The paper focuses on the development of protocols for brokering-based agent communities in e-Business. The global market is driving e-Business to become service-centric, offering highly modular e-Services that can be flexibly and dynamically composed into rapidly deployable e-Businesses. This trend is giving rise to a new set of requirements of negotiation-based, autonomous, and intelligent computing. It is, therefore, expected that in the near future, e-Services will be designed and implemented as software agents (also known as agent-based systems). This paper prepares for the proliferation of agent-based systems in e-Business by contributing a suite of protocols for self-organizing agent communities. The protocols are based on a three-tier architecture of agents, brokers, and superbrokers. We present the architecture and the protocols (Broker-Based Agent Community Protocols, or BBACP). An implementation using JKQML is also presented along with a case study drawn from the electronic auto-trading domain.