coding agent (Claude, Codex, OpenClaw, OpenCode, Hermes, Pi) against Unsloth.",
 )
 # Backwards-compatible hidden alias: `unsloth connect` routes to `unsloth start`.
 app.add_typer(
diff --git a/unsloth_cli/_inference.py b/unsloth_cli/_inference.py
index c3b188710e..a2b0f9c04f 100644
--- a/unsloth_cli/_inference.py
+++ b/unsloth_cli/_inference.py
@@ -18,7 +18,7 @@ _THINK_OPEN = "<think>"
 _THINK_BLOCK = re.compile(rf"{re.escape(_THINK_OPEN)}.*?</think>", re.DOTALL)
 _STREAMED_ERROR_PREFIX = "Error: "
 
-# Cloudflare (in front of remote Studio proxies like RunPod) 403s the default
+# Cloudflare (in front of remote Unsloth proxies like RunPod) 403s the default
 # "Python-urllib/X.Y" User-Agent as a bot; send a real one on every request.
 _USER_AGENT = "unsloth-cli"
 _MPI_ENV_PAIRS = (
@@ -36,7 +36,7 @@ _no_redirect_opener = None
 def urlopen_no_redirect(request, timeout):
     """urlopen that errors on any redirect: following a 3xx would send a bearer
     token (or accept an identity proof) to a base we never vetted, letting a port
-    squatter relay a real Studio's response."""
+    squatter relay a real Unsloth's response."""
     global _no_redirect_opener
     if _no_redirect_opener is None:
         import urllib.error
@@ -235,7 +235,7 @@ def collect_stream(stream, show_thinking: bool) -> str:
 def raise_on_streamed_error(stream):
     # Match real backend errors by type (GenStreamError), not the "Error:" text
     # prefix, so a completion whose text opens with "Error:" is not misread as a
-    # failure that aborts a distributed run.
+    # backend failure.
     try:
         ensure_studio_backend_path()
         from core.inference.orchestrator import GenStreamError
@@ -540,7 +540,7 @@ def find_studio_server(timeout: float = 3.0) -> Optional[str]:
 def is_loopback_url(base: str) -> bool:
     """True only when *base* resolves to loopback. find_studio_server() trusts a
     base after only a health probe, so credentials are auto-sent only to loopback
-    (a local Studio or an SSH tunnel on 127.0.0.1), the targets the auto flows mean."""
+    (a local Unsloth or an SSH tunnel on 127.0.0.1), the targets the auto flows mean."""
     from urllib.parse import urlparse
 
     host = (urlparse(base).hostname or "").lower()
@@ -554,7 +554,7 @@ def is_loopback_url(base: str) -> bool:
 
 
 def verify_studio_identity(base: str, timeout: float = 3.0) -> bool:
-    """Confirm `base` is really this machine's Studio before sending a secret.
+    """Confirm `base` is really this machine's Unsloth before sending a secret.
 
     Send a random nonce to /api/auth/identity and check the returned HMAC against
     the one computed from the local same-user secret; an endpoint without that
@@ -578,7 +578,7 @@ def verify_studio_identity(base: str, timeout: float = 3.0) -> bool:
     port = parsed.port or (443 if parsed.scheme == "https" else 80)
     # Resolve to one concrete address and talk to *that* address, then bind the
     # proof to (address, port). A name like localhost can resolve to a squatter on
-    # ::1 while the real Studio is on 127.0.0.1; connecting to the resolved IP and
+    # ::1 while the real Unsloth is on 127.0.0.1; connecting to the resolved IP and
     # binding to it means a proof relayed from a different address/port won't match.
     try:
         ip = socket.getaddrinfo(host, port, type = socket.SOCK_STREAM)[0][4][0]
@@ -592,7 +592,7 @@ def verify_studio_identity(base: str, timeout: float = 3.0) -> bool:
         headers = {"User-Agent": _USER_AGENT, "Host": parsed.netloc},
     )
     try:
-        # No redirects: a 302 could relay a real Studio's proof (see urlopen_no_redirect).
+        # No redirects: a 302 could relay a real Unsloth's proof (see urlopen_no_redirect).
         # Cap the read: the server is still unverified, so don't trust its length.
         with urlopen_no_redirect(request, timeout = timeout) as response:
             proof = json.loads(response.read(65536).decode() or "{}").get("proof")
@@ -623,7 +623,7 @@ def _studio_token() -> Optional[str]:
 
 
 class HttpChatBackend:
-    """Chat against a running Studio server over its OpenAI-compatible API.
+    """Chat against a running Unsloth server over its OpenAI-compatible API.
 
     close() leaves the model loaded on purpose — the next session (or the
     UI) starts instantly.
@@ -666,7 +666,7 @@ class HttpChatBackend:
         tensor_parallel: bool = False,
         llama_extra_args: Optional[List[str]] = None,
     ) -> None:
-        typer.echo(f"Loading {model} on the Studio server", err = True)
+        typer.echo(f"Loading {model} on the Unsloth server", err = True)
         payload = {
             "model_path": model,
             "hf_token": hf_token,
@@ -769,7 +769,7 @@ def connect_studio_server(
     tensor_parallel: bool = False,
     llama_extra_args: Optional[List[str]] = None,
 ):
-    """Backend on a running Studio server, or None (caller loads locally)."""
+    """Backend on a running Unsloth server, or None (caller loads locally)."""
     base_url = find_studio_server()
     if not base_url:
         return None
@@ -782,20 +782,20 @@ def connect_studio_server(
         if not explicit:
             return None
         typer.echo(
-            f"Can't attach to the Studio server at {base_url}: {reason} Run Studio "
+            f"Can't attach to the Unsloth server at {base_url}: {reason} Run Unsloth "
             "on this machine, or unset UNSLOTH_STUDIO_URL to load the model locally.",
             err = True,
         )
         raise typer.Exit(code = 1)
 
     # Only hand the self-issued JWT (signed with the local secret) to loopback: a
-    # remote URL is unverified and a real remote Studio would reject it anyway.
+    # remote URL is unverified and a real remote Unsloth would reject it anyway.
     if not is_loopback_url(base_url):
         return _refuse(
-            "it isn't a local Studio, so a self-issued token can't "
+            "it isn't a local Unsloth, so a self-issued token can't "
             "authenticate to it and must not be sent to it."
         )
-    # Confirm the loopback responder is really our Studio (not a port squatter).
+    # Confirm the loopback responder is really our Unsloth (not a port squatter).
     if not verify_studio_identity(base_url):
         return _refuse(
             "its identity couldn't be verified (it may be running as a "
@@ -803,7 +803,7 @@ def connect_studio_server(
         )
     token = _studio_token()
     if not token:
-        return _refuse("couldn't self-issue a Studio token (is Studio set up here?).")
+        return _refuse("couldn't self-issue an Unsloth token (is Unsloth set up here?).")
     backend = HttpChatBackend(base_url, token)
     backend.ensure_loaded(
         model,
diff --git a/unsloth_cli/claude_subagent_mcp.py b/unsloth_cli/claude_subagent_mcp.py
new file mode 100644
index 0000000000..e044d78705
--- /dev/null
+++ b/unsloth_cli/claude_subagent_mcp.py
@@ -0,0 +1,433 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Small stdio MCP bridge from cloud Claude Code to a local Claude Code child."""
+
+from __future__ import annotations
+
+import json
+import os
+import signal
+import shutil
+import subprocess
+import sys
+import threading
+import time
+from typing import Any, Callable
+
+from unsloth_cli.commands.start import (
+    _CLAUDE_ENV_UNSET,
+    _SUBAGENT_DESCRIPTION,
+    _SUBAGENT_INSTRUCTIONS,
+    _SUBAGENT_PLAN_DESCRIPTION,
+    _SUBAGENT_PLAN_INSTRUCTIONS,
+    _claude_flags,
+    _claude_local_env,
+    _wsl_shim_env,
+)
+
+_MAX_RESULT_CHARACTERS = 100_000
+_CANCEL_POLL_SECONDS = 0.1
+_CANCEL_GRACE_SECONDS = 2.0
+
+
+def _required_env(name: str) -> str:
+    value = os.environ.get(name, "").strip()
+    if not value:
+        raise RuntimeError(f"Missing {name}.")
+    return value
+
+
+def _bounded(text: str) -> str:
+    if len(text) <= _MAX_RESULT_CHARACTERS:
+        return text
+    return text[:_MAX_RESULT_CHARACTERS] + "\n\n[Local agent output truncated]"
+
+
+def _result_text(stdout: str) -> str:
+    lines = [line for line in stdout.splitlines() if line.strip()]
+    candidates = [stdout.strip(), *reversed(lines)]
+    for candidate in candidates:
+        try:
+            payload = json.loads(candidate)
+        except ValueError:
+            continue
+        if not isinstance(payload, dict):
+            continue
+        result = payload.get("result")
+        if payload.get("is_error"):
+            raise RuntimeError(str(result or "The local Claude agent failed."))
+        if isinstance(result, str) and result.strip():
+            return _bounded(result.strip())
+    raise RuntimeError("The local Claude agent returned no readable result.")
+
+
+def _stop_child(process: subprocess.Popen) -> None:
+    """Stop the Claude child and any tool processes it started."""
+    if process.poll() is not None:
+        if os.name != "nt":
+            # Leader exited, but its tool processes may still be running.
+            try:
+                os.killpg(process.pid, signal.SIGTERM)
+            except OSError:
+                return
+            time.sleep(_CANCEL_GRACE_SECONDS)
+            try:
+                os.killpg(process.pid, signal.SIGKILL)
+            except OSError:
+                pass
+        return
+    if os.name == "nt":
+        try:
+            completed = subprocess.run(
+                ["taskkill", "/PID", str(process.pid), "/T", "/F"],
+                capture_output = True,
+                timeout = 15,
+                check = False,
+            )
+        except Exception:
+            completed = None
+        # A failed taskkill must not leave the child running through the grace wait.
+        if (completed is None or completed.returncode != 0) and process.poll() is None:
+            process.terminate()
+    else:
+        try:
+            os.killpg(process.pid, signal.SIGTERM)
+        except OSError:
+            process.terminate()
+    try:
+        process.wait(timeout = _CANCEL_GRACE_SECONDS)
+    except subprocess.TimeoutExpired:
+        if os.name == "nt":
+            process.kill()
+        else:
+            try:
+                os.killpg(process.pid, signal.SIGKILL)
+            except OSError:
+                process.kill()
+        process.wait()
+    else:
+        if os.name != "nt":
+            # Leader is gone; kill any surviving group members.
+            try:
+                os.killpg(process.pid, signal.SIGKILL)
+            except OSError:
+                pass
+
+
+def run_local_agent(
+    task: str,
+    cancel_event: threading.Event | None = None,
+    read_only: bool = False,
+) -> str:
+    base = _required_env("UNSLOTH_CLAUDE_SUBAGENT_BASE_URL")
+    key = _required_env("UNSLOTH_CLAUDE_SUBAGENT_API_KEY")
+    model = _required_env("UNSLOTH_CLAUDE_SUBAGENT_MODEL")
+    window = int(os.environ.get("UNSLOTH_CLAUDE_SUBAGENT_CONTEXT_WINDOW", "0") or 0)
+    entry = {"id": model, "context_length": window}
+    local_env = _claude_local_env(base, key, entry)
+    child_env = dict(os.environ)
+
+    executable = shutil.which("claude")
+    if executable is None:
+        raise RuntimeError("`claude` is not installed or is not on PATH.")
+    cancel_event = cancel_event or threading.Event()
+    if cancel_event.is_set():
+        raise RuntimeError("The local Claude agent was cancelled.")
+    command = [
+        "claude",
+        "--model",
+        model,
+        *_claude_flags(model),
+        "--permission-mode",
+        (
+            "plan"
+            if read_only
+            else (
+                "bypassPermissions"
+                if os.environ.get("UNSLOTH_CLAUDE_SUBAGENT_BYPASS_PERMISSIONS") == "1"
+                else "acceptEdits"
+            )
+        ),
+        "--print",
+        "--output-format",
+        "json",
+        "--no-session-persistence",
+        "--append-system-prompt",
+        _SUBAGENT_PLAN_INSTRUCTIONS if read_only else _SUBAGENT_INSTRUCTIONS,
+        f"Task: {task}",
+    ]
+    bridged, wsl_names = _wsl_shim_env(command, local_env, _CLAUDE_ENV_UNSET)
+    if wsl_names:
+        from unsloth_cli.commands.start import _merge_wslenv
+
+        bridged = {**bridged, "PWD": os.getcwd()}
+        child_env["WSLENV"] = _merge_wslenv(child_env.get("WSLENV", ""), wsl_names)
+        for name in _CLAUDE_ENV_UNSET:
+            child_env[name] = ""
+    else:
+        for name in _CLAUDE_ENV_UNSET:
+            child_env.pop(name, None)
+    child_env.update(bridged)
+    popen_kwargs: dict[str, Any] = {
+        "cwd": os.environ.get("CLAUDE_PROJECT_DIR") or os.getcwd(),
+        "env": child_env,
+        "stdin": subprocess.DEVNULL,
+        "stdout": subprocess.PIPE,
+        "stderr": subprocess.PIPE,
+        "text": True,
+    }
+    if os.name == "nt":
+        popen_kwargs["creationflags"] = subprocess.CREATE_NEW_PROCESS_GROUP
+    else:
+        popen_kwargs["start_new_session"] = True
+    process = subprocess.Popen(
+        [executable, *command[1:]],
+        **popen_kwargs,
+    )
+    try:
+        while True:
+            try:
+                stdout, stderr = process.communicate(timeout = _CANCEL_POLL_SECONDS)
+                break
+            except subprocess.TimeoutExpired:
+                if cancel_event.is_set():
+                    _stop_child(process)
+                    raise RuntimeError("The local Claude agent was cancelled.")
+    except BaseException:
+        if process.poll() is None:
+            _stop_child(process)
+        raise
+    if process.returncode != 0:
+        detail = stderr.strip() or stdout.strip()
+        raise RuntimeError(
+            _bounded(detail) or f"Local Claude exited with code {process.returncode}."
+        )
+    return _result_text(stdout)
+
+
+def _response(
+    request: dict,
+    run_agent: Callable[[str], str] = run_local_agent,
+    tool_name: str = "unsloth_agent",
+    tool_description: str | None = None,
+    run_read_only_agent: Callable[[str], str] | None = None,
+    read_only_tool_name: str | None = None,
+    instructions: str | None = None,
+) -> dict | None:
+    request_id = request.get("id")
+    method = request.get("method")
+    if request_id is None:
+        return None
+    if method == "initialize":
+        protocol = (request.get("params") or {}).get("protocolVersion") or "2025-06-18"
+        result = {
+            "protocolVersion": protocol,
+            "capabilities": {"tools": {"listChanged": False}},
+            "serverInfo": {"name": "unsloth-local-agent", "version": "1.0.0"},
+        }
+        if instructions:
+            result["instructions"] = instructions
+    elif method == "ping":
+        result = {}
+    elif method == "tools/list":
+
+        def tool_definition(name: str, description: str, read_only: bool) -> dict:
+            return {
+                "name": name,
+                "title": "Unsloth local plan agent" if read_only else "Unsloth local agent",
+                "description": description,
+                "inputSchema": {
+                    "type": "object",
+                    "properties": {
+                        "task": {
+                            "type": "string",
+                            "description": "The complete task for the local Unsloth agent.",
+                        }
+                    },
+                    "required": ["task"],
+                    "additionalProperties": False,
+                },
+                "annotations": {
+                    "readOnlyHint": read_only,
+                    "destructiveHint": not read_only,
+                    "idempotentHint": read_only,
+                    "openWorldHint": True,
+                },
+                "_meta": {"anthropic/maxResultSizeChars": _MAX_RESULT_CHARACTERS},
+            }
+
+        tools = [tool_definition(tool_name, tool_description or _SUBAGENT_DESCRIPTION, False)]
+        if read_only_tool_name and run_read_only_agent:
+            tools.append(tool_definition(read_only_tool_name, _SUBAGENT_PLAN_DESCRIPTION, True))
+        result = {"tools": tools}
+    elif method == "tools/call":
+        params = request.get("params") or {}
+        arguments = params.get("arguments") or {}
+        requested_tool = params.get("name")
+        selected_agent = (
+            run_agent
+            if requested_tool == tool_name
+            else (
+                run_read_only_agent
+                if requested_tool == read_only_tool_name and run_read_only_agent
+                else None
+            )
+        )
+        task = arguments.get("task") if selected_agent else None
+        if not isinstance(task, str) or not task.strip():
+            result = {
+                "content": [{"type": "text", "text": "A non-empty task is required."}],
+                "isError": True,
+            }
+        else:
+            try:
+                text = selected_agent(task.strip())
+                result = {"content": [{"type": "text", "text": text}], "isError": False}
+            except Exception as exc:
+                result = {
+                    "content": [{"type": "text", "text": str(exc)}],
+                    "isError": True,
+                }
+    else:
+        return {
+            "jsonrpc": "2.0",
+            "id": request_id,
+            "error": {"code": -32601, "message": f"Method not found: {method}"},
+        }
+    return {"jsonrpc": "2.0", "id": request_id, "result": result}
+
+
+def serve(
+    stdin: Any = sys.stdin,
+    stdout: Any = sys.stdout,
+    run_agent: Callable[[str, threading.Event], str] = run_local_agent,
+    tool_name: str = "unsloth_agent",
+    tool_description: str | None = None,
+    run_read_only_agent: Callable[[str, threading.Event], str] | None = None,
+    read_only_tool_name: str | None = None,
+    instructions: str | None = None,
+) -> None:
+    active: dict[object, threading.Event] = {}
+    workers: list[threading.Thread] = []
+    state_lock = threading.RLock()
+    output_lock = threading.Lock()
+    shutdown_started = threading.Event()
+
+    def cancel_active() -> None:
+        with state_lock:
+            pending = list(active.values())
+        for cancel_event in pending:
+            cancel_event.set()
+
+    def handle_shutdown(_signum: int, _frame: Any) -> None:
+        # Claude Code sends SIGINT (possibly repeatedly) to cancel a tool call. Only
+        # the first unwinds stdin; later ones must not interrupt process-tree cleanup.
+        first_signal = not shutdown_started.is_set()
+        shutdown_started.set()
+        cancel_active()
+        if first_signal:
+            raise KeyboardInterrupt
+
+    previous_handlers: dict[int, Any] = {}
+    if threading.current_thread() is threading.main_thread():
+        for signum in (signal.SIGINT, signal.SIGTERM):
+            previous_handlers[signum] = signal.signal(signum, handle_shutdown)
+
+    def send(response: dict | None) -> None:
+        if response is None:
+            return
+        with output_lock:
+            stdout.write(json.dumps(response, separators = (",", ":")) + "\n")
+            stdout.flush()
+
+    def call_tool(request: dict, request_id: object, cancel_event: threading.Event) -> None:
+        try:
+            response = _response(
+                request,
+                run_agent = lambda task: run_agent(task, cancel_event),
+                tool_name = tool_name,
+                tool_description = tool_description,
+                run_read_only_agent = (
+                    (lambda task: run_read_only_agent(task, cancel_event))
+                    if run_read_only_agent
+                    else None
+                ),
+                read_only_tool_name = read_only_tool_name,
+                instructions = instructions,
+            )
+            if not cancel_event.is_set():
+                send(response)
+        finally:
+            with state_lock:
+                if active.get(request_id) is cancel_event:
+                    active.pop(request_id, None)
+
+    try:
+        for line in stdin:
+            try:
+                request = json.loads(line)
+                if not isinstance(request, dict):
+                    response = None
+                elif request.get("method") == "notifications/cancelled":
+                    request_id = (request.get("params") or {}).get("requestId")
+                    with state_lock:
+                        cancel_event = active.get(request_id)
+                    if cancel_event is not None:
+                        cancel_event.set()
+                    response = None
+                elif request.get("method") == "tools/call" and request.get("id") is not None:
+                    request_id = request["id"]
+                    cancel_event = threading.Event()
+                    with state_lock:
+                        active[request_id] = cancel_event
+                    worker = threading.Thread(
+                        target = call_tool,
+                        args = (request, request_id, cancel_event),
+                        name = f"unsloth-agent-{request_id}",
+                    )
+                    workers.append(worker)
+                    worker.start()
+                    response = None
+                else:
+                    response = _response(
+                        request,
+                        tool_name = tool_name,
+                        tool_description = tool_description,
+                        run_read_only_agent = (
+                            (lambda task: run_read_only_agent(task, threading.Event()))
+                            if run_read_only_agent
+                            else None
+                        ),
+                        read_only_tool_name = read_only_tool_name,
+                        instructions = instructions,
+                    )
+            except Exception as exc:
+                response = {
+                    "jsonrpc": "2.0",
+                    "id": None,
+                    "error": {"code": -32603, "message": str(exc)},
+                }
+            send(response)
+    except KeyboardInterrupt:
+        pass
+    finally:
+        cancel_active()
+        for worker in workers:
+            if worker.ident is not None:
+                worker.join()
+        for signum, handler in previous_handlers.items():
+            signal.signal(signum, handler)
+
+
+def main() -> None:
+    serve(
+        run_read_only_agent = lambda task, cancel_event: run_local_agent(
+            task, cancel_event, read_only = True
+        ),
+        read_only_tool_name = "unsloth_plan_agent",
+    )
+
+
+if __name__ == "__main__":
+    main()
diff --git a/unsloth_cli/codex_subagent_mcp.py b/unsloth_cli/codex_subagent_mcp.py
new file mode 100644
index 0000000000..f075e66404
--- /dev/null
+++ b/unsloth_cli/codex_subagent_mcp.py
@@ -0,0 +1,171 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Small stdio MCP bridge from cloud Codex to an explicit local Codex child."""
+
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import subprocess
+import sys
+import threading
+from pathlib import Path
+from typing import Any
+
+from unsloth_cli.claude_subagent_mcp import _bounded, _stop_child, serve
+from unsloth_cli.commands.start import (
+    _CODEX_ENV_KEY,
+    _CODEX_ENV_UNSET,
+    _CODEX_PROFILE,
+    _CODEX_SUBAGENT_CONFIG_ENV,
+    _CODEX_SUBAGENT_MCP_TOOL,
+    _CODEX_SUBAGENT_TOOL_DESCRIPTION,
+    _CODEX_SUBAGENT_ROUTING_INSTRUCTIONS,
+    _SUBAGENT_INSTRUCTIONS,
+    _merge_wslenv,
+    _wsl_shim_env,
+)
+
+_CANCEL_POLL_SECONDS = 0.1
+_SERVER_INSTRUCTIONS = _CODEX_SUBAGENT_ROUTING_INSTRUCTIONS
+
+
+def _config() -> dict:
+    path = os.environ.get(_CODEX_SUBAGENT_CONFIG_ENV, "").strip()
+    if not path:
+        raise RuntimeError(f"Missing {_CODEX_SUBAGENT_CONFIG_ENV}.")
+    try:
+        config = json.loads(Path(path).read_text(encoding = "utf-8"))
+    except (OSError, ValueError) as exc:
+        raise RuntimeError("Could not read the local Codex agent configuration.") from exc
+    if not isinstance(config, dict):
+        raise RuntimeError("The local Codex agent configuration must be an object.")
+    for name in ("api_key", "codex_home"):
+        if not isinstance(config.get(name), str) or not config[name].strip():
+            raise RuntimeError(f"The local Codex agent configuration is missing {name}.")
+    return config
+
+
+def _result_text(stdout: str) -> str:
+    messages = []
+    errors = []
+    for line in stdout.splitlines():
+        try:
+            event = json.loads(line)
+        except ValueError:
+            continue
+        if not isinstance(event, dict):
+            continue
+        item = event.get("item")
+        if (
+            event.get("type") == "item.completed"
+            and isinstance(item, dict)
+            and item.get("type") == "agent_message"
+            and isinstance(item.get("text"), str)
+            and item["text"].strip()
+        ):
+            messages.append(item["text"].strip())
+        if event.get("type") in ("error", "turn.failed"):
+            detail = event.get("message") or event.get("error")
+            if isinstance(detail, dict):
+                detail = detail.get("message") or json.dumps(detail)
+            if detail:
+                errors.append(str(detail))
+    if errors:
+        raise RuntimeError(_bounded(errors[-1]))
+    if messages:
+        return _bounded(messages[-1])
+    raise RuntimeError("The local Codex agent returned no readable result.")
+
+
+def run_local_agent(task: str, cancel_event: threading.Event | None = None) -> str:
+    config = _config()
+    executable = shutil.which("codex")
+    if executable is None:
+        raise RuntimeError("`codex` is not installed or is not on PATH.")
+    cancel_event = cancel_event or threading.Event()
+    if cancel_event.is_set():
+        raise RuntimeError("The local Codex agent was cancelled.")
+
+    permissions = (
+        ["--dangerously-bypass-approvals-and-sandbox"]
+        if config.get("bypass_permissions") is True
+        else ["--sandbox", "workspace-write", "--ask-for-approval", "never"]
+    )
+    command = [
+        "codex",
+        "--oss",
+        "--profile",
+        _CODEX_PROFILE,
+        *permissions,
+        "exec",
+        "--ephemeral",
+        "--json",
+        "--skip-git-repo-check",
+        f"{_SUBAGENT_INSTRUCTIONS}\n\nTask: {task}",
+    ]
+    local_env = {
+        _CODEX_ENV_KEY: config["api_key"],
+        "CODEX_HOME": config["codex_home"],
+        "CODEX_SQLITE_HOME": config["codex_home"],
+    }
+    bridged, wsl_names = _wsl_shim_env(command, local_env, _CODEX_ENV_UNSET)
+    child_env = dict(os.environ)
+    if wsl_names:
+        bridged = {**bridged, "PWD": os.getcwd()}
+        child_env["WSLENV"] = _merge_wslenv(child_env.get("WSLENV", ""), wsl_names)
+        for name in _CODEX_ENV_UNSET:
+            child_env[name] = ""
+    else:
+        for name in _CODEX_ENV_UNSET:
+            child_env.pop(name, None)
+    child_env.update(bridged)
+    popen_kwargs: dict[str, Any] = {
+        "cwd": os.getcwd(),
+        "env": child_env,
+        "stdin": subprocess.DEVNULL,
+        "stdout": subprocess.PIPE,
+        "stderr": subprocess.PIPE,
+        "text": True,
+    }
+    if os.name == "nt":
+        popen_kwargs["creationflags"] = subprocess.CREATE_NEW_PROCESS_GROUP
+    else:
+        popen_kwargs["start_new_session"] = True
+    process = subprocess.Popen([executable, *command[1:]], **popen_kwargs)
+    try:
+        while True:
+            try:
+                stdout, stderr = process.communicate(timeout = _CANCEL_POLL_SECONDS)
+                break
+            except subprocess.TimeoutExpired:
+                if cancel_event.is_set():
+                    _stop_child(process)
+                    raise RuntimeError("The local Codex agent was cancelled.")
+    except BaseException:
+        if process.poll() is None:
+            _stop_child(process)
+        raise
+    if process.returncode != 0:
+        detail = stderr.strip() or stdout.strip()
+        raise RuntimeError(
+            _bounded(detail) or f"Local Codex exited with code {process.returncode}."
+        )
+    return _result_text(stdout)
+
+
+def main() -> None:
+    if len(sys.argv) > 1:
+        os.environ[_CODEX_SUBAGENT_CONFIG_ENV] = sys.argv[1]
+    serve(
+        run_agent = run_local_agent,
+        tool_name = _CODEX_SUBAGENT_MCP_TOOL,
+        tool_description = _CODEX_SUBAGENT_TOOL_DESCRIPTION,
+        instructions = _SERVER_INSTRUCTIONS,
+    )
+
+
+if __name__ == "__main__":
+    main()
diff --git a/unsloth_cli/commands/_password_prompt.py b/unsloth_cli/commands/_password_prompt.py
index b6fd8ca34d..55f50acbf1 100644
--- a/unsloth_cli/commands/_password_prompt.py
+++ b/unsloth_cli/commands/_password_prompt.py
@@ -191,6 +191,10 @@ def prompt_new_password(verify_current: Callable[[str], bool], out: TextIO | Non
             out.write(f"Password must be at least {MIN_PASSWORD_LENGTH} characters. Try again.\n")
             out.flush()
             continue
+        if any(ch.isspace() for ch in password):
+            out.write("Password cannot contain spaces. Try again.\n")
+            out.flush()
+            continue
         if verify_current(password):
             out.write("New password must differ from the current password. Try again.\n")
             out.flush()
@@ -233,6 +237,8 @@ def validate_new_password(candidate: str, verify_current: Callable[[str], bool])
     current password), else None. Same policy as the interactive loop."""
     if len(candidate) < MIN_PASSWORD_LENGTH:
         return f"Password must be at least {MIN_PASSWORD_LENGTH} characters."
+    if any(ch.isspace() for ch in candidate):
+        return "Password cannot contain spaces."
     if verify_current(candidate):
         return "New password must differ from the current password."
     return None
diff --git a/unsloth_cli/commands/chat.py b/unsloth_cli/commands/chat.py
index bc4a72f36c..fdc5577700 100644
--- a/unsloth_cli/commands/chat.py
+++ b/unsloth_cli/commands/chat.py
@@ -206,7 +206,7 @@ def chat(
     no_server: bool = typer.Option(
         False,
         "--no-server",
-        help = "Load the model in-process even if a Studio server is running.",
+        help = "Load the model in-process even if an Unsloth server is running.",
     ),
 ):
     """Start an interactive chat with a model (loads once, stays warm)."""
@@ -262,14 +262,14 @@ def chat(
         llama_extra_args = llama_extra_args,
     )
 
-    # Prefer a running Studio server: instant starts, model shared with the UI.
+    # Prefer a running Unsloth server: instant starts, model shared with the UI.
     chat_backend = (
         None if (no_server or is_mlx_distributed) else connect_studio_server(model, **load_opts)
     )
     server_mode = chat_backend is not None
     if server_mode and should_print:
         console.print(
-            "(Studio server connected — model stays warm after /exit)",
+            "(Unsloth server connected — model stays warm after /exit)",
             style = "bright_black",
         )
     else:
@@ -331,7 +331,7 @@ def chat(
             enable_thinking = show_thinking,
             use_adapter = use_adapter,
         )
-        return raise_on_streamed_error(stream) if is_mlx_distributed else stream
+        return raise_on_streamed_error(stream)
 
     if should_print:
         console.print()
diff --git a/unsloth_cli/commands/inference.py b/unsloth_cli/commands/inference.py
index 84a126163e..7df05cef94 100644
--- a/unsloth_cli/commands/inference.py
+++ b/unsloth_cli/commands/inference.py
@@ -67,7 +67,7 @@ def inference(
     no_server: bool = typer.Option(
         False,
         "--no-server",
-        help = "Load the model in-process even if a Studio server is running.",
+        help = "Load the model in-process even if an Unsloth server is running.",
     ),
 ):
     """Run a single inference using the specified model."""
@@ -85,7 +85,7 @@ def inference(
             )
         raise typer.Exit(code = 1)
 
-    # A running Studio server keeps the model warm between runs. Under
+    # A running Unsloth server keeps the model warm between runs. Under
     # mlx.launch, every rank must enter the local MLX path instead of rank 0
     # alone talking to a server.
     load_opts = dict(
@@ -111,15 +111,12 @@ def inference(
             repetition_penalty = repetition_penalty,
             enable_thinking = think,
         )
-        if is_mlx_distributed:
-            stream = raise_on_streamed_error(stream)
+        stream = raise_on_streamed_error(stream)
         if rank == 0:
             typer.echo("Assistant:")
             try:
                 stream_to_stdout(stream, show_thinking = think)
             except RuntimeError as exc:
-                if not is_mlx_distributed:
-                    raise
                 typer.echo(f"Error: {exc}", err = True)
                 raise typer.Exit(code = 1)
         else:
diff --git a/unsloth_cli/commands/start.py b/unsloth_cli/commands/start.py
index fa39fdf761..408ea4bd34 100644
--- a/unsloth_cli/commands/start.py
+++ b/unsloth_cli/commands/start.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""`unsloth start` — launch a coding agent against a running Studio server."""
+"""`unsloth start` — launch a coding agent against a running Unsloth server."""
 
 import atexit
 import contextlib
@@ -14,15 +14,17 @@ import signal
 import subprocess
 import sys
 import tempfile
+import threading
 import time
 import urllib.error
 import urllib.request
 from pathlib import Path
 from typing import NamedTuple, NoReturn, Optional
-from urllib.parse import urlparse
+from urllib.parse import urlencode, urlparse
 
 import click
 import typer
+from typer.core import TyperCommand
 
 from unsloth_cli._inference import (
     _USER_AGENT,
@@ -35,7 +37,7 @@ from unsloth_cli._inference import (
 )
 
 start_app = typer.Typer(
-    help = "Start a coding agent against a running Studio server.",
+    help = "Start a coding agent against a running Unsloth server.",
     no_args_is_help = True,
     context_settings = {"help_option_names": ["-h", "--help"]},
 )
@@ -49,13 +51,22 @@ _HERMES_PROVIDER = "unsloth"
 # the wizard's global API-key/model prompts would block the launch and point the
 # user at a different (global) provider than the one Unsloth just configured.
 # Both installers expose a skip flag: `-SkipSetup` (PowerShell) and
-# `--skip-setup` (POSIX; passed to the piped script via `bash -s --`).
+# `--skip-setup` (POSIX; passed to the piped script via `bash -s --`). Pin both
+# the fetched script and the repository checkout it performs to the same full
+# commit so a later change to either upstream branch cannot silently replace
+# code that Unsloth executes with the user's privileges.
+_HERMES_INSTALL_COMMIT = "f1af945f6c576eccb126fa955edc9be258b33020"
+_HERMES_INSTALL_BASE = (
+    "https://raw.githubusercontent.com/NousResearch/hermes-agent/"
+    f"{_HERMES_INSTALL_COMMIT}/scripts"
+)
 _HERMES_WINDOWS_INSTALL_HINT = (
-    "& ([scriptblock]::Create((irm https://hermes-agent.nousresearch.com/install.ps1))) -SkipSetup"
+    f"& ([scriptblock]::Create((irm {_HERMES_INSTALL_BASE}/install.ps1)))"
+    f" -SkipSetup -Commit {_HERMES_INSTALL_COMMIT}"
 )
 _HERMES_POSIX_INSTALL_HINT = (
-    "curl -fsSL https://raw.githubusercontent.com/NousResearch/hermes-agent"
-    "/main/scripts/install.sh | bash -s -- --skip-setup"
+    f"curl -fsSL {_HERMES_INSTALL_BASE}/install.sh | bash -s --"
+    f" --skip-setup --commit {_HERMES_INSTALL_COMMIT}"
 )
 # Hermes refuses to initialize when the model window is under 64,000 tokens; its
 # error message points at the model.context_length / auxiliary.compression
@@ -63,63 +74,212 @@ _HERMES_POSIX_INSTALL_HINT = (
 # windows and scales the compaction threshold back down to the real window.
 _HERMES_MIN_CONTEXT = 65536
 _PI_PROVIDER = "unsloth"
-# OpenCode selects a model by "<providerID>/<modelID>" and honors a user
-# disabled_providers list. Register the session provider under a dedicated id a
-# user's disable list would never target, so the model is always selectable
-# without the wrapper having to reconstruct (and override) OpenCode's full,
-# multi-layer disabled_providers resolution.
+_SUBAGENT_NAME = "unsloth"
+_SUBAGENT_DESCRIPTION = (
+    "Local coding subagent powered by Unsloth for debugging, implementation, and codebase "
+    "research. Use when the user asks to spawn an Unsloth or local agent."
+)
+_SUBAGENT_INSTRUCTIONS = (
+    "You are a local coding subagent powered by Unsloth. Complete the assigned task directly, "
+    "use the available tools when useful, verify your work, and return a concise result to the "
+    "parent agent."
+)
+_SUBAGENT_PLAN_DESCRIPTION = (
+    "Read-only local coding subagent powered by Unsloth for planning and codebase research. "
+    "Use this local agent when Claude is in plan mode."
+)
+_SUBAGENT_PLAN_INSTRUCTIONS = (
+    "You are a read-only local coding subagent powered by Unsloth. Investigate the assigned "
+    "task with read-only tools, produce a concrete plan or answer, and return a concise result "
+    "to the parent agent. Do not modify files."
+)
+_CLAUDE_SUBAGENT_MCP_MODULE = "unsloth_cli.claude_subagent_mcp"
+_CLAUDE_SUBAGENT_TOOL = "mcp__plugin_unsloth-local-agent_unsloth__unsloth_agent"
+_CLAUDE_SUBAGENT_PLAN_TOOL = "mcp__plugin_unsloth-local-agent_unsloth__unsloth_plan_agent"
+_CODEX_SUBAGENT_MCP_MODULE = "unsloth_cli.codex_subagent_mcp"
+_CODEX_SUBAGENT_MCP_SERVER = "unsloth_local_agent"
+_CODEX_SUBAGENT_MCP_TOOL = "spawn_local_agent"
+_CODEX_SUBAGENT_CONFIG_ENV = "UNSLOTH_CODEX_SUBAGENT_CONFIG"
+_CODEX_PARENT_OVERLAY_MANIFEST = ".unsloth-parent-overlay.json"
+_CODEX_SUBAGENT_TOOL_DESCRIPTION = (
+    f"{_SUBAGENT_DESCRIPTION} Use this tool instead of the built-in spawn_agent tool for those "
+    "requests. Other subagent requests may use the built-in tools normally."
+)
+_CODEX_SUBAGENT_ROUTING_INSTRUCTIONS = (
+    "When the user asks to spawn an Unsloth agent or local agent, you must call the "
+    "spawn_local_agent MCP tool once with the complete task. Do not answer, simulate the "
+    "result, call wait, or use a built-in subagent before calling the tool. Use built-in "
+    "subagents for other delegation requests."
+)
+_PI_SUBAGENT_EXTENSION = Path(__file__).parent.parent / "pi_subagent.ts"
+# OpenCode selects a model by "<providerID>/<modelID>". Use a dedicated id to avoid
+# colliding with a user's providers; provider filters are set in the launch-time overlay.
 _OPENCODE_PROVIDER = "unsloth-studio"
 _PROVIDER_HEADER = f"[model_providers.{_CODEX_PROFILE}]"
 _PASSTHROUGH = {"allow_extra_args": True, "ignore_unknown_options": True}
+
+
+class _PassthroughCommand(TyperCommand):
+    """Preserve the option separator when forwarding arguments to an agent."""
+
+    def parse_args(self, ctx: click.Context, args: list[str]) -> list[str]:
+        raw_args = list(args)
+        try:
+            separator = raw_args.index("--")
+        except ValueError:
+            return super().parse_args(ctx, args)
+        trailing_count = len(raw_args) - separator - 1
+        remaining = super().parse_args(ctx, args)
+        insert_at = max(0, len(remaining) - trailing_count)
+        if insert_at >= len(remaining) or remaining[insert_at] != "--":
+            remaining.insert(insert_at, "--")
+            ctx.args = remaining
+        return remaining
+
+
 _CLAUDE_ENV_UNSET = ("ANTHROPIC_API_KEY", "CLAUDE_CODE_OAUTH_TOKEN")
+_CODEX_ENV_UNSET = ("OPENAI_API_KEY", "CODEX_API_KEY", "CODEX_ACCESS_TOKEN")
 
 # Shared by every agent command; only the config/env/command differ.
+# Help is grouped into rich panels so `--help` reads as Model / Server / Session
+# instead of one long unaligned list.
+_PANEL_MODEL = "Model"
+_PANEL_SERVER = "Server"
+_PANEL_SAMPLING = "Sampling"
+_PANEL_SESSION = "Agent session"
+
 _MODEL_OPTION = typer.Option(
-    None, "--model", "-m", help = "Model for the agent; defaults to the one loaded in Studio."
-)
-_KEY_OPTION = typer.Option(
     None,
-    "--api-key",
-    envvar = "UNSLOTH_API_KEY",
-    help = (
-        "Studio API key. For a local Studio it is minted automatically and "
-        "remembered per server. For a remote server, pass one with --api-key "
-        "(or UNSLOTH_API_KEY); it is remembered for next time."
-    ),
+    "--model",
+    "-m",
+    rich_help_panel = _PANEL_MODEL,
+    help = "Model for the agent, or a bare `org/name(:variant)` positional. "
+    "Defaults to the one loaded in Unsloth.",
 )
-_LAUNCH_OPTION = typer.Option(
-    True,
-    "--launch/--no-launch",
-    help = "--no-launch prints the env and command instead (remote shells, WSL).",
-)
-_SERVE_OPTION = typer.Option(
-    True,
-    "--serve/--no-serve",
-    help = (
-        "If no Studio server is running, auto-start one for --model and stop it when the "
-        "agent exits. --no-serve keeps the old behavior of erroring out."
-    ),
-)
-# Model-load knobs mirrored from `unsloth run`; only used when --model triggers a
-# load on the server. Server-startup flags (--host/--port/--cloudflare/...) do not
-# apply here because `unsloth start` attaches to an already-running server.
 _GGUF_VARIANT_OPTION = typer.Option(
-    None, "--gguf-variant", help = "GGUF quant variant to load (e.g. UD-Q4_K_XL)."
+    None,
+    "--gguf-variant",
+    rich_help_panel = _PANEL_MODEL,
+    help = "GGUF quant variant to load (e.g. UD-Q4_K_XL). Defaults to UD-Q4_K_XL for "
+    "unsloth/* GGUF repos, else Q4_K_M.",
 )
 _CONTEXT_OPTION = typer.Option(
     0,
     "--max-seq-length",
     "--context-length",
+    rich_help_panel = _PANEL_MODEL,
     help = "Context length in tokens for the load (0 = model default).",
 )
 _LOAD_4BIT_OPTION = typer.Option(
-    True, "--load-in-4bit/--no-load-in-4bit", help = "Load hub models in 4-bit (ignored for GGUF)."
+    True,
+    "--load-in-4bit/--no-load-in-4bit",
+    rich_help_panel = _PANEL_MODEL,
+    help = "Load hub models in 4-bit (ignored for GGUF).",
 )
 _TENSOR_PARALLEL_OPTION = typer.Option(
     False,
     "--tensor-parallel/--no-tensor-parallel",
+    rich_help_panel = _PANEL_MODEL,
     help = "Split a GGUF across GPUs by tensor instead of by layer (multi-GPU only).",
 )
+
+# Server knobs. Only used when `unsloth start` auto-starts the server (--serve);
+# they have no effect when attaching to a server someone else already started.
+_SERVE_OPTION = typer.Option(
+    True,
+    "--serve/--no-serve",
+    rich_help_panel = _PANEL_SERVER,
+    help = "If no Unsloth server is running, auto-start one for --model and keep it "
+    "available after the agent exits. --no-serve errors out instead.",
+)
+_ENABLE_TOOLS_OPTION = typer.Option(
+    False,
+    "--enable-tools/--disable-tools",
+    rich_help_panel = _PANEL_SERVER,
+    help = "Server-side tools (web search, code execution) for the auto-started server. "
+    "Default off so the agent's own tools are relayed unchanged.",
+)
+_TOOL_CALL_HEALING_OPTION = typer.Option(
+    None,
+    "--enable-tool-call-healing/--disable-tool-call-healing",
+    rich_help_panel = _PANEL_SERVER,
+    help = "Promote text-form tool calls from small GGUFs back into structured calls. On by "
+    "default; when the flag is omitted an inherited UNSLOTH_DISABLE_TOOL_CALL_HEALING is kept.",
+)
+_TOOL_CALL_NUDGING_OPTION = typer.Option(
+    None,
+    "--enable-tool-call-nudging/--disable-tool-call-nudging",
+    rich_help_panel = _PANEL_SERVER,
+    help = "Retry once with a nudge when a non-streaming passthrough tool call can't be healed. "
+    "On by default; when the flag is omitted an inherited UNSLOTH_TOOL_CALL_NUDGE is kept.",
+)
+# Sampling overrides pin a value on the auto-started server (winning over the client and the
+# per-model recommendation). Default unset -> the model's recommended sampling is used.
+_TEMPERATURE_OPTION = typer.Option(
+    None,
+    "--temperature",
+    min = 0.0,
+    max = 2.0,
+    rich_help_panel = _PANEL_SAMPLING,
+    help = "Pin the sampling temperature. Default: unset (per-model recommendation).",
+)
+_TOP_P_OPTION = typer.Option(
+    None,
+    "--top-p",
+    min = 0.0,
+    max = 1.0,
+    rich_help_panel = _PANEL_SAMPLING,
+    help = "Pin top-p (nucleus) sampling. Default: unset (per-model recommendation).",
+)
+_TOP_K_OPTION = typer.Option(
+    None,
+    "--top-k",
+    min = -1,
+    max = 100,
+    rich_help_panel = _PANEL_SAMPLING,
+    help = "Pin top-k sampling. Default: unset (per-model recommendation).",
+)
+_MIN_P_OPTION = typer.Option(
+    None,
+    "--min-p",
+    min = 0.0,
+    max = 1.0,
+    rich_help_panel = _PANEL_SAMPLING,
+    help = "Pin min-p sampling threshold. Default: unset (per-model recommendation).",
+)
+_REPETITION_PENALTY_OPTION = typer.Option(
+    None,
+    "--repetition-penalty",
+    min = 1.0,
+    max = 2.0,
+    rich_help_panel = _PANEL_SAMPLING,
+    help = "Pin the repetition penalty. Default: unset (per-model recommendation).",
+)
+_PRESENCE_PENALTY_OPTION = typer.Option(
+    None,
+    "--presence-penalty",
+    min = 0.0,
+    max = 2.0,
+    rich_help_panel = _PANEL_SAMPLING,
+    help = "Pin the presence penalty. Default: unset (per-model recommendation).",
+)
+
+# Agent-session knobs.
+_KEY_OPTION = typer.Option(
+    None,
+    "--api-key",
+    envvar = "UNSLOTH_API_KEY",
+    rich_help_panel = _PANEL_SESSION,
+    help = "Unsloth API key. For a local Unsloth it is minted automatically and "
+    "remembered per server. For a remote server, pass one with --api-key "
+    "(or UNSLOTH_API_KEY); it is remembered for next time.",
+)
+_LAUNCH_OPTION = typer.Option(
+    True,
+    "--launch/--no-launch",
+    rich_help_panel = _PANEL_SESSION,
+    help = "--no-launch prints the env and command instead (remote shells, WSL).",
+)
 # One normalized "run tools without prompting" switch. Each agent spells this
 # differently and it's easy to forget which is which, so accept every spelling and
 # route to the agent's own mechanism in _yolo_command_flags / the config writers.
@@ -128,14 +288,14 @@ _YOLO_OPTION = typer.Option(
     "--yolo",
     "--dangerously-skip-permissions",
     "--dangerously-bypass-approvals-and-sandbox",
-    help = (
-        "Auto-approve all tool actions for this session; routed to the agent's own "
-        "flag/config. Any of the three spellings works for any agent."
-    ),
+    rich_help_panel = _PANEL_SESSION,
+    help = "Auto-approve all tool actions for this session; routed to the agent's own "
+    "flag/config. Any of the three spellings works for any agent.",
 )
 _PERSIST_OPTION = typer.Option(
     False,
     "--persist/--no-persist",
+    rich_help_panel = _PANEL_SESSION,
     help = (
         "Keep this agent's Unsloth-managed session dir so you can resume it later. "
         "codex/openclaw/hermes/pi have their whole home relocated into an Unsloth dir "
@@ -148,9 +308,15 @@ _PERSIST_OPTION = typer.Option(
         "the agent unchanged."
     ),
 )
+_AS_SUBAGENT_OPTION = typer.Option(
+    False,
+    "--as-subagent",
+    rich_help_panel = _PANEL_SESSION,
+    help = "Keep the coding agent's current model and add Unsloth as a local subagent.",
+)
 
-# Per-agent CLI flag for "run tools without prompting". opencode and openclaw have no
-# such flag (config only) and are handled in their config writers, so they are absent.
+# Per-agent CLI flag for "run tools without prompting". OpenCode (native --auto is
+# command-scoped, handled below) and OpenClaw (config-only) are absent from this prefix map.
 _YOLO_COMMAND_FLAGS = {
     "claude": ["--dangerously-skip-permissions"],
     "codex": ["--dangerously-bypass-approvals-and-sandbox"],
@@ -166,6 +332,84 @@ def _yolo_command_flags(agent: str, yolo: bool) -> list:
     return _YOLO_COMMAND_FLAGS.get(agent, []) if yolo else []
 
 
+# Subcommands that reject --auto (OpenCode exposes it only on the default TUI and `run`),
+# so `opencode serve --auto` is never emitted. Includes console/generate, hidden from
+# `opencode --help` but still registered. Unknown first positionals are TUI paths -> --auto.
+_OPENCODE_NON_AUTO_SUBCOMMANDS = frozenset(
+    "completion acp mcp attach debug providers auth agent upgrade uninstall serve web "
+    "models stats export import github pr session plugin plug db console generate".split()
+)
+_OPENCODE_GLOBAL_BOOLEAN_OPTIONS = frozenset(
+    "-h --help -v --version --print-logs --pure --mdns".split()
+)
+_OPENCODE_GLOBAL_VALUE_OPTIONS = frozenset(
+    "--log-level --port --hostname --mdns-domain --cors".split()
+)
+_OPENCODE_NATIVE_AUTO_MIN_VERSION = (1, 17, 12)
+
+
+def _opencode_supports_native_auto() -> bool:
+    executable = _which_with_install_dirs("opencode")
+    if executable is None:
+        # No local binary: a --no-launch recipe may run elsewhere, and _run installs the
+        # current release on launch -- either way assume native --auto is available.
+        return True
+    try:
+        output = subprocess.check_output(
+            [executable, "--version"],
+            text = True,
+            timeout = 10,
+            stderr = subprocess.DEVNULL,
+        )
+    except Exception:
+        return False
+    match = re.search(r"(\d+)\.(\d+)\.(\d+)", output)
+    return bool(match) and tuple(int(part) for part in match.groups()) >= (
+        _OPENCODE_NATIVE_AUTO_MIN_VERSION
+    )
+
+
+def _opencode_subcommand(args: list[str]) -> Optional[str]:
+    """Return an explicit OpenCode subcommand after supported global options."""
+    index = 0
+    while index < len(args):
+        arg = args[index]
+        if arg == "--":
+            return None
+        if arg in _OPENCODE_GLOBAL_BOOLEAN_OPTIONS:
+            index += 1
+            continue
+        if arg in _OPENCODE_GLOBAL_VALUE_OPTIONS:
+            index += 2
+            continue
+        if any(arg.startswith(f"{option}=") for option in _OPENCODE_GLOBAL_VALUE_OPTIONS):
+            index += 1
+            continue
+        # A non-global option (e.g. --session) is a TUI flag; stop before its value is
+        # mistaken for a subcommand.
+        if arg.startswith("-"):
+            return None
+        return arg
+    return None
+
+
+def _opencode_native_auto_args(args: list[str], yolo: bool) -> tuple[list[str], bool]:
+    """Add OpenCode's native --auto when the selected command supports it."""
+    routed = list(args)
+    if not yolo:
+        return routed, False
+    if _opencode_subcommand(routed) in _OPENCODE_NON_AUTO_SUBCOMMANDS:
+        return routed, False
+    separator = routed.index("--") if "--" in routed else len(routed)
+    # --mini's runMini TUI forces auto=false and never forwards --auto, so appending it is
+    # useless; fall back to the config permission block so --yolo still auto-approves.
+    if any(arg == "--mini" or arg.startswith("--mini=") for arg in routed[:separator]):
+        return routed, False
+    if "--auto" not in routed[:separator]:
+        routed.insert(separator, "--auto")
+    return routed, True
+
+
 def _hermes_install_hint() -> str:
     return _HERMES_WINDOWS_INSTALL_HINT if os.name == "nt" else _HERMES_POSIX_INSTALL_HINT
 
@@ -216,6 +460,20 @@ class LoadOptions(NamedTuple):
     tensor_parallel: bool = False
 
 
+class ServerOptions(NamedTuple):
+    """Tool-call knobs forwarded to an auto-started `unsloth run` server."""
+
+    enable_tools: bool = False
+    tool_call_healing: Optional[bool] = None
+    tool_call_nudging: Optional[bool] = None
+    temperature: Optional[float] = None
+    top_p: Optional[float] = None
+    top_k: Optional[int] = None
+    min_p: Optional[float] = None
+    repetition_penalty: Optional[float] = None
+    presence_penalty: Optional[float] = None
+
+
 def _split_repo_variant(model: str) -> tuple:
     """Split ``org/name:QUANT`` into ``(repo, variant)`` -> ``("org/name", "QUANT")``.
 
