A centralized location for discovery and data exchange for web applications. Embodiments of the invention are directed to providing a centralized interface location to send data to and receive data from one or more web applications hosted on application servers different from a server hosting the centralized interface. An application developer for a subscriber having an account with the web application may therefore easily extend the functionality of one or more web applications by communicating with a single interface provided, rather than with separate interfaces for each application. The centralized interface may provide information such as a list of all web applications or functionality to which a particular subscriber has access, and may support any desired extension (e.g., addition of users).