[BUG] Antigravity. HTTP 400 "Invalid project resource name projects/" - AI Ultra subscriber, macOS

Google Antigravity
1

Environment

  • OS: macOS (Apple Silicon)
  • Antigravity version: 1.16.5
  • Account: Google AI Ultra subscriber
  • Email: ...@gmail.com

Problem

All AI agent requests fail with HTTP 400 Bad Request.
The error shows the project resource name is empty: projects/ (missing project ID).

Error Details

{
  "error": {
    "code": 400,
    "message": "Invalid project resource name projects/",
    "status": "INVALID_ARGUMENT",
    "details": [{
      "@type": "type.googleapis.com/google.rpc.BadRequest",
      "fieldViolations": [{
        "description": "Invalid project resource name",
        "field": "name"
      }]
    }]
  }
}


Trace IDs (for backend investigation)

- Trajectory ID: ebc3cc55-432d-....
- TraceID: 0xc02e5b099a....
- Trajectory ID: 488d3a0d-3b45-....
- TraceID: 0x3af3e6c6615a...
- Trajectory ID: a32827a6-d8f3-.....
- TraceID: 0xaf672f2a38...

Troubleshooting Already Attempted

1. Signed out and signed back in
2. Cleared cache: rm -rf ~/.antigravity and restarted
3. Enabled Vertex AI API and Cloud AI Companion API on GCP project
4. Set gcloud auth application-default set-quota-project eng-cell-461004-q8
5. Launched with GOOGLE_CLOUD_PROJECT=eng-cell-461004-q8 env var
6. Installed Gemini Code Assist extension inside Antigravity
7. Attempted downgrade to v1.13.3 (blocked - version no longer supported)
8. Full reinstall via brew install --cask antigravity

None of the above resolved the issue. The project ID remains empty in API requests.

Request

Could you please:
1. Check the Trace IDs above to identify why the project provisioning is failing for my account
2. Confirm if this is a known backend issue
3. Provide a workaround or manual project binding method

Thank you.
2

I’m only a pro user but had exactly the same error.. This helped me : Critical Bug: Persistent HTTP 400 "Invalid project resource name projects/" even after Gmail switch - #27 by mattorq