DCP is breaking Gemini thinking signature #262
Description
Please see this: NoeFabris/opencode-antigravity-auth#184
Bug Description
Upon making the first request in a session, I see that the request begins, but then it terminates early with a 400 error.
Steps to Reproduce
Use an antigravity model in OpenCode
Watch it begin
Then observe signature error
Expected Behavior
Succeed like it did yesterday
Actual Behavior
An error:
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:context_info , position 4. Please refer to https://ai.google.dev/gemini-api/docs/thought-signatures for more details.
...
[opencode-antigravity-auth debug]
- request=https://generativelanguage.googleapis.com/v1beta/models/antigravity-gemini-3-pro:streamGenerateContent?alt=sse
- selected idx=0 email=bowmanjd@gmail.com family=gemini accounts=1 strategy=sticky
- headerStyle=antigravity explicit=true
- endpoint=https://daily-cloudcode-pa.sandbox.googleapis.com
- resolved=https://daily-cloudcode-pa.sandbox.googleapis.com/v1internal:streamGenerateContent?alt=sse
- status=400 Bad Request
Environment
opencode version: 1.1.12
Plugin version: @beta
Operating System: Linux
Node.js version: v24.12.0
Logs
antigravity-debug-2026-01-14T12-30-25-158Z.log
Compliance Checklist
Please confirm:
I'm using this plugin for personal development only
I have an active Google Cloud project with Antigravity enabled
This issue is not related to attempting commercial use or TOS violations
I've reviewed the README troubleshooting section