# Plans and rate limits

| Plan | Usage | Burst | Sustained |
| --- | --- | --- | --- |
| Free | 1,000 calls a month | 5 a second | 120 a minute |
| Growth | Billed per call | 10 a second | 600 a minute |
| Scale | Billed per call | 50 a second | 3,000 a minute |
| Enterprise | By contract | 100 a second | 6,000 a minute |

Full prices are on the [pricing page](https://developers.motorsdynamic.com/pricing).

## What counts as a call

A call is counted, and billed on paid plans, when it answers with a 2xx status. Errors, timeouts and rate-limited requests are free.

On paid plans each endpoint has a unit cost, shown on its reference page and in the `X-MD-Units` header. One unit is $0.0001 on Growth and $0.00006 on Scale.

## Rate limit headers

| Header | Meaning |
| --- | --- |
| `X-RateLimit-Limit` | Requests allowed per minute on your plan. |
| `X-RateLimit-Remaining` | Requests left in the current minute. |
| `X-RateLimit-Reset` | Seconds until the minute resets. |
| `Retry-After` | On a 429: seconds to wait before the next request. |

When you pass a limit the API answers `429 rate_limited`. Wait for `Retry-After` seconds and retry.

## The Free monthly allowance

Free includes 1,000 calls each calendar month (UTC), shared by all keys on the account. `X-MD-Calls-Remaining` counts down on every response. At zero the API answers `429 quota_exceeded` with the reset time and a link to upgrade. Paid plans have no monthly cap.

## Search, feeds and bulk

Market search, cursors that walk a dealer's full inventory, change feeds and bulk delivery are part of Enterprise. [Talk to sales](mailto:sales@motorsdynamic.com).