Does Replit Nix even work?
If you're doing something simple, yes. I've been using Replit for over a year and I've had to stop using it because many of my previous workflows or very specific set ups don't work. (Either the replit package list isn't update to the nix-os list or some functions like "nix search" simply don't work).
Nix in Replit still feels like a prematurely released alpha