# Rate Limits and Quotas

The API enforces usage limits to protect reliability and prevent runaway cost.

API access is available on every plan. API jobs draw from the same page quota as web uploads, including subscription quota and any credit pack balance.

## What to expect

- `402` when quota/credits are insufficient
- `429` when request or concurrency limits are exceeded

## Recommended client behavior

- Enforce your own per-tenant limits before calling the API.
- Use queues to smooth spikes.
- Retry `429` with exponential backoff and jitter.
- Use idempotency keys to prevent duplicate work.

## Capacity planning checklist

- Track pages per document before upload.
- Track active job count per customer.
- Alert on sustained `402`/`429` responses.
- Add circuit breakers when upstream systems spike.

## Billing and quota signals

Treat `402 quota_exceeded` as an actionable product signal:

- prompt customer to buy credits or upgrade plan
- pause automatic retries
- resume once quota is restored