unsloth/unsloth_cli/commands/studio.py

# 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 importlib.util
import hashlib
import hmac
import json
import os
import platform
import re
import secrets
import sqlite3
import subprocess
import sys
import tempfile
import time
import types
import urllib.error
import urllib.request
from datetime import datetime, timezone
from pathlib import Path
from typing import List, Optional
import typer

from unsloth_cli.commands import _password_prompt

studio_app = typer.Typer(help = "Unsloth Studio commands.")


def _enable_verbose_access_logs() -> None:
    """Restore every per-request access log by disabling the burst dedup and the
    quiet-poll heartbeat. Inherited by the spawned/re-exec'd server via the env."""
    os.environ["UNSLOTH_STUDIO_ACCESS_LOG_DEDUP_MS"] = "0"
    os.environ["UNSLOTH_STUDIO_ACCESS_LOG_POLL_DEDUP_MS"] = "0"


# Resolve install root: UNSLOTH_STUDIO_HOME, then STUDIO_HOME alias, then
# sys.prefix inference (so a direct call to <root>/bin/unsloth resolves after
# the installer's env var has expired), then legacy ~/.unsloth/studio.
# 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.
    """
    shim_name = "unsloth.exe" if platform.system() == "Windows" else "unsloth"
    return (candidate / "share" / "studio.conf").is_file() or (
        candidate / "bin" / shim_name
    ).is_file()


def _resolve_studio_home() -> tuple[Path, bool]:
    override = (os.environ.get("UNSLOTH_STUDIO_HOME") or "").strip()
    if not override:
        override = (os.environ.get("STUDIO_HOME") or "").strip()
    if override:
        try:
            return Path(override).expanduser().resolve(), True
        except (OSError, ValueError):
            return Path(override).expanduser(), True
    try:
        prefix = Path(sys.prefix).resolve()
        if prefix.name == "unsloth_studio":
            inferred = prefix.parent
            legacy = (Path.home() / ".unsloth" / "studio").resolve()
            if inferred != legacy and _looks_like_installer_managed_studio_home(inferred):
                return inferred, True
    except (OSError, ValueError):
        pass
    return Path.home() / ".unsloth" / "studio", False


STUDIO_HOME, _STUDIO_HOME_IS_CUSTOM = _resolve_studio_home()


def _ensure_studio_env_exported() -> None:
    """Re-export UNSLOTH_STUDIO_HOME / UNSLOTH_LLAMA_CPP_PATH only for real
    custom roots so subprocesses inherit the right install. Called from each
    studio subcommand entry rather than at import time, to avoid leaking env
    state into unrelated importers (tests, --help, CLI introspection).
    """
    if not _STUDIO_HOME_IS_CUSTOM:
        return
    # Truthy-check (not setdefault) so a blank UNSLOTH_STUDIO_HOME= does not
    # suppress the inferred custom root.
    if not os.environ.get("UNSLOTH_STUDIO_HOME"):
        os.environ["UNSLOTH_STUDIO_HOME"] = str(STUDIO_HOME)
    # When override == legacy default, llama.cpp stays at ~/.unsloth/llama.cpp.
    try:
        _legacy_studio = (Path.home() / ".unsloth" / "studio").resolve()
        _is_legacy = STUDIO_HOME.resolve() == _legacy_studio
    except (OSError, ValueError):
        _is_legacy = STUDIO_HOME == (Path.home() / ".unsloth" / "studio")
    if _is_legacy:
        _llama_dir = Path.home() / ".unsloth" / "llama.cpp"
    else:
        _llama_dir = STUDIO_HOME / "llama.cpp"
    if not os.environ.get("UNSLOTH_LLAMA_CPP_PATH"):
        os.environ["UNSLOTH_LLAMA_CPP_PATH"] = str(_llama_dir)


BOOTSTRAP_PASSWORD_FILE = ".bootstrap_password"
DESKTOP_SECRET_FILE = ".desktop_secret"
DEFAULT_ADMIN_USERNAME = "unsloth"
DESKTOP_SECRET_PREFIX = "desktop-"
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

# __file__ is unsloth_cli/commands/studio.py -- two parents up is the package root
# (either site-packages or the repo root for editable installs).
_PACKAGE_ROOT = Path(__file__).resolve().parent.parent.parent


def _should_hide_windows_subprocesses() -> bool:
    """Hide child console windows only for non-interactive Windows launches."""
    if platform.system() != "Windows":
        return False
    try:
        return not sys.stdout.isatty()
    except (AttributeError, OSError, ValueError):
        return True


def _windows_hidden_subprocess_kwargs() -> dict[str, object]:
    """Return Windows-only Popen kwargs that suppress transient console windows."""
    if not _should_hide_windows_subprocesses():
        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 _stream_for_subprocess(stream):
    """Return *stream* if it has a real OS file descriptor, else None.

    subprocess.run on Windows refuses to inherit std handles unless
    they're passed explicitly (otherwise close_fds=True forces
    bInheritHandles=False, and a CREATE_NO_WINDOW child ends up with
    no stdio at all). When sys.stdout / sys.stderr is a real fd-backed
    stream we want to hand it through; when it's been captured by a
    test harness (pytest's capsys, an in-memory wrapper, etc) we fall
    back to None so subprocess uses its default.
    """
    if stream is None:
        return None
    try:
        stream.fileno()
    except (AttributeError, OSError, ValueError):
        return None
    return stream


def _display_host_for_bind(run_mod, host: str) -> str:
    return run_mod._resolve_external_ip() if host in ("0.0.0.0", "::") else host


def _loopback_bind_host_for(host: str) -> str:
    return "::1" if host == "::" else "127.0.0.1"


def _url_host(host: str) -> str:
    return (
        f"[{host}]" if ":" in host and not (host.startswith("[") and host.endswith("]")) else host
    )


def _emit_run_cloudflare_notice(
    run_mod, host: str, display_host: str, actual_port: int, secure: bool
) -> None:
    from unsloth_cli._tool_policy import is_external_host

    if not is_external_host(host):
        return
    run_mod._verify_global_reachability(display_host, actual_port)
    run_mod._print_cloudflare_line(
        secure = secure,
        loopback_host = _loopback_bind_host_for(host),
    )


def _studio_venv_python() -> Optional[Path]:
    """Return the studio venv Python binary, or None if not set up."""
    if platform.system() == "Windows":
        p = STUDIO_HOME / "unsloth_studio" / "Scripts" / "python.exe"
    else:
        p = STUDIO_HOME / "unsloth_studio" / "bin" / "python"
    return p if p.is_file() else None


def _find_run_py() -> Optional[Path]:
    """Find studio/backend/run.py.

    No CWD dependency — works from any directory.
    Since studio/ is now a proper package (has __init__.py), it lives in
    site-packages after pip install, right next to unsloth_cli/.
    """
    # 1. Relative to __file__ (site-packages or editable repo root)
    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)
    for pattern in (
        "lib/python*/site-packages/studio/backend/run.py",
        "Lib/site-packages/studio/backend/run.py",
    ):
        for match in (STUDIO_HOME / "unsloth_studio").glob(pattern):
            return match
    return None


_RUN_MODULE = None


def _load_run_module():
    """Import studio.backend.run without relying on package resolution.

    `studio update` can leave a partial ``site-packages/studio/backend/``
    tree (plugin build artefacts only). That shadowed tree wins over an
    editable install and breaks ``from studio.backend.run import ...``.
    Loading by file path sidesteps the conflict.
    """
    global _RUN_MODULE
    if _RUN_MODULE is not None:
        return _RUN_MODULE

    run_py = _find_run_py()
    if run_py is None:
        raise ImportError("Could not find studio/backend/run.py. Re-run: unsloth studio setup")

    loaded = sys.modules.get("studio.backend.run")
    if loaded is not None:
        # __file__ can be None for namespace packages from partial trees.
        loaded_path = Path(getattr(loaded, "__file__", None) or "").resolve()
        if loaded_path == run_py.resolve():
            _RUN_MODULE = loaded
            return _RUN_MODULE

    spec = importlib.util.spec_from_file_location("studio.backend.run", run_py)
    if spec is None or spec.loader is None:
        raise ImportError(f"Could not load studio backend from {run_py}")
    module = importlib.util.module_from_spec(spec)
    sys.modules["studio.backend.run"] = module
    try:
        spec.loader.exec_module(module)
    except Exception:
        sys.modules.pop("studio.backend.run", None)
        raise
    _RUN_MODULE = module
    return _RUN_MODULE


def _find_setup_script() -> Optional[Path]:
    """Find studio/setup.sh or studio/setup.ps1.

    No CWD dependency — works from any directory.
    """
    name = "setup.ps1" if platform.system() == "Windows" else "setup.sh"
    # 1. Relative to __file__ (site-packages or editable repo root)
    s = _PACKAGE_ROOT / "studio" / name
    if s.is_file():
        return s
    # 2. Studio venv's site-packages
    for pattern in (
        f"lib/python*/site-packages/studio/{name}",
        f"Lib/site-packages/studio/{name}",
    ):
        for match in (STUDIO_HOME / "unsloth_studio").glob(pattern):
            return match
    return None


# Mirror in studio/backend/run.py argparse + backend denylist test;
# bumping the cap in one place only desyncs.
_PARALLEL_MIN = 1
_PARALLEL_MAX = 64
_PARALLEL_DEFAULT_RUN = 4  # pre-PR hardcoded for `unsloth studio run`
_PARALLEL_DEFAULT_PLAIN = 1  # pre-PR effective for plain `unsloth studio`


def _resolve_secure(secure: bool, not_secure: bool) -> bool:
    """Reconcile the deprecated --not-secure alias with --secure/--no-secure.

    Typer parses --secure and --not-secure as independent options, so the alias
    cannot lean on Click's last-wins ordering the way --secure/--no-secure do.
    Restore that ordering from argv: --not-secure only forces secure off when it
    is the last of the secure flags on the command line, matching the backend's
    BooleanOptionalAction.
    """
    if not not_secure:
        return secure
    last_secure = max(
        (i for i, a in enumerate(sys.argv) if a in ("--secure", "--no-secure")),
        default = -1,
    )
    last_not_secure = max(
        (i for i, a in enumerate(sys.argv) if a == "--not-secure"),
        default = -1,
    )
    return secure if last_secure > last_not_secure else False


def _iter_editable_studio_source_roots(venv_dir: Path):
    """Yield repo roots from setuptools `__editable___*_finder.py` files in
    *venv_dir*'s site-packages whose MAPPING includes a `studio` entry.

    Returns the parent dir of the mapped `studio` package (i.e. the repo
    root), so callers can append `/studio/...` to reach any subdir.
    """
    import ast
    import re

    for sp_pattern in ("lib/python*/site-packages", "Lib/site-packages"):
        for sp in venv_dir.glob(sp_pattern):
            for finder in sp.glob("__editable___*_finder.py"):
                try:
                    src = finder.read_text(encoding = "utf-8")
                except OSError:
                    continue
                # Tolerate single- or multi-line dict literals; [^}]* still
                # rejects nested dicts, which the setuptools template never
                # emits for editable installs.
                m = re.search(r"^MAPPING\s*(?::[^=]*)?=\s*(\{[^}]*\})", src, re.M | re.S)
                if not m:
                    continue
                try:
                    mapping = ast.literal_eval(m.group(1))
                except (SyntaxError, ValueError):
                    continue
                # Defensive: literal_eval can return a set / list / None if the
                # matched literal is not a dict (regex captures `{...}`).
                if not isinstance(mapping, dict):
                    continue
                studio_pkg = mapping.get("studio")
                if studio_pkg:
                    yield Path(studio_pkg).parent


def _find_frontend_dist() -> Optional[Path]:
    """Locate a built `studio/frontend/dist` (containing index.html).

