Subagent demo not work

[sorryxgb]

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right place. **
Contribution guide.

Describe the bug

// Conceptual Code: Coordinator using LLM Transfer
import { LlmAgent } from '@google/adk';

const billingAgent = new LlmAgent({name: 'Billing', description: 'Handles billing inquiries.'});
const supportAgent = new LlmAgent({name: 'Support', description: 'Handles technical support requests.'});

const coordinator = new LlmAgent({
    name: 'HelpDeskCoordinator',
    model: 'gemini-2.5-flash',
    instruction: 'Route user requests: Use Billing agent for payment issues, Support agent for technical problems.',
    description: 'Main help desk router.',
    // allowTransfer=true is often implicit with subAgents in AutoFlow
    subAgents: [billingAgent, supportAgent]
});
// User asks "My payment failed" -> Coordinator's LLM should call {functionCall: {name: 'transfer_to_agent', args: {agent_name: 'Billing'}}}
// User asks "I can't log in" -> Coordinator's LLM should call {functionCall: {name: 'transfer_to_agent', args: {agent_name: 'Support'}}}

this demo doesn't work, if tranfer to subagent 'Billing', and then answer. if i ask other problems about technical, subagent will tranfer to 'Support', finnaly, throw {"error":"Agent Support not found in the agent tree."}

[Varun-S10]

Hi @sorryxgb ,
We tested your code and it is working correctly on our side with one minor change. The adk-js specifically looks for a rootAgent.

Before:
const coordinator = new LlmAgent({ ... });
After:
export const rootAgent = new LlmAgent({ ... });

You can find more details regarding this in the documentation here

let us know if you encounter any further issues.