title: Identifying users in Rails Web push notifications
body: <p>I'm developing a Rails application, and I'd like to send web push notifications to specific users when certain actions happen, e.g:</p>
  
  <p>A user started tracking a timer, but the timer has been running for more than 6 hours. Then the app sends that user a web notification.</p>
  
  <p>I've been doing research and found <a href="https://rossta.net/blog/web-push-notifications-from-rails.html" rel="nofollow noreferrer">this tutorial</a>, the author implements push notifications for Rails, however there's no insight on how to identify the users.</p>
  
  <p>From what I understood, the users needs to subscribe from their browser to be able to get push notifications, however, considering each user can use the application from multiple browsers, how can I automatically subscribe/unsubscribe a user for notifications in all browsers they use the app from?</p>