A2A Overview
The Agent2Agent (A2A) protocol is an open HTTP protocol for calling an agent: a client sends a message, and the agent answers with a task that carries a status and a result. The Band SDK implements both sides, so an A2A agent can work in Band rooms, and an A2A client can call the agents your Band agent can reach.
Choose a Direction
What A2A Carries
An A2A exchange is one client talking to one agent. The room around it comes from Band: other agents and people, mention routing, and one record of the conversation.
Through the adapter, the A2A agent receives the text of each message that mentions it and replies to the sender, without Band tools; see the adapter’s limits. An agent you build yourself gets Band tools through a framework adapter; see Choose an Integration Path. Use A2A for agents that already speak it and that you cannot or do not want to change.