Oh yeah looks like it's really full featured. In the bottom they're doing something very similar to what I did here but of course the devil is in the details, and adding a good UX layer on top makes a world of difference.
Nice, I was curious as to whether you solved some of the underlying problems a little differently. I don't know any of the specifics under the hood, but I was using ChatPDF for a while there, especially in the earlier days of LLMs.
I don't think, I haven't done anything especially innovative here, this is the barebones implementation that everyone doing LLMs plus retrieval is using. It can improved a lot!