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fix: keep initialize on legacy protocol versions (#1228)

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Claude-Session: https://claude.ai/code/session_01EPcBfiUWJJueJn5cve1sjp
This commit is contained in:
Dale Seo 2026-09-01 07:38:57 +09:00 • committed by GitHub
commit ad9832ec21
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1 changed files with 369 additions and 120 deletions
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30
crates/rmcp/src/transport/streamable_http_server/tower.rs
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@ -322,7 +322,7 @@ impl<S: Service<RoleServer>> Service<RoleServer> for NegotiatingStatelessHttpSer
&requested,
result.protocol_version.clone(),
&self.0.supported_protocol_versions(),
);
)?;
if let Some(peer_info) = peer.peer_info() {
let mut peer_info = (*peer_info).clone();
peer_info.protocol_version = result.protocol_version.clone();
@ -375,22 +375,30 @@ fn is_legacy_request(
validate_request_protocol_version_meta(headers, message)?;
}
// An `initialize` request selects legacy semantics whatever version it names:
// the handshake exists only in the revisions before 2026-07-28, so the
// version in its params never routes it to the stateless path. The
// handshake itself answers with a legacy version the server supports.
if matches!(
message,
Some(ClientJsonRpcMessage::Request(req))
if matches!(&req.request, ClientRequest::InitializeRequest(_))
) {
return Ok(true);
}
let uses_discover_lifecycle = matches!(
message,
Some(ClientJsonRpcMessage::Request(req))
if !matches!(&req.request, ClientRequest::InitializeRequest(_))
&& req
.request
.get_meta()
.missing_required_keys(&ProtocolVersion::V_2026_07_28)
.is_empty()
if req
.request
.get_meta()
.missing_required_keys(&ProtocolVersion::V_2026_07_28)
.is_empty()
);
let from_body = match message {
Some(ClientJsonRpcMessage::Request(req)) => match &req.request {
ClientRequest::InitializeRequest(init) => Some(init.params.protocol_version.clone()),
_ => req.request.get_meta().protocol_version(),
},
Some(ClientJsonRpcMessage::Request(req)) => req.request.get_meta().protocol_version(),
_ => None,
};
let version = from_body