I use an agent to author my nix config - personally I don't have the determination to have picked Nix up entirely on my own so I find it to be a godsend. I can code review config changes and keep it all in git - also makes it easy to pick up the entire config and deploy it on a different machine.
Plus if it messes up, you can just roll back.
I don't vibe code my config but this is still my favorite part. If I had it working at some point, I can always get my full system back to there