A system enables universal remote media control across multiple platforms, devices, and users. A protocol allows a cast controller to have access to media operations and a state(s) associated with media content. The system receives commands from a cast controller, provides the commands to a media player, loads new media content into the media player, based on the commands, and receives state notifications from the media player. Another cast controller can receive the state notifications from the media player and control the media player based on the media operations and state(s) associated with media content.