{
  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-20.09";
  inputs.nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";

  inputs.home-manager.url = "github:nix-community/home-manager/master";
  inputs.home-manager.inputs.nixpkgs.follows = "/nixpkgs";

  outputs = inputs: {

    nixosConfigurations.nixos = inputs.nixpkgs.lib.nixosSystem {
      system = "x86_64-linux";
      # Things in this set are passed to modules and accessible
      # in the top-level arguments (e.g. `{ pkgs, lib, inputs, ... }:`).
      specialArgs = {
        inherit inputs;
      };
      modules = [
        inputs.home-manager.nixosModules.home-manager

        ({ pkgs, ... }: {
          nix.extraOptions = "experimental-features = nix-command flakes";
          nix.package = pkgs.nixFlakes;
          nix.registry.nixpkgs.flake = inputs.nixpkgs;

          home-manager.useGlobalPkgs = true;

	  # for using unstable packages
          #nixpkgs.overlays = [
          #  (final: prev: {
          #    unstable = import inputs.nixpkgs-unstable { inherit system; config.allowUnfree = true;  };
          #  })
          #];
        })

        ./configuration.nix
      ];
    };

  };
}