Google Agent Development Kit (ADK) review

Google's Agent Development Kit is the most complete option for teams that do not live in a single language. The docs cover Python, TypeScript, Go, Java and Kotlin, and ADK 2.0 adds graph workflows next to the existing sequential, loop and parallel templates. Agents can delegate to sub-agents, call function, MCP and OpenAPI tools, and talk to remote agents through the A2A protocol. ADK also handles live and voice agents, and ships a web interface, a visual builder, a CLI and an API server for running and testing them. Evaluation features include criteria, user simulation and custom metrics. Model support goes beyond Gemini to Claude, OpenAI, Ollama, vLLM and LiteLLM. The framework is Apache 2.0 licensed and free. Its deployment guides point to Google's Agent Runtime, Cloud Run and GKE, which suits Google Cloud teams but means extra work elsewhere, and the sheer number of features makes the first week steeper than with the OpenAI SDK.

Who it is for

Teams on Google Cloud or with mixed-language stacks that want one framework across Python, TypeScript, Go, Java and Kotlin.

Price

Free and open source (Apache 2.0); you pay for models and hosting.

ADK is the open-source agent development framework that lets you build, debug, and deploy reliable AI agents at enterprise scale.
Quoted from the vendor pricing page on November 6, 2026.

Key features

• Graph workflows plus sequential, loop and parallel workflow templates
• A2A protocol support for exposing and consuming remote agents
• Live and voice agents with speech-to-speech and cascade designs
• Web interface, visual builder, CLI and API server for running agents
• Deployment to Agent Runtime, Cloud Run or GKE

Strengths and weaknesses

• Strength: The widest language coverage on this list
• Strength: Built-in evaluation, user simulation and observability docs
• Strength: Works with non-Google models including Claude and OpenAI
• Weakness: Managed deployment paths center on Google Cloud
• Weakness: Feature parity varies across the five language SDKs
• Weakness: Large surface area to learn compared with smaller SDKs

Key facts

• License: Apache 2.0
• Languages: Python, TypeScript, Go, Java, Kotlin
• Latest major: ADK 2.0, TypeScript 2.0 GA with graph workflows
• Install (Python): pip install google-adk

Where it ranks

Google Agent Development Kit (ADK) is No. 2 in our Best AI Agent Frameworks verdict.