Synthetix subgraph websocket

sub.js

'use strict';

const WebSocket = require('ws');

const client = new WebSocket('wss://api.thegraph.com/subgraphs/name/synthetixio-team/synthetix-exchanges', [
	'graphql-ws',
]);

client.on('open', () => {
	console.log('open');
	client.send(JSON.stringify({ id: 123, type: 'GQL_CONNECTION_INIT' }));
	// client.send(' subscription { synthExchanges { id } }');
});
client.on('message', data => console.log('message', data));
client.on('close', () => console.log('close'));
client.on('error', err => {
	console.log('error', err);
});