Subagents Setup - Copilotkit

<Steps> <Step> ### Install the ADK + AG-UI bridge

```bash
pip install ag-ui-adk
```

</Step> <Step> ### Add `AGUIToolset()` to your supervisor agent

Sub-agents are tools on a supervisor `LlmAgent`. The showcase uses
`google.genai.Client.models.generate_content` for each sub-agent call —
much lighter than spawning a separate `LlmAgent` + `Runner` per
delegation. Delegation events are written to `tool_context.state` and
flow back to the UI through CopilotKit's shared-state channel.

<DemoCode file="src/agents/hitl_in_chat_agent.py" region="setup" />

See `src/agents/subagents_agent.py` for the supervisor + three
sub-agents pattern with a live delegation log.

</Step> </Steps>