FastMCP Files

This release contains important security and bug fixes. All users are encouraged to upgrade. Thanks to our 2 contributors.

What's Changed

Security 🔒

• [3.x] Apply Host/Origin protection settings to the SSE transport by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/5428
• [3.x] Exclude Cookie from forwarded HTTP headers by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/5429
• [3.x] Pass client CLI arguments literally to Windows .cmd wrappers by @jlowin and @strawgate in https://github.com/PrefectHQ/fastmcp/pull/5420
• [3.x] Use the server's auth provider for component manager routes by @jlowin and @strawgate in https://github.com/PrefectHQ/fastmcp/pull/5426
• [3.x] Bound CIMD cache growth by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/5430
• [3.x] Include resource metadata in component manager auth challenges by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/5435
• [3.x] Apply transforms, enabled state, and auth to hashed tool lookups by @jlowin and @strawgate in https://github.com/PrefectHQ/fastmcp/pull/5416
• [3.x] Build client schema types with create_model and bounded caches by @jlowin and @strawgate in https://github.com/PrefectHQ/fastmcp/pull/5414
• [3.x] Keep $ref pointers when inlining would produce an oversized schema by @jlowin and @strawgate in https://github.com/PrefectHQ/fastmcp/pull/5422
• [3.x] Resolve injected tools through the server's tool lookup by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/5432
• [3.x] Require a startup-URL session for the fastmcp dev apps preview by @jlowin and @strawgate in https://github.com/PrefectHQ/fastmcp/pull/5418
• [3.x] Inline schemas whose pointers pass through alias definitions by @jlowin and @strawgate in https://github.com/PrefectHQ/fastmcp/pull/5439
• [3.x] OpenAPI components send only declared arguments and keep configured headers by @jlowin and @strawgate in https://github.com/PrefectHQ/fastmcp/pull/5424

Docs 📚

• docs: add v3.4.8 changelog entries by @jlowin in https://github.com/PrefectHQ/fastmcp/pull/5445

Full Changelog: https://github.com/PrefectHQ/fastmcp/compare/v3.4.7...v3.4.8