WebSocket API

The WebSocket API provides real-time subscriptions for market data including prices, trades, and orderbook updates.

Access

const dflow = new DFlowClient();
const ws = dflow.ws;

Connection

connect

Establish a WebSocket connection.

await dflow.ws.connect();
console.log('Connected:', dflow.ws.isConnected);

disconnect

Close the WebSocket connection.

dflow.ws.disconnect();

isConnected

Check connection status.

if (dflow.ws.isConnected) {
  console.log('WebSocket is connected');
}

Subscriptions

Price Updates

Subscribe to real-time price updates.

// Subscribe to specific markets
dflow.ws.subscribePrices(['BTCD-25DEC0313-T92749.99', 'ANOTHER-MARKET']);
 
// Subscribe to all markets
dflow.ws.subscribeAllPrices();
 
// Handle updates
const unsubscribe = dflow.ws.onPrice((update) => {
  console.log(`${update.ticker}: YES=${update.yesPrice} NO=${update.noPrice}`);
});
 
// Later: unsubscribe
unsubscribe();

PriceUpdate object:

interface PriceUpdate {
  channel: 'prices';
  ticker: string;
  yesPrice: number;
  noPrice: number;
  timestamp: string;
}

Trade Updates

Subscribe to real-time trades.

// Subscribe to specific markets
dflow.ws.subscribeTrades(['BTCD-25DEC0313-T92749.99']);
 
// Subscribe to all trades
dflow.ws.subscribeAllTrades();
 
// Handle updates
dflow.ws.onTrade((trade) => {
  console.log(`Trade: ${trade.side} @ ${trade.price} - ${trade.quantity} shares`);
});

TradeUpdate object:

interface TradeUpdate {
  channel: 'trades';
  ticker: string;
  side: 'yes' | 'no';
  price: number;
  quantity: number;
  timestamp: string;
}

Orderbook Updates

Subscribe to real-time orderbook changes.

// Subscribe to specific markets
dflow.ws.subscribeOrderbook(['BTCD-25DEC0313-T92749.99']);
 
// Subscribe to all orderbooks
dflow.ws.subscribeAllOrderbook();
 
// Handle updates
dflow.ws.onOrderbook((book) => {
  console.log(`Orderbook update for ${book.ticker}`);
  console.log(`YES Bids: ${book.yesBid?.length}, Asks: ${book.yesAsk?.length}`);
});

OrderbookUpdate object:

interface OrderbookUpdate {
  channel: 'orderbook';
  ticker: string;
  yesBid: OrderbookLevel[] | null;
  yesAsk: OrderbookLevel[] | null;
  noBid: OrderbookLevel[] | null;
  noAsk: OrderbookLevel[] | null;
}

Unsubscribe

Stop receiving updates for a channel.

// Unsubscribe from specific markets
dflow.ws.unsubscribe('prices', ['BTCD-25DEC0313-T92749.99']);
 
// Unsubscribe from all on a channel
dflow.ws.unsubscribe('prices');

Event Handlers

onError

Handle WebSocket errors.

dflow.ws.onError((error) => {
  console.error('WebSocket error:', error.message);
});

onClose

Handle connection close events.

dflow.ws.onClose((event) => {
  console.log('WebSocket closed:', event.code, event.reason);
});

Configuration

Configure WebSocket behavior at client initialization:

const dflow = new DFlowClient({
  wsOptions: {
    url: 'wss://custom-websocket-url',
    reconnect: true,           // Auto-reconnect (default: true)
    reconnectInterval: 5000,   // Milliseconds between attempts (default: 5000)
    maxReconnectAttempts: 10,  // Max attempts (default: 10)
  },
});

Complete Example

import { DFlowClient } from 'dflow-sdk';
 
const dflow = new DFlowClient();
 
async function streamMarketData() {
  // Connect
  await dflow.ws.connect();
  console.log('Connected to WebSocket');
 
  // Handle errors
  dflow.ws.onError((error) => {
    console.error('Error:', error.message);
  });
 
  // Handle disconnection
  dflow.ws.onClose(() => {
    console.log('Disconnected');
  });
 
  // Subscribe to prices
  const market = 'BTCD-25DEC0313-T92749.99';
  dflow.ws.subscribePrices([market]);
 
  // Handle price updates
  dflow.ws.onPrice((update) => {
    const time = new Date(update.timestamp).toLocaleTimeString();
    console.log(`[${time}] ${update.ticker}`);
    console.log(`  YES: $${update.yesPrice.toFixed(2)}`);
    console.log(`  NO: $${update.noPrice.toFixed(2)}`);
  });
 
  // Subscribe to trades
  dflow.ws.subscribeTrades([market]);
 
  dflow.ws.onTrade((trade) => {
    console.log(`Trade: ${trade.side.toUpperCase()} ${trade.quantity} @ $${trade.price}`);
  });
 
  // Run for 60 seconds
  await new Promise((resolve) => setTimeout(resolve, 60000));
 
  // Cleanup
  dflow.ws.disconnect();
}
 
streamMarketData();

The WebSocket automatically reconnects on disconnection. You can disable this by setting reconnect: false in options.

Best Practices

Single Connection: Use one WebSocket connection per client instance
Unsubscribe When Done: Clean up subscriptions to reduce bandwidth
Handle Reconnection: Your callbacks persist through reconnections
Error Handling: Always set up error handlers for production

WebSocket API

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