Mcp Get

GET on the MCP endpoint — 405, because we offer no SSE stream here.

A Streamable HTTP client may GET the endpoint to open an SSE channel for server-initiated messages. We never push any, and 405 with an Allow header is the transport's answer for "no stream at this endpoint" — the one response a conforming client treats as final.

This used to return a friendly 200 with a JSON hint, which is what a client sees as "the stream died": it reconnected forever. In July 2026 that loop was 80% of all production requests (~600k/day from six clients, zero successful tool calls). The hint survives in the 405 body, so a curl probe still learns the right method.