    Probes (in order): package-local default, installer venv site-packages,
    editable source roots referenced from the installer venv. Returns None
    if nothing servable is found, so callers can decide to error or proceed
    in `--api-only` mode.

    Fixes the silent 404 when another `unsloth` on PATH shadows the
    installer's binary and points `_PACKAGE_ROOT` at a site-packages copy
    that never received a vite build.
    """
    candidates: List[Path] = [_PACKAGE_ROOT / "studio" / "frontend" / "dist"]
    venv_dir = STUDIO_HOME / "unsloth_studio"
    for pattern in (
        "lib/python*/site-packages/studio/frontend/dist",
        "Lib/site-packages/studio/frontend/dist",
    ):
        candidates.extend(venv_dir.glob(pattern))
    for repo_root in _iter_editable_studio_source_roots(venv_dir):
        candidates.append(repo_root / "studio" / "frontend" / "dist")
    seen: set[Path] = set()
    for c in candidates:
        try:
            resolved = c.resolve()
        except OSError:
            resolved = c
        if resolved in seen:
            continue
        seen.add(resolved)
        if (c / "index.html").is_file():
            return c
    return None


# ── helpers for `unsloth studio run` ────────────────────────────────


def _wait_for_server(port: int, timeout: int = 30) -> bool:
    """Poll ``GET /api/health`` until the server responds 200 or *timeout* expires."""
    import urllib.request
    import urllib.error

    url = f"http://127.0.0.1:{port}/api/health"
    deadline = time.monotonic() + timeout
    while time.monotonic() < deadline:
        try:
            with urllib.request.urlopen(url, timeout = 2) as resp:
                if resp.status == 200:
                    return True
        except (urllib.error.URLError, OSError, ConnectionError):
            pass
        time.sleep(0.5)
    return False


def _create_api_key_inprocess(name: str) -> str:
    """Create an API key via direct storage call (no HTTP needed).

    Bypasses the ``must_change_password`` gate that blocks HTTP
    ``POST /api/auth/api-keys`` on fresh installs.  Safe because the
    CLI already has filesystem access to ``~/.unsloth/studio``.
    """
    storage = _load_backend_auth_storage()

    raw_key, _row = storage.create_api_key(
        username = storage.DEFAULT_ADMIN_USERNAME,
        name = name,
    )
    return raw_key


def _load_backend_auth_storage():
    run_py = _find_run_py()
    backend_dir = run_py.parent if run_py is not None else _PACKAGE_ROOT / "studio" / "backend"
    if backend_dir.is_dir() and str(backend_dir) not in sys.path:
        sys.path.insert(0, str(backend_dir))

    auth_dir = backend_dir / "auth"
    storage_py = auth_dir / "storage.py"
    loaded = sys.modules.get("auth.storage")
    if loaded is not None:
        # __file__ can be None for namespace packages from partial trees.
        loaded_path = Path(getattr(loaded, "__file__", None) or "").resolve()
        if loaded_path == storage_py.resolve():
            return loaded

    package = sys.modules.get("auth")
    package_paths = [Path(path).resolve() for path in getattr(package, "__path__", [])]
    if package is None or auth_dir.resolve() not in package_paths:
        package = types.ModuleType("auth")
        package.__path__ = [str(auth_dir)]
        package.__package__ = "auth"
        package.__file__ = str(auth_dir / "__init__.py")
        sys.modules["auth"] = package

    spec = importlib.util.spec_from_file_location("auth.storage", storage_py)
    if spec is None or spec.loader is None:
        raise ImportError(f"Could not load backend auth storage from {storage_py}")
    storage = importlib.util.module_from_spec(spec)
    sys.modules["auth.storage"] = storage
    spec.loader.exec_module(storage)

    return storage


def _write_auth_secret(path: Path, secret: str) -> None:
    path.parent.mkdir(parents = True, exist_ok = True)
    fd, tmp_name = tempfile.mkstemp(prefix = f".{path.name}.", dir = path.parent)
    tmp_path = Path(tmp_name)
    try:
        try:
            os.chmod(tmp_path, 0o600)
        except OSError:
            pass
        with os.fdopen(fd, "w", encoding = "utf-8") as f:
            fd = -1
            f.write(secret)
        os.replace(tmp_path, path)
    except Exception:
        if fd >= 0:
            os.close(fd)
        tmp_path.unlink(missing_ok = True)
        raise
    try:
        os.chmod(path, 0o600)
    except OSError:
        pass


def _connect_auth_db() -> sqlite3.Connection:
    auth_dir = STUDIO_HOME / "auth"
    auth_dir.mkdir(parents = True, exist_ok = True)
    conn = sqlite3.connect(auth_dir / "auth.db")
    # Mirror backend storage.get_connection: this path can create auth/ and
    # auth.db (the pre-exposure gate writes here first), and sqlite3.connect
    # makes the DB 0644 under a 022 umask. Keep both private.
    for _path, _mode in ((auth_dir, 0o700), (auth_dir / "auth.db", 0o600)):
        try:
            os.chmod(_path, _mode)
        except OSError:
            pass
    conn.execute(
        """
        CREATE TABLE IF NOT EXISTS auth_user (
            id INTEGER PRIMARY KEY,
            username TEXT UNIQUE NOT NULL,
            password_salt TEXT NOT NULL,
            password_hash TEXT NOT NULL,
            jwt_secret TEXT NOT NULL,
            must_change_password INTEGER NOT NULL DEFAULT 0
        );
        """
    )
    conn.execute(
        """
        CREATE TABLE IF NOT EXISTS refresh_tokens (
            id INTEGER PRIMARY KEY,
            token_hash TEXT NOT NULL,
            username TEXT NOT NULL,
            expires_at TEXT NOT NULL,
            is_desktop INTEGER NOT NULL DEFAULT 0
        );
        """
    )
    conn.execute(
        """
        CREATE TABLE IF NOT EXISTS api_keys (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            username TEXT NOT NULL,
            key_prefix TEXT NOT NULL,
            key_hash TEXT NOT NULL UNIQUE,
            name TEXT NOT NULL DEFAULT '',
            created_at TEXT NOT NULL,
            last_used_at TEXT,
            expires_at TEXT,
            is_active INTEGER NOT NULL DEFAULT 1
        );
        """
    )
    conn.execute(
        """
        CREATE TABLE IF NOT EXISTS app_secrets (
            key TEXT PRIMARY KEY,
            value TEXT NOT NULL
        );
        """
    )
    auth_columns = {row[1] for row in conn.execute("PRAGMA table_info(auth_user)")}
    if "must_change_password" not in auth_columns:
        conn.execute(
            "ALTER TABLE auth_user ADD COLUMN must_change_password INTEGER NOT NULL DEFAULT 0"
        )
    refresh_columns = {row[1] for row in conn.execute("PRAGMA table_info(refresh_tokens)")}
    if "is_desktop" not in refresh_columns:
        conn.execute("ALTER TABLE refresh_tokens ADD COLUMN is_desktop INTEGER NOT NULL DEFAULT 0")
    conn.commit()
    return conn


def _pbkdf2_hex(value: str, salt: bytes) -> str:
    return hashlib.pbkdf2_hmac(
        "sha256",
        value.encode("utf-8"),
        salt,
        PBKDF2_ITERATIONS,
    ).hex()


def _hash_password(password: str) -> tuple[str, str]:
    salt = secrets.token_hex(16)
    pwd_hash = _pbkdf2_hex(password, salt.encode("utf-8"))
    return salt, pwd_hash


def _get_or_create_api_key_pbkdf2_salt(conn: sqlite3.Connection) -> bytes:
    row = conn.execute(
        "SELECT value FROM app_secrets WHERE key = ?",
        (API_KEY_PBKDF2_SALT_KEY,),
    ).fetchone()
    if row is None:
        salt_hex = secrets.token_hex(32)
        conn.execute(
            "INSERT OR IGNORE INTO app_secrets (key, value) VALUES (?, ?)",
            (API_KEY_PBKDF2_SALT_KEY, salt_hex),
        )
        row = conn.execute(
            "SELECT value FROM app_secrets WHERE key = ?",
            (API_KEY_PBKDF2_SALT_KEY,),
        ).fetchone()
    return bytes.fromhex(row[0])


def _ensure_cli_default_admin(conn: sqlite3.Connection) -> None:
    row = conn.execute(
        "SELECT 1 FROM auth_user WHERE username = ?",
        (DEFAULT_ADMIN_USERNAME,),
    ).fetchone()
    if row is not None:
        return

    bootstrap_password = secrets.token_urlsafe(32)
    password_salt, password_hash = _hash_password(bootstrap_password)
    conn.execute(
        """
        INSERT INTO auth_user (
            username,
            password_salt,
            password_hash,
            jwt_secret,
            must_change_password
        )
        VALUES (?, ?, ?, ?, ?)
        """,
        (
            DEFAULT_ADMIN_USERNAME,
            password_salt,
            password_hash,
            secrets.token_urlsafe(64),
            1,
        ),
    )
    _write_auth_secret(
        STUDIO_HOME / "auth" / BOOTSTRAP_PASSWORD_FILE,
        bootstrap_password,
    )


def _create_desktop_secret_in_cli() -> str:
    raw_secret = DESKTOP_SECRET_PREFIX + secrets.token_urlsafe(48)
    now = datetime.now(timezone.utc).isoformat()
    conn = _connect_auth_db()
    try:
        _ensure_cli_default_admin(conn)
        secret_hash = _pbkdf2_hex(raw_secret, _get_or_create_api_key_pbkdf2_salt(conn))
        conn.execute(
            "INSERT OR REPLACE INTO app_secrets (key, value) VALUES (?, ?)",
            (DESKTOP_SECRET_HASH_KEY, secret_hash),
        )
        conn.execute(
            "INSERT OR REPLACE INTO app_secrets (key, value) VALUES (?, ?)",
            (DESKTOP_SECRET_CREATED_AT_KEY, now),
        )
        conn.commit()
        return raw_secret
    finally:
        conn.close()


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.

    CLI mirror of run.py's _cloudflare_tunnel_should_start, minus the Colab
    case (Colab launches never come through this CLI path). --secure implies
    the tunnel; --cloudflare only tunnels non-api-only wildcard binds.
    """
    if secure:
        return True
    if cloudflare is not True:
        return False
    return host in ("0.0.0.0", "::") and not api_only


def _prompt_streams_interactive() -> bool:
    """The prompt needs a real terminal for input and for the masked echo."""
    try:
        return sys.stdin.isatty() and sys.stderr.isatty()
    except (AttributeError, ValueError):
        return False


def _bootstrap_deadline_active() -> bool:
    """Whether the backend's bootstrap shutdown deadline will arm.

