The current response given for too many requests is :

{"errors":[{"status":429,"title":"Exceeded API rate limit of 30 per 60 seconds","Retry-After":"60 seconds"}]}

what would be useful if the key "Retry-After" gave you the amount of seconds required before retry and was just a number not a string. It appears it just gives you 60 seconds regardless of how long you've been in API jail.

either that or add a new key entirely for this purpose (probably would make change control easier to add a new key)

currently when im looping and uploading im having to work this out myself. Though i'm having now to amend this as it doesn't cater for multiple uses and is session specific. I'm instead going to have to log the api call as a record (not session specific) and check the prior records based on time and work it out this way.