Google Antigravity IDE OAuth auth plugin for Opencode - access Gemini 3 Pro and Claude 4.5 using Google credentials (Fixed rate limit rotation)
npm install rishav-antigravity-auth
> 🔧 Fixed Fork: This is a fork of opencode-antigravity-auth with multi-account rotation bug fixes. Issues #134, #135, and #136 are resolved - accounts now properly rotate when rate-limited instead of repeatedly using the same account.
Enable Opencode to authenticate against Antigravity (Google's IDE) via OAuth so you can use Antigravity rate limits and access models like gemini-3-pro-high and claude-opus-4-5-thinking with your Google credentials.
- Google OAuth sign-in with automatic token refresh via opencode auth login
- Dual Quota System - Access both Antigravity quota (Claude, Gemini 3) and Gemini CLI quota from a single plugin
- Multi-Account Rotation - Add multiple Google accounts; automatically rotates when one is rate-limited
- Real-time SSE streaming including thinking blocks and incremental output
- Extended Thinking - Native support for Claude thinking budgets and Gemini 3 thinking levels
- Auto Recovery - Automatic session recovery from Claude tool_result_missing errors
- Plugin Compatible - Works alongside other OpenCode plugins (opencodesync, etc.)
Option A: Let an LLM do it
Paste this into any LLM agent (Claude Code, OpenCode, Cursor, etc.):
``
Install the rishav-antigravity-auth plugin (fixed fork with proper account rotation) and add the Antigravity model definitions to ~/.config/opencode/opencode.json by following: https://raw.githubusercontent.com/irishavmishra/opencode-antigravity-auth/main/README.md
Option B: Manual setup
1. Add the plugin to your config (~/.config/opencode/opencode.json):
`json`
{
"plugin": ["rishav-antigravity-auth@1.2.8"]
}
2. Authenticate:
`bash`
opencode auth login
3. Add models (see Available Models for full list):
`json`
{
"plugin": ["rishav-antigravity-auth@1.2.8"],
"provider": {
"google": {
"models": {
"antigravity-claude-sonnet-4-5": {
"name": "Claude Sonnet 4.5 (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
}
}
}
}
}
4. Use it:
`bash`
opencode run "Hello" --model=google/antigravity-claude-sonnet-4-5
Installation Guide for LLM Agents
1. Edit the OpenCode configuration file:
- Linux/Mac: ~/.config/opencode/opencode.json
- Windows:
2. Add the plugin to the plugins array
3. Set provider to "google" and choose a model
Create ~/.config/opencode/opencode.json:`json`
{
"$schema": "https://opencode.ai/config.json",
"plugin": ["rishav-antigravity-auth@1.2.8"],
"provider": {
"google": {
"models": {
"antigravity-gemini-3-pro-low": {
"name": "Gemini 3 Pro Low (Antigravity)",
"limit": { "context": 1048576, "output": 65535 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-gemini-3-pro-high": {
"name": "Gemini 3 Pro High (Antigravity)",
"limit": { "context": 1048576, "output": 65535 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-gemini-3-flash": {
"name": "Gemini 3 Flash (Antigravity)",
"limit": { "context": 1048576, "output": 65536 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"gemini-3-pro-low": {
"name": "Gemini 3 Pro Low (Gemini)",
"limit": { "context": 1048576, "output": 65535 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"gemini-3-pro-high": {
"name": "Gemini 3 Pro High (Gemini)",
"limit": { "context": 1048576, "output": 65535 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"gemini-3-flash": {
"name": "Gemini 3 Flash (Gemini)",
"limit": { "context": 1048576, "output": 65536 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-sonnet-4-5": {
"name": "Claude Sonnet 4.5 (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-sonnet-4-5-thinking-low": {
"name": "Claude Sonnet 4.5 Low (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-sonnet-4-5-thinking-medium": {
"name": "Claude Sonnet 4.5 Medium (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-sonnet-4-5-thinking-high": {
"name": "Claude Sonnet 4.5 High (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-opus-4-5-thinking-low": {
"name": "Claude Opus 4.5 Low (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-opus-4-5-thinking-medium": {
"name": "Claude Opus 4.5 Medium (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-opus-4-5-thinking-high": {
"name": "Claude Opus 4.5 High (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
}
}
}
}
}
`bash`
