openclaw - 💡(How to fix) Fix [Bug] thought_signature 400 regression in 2026.4.25 – fix was supposedly in 2026.4.24 [1 comments, 2 participants]

TL;DR

The thought_signature is being dropped or stripped in the request pipeline for the Google Generative AI provider, causing a 400 error, and a revised fix is needed to ensure its inclusion.

Guidance

• Review the changes made in the 2026.4.24 release to understand what previously resolved the issue and how it may have regressed.
• Investigate the request pipeline for the native Google Generative AI provider to identify where the thought_signature is being dropped or stripped.
• Compare the implementation with related issues (#53658, #34008, #33272, #509) to see if a similar fix can be applied.
• Consider adding logging or debugging statements to track the thought_signature through the request pipeline to pinpoint the issue.

Example

No code snippet is provided due to the lack of specific implementation details in the issue.

Notes

The issue seems to be specific to the Google Generative AI (Gemini) model and the OpenClaw agent runtime, so any fix may need to be tailored to this environment.

Recommendation

Apply a workaround to ensure the thought_signature is included in the request pipeline, as the previous fix in 2026.4.24 is no longer sufficient. This is recommended because the error is causing degraded model performance and the previous fix has regressed.