Opencode-antigravity-auth is an OAuth authentication plugin that enables Opencode to access Google's Antigravity IDE and its AI models using Google credentials.
The plugin solves the problem of accessing advanced AI models like Gemini 3.1 Pro and Claude Opus 4.6 through Opencode while respecting Antigravity's rate limits. It works by establishing OAuth authentication with Google, allowing users to leverage both Antigravity and Gemini CLI quotas from a single integration. The tool supports multi-account setup with automatic rotation when rate limits are hit, extended thinking modes for compatible models, and optional Google Search grounding for Gemini.
Developers should be aware that the README includes a prominent terms of service warning stating that using this plugin violates Google's Terms of Service and that users have reported account bans or shadow-bans. The tool is suited for developers who need access to these specific models through Opencode and are willing to accept the account risk. The plugin works alongside other Opencode plugins and offers both manual configuration and LLM-assisted setup options.
The project maintains active engagement with its user base, with most open issues coming from outside users rather than the core team, indicating a substantial base of real-world adopters. Maintainers typically respond to new issues and pull requests within hours. Work in the issue tracker centers on bug reports, enhancement requests, and user questions.