opencode run "Hello" --model=google/antigravity-claude-sonnet-4-5
Models with antigravity- prefix use Antigravity quota:
| Model | Description |
|-------|-------------|
| google/antigravity-gemini-3-flash | Gemini 3 Flash (minimal thinking) |google/antigravity-gemini-3-pro-low
| | Gemini 3 Pro with low thinking |google/antigravity-gemini-3-pro-high
| | Gemini 3 Pro with high thinking |google/antigravity-claude-sonnet-4-5
| | Claude Sonnet 4.5 (no thinking) |google/antigravity-claude-sonnet-4-5-thinking-low
| | Sonnet with 8K thinking budget |google/antigravity-claude-sonnet-4-5-thinking-medium
| | Sonnet with 16K thinking budget |google/antigravity-claude-sonnet-4-5-thinking-high
| | Sonnet with 32K thinking budget |google/antigravity-claude-opus-4-5-thinking-low
| | Opus with 8K thinking budget |google/antigravity-claude-opus-4-5-thinking-medium
| | Opus with 16K thinking budget |google/antigravity-claude-opus-4-5-thinking-high
| | Opus with 32K thinking budget |
> Backward compatibility: Old model names (gemini-3-pro-low, gemini-3-pro-high, gemini-3-flash) still work as a fallback. However, you should update to the antigravity- prefix for stability. See Migration Guide.
Models with -preview suffix use Gemini CLI quota:
| Model | Description |
|-------|-------------|
| google/gemini-2.5-flash | Gemini 2.5 Flash |google/gemini-2.5-pro
| | Gemini 2.5 Pro |google/gemini-3-flash-preview
| | Gemini 3 Flash (preview) |google/gemini-3-pro-preview
| | Gemini 3 Pro (preview) |
Full models configuration
`json`
{
"$schema": "https://opencode.ai/config.json",
"plugin": ["rishav-antigravity-auth@1.2.8"],
"provider": {
"google": {
"models": {
"antigravity-gemini-3-pro-low": {
"name": "Gemini 3 Pro Low (Antigravity)",
"limit": { "context": 1048576, "output": 65535 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-gemini-3-pro-high": {
"name": "Gemini 3 Pro High (Antigravity)",
"limit": { "context": 1048576, "output": 65535 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-gemini-3-flash": {
"name": "Gemini 3 Flash (Antigravity)",
"limit": { "context": 1048576, "output": 65536 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"gemini-3-pro-low": {
"name": "Gemini 3 Pro Low (Antigravity)",
"limit": { "context": 1048576, "output": 65535 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"gemini-3-pro-high": {
"name": "Gemini 3 Pro High (Antigravity)",
"limit": { "context": 1048576, "output": 65535 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"gemini-3-flash": {
"name": "Gemini 3 Flash (Antigravity)",
"limit": { "context": 1048576, "output": 65536 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-sonnet-4-5": {
"name": "Claude Sonnet 4.5 (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-sonnet-4-5-thinking-low": {
"name": "Claude Sonnet 4.5 Think Low (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-sonnet-4-5-thinking-medium": {
"name": "Claude Sonnet 4.5 Think Medium (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-sonnet-4-5-thinking-high": {
"name": "Claude Sonnet 4.5 Think High (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-opus-4-5-thinking-low": {
"name": "Claude Opus 4.5 Think Low (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-opus-4-5-thinking-medium": {
"name": "Claude Opus 4.5 Think Medium (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"antigravity-claude-opus-4-5-thinking-high": {
"name": "Claude Opus 4.5 Think High (Antigravity)",
"limit": { "context": 200000, "output": 64000 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"gemini-2.5-flash": {
"name": "Gemini 2.5 Flash (CLI)",
"limit": { "context": 1048576, "output": 65536 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"gemini-2.5-pro": {
"name": "Gemini 2.5 Pro (CLI)",
"limit": { "context": 1048576, "output": 65536 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"gemini-3-flash-preview": {
"name": "Gemini 3 Flash Preview (CLI)",
"limit": { "context": 1048576, "output": 65536 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
},
"gemini-3-pro-preview": {
"name": "Gemini 3 Pro Preview (CLI)",
"limit": { "context": 1048576, "output": 65535 },
"modalities": { "input": ["text", "image", "pdf"], "output": ["text"] }
}
}
}
}
}
Add multiple Google accounts for higher combined quotas. The plugin automatically rotates between accounts when one is rate-limited.