    Mirror of studio/backend/auth/bootstrap_timeout.py bootstrap_timeout_seconds:
    unset/blank/malformed UNSLOTH_STUDIO_BOOTSTRAP_TIMEOUT falls back to the 1h
    default (a typo must not remove protection); 0 or negative disables it.
    """
    raw = os.environ.get("UNSLOTH_STUDIO_BOOTSTRAP_TIMEOUT", "").strip()
    if not raw:
        return True
    try:
        return int(raw) > 0
    except ValueError:
        return True


def _cli_update_password(conn: sqlite3.Connection, username: str, new_password: str) -> None:
    """CLI mirror of backend update_password + change-password route effects.

    One transaction: rehash, rotate the JWT secret, clear must_change_password,
    revoke refresh tokens (PR #6651 finding), and drop the desktop secret. File
    cleanup happens after commit; a failed unlink must not roll the change back.
    """
    password_salt, password_hash = _hash_password(new_password)
    with conn:
        conn.execute(
            """
            UPDATE auth_user
            SET password_salt = ?, password_hash = ?, jwt_secret = ?, must_change_password = 0
            WHERE username = ?
            """,
            (password_salt, password_hash, secrets.token_urlsafe(64), username),
        )
        conn.execute("DELETE FROM refresh_tokens WHERE username = ?", (username,))
        conn.execute(
            "DELETE FROM app_secrets WHERE key IN (?, ?)",
            (DESKTOP_SECRET_HASH_KEY, DESKTOP_SECRET_CREATED_AT_KEY),
        )
    for stale in (BOOTSTRAP_PASSWORD_FILE, DESKTOP_SECRET_FILE):
        stale_path = STUDIO_HOME / "auth" / stale
        try:
            stale_path.unlink(missing_ok = True)
        except OSError as exc:
            # The hash is already committed, so a failed unlink must NOT roll the
            # change back. But a locked-yet-writable file (Windows AV, read-only
            # auth dir) must be truncated: otherwise its stale plaintext survives
            # and generate_bootstrap_password() would re-validate this revoked
            # credential after a later reset-password deletes auth.db. Mirrors
            # backend clear_bootstrap_password().
            try:
                stale_path.write_text("")
                cleared = True
            except OSError:
                cleared = False
            if cleared:
                typer.echo(
                    f"Warning: could not remove stale {stale} file ({exc}); cleared its "
                    "contents so the old credential cannot be reused.",
                    err = True,
                )
            else:
                typer.echo(
                    f"Warning: could not remove or clear stale {stale} file ({exc}); the "
                    "old credential is still on disk. Remove it manually to prevent reuse "
                    "after a reset.",
                    err = True,
                )


def _apply_supplied_password_before_launch(supplied_password: "str | None") -> None:
    """Non-interactively set the INITIAL admin password (from --password /
    UNSLOTH_STUDIO_PASSWORD / stdin) before the server binds, while the account
    still has its auto-generated bootstrap password.

    Only ever sets the FIRST password: an already-set one is a hard error (an
    override would be an auth bypass on a public launch), and an invalid value
    fails closed. Runs in the parent before any re-exec so the secret never
    crosses to the child argv.
    """
    if not supplied_password:
        return
    try:
        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.",
            err = True,
        )
        raise typer.Exit(1)
    try:
        _ensure_cli_default_admin(conn)
        conn.commit()
        row = conn.execute(
            "SELECT password_salt, password_hash, must_change_password "
            "FROM auth_user WHERE username = ?",
            (DEFAULT_ADMIN_USERNAME,),
        ).fetchone()
        if not row:
            typer.echo(
                "Error: --password could not initialize the admin account; not starting.",
                err = True,
            )
            raise typer.Exit(1)
        if not row[2]:
            typer.echo(
                "Error: a Studio 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,
            )
            raise typer.Exit(1)
        password_salt, password_hash = row[0], row[1]

        def _is_current_password(candidate: str) -> bool:
            return hmac.compare_digest(
                _pbkdf2_hex(candidate, password_salt.encode("utf-8")), password_hash
            )

        problem = _password_prompt.validate_new_password(supplied_password, _is_current_password)
        if problem is not None:
            typer.echo(f"Error: {problem} Not starting.", err = True)
            raise typer.Exit(1)
        _cli_update_password(conn, DEFAULT_ADMIN_USERNAME, supplied_password)
        typer.echo(f"Password updated for '{DEFAULT_ADMIN_USERNAME}'.", err = True)
    except (OSError, sqlite3.Error) as exc:
        # 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.",
            err = True,
        )
        raise typer.Exit(1)
    finally:
        conn.close()


def _strip_seeded_bootstrap_password_or_exit(*, context: str) -> None:
    """Remove the seeded plaintext bootstrap password before a public re-exec.

    Version-independent protection: a re-exec'd child of ANY version (including an
    old studio-venv predating the pre-bind gate) then reads None instead of
    injecting the default credential into the public page. must_change_password
    stays set, so the login page still forces a change and the timer still arms.
    Removal IS the protection, so if it fails (locked file, read-only auth dir)
    fail closed rather than publish it.
    """
    bootstrap_file = STUDIO_HOME / "auth" / BOOTSTRAP_PASSWORD_FILE
    try:
        bootstrap_file.unlink(missing_ok = True)
    except OSError as exc:
        typer.echo(
            "Error: refusing to publish Studio 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}). "
            "Delete it manually or change the admin password (run `unsloth studio` "
            "locally with a terminal attached, or `unsloth studio reset-password`), "
            "then retry.",
            err = True,
        )
        raise typer.Exit(1)


def _require_servable_frontend_or_exit(
    *, frontend: Optional[Path], api_only: bool, cloudflare: Optional[bool], host: str, secure: bool
) -> Optional[Path]:
    """Fail closed BEFORE the pre-exposure gate if a public UI launch has no
    login page to change the seeded password.

    The gate strips the seeded .bootstrap_password on a headless public launch,
    so if the child then cannot serve the login page the admin is locked out
    (must_change_password=1, no file, no UI) until `unsloth studio reset-password`.
    The login page is the ONLY in-band way to change the seeded password, so a
    public non-api-only launch must have a servable dist before the strip.

    Returns the dist to serve: a user-supplied --frontend (validated to contain
    index.html) or the auto-resolved built dist. Returns `frontend` unchanged for
    non-public or --api-only launches (no login page needed).
    """
    if api_only or not _should_prompt_password_change(
        cloudflare = cloudflare, host = host, secure = secure, api_only = api_only
    ):
        return frontend
    if frontend is not None:
        # A user-supplied dist is not vetted by _find_frontend_dist, so verify it
        # can serve the login page; else `--frontend /bad/path` bypasses the guard.
        if (Path(frontend) / "index.html").is_file():
            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 "
            "admin password. Point --frontend at a built dist, rebuild it (re-run "
            "install.sh), or use --api-only.",
            err = True,
        )
        raise typer.Exit(1)
    # _find_frontend_dist only returns a path that already contains index.html.
    resolved = _find_frontend_dist()
    if resolved is not None:
        return resolved
    typer.echo(
        "Error: the Studio 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,
    )
    raise typer.Exit(1)


def _validate_inproc_backend_before_strip(
    *, cloudflare: Optional[bool], host: str, secure: bool, api_only: bool
) -> None:
    """In-venv (in-process) analogue of the re-exec launcher check.

    In-venv there is no re-exec, so the backend is imported in-process only AFTER
    the gate. On the headless public path the gate strips the seeded
    .bootstrap_password, so a broken venv that fails at import would leave
    must_change_password=1 with no password to log in. Import the backend up front
    on that path and exit cleanly if broken, before anything is stripped.
    Headless-only so an interactive prompt is not delayed behind the import.
    """
    if not _should_prompt_password_change(
        cloudflare = cloudflare, host = host, secure = secure, api_only = api_only
    ):
        return
    if _prompt_streams_interactive():
        return
    try:
        _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: "
            "unsloth studio setup",
            err = True,
        )
        raise typer.Exit(1)


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.

    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
    that will never come up. Loads the stdlib-only cloudflare_tunnel helper by
    file path so the check runs in the parent, before the strip.

    Returns False on ANY uncertainty: a possible credential leak outweighs a
    recoverable lockout, so the caller keeps the strip unless the tunnel is
    provably dead.
    """
    run_py = _find_run_py()
    if run_py is None:
        return False
    backend_dir = run_py.parent
    tunnel_py = backend_dir / "cloudflare_tunnel.py"
    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,
    # 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
    try:
        if str(backend_dir) not in sys.path:
            sys.path.insert(0, str(backend_dir))
            added_backend_path = True
        spec = importlib.util.spec_from_file_location("studio.backend.cloudflare_tunnel", tunnel_py)
        if spec is None or spec.loader is None:
            return False
        module = importlib.util.module_from_spec(spec)
        spec.loader.exec_module(module)
        return module.ensure_cloudflared() is None
    except Exception:
        return False
    finally:
        if added_backend_path:
            try:
                sys.path.remove(str(backend_dir))
            except ValueError:
                pass


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
    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
    a lockout if the tunnel never comes up, keeping the file for LOCAL recovery.

    True iff we run in-process here, or the re-exec target is the outer install's
    own run.py (identity match). False on ANY doubt -- a studio-venv console script
    or a venv run.py that may predate the gate -- so the strip stays in force
    wherever an old child is possible.
    """
    if in_studio_venv:
        return True
    if child_run_py is None:
        return False
    try:
        outer_run_py = (_PACKAGE_ROOT / "studio" / "backend" / "run.py").resolve()
        return child_run_py.resolve() == outer_run_py
    except OSError:
        return False


def _enforce_password_change_before_exposure(
    *,
    cloudflare: Optional[bool],
    host: str,
    secure: bool,
    api_only: bool,
    child_self_suppresses: bool = False,
) -> None:
    """Force a terminal password change before the first public (tunnel) exposure.

