Added
- (client) cancel an abandoned tools/call, prompts/get or resources/read (#1344)
- (auth) add initial authorization scope selection (#1352)
- (transport) add non-blocking stdio_pipes transport (#1304)
Fixed
- (server) reject requests to 2026-07-28 clients (#1326)
- (streamable-http-server) look up tool schemas per request (#1349)
- (transport) follow same-origin 307/308 redirects in the default Streamable HTTP client (#1367)
- (streamable-http-server) answer a session-less non-initialize POST with 400 (#1377)
- (model) read a request id written in float form as that integer (#1346)
- (client) answer a server ping during the initialize handshake (#1366)
- (transport) accept nested x-mcp-header annotations (#1359)
- (streamable-http-client) handle error responses to initialize (#1361)
- (transport) bound the incoming line buffer in AsyncRwTransport (#1049)
- (model) reject malformed JSON-RPC messages with conflicting result and error fields (#1283) (#1287)
- ship LICENSE in rmcp and rmcp-macros crates (#1342)
- (streamable-http-server) release the session map lock before waiting on a session (#1323)
- (rmcp) gate client- and server-only helpers behind their features (#1329)
- cancel pending request tokens after transport EOF (#1333)
- (rmcp) import base64-only prompt content types under the feature (#1314)
Other
- combine AI issue triage with a maintainer rotation as the responsible reviewer (#1260)