Systems, methods, and apparatus, including computer program products, for configuring online properties, such as content pages of a website, through an online user interface. A system generates the online user interface and receives, over a network and through the online user interface presented by a client device, a request to insert a restricted third party file into a user's online property. The online user interface is updated to inform the user that inclusion of the third party file in the user's online property is restricted and to provide the user with options for satisfying requirements for including the third party file in the user's online property. In response to detecting a user selection of at least one of the options, the restricted third party file is received from a content repository, and is inserted into the user's online property.