claude-code - 💡(How to fix) Fix PostToolUse prompt hooks fail on Vertex AI backend with 'output_config: Extra inputs are not permitted' [2 comments, 2 participants]

PostToolUse:mcp__github__issue_write hook error
Hook evaluator API error: API Error: 400
{"type":"error","error":{"type":"invalid_request_error","message":"output_config: Extra inputs are not permitted"}}

The request ID prefix req_vrtx_ confirms this is a Vertex AI backend call.

TL;DR

Remove or modify the output_config parameter in the hook evaluator's API call to resolve the 400 error with Vertex AI.

Guidance

• Verify that the output_config parameter is indeed the cause of the error by checking the API documentation for Vertex AI and the hook evaluator's implementation.
• Check the plugin configuration and hook definition to ensure that no extra inputs are being sent in the API call.
• Consider modifying the plugin to handle different API backends (e.g., Vertex AI, Anthropic API, Bedrock) and their respective requirements for the output_config parameter.
• Test non-prompt hook types (e.g., "type": "command") to see if they exhibit the same behavior.

Example

No code snippet is provided as the issue is related to the API call and parameter configuration, which is not explicitly shown in the provided code.

Notes

The solution may require modifications to the plugin or the hook evaluator's implementation to handle the differences in API requirements between Vertex AI and other backends.

Recommendation

Apply a workaround by modifying the plugin or hook evaluator to remove or modify the output_config parameter for Vertex AI backend calls, as the error message suggests that this parameter is not permitted.