Design is a discipline, which requires support for the combination of different systems and tools, spontaneous interaction between designers, sharing of (design) data, and adaptability to altering conditions. When looking at design processes it is a demanding task to coordinate and organize the work of the different team members. The work of a single person not only depends upon the work of others, but can also influence the work of other designers as well. Correspondingly, patterns of cooperation are to be established to minimize or resolve resulting conflicts, support the concurrent use of data, and to coordinate the work process. In order to fulfill those requirements the ASCEND Designflow Model and its prototype CASSY offer a corresponding object model, an architecture combining workflow and groupware systems, and finally a protocol integration layer based on agent communication. This protocol layer helps to flexibly combine the functionality of the different systems and services, since it can be adapted to different application scenarios. In this paper, we will describe the concepts of the protocols and their implementation architecture, resulting in a generic protocol engine.