AI Vocabulary · 05 Agents
What is Agent2Agent (A2A)?
An open protocol that lets AI agents from different vendors find each other, hand over tasks and return results.
A2A is an open standard for conversations between agents. Every A2A agent publishes an Agent Card, a short profile in JSON with its identity, skills, address and login requirements. Another agent reads the card, hands over a task with its own ID and receives the result as an artifact, such as a document or a data set.
The agents stay opaque to each other: they share no internal plans or tool details. MCP connects one agent to its tools and data; A2A connects agents with each other, also across company boundaries. Google launched A2A in April 2025, version 1.0 is the first stable release, and since August 2026 it sits with the Agentic AI Foundation under the Linux Foundation, next to MCP.
Why it matters for you
You rarely need A2A on day one. It becomes relevant when your agent has to work with a customer's or partner's agent, for example to book, order or exchange documents without a person copying data between systems.
Own it
An open standard reduces dependence on one vendor's platform. If a partner asks how your agent will talk to theirs, ask whether both sides support A2A, and check which login methods the Agent Cards require.
Where it comes from
The protocol is defined in the A2A specification of the A2A Project under the Linux Foundation. Its move to the Agentic AI Foundation is described in A2A joins AAIF (17 August 2026).
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