How to get browser Idle time in NodeJS script? - node.js

Question

I'm planning to create simple users browser tracking system, where I want to track whether user is idle for certain time or not. I thought NodeJS would be the ideal choice.
Found certain NodeJS modules as well. But the problem is that all of them are using document. But in my case there is not document object is available, as I'm using pure NodeJS where there is no browser interaction is possible as I want to tack browser inactivity in background.
I tried below NPM Module.
https://www.npmjs.com/package/away
Which gives below error.
ReferenceError: document is not defined
at Object.<anonymous> (/media/d/Projects/PHPProjects/ets/node_modules/away/index.js:16:14)
at Module._compile (module.js:571:32)
at Object.Module._extensions..js (module.js:580:10)
at Module.load (module.js:488:32)
at tryModuleLoad (module.js:447:12)
at Function.Module._load (module.js:439:3)
at Module.require (module.js:498:17)
at require (internal/module.js:20:19)
at Object.<anonymous> (/media/d/Projects/PHPProjects/ets/index.js:16:16)
at Module._compile (module.js:571:32)
Here is my implementation
// HTTP Module
var http = require('http');
// OS Utility Module
var os = require('os-utils');
// Native OS object
var osNative = require('os');
// MySQL Connection Setup
var mysql = require('mysql');
// Create server
var server = http.createServer(function() {});
var away = require('away');
// detect users who are idle for 10 seconds
var timer = away(5000);
timer.on('idle', function() {
console.log('user is idle');
});
timer.on('active', function() {
console.log('user is active');
});