MCP Inspector 405 Method Not Allowed on a POST-only server

A 405 in Inspector's log against Sume is expected: the MCP endpoint serves POST JSON-RPC only, and a GET to /mcp returns 405 with allow: POST and the text "Remote MCP uses POST JSON-RPC requests." Inspector 2.8.0 added a per-server setting to suppress the standalone GET notification stream, which is the setting to use with a POST-only server like Sume.

Inspector's change is from its GitHub releases page; Sume's responses are from the MCP server source and docs, read 2026-10-01. I did not find the setting's exact label in the release notes, so look for it in the server's connection settings.

What does the Inspector release say?

The 2.8.0 notes (2026-09-23) list "per-server setting to suppress the standalone GET notification stream". The standalone GET stream is how a client can receive server-pushed notifications on some servers; a server that does not offer one has nothing to send there.

What does Sume answer?

Does the 405 mean my connection is broken?

No. A client that tolerates a 405 on the optional GET carries on with POST. If tools list and calls succeed, the connection is fine and the 405 is noise; suppressing the stream removes it. If POST fails too, the cause is elsewhere, such as the credential: see one Sume key in Inspector's headers.

How do I follow a long job without a stream?

Poll. The docs say each jobs_wait call holds at most 55 seconds (default 50); on wait_slice_expired, call it again with the same ids and never resubmit the paid create. Background on why there is no push is in no push, listChanged false.