The Web Service Choreography Interface (WSCI) is an XML-based language used to describe the flow of messages exchanged by a web service in the context of a process. WSCI is an example of a web service orchestration language. It allows the description of the observable behavior of a Web service in a message exchange.

WSCI also describes the collective message exchange among interacting Web services, providing a global, message-oriented view of a process involving multiple web services.

BEA, Intalio, SAP and Sun Microsystems initially championed the specification. BEA later backed the BPEL4WS specification along with IBM and Microsoft.