Implementations of the invention provide an API that supports a diverse range of products, and in particular diverse products of highly varying display and UI formfactors. A data template is established at the time of creation of a session, and the same is honored by the NP for the entirety of the browsing experience. In this way, a store experience, e.g., categories and products returned for a query, are customized according to the receiving device. The efficiency of the store experience is maximized for each user/device by sending only the data the device needs. Similarly, the protocol employed for the data transfer may be customized for the particular device, e.g., responses may be rendered in XML, JSON, Protocol Buffer, or the like.