It's not mine unless it's running on my own servers or computer - I created a really rough version of this several years ago that is saved to my computer (and from there into box).
I adapted a bash script someone posted here, it uses Firefox bookmarks (pages.sqlite). Cron runs the script and downloads every page I've bookmarked that month (after some filtering). I don't use it often but sometimes I'll awk-grep it; I'm a hoarder in real life too!
https://www.gwern.net/Archiving%20URLs was the initial idea and base for my code. I see now he's updated his page considerably - IIRC - from what was there before.
My normal medium is clay so I'd rely on his stuff rather than mine (linked below).