    When the launch will start the tunnel and the admin still has its
    auto-generated bootstrap password, ask for a new one in the terminal (masked,
    confirmed) before any server or tunnel exists. Committing here, in the parent,
    keeps the password off argv/env and an older studio-venv child sees it
    immediately. Without a terminal, warn and fall back to the bootstrap shutdown
    timer (~1h, UNSLOTH_STUDIO_BOOTSTRAP_TIMEOUT).
    """
    if not _should_prompt_password_change(
        cloudflare = cloudflare, host = host, secure = secure, api_only = api_only
    ):
        return
    # Before public exposure we must PROVE the admin password is no longer the
    # seeded default. If we cannot (auth DB won't open, or a fresh admin cannot be
    # seeded + committed below), an old studio-venv child could regenerate a fresh
    # bootstrap credential and serve it; stripping a file we can't vouch for cannot
    # stop a regeneration. So those cases fail closed, as does a failure after the
    # user typed a new password.
    try:
        conn = _connect_auth_db()
    except (OSError, sqlite3.Error) as exc:
        # Cannot open the auth DB, so cannot confirm a committed admin exists.
        # 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 "
            "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`).",
            err = True,
        )
        raise typer.Exit(1)
    try:
        try:
            _ensure_cli_default_admin(conn)
            # Persist a freshly seeded admin before we might re-exec: the INSERT is
            # otherwise uncommitted and rolls back on conn.close(). If the seed or
            # commit fails, no admin is committed, so a re-exec'd OLD child finds
            # none, regenerates a fresh bootstrap password + file, and serves THAT
            # -- stripping cannot stop a regeneration. Can't prove a committed
            # admin, so fail closed.
            conn.commit()
        except (OSError, sqlite3.Error) as exc:
            # Best-effort remove any half-written seed file (its row rolled back);
            # the launch is refused regardless.
            try:
                (STUDIO_HOME / "auth" / BOOTSTRAP_PASSWORD_FILE).unlink(missing_ok = True)
            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 "
                "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 "
                "studio reset-password`).",
                err = True,
            )
            raise typer.Exit(1)
        try:
            row = conn.execute(
                "SELECT password_salt, password_hash, must_change_password "
                "FROM auth_user WHERE username = ?",
                (DEFAULT_ADMIN_USERNAME,),
            ).fetchone()
        except (OSError, sqlite3.Error) as exc:
            if child_self_suppresses:
                # Could not read must_change back, but the child is this install's
                # own backend and suppresses the injection, so nothing serves the
                # seeded credential; proceed without stripping.
                return
            # The admin is committed above, so an old child finds it and won't
            # 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}); "
                "removing the seeded bootstrap password before public exposure.",
                err = True,
            )
            _strip_seeded_bootstrap_password_or_exit(context = "auth DB row unreadable")
            return
        if not row or not row[2]:
            return
        if not _prompt_streams_interactive():
            # Only proceed headless if the bootstrap shutdown deadline will protect
            # 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 "
                    "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 UNSLOTH_STUDIO_BOOTSTRAP_TIMEOUT=0). Change the "
                    "password first (run `unsloth studio` locally and log in, "
                    "or re-run with a terminal attached), then retry.",
                    err = True,
                )
                raise typer.Exit(1)
            if child_self_suppresses:
                # The child is this install's own backend, whose pre-bind gate sets
                # app.state.suppress_bootstrap_injection, so the seeded credential
                # is never served publicly even with the file on disk. Skip the
                # strip: unnecessary here, and it would lock the user out if the
                # tunnel never comes up (e.g. a --secure loopback whose tunnel
                # 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 "
                    "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 "
                    "stays unchanged (UNSLOTH_STUDIO_BOOTSTRAP_TIMEOUT).",
                    err = True,
                )
                return
            # The strip permanently removes the only plaintext recovery credential.
            # On --secure the bind is loopback, so the tunnel is the ONLY public
            # exposure: if cloudflared is provably unavailable no public URL can
            # start, so stripping would just lock the user out. Refuse with the
            # credential preserved. (A wildcard --cloudflare bind is public
            # regardless of the tunnel, so it still strips below, as does any
            # uncertainty.)
            if secure and _tunnel_binary_confirmed_unavailable():
                typer.echo(
                    "Error: refusing to expose Studio: 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 "
                    "first (`unsloth studio` locally, or `unsloth studio "
                    "reset-password`).",
                    err = True,
                )
                raise typer.Exit(1)
            # Mixed-version safety: an OLD studio-venv child (predating this gate)
            # has no pre-bind suppression and would read the seeded credential back
            # from disk and inject it into the public HTML until the deadline.
            # Delete the file here, in the parent, so a fresh child of ANY version
            # reads None. must_change_password stays set, so the login page still
            # 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 "
                "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 "
                "password stays unchanged (UNSLOTH_STUDIO_BOOTSTRAP_TIMEOUT).",
                err = True,
            )
            return
        password_salt, password_hash = row[0], row[1]

        def _is_current_password(candidate: str) -> bool:
            return hmac.compare_digest(
                _pbkdf2_hex(candidate, password_salt.encode("utf-8")), password_hash
            )

        typer.echo(
            "Unsloth Studio will be exposed on the public internet, so set a "
            "password now. Ctrl+C to abort.",
            err = True,
        )
        try:
            new_password = _password_prompt.prompt_new_password(_is_current_password)
        except (KeyboardInterrupt, EOFError):
            typer.echo(
                "\nError: password change aborted; refusing to expose Studio "
                "with the default admin password. Re-run and set a password, "
                "or launch without --secure/--cloudflare.",
                err = True,
            )
            raise typer.Exit(1)
        _cli_update_password(conn, DEFAULT_ADMIN_USERNAME, new_password)
        typer.echo(f"Password updated for '{DEFAULT_ADMIN_USERNAME}'.", err = True)
    finally:
        conn.close()


def _load_model_via_http(
    port: int,
    api_key: str,
    model: str,
    gguf_variant: Optional[str],
    max_seq_length: int,
    load_in_4bit: bool,
    tensor_parallel: bool = False,
    llama_extra_args: Optional[List[str]] = None,
    timeout: int = 600,
) -> dict:
    """POST to ``/api/inference/load`` using the API key for auth."""
    import json
    import urllib.request
    import urllib.error

    payload: dict = {
        "model_path": model,
        "max_seq_length": max_seq_length,
        "load_in_4bit": load_in_4bit,
    }
    if gguf_variant:
        payload["gguf_variant"] = gguf_variant
    if tensor_parallel:
        payload["tensor_parallel"] = True
    if llama_extra_args:
        payload["llama_extra_args"] = list(llama_extra_args)

    data = json.dumps(payload).encode()
    req = urllib.request.Request(
        f"http://127.0.0.1:{port}/api/inference/load",
        data = data,
        headers = {
            "Content-Type": "application/json",
            "Authorization": f"Bearer {api_key}",
        },
        method = "POST",
    )
    try:
        with urllib.request.urlopen(req, timeout = timeout) as resp:
            return json.loads(resp.read())
    except urllib.error.HTTPError as exc:
        body = exc.read().decode(errors = "replace")
        raise RuntimeError(f"Model load failed (HTTP {exc.code}): {body}") from exc


def _format_context_length_line(load_result: dict) -> Optional[str]:
    value = load_result.get("context_length")
    if isinstance(value, bool):
        return None
    try:
        value_int = int(value)
    except (TypeError, ValueError):
        return None
    if value_int <= 0:
        return None
    return f"  Context length: {value_int} tokens"


# ── unsloth studio (server) ──────────────────────────────────────────


@studio_app.callback(invoke_without_command = True)
def studio_default(
    ctx: typer.Context,
    port: int = typer.Option(8888, "--port", "-p"),
    host: str = typer.Option("127.0.0.1", "--host", "-H"),
    frontend: Optional[Path] = typer.Option(None, "--frontend", "-f"),
    silent: bool = typer.Option(False, "--silent", "-q"),
    api_only: bool = typer.Option(
        False,
        "--api-only",
        help = "Run API server only, no frontend serving (for Tauri desktop app)",
    ),
    parallel: int = typer.Option(
        _PARALLEL_DEFAULT_PLAIN,
        "--parallel",
        "--n-parallel",
        min = _PARALLEL_MIN,
        max = _PARALLEL_MAX,
        help = (
            f"llama-server parallel decode slots ({_PARALLEL_MIN}..{_PARALLEL_MAX}). "
            f"Default {_PARALLEL_DEFAULT_PLAIN}; `unsloth studio run` "
            f"defaults to {_PARALLEL_DEFAULT_RUN}."
        ),
    ),
    cloudflare: Optional[bool] = typer.Option(
        None,
        "--cloudflare/--no-cloudflare",
        help = "Expose Studio 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.",
    ),
    secure: bool = typer.Option(
        False,
        "--secure/--no-secure",
        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.",
    ),
    not_secure: bool = typer.Option(
        False,
        "--not-secure",
        hidden = True,
        help = "Deprecated alias for --no-secure.",
    ),
    verbose: bool = typer.Option(
        False,
        "--verbose",
        "-v",
        help = "Log every API request, including the high-frequency polling that is "
        "deduplicated by default.",
    ),
    enable_tools: Optional[bool] = typer.Option(
        None,
        "--enable-tools/--disable-tools",
        help = "Force server-side tools (web search, code execution) on or off for "
        "every request. Default: on for every bind, with the per-chat UI toggle honored.",
    ),
    password: str = typer.Option(
        "",
        "--password",
        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`.",
    ),
):
    """Launch the Unsloth Studio server."""
    # Back-compat: --not-secure is a deprecated alias for --no-secure.
    secure = _resolve_secure(secure, not_secure)
    # Runs before every subcommand (run/setup/update/...).
    _ensure_studio_env_exported()
    if ctx.invoked_subcommand is not None:
        # Typer doesn't forward parent options to subcommands, so
        # `unsloth studio --parallel N run ...` would silently drop N.
        if parallel != _PARALLEL_DEFAULT_PLAIN:
            typer.echo(
                f"Error: --parallel on `unsloth studio` applies to the "
                f"plain-server path only. For `unsloth studio "
                f"{ctx.invoked_subcommand}`, put the flag after the "
                f"subcommand: `unsloth studio {ctx.invoked_subcommand} "
                f"--parallel {parallel} ...`",
                err = True,
            )
            raise typer.Exit(2)
        # Same for --cloudflare/--no-cloudflare: it would not reach the subcommand.
        if cloudflare is not None:
            _cf_flag = "--cloudflare" if cloudflare else "--no-cloudflare"
            typer.echo(
                f"Error: {_cf_flag} on `unsloth studio` applies to the "
                f"plain-server path only. For `unsloth studio "
                f"{ctx.invoked_subcommand}`, put it after the subcommand: "
                f"`unsloth studio {ctx.invoked_subcommand} {_cf_flag} ...`",
                err = True,
            )
            raise typer.Exit(2)
        # Same for --secure: it would not reach the subcommand.
        if secure:
            typer.echo(
                f"Error: --secure on `unsloth studio` applies to the "
                f"plain-server path only. For `unsloth studio "
                f"{ctx.invoked_subcommand}`, put it after the subcommand: "
                f"`unsloth studio {ctx.invoked_subcommand} --secure ...`",
                err = True,
            )
            raise typer.Exit(2)
        # Same for --verbose: it would not reach the subcommand.
        if verbose:
            typer.echo(
                f"Error: --verbose on `unsloth studio` applies to the "
                f"plain-server path only. For `unsloth studio "
                f"{ctx.invoked_subcommand}`, put it after the subcommand: "
                f"`unsloth studio {ctx.invoked_subcommand} --verbose ...`",
                err = True,
            )
            raise typer.Exit(2)
        # Same for --enable-tools/--disable-tools: it would not reach the subcommand.
        if enable_tools is not None:
            _tool_flag = "--enable-tools" if enable_tools else "--disable-tools"
            typer.echo(
                f"Error: {_tool_flag} on `unsloth studio` applies to the "
                f"plain-server path only. For `unsloth studio "
                f"{ctx.invoked_subcommand}`, put it after the subcommand: "
                f"`unsloth studio {ctx.invoked_subcommand} {_tool_flag} ...`",
                err = True,
            )
            raise typer.Exit(2)
        # Same for --api-only: dropping it here would silently serve the UI.
        if api_only:
            typer.echo(
                f"Error: --api-only on `unsloth studio` applies to the "
                f"plain-server path only. For `unsloth studio "
                f"{ctx.invoked_subcommand}`, put it after the subcommand: "
                f"`unsloth studio {ctx.invoked_subcommand} --api-only ...`",
                err = True,
            )
            raise typer.Exit(2)
        # Same for --password: it applies to the plain-server path only.
        if password:
            typer.echo(
                f"Error: --password on `unsloth studio` applies to the "
                f"plain-server path only. For `unsloth studio "
                f"{ctx.invoked_subcommand}`, put it after the subcommand: "
                f"`unsloth studio {ctx.invoked_subcommand} --password ...`",
                err = True,
            )
            raise typer.Exit(2)
        return

