Abstract: In accordance with one embodiment of the invention, a set of API's for integrated retailers to perform standard order fulfillment operations to fulfill and return products on behalf of their clients is described. A common catalog on a software platform is intended be a flexible common hub around which many different commerce models can be implemented. Integrated retailer is one such model on which e-commerce occurs. Integrated retailers are permitted to sell product from the common catalog with another company providing back-end fulfillment. The common catalog infrastructure's pre-existing XML catalog export facility provides product information to the retailer. The Retail Web Service (RWS) provides the fulfillment functions as a REST-style web service.