Issues

• mcp: a handler error without a code reaches the peer as JSON-RPC error code 0

  modelcontextprotocol/go-sdk#1394 · Filter by author talhayme opened on Oct 12, 2026
  1

• mcp: rejected request IDs receive no JSON-RPC error envelope

  modelcontextprotocol/go-sdk#1391 · Filter by author skosovsky opened on Oct 12, 2026

• mcp: deferred cancellation can target a new invocation reusing the request ID

  modelcontextprotocol/go-sdk#1389 · Filter by author skosovsky opened on Oct 12, 2026

• mcp: typed tool handler adds zero structuredContent to an IsError result

  modelcontextprotocol/go-sdk#1387 · Filter by author Ilyuha888 opened on Oct 12, 2026
  1

• auth: resource metadata lookup accepts URLs from non-Bearer challenges

  modelcontextprotocol/go-sdk#1379 · Filter by author harsh543 opened on Oct 12, 2026

• Ping on 2026-07-28 sessions sends a removed method and surfaces confusing errors - propose failing fast

  modelcontextprotocol/go-sdk#1377 · Filter by author azilber opened on Oct 12, 2026

• jsonrpc: numeric request IDs above 2^53 lose precision

  modelcontextprotocol/go-sdk#1376 · Filter by author skosovsky opened on Oct 11, 2026

• examples/client: add a remote search and fetch example with Parallel MCP

  modelcontextprotocol/go-sdk#1372 · Filter by author georgeatparallel opened on Oct 11, 2026

• mcp: a response that has already arrived is discarded when the caller's context is cancelled during decoding, and notifications/cancelled is sent for the completed request

  modelcontextprotocol/go-sdk#1368 · Filter by author vbcherepanov opened on Oct 10, 2026

• mcp: Unsubscribe followed by Subscribe can leave a 2026-07-28 session subscribed to nothing

  modelcontextprotocol/go-sdk#1359 · Filter by author jmrplens opened on Oct 8, 2026

• Streamable HTTP: a tool result that fails to marshal leaves the POST hanging (no JSON-RPC error)

  modelcontextprotocol/go-sdk#1358 · Filter by author jholhewres opened on Oct 8, 2026
  1

• auth: Authorize fails against a 2025-03-26 server whose URL has a query string

  modelcontextprotocol/go-sdk#1347 · Filter by author akshita317 opened on Oct 6, 2026

• Client returns a call's result before handling notifications that preceded it

  P3
  modelcontextprotocol/go-sdk#1337 · Filter by author serverplumber opened on Oct 3, 2026
  1

• mcp: Client.Connect never falls back to initialize when a stdio server ignores server/discover

  modelcontextprotocol/go-sdk#1332 · Filter by author chaholl opened on Oct 2, 2026
  3

• mcp: SSEClientTransport ties the event stream to the context passed to Connect

  modelcontextprotocol/go-sdk#1331 · Filter by author chaholl opened on Oct 2, 2026
  2

• mcp: client skips elicitation schema defaults when the handler returns no content, and validates before applying them

  modelcontextprotocol/go-sdk#1330 · Filter by author chaholl opened on Oct 2, 2026
  1

• auth: allow advertising different scopes in WWW-Authenticate than the ones RequireBearerToken enforces

  Bug

  modelcontextprotocol/go-sdk#1329 · Filter by author pmokeev opened on Oct 2, 2026
  1

• mcp: LoggingTransport drops session state updates, so a wrapped transport behaves differently

  modelcontextprotocol/go-sdk#1328 · Filter by author Zhuoxi2000 opened on Oct 1, 2026
  1

• mcp: allow advertising the top-level events capability (MCP Events extension draft)

  P3
  modelcontextprotocol/go-sdk#1325 · Filter by author cxbitz opened on Oct 1, 2026
  1

• mcp: 2026-only server silently serves legacy clients instead of returning -32022

  modelcontextprotocol/go-sdk#1313 · Filter by author Enigmage opened on Sep 28, 2026
  3

• mcp: tool schemas and metadata lose JSON number precision

  modelcontextprotocol/go-sdk#1310 · Filter by author Tangerg opened on Sep 28, 2026

• mcp: client receiving middleware doesn't see input requests on 2026-07-28

  modelcontextprotocol/go-sdk#1305 · Filter by author po-et opened on Sep 27, 2026
  1

• mcp: requests to the client aren't checked against the capabilities it declared

  modelcontextprotocol/go-sdk#1303 · Filter by author po-et opened on Sep 26, 2026
  1

• mcp: the streamable client does not start a new session after a 404, which the 2025-11-25 transport requires

  P2
  modelcontextprotocol/go-sdk#1299 · Filter by author jmrplens opened on Sep 25, 2026
  2

• proposal: ClientOptions.ResourceSubscriptionEndedHandler for observing resource-subscription termination

  modelcontextprotocol/go-sdk#1284 · Filter by author jeremy opened on Sep 20, 2026