Google ADK Framework

The Agent Development Kit

Google ADK (Agent Development Kit) is an open-source framework for building, orchestrating, and deploying AI agents. As of 2026, it supports Python, Go, Java, and TypeScript.

ADK vs Other Frameworks

Key ADK Features (2026)

• Visual Agent Builder: Drag-and-drop UI for composing agent hierarchies and testing in real-time.
• YAML-Based Authoring: Define agent logic declaratively — great for version control and CI/CD.
• Session Rewind: Debug by rewinding a session to any previous state and replaying.
• Code Execution Sandbox: Safely execute agent-generated code via Vertex AI sandbox.
• Multi-Provider Models: Use Gemini, Claude, or GPT as the reasoning engine.

ADK Agent Definition (Python)

from google.adk import Agent, Tool

# Define tools
search_tool = Tool(
    name="search_knowledge_base",
    description="Search internal docs",
    function=search_kb_function
)

# Create agent
agent = Agent(
    name="support_agent",
    model="gemini-2.0-flash",
    tools=[search_tool],
    instruction="You are a helpful support agent...",
    sub_agents=[billing_agent, shipping_agent]  # Hierarchy!
)

# Run
response = agent.run("What is the refund policy?")