It is often difficult to reliably monitor contract performance and receive timely information as to whether a party is actually going to carry out their contractual obligations. Accordingly the invention provides an apparatus and methods for communicating the changes in states of the contractual commitments of contracting parties according to an agreed commitment model and using agreed messaging protocols. There is a storage facility for the commitment data which is accessible by an encoding engine, in addition to a commitment state store that forms a part of the commitment model and stores the known commitment state of parties. The encoding engine encodes commitment data according to the commitment model and data received by an external information source, before passing the message to a messaging module for formatting and sending out to the other contracting party.