    # --secure requires the tunnel; force a loopback bind.
    if secure:
        if cloudflare is False:
            typer.echo(
                "Error: --secure requires the Cloudflare tunnel; do not combine it "
                "with --no-cloudflare.",
                err = True,
            )
            raise typer.Exit(2)
        if host not in ("127.0.0.1", "localhost", "::1"):
            typer.echo(
                "Note: --secure ignores -H (it binds loopback and serves only "
                "through the Cloudflare tunnel). Drop --secure to bind "
                f"{host} directly, or keep --secure for a tunnel-only public link.",
                err = True,
            )
        host = "127.0.0.1"

    # --verbose restores the per-request access logs that are suppressed by
    # default (plain-server path; the `run` subcommand has its own --verbose).
    if verbose:
        _enable_verbose_access_logs()

    # Use the studio venv if present and not already in it. Resolve the child
    # launcher BEFORE the gate: a headless gate strips the seeded
    # .bootstrap_password, so aborting afterward (venv/run.py missing) would leave
    # must_change_password=1 with no password to log in.
    studio_venv_dir = STUDIO_HOME / "unsloth_studio"
    in_studio_venv = sys.prefix.startswith(str(studio_venv_dir))
    studio_python = run_py = None
    resolved_frontend = frontend
    if not in_studio_venv:
        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.")
            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
        # it. Also returns the resolved dist so the child serves a real build
        # regardless of where its __file__ lands (fixes the shadowed silent 404).
        resolved_frontend = _require_servable_frontend_or_exit(
            frontend = resolved_frontend,
            api_only = api_only,
            cloudflare = cloudflare,
            host = host,
            secure = secure,
        )
        # Non-public / api-only launches skip that validation but still forward an
        # explicitly resolved dist for the same silent-404 reason.
        if resolved_frontend is None and not api_only:
            resolved_frontend = _find_frontend_dist()
    else:
        # Already in the studio venv: no re-exec, served in-process below. On the
        # headless public path the gate strips the seeded .bootstrap_password, so
        # validate BOTH FIRST -- else a bad dist or broken venv fails only after
        # the strip (must_change_password=1, no password to log in). Frontend check
        # first (cheap); the backend import is headless-only so an interactive
        # prompt is not delayed behind it.
        resolved_frontend = _require_servable_frontend_or_exit(
            frontend = resolved_frontend,
            api_only = api_only,
            cloudflare = cloudflare,
            host = host,
            secure = secure,
        )
        _validate_inproc_backend_before_strip(
            cloudflare = cloudflare, host = host, secure = secure, api_only = api_only
        )

    # A supplied --password / UNSLOTH_STUDIO_PASSWORD / stdin sets the initial
    # admin password here in the parent, before the gate and any re-exec, so the
    # secret never reaches the child argv; strip the env var so a re-exec'd child
    # can't re-read it. The interactive gate below then no-ops.
    _apply_supplied_password_before_launch(_password_prompt.resolve_supplied_password(password))
    os.environ.pop(_password_prompt.SUPPLIED_PASSWORD_ENV, None)

    # Public (tunnel) exposure with the seeded default password: force a terminal
    # password change first, before any re-exec or server exists. The child is
    # self-suppressing when we serve in-process or re-exec this install's own
    # run.py (its pre-bind gate suppresses the injection), so the gate can skip
    # the destructive strip.
    _enforce_password_change_before_exposure(
        cloudflare = cloudflare,
        host = host,
        secure = secure,
        api_only = api_only,
        child_self_suppresses = _child_self_suppresses(
            in_studio_venv = in_studio_venv, child_run_py = run_py
        ),
    )

    if not in_studio_venv:
        if studio_python and run_py:
            if not silent:
                typer.echo("Launching Unsloth Studio... Please wait...")
            args = [
                str(studio_python),
                str(run_py),
                "--host",
                host,
                "--port",
                str(port),
                "--parallel",
                str(parallel),
            ]
            # Forward the frontend dist resolved before the gate (skipped in
            # --api-only, which serves no UI).
            if resolved_frontend is not None:
                args.extend(["--frontend", str(resolved_frontend)])
            if silent:
                args.append("--silent")
            if api_only:
                args.append("--api-only")
            # Forward polarity explicitly: _find_run_py can fall back to an older
            # run.py (--cloudflare defaulted on), so an unset default must not let a
            # mixed install silently re-enable the tunnel. --secure implies it, so
            # forward nothing then.
            if cloudflare is True:
                args.append("--cloudflare")
            elif not secure:
                args.append("--no-cloudflare")
            args.append("--secure" if secure else "--no-secure")
            # Forward an explicit tool policy; None -> run.py leaves it unset (tools on).
            if enable_tools is True:
                args.append("--enable-tools")
            elif enable_tools is False:
                args.append("--disable-tools")
            # On Windows os.execvp keeps the parent alive, so Ctrl+C
            # would orphan the child; use Popen+wait instead.
            if sys.platform == "win32":
                import subprocess as _sp

                proc = _sp.Popen(args, **_windows_hidden_subprocess_kwargs())
                try:
                    rc = proc.wait()
                except KeyboardInterrupt:
                    # Child handles its own signal; let it finish.
                    rc = proc.wait()
                if rc != 0:
                    typer.echo(
                        f"\nError: Studio server exited unexpectedly (code {rc}).",
                        err = True,
                    )
                    typer.echo(
                        "Check the error above. If a package is missing, "
                        "re-run: unsloth studio setup",
                        err = True,
                    )
                raise typer.Exit(rc)
            else:
                os.execvp(str(studio_python), args)
        else:
            typer.echo("Studio not set up. Run install.sh first.")
            raise typer.Exit(1)

    run_mod = _load_run_module()
    run_server = run_mod.run_server

    if not silent:
        display_host = _display_host_for_bind(run_mod, host)
        typer.echo(f"Starting Unsloth Studio on http://{_url_host(display_host)}:{port}")

    run_kwargs = dict(
        host = host,
        port = port,
        silent = silent,
        api_only = api_only,
        llama_parallel_slots = parallel,
        cloudflare = cloudflare,
        secure = secure,
        enable_tools = enable_tools,
    )
    # Forward the frontend validated before the gate (in-venv path), so the
    # in-process server serves exactly the dist we vouched for.
    if resolved_frontend is not None:
        run_kwargs["frontend_path"] = resolved_frontend
    run_server(**run_kwargs)

    try:
        if run_mod._shutdown_event is not None:
            # Event.wait() with no timeout blocks at C-level on Linux
            # and swallows SIGINT; loop with a 1s timeout instead.
            while not run_mod._shutdown_event.is_set():
                run_mod._shutdown_event.wait(timeout = 1)
        else:
            while True:
                time.sleep(1)
    except KeyboardInterrupt:
        run_mod._graceful_shutdown(run_mod._server)
        typer.echo("\nShutting down...")
    finally:
        getattr(run_mod, "_wait_for_server_shutdown", lambda: None)()


# ── unsloth studio run ───────────────────────────────────────────────


def _split_repo_variant(model_arg: str) -> tuple[str, Optional[str]]:
    """Split ``org/name:variant`` into ``(repo, variant)``; mirrors
    llama.cpp's ``-hf <repo>:<quant>``. Local paths, Windows drives,
    and ids without ``:`` pass through verbatim."""
    s = model_arg.strip()
    if not s:
        return s, None
    if s.startswith(("/", "./", "../", "~")) or s == ".":
        return s, None
    # Windows drive letter (e.g. "C:\path"): colon is a path separator.
    if len(s) >= 2 and s[1] == ":" and s[0].isalpha():
        return s, None
    if ":" not in s:
        return s, None
    repo, _, variant = s.rpartition(":")
    if not repo or not variant:
        return s, None
    # Quant labels never contain a slash; `foo:bar/baz` isn't repo:variant.
    if "/" in variant:
        return s, None
    return repo, variant


def _expand_attached_np_short() -> None:
    # Click clusters `-np8` as `-n -p 8` (-p = --port), dropping the parallel
    # value. Split to `-np <N>` so typer's alias matches. Stops at `--`;
    # accepts signed/junk forms so typer reports a clean error against `-np`.
    # Kept in lockstep with the backend `_flag_name` recogniser.
    i = 0
    while i < len(sys.argv):
        tok = sys.argv[i]
        if tok == "--":
            break
        if len(tok) > 3 and tok.startswith("-np") and tok[3] != "=":
            suffix = tok[3:]
            first_numeric = suffix[0].isdigit() or (
                len(suffix) > 1 and suffix[0] in {"-", "+"} and suffix[1].isdigit()
            )
            if first_numeric:
                sys.argv[i : i + 1] = ["-np", suffix]
                i += 2
                continue
        i += 1


def _consume_legacy_short_aliases(
    args: List[str], aliases: tuple[str, ...], current: Optional[str], canonical: str
) -> tuple[Optional[str], List[str]]:
    """Pop exact-match legacy shorts (`-m`/`-hfr`/`-f`) from args;
    leave clusters (`-mg`/`-fa`/...) for the llama-server tail. Inline
    `-x=value` form also accepted."""
    out: List[str] = []
    value = current
    i, n = 0, len(args)
    while i < n:
        tok = args[i]
        if tok == "--":  # end of options; tail is raw payload.
            out.extend(args[i:])
            break
        name, sep, inline = tok.partition("=")
        if name not in aliases:
            out.append(tok)
            i += 1
            continue
        if value is not None:
            raise typer.BadParameter(f"{name} conflicts with {canonical} already provided")
        if sep:
            if inline == "":  # `-m=` would become --model '' (Path('')='.').
                raise typer.BadParameter(f"{name} requires a non-empty value")
            value = inline
            i += 1
        elif i + 1 < n:
            nxt = args[i + 1]
            # `--long` is unambiguously a flag; single-dash `-x` may be a path.
            if nxt.startswith("--") and nxt != "--":
                raise typer.BadParameter(f"{name} expects a value but got the flag {nxt}")
            value = nxt
            i += 2
        else:
            raise typer.BadParameter(f"{name} requires a value")
    return value, out


