The 4 core A2A information shapes
A2A organizes communication round 4 major object varieties, every representing a definite part within the workflow:
- Agent card. A small JSON file (agent.json) that publicly describes an agent’s identification, capabilities, authentication strategies, and non-compulsory digital signature. Different brokers learn these playing cards to find potential collaborators and confirm belief.
- Activity. Â A structured work request that features a distinctive
task_id, an enter payload, and metadata about precedence, expiration, or required modalities. The duty defines what must be carried out and serves because the anchor for all subsequent communication. - Message. A stream of standing updates and intermediate details about the duty. Messages carry progress indicators, requests for extra enter, or contextual notes, and are sometimes transmitted over SSE or gRPC streams.
- Artifact. The results of the finished job. Artifacts can include textual content, recordsdata, or structured information. They finalize the transaction and could be saved, validated, or chained into one other Activity for additional processing.
In a typical trade, the requesting agent first retrieves an agent card to substantiate one other agent’s capabilities and supported protocols. The requesting agent is known as a consumer, and the agent that it’s interrogating about providers known as a server, however these aren’t everlasting states: an agent might act as a consumer in a single context and a server in one other, and in reality the 2 would possibly swap roles in the middle of a single interplay.
At any charge, the consumer agent points a createTask request, which the server agent acknowledges by returning a task_id. As the duty runs, the supplier streams Message objects that point out standing or request clarification. When the work is completed — or if it fails — the supplier emits a number of Artifact objects, together with a completion code.
