{
  pkgs,
  lib,
  # flakes
  nixpkgs_as_input,
  templates,
  self,
  ...
}: {
  nix = {
    package = pkgs.nixUnstable;

    # This is nice to have in the repl:
    # :l <nixpkgs>
    nixPath = lib.mkForce ["nixpkgs=${nixpkgs_as_input}"];
    channel.enable = false;

    registry = {
      nixpkgs.flake = nixpkgs_as_input;
      n.flake = nixpkgs_as_input;

      t.flake = templates;

      my_flake.flake = self;
      m.flake = self;
    };

    gc = {
      automatic = true;
      dates = "weekly";
      options = "--delete-older-than 7d";
    };
    settings = {
      auto-optimise-store = true;
      experimental-features = [
        "nix-command"
        "flakes"
        #"ca-derivations"
      ];

      use-xdg-base-directories = true;

      #substituters = ["https://cache.ngi0.nixos.org/"];
      #trusted-public-keys = ["cache.ngi0.nixos.org-1:KqH5CBLNSyX184S9BKZJo1LxrxJ9ltnY2uAs5c/f1MA="];

      fallback = true; # Build from source, if binary can't be substituted

      keep-failed = true; # keep failed tmp build dirs
      pure-eval = true; # restrict file system and network access to hash

      sandbox-fallback = false; # Don't disable the sandbox, if the kernel doesn't support
      # it
    };
  };
}