Abstract: A method and system for providing scalable communication capabilities in a financial fulfillment network. Computer systems external to the financial fulfillment network may communicate with each other and with the network using a uniform interface, such as an Applications Programming Interface (API). The API may allow systems communicating with and within the network to structure messages in a uniform and predictable way depending on the purpose for communications. A set of information packets may be assembled in suitable sets, and used to structure the content of messages related to a plurality of different purposes, such as different financial services. Interactive communication between systems is also supported, e.g., while a financial transaction is ongoing.