A social networking system includes a mechanism for integrating user actions on objects outside of the social networking system in the social graph. For example, streaming music on external systems may be integrated into the user experience on the social networking system. Third-party developers, in addition to administrators of the social networking system, may define objects and actions that enable integration of external music sources to be played and controlled using the social networking system while also providing socially relevant information to other users of the social networking system. Actions and objects recorded from these external user interactions are structured to enable aggregation and structured querying, which enables data visualizations of the information discoverable on the social graph. In this way, interesting information about users' actions outside of the domain of the social networking system may be shared and compared with other users on the social networking system.