Abstract: Agent-based solutions are promising for ameliorating Web services, since they promote the modular construction of Web servers, relieve the network from transferring useless data, support user mobility, etc. However, existing Web servers do not favor the hosting of agents. In this paper, we propose a description of agent behaviors in terms of its requirements regarding resource utilization (e.g. memory, and disk space), functional services (e.g. system calls), and Quality of Services (e.g. degree of replication, and access control). These requirements, when formally expressed, can be used in an automated decision process which employs software specification matching techniques. On the acceptance of an agent, the host can use the agent's requirements to construct an environment customized to its execution. We discuss the benefits of this approach, and how it can be used to promote existing agent-based solutions in the Web framework.