Gemini 3 Pro "Function call is missing a thought_signature in functionCall parts"

[adam-elston-upguard]

Before submitting your bug report

• I've tried using the "Ask AI" feature on the Continue docs site to see if the docs have an answer
• I'm not able to find a related conversation on GitHub discussions that reports the same bug
• I'm not able to find an open issue that reports the same bug
• I've seen the troubleshooting guide on the Continue Docs

Relevant environment info

- OS:macOS
- Continue version: 1.2.10
- IDE version: 1.106.0
- Model: gemini-3-pro-preview
- config:
  
- name: Gemini 3 Pro
    provider: gemini
    model: gemini-3-pro-preview
    apiKey: ${{ secrets.GEMINI_API_KEY }}
    roles:
      - chat
      - edit
      - apply
    defaultCompletionOptions:
      contextLength: 1048576
      maxTokens: 65536
    capabilities:
      - tool_use
      - image_input
  
  OR link to agent in Continue hub:

Description

Tool use results in the following error:

[{ "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. Additional data, function call default_api:grep_search , position 3. please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.", "status": "INVALID_ARGUMENT" } } ]

To reproduce

No response

Log output

[@continuedev] error: HTTP 400 Bad Request from https://generativelanguage.googleapis.com/v1beta/models/gemini-3-pro-preview:streamGenerateContent
[{
  "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. Additional data, function call `default_api:grep_search` , position 3. please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.",
    "status": "INVALID_ARGUMENT"
  }
}
] {"context":"llm_fetch","url":"https://generativelanguage.googleapis.com/v1beta/models/gemini-3-pro-preview:streamGenerateContent","method":"POST","model":"gemini-3-pro-preview","provider":"gemini"}
[@continuedev] error: HTTP 400 Bad Request from https://generativelanguage.googleapis.com/v1beta/models/gemini-3-pro-preview:streamGenerateContent
[{
  "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. Additional data, function call `default_api:grep_search` , position 3. please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.",
    "status": "INVALID_ARGUMENT"
  }
}
] {"context":"llm_stream_chat","model":"gemini-3-pro-preview","provider":"gemini","useOpenAIAdapter":false,"streamEnabled":true,"templateMessages":false}

[murphyXu]

I am encountering a 400 INVALID_ARGUMENT error in agent mode when using Gemini 3.0 Pro via both Vertex AI and OpenRouter. According to the Google Vertex documentation, Gemini 3.0 Pro requires 'Thought Signatures'. I noticed that Cline has already implemented support for this. I look forward to seeing support for Thought Signatures in Continue for Gemini 3.0 Pro.

doc: https://docs.cloud.google.com/vertex-ai/generative-ai/docs/start/get-started-with-gemini-3#thought_signatures

cline ：cline/cline#7536

[nansenli]

have same issue

[jmwang326]

Same issue, although for the first few hours of gemini 3.0 existence, this wasn't an issue.