{
  nix = {
    settings = {
      experimental-features = [
        "nix-command"
        "flakes"
      ];
      auto-optimise-store = true;
      # parallel builds, each using all cores
      max-jobs = "auto";
      cores = 0;
      # cache.nixos.org is the default, these come on top
      extra-substituters = [ "https://nix-community.cachix.org" ];
      extra-trusted-public-keys = [
        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
      ];
      trusted-users = [
        "root"
        "@wheel"
      ];
    };

    gc = {
      automatic = true;
      dates = "weekly";
      options = "--delete-older-than 7d";
    };
  };

  # steam, protonvpn, discord, etc.
  nixpkgs.config.allowUnfree = true;

  # links /libexec from derivations to /run/current-system/sw
  environment.pathsToLink = [ "/libexec" ];
}