Agent Development Kit (ADK) for Kotlin

Agent Development Kit (ADK) is designed for developers seeking fine-grained control and flexibility when building advanced AI agents that are tightly integrated with services in Google Cloud. It allows you to define agent behavior, orchestration, and tool use directly in code, enabling robust debugging, versioning, and deployment anywhere – from your laptop to the cloud.

• Rich Tool Ecosystem: Utilize pre-built tools, custom functions, OpenAPI specs, or integrate existing tools to give agents diverse capabilities, all for tight integration with the Google ecosystem.

• Code-First Development: Define agent logic, tools, and orchestration directly in Kotlin for ultimate flexibility, testability, and versioning.

• Modular Multi-Agent Systems: Design scalable applications by composing multiple specialized agents into flexible hierarchies.

• On-device & Cloud Agents on Android: Run agents fully on-device with LiteRT-LM (with tool calling) or Gemini Nano via ML Kit, reach the cloud with Firebase AI, and compose on-device and cloud models into a single hybrid system. See On-device and Cloud Agents on Android.

If you're using Maven, add the following to your dependencies:

<dependency>
  <groupId>com.google.adk</groupId>
  <artifactId>google-adk-kotlin-core-jvm</artifactId>
  <version>0.8.0</version>
</dependency>

If you're using Gradle:

implementation("com.google.adk:google-adk-kotlin-core:0.8.0")

Every module is published under the com.google.adk group and shares the version shown above.

For building, evaluating, and deploying agents by follow the Kotlin documentation & samples:

• Documentation
• Samples

import com.google.adk.kt.agents.LlmAgent
import com.google.adk.kt.agents.Instruction
import com.google.adk.kt.models.Gemini
import com.google.adk.kt.tools.GoogleSearchTool

val rootAgent = LlmAgent(
    name = "search_assistant",
    description = "An assistant that can search the web.",
    model = Gemini(name = "gemini-3.1-flash-lite-preview"),
    instruction = Instruction("You are a helpful assistant. Answer user questions using Google Search when needed."),
    tools = listOf(GoogleSearchTool())
)

GenAI SDK based Gemini currently prevents usage of API_KEY and GoogleCredentials on Android. Use Firebase AI instead.

ADK Kotlin agents run on Android either fully on-device — no API key and no network at inference time, for offline, low-latency, or privacy-sensitive use — or against the cloud. Every backend is a Model behind the same LlmAgent API, so switching between them is a one-line change.

• LiteRT-LM runs open models such as Gemma on-device through LiteRT-LM, Google's on-device inference framework, with full tool / function calling so an on-device agent can drive custom tools. It runs on both Android and the JVM (desktop). See litertlm/README.md.
• ML Kit (Gemini Nano) runs the built-in Gemini Nano model through the ML Kit GenAI Prompt API. It is Android-only and published as a -beta pre-release; tool calling is not supported yet (functionCall / functionResponse parts are dropped), so use it for plain chat/generation for now.
• Firebase AI reaches a cloud Gemini model through Firebase AI Logic — the recommended way to call Gemini from Android without embedding an API key — with full tool calling.

Because on-device and cloud models are interchangeable Model implementations, you can compose them into a single multi-agent system: an on-device agent can handle offline, cheap, or privacy-sensitive turns and delegate harder tasks to a cloud agent, all within one LlmAgent hierarchy. See Modular Multi-Agent Systems for how agents are composed.

All three backends have runnable multi-turn chat examples in the examples/android/ Compose app — LiteRT-LM chat, ML Kit chat, and Firebase AI. See the Android examples README for how to build and run the app, obtain the on-device models, and configure Firebase.

Same as the beloved Python Development UI. A built-in development UI to help you test, evaluate, debug, and showcase your agent(s).

The snippet above is the short version. Every runnable example lives under the examples directory of this repository.

• examples/ — JVM examples.

• examples/android/ — a Compose app showing the Android side, including the on-device (LiteRT-LM, ML Kit) and cloud (Firebase AI) agents described in On-device and Cloud Agents on Android.

We welcome contributions from the community! Whether it's bug reports, feature requests, documentation improvements, or code contributions, please see our CONTRIBUTING.md to get started.

This project is licensed under the Apache 2.0 License - see the LICENSE file for details.

This feature is subject to the "Pre-GA Offerings Terms" in the General Service Terms section of the Service Specific Terms. Pre-GA features are available "as is" and might have limited support. For more information, see the launch stage descriptions.

Happy Agent Building!