`bash`
opencode auth login
How multi-account works
- Sticky account selection - Sticks to the same account until rate-limited (preserves Anthropic's prompt cache)
- Per-model-family limits - Rate limits tracked separately for Claude and Gemini models
- Dual quota pools for Gemini - Automatic fallback between Antigravity quota and Gemini CLI quota before switching accounts
- Smart retry threshold - Short rate limits (≤5s) are retried on same account
- Exponential backoff - Increasing delays for consecutive rate limits
For Gemini models, the plugin accesses two independent quota pools per account:
| Quota Pool | When Used |
|------------|-----------|
| Antigravity | Primary (tried first) |
| Gemini CLI | Fallback when Antigravity is rate-limited |
This effectively doubles your Gemini quota per account.
When running opencode auth login with existing accounts:
`
2 account(s) saved:
1. user1@gmail.com
2. user2@gmail.com
(a)dd new account(s) or (f)resh start? [a/f]:
`
- Stored in ~/.config/opencode/antigravity-accounts.json
- Contains OAuth refresh tokens - treat like a password
- If Google revokes a token (), that account is automatically removed
Create ~/.config/opencode/antigravity.json (or .opencode/antigravity.json in project root):
| Option | Default | Description |
|--------|---------|-------------|
| quiet_mode | false | Suppress toast notifications (except recovery) |debug
| | false | Enable debug logging to file |log_dir
| | OS default | Custom directory for debug logs |auto_update
| | true | Enable automatic plugin updates |
| Option | Default | Description |
|--------|---------|-------------|
| session_recovery | true | Auto-recover from tool_result_missing errors |auto_resume
| | true | Auto-send resume prompt after recovery |resume_text
| | "continue" | Text to send when auto-resuming |
| Option | Default | Description |
|--------|---------|-------------|
| empty_response_max_attempts | 4 | Retries for empty API responses |empty_response_retry_delay_ms
| | 2000 | Delay between retries |tool_id_recovery
| | true | Fix mismatched tool IDs from context compaction |claude_tool_hardening
| | true | Prevent tool parameter hallucination |
| Option | Default | Description |
|--------|---------|-------------|
| proactive_token_refresh | true | Refresh tokens before expiry |proactive_refresh_buffer_seconds
| | 1800 | Refresh 30min before expiry |max_rate_limit_wait_seconds
| | 300 | Max wait time when rate limited (0=unlimited) |quota_fallback
| | false | Try alternate quota when rate limited |
`bash`
OPENCODE_ANTIGRAVITY_QUIET=1 # quiet_mode
OPENCODE_ANTIGRAVITY_DEBUG=1 # debug
OPENCODE_ANTIGRAVITY_LOG_DIR=/path # log_dir
OPENCODE_ANTIGRAVITY_KEEP_THINKING=1 # keep_thinking
Full configuration example
`json`
{
"$schema": "https://raw.githubusercontent.com/NoeFabris/opencode-antigravity-auth/main/assets/antigravity.schema.json",
"quiet_mode": false,
"debug": false,
"log_dir": "/custom/log/path",
"auto_update": true,
"keep_thinking": false,
"session_recovery": true,
"auto_resume": true,
"resume_text": "continue",
"empty_response_max_attempts": 4,
"empty_response_retry_delay_ms": 2000,
"tool_id_recovery": true,
"claude_tool_hardening": true,
"proactive_token_refresh": true,
"proactive_refresh_buffer_seconds": 1800,
"proactive_refresh_check_interval_seconds": 300,
"max_rate_limit_wait_seconds": 300,
"quota_fallback": false,
"signature_cache": {
"enabled": true,
"memory_ttl_seconds": 3600,
"disk_ttl_seconds": 172800,
"write_interval_seconds": 60
}
}
and auth again$3
Try add this line to in google field under provider
$3
If you encounter error during the session, try chat the recover session mechanism should be trigger and you can continue the session, if the error blocked the session please workaround by use command /undo to revert to the state before the error and try again it should workKnown Plugin Interactions
$3
DCP creates synthetic assistant messages that lack thinking blocks. Our plugin must be listed BEFORE DCP:
`json
{
"plugin": [
"opencode-antigravity-auth@beta",
"@tarquinen/opencode-dcp@latest",
]
}
`$3
When using opencode-antigravity-auth, disable the built-in auth and override agent models in oh-my-opencode.json:
json
{
"google_auth": false,
"agents": {
"frontend-ui-ux-engineer": { "model": "google/gemini-3-pro-high" },
"document-writer": { "model": "google/gemini-3-flash" },
"multimodal-looker": { "model": "google/gemini-3-flash" }
}
}
`When spawning parallel subagents, multiple processes may select the same account causing rate limit errors. Workaround: Add more accounts via
.$3
- gemini-auth plugins - Not needed. This plugin handles all Google OAuth authentication.
