FastMCP Rust
A Rust port of the Python FastMCP framework for building Model Context Protocol servers, adding cooperative-cancellation primitives and async capability contexts on top of MCP's tool, resource and prompt abstractions.
FastMCP Rust is a cancel-aware framework for building MCP servers, extending the design of the Python jlowin/fastmcp project with async capability contexts and cooperative-cancellation primitives. It targets the root MCP protocol version from November 2024, while a modern facade separately tracks a newer draft version, which the project describes as still under implementation and unverified.
The project documents its own qualification status in detail rather than claiming full conformance: wire cancellation is only partially qualified, with the Unix stdio transport able to route cancellation into independent request-owned children while other transports keep sequential or blocking boundaries; bidirectional calls such as sampling, elicitation and roots requests are only partly qualified, working over the Unix stdio and WebSocket transports but not yet over non-Unix stdio, unsplit custom transports or SSE; and response caching is conservatively partitioned by committed authorization. It is written in Rust and used as a dependency, not a standalone application.