diff --git a/studio/Unsloth_Studio_Colab.ipynb b/studio/Unsloth_Studio_Colab.ipynb
index c3aec04820..00eecfe51d 100644
--- a/studio/Unsloth_Studio_Colab.ipynb
+++ b/studio/Unsloth_Studio_Colab.ipynb
@@ -84,26 +84,7 @@
"id": "277e431e"
},
"outputs": [],
- "source": [
- "import sys, time\n",
- "sys.path.insert(0, \"/content/unsloth/studio/backend\")\n",
- "from colab import start\n",
- "start()"
- ]
- },
- {
- "cell_type": "code",
- "source": [
- "from google.colab import output\n",
- "output.serve_kernel_port_as_iframe(8888, height = 1200, width = \"100%\")\n",
- "for _ in range(10000): time.sleep(300), print(\"=\", end = \"\")"
- ],
- "metadata": {
- "id": "wb9UELh--XzX"
- },
- "id": "wb9UELh--XzX",
- "execution_count": null,
- "outputs": []
+ "source": "import sys\nsys.path.insert(0, \"/content/unsloth/studio/backend\")\nfrom colab import start\nstart()"
},
{
"cell_type": "markdown",
@@ -150,4 +131,4 @@
},
"nbformat": 4,
"nbformat_minor": 5
-}
+}
\ No newline at end of file
diff --git a/studio/backend/colab.py b/studio/backend/colab.py
index 7336f8a532..1bca16359b 100644
--- a/studio/backend/colab.py
+++ b/studio/backend/colab.py
@@ -26,30 +26,68 @@ logger = get_logger(__name__)
def get_colab_url(port: int = 8888) -> str:
"""
Get the actual Colab proxy URL for a port.
+
+ Retries up to 3 times and validates that the result is a real HTTPS Colab
+ URL before returning. Falls back to http://localhost:{port} only when all
+ attempts fail.
"""
+ import time as _time
+
+ fallback = f"http://localhost:{port}"
+
try:
from google.colab.output import eval_js
+ except ImportError:
+ return fallback
- # Use Colab's proxy mechanism
- url = eval_js(f"google.colab.kernel.proxyPort({port})", timeout_sec = 5)
- return url if url else f"http://localhost:{port}"
- except Exception as e:
- logger.info(f"Note: Could not get Colab URL ({e})")
- return f"http://localhost:{port}"
+ for attempt in range(3):
+ try:
+ url = eval_js(f"google.colab.kernel.proxyPort({port})", timeout_sec = 10)
+ # A valid Colab proxy URL starts with https:// and embeds the port.
+ if (
+ url
+ and isinstance(url, str)
+ and url.startswith("https://")
+ and str(port) in url
+ ):
+ return url.rstrip("/")
+ except Exception as e:
+ logger.info(f"Note: Could not get Colab URL (attempt {attempt + 1}/3: {e})")
+ if attempt < 2:
+ _time.sleep(1)
+
+ logger.warning(
+ f"Could not get a valid Colab proxy URL after 3 attempts — using localhost fallback. "
+ f"The link/iframe may not work from outside the runtime."
+ )
+ return fallback
-def show_link(port: int = 8888):
- """Display a styled clickable link to the UI."""
+def show_link(port: int = 8888, *, _url: "str | None" = None):
+ """Display a styled clickable link to the UI.
+
+ *_url* is an optional pre-fetched Colab proxy URL. When omitted,
+ ``get_colab_url(port)`` is called internally. Pass it from
+ ``_show_and_embed`` to avoid a second ``eval_js`` round-trip.
+ """
from IPython.display import display, HTML
- # Get real Colab proxy URL
- url = get_colab_url(port)
+ url = _url if _url is not None else get_colab_url(port)
+
+ # Build a truncated display URL. Wrap in try/except so an unexpected URL
+ # shape never prevents the link from rendering.
+ try:
+ port_prefix = f"{port}-"
+ idx = url.index(port_prefix)
+ next_dash = url.index("-", idx + len(port_prefix))
+ short_url = url[: next_dash + 1] + "..."
