The technology described herein is directed towards content rights data that are associated with content (a data item) to make that content selectively available or unavailable in responses by a data service to client requests. A client includes client content rights data in association with each request, (e.g., via a token), and the data service uses that client content rights data as query parameters (constraint criteria) in making a request for a data item. Client content rights data also may be used for accessing cached data. Availability constraints may include client location, brand, channel, device class and time (commence and cease).