@@ -239,11 +497,87 @@ def _split_repo_variant(model: str) -> tuple:
     return repo, variant
 
 
+def _looks_like_model(token: str) -> bool:
+    """True for a bare `org/name(:variant)` hub id that is not a flag or a local path.
+
+    Reuses `_is_hub_model_id`, so a relative dir like `owner/repo` that actually exists
+    is left for the agent (e.g. OpenCode opens it as a project) instead of being taken
+    as a model; a non-existent `org/name` is treated as a hub id.
+    """
+    if not token or token.startswith("-") or " " in token:
+        return False
+    repo, _ = _split_repo_variant(token)
+    return _is_hub_model_id(repo)
+
+
+def _consume_positional_model(model: Optional[str], args: list) -> tuple:
+    """Route a leading `org/name` positional to --model when --model was not given.
+
+    Only the FIRST token is considered so an option value like `--profile owner/repo`
+    is never stolen, and only when --model is absent so an explicit --model always wins.
+    Returns (model, remaining_args) with the consumed token removed from the passthrough.
+    """
+    args = list(args)
+    if model or not args or not _looks_like_model(args[0]):
+        return model, args
+    return args[0], args[1:]
+
+
+def _display_model_spec(model: str, variant: Optional[str]) -> str:
+    """Return a user-facing model name that includes the selected GGUF variant."""
+    repo, inline_variant = _split_repo_variant(model)
+    selected_variant = variant or inline_variant
+    return f"{repo}:{selected_variant}" if selected_variant else model
+
+
+def _subagent_model_id(
+    base: str,
+    key: str,
+    entry: dict,
+    requested_model: Optional[str],
+    requested_variant: Optional[str],
+) -> str:
+    """Return an API model id that preserves the selected GGUF variant.
+
+    Coding-agent model definitions outlive the initial load. If Unsloth later
+    unloads the model, a bare repository id may resolve to a different cached
+    quant. Include the explicit or currently loaded variant so an automatic
+    reload selects the same weights.
+    """
+    model_id = str(entry["id"])
+    _, inline_variant = _split_repo_variant(requested_model or "")
+    variant = requested_variant or inline_variant
+    if not variant:
+        try:
+            status = _http_json("GET", f"{base}/api/inference/status", key)
+        except Exception:
+            status = {}
+            typer.echo(
+                "Warning: could not verify the loaded GGUF variant; a later reload "
+                "may pick a different cached quant. Pass :variant to pin it.",
+                err = True,
+            )
+        if status.get("is_gguf"):
+            variant = status.get("gguf_variant")
+    return (
+        _display_model_spec(model_id, str(variant))
+        if variant and _is_hub_model_id(model_id)
+        else model_id
+    )
+
+
 def _fail(message: str) -> NoReturn:
     typer.echo(message, err = True)
     raise typer.Exit(code = 1)
 
 
+def _reject_as_subagent(agent: str, args: list) -> None:
+    # Reject early; otherwise the flag reaches the agent binary and fails after
+    # Studio has already loaded the model.
+    if "--as-subagent" in args:
+        _fail(f"--as-subagent is not supported for {agent}.")
+
+
 def _http_error_detail(exc: urllib.error.HTTPError) -> str:
     try:
         body = json.loads(exc.read().decode())
@@ -286,11 +620,265 @@ def _http_json(
 
 
 # A server that WE auto-started (never one we merely found). Kept at module scope so
-# _run's finally and the atexit backstop can tear it down without threading a handle
+# failure paths and the atexit backstop can tear it down without threading a handle
 # through all six agent commands. Only one agent runs per process, so one slot is enough.
 _auto_served_server: Optional[subprocess.Popen] = None
 # Model download + load can be slow; give the auto-started server room before giving up.
 _SERVER_START_TIMEOUT_S = 900
+_DOWNLOAD_POLL_INTERVAL_S = 1.0
+_START_API_KEY_PREFIX = "UNSLOTH_START_API_KEY: "
+_START_API_KEY_MARKER_ENV = "_UNSLOTH_START_API_KEY_MARKER"
+
+
+def _format_download_bytes(value: int) -> str:
+    value = max(0, int(value))
+    for unit in ("B", "KiB", "MiB", "GiB", "TiB"):
+        if value < 1024 or unit == "TiB":
+            precision = 0 if unit in ("B", "KiB") else 1
+            return f"{value:.{precision}f} {unit}"
+        value /= 1024
+    return "0 B"
+
+
+def _format_download_eta(seconds: float) -> str:
+    seconds = max(0, int(seconds))
+    if seconds < 60:
+        return f"{seconds}s"
+    minutes, seconds = divmod(seconds, 60)
+    if minutes < 60:
+        return f"{minutes}m {seconds:02d}s"
+    hours, minutes = divmod(minutes, 60)
+    return f"{hours}h {minutes:02d}m"
+
+
+class _DownloadProgressDisplay:
+    """Render download progress without making redirected output noisy."""
+
+    def __init__(self) -> None:
+        self._samples: list[tuple[float, int]] = []
+        self._shown = False
+        self._last_bucket = -1
+        self._last_line_length = 0
+        self._last_expected = 0
+        self._interactive = bool(getattr(sys.stdout, "isatty", lambda: False)())
+
+    def update(self, progress: dict) -> None:
+        downloaded = max(0, int(progress.get("downloaded_bytes") or 0))
+        completed = max(0, int(progress.get("completed_bytes") or 0))
+        expected = max(0, int(progress.get("expected_bytes") or 0))
+        self._last_expected = max(self._last_expected, expected)
+        fraction = float(progress.get("progress") or 0)
+        if downloaded <= 0:
+            return
+        # A fully cached snapshot can report 99% with no incomplete bytes; that is
+        # not a transfer, so don't show it as a download.
+        if completed >= downloaded > 0:
+            return
+
+        now = time.monotonic()
+        if self._samples and downloaded < self._samples[-1][1]:
+            self._samples.clear()
+        self._samples.append((now, downloaded))
+        cutoff = now - 15.0
+        while len(self._samples) > 2 and self._samples[0][0] < cutoff:
+            self._samples.pop(0)
+
+        rate = 0.0
+        if len(self._samples) >= 2:
+            elapsed = self._samples[-1][0] - self._samples[0][0]
+            delta = self._samples[-1][1] - self._samples[0][1]
+            if elapsed >= 1.0 and delta > 0:
+                rate = delta / elapsed
+
+        if expected > 0:
+            # The endpoint caps at 99% while bytes remain in an incomplete file; trust it.
+            fraction = min(1.0, max(0.0, fraction))
+            percent = min(100, max(0, int(fraction * 100)))
+            filled = min(24, int(fraction * 24))
+            bar = "=" * filled + ">" + "." * max(0, 23 - filled) if filled < 24 else "=" * 24
+            line = (
+                f"Downloading model [{bar}] {percent:3d}% "
+                f"{_format_download_bytes(downloaded)} / {_format_download_bytes(expected)}"
+            )
+            bucket = percent // 10
+            if rate > 0:
+                line += f" | {_format_download_bytes(rate)}/s"
+                if downloaded < expected:
+                    line += f" | ETA {_format_download_eta((expected - downloaded) / rate)}"
+        else:
+            line = f"Downloading model: {_format_download_bytes(downloaded)}"
+            bucket = downloaded // (1024**3)
+            if rate > 0:
+                line += f" | {_format_download_bytes(rate)}/s"
+
+        if self._interactive:
+            padding = " " * max(0, self._last_line_length - len(line))
+            typer.echo(f"\r{line}{padding}", nl = False)
+            sys.stdout.flush()
+            self._last_line_length = len(line)
+        elif not self._shown or bucket > self._last_bucket:
+            typer.echo(line)
+            self._last_bucket = bucket
+        self._shown = True
+
+    def close(self) -> None:
+        if self._interactive and self._shown:
+            typer.echo()
+        self._last_line_length = 0
+
+    def complete(self) -> None:
+        """Finish a displayed transfer after the model load confirms success."""
+        if not self._shown:
+            return
+        downloaded = self._samples[-1][1] if self._samples else 0
+        expected = max(downloaded, getattr(self, "_last_expected", 0))
+        self.update(
+            {
+                "downloaded_bytes": expected,
+                "expected_bytes": expected,
+                "progress": 1.0,
+            }
+        )
+
+
+def _normalized_variant(value: object) -> str:
+    return re.sub(r"[^a-z0-9]", "", str(value or "").lower())
+
+
+class _ModelDownloadProgress:
+    """Best-effort polling of the model download endpoints."""
+
+    def __init__(self, base: str, key: str, model: str, variant: Optional[str]) -> None:
+        self._base = base
+        self._key = key
+        self._model = model
+        self._variant = variant or ""
+        self._expected_bytes = 0
+        self._display = _DownloadProgressDisplay()
+        self._configured = False
+        self._disabled = not _is_hub_model_id(model)
+        self._progress_prefix = "/api/hub"
+
+    def _configure(self) -> None:
+        self._configured = True
+        if self._disabled:
+            return
+        # GGUF repos need the selected quant's size; the repo endpoint totals every
+        # quant. Resolve the variant first, otherwise show bytes only.
+        if self._variant or "gguf" in self._model.lower():
+            try:
+                params = urlencode({"repo_id": self._model})
+                try:
+                    info = _http_json(
+                        "GET",
+                        f"{self._base}/api/hub/gguf-variants?{params}",
+                        self._key,
+                        timeout = 10,
+                    )
+                except urllib.error.HTTPError as exc:
+                    if exc.code != 404:
+                        raise
+                    self._progress_prefix = "/api/models"
+                    info = _http_json(
+                        "GET",
+                        f"{self._base}/api/models/gguf-variants?{params}",
+                        self._key,
+                        timeout = 10,
+                    )
+                self._variant = self._variant or str(info.get("default_variant") or "")
+                wanted = _normalized_variant(self._variant)
+                for item in info.get("variants") or []:
+                    quant = _normalized_variant(item.get("quant"))
+                    filename = _normalized_variant(item.get("filename"))
+                    if wanted and (wanted == quant or wanted in filename):
+                        self._expected_bytes = int(
+                            item.get("download_size_bytes") or item.get("size_bytes") or 0
+                        )
+                        break
+            except Exception:
+                # Older servers lack this endpoint; byte progress is still useful.
+                pass
+
+    def poll(self) -> None:
+        if not self._configured:
+            self._configure()
+        if self._disabled:
+            return
+        try:
+            if self._variant or "gguf" in self._model.lower():
+                params = urlencode(
+                    {
+                        "repo_id": self._model,
+                        "variant": self._variant,
+                        "expected_bytes": self._expected_bytes,
+                    }
+                )
+                url = f"{self._base}{self._progress_prefix}/gguf-download-progress?{params}"
+            else:
+                url = (
+                    f"{self._base}{self._progress_prefix}/download-progress?"
+                    f"{urlencode({'repo_id': self._model})}"
+                )
+            try:
+                reading = _http_json("GET", url, self._key, timeout = 10)
+            except urllib.error.HTTPError as exc:
+                if exc.code != 404 or self._progress_prefix == "/api/models":
+                    raise
+                self._progress_prefix = "/api/models"
+                self.poll()
+                return
+            self._display.update(reading)
+        except Exception:
+            # Progress is best-effort; never fail the load over a polling error.
+            self._disabled = True
+
+    def close(self) -> None:
+        self._display.close()
+
+    def complete(self) -> None:
+        self._display.complete()
+
+
+def _load_model_with_progress(
+    base: str, key: str, model: str, load: LoadOptions, payload: dict
+) -> dict:
+    """Run the blocking load request while polling its download progress."""
+    result: list[tuple[bool, object]] = []
+    done = threading.Event()
+
+    def _load() -> None:
+        try:
+            value = _http_json(
+                "POST",
+                f"{base}/api/inference/load",
+                key,
+                payload,
+                timeout = 3600,
+                error = "Model load failed",
+            )
+            result.append((True, value))
+        except BaseException as exc:
+            result.append((False, exc))
+        finally:
+            done.set()
+
+    threading.Thread(target = _load, name = "unsloth-model-load", daemon = True).start()
+    progress = _ModelDownloadProgress(base, key, model, load.gguf_variant)
+    loading_announced = False
+    try:
+        while not done.wait(_DOWNLOAD_POLL_INTERVAL_S):
+            if not loading_announced:
+                typer.echo(f"Loading model: {_display_model_spec(model, load.gguf_variant)}")
+                loading_announced = True
+            progress.poll()
+        ok, value = result[0]
+        if not ok:
+            assert isinstance(value, BaseException)
+            raise value
+        progress.complete()
+        return value if isinstance(value, dict) else {}
+    finally:
+        progress.close()
 
 
 def _studio_healthy(base: str, timeout: float = 3.0) -> bool:
@@ -309,6 +897,11 @@ def _log_tail(path: Path, lines: int = 20) -> str:
         return "(no server log)"
 
 
+def _redacted_log_tail(path: Path, lines: int = 20) -> str:
+    """Tail with minted keys removed; only for tails shown on the terminal."""
+    return re.sub(r"sk-unsloth-\S+", "sk-unsloth-[redacted]", _log_tail(path, lines))
+
+
 def _shutdown_server(server: Optional[subprocess.Popen]) -> None:
     # Idempotent teardown of a server WE started, plus its own children (llama-server,
     # cloudflared). A no-op once the process is already gone.
@@ -347,17 +940,32 @@ def _shutdown_auto_served() -> None:
     global _auto_served_server
     server, _auto_served_server = _auto_served_server, None
     if server is not None and server.poll() is None:
-        typer.echo("Stopping the auto-started Studio server…")
+        typer.echo("Stopping the auto-started Unsloth server…")
         _shutdown_server(server)
 
 
-def _start_studio_server(base: str, model: str, load: LoadOptions) -> subprocess.Popen:
+def _keep_auto_served() -> bool:
+    """Release ownership so a successfully started server survives this CLI."""
+    global _auto_served_server
+    server, _auto_served_server = _auto_served_server, None
+    atexit.unregister(_shutdown_auto_served)
+    return server is not None and server.poll() is None
+
+
+def _start_studio_server(
+    base: str,
+    model: str,
+    load: LoadOptions,
+    server: ServerOptions = ServerOptions(),
+) -> subprocess.Popen:
     """Spawn `unsloth run` for `model`, wait until it is fully ready, and return it."""
     global _auto_served_server
     unsloth = shutil.which("unsloth") or "unsloth"
     parsed = urlparse(base)
-    # --disable-tools = passthrough mode (relay the agent's own tools); --no-cloudflare =
-    # loopback only, no tunnel. Mirrors .github/scripts/serve-unsloth-run.sh.
+    # Tools default off = passthrough mode (relay the agent's own tools); --no-cloudflare =
+    # loopback only, no tunnel. Mirrors .github/scripts/serve-unsloth-run.sh. Healing/nudging
+    # travel via the child env below (version-agnostic) rather than new run flags that an
+    # older re-exec'd run could mistake for llama-server args.
     command = [
         unsloth,
         "run",
@@ -365,7 +973,7 @@ def _start_studio_server(base: str, model: str, load: LoadOptions) -> subprocess
         parsed.hostname or "127.0.0.1",
         "-p",
         str(parsed.port or 8888),
-        "--disable-tools",
+        "--enable-tools" if server.enable_tools else "--disable-tools",
         "--no-cloudflare",
         "--model",
         model,
@@ -380,9 +988,8 @@ def _start_studio_server(base: str, model: str, load: LoadOptions) -> subprocess
         command += ["--tensor-parallel"]
 
     log_path = Path(tempfile.gettempdir()) / f"unsloth-start-server-{os.getpid()}.log"
-    typer.echo(
-        f"No Studio server at {base}. Starting one for {model} (loading the model can take a while)…"
-    )
+    typer.echo("Starting Unsloth server")
+    typer.echo(f"Model: {_display_model_spec(model, load.gguf_variant)}")
     typer.echo(f"Server log: {log_path}")
     # 0600: the `unsloth run` banner in this log carries the minted sk-unsloth- key, and
     # the tempdir is world-traversable. Unlink first so a stale looser-mode file (pid
@@ -390,8 +997,42 @@ def _start_studio_server(base: str, model: str, load: LoadOptions) -> subprocess
     log_path.unlink(missing_ok = True)
     log = os.fdopen(os.open(log_path, os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0o600), "wb")
     # Own session/process group so a mid-session Ctrl+C (cancel a turn) doesn't reach the
-    # server; we tear it down explicitly when the agent exits.
-    kwargs: dict = {"stdout": log, "stderr": subprocess.STDOUT, "stdin": subprocess.DEVNULL}
+    # server. It survives a successful agent session; torn down on startup/launch failure.
+    child_env = os.environ.copy()
+    # Pass the marker via env so an older launcher ignores it instead of treating an
+    # unknown CLI flag as a llama-server arg; new launchers preserve it across re-exec.
+    child_env[_START_API_KEY_MARKER_ENV] = "1"
+    # Convey healing/nudging through the env; `unsloth run` reads these when its own
+    # flags are omitted, so this works even if run re-execs into an older Studio venv.
+    # Only write when the operator set the flag explicitly; otherwise keep whatever they
+    # already exported (child_env is a copy of os.environ), falling back to the start
+    # defaults (healing on, nudging on) when nothing was inherited.
+    if server.tool_call_healing is not None:
+        child_env["UNSLOTH_DISABLE_TOOL_CALL_HEALING"] = "0" if server.tool_call_healing else "1"
+    elif "UNSLOTH_DISABLE_TOOL_CALL_HEALING" not in child_env:
+        child_env["UNSLOTH_DISABLE_TOOL_CALL_HEALING"] = "0"
+    if server.tool_call_nudging is not None:
+        child_env["UNSLOTH_TOOL_CALL_NUDGE"] = "1" if server.tool_call_nudging else "0"
+    elif "UNSLOTH_TOOL_CALL_NUDGE" not in child_env:
+        child_env["UNSLOTH_TOOL_CALL_NUDGE"] = "1"
+    # Forward any sampling pin via the env; `unsloth run` reads UNSLOTH_SAMPLING_* and the
+    # backend resolver applies it as a hard override. Only set fields the operator specified.
+    for _sampling_env, _sampling_value in (
+        ("UNSLOTH_SAMPLING_TEMPERATURE", server.temperature),
+        ("UNSLOTH_SAMPLING_TOP_P", server.top_p),
+        ("UNSLOTH_SAMPLING_TOP_K", server.top_k),
+        ("UNSLOTH_SAMPLING_MIN_P", server.min_p),
+        ("UNSLOTH_SAMPLING_REPETITION_PENALTY", server.repetition_penalty),
+        ("UNSLOTH_SAMPLING_PRESENCE_PENALTY", server.presence_penalty),
+    ):
+        if _sampling_value is not None:
+            child_env[_sampling_env] = str(_sampling_value)
+    kwargs: dict = {
+        "stdout": log,
+        "stderr": subprocess.STDOUT,
+        "stdin": subprocess.DEVNULL,
+        "env": child_env,
+    }
     if os.name == "nt":
         kwargs["creationflags"] = subprocess.CREATE_NEW_PROCESS_GROUP
     else:
@@ -404,20 +1045,48 @@ def _start_studio_server(base: str, model: str, load: LoadOptions) -> subprocess
     atexit.register(_shutdown_auto_served)
 
     deadline = time.monotonic() + _SERVER_START_TIMEOUT_S
-    while time.monotonic() < deadline:
-        if server.poll() is not None:
-            tail = _log_tail(log_path)
-            _shutdown_auto_served()
-            _fail(f"The Studio server stopped before it was ready. Last log lines:\n{tail}")
-        # `unsloth run` prints the minted key only after the server is up AND the model is
-        # loaded, so it is the fully-ready signal (same contract serve-unsloth-run.sh uses).
-        if _studio_healthy(base) and "sk-unsloth-" in _log_tail(log_path, lines = 400):
-            typer.echo(f"Studio server ready at {base}.")
-            return server
-        time.sleep(2.0)
+    progress: Optional[_ModelDownloadProgress] = None
+    early_key_seen = False
+    try:
+        while time.monotonic() < deadline:
+            if server.poll() is not None:
+                # The early key marker lands here before load finishes; redact it.
+                tail = _redacted_log_tail(log_path)
+                _shutdown_auto_served()
+                _fail(f"The Unsloth server stopped before it was ready. Last log lines:\n{tail}")
+            tail = _log_tail(log_path, lines = 400)
+            if progress is None:
+                marker = re.search(
+                    rf"^{re.escape(_START_API_KEY_PREFIX)}(sk-unsloth-[^\s]+)$",
+                    tail,
+                    flags = re.MULTILINE,
+                )
+                if marker:
+                    early_key_seen = True
+                    progress = _ModelDownloadProgress(
+                        base,
+                        marker.group(1),
+                        model,
+                        load.gguf_variant,
+                    )
+            if progress is not None:
+                progress.poll()
+            # New children emit an early key marker, so wait for the final model banner;
+            # older children only print the key after load, so fall back to that.
+            ready_signal = "Model loaded:" in tail if early_key_seen else "sk-unsloth-" in tail
+            if _studio_healthy(base) and ready_signal:
+                if progress is not None:
+                    progress.complete()
+                    progress.close()
+                    progress = None
+                return server
+            time.sleep(2.0)
+    finally:
+        if progress is not None:
+            progress.close()
     _shutdown_auto_served()
     _fail(
-        f"The Studio server didn't become ready within {_SERVER_START_TIMEOUT_S}s. See {log_path}."
+        f"The Unsloth server didn't become ready within {_SERVER_START_TIMEOUT_S}s. See {log_path}."
     )
 
 
@@ -440,10 +1109,35 @@ def _require_studio(
     *,
     serve: bool = False,
     launch: bool = True,
+    server_options: ServerOptions = ServerOptions(),
 ) -> tuple:
     """Return (base, server). server is a Popen only when WE auto-started it."""
     base = find_studio_server()
     if base is not None:
+        # Attaching to a server someone else started: UNSLOTH_SAMPLING_* pins only reach the
+        # server process when WE launch it (via _start_studio_server), so a sampling flag on the
+        # attach path can't take effect. Warn instead of silently dropping it, so the operator is
+        # not misled into thinking generation now uses the pinned value.
+        _pinned = [
+            _flag
+            for _flag, _value in (
+                ("--temperature", server_options.temperature),
+                ("--top-p", server_options.top_p),
+                ("--top-k", server_options.top_k),
+                ("--min-p", server_options.min_p),
+                ("--repetition-penalty", server_options.repetition_penalty),
+                ("--presence-penalty", server_options.presence_penalty),
+            )
+            if _value is not None
+        ]
+        if _pinned:
+            typer.echo(
+                f"Warning: an Unsloth server is already running at {base}; sampling pins "
+                f"({', '.join(_pinned)}) apply only when this command starts the server, so the "
+                "running server keeps its current sampling. Stop it with `unsloth studio stop` "
+                "and re-run to apply them.",
+                err = True,
+            )
         return base, None
     expected = os.environ.get("UNSLOTH_STUDIO_URL", "http://127.0.0.1:8888").rstrip("/")
     # Auto-start a local server only for an interactive launch with a model to serve, and
@@ -460,10 +1154,14 @@ def _require_studio(
         # Normalize to the port unsloth run actually binds, so the health poll and the
         # returned base hit the same server we launch (not a portless :80).
         expected = _effective_base(expected)
-        return expected, _start_studio_server(expected, model, load or LoadOptions())
+        load = load or LoadOptions()
+        # Leave a bare GGUF repo's variant unset: the server's own quant preference already
+        # picks the best available (UD-Q4_K_XL for Unsloth uploads, else Q4_K_M) and falls back
+        # when that exact quant is missing, which forcing a fixed variant here would break.
+        return expected, _start_studio_server(expected, model, load, server_options)
     model_hint = "" if model else " Pass --model to have it start one for you, or"
     _fail(
-        f"No running Studio server found at {expected}.{model_hint} start one with "
+        f"No running Unsloth server found at {expected}.{model_hint} start one with "
         "`unsloth studio`, or point UNSLOTH_STUDIO_URL at a remote server."
     )
 
@@ -514,6 +1212,13 @@ def _write_private_json(path: Path, data: dict) -> None:
         handle.write(json.dumps(data, indent = 2) + "\n")
 
 
+def _write_private_text(path: Path, text: str) -> None:
+    path.parent.mkdir(parents = True, exist_ok = True, mode = 0o700)
+    fd = os.open(path, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
+    with os.fdopen(fd, "w", encoding = "utf-8") as handle:
+        handle.write(text)
+
+
 def _read_json_object(path: Path) -> Optional[dict]:
     # {} when missing, None when it can't be parsed as an object (so the caller
     # leaves a user-managed file untouched rather than clobbering it).
@@ -567,12 +1272,12 @@ def _key_accepted(base: str, key: str) -> bool:
         if exc.code in (401, 403):
             return False
         _fail(
-            f"Studio server error while checking an API key ({exc.code}). "
+            f"Unsloth server error while checking an API key ({exc.code}). "
             "The server may be starting up or unhealthy; try again shortly."
         )
     except (urllib.error.URLError, TimeoutError) as exc:
         _fail(
-            "Couldn't reach the Studio server while checking an API key: "
+            "Couldn't reach the Unsloth server while checking an API key: "
             f"{getattr(exc, 'reason', None) or exc}"
         )
 
@@ -592,10 +1297,10 @@ def _agent_api_key(
         # UNSLOTH_API_KEY meant for some other server must not fail the
         # launch: the loopback mint path below is guaranteed to work.
         # (An explicit key that the fresh server accepts, e.g. one persisted
-        # in this Studio home's auth db, is still honored above.)
+        # in this Unsloth home's auth db, is still honored above.)
 
     # Replay a key the user saved for *this exact* server first (scoped per base,
-    # so it only goes back there -- including a remote/SSH-tunnelled Studio whose
+    # so it only goes back there -- including a remote/SSH-tunnelled Unsloth whose
     # secret the local handshake can't match). Skip ones the server rejects.
     for key in _cached_keys(cache, base, "saved"):
         if _key_accepted(base, key):
@@ -608,15 +1313,15 @@ def _agent_api_key(
     if not is_loopback_url(base):
         _fail(
             f"No saved API key for {base} and automatic minting only runs against "
-            "a local Studio. Create an API key in Studio → Settings → API and "
+            "a local Unsloth. Create an API key in Unsloth → Settings → API and "
             "pass it with --api-key (it is remembered per server), or set "
             "UNSLOTH_API_KEY."
         )
     if not verify_studio_identity(base):
         _fail(
-            f"Couldn't verify that {base} is your Studio (it may be running as a "
+            f"Couldn't verify that {base} is your Unsloth (it may be running as a "
             "different OS user, or another process took the port). Create an API "
-            "key in Studio → Settings → API and pass it with --api-key, or set "
+            "key in Unsloth → Settings → API and pass it with --api-key, or set "
             "UNSLOTH_API_KEY."
         )
 
@@ -630,8 +1335,8 @@ def _agent_api_key(
     token = _studio_token()
     if token is None:
         _fail(
-            "Couldn't authenticate with the Studio server automatically. Create "
-            "an API key in Studio → Settings → API and pass it with --api-key, "
+            "Couldn't authenticate with the Unsloth server automatically. Create "
+            "an API key in Unsloth → Settings → API and pass it with --api-key, "
             "or set UNSLOTH_API_KEY."
         )
     key = _http_json(
@@ -664,7 +1369,7 @@ def _is_hub_model_id(value: object) -> bool:
         return False
     # A hub id is exactly "namespace/name" over a restricted charset. Anything with
     # extra path segments (e.g. a server-side relative path such as
-    # models/Llama/Foo.gguf on a remote Studio) is not a hub id and must not be
+    # models/Llama/Foo.gguf on a remote Unsloth) is not a hub id and must not be
     # casefold-matched against a differently cased path on a case-sensitive
     # filesystem. This is host independent, unlike the existence probe below which
     # cannot see a path that only exists on the server.
@@ -690,8 +1395,8 @@ def _model_id_matches(
     if actual == requested:
         return True
     # Case-insensitive matching is only safe when the local existence probe in
-    # _is_hub_model_id is authoritative, i.e. against a loopback Studio on this host.
-    # Against a remote Studio a two-segment string is indistinguishable from a
+    # _is_hub_model_id is authoritative, i.e. against a loopback Unsloth on this host.
+    # Against a remote Unsloth a two-segment string is indistinguishable from a
     # server-side relative path (e.g. Models/Foo vs models/foo), so casefolding it
     # could attach to the wrong model on a case-sensitive server; defer to an exact
     # match there and let the load endpoint resolve the requested path.
@@ -709,7 +1414,8 @@ def _resolve_model(
     load: LoadOptions = LoadOptions(),
 ) -> dict:
     models = _loaded_models(base, key)
-    # Only casefold-match ids against a loopback Studio, where _is_hub_model_id's
+    load_requested = False
+    # Only casefold-match ids against a loopback Unsloth, where _is_hub_model_id's
     # local existence probe can actually reject a server-side path; see the note there.
     allow_casefold = is_loopback_url(base)
     # /v1/models reports the model id but not the active GGUF variant or runtime load
@@ -738,11 +1444,30 @@ def _resolve_model(
         )
     )
     if requested and match is None:
-        typer.echo(
-            f"Ensuring {requested} is loaded with the requested settings…"
-            if load_has_overrides
-            else f"Loading {requested} on the Studio server (this can take a while)…"
-        )
+        load_requested = True
+        active = next((m for m in models if m.get("loaded") is not False), None)
+        active_id = active.get("id") if active else None
+        if active_id and not _model_id_matches(
+            active_id,
+            requested,
+            allow_casefold = allow_casefold,
+        ):
+            typer.echo(f"Switching the Unsloth server from {active_id} to {requested}.")
+            typer.echo("This unloads the current model for every attached session.")
+        elif active_id and load.gguf_variant:
+            # Same repo id but an explicit quant still replaces the resident
+            # weights; /v1/models has no variant, so ask the status endpoint.
+            try:
+                status = _http_json("GET", f"{base}/api/inference/status", key)
+            except Exception:
+                status = {}
+            resident = status.get("gguf_variant") if status.get("is_gguf") else None
+            if resident and _normalized_variant(resident) != _normalized_variant(load.gguf_variant):
+                typer.echo(
+                    f"Switching the Unsloth server from {active_id}:{resident} "
+                    f"to {requested}:{load.gguf_variant}."
+                )
+                typer.echo("This unloads the current model for every attached session.")
         # Mirror `unsloth run`'s load knobs; keep the default payload as just
         # model_path so a bare `--model` load is unchanged.
         payload = {"model_path": requested}
@@ -754,15 +1479,10 @@ def _resolve_model(
             payload["load_in_4bit"] = False
         if load.tensor_parallel:
             payload["tensor_parallel"] = True
-        loaded = _http_json(
-            "POST",
-            f"{base}/api/inference/load",
-            key,
-            payload,
-            timeout = 3600,
-            error = "Model load failed",
-        )
-        # Studio registers the model under a canonical id (resolved identifier,
+        loaded = _load_model_with_progress(base, key, requested, load, payload)
+        if loaded.get("status") == "already_loaded":
+            typer.echo(f"Reusing loaded model: {_display_model_spec(requested, load.gguf_variant)}")
+        # Unsloth registers the model under a canonical id (resolved identifier,
         # casing) that /v1/models echoes but which may differ from the path we
         # passed; match on the id the load reports so we don't silently fall
         # through to models[0] and connect to a different loaded model.
@@ -774,31 +1494,40 @@ def _resolve_model(
             (
                 m
                 for m in models
-                if any(
+                if m.get("loaded") is not False
+                and any(
                     _model_id_matches(m.get("id"), w, allow_casefold = allow_casefold) for w in wanted
                 )
             ),
             None,
         )
     if match is not None:
+        if requested and not load_requested:
+            typer.echo(f"Reusing loaded model: {_display_model_spec(requested, load.gguf_variant)}")
         return match
     if requested:
-        # We asked Studio to load it and it didn't surface in /v1/models; don't
+        # We asked Unsloth to load it and it didn't surface in /v1/models; don't
         # silently hand back an unrelated loaded model.
         _fail(
-            f"Studio didn't report '{requested}' as loaded. Double-check the model "
+            f"Unsloth didn't report '{requested}' as loaded. Double-check the model "
             "id, or load it from the model dropdown in the UI."
         )
     if not models:
         _fail(
-            "No model is loaded in Studio. Load one from the model dropdown in "
+            "No model is loaded in Unsloth. Load one from the model dropdown in "
             "the UI, or pass --model <hf-id-or-path> to load it from here."
         )
-    return models[0]
+    resident = next((m for m in models if m.get("loaded") is not False), None)
+    if resident is None:
+        _fail(
+            "No model is currently resident in Unsloth. Pass --model <hf-id-or-path> "
+            "to reload one, or load it from the model dropdown in the UI."
+        )
+    return resident
 
 
 def _require_gguf_for_codex(base: str, key: str, model_id: str) -> None:
-    # Codex always streams, and Studio only streams /v1/responses from llama-server.
+    # Codex always streams, and Unsloth only streams /v1/responses from llama-server.
     try:
         status = _http_json("GET", f"{base}/api/inference/status", key)
     except urllib.error.HTTPError as exc:
@@ -815,17 +1544,29 @@ def _require_gguf_for_codex(base: str, key: str, model_id: str) -> None:
 
 
 _DYNAMIC_SECTIONS_FLAG = "--exclude-dynamic-system-prompt-sections"
-# Session overlay applied via `claude --settings`; suppresses the attribution header
-# for THIS run only (no ~/.claude write) so llama.cpp KV-cache reuse is preserved. It
-# reinforces the CLAUDE_CODE_ATTRIBUTION_HEADER env var on builds that read the setting
-# only from settings.json.
-_CLAUDE_SETTINGS_OVERLAY = '{"env":{"CLAUDE_CODE_ATTRIBUTION_HEADER":"0"}}'
+
+
+def _claude_settings_overlay(model_id: str) -> str:
+    # Session-only `claude --settings` overlay (command-line tier, no ~/.claude write):
+    # suppress the attribution header, keep every subagent on the served model (a user
+    # CLAUDE_CODE_SUBAGENT_MODEL pin would otherwise route delegated work off the local
+    # endpoint), and pin availableModels to the served model so a user allowlist can't
+    # reject it. The pin must be non-empty; [] is ignored.
+    return json.dumps(
+        {
+            "env": {
+                "CLAUDE_CODE_ATTRIBUTION_HEADER": "0",
+                "CLAUDE_CODE_SUBAGENT_MODEL": "inherit",
+            },
+            "availableModels": [model_id],
+        }
+    )
 
 
 def _claude_version() -> Optional[tuple]:
     # None = no local `claude` (a --no-launch printout for another machine; assume a
     # current build). An unparseable version is treated as too old for the new flags.
-    executable = shutil.which("claude")
+    executable = _which_with_install_dirs("claude")
     if executable is None:
         return None
     try:
@@ -842,16 +1583,33 @@ def _claude_version() -> Optional[tuple]:
         return (0,)
 
 
-def _claude_flags() -> list:
-    # Both knobs preserve llama.cpp KV-cache reuse: --exclude-dynamic-system-prompt-sections
-    # moves per-session context out of the system prompt, and --settings suppresses the
-    # attribution header for this session only (no persistent ~/.claude write; the env var
-    # sets it too). Claude Code < 2.1.98 aborts on unknown flags, so gate on the version;
-    # no local binary means a printout for another machine, so assume a current build.
+def _claude_flags(model_id: str) -> list:
+    # KV-cache-preserving flags: move per-session context out of the system prompt and pass
+    # the session overlay. claude < 2.1.98 rejects unknown flags; no local binary means a
+    # printout for another machine, so assume a current build.
     version = _claude_version()
     if version is not None and version < (2, 1, 98):
         return []
-    return [_DYNAMIC_SECTIONS_FLAG, "--settings", _CLAUDE_SETTINGS_OVERLAY]
+    return [_DYNAMIC_SECTIONS_FLAG, "--settings", _claude_settings_overlay(model_id)]
+
+
+def _claude_local_env(base: str, key: str, entry: dict) -> dict:
+    """Build the local endpoint, cache, display, and compaction environment."""
+    model_id = entry["id"]
+    env = {
+        "ANTHROPIC_BASE_URL": base,
+        "ANTHROPIC_AUTH_TOKEN": key,
+        "ANTHROPIC_MODEL": model_id,
+        "CLAUDE_CODE_ATTRIBUTION_HEADER": "0",
+        "CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC": "1",
+        "CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS": "1",
+        "CLAUDE_CODE_NO_FLICKER": "1",
+    }
+    window = entry.get("context_length") or entry.get("max_context_length")
+    if window:
+        env["CLAUDE_CODE_AUTO_COMPACT_WINDOW"] = str(int(window))
+        env["CLAUDE_AUTOCOMPACT_PCT_OVERRIDE"] = "90"
+    return env
 
 
 def _merge_codex_config(existing: str, base: str) -> str:
@@ -884,7 +1642,7 @@ _CODEX_MODEL_CATALOG_MIN_VERSION = (0, 110, 0)
 
 
 def _codex_supports_model_catalog() -> bool:
-    executable = shutil.which("codex")
+    executable = _which_with_install_dirs("codex")
     if executable is None:
         # A --no-launch recipe may be copied to another machine; assume a current Codex.
         return True
@@ -901,7 +1659,7 @@ def _codex_supports_model_catalog() -> bool:
 
 
 def _codex_model_catalog(model: dict) -> dict:
-    """Return conservative metadata for a Studio model unknown to Codex's built-in catalog."""
+    """Return conservative metadata for an Unsloth model unknown to Codex's built-in catalog."""
     model_id = model["id"]
     window = model.get("context_length") or model.get("max_context_length")
     entry = {
@@ -967,6 +1725,375 @@ def write_codex_config(base: str, model: dict, home: Path) -> None:
         typer.echo(f"Updated {profile}")
 
