This paper presents a framework for specifying Web services communities. A Web service is an accessible application that humans, software agents, and other applications in general can discover, compose, and invoke in order to satisfy users' needs like hotel booking. Web services providing the same functionality are gathered into one community, independently of their origins. This framework shows how software agents that are able to argue, negotiate, and reason about Web services can be used to specify these Web services and to manage their respective communities. The use of what we call argumentative agents helps Web services in being better organized within communities and in achieving the goals for which they are conceived. The community is led by a master component, which among others attracts new Web services to the community, retains existing Web services in the community, and identifies the Web services in the community that will participate in composite Web services. All these operations are managed by interacting agents through flexible conversations made up by argumentation, persuasion, and negotiation phases called dialogue games. © 2007 IEEE.