sakaya is a program that lets users easily run GUI applications inside declarative systemd-nspawn containers, useful for sandboxing things.
The source code is available on GitHub.
systemd-nspawn containers are pretty good at isolating programs from the rest of your system. Although it’s not perfect, it will stop naive applications that assume full access to the host from accessing your files.
The main advantage of sakaya is that users no longer have to enter their password multiple times when starting sandboxed applications.
This makes sandboxing more convenient. Users are more likely to run sandboxed applications when running them requires no additional effort on their part.
Installation and usage instructions can be found in the README.
The main thing to keep in mind is auto-starting the sakaya server inside the declarative container. You’ll also want to make sure that your GPU is accessible inside the container for GPU-intensive applications.