OAuth Plugin for Opencode with Gemini

Opencode-gemini-auth is an open-source plugin (current stable v1.4.10, released 2025) that authenticates the Opencode CLI using your Google account, enabling access to Gemini models including the free tier. It spins up a local OAuth callback server, supports manual URL paste fallback, and provides a `/gquota` command. Actively maintained with frequent releases. Differentiators: eliminates the need for a separate Google AI API key, supports Gemini Code Assist subscriptions via `projectId`, and includes automatic token refresh. Written in TypeScript, ships with types, peer-depends on TypeScript ^5.9.3.