First thing to do, it's include the firebase library on the site headers.

	
		<script src="https://www.gstatic.com/firebasejs/4.2.0/firebase.js"></script>
	

Now, we need to initialize the SDK using the next code instructions:

	
		var config = {
			apiKey: "PUBLIC_API_KEY",
			authDomain: "DOMAIN",
			databaseURL: "DATABASE_URL",
			storageBucket: "STORAGE_BUCKED",
			messagingSenderId: "SENDER_ID"
		};
		firebase.initializeApp(config);
	

RealTime Users Analytics

	
		<script src='https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.1.6/Chart.bundle.min.js'></script>
		<script src='/js/RealTimeAnalytics.js'></script>
		

	
		<canvas id='realtimeAnalytics' width='500' height='300'></canvas>
		

	
		function initRealtimeTracker(){
			var body = $('body');
			$('.tracked').each(function(i, item){
				var $item = $(item),
					events = $item.data('evts');
					$item.on(events, trackEvent);
			});
		}
		

	
		function trackEvent(evt) {
			var $element = $(this),
				eid = $element.attr('id');
			if (eid){
				var type = evt.type,
					tracker = firebase.database().ref('/tracks/' + eid + '/' + type);
				try {
					tracker.transaction(function(track){
						return track ? track + 1 : 1;
					});
				} catch (ex) {}
			}
		}
	

	
		initRealtimeTracker();