v4.22.2
ysharma3501/NovaSRv4.22.2Oct 4, 2026by github-actions[bot]
Upgrading?
AI Summary
Bug fixes for MCP protocol version handling and error responses.
Key Highlights
- Answer 400 for unsupported MCP-Protocol-Version header.
- Return throwing tool errors as `isError` results.
- Avoid secondary parameter name collisions.
- Preserve empty property names in JSON Schema issue paths.
New Features
- Protocol version error handling
- Error result type fixes
- Parameter collision resolution
- JSON Schema property preservation
Full Release Notes
## [4.22.2](https://github.com/punkpeye/fastmcp/compare/v4.22.1...v4.22.2) (2026-10-04) ### Bug Fixes * **edge:** answer 400 for an unsupported MCP-Protocol-Version header ([#415](https://github.com/punkpeye/fastmcp/issues/415)) ([85a2b83](https://github.com/punkpeye/fastmcp/commit/85a2b83911cb09b232571cae952062cbcd94c2e9)) * **edge:** return a throwing tool's error as an isError result ([#410](https://github.com/punkpeye/fastmcp/issues/410)) ([5b7dfea](https://github.com/punkpeye/fastmcp/commit/5b7dfea7688588f85579a0f5ce917449bfaeb6f4)) * **openapi:** avoid secondary parameter name collisions ([#409](https://github.com/punkpeye/fastmcp/issues/409)) ([6670e7a](https://github.com/punkpeye/fastmcp/commit/6670e7abecdb0b1e39e5203e04ef08d9e0063146)) * preserve empty property names in JSON Schema issue paths ([#412](https://github.com/punkpeye/fastmcp/issues/412)) ([0c1cbe8](https://github.com/punkpeye/fastmcp/commit/0c1cbe85e02b64a2a34e8ce54a6ae80e9a73b58e))
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