Agent Based Web Services Market (AWSM) is a framework for agents to present and sell their capabilities as web services. Agents take certain roles and cooperate to constitute agent societies execute their functionality as web services. The roles they possess determine which web service they can provide. Roles in an agent society are a collection of services and can be taken and be left dynamically by agents at runtime. Service provider agents in AWSM register their services as web services. Client that needs web services can apply AWSM to find a web service according to services information, service level parameter and cost criteria. The system organizes a tender to determine the best matching web service and provider agent. The client then can call the web service that is provided by the awarded agent. Service level and performance of this call is registered by system to assess the awarded agent's performance and commitment and to later use this information in future tenders.