Google ADK: A Practical Tool for Building Multi-Agent AI Systems

Google recently introduced the Agent Development Kit (ADK) at Cloud NEXT 2025, an open-source framework designed to make building complex, multi-agent AI applications easier. While many current AI tools focus on single-task models, ADK is built for the growing need to coordinate multiple specialized agents in real-world use cases.

What Is ADK?

ADK is a full-stack development framework that supports the entire lifecycle of building agentic systems: from design and evaluation to deployment. It's already used inside Google products like Agentspace and Customer Engagement Suite, and now it's open to developers everywhere.

Key Features

• Multi-Agent by Design: Build modular systems by coordinating specialized agents that can delegate tasks.

• Model Flexibility: Choose from Google Gemini, Vertex AI Model Garden, or other providers like Anthropic and Meta through LiteLLM.

• Tool Ecosystem: Use built-in tools like search, code execution, or plug in third-party libraries like LangChain or LlamaIndex.

• Streaming Interaction: ADK supports bi-directional audio and video streaming for real-time, human-like interactions.

• Integrated Development Experience: Offers CLI and Web UI for building, debugging, and monitoring agents.

• Evaluation and Deployment: Includes tools to test agent logic and push to production via container runtimes or Vertex AI.
  

A Simple Use Case

Imagine you’re creating a weather assistant. With ADK, you can:

1. Define a tool that fetches weather data.

2. Build a primary agent that answers weather questions.

3. Create sub-agents for greetings and farewells.

4. Let the system automatically route requests to the right agent based on the user's input.

This delegation works because ADK agents are defined with clear descriptions, which the system uses to make smart decisions.

Developer Experience

The framework supports multiple ways to interact with agents, including Python APIs, command-line tools, and a web interface. You can run agents locally or deploy them on cloud services.

ADK vs. Genkit

While Genkit provides general-purpose GenAI tools, ADK is more focused on building structured multi-agent systems. If you’re managing teams of agents with specific roles and tools, ADK offers more structure out of the box.

A Balanced Take

ADK shows real promise for developers building multi-agent applications, especially in customer service, education, and automation. That said, it's still evolving and will require thoughtful implementation to handle complex workflows reliably.

If you're curious about building with ADK, check out the official documentation and examples — and consider how this might fit into your own AI stack. Check out our Udemy Course to learn how to apply this into your own workflow.