In order to simplify the development of agent-based distributed systems, their deployment, and their execution in open and unstable distributed environments, we propose a generic model and an architectural style of adaptive agent. Our approach allows developers to build agent models by assembling finegrained reusable components which implement non-behavioral mechanisms such as communication, mobility or adaptation skills. Then, at run time, agents can autonomously change one or several of these components. Agentφ is a tool for modeling adaptive agents from reusable components. At design time, agent models are defined from the generic agent model in order to fit the requirements of the development, and safety of architectures (satisfaction of the dependence constraints between components) is checked; then, skeletons of codes are generated and architectures are optimized. Then, agents are configured and can reconfigure themselves at run time; so they are able to react to changes in the execution environment. From our point of view, Agentφ can be considered as a generator of domain-specific (or applicationspecific) adaptive multi-agent platform. The design of an embedded agent and of an agent responsible for deployment of Grid components illustrates our proposal