Ask HN: Secure wrapper for coding agents?

I believe someone recently posted sort of a secure harness/wrapper for running coding agents in a secure sandbox. I can't find the project. Of course I can make my own wrapper with systemd-nspawn, kata or bspawn, but I believe I saw a decently well-maintained project just a while back. Does anyone have a suggestion or link? It's become extremely hard to find things on GitHub with all the generated projects.