v4.20.11
punkpeye/fastmcpv4.20.11Sep 11, 2026by github-actions[bot]
Upgrading?
AI Summary
This release fixes a bug where additional properties in tool output schemas were not being preserved correctly. It serves as a maintenance update to ensure data integrity and proper schema handling for MCP tools.
Key Highlights
- Preserved additional properties in tool output schemas
- Fixed issue #373 regarding schema preservation
- Maintenance update for data integrity
Full Release Notes
## [4.20.11](https://github.com/punkpeye/fastmcp/compare/v4.20.10...v4.20.11) (2026-09-11) ### Bug Fixes * preserve additional properties in tool output schemas ([#373](https://github.com/punkpeye/fastmcp/issues/373)) ([6872cf0](https://github.com/punkpeye/fastmcp/commit/6872cf0f46e3b71318b2c72f5859d90a955daa57))
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