+ except (ValueError, IndexError):
+ short_url = url
+
+ # Also emit a plain-text line so the URL is visible even if HTML display
+ # is suppressed or fails.
+ logger.info(f"🌐 Unsloth Studio URL: {url}")
- short_url = (
- url[: url.index("-", url.index(f"{port}-") + len(str(port)) + 1) + 1] + "..."
- if f"{port}-" in url
- else url
- )
html = f"""
@@ -59,10 +97,10 @@ def show_link(port: int = 8888):
height="48" style="display:block;">
Unsloth Studio is Ready!
-
+ font-weight: 800; font-size: 16px; cursor: pointer;">
Open Unsloth Studio
@@ -77,6 +115,75 @@ def show_link(port: int = 8888):
display(HTML(html))
+def _is_studio_healthy(port: int, timeout: float = 2.0) -> bool:
+ """Return True if a Studio backend is already answering health checks on *port*."""
+ import urllib.request
+
+ try:
+ with urllib.request.urlopen(
+ f"http://localhost:{port}/api/health", timeout = timeout
+ ):
+ return True
+ except Exception:
+ return False
+
+
+def _show_and_embed(port: int):
+ """Embed the Studio inline for *port* with a branded header bar.
+
+ Fetches the Colab proxy URL once (registering the port with Colab's
+ reverse-proxy at the same time) then renders a header bar + full-height
+ iframe as a single HTML block.
+
+ Falls back to ``serve_kernel_port_as_iframe`` if ``IPython.display.HTML``
+ is unavailable for any reason.
+ """
+ url = get_colab_url(port)
+ logger.info(f"🌐 Unsloth Studio URL: {url}")
+
+ try:
+ from IPython.display import HTML, display
+
+ iframe_id = f"unsloth-studio-{port}"
+
+ # Truncated URL shown in the header — best-effort, falls back to full URL.
+ try:
+ port_prefix = f"{port}-"
+ idx = url.index(port_prefix)
+ next_dash = url.index("-", idx + len(port_prefix))
+ short_url = url[: next_dash + 1] + "..."
+ except (ValueError, IndexError):
+ short_url = url
+
+ display(
+ HTML(f"""
+
+
+
+ Unsloth Studio
+ {short_url}
+
+
+
+""")
+ )
+ except Exception:
+ # Fallback: Colab's built-in helper (less control, but always works)
+ try:
+ from google.colab import output as colab_output
+
+ colab_output.serve_kernel_port_as_iframe(port, height = 900, width = "100%")
+ except ImportError:
+ pass
+
+
def start(port: int = 8888):
"""
Start Unsloth Studio server in Colab and display the URL.
@@ -85,10 +192,26 @@ def start(port: int = 8888):
from colab import start
start()
"""
- import sys
+ import time
logger.info("🦥 Starting Unsloth Studio...")
+ # --- Fast path: Studio is already running (cell re-run) ---
+ # Re-launching would either collide on the port or silently shift to a new
+ # port and confuse the user. Just re-show the link and iframe instead.
+ if _is_studio_healthy(port):
+ logger.info(
+ f" Studio is already running on port {port} — reusing existing server."
+ )
+ _show_and_embed(port)
+ try:
+ for _ in range(10000):
+ time.sleep(300)
+ print("=", end = "", flush = True)
+ except KeyboardInterrupt:
+ logger.info("\nUnsloth Studio keepalive stopped.")
+ return
+
logger.info(" Loading backend...")
from run import run_server
@@ -96,18 +219,63 @@ def start(port: int = 8888):
repo_root = Path(__file__).parent.parent
frontend_path = repo_root / "frontend" / "dist"
- if not frontend_path.exists():
+ if not (frontend_path / "index.html").exists():
logger.info("❌ Frontend not built! Please run the setup cell first.")
return
logger.info(" Starting server...")
