Creativity · Agent Protocol

Google A2A (Agent-to-Agent) Protocol

Agent-to-Agent (A2A) is Google's open protocol, introduced in 2025, for letting independently-built agents discover each other, publish their capabilities, exchange task state, and hand off work. It's the 'HTTP for agents' positioning — a complement, not a replacement, to MCP, which governs agent-to-tool communication.

Protocol facts

Sponsor
Google (+ industry partners)
Status
proposed
Spec
https://google.github.io/A2A/
Interop with
MCP, HTTP/REST, JSON-RPC

Frequently asked questions

What is the A2A protocol?

Agent-to-Agent (A2A) is an open protocol sponsored by Google and dozens of industry partners that lets agents built by different teams discover each other, exchange capability metadata, and hand off tasks — the 'HTTP for agents' layer.

How is A2A different from MCP?

MCP (Model Context Protocol) governs how an agent talks to tools and data. A2A governs how an agent talks to another agent. They're layered: an A2A agent may internally use MCP servers to do its work.

Is A2A a standard?

A2A is an open specification with multiple implementations and industry participation, but it is not yet a ratified standard (as of April 2026). Status is 'proposed / actively evolving'.

Sources

  1. Google — A2A overview — accessed 2026-04-20