We consider methods for handling constraints over finite domains based on the notion of path consistency. We show that these methods can be easily integrated in the glassbox constraint-solver of the clp(FD) system. Besides the clp(FD) indexical constraints encoding (partial) arc-consistency methods, we introduce new primitive constraints, that we call m constraints, which encode path-consistency methods. We describe how to accommodate these new constraints in the clp(FD) extended WAM architecture.