 
+def write_codex_subagent_bridge(
+    base: str, key: str, model: dict, home: Path, *, yolo: bool
+) -> Path:
+    """Write private config for an explicit local Codex child launched through MCP."""
+    child_home = home / "child"
+    write_codex_config(base, model, child_home)
+    path = home / "subagent.json"
+    _write_private_json(
+        path,
+        {
+            "api_key": key,
+            "codex_home": str(child_home),
+            "bypass_permissions": yolo,
+        },
+    )
+    return path
+
+
+def _wsl_windows_user_profile(executable: str) -> Path:
+    """Return the Windows user profile as a path accessible from WSL."""
+    profile = os.environ.get("USERPROFILE", "").strip()
+    if not profile:
+        try:
+            profile = subprocess.check_output(
+                ["cmd.exe", "/d", "/c", "echo %USERPROFILE%"],
+                text = True,
+                stderr = subprocess.DEVNULL,
+                cwd = str(Path(executable).parent),
+            ).strip()
+        except (OSError, subprocess.CalledProcessError) as exc:
+            _fail(f"Could not find the Windows user profile for Codex: {exc}")
+    if not profile or profile == "%USERPROFILE%":
+        _fail("Could not find the Windows user profile for Codex.")
+    if profile.startswith("/"):
+        return Path(profile)
+    try:
+        translated = subprocess.check_output(
+            ["wslpath", "-u", profile],
+            text = True,
+            stderr = subprocess.DEVNULL,
+        ).strip()
+    except (OSError, subprocess.CalledProcessError) as exc:
+        _fail(f"Could not translate Windows user profile {profile}: {exc}")
+    if not translated:
+        _fail(f"Could not translate Windows user profile {profile}.")
+    return Path(translated)
+
+
+def _codex_source_home(*, ignore_configured: bool = False) -> Path:
+    configured = None if ignore_configured else os.environ.get("CODEX_HOME")
+    if configured:
+        if _wsl_windows_executable(["codex"]) and _looks_like_path(configured):
+            if not configured.startswith("/"):
+                try:
+                    configured = subprocess.check_output(
+                        ["wslpath", "-u", configured],
+                        text = True,
+                        stderr = subprocess.DEVNULL,
+                    ).strip()
+                except (OSError, subprocess.CalledProcessError) as exc:
+                    _fail(f"Could not translate Windows CODEX_HOME {configured}: {exc}")
+                if not configured:
+                    _fail("Could not translate Windows CODEX_HOME.")
+        return Path(configured).expanduser()
+    executable = _wsl_windows_executable(["codex"])
+    if executable:
+        return _wsl_windows_user_profile(executable) / ".codex"
+    return Path.home() / ".codex"
+
+
+def _remove_overlay_entry(path: Path) -> None:
+    is_junction = getattr(path, "is_junction", None)
+    if is_junction and is_junction():
+        path.rmdir()
+    elif path.is_symlink() or path.is_file():
+        path.unlink()
+    elif path.is_dir():
+        shutil.rmtree(path)
+    elif path.exists():
+        path.unlink()
+
+
+def _create_directory_junction(source: Path, target: Path) -> bool:
+    if os.name != "nt":
+        return False
+    try:
+        result = subprocess.run(
+            ["cmd.exe", "/d", "/c", "mklink", "/J", str(target), str(source)],
+            capture_output = True,
+            text = True,
+            timeout = 30,
+            check = False,
+        )
+    except (OSError, subprocess.SubprocessError):
+        return False
+    return result.returncode == 0
+
+
+def write_codex_parent_overlay(overlay: Path) -> Path:
+    """Add local-agent routing without replacing the cloud parent's configuration."""
+    overlay.mkdir(parents = True, exist_ok = True, mode = 0o700)
+
+    manifest_path = overlay / _CODEX_PARENT_OVERLAY_MANIFEST
+    try:
+        manifest = json.loads(manifest_path.read_text(encoding = "utf-8"))
+    except (FileNotFoundError, OSError, json.JSONDecodeError):
+        manifest = None
+    source_home = _codex_source_home()
+    overlay_key = str(overlay.resolve(strict = False))
+    source_key = str(source_home.resolve(strict = False))
+    if source_key == overlay_key:
+        previous_source = manifest.get("source_home") if isinstance(manifest, dict) else None
+        if isinstance(previous_source, str) and previous_source:
+            candidate = Path(previous_source).expanduser()
+            if str(candidate.resolve(strict = False)) != overlay_key:
+                source_home = candidate
+            else:
+                source_home = _codex_source_home(ignore_configured = True)
+        else:
+            source_home = _codex_source_home(ignore_configured = True)
+        source_key = str(source_home.resolve(strict = False))
+    same_source = isinstance(manifest, dict) and manifest.get("source_home") == source_key
+    if same_source:
+        managed_entries = manifest.get("entries", [])
+        if not isinstance(managed_entries, list):
+            managed_entries = []
+        for name in managed_entries:
+            if isinstance(name, str) and name not in {"", ".", ".."} and Path(name).name == name:
+                _remove_overlay_entry(overlay / name)
+    else:
+        # A reused overlay must never mix credentials, config, or plugins from two
+        # different Codex homes. Legacy overlays have no manifest, so rebuild them once.
+        for target in list(overlay.iterdir()):
+            _remove_overlay_entry(target)
+
+    # Keep the user's auth, config, plugins, agents, skills, rules, and session state visible.
+    # Symlinks make this an overlay rather than a stale copy. If Windows denies them,
+    # use directory junctions so large runtime state remains shared without a bulk copy.
+    # Copy the configuration surfaces and sessions only if both link forms are unavailable.
+    fallback_dirs = {"agents", "skills", "rules", "plugins", "marketplaces", "sessions"}
+    entries = []
+    if source_home.is_dir():
+        for source in source_home.iterdir():
+            if source.name in {
+                "AGENTS.md",
+                "AGENTS.override.md",
+                _CODEX_PARENT_OVERLAY_MANIFEST,
+            }:
+                continue
+            target = overlay / source.name
+            _remove_overlay_entry(target)
+            try:
+                target.symlink_to(source, target_is_directory = source.is_dir())
+                entries.append(source.name)
+            except OSError:
+                if source.is_file():
+                    shutil.copy2(source, target)
+                    entries.append(source.name)
+                elif source.is_dir():
+                    if _create_directory_junction(source, target):
+                        entries.append(source.name)
+                    elif source.name in fallback_dirs:
+                        shutil.copytree(source, target)
+                        entries.append(source.name)
+
+    _write_private_json(
+        manifest_path,
+        {"source_home": source_key, "entries": sorted(entries)},
+    )
+
+    inherited = ""
+    instruction_name = "AGENTS.md"
+    for candidate in (source_home / "AGENTS.override.md", source_home / "AGENTS.md"):
+        try:
+            text = candidate.read_text(encoding = "utf-8")
+        except FileNotFoundError:
+            continue
+        except OSError as exc:
+            _fail(f"Could not preserve Codex instructions from {candidate}: {exc}")
+        if text.strip():
+            inherited = text.rstrip()
+            instruction_name = candidate.name
+            break
+
+    other_name = "AGENTS.md" if instruction_name == "AGENTS.override.md" else "AGENTS.override.md"
+    other = overlay / other_name
+    if other.is_file() or other.is_symlink():
+        other.unlink()
+    routing = _CODEX_SUBAGENT_ROUTING_INSTRUCTIONS
+    combined = f"{inherited}\n\n{routing}\n" if inherited else f"{routing}\n"
+    _write_private_text(overlay / instruction_name, combined)
+    return overlay
+
+
+@contextlib.contextmanager
+def _codex_parent_overlay(session_home: Path, *, launch: bool, persist: bool):
+    if launch and not persist:
+        temp_root = _agents_config_root() / ".tmp"
+        temp_root.mkdir(parents = True, exist_ok = True, mode = 0o700)
+        overlay = Path(tempfile.mkdtemp(prefix = "codex-parent-", dir = temp_root))
+        try:
+            yield write_codex_parent_overlay(overlay)
+        finally:
+            shutil.rmtree(overlay, ignore_errors = True)
+    else:
+        yield write_codex_parent_overlay(session_home / "parent")
+
+
+def _agent_config_path(path: Path, command: list) -> str:
+    """Translate a generated config path when a Windows agent runs through WSL."""
+    return _wsl_windows_path(path) if _wsl_windows_executable(command) else str(path)
+
+
+def _opencode_subagent_inline_config(path: Path, permission: dict) -> dict:
+    """Keep the local provider visible without hiding the parent's allowed providers."""
+    inline: dict = {}
+    inherited = os.environ.get("OPENCODE_CONFIG_CONTENT")
+    if inherited:
+        try:
+            parsed = json.loads(inherited)
+        except ValueError:
+            _fail("OPENCODE_CONFIG_CONTENT is not valid JSON.")
+        if not isinstance(parsed, dict):
+            _fail("OPENCODE_CONFIG_CONTENT must contain a JSON object.")
+        inline.update(parsed)
+
+    def merge_provider_filters(effective_config: dict) -> None:
+        enabled = effective_config.get("enabled_providers")
+        if isinstance(enabled, list):
+            inline["enabled_providers"] = list(dict.fromkeys([*enabled, _OPENCODE_PROVIDER]))
+        disabled = effective_config.get("disabled_providers")
+        if isinstance(disabled, list) and _OPENCODE_PROVIDER in disabled:
+            inline["disabled_providers"] = [
+                provider for provider in disabled if provider != _OPENCODE_PROVIDER
+            ]
+
+    # The inherited inline layer is already highest priority. Merge it even when
+    # OpenCode is not installed yet, as in fresh-install and --no-launch flows.
+    merge_provider_filters(inline)
+    effective = inline
+
+    executable = _which_with_install_dirs("opencode")
+    if executable is None:
+        typer.echo(
+            f"Warning: OpenCode is not installed, so provider filters could not be checked. "
+            f"The target configuration must allow '{_OPENCODE_PROVIDER}'.",
+            err = True,
+        )
+    else:
+        env = os.environ.copy()
+        env["OPENCODE_CONFIG"] = _agent_config_path(path, ["opencode"])
+        try:
+            resolved = subprocess.run(
+                [executable, "debug", "config"],
+                capture_output = True,
+                text = True,
+                timeout = 15,
+                env = env,
+            )
+        except Exception as exc:
+            _fail(f"Could not inspect OpenCode provider filters: {exc}")
+        if resolved.returncode != 0:
+            detail = resolved.stderr.strip() or resolved.stdout.strip()
+            _fail(f"Could not inspect OpenCode provider filters: {detail or 'unknown error'}")
+        try:
+            effective = json.loads(resolved.stdout)
+        except ValueError:
+            _fail("Could not inspect OpenCode provider filters: invalid JSON response.")
+        if not isinstance(effective, dict):
+            _fail("Could not inspect OpenCode provider filters: expected a JSON object.")
+
+        merge_provider_filters(effective)
+
+    depth = effective.get("subagent_depth")
+    inline["subagent_depth"] = (
+        depth if isinstance(depth, int) and not isinstance(depth, bool) and depth > 0 else 1
+    )
+    if permission:
+        inline["permission"] = permission
+    return inline
+
+
+def write_claude_subagent_plugin(path: Path, server_env: dict) -> Path:
+    """Write a session plugin that exposes the local Claude child through MCP."""
+    plugin = path / "unsloth-local-agent"
+    command = sys.executable
+    args = ["-m", _CLAUDE_SUBAGENT_MCP_MODULE]
+    mcp_env = dict(server_env)
+    if _wsl_windows_executable(["claude"]):
+        command = "wsl.exe"
+        args = [
+            "-d",
+            os.environ["WSL_DISTRO_NAME"],
+            "--",
+            sys.executable,
+            "-m",
+            _CLAUDE_SUBAGENT_MCP_MODULE,
+        ]
+        mcp_env["WSLENV"] = _merge_wslenv(
+            os.environ.get("WSLENV", ""),
+            _wsl_bridge_names(server_env, ()),
+        )
+    _write_private_json(
+        plugin / ".claude-plugin" / "plugin.json",
+        {
+            "name": "unsloth-local-agent",
+            "version": "1.0.0",
+            "description": _SUBAGENT_DESCRIPTION,
+            "author": {"name": "Unsloth AI"},
+        },
+    )
+    _write_private_json(
+        plugin / ".mcp.json",
+        {
+            "mcpServers": {
+                "unsloth": {
+                    "type": "stdio",
+                    "command": command,
+                    "args": args,
+                    "env": mcp_env,
+                }
+            }
+        },
+    )
+    skill = plugin / "skills" / "local-agent" / "SKILL.md"
+    skill.parent.mkdir(parents = True, exist_ok = True, mode = 0o700)
+    skill.write_text(
+        "---\n"
+        "description: Delegate a task to the local agent powered by Unsloth. Use when the "
+        "user asks to spawn an Unsloth agent or local agent.\n"
+        "---\n\n"
+        "Call the Unsloth local agent tool once with the complete task. In plan mode, call "
+        "the read-only Unsloth plan agent instead. Return its result to the user without "
+        "claiming that the cloud parent completed the local work.\n",
+        encoding = "utf-8",
+    )
+    return plugin
+
+
+def _codex_subagent_flags(path: Path) -> list[str]:
+    command = sys.executable
+    package_root = str(Path(__file__).resolve().parents[2])
+    bootstrap = (
+        f"import sys;sys.path.insert(0,{json.dumps(package_root)});"
+        f"from {_CODEX_SUBAGENT_MCP_MODULE} import main;main()"
+    )
+    args = ["-c", bootstrap, str(path)]
+    if _wsl_windows_executable(["codex"]):
+        command = "wsl.exe"
+        args = [
+            "-d",
+            os.environ["WSL_DISTRO_NAME"],
+            "--",
+            sys.executable,
+            "-c",
+            bootstrap,
+            str(path),
+        ]
+    server = (
+        "{ "
+        f"command = {json.dumps(command)}, "
+        f"args = {json.dumps(args)}, "
+        f"required = true, enabled_tools = [{json.dumps(_CODEX_SUBAGENT_MCP_TOOL)}], "
+        'default_tools_approval_mode = "approve", '
+        "startup_timeout_sec = 15, tool_timeout_sec = 3600 }"
+    )
+    return ["-c", f"mcp_servers.{_CODEX_SUBAGENT_MCP_SERVER}={server}"]
+
+
 def _wsl_windows_executable(command: list) -> Optional[str]:
     if os.name == "nt" or not os.environ.get("WSL_DISTRO_NAME"):
         return None
@@ -1115,12 +2242,69 @@ def _refresh_windows_path() -> None:
         os.environ["PATH"] = os.pathsep.join(entries)
 
 
+def _augment_path_with_install_dirs() -> None:
+    # Append known install dirs to PATH so a freshly installed agent resolves without a new
+    # shell: some installers write the binary but not PATH (claude drops ~/.local/bin and
+    # only prints a note; npm -g shims land in %APPDATA%\npm). Appended, so precedence holds.
+    try:
+        home = Path.home()
+    except (RuntimeError, OSError):
+        return
+    candidates = [home / ".local" / "bin"]
+    if os.name == "nt":
+        appdata = os.environ.get("APPDATA")
+        if appdata:
+            candidates.append(Path(appdata) / "npm")
+    current = os.environ.get("PATH")
+    if current is None:
+        # PATH unset: shutil.which() and exec*p* fall back to os.defpath (e.g. /bin:/usr/bin), so
+        # keep that default instead of collapsing to just the install dirs (which would hide a
+        # system-installed agent and strip the launched child's normal PATH). An explicitly empty
+        # PATH is left as-is: like shutil.which, it means "search nothing", not os.defpath.
+        current = os.defpath
+    seen = {os.path.normcase(entry) for entry in current.split(os.pathsep) if entry}
+    additions = [
+        str(directory)
+        for directory in candidates
+        if directory.is_dir() and os.path.normcase(str(directory)) not in seen
+    ]
+    if additions:
+        os.environ["PATH"] = os.pathsep.join([current, *additions] if current else additions)
+
+
+def _which_with_install_dirs(name: str) -> Optional[str]:
+    # shutil.which(name), but searching the known agent install dirs too, so a version probe
+    # resolves the same binary _launch() will (it augments PATH before it runs). Without this an
+    # agent present only in ~/.local/bin / %APPDATA%\npm is missed, wrongly assumed current, and
+    # launched with flags an older build rejects. PATH is restored afterward: only _launch()
+    # should persist the augmentation for the child process.
+    original = os.environ.get("PATH")
+    _augment_path_with_install_dirs()
+    try:
+        return shutil.which(name)
+    finally:
+        if original is None:
+            os.environ.pop("PATH", None)
+        else:
+            os.environ["PATH"] = original
+
+
 def _install_source(install_hint: str) -> Optional[str]:
     """The first http(s) URL an install hint fetches, or None (e.g. an npm install)."""
     match = re.search(r"https?://[^\s'\")]+", install_hint)
     return match.group(0) if match else None
 
 
+def _pinned_raw_github_commit(source: str) -> Optional[str]:
+    """Return the immutable full commit in a raw GitHub URL, if present."""
+    match = re.match(
+        r"^https://raw\.githubusercontent\.com/[^/]+/[^/]+/([0-9a-f]{40})/",
+        source,
+        flags = re.IGNORECASE,
+    )
+    return match.group(1).lower() if match else None
+
+
 def _install_agent(name: str, install_hint: str) -> Optional[str]:
     # Missing agent under --launch: offer to run its documented install command, then
     # re-resolve it on PATH. Consent-based (we never auto-run a remote install script
@@ -1134,25 +2318,58 @@ def _install_agent(name: str, install_hint: str) -> Optional[str]:
     # and nothing checks a signature or hash on the fetched content. Naming the source
     # turns a blind "yes" into informed consent.
     source = _install_source(install_hint)
-    warning = (
-        f"This will download and RUN a script from {source} with your privileges"
-        if source
-        else f"This will RUN `{install_hint}` with your privileges"
-    )
-    typer.secho(f"{warning}; there is no signature or hash check.", fg = "yellow", err = True)
+    if source:
+        pinned_commit = _pinned_raw_github_commit(source)
+        if pinned_commit:
+            warning = (
+                "Security warning: This will download and execute a third-party script "
+                f"from {source} with your privileges. Unsloth pins this content to "
+                f"immutable upstream commit {pinned_commit}, but does not independently "
+                "verify or sandbox it. Continue only if you trust this source and commit."
+            )
+        else:
+            warning = (
+                "Security warning: This will download and execute an unverified third-party "
+                f"script from {source} with your privileges. Unsloth does not pin or verify "
+                "the downloaded content. Continue only if you trust this source."
+            )
+    else:
+        warning = (
+            f"This will RUN `{install_hint}` with your privileges; "
+            "there is no signature or hash check."
+        )
+    typer.secho(warning, fg = "yellow", err = True)
     if not typer.confirm(f"Install `{name}` now with `{install_hint}`?", default = False):
         return None
-    # Run each hint through the shell it is written for: PowerShell (irm | iex, or npm)
-    # on Windows, /bin/sh (curl | bash, or npm) everywhere else.
+    # Run each hint through its shell: PowerShell on Windows, /bin/sh elsewhere.
+    # -ExecutionPolicy Bypass is process-scoped (nothing persistent) so npm's npm.ps1 and
+    # irm | iex run under the Windows default Restricted policy instead of failing with a
+    # PSSecurityException.
     if os.name == "nt":
-        install_command = ["powershell", "-NoProfile", "-Command", install_hint]
+        install_command = [
+            "powershell",
+            "-NoProfile",
+            "-ExecutionPolicy",
+            "Bypass",
+            "-Command",
+            install_hint,
+        ]
     else:
         install_command = ["/bin/sh", "-c", install_hint]
     if subprocess.run(install_command).returncode != 0:
-        _fail(f"Install command failed. Run it yourself, then re-run: {install_hint}")
-    # The installer just wrote PATH to the registry (Windows); pull it into this
-    # process so the freshly installed agent resolves without a shell restart.
+        message = f"Install command failed. Run it yourself, then re-run: {install_hint}"
+        if os.name == "nt":
+            # A hand-run retry can still hit the policy; point at the one-time per-user fix.
+            message += (
+                "\nIf it fails because running scripts is disabled (PSSecurityException), "
+                "allow local scripts for your user, then retry:\n"
+                "  Set-ExecutionPolicy -Scope CurrentUser -ExecutionPolicy RemoteSigned"
+            )
+        _fail(message)
+    # Resolve the freshly installed agent without a shell restart: pull registry PATH
+    # (Windows) plus well-known install dirs the installer may not have added to PATH.
     _refresh_windows_path()
+    _augment_path_with_install_dirs()
     executable = shutil.which(name)
     if executable is None:
         _fail(
@@ -1162,18 +2379,33 @@ def _install_agent(name: str, install_hint: str) -> Optional[str]:
     return executable
 
 
+def _wsl_shim_env(command: list, env: dict, unset_env: tuple) -> tuple[dict, tuple]:
+    wsl_env_bridge = _wsl_bridge_names(env, unset_env) if _wsl_windows_executable(command) else ()
+    if not wsl_env_bridge:
+        return env, wsl_env_bridge
+    # Bridge PWD via WSLENV (PWD/p) so the Windows shim finds its project root from the
+    # live cwd, not a stale inherited Linux PWD. Don't freeze env["PWD"]: a --no-launch
+    # recipe must translate the live PWD when run, not when generated; _launch overrides it.
+    return env, (*wsl_env_bridge, "PWD/p")
+
+
 def _launch(
     command: list,
     env: dict,
     install_hint: str,
     unset_env: tuple = (),
-) -> NoReturn:
+) -> int:
+    # Resolve well-known install dirs (e.g. ~/.local/bin) first, so an already-installed
+    # agent not yet on PATH is found instead of prompting a needless reinstall.
+    _augment_path_with_install_dirs()
     executable = shutil.which(command[0]) or _install_agent(command[0], install_hint)
     if executable is None:
         _fail(f"`{command[0]}` not found on PATH. Install it with: {install_hint}")
-    wsl_env_bridge = _wsl_bridge_names(env, unset_env) if _wsl_windows_executable(command) else ()
+    env, wsl_env_bridge = _wsl_shim_env(command, env, unset_env)
     child_env = dict(os.environ)
     if wsl_env_bridge:
+        # Override stale inherited PWD with the real cwd so the shim resolves the project root.
+        env = {**env, "PWD": os.getcwd()}
         child_env["WSLENV"] = _merge_wslenv(child_env.get("WSLENV", ""), wsl_env_bridge)
         for name in unset_env:
             child_env[name] = ""
@@ -1181,6 +2413,11 @@ def _launch(
         for name in unset_env:
             child_env.pop(name, None)
     child_env.update(env)
+    if os.name != "nt" and not wsl_env_bridge:
+        # Keep POSIX child processes from seeing a stale inherited PWD when
+        # subprocess cwd was changed by the caller. Some Node CLIs use PWD for
+        # project-root discovery instead of process.cwd().
+        child_env["PWD"] = os.getcwd()
     # Ctrl+C cancels a turn inside the agent; don't let it kill this wrapper.
     previous = signal.signal(signal.SIGINT, signal.SIG_IGN)
     try:
@@ -1188,7 +2425,7 @@ def _launch(
     finally:
         signal.signal(signal.SIGINT, previous)
     # Negative returncode means killed by signal N; shells expect 128+N.
-    raise typer.Exit(code = code if code >= 0 else 128 - code)
+    return code if code >= 0 else 128 - code
 
 
 def _connect(
@@ -1198,18 +2435,21 @@ def _connect(
     *,
     serve: bool = False,
     launch: bool = True,
+    server_options: ServerOptions = ServerOptions(),
 ) -> tuple:
     # `--model org/name:QUANT` is shorthand for `--model org/name --gguf-variant QUANT`.
     # Split it before we match/serve so the attach path resolves against the already-loaded
     # `org/name` (listed without the suffix) instead of reloading a `:`-suffixed repo id --
-    # which Studio rejects and which would evict a model another session is using.
+    # which Unsloth rejects and which would evict a model another session is using.
     if model:
         repo, variant = _split_repo_variant(model)
         if variant:
             model = repo
             if not load.gguf_variant:
                 load = load._replace(gguf_variant = variant)
-    base, server = _require_studio(model, load, serve = serve, launch = launch)
+    base, server = _require_studio(
+        model, load, serve = serve, launch = launch, server_options = server_options
+    )
     try:
         key = _agent_api_key(base, api_key, auto_started = server is not None)
         # A server we just started has exactly the requested model loaded, so resolve to
@@ -1240,16 +2480,35 @@ def _run(
     # --no-launch recipes stay intact.
     if launch and clear_screen:
         click.clear()
-    typer.echo(f"Studio {base} · model {entry['id']}")
-    wsl_env_bridge = _wsl_bridge_names(env, unset_env) if _wsl_windows_executable(command) else ()
+    typer.echo(f"Unsloth ready at {base} · model {entry['id']}")
     if not launch:
+        env, wsl_env_bridge = _wsl_shim_env(command, env, unset_env)
         _print_env(env, command, unset_env = unset_env, wsl_env_bridge = wsl_env_bridge)
+        if _keep_auto_served():
+            typer.echo(f"Unsloth Studio is still running at {base}.")
+            typer.echo("Stop it with: unsloth studio stop")
         return
     try:
-        _launch(command, env, install_hint = install_hint, unset_env = unset_env)
-    finally:
-        # Tear down a server we auto-started once the agent session ends (no-op otherwise).
+        code = _launch(command, env, install_hint = install_hint, unset_env = unset_env)
+    except BaseException:
+        # Startup succeeded but the agent failed to launch; tear the server down
+        # rather than orphan it.
         _shutdown_auto_served()
+        raise
+    auto_started = _auto_served_server is not None
+    kept = _keep_auto_served()
+    if auto_started and not kept:
+        typer.echo(f"The auto-started Unsloth server at {base} stopped during the session.")
+        raise typer.Exit(code = code)
+    if code:
+        # The server status below must not read as a successful agent session.
+        typer.echo(f"The agent exited with code {code}.")
+    if is_loopback_url(base):
+        typer.echo(f"Unsloth Studio is still running at {base}.")
+        typer.echo("Stop it with: unsloth studio stop")
+    else:
+        typer.echo(f"The remote Unsloth server is still running at {base}.")
+    raise typer.Exit(code = code)
 
 
 def _agents_config_root() -> Path:
@@ -1306,7 +2565,7 @@ def write_openclaw_config(
         )
         return
     before = json.dumps(config, sort_keys = True)
-    # Studio is a generic OpenAI-compatible /v1 endpoint (the vLLM/LM Studio path).
+    # Unsloth is a generic OpenAI-compatible /v1 endpoint (the vLLM/LM Studio path).
     provider_model = {"id": model["id"], "name": model["id"]}
     window = model.get("context_length") or model.get("max_context_length")
     if window:
@@ -1426,6 +2685,7 @@ def write_opencode_config(
     model: dict,
     path: Path,
     yolo: bool = False,
+    as_subagent: bool = False,
 ) -> dict:
     config = _read_json_object(path)
     if config is None:
@@ -1437,10 +2697,8 @@ def write_opencode_config(
         return {}
     before = json.dumps(config, sort_keys = True)
     config.setdefault("$schema", "https://opencode.ai/config.json")
-    # The session provider is registered under a dedicated id (_OPENCODE_PROVIDER)
-    # that a user's disabled_providers list would never target, so it is always
-    # selectable without this overlay having to reconstruct or override OpenCode's
-    # disabled_providers resolution.
+    # Keep the provider definition in this private session file. The launch path
+    # adjusts effective provider filters in the higher-priority inline overlay.
     model_entry = {"name": model["id"]}
     window = model.get("context_length") or model.get("max_context_length")
     if window:
@@ -1455,20 +2713,41 @@ def write_opencode_config(
         "options": {"baseURL": f"{base}/v1", "apiKey": key},
         "models": {model["id"]: model_entry},
     }
-    # OpenCode selects a model by "<providerID>/<modelID>".
-    config["model"] = f"{_OPENCODE_PROVIDER}/{model['id']}"
-    if window:
+    # Normal mode pins this as the session model. Subagent mode leaves the user's
+    # main/small models alone and exposes the local model to @unsloth and /models.
+    opencode_model = f"{_OPENCODE_PROVIDER}/{model['id']}"
+    if as_subagent:
+        for field in ("model", "small_model"):
+            if str(config.get(field) or "").startswith(f"{_OPENCODE_PROVIDER}/"):
+                config.pop(field, None)
+        managed_compaction = {"auto": True, "reserved": max(1, window // 10)} if window else None
+        if managed_compaction and config.get("compaction") == managed_compaction:
+            config.pop("compaction", None)
+        _subdict(config, "agent")[_SUBAGENT_NAME] = {
+            "description": _SUBAGENT_DESCRIPTION,
+            "mode": "subagent",
+            "model": opencode_model,
+            "prompt": _SUBAGENT_INSTRUCTIONS,
+        }
+    else:
+        config["model"] = opencode_model
+        agents = config.get("agent")
+        if isinstance(agents, dict):
+            agents.pop(_SUBAGENT_NAME, None)
+            if not agents:
+                config.pop("agent", None)
+    if window and not as_subagent:
         # Compact with ~10% headroom (near 90% full). The fixed 20k-token default
         # buffer over-compacts, or never settles, on a small local context.
         compaction = _subdict(config, "compaction")
         compaction["auto"] = True
         compaction["reserved"] = max(1, window // 10)
-    tools = ("edit", "bash", "webfetch")
+    tools = ("edit", "bash", "webfetch", *(("task",) if as_subagent else ()))
     if yolo:
-        # OpenCode has no --yolo flag; auto-approve is the config `permission` block
-        # (singular). Allow the prompting tools and paths outside the launch directory so
-        # tool calls don't block on the TUI. This rides inline (OPENCODE_CONFIG_CONTENT) so
-        # --yolo works even over a project config.
+        # Fallback for commands without native --auto and for the append-safe bare
+        # --no-launch command (subcommand unknown yet). Rides inline (OPENCODE_CONFIG_CONTENT)
+        # so it wins over a project config. TUI and `run` launches use --auto and call here
+        # with yolo=False, letting OpenCode preserve explicit deny rules.
         session_permission = {t: "allow" for t in tools}
         session_permission["external_directory"] = {"*": "allow"}
         config["permission"] = dict(session_permission)
@@ -1570,14 +2849,14 @@ def write_pi_config(base: str, key: str, model: dict, path: Path) -> None:
         return
     before = json.dumps(config, sort_keys = True)
     # Pi reads custom providers from ~/.pi/agent/models.json (HOME-relocated for the
-    # session). Studio is a generic OpenAI-compatible /v1 endpoint, and the key lives
+    # session). Unsloth is a generic OpenAI-compatible /v1 endpoint, and the key lives
     # in the config rather than the env (matching openclaw/opencode).
     provider_model = {"id": model["id"]}
     window = model.get("context_length") or model.get("max_context_length")
     if window:
         window = int(window)
         # An unspecified model defaults to contextWindow 128000 / maxTokens 16384,
-        # far larger than a small Studio context, so Pi compacts too late and overflows
+        # far larger than a small Unsloth context, so Pi compacts too late and overflows
         # the server. Pin the real window and a sane output cap (mirrors OpenCode).
         provider_model["contextWindow"] = window
         provider_model["maxTokens"] = min(window // 4, 8192)
@@ -1592,7 +2871,23 @@ def write_pi_config(base: str, key: str, model: dict, path: Path) -> None:
         typer.echo(f"Updated {path}")
 
 
-@start_app.command("claude", context_settings = _PASSTHROUGH)
+def write_pi_subagent_config(base: str, key: str, model: dict, path: Path) -> None:
+    """Write private bootstrap data for the bundled Pi extension."""
+    window = model.get("context_length") or model.get("max_context_length")
+    window = int(window) if window else 32768
+    _write_private_json(
+        path,
+        {
+            "baseUrl": f"{base}/v1",
+            "apiKey": key,
+            "model": model["id"],
+            "contextWindow": window,
+            "maxTokens": min(window // 4, 8192),
+        },
+    )
+
+
+@start_app.command("claude", cls = _PassthroughCommand, context_settings = _PASSTHROUGH)
 def claude(
     ctx: typer.Context,
     model: Optional[str] = _MODEL_OPTION,
@@ -1602,50 +2897,88 @@ def claude(
     max_seq_length: int = _CONTEXT_OPTION,
     load_in_4bit: bool = _LOAD_4BIT_OPTION,
     tensor_parallel: bool = _TENSOR_PARALLEL_OPTION,
+    enable_tools: bool = _ENABLE_TOOLS_OPTION,
+    tool_call_healing: Optional[bool] = _TOOL_CALL_HEALING_OPTION,
+    tool_call_nudging: Optional[bool] = _TOOL_CALL_NUDGING_OPTION,
+    temperature: Optional[float] = _TEMPERATURE_OPTION,
+    top_p: Optional[float] = _TOP_P_OPTION,
+    top_k: Optional[int] = _TOP_K_OPTION,
+    min_p: Optional[float] = _MIN_P_OPTION,
+    repetition_penalty: Optional[float] = _REPETITION_PENALTY_OPTION,
+    presence_penalty: Optional[float] = _PRESENCE_PENALTY_OPTION,
     serve: bool = _SERVE_OPTION,
     yolo: bool = _YOLO_OPTION,
     persist: bool = _PERSIST_OPTION,
+    as_subagent: bool = _AS_SUBAGENT_OPTION,
 ):
-    """Point Claude Code at the running Studio server and start it."""
+    """Point Claude Code at the running Unsloth server and start it."""
+    # Route a leading `org/name` positional to --model; forward the rest to the agent.
+    model, ctx.args[:] = _consume_positional_model(model, ctx.args)
     base, key, entry = _connect(
         api_key,
         model,
         LoadOptions(gguf_variant, max_seq_length, load_in_4bit, tensor_parallel),
         serve = serve,
         launch = launch,
+        server_options = ServerOptions(
+            enable_tools = enable_tools,
+            tool_call_healing = tool_call_healing,
+            tool_call_nudging = tool_call_nudging,
+            temperature = temperature,
+            top_p = top_p,
+            top_k = top_k,
+            min_p = min_p,
+            repetition_penalty = repetition_penalty,
+            presence_penalty = presence_penalty,
+        ),
     )
     model_id = entry["id"]
+    install_hint = (
+        "irm https://claude.ai/install.ps1 | iex"
+        if os.name == "nt"
+        else "curl -fsSL https://claude.ai/install.sh | bash"
+    )
+    if as_subagent:
+        subagent_id = _subagent_model_id(base, key, entry, model, gguf_variant)
+        subagent_model = {**entry, "id": subagent_id}
+        window = subagent_model.get("context_length") or subagent_model.get("max_context_length")
+        server_env = {
+            "UNSLOTH_CLAUDE_SUBAGENT_BASE_URL": base,
+            "UNSLOTH_CLAUDE_SUBAGENT_API_KEY": key,
+            "UNSLOTH_CLAUDE_SUBAGENT_MODEL": subagent_id,
+            "UNSLOTH_CLAUDE_SUBAGENT_BYPASS_PERMISSIONS": "1" if yolo else "0",
+        }
+        if window:
+            server_env["UNSLOTH_CLAUDE_SUBAGENT_CONTEXT_WINDOW"] = str(int(window))
+        with _session_config("claude-subagent", launch, persist = persist) as config:
+            plugin = write_claude_subagent_plugin(config, server_env)
+            command = [
+                "claude",
+                "--plugin-dir",
+                _agent_config_path(plugin, ["claude"]),
+                # Before ctx.args: a forwarded `--` would turn later flags positional.
+                "--allowedTools",
+                f"{_CLAUDE_SUBAGENT_TOOL},{_CLAUDE_SUBAGENT_PLAN_TOOL}",
+                *_yolo_command_flags("claude", yolo),
+                *ctx.args,
+            ]
+            typer.echo(
+                "Unsloth is available as a local agent. "
+                "Ask Claude to spawn an Unsloth or local agent."
+            )
+            _run(
+                base,
+                subagent_model,
+                {},
+                command,
+                launch = launch,
+                install_hint = install_hint,
+            )
+        return
 
-    env = {
-        "ANTHROPIC_BASE_URL": base,
-        "ANTHROPIC_AUTH_TOKEN": key,
-        "ANTHROPIC_MODEL": model_id,
-        # Session-only (no ~/.claude write): suppress the attribution header so
-        # llama.cpp KV-cache reuse is preserved; --settings below reinforces it.
-        "CLAUDE_CODE_ATTRIBUTION_HEADER": "0",
-        # Update checks, beta features, and other background requests either
-        # stall against a local server or evict the conversation from
-        # llama-server's KV-cache slots, so turn off everything nonessential.
-        "CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC": "1",
-        "CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS": "1",
-        # A local server streams in bursts; disable the full-screen TUI redraw so the
-        # terminal doesn't flicker between tokens.
-        "CLAUDE_CODE_NO_FLICKER": "1",
-    }
-    # Claude Code auto-compacts against its native (~600k token) window; a local
-    # model's context is usually far smaller, so size the window to the loaded
-    # model's real context length. Otherwise the conversation overflows the
-    # server's window (silent truncation) long before Claude decides to compact.
-    # codex/openclaw get the same value through their config (model_context_window
-    # / contextWindow); Claude has no config file, so it rides on the env var.
-    window = entry.get("context_length") or entry.get("max_context_length")
-    if window:
-        env["CLAUDE_CODE_AUTO_COMPACT_WINDOW"] = str(int(window))
-        # Compact at 90% of that window; the override only takes effect once the
-        # window is set, and it can only lower the threshold, so it just guarantees
-        # headroom before the server's context limit instead of relying on Claude's
-        # default (which is tuned for its native 200K/1M window).
-        env["CLAUDE_AUTOCOMPACT_PCT_OVERRIDE"] = "90"
+    env = _claude_local_env(base, key, entry)
+    # Claude Code auto-compacts against its native context window. The local env
+    # above supplies the loaded model's real window and a 90% threshold instead.
     # --yolo (or its aliases) maps to Claude's own --dangerously-skip-permissions.
     # IS_SANDBOX is left unset on purpose: Claude refuses bypass mode as root unless a
     # sandbox is detected, and we don't want to falsely claim one on the user's host.
@@ -1656,15 +2989,10 @@ def claude(
         "claude",
         "--model",
         model_id,
-        *_claude_flags(),
+        *_claude_flags(model_id),
         *_yolo_command_flags("claude", yolo),
         *ctx.args,
     ]
-    install_hint = (
-        "irm https://claude.ai/install.ps1 | iex"
-        if os.name == "nt"
-        else "curl -fsSL https://claude.ai/install.sh | bash"
-    )
     _run(
         base,
         entry,
@@ -1676,7 +3004,7 @@ def claude(
     )
 
 
-@start_app.command("codex", context_settings = _PASSTHROUGH)
+@start_app.command("codex", cls = _PassthroughCommand, context_settings = _PASSTHROUGH)
 def codex(
     ctx: typer.Context,
     model: Optional[str] = _MODEL_OPTION,
@@ -1686,26 +3014,80 @@ def codex(
     max_seq_length: int = _CONTEXT_OPTION,
     load_in_4bit: bool = _LOAD_4BIT_OPTION,
     tensor_parallel: bool = _TENSOR_PARALLEL_OPTION,
+    enable_tools: bool = _ENABLE_TOOLS_OPTION,
+    tool_call_healing: Optional[bool] = _TOOL_CALL_HEALING_OPTION,
+    tool_call_nudging: Optional[bool] = _TOOL_CALL_NUDGING_OPTION,
+    temperature: Optional[float] = _TEMPERATURE_OPTION,
+    top_p: Optional[float] = _TOP_P_OPTION,
+    top_k: Optional[int] = _TOP_K_OPTION,
+    min_p: Optional[float] = _MIN_P_OPTION,
+    repetition_penalty: Optional[float] = _REPETITION_PENALTY_OPTION,
+    presence_penalty: Optional[float] = _PRESENCE_PENALTY_OPTION,
     serve: bool = _SERVE_OPTION,
     yolo: bool = _YOLO_OPTION,
     persist: bool = _PERSIST_OPTION,
+    as_subagent: bool = _AS_SUBAGENT_OPTION,
 ):
-    """Point OpenAI Codex at the running Studio server and start it."""
+    """Point OpenAI Codex at the running Unsloth server and start it."""
+    # Route a leading `org/name` positional to --model; forward the rest to the agent.
+    model, ctx.args[:] = _consume_positional_model(model, ctx.args)
     base, key, entry = _connect(
         api_key,
         model,
         LoadOptions(gguf_variant, max_seq_length, load_in_4bit, tensor_parallel),
         serve = serve,
         launch = launch,
+        server_options = ServerOptions(
+            enable_tools = enable_tools,
+            tool_call_healing = tool_call_healing,
+            tool_call_nudging = tool_call_nudging,
+            temperature = temperature,
+            top_p = top_p,
+            top_k = top_k,
+            min_p = min_p,
+            repetition_penalty = repetition_penalty,
+            presence_penalty = presence_penalty,
+        ),
     )
     # This preflight runs after _connect may have auto-started a server but before _run
-    # installs its teardown finally, so tear the server down here if it rejects the model
+    # takes over its lifecycle, so tear the server down here if it rejects the model
     # (e.g. a transformers-backend model) rather than leaving it on the atexit backstop.
     try:
         _require_gguf_for_codex(base, key, entry["id"])
     except BaseException:
         _shutdown_auto_served()
         raise
+    if as_subagent:
+        subagent_id = _subagent_model_id(base, key, entry, model, gguf_variant)
+        subagent_model = {**entry, "id": subagent_id}
+        with _session_config("codex-subagent", launch, persist = persist) as home:
+            bridge_config = write_codex_subagent_bridge(
+                base,
+                key,
+                subagent_model,
+                home,
+                yolo = yolo,
+            )
+            with _codex_parent_overlay(home, launch = launch, persist = persist) as parent_home:
+                command = [
+                    "codex",
+                    *_codex_subagent_flags(bridge_config),
+                    *_yolo_command_flags("codex", yolo),
+                    *ctx.args,
+                ]
+                typer.echo(
+                    "Unsloth is available as a local agent. "
+                    "Ask Codex to spawn an Unsloth or local agent."
+                )
+                _run(
+                    base,
+                    subagent_model,
+                    {"CODEX_HOME": str(parent_home)},
+                    command,
+                    launch = launch,
+                    install_hint = "npm install -g @openai/codex",
+                )
+        return
     command = [
         "codex",
         "--oss",
@@ -1720,7 +3102,7 @@ def codex(
         _run(base, entry, env, command, launch = launch, install_hint = "npm install -g @openai/codex")
 
 
-@start_app.command("openclaw", context_settings = _PASSTHROUGH)
+@start_app.command("openclaw", cls = _PassthroughCommand, context_settings = _PASSTHROUGH)
 def openclaw(
     ctx: typer.Context,
     model: Optional[str] = _MODEL_OPTION,
@@ -1730,17 +3112,40 @@ def openclaw(
     max_seq_length: int = _CONTEXT_OPTION,
     load_in_4bit: bool = _LOAD_4BIT_OPTION,
     tensor_parallel: bool = _TENSOR_PARALLEL_OPTION,
+    enable_tools: bool = _ENABLE_TOOLS_OPTION,
+    tool_call_healing: Optional[bool] = _TOOL_CALL_HEALING_OPTION,
+    tool_call_nudging: Optional[bool] = _TOOL_CALL_NUDGING_OPTION,
+    temperature: Optional[float] = _TEMPERATURE_OPTION,
+    top_p: Optional[float] = _TOP_P_OPTION,
+    top_k: Optional[int] = _TOP_K_OPTION,
+    min_p: Optional[float] = _MIN_P_OPTION,
+    repetition_penalty: Optional[float] = _REPETITION_PENALTY_OPTION,
+    presence_penalty: Optional[float] = _PRESENCE_PENALTY_OPTION,
     serve: bool = _SERVE_OPTION,
     yolo: bool = _YOLO_OPTION,
     persist: bool = _PERSIST_OPTION,
 ):
-    """Point OpenClaw at the running Studio server and start it."""
+    """Point OpenClaw at the running Unsloth server and start it."""
+    # Route a leading `org/name` positional to --model; forward the rest to the agent.
+    model, ctx.args[:] = _consume_positional_model(model, ctx.args)
+    _reject_as_subagent("openclaw", ctx.args)
     base, key, entry = _connect(
         api_key,
         model,
         LoadOptions(gguf_variant, max_seq_length, load_in_4bit, tensor_parallel),
         serve = serve,
         launch = launch,
+        server_options = ServerOptions(
+            enable_tools = enable_tools,
+            tool_call_healing = tool_call_healing,
+            tool_call_nudging = tool_call_nudging,
+            temperature = temperature,
+            top_p = top_p,
+            top_k = top_k,
+            min_p = min_p,
+            repetition_penalty = repetition_penalty,
+            presence_penalty = presence_penalty,
+        ),
     )
     openclaw_args = list(ctx.args)
     # Default a bare `unsloth start openclaw` to the local TUI. Anything the caller
@@ -1777,7 +3182,7 @@ def openclaw(
         _run(base, entry, env, command, launch = launch, install_hint = install_hint)
 
 
-@start_app.command("opencode", context_settings = _PASSTHROUGH)
+@start_app.command("opencode", cls = _PassthroughCommand, context_settings = _PASSTHROUGH)
 def opencode(
     ctx: typer.Context,
     model: Optional[str] = _MODEL_OPTION,
@@ -1787,18 +3192,85 @@ def opencode(
     max_seq_length: int = _CONTEXT_OPTION,
     load_in_4bit: bool = _LOAD_4BIT_OPTION,
     tensor_parallel: bool = _TENSOR_PARALLEL_OPTION,
+    enable_tools: bool = _ENABLE_TOOLS_OPTION,
+    tool_call_healing: Optional[bool] = _TOOL_CALL_HEALING_OPTION,
+    tool_call_nudging: Optional[bool] = _TOOL_CALL_NUDGING_OPTION,
+    temperature: Optional[float] = _TEMPERATURE_OPTION,
+    top_p: Optional[float] = _TOP_P_OPTION,
+    top_k: Optional[int] = _TOP_K_OPTION,
+    min_p: Optional[float] = _MIN_P_OPTION,
+    repetition_penalty: Optional[float] = _REPETITION_PENALTY_OPTION,
+    presence_penalty: Optional[float] = _PRESENCE_PENALTY_OPTION,
     serve: bool = _SERVE_OPTION,
     yolo: bool = _YOLO_OPTION,
     persist: bool = _PERSIST_OPTION,
+    as_subagent: bool = _AS_SUBAGENT_OPTION,
 ):
-    """Point OpenCode at the running Studio server and start it."""
+    """Point OpenCode at the running Unsloth server and start it."""
+    # Route a leading `org/name` positional to --model; forward the rest to the agent.
+    model, ctx.args[:] = _consume_positional_model(model, ctx.args)
     base, key, entry = _connect(
         api_key,
         model,
         LoadOptions(gguf_variant, max_seq_length, load_in_4bit, tensor_parallel),
         serve = serve,
         launch = launch,
+        server_options = ServerOptions(
+            enable_tools = enable_tools,
+            tool_call_healing = tool_call_healing,
+            tool_call_nudging = tool_call_nudging,
+            temperature = temperature,
+            top_p = top_p,
+            top_k = top_k,
+            min_p = min_p,
+            repetition_penalty = repetition_penalty,
+            presence_penalty = presence_penalty,
+        ),
     )
+    if as_subagent:
+        subagent_id = _subagent_model_id(base, key, entry, model, gguf_variant)
+        subagent_model = {**entry, "id": subagent_id}
+        # Stay append-safe for a bare no-launch recipe: a later `run <prompt>` would make
+        # `opencode --auto run ...` parse as the TUI, so keep yolo in the inline fallback.
+        route_native_auto = yolo and _opencode_supports_native_auto() and (launch or bool(ctx.args))
+        opencode_args, native_auto = _opencode_native_auto_args(list(ctx.args), route_native_auto)
+        command = ["opencode", *opencode_args]
+        with _session_config("opencode-subagent", launch, persist = persist) as cfg:
+            config_path = cfg / "opencode.json"
+            session_permission = write_opencode_config(
+                base,
+                key,
+                subagent_model,
+                config_path,
+                yolo = yolo and not native_auto,
+                as_subagent = True,
+            )
+            env = {"OPENCODE_CONFIG": str(config_path)}
+            if launch and _which_with_install_dirs("opencode") is None:
+                # Provider-filter inspection needs the binary; offer the install now so
+                # a global/project allowlist is honored on this first launch instead of
+                # being read only after _launch installs OpenCode.
+                _install_agent("opencode", "npm install -g opencode-ai")
+            inline_config = _opencode_subagent_inline_config(config_path, session_permission)
+            # A project opencode.json outranks the session file and could field-merge its
+            # own agent.unsloth over ours. Pin ours in the inline overlay so it wins.
+            inline_config.setdefault("agent", {})[_SUBAGENT_NAME] = {
+                "description": _SUBAGENT_DESCRIPTION,
+                "mode": "subagent",
+                "model": f"{_OPENCODE_PROVIDER}/{subagent_model['id']}",
+                "prompt": _SUBAGENT_INSTRUCTIONS,
+            }
+            env["OPENCODE_CONFIG_CONTENT"] = json.dumps(inline_config)
+            typer.echo("Unsloth is available as @unsloth and in /models.")
+            _run(
+                base,
+                subagent_model,
+                env,
+                command,
+                launch = launch,
+                install_hint = "npm install -g opencode-ai",
+            )
+        return
     opencode_model = f"{_OPENCODE_PROVIDER}/{entry['id']}"
     # The inline OPENCODE_CONFIG_CONTENT below pins the model in the highest-priority
     # layer, so the session model is forced without a --model flag. Only add --model for
@@ -1807,11 +3279,20 @@ def opencode(
     # --no-launch, where the printed command is consumed by drivers that append a
     # subcommand such as `run <prompt>`; a leading --model would land before that
     # subcommand and break it. Those paths rely on the inline pin instead.
+    native_auto = False
+    route_native_auto = yolo and _opencode_supports_native_auto()
     if ctx.args:
-        command = ["opencode", *ctx.args]
+        opencode_args, native_auto = _opencode_native_auto_args(list(ctx.args), route_native_auto)
+        command = ["opencode", *opencode_args]
     elif launch:
-        command = ["opencode", "--model", opencode_model]
+        opencode_args, native_auto = _opencode_native_auto_args(
+            ["--model", opencode_model],
+            route_native_auto,
+        )
+        command = ["opencode", *opencode_args]
     else:
+        # Append-safe base: `opencode --auto run ...` parses as the TUI with a project
+        # "run", not the run subcommand. Command unknown here, so keep the config fallback.
         command = ["opencode"]
     # opencode keeps sessions in ~/.local/share/opencode (never relocated), so resume
     # already survives exit; reopen the last one by passing `opencode --continue` through.
@@ -1820,12 +3301,18 @@ def opencode(
         # OPENCODE_CONFIG is an overlay (loaded between the user's global and project
         # configs), so this adds the Unsloth provider/model for the session without
         # changing the user's default model. Key lives in the config, not the env.
-        session_permission = write_opencode_config(base, key, entry, config_path, yolo = yolo)
+        session_permission = write_opencode_config(
+            base,
+            key,
+            entry,
+            config_path,
+            yolo = yolo and not native_auto,
+        )
         # A project's own opencode.json outranks OPENCODE_CONFIG, so the session model pin
         # would silently lose to a repo config. Carry it in OPENCODE_CONFIG_CONTENT, which
         # outranks project config; the API key stays in the private file, never the env.
-        # Only --yolo carries a permission here (its allow must win over a project config);
-        # a non-yolo session returns no permission, so the project's own rules are honored.
+        # Only the config fallback carries a permission. Native --auto omits it (auto-approve
+        # asks, keep explicit denies); a non-yolo session omits it too, honoring project rules.
         # opencode filters every provider (a config-defined custom one included) through
         # its enabled_providers allowlist and disabled_providers denylist, and a model pin
         # does not bypass that gate -- a filtered provider resolves to ModelNotFoundError.
@@ -1835,7 +3322,7 @@ def opencode(
         # setting them in the highest-priority inline overlay neutralizes any user allowlist
         # or denylist for the launch. It is session-only: it lives in OPENCODE_CONFIG_CONTENT
         # for this invocation and never touches the user's config files, so their normal
-        # `opencode` is unchanged; only this session is limited to the Studio provider.
+        # `opencode` is unchanged; only this session is limited to the Unsloth provider.
         # small_model is opencode's separate model for lightweight tasks; pin it to the
         # session model too, or a user/project small_model on another (now filtered)
         # provider would resolve a not-found error mid-session. The session serves one
@@ -1855,7 +3342,7 @@ def opencode(
         _run(base, entry, env, command, launch = launch, install_hint = "npm install -g opencode-ai")
 
