Spring-boot application for charge har files (in json or xml).
The idea is be able to reproduce the har content like a "navigation-video".
for example, if one of your clients have an javascript error, and you cannot reproduce it due to connectivity (proxies, firewalls...) or security (private user/pass, sensible environment info...) he can send yoy a har file with navigation; after, you can reproduce any request like a "live-video" and this way reproduce same error.
You can test it with any navigator, add whished headers for try to solve problem, change jquery/javascript code, etc...