I got an idea to solve it by using url parameters like:

site.com/?frame1=photos.html&frame2=books

but then I need a way to continue this pattern for frames inside of frames and these params can only work for flat data. I need a URL tree structure.

Edit:

This syntax seems to work! [] and ; for nested params.

https://en.wikipedia.org/wiki/Cat?frame1=photos[a=1;b=2]&fra...