@studio_app.command(
    context_settings = {
        "allow_extra_args": True,
        "ignore_unknown_options": True,
    },
)
def run(
    ctx: typer.Context,
    model: Optional[str] = typer.Option(
        None,
        "--model",
        "-hf",
        "--hf-repo",
        # `-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).
        help = (
            "Model path or HF repo. Accepts llama.cpp-style "
            "`org/repo:variant` syntax. `-hf` / `--hf-repo` match "
            "llama-server's spelling."
        ),
    ),
    gguf_variant: Optional[str] = typer.Option(
        None, "--gguf-variant", help = "GGUF quant variant (e.g. UD-Q4_K_XL)"
    ),
    verbose: bool = typer.Option(
        False,
        "--verbose",
        "-v",
        help = "Log every API request, including the high-frequency polling that is "
        "deduplicated by default.",
    ),
    max_seq_length: int = typer.Option(
        0,
        "--max-seq-length",
        "--context-length",
        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"
    ),
    port: int = typer.Option(8888, "--port", "-p"),
    host: str = typer.Option("127.0.0.1", "--host", "-H"),
    # `-f` removed (clustered `-fa`/`-fit*`); studio_default keeps it.
    frontend: Optional[Path] = typer.Option(None, "--frontend"),
    api_only: bool = typer.Option(
        False,
        "--api-only",
        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"),
    enable_tools: Optional[bool] = typer.Option(
        None,
        "--enable-tools/--disable-tools",
        help = (
            "Force server-side tools (web search, code execution) on or off for "
            "every request. Default: on for every bind."
        ),
    ),
    yes: bool = typer.Option(
        False,
        "--yes",
        "-y",
        help = "Accepted for backward compatibility; the tool policy no longer prompts.",
    ),
    parallel: int = typer.Option(
        _PARALLEL_DEFAULT_RUN,
        "--parallel",
        "--n-parallel",
        "-np",
        min = _PARALLEL_MIN,
        max = _PARALLEL_MAX,
        help = (
            "llama-server parallel decode slots. N requests share one "
            "loaded model; each slot gets ctx/N KV cache. Default "
            f"{_PARALLEL_DEFAULT_RUN} (pre-PR hardcoded value)."
        ),
    ),
    cloudflare: Optional[bool] = typer.Option(
        None,
        "--cloudflare/--no-cloudflare",
        help = "Expose Studio 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.",
    ),
    secure: bool = typer.Option(
        False,
        "--secure/--no-secure",
        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.",
    ),
    not_secure: bool = typer.Option(
        False,
        "--not-secure",
        hidden = True,
        help = "Deprecated alias for --no-secure.",
    ),
    tensor_parallel: bool = typer.Option(
        False,
        "--tensor-parallel/--no-tensor-parallel",
        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."
        ),
    ),
    password: str = typer.Option(
        "",
        "--password",
        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.

    Unknown flags pass through to llama-server (GGUF only). Studio
    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.

    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 some-model --chat-template-file /path/to/tpl.jinja
        unsloth studio run --model unsloth/Qwen3-27B-GGUF --gguf-variant Q8_0 --tensor-parallel
    """
    # 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 []

    # 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.
    if verbose:
        _enable_verbose_access_logs()
        if not any(a in ("--verbose", "-v", "--log-verbose") for a in extra_llama_args):
            extra_llama_args.append("--log-verbose")

    # Promote legacy exact `-m`/`-hfr`/`-f` back into typer params;
    # clusters stay in extras.
    model, extra_llama_args = _consume_legacy_short_aliases(
        extra_llama_args,
        ("-m", "-hfr"),
        model,
        "--model",
    )
    legacy_frontend, extra_llama_args = _consume_legacy_short_aliases(
        extra_llama_args,
        ("-f",),
        str(frontend) if frontend is not None else None,
        "--frontend",
    )
    if legacy_frontend is not None and frontend is None:
        frontend = Path(legacy_frontend)

    if model is None:
        typer.echo(
            "Error: Missing option '--model' / '-hf' / '--hf-repo' "
            "(legacy aliases '-m' / '-hfr' are still accepted).",
            err = True,
        )
        raise typer.Exit(2)

    # 0. Parse llama.cpp `repo:variant` in --model; error if also paired
    # with --gguf-variant and they disagree.
    parsed_repo, embedded_variant = _split_repo_variant(model)
    if embedded_variant:
        if gguf_variant and gguf_variant != embedded_variant:
            typer.echo(
                f"Error: --model embeds variant '{embedded_variant}' but "
                f"--gguf-variant '{gguf_variant}' was also provided.",
                err = True,
            )
            raise typer.Exit(1)
        model = parsed_repo
        gguf_variant = gguf_variant or embedded_variant

    # --secure requires the tunnel; force a loopback bind so the raw port is never public.
    if secure:
        if cloudflare is False:
            typer.echo(
                "Error: --secure requires the Cloudflare tunnel; do not combine it "
                "with --no-cloudflare.",
                err = True,
            )
            raise typer.Exit(2)
        if host not in ("127.0.0.1", "localhost", "::1"):
            typer.echo(
                "Note: --secure ignores -H (it binds loopback and serves only "
                "through the Cloudflare tunnel). Drop --secure to bind "
                f"{host} directly, or keep --secure for a tunnel-only public link.",
                err = True,
            )
        host = "127.0.0.1"

    # Tool policy no longer depends on the bind: tools default on everywhere
    # (--secure is a loopback tunnel; the operator owns a raw bind). Resolve here
    # so the re-exec'd child inherits a concrete decision.
    from unsloth_cli._tool_policy import is_external_host, resolve_tool_policy

    enable_tools = resolve_tool_policy(
        host = host,
        flag = enable_tools,
        yes = yes,
        silent = silent,
    )

    # 1. Re-exec into the studio venv (same pattern as studio_default). Resolve
    # the child launcher BEFORE the gate: a headless gate strips the seeded
    # .bootstrap_password, so aborting afterward (venv/entry point missing) would
    # leave must_change_password=1 with no password to log in.
    studio_venv_dir = STUDIO_HOME / "unsloth_studio"
    in_studio_venv = sys.prefix.startswith(str(studio_venv_dir))
    studio_bin = None
    resolved_frontend = frontend
    if not in_studio_venv:
        studio_python = _studio_venv_python()
        if not studio_python:
            typer.echo("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")
            raise typer.Exit(1)
        # `run` serves the same Studio 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.
        resolved_frontend = _require_servable_frontend_or_exit(
            frontend = frontend,
            api_only = api_only,
            cloudflare = cloudflare,
            host = host,
            secure = secure,
        )
    else:
        # In-venv (in-process) run: validate the servable frontend and importable
        # backend before the headless gate strips the seeded password. Frontend
        # check first (cheap); backend import is headless-only so a prompt isn't
        # delayed.
        resolved_frontend = _require_servable_frontend_or_exit(
            frontend = frontend,
            api_only = api_only,
            cloudflare = cloudflare,
            host = host,
            secure = secure,
        )
        _validate_inproc_backend_before_strip(
            cloudflare = cloudflare, host = host, secure = secure, api_only = api_only
        )

    # A supplied --password / UNSLOTH_STUDIO_PASSWORD / stdin sets the initial
    # admin password here in the parent, before the gate and any re-exec, so the
    # secret never reaches the child argv; strip the env var so a re-exec'd child
    # can't re-read it. The interactive gate below then no-ops.
    _apply_supplied_password_before_launch(_password_prompt.resolve_supplied_password(password))
    os.environ.pop(_password_prompt.SUPPLIED_PASSWORD_ENV, None)

    # Public (tunnel) exposure with the seeded default password: force a terminal
    # password change first, before any re-exec or server exists. The re-exec here
    # runs the studio venv's `unsloth` console script (a possibly-OLD child), so it
    # is NOT provably self-suppressing -- only the in-process case is, and the
    # strip stays in force otherwise.
    _enforce_password_change_before_exposure(
        cloudflare = cloudflare,
        host = host,
        secure = secure,
        api_only = api_only,
        child_self_suppresses = _child_self_suppresses(
            in_studio_venv = in_studio_venv, child_run_py = None
        ),
    )

    if not in_studio_venv:
        args = [
            str(studio_bin),
            "studio",
            "run",
            "--model",
            model,
            "--max-seq-length",
            str(max_seq_length),
            "--api-key-name",
            api_key_name,
            "--port",
            str(port),
            "--host",
            host,
        ]
        if gguf_variant:
            args.extend(["--gguf-variant", gguf_variant])
        # Forward the explicit polarity; a future default flip on one
        # layer must not silently invert behaviour for the other.
        args.append("--load-in-4bit" if load_in_4bit else "--no-load-in-4bit")
        # Forward the frontend resolved before the gate, not just a user-supplied
        # one: the parent may have found a built dist the shadowed child cannot,
        # and stripping without forwarding it would abort the child at frontend
        # setup (lockout).
        if resolved_frontend is not None:
            args.extend(["--frontend", str(resolved_frontend)])
        if api_only:
            args.append("--api-only")
        if silent:
            args.append("--silent")
        # Forward the resolved tool policy so the child doesn't re-resolve.
        if enable_tools:
            args.append("--enable-tools")
        else:
            args.append("--disable-tools")
        # Forward --yes only if the user passed it; resolution no longer prompts.
        if yes:
            args.append("--yes")
        # Typer claims --parallel outside ctx.args; without this the
        # child reverts to its default and silently drops the value.
        args.extend(["--parallel", str(parallel)])
        # Always forward explicit polarity: a mixed-version studio venv whose old
        # default was --cloudflare-on must not silently re-enable the tunnel.
        # --secure implies it, so forward nothing then.
        if cloudflare is True:
            args.append("--cloudflare")
        elif not secure:
            args.append("--no-cloudflare")
        args.append("--secure" if secure else "--no-secure")
        args.append("--tensor-parallel" if tensor_parallel else "--no-tensor-parallel")
        if verbose:
            args.append("--verbose")
        # llama-server pass-through extras → child ctx.args → load payload.
        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)

    # ── 2. Start server (always suppress built-in banner) ─────────────
    run_mod = _load_run_module()
    run_server = run_mod.run_server

    # Match the route handlers' import path: run.py adds studio/backend/ to
    # sys.path, so they import as `state.tool_policy`. Set this before
    # run_server() starts uvicorn; once sockets are bound, routes can be hit.
    from state.tool_policy import set_tool_policy

    set_tool_policy(enable_tools)

    run_kwargs = dict(
        host = host,
        port = port,
        silent = True,
        api_only = api_only,
        llama_parallel_slots = parallel,
        cloudflare = cloudflare,
        secure = secure,
        # Headless serving prints its own URL/API-key banner; the Tauri-only
        # TAURI_PORT line would corrupt that machine-parseable output.
        emit_tauri_port = False,
    )
    # Forward the frontend validated before the gate (in-venv path).
    if resolved_frontend is not None:
        run_kwargs["frontend_path"] = resolved_frontend
    app = run_server(**run_kwargs)
    actual_port = getattr(app.state, "server_port", port) or port

    # Steps 3-5 can abort (health timeout, model-load error, or Ctrl+C during the
    # slow load); tear the server and its children (llama-server, cloudflared) down
    # on any abort so they never orphan.
    from studio.backend.run import _graceful_shutdown, _server

    try:
        # 3. Wait for server health.
        if not silent:
            typer.echo("Starting Unsloth Studio...")
        if not _wait_for_server(actual_port):
            typer.echo("Error: server did not become healthy within 30 seconds.", err = True)
            raise typer.Exit(1)

