NoeFabris/opencode-antigravity-auth

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 and claude-opus-4-5-thinking with your Google credentials.

What it solves

OpenCode users who have a Google account with Antigravity access can't directly use Antigravity's models or rate limits without additional authentication. This plugin adds a Google OAuth flow specifically for Antigravity, so you can log in once with your Google credentials and then use models like gemini-3.1-pro and claude-opus-4-6-thinking in OpenCode while taking advantage of Antigravity's rate limits.

How it works

After installing the plugin (via the OpenCode config file) and running opencode auth login google, you choose the "Google OAuth (Antigravity)" option. The plugin stores your account credentials in a local file, discovers the models available to you, and caches that model list for an hour. Inside OpenCode, you can open the /antigravity (or /ag) command to see logged-in accounts, current selection, quota usage and reset times, add or remove accounts, and refresh the model list. The plugin also hides native Google API-key models while you're on an Antigravity connection, and brings them back when you switch to an API-key setup.

Who it's for

Developers who use OpenCode and have a Google account with Antigravity access. It's for anyone who wants to work with Antigravity's models inside OpenCode without manually juggling API keys or separate credentials. The plugin is unofficial, so it suits users comfortable with a community-maintained tool that may be affected by Google's third-party client policies.

Highlights

  • Adds Google OAuth authentication for Antigravity directly in OpenCode.
  • Lets you use Antigravity models like gemini-3.1-pro and claude-opus-4-6-thinking with your Google credentials.
  • Manages multiple accounts: add, select, enable, disable, re-authenticate, or delete them.
  • Shows Antigravity and Gemini CLI quota usage and reset times.
  • Caches the model list for an hour to speed up model selection.
  • Supports a dedicated /antigravity command for account and quota management inside OpenCode.

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