Fix: GET on the MCP endpoint answers fast (not a held-open hang)
Web-audit fix skill for the
mcp-get-fast-failcheck (MCP & API, SHOULD).
Goal
Answer GET on the MCP endpoint fast (a fast-fail status or a documented surface), never a held-open hang.
Fix
Answer a GET on the MCP endpoint promptly; this check fails only when the connection is held open. A streamable-HTTP GET routed into the transport opens the server-to-client SSE notification stream, and a stateless server (nothing to push) parks that connection until the caller times out. Answer one of two ways instead: fast-fail non-POST at the router with 405 Method Not Allowed and an Allow: POST header; or serve a documented surface on GET (a human- and agent-readable docs page, or a redirect to your .well-known MCP server card) so the GET returns content rather than a rejection. Any prompt, completed response passes (a fast-fail status, or a documented 2xx/redirect); only a held-open hang or a 5xx fails.
Resources
Copy-paste prompt
Paste this into your coding agent, replacing the Issue line with the Result line from your audit:
Verify
Re-run the audit at https://anc.dev/web-audit or call the audit_website MCP tool; the mcp-get-fast-fail check should report pass.