 
-@start_app.command("hermes", context_settings = _PASSTHROUGH)
+@start_app.command("hermes", cls = _PassthroughCommand, context_settings = _PASSTHROUGH)
 def hermes(
     ctx: typer.Context,
     model: Optional[str] = _MODEL_OPTION,
@@ -1865,11 +3352,23 @@ def hermes(
     max_seq_length: int = _CONTEXT_OPTION,
     load_in_4bit: bool = _LOAD_4BIT_OPTION,
     tensor_parallel: bool = _TENSOR_PARALLEL_OPTION,
+    enable_tools: bool = _ENABLE_TOOLS_OPTION,
+    tool_call_healing: Optional[bool] = _TOOL_CALL_HEALING_OPTION,
+    tool_call_nudging: Optional[bool] = _TOOL_CALL_NUDGING_OPTION,
+    temperature: Optional[float] = _TEMPERATURE_OPTION,
+    top_p: Optional[float] = _TOP_P_OPTION,
+    top_k: Optional[int] = _TOP_K_OPTION,
+    min_p: Optional[float] = _MIN_P_OPTION,
+    repetition_penalty: Optional[float] = _REPETITION_PENALTY_OPTION,
+    presence_penalty: Optional[float] = _PRESENCE_PENALTY_OPTION,
     serve: bool = _SERVE_OPTION,
     yolo: bool = _YOLO_OPTION,
     persist: bool = _PERSIST_OPTION,
 ):
-    """Point Hermes (Nous Research) at the running Studio server and start it."""
+    """Point Hermes (Nous Research) at the running Unsloth server and start it."""
+    # Route a leading `org/name` positional to --model; forward the rest to the agent.
+    model, ctx.args[:] = _consume_positional_model(model, ctx.args)
+    _reject_as_subagent("hermes", ctx.args)
     native_args = [*_yolo_command_flags("hermes", yolo), *ctx.args]
     command = ["hermes", *_hermes_resume_oneshot_args(native_args)]
     base, key, entry = _connect(
@@ -1878,6 +3377,17 @@ def hermes(
         LoadOptions(gguf_variant, max_seq_length, load_in_4bit, tensor_parallel),
         serve = serve,
         launch = launch,
+        server_options = ServerOptions(
+            enable_tools = enable_tools,
+            tool_call_healing = tool_call_healing,
+            tool_call_nudging = tool_call_nudging,
+            temperature = temperature,
+            top_p = top_p,
+            top_k = top_k,
+            min_p = min_p,
+            repetition_penalty = repetition_penalty,
+            presence_penalty = presence_penalty,
+        ),
     )
     install_hint = _hermes_install_hint()
     with _session_config("hermes", launch, persist = persist) as home:
@@ -1888,7 +3398,7 @@ def hermes(
         _run(base, entry, env, command, launch = launch, install_hint = install_hint)
 
 
-@start_app.command("pi", context_settings = _PASSTHROUGH)
+@start_app.command("pi", cls = _PassthroughCommand, context_settings = _PASSTHROUGH)
 def pi(
     ctx: typer.Context,
     model: Optional[str] = _MODEL_OPTION,
@@ -1898,18 +3408,72 @@ def pi(
     max_seq_length: int = _CONTEXT_OPTION,
     load_in_4bit: bool = _LOAD_4BIT_OPTION,
     tensor_parallel: bool = _TENSOR_PARALLEL_OPTION,
+    enable_tools: bool = _ENABLE_TOOLS_OPTION,
+    tool_call_healing: Optional[bool] = _TOOL_CALL_HEALING_OPTION,
+    tool_call_nudging: Optional[bool] = _TOOL_CALL_NUDGING_OPTION,
+    temperature: Optional[float] = _TEMPERATURE_OPTION,
+    top_p: Optional[float] = _TOP_P_OPTION,
+    top_k: Optional[int] = _TOP_K_OPTION,
+    min_p: Optional[float] = _MIN_P_OPTION,
+    repetition_penalty: Optional[float] = _REPETITION_PENALTY_OPTION,
+    presence_penalty: Optional[float] = _PRESENCE_PENALTY_OPTION,
     serve: bool = _SERVE_OPTION,
     yolo: bool = _YOLO_OPTION,
     persist: bool = _PERSIST_OPTION,
+    as_subagent: bool = _AS_SUBAGENT_OPTION,
 ):
-    """Point Pi (coding agent) at the running Studio server and start it."""
+    """Point Pi (coding agent) at the running Unsloth server and start it."""
+    # Route a leading `org/name` positional to --model; forward the rest to the agent.
+    model, ctx.args[:] = _consume_positional_model(model, ctx.args)
     base, key, entry = _connect(
         api_key,
         model,
         LoadOptions(gguf_variant, max_seq_length, load_in_4bit, tensor_parallel),
         serve = serve,
         launch = launch,
+        server_options = ServerOptions(
+            enable_tools = enable_tools,
+            tool_call_healing = tool_call_healing,
+            tool_call_nudging = tool_call_nudging,
+            temperature = temperature,
+            top_p = top_p,
+            top_k = top_k,
+            min_p = min_p,
+            repetition_penalty = repetition_penalty,
+            presence_penalty = presence_penalty,
+        ),
     )
+    install_hint = "npm install -g --ignore-scripts @earendil-works/pi-coding-agent"
+    if as_subagent:
+        if not _PI_SUBAGENT_EXTENSION.is_file():
+            _fail(f"Missing Pi subagent extension: {_PI_SUBAGENT_EXTENSION}")
+        subagent_id = _subagent_model_id(base, key, entry, model, gguf_variant)
+        subagent_model = {**entry, "id": subagent_id}
+        extension = _agent_config_path(_PI_SUBAGENT_EXTENSION, ["pi"])
+        with _session_config("pi-subagent", launch, persist = persist) as config:
+            config_path = config / "subagent.json"
+            write_pi_subagent_config(base, key, subagent_model, config_path)
+            command = [
+                "pi",
+                "--extension",
+                extension,
+                *_yolo_command_flags("pi", yolo),
+                *ctx.args,
+            ]
+            typer.echo(
+                "Unsloth is available as a local agent and in /model. "
+                "Ask Pi to spawn an Unsloth or local agent."
+            )
+            _run(
+                base,
+                subagent_model,
+                {"UNSLOTH_PI_SUBAGENT_CONFIG": str(config_path)},
+                command,
+                launch = launch,
+                install_hint = install_hint,
+                clear_screen = True,
+            )
+        return
     # Pi defaults to the google provider, so pin our provider/model on the command
     # line; the custom OpenAI-compatible endpoint itself is only configurable via
     # ~/.pi/agent/models.json.
@@ -1924,7 +3488,6 @@ def pi(
     ]
     # --ignore-scripts matches Pi's documented install recipe (its README notes Pi needs
     # no install scripts), so accepting the prompt skips dependency lifecycle scripts.
-    install_hint = "npm install -g --ignore-scripts @earendil-works/pi-coding-agent"
     with _session_config("pi", launch, persist = persist) as home:
         # Pi resolves its config dir from PI_CODING_AGENT_DIR first (getAgentDir() prefers
         # it over $HOME/.pi/agent), so pin it at the session dir: an inherited
diff --git a/unsloth_cli/commands/studio.py b/unsloth_cli/commands/studio.py
index 09355bd454..84c22aa4ac 100644
--- a/unsloth_cli/commands/studio.py
+++ b/unsloth_cli/commands/studio.py
@@ -40,7 +40,7 @@ def _enable_verbose_access_logs() -> None:
 # UNSLOTH_STUDIO_HOME wins when both env vars are set.
 def _looks_like_installer_managed_studio_home(candidate: Path) -> bool:
     """Sentinel check (studio.conf or bin shim) so a dev venv named
-    unsloth_studio is not misidentified as a custom Studio root.
+    unsloth_studio is not misidentified as a custom Unsloth root.
     """
     shim_name = "unsloth.exe" if platform.system() == "Windows" else "unsloth"
     return (candidate / "share" / "studio.conf").is_file() or (
@@ -106,6 +106,13 @@ API_KEY_PBKDF2_SALT_KEY = "api_key_pbkdf2_salt"
 DESKTOP_SECRET_HASH_KEY = "desktop_secret_hash"
 DESKTOP_SECRET_CREATED_AT_KEY = "desktop_secret_created_at"
 PBKDF2_ITERATIONS = 100_000
+_START_API_KEY_MARKER_ENV = "_UNSLOTH_START_API_KEY_MARKER"
+
+
+def _consume_start_api_key_marker_env() -> bool:
+    """Consume the one-shot readiness marker passed across a Studio re-exec."""
+    return os.environ.pop(_START_API_KEY_MARKER_ENV, None) == "1"
+
 
 # __file__ is unsloth_cli/commands/studio.py -- two parents up is the package root
 # (either site-packages or the repo root for editable installs).
@@ -212,7 +219,7 @@ def _find_run_py() -> Optional[Path]:
     run_py = _PACKAGE_ROOT / "studio" / "backend" / "run.py"
     if run_py.is_file():
         return run_py
-    # 2. Studio venv's site-packages (Linux + Windows layouts)
+    # 2. Unsloth venv's site-packages (Linux + Windows layouts)
     for pattern in (
         "lib/python*/site-packages/studio/backend/run.py",
         "Lib/site-packages/studio/backend/run.py",
@@ -273,7 +280,7 @@ def _find_setup_script() -> Optional[Path]:
     s = _PACKAGE_ROOT / "studio" / name
     if s.is_file():
         return s
-    # 2. Studio venv's site-packages
+    # 2. Unsloth venv's site-packages
     for pattern in (
         f"lib/python*/site-packages/studio/{name}",
         f"Lib/site-packages/studio/{name}",
@@ -641,7 +648,7 @@ def _create_desktop_secret_in_cli() -> str:
 def _should_prompt_password_change(
     *, cloudflare: Optional[bool], host: str, secure: bool, api_only: bool
 ) -> bool:
-    """Whether this launch will expose Studio through the Cloudflare tunnel.
+    """Whether this launch will expose Unsloth through the Cloudflare tunnel.
 
     CLI mirror of run.py's _cloudflare_tunnel_should_start, minus the Colab
     case (Colab launches never come through this CLI path). --secure implies
@@ -747,7 +754,7 @@ def _apply_supplied_password_before_launch(supplied_password: "str | None") -> N
         conn = _connect_auth_db()
     except (OSError, sqlite3.Error) as exc:
         typer.echo(
-            f"Error: --password could not open the Studio auth database ({exc}); not starting.",
+            f"Error: --password could not open the Unsloth auth database ({exc}); not starting.",
             err = True,
         )
         raise typer.Exit(1)
@@ -767,7 +774,7 @@ def _apply_supplied_password_before_launch(supplied_password: "str | None") -> N
             raise typer.Exit(1)
         if not row[2]:
             typer.echo(
-                "Error: a Studio admin password is already set; --password only sets "
+                "Error: an Unsloth admin password is already set; --password only sets "
                 "the initial password. Run `unsloth studio reset-password` first "
                 "(or change it in the UI).",
                 err = True,
@@ -790,7 +797,7 @@ def _apply_supplied_password_before_launch(supplied_password: "str | None") -> N
         # Any DB failure fails closed (typer.Exit is not caught here, so the
         # deliberate Exit(1) branches above propagate unchanged).
         typer.echo(
-            f"Error: --password could not update the Studio auth database ({exc}); not starting.",
+            f"Error: --password could not update the Unsloth auth database ({exc}); not starting.",
             err = True,
         )
         raise typer.Exit(1)
@@ -813,9 +820,9 @@ def _strip_seeded_bootstrap_password_or_exit(*, context: str) -> None:
         bootstrap_file.unlink(missing_ok = True)
     except OSError as exc:
         typer.echo(
-            "Error: refusing to publish Studio on a public Cloudflare URL: "
+            "Error: refusing to publish Unsloth on a public Cloudflare URL: "
             f"could not remove the seeded bootstrap password file ({exc}), so an "
-            f"older Studio child could still serve the default credential ({context}). "
+            f"older Unsloth child could still serve the default credential ({context}). "
             "Delete it manually or change the admin password (run `unsloth studio` "
             "locally with a terminal attached, or `unsloth studio reset-password`), "
             "then retry.",
@@ -851,7 +858,7 @@ def _require_servable_frontend_or_exit(
             return frontend
         typer.echo(
             "Error: --frontend points at a directory with no index.html, so a "
-            "public Studio launch would have no login page to change the seeded "
+            "public Unsloth launch would have no login page to change the seeded "
             "admin password. Point --frontend at a built dist, rebuild it (re-run "
             "install.sh), or use --api-only.",
             err = True,
@@ -862,7 +869,7 @@ def _require_servable_frontend_or_exit(
     if resolved is not None:
         return resolved
     typer.echo(
-        "Error: the Studio frontend is not built, so a public launch would have "
+        "Error: the Unsloth frontend is not built, so a public launch would have "
         "no login page to change the seeded admin password. Build it (re-run "
         "install.sh), pass --frontend PATH to a built dist, or use --api-only.",
         err = True,
@@ -892,8 +899,8 @@ def _validate_inproc_backend_before_strip(
         _load_run_module()
     except Exception as exc:
         typer.echo(
-            f"Error: the Studio backend could not be loaded ({exc}); refusing to "
-            "expose Studio publicly before it is confirmed runnable. Re-run: "
+            f"Error: the Unsloth backend could not be loaded ({exc}); refusing to "
+            "expose Unsloth publicly before it is confirmed runnable. Re-run: "
             "unsloth studio setup",
             err = True,
         )
@@ -902,7 +909,7 @@ def _validate_inproc_backend_before_strip(
 
 def _tunnel_binary_confirmed_unavailable() -> bool:
     """True only if cloudflared is provably unavailable (found nowhere on PATH or
-    in the Studio cache AND the download failed), so the tunnel cannot start.
+    in the Unsloth cache AND the download failed), so the tunnel cannot start.
 
     Used on the --secure path (loopback bind, so the tunnel is the ONLY public
     exposure) to skip stripping the seeded recovery password before a public URL
@@ -921,7 +928,7 @@ def _tunnel_binary_confirmed_unavailable() -> bool:
     if not tunnel_py.is_file():
         return False
     # ensure_cloudflared() lazily imports utils.paths.storage_roots to resolve the
-    # Studio bin cache. The outer CLI hasn't added studio/backend to sys.path yet,
+    # Unsloth bin cache. The outer CLI hasn't added studio/backend to sys.path yet,
     # so that import would fail and return None (a false "unavailable" that wrongly
     # refuses --secure). Add the backend dir so the cache path resolves as in the child.
     added_backend_path = False
@@ -946,7 +953,7 @@ def _tunnel_binary_confirmed_unavailable() -> bool:
 
 
 def _child_self_suppresses(*, in_studio_venv: bool, child_run_py: Optional[Path]) -> bool:
-    """True when the child that will serve Studio is provably THIS install's
+    """True when the child that will serve Unsloth is provably THIS install's
     backend, whose pre-bind gate sets app.state.suppress_bootstrap_injection and
     so never serves the seeded credential publicly -- even with .bootstrap_password
     on disk. The parent-side strip is then unnecessary and can be skipped to avoid
@@ -1002,8 +1009,8 @@ def _enforce_password_change_before_exposure(
         # Refuse rather than risk a child serving the default login; a transient
         # lock clears on retry.
         typer.echo(
-            "Error: refusing to publish Studio on a public Cloudflare URL: could "
-            f"not open the Studio auth database ({exc}) to confirm the admin "
+            "Error: refusing to publish Unsloth on a public Cloudflare URL: could "
+            f"not open the Unsloth auth database ({exc}) to confirm the admin "
             "password was changed. Retry (a transient database lock clears), or "
             "change the password first (run `unsloth studio` locally with a "
             "terminal attached, or `unsloth studio reset-password`).",
@@ -1028,8 +1035,8 @@ def _enforce_password_change_before_exposure(
             except OSError:
                 pass
             typer.echo(
-                "Error: refusing to publish Studio on a public Cloudflare URL: could "
-                f"not initialize the admin account ({exc}), so a re-exec'd Studio "
+                "Error: refusing to publish Unsloth on a public Cloudflare URL: could "
+                f"not initialize the admin account ({exc}), so a re-exec'd Unsloth "
                 "child could regenerate and serve a default credential. Retry (a "
                 "transient database lock clears), or change the password first (run "
                 "`unsloth studio` locally with a terminal attached, or `unsloth "
@@ -1053,7 +1060,7 @@ def _enforce_password_change_before_exposure(
             # regenerate; we just couldn't read must_change back. Strip the seeded
             # file so nothing serves it, failing closed if the strip itself fails.
             typer.echo(
-                f"Warning: could not read the Studio admin state back ({exc}); "
+                f"Warning: could not read the Unsloth admin state back ({exc}); "
                 "removing the seeded bootstrap password before public exposure.",
                 err = True,
             )
@@ -1066,7 +1073,7 @@ def _enforce_password_change_before_exposure(
             # the launch: it never arms for api-only, and TIMEOUT=0 disables it.
             if api_only or not _bootstrap_deadline_active():
                 typer.echo(
-                    "Error: refusing to publish Studio on a public Cloudflare "
+                    "Error: refusing to publish Unsloth on a public Cloudflare "
                     "URL: the default admin password was never changed, no "
                     "terminal is attached to change it here, and the bootstrap "
                     "shutdown deadline does not apply to this launch (api-only, "
@@ -1085,12 +1092,12 @@ def _enforce_password_change_before_exposure(
                 # fails). Keep the file for LOCAL recovery; must_change stays set
                 # and the deadline arms.
                 typer.echo(
-                    "Warning: Studio is being exposed publicly while the admin "
+                    "Warning: Unsloth is being exposed publicly while the admin "
                     "account still uses its auto-generated bootstrap password. The "
                     "login page forces a change and the credential is never served "
                     "on the public page. Set a new password by running `unsloth "
                     "studio` locally with a terminal attached, or `unsloth studio "
-                    "reset-password`; Studio shuts down after ~1h if the password "
+                    "reset-password`; Unsloth shuts down after ~1h if the password "
                     "stays unchanged (UNSLOTH_STUDIO_BOOTSTRAP_TIMEOUT).",
                     err = True,
                 )
@@ -1104,7 +1111,7 @@ def _enforce_password_change_before_exposure(
             # uncertainty.)
             if secure and _tunnel_binary_confirmed_unavailable():
                 typer.echo(
-                    "Error: refusing to expose Studio: the Cloudflare tunnel binary "
+                    "Error: refusing to expose Unsloth: the Cloudflare tunnel binary "
                     "(cloudflared) is unavailable and could not be downloaded, so no "
                     "public URL can start. The seeded bootstrap password is preserved "
                     "for recovery; fix connectivity and retry, or change the password "
@@ -1121,11 +1128,11 @@ def _enforce_password_change_before_exposure(
             # forces a change and the timer still arms; only the on-disk copy goes.
             _strip_seeded_bootstrap_password_or_exit(context = "no terminal to change it")
             typer.echo(
-                "Warning: Studio is being exposed publicly while the admin account "
+                "Warning: Unsloth is being exposed publicly while the admin account "
                 "still uses its auto-generated bootstrap password. The seeded password "
                 "file has been removed so it is not served on the public page. Set a new "
                 "password by running `unsloth studio` locally with a terminal attached, "
-                "or `unsloth studio reset-password`; Studio shuts down after ~1h if the "
+                "or `unsloth studio reset-password`; Unsloth shuts down after ~1h if the "
                 "password stays unchanged (UNSLOTH_STUDIO_BOOTSTRAP_TIMEOUT).",
                 err = True,
             )
@@ -1146,7 +1153,7 @@ def _enforce_password_change_before_exposure(
             new_password = _password_prompt.prompt_new_password(_is_current_password)
         except (KeyboardInterrupt, EOFError):
             typer.echo(
-                "\nError: password change aborted; refusing to expose Studio "
+                "\nError: password change aborted; refusing to expose Unsloth "
                 "with the default admin password. Re-run and set a password, "
                 "or launch without --secure/--cloudflare.",
                 err = True,
@@ -1247,7 +1254,7 @@ def studio_default(
     cloudflare: Optional[bool] = typer.Option(
         None,
         "--cloudflare/--no-cloudflare",
-        help = "Expose Studio on a PUBLIC internet URL via a free Cloudflare HTTPS "
+        help = "Expose Unsloth on a PUBLIC internet URL via a free Cloudflare HTTPS "
         "tunnel, for non-api-only wildcard binds (0.0.0.0 or ::). Off by default; "
         "pass --cloudflare to enable it (--secure implies it). --no-cloudflare forces "
         "it off but does not change a raw wildcard bind.",
@@ -1404,7 +1411,7 @@ def studio_default(
         studio_python = _studio_venv_python()
         run_py = _find_run_py()
         if not (studio_python and run_py):
-            typer.echo("Studio not set up. Run install.sh first.")
+            typer.echo("Unsloth Studio not set up. Run install.sh first.")
             raise typer.Exit(1)
         # A public UI launch must have a servable login page BEFORE the gate can
         # strip the seeded .bootstrap_password, or the child has no way to change
@@ -1510,7 +1517,7 @@ def studio_default(
                     rc = proc.wait()
                 if rc != 0:
                     typer.echo(
-                        f"\nError: Studio server exited unexpectedly (code {rc}).",
+                        f"\nError: Unsloth server exited unexpectedly (code {rc}).",
                         err = True,
                     )
                     typer.echo(
@@ -1522,7 +1529,7 @@ def studio_default(
             else:
                 os.execvp(str(studio_python), args)
         else:
-            typer.echo("Studio not set up. Run install.sh first.")
+            typer.echo("Unsloth Studio not set up. Run install.sh first.")
             raise typer.Exit(1)
 
     run_mod = _load_run_module()
@@ -1650,6 +1657,14 @@ def _consume_legacy_short_aliases(
     return value, out
 
 
+# Help panels so `unsloth run --help` groups options instead of one long list.
+_RUN_PANEL_MODEL = "Model"
+_RUN_PANEL_SERVER = "Server & network"
+_RUN_PANEL_TOOLS = "Tool calls"
+_RUN_PANEL_SAMPLING = "Sampling"
+_RUN_PANEL_ADVANCED = "Advanced"
+
+
 @studio_app.command(
     context_settings = {
         "allow_extra_args": True,
@@ -1666,6 +1681,7 @@ def run(
         # `-m` / `-hfr` removed (Click would cluster `-mg`/`-md`/...).
         # Exact-match `-m`/`-hfr` still work via the legacy shim below.
         # `-hf` stays (multi-char shorts don't cluster).
+        rich_help_panel = _RUN_PANEL_MODEL,
         help = (
             "Model path or HF repo. Accepts llama.cpp-style "
             "`org/repo:variant` syntax. `-hf` / `--hf-repo` match "
@@ -1673,12 +1689,16 @@ def run(
         ),
     ),
     gguf_variant: Optional[str] = typer.Option(
-        None, "--gguf-variant", help = "GGUF quant variant (e.g. UD-Q4_K_XL)"
+        None,
+        "--gguf-variant",
+        rich_help_panel = _RUN_PANEL_MODEL,
+        help = "GGUF quant variant (e.g. UD-Q4_K_XL)",
     ),
     verbose: bool = typer.Option(
         False,
         "--verbose",
         "-v",
+        rich_help_panel = _RUN_PANEL_ADVANCED,
         help = "Log every API request, including the high-frequency polling that is "
         "deduplicated by default.",
     ),
@@ -1686,35 +1706,115 @@ def run(
         0,
         "--max-seq-length",
         "--context-length",
+        rich_help_panel = _RUN_PANEL_MODEL,
         help = "Runtime context length in tokens (0 = model default for GGUF; 2048 for hub models)",
     ),
-    load_in_4bit: bool = typer.Option(True, "--load-in-4bit/--no-load-in-4bit"),
-    api_key_name: str = typer.Option(
-        "cli", "--api-key-name", help = "Label for the auto-generated API key"
+    load_in_4bit: bool = typer.Option(
+        True, "--load-in-4bit/--no-load-in-4bit", rich_help_panel = _RUN_PANEL_MODEL
     ),
-    port: int = typer.Option(8888, "--port", "-p"),
-    host: str = typer.Option("127.0.0.1", "--host", "-H"),
+    api_key_name: str = typer.Option(
+        "cli",
+        "--api-key-name",
+        rich_help_panel = _RUN_PANEL_ADVANCED,
+        help = "Label for the auto-generated API key",
+    ),
+    port: int = typer.Option(8888, "--port", "-p", rich_help_panel = _RUN_PANEL_SERVER),
+    host: str = typer.Option("127.0.0.1", "--host", "-H", rich_help_panel = _RUN_PANEL_SERVER),
     # `-f` removed (clustered `-fa`/`-fit*`); studio_default keeps it.
-    frontend: Optional[Path] = typer.Option(None, "--frontend"),
+    frontend: Optional[Path] = typer.Option(None, "--frontend", rich_help_panel = _RUN_PANEL_SERVER),
     api_only: bool = typer.Option(
         False,
         "--api-only",
+        rich_help_panel = _RUN_PANEL_SERVER,
         help = "Serve only the API (no web UI), for a headless model server. "
         "Pairs with --secure to expose the API over the Cloudflare link alone.",
     ),
-    silent: bool = typer.Option(False, "--silent", "-q"),
+    silent: bool = typer.Option(False, "--silent", "-q", rich_help_panel = _RUN_PANEL_ADVANCED),
     enable_tools: Optional[bool] = typer.Option(
         None,
         "--enable-tools/--disable-tools",
+        rich_help_panel = _RUN_PANEL_TOOLS,
         help = (
             "Force server-side tools (web search, code execution) on or off for "
             "every request. Default: on for every bind."
         ),
     ),
+    tool_call_healing: Optional[bool] = typer.Option(
+        None,
+        "--enable-tool-call-healing/--disable-tool-call-healing",
+        rich_help_panel = _RUN_PANEL_TOOLS,
+        help = (
+            "Promote text-form tool calls (small GGUFs often emit <tool_call>...) "
+            "back into structured calls on the client-tool passthrough. Default: on. "
+            "An explicit --disable-tool-call-healing is an absolute server kill-switch."
+        ),
+    ),
+    tool_call_nudging: Optional[bool] = typer.Option(
+        None,
+        "--enable-tool-call-nudging/--disable-tool-call-nudging",
+        rich_help_panel = _RUN_PANEL_TOOLS,
+        help = (
+            "On the non-streaming client-tool passthrough, retry once with a short "
+            "nudge when the model emitted a tool signal that healing could not repair. "
+            "Default: on. No effect on streaming requests or the server-side agentic loop."
+        ),
+    ),
+    temperature: Optional[float] = typer.Option(
+        None,
+        "--temperature",
+        min = 0.0,
+        max = 2.0,
+        rich_help_panel = _RUN_PANEL_SAMPLING,
+        help = (
+            "Pin the sampling temperature for every request that omits it, overriding the "
+            "model's recommended value. Default: unset (use the per-model recommendation)."
+        ),
+    ),
+    top_p: Optional[float] = typer.Option(
+        None,
+        "--top-p",
+        min = 0.0,
+        max = 1.0,
+        rich_help_panel = _RUN_PANEL_SAMPLING,
+        help = "Pin top-p (nucleus) sampling. Default: unset (per-model recommendation).",
+    ),
+    top_k: Optional[int] = typer.Option(
+        None,
+        "--top-k",
+        min = -1,
+        max = 100,
+        rich_help_panel = _RUN_PANEL_SAMPLING,
+        help = "Pin top-k sampling. Default: unset (per-model recommendation).",
+    ),
+    min_p: Optional[float] = typer.Option(
+        None,
+        "--min-p",
+        min = 0.0,
+        max = 1.0,
+        rich_help_panel = _RUN_PANEL_SAMPLING,
+        help = "Pin min-p sampling threshold. Default: unset (per-model recommendation).",
+    ),
+    repetition_penalty: Optional[float] = typer.Option(
+        None,
+        "--repetition-penalty",
+        min = 1.0,
+        max = 2.0,
+        rich_help_panel = _RUN_PANEL_SAMPLING,
+        help = "Pin the repetition penalty. Default: unset (per-model recommendation).",
+    ),
+    presence_penalty: Optional[float] = typer.Option(
+        None,
+        "--presence-penalty",
+        min = 0.0,
+        max = 2.0,
+        rich_help_panel = _RUN_PANEL_SAMPLING,
+        help = "Pin the presence penalty. Default: unset (per-model recommendation).",
+    ),
     yes: bool = typer.Option(
         False,
         "--yes",
         "-y",
+        rich_help_panel = _RUN_PANEL_ADVANCED,
         help = "Accepted for backward compatibility; the tool policy no longer prompts.",
     ),
     parallel: int = typer.Option(
@@ -1724,6 +1824,7 @@ def run(
         "-np",
         min = _PARALLEL_MIN,
         max = _PARALLEL_MAX,
+        rich_help_panel = _RUN_PANEL_SERVER,
         help = (
             "llama-server parallel decode slots. N requests share one "
             "loaded model; each slot gets ctx/N KV cache. Default "
@@ -1733,7 +1834,8 @@ def run(
     cloudflare: Optional[bool] = typer.Option(
         None,
         "--cloudflare/--no-cloudflare",
-        help = "Expose Studio on a PUBLIC internet URL via a free Cloudflare HTTPS "
+        rich_help_panel = _RUN_PANEL_SERVER,
+        help = "Expose Unsloth on a PUBLIC internet URL via a free Cloudflare HTTPS "
         "tunnel, for non-api-only wildcard binds (0.0.0.0 or ::). Off by default; "
         "pass --cloudflare to enable it (--secure implies it). --no-cloudflare forces "
         "it off but does not change a raw wildcard bind.",
@@ -1741,6 +1843,7 @@ def run(
     secure: bool = typer.Option(
         False,
         "--secure/--no-secure",
+        rich_help_panel = _RUN_PANEL_SERVER,
         help = "Expose ONLY a Cloudflare HTTPS link: bind localhost and fail closed "
         "if the tunnel can't start. Without it, --no-secure also serves the raw "
         "0.0.0.0 port, which is reachable from anywhere on the network.",
@@ -1754,45 +1857,89 @@ def run(
     tensor_parallel: bool = typer.Option(
         False,
         "--tensor-parallel/--no-tensor-parallel",
+        rich_help_panel = _RUN_PANEL_MODEL,
         help = (
             "Split a GGUF across GPUs by tensor (--split-mode tensor) instead of "
             "by layer. Multi-GPU only (no effect on one GPU); dense models gain "
             "decode speed, MoE usually don't."
         ),
     ),
+    start_api_key_marker: bool = typer.Option(
+        False,
+        "--start-api-key-marker",
+        hidden = True,
+        help = "Emit an early API key marker for the unsloth start parent process.",
+    ),
     password: str = typer.Option(
         "",
         "--password",
+        rich_help_panel = _RUN_PANEL_ADVANCED,
         help = "Set the INITIAL admin password non-interactively (headless setups), "
         "only when none is set yet. Also reads the UNSLOTH_STUDIO_PASSWORD env var, or "
         "`--password -` to read one line from stdin. A literal value is visible in the "
         "process list and shell history. Rotate later with `unsloth studio reset-password`.",
     ),
 ):
-    """Start Studio, load a model, print an API key -- one-liner server.
+    """Start Unsloth, load a model, print an API key -- one-liner server.
 
-    Unknown flags pass through to llama-server (GGUF only). Studio
+    Unknown flags pass through to llama-server (GGUF only). Unsloth
     rejects managed flags with HTTP 400: model identity, network
     (--host/--port/--path/--api-prefix/--reuse-port), auth/TLS
     (--api-key/--ssl-*), single-model UI (--ui/--models-*/--webui),
     and parallel slots (use --parallel above). Full denylist in
     studio/backend/core/inference/llama_server_args.py. Other knobs
     (-c, -ngl, --jinja, --flash-attn, -t, ...) pass through and
-    last-wins-override Studio's auto-set value.
+    last-wins-override Unsloth's auto-set value.
 
     Example:
         unsloth studio run --model unsloth/Qwen3-1.7B-GGUF --gguf-variant UD-Q4_K_XL
-        unsloth studio run --model unsloth/Qwen3-1.7B-GGUF --top-k 20 --seed 42 --parallel 8
+        unsloth studio run --model unsloth/Qwen3-1.7B-GGUF --temperature 0.7 --seed 42 --parallel 8
         unsloth studio run --model some-model --chat-template-file /path/to/tpl.jinja
         unsloth studio run --model unsloth/Qwen3-27B-GGUF --gguf-variant Q8_0 --tensor-parallel
     """
+    # A newer outer CLI can re-exec into an older Studio venv; pass this signal via
+    # env so an older child ignores it instead of treating it as a llama-server arg.
+    inherited_start_api_key_marker = _consume_start_api_key_marker_env()
+    start_api_key_marker = start_api_key_marker or inherited_start_api_key_marker
+
     # Back-compat: --not-secure is a deprecated alias for --no-secure.
     secure = _resolve_secure(secure, not_secure)
     extra_llama_args: List[str] = list(ctx.args) if ctx.args else []
 
+    # Tool-call healing/nudging are read from the env at backend import. Resolve here
+    # (before any re-exec/import) so the in-venv child inherits the decision. When the
+    # flag is omitted, respect a value the parent already set (e.g. `unsloth start`
+    # forwards its choice via the env) and otherwise apply the default: healing on,
+    # nudging on for a CLI-launched server.
+    _healing_disabled = (
+        os.environ.get("UNSLOTH_DISABLE_TOOL_CALL_HEALING") == "1"
+        if tool_call_healing is None
+        else not tool_call_healing
+    )
+    os.environ["UNSLOTH_DISABLE_TOOL_CALL_HEALING"] = "1" if _healing_disabled else "0"
+    if tool_call_nudging is not None:
+        os.environ["UNSLOTH_TOOL_CALL_NUDGE"] = "1" if tool_call_nudging else "0"
+    elif "UNSLOTH_TOOL_CALL_NUDGE" not in os.environ:
+        os.environ["UNSLOTH_TOOL_CALL_NUDGE"] = "1"
+
+    # Sampling overrides: the backend resolver reads UNSLOTH_SAMPLING_* to hard-pin a field
+    # (winning over both the client and the per-model recommendation). Only write a flag that
+    # was set explicitly so an omitted flag inherits any value the parent forwarded (e.g.
+    # `unsloth start`) and, when nothing is set, leaves the per-model recommendation in charge.
+    for _sampling_env, _sampling_value in (
+        ("UNSLOTH_SAMPLING_TEMPERATURE", temperature),
+        ("UNSLOTH_SAMPLING_TOP_P", top_p),
+        ("UNSLOTH_SAMPLING_TOP_K", top_k),
+        ("UNSLOTH_SAMPLING_MIN_P", min_p),
+        ("UNSLOTH_SAMPLING_REPETITION_PENALTY", repetition_penalty),
+        ("UNSLOTH_SAMPLING_PRESENCE_PENALTY", presence_penalty),
+    ):
+        if _sampling_value is not None:
+            os.environ[_sampling_env] = str(_sampling_value)
+
     # Set before any re-exec so the in-venv server inherits it via the env.
     # `run --verbose` used to pass through to llama-server (its own -v); keep
-    # that by forwarding --log-verbose so we add Studio logs without dropping it.
+    # that by forwarding --log-verbose so we add Unsloth logs without dropping it.
     if verbose:
         _enable_verbose_access_logs()
         if not any(a in ("--verbose", "-v", "--log-verbose") for a in extra_llama_args):
@@ -1878,14 +2025,14 @@ def run(
     if not in_studio_venv:
         studio_python = _studio_venv_python()
         if not studio_python:
-            typer.echo("Studio not set up. Run install.sh first.")
+            typer.echo("Unsloth Studio not set up. Run install.sh first.")
             raise typer.Exit(1)
         # Re-exec via the studio venv's `unsloth` console-script.
         studio_bin = studio_python.parent / "unsloth"
         if not studio_bin.is_file():
-            typer.echo("Studio venv missing 'unsloth' entry point. Re-run: unsloth studio setup")
+            typer.echo("Unsloth venv missing 'unsloth' entry point. Re-run: unsloth studio setup")
             raise typer.Exit(1)
-        # `run` serves the same Studio UI (unless --api-only); a public launch must
+        # `run` serves the same Unsloth UI (unless --api-only); a public launch must
         # have a servable login page BEFORE the gate strips the seeded password, or
         # the child has no way to change it. Validate here and forward the resolved
         # dist so a shadowed child that can't self-resolve one still serves it.
@@ -1991,15 +2138,21 @@ def run(
         if extra_llama_args:
             args.extend(extra_llama_args)
 
-        if sys.platform == "win32":
-            proc = subprocess.Popen(args)
-            try:
-                rc = proc.wait()
-            except KeyboardInterrupt:
-                rc = proc.wait()
-            raise typer.Exit(rc)
-        else:
-            os.execvp(str(studio_bin), args)
+        if start_api_key_marker:
+            os.environ[_START_API_KEY_MARKER_ENV] = "1"
+        try:
+            if sys.platform == "win32":
+                proc = subprocess.Popen(args)
+                try:
+                    rc = proc.wait()
+                except KeyboardInterrupt:
+                    rc = proc.wait()
+                raise typer.Exit(rc)
+            else:
+                os.execvp(str(studio_bin), args)
+        finally:
+            # execvp doesn't return on success; restore env after a Windows wait or a failed launch.
+            os.environ.pop(_START_API_KEY_MARKER_ENV, None)
 
     # ── 2. Start server (always suppress built-in banner) ─────────────
     run_mod = _load_run_module()
@@ -2045,6 +2198,10 @@ def run(
 
         # 4. Create API key in-process.
         api_key = _create_api_key_inprocess(api_key_name)
+        if start_api_key_marker:
+            # `unsloth start` reads this key from a private 0600 log to authenticate
+            # download-progress polling; the normal `unsloth run` output is unchanged.
+            typer.echo(f"UNSLOTH_START_API_KEY: {api_key}")
 
         # 5. Load model via HTTP.
         if not silent:
@@ -2216,7 +2373,7 @@ def stop():
     import signal as _signal
 
     if not _PID_FILE.is_file():
-        typer.echo("No running Studio server found (no PID file).")
+        typer.echo("No running Unsloth server found (no PID file).")
         raise typer.Exit(0)
 
     pid_text = _PID_FILE.read_text().strip()
@@ -2229,23 +2386,24 @@ def stop():
 
     # Check if still alive (os.kill(pid, 0) is invalid on Windows -- see _pid_alive).
     if not _pid_alive(pid):
-        typer.echo(f"Studio server (PID {pid}) is not running. Cleaning up stale PID file.")
+        typer.echo(f"Unsloth server (PID {pid}) is not running. Cleaning up stale PID file.")
         _PID_FILE.unlink(missing_ok = True)
         raise typer.Exit(0)
 
     # Send SIGTERM (graceful shutdown) or TerminateProcess on Windows
     try:
         if sys.platform == "win32":
-            subprocess.run(["taskkill", "/PID", str(pid), "/F"], check = True)
+            # /T also stops llama-server children, which otherwise keep GPU and port.
+            subprocess.run(["taskkill", "/PID", str(pid), "/T", "/F"], check = True)
         else:
             os.kill(pid, _signal.SIGTERM)
-        typer.echo(f"Sent shutdown signal to Studio server (PID {pid}).")
+        typer.echo(f"Sent shutdown signal to Unsloth server (PID {pid}).")
     except ProcessLookupError:
-        typer.echo(f"Studio server (PID {pid}) already exited.")
+        typer.echo(f"Unsloth server (PID {pid}) already exited.")
         _PID_FILE.unlink(missing_ok = True)
         raise typer.Exit(0)
     except Exception as e:
-        typer.echo(f"Failed to stop Studio server (PID {pid}): {e}", err = True)
+        typer.echo(f"Failed to stop Unsloth server (PID {pid}): {e}", err = True)
         raise typer.Exit(1)
 
     # Wait briefly for the process to exit and clean up.
@@ -2253,10 +2411,10 @@ def stop():
         time.sleep(0.5)
         if not _pid_alive(pid):
             _PID_FILE.unlink(missing_ok = True)
-            typer.echo("Studio server stopped.")
+            typer.echo("Unsloth server stopped.")
             raise typer.Exit(0)
 
-    typer.echo("Studio server is shutting down (may take a few seconds).")
+    typer.echo("Unsloth server is shutting down (may take a few seconds).")
 
 
 # ── unsloth studio setup / update ─────────────────────────────────────
@@ -2471,7 +2629,7 @@ def setup(
         help = "Full pip/build output during setup for troubleshooting.",
     ),
 ):
-    """Run Studio setup (called by install.ps1 / install.sh)."""
+    """Run Unsloth setup (called by install.ps1 / install.sh)."""
     _run_setup_script(verbose = verbose)
 
 
@@ -2632,10 +2790,10 @@ def provision_desktop_auth():
 
 @studio_app.command("reset-password")
 def reset_password():
-    """Reset the Studio admin password.
+    """Reset the Unsloth admin password.
 
