Rate limits and concurrency - Mage

The main limit is concurrency: how many generations an account may have queued or running at once. There is no charge for a refused request.

Generations in flight

An account may have 20 generations in flight at once, counting the API and the app together. A submit past that cap is refused with 429 too_many_requests and nothing is charged. The cap can be changed for an account; write to mage@mage.space with your use case.

{
  "error": {
    "code": "too_many_requests",
    "message": "At most 20 generations may be in flight at once for this account; 20 are running now."
  }
}

The check reads the count at submit time. A burst of simultaneous submits can therefore slightly exceed the cap; every admitted generation is still paid for as usual.

Other limits

Limit	Value
Active API keys per account	10
Request body	4.5 MB
One media input	100 MB, whether fetched, decoded, or uploaded
Fetching one input URL	60 seconds and 3 redirects
`Idempotency-Key`	1 to 255 characters
Results and inputs	Kept 30 days

Requests may also be rate limited at the edge during bursts. Treat any 429 as a signal to wait, whatever its body.

Designing around the limits

Keep a worker pool no larger than your cap and submit from it, rather than submitting everything at once and handling the refusals.
Poll on a separate schedule from submission, with backoff, so status reads do not compete with submits.
Store request_id as soon as a submit returns; the status link is how you recover from anything that happens afterwards.
Send an Idempotency-Key with every submit so a retry never pays twice.

Last modified on September 17, 2026