❯ Guillaume Laforge

An ADK Java GitHub template for your first Java AI agent

java agent-development-kit large-language-models ai-agents

With the unveiling of the Java version of Agent Development Kit (ADK) which lets you build AI agents in Java, I recently covered how to get started developing your first agent.

The installation and quickstart documentation also helps for the first steps, but I realized that it would be handy to provide a template project, to further accelarate your time-to-first-conversation with your Java agents! This led me to play with GitHub’s template project feature, which allows you to create a copy of the template project on your own account or organization. It comes with a ready-made project structure, a configured pom.xml file, and a first Java agent you can customize at will, and run from both the command-line or the ADK Dev UI.

➡️ Clone the adk-java-maven-template project! ⬅️

The project follows a standard Java project structure:

project_folder/
├── pom.xml
└── src/
    └── main/
        └── java/
            └── com/
                └── example/
                    └── agent/
                        └── HelloWeatherAgent.java

The pom.xml build file declares the two ADK dependencies:

<!-- The ADK core dependency -->
<dependency>
    <groupId>com.google.adk</groupId>
    <artifactId>google-adk</artifactId>
    <version>0.1.0</version>
</dependency>
<!-- The ADK dev web UI to debug your agent -->
<dependency>
    <groupId>com.google.adk</groupId>
    <artifactId>google-adk-dev</artifactId>
    <version>0.1.0</version>
</dependency>

And the HelloWeatherAgent.java class shows how to create a simple agent:

//...
LlmAgent.builder()
    .name("hello-weather-agent")
    .description("Hello World")
    .instruction("""
        You are a friendly assistant,
        answering questions in a concise manner.

        When asked about weather information,
        you MUST use the `getWeather` function.
        """)
    .model("gemini-2.0-flash")
    .tools(FunctionTool.create(HelloWeatherAgent.class, "getWeather"))
    .build();
//...

An agent that makes use of a tool to request weather forecasts:

//...
@Schema(description = "Get the weather forecast for a given city")
public static Map<String, String> getWeather(
        @Schema(name = "city",
        description = "Name of the city to get the weather forecast for")
        String city) {
    return Map.of(
        "city", city,
        "forecast", "Sunny day, clear blue sky, temperature up to 24°C"
    );
}
//...

There are two ways to run the agent, via the command-line:

mvn compile exec:java \
    -Dexec.mainClass="com.example.agent.HelloWeatherAgent"

Or the ADK Dev UI:

mvn compile exec:java \
    -Dexec.mainClass="com.google.adk.web.AdkWebServer" \
    -Dexec.classpathScope="compile"

Which will show the nice and handy development UI, to help you prototype and debug your agent:

😃 Happy Java AI agent building! 🛠️