     Deletes the auth database so that a fresh admin account with a new
-    random password is created on the next server start.  The Studio
+    random password is created on the next server start.  The Unsloth
     server must be restarted after running this command.
     """
     auth_dir = STUDIO_HOME / "auth"
@@ -2647,7 +2805,7 @@ def reset_password():
     had_db = db_file.exists()
 
     # Delete auth.db FIRST and prove it is gone before touching the seeded
-    # credential files. If it cannot be removed (a running Studio or Windows
+    # credential files. If it cannot be removed (a running Unsloth or Windows
     # holds it open, or a read-only auth dir), abort with the credential files
     # untouched: deleting them while an un-resettable DB (must_change_password=1)
     # survives would lock a forgotten-password reset out of any recovery
@@ -2657,7 +2815,7 @@ def reset_password():
     except OSError as exc:
         typer.echo(
             f"Error: could not delete the auth database ({exc}). Stop any running "
-            "Studio and retry; no credential files were changed.",
+            "Unsloth and retry; no credential files were changed.",
             err = True,
         )
         raise typer.Exit(1)
@@ -2679,7 +2837,7 @@ def reset_password():
             except OSError as exc:
                 typer.echo(
                     f"Error: could not remove or clear {path.name} ({exc}); delete "
-                    "it manually before restarting Studio or the old password may "
+                    "it manually before restarting Unsloth or the old password may "
                     "be reused.",
                     err = True,
                 )
diff --git a/unsloth_cli/config.py b/unsloth_cli/config.py
index 8192f7d749..dbc7701f70 100644
--- a/unsloth_cli/config.py
+++ b/unsloth_cli/config.py
@@ -41,6 +41,7 @@ class LoraConfig(BaseModel):
     vision_all_linear: bool = False
     use_rslora: bool = False
     use_loftq: bool = False
+    use_dora: bool = False
     finetune_vision_layers: bool = True
     finetune_language_layers: bool = True
     finetune_attention_modules: bool = True
@@ -100,6 +101,7 @@ class Config(BaseModel):
             "use_gradient_checkpointing": self.training.gradient_checkpointing,
             "use_rslora": self.lora.use_rslora,
             "use_loftq": self.lora.use_loftq,
+            "use_dora": self.lora.use_dora,
         }
 
     def training_kwargs(self) -> dict:
diff --git a/unsloth_cli/pi_subagent.ts b/unsloth_cli/pi_subagent.ts
new file mode 100644
index 0000000000..f4ef0c7d9e
--- /dev/null
+++ b/unsloth_cli/pi_subagent.ts
@@ -0,0 +1,406 @@
+import { spawn, type ChildProcess } from "node:child_process";
+import * as fs from "node:fs";
+import * as path from "node:path";
+import { fileURLToPath } from "node:url";
+import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
+import { Type } from "typebox";
+
+const provider = "unsloth";
+const maxResultCharacters = 100_000;
+const maxParallelAgents = 4;
+const cancelGraceMilliseconds = 2_000;
+const configPath = process.env.UNSLOTH_PI_SUBAGENT_CONFIG || "";
+delete process.env.UNSLOTH_PI_SUBAGENT_CONFIG;
+let config: Record<string, unknown> = {};
+if (configPath) {
+	try {
+		const parsed = JSON.parse(fs.readFileSync(configPath, "utf8"));
+		if (!parsed || typeof parsed !== "object" || Array.isArray(parsed)) {
+			throw new Error("expected a JSON object");
+		}
+		config = parsed;
+	} catch (error) {
+		throw new Error(`Could not read Unsloth subagent configuration: ${error}`);
+	}
+}
+const model = typeof config.model === "string" ? config.model : "";
+const baseUrl = typeof config.baseUrl === "string" ? config.baseUrl : "";
+const apiKey = typeof config.apiKey === "string" ? config.apiKey : "";
+const contextWindow = positiveInt(config.contextWindow, 32768);
+const maxTokens = positiveInt(config.maxTokens, Math.min(Math.floor(contextWindow / 4), 8192));
+let activeAgents = 0;
+const waitingAgents: Array<() => boolean> = [];
+
+function positiveInt(value: unknown, fallback: number): number {
+	const parsed = Number.parseInt(typeof value === "string" ? value : String(value || ""), 10);
+	return Number.isFinite(parsed) && parsed > 0 ? parsed : fallback;
+}
+
+function finalText(message: any): string {
+	if (message?.role !== "assistant" || !Array.isArray(message.content)) return "";
+	return message.content
+		.filter((part: any) => part?.type === "text" && typeof part.text === "string")
+		.map((part: any) => part.text)
+		.join("\n")
+		.trim();
+}
+
+function boundedResult(text: string): string {
+	if (text.length <= maxResultCharacters) return text;
+	return `${text.slice(0, maxResultCharacters)}\n\n[Local agent output truncated]`;
+}
+
+function agentSlotRelease(): () => void {
+	let released = false;
+	return () => {
+		if (released) return;
+		released = true;
+		while (waitingAgents.length) {
+			if (waitingAgents.shift()!()) return;
+		}
+		activeAgents -= 1;
+	};
+}
+
+function acquireAgentSlot(signal: AbortSignal | undefined): Promise<() => void> {
+	if (signal?.aborted) return Promise.reject(new Error("The local Unsloth agent was cancelled."));
+	if (activeAgents < maxParallelAgents) {
+		activeAgents += 1;
+		return Promise.resolve(agentSlotRelease());
+	}
+	return new Promise((resolve, reject) => {
+		let waiting = true;
+		const grant = () => {
+			if (!waiting) return false;
+			waiting = false;
+			signal?.removeEventListener("abort", cancel);
+			resolve(agentSlotRelease());
+			return true;
+		};
+		const cancel = () => {
+			if (!waiting) return;
+			waiting = false;
+			const index = waitingAgents.indexOf(grant);
+			if (index >= 0) waitingAgents.splice(index, 1);
+			reject(new Error("The local Unsloth agent was cancelled."));
+		};
+		waitingAgents.push(grant);
+		signal?.addEventListener("abort", cancel, { once: true });
+	});
+}
+
+function piInvocation(args: string[]): { command: string; args: string[] } {
+	const currentScript = process.argv[1];
+	const bunVirtualScript = currentScript?.startsWith("/$bunfs/root/");
+	if (currentScript && !bunVirtualScript && fs.existsSync(currentScript)) {
+		return { command: process.execPath, args: [currentScript, ...args] };
+	}
+	const executable = path.basename(process.execPath).toLowerCase();
+	if (!/^(node|bun)(\.exe)?$/.test(executable)) return { command: process.execPath, args };
+	return { command: "pi", args };
+}
+
+function signalProcessGroup(child: ChildProcess, signal: NodeJS.Signals): void {
+	if (!child.pid) return;
+	try {
+		process.kill(-child.pid, signal);
+	} catch {
+		try {
+			child.kill(signal);
+		} catch {
+			// The process tree already exited.
+		}
+	}
+}
+
+async function stopChildTree(child: ChildProcess): Promise<void> {
+	if (!child.pid) return;
+	if (process.platform === "win32") {
+		await new Promise<void>((resolve) => {
+			const killer = spawn("taskkill", ["/PID", String(child.pid), "/T", "/F"], {
+				shell: false,
+				stdio: "ignore",
+				windowsHide: true,
+			});
+			killer.once("error", () => {
+				try {
+					child.kill("SIGKILL");
+				} catch {
+					// The child already exited.
+				}
+				resolve();
+			});
+			killer.once("close", (code) => {
+				if (code !== 0) {
+					try {
+						child.kill("SIGKILL");
+					} catch {
+						// The child already exited.
+					}
+				}
+				resolve();
+			});
+		});
+		return;
+	}
+
+	signalProcessGroup(child, "SIGTERM");
+	await new Promise((resolve) => setTimeout(resolve, cancelGraceMilliseconds));
+	signalProcessGroup(child, "SIGKILL");
+}
+
+interface LocalAgentResult {
+	task: string;
+	response: string;
+	transcript: any[];
+	error?: string;
+}
+
+async function runLocalAgent(
+	task: string,
+	cwd: string,
+	signal: AbortSignal | undefined,
+	onProgress: (result: LocalAgentResult) => void,
+): Promise<LocalAgentResult> {
+	const extension = fileURLToPath(import.meta.url);
+	const args = [
+		"--mode",
+		"json",
+		"--print",
+		"--no-session",
+		"--provider",
+		provider,
+		"--model",
+		model,
+		"--no-extensions",
+		"--extension",
+		extension,
+		`Task: ${task}`,
+	];
+	const invocation = piInvocation(args);
+	let output = "";
+	let stderr = "";
+	let childError = "";
+	let aborted = false;
+	const result: LocalAgentResult = { task, response: "", transcript: [] };
+	const transcriptEntries = new Set<string>();
+	const appendTranscript = (messages: any[]): boolean => {
+		let changed = false;
+		for (const message of messages) {
+			const entry = JSON.stringify(message);
+			if (transcriptEntries.has(entry)) continue;
+			transcriptEntries.add(entry);
+			result.transcript.push(message);
+			changed = true;
+		}
+		return changed;
+	};
+	const processLine = (line: string) => {
+		try {
+			const event = JSON.parse(line);
+			if (event.type === "message_end" && event.message && appendTranscript([event.message])) {
+				onProgress(result);
+			}
+			if (
+				event.type === "turn_end" &&
+				Array.isArray(event.toolResults) &&
+				event.toolResults.length &&
+				appendTranscript(event.toolResults)
+			) {
+				onProgress(result);
+			}
+			if (event.type !== "message_end") return;
+			const message = event.message;
+			// Pi reports model/API failures as message_end events while still
+			// exiting 0, so the exit status alone cannot surface them.
+			if (message?.stopReason === "error" || message?.stopReason === "aborted") {
+				childError =
+					(typeof message.errorMessage === "string" && message.errorMessage) ||
+					`The local Unsloth agent stopped: ${message.stopReason}.`;
+				return;
+			}
+			const response = finalText(message);
+			if (response) {
+				result.response = boundedResult(response);
+				childError = "";
+			}
+		} catch {
+			// Ignore non-JSON diagnostic lines. The exit status still reports failures.
+		}
+	};
+
+	const exitCode = await new Promise<number>((resolve, reject) => {
+		const child = spawn(invocation.command, invocation.args, {
+			cwd,
+			detached: process.platform !== "win32",
+			shell: false,
+			stdio: ["ignore", "pipe", "pipe"],
+			env: {
+				...process.env,
+				UNSLOTH_PI_SUBAGENT_CHILD: "1",
+				UNSLOTH_PI_SUBAGENT_CONFIG: configPath,
+			},
+		});
+		let cleanup: Promise<void> | undefined;
+		const cancel = () => {
+			if (aborted) return;
+			aborted = true;
+			cleanup = stopChildTree(child);
+		};
+		child.on("error", (error) => {
+			signal?.removeEventListener("abort", cancel);
+			reject(error);
+		});
+		child.stdout.on("data", (chunk) => {
+			output += chunk.toString();
+			const lines = output.split("\n");
+			output = lines.pop() || "";
+			for (const line of lines) processLine(line);
+		});
+		child.stderr.on("data", (chunk) => {
+			stderr = (stderr + chunk.toString()).slice(-100_000);
+		});
+		child.on("close", async (code) => {
+			signal?.removeEventListener("abort", cancel);
+			await cleanup;
+			if (output.trim()) processLine(output);
+			resolve(code ?? 1);
+		});
+		signal?.addEventListener("abort", cancel, { once: true });
+		if (signal?.aborted) cancel();
+	});
+
+	if (aborted) throw new Error("The local Unsloth agent was cancelled.");
+	if (exitCode !== 0) {
+		result.error = stderr.trim() || `The local Unsloth agent exited with code ${exitCode}.`;
+	}
+	if (childError) result.error = boundedResult(childError);
+	if (!result.response && !result.error) result.response = "The local agent returned no text.";
+	return result;
+}
+
+export default function unslothSubagent(pi: ExtensionAPI): void {
+	if (!model || !baseUrl || !apiKey || !configPath) {
+		throw new Error("Unsloth subagent configuration is incomplete.");
+	}
+
+	pi.registerProvider(provider, {
+		name: "Unsloth Studio",
+		baseUrl,
+		apiKey,
+		api: "openai-completions",
+		authHeader: true,
+		models: [
+			{
+				id: model,
+				name: `${model} via Unsloth`,
+				reasoning: false,
+				input: ["text"],
+				cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+				contextWindow,
+				maxTokens,
+			},
+		],
+	});
+
+	if (process.env.UNSLOTH_PI_SUBAGENT_CHILD === "1") return;
+
+	pi.registerTool({
+		name: "unsloth_agent",
+		label: "Unsloth agent",
+		description:
+			"Run local coding agents powered by Unsloth for debugging, implementation, and codebase research. Use task for one agent. To run multiple independent agents, use tasks; up to four run concurrently. The tool returns only after every requested agent finishes.",
+		parameters: Type.Object({
+			task: Type.Optional(
+				Type.String({ description: "The complete task for one local Unsloth agent." }),
+			),
+			tasks: Type.Optional(
+				Type.Array(Type.String({ description: "A complete task for one local Unsloth agent." }), {
+					description: "Independent tasks to run concurrently, one local agent per task.",
+					minItems: 2,
+					maxItems: maxParallelAgents,
+				}),
+			),
+		}),
+		executionMode: "parallel",
+		async execute(_toolCallId, params, signal, onUpdate, ctx) {
+			const singleTask = typeof params.task === "string" && params.task.trim() ? params.task.trim() : "";
+			const parallelTasks = Array.isArray(params.tasks)
+				? params.tasks.map((task) => task.trim()).filter(Boolean)
+				: [];
+			if (Boolean(singleTask) === Boolean(parallelTasks.length)) {
+				throw new Error("Provide exactly one of task or tasks.");
+			}
+			if (parallelTasks.length > maxParallelAgents) {
+				throw new Error(`At most ${maxParallelAgents} local agents can run concurrently.`);
+			}
+			if (parallelTasks.length === 1) {
+				throw new Error("Use task for one local agent, or tasks for two to four agents.");
+			}
+
+			const tasks = singleTask ? [singleTask] : parallelTasks;
+			const results: Array<LocalAgentResult | undefined> = new Array(tasks.length);
+			let completed = 0;
+			const details = () => ({
+				provider,
+				model,
+				mode: tasks.length === 1 ? "single" : "parallel",
+				results: results.filter((result): result is LocalAgentResult => Boolean(result)),
+			});
+			const emitUpdate = () => {
+				onUpdate?.({
+					content: [
+						{
+							type: "text",
+							text: `Local agents: ${completed}/${tasks.length} completed`,
+						},
+					],
+					details: details(),
+				});
+			};
+			await Promise.all(
+				tasks.map(async (task, index) => {
+					let releaseAgentSlot: (() => void) | undefined;
+					try {
+						releaseAgentSlot = await acquireAgentSlot(signal);
+						results[index] = await runLocalAgent(task, ctx.cwd, signal, (partial) => {
+							results[index] = partial;
+							emitUpdate();
+						});
+					} catch (error) {
+						results[index] = {
+							task,
+							response: "",
+							transcript: results[index]?.transcript || [],
+							error: String(error),
+						};
+					} finally {
+						releaseAgentSlot?.();
+						completed += 1;
+						emitUpdate();
+					}
+				}),
+			);
+			if (signal?.aborted) throw new Error("The local Unsloth agent was cancelled.");
+			const completedResults = results.filter(
+				(result): result is LocalAgentResult => Boolean(result),
+			);
+			const succeeded = completedResults.filter((result) => !result.error).length;
+			const response =
+				completedResults.length === 1
+					? completedResults[0].error || completedResults[0].response
+					: [
+							`Parallel: ${succeeded}/${tasks.length} local agents succeeded`,
+							...completedResults.map(
+								(result, index) =>
+									`\n### Agent ${index + 1}${result.error ? " failed" : ""}\n\n${result.error || result.response}`,
+							),
+						].join("\n");
+			if (succeeded !== completedResults.length) throw new Error(response);
+			return {
+				content: [{ type: "text", text: response }],
+				details: details(),
+			};
+		},
+	});
+}
diff --git a/unsloth_cli/tests/test_claude_subagent_mcp.py b/unsloth_cli/tests/test_claude_subagent_mcp.py
new file mode 100644
index 0000000000..568dc76ff5
--- /dev/null
+++ b/unsloth_cli/tests/test_claude_subagent_mcp.py
@@ -0,0 +1,405 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+from __future__ import annotations
+
+import io
+import json
+import os
+import subprocess
+import sys
+import time
+
+import pytest
+
+import unsloth_cli.claude_subagent_mcp as bridge
+
+
+def test_protocol_lists_and_calls_local_agent():
+    initialized = bridge._response(
+        {"jsonrpc": "2.0", "id": 1, "method": "initialize", "params": {}},
+    )
+    assert initialized["result"]["serverInfo"]["name"] == "unsloth-local-agent"
+
+    listed = bridge._response({"jsonrpc": "2.0", "id": 2, "method": "tools/list"})
+    tool = listed["result"]["tools"][0]
+    assert tool["name"] == "unsloth_agent"
+    assert "spawn an Unsloth or local agent" in tool["description"]
+    assert tool["inputSchema"]["required"] == ["task"]
+    assert tool["_meta"]["anthropic/maxResultSizeChars"] == 100_000
+
+    called = bridge._response(
+        {
+            "jsonrpc": "2.0",
+            "id": 3,
+            "method": "tools/call",
+            "params": {"name": "unsloth_agent", "arguments": {"task": " inspect this "}},
+        },
+        run_agent = lambda task: f"completed: {task}",
+    )
+    assert called["result"] == {
+        "content": [{"type": "text", "text": "completed: inspect this"}],
+        "isError": False,
+    }
+
+
+def test_protocol_exposes_read_only_agent_for_claude_plan_mode():
+    listed = bridge._response(
+        {"jsonrpc": "2.0", "id": 1, "method": "tools/list"},
+        run_read_only_agent = lambda task: task,
+        read_only_tool_name = "unsloth_plan_agent",
+    )
+    tools = {tool["name"]: tool for tool in listed["result"]["tools"]}
+    assert tools["unsloth_agent"]["annotations"]["readOnlyHint"] is False
+    assert tools["unsloth_plan_agent"]["annotations"] == {
+        "readOnlyHint": True,
+        "destructiveHint": False,
+        "idempotentHint": True,
+        "openWorldHint": True,
+    }
+
+    called = bridge._response(
+        {
+            "jsonrpc": "2.0",
+            "id": 2,
+            "method": "tools/call",
+            "params": {
+                "name": "unsloth_plan_agent",
+                "arguments": {"task": " inspect this "},
+            },
+        },
+        run_agent = lambda task: f"write: {task}",
+        run_read_only_agent = lambda task: f"plan: {task}",
+        read_only_tool_name = "unsloth_plan_agent",
+    )
+    assert called["result"] == {
+        "content": [{"type": "text", "text": "plan: inspect this"}],
+        "isError": False,
+    }
+
+
+def test_protocol_returns_tool_errors_to_parent():
+    response = bridge._response(
+        {
+            "jsonrpc": "2.0",
+            "id": 1,
+            "method": "tools/call",
+            "params": {"name": "unsloth_agent", "arguments": {"task": "test"}},
+        },
+        run_agent = lambda task: (_ for _ in ()).throw(RuntimeError("local failure")),
+    )
+    assert response["result"]["isError"] is True
+    assert response["result"]["content"][0]["text"] == "local failure"
+
+
+def test_stdio_server_ignores_notifications_and_answers_requests():
+    requests = "\n".join(
+        [
+            json.dumps({"jsonrpc": "2.0", "method": "notifications/initialized"}),
+            json.dumps({"jsonrpc": "2.0", "id": 4, "method": "ping"}),
+        ]
+    )
+    output = io.StringIO()
+    bridge.serve(io.StringIO(requests), output)
+    assert json.loads(output.getvalue()) == {"jsonrpc": "2.0", "id": 4, "result": {}}
+
+
+def test_stdio_cancellation_reaches_the_running_local_agent():
+    requests = "\n".join(
+        [
+            json.dumps(
+                {
+                    "jsonrpc": "2.0",
+                    "id": "call-1",
+                    "method": "tools/call",
+                    "params": {"name": "unsloth_agent", "arguments": {"task": "wait"}},
+                }
+            ),
+            json.dumps(
+                {
+                    "jsonrpc": "2.0",
+                    "method": "notifications/cancelled",
+                    "params": {"requestId": "call-1", "reason": "user cancelled"},
+                }
+            ),
+        ]
+    )
+    output = io.StringIO()
+    cancelled = []
+
+    def run_agent(task, cancel_event):
+        assert task == "wait"
+        assert cancel_event.wait(timeout = 1)
+        cancelled.append(task)
+        raise RuntimeError("The local Claude agent was cancelled.")
+
+    bridge.serve(io.StringIO(requests), output, run_agent = run_agent)
+    assert cancelled == ["wait"]
+    assert output.getvalue() == ""
+
+
+def test_stdio_sigint_stops_the_running_local_agent(monkeypatch):
+    request = json.dumps(
+        {
+            "jsonrpc": "2.0",
+            "id": "call-1",
+            "method": "tools/call",
+            "params": {"name": "unsloth_agent", "arguments": {"task": "wait"}},
+        }
+    )
+    handlers = {}
+    started = bridge.threading.Event()
+    cancelled = []
+
+    def set_handler(signum, handler):
+        previous = handlers.get(signum, bridge.signal.SIG_DFL)
+        handlers[signum] = handler
+        return previous
+
+    monkeypatch.setattr(bridge.signal, "signal", set_handler)
+
+    class InterruptingInput:
+        def __init__(self):
+            self.sent = False
+
+        def __iter__(self):
+            return self
+
+        def __next__(self):
+            if not self.sent:
+                self.sent = True
+                return request + "\n"
+            assert started.wait(timeout = 1)
+            handlers[bridge.signal.SIGINT](bridge.signal.SIGINT, None)
+            raise AssertionError("SIGINT handler must unwind the stdin loop")
+
+    def run_agent(task, cancel_event):
+        assert task == "wait"
+        started.set()
+        assert cancel_event.wait(timeout = 1)
+        # Real Claude Code sends SIGINT twice. The second one must not abort cleanup.
+        handlers[bridge.signal.SIGINT](bridge.signal.SIGINT, None)
+        cancelled.append(task)
+        raise RuntimeError("The local Claude agent was cancelled.")
+
+    output = io.StringIO()
+    bridge.serve(InterruptingInput(), output, run_agent = run_agent)
+    assert cancelled == ["wait"]
+    assert output.getvalue() == ""
+
+
+@pytest.mark.parametrize(
+    ("bypass", "permission"),
+    [("0", "acceptEdits"), ("1", "bypassPermissions")],
+)
+def test_local_child_uses_unsloth_without_overwriting_parent_auth(
+    monkeypatch, tmp_path, bypass, permission
+):
+    captured = {}
+    monkeypatch.setenv("UNSLOTH_CLAUDE_SUBAGENT_BASE_URL", "http://127.0.0.1:8888")
+    monkeypatch.setenv("UNSLOTH_CLAUDE_SUBAGENT_API_KEY", "sk-unsloth-test")
+    monkeypatch.setenv("UNSLOTH_CLAUDE_SUBAGENT_MODEL", "unsloth/model-GGUF:Q4_K_M")
+    monkeypatch.setenv("UNSLOTH_CLAUDE_SUBAGENT_CONTEXT_WINDOW", "32768")
+    monkeypatch.setenv("UNSLOTH_CLAUDE_SUBAGENT_BYPASS_PERMISSIONS", bypass)
+    monkeypatch.setenv("ANTHROPIC_API_KEY", "cloud-key")
+    monkeypatch.setenv("CLAUDE_CODE_OAUTH_TOKEN", "cloud-oauth")
+    monkeypatch.setenv("CLAUDE_PROJECT_DIR", str(tmp_path))
+    monkeypatch.setattr(bridge.shutil, "which", lambda _: "/usr/local/bin/claude")
+    monkeypatch.setattr(bridge, "_claude_flags", lambda model: ["--settings", "{}"])
+
+    class Process:
+        pid = 1234
+        returncode = 0
+
+        def communicate(self, timeout):
+            captured["timeout"] = timeout
+            return json.dumps({"is_error": False, "result": "LOCAL_OK"}), ""
+
+        def poll(self):
+            return self.returncode
+
+    def popen(command, **kwargs):
+        captured["command"] = command
+        captured.update(kwargs)
+        return Process()
+
+    monkeypatch.setattr(bridge.subprocess, "Popen", popen)
+    assert bridge.run_local_agent("reply exactly LOCAL_OK") == "LOCAL_OK"
+    command = captured["command"]
+    assert command[:3] == ["/usr/local/bin/claude", "--model", "unsloth/model-GGUF:Q4_K_M"]
+    assert command[command.index("--permission-mode") + 1] == permission
+    assert "--no-session-persistence" in command
+    assert captured["cwd"] == str(tmp_path)
+    assert captured["stdin"] is bridge.subprocess.DEVNULL
+    assert captured["stdout"] is bridge.subprocess.PIPE
+    assert captured["stderr"] is bridge.subprocess.PIPE
+    if os.name == "nt":
+        assert captured["creationflags"] == bridge.subprocess.CREATE_NEW_PROCESS_GROUP
+    else:
+        assert captured["start_new_session"] is True
+    child_env = captured["env"]
+    assert child_env["ANTHROPIC_BASE_URL"] == "http://127.0.0.1:8888"
+    assert child_env["ANTHROPIC_AUTH_TOKEN"] == "sk-unsloth-test"
+    assert child_env["ANTHROPIC_MODEL"] == "unsloth/model-GGUF:Q4_K_M"
+    assert child_env["CLAUDE_CODE_AUTO_COMPACT_WINDOW"] == "32768"
+    assert child_env["CLAUDE_AUTOCOMPACT_PCT_OVERRIDE"] == "90"
+    assert "ANTHROPIC_API_KEY" not in child_env
+    assert "CLAUDE_CODE_OAUTH_TOKEN" not in child_env
+
+
+def test_read_only_local_child_uses_plan_mode(monkeypatch, tmp_path):
+    captured = {}
+    monkeypatch.setenv("UNSLOTH_CLAUDE_SUBAGENT_BASE_URL", "http://127.0.0.1:8888")
+    monkeypatch.setenv("UNSLOTH_CLAUDE_SUBAGENT_API_KEY", "sk-unsloth-test")
+    monkeypatch.setenv("UNSLOTH_CLAUDE_SUBAGENT_MODEL", "unsloth/model-GGUF:Q4_K_M")
+    monkeypatch.setenv("UNSLOTH_CLAUDE_SUBAGENT_BYPASS_PERMISSIONS", "1")
+    monkeypatch.setenv("CLAUDE_PROJECT_DIR", str(tmp_path))
+    monkeypatch.setattr(bridge.shutil, "which", lambda _: "/usr/local/bin/claude")
+    monkeypatch.setattr(bridge, "_claude_flags", lambda model: [])
+
+    class Process:
+        pid = 1234
+        returncode = 0
+
+        def communicate(self, timeout):
+            return json.dumps({"is_error": False, "result": "PLAN_OK"}), ""
+
+        def poll(self):
+            return self.returncode
+
+    def popen(command, **kwargs):
+        captured["command"] = command
+        return Process()
+
+    monkeypatch.setattr(bridge.subprocess, "Popen", popen)
+    assert bridge.run_local_agent("plan this", read_only = True) == "PLAN_OK"
+    command = captured["command"]
+    assert command[command.index("--permission-mode") + 1] == "plan"
+    prompt = command[command.index("--append-system-prompt") + 1]
+    assert "read-only local coding subagent" in prompt
+
+
+def test_local_child_process_is_stopped_on_cancellation(monkeypatch, tmp_path):
+    monkeypatch.setenv("UNSLOTH_CLAUDE_SUBAGENT_BASE_URL", "http://127.0.0.1:8888")
+    monkeypatch.setenv("UNSLOTH_CLAUDE_SUBAGENT_API_KEY", "sk-unsloth-test")
+    monkeypatch.setenv("UNSLOTH_CLAUDE_SUBAGENT_MODEL", "unsloth/model-GGUF:Q4_K_M")
+    monkeypatch.setenv("CLAUDE_PROJECT_DIR", str(tmp_path))
+    monkeypatch.setattr(bridge.shutil, "which", lambda _: "/usr/local/bin/claude")
+    monkeypatch.setattr(bridge, "_claude_flags", lambda model: [])
+    cancel_event = bridge.threading.Event()
+    stopped = []
+
+    class Process:
+        pid = 1234
+        returncode = None
+
+        def communicate(self, timeout):
+            cancel_event.set()
+            raise bridge.subprocess.TimeoutExpired("claude", timeout)
+
+        def poll(self):
+            return self.returncode
+
+    process = Process()
+    monkeypatch.setattr(bridge.subprocess, "Popen", lambda *args, **kwargs: process)
+
+    def stop(child):
+        stopped.append(child)
+        child.returncode = -15
+
+    monkeypatch.setattr(bridge, "_stop_child", stop)
+    with pytest.raises(RuntimeError, match = "cancelled"):
+        bridge.run_local_agent("wait", cancel_event)
+    assert stopped == [process]
+
+
+def test_windows_cancellation_stops_the_child_process_tree(monkeypatch):
+    monkeypatch.setattr(bridge.os, "name", "nt")
+    captured = {}
+
+    class Process:
+        pid = 4321
+        returncode = None
+
+        def poll(self):
+            return self.returncode
+
+        def wait(self, timeout = None):
+            captured["wait_timeout"] = timeout
+            self.returncode = 1
+
+        def terminate(self):
+            raise AssertionError("taskkill should handle the process tree")
+
+    def run(command, **kwargs):
+        captured["command"] = command
+        captured.update(kwargs)
+        return bridge.subprocess.CompletedProcess(command, 0)
+
+    monkeypatch.setattr(bridge.subprocess, "run", run)
+    bridge._stop_child(Process())
+
+    assert captured["command"] == ["taskkill", "/PID", "4321", "/T", "/F"]
+    assert captured["capture_output"] is True
+    assert captured["check"] is False
+    assert captured["wait_timeout"] == bridge._CANCEL_GRACE_SECONDS
+
+
+def test_windows_failed_taskkill_still_terminates_the_child(monkeypatch):
+    monkeypatch.setattr(bridge.os, "name", "nt")
+    captured = {}
+
+    class Process:
+        pid = 4321
+        returncode = None
+
+        def poll(self):
+            return self.returncode
+
+        def wait(self, timeout = None):
+            self.returncode = 1
+
+        def terminate(self):
+            captured["terminated"] = True
+            self.returncode = 1
+
+    monkeypatch.setattr(
+        bridge.subprocess,
+        "run",
+        lambda command, **kwargs: bridge.subprocess.CompletedProcess(command, 1),
+    )
+    bridge._stop_child(Process())
+
+    assert captured.get("terminated") is True
+
+
+@pytest.mark.skipif(os.name == "nt", reason = "POSIX process groups")
+def test_stop_child_kills_survivors_after_leader_exit(monkeypatch, tmp_path):
+    monkeypatch.setattr(bridge, "_CANCEL_GRACE_SECONDS", 0.2)
+    marker = tmp_path / "grandchild-survived"
+    grandchild = (
+        "import pathlib, sys, time; time.sleep(1.0); "
+        "pathlib.Path(sys.argv[1]).write_text('alive')"
+    )
+    process = subprocess.Popen(
+        [
+            sys.executable,
+            "-c",
+            "import subprocess, sys; "
+            "subprocess.Popen([sys.executable, '-c', sys.argv[1], sys.argv[2]])",
+            grandchild,
+            str(marker),
+        ],
+        start_new_session = True,
+    )
+    process.wait()
+
+    bridge._stop_child(process)
+
+    time.sleep(1.2)
+    assert not marker.exists()
+
+
+def test_result_parser_accepts_diagnostics_before_json():
+    output = "connector warning\n" + json.dumps({"is_error": False, "result": "OK"})
+    assert bridge._result_text(output) == "OK"
diff --git a/unsloth_cli/tests/test_codex_subagent_mcp.py b/unsloth_cli/tests/test_codex_subagent_mcp.py
new file mode 100644
index 0000000000..c0c97ca123
--- /dev/null
+++ b/unsloth_cli/tests/test_codex_subagent_mcp.py
@@ -0,0 +1,228 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+from __future__ import annotations
+
+import io
+import json
+import os
+import subprocess
+
+import pytest
+
+import unsloth_cli.codex_subagent_mcp as bridge
+
+
+def _write_config(tmp_path, *, bypass_permissions = False):
+    path = tmp_path / "subagent.json"
+    path.write_text(
+        json.dumps(
+            {
+                "api_key": "sk-unsloth-test",
+                "codex_home": str(tmp_path / "child"),
+                "bypass_permissions": bypass_permissions,
+            }
+        )
+    )
+    return path
+
+
+def test_protocol_uses_codex_specific_tool_name():
+    requests = "\n".join(
+        [
+            json.dumps({"jsonrpc": "2.0", "id": 0, "method": "initialize"}),
+            json.dumps({"jsonrpc": "2.0", "id": 1, "method": "tools/list"}),
+            json.dumps(
+                {
+                    "jsonrpc": "2.0",
+                    "id": 2,
+                    "method": "tools/call",
+                    "params": {
+                        "name": bridge._CODEX_SUBAGENT_MCP_TOOL,
+                        "arguments": {"task": " inspect this "},
+                    },
+                }
+            ),
+        ]
+    )
+    output = io.StringIO()
+    bridge.serve(
+        io.StringIO(requests),
+        output,
+        run_agent = lambda task, cancel_event: f"completed: {task}",
+        tool_name = bridge._CODEX_SUBAGENT_MCP_TOOL,
+        tool_description = bridge._CODEX_SUBAGENT_TOOL_DESCRIPTION,
+        instructions = bridge._SERVER_INSTRUCTIONS,
+    )
+    responses = {
+        response["id"]: response for response in map(json.loads, output.getvalue().splitlines())
+    }
+    assert responses[0]["result"]["instructions"] == bridge._SERVER_INSTRUCTIONS
+    assert len(bridge._SERVER_INSTRUCTIONS) <= 512
+    assert responses[1]["result"]["tools"][0]["name"] == "spawn_local_agent"
+    assert (
+        "Use this tool instead of the built-in spawn_agent tool"
+        in responses[1]["result"]["tools"][0]["description"]
+    )
+    assert responses[1]["result"]["tools"][0]["annotations"]["destructiveHint"] is True
+    assert responses[2]["result"] == {
+        "content": [{"type": "text", "text": "completed: inspect this"}],
+        "isError": False,
+    }
+
+
+@pytest.mark.parametrize("bypass_permissions", [False, True])
+@pytest.mark.parametrize("wsl_bridge", [False, True])
+def test_local_child_uses_explicit_unsloth_profile(
+    monkeypatch, tmp_path, bypass_permissions, wsl_bridge
+):
+    config = _write_config(tmp_path, bypass_permissions = bypass_permissions)
+    monkeypatch.setenv(bridge._CODEX_SUBAGENT_CONFIG_ENV, str(config))
+    credential_names = ("OPENAI_API_KEY", "CODEX_API_KEY", "CODEX_ACCESS_TOKEN")
+    for name in credential_names:
+        monkeypatch.setenv(name, "cloud-key")
+    monkeypatch.setenv("CODEX_SQLITE_HOME", str(tmp_path / "parent-sqlite"))
+    if wsl_bridge:
+        monkeypatch.setattr(
+            bridge,
+            "_wsl_shim_env",
+            lambda command, env, unset: (
+                env,
+                (
+                    bridge._CODEX_ENV_KEY,
+                    "CODEX_HOME/p",
+                    "CODEX_SQLITE_HOME/p",
+                    *unset,
+                    "PWD/p",
+                ),
+            ),
+        )
+    monkeypatch.setattr(bridge.shutil, "which", lambda _: "/usr/local/bin/codex")
+    captured = {}
+
+    class Process:
+        pid = 1234
+        returncode = 0
+
+        def communicate(self, timeout):
+            captured["timeout"] = timeout
+            return (
+                json.dumps(
+                    {
+                        "type": "item.completed",
+                        "item": {"type": "agent_message", "text": "LOCAL_OK"},
+                    }
+                ),
+                "",
+            )
+
+        def poll(self):
+            return self.returncode
+
+    def popen(command, **kwargs):
+        captured["command"] = command
+        captured.update(kwargs)
+        return Process()
+
+    monkeypatch.setattr(bridge.subprocess, "Popen", popen)
+    assert bridge.run_local_agent("reply exactly LOCAL_OK") == "LOCAL_OK"
+    command = captured["command"]
+    assert command[:4] == ["/usr/local/bin/codex", "--oss", "--profile", "unsloth_api"]
+    if bypass_permissions:
+        assert "--dangerously-bypass-approvals-and-sandbox" in command
+    else:
+        assert command[4:8] == ["--sandbox", "workspace-write", "--ask-for-approval", "never"]
+    assert command[command.index("exec") + 1 : command.index("exec") + 4] == [
+        "--ephemeral",
+        "--json",
+        "--skip-git-repo-check",
+    ]
+    assert command[-1].endswith("Task: reply exactly LOCAL_OK")
+    assert captured["cwd"] == os.getcwd()
+    assert captured["stdin"] is subprocess.DEVNULL
+    assert captured["stdout"] is subprocess.PIPE
+    assert captured["stderr"] is subprocess.PIPE
+    if os.name == "nt":
+        assert captured["creationflags"] == subprocess.CREATE_NEW_PROCESS_GROUP
+    else:
+        assert captured["start_new_session"] is True
+    assert captured["env"]["CODEX_HOME"] == str(tmp_path / "child")
+    assert captured["env"]["CODEX_SQLITE_HOME"] == str(tmp_path / "child")
+    assert captured["env"][bridge._CODEX_ENV_KEY] == "sk-unsloth-test"
+    if wsl_bridge:
+        assert all(captured["env"][name] == "" for name in credential_names)
+        wslenv = captured["env"]["WSLENV"].split(":")
+        assert all(
+            name in {entry.split("/", 1)[0] for entry in wslenv} for name in bridge._CODEX_ENV_UNSET
+        )
+        assert "CODEX_SQLITE_HOME/p" in wslenv
+        assert "PWD/p" in wslenv
+    else:
+        assert all(name not in captured["env"] for name in credential_names)
+
+
+def test_local_child_returns_last_agent_message():
+    output = "\n".join(
+        [
+            json.dumps(
+                {
+                    "type": "item.completed",
+                    "item": {"type": "agent_message", "text": "intermediate"},
+                }
+            ),
+            json.dumps(
+                {
+                    "type": "item.completed",
+                    "item": {"type": "agent_message", "text": "final"},
+                }
+            ),
+        ]
+    )
+    assert bridge._result_text(output) == "final"
+
+
+def test_local_child_prioritizes_failed_turn_over_progress():
+    output = "\n".join(
+        [
+            json.dumps(
+                {
+                    "type": "item.completed",
+                    "item": {"type": "agent_message", "text": "still working"},
+                }
+            ),
+            json.dumps({"type": "turn.failed", "error": {"message": "local failure"}}),
+        ]
+    )
+    with pytest.raises(RuntimeError, match = "local failure"):
+        bridge._result_text(output)
+
+
+def test_local_child_process_is_stopped_on_cancellation(monkeypatch, tmp_path):
+    config = _write_config(tmp_path)
+    monkeypatch.setenv(bridge._CODEX_SUBAGENT_CONFIG_ENV, str(config))
+    monkeypatch.setattr(bridge.shutil, "which", lambda _: "/usr/local/bin/codex")
+    cancel_event = bridge.threading.Event()
+    stopped = []
+
+    class Process:
+        pid = 1234
+        returncode = None
+
+        def communicate(self, timeout):
+            cancel_event.set()
+            raise subprocess.TimeoutExpired("codex", timeout)
+
+        def poll(self):
+            return self.returncode
+
+    process = Process()
+    monkeypatch.setattr(bridge.subprocess, "Popen", lambda *args, **kwargs: process)
+
+    def stop(child):
+        stopped.append(child)
+        child.returncode = -15
+
+    monkeypatch.setattr(bridge, "_stop_child", stop)
+    with pytest.raises(RuntimeError, match = "cancelled"):
+        bridge.run_local_agent("wait", cancel_event)
+    assert stopped == [process]
diff --git a/unsloth_cli/tests/test_inference_chat.py b/unsloth_cli/tests/test_inference_chat.py
index 56633408fb..07eed01e97 100644
--- a/unsloth_cli/tests/test_inference_chat.py
+++ b/unsloth_cli/tests/test_inference_chat.py
@@ -372,7 +372,7 @@ def test_find_studio_server_none_when_not_running(monkeypatch):
 
 
 def test_find_studio_server_prefers_ipv4_loopback_for_localhost(monkeypatch):
-    # localhost resolving ::1-first must not hide a Studio bound to 127.0.0.1:
+    # localhost resolving ::1-first must not hide an Unsloth bound to 127.0.0.1:
     # discovery tries each loopback address and returns the one that answers.
     import socket
     import urllib.request
@@ -873,6 +873,104 @@ def test_chat_compare_on_mlx_loads_base_model_side_by_side(monkeypatch):
     assert set(closed) == {"tuned", "base"}
 
