What is Google ADK (Agent Development Kit)?

What is Google ADK (Agent Development Kit)?

Google ADK (Agent Development Kit) is Google's open-source framework for building, deploying, and managing AI agents — particularly multi-agent systems. It's designed for production-grade agentic AI applications integrated with the Google ecosystem.

What ADK Provides

Core Concepts

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from google.adk.agents import Agent
from google.adk.tools import google_search, python_code_execution

# Define a simple ADK agent
root_agent = Agent(
    name="research_assistant",
    model="gemini-2.0-flash",
    description="A research assistant that can search the web and analyze data",
    instruction='''You are a research assistant. When given a research question:
    1. Search for relevant information
    2. Analyze and synthesize findings
    3. Provide a structured summary''',
    tools=[google_search, python_code_execution]
)

Multi-Agent Setup with ADK

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from google.adk.agents import Agent

# Sub-agents with specialized roles
search_agent = Agent(
    name="search_specialist",
    model="gemini-2.0-flash",
    description="Specializes in web research",
    tools=[google_search]
)

analyst_agent = Agent(
    name="data_analyst",
    model="gemini-2.0-flash",
    description="Analyzes data and creates reports",
    tools=[python_code_execution]
)

# Root orchestrator agent manages sub-agents
orchestrator = Agent(
    name="coordinator",
    model="gemini-2.0-flash",
    description="Coordinates research and analysis tasks",
    sub_agents=[search_agent, analyst_agent]  # Hierarchical orchestration
)

Running an ADK Agent

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from google.adk.runners import Runner
from google.adk.sessions import InMemorySessionService

session_service = InMemorySessionService()
runner = Runner(
    agent=root_agent,
    app_name="my_research_app",
    session_service=session_service
)

# Run agent
import asyncio
from google.genai.types import Content, Part

async def main():
    session = await session_service.create_session(
        app_name="my_research_app",
        user_id="user_123"
    )

    async for event in runner.run_async(
        user_id="user_123",
        session_id=session.id,
        new_message=Content(parts=[Part(text="Research AI trends in 2025")])
    ):
        if event.content:
            print(event.content.parts[0].text)

asyncio.run(main())

ADK vs LangGraph vs CrewAI

Deployment on Vertex AI

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# Deploy ADK agent to Google Cloud
gcloud ai agents deploy \
    --agent-config=agent_config.yaml \
    --region=us-central1 \
    --project=your-project-id

ADK is particularly strong for teams already invested in the Google Cloud / Vertex AI ecosystem who want tight integration with Gemini models and Google services.