A2A Protocol
An open protocol published by Google in 2025, built on HTTP and JSON-RPC 2.0. It uses an Agent Card mechanism to enable agents to declare and discover their own capabilities, and is focused on asynchronous, long-running task collaboration between agents.
Core Facts
A2A (Agent-to-Agent) is an inter-agent communication protocol proposed by Google.
The A2A (Agent-to-Agent) protocol manages collaboration between Agents, addressing issues of capability discovery, task delegation, and collaborative interoperability.
The A2A (Agent2Agent) protocol is a set of inter-agent communication specifications built on mature web standards, with the goal of enabling develop-once, connect-anywhere integration rather than being an entirely new underlying protocol.
Timeline (last 90 days)
A team at Microsoft conducted comparative experiments on the A2A protocol and ultimately chose the solution of message passing plus stateless sub-Agents.
The A2A protocol defines the Agent Card, a JSON-RPC-based task lifecycle, streaming updates, and multimodal message-passing mechanisms.
A2A (Agent-to-Agent) is an inter-agent communication protocol proposed by Google.
The A2A (Agent2Agent) protocol is a set of inter-agent communication specifications built on mature web standards, with the goal of enabling develop-once, connect-anywhere integration rather than being an entirely new underlying protocol.
The A2A (Agent-to-Agent) protocol manages collaboration between Agents, addressing issues of capability discovery, task delegation, and collaborative interoperability.
All Facts (6)
A2A (Agent-to-Agent) is an inter-agent communication protocol proposed by Google.
80%VerifiedThe A2A (Agent-to-Agent) protocol manages collaboration between Agents, addressing issues of capability discovery, task delegation, and collaborative interoperability.
75%VerifiedThe A2A (Agent2Agent) protocol is a set of inter-agent communication specifications built on mature web standards, with the goal of enabling develop-once, connect-anywhere integration rather than being an entirely new underlying protocol.
65%VerifiedGoogle released the A2A protocol to drive the industry toward establishing a unified standard for inter-agent communication.
65%UnverifiedA team at Microsoft conducted comparative experiments on the A2A protocol and ultimately chose the solution of message passing plus stateless sub-Agents.
50%UnverifiedThe A2A protocol defines the Agent Card, a JSON-RPC-based task lifecycle, streaming updates, and multimodal message-passing mechanisms.
50%