 
+@pytest.mark.parametrize(
+    ("chunk_kind", "expected_exit"),
+    [
+        ("answer", 0),
+        ("model_text_error", 0),
+        ("real_error", 1),
+    ],
+)
+def test_inference_local_handles_stream(monkeypatch, chunk_kind, expected_exit):
+    from unsloth_cli.commands import inference as infermod
+    from unsloth_cli._inference import ensure_studio_backend_path
+
+    ensure_studio_backend_path()
+    from core.inference.orchestrator import GenStreamError
+
+    chunks = {
+        "answer": ["answer"],
+        "model_text_error": ["Error: printed by the model, not a backend failure"],
+        "real_error": [GenStreamError("Error: generation failed")],
+    }[chunk_kind]
+    closed = []
+
+    class _FakeBackend:
+        def stream(self, messages, **kwargs):
+            return iter(chunks)
+
+        def close(self):
+            closed.append(True)
+
+    monkeypatch.setattr(
+        infermod,
+        "connect_studio_server",
+        lambda *_a, **_k: (_ for _ in ()).throw(AssertionError("server disabled")),
+    )
+    monkeypatch.setattr(infermod, "load_chat_backend", lambda *a, **k: _FakeBackend())
+
+    result = CliRunner().invoke(
+        _inference_app(),
+        ["fake-model", "hello", "--no-server"],
+    )
+
+    assert result.exit_code == expected_exit, result.output
+    assert closed == [True]
+    if chunk_kind == "real_error":
+        assert result.stdout == "Assistant:\n"
+        assert result.stderr == "Error: generation failed\n"
+    else:
+        assert chunks[0] in result.output
+
+
+@pytest.mark.parametrize("chunk_kind", ["answer", "model_text_error", "real_error"])
+def test_chat_local_handles_stream(monkeypatch, chunk_kind):
+    from unsloth_cli._inference import ensure_studio_backend_path
+
+    ensure_studio_backend_path()
+    from core.inference.orchestrator import GenStreamError
+
+    first_chunk = {
+        "answer": "answer",
+        "model_text_error": "Error: printed by the model, not a backend failure",
+        "real_error": GenStreamError("Error: generation failed"),
+    }[chunk_kind]
+    calls, closed = [], []
+
+    class _FakeChatBackend:
+        def stream(self, messages, **kwargs):
+            calls.append([dict(message) for message in messages])
+            return iter([first_chunk if len(calls) == 1 else "second answer"])
+
+        def close(self):
+            closed.append(True)
+
+    monkeypatch.setattr(chatmod, "resolve_model_config", lambda *a, **k: _FakeConfig())
+    monkeypatch.setattr(chatmod, "connect_studio_server", lambda *a, **k: None)
+    monkeypatch.setattr(chatmod, "load_chat_backend", lambda *a, **k: _FakeChatBackend())
+    monkeypatch.setattr(chatmod, "_compare_needs_second_model", lambda: False)
+
+    result = CliRunner().invoke(
+        _chat_app(),
+        ["fake-model"],
+        input = "first\nsecond\n/exit\n",
+    )
+
+    assert result.exit_code == 0, result.output
+    assert closed == [True]
+    if chunk_kind == "real_error":
+        assert calls[1] == [{"role": "user", "content": "second"}]
+        assert "(error: generation failed)" in result.output
+        assert "Error: generation failed" not in result.output
+    else:
+        assert calls[1] == [
+            {"role": "user", "content": "first"},
+            {"role": "assistant", "content": first_chunk},
+            {"role": "user", "content": "second"},
+        ]
+        assert first_chunk in result.output
+
+
 @pytest.mark.parametrize(
     ("chunk_kind", "expected_exit"),
     [
diff --git a/unsloth_cli/tests/test_pi_subagent.py b/unsloth_cli/tests/test_pi_subagent.py
new file mode 100644
index 0000000000..0276366656
--- /dev/null
+++ b/unsloth_cli/tests/test_pi_subagent.py
@@ -0,0 +1,476 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import os
+from pathlib import Path
+import json
+import shutil
+import subprocess
+
+import pytest
+
+
+@pytest.mark.skipif(os.name == "nt", reason = "POSIX process group regression test")
+def test_pi_cancel_kills_child_process_group(tmp_path):
+    bun = shutil.which("bun")
+    if bun is None:
+        pytest.skip("Bun is required to execute the bundled Pi extension")
+
+    ready = tmp_path / "grandchild-ready"
+    marker = tmp_path / "grandchild-survived"
+    config = tmp_path / "subagent.json"
+    config.write_text(
+        json.dumps(
+            {
+                "baseUrl": "http://127.0.0.1:8000/v1",
+                "apiKey": "private-token",
+                "model": "local-model",
+                "contextWindow": 32768,
+                "maxTokens": 8192,
+            }
+        ),
+        encoding = "utf-8",
+    )
+    driver = tmp_path / "pi-driver.js"
+    driver.write_text(
+        """
+import { spawn } from "node:child_process";
+
+spawn(
+    process.execPath,
+    [
+        "-e",
+        `
+            const fs = require("node:fs");
+            process.on("SIGTERM", () => {});
+            fs.writeFileSync(process.env.PI_CHILD_READY, "ready");
+            setTimeout(() => fs.writeFileSync(process.env.PI_CANCEL_MARKER, "alive"), 3000);
+            setInterval(() => {}, 1000);
+        `,
+    ],
+    { stdio: "inherit" },
+);
+process.on("SIGTERM", () => {});
+setInterval(() => {}, 1000);
+""",
+        encoding = "utf-8",
+    )
+    extension = Path(__file__).parents[1] / "pi_subagent.ts"
+    test_file = tmp_path / "pi-cancel.test.ts"
+    test_file.write_text(
+        f"""
+import {{ expect, mock, test }} from "bun:test";
+import {{ existsSync }} from "node:fs";
+import {{ pathToFileURL }} from "node:url";
+
+mock.module("typebox", () => ({{
+    Type: {{
+        Object: (value) => value,
+        String: (value) => value,
+        Optional: (value) => value,
+        Array: (value) => value,
+    }},
+}}));
+
+test("cancellation stops the Pi child process group", async () => {{
+    process.env.UNSLOTH_PI_SUBAGENT_CONFIG = {str(config)!r};
+    process.env.PI_CHILD_READY = {str(ready)!r};
+    process.env.PI_CANCEL_MARKER = {str(marker)!r};
+    process.argv[1] = {str(driver)!r};
+
+    const loaded = await import(pathToFileURL({str(extension)!r}).href);
+    let tool;
+    let provider;
+    loaded.default({{
+        registerProvider(_name, value) {{ provider = value; }},
+        registerTool(value) {{ tool = value; }},
+    }});
+    expect(process.env.UNSLOTH_PI_SUBAGENT_CONFIG).toBeUndefined();
+    expect(process.env.UNSLOTH_PI_SUBAGENT_API_KEY).toBeUndefined();
+    expect(provider.apiKey).toBe("private-token");
+
+    const controller = new AbortController();
+    const execution = tool.execute(
+        "call",
+        {{ task: "wait" }},
+        controller.signal,
+        undefined,
+        {{ cwd: {str(tmp_path)!r} }},
+    );
+    for (let attempt = 0; attempt < 100 && !existsSync({str(ready)!r}); attempt++) {{
+        await Bun.sleep(20);
+    }}
+    expect(existsSync({str(ready)!r})).toBe(true);
+    controller.abort();
+    await expect(execution).rejects.toThrow("cancelled");
+    await Bun.sleep(3200);
+    expect(existsSync({str(marker)!r})).toBe(false);
+}}, 10_000);
+""",
+        encoding = "utf-8",
+    )
+
+    completed = subprocess.run(
+        [bun, "test", str(test_file)],
+        capture_output = True,
+        text = True,
+        timeout = 15,
+    )
+
+    assert completed.returncode == 0, completed.stdout + completed.stderr
+
+
+@pytest.mark.skipif(os.name == "nt", reason = "POSIX driver script")
+def test_pi_child_error_events_fail_the_tool_call(tmp_path):
+    bun = shutil.which("bun")
+    if bun is None:
+        pytest.skip("Bun is required to execute the bundled Pi extension")
+
+    config = tmp_path / "subagent.json"
+    config.write_text(
+        json.dumps(
+            {
+                "baseUrl": "http://127.0.0.1:8000/v1",
+                "apiKey": "private-token",
+                "model": "local-model",
+                "contextWindow": 32768,
+                "maxTokens": 8192,
+            }
+        ),
+        encoding = "utf-8",
+    )
+    # Pi reports model/API failures as message_end events while exiting 0.
+    driver = tmp_path / "pi-driver.js"
+    driver.write_text(
+        """
+const task = process.argv.at(-1).replace(/^Task: /, "");
+const event = task === "pass"
+    ? {
+          type: "message_end",
+          message: {
+              role: "assistant",
+              stopReason: "stop",
+              content: [{ type: "text", text: "PASS_OK" }],
+          },
+      }
+    : {
+          type: "message_end",
+          message: {
+              role: "assistant",
+              stopReason: "error",
+              errorMessage: "backend unreachable",
+              content: [],
+          },
+      };
+console.log(JSON.stringify(event));
+""",
+        encoding = "utf-8",
+    )
+    extension = Path(__file__).parents[1] / "pi_subagent.ts"
+    test_file = tmp_path / "pi-error.test.ts"
+    test_file.write_text(
+        f"""
+import {{ expect, mock, test }} from "bun:test";
+import {{ pathToFileURL }} from "node:url";
+
+mock.module("typebox", () => ({{
+    Type: {{
+        Object: (value) => value,
+        String: (value) => value,
+        Optional: (value) => value,
+        Array: (value) => value,
+    }},
+}}));
+
+test("child error events fail the tool call", async () => {{
+    process.env.UNSLOTH_PI_SUBAGENT_CONFIG = {str(config)!r};
+    process.argv[1] = {str(driver)!r};
+
+    const loaded = await import(pathToFileURL({str(extension)!r}).href);
+    let tool;
+    loaded.default({{
+        registerProvider() {{}},
+        registerTool(value) {{ tool = value; }},
+    }});
+
+    const singleExecution = tool.execute(
+        "call",
+        {{ task: "fail" }},
+        undefined,
+        undefined,
+        {{ cwd: {str(tmp_path)!r} }},
+    );
+    await expect(singleExecution).rejects.toThrow("backend unreachable");
+
+    const parallelExecution = tool.execute(
+        "call",
+        {{ tasks: ["pass", "fail"] }},
+        undefined,
+        undefined,
+        {{ cwd: {str(tmp_path)!r} }},
+    );
+    const parallelError = await parallelExecution.then(
+        () => "",
+        (error) => String(error),
+    );
+    expect(parallelError).toContain("Parallel: 1/2 local agents succeeded");
+    expect(parallelError).toContain("PASS_OK");
+    expect(parallelError).toContain("Agent 2 failed");
+    expect(parallelError).toContain("backend unreachable");
+}}, 10_000);
+""",
+        encoding = "utf-8",
+    )
+
+    completed = subprocess.run(
+        [bun, "test", str(test_file)],
+        capture_output = True,
+        text = True,
+        timeout = 15,
+    )
+
+    assert completed.returncode == 0, completed.stdout + completed.stderr
+
+
+@pytest.mark.skipif(os.name == "nt", reason = "POSIX driver script")
+def test_pi_parallel_agents_run_together_and_preserve_transcripts(tmp_path):
+    bun = shutil.which("bun")
+    if bun is None:
+        pytest.skip("Bun is required to execute the bundled Pi extension")
+
+    config = tmp_path / "subagent.json"
+    config.write_text(
+        json.dumps(
+            {
+                "baseUrl": "http://127.0.0.1:8000/v1",
+                "apiKey": "private-token",
+                "model": "local-model",
+                "contextWindow": 32768,
+                "maxTokens": 8192,
+            }
+        ),
+        encoding = "utf-8",
+    )
+    starts = tmp_path / "starts"
+    driver = tmp_path / "pi-driver.js"
+    driver.write_text(
+        f"""
+import * as fs from "node:fs";
+
+const task = process.argv.at(-1).replace(/^Task: /, "");
+fs.appendFileSync({str(starts)!r}, `${{task}}\\n`);
+for (let attempt = 0; attempt < 100; attempt++) {{
+    const count = fs.readFileSync({str(starts)!r}, "utf8").trim().split("\\n").filter(Boolean).length;
+    if (count >= 2) break;
+    await Bun.sleep(20);
+}}
+const event = {{
+    type: "message_end",
+    message: {{
+        role: "assistant",
+        stopReason: "stop",
+        content: [{{ type: "text", text: `DONE_${{task}}` }}],
+    }},
+}};
+console.log(JSON.stringify(event));
+console.log(JSON.stringify({{
+    type: "tool_execution_end",
+    toolCallId: `tool_${{task}}`,
+    toolName: "read",
+    result: {{ content: [{{ type: "text", text: `TOOL_${{task}}` }}] }},
+    isError: false,
+}}));
+const toolResult = {{
+    role: "toolResult",
+    toolCallId: `tool_${{task}}`,
+    toolName: "read",
+    content: [{{ type: "text", text: `TOOL_${{task}}` }}],
+    isError: false,
+}};
+// Current Pi emits a completed tool result both as message_end and in the
+// following turn_end. Preserve it once in the transcript.
+console.log(JSON.stringify({{
+    type: "message_end",
+    message: toolResult,
+}}));
+console.log(JSON.stringify({{
+    type: "turn_end",
+    message: event.message,
+    toolResults: [toolResult],
+}}));
+""",
+        encoding = "utf-8",
+    )
+    extension = Path(__file__).parents[1] / "pi_subagent.ts"
+    test_file = tmp_path / "pi-parallel.test.ts"
+    test_file.write_text(
+        f"""
+import {{ expect, mock, test }} from "bun:test";
+import {{ pathToFileURL }} from "node:url";
+
+mock.module("typebox", () => ({{
+    Type: {{
+        Object: (value) => value,
+        String: (value) => value,
+        Optional: (value) => value,
+        Array: (value) => value,
+    }},
+}}));
+
+test("parallel tasks launch one child each and retain their transcripts", async () => {{
+    process.env.UNSLOTH_PI_SUBAGENT_CONFIG = {str(config)!r};
+    process.argv[1] = {str(driver)!r};
+
+    const loaded = await import(pathToFileURL({str(extension)!r}).href);
+    let tool;
+    loaded.default({{
+        registerProvider() {{}},
+        registerTool(value) {{ tool = value; }},
+    }});
+
+    expect(tool.executionMode).toBe("parallel");
+    const result = await tool.execute(
+        "call",
+        {{ tasks: ["ALPHA", "BETA"] }},
+        undefined,
+        undefined,
+        {{ cwd: {str(tmp_path)!r} }},
+    );
+    expect(result.content[0].text).toContain("Parallel: 2/2 local agents succeeded");
+    expect(result.content[0].text).toContain("DONE_ALPHA");
+    expect(result.content[0].text).toContain("DONE_BETA");
+    expect(result.details.mode).toBe("parallel");
+    expect(result.details.results).toHaveLength(2);
+    expect(result.details.results[0].transcript).toHaveLength(2);
+    expect(result.details.results[1].transcript).toHaveLength(2);
+    expect(result.details.results[0].transcript[0].content[0].text).toBe("DONE_ALPHA");
+    expect(result.details.results[0].transcript[1].content[0].text).toBe("TOOL_ALPHA");
+    expect(result.details.results[1].transcript[0].content[0].text).toBe("DONE_BETA");
+    expect(result.details.results[1].transcript[1].content[0].text).toBe("TOOL_BETA");
+}}, 10_000);
+""",
+        encoding = "utf-8",
+    )
+
+    completed = subprocess.run(
+        [bun, "test", str(test_file)],
+        capture_output = True,
+        text = True,
+        timeout = 15,
+    )
+
+    assert completed.returncode == 0, completed.stdout + completed.stderr
+
+
+@pytest.mark.skipif(os.name == "nt", reason = "POSIX driver script")
+def test_pi_parallel_agent_cap_spans_concurrent_tool_calls(tmp_path):
+    bun = shutil.which("bun")
+    if bun is None:
+        pytest.skip("Bun is required to execute the bundled Pi extension")
+
+    config = tmp_path / "subagent.json"
+    config.write_text(
+        json.dumps(
+            {
+                "baseUrl": "http://127.0.0.1:8000/v1",
+                "apiKey": "private-token",
+                "model": "local-model",
+                "contextWindow": 32768,
+                "maxTokens": 8192,
+            }
+        ),
+        encoding = "utf-8",
+    )
+    markers = tmp_path / "active"
+    markers.mkdir()
+    peaks = tmp_path / "peaks"
+    driver = tmp_path / "pi-driver.js"
+    driver.write_text(
+        f"""
+import * as fs from "node:fs";
+
+const task = process.argv.at(-1).replace(/^Task: /, "");
+const marker = `{str(markers)!s}/${{process.pid}}`;
+fs.writeFileSync(marker, task);
+await Bun.sleep(150);
+fs.appendFileSync({str(peaks)!r}, `${{fs.readdirSync({str(markers)!r}).length}}\\n`);
+await Bun.sleep(150);
+fs.unlinkSync(marker);
+console.log(JSON.stringify({{
+    type: "message_end",
+    message: {{
+        role: "assistant",
+        stopReason: "stop",
+        content: [{{ type: "text", text: `DONE_${{task}}` }}],
+    }},
+}}));
+""",
+        encoding = "utf-8",
+    )
+    extension = Path(__file__).parents[1] / "pi_subagent.ts"
+    test_file = tmp_path / "pi-global-cap.test.ts"
+    test_file.write_text(
+        f"""
+import {{ expect, mock, test }} from "bun:test";
+import {{ pathToFileURL }} from "node:url";
+
+mock.module("typebox", () => ({{
+    Type: {{
+        Object: (value) => value,
+        String: (value) => value,
+        Optional: (value) => value,
+        Array: (value) => value,
+    }},
+}}));
+
+test("concurrent tool calls share the four-agent cap", async () => {{
+    process.env.UNSLOTH_PI_SUBAGENT_CONFIG = {str(config)!r};
+    process.argv[1] = {str(driver)!r};
+
+    const loaded = await import(pathToFileURL({str(extension)!r}).href);
+    let tool;
+    loaded.default({{
+        registerProvider() {{}},
+        registerTool(value) {{ tool = value; }},
+    }});
+
+    const first = tool.execute(
+        "call-1",
+        {{ tasks: ["A1", "A2", "A3", "A4"] }},
+        undefined,
+        undefined,
+        {{ cwd: {str(tmp_path)!r} }},
+    );
+    const second = tool.execute(
+        "call-2",
+        {{ tasks: ["B1", "B2", "B3", "B4"] }},
+        undefined,
+        undefined,
+        {{ cwd: {str(tmp_path)!r} }},
+    );
+    const results = await Promise.all([first, second]);
+    expect(results[0].content[0].text).toContain("4/4 local agents succeeded");
+    expect(results[1].content[0].text).toContain("4/4 local agents succeeded");
+    const afterQueue = await tool.execute(
+        "call-3",
+        {{ task: "C" }},
+        undefined,
+        undefined,
+        {{ cwd: {str(tmp_path)!r} }},
+    );
+    expect(afterQueue.content[0].text).toContain("DONE_C");
+}}, 10_000);
+""",
+        encoding = "utf-8",
+    )
+
+    completed = subprocess.run(
+        [bun, "test", str(test_file)],
+        capture_output = True,
+        text = True,
+        timeout = 15,
+    )
+
+    assert completed.returncode == 0, completed.stdout + completed.stderr
+    observed = [int(value) for value in peaks.read_text().splitlines()]
+    assert max(observed) == 4
diff --git a/unsloth_cli/tests/test_start.py b/unsloth_cli/tests/test_start.py
index 7e76465144..ade82cc06b 100644
--- a/unsloth_cli/tests/test_start.py
+++ b/unsloth_cli/tests/test_start.py
@@ -7,6 +7,7 @@ from __future__ import annotations
 
 import json
 import os
+import re
 import shlex
 import sys
 import urllib.error
@@ -19,6 +20,7 @@ if str(_REPO_ROOT) not in sys.path:
 
 
 import pytest
+import typer
 from typer.testing import CliRunner
 
 import unsloth_cli.commands.start as start
@@ -60,36 +62,75 @@ def _fake_claude(monkeypatch, version_output: str) -> None:
     )
 
 
+def _path_aware_which(binaries: dict):
+    # A shutil.which fake that resolves a name only when its directory is on PATH at call time.
+    # Lets a test prove a version probe augments PATH before resolving: an agent present only in
+    # an install dir (~/.local/bin, %APPDATA%\npm) must still be found and version-checked.
+    def _which(name):
+        directory = binaries.get(name)
+        if directory is None:
+            return None
+        entries = os.environ.get("PATH", "").split(os.pathsep)
+        # os.path.join (not Path()) so this works when a test has flipped os.name to "nt": under
+        # a simulated os.name, pathlib would build the non-native flavour and raise.
+        return os.path.join(str(directory), name) if str(directory) in entries else None
+
+    return _which
+
+
+def _simulate_windows(monkeypatch) -> None:
+    # Exercise the `os.name == "nt"` branch on any host. Flipping os.name alone makes pathlib
+    # pick the non-native flavour (WindowsPath on POSIX, PosixPath on Windows) when a Path is
+    # constructed, which raises; pin Path to the host-native class (captured before the flip)
+    # so the branch logic runs without that crash. Keeps these tests green on Linux/Mac/WSL too.
+    monkeypatch.setattr(start, "Path", type(Path()))
+    monkeypatch.setattr(start.os, "name", "nt")
+
+
 def test_claude_flags_passed_to_supported_claude(monkeypatch):
     _fake_claude(monkeypatch, "2.1.98 (Claude Code)\n")
-    assert start._claude_flags() == [
+    assert start._claude_flags(MODEL["id"]) == [
         "--exclude-dynamic-system-prompt-sections",
         "--settings",
-        start._CLAUDE_SETTINGS_OVERLAY,
+        start._claude_settings_overlay(MODEL["id"]),
     ]
 
 
 def test_claude_flags_skipped_on_old_claude(monkeypatch):
     _fake_claude(monkeypatch, "2.0.14 (Claude Code)\n")
-    assert start._claude_flags() == []
+    assert start._claude_flags(MODEL["id"]) == []
 
 
 def test_claude_flags_skipped_on_unparseable_version(monkeypatch):
     _fake_claude(monkeypatch, "weird build string\n")
-    assert start._claude_flags() == []
+    assert start._claude_flags(MODEL["id"]) == []
 
 
 def test_claude_flags_detected_when_version_not_first_token(monkeypatch):
     # The X.Y.Z is pulled from anywhere in the output, so a format change (version not
     # the first token) doesn't silently drop the optimization flags.
     _fake_claude(monkeypatch, "claude version 2.1.98\n")
-    assert start._claude_flags() == [
+    assert start._claude_flags(MODEL["id"]) == [
         "--exclude-dynamic-system-prompt-sections",
         "--settings",
-        start._CLAUDE_SETTINGS_OVERLAY,
+        start._claude_settings_overlay(MODEL["id"]),
     ]
 
 
+def test_claude_settings_overlay_pins_served_model():
+    # The session overlay must pin availableModels to the served model: a user's allowlist
+    # in ~/.claude/settings.json otherwise rejects the Unsloth --model ("restricted by your
+    # organization's settings"), and no env var can bypass it. The override must be a
+    # NON-EMPTY array to take effect (an empty [] is ignored and the user's list still
+    # applies), so it lists exactly this model, for this session only.
+    overlay = json.loads(start._claude_settings_overlay(MODEL["id"]))
+    assert overlay["availableModels"] == [MODEL["id"]]
+    # The attribution-header suppression is preserved alongside it.
+    assert overlay["env"]["CLAUDE_CODE_ATTRIBUTION_HEADER"] == "0"
+    # Subagents fall through to the served model instead of a user's opus/sonnet pin.
+    assert overlay["env"]["CLAUDE_CODE_SUBAGENT_MODEL"] == "inherit"
+
+
 def test_install_agent_prompts_then_installs(monkeypatch):
     # TTY + yes: run the documented install command, then re-resolve the now-present binary.
     monkeypatch.setattr(start.os, "name", "posix")
@@ -125,10 +166,55 @@ def test_install_agent_uses_powershell_on_windows(monkeypatch):
     executable = start._install_agent("hermes", install_hint)
 
     assert executable == r"C:\Users\samle\bin\hermes.exe"
-    assert ran == [["powershell", "-NoProfile", "-Command", install_hint]]
+    # -ExecutionPolicy Bypass (process-scoped) lets npm's npm.ps1 wrapper and irm|iex
+    # scripts run even when the machine policy is the Windows default Restricted.
+    assert ran == [
+        ["powershell", "-NoProfile", "-ExecutionPolicy", "Bypass", "-Command", install_hint]
+    ]
 
 
-def test_install_agent_warns_and_names_remote_source(monkeypatch, capsys):
+def test_install_agent_windows_failure_hints_execution_policy(monkeypatch, capsys):
+    # A failed install on Windows points the user at the per-user execution-policy fix:
+    # our subprocess bypasses the policy, but their own shell may still block npm.ps1
+    # (PSSecurityException) when they run the install by hand.
+    monkeypatch.setattr(start.os, "name", "nt")
+    monkeypatch.setattr(start.sys, "stdin", SimpleNamespace(isatty = lambda: True))
+    monkeypatch.setattr(start.typer, "confirm", lambda *a, **k: True)
+    monkeypatch.setattr(
+        start.subprocess,
+        "run",
+        lambda *a, **k: SimpleNamespace(returncode = 1),
+    )
+    monkeypatch.setattr(start.shutil, "which", lambda _: None)
+
+    with pytest.raises(start.typer.Exit):
+        start._install_agent("codex", "npm install -g @openai/codex")
+
+    err = capsys.readouterr().err
+    assert "Install command failed" in err
+    assert "Set-ExecutionPolicy -Scope CurrentUser -ExecutionPolicy RemoteSigned" in err
+
+
+def test_install_agent_posix_failure_omits_execution_policy_hint(monkeypatch, capsys):
+    # The execution-policy hint is Windows-only; a POSIX install failure must not mention it.
+    monkeypatch.setattr(start.os, "name", "posix")
+    monkeypatch.setattr(start.sys, "stdin", SimpleNamespace(isatty = lambda: True))
+    monkeypatch.setattr(start.typer, "confirm", lambda *a, **k: True)
+    monkeypatch.setattr(
+        start.subprocess,
+        "run",
+        lambda *a, **k: SimpleNamespace(returncode = 1),
+    )
+
+    with pytest.raises(start.typer.Exit):
+        start._install_agent("codex", "npm install -g @openai/codex")
+
+    err = capsys.readouterr().err
+    assert "Install command failed" in err
+    assert "Set-ExecutionPolicy" not in err
+
+
+def test_install_agent_warns_remote_installer_is_unverified_third_party(monkeypatch, capsys):
     # Before the confirm, a remote installer must name the URL it fetches so the
     # user consents to a specific source rather than blindly accepting.
     monkeypatch.setattr(start.os, "name", "nt")
@@ -137,9 +223,23 @@ def test_install_agent_warns_and_names_remote_source(monkeypatch, capsys):
     hint = "& ([scriptblock]::Create((irm https://hermes-agent.nousresearch.com/install.ps1))) -SkipSetup"
     assert start._install_agent("hermes", hint) is None
     err = capsys.readouterr().err
+    assert "Security warning" in err
+    assert "unverified third-party script" in err
     assert "https://hermes-agent.nousresearch.com/install.ps1" in err
-    assert "download and RUN" in err
-    assert "signature or hash" in err
+    assert "Unsloth does not pin or verify the downloaded content" in err
+    assert "Continue only if you trust this source" in err
+
+
+def test_install_agent_reports_immutable_remote_installer_pin(monkeypatch, capsys):
+    monkeypatch.setattr(start.os, "name", "posix")
+    monkeypatch.setattr(start.sys, "stdin", SimpleNamespace(isatty = lambda: True))
+    monkeypatch.setattr(start.typer, "confirm", lambda *a, **k: False)
+    assert start._install_agent("hermes", start._HERMES_POSIX_INSTALL_HINT) is None
+    err = capsys.readouterr().err
+    assert start._HERMES_INSTALL_COMMIT in err
+    assert "immutable upstream commit" in err
+    assert "does not independently verify or sandbox it" in err
+    assert "does not pin or verify" not in err
 
 
 def test_install_agent_warns_for_package_installer(monkeypatch, capsys):
@@ -160,8 +260,8 @@ def test_hermes_install_hint_is_windows_native_on_windows(monkeypatch):
     # Scriptblock form so `-SkipSetup` reaches the installer and the interactive
     # setup wizard is skipped during the unattended `unsloth start hermes` run.
     assert start._hermes_install_hint() == (
-        "& ([scriptblock]::Create((irm https://hermes-agent.nousresearch.com/install.ps1)))"
-        " -SkipSetup"
+        f"& ([scriptblock]::Create((irm {start._HERMES_INSTALL_BASE}/install.ps1)))"
+        f" -SkipSetup -Commit {start._HERMES_INSTALL_COMMIT}"
     )
 
 
@@ -170,11 +270,20 @@ def test_hermes_install_hint_is_bash_on_posix(monkeypatch):
 
     # `bash -s -- --skip-setup` forwards the skip flag to the piped installer.
     assert start._hermes_install_hint() == (
-        "curl -fsSL https://raw.githubusercontent.com/NousResearch/hermes-agent"
-        "/main/scripts/install.sh | bash -s -- --skip-setup"
+        f"curl -fsSL {start._HERMES_INSTALL_BASE}/install.sh | bash -s --"
+        f" --skip-setup --commit {start._HERMES_INSTALL_COMMIT}"
     )
 
 
+def test_hermes_install_hints_pin_script_and_checkout_to_full_commit():
+    commit = start._HERMES_INSTALL_COMMIT
+    assert re.fullmatch(r"[0-9a-f]{40}", commit)
+    for hint in (start._HERMES_WINDOWS_INSTALL_HINT, start._HERMES_POSIX_INSTALL_HINT):
+        assert hint.count(commit) == 2
+        assert "/main/" not in hint
+        assert "hermes-agent.nousresearch.com" not in hint
+
+
 def test_refresh_windows_path_noop_off_windows(monkeypatch):
     monkeypatch.setattr(start.os, "name", "posix")
     before = os.environ.get("PATH", "")
@@ -230,6 +339,172 @@ def test_refresh_windows_path_merges_registry_hives(monkeypatch):
     ]
 
 
+def test_augment_path_adds_existing_local_bin(monkeypatch, tmp_path):
+    # Claude's installer drops its binary in ~/.local/bin but only *suggests* adding it to
+    # PATH, so Unsloth appends it in-process to resolve the freshly installed agent.
+    local_bin = tmp_path / ".local" / "bin"
+    local_bin.mkdir(parents = True)
+    monkeypatch.setattr(start.Path, "home", lambda: tmp_path)
+    monkeypatch.setenv("APPDATA", str(tmp_path / "no-appdata"))  # skip the npm candidate
+    monkeypatch.setenv("PATH", str(tmp_path / "existing"))
+    start._augment_path_with_install_dirs()
+    entries = os.environ["PATH"].split(os.pathsep)
+    assert str(local_bin) in entries
+    # Appended (lowest precedence), so it never shadows an existing PATH entry.
+    assert entries[-1] == str(local_bin)
+
+
+def test_augment_path_skips_missing_and_duplicate_dirs(monkeypatch, tmp_path):
+    # A non-existent ~/.local/bin is not added; an already-present one is not duplicated.
+    monkeypatch.setattr(start.Path, "home", lambda: tmp_path)  # no .local/bin created yet
+    monkeypatch.setenv("APPDATA", str(tmp_path / "no-appdata"))  # skip the npm candidate
+    monkeypatch.setenv("PATH", str(tmp_path / "existing"))
+    start._augment_path_with_install_dirs()
+    assert os.environ["PATH"] == str(tmp_path / "existing")
+
+    local_bin = tmp_path / ".local" / "bin"
+    local_bin.mkdir(parents = True)
+    monkeypatch.setenv("PATH", os.pathsep.join([str(tmp_path / "existing"), str(local_bin)]))
+    start._augment_path_with_install_dirs()
+    assert os.environ["PATH"].split(os.pathsep).count(str(local_bin)) == 1
+
+
+def test_augment_path_adds_npm_global_bin_on_windows(monkeypatch, tmp_path):
+    # npm -g shims (codex/opencode/pi) land in %APPDATA%\npm on Windows; add it so a freshly
+    # installed npm agent resolves even when that dir isn't on PATH yet.
+    _simulate_windows(monkeypatch)
+    monkeypatch.setattr(start.Path, "home", lambda: tmp_path)  # no ~/.local/bin created
+    npm_dir = tmp_path / "Roaming" / "npm"
+    npm_dir.mkdir(parents = True)
+    monkeypatch.setenv("APPDATA", str(tmp_path / "Roaming"))
+    monkeypatch.setenv("PATH", str(tmp_path / "existing"))
+    start._augment_path_with_install_dirs()
+    assert str(npm_dir) in os.environ["PATH"].split(os.pathsep)
+
+
+def test_which_with_install_dirs_finds_agent_and_restores_path(monkeypatch, tmp_path):
+    # The probe helper resolves against the augmented PATH but must NOT persist it: only
+    # _launch() should mutate PATH for the child process. Here `claude` is only in ~/.local/bin.
+    local_bin = tmp_path / ".local" / "bin"
+    local_bin.mkdir(parents = True)
+    monkeypatch.setattr(start.Path, "home", lambda: tmp_path)
+    monkeypatch.setenv("APPDATA", str(tmp_path / "no-appdata"))  # skip the npm candidate
+    original = str(tmp_path / "existing")
+    monkeypatch.setenv("PATH", original)  # local_bin NOT on PATH yet
+    monkeypatch.setattr(start.shutil, "which", _path_aware_which({"claude": local_bin}))
+    assert start._which_with_install_dirs("claude") == str(local_bin / "claude")
+    assert os.environ["PATH"] == original  # restored, no global pollution
+
+
+def test_claude_flags_probes_old_agent_only_in_install_dir(monkeypatch, tmp_path):
+    # Regression: the version probe must augment PATH before resolving, so an OLD claude present
+    # only in ~/.local/bin (not yet on PATH) is detected as old and the unsupported flags are
+    # dropped -- the same binary _launch() will run. Before the fix the probe saw no binary,
+    # assumed a current build, and emitted flags the old claude rejects.
+    local_bin = tmp_path / ".local" / "bin"
+    local_bin.mkdir(parents = True)
+    monkeypatch.setattr(start.Path, "home", lambda: tmp_path)
+    monkeypatch.setenv("APPDATA", str(tmp_path / "no-appdata"))
+    monkeypatch.setenv("PATH", str(tmp_path / "existing"))
+    monkeypatch.setattr(start.shutil, "which", _path_aware_which({"claude": local_bin}))
+    monkeypatch.setattr(
+        start.subprocess, "run", lambda *a, **k: SimpleNamespace(stdout = "2.0.14 (Claude Code)\n")
+    )
+    assert start._claude_flags(MODEL["id"]) == []
+
+
+def test_claude_flags_detects_supported_agent_only_in_install_dir(monkeypatch, tmp_path):
+    # The counterpart: a SUPPORTED claude present only in ~/.local/bin is now resolved and gets
+    # the flags, instead of being missed and (coincidentally) also assumed current.
+    local_bin = tmp_path / ".local" / "bin"
+    local_bin.mkdir(parents = True)
+    monkeypatch.setattr(start.Path, "home", lambda: tmp_path)
+    monkeypatch.setenv("APPDATA", str(tmp_path / "no-appdata"))
+    monkeypatch.setenv("PATH", str(tmp_path / "existing"))
+    monkeypatch.setattr(start.shutil, "which", _path_aware_which({"claude": local_bin}))
+    monkeypatch.setattr(
+        start.subprocess, "run", lambda *a, **k: SimpleNamespace(stdout = "2.1.98 (Claude Code)\n")
+    )
+    assert start._claude_flags(MODEL["id"]) == [
+        "--exclude-dynamic-system-prompt-sections",
+        "--settings",
+        start._claude_settings_overlay(MODEL["id"]),
+    ]
+
+
+def test_claude_flags_probes_npm_install_dir_on_windows(monkeypatch, tmp_path):
+    # npm -g shims land in %APPDATA%\npm on Windows; an old claude there (not on PATH) must still
+    # be version-checked so the unsupported flags are dropped.
+    _simulate_windows(monkeypatch)
+    monkeypatch.setattr(start.Path, "home", lambda: tmp_path)  # no ~/.local/bin created
+    npm_dir = tmp_path / "Roaming" / "npm"
+    npm_dir.mkdir(parents = True)
+    monkeypatch.setenv("APPDATA", str(tmp_path / "Roaming"))
+    monkeypatch.setenv("PATH", str(tmp_path / "existing"))
+    monkeypatch.setattr(start.shutil, "which", _path_aware_which({"claude": npm_dir}))
+    monkeypatch.setattr(
+        start.subprocess, "run", lambda *a, **k: SimpleNamespace(stdout = "2.0.14 (Claude Code)\n")
+    )
+    assert start._claude_flags(MODEL["id"]) == []
+
+
+def test_codex_catalog_probes_old_codex_only_in_install_dir(monkeypatch, tmp_path):
+    # Same ordering fix for codex: an old codex present only in an install dir is detected so the
+    # model-catalog config is omitted (the old binary can't consume it).
+    local_bin = tmp_path / ".local" / "bin"
+    local_bin.mkdir(parents = True)
+    monkeypatch.setattr(start.Path, "home", lambda: tmp_path)
+    monkeypatch.setenv("APPDATA", str(tmp_path / "no-appdata"))
+    monkeypatch.setenv("PATH", str(tmp_path / "existing"))
+    monkeypatch.setattr(start.shutil, "which", _path_aware_which({"codex": local_bin}))
+    monkeypatch.setattr(start.subprocess, "check_output", lambda *a, **k: "codex-cli 0.109.0")
+    assert start._codex_supports_model_catalog() is False
+
+
+def test_opencode_native_auto_probes_old_opencode_only_in_install_dir(monkeypatch, tmp_path):
+    # Same ordering fix for opencode: an old opencode present only in an install dir is detected
+    # so native --auto is not assumed (the old binary rejects it).
+    local_bin = tmp_path / ".local" / "bin"
+    local_bin.mkdir(parents = True)
+    monkeypatch.setattr(start.Path, "home", lambda: tmp_path)
+    monkeypatch.setenv("APPDATA", str(tmp_path / "no-appdata"))
+    monkeypatch.setenv("PATH", str(tmp_path / "existing"))
+    monkeypatch.setattr(start.shutil, "which", _path_aware_which({"opencode": local_bin}))
+    monkeypatch.setattr(start.subprocess, "check_output", lambda *a, **k: "1.17.11")
+    assert start._opencode_supports_native_auto() is False
+
+
+def test_augment_path_preserves_defpath_when_path_unset(monkeypatch, tmp_path):
+    # PATH unset: shutil.which() and exec*p* fall back to os.defpath (e.g. /bin:/usr/bin), so the
+    # augmentation must keep those default dirs instead of collapsing to just the install dir
+    # (which would hide a system-installed agent and strip the launched child's normal PATH).
+    local_bin = tmp_path / ".local" / "bin"
+    local_bin.mkdir(parents = True)
+    monkeypatch.setattr(start.Path, "home", lambda: tmp_path)
+    monkeypatch.setenv("APPDATA", str(tmp_path / "no-appdata"))
+    monkeypatch.delenv("PATH", raising = False)
+    start._augment_path_with_install_dirs()
+    entries = os.environ["PATH"].split(os.pathsep)
+    for default_dir in os.defpath.split(os.pathsep):
+        if default_dir:
+            assert default_dir in entries
+    assert str(local_bin) in entries
+
+
+def test_which_with_install_dirs_keeps_defpath_when_path_unset(monkeypatch, tmp_path):
+    # With PATH unset, a system agent on os.defpath (e.g. /usr/bin) must still resolve; the
+    # install-dir augmentation must not drop the default search path. PATH is restored to unset.
+    local_bin = tmp_path / ".local" / "bin"
+    local_bin.mkdir(parents = True)
+    monkeypatch.setattr(start.Path, "home", lambda: tmp_path)
+    monkeypatch.setenv("APPDATA", str(tmp_path / "no-appdata"))
+    monkeypatch.delenv("PATH", raising = False)
+    sysdir = next(part for part in reversed(os.defpath.split(os.pathsep)) if part)
+    monkeypatch.setattr(start.shutil, "which", _path_aware_which({"claude": Path(sysdir)}))
+    assert start._which_with_install_dirs("claude") == os.path.join(sysdir, "claude")
+    assert "PATH" not in os.environ
+
+
 def test_install_agent_declined_returns_none(monkeypatch):
     # TTY + no: never runs anything; caller falls back to the print-hint failure.
     monkeypatch.setattr(start.sys, "stdin", SimpleNamespace(isatty = lambda: True))
@@ -346,6 +621,276 @@ def test_write_codex_config_omits_catalog_for_old_codex(tmp_path, monkeypatch):
     assert not (tmp_path / "model-catalog.json").exists()
 
 
+def test_write_codex_subagent_bridge_keeps_parent_credentials_out(tmp_path, monkeypatch):
+    monkeypatch.setattr(start, "_codex_supports_model_catalog", lambda: True)
+    local = {**MODEL, "id": MODEL["id"] + ":UD-Q4_K_XL"}
+    path = start.write_codex_subagent_bridge(
+        BASE,
+        "private-token",
+        local,
+        tmp_path,
+        yolo = False,
+    )
+    assert json.loads(path.read_text()) == {
+        "api_key": "private-token",
+        "codex_home": str(tmp_path / "child"),
+        "bypass_permissions": False,
+    }
+    assert path.stat().st_mode & 0o077 == 0
+    profile = _parse_toml((tmp_path / "child" / "unsloth_api.config.toml").read_text())
+    assert profile["model"] == local["id"]
+    assert profile["model_provider"] == start._CODEX_PROFILE
+    assert profile["model_context_window"] == MODEL["context_length"]
+    config = _parse_toml((tmp_path / "child" / "config.toml").read_text())
+    assert config["model_providers"][start._CODEX_PROFILE]["base_url"] == f"{BASE}/v1"
+    catalog = json.loads((tmp_path / "child" / profile["model_catalog_json"]).read_text())
+    assert catalog["models"][0]["slug"] == local["id"]
+
+
+def test_write_codex_parent_overlay_preserves_user_state_and_instructions(tmp_path, monkeypatch):
+    source = tmp_path / "user-codex"
+    source.mkdir()
+    (source / "config.toml").write_text('model = "cloud-model"\n')
+    (source / "auth.json").write_text('{"auth": "cloud"}\n')
+    (source / "sessions").mkdir()
+    (source / "AGENTS.override.md").write_text("Keep my existing instructions.\n")
+    monkeypatch.setenv("CODEX_HOME", str(source))
+
+    overlay = start.write_codex_parent_overlay(tmp_path / "managed" / "parent")
+
+    assert (overlay / "config.toml").read_text() == 'model = "cloud-model"\n'
+    assert (overlay / "auth.json").read_text() == '{"auth": "cloud"}\n'
+    assert (overlay / "sessions").is_dir()
+    instructions = (overlay / "AGENTS.override.md").read_text()
+    assert instructions.startswith("Keep my existing instructions.\n")
+    assert start._CODEX_SUBAGENT_ROUTING_INSTRUCTIONS in instructions
+    assert not (overlay / "AGENTS.md").exists()
+    assert (overlay / "AGENTS.override.md").stat().st_mode & 0o077 == 0
+    assert (source / "AGENTS.override.md").read_text() == "Keep my existing instructions.\n"
+
+
+def test_write_codex_parent_overlay_refreshes_reused_entries(tmp_path, monkeypatch):
+    first = tmp_path / "first-codex"
+    first.mkdir()
+    (first / "auth.json").write_text('{"auth": "old"}\n')
+    (first / "old-only.toml").write_text("old\n")
+    second = tmp_path / "second-codex"
+    second.mkdir()
+    (second / "auth.json").write_text('{"auth": "new"}\n')
+    overlay_path = tmp_path / "managed" / "parent"
+
+    monkeypatch.setenv("CODEX_HOME", str(first))
+    overlay = start.write_codex_parent_overlay(overlay_path)
+    assert (overlay / "auth.json").read_text() == '{"auth": "old"}\n'
+    assert (overlay / "old-only.toml").exists()
+
+    monkeypatch.setenv("CODEX_HOME", str(second))
+    overlay = start.write_codex_parent_overlay(overlay_path)
+    assert (overlay / "auth.json").read_text() == '{"auth": "new"}\n'
+    assert not (overlay / "old-only.toml").exists()
+
+
+def test_write_codex_parent_overlay_does_not_use_itself_as_source(tmp_path, monkeypatch):
+    source = tmp_path / "user-codex"
+    source.mkdir()
+    (source / "auth.json").write_text('{"auth": "cloud"}\n')
+    overlay_path = tmp_path / "managed" / "parent"
+    monkeypatch.setenv("CODEX_HOME", str(source))
+    overlay = start.write_codex_parent_overlay(overlay_path)
+
+    monkeypatch.setenv("CODEX_HOME", str(overlay))
+    overlay = start.write_codex_parent_overlay(overlay_path)
+
+    assert (overlay / "auth.json").read_text() == '{"auth": "cloud"}\n'
+    manifest = json.loads((overlay / start._CODEX_PARENT_OVERLAY_MANIFEST).read_text())
+    assert manifest["source_home"] == str(source)
+
+
+def test_write_codex_parent_overlay_refreshes_fallback_copies(tmp_path, monkeypatch):
+    source = tmp_path / "user-codex"
+    source.mkdir()
+    config = source / "config.toml"
+    config.write_text('model = "first"\n')
+    sessions = source / "sessions"
+    sessions.mkdir()
+    (sessions / "existing.jsonl").write_text("existing session\n")
+    monkeypatch.setenv("CODEX_HOME", str(source))
+
+    def deny_symlink(*args, **kwargs):
+        raise OSError("symlinks unavailable")
+
+    monkeypatch.setattr(Path, "symlink_to", deny_symlink)
+    monkeypatch.setattr(start, "_create_directory_junction", lambda source, target: False)
+    overlay = start.write_codex_parent_overlay(tmp_path / "managed" / "parent")
+    (overlay / "history.jsonl").write_text("session state\n")
+    config.write_text('model = "second"\n')
+
+    overlay = start.write_codex_parent_overlay(overlay)
+
+    assert (overlay / "config.toml").read_text() == 'model = "second"\n'
+    assert (overlay / "sessions" / "existing.jsonl").read_text() == "existing session\n"
+    assert (overlay / "history.jsonl").read_text() == "session state\n"
+
+    config.unlink()
+    overlay = start.write_codex_parent_overlay(overlay)
+    assert not (overlay / "config.toml").exists()
+    assert (overlay / "history.jsonl").read_text() == "session state\n"
+
+
+def test_create_directory_junction_uses_windows_mklink(tmp_path, monkeypatch):
+    captured = {}
+    monkeypatch.setattr(start.os, "name", "nt")
+
+    def run(command, **kwargs):
+        captured["command"] = command
+        captured["kwargs"] = kwargs
+        return SimpleNamespace(returncode = 0)
+
+    monkeypatch.setattr(start.subprocess, "run", run)
+    source = tmp_path / "source"
+    target = tmp_path / "target"
+
+    assert start._create_directory_junction(source, target) is True
+    assert captured["command"] == [
+        "cmd.exe",
+        "/d",
+        "/c",
+        "mklink",
+        "/J",
+        str(target),
+        str(source),
+    ]
+    assert captured["kwargs"] == {
+        "capture_output": True,
+        "text": True,
+        "timeout": 30,
+        "check": False,
+    }
+
+
+@pytest.mark.skipif(os.name == "nt", reason = "WSL scenario")
+def test_write_codex_parent_overlay_uses_windows_home_for_windows_codex(tmp_path, monkeypatch):
+    windows_profile = tmp_path / "windows-profile"
+    source = windows_profile / ".codex"
+    source.mkdir(parents = True)
+    (source / "auth.json").write_text('{"auth": "windows"}\n')
+    executable = "/mnt/c/Users/x/AppData/Roaming/npm/codex"
+    monkeypatch.delenv("CODEX_HOME", raising = False)
+    monkeypatch.delenv("USERPROFILE", raising = False)
+    monkeypatch.setenv("WSL_DISTRO_NAME", "Ubuntu")
+    monkeypatch.setattr(start.shutil, "which", lambda _: executable)
+
+    def check_output(command, **kwargs):
+        if command[0] == "cmd.exe":
+            assert kwargs["cwd"] == str(Path(executable).parent)
+            return r"C:\Users\x" + "\n"
+        assert command == ["wslpath", "-u", r"C:\Users\x"]
+        return str(windows_profile) + "\n"
+
+    monkeypatch.setattr(start.subprocess, "check_output", check_output)
+
+    overlay = start.write_codex_parent_overlay(tmp_path / "managed" / "parent")
+
+    assert (overlay / "auth.json").read_text() == '{"auth": "windows"}\n'
+
+
+def test_codex_parent_overlay_launch_uses_private_temp_root_and_cleans_up(tmp_path, monkeypatch):
+    source = tmp_path / "user-codex"
+    source.mkdir()
+    (source / "auth.json").write_text("{}\n")
+    monkeypatch.setenv("CODEX_HOME", str(source))
+    agents_root = tmp_path / "agents"
+    monkeypatch.setattr(start, "_agents_config_root", lambda: agents_root)
+
+    with start._codex_parent_overlay(tmp_path / "session", launch = True, persist = False) as overlay:
+        assert overlay.parent == agents_root / ".tmp"
+        assert start._CODEX_SUBAGENT_ROUTING_INSTRUCTIONS in (overlay / "AGENTS.md").read_text()
+        assert overlay.exists()
+
+    assert not overlay.exists()
+
+
+@pytest.mark.skipif(os.name == "nt", reason = "WSL scenario")
+def test_codex_subagent_bridge_uses_wsl_for_windows_codex(monkeypatch, tmp_path):
+    monkeypatch.setenv("WSL_DISTRO_NAME", "Ubuntu")
+    monkeypatch.setattr(
+        start.shutil,
+        "which",
+        lambda _: "/mnt/c/Users/x/AppData/Roaming/npm/codex.exe",
+    )
+    flags = start._codex_subagent_flags(tmp_path / "subagent.json")
+    prefix = f"mcp_servers.{start._CODEX_SUBAGENT_MCP_SERVER}="
+    override = next(value for value in flags if value.startswith(prefix))
+    server = _parse_toml("server = " + override.removeprefix(prefix))["server"]
+    assert server["command"] == "wsl.exe"
+    assert server["args"] == [
+        "-d",
+        "Ubuntu",
+        "--",
+        sys.executable,
+        "-c",
+        server["args"][5],
+        str(tmp_path / "subagent.json"),
+    ]
+    assert "sys.path.insert" in server["args"][5]
+    assert f"from {start._CODEX_SUBAGENT_MCP_MODULE} import main" in server["args"][5]
+    assert server["required"] is True
+    assert server["enabled_tools"] == [start._CODEX_SUBAGENT_MCP_TOOL]
+    assert server["default_tools_approval_mode"] == "approve"
+    assert not any(value.startswith("developer_instructions=") for value in flags)
+
+
+@pytest.mark.skipif(os.name == "nt", reason = "WSL scenario")
+def test_agent_config_path_translates_for_windows_agent(monkeypatch, tmp_path):
+    windows_path = r"\\wsl.localhost\Ubuntu\tmp\unsloth.toml"
+    monkeypatch.setenv("WSL_DISTRO_NAME", "Ubuntu")
+    monkeypatch.setattr(
+        start.shutil,
+        "which",
+        lambda _: "/mnt/c/Users/x/AppData/Roaming/npm/codex",
+    )
+    monkeypatch.setattr(start.subprocess, "check_output", lambda *args, **kwargs: windows_path)
+
+    assert start._agent_config_path(tmp_path / "unsloth.toml", ["codex"]) == windows_path
+
+
+def test_subagent_model_id_preserves_explicit_variant(monkeypatch):
+    monkeypatch.setattr(
+        start,
+        "_http_json",
+        lambda *args, **kwargs: pytest.fail("explicit variant should not need status"),
+    )
+    assert (
+        start._subagent_model_id(BASE, "key", MODEL, MODEL["id"], "UD-Q4_K_XL")
+        == MODEL["id"] + ":UD-Q4_K_XL"
+    )
+
+
+def test_subagent_model_id_uses_loaded_variant(monkeypatch):
+    monkeypatch.setattr(
+        start,
+        "_http_json",
+        lambda *args, **kwargs: {"is_gguf": True, "gguf_variant": "Q5_K_M"},
+    )
+    assert start._subagent_model_id(BASE, "key", MODEL, None, None) == MODEL["id"] + ":Q5_K_M"
+
+
+def test_subagent_model_id_warns_when_status_unavailable(monkeypatch, capsys):
+    def raise_error(*args, **kwargs):
+        raise OSError("connection refused")
+
+    monkeypatch.setattr(start, "_http_json", raise_error)
+    assert start._subagent_model_id(BASE, "key", MODEL, None, None) == MODEL["id"]
+    assert "could not verify the loaded GGUF variant" in capsys.readouterr().err
+
+
+@pytest.mark.parametrize("agent", ["openclaw", "hermes"])
+def test_unsupported_agents_reject_as_subagent(agent):
+    result = CliRunner().invoke(start.start_app, [agent, "--as-subagent"])
+    assert result.exit_code == 1
+    assert f"--as-subagent is not supported for {agent}." in result.output
+
+
 @pytest.fixture()
 def fake_studio(tmp_path, monkeypatch):
     calls = []
@@ -367,8 +912,13 @@ def fake_studio(tmp_path, monkeypatch):
         if url.endswith("/api/auth/api-keys"):
             return {"key": "sk-unsloth-feedfacefeedface"}
         if url.endswith("/api/inference/load"):
+            already_loaded = state["models"][0]["id"] == payload["model_path"]
             state["models"] = [{"id": payload["model_path"], "context_length": 4096}]
-            return {}
+            return {
+                "status": "already_loaded" if already_loaded else "loaded",
+                "model": payload["model_path"],
+                "display_name": payload["model_path"],
+            }
         raise AssertionError(f"unexpected request: {method} {url}")
 
     monkeypatch.setattr(start, "find_studio_server", lambda: BASE)
@@ -408,10 +958,90 @@ def test_connect_claude_no_launch(fake_studio):
     _assert_env_set(result.output, "CLAUDE_AUTOCOMPACT_PCT_OVERRIDE", "90")
     assert f"claude --model {MODEL['id']} --exclude-dynamic-system-prompt-sections" in result.output
     # Overlay is passed inline (session-only), not a path into the user's ~/.claude.
-    assert "--settings" in result.output
+    command = _launch_command(result.output)
+    settings = json.loads(command[command.index("--settings") + 1])
+    assert settings["env"]["CLAUDE_CODE_SUBAGENT_MODEL"] == "inherit"
+    assert "--plugin-dir" not in command
     assert ".claude/settings.json" not in result.output
 