        # 4. Create API key in-process.
        api_key = _create_api_key_inprocess(api_key_name)

        # 5. Load model via HTTP.
        if not silent:
            typer.echo(f"Loading model: {model}...")
        try:
            result = _load_model_via_http(
                port = actual_port,
                api_key = api_key,
                model = model,
                gguf_variant = gguf_variant,
                max_seq_length = max_seq_length,
                load_in_4bit = load_in_4bit,
                tensor_parallel = tensor_parallel,
                llama_extra_args = extra_llama_args,
            )
        except RuntimeError as exc:
            typer.echo(f"Error: {exc}", err = True)
            raise typer.Exit(1)
    except BaseException:
        _graceful_shutdown(_server)
        getattr(run_mod, "_wait_for_server_shutdown", lambda: None)()
        raise

    loaded_model = result.get("model", model)
    display_variant = f" ({gguf_variant})" if gguf_variant else ""
    context_length_line = _format_context_length_line(result)

    # 6. Print banner.
    display_host = _display_host_for_bind(run_mod, host)
    base_url = f"http://{_url_host(display_host)}:{actual_port}"
    sdk_base_url = f"{base_url}/v1"
    # run_server started the tunnel during the silent run above (wildcard or --secure).
    _cf_url = getattr(app.state, "cloudflare_url", None)
    # --secure: examples must use the public tunnel URL, not the loopback address.
    if secure and _cf_url:
        sdk_base_url = f"{_cf_url}/v1"

    # Orange so the tool-policy notice stands out; printed under
    # --silent / --yes too so the policy is never invisible.
    _tool_notice_fg = (217, 119, 87)
    _is_external = is_external_host(host)
    if not enable_tools:
        _tool_notice = "Server-side tools are DISABLED (--disable-tools)."
    elif secure:
        _tool_notice = (
            "Server-side tools are ENABLED, reachable via the authenticated "
            "Cloudflare HTTPS tunnel. Anyone with the API key can run code on "
            "this machine. Do not share the API key. Pass --disable-tools to turn off."
        )
    elif _is_external:
        _tool_notice = (
            "Server-side tools are ENABLED and this port is network-reachable. "
            "Anyone who can reach it with the API key can run code on this "
            "machine. Do not share the API key. Pass --disable-tools to turn off."
        )
    else:
        _tool_notice = (
            "Server-side tools are ENABLED for loopback. Pass --disable-tools to turn off."
        )

    if not silent:
        typer.echo("")
        typer.echo("=" * 56)
        if secure and _cf_url:
            typer.echo(f"  Unsloth Studio running (secure) at {_cf_url}")
            typer.echo(f"  On this machine only: {base_url}")
        else:
            typer.echo(f"  Unsloth Studio running at {base_url}")
            _emit_run_cloudflare_notice(run_mod, host, display_host, actual_port, secure)
        typer.echo(f"  Model loaded: {loaded_model}{display_variant}")
        if context_length_line:
            typer.echo(context_length_line)
        typer.echo(f"  API Key:      {api_key}")
        typer.echo("")
        typer.echo("  OpenAI / Anthropic SDK base URL:")
        typer.echo(f"    {sdk_base_url}")
        typer.echo("=" * 56)
        typer.secho(_tool_notice, fg = _tool_notice_fg, bold = True)
        typer.echo("")
        typer.echo("OpenAI Chat Completions:")
        typer.echo(f"  curl {sdk_base_url}/chat/completions \\")
        typer.echo(f'    -H "Authorization: Bearer {api_key}" \\')
        typer.echo('    -H "Content-Type: application/json" \\')
        typer.echo(
            """    -d '{"messages": [{"role": "user", "content": "Hello"}], "stream": true}'"""
        )
        typer.echo("")
        typer.echo("Anthropic Messages:")
        typer.echo(f"  curl {sdk_base_url}/messages \\")
        typer.echo(f'    -H "Authorization: Bearer {api_key}" \\')
        typer.echo('    -H "Content-Type: application/json" \\')
        typer.echo(
            """    -d '{"max_tokens": 256, "messages": [{"role": "user", "content": "Hello"}], "stream": true}'"""
        )
        typer.echo("")
        typer.echo("OpenAI Responses:")
        typer.echo(f"  curl {sdk_base_url}/responses \\")
        typer.echo(f'    -H "Authorization: Bearer {api_key}" \\')
        typer.echo('    -H "Content-Type: application/json" \\')
        typer.echo("""    -d '{"input": "Hello", "stream": true}'""")
        typer.echo("")
    else:
        # Silent still prints URL + API key + tool-status policy.
        if secure and _cf_url:
            typer.echo(f"URL:     {_cf_url}")
            typer.echo(f"Local:   {base_url}")
        else:
            typer.echo(f"URL:     {base_url}")
            _emit_run_cloudflare_notice(run_mod, host, display_host, actual_port, secure)
        if context_length_line:
            typer.echo(context_length_line.strip())
        typer.echo(f"API Key: {api_key}")
        typer.secho(_tool_notice, fg = _tool_notice_fg, bold = True)

    # 7. Wait for Ctrl+C.
    try:
        if run_mod._shutdown_event is not None:
            while not run_mod._shutdown_event.is_set():
                run_mod._shutdown_event.wait(timeout = 1)
        else:
            while True:
                time.sleep(1)
    except KeyboardInterrupt:
        run_mod._graceful_shutdown(run_mod._server)
        typer.echo("\nShutting down...")
    finally:
        getattr(run_mod, "_wait_for_server_shutdown", lambda: None)()


# ── unsloth studio stop ───────────────────────────────────────────────

_PID_FILE = STUDIO_HOME / "studio.pid"


def _pid_alive(pid: int) -> bool:
    """Return True if a process with ``pid`` exists.

    ``os.kill(pid, 0)`` raises OSError (WinError 87) for every pid on Windows,
    so use ``tasklist`` there and the signal-0 probe elsewhere.
    """
    if sys.platform == "win32":
        try:
            out = subprocess.run(
                ["tasklist", "/FI", f"PID eq {int(pid)}", "/NH", "/FO", "CSV"],
                capture_output = True,
                text = True,
                timeout = 10,
            ).stdout
        except Exception:
            # Can't determine -- assume alive; taskkill no-ops if already gone.
            return True
        return f'"{int(pid)}"' in out
    try:
        os.kill(pid, 0)
    except ProcessLookupError:
        return False
    except PermissionError:
        return True
    return True


@studio_app.command()
def stop():
    """Stop a running Unsloth Studio server.

    Reads the PID from ~/.unsloth/studio/studio.pid and sends SIGTERM
    (or TerminateProcess on Windows) to shut it down gracefully.
    """
    import signal as _signal

    if not _PID_FILE.is_file():
        typer.echo("No running Studio server found (no PID file).")
        raise typer.Exit(0)

    pid_text = _PID_FILE.read_text().strip()
    if not pid_text.isdigit():
        typer.echo(f"Invalid PID file contents: {pid_text}")
        _PID_FILE.unlink(missing_ok = True)
        raise typer.Exit(1)

    pid = int(pid_text)

    # 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.")
        _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)
        else:
            os.kill(pid, _signal.SIGTERM)
        typer.echo(f"Sent shutdown signal to Studio server (PID {pid}).")
    except ProcessLookupError:
        typer.echo(f"Studio 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)
        raise typer.Exit(1)

    # Wait briefly for the process to exit and clean up.
    for _ in range(10):
        time.sleep(0.5)
        if not _pid_alive(pid):
            _PID_FILE.unlink(missing_ok = True)
            typer.echo("Studio server stopped.")
            raise typer.Exit(0)

    typer.echo("Studio server is shutting down (may take a few seconds).")


# ── unsloth studio setup / update ─────────────────────────────────────


def _run_setup_script(*, verbose: bool = False) -> None:
    """Find and run the studio setup/update script."""
    script = _find_setup_script()
    if not script:
        typer.echo("Error: Could not find setup script (setup.sh / setup.ps1).")
        raise typer.Exit(1)

    env = {**os.environ, "UNSLOTH_VERBOSE": "1"} if verbose else None

    if platform.system() == "Windows":
        powershell_args = ["powershell.exe"]
        if _should_hide_windows_subprocesses():
            powershell_args.extend(
                ["-NoLogo", "-NoProfile", "-NonInteractive", "-WindowStyle", "Hidden"]
            )
        # Use -Command + `*>&1` (not -File) so setup.ps1's Write-Host output
        # (Information stream #6) merges into stdout. -File drops it when
        # stdout is a pipe, e.g. `unsloth studio update --local 2>&1 | tee`.
        # Single-quote escaping handles paths containing apostrophes.
        script_pwsh_literal = str(script).replace("'", "''")
        powershell_args.extend(
            [
                "-ExecutionPolicy",
                "Bypass",
                "-Command",
                f"& '{script_pwsh_literal}' *>&1",
            ]
        )
        # Explicitly hand std handles to the child so CI tee sees setup.ps1's
        # output. On Windows, subprocess.run defaults to close_fds=True
        # (bInheritHandles=False); combined with CREATE_NO_WINDOW the child
        # has no console and no inherited handles, so Write-Host writes to
        # nothing. Passing stdout/stderr makes Python mark the std handles
        # inheritable via PROC_THREAD_ATTRIBUTE_HANDLE_LIST. Empty update.log
        # on windows-latest CI was the smoking gun (runs 25533694490/25534292239).
        result = subprocess.run(
            powershell_args,
            env = env,
            stdin = _stream_for_subprocess(sys.stdin),
            stdout = _stream_for_subprocess(sys.stdout),
            stderr = _stream_for_subprocess(sys.stderr),
            **_windows_hidden_subprocess_kwargs(),
        )
    else:
        result = subprocess.run(["bash", str(script)], env = env)

    if result.returncode != 0:
        raise typer.Exit(result.returncode)


_INSTALLER_URL_BASH = "https://unsloth.ai/install.sh"
_INSTALLER_URL_PWSH = "https://unsloth.ai/install.ps1"


def _refresh_desktop_shortcuts(*, verbose: bool = False) -> None:
    """Re-run installer with --shortcuts-only to refresh launchers post-update."""
    env = {**os.environ}
    if verbose:
        env["UNSLOTH_VERBOSE"] = "1"

    is_windows = platform.system() == "Windows"
    installer_name = "install.ps1" if is_windows else "install.sh"
    installer_url = _INSTALLER_URL_PWSH if is_windows else _INSTALLER_URL_BASH

    # Prefer local checkout, fall back to package dir, then network fetch.
    local_repo = (os.environ.get("STUDIO_LOCAL_REPO") or "").strip()
    candidates: list[Path] = []
    if local_repo:
        candidates.append(Path(local_repo) / installer_name)
    candidates.append(_PACKAGE_ROOT / installer_name)

    args = ["--shortcuts-only"]
    if verbose:
        args.append("--verbose")

    if is_windows:
        ps_argv: list[str] = ["powershell.exe"]
        if _should_hide_windows_subprocesses():
            ps_argv.extend(["-NoLogo", "-NoProfile", "-NonInteractive", "-WindowStyle", "Hidden"])

        for script in candidates:
            try:
                if script.is_file():
                    quoted = str(script).replace("'", "''")
                    argv = list(ps_argv)
                    argv.extend(
                        [
                            "-ExecutionPolicy",
                            "Bypass",
                            "-Command",
                            f"& '{quoted}' {' '.join(args)} *>&1",
                        ]
                    )
                    result = subprocess.run(
                        argv,
                        env = env,
                        check = False,
                        **_windows_hidden_subprocess_kwargs(),
                    )
                    if result.returncode != 0:
                        typer.echo(f"  refresh-launcher  install.ps1 exited {result.returncode}")
                    return
            except OSError:
                continue

