In this paper we detail the design and implementation of an Eclipse plug-in for an integrated, model-based approach, to the engineering of web service compositions. The plug-in allows a designer to specify a service’s obligations for coordinated web service compositions in the form of Message Sequence Charts (MSCs) and then generate policies in the form of WS-CDL and services in the form of BPEL4WS. The approach uses finite state machine representations of web service compositions and service choreography rules, and assigns semantics to the distributed process interactions. The move towards implementing web service choreography requires design time verification of these service interactions to ensure that service implementations fulfill requirements for multiple interested partners before such compositions and choreographies are deployed. The plug-in provides a tool for integrated specification, formal modeling, animation and providing verification results from choreographed web ser...