FastMCP Files

First patch after 3.0 — mostly smoothing out rough edges discovered in the wild. The big ones: middleware state that wasn't surviving the trip to tool handlers now does, Tool.from_tool() accepts callables again, OpenAPI schemas with circular references no longer crash discovery, and decorator overloads now return the correct types in function mode. Also adds verify_id_token to OIDCProxy for providers (like some Azure AD configs) that issue opaque access tokens but standard JWT id_tokens.

What's Changed

Enhancements 🔧

• Add verify_id_token option to OIDCProxy by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3248

Fixes 🐞

• Fix v3.0.0 changelog compare link by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3223
• Fix MDX parse error in upgrade guide prompts by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3227
• Fix non-serializable state lost between middleware and tools by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3234
• Accept callables in Tool.from_tool() by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3235
• Preserve skill metadata through provider wrapping by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3237
• Fix circular reference crash in OpenAPI schemas by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3245
• Fix NameError with future annotations and Context/Depends parameters by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3243
• Fix ty ignore syntax in OpenAPI provider by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3253
• Use max_completion_tokens instead of deprecated max_tokens in OpenAI handler by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3254
• Fix ty compatibility with upgraded deps by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3257
• Fix decorator overload return types for function mode by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3258

Docs 📚

• Sync README with welcome.mdx, fix install count by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3224
• Document dict-to-Message prompt migration in upgrade guides by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3225
• Fix v2 upgrade guide: remove incorrect v1 import advice by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3226
• Animated banner by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3231
• Document mounted server state store isolation in upgrade guide by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/3236

Full Changelog: https://github.com/PrefectHQ/fastmcp/compare/v3.0.0...v3.0.1