Node server that broadcasts messages and connects nodes

MessageBroadcaster.js

/* package.json

{
  "name": "nodecoin",
  "version": "1.0.0",
  "description": "Implementation of Bitcoin / cryptocurrency using NodeJS",
  "main": "index.js",
  "dependencies": {
    "body-parser": "^1.18.2",
    "dotenv": "^5.0.0",
    "express": "^4.16.2",
    "pusher": "^1.5.1"
  },
  "scripts": {
    "start": "node index.js"
  }
}

*/

/* index.js */
const Pusher = require('pusher');
const express = require('express');
const bodyParser = require('body-parser');

require('dotenv').config(); // initialize process.env variables

const app = express();

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

const options = {
  appId: process.env.PUSHER_APP_ID,
  key: process.env.PUSHER_APP_KEY,
  secret: process.env.PUSHER_SECRET,
  cluster: 'us2',
  encrypted: true
};

const socket = new Pusher(options);

// keep track of IP addresses connected to network
app.post('/pusher/auth', function(req, res) {
  const auth = socket.authenticate(
    req.body.socket_id, 
    req.body.channel_name, 
    { user_id: req.body.ip_addr, port: parseInt(req.body.port) }
  );
  res.send(auth);
});

// broadcast new transaction
app.post('/transactions/new', function(req, res) {
  socket.trigger('presence-node-coin', 'transaction:new', { tx: req.body.tx });
  res.status(200).send({ sent: true });
});

// broadcast new block
app.post('/blocks/new', function(req, res) {
  socket.trigger('presence-node-coin', 'block:new', { block: req.body.block });
  res.status(200).send({ sent: true });
});

app.listen(process.env.PORT || 3001, function() {
  console.log('> Server listening on port: ', process.env.PORT);
});