# useActiveTurns

Subscribe to the set of active turns on the channel. Returns a reactive `Map` keyed by `clientId`, where each value is a `Set` of `turnId`s for that client. Re-renders when turns start or end. Use it to drive UI such as a send-or-stop button, per-client streaming indicators, or a "wait for all turns to finish" guard.

This hook must be used within a [`TransportProvider`](https://ably.com/docs/ai-transport/api/react/providers.md#TransportProvider) or a [`ChatTransportProvider`](https://ably.com/docs/ai-transport/api/react/providers.md#ChatTransportProvider).

<Code>

#### React

```
import { useActiveTurns } from '@ably/ai-transport/react';

function SendOrStop({ onSend, onStop }) {
  const activeTurns = useActiveTurns();
  return activeTurns.size > 0
    ? <button onClick={onStop}>Stop</button>
    : <button onClick={onSend}>Send</button>;
}
```
</Code>

## Parameters

<Table id='UseActiveTurnsProps'>

| Prop | Required | Description | Type |
| --- | --- | --- | --- |
| transport | Optional | Transport to track turns for. Defaults to the nearest provider when omitted. | `ClientTransport<TEvent, TMessage>` or Null |

</Table>

## Returns

`Map<string, Set<string>>`

A reactive map. The outer key is the `clientId` that owns the turns. The inner `Set` holds the `turnId`s currently active for that client.

Common patterns:

- `activeTurns.size > 0` — any turn is active anywhere on the channel.
- `activeTurns.has('agent-1')` — a specific client (typically the agent) has at least one active turn.
- `activeTurns.get(clientId)?.size ?? 0` — how many turns a specific client has open.

The map updates in real time across every connected client, not just the local one. If another tab on the same session starts a turn, this hook's value updates in this component too.

## Example

<Code>

### React

```
import { useActiveTurns, useView } from '@ably/ai-transport/react';
import { useState } from 'react';

function Composer() {
  const { send } = useView();
  const activeTurns = useActiveTurns();
  const [input, setInput] = useState('');

  const isStreaming = activeTurns.size > 0;

  const onSend = async () => {
    const text = input;
    setInput('');
    await send({ id: crypto.randomUUID(), role: 'user', parts: [{ type: 'text', text }] });
  };

  return (
    <form onSubmit={(e) => { e.preventDefault(); onSend(); }}>
      <input value={input} onChange={(e) => setInput(e.target.value)} />
      {isStreaming
        ? <button type="button" disabled>Streaming…</button>
        : <button type="submit">Send</button>}
    </form>
  );
}
```
</Code>

## Related Topics

- [Providers](https://ably.com/docs/ai-transport/api/react/providers.md): TransportProvider and ChatTransportProvider for the AI Transport React integration.
- [useClientTransport](https://ably.com/docs/ai-transport/api/react/use-client-transport.md): Read a ClientTransport from the nearest TransportProvider in the AI Transport React integration.
- [useView](https://ably.com/docs/ai-transport/api/react/use-view.md): Subscribe to a paginated, branch-aware view of the AI Transport conversation tree from React.
- [useCreateView](https://ably.com/docs/ai-transport/api/react/use-create-view.md): Create an independent View over the AI Transport conversation tree from React, with its own branch selections and pagination.
- [useTree](https://ably.com/docs/ai-transport/api/react/use-tree.md): Stable structural query callbacks for the AI Transport conversation tree from React.
- [useAblyMessages](https://ably.com/docs/ai-transport/api/react/use-ably-messages.md): Subscribe to raw Ably InboundMessages on the AI Transport channel from React.
- [useChatTransport](https://ably.com/docs/ai-transport/api/react/use-chat-transport.md): Read a ChatTransport and its underlying ClientTransport from the nearest ChatTransportProvider in AI Transport.
- [useMessageSync](https://ably.com/docs/ai-transport/api/react/use-message-sync.md): Wire AI Transport message updates into Vercel useChat's message state from React.

## Documentation Index

To discover additional Ably documentation:

1. Fetch [llms.txt](https://ably.com/llms.txt) for the canonical list of available pages.
2. Identify relevant URLs from that index.
3. Fetch target pages as needed.

Avoid using assumed or outdated documentation paths.