Search results

Dead code path in MCPServer._handle_call_tool and incorrect call_tool return type

Status: Open.

#2695 In modelcontextprotocol/python-sdk;

· SHAI-Akshay-Tripathi opened on May 26, 2026

ClientSessionGroup attempts to use capabilities that were not advertised

Status: Open.

#2689 In modelcontextprotocol/python-sdk;

· mr-brobot opened on May 26, 2026

TransportSecuritySettings.allowed_hosts=[] (default) silently rejects external Host headers with HTTP 421

Status: Open.

#2688 In modelcontextprotocol/python-sdk;

· ptrhrsch-arch opened on May 26, 2026

OAuthClientInformationFull.redirect_uris: pydantic strict-type-equality breaks AnyUrl(x) != AnyHttpUrl(x) round-trip

Status: Open.

#2687 In modelcontextprotocol/python-sdk;

· ptrhrsch-arch opened on May 26, 2026

FastMCP/stdio: in-flight tool responses dropped on stdin EOF when input is bash-redirected from a file

Status: Open.

#2678 In modelcontextprotocol/python-sdk;

· theone139344 opened on May 25, 2026

ClientSession receive loop swallows callback exceptions, replying "Invalid request parameters" to the server instead of propagating to the call_tool awaiter

Status: Open.

#2673 In modelcontextprotocol/python-sdk;

· danielgshea opened on May 24, 2026

FastMCP.run(transport="stdio") produces noisy traceback on KeyboardInterrupt instead of clean exit

Status: Open.

#2663 In modelcontextprotocol/python-sdk;

· MikeNjoroge opened on May 22, 2026

Streamable HTTP server silently drops in-flight request when client reuses a JSON-RPC id

Status: Open.

#2655 In modelcontextprotocol/python-sdk;

· dexteradeus opened on May 21, 2026

mcp.server.fastmcp.FastMCP HTTP transport deadlocks after ~5 sequential client sessions on Windows (companion to PrefectHQ/fastmcp#4192)

Status: Open.

#2653 In modelcontextprotocol/python-sdk;

· colinlabrooy opened on May 21, 2026

Add invalid_target to AuthorizationErrorCode (RFC 8707)

Status: Open.

#2641 In modelcontextprotocol/python-sdk;

· stephaneberle9 opened on May 18, 2026

DCR registration accepts redirect_uris with non-HTTPS / non-loopback / fragmented schemes

Status: Open.

#2629 In modelcontextprotocol/python-sdk;

· CrypticCortex opened on May 18, 2026

Add option to skip output validation for mcp client

Status: Open.

#2626 In modelcontextprotocol/python-sdk;

· germanbecker opened on May 17, 2026