a computer - implemented method , apparatus and computer program product for providing an interface between a client application and a web service is disclosed . a first request from the client application is received . the first request is associated with a response schema specifying a format for responding to the client application . a service request is sent to the web service dependent on the first request . an output from the web service is obtained responsive to the service request . the output is in a predefined output format associated with the web service . the output is transformed to conform to the response schema . the transformed output is provided to the client application .