> ## 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 — WebSocket

## WebSocket Streaming

Subscribe to real-time events with a builder pattern:

```typescript theme={null}
const sub = await pn.ws.subscribe('settlements')
  .minSize(100)
  .status('pending')
  .snapshotCount(20)
  .send();
```

### Event Callbacks

```typescript theme={null}
sub.on('settlement', (event) => {
  console.log(`${event.taker_side} $${event.taker_size} on ${event.market_title}`);
});

sub.on('status_update', (event) => {
  console.log(`Confirmed in ${event.latency_ms}ms`);
});

// Catch-all
sub.on('*', (event) => {
  console.log(event.event_type, event);
});
```

### Async Iterator

```typescript theme={null}
for await (const event of sub) {
  if (event.event_type === 'settlement') {
    console.log(event.taker_wallet, event.taker_size);
  }
}
```

### Subscription Filters

All filters from the [Subscriptions & Filters](/websocket/subscribing) page are supported:

```typescript theme={null}
pn.ws.subscribe('settlements')
  .wallets(['0xabc...'])          // by wallet
  .tokens(['21742633...'])        // by token ID
  .slugs(['bitcoin-100k'])        // by market slug
  .conditionIds(['0xabc...'])     // by condition ID
  .side('BUY')                    // BUY or SELL
  .status('pending')              // pending, confirmed, or all
  .minSize(100)                   // min USD size
  .maxSize(10000)                 // max USD size
  .eventTypes(['settlement'])     // override event types
  .snapshotCount(50)              // initial snapshot (max 200)
  .feeds(['BTC/USD'])             // chainlink feeds
  .send();
```

### Subscription Types

```typescript theme={null}
pn.ws.subscribe('settlements')   // pending + confirmed settlements
pn.ws.subscribe('trades')        // all trade activity
pn.ws.subscribe('prices')        // price-moving events
pn.ws.subscribe('blocks')        // new Polygon blocks
pn.ws.subscribe('wallets')       // all wallet activity
pn.ws.subscribe('markets')       // all market activity
pn.ws.subscribe('large_trades')  // $1K+ trades
pn.ws.subscribe('oracle')        // UMA resolution events
pn.ws.subscribe('chainlink')     // real-time price feeds
```

### Multiple Subscriptions

Subscriptions stack on the same connection:

```typescript theme={null}
const whales = await pn.ws.subscribe('large_trades')
  .minSize(5000).send();

const myWallet = await pn.ws.subscribe('wallets')
  .wallets(['0xabc...']).send();

// Both active simultaneously, events deduplicated
```

### Compression

Zlib compression is enabled by default for all WebSocket connections (\~50% bandwidth savings). No configuration needed.

To disable compression (not recommended):

```typescript theme={null}
const ws = pn.configureWs({ compress: false });
```

### Auto-Reconnect

Enabled by default. The SDK reconnects with exponential backoff and replays all active subscriptions:

```typescript theme={null}
const ws = pn.configureWs({
  autoReconnect: true,           // default: true
  maxReconnectAttempts: Infinity, // default: unlimited
  reconnectBaseDelay: 1000,      // default: 1s
  reconnectMaxDelay: 30000,      // default: 30s
});

ws.onConnect(() => console.log('connected'));
ws.onDisconnect((reason) => console.log('disconnected:', reason));
ws.onReconnect((attempt) => console.log('reconnected, attempt', attempt));
ws.onError((err) => console.error(err));
```

### Cleanup

```typescript theme={null}
sub.unsubscribe();     // remove one subscription
pn.ws.unsubscribeAll(); // remove all
pn.ws.disconnect();     // close connection
```