Various aspects of the subject technology relate to systems, methods, and machine-readable media for providing an updated list of public content items to a search engine. A system is configured to determine whether a sharing property of a content item stored by a first service has been altered, wherein the sharing property indicates whether the content item is available to a different set of users, update a list of content items if the sharing property has been altered, and provide the updated list of content items to a second service.