Rahul K B
Published on

Building Multi-Agent Systems with Google ADK

Authors

The Era of Agentic AI

We are moving beyond simple chatbots to Agentic AI—systems that can reason, plan, and execute tasks to achieve complex goals. Google's Agent Development Kit (ADK) is at the forefront of this shift, providing a robust framework for building sophisticated Multi-Agent Systems (MAS).

What is Google ADK?

The Google Agent Development Kit (ADK) is a flexible, modular, and open-source framework designed to simplify the development of AI agents. While optimized for Gemini and the Google Cloud ecosystem, it is model-agnostic, allowing developers to build agents that can leverage various LLMs and tools.

Key capabilities include:

  • Agent Composition: Building complex architectures with hierarchical or cooperative agent teams.
  • Orchestration: Managing workflows between agents (Sequential, Parallel, or Router-based).
  • Tool Integration: Seamlessly connecting agents to APIs, databases, and custom functions.
  • Memory & State: Managing context across long-running interactions.

Core Concepts of ADK

1. The Agent

In ADK, an agent is more than just a prompt. It's a cohesive unit with:

  • Persona: Defined by system instructions and role.
  • Tools: Capabilities it can invoke (e.g., GoogleSearch, CodeInterpreter).
  • Memory: Context from previous interactions.
# Conceptual example of defining an ADK Agent
from google.adk import Agent, Tool

researcher = Agent(
    name="Researcher",
    model="gemini-1.5-pro",
    instructions="You are an expert researcher. Use tools to find verifiable facts.",
    tools=[GoogleSearchTool()]
)

2. Multi-Agent Orchestration

The real power of ADK lies in Multi-Agent Systems. You can compose agents to solve problems that are too complex for a single model.

Patterns:

  • Handoffs: Agent A passes a task to Agent B.
  • Supervisor/Worker: A central router delegates tasks to specialized workers.
  • Debate: Multiple agents critique each other's work to improve accuracy.
# Orchestrating a workflow
from google.adk import SequentialWorkflow

writer = Agent(name="Writer", instructions="Write a blog post based on research.")

# Create a workflow: Research -> Write
workflow = SequentialWorkflow(
    agents=[researcher, writer],
    memory=SharedMemory()
)

response = workflow.run("Explain the future of quantum computing.")

3. Deployment & Evaluation

ADK isn't just for prototyping. It includes tools for:

  • Evaluation: Systematically testing agent performance against golden datasets.
  • Deployment: Containerizing agents for Cloud Run or Vertex AI Agent Engine.

Why ADK Matters for Leaders

As we build the next generation of AI applications, structure and reliability are paramount. ADK brings software engineering rigor to AI development. It allows teams to:

  • Modularize AI logic (treat agents as microservices).
  • Scale development across large teams.
  • Govern agent behavior with strict definitions and guardrails.

Getting Started

To start building with ADK:

  1. Explore the Google ADK GitHub repository.
  2. Experiment with the Agent Playground to visualize agent interactions.
  3. Start small: Build a single agent with tools, then expand to a multi-agent workflow.

The future is agentic, and ADK is the toolkit to build it.