After fixing the /mcp path forwarding in 1fd303a, requests now reach
FastMCP — but its StreamableHTTPSessionManager raises:
RuntimeError: Task group is not initialized. Make sure to use run().
The session manager owns a task group that must be running before it
can handle requests. In a stand-alone Starlette app this happens via
the `lifespan` parameter (lifespan = session_manager.run). Hosted
inside Quart, my dispatch wrapper only forwards HTTP events, not
lifespan, so the manager never got its startup signal.
Fix: hook session_manager.run() (an async context manager) into
Quart's @app.before_serving and @app.after_serving so the task group
is alive across the serving window.
The CI integration test was hitting the same crash because it drives
app.asgi_app raw without going through Quart's serving lifecycle —
@before_serving never fires. Updated the test to manually enter
session_manager.run() around the request.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
bvandeusen
65d3711a11