The paper presents a system for knowledge representation and coordination, where autonomous agents reason and act in a shared environment. Agents autonomously pursue individual goals, but can interact through a shared knowledge repository. In their interactions, agents deal with problems of synchronization and concurrency, and have to realize coordination by developing proper strategies in order to ensure a consistent global execution of their autonomously derived plans. This kind of knowledge is modeled using an extension of the action description language B. A distributed planning problem is formalized by providing a number of declarative specifications of the portion of the problem pertaining a single agent. Each of these specifications is executable by a stand-alone CLP-based planner. The coordination platform, implemented in Prolog, is easily modifiable and extensible. New user-defined interaction protocols can be integrated.