npm i bitmex-ws-orderbook

import { BitmexOrderBookKeeper } from 'qs-ws-orderbook';
const bitmexOb = new BitmexOrderBookKeeper({ testnet: true, enableEvent: true });
bitmexOb.onSocketMessage(msg);
const ob = await bitmexOb.getOrderBook('XBTUSD');

//event
bitmexOb.onOrderBookUpdated((ob: BitmexOb.OrderBookSchema) => {
    console.log(`orderbook from event`, ob);
})