Google ADK A2A Server for Cookbook Examples

Uses Google’s ADK to create an A2A-compatible agent.

Uses Google’s ADK to create an A2A-compatible agent. Requires GOOGLE_API_KEY environment variable.

adk_server.py

"""
Google ADK A2A Server for Cookbook Examples.

Uses Google's ADK to create an A2A-compatible agent.
Requires GOOGLE_API_KEY environment variable.

This server exposes a facts-agent that provides interesting facts,
using pure JSON-RPC at root "/" endpoint (Google ADK style).

Start this server before running 05_remote_adk_agent.py
"""

import os

from a2a.types import AgentCapabilities, AgentCard
from google.adk import Agent
from google.adk.a2a.utils.agent_to_a2a import to_a2a
from google.adk.tools import google_search

# ---------------------------------------------------------------------------
# Create Example
# ---------------------------------------------------------------------------

port = int(os.getenv("PORT", "7780"))

agent = Agent(
    name="facts_agent",
    model="gemini-2.5-flash-lite",
    description="Agent that provides interesting facts.",
    instruction="You are a helpful agent who provides interesting facts.",
    tools=[google_search],
)

# Define A2A agent card
agent_card = AgentCard(
    name="facts_agent",
    description="Agent that provides interesting facts.",
    url=f"http://localhost:{port}",
    version="1.0.0",
    capabilities=AgentCapabilities(
        streaming=True, push_notifications=False, state_transition_history=False
    ),
    skills=[],
    default_input_modes=["text/plain"],
    default_output_modes=["text/plain"],
)

app = to_a2a(agent, port=port, agent_card=agent_card)

# ---------------------------------------------------------------------------
# Run Example
# ---------------------------------------------------------------------------

if __name__ == "__main__":
    import uvicorn

    uvicorn.run(app, host="0.0.0.0", port=port)

Run the Example

1. Set up your virtual environment

   Mac

   uv venv --python 3.12
   source .venv/bin/activate
   

   uv venv --python 3.12
   .venv\Scripts\activate
   
2. Install dependencies

   uv pip install -U a2a-sdk google-adk uvicorn
   
3. Export your API keys

   Mac/Linux

   export GOOGLE_API_KEY="your_google_api_key_here"
   

   $Env:GOOGLE_API_KEY="your_google_api_key_here"
   
4. Run the example

   Save the code above as adk_server.py, then run:

   python adk_server.py
   

Full source: cookbook/05_agent_os/20_remote/servers/adk_server.py