Choreographies: using constraints to satisfy service requests

Interacting with a web service enabled marketplace to achieve a complex task involves sequencing a set of indi-vidual service operations, gathering information from the services, and making choices. In the context of coreogra-phies of web services, we propose to encode the problem of issuing requests as a constraint problem. In particular, we provide a choreographic framework to handle requests, we show how request encoding is performed, and we illustrate an implementation using the Choco constraint system.