opencode-antigravity-auth/docs/TROUBLESHOOTING.md

Troubleshooting

Common issues and solutions for the Antigravity Auth plugin.

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Quick Fixes

Auth problems

Delete the token file and re-login:

rm ~/.config/opencode/antigravity-accounts.json
opencode auth login

"Model not found"

Add this to your google provider config:

"npm": "@ai-sdk/google"

Session errors

Type continue to trigger auto-recovery, or use /undo to rollback.

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Gemini CLI Permission Error

When using Gemini CLI models, you may see:

Permission 'cloudaicompanion.companions.generateChat' denied on resource '//cloudaicompanion.googleapis.com/projects/...'

Why this happens: The plugin defaults to a predefined project ID that doesn't exist in your Google Cloud account. Antigravity models work, but Gemini CLI models need your own project.

Solution:

1. Go to Google Cloud Console
2. Create or select a project
3. Enable the Gemini for Google Cloud API (cloudaicompanion.googleapis.com)
4. Add projectId to your account in ~/.config/opencode/antigravity-accounts.json:

{
  "version": 3,
  "accounts": [
    {
      "email": "you@gmail.com",
      "refreshToken": "...",
      "projectId": "your-project-id"
    }
  ]
}

Note: For multi-account setups, add projectId to each account.

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Safari OAuth Callback Fails (macOS)

Symptoms:

• "fail to authorize" after successful Google login
• Safari shows "Safari can't open the page" or connection refused

Cause: Safari's "HTTPS-Only Mode" blocks the http://localhost callback URL.

Solutions:

1. Use a different browser (easiest): Copy the URL from opencode auth login and paste it into Chrome or Firefox.

2. Temporarily disable HTTPS-Only Mode:

   • Safari > Settings (⌘,) > Privacy
   • Uncheck "Enable HTTPS-Only Mode"
   • Run opencode auth login
   • Re-enable after authentication

3. Manual callback extraction (advanced):

   • When Safari shows the error, the address bar contains ?code=...&scope=...
   • See issue #119 for manual auth support

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Port Already in Use

If OAuth fails with "Address already in use":

macOS / Linux:

lsof -i :8080
kill -9 <PID>
opencode auth login

Windows:

netstat -ano | findstr :8080
taskkill /PID <PID> /F
opencode auth login

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WSL2 / Remote Development

The OAuth callback requires the browser to reach localhost on the machine running OpenCode.

• WSL2: Configure port forwarding, or use VS Code's port forwarding
• SSH: Use ssh -L 8080:localhost:8080 user@remote
• Headless servers: See issue #119 for manual auth

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Plugin Compatibility Issues

@tarquinen/opencode-dcp

DCP creates synthetic assistant messages that lack thinking blocks. List this plugin BEFORE DCP:

{
  "plugin": [
    "opencode-antigravity-auth@latest",
    "@tarquinen/opencode-dcp@latest"
  ]
}

oh-my-opencode

Disable built-in auth:

{
  "google_auth": false
}

When spawning parallel subagents, multiple processes may hit the same account. Workaround: Enable pid_offset_enabled: true or add more accounts.

Other gemini-auth plugins

You don't need them. This plugin handles all Google OAuth.

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Migration Guides

v1.2.8+ (Variants)

v1.2.8+ introduces model variants for dynamic thinking configuration.

Before (v1.2.7):

{
  "antigravity-claude-sonnet-4-5-thinking-low": { ... },
  "antigravity-claude-sonnet-4-5-thinking-max": { ... }
}

After (v1.2.8+):

{
  "antigravity-claude-sonnet-4-5-thinking": {
    "variants": {
      "low": { "thinkingConfig": { "thinkingBudget": 8192 } },
      "max": { "thinkingConfig": { "thinkingBudget": 32768 } }
    }
  }
}

Old tier-suffixed models still work for backward compatibility.

v1.2.7 (Prefix)

v1.2.7+ uses explicit antigravity- prefix:

Old Name	New Name
gemini-3-pro-low	antigravity-gemini-3-pro
claude-sonnet-4-5	antigravity-claude-sonnet-4-5

Old names work as fallback, but antigravity- prefix is recommended.

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Debugging

Enable debug logging:

OPENCODE_ANTIGRAVITY_DEBUG=1 opencode   # Basic
OPENCODE_ANTIGRAVITY_DEBUG=2 opencode   # Verbose (full request/response)

Logs are in ~/.config/opencode/antigravity-logs/.

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E2E Testing

The plugin includes regression tests (consume API quota):

npx tsx script/test-regression.ts --sanity      # 7 tests, ~5 min
npx tsx script/test-regression.ts --heavy       # 4 tests, ~30 min
npx tsx script/test-regression.ts --dry-run     # List tests

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Still stuck?

Open an issue on GitHub.