A2A

Expose Agno agents via the A2A protocol

v2.1.2

Google’s Agent-to-Agent Protocol (A2A) provides a standard way for agents to communicate with each other.

Agno integrates with A2A, enabling Agno agents and teams to be exposed in an A2A-compatible format.

The A2A interface works with the AgentOS runtime to provide this functionality.

Setup

Set a2a_interface=True when creating an AgentOS instance:

a2a_agentos.py

from agno.agent import Agent
from agno.os import AgentOS
from agno.os.interfaces.a2a import A2A

agent = Agent(name="My Agno Agent",id="my_agent")

agent_os = AgentOS(
    agents=[agent],
    a2a_interface=True,
)
app = agent_os.get_app()

if __name__ == "__main__":
    agent_os.serve(app="a2a:app", reload=True)

By default, all agents, teams, and workflows in the AgentOS are exposed via A2A.

Specific agents, teams, and workflows can be exposed by initializing the interface explicitly:

a2a-interface-initialization.py

from agno.agent import Agent
from agno.os import AgentOS
from agno.os.interfaces.a2a import A2A

agent = Agent(name="My Agno Agent",id="my_agent")

# Initialize the A2A interface specifying the agents to expose
a2a = A2A(agents=[agent])

agent_os = AgentOS(
    agents=[agent],
    interfaces=[a2a], # Pass the A2A interface to the AgentOS using the `interfaces` parameter
)
app = agent_os.get_app()

if __name__ == "__main__":
    agent_os.serve(app="a2a-interface-initialization:app", reload=True)

A2A Endpoints

For each available agent, team and workflow, the following A2A-compatible endpoints will be available:

Agents

• /a2a/agents/{id}/.well-known/agent-card.json: Returns the Agent Card describing the agent in A2A format. See API reference.

• /a2a/agents/{id}/v1/message:stream: Runs the agent, streaming the responses as events in A2A format. See API reference and A2A protocol docs.

• /a2a/agents/{id}/v1/message:send: Runs the agen, returning the response in A2A format (non-streaming). See A2A protocol docs.

Teams

• /a2a/teams/{id}/.well-known/agent-card.json: Returns the Team Card describing the Team in A2A format. See API reference.

• /a2a/teams/{id}/v1/message:stream: Runs the team, streaming the responses as events in A2A format. See API reference and A2A protocol docs.

• /a2a/teams/{id}/v1/message:send: Runs the team, returning the response in A2A format (non-streaming). See API reference.

Workflows

• /a2a/workflows/{id}/.well-known/agent-card.json: Returns the Workflow Card describing the Workflow in A2A format. See API reference.

• /a2a/workflows/{id}/v1/message:stream: Runs the workflow, streaming the responses as events in A2A format. See API reference and A2A protocol docs.

• /a2a/workflows/{id}/v1/message:send: Runs the workflow, returning the response in A2A format (non-streaming). See API reference.

A2A clients expect a server to expose only a single agent. To use your Agno A2A interface with those clients, simply use /a2a/agents/{id}/ (or /a2a/teams/{id}/, /a2a/workflows/{id}/) as the base url.

Connecting to A2A Servers

Agno provides two ways to connect to A2A-compatible servers:

Using A2AClient

For direct A2A protocol access:

from agno.client.a2a import A2AClient

client = A2AClient("http://localhost:7003/a2a/agents/my-agent")
result = await client.send_message(message="Hello!")

See A2A Client for full documentation.

Using RemoteAgent

For a higher-level agent interface:

from agno.agent import RemoteAgent

agent = RemoteAgent(
    base_url="http://localhost:7003",
    agent_id="my-agent",
    protocol="a2a",
)
response = await agent.arun("Hello!")

See RemoteAgent Reference for full documentation.

Developer Resources

• AgentOS Reference
• A2A Client Documentation
• A2A Protocol Documentation
• Examples