Unsloth is a local UI for training and running Gemma 4, Qwen3.6, DeepSeek, Kimi, GLM and other models. https://unsloth.ai/docs
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Daniel Han 7d1b68079e
Studio: Anthropic fast_mode toggle and streaming refusal handling (#5715)
* Studio: add Anthropic fast_mode toggle + surface streaming refusals

Fast mode (beta `fast-mode-2026-02-01`) lets Claude Opus 4.6 and 4.7
generate output tokens up to 2.5x faster at 6x standard Opus
pricing. The toggle lives in Configuration → Provider when the
selected Anthropic model is Opus 4.6 or 4.7 and is otherwise
hidden. Backend gates the same prefixes a second time so a stale
frontend cannot make Anthropic 400 the request, and the
`fast-mode-2026-02-01` beta header is merged onto whatever other
betas the request already needed (code-execution, compaction).

Streaming refusals (`message_delta.delta.stop_reason="refusal"` on
Claude 4 models) now surface a short user-facing notice in the
assistant message before the translated OpenAI chunk emits the
existing `finish_reason="content_filter"`. Previously the chat
bubble truncated silently because the SSE stopped mid-stream with
no visible explanation. Per the upstream docs the conversation
must be reset before continuing, so the notice tells the user
exactly that.

Reference:
- https://platform.claude.com/docs/en/build-with-claude/fast-mode
- https://platform.claude.com/docs/en/test-and-evaluate/strengthen-guardrails/handle-streaming-refusals

Tests:
- studio/backend/tests/test_anthropic_fast_mode_and_refusal.py (8 cases
  pinning fast_mode pass-through on 4.6/4.7, silent drop on Sonnet /
  Haiku / older Opus / None / False, and the refusal notice + finish
  reason on a synthetic refusal stream).

* Studio: drop refused Anthropic turns from the next request

Anthropic's streaming-refusal guidance says the refused assistant
turn must be removed or updated before the next call -- otherwise
the safety classifier keeps refusing. The PR only added a
user-visible notice; the partial assistant output (plus the notice
itself) still rode the next request via toOpenAIMessage.

Tag the refusal turn with an HTML-comment sentinel emitted alongside
the notice. The chat-adapter checks for that sentinel in
toOpenAIMessage and returns null, so the refused turn is excluded
from outboundMessages. The notice still renders in the transcript
(HTML comments don't display), so users keep the explanation.

* Studio: filter None finish_reason entries in test helper

test_refusal_maps_to_content_filter expects only ['content_filter']
in the finish_reasons list, but the post-PR refusal path emits a
user-visible content notice chunk first. Every _content_chunk
carries 'finish_reason: None' by construction; the helper was
appending those, so the assertion saw [None, 'content_filter']
instead of ['content_filter'].

None is not a finish reason -- it's just mid-stream delta noise.
Skip None values in _finish_reasons so the helper reflects what
the test names actually claim to check. Same fix applies cleanly
to the other helper usages (pause_turn test expects [] and the
sibling stop test expects ['stop'], both unaffected).

* Studio: cover Anthropic fast-mode edge cases

Adds 19 cases on top of the 9 in test_anthropic_fast_mode_and_refusal.
The base file pins the happy path; this file fills in the cliffs:

* Dated-snapshot prefix matching: claude-opus-4-7-2026-02-01 and
  claude-opus-4-6-2026-02-01 still gate fast_mode through, while
  claude-opus-4-5-2025-08-01 and claude-sonnet-4-6-2026-02-01 do not.
* Strict opt-in: a future claude-opus-4-8 or claude-opus-5 does NOT
  auto-enable fast_mode -- the prefix tuple must be bumped explicitly
  when a new family is whitelisted upstream.
* Beta-header merge: fast_mode coexists with code-execution-2025-08-25
  and compact-2026-01-12 in one comma-separated anthropic-beta header
  with no duplicates and no truncation. Pins the value to the exact
  fast-mode-2026-02-01 docs token so a typo would fail CI.
* Non-destruction: fast_mode=None produces byte-identical outbound
  body and headers to the version that omits the argument entirely.
  Same for fast_mode=False. Guarantees the upgrade path is
  non-breaking on existing Anthropic streams.
* Refusal stream ordering: the user-visible notice precedes the
  finish_reason chunk so a streaming UI paints text before flipping
  to content_filter. Refusal sentinel emitted exactly once. Notice
  rides a normal content delta chunk with finish_reason still null.
  Partial assistant deltas survive before the notice.
* Provider-side refusal coverage: a refusal on Sonnet (not just Opus)
  still emits the notice + sentinel + content_filter mapping, since
  refusal handling is not gated on fast-mode capability.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Persist fastMode, drop refused user message on retry

Two follow-ups on #5715:

1) sanitizeInferenceParams stripped fastMode. fastMode is in
   PERSISTED_INFERENCE_PARAM_KEYS but the storage sanitizer only kept
   numeric fields plus systemPrompt and trustRemoteCode, so the new
   toggle was silently dropped on reload and on the
   /api/chat/settings round-trip. Save it the same way trustRemoteCode
   is saved.

