MCP Python SDK v2.1.0

MCP Python SDK releases published MCP Python SDK v2.1.0. This release-watch entry was generated from the project's official GitHub release feed and is kept separate from human-reviewed editorial analysis. Release notes: Highlights Client accepts StdioServerParameters directly: Client(StdioServerParameters(command="uv", args= "run", "server.py" )) ( 3321 ). Prompt messages accept Image and Audio , prompt functions may return bare content blocks, and Message / UserMessage / AssistantMessage are exported from mcp.server.mcpserver ( 3320 ). The 4 MiB request body limit now also covers the SSE transport and the OAuth endpoints; SseServerTransport and MCPServer.sse app() take max request body size , and the SSE message endpoint answers 405 to non-POST requests ( 3336 ). Behaviour changes to be aware of Handler exceptions ( 3314 ): an unexpected exception from a tool, resource or prompt handler is logged once at ERROR with its traceback, and the client now sees only Error executing tool (or the resource/prompt equivalent) rather than the exception text. Raise ToolError / ResourceError when the message is…

• Review the official MCP Python SDK releases release notes before upgrading.
• Check compatibility, migration, and security notes against your current agent stack.
• Run focused regression tests before production rollout.