 
+def test_connect_claude_as_subagent_preserves_cloud_parent(fake_studio, tmp_path):
+    result = CliRunner().invoke(
+        start.start_app,
+        [
+            "claude",
+            "--as-subagent",
+            "--no-launch",
+            "--model",
+            MODEL["id"] + ":UD-Q4_K_XL",
+            "hello",
+        ],
+    )
+    assert result.exit_code == 0, result.output
+    command = _launch_command(result.output)
+    plugin = tmp_path / "agents" / "claude-subagent" / "unsloth-local-agent"
+    assert command == [
+        "claude",
+        "--plugin-dir",
+        str(plugin),
+        "--allowedTools",
+        f"{start._CLAUDE_SUBAGENT_TOOL},{start._CLAUDE_SUBAGENT_PLAN_TOOL}",
+        "hello",
+    ]
+    assert "--model" not in command
+    parent_base = "$env:ANTHROPIC_BASE_URL" if os.name == "nt" else "export ANTHROPIC_BASE_URL="
+    parent_token = (
+        "$env:ANTHROPIC_AUTH_TOKEN" if os.name == "nt" else "export ANTHROPIC_AUTH_TOKEN="
+    )
+    assert parent_base not in result.output
+    assert parent_token not in result.output
+    assert "unset ANTHROPIC_API_KEY" not in result.output
+    assert "UNSLOTH_CLAUDE_SUBAGENT_API_KEY" not in result.output
+    assert "sk-unsloth-feedfacefeedface" not in result.output
+    assert json.loads((plugin / ".claude-plugin" / "plugin.json").read_text())["name"] == (
+        "unsloth-local-agent"
+    )
+    mcp = json.loads((plugin / ".mcp.json").read_text())["mcpServers"]["unsloth"]
+    assert mcp["command"] == sys.executable
+    assert mcp["args"] == ["-m", start._CLAUDE_SUBAGENT_MCP_MODULE]
+    assert mcp["env"] == {
+        "UNSLOTH_CLAUDE_SUBAGENT_BASE_URL": BASE,
+        "UNSLOTH_CLAUDE_SUBAGENT_API_KEY": "sk-unsloth-feedfacefeedface",
+        "UNSLOTH_CLAUDE_SUBAGENT_MODEL": MODEL["id"] + ":UD-Q4_K_XL",
+        "UNSLOTH_CLAUDE_SUBAGENT_BYPASS_PERMISSIONS": "0",
+        "UNSLOTH_CLAUDE_SUBAGENT_CONTEXT_WINDOW": "4096",
+    }
+    skill = (plugin / "skills" / "local-agent" / "SKILL.md").read_text()
+    assert "spawn an Unsloth agent or local agent" in skill
+    assert "In plan mode" in skill
+    assert "Ask Claude to spawn an Unsloth or local agent." in result.output
+
+
+@pytest.mark.skipif(os.name == "nt", reason = "WSL scenario")
+def test_claude_subagent_plugin_uses_wsl_for_windows_claude(monkeypatch, tmp_path):
+    monkeypatch.setenv("WSL_DISTRO_NAME", "Ubuntu")
+    monkeypatch.setenv("WSLENV", "EXISTING")
+    monkeypatch.setattr(
+        start.shutil,
+        "which",
+        lambda _: "/mnt/c/Users/x/AppData/Local/Programs/claude.exe",
+    )
+    server_env = {"UNSLOTH_CLAUDE_SUBAGENT_API_KEY": "secret"}
+    plugin = start.write_claude_subagent_plugin(tmp_path, server_env)
+    mcp = json.loads((plugin / ".mcp.json").read_text())["mcpServers"]["unsloth"]
+    assert mcp["command"] == "wsl.exe"
+    assert mcp["args"] == [
+        "-d",
+        "Ubuntu",
+        "--",
+        sys.executable,
+        "-m",
+        start._CLAUDE_SUBAGENT_MCP_MODULE,
+    ]
+    assert mcp["env"]["UNSLOTH_CLAUDE_SUBAGENT_API_KEY"] == "secret"
+    assert mcp["env"]["WSLENV"].split(":") == ["EXISTING", "UNSLOTH_CLAUDE_SUBAGENT_API_KEY"]
+
+
 def test_connect_claude_compact_window_omitted_without_context(fake_studio, monkeypatch):
     # A model that doesn't report a context length -> leave Claude's default window
     # rather than guessing one.
@@ -422,12 +1052,33 @@ def test_connect_claude_compact_window_omitted_without_context(fake_studio, monk
     assert "CLAUDE_AUTOCOMPACT_PCT_OVERRIDE" not in result.output
 
 
+def test_launch_native_posix_child_gets_current_pwd(fake_studio, monkeypatch, tmp_path):
+    captured = {}
+    monkeypatch.chdir(tmp_path)
+    monkeypatch.setenv("PWD", "/stale/outer/repo")
+    monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/opencode")
+
+    def run(command, env):
+        captured["command"] = command
+        captured["env"] = env
+        return SimpleNamespace(returncode = 0)
+
+    monkeypatch.setattr(start.subprocess, "run", run)
+
+    result = CliRunner().invoke(start.start_app, ["opencode"])
+
+    assert result.exit_code == 0, result.output
+    assert captured["command"][0] == "/usr/local/bin/opencode"
+    if os.name != "nt":
+        assert captured["env"]["PWD"] == os.getcwd()
+
+
 def test_connect_claude_launch_scrubs_conflicting_auth_env(fake_studio, monkeypatch):
     captured = {}
     monkeypatch.setenv("ANTHROPIC_API_KEY", "sk-anthropic-stale")
     monkeypatch.setenv("CLAUDE_CODE_OAUTH_TOKEN", "oauth-stale")
     monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/claude")
-    monkeypatch.setattr(start, "_claude_flags", lambda: [])
+    monkeypatch.setattr(start, "_claude_flags", lambda *a, **k: [])
 
     def run(command, env):
         captured["command"] = command
@@ -452,15 +1103,17 @@ def test_connect_claude_launch_scrubs_conflicting_auth_env(fake_studio, monkeypa
     reason = "WSL-from-Linux scenario (calling a Windows agent .exe from inside WSL); "
     "os.name is 'posix' under WSL, so this path can't run on a native Windows runner.",
 )
-def test_connect_claude_windows_shim_from_wsl_bridges_env(fake_studio, monkeypatch):
+def test_connect_claude_windows_shim_from_wsl_bridges_env(fake_studio, monkeypatch, tmp_path):
     captured = {}
+    monkeypatch.chdir(tmp_path)
+    monkeypatch.setenv("PWD", "/stale/outer/repo")
     monkeypatch.setenv("WSL_DISTRO_NAME", "Ubuntu")
     monkeypatch.setenv("ANTHROPIC_API_KEY", "sk-anthropic-stale")
     monkeypatch.setenv("CLAUDE_CODE_OAUTH_TOKEN", "oauth-stale")
     monkeypatch.setattr(
         start.shutil, "which", lambda _: "/mnt/c/Users/samle/AppData/Roaming/npm/claude"
     )
-    monkeypatch.setattr(start, "_claude_flags", lambda: [])
+    monkeypatch.setattr(start, "_claude_flags", lambda *a, **k: [])
 
     def run(command, env):
         captured["command"] = command
@@ -481,6 +1134,8 @@ def test_connect_claude_windows_shim_from_wsl_bridges_env(fake_studio, monkeypat
     assert captured["env"]["ANTHROPIC_AUTH_TOKEN"] == "sk-unsloth-feedfacefeedface"
     assert captured["env"]["ANTHROPIC_BASE_URL"] == BASE
     assert captured["env"]["ANTHROPIC_MODEL"] == MODEL["id"]
+    assert captured["env"]["PWD"] == str(tmp_path)
+    assert "PWD/p" in captured["env"]["WSLENV"].split(":")
     for name in (
         "ANTHROPIC_AUTH_TOKEN",
         "ANTHROPIC_BASE_URL",
@@ -496,7 +1151,11 @@ def test_connect_claude_windows_shim_from_wsl_bridges_env(fake_studio, monkeypat
     reason = "WSL-from-Linux scenario (calling a Windows agent .exe from inside WSL); "
     "os.name is 'posix' under WSL, so this path can't run on a native Windows runner.",
 )
-def test_connect_claude_no_launch_windows_shim_from_wsl_prints_wslenv(fake_studio, monkeypatch):
+def test_connect_claude_no_launch_windows_shim_from_wsl_prints_wslenv(
+    fake_studio, monkeypatch, tmp_path
+):
+    monkeypatch.chdir(tmp_path)
+    monkeypatch.setenv("PWD", "/stale/outer/repo")
     monkeypatch.setenv("WSL_DISTRO_NAME", "Ubuntu")
     monkeypatch.setattr(
         start.shutil, "which", lambda _: "/mnt/c/Users/samle/AppData/Roaming/npm/claude"
@@ -508,6 +1167,10 @@ def test_connect_claude_no_launch_windows_shim_from_wsl_prints_wslenv(fake_studi
     assert "export ANTHROPIC_API_KEY=" in result.output
     assert "export CLAUDE_CODE_OAUTH_TOKEN=" in result.output
     assert "export WSLENV=" in result.output
+    # PWD must NOT be frozen into the recipe (no `export PWD=`): WSLENV PWD/p translates the
+    # shell's live PWD at run time, so a recipe reused from another dir resolves the project root.
+    assert "export PWD=" not in result.output
+    assert "PWD/p" in result.output
     assert "ANTHROPIC_AUTH_TOKEN" in result.output
     assert "CLAUDE_CODE_OAUTH_TOKEN" in result.output
 
@@ -524,6 +1187,57 @@ def test_connect_codex_no_launch(fake_studio, tmp_path):
     assert (home / "unsloth_api.config.toml").exists()
 
 
+def test_connect_codex_as_subagent_preserves_cloud_parent(fake_studio, tmp_path, monkeypatch):
+    monkeypatch.setattr(start, "_codex_supports_model_catalog", lambda: True)
+    source_home = tmp_path / "user-codex"
+    source_home.mkdir()
+    (source_home / "config.toml").write_text('model = "cloud-model"\n')
+    (source_home / "AGENTS.md").write_text("Keep the user's guidance.\n")
+    monkeypatch.setenv("CODEX_HOME", str(source_home))
+    result = CliRunner().invoke(
+        start.start_app,
+        [
+            "codex",
+            "--as-subagent",
+            "--no-launch",
+            "--model",
+            MODEL["id"] + ":UD-Q4_K_XL",
+        ],
+    )
+    assert result.exit_code == 0, result.output
+    command = _launch_command(result.output)
+    assert command[0] == "codex"
+    assert "--oss" not in command
+    assert "--profile" not in command
+    assert "--model" not in command
+    parent_home = tmp_path / "agents" / "codex-subagent" / "parent"
+    _assert_env_set(result.output, "CODEX_HOME", str(parent_home))
+    assert start._CODEX_ENV_KEY not in result.output
+    assert "sk-unsloth-feedfacefeedface" not in result.output
+    home = tmp_path / "agents" / "codex-subagent"
+    bridge_path = home / "subagent.json"
+    bridge = json.loads(bridge_path.read_text())
+    assert bridge["api_key"] == "sk-unsloth-feedfacefeedface"
+    assert bridge["codex_home"] == str(home / "child")
+    assert bridge["bypass_permissions"] is False
+    profile = _parse_toml((home / "child" / "unsloth_api.config.toml").read_text())
+    assert profile["model"] == MODEL["id"] + ":UD-Q4_K_XL"
+    prefix = f"mcp_servers.{start._CODEX_SUBAGENT_MCP_SERVER}="
+    override = next(value for value in command if value.startswith(prefix))
+    assert override.startswith(prefix)
+    server = _parse_toml("server = " + override.removeprefix(prefix))["server"]
+    assert server["command"] == sys.executable
+    assert server["args"] == ["-c", server["args"][1], str(bridge_path)]
+    assert "sys.path.insert" in server["args"][1]
+    assert f"from {start._CODEX_SUBAGENT_MCP_MODULE} import main" in server["args"][1]
+    assert server["enabled_tools"] == [start._CODEX_SUBAGENT_MCP_TOOL]
+    assert not any(value.startswith("developer_instructions=") for value in command)
+    parent_instructions = (parent_home / "AGENTS.md").read_text()
+    assert parent_instructions.startswith("Keep the user's guidance.\n")
+    assert start._CODEX_SUBAGENT_ROUTING_INSTRUCTIONS in parent_instructions
+    assert "Ask Codex to spawn an Unsloth or local agent." in result.output
+
+
 def test_connect_codex_matches_requested_model_case_insensitively(fake_studio, tmp_path):
     result = CliRunner().invoke(
         start.start_app,
@@ -540,7 +1254,7 @@ def test_connect_codex_matches_requested_model_case_insensitively(fake_studio, t
     assert profile["model"] == MODEL["id"]
 
 
-def test_resolve_model_matches_loaded_canonical_case_after_load(monkeypatch):
+def test_resolve_model_matches_loaded_canonical_case_after_load(monkeypatch, capsys):
     calls = []
     state = {"loaded": False}
 
@@ -578,6 +1292,8 @@ def test_resolve_model_matches_loaded_canonical_case_after_load(monkeypatch):
 
     assert entry["id"] == "unsloth/gemma-4-E2B-it-GGUF"
     assert any(c[1].endswith("/api/inference/load") for c in calls)
+    output = capsys.readouterr().out
+    assert "please wait" not in output
 
 
 def test_resolve_model_loads_when_catalog_hit_is_not_loaded(monkeypatch):
@@ -619,6 +1335,35 @@ def test_resolve_model_loads_when_catalog_hit_is_not_loaded(monkeypatch):
     assert any(u.endswith("/api/inference/load") for _, u in calls)
 
 
+def test_resolve_model_does_not_attach_if_catalog_stays_unloaded(monkeypatch):
+    def http_json(
+        method,
+        url,
+        token,
+        payload = None,
+        timeout = 30,
+        error = None,
+    ):
+        if url.endswith("/v1/models"):
+            return {
+                "data": [
+                    {
+                        "id": "unsloth/Gemma-4-GGUF",
+                        "loaded": False,
+                        "context_length": 131072,
+                    }
+                ]
+            }
+        if url.endswith("/api/inference/load"):
+            return {"status": "loaded", "model": "unsloth/Gemma-4-GGUF"}
+        raise AssertionError(f"unexpected request: {method} {url}")
+
+    monkeypatch.setattr(start, "_http_json", http_json)
+
+    with pytest.raises(typer.Exit):
+        start._resolve_model(BASE, "sk-test", "unsloth/gemma-4-gguf")
+
+
 def test_resolve_model_attaches_to_loaded_catalog_hit_without_reload(monkeypatch):
     # The mirror case: a loaded entry (loaded == True) that case-matches attaches with
     # no /api/inference/load call.
@@ -647,8 +1392,27 @@ def test_resolve_model_attaches_to_loaded_catalog_hit_without_reload(monkeypatch
     assert not any(u.endswith("/api/inference/load") for _, u in calls)
 
 
+def test_resolve_model_without_request_rejects_unloaded_catalog(monkeypatch):
+    monkeypatch.setattr(
+        start,
+        "_http_json",
+        lambda *a, **k: {
+            "data": [
+                {
+                    "id": "unsloth/Gemma-4-GGUF",
+                    "loaded": False,
+                    "context_length": 131072,
+                }
+            ]
+        },
+    )
+
+    with pytest.raises(typer.Exit):
+        start._resolve_model(BASE, "sk-test", None)
+
+
 def test_resolve_model_remote_studio_does_not_casefold_attach(monkeypatch):
-    # Against a remote Studio the local existence probe cannot see server-side paths,
+    # Against a remote Unsloth the local existence probe cannot see server-side paths,
     # so a case-variant loaded id must NOT attach without a load: it could be a distinct
     # server-side path on a case-sensitive host. The load endpoint resolves the request.
     calls = []
@@ -738,7 +1502,7 @@ def test_no_launch_output_is_parseable(fake_studio):
     result = CliRunner().invoke(start.start_app, ["codex", "--no-launch"])
     assert result.exit_code == 0, result.output
     lines = [ln for ln in result.output.splitlines() if ln.strip()]
-    skip = ("export ", "unset ", "Studio ", "Updated ", "Disabled ", "Warning", "Loading")
+    skip = ("export ", "unset ", "Unsloth ", "Updated ", "Disabled ", "Warning", "Loading")
     body = [ln for ln in lines if not ln.startswith(skip)]
     assert "codex --oss --profile unsloth_api" in body[-1]
     assert any(ln.startswith("export CODEX_HOME=") for ln in lines)
@@ -767,7 +1531,7 @@ def test_no_launch_last_line_is_self_contained(fake_studio, tmp_path):
 
 def test_no_launch_claude_last_line_blanks_conflicting_auth(fake_studio):
     # The unset vars must be neutralized inline too, or a partial copy would send the
-    # user's own ANTHROPIC_API_KEY to the Studio base.
+    # user's own ANTHROPIC_API_KEY to the Unsloth base.
     result = CliRunner().invoke(start.start_app, ["claude", "--no-launch"])
     assert result.exit_code == 0, result.output
     last = [ln for ln in result.output.splitlines() if ln.strip()][-1]
@@ -814,7 +1578,7 @@ def test_https_loopback_never_auto_serves(fake_studio, monkeypatch):
     )
     result = CliRunner().invoke(start.start_app, ["claude", "--model", "unsloth/Qwen3-1.7B-GGUF"])
     assert result.exit_code == 1
-    assert "No running Studio server" in result.output
+    assert "No running Unsloth server" in result.output
     assert started["called"] is False
 
 
@@ -929,6 +1693,9 @@ def test_connect_model_flag_loads_on_server(fake_studio):
     assert loads == [
         ("POST", f"{BASE}/api/inference/load", {"model_path": "unsloth/Qwen3.5-35B-A3B"})
     ]
+    assert result.output.index(
+        f"Switching the Unsloth server from {MODEL['id']} to unsloth/Qwen3.5-35B-A3B.\n"
+    ) < result.output.index("This unloads the current model for every attached session.\n")
     _assert_env_set(result.output, "ANTHROPIC_MODEL", "unsloth/Qwen3.5-35B-A3B")
 
 
@@ -967,7 +1734,7 @@ def test_connect_model_flag_forwards_load_options(fake_studio):
 
 
 def test_connect_model_flag_matches_canonical_id(fake_studio, monkeypatch):
-    # Studio registers a loaded model under a canonical id (resolved identifier
+    # Unsloth registers a loaded model under a canonical id (resolved identifier
     # / casing) that can differ from the path we passed. The agent must connect
     # to that model, not silently fall through to the first loaded one.
     requested = "Unsloth/Qwen3.5-35B-A3B"
@@ -1012,6 +1779,323 @@ def test_split_repo_variant(model, expected):
     assert start._split_repo_variant(model) == expected
 
 
+@pytest.mark.parametrize(
+    "token, expected",
+    [
+        ("unsloth/gemma-4-E2B-it-GGUF", True),
+        ("unsloth/gemma-4-E2B-it-GGUF:UD-Q4_K_XL", True),
+        ("some-org/model.name_1", True),
+        ("--continue", False),  # flag
+        ("resume", False),  # single word, no slash
+        ("/models/local.gguf", False),  # absolute path
+        ("./rel.gguf", False),  # relative path
+        ("C:\\models\\x.gguf", False),  # Windows drive
+        ("my models/foo", False),  # has a space
+        ("owner/repo/extra", False),  # too many segments
+    ],
+)
+def test_looks_like_model(token, expected):
+    assert start._looks_like_model(token) is expected
+
+
+def test_consume_positional_model_leading_token():
+    # A leading org/name positional routes to --model and is dropped from the passthrough.
+    model, rest = start._consume_positional_model(None, ["unsloth/Model-GGUF", "--continue"])
+    assert model == "unsloth/Model-GGUF"
+    assert rest == ["--continue"]
+
+
+def test_looks_like_model_leaves_existing_local_dir_for_agent(tmp_path, monkeypatch):
+    # A relative `owner/repo` that actually exists (e.g. an OpenCode project dir) must
+    # stay an agent argument, not be consumed as a model.
+    monkeypatch.chdir(tmp_path)
+    (tmp_path / "owner" / "repo").mkdir(parents = True)
+    assert start._looks_like_model("owner/repo") is False
+    model, rest = start._consume_positional_model(None, ["owner/repo"])
+    assert model is None and rest == ["owner/repo"]
+    # The same shape, when it does not exist locally, is still treated as a model.
+    assert start._looks_like_model("owner/absent-repo") is True
+
+
+def test_consume_positional_model_ignores_non_leading_and_explicit_model():
+    # An org/name that is an option value (not leading) is never stolen.
+    model, rest = start._consume_positional_model(None, ["--profile", "owner/repo"])
+    assert model is None and rest == ["--profile", "owner/repo"]
+    # An explicit --model always wins; the positional is left untouched.
+    model, rest = start._consume_positional_model("explicit/model", ["owner/repo"])
+    assert model == "explicit/model" and rest == ["owner/repo"]
+
+
+def test_start_separator_preserves_model_shaped_agent_argument(fake_studio):
+    result = CliRunner().invoke(
+        start.start_app,
+        ["codex", "--no-launch", "--", "owner/repo"],
+    )
+
+    assert result.exit_code == 0, result.output
+    command = _launch_command(result.output)
+    assert command[-2:] == ["--", "owner/repo"]
+
+    result = CliRunner().invoke(
+        start.start_app,
+        ["codex", "--no-launch", MODEL["id"], "--", "--continue"],
+    )
+    assert result.exit_code == 0, result.output
+    command = _launch_command(result.output)
+    assert command[-2:] == ["--", "--continue"]
+
+
+def test_start_positional_model_routes_to_model_on_auto_serve(fake_studio, monkeypatch):
+    # `unsloth start claude unsloth/Model-GGUF` (no --model): the positional becomes the
+    # model; the GGUF variant is left unset so the server's own quant preference selects it.
+    monkeypatch.setenv("UNSLOTH_STUDIO_URL", "http://127.0.0.1:8888")
+    monkeypatch.setattr(start, "find_studio_server", lambda: None)
+    captured = {}
+    fake = SimpleNamespace(pid = 1, poll = lambda: None)
+
+    def fake_start(
+        base,
+        model,
+        load,
+        server_options = None,
+    ):
+        captured["model"] = model
+        captured["load"] = load
+        captured["server_options"] = server_options
+        start._auto_served_server = fake
+        return fake
+
+    monkeypatch.setattr(start, "_start_studio_server", fake_start)
+    monkeypatch.setattr(start, "_shutdown_server", lambda server: None)
+    monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/claude")
+    monkeypatch.setattr(start.subprocess, "run", lambda command, env: SimpleNamespace(returncode = 0))
+
+    result = CliRunner().invoke(start.start_app, ["claude", "unsloth/gemma-4-E2B-it-GGUF"])
+    assert result.exit_code == 0, result.output
+    assert captured["model"] == "unsloth/gemma-4-E2B-it-GGUF"
+    assert captured["load"].gguf_variant is None
+
+
+def test_start_local_gguf_path_keeps_no_default_variant(fake_studio, monkeypatch, tmp_path):
+    # A local GGUF dir/path ending in -GGUF must NOT get a forced default quant: the dir
+    # may only hold a different quant, and pre-PR the server picked whatever was available.
+    monkeypatch.setenv("UNSLOTH_STUDIO_URL", "http://127.0.0.1:8888")
+    monkeypatch.setattr(start, "find_studio_server", lambda: None)
+    local = tmp_path / "Qwen3-1.7B-GGUF"
+    local.mkdir()
+    captured = {}
+    fake = SimpleNamespace(pid = 1, poll = lambda: None)
+
+    def fake_start(
+        base,
+        model,
+        load,
+        server_options = None,
+    ):
+        captured["load"] = load
+        start._auto_served_server = fake
+        return fake
+
+    monkeypatch.setattr(start, "_start_studio_server", fake_start)
+    monkeypatch.setattr(start, "_shutdown_server", lambda server: None)
+    monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/claude")
+    monkeypatch.setattr(start.subprocess, "run", lambda command, env: SimpleNamespace(returncode = 0))
+
+    result = CliRunner().invoke(start.start_app, ["claude", "--model", str(local)])
+    assert result.exit_code == 0, result.output
+    assert captured["load"].gguf_variant is None
+
+
+def test_start_studio_server_forwards_tool_flags_via_command_and_env(monkeypatch):
+    captured = {}
+
+    class FakePopen:
+        def __init__(self, command, **kwargs):
+            captured["command"] = command
+            captured["kwargs"] = kwargs
+            self.pid = 1
+
+        def poll(self):
+            return None
+
+    monkeypatch.setattr(start.subprocess, "Popen", FakePopen)
+    monkeypatch.setattr(start, "_studio_healthy", lambda base, timeout = 3.0: True)
+    monkeypatch.setattr(start, "_log_tail", lambda path, lines = 20: "API Key: sk-unsloth-x")
+    monkeypatch.setattr(start.time, "sleep", lambda _s: None)
+    # No inherited kill switches, so the omitted-flag default applies.
+    monkeypatch.delenv("UNSLOTH_DISABLE_TOOL_CALL_HEALING", raising = False)
+    monkeypatch.delenv("UNSLOTH_TOOL_CALL_NUDGE", raising = False)
+
+    # Default start: tools off (passthrough), healing + nudging on.
+    start._start_studio_server("http://127.0.0.1:8888", "unsloth/M-GGUF", start.LoadOptions())
+    cmd, env = captured["command"], captured["kwargs"]["env"]
+    assert "--disable-tools" in cmd and "--enable-tools" not in cmd
+    assert env["UNSLOTH_DISABLE_TOOL_CALL_HEALING"] == "0"
+    assert env["UNSLOTH_TOOL_CALL_NUDGE"] == "1"
+
+    # Flipped: tools on, healing off, nudging off.
+    start._start_studio_server(
+        "http://127.0.0.1:8888",
+        "unsloth/M-GGUF",
+        start.LoadOptions(),
+        start.ServerOptions(enable_tools = True, tool_call_healing = False, tool_call_nudging = False),
+    )
+    cmd, env = captured["command"], captured["kwargs"]["env"]
+    assert "--enable-tools" in cmd and "--disable-tools" not in cmd
+    assert env["UNSLOTH_DISABLE_TOOL_CALL_HEALING"] == "1"
+    assert env["UNSLOTH_TOOL_CALL_NUDGE"] == "0"
+
+
+def test_start_studio_server_respects_inherited_tool_call_env(monkeypatch):
+    # With the flags omitted, an operator's pre-exported kill switch must survive into the
+    # child server instead of being overwritten with the start defaults.
+    captured = {}
+
+    class FakePopen:
+        def __init__(self, command, **kwargs):
+            captured["kwargs"] = kwargs
+            self.pid = 1
+
+        def poll(self):
+            return None
+
+    monkeypatch.setattr(start.subprocess, "Popen", FakePopen)
+    monkeypatch.setattr(start, "_studio_healthy", lambda base, timeout = 3.0: True)
+    monkeypatch.setattr(start, "_log_tail", lambda path, lines = 20: "API Key: sk-unsloth-x")
+    monkeypatch.setattr(start.time, "sleep", lambda _s: None)
+    monkeypatch.setenv("UNSLOTH_DISABLE_TOOL_CALL_HEALING", "1")
+    monkeypatch.setenv("UNSLOTH_TOOL_CALL_NUDGE", "0")
+
+    # Flags omitted -> inherited values are preserved.
+    start._start_studio_server("http://127.0.0.1:8888", "unsloth/M-GGUF", start.LoadOptions())
+    env = captured["kwargs"]["env"]
+    assert env["UNSLOTH_DISABLE_TOOL_CALL_HEALING"] == "1"
+    assert env["UNSLOTH_TOOL_CALL_NUDGE"] == "0"
+
+    # An explicit flag still overrides the inherited env.
+    start._start_studio_server(
+        "http://127.0.0.1:8888",
+        "unsloth/M-GGUF",
+        start.LoadOptions(),
+        start.ServerOptions(tool_call_healing = True, tool_call_nudging = True),
+    )
+    env = captured["kwargs"]["env"]
+    assert env["UNSLOTH_DISABLE_TOOL_CALL_HEALING"] == "0"
+    assert env["UNSLOTH_TOOL_CALL_NUDGE"] == "1"
+
+
+def test_start_studio_server_forwards_sampling_via_env(monkeypatch):
+    # Sampling pins ride to the child server through UNSLOTH_SAMPLING_*; unset ones stay absent
+    # so the backend keeps the per-model recommendation.
+    captured = {}
+
+    class FakePopen:
+        def __init__(self, command, **kwargs):
+            captured["kwargs"] = kwargs
+            self.pid = 1
+
+        def poll(self):
+            return None
+
+    monkeypatch.setattr(start.subprocess, "Popen", FakePopen)
+    monkeypatch.setattr(start, "_studio_healthy", lambda base, timeout = 3.0: True)
+    monkeypatch.setattr(start, "_log_tail", lambda path, lines = 20: "API Key: sk-unsloth-x")
+    monkeypatch.setattr(start.time, "sleep", lambda _s: None)
+    for _v in ("TEMPERATURE", "TOP_P", "TOP_K", "MIN_P", "REPETITION_PENALTY", "PRESENCE_PENALTY"):
+        monkeypatch.delenv(f"UNSLOTH_SAMPLING_{_v}", raising = False)
+
+    # No sampling flags -> nothing forwarded.
+    start._start_studio_server("http://127.0.0.1:8888", "unsloth/M-GGUF", start.LoadOptions())
+    env = captured["kwargs"]["env"]
+    assert not any(k.startswith("UNSLOTH_SAMPLING_") for k in env)
+
+    # Pins are forwarded; unset ones stay absent.
+    start._start_studio_server(
+        "http://127.0.0.1:8888",
+        "unsloth/M-GGUF",
+        start.LoadOptions(),
+        start.ServerOptions(temperature = 0.3, top_k = 40, min_p = 0.05),
+    )
+    env = captured["kwargs"]["env"]
+    assert env["UNSLOTH_SAMPLING_TEMPERATURE"] == "0.3"
+    assert env["UNSLOTH_SAMPLING_TOP_K"] == "40"
+    assert env["UNSLOTH_SAMPLING_MIN_P"] == "0.05"
+    assert "UNSLOTH_SAMPLING_TOP_P" not in env
+
+
+def test_require_studio_warns_on_sampling_pin_when_reusing_server(monkeypatch, capsys):
+    # Attaching to an already-running server can't apply UNSLOTH_SAMPLING_* pins (only
+    # _start_studio_server forwards them), so a sampling flag on the attach path must warn
+    # instead of being silently dropped while the command "succeeds".
+    monkeypatch.setattr(start, "find_studio_server", lambda: BASE)
+    base, server = start._require_studio(
+        "unsloth/M-GGUF",
+        start.LoadOptions(),
+        serve = True,
+        launch = True,
+        server_options = start.ServerOptions(temperature = 0.3, top_k = 40),
+    )
+    assert base == BASE
+    assert server is None  # attach path: we did not start the server
+    err = capsys.readouterr().err
+    assert "already running" in err
+    assert "--temperature" in err and "--top-k" in err
+    # Only the pinned fields are named; an unset one is not.
+    assert "--top-p" not in err
+
+
+def test_require_studio_no_sampling_warning_without_pins(monkeypatch, capsys):
+    # Reusing a server with no sampling pins stays silent (tool flags are out of scope here).
+    monkeypatch.setattr(start, "find_studio_server", lambda: BASE)
+    base, server = start._require_studio(
+        "unsloth/M-GGUF",
+        start.LoadOptions(),
+        serve = True,
+        server_options = start.ServerOptions(enable_tools = True),
+    )
+    assert base == BASE and server is None
+    assert "sampling" not in capsys.readouterr().err.lower()
+
+
+def test_start_claude_parses_sampling_flags(fake_studio, monkeypatch):
+    # `unsloth start claude ... --temperature 0.3 --top-k 40` routes the pins into ServerOptions.
+    monkeypatch.setenv("UNSLOTH_STUDIO_URL", "http://127.0.0.1:8888")
+    monkeypatch.setattr(start, "find_studio_server", lambda: None)
+    captured = {}
+    fake = SimpleNamespace(pid = 1, poll = lambda: None)
+
+    def fake_start(
+        base,
+        model,
+        load,
+        server_options = None,
+    ):
+        captured["server_options"] = server_options
+        start._auto_served_server = fake
+        return fake
+
+    monkeypatch.setattr(start, "_start_studio_server", fake_start)
+    monkeypatch.setattr(start, "_shutdown_server", lambda server: None)
+    monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/claude")
+    monkeypatch.setattr(start.subprocess, "run", lambda command, env: SimpleNamespace(returncode = 0))
+
+    result = CliRunner().invoke(
+        start.start_app,
+        [
+            "claude",
+            "--model",
+            "unsloth/gemma-4-E2B-it-GGUF",
+            "--temperature",
+            "0.3",
+            "--top-k",
+            "40",
+        ],
+    )
+    assert result.exit_code == 0, result.output
+    so = captured["server_options"]
+    assert so.temperature == 0.3 and so.top_k == 40 and so.top_p is None
+
+
 def test_connect_model_bare_id_matches_loaded_without_reload(fake_studio):
     # A bare `--model <loaded repo>` (no load knobs) attaches to the already-loaded model
     # without touching /api/inference/load, so it can never evict another session.
@@ -1019,12 +2103,13 @@ def test_connect_model_bare_id_matches_loaded_without_reload(fake_studio):
     assert result.exit_code == 0, result.output
     loads = [c for c in fake_studio if c[1].endswith("/api/inference/load")]
     assert loads == []
+    assert f"Reusing loaded model: {MODEL['id']}\n" in result.output
     _assert_env_set(result.output, "ANTHROPIC_MODEL", MODEL["id"])
 
 
 def test_connect_model_variant_suffix_defers_to_server_dedup(fake_studio):
     # `--model repo:QUANT` splits into a VALID load payload (bare repo + gguf_variant),
-    # never the `:`-suffixed repo id Studio rejects. The variant knob defers to
+    # never the `:`-suffixed repo id Unsloth rejects. The variant knob defers to
     # /api/inference/load, whose already-loaded dedup answers without reloading when the
     # active variant+settings match -- so a second session running the same command
     # attaches without evicting the first, while a genuinely different quant reloads.
@@ -1040,6 +2125,7 @@ def test_connect_model_variant_suffix_defers_to_server_dedup(fake_studio):
             {"model_path": MODEL["id"], "gguf_variant": "UD-Q4_K_XL"},
         )
     ]
+    assert f"Reusing loaded model: {MODEL['id']}:UD-Q4_K_XL\n" in result.output
     _assert_env_set(result.output, "ANTHROPIC_MODEL", MODEL["id"])
 
 
@@ -1116,7 +2202,7 @@ def test_connect_no_model_loaded_errors(fake_studio, monkeypatch):
 
 
 def test_connect_requested_model_not_loaded_fails(fake_studio, monkeypatch):
-    # Studio never surfaces the requested model; fail loudly rather than
+    # Unsloth never surfaces the requested model; fail loudly rather than
     # silently connecting to whatever else happens to be loaded.
     inner = start._http_json
 
@@ -1187,7 +2273,7 @@ def test_connect_nonloopback_explicit_key_is_allowed(fake_studio, monkeypatch):
 
 
 def test_connect_nonloopback_replays_saved_key(fake_studio, tmp_path, monkeypatch):
-    # A key saved for a remote (non-loopback) Studio is replayed on keyless runs;
+    # A key saved for a remote (non-loopback) Unsloth is replayed on keyless runs;
     # auto-minting stays blocked for non-loopback.
     remote = "http://studio.example:8888"
     monkeypatch.setattr(start, "find_studio_server", lambda: remote)
@@ -1201,7 +2287,7 @@ def test_connect_nonloopback_replays_saved_key(fake_studio, tmp_path, monkeypatc
 
 
 def test_connect_studio_server_errors_on_explicit_remote(monkeypatch):
-    # A user who pointed UNSLOTH_STUDIO_URL at a remote Studio should get an
+    # A user who pointed UNSLOTH_STUDIO_URL at a remote Unsloth should get an
     # error, not a silent local model load (which they did not ask for).
     import typer
 
@@ -1242,7 +2328,7 @@ def test_connect_unverified_loopback_without_cached_key_refuses_to_mint(
 
 
 def test_connect_replays_saved_key_without_identity_check(fake_studio, tmp_path, monkeypatch):
-    # A "saved" key (e.g. for an SSH-tunnelled Studio the handshake can't match)
+    # A "saved" key (e.g. for an SSH-tunnelled Unsloth the handshake can't match)
     # replays on keyless runs without the handshake, scoped to its own base.
     cache = tmp_path / "agent_api_key.json"
     cache.write_text(json.dumps({"servers": {BASE: {"saved": ["sk-unsloth-deadbeefdeadbeef"]}}}))
@@ -1358,7 +2444,7 @@ def _serve_redirect(target):
 
 
 def test_verify_studio_identity_rejects_redirect(tmp_path, monkeypatch):
-    # A squatter could 302 /api/auth/identity to the real Studio and relay its
+    # A squatter could 302 /api/auth/identity to the real Unsloth and relay its
     # proof; redirects must be refused so the squatter's base isn't accepted.
     import unsloth_cli._inference as inference
 
@@ -1384,7 +2470,7 @@ def test_verify_studio_identity_rejects_redirect(tmp_path, monkeypatch):
 
 
 def test_verify_studio_identity_rejects_relayed_proof(tmp_path, monkeypatch):
-    # A squatter that proxies the nonce to the real Studio on another port gets a
+    # A squatter that proxies the nonce to the real Unsloth on another port gets a
     # proof bound to *that* port; the client expects one bound to the port it
     # connected to, so the relayed proof is rejected.
     import unsloth_cli._inference as inference
@@ -1435,7 +2521,7 @@ def test_connect_no_studio_errors(fake_studio, monkeypatch):
     monkeypatch.setattr(start, "find_studio_server", lambda: None)
     result = CliRunner().invoke(start.start_app, ["claude", "--no-launch"])
     assert result.exit_code == 1
-    assert "No running Studio server" in result.output
+    assert "No running Unsloth server" in result.output
 
 
 @pytest.fixture(autouse = True)
@@ -1446,8 +2532,9 @@ def _reset_auto_served():
     start._auto_served_server = None
 
 
-def test_start_studio_server_builds_command_and_waits(monkeypatch):
+def test_start_studio_server_builds_command_and_waits(monkeypatch, capsys):
     captured = {}
+    monkeypatch.setenv(start._START_API_KEY_MARKER_ENV, "parent")
 
     class FakePopen:
         def __init__(self, command, **kwargs):
@@ -1477,18 +2564,210 @@ def test_start_studio_server_builds_command_and_waits(monkeypatch):
     assert cmd[cmd.index("--gguf-variant") + 1] == "UD-Q4_K_XL"
     assert cmd[cmd.index("--context-length") + 1] == "8192"
     assert "--tensor-parallel" in cmd
+    assert "--start-api-key-marker" not in cmd
+    assert captured["kwargs"]["env"][start._START_API_KEY_MARKER_ENV] == "1"
+    assert start.os.environ[start._START_API_KEY_MARKER_ENV] == "parent"
     assert cmd[cmd.index("-p") + 1] == "8888"
     assert start.LoadOptions().load_in_4bit is True and "--no-load-in-4bit" not in cmd
     assert captured["kwargs"].get("start_new_session") is True  # own process group
     assert server.pid == 4321
+    output = capsys.readouterr().out
+    assert "Starting Unsloth server\n" in output
+    assert "Model: unsloth/Qwen3-1.7B-GGUF:UD-Q4_K_XL\n" in output
+    assert "No Unsloth server at" not in output
+    assert "server ready" not in output
 
 
-def test_auto_serves_when_no_server_then_tears_down(fake_studio, monkeypatch):
+def test_start_studio_server_polls_progress_from_early_key(monkeypatch):
+    class FakePopen:
+        pid = 4321
+
+        def poll(self):
+            return None
+
+    tails = iter(
+        [
+            "UNSLOTH_START_API_KEY: sk-unsloth-early\nLoading model...",
+            "UNSLOTH_START_API_KEY: sk-unsloth-early\nModel loaded: owner/model",
+        ]
+    )
+    created = []
+
+    class FakeProgress:
+        def __init__(self, base, key, model, variant):
+            created.append((base, key, model, variant, "created"))
+
+        def poll(self):
+            created.append("poll")
+
+        def close(self):
+            created.append("close")
+
+        def complete(self):
+            created.append("complete")
+
+    monkeypatch.setattr(start.subprocess, "Popen", lambda *a, **k: FakePopen())
+    monkeypatch.setattr(start, "_studio_healthy", lambda *a, **k: True)
+    monkeypatch.setattr(start, "_log_tail", lambda *a, **k: next(tails))
+    monkeypatch.setattr(start, "_ModelDownloadProgress", FakeProgress)
+    monkeypatch.setattr(start.time, "sleep", lambda _s: None)
+    monkeypatch.setattr(
+        start.typer,
+        "echo",
+        lambda message = "", **_kwargs: created.append(("echo", message)),
+    )
+
+    server = start._start_studio_server(
+        BASE,
+        "owner/model-GGUF",
+        start.LoadOptions(gguf_variant = "Q4_K_M"),
+    )
+
+    assert server.pid == 4321
+    assert (BASE, "sk-unsloth-early", "owner/model-GGUF", "Q4_K_M", "created") in created
+    assert created.count("poll") == 2
+    assert created[-2:] == ["complete", "close"]
+    assert not any(isinstance(event, tuple) and "server ready" in event[-1] for event in created)
+
+
+def test_load_model_with_progress_uses_selected_gguf_size(monkeypatch, capsys):
+    release = start.threading.Event()
+    calls = []
+
+    def http_json(
+        method,
+        url,
+        token,
+        payload = None,
+        timeout = 30,
+        error = None,
+    ):
+        calls.append((method, url, payload))
+        if url.endswith("/api/inference/load"):
+            assert release.wait(timeout = 2)
+            return {"model": "owner/model-GGUF"}
+        if "/api/hub/gguf-variants?" in url:
+            return {
+                "default_variant": "Q8_0",
+                "variants": [
+                    {
+                        "quant": "UD-Q4_K_XL",
+                        "filename": "model-UD-Q4_K_XL.gguf",
+                        "size_bytes": 4 * 1024**3,
+                        "download_size_bytes": 4 * 1024**3,
+                    }
+                ],
+            }
+        if "/api/hub/gguf-download-progress?" in url:
+            release.set()
+            return {
+                "downloaded_bytes": 2 * 1024**3,
+                "expected_bytes": 4 * 1024**3,
+                "progress": 0.5,
+            }
+        raise AssertionError(f"unexpected request: {method} {url}")
+
+    monkeypatch.setattr(start, "_http_json", http_json)
+    monkeypatch.setattr(start, "_DOWNLOAD_POLL_INTERVAL_S", 0.001)
+    result = start._load_model_with_progress(
+        BASE,
+        "sk-test",
+        "owner/model-GGUF",
+        start.LoadOptions(gguf_variant = "UD-Q4_K_XL"),
+        {"model_path": "owner/model-GGUF", "gguf_variant": "UD-Q4_K_XL"},
+    )
+
+    assert result == {"model": "owner/model-GGUF"}
+    output = capsys.readouterr().out
+    assert "Downloading model" in output
+    assert "100%" in output
+    progress_url = next(url for method, url, _ in calls if "gguf-download-progress" in url)
+    assert "variant=UD-Q4_K_XL" in progress_url
+    assert f"expected_bytes={4 * 1024**3}" in progress_url
+
+
+def test_download_progress_ignores_fully_cached_bytes(capsys):
+    display = start._DownloadProgressDisplay()
+    display.update(
+        {
+            "downloaded_bytes": 4 * 1024**3,
+            "completed_bytes": 4 * 1024**3,
+            "expected_bytes": 4 * 1024**3,
+            "progress": 0.99,
+        }
+    )
+    display.close()
+
+    assert capsys.readouterr().out == ""
+
+
+def test_resolve_model_warns_on_same_repo_quant_switch(monkeypatch, capsys):
+    models = [{"id": "owner/model-GGUF", "loaded": True}]
+
+    def http_json(
+        method,
+        url,
+        key,
+        payload = None,
+        timeout = 30,
+        error = None,
+    ):
+        assert url.endswith("/api/inference/status"), url
+        return {"is_gguf": True, "gguf_variant": "Q4_K_M"}
+
+    monkeypatch.setattr(start, "_loaded_models", lambda base, key: models)
+    monkeypatch.setattr(start, "_http_json", http_json)
+    monkeypatch.setattr(
+        start,
+        "_load_model_with_progress",
+        lambda base, key, model, load, payload: {"status": "loaded", "model": "owner/model-GGUF"},
+    )
+
+    start._resolve_model(BASE, "key", "owner/model-GGUF", start.LoadOptions(gguf_variant = "Q8_0"))
+
+    out = capsys.readouterr().out
+    assert (
+        "Switching the Unsloth server from owner/model-GGUF:Q4_K_M to owner/model-GGUF:Q8_0." in out
+    )
+    assert "every attached session" in out
+
+
+def test_resolve_model_same_quant_prints_no_switch_warning(monkeypatch, capsys):
+    models = [{"id": "owner/model-GGUF", "loaded": True}]
+
+    monkeypatch.setattr(start, "_loaded_models", lambda base, key: models)
+    monkeypatch.setattr(
+        start,
+        "_http_json",
+        lambda *a, **k: {"is_gguf": True, "gguf_variant": "Q8_0"},
+    )
+    monkeypatch.setattr(
+        start,
+        "_load_model_with_progress",
+        lambda base, key, model, load, payload: {
+            "status": "already_loaded",
+            "model": "owner/model-GGUF",
+        },
+    )
+
+    start._resolve_model(BASE, "key", "owner/model-GGUF", start.LoadOptions(gguf_variant = "Q8_0"))
+
+    out = capsys.readouterr().out
+    assert "Switching" not in out
+    assert "Reusing loaded model: owner/model-GGUF:Q8_0" in out
+
+
+def test_auto_serves_when_no_server_then_keeps_server(fake_studio, monkeypatch):
     monkeypatch.setattr(start, "find_studio_server", lambda: None)
     started = {}
     fake = SimpleNamespace(pid = 999, poll = lambda: None)
 