2) Refusal recovery now also drops the triggering user turn.
   Returning null from toOpenAIMessage on the assistant side left the
   user prompt that caused the refusal in the outbound history, so
   the very next request would re-trigger the same classifier.
   Anthropic's refusal-handling guidance is explicit on this: remove
   the refused turn AND the user message that triggered it before
   the next call. Implemented via a pre-pass that pops the trailing
   user message when an assistant carries the refusal sentinel.

Typecheck clean.

* Studio: out-of-band refusal signal + fast-mode prefix/usage/pricing fixes

The text sentinel for the Anthropic refusal drop signal was spoofable:
any assistant message containing the literal
<!--studio:anthropic-refusal--> would prune the prior user + assistant
pair on the next request. Move the signal onto a separate _toolEvent
chunk that the chat adapter latches into
assistant.metadata.custom.anthropicRefusal; assistant text can no
longer control the pruner.

Tighten the fast-mode model gate (backend + frontend) to require a "-"
family boundary so claude-opus-4-70 / claude-opus-4-7b style IDs do
not get speed: "fast" on a naive startswith match.

Use survivingMessages for the image / audio attachment scan so a
refused user turn does not gate or mis-attribute the next non-refused
turn.

Propagate Anthropic usage.speed onto the OpenAI-style usage chunk and
apply the documented 6x fast-mode multiplier in the cost calculator
(stacks with prompt-cache multipliers per the docs); expose the new
multiplier on the pricing snapshot for the UI tooltip.

Tests cover the tool-event chunk shape, the prefix-collision rejects,
usage.speed propagation, the 6x pricing math, and that the visible
refusal text carries no embedded sentinel.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Shorten fast-mode and refusal comments for PR #5715

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
2026-05-25 23:37:12 -07:00
.github ci: unblock Studio Windows + Linux + Mac smoke (#5741) 2026-05-23 06:59:16 -07:00
images images: use narrower Discord button and drop duplicate (#5552) 2026-05-18 05:00:59 -07:00
scripts Move uninstall scripts into scripts/ and fix references (#5644) 2026-05-20 04:42:03 -07:00
studio Studio: Anthropic fast_mode toggle and streaming refusal handling (#5715) 2026-05-25 23:37:12 -07:00
tests fix(chat_templates): check find() return value before slicing on placeholders (#5763) 2026-05-25 06:19:01 -07:00
unsloth fix(chat_templates): check find() return value before slicing on placeholders (#5763) 2026-05-25 06:19:01 -07:00
unsloth_cli studio: regenerate desktop launcher on unsloth studio update (macOS + Linux + Windows) (#5577) 2026-05-19 05:49:10 -07:00
.gitattributes EOL LF (unix line endings) normalization (#3478) 2025-10-17 16:22:42 -07:00
.gitignore ci: advisory lockfile supply-chain audit (no install-script changes) (#5604) 2026-05-19 05:56:56 -07:00
.pre-commit-ci.yaml pre-commit CI config (#3565) 2025-11-07 14:44:18 -08:00
.pre-commit-config.yaml [pre-commit.ci] pre-commit autoupdate (#5773) 2026-05-25 22:21:43 -07:00
build.sh Add Studio web update banner and release version display (#5308) 2026-05-11 18:24:01 +04:00
cli.py Rename cli/ to unsloth_cli/ to fix namespace collision with stringzilla (#4393) 2026-03-17 20:40:21 -07:00
CODE_OF_CONDUCT.md Update CODE_OF_CONDUCT.md 2025-10-25 19:31:05 -07:00
CONTRIBUTING.md Revert "Improve documentation on how to export model from Colab" 2026-03-13 22:38:41 -07:00
COPYING Rename cli/ to unsloth_cli/ to fix namespace collision with stringzilla (#4393) 2026-03-17 20:40:21 -07:00
install.ps1 Bump install.sh / install.ps1 pin to unsloth>=2026.5.7 (#5753) 2026-05-24 07:22:49 -07:00
install.sh Bump install.sh / install.ps1 pin to unsloth>=2026.5.7 (#5753) 2026-05-24 07:22:49 -07:00
LICENSE Rename cli/ to unsloth_cli/ to fix namespace collision with stringzilla (#4393) 2026-03-17 20:40:21 -07:00
pyproject.toml API fixes + pypi 2026-05-22 09:16:53 -07:00
README.md Adding Connect a Provider README changes 2026-05-21 05:08:59 -07:00
unsloth-cli.py Merge pull request #3612 from Vangmay/feature/raw-text-dataprep 2026-01-08 03:38:15 -08:00

Unsloth logo

Unsloth Studio lets you run and train models locally.

