my-pal-mcp-server/docs/antigravity_provider.md

Antigravity Provider

The Antigravity provider enables access to Claude, Gemini, and other models through Google's unified gateway API. This provides an alternative way to access high-quality models using Google OAuth2 authentication instead of individual API keys.

Important Warning

Terms of Service Risk: Using the Antigravity provider may violate Google's Terms of Service. Users have reported account bans when using this approach.

High-Risk Scenarios:

• Fresh Google accounts have a very high chance of getting banned
• New accounts with Pro/Ultra subscriptions are frequently flagged

By using this provider, you acknowledge and accept all associated risks.

Available Models

Antigravity Quota Pool

These models use the Antigravity unified gateway quota:

Model ID	Description	Thinking Support
claude-opus-4-5-thinking	Claude Opus 4.5 with extended thinking	Yes (up to 32K tokens)
claude-sonnet-4-5-thinking	Claude Sonnet 4.5 with extended thinking	Yes (up to 32K tokens)
claude-sonnet-4-5	Claude Sonnet 4.5 standard	No
gemini-3-pro-high	Gemini 3 Pro with high thinking budget	Yes (up to 65K tokens)
gemini-3-pro-low	Gemini 3 Pro with low thinking budget	Yes (up to 16K tokens)
gemini-3-flash	Gemini 3 Flash	Yes (up to 32K tokens)
gpt-oss-120b-medium	GPT-OSS 120B	No

Gemini CLI Quota Pool

These models use a separate Gemini CLI quota:

Model ID	Description	Thinking Support
gemini-3-flash-preview	Gemini 3 Flash Preview	Yes
gemini-3-pro-preview	Gemini 3 Pro Preview	Yes
gemini-2.5-pro	Gemini 2.5 Pro	Yes
gemini-2.5-flash	Gemini 2.5 Flash	Yes

Setup

Option 1: OpenCode Integration (Recommended)

If you use OpenCode with the opencode-antigravity-auth plugin, your accounts are automatically detected from:

~/.config/opencode/antigravity-accounts.json

No additional configuration is needed. The PAL MCP server will automatically discover and use these accounts.

Option 2: Manual Refresh Token

Set the refresh token directly via environment variable:

export ANTIGRAVITY_REFRESH_TOKEN="your_oauth_refresh_token"
export ANTIGRAVITY_PROJECT_ID="your_gcp_project_id"  # Optional

Option 3: Custom Accounts File

Create ~/.config/opencode/antigravity-accounts.json manually:

{
  "version": 3,
  "accounts": [
    {
      "email": "your.email@gmail.com",
      "refreshToken": "1//your_refresh_token_here",
      "projectId": "your-gcp-project-id",
      "enabled": true
    }
  ],
  "activeIndex": 0
}

Environment Variables

Variable	Required	Description
ANTIGRAVITY_REFRESH_TOKEN	No*	OAuth2 refresh token (overrides accounts file)
ANTIGRAVITY_PROJECT_ID	No	Google Cloud project ID (defaults to rising-fact-p41fc)
ANTIGRAVITY_BASE_URL	No	API endpoint (defaults to production cloudcode-pa.googleapis.com)

*Either ANTIGRAVITY_REFRESH_TOKEN or a valid accounts file at ~/.config/opencode/antigravity-accounts.json is required.

Features

Multi-Account Rotation

When multiple accounts are configured, the provider automatically:

• Rotates between accounts when one is rate-limited
• Tracks per-model rate limits separately
• Preserves account preferences for cache efficiency

Extended Thinking

For models that support thinking (Claude and Gemini 3), you can control the thinking budget:

# Thinking modes: minimal, low, medium, high, max
response = provider.generate_content(
    prompt="Explain quantum computing",
    model_name="claude-opus-4-5-thinking",
    thinking_mode="high"  # Uses 67% of max thinking budget
)

Mode	Budget Percentage
minimal	0.5%
low	8%
medium	33% (default)
high	67%
max	100%

Image Support

Models with vision capability support image inputs:

response = provider.generate_content(
    prompt="What's in this image?",
    model_name="gemini-3-flash",
    images=["/path/to/image.png"]
)

Troubleshooting

"No Antigravity accounts configured"

Ensure either:

1. ANTIGRAVITY_REFRESH_TOKEN environment variable is set, or
2. ~/.config/opencode/antigravity-accounts.json exists with valid accounts

"All Antigravity accounts are rate limited"

The provider has exhausted all available accounts. Either:

1. Wait for rate limits to reset (usually 60 seconds to a few minutes)
2. Add more accounts to the accounts file

"Token refresh failed"

Your refresh token may have expired. Re-authenticate:

1. If using OpenCode: opencode auth login
2. If manual: Obtain a new refresh token via OAuth2 flow

403 Permission Denied

Your Google Cloud project may not have the required APIs enabled:

1. Go to Google Cloud Console
2. Enable the Gemini for Google Cloud API (cloudaicompanion.googleapis.com)

API Format

The Antigravity API uses Gemini-style request format internally:

{
  "project": "your-project-id",
  "model": "claude-opus-4-5-thinking",
  "request": {
    "contents": [
      {"role": "user", "parts": [{"text": "Your prompt"}]}
    ],
    "generationConfig": {
      "temperature": 0.7,
      "maxOutputTokens": 8192,
      "thinkingConfig": {
        "thinkingBudget": 8000,
        "includeThoughts": true
      }
    }
  }
}

This transformation is handled automatically by the provider.

Related Resources

• opencode-antigravity-auth - OpenCode plugin for Antigravity authentication
• Antigravity API Specification - Detailed API documentation