opencode is an open-source AI coding agent built for the terminal. It features a native TUI, multi-session support, and is model-agnostic, letting you use Claude, OpenAI, Google, or even local models.

opencode zen is a curated, “ready-to-use” gateway of tested models optimized for coding agents. It integrates as an optional provider within opencode, offering pay-as-you-go access to top models (e.g. GPT-5, Claude, Grok) with no lock-in.