The Quota web service is a REST-based web service that is built on top of the Quota object model. The web service holds a cache of Quota Engine objects which provide access to the quota data by using an appropriate Quota Provider, which on the server is the Microsoft SQL Server Provider, QuotaProvider_MSQL.

The Quota API can read quota definitions and modify quota properties (AllowOverQuota and IsCounterOnly) and counts.

Users are authenticated by a separate web service called UserAuth. For more information, see UserAuth web service.