The Envoy Framework addresses a need for computer-based assistants or agents that operate in conjunction with users’ existing applications, helping them perform tedious, repetitive, or time-consuming tasks more easily and efficiently. Envoys carry out missions for users by invoking envoy-aware applications called operatives and inform users of mission results via envoy-aware applications called informers, The distributed, open architecture developed for Envoys is derived from an analysis of the best characteristics of existing agent systems. This architecture has been designed as a model for how agent technology can be seamlessly integrated into the electronic desktop. It defines a set of application programmer’s interfaces so that developers may convert their software to envoy-aware applications. A subset of the architecture described in this paper has been implemented in an Envoy Framework prototype.