poly.js

const WebSocket = require('ws')
const ws = new WebSocket('wss://socket.polygon.io/forex')

// Connection Opened:
ws.on('open', () => {
	ws.send(`{"action":"auth","params":"APIKEY"}`)
	ws.send(`{"action":"subscribe","params":"C.AUD/USD,C.USD/EUR,C.USD/JPY"}`)
})

// Per message packet:
ws.on('message', ( data ) => {
	(JSON.parse( data )).map(( msg ) => {
		if( msg.ev === 'status' )
			return console.log('Status Update:', msg.message)
		console.log('Tick:', msg)
	})
})

ws.on('error', console.log)