FeaturesQuickstartNotebooksDocumentation


unsloth studio ui homepage

Get started

macOS, Linux, WSL:

curl -fsSL https://unsloth.ai/install.sh | sh

Windows:

irm https://unsloth.ai/install.ps1 | iex

Community:

Features

Unsloth Studio (Beta) lets you run and train text, audio, embedding, vision models on Windows, Linux and macOS.

Inference

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 and Hugging Face.
  • Data Recipes: Auto-create datasets from PDF, CSV, DOCX etc. Edit data in a visual-node workflow.
  • Reinforcement Learning (RL): The most efficient RL library, using 80% less VRAM for GRPO, FP8 etc.
  • Supports full fine-tuning, RL, pretraining, 4-bit, 16-bit and, FP8 training.
  • Observability: Monitor training live, track loss and GPU usage and customize graphs.
  • Multi-GPU training is supported, with major improvements coming soon.

📥 Install

Unsloth can be used in two ways: through Unsloth Studio, the web UI, or through Unsloth Core, the code-based version. Each has different requirements.

Unsloth Studio (web UI)

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. Studio support is out soon.
  • Multi-GPU: Available now, with a major upgrade on the way

macOS, Linux, WSL:

curl -fsSL https://unsloth.ai/install.sh | sh

Windows:

irm https://unsloth.ai/install.ps1 | iex

Launch

unsloth studio -p 8888

For cloud or global access, add -H 0.0.0.0. By default, Unsloth is accessible only locally.

Update

To update, use the same install commands above or use unsloth studio update.

Docker

Use our Docker image unsloth/unsloth container. Run:

docker run -d -e JUPYTER_PASSWORD="mypassword" \
  -p 8888:8888 -p 8000:8000 -p 2222:22 \
  -v $(pwd)/work:/workspace/work \
  --gpus all \
  unsloth/unsloth

Developer, Nightly, Uninstall

To see developer, nightly and uninstallation etc. instructions, see advanced installation.

Unsloth Core (code-based)

Linux, WSL:

curl -LsSf https://astral.sh/uv/install.sh | sh
uv venv unsloth_env --python 3.13
source unsloth_env/bin/activate
uv pip install unsloth --torch-backend=auto

Windows:

winget install -e --id Python.Python.3.13
winget install --id=astral-sh.uv  -e
uv venv unsloth_env --python 3.13
.\unsloth_env\Scripts\activate
uv pip install unsloth --torch-backend=auto

For Windows, pip install unsloth works only if you have PyTorch installed. Read our Windows Guide. 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 and DGX Spark.
To install Unsloth on AMD and Intel GPUs, follow our AMD Guide and Intel Guide.

📒 Free Notebooks

Train for free with our notebooks. You can use our new free Unsloth Studio notebook to run and train models for free in a web UI. Read our guide. Add dataset, run, then deploy your trained model.

Model Free Notebooks Performance Memory use
Gemma 4 (E2B) ▶️ Start for free 1.5x faster 50% less
Qwen3.5 (4B) ▶️ Start for free 1.5x faster 60% less
gpt-oss (20B) ▶️ Start for free 2x faster 70% less
Qwen3.5 GSPO ▶️ Start for free 2x faster 70% less
gpt-oss (20B): GRPO ▶️ Start for free 2x faster 80% less
Qwen3: Advanced GRPO ▶️ Start for free 2x faster 70% less
embeddinggemma (300M) ▶️ Start for free 2x faster 20% less
Mistral Ministral 3 (3B) ▶️ Start for free 1.5x faster 60% less
Llama 3.1 (8B) Alpaca ▶️ Start for free 2x faster 70% less
Llama 3.2 Conversational ▶️ Start for free 2x faster 70% less
Orpheus-TTS (3B) ▶️ Start for free 1.5x faster 50% less

