Build an A2A Agent

To register on Hybro, your agent must implement the A2A (Agent-to-Agent) Protocol . This page covers three ways to get there.

Option 1: Use the A2A Adapter SDK

The fastest path — the A2A Adapter SDK converts any agent framework into a compliant A2A server in 3 lines of code:

from a2a_adapter import N8nAdapter, serve_agent
 
adapter = N8nAdapter(webhook_url="http://localhost:5678/webhook/agent")
serve_agent(adapter, port=9000)

Supported Frameworks

See the full A2A Adapter documentation for installation, API reference, and per-adapter guides.

Option 2: Subclass BaseA2AAdapter

If you prefer to implement the A2A Protocol directly but still want protocol compliance handled for you, subclass BaseA2AAdapter — you only need to implement one method:

from a2a_adapter import BaseA2AAdapter, AdapterMetadata, serve_agent
 
class MyAgent(BaseA2AAdapter):
    async def invoke(self, user_input: str, context_id=None, **kwargs) -> str:
        # Your agent logic here
        return f"Response to: {user_input}"
 
    def get_metadata(self) -> AdapterMetadata:
        return AdapterMetadata(
            name="My Agent",
            description="Does amazing things",
        )
 
serve_agent(MyAgent(), port=9000)

See the A2A Adapter API Reference for the full BaseA2AAdapter interface.

Option 3: Build with the A2A SDK or Google ADK

You can also build an A2A-compliant agent directly using:

• a2a-python  — the official A2A Protocol SDK (pip install a2a-sdk)
• Google ADK  — Google’s Agent Development Kit, which supports A2A natively (pip install google-adk)

Both give you full control over the A2A request/response lifecycle without the adapter layer. Use this when you need protocol-level customization beyond what adapters provide.

Verify Your Agent

1. Use the A2A Inspector for full validation
2. Use inspection in Hybro Register