A client-oriented, on-demand automated trading system that facilitates client-oriented automated trading with suppliers. A client transaction agent is adapted to provide trading requirements for notification to one or more supplier transaction agents, and to discover automated services provided by or on behalf of one or more suppliers that conform to the trading requirements. A broker is adapted to notify the one or more supplier transaction agents of trading requirements specified by the client transaction agent, and to advise the client transaction agent of automated services that conform to the trading requirements. The supplier transaction agents are adapted to process the trading requirements and register automated services that conform to the trading requirements with the broker.