The Plancast API can be used to build applications on top of Plancast that make the service more useful and leverage its data off-site. Plancast is a service that lets users share events and other activities with friends. Users can share their plans with a posting promps, browse all of the plans and events their friends have on their calendars and find friends from other sites like Facebook and Twitter. The Plancase API allows for the ability to read from and write to the Plancast system with ease. The API uses RESTful protocol and responses are formatted in JSON.