A method and system for dynamically specifying a format for data provided by a web service invocation. A server providing a web service receives a client request for data residing on the server. The server receives an executable template script within the request. The template script includes an instruction for invoking a function residing in the server and a definition specifying a format to structure the requested data. The server executes the template script to perform the instruction, invoke the function to retrieve the data, and generate formatted data based on the definition. The formatted data is the retrieved data structured in the format specified by the definition. The server sends the formatted data to the client.