1. A system for determining the data used to create a web page, comprising a web server coupled to a content management system, the web server configured to, in response to receiving a request specifying a web page from a requesting entity: retrieve a plurality of copies of a plurality of content objects from the content management system, wherein the content management system is configured to store and manage the plurality of content objects; generate the web page using the retrieved plurality of copies of the plurality of content objects; prior to returning the generated web page to the requesting entity, generate a content manifest header containing a list of content identifiers, wherein each content identifier in the list of content identifiers uniquely identifies, within the content management system, a respective one of the plurality of content objects, and wherein each content identifier can be used to query the content management system to access the corresponding content object; insert the generated content manifest header into an HTTP header of the web page, such that the requesting entity can query the content management system using the list of content identifiers within the generated content manifest header to access and edit the plurality of content objects within the content management system; and return the web page containing the generated content manifest header to the requesting entity, wherein the requesting entity is configured to provide an interface that depicts (i) a rendered form of the web page and (ii) the plurality of copies of the plurality of content objects, wherein the interface is generated based on the list of content identifiers within the content manifest header of the web page, and wherein the interface enables users to access and edit the plurality of content objects within the content management system by submitting a query to the content management system specifying content identifiers from the list of content identifiers to access the corresponding content objects within the content management system.