        # PyPI installs lack install.ps1: fetch + pipe to powershell stdin.
        try:
            request = urllib.request.Request(
                installer_url, headers = {"User-Agent": "unsloth-studio-update"}
            )
            with urllib.request.urlopen(request, timeout = 30) as response:
                installer = response.read().decode("utf-8", errors = "replace")
        except (urllib.error.URLError, TimeoutError, OSError) as exc:
            typer.echo(f"  refresh-launcher  skipped: could not fetch {installer_url} ({exc})")
            return

        # install.ps1 auto-invokes `Install-UnslothStudio @args` at EOF; over
        # stdin `$args` is empty so that triggers the full installer flow
        # (deps, venv, prompts) before our shortcuts-only call. Strip it.
        installer = re.sub(
            r"(?m)^[ \t]*Install-UnslothStudio[ \t]+@args[ \t]*\r?\n?",
            "",
            installer,
        )
        # stdin-piped scripts have empty $args, so call Install-UnslothStudio explicitly.
        marker_args = " ".join(args)
        wrapper = installer + f"\nInstall-UnslothStudio {marker_args}\n"

        # Write to a UTF-8 BOM tempfile and use -File rather than -Command -.
        # `powershell.exe -Command -` reads stdin via [Console]::InputEncoding
        # (CP1252/OEM on most Windows boxes), which mangles box-drawing chars
        # in install.ps1. -File reads the BOM and decodes correctly. The
        # prefix gives AV/EDR engines (and grep'ing users) a clear identity.
        ps1_fd, ps1_path = tempfile.mkstemp(
            prefix = "unsloth-studio-refresh-",
            suffix = ".ps1",
        )
        try:
            with os.fdopen(ps1_fd, "wb") as fh:
                fh.write(b"\xef\xbb\xbf" + wrapper.encode("utf-8"))
            argv = list(ps_argv)
            argv.extend(["-ExecutionPolicy", "Bypass", "-File", ps1_path])
            try:
                result = subprocess.run(
                    argv,
                    env = env,
                    check = False,
                    **_windows_hidden_subprocess_kwargs(),
                )
                if result.returncode != 0:
                    typer.echo(
                        f"  refresh-launcher  fetched install.ps1 exited {result.returncode}"
                    )
            except OSError as exc:
                typer.echo(f"  refresh-launcher  skipped: powershell exec failed ({exc})")
        finally:
            try:
                os.unlink(ps1_path)
            except OSError:
                pass
        return

    for script in candidates:
        try:
            if script.is_file():
                result = subprocess.run(
                    ["bash", str(script), *args],
                    env = env,
                    check = False,
                )
                if result.returncode != 0:
                    typer.echo(f"  refresh-launcher  install.sh exited {result.returncode}")
                return
        except OSError:
            continue

    # PyPI installs lack install.sh: fetch upstream.
    try:
        request = urllib.request.Request(
            installer_url, headers = {"User-Agent": "unsloth-studio-update"}
        )
        with urllib.request.urlopen(request, timeout = 30) as response:
            installer = response.read()
    except (urllib.error.URLError, TimeoutError, OSError) as exc:
        typer.echo(f"  refresh-launcher  skipped: could not fetch {installer_url} ({exc})")
        return

    try:
        result = subprocess.run(
            ["bash", "-s", "--", *args],
            input = installer,
            env = env,
            check = False,
        )
        if result.returncode != 0:
            typer.echo(f"  refresh-launcher  fetched install.sh exited {result.returncode}")
    except OSError as exc:
        typer.echo(f"  refresh-launcher  skipped: bash exec failed ({exc})")


@studio_app.command(hidden = True)
def setup(
    verbose: bool = typer.Option(
        False,
        "--verbose",
        "-v",
        help = "Full pip/build output during setup for troubleshooting.",
    ),
):
    """Run Studio setup (called by install.ps1 / install.sh)."""
    _run_setup_script(verbose = verbose)


@studio_app.command()
def update(
    local: bool = typer.Option(False, "--local", help = "Install from local repo instead of PyPI"),
    package: str = typer.Option(
        "unsloth", "--package", help = "Package name to install/update (for testing)"
    ),
    verbose: bool = typer.Option(
        False,
        "--verbose",
        "-v",
        help = "Full pip/build output during update for troubleshooting.",
    ),
):
    """Update Unsloth Studio dependencies and rebuild."""
    # Re-export UNSLOTH_STUDIO_HOME for env-mode installs so the refresh
    # subprocess resolves the same install root the user originally chose.
    _ensure_studio_env_exported()
    # Ensure SKIP_STUDIO_BASE is not inherited from a parent install.ps1 session
    os.environ.pop("SKIP_STUDIO_BASE", None)
    os.environ["STUDIO_PACKAGE_NAME"] = package
    if local:
        os.environ["STUDIO_LOCAL_INSTALL"] = "1"
        # Pass the repo root explicitly so install_python_stack.py doesn't
        # have to guess from SCRIPT_DIR (which may be inside site-packages).
        repo_root = Path(__file__).resolve().parents[2]
        os.environ["STUDIO_LOCAL_REPO"] = str(repo_root)
    else:
        os.environ["STUDIO_LOCAL_INSTALL"] = "0"
        os.environ.pop("STUDIO_LOCAL_REPO", None)
    _release_self_exe_lock_windows()
    try:
        _run_setup_script(verbose = verbose)
    except BaseException:
        # Restore unsloth.exe from .deleteme if setup failed before pip
        # produced a replacement; otherwise the user has no CLI for recovery.
        _restore_self_exe_lock_windows()
        raise
    # On Windows clear the .deleteme orphan now that pip wrote a fresh
    # unsloth.exe; on next update os.replace would overwrite it anyway,
    # but leaving a stale binary around invites cross-version restore
    # confusion from _restore_self_exe_lock_windows.
    _cleanup_self_exe_lock_windows()
    # Tauri desktop owns its own bundle entries; skip CLI launcher refresh
    # so a Tauri-initiated update doesn't create duplicate shortcuts.
    if os.environ.get("UNSLOTH_TAURI_UPDATE") == "1":
        if verbose:
            typer.echo("  refresh-launcher  skipped (Tauri update)")
        return
    _refresh_desktop_shortcuts(verbose = verbose)


def _release_self_exe_lock_windows() -> None:
    """Rename running unsloth.exe so pip can replace it. setup.ps1 also retries."""
    if platform.system() != "Windows":
        return
    try:
        venv_scripts = Path(sys.executable).resolve().parent
    except OSError:
        return
    exe = venv_scripts / "unsloth.exe"
    if not exe.exists():
        return
    stale = exe.with_suffix(".exe.deleteme")
    try:
        # os.replace is atomic-overwrite on Windows; os.rename would raise
        # FileExistsError if a prior aborted update left a .deleteme behind.
        os.replace(exe, stale)
    except OSError as e:
        # Not fatal; setup.ps1 retries from a sibling process.
        print(f"[update] could not rename {exe.name} -> {stale.name}: {e}")


def _restore_self_exe_lock_windows() -> None:
    """If setup failed before pip wrote a working unsloth.exe, restore .deleteme."""
    if platform.system() != "Windows":
        return
    try:
        venv_scripts = Path(sys.executable).resolve().parent
    except OSError:
        return
    exe = venv_scripts / "unsloth.exe"
    stale = exe.with_suffix(".exe.deleteme")
    if not stale.exists():
        return
    # Treat a missing or zero-byte exe as "pip didn't produce a usable
    # replacement"; otherwise leave the new binary alone.
    if exe.exists():
        try:
            if exe.stat().st_size > 0:
                return
        except OSError:
            return
    try:
        os.replace(stale, exe)
    except OSError as e:
        print(f"[update] could not restore {stale.name} -> {exe.name}: {e}")


def _cleanup_self_exe_lock_windows() -> None:
    """Remove the .deleteme orphan after a successful update on Windows."""
    if platform.system() != "Windows":
        return
    try:
        venv_scripts = Path(sys.executable).resolve().parent
    except OSError:
        return
    stale = (venv_scripts / "unsloth.exe").with_suffix(".exe.deleteme")
    try:
        stale.unlink(missing_ok = True)
    except OSError:
        pass


# ── unsloth studio reset-password ────────────────────────────────────


@studio_app.command("desktop-capabilities", hidden = True)
def desktop_capabilities(
    json_output: bool = typer.Option(
        False,
        "--json",
        help = "Emit machine-readable JSON.",
    ),
):
    payload = {
        "desktop_protocol_version": 1,
        "desktop_manageability_version": 1,
        "supports_provision_desktop_auth": True,
        "supports_api_only": True,
        "supports_desktop_backend_ownership": True,
        "version": "unknown",
    }
    try:
        from importlib.metadata import version as package_version
        payload["version"] = package_version("unsloth")
    except Exception:
        pass

    if json_output:
        typer.echo(json.dumps(payload, sort_keys = True))
        return

    for key, value in payload.items():
        typer.echo(f"{key}: {value}")


@studio_app.command("provision-desktop-auth", hidden = True)
def provision_desktop_auth():
    """Create/repair desktop auth state for the local machine."""
    auth_dir = STUDIO_HOME / "auth"
    secret = _create_desktop_secret_in_cli()
    _write_auth_secret(auth_dir / DESKTOP_SECRET_FILE, secret)
    typer.echo("Desktop auth ready.")


@studio_app.command("reset-password")
def reset_password():
    """Reset the Studio 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
    server must be restarted after running this command.
    """
    auth_dir = STUDIO_HOME / "auth"
    db_file = auth_dir / "auth.db"
    stale_files = [
        auth_dir / BOOTSTRAP_PASSWORD_FILE,
        auth_dir / DESKTOP_SECRET_FILE,
    ]
    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
    # 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
    # credential. Failing here leaves a consistent, still-recoverable state.
    try:
        db_file.unlink(missing_ok = True)
    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.",
            err = True,
        )
        raise typer.Exit(1)

    # The DB is gone, so the next start re-seeds. Invalidate the seeded plaintext
    # credential files so that re-seed generates a FRESH password instead of
    # reusing a stale one: unlink only ignores FileNotFoundError, so a
    # locked/undeletable file (Windows AV, read-only dir) would otherwise survive
    # and generate_bootstrap_password() would read it back and re-validate the
    # credential this reset revoked. Truncate on unlink failure; if a file can be
    # neither removed nor truncated, fail closed -- the DB is already gone, so a
    # surviving plaintext would be reused, and the user must remove it manually.
    for path in stale_files:
        try:
            path.unlink(missing_ok = True)
        except OSError:
            try:
                path.write_text("")
            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 "
                    "be reused.",
                    err = True,
                )
                raise typer.Exit(1)

    if not had_db:
        typer.echo("No auth database found -- nothing to reset.")
        raise typer.Exit(0)

    typer.echo("Auth database deleted. Restart Unsloth Studio to get a new password.")