Ambient and mobile systems consist of networked devices and software components surrounding human users and providing services. From the services present in the environment, other services can be composed opportunistically and automatically by an intelligent system and proposed to the user. The latter must not only to be aware of existing services but also be kept in the loop in order to both control actively the services and influence the automated decisions. This paper first explores the requirements for placing the user in the ambient intelligence loop. Then it describes our approach aimed at answering the requirements, which originality sets in the use of the model-driven engineering paradigm. It reports on the prototype that has been developed , and analyzes the current status of our work towards the different research questions that we have identified.