- # Start server silently
- run_server(host = "0.0.0.0", port = port, frontend_path = frontend_path, silent = True)
+ try:
+ app = run_server(
+ host = "0.0.0.0", port = port, frontend_path = frontend_path, silent = True
+ )
+ except SystemExit as exc:
+ logger.error(f"❌ Unsloth Studio failed to start: {exc}")
+ return
+ except Exception as exc:
+ logger.error(f"❌ Unsloth Studio failed to start: {exc}")
+ return
- logger.info(" Server started!")
+ # run_server auto-increments the port when the requested one is already in
+ # use (e.g. Jupyter occupying 8888). Read back the actual bound port so the
+ # Colab proxy URL and iframe always point at the right place.
+ actual_port: int = getattr(getattr(app, "state", None), "server_port", None) or port
- # Show the clickable link with real URL
- show_link(port)
+ logger.info(f" Server started on port {actual_port}!")
+
+ # Poll health endpoint to confirm the server is truly reachable before
+ # showing the link and registering the iframe — avoids the race where
+ # ready_event fires but the process hasn't finished binding.
+ import urllib.request
+
+ server_ready = False
+ for _ in range(40):
+ try:
+ with urllib.request.urlopen(
+ f"http://localhost:{actual_port}/api/health", timeout = 1
+ ):
+ server_ready = True
+ break
+ except Exception:
+ time.sleep(0.5)
+
+ if not server_ready:
+ logger.error(
+ f"❌ Unsloth Studio did not become healthy on port {actual_port}. "
+ "Check for errors above."
+ )
+ return
+
+ _show_and_embed(actual_port)
+
+ # Keep kernel alive so the daemon server thread stays running.
+ # Handle KeyboardInterrupt cleanly so the user gets a readable message
+ # rather than a raw traceback when they interrupt the cell.
+ try:
+ for _ in range(10000):
+ time.sleep(300)
+ print("=", end = "", flush = True)
+ except KeyboardInterrupt:
+ logger.info("\nUnsloth Studio keepalive stopped.")
if __name__ == "__main__":
diff --git a/studio/backend/main.py b/studio/backend/main.py
index 8457da0b2d..fbf1c31de3 100644
--- a/studio/backend/main.py
+++ b/studio/backend/main.py
@@ -328,20 +328,58 @@ from starlette.requests import Request as _StarletteRequest # noqa: E402
_CSP_SCRIPT_NONCE_HEADER = "x-internal-script-nonce"
+# /content is Colab's working directory — more reliable than env vars which
+# aren't always set depending on Colab runtime version.
+import importlib.util as _importlib_util
+
+_IS_COLAB = os.path.isdir("/content") and (
+ bool(os.environ.get("COLAB_BACKEND_URL"))
+ or bool(os.environ.get("COLAB_JUPYTER_IP"))
+ or _importlib_util.find_spec("google.colab") is not None
+)
+
+
def _build_csp(script_nonce: "str | None" = None) -> str:
script_src = "script-src 'self'"
if script_nonce:
script_src += f" 'nonce-{script_nonce}'"
+ # In Colab the parent frame can be colab.research.google.com, a multi-level
+ # *.prod.colab.dev subdomain (e.g. foo.region.prod.colab.dev — note: CSP
+ # wildcards only match one level, so *.prod.colab.dev misses these), or a
+ # sandboxed null-origin output iframe. Use '*' so any ancestor is allowed;
+ # Colab is already a sandboxed single-user environment.
+ frame_ancestors = "*" if _IS_COLAB else "'none'"
+
+ # In Colab the frontend is served over the Colab reverse-proxy at an HTTPS
+ # *.prod.colab.dev URL. Colab's kernel communication layer and the output
+ # iframe scaffolding inject scripts from *.prod.colab.dev and
+ # *.googleusercontent.com, and make fetch/WebSocket connections to those
+ # same origins. Widen script-src and connect-src in Colab mode so those
+ # requests are not blocked. 'unsafe-inline' for scripts is still omitted;
+ # our own inline script uses a nonce.
