# Rate limits

Each API key can send 600 requests per minute by default. Over that, requests get `429` until the minute is up.

## How the limit works

- **Per key.** Every key has its own limit, shown on the [API keys](https://layahost.com/keys) page.
- **Per request, not per question.** A `/v1/systemone` request with 32 questions counts once. Every authenticated request counts, including `GET /v1/models` and `GET /v1/templates`.
- **Fixed one-minute window.** The window opens with the first request and resets 60 seconds later.
- **Invalid keys don't count.** Requests rejected with `401` are not counted against any key.

Responses don't include remaining-quota headers. Pace your client to stay under the limit and handle `429` when it happens.

If you need a higher limit, [contact support](mailto:support@layahost.com): limits can be raised per key.

## When you hit the limit

You get `429` with `error_type` `rate_limit_error`. The `retry-after` header says how many seconds remain until the window resets:

Response · 429

```http
HTTP/1.1 429 Too Many Requests
content-type: application/json
retry-after: 38
x-request-id: req_0t9rn7vlp9c6tl5rgaeetoc8
x-typesafe-request-id: req_0t9rn7vlp9c6tl5rgaeetoc8

{
  "detail": {
    "error_type": "rate_limit_error",
    "message": "Rate limit of 600 requests per minute exceeded."
  }
}
```

Wait that long, then retry. Rate-limited requests are not billed. The Jev SDKs retry `429` automatically and honour `retry-after`.

## Capacity errors

The rate limit is separate from capacity. When the service is busy, a request within your limit can still get `529` `overloaded_error`, or `503` `api_error` if the backend is briefly unavailable. Both are temporary: retry after a short delay with backoff. See [Errors](https://layahost.com/docs/errors).

## Staying under the limit

- **Batch questions.** If you ask several things about the same text, send them as up to 32 questions in one [`/v1/systemone`](https://layahost.com/docs/systemone) request. At 600 requests per minute, that allows up to 19,200 decisions per minute per key. Billing is still per question.
- **Cap concurrency.** Run requests through a small worker pool instead of starting them all at once. See the batch example in [Code examples](https://layahost.com/docs/code-examples).
- **Separate workloads.** Give batch jobs their own key so a backfill cannot use up the limit of your production traffic.
- **Retry politely.** On `429`, wait for `retry-after`. Retrying immediately only fails again.