Zen Proxy

zen-proxy
Use OpenCode Zen's free models from any AI coding agent.
No account. No API key. OpenAI and Anthropic compatible. Runs on your machine.

    ▶ full video with sound

Start here

Install

That is the entire installation — no account, no API key, no npm install. Now pick your agent below.

Claude Code

Identical on Linux, macOS and Windows.

It starts the proxy if it is not already running, loads every live free Zen model into Claude Code's /model picker, runs Claude Code, and stops the proxy again when you exit. Your existing Claude Code config is never touched.

Any OpenAI-compatible agent

Cline, Roo Code, Continue, Aider, mimo, opencode forks — anything with a baseURL setting.

Confirm the proxy is up:

Run the proxy yourself

It stays up until you stop it, so you point your agent at it once and keep using it. zen-claude does this for you and cleans up after.

What you get

The free-model catalog in models.json is refreshed from OpenCode's public catalog by a GitHub Action every 6 hours.

Why a proxy is needed

OpenCode's free models are served only to the OpenCode CLI itself. Everyone else gets one of:

Since OpenCode 2, the second one is what a non-CLI client sees — with a retry-after window and zero personal usage. It is not your quota: it is the gate's verdict on the request.

zen-proxy sits in front of that gateway and makes your agent's traffic indistinguishable from the CLI's, on three layers — all measured from a byte-capture of a real OpenCode 2.1.4 request.

What it actually changes

Run it with bun (bun zen-proxy.mjs, or through zen-proxy/zen-claude, which pick bun when present): that is the one requirement node cannot substitute away — the gateway 429s node's stack even though headers, sessions and bodies are byte-identical.

For…