Migration Guide (v1.2.7+)
If upgrading from v1.2.6 or earlier:
$3
v1.2.7+ uses explicit prefixes to distinguish quota sources:
| Model Type | New Name (Recommended) | Old Name (Still Works) |
|------------|------------------------|------------------------|
| Gemini 3 (Antigravity) |
antigravity-gemini-3-pro-low | gemini-3-pro-low |
| Gemini 3 (Antigravity) | antigravity-gemini-3-pro-high | gemini-3-pro-high |
| Gemini 3 (Antigravity) | antigravity-gemini-3-flash | gemini-3-flash |
| Gemini 3 (CLI) | gemini-3-pro-preview | N/A |
| Claude | antigravity-claude-sonnet-4-5 | claude-sonnet-4-5 |$3
Update your config to use
antigravity- prefix:`diff
- "gemini-3-pro-low": { ... }
+ "antigravity-gemini-3-pro-low": { ... }
`> Why update? Old names work now as a fallback, but this depends on Gemini CLI using
suffix. If Google removes -preview in the future, old names may route to the wrong quota. The antigravity- prefix is explicit and stable.$3
`bash
rm -rf ~/.config/opencode/antigravity-account.json
opencode auth login
`$3
Models now use
prefix for Antigravity quota. See Available Models.$3
`json
{
"$schema": "https://raw.githubusercontent.com/NoeFabris/opencode-antigravity-auth/main/assets/antigravity.schema.json",
"quiet_mode": false,
"debug": false
}
`
E2E Testing
The plugin includes regression tests for stability verification. Tests consume API quota.
bash
Sanity tests (7 tests, ~5 min)
npx tsx script/test-regression.ts --sanityHeavy tests (4 tests, ~30 min)
npx tsx script/test-regression.ts --heavyConcurrent tests (3 tests)
npx tsx script/test-regression.ts --category concurrencyRun specific test
npx tsx script/test-regression.ts --test thinking-tool-useList tests without running
npx tsx script/test-regression.ts --dry-run
`Debugging
bash
OPENCODE_ANTIGRAVITY_DEBUG=1 opencode # Basic logging
OPENCODE_ANTIGRAVITY_DEBUG=2 opencode # Verbose (full request/response bodies)
`Logs are written to
- Architecture - Plugin internals and request flow
- API Spec - Antigravity API reference
Safety, Usage & Legal
- Personal / internal development only
- Respect internal quotas and data handling policies
- Not for production services or bypassing intended limits
By using this plugin, you acknowledge:
- Terms of Service risk - This approach may violate ToS of AI model providers
- Account risk - Providers may suspend or ban accounts
- No guarantees - APIs may change without notice
- Assumption of risk - You assume all legal, financial, and technical risks
- Not affiliated with Google. This is an independent open-source project.
- "Antigravity", "Gemini", "Google Cloud", and "Google" are trademarks of Google LLC.
- Software is provided "as is", without warranty.
Built with help from:
- opencode-gemini-auth - Gemini OAuth groundwork by @jenslys
- CLIProxyAPI - Antigravity API reference
If this plugin helps you, consider supporting its continued maintenance:
MIT