OpenCode runs as a TUI in any shell. Plan, edit, and ship code with the model of your choice — no IDE, no browser, no telemetry. Bring your own key. Bring your own LSP. Bring your own agent.
A 100% open source, terminal-native AI coding agent. Runs as a TUI in any shell. Auto-loads the right LSPs. Plans, edits, runs tests, opens PRs. Works with Claude, GPT, Gemini, local models, or your own. No IDE plugin. No browser. Nothing leaves your machine unless you tell it to.
OpenCode itself is free. Zen is the managed routing layer that load-balances across providers and gives you one bill instead of five.
Yes. The agent, the TUI, the LSP integration — all MIT. Zen is the optional managed routing tier. You never need it.
If your model does, yes. Point it at a local llama.cpp endpoint and the whole stack runs without an internet connection.
Only the prompt you send to the model you chose. We don't run an inference layer. We don't proxy. We don't log.
Those are editors and terminals with an AI panel. OpenCode is the inverse — an agent that lives in the terminal you already use, with no UI of its own beyond the TUI.
A single-font system. Berkeley Mono carries every text role; here it's substituted by JetBrains Mono and IBM Plex Mono. Warm cream canvas. 4px radius on interactive elements only. 0px everywhere else. ASCII brackets are the icons. Source — DESIGN.md.
[ink] — the only "brand color"
[surface] — cream is the only body background
[text] — 4-tier neutral ladder
[semantic] — reserved for the in-product TUI only
Berkeley Mono → JetBrains Mono / IBM Plex Mono fallback. One face. One mood. The page IS a man page.
[buttons] — 4px radius. Interactive elements only.
[inputs] — surface-soft default · canvas + ink border on focus
[badges] — small chips, ASCII brackets, 4px radius
[card variants] — flat-on-cream · the dark card is the only "elevated" surface
Bracket marker + bold key + body description. Sits in a flat list with a hairline rule beneath it.
Sparse inline SVG plot. Caption underneath: Fig N. label. Never specific data points — the chart is decorative type.
The single dark surface. Reserved for the hero TUI preview — never used as chrome treatment elsewhere.