Wires FastMCP's streamable-HTTP ASGI sub-app into the Quart app via
asgi_app replacement. Requests under /mcp are stripped, auth-checked
against api_keys, and forwarded to FastMCP with fable_user_id set on
the ASGI scope. All other paths pass through to the original Quart
dispatch unchanged.
Tests cover the three auth paths (no header, invalid token, valid
token) plus a regression check that non-/mcp paths bypass the MCP
dispatch.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
