Release v2.3.0 · modelcontextprotocol/python-sdk

pip install -U mcp. Docs: https://py.sdk.modelcontextprotocol.io/ Mostly fixes, plus three new options. A few things behave differently, so skim these first: Behaviour changes httpx2>=2.10.0 is now required (#3600) It was >=2.5.0. The new max_sse_event_size option needs it. Nothing to do unless you pin httpx2 below 2.10. A tool with an invalid x-mcp-header annotation fails at registration (#3620) @mcp.tool(), add_tool and Tool.from_function raise InvalidSignature, naming the tool and the problem.