Google ADK

Google ADK is Google's open-source agent SDK. The Python repo google/adk-python is Apache-2.0 and showed about 16,991 stars. The docs index now lists Python, Java, Go, and TypeScript. A2A is not inside ADK. It is the sibling protocol at google/A2A.

Compare LangGraph if you want a graph runtime, and the OpenAI Agents SDK if you want OpenAI's official primitives.

Key Features

• Code-native agents: Define agents in the language SDKs, not a closed DSL.
• Four languages: Python, Java, Go, TypeScript on the current docs home.
• Gemini-shaped, not Gemini-only: Docs still lean Vertex / Gemini. Other models go through documented adapters such as LiteLLM. Confirm that page.
• MCP: Client/server tool sharing is documented.
• A2A is separate: Do not describe A2A as an ADK submodule.

Use Cases

• Vertex / Gemini shops that want Google's own SDK.
• Multi-language teams that cannot stay on Python only.
• People wiring A2A who need both repos, not one.

ADK itself is OSS. Vertex / Gemini usage is a different Google Cloud bill.

Pricing

Getting Started

1. Read adk-docs.
2. Clone or pip install from adk-python if you are on Python.
3. Add MCP tools only after a single agent runs.
4. If you need cross-vendor agents, open the A2A repo as a second project.

Frequently Asked Questions

Python only?

No. The docs home lists Python, Java, Go, and TypeScript.

Is A2A part of ADK?

No. Different repository.

Do I pay Google for ADK?

The SDK is free. Model and Vertex bills are not.

Alternatives

• LangGraph: Durable graphs.
• OpenAI Agents SDK: Official OpenAI runtime.
• CrewAI: Role crews.

Tips

1. Quote ~17k stars from the API date, not an old "multi-agent Google I/O" blurb only.
2. Keep A2A and ADK in different sentences.
3. Confirm TypeScript. It was easy to miss on older cards.

Conclusion

ADK is Google's free multi-language agent SDK, with A2A living next door. Start at adk-docs, then decide whether you actually wanted LangGraph.