REST APIs: Retry-After header on rate limited responses

Rate limited requests to the Trackunit REST APIs now get a Retry-After header on the 429 Too Many Requests response. It gives the number of seconds to wait before sending the request again.

HTTP/1.1 429 Too Many Requests
Retry-After: 42

The value includes a small random delay, so clients that were limited at the same time don't all retry at the same moment. Wait at least that long before retrying; retrying sooner is likely to be rate limited again. The value is an estimate, so keep handling 429 with a backoff. Requests that are rate limited don't count towards your rate limits.

For the AEMP ISO 15143-3 API, expect a second or two for the per-second limits, and up to 15 minutes once the 15-minute limit and the pool of additional requests are used up.

See Rate & Size Limiting for details.