The MCP Python SDK is the official Python library for the Model Context Protocol (MCP), an open-source standard for connecting AI applications such as Claude or ChatGPT to external systems: data sources, tools and workflows. An SDK (software development kit) is a library that implements a protocol, so that developers do not write the protocol handling themselves.
With the SDK a developer builds MCP servers, which expose tools (functions that a model can call), resources (data that a model can read) and prompts to any MCP host, and MCP clients, which connect to any MCP server. A server can be a few type-hinted Python functions with decorators: the SDK derives the JSON Schema from the type hints and handles request parsing, validation and the protocol. It supports the standard transports stdio (a local subprocess), Streamable HTTP and SSE, and its mcp command runs a server and opens the MCP Inspector, an interactive test interface. It needs Python 3.11 or later.
The SDK is free and open source under the MIT License and installs with pip or uv as the package mcp.