{
  pkgs,
  lib,
  ...
}:
{
  nix = {
    enable = true;
    package = pkgs.nix;

    settings = {
      experimental-features = [
        "nix-command"
        "flakes"
      ];
      substituters = [ "https://nix-community.cachix.org" ];
      trusted-public-keys = [
        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
      ];
      builders-use-substitutes = true;
      auto-optimise-store = false; # issue https://github.com/NixOS/nix/issues/7273
    };

    gc = {
      automatic = lib.mkDefault true;
      options = lib.mkDefault "--delete-older-than 7d";
    };
  };
}