alt Hacker NewsHi, author here. The app itself (Ilograph[0]) is fairly old; its first ShowHN was in 2019.
These particular yt-dlp diagrams were an experiment in getting meaningful sequence diagrams from a code repo using Claude. If you open the black tab on the left, you can see the source of the diagrams. Claude was able to generate most of this, albeit with a good amount of back-and-forth to get the details right, plus some manual tweaking in the end.
Kind of despised the way you didn't even let me see a preview of my own created graph without having to signup, and the signup prompt didn't show up until I fixed the mistakes in the YAML. So I pasted something (generated), spent some minutes fixing the mistakes, then get hit with a signup prompt, before being able to see the graph... Just be upfront with the signup requirement, don't let me edit anything, if you're gonna gate it like that.