Getting Started with Google ADK in Go

Google released the Agent Development Kit for building AI agents across multiple languages. The Go SDK makes it straightforward to create agents powered by Gemini with built-in tool support and both CLI and web interfaces.

Setup

You need Go 1.24+ and a Gemini API key from Google AI Studio.

mkdir -p my_agent && cd my_agent
go mod init my-agent/main

Building an agent

The core flow is: create a model, create an agent with tools, wrap it in a launcher, and execute. Here is a minimal agent that uses Google Search to answer questions:

package main

import (
    "context"
    "log"
    "os"

    "google.golang.org/adk/agent"
    "google.golang.org/adk/agent/llmagent"
    "google.golang.org/adk/cmd/launcher"
    "google.golang.org/adk/cmd/launcher/full"
    "google.golang.org/adk/model/gemini"
    "google.golang.org/adk/tool"
    "google.golang.org/adk/tool/geminitool"
    "google.golang.org/genai"
)

func main() {
    ctx := context.Background()

    model, err := gemini.NewModel(ctx, "gemini-flash-latest", &genai.ClientConfig{
        APIKey: os.Getenv("GOOGLE_API_KEY"),
    })
    if err != nil {
        log.Fatalf("Failed to create model: %v", err)
    }

    timeAgent, err := llmagent.New(llmagent.Config{
        Name:        "hello_time_agent",
        Model:       model,
        Description: "Tells the current time in a specified city.",
        Instruction: "You are a helpful assistant that tells the current time in a city.",
        Tools: []tool.Tool{
            geminitool.GoogleSearch{},
        },
    })
    if err != nil {
        log.Fatalf("Failed to create agent: %v", err)
    }

    config := &launcher.Config{
        AgentLoader: agent.NewSingleLoader(timeAgent),
    }

    l := full.NewLauncher()
    if err = l.Execute(ctx, config, os.Args[1:]); err != nil {
        log.Fatalf("Run failed: %v\n\n%s", err, l.CommandLineSyntax())
    }
}

Running it

Set your API key and run:

export GOOGLE_API_KEY="your-key-here"
go run agent.go

This starts an interactive CLI session. For a web interface with a chat UI on localhost:8080:

go run agent.go web api webui

Key concepts

The SDK is built around five pieces: Models are the underlying LLM created via gemini.NewModel. Tools are capabilities like Google Search passed as a slice in the agent config. Agents combine a model, tools, and instructions via llmagent.New. The Launcher handles execution in CLI or web mode. The AgentLoader wires agents into the launcher config.

The web interface is for development and debugging only. For production, you would integrate the agent into your own server.

Full documentation at adk.dev/get-started/go.