Usage of the API is subject to rate limits. The limits can be of varying types as described here. If you find that you are hitting rate limits, please contact support for assistance.
Fixed window rate limiting uses a fixed time window to limit requests. When the time window expires, a new time window starts and the request limit is reset.
Sliding window rate limiting is similar to the fixed window limiter but adds segments per window. The window slides one segment each segment interval and requests taken from the expired time segment one window back are added to the current segment.
The token bucket limiter is similar to the sliding window limiter, but rather than adding back the requests taken from the expired segment, a fixed number of tokens are added each replenishment period. The tokens added each segment can't increase the available tokens to a number higher than the token bucket limit.
The concurrency limiter limits the number of concurrent requests. Each request reduces the concurrency limit by one. When a request completes, the limit is increased by one. Unlike the other requests limiters that limit the total number of requests for a specified period, the concurrency limiter limits only the number of concurrent requests and doesn't cap the number of requests in a time period.
Different rate limiting types are utilized in difference scenarios. For example, anonymous api endpoints, authentication related api endpoints, and other api endpoints may all have different types of rate limiting used and/or different rate thresholds allowed. In some cases rate limiting may be tied to a given user or ip address.
When usage exceeds the limits allowed, the excess requests may go into a queue to be serviced on first-come-first-serve bases once the limits have been lifted. If no queue is configured or if the request exceeds the allowed queue depth an error will be returned. The error will typically have status code 429 (too many requests) and will include a message indicating that the rate limit has been exceeded.
If the rate limits are interfering with your application's ability to function, please contact support for assistance.