Pi

Run Pi against AnyRouter as a custom OpenAI-compatible provider — one key, unified billing, and any AnyRouter model from a single config file.

Pi can use custom OpenAI-compatible providers declared in ~/.pi/agent/models.json. Register AnyRouter once and you can run Pi against any AnyRouter model id — with one sk-ar- key, unified billing, and full audit logs.

Why route through AnyRouter

One key for every model Pi can call.
Audit logs with cost, latency, and tokens per request.
Swap models freely — add ids to models.json, no key rotation.

Fastest path

curl -fsSL https://anyrouter.dev/setup.sh | bash
anyr pi
anyr pi --install --ok

The launcher writes a Pi agent dir (PI_CODING_AGENT_DIR) with AnyRouter already in models.json, sets ANYROUTER_API_KEY, and starts pi --provider anyrouter. Manual models.json below is only if you run pi yourself.

Set it up

Step 1 — Create an AnyRouter API key

Create an API key in your dashboard. AnyRouter keys start with sk-ar-. Add it to your shell:

export ANYROUTER_API_KEY="sk-ar-your-anyrouter-key"

Put the same line in ~/.zshrc or ~/.bashrc if you want it to persist.

Step 2 — Add AnyRouter to Pi

Create or edit ~/.pi/agent/models.json:

{
  "providers": {
    "anyrouter": {
      "baseUrl": "https://anyrouter.dev/api/v1",
      "api": "openai-completions",
      "apiKey": "ANYROUTER_API_KEY",
      "models": [
        { "id": "openai/gpt-5.4-mini" },
        { "id": "anthropic/claude-sonnet-4.6" }
      ]
    }
  }
}

apiKey is the environment variable name, not the secret value. Do not paste your sk-ar- key into this file.

Step 3 — Run Pi

Use the custom provider and pick one of the model ids from models.json:

pi --provider anyrouter --model "openai/gpt-5.4-mini"

Add more models from the model catalog by appending entries to the models array. Keep the id exactly as shown in AnyRouter, such as google/gemini-3.1-flash-lite or z-ai/glm-4.7-flash.

Verify

Run a prompt through the custom provider, then open your request logs. The call should appear within a second or two with the model name, token counts, and cost — confirmation you're routing through AnyRouter.

Troubleshooting

401 or 403 — confirm echo $ANYROUTER_API_KEY prints your key and that the key is active in the dashboard.

Model not found — make sure the model id in Pi exactly matches an AnyRouter model id.

429 — Pi can send repeated agent calls quickly. Wait for the rate-limit window to reset or use a key with a higher limit.