mcp: send the proposed protocol version in the initialize header - #1165
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The legacy initialize handshake pins params.protocolVersion but sends no Mcp-Protocol-Version header of its own: setMCPHeaders finds c.initializedResult still nil, since it is assigned a few lines later, and the message carries no _meta.protocolVersion, so the header falls to the request context. For a standalone client that context is empty and the header is absent; for a process that is both a server and a client it holds that process's inbound version, which then contradicts the body it accompanies. This is the client-side mirror of modelcontextprotocol#963. Declares the proposed version on the context of the initialize send, the same way the server/discover probe immediately above already does, so the header always states what the body proposes. The fake server asserted wantProtocolVersion for other methods but for none of its sixteen initialize cases, so neither an absent nor a contradicting header was covered. Asserts header/body agreement centrally instead, since it holds for every initialize unconditionally. Fixes modelcontextprotocol#1164
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The legacy initialize handshake pins params.protocolVersion but sends no
Mcp-Protocol-Version header of its own: setMCPHeaders finds c.initializedResult
still nil, since it is assigned a few lines later, and the message carries no
_meta.protocolVersion, so the header falls to the request context. For a
standalone client that context is empty and the header is absent; for a process
that is both a server and a client it holds that process's inbound version,
which then contradicts the body it accompanies. This is the client-side mirror
of #963.
Declares the proposed version on the context of the initialize send, the same
way the server/discover probe immediately above already does, so the header
always states what the body proposes.
The fake server asserted wantProtocolVersion for other methods but for none of
its sixteen initialize cases, so neither an absent nor a contradicting header
was covered. Asserts header/body agreement centrally instead, since it holds
for every initialize unconditionally.
Fixes #1164