amberdata-websockets.js

const socket = new WebSocket(`wss://ws.web3api.io?x-api-key=${YOUR_API_KEY_HERE}`)

socket.addEventListener('open', event => {
  console.log('Connection opened - ', event)
})

// Closed Connection
socket.addEventListener('close', event => {
  console.log('Connection closed - ', event.data)
})

// Open Connection
socket.addEventListener('open', event => {

  // Subscribe using 'socket' Connection
  socket.send(`{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "subscribe",
    "params": ["block"]
  }`)
})

// Response Handler
const responseHandler = event => {
  const data = JSON.parse(event.data)
  console.log('New Event', data.id, data)
}
// Listen for messages
socket.addEventListener('message', responseHandler)