Semantic wikis are new generation of collaborative tools. They allow to embed semantic annotations in the wiki content. These annotations allow to better organize and structure the wiki contents. It is then possible for users to build knowledge understandable by humans and computers. By this way, machines are allowed to produce or update semantic wiki pages as humans can do. In this paper, we propose a new smart agent based on Formal Concept Analysis. This smart agent can compute automatically category trees based on defined semantic properties. In order to reduce human-machine collaboration problems, humans just validate changes proposed by the smart agent. A distributed version of wiki is used to ensure consistency of the content during the validation process.