HAXeditor keeps so much functionality on the front-end that there's really very little tying it to..well.. anything. As a result, HAX is easy to integrate into systems that currently have WYSIWYG capabilities.
All integrations effectively boil down to four things
Because web components are valid HTML tags your system may accept them when saved into your database but you may also be doing tag filtering or other XSS sanitization prior to storage. If you do process prior to storage (and you should) but it strips the web components out of the mark up, you'll need to add some filtering / white-listing capabilities to your system in order to ensure that the web component html tags pass through that should.