# Usage & credits

# Usage & credits

Endpoints that compute air quality draw from a single monthly **credit pool** — one
balance you spend however you like across the API. There are no per-endpoint quotas:
a credit spent on a forecast is a credit not spent on route enrichment.

An AirTrack **Premium** subscription includes **1,000 credits per month**, with a
**daily burst cap of 100** (see below). The allowance belongs to the user, not the
token: every connection a user pairs draws from the same pool.

## What each call costs

Each endpoint costs credits roughly in proportion to the work it does:

| Endpoint | Credits per call |
|----------|------------------|
| Score a point | 1 |
| Forecast a day | 2 |
| Enrich a route | 1 per waypoint |
| Plan a route | 25 (flat) |

Checking your balance with [`GET /v1/quota`](/api/quota#get-quota) is free, as are
redeeming a pairing code and polling for a route-plan result.

## Daily burst cap

A smaller **daily burst cap** sits inside the monthly pool and stops the whole month
being spent at once. Both limits travel together: a call must fit within whatever
remains of each. [`GET /v1/quota`](/api/quota#get-quota) reports both balances.

## When a limit is reached

When either limit is exhausted, calls return `429` with a `Retry-After` header giving
the number of seconds until the relevant window resets. Back off until then rather
than retrying in a loop; the [errors guide](/errors) covers retry patterns.

## Refunds

Calls that fail before delivering a result are refunded automatically — for example a
`503` upstream outage, or a route plan the planner rejects. Validation failures
(`400`/`422`) are never charged in the first place.