{ lib, pkgs, inputs, config, ... }:
{
  environment.variables = {
    NIXPKGS_ALLOW_UNFREE = "1";
  };

  nixpkgs.flake.setNixPath = true;
  nixpkgs.flake.setFlakeRegistry = true;

  nix = {
    package = pkgs.nixVersions.latest;

    settings = {
      experimental-features = [ "nix-command" "flakes" ];

      auto-optimise-store = true;

      keep-outputs = true;
      keep-derivations = true;

      substituters = [
        "https://nix-community.cachix.org"
      ];
      trusted-public-keys = [
        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
      ];
    };
  };

  nix.optimise.automatic = true;
  nix.gc = {
    automatic = true;
    dates = "weekly";
    options = "--delete-older-than 30d";
  };
}