A system and method for providing a dynamic invocation and service interface for use in a middleware or other environment. At the service-side, messages can be inserted into an inbound processing chain. After service-side inbound processing, messages are given to the user via a provider request function. The user gives a response by using a provider response function that inserts messages into a service-side outbound processing chain. After service-side outbound processing, messages are given to the user's service response transport. On the client side, the user can insert messages into the outbound processing chain using a dispatcher request. After client-side outbound processing, messages are given to the user's client request transport. This decouples message processing from the transport and makes the message processing asynchronous in nature. When the response is received, a user uses a client response transport function to insert the response into the client-side inbound processing chain.