HTTP 400: No tool call found for function call output with callid xxxx

[flyinsz]

Pre-checks

• I have searched existing issues and this is not a duplicate.

Deployment Method

Docker

Steps to Reproduce

新开session对话轮数多了之后几乎100%复现，出现问题后session就再也无法正常对话了：
[LLM Error] HTTP 400: {
"error": {
"message": "No tool call found for function call output with call_id call_f6db199d-c470-4bb3-8188-1c9eeb43cc60.",
"type": "invalid_request_error",
"param": "input",
"code": null
}
}

Expected vs Actual Behavior

100%复现

Logs / Screenshots

No response

[yaojin3616]

Fixed. The issue was caused by tool call message pairs (assistant + tool) being broken down during history truncation. The fix ensures these pairs remain intact, preventing the 'No tool call found for function call output' error.

Fix commit: 4921623