opencode-antigravity-auth

An OpenCode plugin that provides OAuth authentication against Google's Antigravity IDE, enabling access to Antigravity models and quotas using your Google credentials.

Supported Models

Real Models

• antigravity-claude-opus-4-6-thinking
• antigravity-gemini-3.1-pro
• antigravity-claude-sonnet-4-6
• antigravity-gemini-3-flash

Auto Models

Auto models automatically select the best available model based on rate limit availability, falling back to the next tier if needed.

• antigravity-auto — Uses the best available model (configurable via auto_mode_stage)
• antigravity-auto-best — Starts at Opus 4.6 Thinking, falls back down
• antigravity-auto-high — Starts at Gemini 3.1 Pro, falls back down
• antigravity-auto-balanced — Starts at Sonnet 4.6, falls back down
• antigravity-auto-fastest — Gemini 3 Flash only

When auto mode is active, the toast notification shows which model was actually selected and at which tier, e.g. Using account@gmail.com (1/2) (Auto: Best - antigravity-claude-opus-4-6-thinking).

Installation

Option A: Using Plugin Updater (Recommended)

1. Install opencode-plugin-updater.
2. Use the updater to install opencode-antigravity-auth.

Option B: Manual Installation

Copy the plugin file into your OpenCode plugins directory:

cp opencode-antigravity-auth.js ~/.config/opencode/plugin/

Restart OpenCode to load the plugin.

Configuration

Create ~/.config/opencode/config/antigravity.json (or .opencode/antigravity.json for per-project):

{
  "auto_mode": true,
  "auto_mode_stage": "best",
  "fallback_enabled": false,
  "account_selection_strategy": "hybrid"
}

Key Options

Option	Type	Default	Description
auto_mode	bool	false	Enable automatic model selection
auto_mode_stage	"best" | "high" | "balanced" | "fastest"	"best"	Starting tier for antigravity-auto
fallback_enabled	bool	false	Walk down the ranking on rate limit
model_ranking	string[]	hardcoded 4-tier list	Override the fallback order
account_selection_strategy	"hybrid" | "sticky" | "round-robin"	"hybrid"	How accounts are rotated

Disclaimer

Warning: Using this plugin (and any proxy for Antigravity) violates Google's Terms of Service. Your account may be suspended or permanently banned. Use at your own risk.