Google ADK JavaScript quickstart

npm install @ag-ui/adk-js @google/adk @copilotkit/runtime hono

GOOGLE_GENAI_API_KEY=your-api-key
GOOGLE_GENAI_USE_VERTEXAI=0

import { ADKJSAgent } from "@ag-ui/adk-js"
import {
  CopilotRuntime,
  InMemoryAgentRunner,
  createCopilotEndpointSingleRoute,
} from "@copilotkit/runtime/v2"
import { Agent, InMemorySessionService } from "@google/adk"
import { handle } from "hono/vercel"

export const runtime = "nodejs"

const rootAgent = new Agent({
  name: "assistant",
  model: "gemini-2.5-flash",
  instruction: "Be concise and use frontend tools when appropriate.",
})

const copilotRuntime = new CopilotRuntime({
  agents: {
    assistant: new ADKJSAgent({
      appName: "assistant_app",
      sessionService: new InMemorySessionService(),
      agent: rootAgent,
      userId: "user-123", // resolve from server-side auth
    }),
  },
  runner: new InMemoryAgentRunner(),
})

const endpoint = createCopilotEndpointSingleRoute({
  runtime: copilotRuntime,
  basePath: "/api/copilotkit",
})

export const POST = handle(endpoint)