+ if _IS_COLAB:
+ script_src += " https://*.prod.colab.dev https://*.googleusercontent.com"
+ connect_src = (
+ "'self' blob: data: "
+ "https://huggingface.co https://datasets-server.huggingface.co "
+ "https://*.prod.colab.dev wss://*.prod.colab.dev "
+ "https://*.googleusercontent.com wss://*.googleusercontent.com"
+ )
+ else:
+ connect_src = (
+ "'self' https://huggingface.co https://datasets-server.huggingface.co"
+ )
+
return (
"default-src 'self'; "
"img-src 'self' data: blob: https://t0.gstatic.com "
"https://t1.gstatic.com https://t2.gstatic.com "
"https://t3.gstatic.com https://www.google.com; "
- "connect-src 'self' https://huggingface.co https://datasets-server.huggingface.co; "
+ f"connect-src {connect_src}; "
"style-src 'self' 'unsafe-inline'; "
f"{script_src}; "
"font-src 'self' data:; "
- "frame-ancestors 'none'; "
+ f"frame-ancestors {frame_ancestors}; "
"form-action 'self'; "
"base-uri 'self'"
)
@@ -357,7 +395,10 @@ class SecurityHeadersMiddleware(BaseHTTPMiddleware):
if nonce is not None:
del response.headers[_CSP_SCRIPT_NONCE_HEADER]
response.headers.setdefault("Content-Security-Policy", _build_csp(nonce))
- response.headers.setdefault("X-Frame-Options", "DENY")
+ # Omit X-Frame-Options in Colab — CSP frame-ancestors handles it, and
+ # DENY would block serve_kernel_port_as_iframe regardless of CSP.
+ if not _IS_COLAB:
+ response.headers.setdefault("X-Frame-Options", "DENY")
response.headers.setdefault("X-Content-Type-Options", "nosniff")
response.headers.setdefault("Referrer-Policy", "no-referrer")
response.headers.setdefault(
diff --git a/studio/backend/run.py b/studio/backend/run.py
index 5ddf404370..f401bc2ec1 100644
--- a/studio/backend/run.py
+++ b/studio/backend/run.py
@@ -653,7 +653,7 @@ def run_server(
from threading import Thread, Event
import uvicorn
- from main import app, setup_frontend
+ from main import app, setup_frontend, _IS_COLAB
from utils.paths import ensure_studio_directories
# Create all standard directories on startup
@@ -737,14 +737,22 @@ def run_server(
ready_event.set()
# server_header=False suppresses uvicorn's "Server: uvicorn"; SecurityHeadersMiddleware sets its own.
- config = uvicorn.Config(
- app,
+ config_kwargs = dict(
host = host,
port = port,
log_level = "info",
access_log = False,
server_header = False,
)
+ # Only in Colab: trust X-Forwarded-* from Colab's reverse proxy so the app
+ # sees the real https origin. forwarded_allow_ips="*" is fine inside Colab's
+ # single-user sandbox, but would be an unwanted security relaxation for a
+ # normal local/standalone Studio, so leave uvicorn's safe defaults
+ # (forwarded headers trusted from loopback only) in place there.
+ if _IS_COLAB:
+ config_kwargs["proxy_headers"] = True
+ config_kwargs["forwarded_allow_ips"] = "*"
+ config = uvicorn.Config(app, **config_kwargs)
_server = _ReadyServer(config)
_shutdown_event = Event()
@@ -766,14 +774,21 @@ def run_server(
app.state.trigger_shutdown = _trigger_shutdown
- # Run server in a daemon thread
+ # Run server in a daemon thread.
+ # Use an explicit new_event_loop() + run_until_complete() instead of
+ # asyncio.run() to avoid nest_asyncio's global patches to asyncio.run
+ # interfering when called from a thread while Colab/IPython already has
+ # a running loop on the main thread.
def _run():
+ loop = asyncio.new_event_loop()
+ asyncio.set_event_loop(loop)
try:
- asyncio.run(_server.serve())
+ loop.run_until_complete(_server.serve())
except BaseException as exc:
startup_errors.append(exc)
startup_failed.set()
finally:
+ loop.close()
if not ready_event.is_set():
startup_failed.set()