1{
 2  den.aspects.core.nix.nh = {
 3    nixos = {
 4      programs.nh = {
 5        enable = true;
 6        clean.enable = true;
 7        clean.extraArgs = "--keep-since 4d --keep 3";
 8      };
 9
10      system.tools = {
11        # disable useless tools
12        nixos-build-vms.enable = false;
13        nixos-enter.enable = false;
14        nixos-generate-config.enable = false;
15        nixos-install.enable = false;
16        nixos-option.enable = false;
17        nixos-rebuild.enable = false; # No needed, use `nh os` instead.
18      };
19    };
20  };
21}