> ## Documentation Index
> Fetch the complete documentation index at: https://docs.polynode.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# TypeScript Perps Stream

> Subscribe to managed perps tickers, BBO, full books, trades, statistics, and klines.

The V3 perps WebSocket is separate from the event and prediction-market orderbook sockets.

```typescript theme={null}
import { PolyNode, perpsChannels } from 'polynode-sdk';

const apiKey = process.env.POLYNODE_API_KEY;
if (!apiKey) throw new Error('Set POLYNODE_API_KEY');
const pn = new PolyNode({ apiKey });

const perps = pn.configurePerps({ queueCapacity: 4096 });
perps.onReconnect((notice) => console.warn('gap possible', notice));
perps.onOverflow((notice) => console.error('local overflow', notice));

const ack = await perps.subscribe([
  perpsChannels.tickers,
  perpsChannels.bbo('BTC-USD'),
  perpsChannels.book('BTC-USD'),
  perpsChannels.trades('BTC-USD'),
  perpsChannels.klines('BTC-USD', '1m'),
]);

if (ack.rejected.length) console.warn('rejected channels', ack.rejected);

perps.onMessage((message) => {
  if (message.type === 'event') {
    console.log(message.channel, message.data);
  }
});
```

One subscribe request can be partially accepted. Always inspect `ack.channels` and `ack.rejected` rather than assuming every requested channel is active.

Every `perps_book` event is a complete replacement for that instrument's cached book, not an incremental patch. `perps.book('BTC-USD')` returns the latest managed copy, or `null` until the first book event arrives. A successful acknowledgement confirms the channel, not book readiness; use the [V3 perps orderbook](/perps/market-data/book) when startup needs immediate state.

The client reconnects and resubscribes after non-terminal disconnects, but the stream does not promise replay. A `reconnect` notice has `gap_possible: true`; backfill through V3 REST if completeness matters. Authentication (`4401`) and connection-limit (`4429`) closes are terminal until the caller changes the failing condition.

```typescript theme={null}
perps.disconnect();
```

See the [shared perps guide](/sdks/perps) for channel definitions, lag behavior, and lifecycle details.