fix(initialization): accept 204 in addition to 202 on initialize #497
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Picks up modelcontextprotocol/rust-sdk#497 which fixes #5208 by allowing 204 response to MCP initialize notifications instead of just 202.
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Motivation and Context
Most MCP servers return a 202 in response to
notifications/initialized. However, it seams like some such as the allflow server from openai/codex#5208 return a 204. Other clients such as claude code andnpx @modelcontextprotocol/inspectoraccept 204 so it seems reasonable to do so here.The spec is ambiguous here from what I can tell. I don't see it explicitly mention that the notification response must be a 202.
How Has This Been Tested?
Test the failing server from openai/codex#5208. It now works.
Breaking Changes
None
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