-    def fake_start(base, model, load):
+    def fake_start(
+        base,
+        model,
+        load,
+        server_options = None,
+    ):
         started.update(base = base, model = model, load = load)
         start._auto_served_server = fake
         return fake
@@ -1509,8 +2788,134 @@ def test_auto_serves_when_no_server_then_tears_down(fake_studio, monkeypatch):
     assert started["model"] == "unsloth/Qwen3-1.7B-GGUF"
     assert started["load"].gguf_variant == "UD-Q4_K_XL"
     assert started["base"] == BASE
-    # Torn down after the agent session ended.
-    assert started.get("down") is fake
+    # A successful agent exit releases ownership and leaves the server available
+    # for another terminal. Explicit startup failures still use the cleanup path.
+    assert "down" not in started
+    assert start._auto_served_server is None
+    assert "is still running" in result.output
+    assert "unsloth studio stop" in result.output
+
+
+def test_auto_served_agent_launch_failure_stops_server(fake_studio, monkeypatch):
+    monkeypatch.setattr(start, "find_studio_server", lambda: None)
+    stopped = []
+    fake = SimpleNamespace(pid = 999, poll = lambda: None)
+
+    def fake_start(*_args):
+        start._auto_served_server = fake
+        return fake
+
+    monkeypatch.setattr(start, "_start_studio_server", fake_start)
+    monkeypatch.setattr(start, "_shutdown_server", stopped.append)
+    monkeypatch.setattr(
+        start,
+        "_launch",
+        lambda *a, **k: (_ for _ in ()).throw(RuntimeError("agent launch failed")),
+    )
+
+    result = CliRunner().invoke(
+        start.start_app,
+        ["claude", "--model", "unsloth/Qwen3-1.7B-GGUF"],
+    )
+
+    assert result.exit_code == 1
+    assert stopped == [fake]
+    assert "is still running" not in result.output
+
+
+def test_auto_served_server_exit_is_not_reported_as_running(fake_studio, monkeypatch):
+    monkeypatch.setattr(start, "find_studio_server", lambda: None)
+    fake = SimpleNamespace(pid = 999, poll = lambda: 1)
+
+    def fake_start(*_args):
+        start._auto_served_server = fake
+        return fake
+
+    monkeypatch.setattr(start, "_start_studio_server", fake_start)
+    monkeypatch.setattr(start, "_launch", lambda *a, **k: 0)
+
+    result = CliRunner().invoke(
+        start.start_app,
+        ["claude", "--model", "unsloth/Qwen3-1.7B-GGUF"],
+    )
+
+    assert result.exit_code == 0, result.output
+    assert "stopped during the session" in result.output
+    assert "is still running" not in result.output
+
+
+def test_attached_server_prints_stop_hint_after_agent_exits(fake_studio, monkeypatch):
+    monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/claude")
+    monkeypatch.setattr(start, "_claude_flags", lambda *a, **k: [])
+    monkeypatch.setattr(
+        start.subprocess,
+        "run",
+        lambda command, env: SimpleNamespace(returncode = 0),
+    )
+
+    result = CliRunner().invoke(start.start_app, ["claude"])
+
+    assert result.exit_code == 0, result.output
+    assert f"Unsloth ready at {BASE} · model {MODEL['id']}\n" in result.output
+    assert f"Unsloth Studio is still running at {BASE}." in result.output
+    assert "Stop it with: unsloth studio stop\n" in result.output
+
+
+def test_no_launch_recipe_does_not_print_stop_hint(fake_studio):
+    result = CliRunner().invoke(start.start_app, ["claude", "--no-launch"])
+    assert result.exit_code == 0, result.output
+    assert "is still running" not in result.output
+
+
+def test_nonzero_agent_exit_notes_code_before_stop_hint(fake_studio, monkeypatch):
+    monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/claude")
+    monkeypatch.setattr(start, "_claude_flags", lambda *a, **k: [])
+    monkeypatch.setattr(
+        start.subprocess,
+        "run",
+        lambda command, env: SimpleNamespace(returncode = 3),
+    )
+
+    result = CliRunner().invoke(start.start_app, ["claude"])
+
+    assert result.exit_code == 3
+    assert "The agent exited with code 3." in result.output
+    assert f"Unsloth Studio is still running at {BASE}." in result.output
+
+
+def test_redacted_log_tail_strips_minted_keys(tmp_path):
+    log = tmp_path / "server.log"
+    log.write_text(
+        "booting\nUNSLOTH_START_API_KEY: sk-unsloth-feedfacefeedface\nerror: load failed\n",
+        encoding = "utf-8",
+    )
+
+    tail = start._redacted_log_tail(log)
+
+    assert "sk-unsloth-feedfacefeedface" not in tail
+    assert "sk-unsloth-[redacted]" in tail
+    assert "error: load failed" in tail
+
+
+def test_startup_failure_output_redacts_minted_key(monkeypatch, tmp_path, capsys):
+    monkeypatch.setattr(start.tempfile, "gettempdir", lambda: str(tmp_path))
+    fake = SimpleNamespace(pid = 4242, poll = lambda: 1)
+
+    def fake_popen(command, **kwargs):
+        # The child prints the early key marker, then dies before it is ready.
+        kwargs["stdout"].write(b"UNSLOTH_START_API_KEY: sk-unsloth-secretsecret\nload failed\n")
+        kwargs["stdout"].flush()
+        return fake
+
+    monkeypatch.setattr(start.subprocess, "Popen", fake_popen)
+
+    with pytest.raises(start.typer.Exit):
+        start._start_studio_server(BASE, "owner/model-GGUF", start.LoadOptions())
+
+    err = capsys.readouterr().err
+    assert "stopped before it was ready" in err
+    assert "sk-unsloth-secretsecret" not in err
+    assert "sk-unsloth-[redacted]" in err
 
 
 def test_codex_preflight_failure_tears_down_auto_served(fake_studio, monkeypatch):
@@ -1521,7 +2926,12 @@ def test_codex_preflight_failure_tears_down_auto_served(fake_studio, monkeypatch
     started = {}
     fake = SimpleNamespace(pid = 999, poll = lambda: None)
 
-    def fake_start(base, model, load):
+    def fake_start(
+        base,
+        model,
+        load,
+        server_options = None,
+    ):
         started.update(base = base, model = model)
         start._auto_served_server = fake
         return fake
@@ -1564,7 +2974,7 @@ def test_no_serve_preserves_error(fake_studio, monkeypatch):
         start.start_app, ["claude", "--model", "unsloth/Qwen3-1.7B-GGUF", "--no-serve"]
     )
     assert result.exit_code == 1
-    assert "No running Studio server" in result.output
+    assert "No running Unsloth server" in result.output
     assert started["called"] is False
 
 
@@ -1578,7 +2988,7 @@ def test_no_launch_never_serves(fake_studio, monkeypatch):
         start.start_app, ["claude", "--model", "unsloth/Qwen3-1.7B-GGUF", "--no-launch"]
     )
     assert result.exit_code == 1
-    assert "No running Studio server" in result.output
+    assert "No running Unsloth server" in result.output
     assert started["called"] is False
 
 
@@ -1616,7 +3026,12 @@ def test_auto_serve_normalizes_portless_url(fake_studio, monkeypatch):
     started = {}
     fake = SimpleNamespace(pid = 999, poll = lambda: None)
 
-    def fake_start(base, model, load):
+    def fake_start(
+        base,
+        model,
+        load,
+        server_options = None,
+    ):
         started["base"] = base
         start._auto_served_server = fake
         return fake
@@ -1808,8 +3223,7 @@ def test_write_opencode_config_fresh(tmp_path):
         MODEL["id"]: {"name": MODEL["id"], "limit": {"context": 131072, "output": 8192}}
     }
     assert config["model"] == f"{start._OPENCODE_PROVIDER}/{MODEL['id']}"
-    # The overlay never writes disabled_providers; the dedicated provider id is one a
-    # user's disable list would not target, so nothing needs re-enabling.
+    # Provider filters belong to the launch-time inline overlay, not this config writer.
     assert "disabled_providers" not in config
     # Compaction buffer scaled to ~10% of the window (compact near 90%).
     assert config["compaction"] == {"auto": True, "reserved": 131072 // 10}
@@ -1850,6 +3264,109 @@ def test_write_opencode_config_keeps_foreign_disabled_providers(tmp_path):
     assert config["disabled_providers"] == ["openai", "gemini"]
 
 
+def test_write_opencode_config_as_subagent_preserves_parent_model(tmp_path):
+    path = tmp_path / "opencode.json"
+    path.write_text(
+        json.dumps(
+            {
+                "model": "anthropic/claude-sonnet-4-5",
+                "small_model": "anthropic/claude-haiku-4-5",
+                "compaction": {"auto": False},
+            }
+        )
+    )
+    local = {**MODEL, "id": MODEL["id"] + ":UD-Q4_K_XL"}
+    start.write_opencode_config(
+        BASE,
+        "sk-unsloth-abc",
+        local,
+        path,
+        as_subagent = True,
+    )
+    config = json.loads(path.read_text())
+    assert config["model"] == "anthropic/claude-sonnet-4-5"
+    assert config["small_model"] == "anthropic/claude-haiku-4-5"
+    assert config["compaction"] == {"auto": False}
+    agent = config["agent"]["unsloth"]
+    assert agent["mode"] == "subagent"
+    assert agent["model"] == f"{start._OPENCODE_PROVIDER}/{local['id']}"
+    assert "local agent" in agent["description"].lower()
+    assert local["id"] in config["provider"][start._OPENCODE_PROVIDER]["models"]
+
+
+def test_opencode_subagent_inline_keeps_parent_provider_filters(monkeypatch, tmp_path):
+    config_path = tmp_path / "opencode.json"
+    inherited = {"theme": "tokyonight"}
+    monkeypatch.setenv("OPENCODE_CONFIG_CONTENT", json.dumps(inherited))
+    monkeypatch.setattr(start, "_which_with_install_dirs", lambda _: "/usr/bin/opencode")
+    captured = {}
+
+    def run(command, **kwargs):
+        captured["command"] = command
+        captured.update(kwargs)
+        return SimpleNamespace(
+            returncode = 0,
+            stdout = json.dumps(
+                {
+                    "enabled_providers": ["opencode-go"],
+                    "disabled_providers": ["ollama", start._OPENCODE_PROVIDER],
+                    "subagent_depth": 0,
+                }
+            ),
+            stderr = "",
+        )
+
+    monkeypatch.setattr(start.subprocess, "run", run)
+    permission = {"edit": "allow"}
+    inline = start._opencode_subagent_inline_config(config_path, permission)
+
+    assert captured["command"] == ["/usr/bin/opencode", "debug", "config"]
+    assert captured["env"]["OPENCODE_CONFIG"] == str(config_path)
+    assert inline == {
+        "theme": "tokyonight",
+        "enabled_providers": ["opencode-go", start._OPENCODE_PROVIDER],
+        "disabled_providers": ["ollama"],
+        "subagent_depth": 1,
+        "permission": permission,
+    }
+
+
+def test_opencode_subagent_inline_preserves_positive_depth(monkeypatch, tmp_path):
+    monkeypatch.setattr(start, "_which_with_install_dirs", lambda _: "/usr/bin/opencode")
+    monkeypatch.setattr(
+        start.subprocess,
+        "run",
+        lambda *args, **kwargs: SimpleNamespace(
+            returncode = 0,
+            stdout = json.dumps({"subagent_depth": 3}),
+            stderr = "",
+        ),
+    )
+
+    inline = start._opencode_subagent_inline_config(tmp_path / "opencode.json", {})
+
+    assert inline["subagent_depth"] == 3
+
+
+def test_opencode_subagent_inline_merges_inherited_filters_without_binary(monkeypatch, tmp_path):
+    monkeypatch.setenv(
+        "OPENCODE_CONFIG_CONTENT",
+        json.dumps(
+            {
+                "enabled_providers": ["opencode-go"],
+                "disabled_providers": ["ollama", start._OPENCODE_PROVIDER],
+            }
+        ),
+    )
+    monkeypatch.setattr(start, "_which_with_install_dirs", lambda _: None)
+
+    inline = start._opencode_subagent_inline_config(tmp_path / "opencode.json", {})
+
+    assert inline["enabled_providers"] == ["opencode-go", start._OPENCODE_PROVIDER]
+    assert inline["disabled_providers"] == ["ollama"]
+    assert inline["subagent_depth"] == 1
+
+
 def _opencode_inline_config(output: str) -> dict:
     # --no-launch prints OPENCODE_CONFIG_CONTENT as a POSIX `export NAME=<shell-quoted>`
     # line on Unix/WSL and a PowerShell `$env:NAME = "<escaped>"` line on native Windows;
@@ -1871,7 +3388,7 @@ def _opencode_inline_config(output: str) -> dict:
 def test_opencode_inline_scopes_session_to_studio_provider(fake_studio):
     # opencode filters even config-defined providers through enabled/disabled_providers,
     # and a model pin does not bypass that gate. The inline overlay (session-only, highest
-    # layer, arrays replace) allowlists our provider and clears the denylist so the Studio
+    # layer, arrays replace) allowlists our provider and clears the denylist so the Unsloth
     # model always loads regardless of the user's config, without reading or editing it.
     result = CliRunner().invoke(start.start_app, ["opencode", "--no-launch"])
     assert result.exit_code == 0, result.output
@@ -1938,6 +3455,130 @@ def test_connect_opencode_no_launch(fake_studio, tmp_path):
     assert not any(c[1].endswith("/api/inference/status") for c in fake_studio)
 
 
+def test_connect_opencode_as_subagent_preserves_cloud_parent(fake_studio, tmp_path, monkeypatch):
+    monkeypatch.setattr(start, "_opencode_subagent_inline_config", lambda path, permission: {})
+    result = CliRunner().invoke(
+        start.start_app,
+        [
+            "opencode",
+            "--as-subagent",
+            "--no-launch",
+            "--model",
+            MODEL["id"] + ":UD-Q4_K_XL",
+        ],
+    )
+    assert result.exit_code == 0, result.output
+    assert _launch_command(result.output) == ["opencode"]
+    expected_model = f"{start._OPENCODE_PROVIDER}/{MODEL['id']}:UD-Q4_K_XL"
+    # The agent rides in the inline overlay; nothing else comes from the empty base.
+    assert _opencode_inline_config(result.output) == {
+        "agent": {
+            "unsloth": {
+                "description": start._SUBAGENT_DESCRIPTION,
+                "mode": "subagent",
+                "model": expected_model,
+                "prompt": start._SUBAGENT_INSTRUCTIONS,
+            }
+        }
+    }
+    path = tmp_path / "agents" / "opencode-subagent" / "opencode.json"
+    config = json.loads(path.read_text())
+    assert "model" not in config
+    assert "small_model" not in config
+    assert "compaction" not in config
+    agent = config["agent"]["unsloth"]
+    assert agent["model"] == expected_model
+    assert "Unsloth is available as @unsloth and in /models." in result.output
+
+
+def test_claude_subagent_allowed_tools_precede_forwarded_delimiter(fake_studio):
+    # A forwarded `--` makes everything after it positional; the tool pre-approval
+    # must be parsed as an option, so it rides before ctx.args.
+    result = CliRunner().invoke(
+        start.start_app,
+        ["claude", "--as-subagent", "--no-launch", "--", "--resume", "abc123"],
+    )
+    assert result.exit_code == 0, result.output
+    command = _launch_command(result.output)
+    assert command.index("--allowedTools") < command.index("--resume")
+
+
+def test_opencode_subagent_installs_binary_before_filter_inspection(fake_studio, monkeypatch):
+    # The effective-config inspection needs the opencode binary; a first launch must
+    # offer the install before building the overlay, or a global allowlist read only
+    # after _launch installs OpenCode would filter out the new provider.
+    installed = {}
+    monkeypatch.setattr(
+        start,
+        "_which_with_install_dirs",
+        lambda name: "/usr/local/bin/opencode" if installed.get("done") else None,
+    )
+
+    def install(name, hint):
+        installed["done"] = True
+        installed["name"] = name
+        return "/usr/local/bin/opencode"
+
+    monkeypatch.setattr(start, "_install_agent", install)
+    inspected = {}
+
+    def inline(path, permission):
+        inspected["binary"] = start._which_with_install_dirs("opencode")
+        return {}
+
+    monkeypatch.setattr(start, "_opencode_subagent_inline_config", inline)
+    monkeypatch.setattr(start, "_run", lambda *a, **k: None)
+
+    result = CliRunner().invoke(start.start_app, ["opencode", "--as-subagent"])
+
+    assert result.exit_code == 0, result.output
+    assert installed["name"] == "opencode"
+    assert inspected["binary"] == "/usr/local/bin/opencode"
+
+
+def test_opencode_subagent_pins_agent_in_inline_overlay(fake_studio, monkeypatch):
+    # A project opencode.json outranks the session file, so the agent must ride in
+    # OPENCODE_CONFIG_CONTENT where a repo's own agent.unsloth cannot field-merge over it.
+    monkeypatch.setattr(start, "_opencode_subagent_inline_config", lambda path, permission: {})
+    result = CliRunner().invoke(
+        start.start_app,
+        ["opencode", "--as-subagent", "--no-launch", "--model", MODEL["id"] + ":UD-Q4_K_XL"],
+    )
+    assert result.exit_code == 0, result.output
+    agent = _opencode_inline_config(result.output)["agent"]["unsloth"]
+    assert agent["mode"] == "subagent"
+    assert agent["model"] == f"{start._OPENCODE_PROVIDER}/{MODEL['id']}:UD-Q4_K_XL"
+    assert agent["prompt"] == start._SUBAGENT_INSTRUCTIONS
+    assert agent["description"] == start._SUBAGENT_DESCRIPTION
+
+
+def test_connect_opencode_subagent_yolo_no_launch_stays_append_safe(fake_studio, monkeypatch):
+    monkeypatch.setattr(start, "_opencode_supports_native_auto", lambda: True)
+    captured = {}
+
+    def inline(path, permission):
+        captured["permission"] = permission
+        return {"permission": permission}
+
+    monkeypatch.setattr(start, "_opencode_subagent_inline_config", inline)
+    result = CliRunner().invoke(
+        start.start_app,
+        ["opencode", "--as-subagent", "--no-launch", "--yolo"],
+    )
+
+    assert result.exit_code == 0, result.output
+    assert _launch_command(result.output) == ["opencode"]
+    assert "--auto" not in result.output
+    assert captured["permission"] == {
+        "edit": "allow",
+        "bash": "allow",
+        "webfetch": "allow",
+        "task": "allow",
+        "external_directory": {"*": "allow"},
+    }
+    assert _opencode_inline_config(result.output)["permission"] == captured["permission"]
+
+
 # ── Hermes (OpenAI /v1/chat/completions, key via env) ────────────────
 
 
@@ -2080,6 +3721,39 @@ def test_connect_pi_no_launch(fake_studio, tmp_path):
     assert not any(c[1].endswith("/api/inference/status") for c in fake_studio)
 
 
+def test_connect_pi_as_subagent_preserves_cloud_parent(fake_studio, tmp_path):
+    result = CliRunner().invoke(
+        start.start_app,
+        [
+            "pi",
+            "--as-subagent",
+            "--no-launch",
+            "--model",
+            MODEL["id"] + ":UD-Q4_K_XL",
+        ],
+    )
+    assert result.exit_code == 0, result.output
+    command = _launch_command(result.output)
+    assert command[:2] == ["pi", "--extension"]
+    assert command[2].endswith("unsloth_cli/pi_subagent.ts")
+    assert "--provider" not in command
+    assert "--model" not in command
+    assert "PI_CODING_AGENT_DIR" not in result.output
+    assert "export HOME=" not in result.output
+    assert "UNSLOTH_PI_SUBAGENT_API_KEY" not in result.output
+    assert "sk-unsloth-feedfacefeedface" not in result.output
+    config_path = tmp_path / "agents" / "pi-subagent" / "subagent.json"
+    _assert_env_set(result.output, "UNSLOTH_PI_SUBAGENT_CONFIG", str(config_path))
+    assert json.loads(config_path.read_text()) == {
+        "baseUrl": f"{BASE}/v1",
+        "apiKey": "sk-unsloth-feedfacefeedface",
+        "model": MODEL["id"] + ":UD-Q4_K_XL",
+        "contextWindow": 4096,
+        "maxTokens": 1024,
+    }
+    assert "Ask Pi to spawn an Unsloth or local agent." in result.output
+
+
 def test_connect_pi_no_launch_windows_relocates_userprofile(fake_studio, tmp_path, monkeypatch):
     # On native Windows Node resolves ~/.pi via USERPROFILE, not HOME, so the session
     # must point USERPROFILE at the relocated home or Pi reads the user's real ~/.pi.
@@ -2139,8 +3813,9 @@ def test_powershell_quote_single_quotes_json():
     # keeps the embedded double quotes literal (list2cmdline's backslashes would not).
     assert start._powershell_quote("--settings") == "--settings"
     assert start._powershell_quote("unsloth/gemma-4-26B") == "unsloth/gemma-4-26B"
-    quoted = start._powershell_quote(start._CLAUDE_SETTINGS_OVERLAY)
-    assert quoted == "'" + start._CLAUDE_SETTINGS_OVERLAY + "'"
+    overlay = start._claude_settings_overlay("unsloth/gemma-4-26B")
+    quoted = start._powershell_quote(overlay)
+    assert quoted == "'" + overlay + "'"
     assert "\\" not in quoted  # no cmd.exe backslash escaping
     assert start._powershell_quote("a'b") == "'a''b'"  # embedded quote doubled
 
@@ -2190,8 +3865,18 @@ def test_yolo_aliases_are_interchangeable(fake_studio, alias):
     assert "--dangerously-bypass-approvals-and-sandbox" in codex.output
     assert "--dangerously-skip-permissions" not in codex.output
 
+    opencode = CliRunner().invoke(
+        start.start_app,
+        ["opencode", alias, "--no-launch", "run", "hello"],
+    )
+    assert opencode.exit_code == 0, opencode.output
+    assert _launch_command(opencode.output) == ["opencode", "run", "hello", "--auto"]
+    assert "permission" not in _opencode_inline_config(opencode.output)
 
-def test_yolo_opencode_writes_permission_block(fake_studio, tmp_path):
+
+def test_yolo_opencode_bare_no_launch_uses_permission_fallback(fake_studio, tmp_path):
+    # A bare --no-launch recipe stays append-safe (callers add a subcommand later);
+    # `opencode --auto run ...` would select the TUI, not `run`, so keep the config fallback.
     result = CliRunner().invoke(start.start_app, ["opencode", "--yolo", "--no-launch"])
     assert result.exit_code == 0, result.output
     config = json.loads((tmp_path / "agents" / "opencode" / "opencode.json").read_text())
@@ -2203,6 +3888,172 @@ def test_yolo_opencode_writes_permission_block(fake_studio, tmp_path):
     }
 
 
+def test_yolo_opencode_run_uses_native_auto(fake_studio):
+    result = CliRunner().invoke(
+        start.start_app,
+        ["opencode", "--yolo", "--no-launch", "run", "hello"],
+    )
+    assert result.exit_code == 0, result.output
+    command = _launch_command(result.output)
+    assert command == ["opencode", "run", "hello", "--auto"]
+    assert "permission" not in _opencode_inline_config(result.output)
+
+
+def test_yolo_opencode_tui_resume_uses_native_auto(fake_studio):
+    result = CliRunner().invoke(
+        start.start_app,
+        ["opencode", "--yolo", "--no-launch", "--session", "sid"],
+    )
+    assert result.exit_code == 0, result.output
+    command = _launch_command(result.output)
+    assert command == ["opencode", "--session", "sid", "--auto"]
+    assert "permission" not in _opencode_inline_config(result.output)
+
+
+def test_no_yolo_opencode_run_omits_native_auto(fake_studio):
+    result = CliRunner().invoke(
+        start.start_app,
+        ["opencode", "--no-launch", "run", "hello"],
+    )
+    assert result.exit_code == 0, result.output
+    assert _launch_command(result.output) == ["opencode", "run", "hello"]
+    assert "permission" not in _opencode_inline_config(result.output)
+
+
+def test_yolo_opencode_bare_launch_uses_native_auto(fake_studio, monkeypatch):
+    monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/opencode")
+    monkeypatch.setattr(start, "_opencode_supports_native_auto", lambda: True)
+    captured = _capture_launch(monkeypatch, ["opencode", "--yolo"])
+    assert captured["command"][1:] == [
+        "--model",
+        f"{start._OPENCODE_PROVIDER}/{MODEL['id']}",
+        "--auto",
+    ]
+    assert "permission" not in json.loads(captured["env"]["OPENCODE_CONFIG_CONTENT"])
+
+
+def test_yolo_opencode_native_auto_clears_prior_config_fallback(fake_studio, tmp_path):
+    fallback = CliRunner().invoke(
+        start.start_app,
+        ["opencode", "--yolo", "--no-launch"],
+    )
+    assert fallback.exit_code == 0, fallback.output
+
+    native = CliRunner().invoke(
+        start.start_app,
+        ["opencode", "--yolo", "--no-launch", "run", "hello"],
+    )
+    assert native.exit_code == 0, native.output
+    assert _launch_command(native.output) == ["opencode", "run", "hello", "--auto"]
+    assert "permission" not in _opencode_inline_config(native.output)
+    config = json.loads((tmp_path / "agents" / "opencode" / "opencode.json").read_text())
+    assert config["permission"] == {
+        "edit": "ask",
+        "bash": "ask",
+        "webfetch": "ask",
+        "external_directory": {"*": "ask"},
+    }
+
+
+@pytest.mark.parametrize(
+    ("version", "expected"),
+    [
+        ("1.17.11", False),
+        ("1.17.12", True),
+        ("opencode 1.18.2", True),
+        ("development build", False),
+    ],
+)
+def test_opencode_native_auto_version_gate(monkeypatch, version, expected):
+    monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/opencode")
+    monkeypatch.setattr(start.subprocess, "check_output", lambda *args, **kwargs: version)
+    assert start._opencode_supports_native_auto() is expected
+
+
+def test_opencode_native_auto_assumes_current_without_local_binary(monkeypatch):
+    monkeypatch.setattr(start.shutil, "which", lambda _: None)
+    assert start._opencode_supports_native_auto() is True
+
+
+def test_yolo_opencode_old_version_uses_config_fallback(fake_studio, monkeypatch):
+    monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/opencode")
+    monkeypatch.setattr(start.subprocess, "check_output", lambda *args, **kwargs: "1.17.11")
+    result = CliRunner().invoke(
+        start.start_app,
+        ["opencode", "--yolo", "--no-launch", "run", "hello"],
+    )
+    assert result.exit_code == 0, result.output
+    assert _launch_command(result.output) == ["opencode", "run", "hello"]
+    assert _opencode_inline_config(result.output)["permission"] == {
+        "edit": "allow",
+        "bash": "allow",
+        "webfetch": "allow",
+        "external_directory": {"*": "allow"},
+    }
+
+
+@pytest.mark.parametrize(
+    ("args", "expected", "native"),
+    [
+        ([], ["--auto"], True),
+        (["run", "hello"], ["run", "hello", "--auto"], True),
+        (
+            ["run", "hello", "--", "--literal"],
+            ["run", "hello", "--auto", "--", "--literal"],
+            True,
+        ),
+        (["--print-logs", "run", "hello"], ["--print-logs", "run", "hello", "--auto"], True),
+        (["--session", "serve"], ["--session", "serve", "--auto"], True),
+        (["serve"], ["serve"], False),
+        (["--print-logs", "serve"], ["--print-logs", "serve"], False),
+        (["run", "--auto", "hello"], ["run", "--auto", "hello"], True),
+        # Hidden commands that reject --auto fall back like the visible utility ones.
+        (["generate"], ["generate"], False),
+        (["console", "login"], ["console", "login"], False),
+        # --mini ignores --auto (runMini forces auto=false), so use the config fallback.
+        (["--mini"], ["--mini"], False),
+        (["--session", "sid", "--mini"], ["--session", "sid", "--mini"], False),
+    ],
+)
+def test_opencode_native_auto_args(args, expected, native):
+    assert start._opencode_native_auto_args(args, True) == (expected, native)
+    assert start._opencode_native_auto_args(args, False) == (args, False)
+
+
+def test_yolo_opencode_non_agent_subcommand_uses_config_fallback(fake_studio):
+    result = CliRunner().invoke(
+        start.start_app,
+        ["opencode", "--yolo", "--no-launch", "serve"],
+    )
+    assert result.exit_code == 0, result.output
+    command = _launch_command(result.output)
+    assert command == ["opencode", "serve"]
+    assert _opencode_inline_config(result.output)["permission"] == {
+        "edit": "allow",
+        "bash": "allow",
+        "webfetch": "allow",
+        "external_directory": {"*": "allow"},
+    }
+
+
+@pytest.mark.parametrize("passthrough", (["generate"], ["console", "login"], ["--mini"]))
+def test_yolo_opencode_no_auto_command_uses_config_fallback(fake_studio, passthrough):
+    # generate/console are hidden and reject --auto, --mini ignores it: none get --auto,
+    # all keep the config permission fallback.
+    result = CliRunner().invoke(
+        start.start_app,
+        ["opencode", "--yolo", "--no-launch", *passthrough],
+    )
+    assert result.exit_code == 0, result.output
+    assert _launch_command(result.output) == ["opencode", *passthrough]
+    assert _opencode_inline_config(result.output)["permission"] == {
+        "edit": "allow",
+        "bash": "allow",
+        "webfetch": "allow",
+        "external_directory": {"*": "allow"},
+    }
+
+
 def test_no_yolo_opencode_has_no_permission_block(fake_studio, tmp_path):
     result = CliRunner().invoke(start.start_app, ["opencode", "--no-launch"])
     assert result.exit_code == 0, result.output
@@ -2446,6 +4297,27 @@ def test_opencode_non_yolo_flips_only_explicit_allow(tmp_path):
     assert session == {}  # a non-yolo session carries no permission inline
 
 
+def test_opencode_subagent_non_yolo_clears_yolo_task_permission(tmp_path):
+    path = tmp_path / "opencode.json"
+    start.write_opencode_config(
+        BASE,
+        "sk-unsloth-abc",
+        MODEL,
+        path,
+        yolo = True,
+        as_subagent = True,
+    )
+    start.write_opencode_config(
+        BASE,
+        "sk-unsloth-abc",
+        MODEL,
+        path,
+        as_subagent = True,
+    )
+
+    assert json.loads(path.read_text())["permission"]["task"] == "ask"
+
+
 def test_opencode_non_yolo_leaves_string_permission(tmp_path):
     # A global string rule ("deny") is a user-managed catch-all; leave it untouched and
     # carry no inline override.
@@ -2549,15 +4421,16 @@ def test_openclaw_non_yolo_preserves_full_mode(tmp_path):
 
 
 def test_yolo_command_flags_unmapped_agent_is_empty():
-    # Config-based agents (and any typo) must yield no flag, not a KeyError.
+    # Placement-aware/config-based agents (and any typo) must yield no prefix flag.
     assert start._yolo_command_flags("opencode", True) == []
     assert start._yolo_command_flags("openclaw", True) == []
     assert start._yolo_command_flags("claude", True) == ["--dangerously-skip-permissions"]
     assert start._yolo_command_flags("claude", False) == []
 
 
-def test_yolo_config_agents_add_no_command_flag(fake_studio):
-    # opencode/openclaw auto-approve is config-only; nothing should leak onto argv.
+def test_yolo_config_fallbacks_add_no_legacy_command_flag(fake_studio):
+    # OpenClaw is config-only; OpenCode's append-safe bare recipe uses its config fallback.
+    # Neither should leak a legacy yolo/dangerous alias onto argv.
     for agent in ("opencode", "openclaw"):
         result = CliRunner().invoke(start.start_app, [agent, "--yolo", "--no-launch"])
         assert result.exit_code == 0, result.output
@@ -2598,7 +4471,7 @@ def test_claude_launch_does_not_clear(fake_studio, monkeypatch):
     calls = []
     monkeypatch.setattr(start.click, "clear", lambda: calls.append("clear"))
     monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/claude")
-    monkeypatch.setattr(start, "_claude_flags", lambda: [])
+    monkeypatch.setattr(start, "_claude_flags", lambda *a, **k: [])
     monkeypatch.setattr(start.subprocess, "run", lambda command, env: SimpleNamespace(returncode = 0))
     result = CliRunner().invoke(start.start_app, ["claude"])
     assert result.exit_code == 0, result.output
@@ -2657,7 +4530,7 @@ def test_agent_api_key_auto_started_rejected_env_key_falls_back(fake_studio, tmp
 
 
 def test_agent_api_key_auto_started_accepted_key_is_honored(fake_studio, tmp_path):
-    # An explicit key the fresh server accepts (e.g. persisted in this Studio
+    # An explicit key the fresh server accepts (e.g. persisted in this Unsloth
     # home's auth db across restarts) keeps working exactly as before.
     key = start._agent_api_key(BASE, "sk-unsloth-deadbeefdeadbeef", auto_started = True)
     assert key == "sk-unsloth-deadbeefdeadbeef"
@@ -2775,7 +4648,7 @@ def test_persist_bare_opencode_launch_has_no_resume_token(fake_studio, monkeypat
 
 def test_persist_bare_claude_launch_has_no_resume_token(fake_studio, monkeypatch):
     monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/claude")
-    monkeypatch.setattr(start, "_claude_flags", lambda: [])
+    monkeypatch.setattr(start, "_claude_flags", lambda *a, **k: [])
     captured = _capture_launch(monkeypatch, ["claude", "--persist"])
     assert "--continue" not in captured["command"]
     assert captured["command"][1:] == ["--model", MODEL["id"]]
@@ -2937,11 +4810,11 @@ def test_hermes_resume_oneshot_rejects_usage_file(monkeypatch, usage_arg):
 def test_native_resume_flag_passes_through_unchanged(fake_studio, monkeypatch):
     # The persistence flag is --persist, NOT --resume, so an agent's own
     # `--resume <id>` (e.g. `unsloth start claude --resume <guid>`) still flows
-    # through to the agent verbatim and is not swallowed as a Studio option.
+    # through to the agent verbatim and is not swallowed as an Unsloth option.
     monkeypatch.setattr(start.shutil, "which", lambda _: "/usr/local/bin/claude")
-    monkeypatch.setattr(start, "_claude_flags", lambda: [])
+    monkeypatch.setattr(start, "_claude_flags", lambda *a, **k: [])
     captured = _capture_launch(monkeypatch, ["claude", "--resume", "some-session-guid"])
     assert captured["command"][-2:] == ["--resume", "some-session-guid"]
-    # Studio never auto-appends its own resume token when the user drives resume.
+    # Unsloth never auto-appends its own resume token when the user drives resume.
     assert captured["command"].count("--resume") == 1
     assert "--continue" not in captured["command"]
diff --git a/unsloth_cli/tests/test_studio_cloudflare_flag.py b/unsloth_cli/tests/test_studio_cloudflare_flag.py
index fb57d7aaf4..7287737f75 100644
--- a/unsloth_cli/tests/test_studio_cloudflare_flag.py
+++ b/unsloth_cli/tests/test_studio_cloudflare_flag.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Tests for the `--cloudflare/--no-cloudflare` Studio flag.
+"""Tests for the `--cloudflare/--no-cloudflare` Unsloth flag.
 
 Pins the typer Option (tri-state, default off / None) on both `unsloth studio`
 and `unsloth studio run`, and that the chosen polarity reaches the re-exec'd
diff --git a/unsloth_cli/tests/test_studio_password_prompt.py b/unsloth_cli/tests/test_studio_password_prompt.py
index 7bbdfe3703..6e9a2c1d52 100644
--- a/unsloth_cli/tests/test_studio_password_prompt.py
+++ b/unsloth_cli/tests/test_studio_password_prompt.py
@@ -885,7 +885,7 @@ def test_run_non_tty_deletes_bootstrap_password_file(monkeypatch, tmp_path):
 
 def test_run_missing_frontend_exits_before_stripping_bootstrap(monkeypatch, tmp_path):
     # Regression (item B / reviewer finding 4): `unsloth studio run` serves the
-    # same Studio UI and strips the seeded password on a headless public launch,
+    # same Unsloth UI and strips the seeded password on a headless public launch,
     # so a missing frontend dist must abort BEFORE the strip -- the same lockout
     # guard as `unsloth studio`, not just `studio run`'s model-load residual.
     import typer as _typer
@@ -1104,7 +1104,7 @@ def test_cli_update_password_truncates_locked_bootstrap_after_change(monkeypatch
 
 
 def test_reset_password_fails_closed_when_db_cannot_be_deleted(monkeypatch, tmp_path):
-    # If auth.db cannot be removed (running Studio / Windows lock, read-only dir),
+    # If auth.db cannot be removed (running Unsloth / Windows lock, read-only dir),
     # reset must abort BEFORE touching the credential files -- deleting them while
     # an un-resettable must_change_password=1 DB survives would lock a
     # forgotten-password reset out with no recovery credential.
diff --git a/unsloth_cli/tests/test_studio_run_parallel_flag.py b/unsloth_cli/tests/test_studio_run_parallel_flag.py
index 558b268a4d..972abb5d4d 100644
--- a/unsloth_cli/tests/test_studio_run_parallel_flag.py
+++ b/unsloth_cli/tests/test_studio_run_parallel_flag.py
@@ -170,13 +170,24 @@ def _install_reexec_capture(monkeypatch, *, platform):
 
     monkeypatch.setattr(sys, "platform", platform)
 
+    def capture(kind, argv):
+        captured.append(
+            {
+                "kind": kind,
+                "argv": list(argv),
+                "start_api_key_marker": studio_mod.os.environ.get(
+                    studio_mod._START_API_KEY_MARKER_ENV
+                ),
+            }
+        )
+
     def fake_execvp(file, argv):
-        captured.append({"kind": "execvp", "argv": list(argv)})
+        capture("execvp", argv)
         raise _ExecCaptured(argv)
 
     class _FakePopen:
         def __init__(self, argv, *a, **kw):
-            captured.append({"kind": "popen", "argv": list(argv)})
+            capture("popen", argv)
             self._argv = argv
 
         def wait(self):
@@ -235,6 +246,102 @@ def test_reexec_forwards_parallel_all_aliases(monkeypatch, flag, value):
     ), f"{flag} {value} was dropped on re-exec; argv = {argv}"
 
 
+@pytest.mark.parametrize("platform", ["linux", "darwin", "win32"])
+def test_reexec_hands_off_start_api_key_marker_out_of_band(monkeypatch, platform):
+    """A new child receives the marker while an old child sees no unknown flag."""
+    result, captured = _invoke_run(
+        monkeypatch,
+        _BASE + ["--start-api-key-marker"],
+        platform = platform,
+    )
+    assert len(captured) == 1, result.output
+    assert "--start-api-key-marker" not in captured[0]["argv"]
+    assert captured[0]["start_api_key_marker"] == "1"
+
+
+def test_reexeced_child_consumes_start_api_key_marker_env(monkeypatch):
+    """A supported child consumes the handoff before starting descendants."""
+    studio_mod = _load_run_command()
+    monkeypatch.setenv(studio_mod._START_API_KEY_MARKER_ENV, "1")
+
+    inherited = studio_mod._consume_start_api_key_marker_env()
+
+    assert inherited is True
+    assert studio_mod._START_API_KEY_MARKER_ENV not in studio_mod.os.environ
+
+
+def test_run_default_sets_tool_call_env(monkeypatch):
+    """Plain `unsloth run` enables healing and nudging via the inherited env
+    (written before the re-exec so the child server picks them up at import)."""
+    studio_mod = _load_run_command()
+    monkeypatch.delenv("UNSLOTH_DISABLE_TOOL_CALL_HEALING", raising = False)
+    monkeypatch.delenv("UNSLOTH_TOOL_CALL_NUDGE", raising = False)
+    _invoke_run(monkeypatch, _BASE)
+    assert studio_mod.os.environ["UNSLOTH_DISABLE_TOOL_CALL_HEALING"] == "0"
+    assert studio_mod.os.environ["UNSLOTH_TOOL_CALL_NUDGE"] == "1"
+
+
+def test_run_disable_flags_set_tool_call_env(monkeypatch):
+    """`--disable-tool-call-healing --disable-tool-call-nudging` flips both env vars."""
+    studio_mod = _load_run_command()
+    monkeypatch.delenv("UNSLOTH_DISABLE_TOOL_CALL_HEALING", raising = False)
+    monkeypatch.delenv("UNSLOTH_TOOL_CALL_NUDGE", raising = False)
+    _invoke_run(
+        monkeypatch,
+        _BASE + ["--disable-tool-call-healing", "--disable-tool-call-nudging"],
+    )
+    assert studio_mod.os.environ["UNSLOTH_DISABLE_TOOL_CALL_HEALING"] == "1"
+    assert studio_mod.os.environ["UNSLOTH_TOOL_CALL_NUDGE"] == "0"
+
+
+@pytest.mark.parametrize("inherited", ["0", "false", "False", "no", ""])
+def test_run_omitted_flag_respects_inherited_env(monkeypatch, inherited):
+    """When the flag is omitted, a value the parent set (e.g. `unsloth start`) wins
+    instead of being reset to the default."""
+    studio_mod = _load_run_command()
+    monkeypatch.setenv("UNSLOTH_TOOL_CALL_NUDGE", inherited)
+    monkeypatch.delenv("UNSLOTH_DISABLE_TOOL_CALL_HEALING", raising = False)
+    _invoke_run(monkeypatch, _BASE)
+    assert studio_mod.os.environ["UNSLOTH_TOOL_CALL_NUDGE"] == inherited
+
+
+_SAMPLING_ENV_SUFFIXES = (
+    "TEMPERATURE",
+    "TOP_P",
+    "TOP_K",
+    "MIN_P",
+    "REPETITION_PENALTY",
+    "PRESENCE_PENALTY",
+)
+
+
+def test_run_sampling_flags_set_env(monkeypatch):
+    """`--temperature`/`--top-k` write UNSLOTH_SAMPLING_* (a hard override the backend applies);
+    an omitted sampling flag leaves its env unset so the per-model recommendation stays."""
+    studio_mod = _load_run_command()
+    for _v in _SAMPLING_ENV_SUFFIXES:
+        monkeypatch.delenv(f"UNSLOTH_SAMPLING_{_v}", raising = False)
+    _invoke_run(monkeypatch, _BASE + ["--temperature", "0.3", "--top-k", "40"])
+    assert studio_mod.os.environ["UNSLOTH_SAMPLING_TEMPERATURE"] == "0.3"
+    assert studio_mod.os.environ["UNSLOTH_SAMPLING_TOP_K"] == "40"
+    assert "UNSLOTH_SAMPLING_TOP_P" not in studio_mod.os.environ
+
+
+def test_run_no_sampling_flags_leaves_env_unset(monkeypatch):
+    """Plain `unsloth run` writes no UNSLOTH_SAMPLING_*; the server keeps the recommendation."""
+    studio_mod = _load_run_command()
+    for _v in _SAMPLING_ENV_SUFFIXES:
+        monkeypatch.delenv(f"UNSLOTH_SAMPLING_{_v}", raising = False)
+    _invoke_run(monkeypatch, _BASE)
+    assert not any(k.startswith("UNSLOTH_SAMPLING_") for k in studio_mod.os.environ)
+
+
+def test_run_rejects_out_of_range_sampling_flag(monkeypatch):
+    """typer enforces the documented ranges before a value can reach the server."""
+    result, _captured = _invoke_run(monkeypatch, _BASE + ["--temperature", "9"])
+    assert result.exit_code != 0
+
+
 @pytest.mark.parametrize("platform", ["linux", "darwin", "win32"])
 def test_reexec_argv_is_consistent_across_platforms(monkeypatch, platform):
     """Linux/Darwin (execvp) and Windows (Popen) must build the same argv."""
@@ -274,12 +381,14 @@ def test_reexec_mixed_parallel_with_passthrough(monkeypatch):
     """--parallel + llama-server pass-through flags must all reach the child."""
     result, captured = _invoke_run(
         monkeypatch,
-        _BASE + ["--parallel", "8", "--top-k", "20", "--temp", "0.7"],
+        # --top-k is now a first-class sampling flag (routed via UNSLOTH_SAMPLING_*), so use
+        # --seed / --temp here, which remain genuine llama-server pass-through flags.
+        _BASE + ["--parallel", "8", "--seed", "42", "--temp", "0.7"],
     )
     assert len(captured) == 1
     argv = captured[0]["argv"]
     assert _value_after(argv, "--parallel") == "8", argv
-    assert _value_after(argv, "--top-k") == "20", argv
+    assert _value_after(argv, "--seed") == "42", argv
     assert _value_after(argv, "--temp") == "0.7", argv
 
 
diff --git a/unsloth_cli/tests/test_studio_secure_flag.py b/unsloth_cli/tests/test_studio_secure_flag.py
index 5e5895309c..2a67aad95a 100644
--- a/unsloth_cli/tests/test_studio_secure_flag.py
+++ b/unsloth_cli/tests/test_studio_secure_flag.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Tests for the `--secure/--no-secure` Studio flag: option registration,
+"""Tests for the `--secure/--no-secure` Unsloth flag: option registration,
 re-exec/run_server forwarding, the forced 127.0.0.1 bind, and rejection
 alongside --no-cloudflare or before a subcommand. Modeled on
 test_studio_cloudflare_flag.py."""
diff --git a/unsloth_cli/tests/test_studio_verbose_flag.py b/unsloth_cli/tests/test_studio_verbose_flag.py
index 4af32fd4a2..20468b5f02 100644
--- a/unsloth_cli/tests/test_studio_verbose_flag.py
+++ b/unsloth_cli/tests/test_studio_verbose_flag.py
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
-"""Tests for the `--verbose/-v` Studio flag: option registration on both the
+"""Tests for the `--verbose/-v` Unsloth flag: option registration on both the
 plain callback and the `run` subcommand, re-exec forwarding, the access-log
 env override, and rejection before a subcommand. Modeled on
 test_studio_secure_flag.py."""
@@ -123,7 +123,7 @@ def test_run_without_verbose_leaves_env_unset(monkeypatch):
 
 
 def test_run_verbose_preserves_llama_server_verbosity(monkeypatch):
-    # Studio consumes --verbose but still forwards llama-server's own verbosity.
+    # Unsloth consumes --verbose but still forwards llama-server's own verbosity.
     monkeypatch.delenv(_DEDUP, raising = False)
     monkeypatch.delenv(_POLL, raising = False)
     captured = _invoke_run(monkeypatch, _BASE + ["--verbose"])