# Agent2Agent (A2A)

[6 · Coordinate](/category/coordinate/)

| Agent2Agent (A2A) |
| --- |
| Category | [Coordinate](/category/coordinate/) |
| Also known as | Agent2Agent, A2A protocol |
| Related | [Agent2Agent Protocol](/protocols/a2a/), [Model Context Protocol](/protocols/mcp/) |

[Coordinate](/category/coordinate/) Agent2Agent (A2A) is an open protocol—launched by Google in April 2025 and stewarded by the Linux Foundation Agentic AI Foundation (AAIF)—for peer-to-peer communication and task delegation between opaque autonomous agents across organizational boundaries. Where MCP connects a host model to tools and data sources (Step 5: Act), A2A coordinates multi-turn, potentially long-running Tasks between independent agents (Step 6: Coordinate) that discover each other via /.well-known/agent-card.json, exchange typed Part messages and output Artifact objects, and stream updates over SSE or webhook push notifications without exposing internal memory or prompts. Used by: a2a.

## Instances

Not applicable.

## See also

- [Agent2Agent Protocol](/protocols/a2a/)
- [Model Context Protocol](/protocols/mcp/)

## References

- [https://a2a-protocol.org/latest/specification/](https://a2a-protocol.org/latest/specification/) (2026-09-05) VERIFIED
- [https://aaif.io/blog/a2a-joins-aaif](https://aaif.io/blog/a2a-joins-aaif) (2026-09-05) VERIFIED

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