# Exceeding the rate limit

In case a request is rate limited, APIs return a HTTP response code 429 (too many requests) to the client. Depending on the use cases, we may enqueue the rate-limited requests to be processed later. For example, if some orders are rate limited due to system overload, we may keep those orders to be processed later. 

**Rate limiter headers** 

How does a client know whether it is being throttled? And how does a client know the number of allowed remaining requests before being throttled? The answer lies in HTTP response headers. The rate limiter returns the following HTTP headers to clients:

*X-Ratelimit-Remaining*: The remaining number of allowed requests within the window.

*X-Ratelimit-Limit*: It indicates how many calls the client can make per time window. 

*X-Ratelimit-Retry-After*: The number of seconds to wait until you can make a request again without being throttled. 

When a user has sent too many requests, a 429 too many requests error and *X-Ratelimit-Retry-After* header are returned to the client.