Agent Development Kit (ADK) for Go

ADK for Go 2.x offers several ways to structure agents. An llmagent runs a model-and-tool loop and can list sub-agents that the model may transfer control to. Template workflow agents (sequentialagent, parallelagent, loopagent) run sub-agents in a fixed pattern. Since 2.0, the workflow package adds graph-based workflows in which agents, functions and tools are nodes joined by edges, with branching, joins, parallel workers, retries and human-input nodes, plus collaborative teams where a coordinator delegates to sub-agents in chat, task or single-turn mode.

A runner executes the root agent against a session. Session services keep event history and state in memory, in a database or in Vertex AI; memory services add cross-session search. An agent's OutputKey stores its answer in session state for later agents. The cmd/launcher package turns one program into a CLI, a REST API server or the ADK Web dev UI.

The repository maintains two lines: v2 under the module path google.golang.org/adk/v2, which changed some APIs (for example session.NewEvent now takes a context and tool and callback contexts were merged), and v1, which receives backported fixes.

Two mechanisms are documented with Go samples. Tool confirmation, marked Experimental, is enabled by setting RequireConfirmation: true in functiontool.Config, which pauses each call for a yes/no answer; a tool can also request a structured confirmation through its context and read the reply when called again. The guide notes that confirmation does not work with the database or Vertex AI session services. In graph workflows (ADK Go 2.0+), a human-input node pauses the workflow until the user replies, and the reply becomes the next node's input. Answers can be given in the ADK Web UI or sent through the REST API server.

go get google.golang.org/adk/v2

// imports: context, os, google.golang.org/genai, and from google.golang.org/adk/v2:
// agent, agent/llmagent, agent/workflowagents/sequentialagent, cmd/launcher, cmd/launcher/full, model/gemini
func main() {
	ctx := context.Background()
	m, _ := gemini.NewModel(ctx, "gemini-flash-latest", &genai.ClientConfig{APIKey: os.Getenv("GOOGLE_API_KEY")})
	drafter, _ := llmagent.New(llmagent.Config{Name: "drafter", Model: m,
		Instruction: "Draft a short release note for the user's change.", OutputKey: "draft"})
	editor, _ := llmagent.New(llmagent.Config{Name: "editor", Model: m,
		Instruction: "Shorten this note to two sentences: {draft}"})
	notes, _ := sequentialagent.New(sequentialagent.Config{
		AgentConfig: agent.Config{Name: "notes", SubAgents: []agent.Agent{drafter, editor}}})
	cfg := &launcher.Config{AgentLoader: agent.NewSingleLoader(notes)}
	_ = full.NewLauncher().Execute(ctx, cfg, os.Args[1:]) // `go run . web api webui` opens the dev UI
}

• The quickstart asks for Go 1.25+ and ADK Go v2.0.0+, but the v2 go.mod currently declares go 1.26.6, so an older toolchain has to download a newer one.
• Import paths use the /v2 module suffix (google.golang.org/adk/v2/...); v1 code must be migrated (for example session.NewEvent now takes a context.Context, and tool and callback contexts were merged).
• GOOGLE_API_KEY must be set for Gemini API models.
• ADK Web (go run agent.go web api webui) is for development only.
• Tool confirmation is experimental and does not support the database or Vertex AI session services.

Yes, as a client: the mcptoolset package loads tools from MCP servers. The guide for exposing an ADK agent as an MCP server only shows Python.

Yes, in both directions (remoteagent to consume, server/adka2a to expose), but the Go A2A quickstarts are labeled Experimental.

The quickstart targets v2 (go get google.golang.org/adk/v2), which adds graph workflows and collaborative teams. v1 still gets backported fixes, most recently v1.7.0 on 2026-09-14.

The library is Apache-2.0. Google charges for managed services such as Agent Runtime and its sessions, listed on the Gemini Enterprise Agent Platform pricing page.

Go has ADK 2.0 graph workflows, collaborative agent teams and Agent Runtime deployment documented; these pages do not cover Java.