pi-freerouter

Pi coding agent extension that routes every request through OpenRouter's free model tier — no paid API key needed beyond your OpenRouter account.

Quick start

1. Install

pi install npm:pi-freerouter

2. Set your OpenRouter API key

export OPENROUTER_API_KEY=sk-or-...

Free key at openrouter.ai/keys.

3. Start Pi and select FreeRouter

FreeRouter appears in the model picker as auto [free-router]. Select it when you want requests routed through OpenRouter's free model tier. If OPENROUTER_API_KEY is not set, Pi still starts normally; pi-freerouter shows the key error only after you send a prompt with auto [free-router] selected.

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How free model routing works

OpenRouter exposes dozens of free models (models with a :free suffix). Each has its own rate limit — typically a few requests per minute per model. The trick is to spread load across all of them automatically.

Parallel racing

Every time Pi sends a request, pi-freerouter doesn't pick one model and hope for the best. It picks the next 3 available models from its sorted list and fires all three requests simultaneously.

Request arrives
    │
    ├── model A ──────────────────── first token ──▶ WINNER → stream to Pi
    ├── model B ───── (slower)                      → aborted
    └── model C ─── (even slower)                   → aborted

Whichever model emits its first token wins. The other two are immediately cancelled. Pi sees a single clean stream — it has no idea a race happened.

Automatic fallback

Failed models are skipped for a short cooldown period and then return to the pool:

Failure	Cooldown
Rate limit (429) or server error (5xx)	90 s
No first token within 30 s	15 s
Request rejected (400/422)	90 s

Batch 1: [model A, model B, model C]  → all hit quota
Batch 2: [model D, model E, model F]  → model D wins
         ↑ model A–C recover after 90s and rejoin the pool

Each model is tried at most once per request. Once a winner is streaming, a 30-second idle window per chunk ensures a stalled connection is aborted promptly rather than left open.

Provider priority

Free models are sorted so the lowest-latency inference providers are always tried first:

1. Groq
2. Cerebras
3. Fireworks
4. Together
5. Mistral
6. Everything else (sorted by context window ascending)

Model list refresh

The list of available free models is fetched when you first send a prompt with auto [free-router] selected, then refreshed every hour in the background.

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Requirements

• Pi coding agent v0.78+
• OpenRouter API key (free tier is sufficient)

License

MIT