Where's the repository hosting the code which builds Silverblue images?

I’ve searched in these pages:

but I could find only a link to the Silverblue issue tracker.

I was curious to find out how the image is built.

And I was also wondering when I could expect some GNOME packages in the image to be upgraded from 40.alpha to 40.beta (e.g. gnome-shell 40.beta released two days ago). I’m using Fedora 34 Prerelease (Silverblue).

The config used to build Silverblue, Kinoite and other variants is in Overview - workstation-ostree-config - Pagure.io.

I summarized instructions to build your own in Kinoite, a KDE (and now XFCE) version of Fedora Silverblue - #25 by Siosm which itself is based on others instructions linked at the bottom that you can follow.

The build process itself is configured in Overview - pungi-fedora - Pagure.io but this is very specific to Fedora infrastructure.