fastmcp releases
PyPI package, released from PrefectHQ/fastmcp on GitHub · No. 359 of the most used PyPI packages in the paper's catalog
Also released from it: fastmcp-slim
Latest release the paper recorded: fastmcp v3.4.9, Oct 16, 2026. Its newest GitHub release when last read: Oct 16, 2026.
Latest releases
Newest first, each linking to its notes on GitHub; the excerpt is the notes' own opening, where they have text.
- fastmcp v3.4.9
From the release notesThis release backports security fixes from 4.1: OpenAPI path parameters reject . and .. segments, a skill's SKILL.md must stay inside its skill folder, regex tool search is bounded in time and pattern length, and JWT ver…
- fastmcp v4.1.0
From the release notesFastMCP 4.1.0 is a maintenance release at heart: a broad sweep of fixes across OpenAPI, proxies, auth, tasks, and the CLI, plus full Python 3.15 support. It doesn't change how most servers behave. A few security fixes do…
- fastmcp v4.0.11
From the release notesThis release contains important security and bug fixes. All users are encouraged to upgrade. Thanks to our 10 contributors, including 6 first time contributors. What's Changed Enhancements agents: make AGENTS.md the entr…
- fastmcp v4.0.10
From the release notesTask enabled tools now work behind search transforms and CodeMode: they're registered with the task backend even when hidden, and a tool, resource, or prompt that calls one through ctx.fastmcp.call tool() (including the…