receiveMessagesWithRedisClient.js

const redis = require('redis')

// Create a standart redis client which will be subscriber in our case.
const sub = redis.createClient()

// Attach a listener to receive new messages as soon as subscribe to a channel.
sub.on('message', function(channel, message) {
  // message is json string in our case so we are going to parse it.
  try {
    const json = JSON.parse(message)
    // json.csrfToken is our csrfToken we have created in our frontend server!
  } catch (e) {
    // This error indicates that we receive a message that is not in the json format.
  }
})

// Subscribe to a channel and start handling messages
sub.subscribe('parameter-mapping')