With the explosion of the Internet, we are evolving a worldwide network-computing environment. At this point, the surged challenge is the next evolutionary technology for the Internet-oriented applications. A KODAMA (Kyushu university Open & Distributed Autonomous Multi-Agent) system is deployed for this demand. KODAMA system can interconnect disparate and distributed agents together to solve some problem whose solution is typically beyond any singular agent's capabilities. The key aspects of KODAMA agents are their autonomy, collaboration, flexibility, as well as stability. To obtain all these features, appropriate scheme of collaboration among agents is clearly critical. Our new approach focuses on both raising the level of abstraction at which agents cooperate with each other, and hiding the implementation details of communications from agents.