An apparatus and method for aggregating web services in generating a user interface for a computing device. Web service descriptions are received that define a web service interface to each of a plurality of web services. The web service descriptions are processed to identify inputs to first web services obtainable by invoking one or more second web services. A user interface is generated for the computing device that aggregates these first and second web services. By identifying instances in which the input to one web service may be obtained by invoking another web service, a user interface which aggregates these web services may be automatically generated.