---
Title: "What Is the Agent2Agent (A2A) Protocol?"
Url: "https://computer.io/glossary/agent2agent-protocol"
Topic: "Agentic AI"
Description: "The Agent2Agent (A2A) protocol is an open standard that lets AI agents from different vendors discover each other and collaborate on tasks. How it works."
---

# What is the Agent2Agent (A2A) protocol?

The Agent2Agent (A2A) protocol is an open standard, introduced by Google in 2025, that lets AI agents built by different vendors discover each other's capabilities, exchange messages and coordinate tasks securely. It complements MCP, which connects agents to tools and data.

## Key concepts

| Concept | Meaning |
| --- | --- |
| Agent card | Describes an agent's skills |
| Task | Unit of work between agents |
| Messages | Exchanged during a task |
| Artifacts | Outputs |

## A2A vs MCP

|  | MCP | A2A |
| --- | --- | --- |
| Connects | Agent to tools/data | Agent to agent |
| Example | Read a ticket | Ask a billing agent to refund |

## Use case

A support agent hands a refund task to a finance agent from another vendor.

## FAQ

### Who created A2A?

Google announced it in April 2025 with many partners.

### Does A2A replace MCP?

No, they solve different problems and are often used together.

### Is A2A widely adopted?

Adoption is growing; check vendor support.

## Related terms

- [Model Context Protocol (MCP)](https://computer.io/glossary/model-context-protocol)
- [Multi-agent system](https://computer.io/glossary/multi-agent-system)
- [Agent orchestration](https://computer.io/glossary/agent-orchestration)

## How Computer helps

- [How computer works](https://computer.io/how-computer-works)

## Further reading

- [Knowledge graph vs mcp interfaces](https://devrev.ai/blog/knowledge-graph-vs-mcp-interfaces)