We have designed and implemented a framework assisting client-side applications to utilize asynchronous Web services that deliver results by calling back the applications in the context of enterprise security. This framework can support a number of rich features such as the Single- Request/Multiple-Response (SRMR) message exchange pattern, resumable clients, intra-enterprise user and terminal mobility, and flexible interaction modes for client applications to communicate with asynchronous Web services. Practical deployment of this framework in a number of cases has illustrated that this framework can effectively minimize development efforts in facilitating client applications to use Web services with callbacks.