🦥 Unsloth News

  • Connections: Connect any API provider (OpenAI, Anthropic) or server (vLLM, Ollama). Guide
  • MTP: Run Qwen3.6 MTP in Unsloth. MTP settings are autoset specific to your hardware. Guide
  • API inference endpoint: Deploy and run local LLMs in Claude Code, Codex tools. Guide
  • Qwen3.6: Qwen3.6-35B-A3B can now be trained and run in Unsloth Studio. Blog
  • Gemma 4: Run and train Googles new models directly in Unsloth. Blog
  • Introducing Unsloth Studio: our new web UI for running and training LLMs. Blog
  • Qwen3.5 - 0.8B, 2B, 4B, 9B, 27B, 35-A3B, 112B-A10B are now supported. Guide + notebooks
  • Train MoE LLMs 12x faster with 35% less VRAM - DeepSeek, GLM, Qwen and gpt-oss. Blog
  • Embedding models: Unsloth now supports ~1.8-3.3x faster embedding fine-tuning. BlogNotebooks
  • New 7x longer context RL vs. all other setups, via our new batching algorithms. Blog
  • New RoPE & MLP Triton Kernels & Padding Free + Packing: 3x faster training & 30% less VRAM. Blog
  • 500K Context: Training a 20B model with >500K context is now possible on an 80GB GPU. Blog
  • FP8 & Vision RL: You can now do FP8 & VLM GRPO on consumer GPUs. FP8 BlogVision RL

📥 Advanced Installation

The below advanced instructions are for Unsloth Studio. For Unsloth Core advanced installation, view our docs.

Developer installs: macOS, Linux, WSL:

git clone https://github.com/unslothai/unsloth
cd unsloth
./install.sh --local
unsloth studio -p 8888

Then to update :

unsloth studio update

Developer installs: Windows PowerShell:

git clone https://github.com/unslothai/unsloth.git
cd unsloth
Set-ExecutionPolicy -Scope Process -ExecutionPolicy Bypass
.\install.ps1 --local
unsloth studio -p 8888

Then to update :

unsloth studio update

Nightly: MacOS, Linux, WSL:

git clone https://github.com/unslothai/unsloth
cd unsloth
git checkout nightly
./install.sh --local
unsloth studio -p 8888

Then to launch every time:

unsloth studio -p 8888

Nightly: Windows:

Run in Windows Powershell:

git clone https://github.com/unslothai/unsloth.git
cd unsloth
git checkout nightly
Set-ExecutionPolicy -Scope Process -ExecutionPolicy Bypass
.\install.ps1 --local
unsloth studio -p 8888

Then to launch every time:

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):

  • MacOS, WSL, Linux: curl -fsSL https://raw.githubusercontent.com/unslothai/unsloth/main/scripts/uninstall.sh | sh
  • Windows (PowerShell): irm https://raw.githubusercontent.com/unslothai/unsloth/main/scripts/uninstall.ps1 | iex

If you only want to drop the install dir and keep the launcher/shortcut for a later reinstall, you can instead run rm -rf ~/.unsloth/studio (Mac/Linux/WSL) or Remove-Item -Recurse -Force "$HOME\.unsloth\studio" (Windows). The model cache at ~/.cache/huggingface is not touched by any of these.

For more info, see our docs.

Deleting model files

You can delete old model files either from the bin icon in model search or by removing the relevant cached model folder from the default Hugging Face cache directory. By default, HF uses:

  • MacOS, Linux, WSL: ~/.cache/huggingface/hub/
  • Windows: %USERPROFILE%\.cache\huggingface\hub\
Type Links
  Discord Join Discord server
  r/unsloth Reddit Join Reddit community
📚 Documentation & Wiki Read Our Docs
  Twitter (aka X) Follow us on X
🔮 Our Models Unsloth Catalog
✍️ Blog Read our Blogs

Citation

You can cite the Unsloth repo as follows:

@software{unsloth,
  author = {Daniel Han, Michael Han and Unsloth team},
  title = {Unsloth},
  url = {https://github.com/unslothai/unsloth},
  year = {2023}
}

If you trained a model with 🦥Unsloth, you can use this cool sticker!  

License

Unsloth uses a dual-licensing model of Apache 2.0 and AGPL-3.0. The core Unsloth package remains licensed under Apache 2.0, while certain optional components, such as the Unsloth Studio UI are licensed under the open-source license AGPL-3.0.

This structure helps support ongoing Unsloth development while keeping the project open source and enabling the broader ecosystem to continue growing.

Thank You to

  • The llama.cpp library that lets users run and save models with Unsloth
  • The Hugging Face team and their libraries: transformers and TRL
  • The Pytorch and Torch AO team for their contributions
  • NVIDIA for their NeMo DataDesigner library and their contributions
  • And of course for every single person who has contributed or has used Unsloth!