All accounts, by default, have a preconfigured set of thresholds, or limits, to manage capacity and prevent abuse of the system. The system recognizes two kinds of limits: rate limits and resource limits. Rate limits are thresholds that are reset after a certain amount of time passes. Absolute limits are fixed. Rate limits are processed via the Repose service.

To view the limits that apply to your account, use the Account API operations.


If the default limits are too low for your particular application, contact Rackspace Cloud support to request an increase. All requests require reasonable justification.

Rate limits

Rate limits are specified in terms of both a human-readable wildcard URI and a machine-processable regular expression. The regular expression boundary matcher ^ takes effect after the root URI path.

/*50000 requests / 24 hours
/entities/*/test-check500 requests / 24 hours
/entities/*/test-alarm500 requests / 24 hours
/notifications/*/test, /test-notifications200 request / 24 hours

Each API response also contains the following rate limit headers:

Header nameDescription
X-RateLimit-LimitLimit in affect for the current request
X-RateLimit-UsedHow close you are to being rate limited
X-RateLimit-WindowRate limit window
X-RateLimit-TypeType of the rate limit which applies to the current request

When you exceed the thresholds established for your account, API requests return the following error: 400, Limit has been reached. The HTTP response includes a Reply-After header (number of seconds) to notify the client when it can attempt to try again.

To view the limits that apply to your account, see the Account API operations in the API Reference.

Resource limits

The following table lists the default limits for different resources. When you exceed the threshold for checks or alarms, API requests to create a check or alarm return the following error: 400 Limit has been reached.


To view the limits that apply to your account, use the Account resource and API operations.