Requests through the API are limited per account, depending on whichever plan you're currently subscribed to.
Once you exceed this limit, you will not be able to make any more consumption requests until the next cycle starts.
The rate limiting information is contained within the response headers of each request. The relevant headers are:
• APILimit-Lookups: The number of lookup requests left for today.
• APILimit-Search: The number of search requests left for today.
• APILimit-Currency: The number of currency lookups left for today.
• APILimit-Reset: This represents the time when the new day cycle starts. The value is given in Unix epoch time.
As long as the RateLimit-Remaining count is above zero, you will be able to make additional requests.
An OAuth token functions as a complete authentication request. In effect, it acts as a substitute for a username and password pair.
. . . APILimit-Lookups: 697 APILimit-Search: 132 APILimit-Currency: 355 APILimit-Reset: 1669593660 . . .