PrefectHQ/fastmcp v3.4.2

v3.4.2: Heads Up

on GitHub

FastMCP 3.4.2 restores JWT compatibility for providers that include private, non-critical JWS header parameters. Tokens from providers like Clerk can carry header metadata such as cat without being rejected before signature and claim validation, while unsupported critical headers are still rejected.

What's Changed

Fixes 🐞

• Allow private JWT headers by @jlowin in #4290

Docs 📚

• Docs: add v3.4.1 changelog entries by @jlowin in #4289

Full Changelog: v3.4.1...v3.4.2