NPM package for ADK

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The official "ADK Starter" uses a Python backend (FastAPI) running the agent. We are using Node.js with the @google/adk package. We do not have a separate Python server running. Trying to build a custom copilotkit-adk-adapter but it is silently failing. Any support is appreciated

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This solution has been AI generated

There isn't an ADK-specific NPM adapter for Node.js. To use your @google/adk agent without a Python server, expose it via the AG-UI protocol by wrapping it in an AbstractAgent and registering it with the CopilotRuntime.

Install

npm install @ag-ui/client

Implement an AG-UI Agent Adapter

Wrap your @google/adk logic in an AbstractAgent and emit the required AG-UI events in order.

import { AbstractAgent, RunAgentInput, RunAgentResult, EventType } from "@ag-ui/client";
import { Observable } from "rxjs";
// import { MyAdkAgent } from "./your-adk-logic"; // your @google/adk instance

export class AdkAgUIAdapter extends AbstractAgent {
  async run(input: RunAgentInput): Promise<RunAgentResult> {
    const events = new Observable<any>((subscriber) => {
      (async () => {
        try {
          subscriber.next({ type: EventType.RunStarted });

          // 1) Send input to your ADK agent
          // 2) Stream back messages using TextMessageStart/TextMessageDelta/TextMessageEnd
          // Example:
          // subscriber.next({ type: EventType.TextMessageStart, role: "assistant" });
          // subscriber.next({ type: EventType.TextMessageDelta, delta: "Hello" });
          // subscriber.next({ type: EventType.TextMessageEnd });

          subscriber.next({ type: EventType.RunFinished });
          subscriber.complete();
        } catch (err) {
          subscriber.error(err);
        }
      })();
    });

    return { events };
  }
}

Register with CopilotRuntime

const runtime = new CopilotRuntime({
  agents: {
    my_adk_agent: new AdkAgUIAdapter(),
  },
});

Common causes of “silent” failures

• Protocol mismatch: Missing or out-of-order events (RunStarted → TextMessage* → RunFinished).
• Bad stream: run() must return { events } where events is a valid RxJS Observable.

• Agent name mismatch: Frontend agent id must match the key in runtime.agents.

References

• ADK Integration Overview: https://docs.copilotkit.ai/adk
• Connecting Existing Agents: https://docs.copilotkit.ai/adk/quickstart#use-an-existing-agent
• AG-UI Client Reference: https://github.com/CopilotKit/CopilotKit/tree/main/CopilotKit/packages/runtime-client-gql

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[green solar]

useAgent: Agent 'default' not found after runtime sync (runtimeUrl=/api/copilotkit?storeSlug=nike-demo&guestId=guest_zk7hxw). No agents registered. Verify your runtime /info and/or agents__unsafe_dev_only.
src/app/shop/[slug]/layout.tsx (41:9) @ ShopLayout

39 |
40 | return (

41 | <CopilotKit runtimeUrl={/api/copilotkit?storeSlug=${store.slug}&guestId=${guestId}}>
| ^
42 | <CartProvider>
43 | <div
44 | className={${theme.font === 'Inter' ? inter.variable : ''} min-h-screen bg-background font-sans antialiased}

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