Carousel is a simple HTTP API designed to send high volume SMS messages to mobile devices in scalable campaigns. The service allows organizations to operate outside of carrier-enforced sending limits by pooling numbers and managing links between those numbers and end-users. Developers can schedule when messages will be sent, and keep record of detailed message logs and analytics. Carousel's platform also offers optional callbacks, and modules for increased functionality and the automation of certain tasks. Messages can be arbitrary in length, and for long messages that exceed text limits, customizable character, word or sentence boundaries can be applied to break up the message.