> ## Documentation Index
> Fetch the complete documentation index at: https://docs.agno.com/llms.txt
> Use this file to discover all available pages before exploring further.

# A2A

> Expose agents via Google's Agent-to-Agent protocol.

The A2A interface exposes any Agno agent, team, or workflow via [Google's A2A protocol](https://a2a-protocol.org/), enabling standardized inter-agent communication.

## Quick Start

```python a2a_agent.py theme={null}
from agno.agent import Agent
from agno.models.openai import OpenAIResponses
from agno.os.app import AgentOS

agent = Agent(name="Assistant", model=OpenAIResponses(id="gpt-5.4"))

agent_os = AgentOS(
    agents=[agent],
    a2a_interface=True,  # expose all agents via A2A
)
app = agent_os.get_app()
```

```bash theme={null}
uv pip install 'agno[a2a]'
python -m agno.os.serve a2a_agent:app --port 9001
```

## How It Works

| Concept         | Behavior                                                    |
| --------------- | ----------------------------------------------------------- |
| **Discovery**   | `/.well-known/agent-card.json` describes agent capabilities |
| **Messaging**   | `message:stream` and `message:send` endpoints               |
| **Multi-agent** | Each agent/team/workflow gets its own endpoint namespace    |
| **Clients**     | Works with any A2A-compatible client                        |

## Setup

No external configuration required. Set `a2a_interface=True` on AgentOS.

**Endpoints:**

* Discovery: `/a2a/agents/{id}/.well-known/agent-card.json`
* Stream: `/a2a/agents/{id}/v1/message:stream`
* Send: `/a2a/agents/{id}/v1/message:send`

## Next Steps

<CardGroup cols={2}>
  <Card title="Full Guide" icon="book" href="/agent-os/interfaces/a2a/introduction">
    Agent cards, messaging, and client integration.
  </Card>

  <Card title="A2A Client" icon="plug" href="/agent-os/client/a2a-client">
    Connect to other A2A agents.
  </Card>

  <Card title="Examples" icon="code" href="/agent-os/usage/interfaces/a2a/basic">
    Basic agent, tools, and team examples.
  </Card>

  <Card title="A2A Protocol" icon="file-code" href="https://a2a-protocol.org/">
    Official protocol specification.
  </Card>
</CardGroup>