[Bug] Gemini 2.5 models fail with "missing thought_signature in functionCall parts" error

[BurakAytas]

Description

When using Gemini 2.5 Flash or 2.5 Pro models via Google AI Studio API, tool calls fail with a 400 error:

API Error: 400 [{"error":{"code":400,"message":"Function call is missing a thought_signature in functionCall parts.
This is required for tools to work correctly, and missing thought_signature may lead to degraded model
performance.","status":"INVALID_ARGUMENT"}}]

Steps to Reproduce

1. Configure openclaude with a Gemini 2.5 Flash/Pro model via AI Studio API key
2. Use any MCP plugin that triggers a tool call (e.g. mcp__plugin_claude-mem_mcp-search__search)
3. The first tool call fails with the above error

Expected Behavior

Tool calls should work correctly with Gemini 2.5 thinking models. The thought_signature from Gemini's response
should be preserved and sent back in the functionResponse.

Workaround

• Use gemini-2.0-flash (no thinking, no signature required)
• Or disable thinking with thinkingBudget: 0 (if supported)

Environment

• openclaude version: 0.1.8
• Model: gemini-2.5-flash (via AI Studio)
• OS: Linux Mint

Reference

Google's documentation on thought signatures:
https://ai.google.dev/gemini-api/docs/thought-signatures

Related issues in similar projects:

• [Bug] Gemini 3 function calling softlocked via Ollama Cloud (missing thought_signature) openclaw/openclaw#34008
• [Bug]: Gemini 3 thoughtSignature field causes "Thought signature is not valid" error in multi-turn conversations openclaw/openclaw#5001

[kevincodex1]

this is known bug already in v0.1.8 please try fresh build from main branch. this should be solve when we release v0.1.9

[AMIA47]

this is known bug already in v0.1.8 please try fresh build from main branch. this should be solve when we release v0.1.9

this is stiil the bug !

[BurakAytas]

My problem solved after branch update thanks.