Get contact data on my website

Hi everyone
I’m very interesting to now is there any solution to get contact information without any development?
Now I change any field by mt function with Google tag manager. But when User comes back I need to know about last her/his status and based on that set tag and trigger (in google tag manager).

the scenario is :
*All Users have to login to website
** I import all contact with user id field and set this field (user id) in data layer. so I know the Users with the own user id.

  1. When User visit the website, Get her/him information from Mautic base on user id
  2. base on user behavior (like fill form, discount request, click on banner and etc) update his / hers profile in Mautic [done with (mt(‘send’, ‘pageview’, {email: ‘my@email.com’, firstname: ‘John’});)]

Please let me know if it’s possible to run in front (jscript, cookies ) instead of backend (API)
thanks a lot