Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for implementing key-value store functionality within a real-time messaging system. An example method includes: providing a plurality of channels, wherein each channel comprises an ordered plurality of messages, wherein each channel represents a unique key, and wherein each message comprises one or more key-value pairs; receiving a function comprising a key for identifying one of the plurality of channels and processing instructions to be applied to a subset of the key-value pairs; and applying the processing instructions based at least in part on the unique key.