Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for media content streaming can include transacting access information associated with a media stream and transacting one or more fragments associated with the media stream to facilitate a delivery of media content associated with the media stream. Access information can include fragment sequencing information to facilitate individual retrieval of fragments associated with the media stream using a uniform resource identifier via a processing device configured to cache content. A fragment can include one or more stream messages. A stream message can include a message header and a corresponding media data sample. The message header can include a message stream identifier, a message type identifier, a timestamp, and a message length value.